The ORT Braude College
Transcript of The ORT Braude College
The ORT Braude College
7th
Interdisciplinary Research Conference
Book of Abstracts
September 19-20, 2011
Pastoral Kfar Blum Hotel, Upper Galilee
ISBN 978-965-91208-5-7
The ORT Braude College 7th
Interdisciplinary Research Conference
Biotechnology Engineering | 1
Profiling Expression of Structural and Functional Proteins in
Engineered Muscle Tissue Following Application of
Various Stretching Regimes
Rosa Azhari1, Iris Bonshtein
1, Ehud Kroll
2
1Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901750, Fax: 972-4-9901839, E-mail: [email protected]
2Faculty of Aerospace Engineering, Technion - Israel Institute of Technology, Technion City, Haifa
32000, Israel, Tel: 972-4-8293813, Fax: 972-4-8292030, E-mail: [email protected]
Keywords: Tissue engineering, skeletal muscle, scaffolds, electrospinning, mechano-
transduction
Mechano-transduction has been demonstrated to play a major role in affecting proliferation
and differentiation of skeletal muscle cells and determining the morphology and properties of
the tissue obtained. Therefore, various mechanical stimulation techniques have been
incorporated as essential components in novel tissue engineering methods developed for
obtaining functional skeletal muscle tissue.
The main objective of this research is to study the effects of applying various stretching
regimes on skeletal muscle cells by profiling the expression of various functional and
structural proteins in the engineered tissue.
Electrospun, hybrid, micro-fibrous scaffolds, developed in our group, combining a synthetic
polymer, poly--caprolactone (PCL), with natural connective tissue components: chondroitin
sulfate and gelatin were used in this study. A computer-controlled stretching machine was
designed to apply various unidirectional and cyclic stretching patterns on cell-seeded
scaffolds, clamped horizontally in a circulating medium bioreactor. Stresses induced in the
constructs were measured continuously. The morphology of tissue obtained was analyzed
using histological methods and the expression of intracellular and extracellular functional and
structural proteins was demonstrated by specific immunostaining and confocal microscopy.
Proteins and RNA were extracted from the constructs using T-PER (Pierce) and the RNeasy
mini kit (Qiagen) respectively.
No significant differences were found between the morphology and characteristics of tissue
produced on non-stretched samples and ones stretched in a slow, gradual, manner, with
deformations up to 50% of the original length (stresses up to 6MPa). On the other hand, the
same deformation applied by abrupt stretches (each 5% of the original length), induced better
alignment of myotubes and higher expression of intracellular and extracellular functional and
structural proteins, including: myosin heavy chain, alpha-actinin, desmin, myogenin, myo D
fibronectin and integrin. Application of a cyclic pattern of sinusoidal stretches was also
examined. Affymetrix Gene Chip microarrays were used to quantify up-regulation and down-
regulation of gene expression in the tissue, following the change in the mechanical
stimulation regimes. It was shown that different patterns of application of mechanical stimuli
induce altered cell responses, even if the final stresses applied are of the same magnitude.
Acknowledgement: This study was supported by grants from the Israeli Science Foundation
(618-08) and the ORT Braude College Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
2 | Biotechnology Engineering
Coca-Cola Consumption as a Risk Factor for Experimental
Fatty Liver Disease
Maria Grozovski
1, Michal Maoz
2, Nimer Assy
3
1Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901895, Fax: 972-4-9901839, E-mail: [email protected]
2Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972- 72 -2463672, Fax: 972-4-9901839, E-mail: [email protected]
3Ziv Medical Center, P.O.Box 1008, Safed 13100, Israel, Tel: 972-4-6828442, Fax: 972-4-6828441,
E-mail: [email protected]
Keywords: Coca- Cola, fatty liver, antioxidants, triglycerides, lipid peroxidation
While the rise in non-alcoholic fatty liver disease (NAFLD) parallels the increase in obesity
and diabetes, a significant increase in Coca-Cola consumption in industrialized countries has
also occurred. The increased consumption of Coca-Cola is linked with complications of the
metabolic syndrome.
The aim of the present study is to determine whether there is a relationship between Coca-
Cola consumption and experimental non-alcoholic fatty liver and to evaluate the effects of
aqueous Inula viscosa extract on the hepatic lipid content and oxidative stress parameters in
"Coca-Cola" rats.
Forty-eight male Sprague–Dawley rats, divided into two groups, were studied: Rats on a
standard rat chow diet for 12 weeks (24 rats) and rats on a fructose enriched diet (FED) for
12 weeks (24 rats). 12 weeks after the initiation of FED each diet group was randomly
divided into four treatment groups: the first group remained untreated, the second group was
given Inula viscosa extract only (5.6 mg/kg per day), the third group was given 4 ml regular
Coca-Cola per day and the fourth group was given 2.8 mg/kg of Inula viscosa extract
together with 4ml of regular Coca-Cola per day for 4 weeks. Hepatic extracts from the rat
livers underwent biochemical assays to determine the levels of cholesterol, triglycerides,
antioxidants, malonic dialdehyde (MDA) and protein C.
Coca-Cola had increased hepatic triglyceride, protein C and MDA (+270%, +30% and +99%,
respectively) and decreased hepatic levels of alpha–tocopherol and paraoxonase (PON)
activity (-25% and -44%, respectively) in healthy rats as compared to the control group.
Coca-Cola had increased hepatic triglyceride, hepatic cholesterol (+78% and +5%,
respectively), decreased the hepatic levels of MDA, alpha-tocopherol and paraoxonase
(PON) activity (-13%, -30% and -32%, respectively) in FED rats as compared to untreated
rats. Combination of Inula viscosa extract and Coca-Cola reduced hepatic triglyceride,
hepatic cholesterol, hepatic MDA and hepatic protein C and increased paraoxonase activity
in the same group compared with untreated rats. Coca-Cola consumption is a risk factor for
fatty liver disease and also supports liver inflammation in FED rats. Administration of
aqueous Inula viscosa extract at a concentration of 5.6 mg per day for 4 weeks, to rats with
the fatty liver disease and "Coca Cola" rats, may improve hepatic lipid metabolism and cause
other favorable changes in the hepatic oxidative – anti oxidative milieu.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
Biotechnology Engineering | 3
Molecular Modeling Studies of Curing of Styrene-Free
Unsaturated Polyester Alkyd
Dafna Knani
1, David Alperstein
2, Iris Mironi-Harpaz
3, Moshe Narkis
3
1Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901875, Fax: 972-4-9901839, E-mail: [email protected]
2Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901944, Fax: 972-4-9901886, E-mail: [email protected]
3Faculty of Chemical Engineering, Technion - Israel Institute of Technology, Technion City, Haifa
32000, Israel, Tel: 972-4-8292937, Fax: 972-4- 8295672, E-mail: [email protected]
Keywords: Styrene-free unsaturated polyester, Density Functional Theory (DFT), Monte
Carlo simulation, crosslinking, binding energies, free radicals
Crosslinking of Unsaturated Polyesters (UPs) without styrene is a new process. Thermoset
UPs are usually obtained by the crosslinking of alkyd chains dissolved in an unsaturated
reactive monomeric diluent, usually styrene. UP alkyd chains (without styrene) were
intrinsically cured into a cross-linked resin in the presence of peroxide. Simulation of the
crosslinking reaction was used to define the species involved in the process.
Two commercial software tools were used for the simulation. DMOL3 by Accelrys, a
quantum code based on density functional theory (DFT) was used for the analysis of the
scission reaction species. DMOL3 was applied to the scission reaction in the following way:
1) All possible intermediate species and products of the scission reaction were formulated.
2) Structures of all possible intermediate species were built and optimized using DMOL3
structural optimization.
3) Structures of all possible products were built and optimized using a standard force-field
minimizer.
4) The lowest energy products were taken as the scission reaction products.
The other simulation tool used was "Networks" by Accelrys, which is a polymer crosslinking
simulation tool, based on a Monte Carlo procedure. "Networks" was used for the simulation
characterization and analysis of the forming cross-linked network.
Binding energies for all the possible radicals obtained in various polymer-chain scission
reactions were calculated using DMOL3 software. The results were compared to the binding
energy of the polyester. The binding energy of the polyester was found to be −5409 kcal/mol.
According to the results, it seems that cleavage of the polyester chain occurs preferably to
yield the following pair of free radicals:
Although each of these radicals is not the lowest energy radical that may be obtained, the
sum of their binding energy is the lowest.
The scission point on the polyester chain where cleavage occurs preferably was identified
using binding energy calculations.
The ORT Braude College 7th
Interdisciplinary Research Conference
4 | Biotechnology Engineering
Improving the Efficiency of Wastewater Treatment in
Biochemical Factories
Vyacheslav V. Korostovenko¹, Vera A. Gron², Natalia M. Kaplichenko³,
Ekaterina G. Kaplichenko4
¹Doctor of Engineering, Professor, Department of Thermal Engineering and Technosphere Safety in
Mining and Metallurgical Production, Siberian Federal University, 79 Svobodny Ave., Krasnoyarsk,
Russia 660041, Tel. 8-(391) 265-54-63, E-mail: [email protected]
²Cand. Sc., Assistant Professor, Department of Thermal Engineering and Technosphere Safety in
Mining and Metallurgical Production, Siberian Federal University, 79 Svobodny Ave., Krasnoyarsk,
Russia 660041, Tel. 8-(391) 265-54-63
³Senior lecturer, Department of Thermal Engineering and Technosphere Safety in Mining and
Metallurgical Production, Siberian Federal University, 79 Svobodny Ave., Krasnoyarsk, Russia
660041, Tel. 8 (391) 201-30-70, E-mail: [email protected]
4Fourth year student, Siberian Federal University, 79 Svobodny Ave., Krasnoyarsk, Russia, 660041
Keywords: Sewage, biochemical factories, microorganisms, organic substances, activated
sludge, purification plants, equipment
Sewage of biochemical production is considered to be highly polluted. It contains dissolved
organic and mineral substances and a variety of insoluble impurities. It is composed of
sulfates, ammonia nitrogen, chloride, furfural, methanol, phenol, formaldehyde, fat, iron,
phosphates and suspended solids, mainly represented by lignohumic complex and it contains
gypsum.
The aim of the study is to develop a wastewater treatment system that allows recycling
industrial water and significantly reduces the load on municipal wastewater purification
plants.
Wastewater pH in hydrolysis factories is 4.5-5.5, so before its treatment the water is
neutralized to pH 6.5-8.5 to ensure the efficient activity of microorganisms. To separate
coarse and floating impurities it was suggested to use two radial sediment ponds, 18 m in
diameter, with central issue of waste water. Their clarification efficiency is up to 70%. Free
from suspended solids, waste water goes to the well hole, and then to the final stage of
treatment. For destruction of organic substances in the liquid waste, it was suggested to use
aerobic biological treatment on the highly efficient filter tank in which the aeration zone is
combined with the secondary sedimentation tank with a sludge chamber for recycling sludge
and removal of excess sludge mixture. Filter tank has a high oxidative capacity due to a large
amount of microorganisms. Freshness of the idea is in filtering the sludge mixture in aeration
tank with initial dose of sludge to 20 g/l using strainers, so that no more than 3-4 g/l of
suspended can go to the secondary tank.
The study was conducted at one of the hydrolysis factories. The average flow of wastewater
was 9500 m³/day, initial TBOD = 4000 mg/l О2, filter tank diameter was 28 m; the sludge
zone diameter was 18 m. The filter tank parameters depend on the dose of activated sludge
and its properties determined by the structure and biochemical oxidation of pollution.
Biochemical destruction of organic pollutants is influenced by bio enosis, which is all biotic
community in the filter tank.
The study suggests a compact efficient wastewater treatment technology with a purification
rate of 97%, and using the treated water with 0.85 coefficient of water cycle.
The ORT Braude College 7th
Interdisciplinary Research Conference
Biotechnology Engineering | 5
Nitrification of Effluent in an Intermittent Bio-Filter System
Isam Sabbah
1, 2, Nedal Masalha
2, Katie Baransi
2, Majida Jiryes
1, Ali Nujedat
3
1Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901750, Fax: 972-4-9901839, E-mail: [email protected]
2The Galilee Society Institute of Applied Research, P.O. Box 437, Shefa-Amr 20200, Israel;Tel: 972- 4
9504523, Fax:972- 4- 950452, E-mail: [email protected]
3Zuckerberg Institute for Water Research- ZIWR, Ben-Gurion University of the Negev, Sede Boqer
Campus; Tel: 972- 8- 6596832, Fax: 972- 8 -6596909, E-mail: [email protected]
Keywords: Wastewater, nitrification, tuff, bio-filter
It is widely recognized that increasing stress on freshwater supply places further emphasis on
the development of sustainable, reliable and cost-effective technologies capable of treatment
and reclamation of wastewater for reuse, especially in rural areas.
Reusing treated effluents unrestrictedly in local agriculture, without removing nutrients, is
not acceptable due to the nutrients‘ negative effects on the environment, such as
eutrophication, contamination of groundwater, ammonia toxicity, etc.
The main objective of this project was to examine Intermittent Bio- Filtration (IBF) as a
simple and cost effective decentralized secondary wastewater treatment process.
The IBF studied systems were fed with effluents of either up flow anaerobic sludge blanket
system (UASB) or chemically enhanced pre-treatment (CEPT). In addition, factors such as
media type (sand and Volcanic Tuff), filter depth, organic and hydraulic loading rate were
tested for improvement of the removal efficiency of organic matter, pathogens and nutrients.
In addition, microbial tests were conducted and included protein, polysaccharide, aerobic
activity, RtPCR and DGGE.
The results show that 93% of the COD after chemically enhanced pre-treatment (CEPT) were
removed by the IBF (Tuff), where the hydraulic and organic loading rates were 160 Ld-1
m-2
and 73 g BOD d-1
m-2
respectively. However, the COD removal was 88% after the same IBF,
which was fed with the effluents of UASB. The hydraulic and organic loading rates were 85
Ld-1
m-2
and 15 g BOD d-1
m-2
, respectively. The microbial tests showed higher protein and
polysaccharide concentration throughout the tuff filter's length. In addition, higher aerobic
activity of the tuff bio-filter was seen at all sections of the filter.
The tuff bio-filter provides more stable effluent quality than the sand bio-filter, under extreme
fluctuations of the inlet. The fecal removal of treated wastewater by the combined UASB-IBF
(Tuff) was higher than the CEPT-IBF (Tuff), where the removal was 4 and 3 orders of
magnitudes for UASB-IBF and CEPT-BIF, respectively. The average removal of the
introduced phosphate to the tuff bio-filter was 50%, where no removal was observed using
sand bio-filter.
The microbial results were expected, based on the observed higher and more stable removal
activity of tuff rather than sand. Furthermore, the DGGE analysis indicated that the diversity
of ammonia oxidizing bacteria species was higher in the tuff than the sand. This result could
be attributed to the higher surface area and special composition of the tuff.
The ORT Braude College 7th
Interdisciplinary Research Conference
6 | Biotechnology Engineering
Cleaning the Anode Gas Emissions from Tarry Substances in
Electrolytic Aluminum Production
Sergei G. Shakhrai¹, Vyacheslav V. Korostovenko², Natalia M. Kaplichenko³
¹Cand. Sc., Assistant Professor, Department of Thermal Engineering and Technosphere Safety in
Mining and Metallurgical Production, Siberian Federal University, 79 Svobodny Ave., Krasnoyarsk,
Russia 660041, Tel. 8-(391) 2-76-00-47, E-mail: [email protected]
²Doctor of Engineering, Professor, Department of Thermal Engineering and Technosphere Safety in
Mining and Metallurgical Production, Siberian Federal University, 79 Svobodny Ave., Krasnoyarsk,
Russia 660041, Tel. 8-(391) 265-54-63, E-mail: [email protected]
³Senior lecturer, Department of Thermal Engineering and Technosphere Safety in Mining and
Metallurgical Production, Siberian Federal University, 79 Svobodny Ave., Krasnoyarsk, Russia
660041, Tel. 8 (391) 201-30-70, E-mail: [email protected]
Keywords: Aluminum production, anode spike, emissions, reduction of tarry substances.
Aluminum production in top-worked cells with self-baking anodes is realized with
considerable amount of contaminants, 9.3 to 19.8 kg tar per a ton of aluminum is ejected into
the environment. Among them, benzopyrene is of the most danger; its emission is 0.015-
0.032 kg per ton of aluminum. Increasing the current capacity during the last 10-15 years has
increased the cell capacity, but the emissions of tar also increased during the process of spike
pulling directly from anode wells and from the spikes surface. In particular during spike
setting, emissions increased by 1.5-1.6 times, and equaled 3.0-4.8 kg per ton of aluminum;
the total amount 10.3-21.6 kg, while the total increases emissions of tar was 10-20%.
The aim of this study is to find technical solutions for capturing tar emissions from anode
spikes extracted for cooling.
Currently spikes are cooled in open cassettes, which are like an open "basket" with cells
fixing spikes in a vertical position. The extracted and cooled spikes are either returned back
into the anode, or transferred for surface cleaning from scale and dirt. It is considered that an
anode paste layer of 3 mm, cakes on the hot part of spikes, if the spikes are not corroded. In
fact, the thickness of caked anode paste and accordingly, the level of emissions may
considerably exceed the indicated values because of high corrosion wear of spikes, leading to
the increase of roughness, and due to deformation of the spikes as a result of high
temperature in the anode. Cooling the spikes with fluids significantly reduces the time of
operation and allows capturing all tar emissions, but it has several disadvantages connected
with dangerous concentrations of new compounds, the complexity of coolant disposal, etc.
It is possible to solve the problem of capturing tar pollutants during cooling anode spikes if
we use the aspirate cassette, developed by the authors (68 512 patent of the Russian
Federation). The cassette is an airproof container with an extraction fan and a filter. Coke
grains can be used as filtering material, they are later returned to the anode paste, or it can be
fibrous combustible material, that can be disposed in coke ignition furnaces.
The use of aspirate cassettes would reduce tarry substances emission in an average of 5%.
The ORT Braude College 7th
Interdisciplinary Research Conference
Biotechnology Engineering | 7
Investigating the Apoptotic Pathway in Human Ovarian Cancer
Cells, Following Exposure to an Ethyl Acetate Extract of
Coprinus comatus
Amal Toubi - Rouhana
1, 2, Solomon P. Wasser
2, Fuad Fares
3
1Prof. Ephraim Katzir
Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901907, Fax: 972-4-9901839, E-mail: [email protected]
2Department of Evolutionary and Environmental Biology, University of Haifa, Mount Carmel, Haifa
31905, Israel. Tel: 972-4-8249218, Fax: 972-4-8688828, E-mail: [email protected]
3Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel,
Haifa 31905, Israel. Tel: 972-4-8288781, Fax: 972-4-8288763, E-mail: [email protected]
Keywords: Ovarian cancer, Coprinus comatus, medicinal mushrooms, apoptosis
In former studies, an Ethyl acetate extract of Coprinus comatus was found to inhibit
proliferation and induce apoptosis in three lines of human ovarian cancer cells (ES-2, SKOV-
3 and SW-626).
The main aims of this research are:
1) To investigate the mechanism of the apoptotic pathway in human ovarian cancer cells,
following exposure to the Ethyl acetate extract of C. comatus.
2) To purify the extract and try to identify the active compounds.
SKOV-3 cells were exposed to an effective concentration of the extract (150 µg/ml) for 24 or
48 hrs. Protein concentrations were determined in the lysates of treated and untreated cells
and they were analyzed for caspase-3 and caspase-9 activities using western blots. For
Chemical analysis, we used a silica gel column to fractionate the extract. The loaded sample
was washed with a gradient of Hexane (100 % - 0 %) and Ethyl acetate (0% - 100 %). 16
fractions were collected and analyzed using TLC. Dimethyl sulfoxide was added to each vile
until the concentration of 100 mg/mL was reached. Several dilutions of these fractions were
tested for their effect on viability of human ovarian cancer cells (ES-2 and SKOV-3). In an
attempt to identify the active compounds, we sent the active fraction for further analysis on
GC-MS and LC-MS.
Both analyzed enzymes were found to be active in the treated cells. The last fraction
collected from the silica gel column was identified as the active fraction. This fraction was 50
-100% more active than the original extract. GC-MS analysis revealed the presence of several
fatty acids and their methyl esters in the active extract. The mass spectra obtained from the
peaks on the LC-MS chromatogram were compared to the spectra of active compounds from
mushrooms (based on literature) but they did not match any known compound
Western blot analysis lead to the conclusion that Ethyl acetate extract of C. comatus induces
apoptosis in human ovarian cancer cells SKOV-3, through the mitochondrial pathway.
Although there is some evidence in the literature that some fatty acids have an anti-cancer
activity, more analyses are needed to confirm that these are the main active compounds in the
extract.
Acknowledgement: This work was supported by a grant from the Planning and Budgeting
Committee of the Council for Higher Education in Israel and a grant from the Israel Ministry
of Science, Culture and Sport.
The ORT Braude College 7th
Interdisciplinary Research Conference
8 | Biotechnology Engineering
Effect of Copper Oxide Nano-Particles on
Cholesterol Levels in the Liver
Iris S. Weitz
1, Nelli Bar-Guy
2, Maria Grozovski
2
1Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel, 21982 Israel, Tel: 972-4-9901896, Fax: 972-4-9901839, E-mail: [email protected]
2Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel, 21982 Israel, Tel: 972-4-9901895, Fax: 972-4-9901839, E-mail: [email protected]
Keywords: Nano-particles, copper oxide, nano-toxicology, cholesterol, liver, statins
Lowering cholesterol in a diet has very little effect on blood cholesterol levels. Thus, using
statins, a family of drugs that inhibit HMG CoA reductase, an enzyme involved in cholesterol
synthesis, may reduce the levels of cholesterol. However, the statins have known side effects
such as gastrointestinal effects, headache and dizziness, unexplained muscle pain, tenderness
and weakness.
Copper oxide (CuO) is an essential nutrient in food supplements (3 mg/day). Copper ions
play an important role in human health. They are necessary for the absorption and utilization
of iron, and aid in the formation of red blood cells. Copper ions also help in proper bone
formation and maintenance, and are needed for the activity of multiple enzymes.
The CuO is transported directly and stored in the liver, the organ where cholesterol synthesis
mainly occurs (80 %). Bulk CuO particles are insoluble in water and CuO bio-vialability is
mainly dependent on the solubilization in the gastrointestinal system. In earlier work, a
synthetic route was well established for the preparation of spherical CuO nano-particles (CuO
NPs) with narrow size distribution (5nm), which are readily soluble in water, hence
increasing their bio-availability. The water soluble CuO NPs were used for direct
functionalization with pravastatin. The pravastatin molecules were self-assembled via ionic
interaction of the carboxylate moiety with the CuO NPs.
Sprague-Dawley rats were subjected to a high cholesterol diet for four weeks, causing
hypercholesterolemia. Then the rats were treated with three different aqueous solutions of
CuO NPs (according to 3 mg/day dose in human food supplements); two solutions contained
statin functionalized CuO NPs and one solution contained pure CuO NPs. A control
experiment was performed by treatment of the rats with soluble pravastatin.
Biochemical analysis revealed that treatment with either bare or functionalized CuO NPs
lowered cholesterol levels in the liver, increased antioxidant Paraoxonase (PON) and
Superoxide-Dismutase activities (SOD), and increased enzymatic activities of Lactate
Dehydrogenase (LDH) and Alkaline Phosphatase (ALP). Liver histology supported the
biochemical results described and verified no copper accumulation in the liver tissue.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
Biotechnology Engineering | 9
The Potential for Using CuO Nano-Particles as a Wood Preservative
Iris S. Weitz
1, Michal Maoz
2, Camille Freitag
3, Jeff J. Morrell
4
1Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901896, Fax: 972-4-9901839, E-mail: [email protected]
2Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901901, Fax: 972-4-9901839, E-mail: [email protected]
3Wood Science and Engineering, Oregon State University, Corvallis, OR 97331 USA. Tel 541-737-
4236, Fax: 541-737-3385, E-mail: [email protected]
4Wood Science and Engineering, Oregon State University, Corvallis, OR, 97331 USA. Tel 541-737-
4222, Fax: 541-737-3385, E-mail: [email protected]
Keywords: Nano-particles, copper oxide, minimum inhibitory concentration, minimum
fungicidal concentration, Gloeophyllum trabeum, Trametes versicolor, wood preservative
Copper-based biocides for wood protection have been used in solubilized forms either in
water or complexes with organic ligands. Micro-dispersed copper systems have the
advantage of reducing the need for a co-solvent. Small spherical nano-particles (5-20 nm) can
more readily move through a wood matrix and penetrate more deeply (10-298 mm) into the
wood layers under treatment, thus reducing the use of pressure impregnation. Metal oxides
acquire an antimicrobial activity: Nano CuO was shown to be over two orders of magnitude
more bio-available than bulk CuO.
The aim of this research is to examine the fungicide effects of aqueous solutions of copper
oxide nano-particles (<10 nm diameter) on selected wood decay fungi.
Antifungal activity of the copper oxide nanoparticles aqueous solution was examined by
exposing wood decay fungi to media containing various concentrations (0.12; 0.09; 0.06;
0.03 and 0.015%) of the nano-particles. The agar dilution method in mini-agar slants was
used, where Gloeophyllum trabeum or Trametes versicolor, as tested fungi, were inoculated.
A wood block test was used; pine wafers were treated under vacuum for 20 minutes or, in a
second test, were submerged in the solutions for 2 days, until they sank.
The brownish CuO nano-particles aqueous suspensions were stable for more than 6 months at
room temperature; however, they rapidly precipitated when exposed to wood. The nano-
copper system was effective against both G. trabeum and T. versicolor in agar at fairly low
levels. Minimum fungicidal concentration (MFC) values were essentially the same as the
minimum inhibitory concentration (MIC) values, suggesting that once the copper affected the
fungus, the effect was lethal. Wood block results, in both impregnation methods, supported
these results.
Nano-copper has potential as a wood protectant, due to aqueous colloidal stability of the
particles which penetrate wood cell walls. Further investigation will be required to
understand the mechanism of the nano-size material and to assess the potential health and
environmental risks.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
10 | Electrical and Electronic Engineering
Fuel Cells in Braude – Improvements during 2010-2011
Eugenia Bubis
1, Hana Faiger
2, Pinchas Schechner
3
1Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901905, Fax: 972-4-9580289, E-mail: [email protected]. il
2Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901901, Fax: 972-4-9901839, E-mail: [email protected]
3Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901905, Fax: 972-4-9580289, E-mail: [email protected]
Keywords: Alkaline Fuel Cell, glucose, Alkaline Fuel Cell, (AFC) power multiplexing
The objective of the ORT Braude College Fuel Cells Research Group is to develop an
alkaline fuel cell fuelled by glucose. Fuel cells are electrochemical devices that allow the
direct production of electricity from fuels. Their theoretical efficiency reaches up to 83%.
Glucose was selected as a renewable fuel because it has unique properties that make it the
ideal fuel. The suggested cell is unique because it includes a combination of electronic
circuits to overcome inherent disadvantages of glucose as a fuel.
The aim of this study is to increase the power of the cell in the following aspects:
1) Temperature;
2) Effect of the concentration of glucose;
3) Multiplexing Power Supply Multiplexed and
4) Use of super-capacitors.
The Peak Power Density, PPD [W/m2] of the self- designed and homemade AFC fueled with
glucose using KOH as the electrolyte was investigated by self-designed and homemade
Automatic Fuel Cell Measurements System. The aimed goals of the investigation were tested
in four different appropriated experimental set-ups.
The results are:
1) There is a maximum in the PPD at a temperature of 47 0C. At this temperature we get a
PPD = 5.4 W/m2 versus = 0.4 W/m
2 at a temperature of 20
0C.
2) There is a maximum in the PPD when the glucose concentration is 0.4 M.
3) The use of Power Multiplexing enables the abstraction of more energy from the system.
4) The loading of a super-capacitor with 4 fuel cells allows an Effective Peak Power Density,
EPPD of approximately 700 W/m2.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee under Grant number 5000.838.1-41.
The ORT Braude College 7th
Interdisciplinary Research Conference
Electrical and Electronic Engineering | 11
Temperature Dependence of Effective Mobility
for NMOS Transistor
Radu Florescu
1, Nisim Sabag
2
1Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901864, Fax: 972-4-9580289, E-mail: [email protected]
2Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901905, Fax: 972-4-9580289, E-mail: [email protected]
Keywords: NMOSFET, threshold voltage, effective mobility, I/V characteristic, BSIM
Simulation Model, temperature dependence
Extensive studies on the experimental determination of effective mobility in NMOSFET have
been carried out by a large number of researchers.
The concept of mobility, resulting from an analysis of stationary transport where carrier
velocity is limited yb scattering phenomena, has been used in microelectronics as a
measurable factor and as a parameter of analytical models developed to predict device
performance.
For the new CMOS technologies, dramatic reduction of the mobility measured at short gate
length has been observed. Moore's Law states that the number of transistors per integrated
circuit doubles every two years. The current 90 nm generation node produces CMOS devices
with Lg of ~50 nm, and a Lg of ~10 nm it is projected.
The aim of this study is the development of a new model of Effective Mobility temperature
dependence for NMOSFET.
In our paper, the results of laboratory tests are compared with the theoretical model and with
the semi empirical BSIM4 Simulation Model (Berkeley Short Channel MOSFET Model),
over a wide temperature range from 25 0C to 125
0C. In order to accurately obtain the
mobility for use in an I-V model a suitable determination of inversion charge and electrical
potential is demonstrated for high-performance, low power CMOS applications (sub-micron
gate length and SiO2 low thickness).
The results are:
1) Numerical simulation is a powerful tool to carry out mobility extraction.
2) The linear model from BSIM4 is not accurate enough, especially for high temperatures.
3) Our theoretical model is better that BSIM, especially for high temperatures.
A more accurate and efficient method to BSIM modeling temperature dependence for VLSI
circuits is needed.
The ORT Braude College 7th
Interdisciplinary Research Conference
12 | Electrical and Electronic Engineering
Supercapacitor: an Alternative for Energy Storage
Radu Florescu
1, Rona Sarfaty
2
1Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901864, Fax: 972-4-9580289, E-mail: [email protected]
2Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901971, Fax: 972-4-9580289, E-mail: [email protected]
Keywords: Supercapacitor, simulation model, power availability, solar panel, fuel cells
The world consumes approximately 15 terawatts of power each year. The amount of annual
have stable solar energy has been estimated at 50 terawatts.
Suprecapacitors are common today in solar panel and fuel cell energy storage.
Supercapacitors are components for energy storage, dedicated for applications where both
energy and power density are needed. Even if their energy density is ten times lower than the
energy density of batteries, supercapacitors offer new alternatives for applications where
energy storage is needed.
The aim of the present study is to evaluate the energy storage capability of supercapacitors.
In our paper, we present some results about a simulation model of supercapacitor, in addition
to efficiency of energy storage. The results of laboratory tests are compared with the "two
branches model", and a good concordance is proved.
Supercapacitors as energy storage systems are recommended for real power injection and
reactive power injection for stabilization of fuel cells or solar energy systems.
The ORT Braude College 7th
Interdisciplinary Research Conference
Electrical and Electronic Engineering | 13
Quantum-Dot Cellular Automata Serial Adder for Novel
Architecture of Nano-Computer
Michael Gladshtein
Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-72-2463668, Fax: 972-4-9580289, E-mail: [email protected]
Keywords: Nano-computer architecture, quantum-dot cellular automata, decimal adder,
Johnson-Mobius code
Quantum-dot Cellular Automata (QCA) is a new technology for nano-electronic computers.
Several QCA arithmetic unit designs have been published in technical literature. However, all
these designs use the fundamental information principles inherited from microelectronic
computers such as the binary number system and bit-parallel data transfer/processing.
Presently, at the transition stage from microelectronic technology to nano-technology, the
basic computer elements essentially vary. Besides, the application area of computers extends.
Computers process large volumes of decimal information in financial, commercial, and
Internet-based applications, which cannot tolerate errors from converting between decimal
and binary formats.
Hence, alternative principles should be chosen for novel nano-computer architecture. The
feasibility of the principles can be tested by experimental design of the main functional
computer unit—an adder—and examination its technical parameters.
First of all, it is preferable to use serial data transfer/processing because the cost function and
delay of the computation QCA elements and communication QCA elements are comparable.
The signal propagation through QCA elements is similar to the signal propagation through a
conventional shift register. Secondly, the growing market of computer applications requires
using of binary coded decimal encoding for direct processing of decimal information without
representation and conversion errors. It is clear that QCA price will be reduced as nano-
technology develops. Besides, there are significant problems in providing high reliability of a
nano-computer due to small device sizes and self-assembly fabrication processes. Therefore,
it is preferable to choose the decimal encoding that supports arithmetic processing by shift
operation and allows detecting and correcting errors.
It is shown that among possible decimal encodings, the Johnson-Mobius code is the most
interesting because it is a biquinary code, which is composed of only 5 bits and supports the
simplest arithmetic processing by two operations: INVERT and TWISTED-RING ROTATE.
Moreover the code redundancy presupposes the error detection and correction capability. The
original serial decimal Johnson-Mobius addition algorithm provided the shortest input-to-
output delay is suggested. The block diagram of the serial decimal Johnson-Mobius adder on
QCA and its full circuit are designed. The required number of QCAs is 1130 and the delay is
10 clock cycles. The simulation results demonstrate that the proposed adder works correctly.
The proposed adder confirms a possibility of novel decimal nano-computer design, which
allows us to avoid both base-conversion errors and machine time losses due to these
conversions as well as simplify programming languages and compilers.
Acknowledgement: This study was supported by a scholarship ―Conversion of hours of
teaching to hours of research‖ from the ORT Braude College Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
14 | Electrical and Electronic Engineering
Reliability of Modified Color Edge Detector Supporting Heavily
Compressed JPEG Images Obtained by Inexpensive Cameras
Samuel Kosolapov
Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901905, Fax: 972-4-9580289, E-mail: [email protected]
Keywords: Edge detector, color edge detector, image processing, JPEG compression
Classical Color Edge Detector techniques are basically derived from standard one-color edge
detectors. However, images obtained from inexpensive cameras in "auto‖ mode (designed
for presenting images to Human observer) are available only after the step of JPEG
compression. Camera noise, automatic camera parameter settings, and JPEG compression,
create a number of artifacts making detection of the color edge position non-reliable,
especially for low resolution images.
The aim of this research is to evaluate influence of camera parameters settings and JPEG
compression on the edges quality, and modify the classical edge detector in order to enable
support for heavily compressed JPEG images obtained from inexpensive cameras.
Model test images emulating defects of JPEG compression were created by using MAPLE
simulation software. Test images contain only a limited number of colors (referred later as
Original Color Set – ―OCS‖). Well-known defects of inexpensive cameras like Uneven Field
Illumination, shot noise, digitization errors and Automatic White balance defects were
simulated. Additionally, colors from ―OSC‖ were ―intentionally distorted‖ (in accordance
with real images appearance). The first modification of the Color Edge Detector was in a
creation of test images which have dedicated self-calibration color zones (SCCZ). Modified
Color Set Colors (MCSC) was extracted from SCCZ. The second modification was a ―vote
selection algorithm‖ using MCSC instead of OSC. Quality of modified color edge detector
was evaluated by using a special test routine, counting outliners as in relevant as in non-
relevant zones.
Modified color edge detector creates significantly less outliners then original one, both for
test images and for real images. Most of the outliners were in the region of edges between
different colors.
Addition of dedicated regions designed for Color Edge Detector self-calibration enables to
use modified color edge detectors even for heavily compressed images grabbed by low-
quality cameras. Obtained results may be useful for other general purpose image processing
algorithms utilizing elements of color recognition.
The ORT Braude College 7th
Interdisciplinary Research Conference
Electrical and Electronic Engineering | 15
Characterization of a Non-Linearity and Interrelations
Shmuel Miller
Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901905, Fax: 972-4-9580289, E-mail: [email protected]
Keywords: Non-linearity, spurii, intermodulation, cross-modulation, harmonics, saturation
Any electronic system will eventually reach a non-linear region depending on its input
signals. Non-linearities affect signals in several ways, including the generation of several
types of unwanted spurii. The technical characterization and measurement of non-linear
performance of systems has been vastly treated over the last seventy years, with basic
compression and intercept point parameterization of systems being a common engineering
practice. This topic is becoming relevant these days in multiple-standards communication
systems that involve the acceptable simultaneous operation of more than one régime in one
system.
The aim of the present study is to re-evaluate the non-linearity performance parameters and
their inter-dependencies, develop close-form expressions for arbitrary-order of harmonics and
intermodulation products. Finally, clarify the implications of industrial measurement methods
on the non-linear system performance evaluation, and suggest new ways for accurate
characterization of a memory-less non-linear system.
Employ multiple harmonic input signals that are represented using complex exponentials.
Develop the response of a non-linear system using a polynomial approximation, and using
the common definitions of several performance parameters, derive new inter-relationships
amongst them. These results enable to clearly conclude the implications of additional
measurements on the accuracy of the modeled non-linearity.
General close-form expressions are obtained for the harmonic and intermodulation terms.
Thus are provided for a two-tone input. The inter-relations among harmonics, compression
points and intermodulation terms are obtained, where applicable. The dependence of certain
performance parameters on a subset of the spurii is shown explicitly. The implications of
measurement procedures of improved characterization of the memory-less non-linearity are
analyzed and discussed.
The classical topic of memory-less non-linear systems is re-visited and analyzed. General
expressions for the spurii and performance parameters that are suitable for higher-order
characterization are derived. Several conclusions that provide insight on measurements that
may improve the assessment of system performance are provided. These rely on higher-order
approximations of the non-linear system characteristics.
Acknowledgement: This study was motivated by several questions raised by Mr. Nadav
Nissan Roda in relation to a radio chip operating Wi-Fi and Bluetooth standards
simultaneously.
The ORT Braude College 7th
Interdisciplinary Research Conference
16 | Electrical and Electronic Engineering
New Compact Printed Antennas for Medical Applications
Albert Sabban
Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901905, Fax: 972-4-8759111, E-mail: [email protected]
Keywords: Antennas, medical applications, micro strip antennas
The biomedical industry is in continuous state of growth in recent years. Low profile
compact antennas are crucial in the development of human bio-medical systems.
This paper presents a study of compact printed antennas for medical applications. Design
considerations, computational results and measured results of several compact micro strip
antennas with high efficiency for medical applications are presented in this paper.
Environment effects on the antennas electrical performance are also presented.
A new compact micro strip loaded dipole antenna has been designed to provide horizontal
polarization. The antenna consists of two layers. The first layer consists of FR4 0.25mm
dielectric substrate. The second layer consists of Kapton 0.25mm dielectric substrate. The
substrate thickness determines the antenna bandwidth. However, with thinner substrate we
may achieve better flexibility. We also designed a thicker double layer micro strip loaded
dipole antenna with wider bandwidth. A printed slot antenna provides a vertical polarization.
The proposed antenna is dual polarized. The printed dipole and the slot antenna provide dual
orthogonal polarizations. The antenna dimensions are 4.5x4.5x0.05cm. The antenna may be
attached to the patients‘ shirt, in the patient stomach or back area.
Usually in medical applications the distance separating the transmitting and receiving
antennas is less than 2D²/λ, where D is the largest dimension of the antenna. In these
applications the amplitude of the electromagnetic field close to the antenna may be quite
powerful, but because of rapid fall-off with distance, it does not radiate energy to infinite
distances, but instead its energies remain trapped in the near region. Thus, the near-fields
only transfer energy to close distances from the receivers. The receiving and transmitting
antennas are magnetically coupled. Change in the current flow through one wire induces a
voltage across the ends of the other wire through electromagnetic induction. The amount of
inductive coupling between two conductors is measured by their mutual inductance.
The antenna bandwidth is around 10% for VSWR better than 2:1. The antenna beam width is
around 100º. The antenna gain is around 2 to 4dBi. The antennas‘ S11 results for different
belt thickness, shirt thickness and air spacing between the antennas and human body are
given in this paper. The effect of the antenna location on the human body should be
considered in the antenna design process. If the air spacing between the sensors and the
human body is increased from 0 mm to 5 mm the antenna resonant frequency shifts by 5%.
The ORT Braude College 7th
Interdisciplinary Research Conference
Electrical and Electronic Engineering | 17
Vertical Multi-Junction (VMJ) Si Micro-Cells
Rona Sarfaty
1, Roni Pozner
2, Gideon Segev
2, Abraham Kribus
3,
Yossi Rosenwaks2
1Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901971, Fax: 972-4-9580289, E-mail: [email protected]
2Department of Physical Electronics, Faculty of Engineering, Tel Aviv University, Ramat-Aviv 69978,
Israel, Tel: 972-3-6406248, Fax: 972-3-6423508, E-mail: [email protected]
3School of Mechanical Engineering Faculty of Engineering, Tel Aviv University, Tel Aviv 69978,
Israel, Tel: 972-3-6405924, Fax: 972-3-6407334, E-mail: [email protected]
Keywords: Vertical p-n Junction, high-voltage and efficiency, pre- patterned macro-pores
Autonomous MEMS require similarly miniaturized power sources. Micropower
environmental energy harvesting generators offer an alternative source of renewable energy.
Photovoltaic cells with high voltage and low current would be very desirable in general and
in particular for light concentrator applications where currents are high and current-
associated losses are a major bottleneck for cell performance. High-voltage silicon Vertical
Multi-Junction (VMJ) cells have been proposed since the 1970‘s, and have shown capability
to accept high concentration with peak efficiency of slightly above 20%. These cells have
been produced by a hybrid process of stacking multiple wafers followed by orthogonal
cutting. We are developing an alternative approach for producing the VMJ structure
monolithically on a single wafer, where the junction geometry can be optimized with greater
freedom than the stacking approach and micro cells with wide of few tens of microns can be
produced.
The aim of this research is to develop and demonstrate a novel Vertical Multi- Junction
(VMJ) cell which consists of series-connected vertical p-n junctions. The proposed device
offers significant advantages over conventional cells: lower series resistance loss allows
maximization of the efficiency under high concentration, higher voltage and smaller inactive
area loss; decoupling of optical and electronic effects into orthogonal dimensions, allowing
better optimization of junction dimensions.
We present comprehensive numerical 2D modeling of a Si vertical junction using Synopsys
TCAD Sentaurus device simulator. Preliminary results of 2D realization process will be
presented. We present here a comprehensive analysis, optimization and measurements of a
monolithically structured VMJ cell, taking into account a wide range of realistic parameters
and concentration levels. A large increase in the active layer photoconductivity, usually
negligible in most PV cells, drastically lowers the cell's series resistance under high
concentration. As a result, the VMJ device exhibits efficiencies well above 30% for
concentration of around 1000 suns.
Preliminary results of 2D realization process will be presented.
The optimal junction dimensions are much smaller than the dimensions used in previous
VMJ cell tests and analyses.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee and from the Israel Ministry of National Infrastructures.
The ORT Braude College 7th
Interdisciplinary Research Conference
18 | Electrical and Electronic Engineering
Models in Electronics: How Students Use Them?
Elena Trotskovsky
1, Nissim Sabag
2
1Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901709, Fax: 972-4-9580289, E-mail: [email protected]
2Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901942, Fax: 972-4-9580289, E-mail: [email protected]
Keywords: Models in electronics, mistakes and misunderstandings, engineering thinking
One interesting issue concerning the development of engineering thinking among students
during their academic studies is the characterization of mistakes and misunderstandings. We
focus on the use and understanding of models by students in electronics studies. Our multiple
years of experience in academic field of Electrical and Electronic Engineering education,
allows us to claim that the knowledge on this issue is insufficient.
The current paper describes a case study in which the relationship of parameters such as type
of model, maturity of student, learning discipline, lecturer, future student specialization, and
the way of understanding and using models in problem solving in Electronic Engineering
disciplines.
A special set of problems was developed for every type of model including three kinds of
problems: problems related to routine use of the model, problems concerned with
understanding of the model‘s purpose, and application problems which demand a deep
understanding of model usage. Nearly two hundred students from the Departments of
Electrical and Electronic Engineering and Mechanical Engineering participated in the study.
First results show that there is no significant difference between students' performance in the
routine problem solving, but significant differences could be observed in the understanding
of model purpose and in the application problems. The salient result is that the students'
grades in the solving of two last kinds of problems in the courses which were taught by
lecturers, who have second and third academic degrees in science and technology education,
were significantly higher than the grades in the courses which were taught by lecturers who
have a Ph.D. in Science and Engineering. This effect must be tested broadly in future study.
The ORT Braude College 7th
Interdisciplinary Research Conference
Industrial Engineering and Management | 19
ORDANOVA: The Analysis of Ordinal Variation
Emil Bashkansky
1, Tamar Gadrich
2
1Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901827, Fax: 972-4-9901852, E-mail: [email protected]
2Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901923, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: Ordinal data, ANOVA, dispersion measures, repeatability, reproducibility study
Consider an object that is measured using an ordinal scale with K ordered categories. Since
only comparisons of ―greater than‖, ―less than‖, ―equal to‖ and ―unequal to‖ can be made
among ordinal variable values, all statistical measures of such ordinal variables must be
based on these limitations.
The focus of the article is on ORDANOVA (Ordinal Data Analysis of Variation), i.e.:
analysis of the variation of ordinal data aimed to utilize such analysis for practical engineering
applications.
In order to fulfill practical engineering applications such as quality/failure classification,
uncertainty evaluations, repeatability and reproducibility (R&R) analysis, distinguishing
feature identification and so on, the desirable properties of such a variation measure were
precisely defined. Based on a literature survey, we assembled a number of ordinal dispersion
measures. Our study showed that all the above mentioned properties are best satisfied by
Blair and Lacy‘s measure. We have developed a method allowing to split this dispersion
measure to ―within‖ and ―between‖ components and discussed how this decomposition looks
while considering the following three engineering applications: 1) making inference about
the multinomial proportions from small samples, 2) analyzing the accuracy of the ordinal
measuring/classification system and 3) searching for a distinguishing factor.
The utilization of ORDANOVA decomposition to the abovementioned engineering
applications led to the following results: 1) If the null hypothesis that all samples come from
the same population characterized by the set { }kp is true, then the total variation is split on the
average in full accordance to the ―within‖ and ―between‖ amounts of degrees of freedom
(and this splitting does not depend on the amount of categories!). Fluctuations in the splitting
are, of course, possible; for each case they may be simulated and their likelihoods can be
assessed. 2) After classification the variation may increase, decrease or remain unchanged
relative to the incoming variation. The result depends on the metrological properties of the
classification matrix. 3) If the factor under study does not yield to segregation between
groups formed according to different levels of the factor, the ―between‖ to ―within‖ variation
parts ratio is expected to be no more significant than the ―between‖ to ―within‖ ratio of
degrees of freedom. We have proposed to use, as an indicator of the segregation power of the
factor under study, the fluctuation of the empirical ratio between these two dispersion
components from its expected 0H value.
The Blair and Lacy's dispersion measure is the most desirable measurement that fulfilled the
essential features for variation measure. Moreover, this measure allowed us to decompose the
total variation to between and within components.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
20 | Industrial Engineering and Management
Setting Release Gates for Activities in Projects with
Stochastic Activity Durations
Illana Bendavid
1, Boaz Golany
2
1Faculty of Industrial Engineering and Management, Technion - Israel Institute of Technology,
Technion City, Haifa 32000, Israel, Tel: 972-4-8121390, Fax: 972-4-8121390, E-mail:
2Faculty of Industrial Engineering and Management, Technion - Israel Institute of Technology,
Technion City, Haifa 32000, Israel, Tel: 972-4-8294512, Fax: 972-4-8295688, E-mail:
Keywords: Project management, gates, cross-entropy, scheduling
This work addresses the problem of controlling the scheduling of activities in projects with
stochastic activity durations. A first approach is to set a gate for each activity i.e., a time
before it the activity cannot begin. Since the resources required for each activity are
scheduled to arrive according to its gate, we incur a ―holding‖ cost when an activity is ready
to be processed, but the resources required for it were scheduled to arrive at a later time; or a
―shortage‖ cost when the required resources have arrived on time but the activity cannot start
because its predecessors are not yet finished.
Our objective is to set the gates so as to minimize the sum of the expected holding and
shortage costs.
A second approach is to set, for each activity, an interval of time and in this way introduces
more flexibility in the contracts with the subcontractors. The subcontractors would now be
expected to start their respective activities within a certain time interval rather than exactly at
a gate. Our objective is to set the intervals so as to minimize the sum of the expected holding,
shortage and interval costs.
In the first approach, all the gates are determined in a ―static‖ way, at ―time zero‖. In this
way, all the risk induced by the uncertainty is assumed by the project manager (PM) only. A
dynamic approach would be to solve the problem at ―time zero‖ to obtain a basic guideline
for the contract and then, each time more information is obtained, the PM can solve the
problem for the remaining activities and to adjust his future decisions in a dynamic way,
allowing him to reduce uncertainty, thus to reduce his costs.
We use a general heuristic method to solve the problem. We chose the Cross-Entropy
method. We applied it on small projects using a discrete generation distribution function. We
extend the method for larger problems, using a continuous generation distribution function.
We checked the performance of the algorithms developed and compared them to other
heuristic methods.
In all examples, the CE-based algorithms developed outperformed other methods to which
they were compared. The advantage of the algorithms developed grows as the size of the
project grows.
The CE algorithms developed in this work proved useful for the basic problem and its
extensions. This work also provides important insights for contract negotiations with
subcontractors.
The ORT Braude College 7th
Interdisciplinary Research Conference
Industrial Engineering and Management | 21
The Question of Truth in Knowledge Management
Doron Faran
Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901824, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: Knowledge management, truth, justification, epistemology
Knowledge is traditionally defined as "justified true belief"; hence the truth is an inherent
part, inseparable from the knowledge. However the definition of truth has changed
significantly along the centuries: from "one and only" and "out there" in ancient Greece to the
multi-facets notion of the post-modernism. Similarly the means for justification has
developed, spanning from rationalism through pragmatism to empiricism. The disciplines
involved in the discussion were mainly Philosophy and Science.
In the last two decades the issue of knowledge has been drawing much more attention in the
management circles than ever before. Once the concept of Knowledge Management (KM)
was introduced in the early 1990's it generated a wave of practical and academic interest that
has kept growing ever since. The topics that the field addresses are diversified: there are
activities such as knowledge creation, transfer, sharing, utilization and retention, to name just
a few; there are issues of essence, as whether "knowledge" is an asset or a process, and there
are questions of the encompassed content.
The research raises two questions: one about the references to truth in the KM literature,
academic and practical alike; the second is more fundamental and asks what in fact the
attitude toward truth and justification is in organizations.
This is a critical, literature-based research. Data will be collected through literature survey.
Both qualities with which we opened, namely truth and justification, have been relatively
marginalized, all the more so in the practical writing.
Since the research is in early stage, the presentation will focus on the background, the
questions and the method.
The ORT Braude College 7th
Interdisciplinary Research Conference
22 | Industrial Engineering and Management
Learning Patterns in Procedural Skills Acquisition with
Enriched Information
Nirit Gavish
Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901923, Fax: 972-4-9901842, E-mail: [email protected]
Keywords: Procedural skills, enriched information, learning
Several past studies have demonstrated that that when a learner of a new procedural skill is
provided with an elaborated knowledge which is called "how-it-works" knowledge or
"context procedures", in addition to the "how-to-do-it" knowledge or "list procedures", his
performance becomes more accurate, faster, and more flexible. However, in some cases the
enriched information did not facilitate performance. Although several assumptions were
made, there is no conclusive agreement about when and why enriched information during
procedural task training improves performance
The goal of this study was to investigate the difference in training patterns which developed
when the trainee is encountered with enriched information compared to learning a procedure
without this information.
Thirty nine undergraduate students from the Technion served as participants, using a training
program for assembling a 76-step Lego helicopter model. The software presented step-by-
step assembly instructions and also included a short task to be performed in each step
(selecting the relevant brick and pointing on its position). Trainees were required to learn
how to assemble the model in order to be able to build the real Lego model in the test phase.
Training time was divided to two segments: In the first segment, trainees actively interacted
with the program, and in the second segment they could only watch the steps. Trainees
decided when to terminate the first segment and move on to the second one, but the entire
training was limited to 19 minutes. A Control group (10 males, 10 females) was trained with
the program only, and a Model group (9 males, 10 females) was also given the real final
Lego model, and they could watch it during the training.
Performance measures were not significantly different among groups. However, Control and
Model groups differed in the correlations between training pattern and performance. While
no significant correlations were found for the Control group in the first segment, in the Model
group two training patterns were negatively correlated with performance: performing each
training step very slowly, which was correlated with longer time to assemble each brick
(r=0.500, p=0.029), and performing each step very fast, which was correlated with a larger
number of errors (r=0.545, p=0.016). Intermediate training time for each step was found to be
the best strategy for this group, and was correlated with shorter performance time (r=-0.577,
p=0.010), shorter time to assemble each brick (r=-0.552, p=0.014) and less errors (r=-0.451,
p=0.053).
Procedural training that is accompanied by additional information becomes more complex,
and hence trainees may wrongly choose training strategies which are not optimal and can
impair their potential performance. Special awareness to this possible danger should be given
to assure that the enriched information will be successfully used to accelerate learning.
Acknowledgment: This research was supported in part by the European Commission
Integrated Project IP-SKILLS-35005.
The ORT Braude College 7th
Interdisciplinary Research Conference
Industrial Engineering and Management | 23
Generating and Evaluating Simulation Scenarios
to Improve Emergency Department Operations
Maya Kaner
1, Tamar Gadrich
1, Shuki Dror
1, Yariv Marmor
2
1Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901854, Fax: 972-4-9901852, E-mails: [email protected],
[email protected], [email protected]
2Division of Health Care Policy and Research, Mayo Clinic, 200 First Street SW Rochester, MN
55905, Minnesota, USA, E-mail: [email protected]
Keywords: Simulation, emergency department, design of experiments, scenarios
The literature describes different problems in Emergency Department (ED) operations. To
resolve some of these problems researchers analyze various operational scenarios through
discrete-event simulation. However, defining possible scenarios is usually not schematic and
depends on the designer‘s intuition.
This paper suggests a framework for schematic generation and evaluation of simulation
scenarios to improve ED processes in real-life environments.
First, we assemble a set of main generic components required for designing simulation
experiments: factors, performance measures and interactions. Second, we develop a
questionnaire for gathering information regarding the relevant factors and their possible
levels and interactions in a specific ED. Using the answers to the questionnaire, we build a
scenario tree whose branches represent possible scenarios. Then we use discrete-event
simulation to simulate the scenarios for the ED and analyze the results, using a Generalized
Linear Model (GLM) for nested (simulation) experiments and Scheffe‘s post hoc test to
group different scenarios.
We illustrate the application of our methodology in a specific ED operating without a Fast
Track (FT). The simulation scenarios were schematically generated based on the answers of
this ED‘s management. Operational alternatives (e.g., FT opening) as well as uncontrollable
changes (e.g., possible increase in the percentage of non-critical patients) were tested. The
average patient length of stay (ALOS) for the defined scenarios varied from 206 minutes to
337 minutes. Among the results, we found: an FT should not be opened under the given
conditions, possible increase in the percentage of non-critical patients decreases the ALOS by
at least 40 minutes and adding a nurse slightly increases (about 3%) the percentage of
patients waiting for first examination by a physician up to the given threshold.
Our methodology can support ED management in improving ED operations through enabling
them to analyze possible scenarios in a simulation environment. We contribute to the area of
ED computer simulation by suggesting a methodology that offers several advantages.
1) Simulation scenarios can be schematically formulated rather than based on trial-and-error
experiments.
2) Heterogeneous dependent and independent ED factors can be handled to avoid the risk of
missing important factors that should be taken into consideration and to analyze complex
interrelationships among these factors.
3) Scenario development can be integrated in the different stages of simulation model
development to support designers and management in understanding ED problems,
improvement goals and data that should be collected and operational changes that should be
applied.
The ORT Braude College 7th
Interdisciplinary Research Conference
24 | Industrial Engineering and Management
Managing Operations in a Smart Grid Environment
Yevgenia Mikhaylidi
1, Liron Yedidsion
1, Hussein Naseraldin
2
1Faculty of Industrial Engineering and Management, Technion-Israel Institute of Technology,
Technion City, Haifa, Israel, E-mail: [email protected]
1Faculty of Industrial Engineering and Management, Technion-Israel Institute of Technology,
Technion City, Haifa, Israel, E-mail: [email protected]
2Department of Industrial Engineering and Management, ORT Braude College, P.O.B. 78, Karmiel
21982, Israel, Tel: 972 -4- 9901977, Fax: 972-4- 9901852, E-mail: [email protected]
Keywords: Smart grid, operations management, approximation algorithms, electricity
storage
Technology development has led to a new form of the electricity network, named Smart Grid.
The basic notion behind the concept of Smart Grid is to improve the overall efficiency of
electricity production, delivery, and consumption, while increasing reliability and security of
the electrical grid. Variations in the electricity consumption rate had led to the development
of varying pricing schemes of electricity. It is plausible to assume that consumers
(individuals and businesses alike) will adapt to the new pricing schemes thus, postpone usage
of some electronic devices until off-peak periods. As a result, costs are reduced.
We consider a finite planning horizon for electric consuming operations that need to be
completed and are available for processing at predetermined periods throughout the planning
horizon. We assume a capacity constraint on the total power consumed in each period due to
infrastructure or provider limitations. Postponing an operation incurs a cumulative penalty for
each time period. Each operation is unique and has its own workload and concave electricity
consumption function. Preemptions of operations are allowed. However, each preemption is
considered as a new operation and may require an additional setup cost.
The aim of this research is to determine when to process each operation within the time
horizon so as to minimize the total electricity consumption and operations postponement
penalty costs, given an exogenous electricity cost for each time period.
We term this as the electricity consumption plan (ECP) problem, in which one determines the
completion of multiple independent operations that share a single constrained capacity
resource throughout a finite time horizon. We show the resemblance between the ECP
problem and the capacitated lot sizing problem. The ECP problem could be regarded as lot
sizing on a single manufacturing facility. We expand the classic lot sizing problem variations
by adding the state- and time-dependent setup cost, which is incurred for a period that starts a
sequence of consecutive periods with non-zero electricity consumption. The setup cost is
different in each period (time dependent) but whether or not it is charged depends on the
previous state of electricity consumption (state dependent). That is, the setup cost for a given
operation is incurred only if that operation was not processed in the previous period.
We consider several special cases of the ECP problem. We show that the single-operation
problem with uniform capacity is solvable in polynomial time, whereas the single-operation
problem with general capacity, as well as the multi-operation problem with uniform capacity,
is both NP-hard. Therefore, the more general multi-operation problem with general capacity
is obviously NP -hard as well.
The ORT Braude College 7th
Interdisciplinary Research Conference
Industrial Engineering and Management | 25
Robust Facility Location under Service Constraints
Hussein Naseraldin
1, Opher Baron
2
1Department of Industrial Engineering and Management, ORT Braude College, P.O.B. 78, Karmiel
21982, Israel, Tel. 972-4-9901917, Fax: 972-4-9901852, E-mail: [email protected]
2Rotman School of Management, University of Toronto, 105 St. George Street, Toronto, Ontario, M5S
3E6, Tel. 1-416-978-4164
Keywords: Facility location, robust optimization, healthcare, service constraints, Lambert
function
Facility location problems are often strategic in nature and are thus very important. Location
problems involve long-term decisions, such as the number of facilities to open, the location
and capacity of each facility. Furthermore, in the healthcare sector, the design of the facilities
must take into account service considerations. The above decisions are determined at the
beginning of the horizon and their values constrain the performance of the system in each of
the consequent periods. Therefore, it is desirable to approach facility location problems in a
two-stage nature -- design followed by evaluating the resulting performance and service. A
major complicating aspect of a facility location problem is data uncertainty. For example, a
healthcare clinic may be designed to serve a specific customer arrival rate; but it is plausible
that the arrival rate would change over time. If the system is not designed to cope with such
uncertainty, public health might be at risk. Hence, locating facilities in the healthcare sector
requires robust solutions under all realizations of the uncertain demand.
The aim of this study is to plan the capacity of a healthcare facility in a robust manner such
that the service level requirements are maintained at a minimal cost.
We adopt the Robust Optimization approach in which one searches for a feasible solution
that is at least as good as all other feasible solutions for most data realizations. We search for
the optimal service rate that minimizes the total costs, which include the fixed cost of
establishing a facility, the capacity cost and the service level cost. The latter is defined as the
possible cost of not meeting the required service level. The methodology of robust
optimization allows either to search for the worst-case solution – solutions that are immune to
all realizations of the uncertain parameters – or a globalized robust solution – a solution in
which one takes into account realizations that don‘t typically happen but when they happen
the impact is huge.
We propose analytical results with regards to the relation between the optimal capacity in
case we ignore the uncertainty in the demand rate (nominal case) versus the optimal robust
capacity in two sub cases: worst-case robust solution and globalized robust solution.
It is imperative to incorporate uncertainty effects into the decision making process, especially
when it pertains to healthcare planning. Moreover, adopting a robust optimization approach
has positive impacts on the system performance.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
26 | Industrial Engineering and Management
Flexible Work Arrangements, National Culture and Organizational
Absenteeism and Turnover: a Longitudinal Study across
Twenty One Countries
Hilla Peretz
1, Yitzhak Fried
2, Ariel Levi
3
1Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901849, Fax: 972-4-9901852, E-mail: [email protected]
2Whitman School of Business, Syracuse University, 721 University Avenue, Syracuse, NY 13244-2450
U.S.A, Tel: 1-315- 443-3639, Fax: 1-315- 442-1449, E-mail: [email protected]
³School of Business Administration, Wayne State University, Detroit, Michigan 48202, U.S.A, Tel: 1-
313- 577-4581, Fax: 1313- 577-4525, E-mail: [email protected]
Keywords: Flexible work arrangements, national values, human resource
In an attempt to attract and retain talented employees and enhance competitive advantage,
employers world-wide have increasingly implemented flexible work arrangements (FWAs)
for both the benefits of the organization and its employees. Most commonly, these FWAs
have included job sharing (in which the job is divided up by two or more employees),
flextime (in which some working hours are determined by the employees), home-based work
(in which employees‘ normal workplace is at home), teleworking (in which employees can
link electronically to the workplace), and job compression (in which employees‘ standard
number of hours is compressed into a reduced number of days). The literature provides
support for the success of FWA programs, by showing their positive effects on psychological
and behavioral outcomes such as burnout, retention, and organizational performance
indicators.
However, a major limitation of previous studies is that they were conducted in organizations
based in the US, neglecting to take into consideration the fact that FWAs have gained
popularity in other countries as part of the global competitive work environment. To date
there is little research on the prevalence and effects of FWAs in different countries in the
global environment.
Therefore, in the present study we will aim to close the gap on this issue by examining the
following: 1) the degree to which organizations located in countries with different national
cultures are likely to implement FWAs and 2) how congruence or lack of congruence
between national cultures and FWAs affect the organizational performance variables of
absenteeism and turnover. We analyze data from two different time periods: 2004 and 2009,
following the global economic crisis of 2007-2008. This enables us to test the stability of the
results with data collected prior to and shortly after the economic downturn.
The ORT Braude College 7th
Interdisciplinary Research Conference
Industrial Engineering and Management | 27
Student Loans - Stated versus Perceived Attitude
David Pundak
1, Arie Maharshak
2
1Web-Learning Unit, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901843,
Fax: 972-4-9901886, E-mail: [email protected]
2Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-72-2463666, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: Students loans, perceived attitude, value curve, Norm theory
It has turned out that higher education constitutes an essential tool for those who wish to cope
successfully in the global market. Research findings show that acquisition of higher
education engenders income gaps, which have become far more meaningful in developing
countries due to the difficulty of funding education costs. The increasingly high academic
fees have become a prevalent phenomenon in many world states, and students are more likely
to work during their studies and apply more frequently for loans.
In Israel, engineering students endure a heavy load of studies during their four year course
and many find it difficult to comply with these demands. Despite the heavy academic burden,
many students choose to work during their studies thus increasing their overall burden. This
research focuses on the Israeli engineering student and explores his attitudes regarding the
dilemma: financing the education by loans, or by work. Since many funds offer comfortable
loans to students during their studies, the following two questions become pertinent as the
research aim.
The aims of this study are:
1) Is the decision to work not a necessity but rather a social norm?
2) Is there a fear of taking loans and creating a worrying debt?
An attitudes questionnaire comprised of 35 statements was answered by a sample of 170
students. The participants were asked to indicate their attitudes by rating the statements on a
Lickert scale of 1-5.
The research results indicate several prevalent attitudes amongst the students:
1) Working during studies harms academic achievements.
2) Working during studies does not constitute an essential part of student life.
3) Taking a loan is a responsible act.
Simultaneously, this study reveals that, despite the benefits of loans, most of the engineering
students in Israel search for work during their studies and only a slight minority of them takes
loans during studies.
According to the 'Value Curve' theory there is a tendency to ascribe a larger risk to small
loans in comparison to the chance of earning a similar sum. Taking a loan is perceived by
students as a large risk in comparison to their anticipated income on graduation. The ‗Norm
Theory‘ may offer additional insight into the apparent contradiction between the research
findings concerning students' stated attitudes and their actual behavior. This theory argues
that if choosing to act is considered as a norm, then inaction is considered as a fault that may
reflect a passive image. A student will decide to work during the period of studies if it seems
to him that this is the accepted norm in his social circle.
The ORT Braude College 7th
Interdisciplinary Research Conference
28 | Industrial Engineering and Management
State Dependent Priorities for Service Systems with
Exchangeable Items
Rachel Ravid
1, David Perry
2, Onno J. Boxma
3,4
1Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901849, Fax: 972-4-9901852, E-mail: [email protected]
2Department of Statistics, University of Haifa, Mount Carmel, Haifa, 31905, Israel, Tel: 972-4-
8249153, Fax: 972-4-253849, E-mail: [email protected]
3Department of Mathematics and Computer Science, Eindhoven University of Technology, P.O. Box
5600 MB Eindhoven, The Netherlands, Tel: +31 (40) 247 2858, E-mail: [email protected]
4EURANDOM
, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, Tel. +31 40 2478100, Fax: +31
40 2478190, E-mail: [email protected]
Keywords: Exchangeable items, longest queue, Markov renewal theory
Exchangeable-item repair systems have received considerable attention in the literature
because repairable-type items are often essential and expensive. Many organizations
extensively use multi-echelon repairable-item systems to support advanced computer systems
and sophisticated medical equipment The main focus of the studies to date has been on the
number of backorders (mainly its expectation), which is the customer queue size in the
terminology used here. Another important performance measure is the customer's sojourn
time distribution. We consider a repair facility which consists of one server and two arrival
streams of failed items, from bases 1 and 2. The arrival processes are independent Poisson
processes with different rates. The service times are independent, exponential random
variables with equal rates. The items are exchangeable, and a failed item from base 1 could
just as well be returned to base 2, and viceversa. The items are admitted to one line but the
customers wait and are marked according to their sources. We assume that the system is in
steady state.
We are interested in key performance measures of this repair facility, like the joint queue
length distribution of failed items of both types, and customer's sojourn time distribution.
First we derive the balance equations for the joint steady-state queue length distribution. We
then study their generating function in order to derive some special probabilistic results.
Differences busy periods and Markov renewal theory are used in order to get some recursive
relations between the equality states.
The steady states distribution of the equality states serves as boundary conditions for the
balance equations. In order to derive the Laplace transform of customer's sojourn time we
build recursive partial difference equations and solve them using the generating function
method.
We provide explicit results for equality state steady state probabilities we also give an
iterative method for obtaining all queue length probabilities. On the continuation, the Laplace
transform of customer‘s sojourn time is determined.
The ORT Braude College 7th
Interdisciplinary Research Conference
Industrial Engineering and Management | 29
Multi-criteria Optimization-based Dynamic Scheduling
for Controlling FMS
Boris Shnits
Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901926, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: FMS control, dynamic scheduling, multi-criteria decision making
This study deals with controlling Flexible Manufacturing Systems (FMS) operating in
volatile production environments. To cope with such environments, most studies recommend
some sort of adaptive scheduling, which on the whole, enables the system to better cope with
randomness and variability. This type of scheduling is usually based on using simple
dispatching rules. However, the dispatching rules do have disadvantages. Their use can result
in myopic decisions based on limited information, and non-delay type scheduling. With non-
delay scheduling no machine is kept idle when it could begin processing some operation.
Such an approach does not guarantee the best scheduling decisions. In addition, the shop
floor control systems presented in most studies are only partially adaptable to changes in the
production environment because they do not consider dynamic changing of the operational
decision criteria in accordance with changes in the system state.
The aim of the present study is to develop a multi-criteria optimization-based dynamic
scheduling methodology for controlling FMS, that combines dynamic selection of the
appropriate decision criterion and solving, subject to this criterion, the optimization-based
local scheduling problem.
The suggested scheduling and control scheme comprises a two-tier decision making
hierarchy. Tier 1, driven by a rule-based algorithm, is used to determine a dominant decision
criterion based on the production order requirements, actual shop floor status and
manufacturing system priorities. On the basis of the designated decision criterion, the
objective function for the local scheduling problem is chosen. Thereafter, Tier 2 is used to
determine the best schedule for the current system state by solving a mixed integer linear
programming (MILP) optimization model. This model takes into account jobs existing on the
shop floor at the time that the decision is made as well as the new jobs that are expected to
arrive at the shop during the nearest scheduling period. The objective function for this
scheduling problem is that determined in Tier 1. The solved model defines the next jobs to be
processed on the available machines.
The performance of the proposed methodology was evaluated by comparing it to some
known scheduling rules/policies using the average flow time and average tardiness
performance measures. The results obtained for the proposed control methodology form an
efficiency frontier, i.e. the proposed methodology outperforms the other tested scheduling
rules/policies.
A multi-criteria optimization-based dynamic scheduling methodology for controlling FMS
was suggested and evaluated. The results obtained demonstrate the superiority of the
proposed methodology.
The ORT Braude College 7th
Interdisciplinary Research Conference
30 | Industrial Engineering and Management
The Main Factors that Lead to Unidentified Risks in Software-
Intensive Projects
Meir Tahan
1, Tsvi Kuflik
2, Efrat Yuval
3
1Department of Industrial Engineering and Management, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-54-2873197, Fax: 972-4-9901852, E-mail: [email protected]
2Information Systems Department, University of Haifa, Mount Carmel, Haifa 31905, Israel, Tel: 972-
4-8288511, Fax: 972-4-8288283, E-mail: [email protected]
3Information Systems Department, University of Haifa, Mount Carmel, Haifa 31905, Israel, Tel: 972-
4-8288511, Fax: 972-4-8288283, E-mail: [email protected]
Keywords: Risk management, risk identification, software projects
In recent years, there has been a growing need for Risk Management in organizations.
Related software, that registers, assesses, monitors and controls the risks, has been purchased
or developed. During the project course, problems pops-up. Some of them were identified as
risks and handled according to the Risk Management Plan defined at the beginning of the
project. Some of them do not appear as a risk, and the question is: what was the reason that
caused the unidentified risk? Was it a management problem? A design problem (Known-
Known or Known-Unknown category) or was it a risk that we could not predict in any way,
―force majeure‖ (Unknown-Unknown category). Unidentified and therefore unmanaged risks
are clearly unchecked threats to a project's objectives, which may lead to significant overruns.
The identification process influences the effectiveness of risk management.
The aim of this research is to reveal the main factors that lead to unidentified risks and to
offer optional directions for preventing such failures in the future.
A semi-constructed interview was built. Four Project managers from four companies
("RAFAEL", "SAP", "Elop" and "Seraphim Optronics Ltd") were interviewed regarding the
risk identification process conducted in their organization. They were asked to describe the
tools and techniques that they used to identify risks. Each project manager shared an example
of a problem raised during a project which was not identified as a risk. He described the
problem, how they handled it and what caused the unidentified risk. All seven projects
ranged between the years 1998 – 2010 (ongoing research).
Eleven factors that caused unidentified risks were found. They were divided to three groups:
Managerial factors, behavioral factors and external factors. Several projects contained more
than one factor.
The ORT Braude College 7th
Interdisciplinary Research Conference
Mathematics | 31
Self-Learning of a Theorem and its Proof
Buma Abramovitz
1, Miryam Berezina
2, Abraham Berman
3,
Ludmila Shvartsman4
1Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-
9901806, Fax: 972-4-9901802, E-mail: [email protected]
2Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-
9901829, Fax: 972-4-9901802, E-mail: [email protected]
3Department of Mathematics, Technion-Israel Institute of Technology, Technion City, Haifa 32000,
Israel, Tel: 972-4- 8294101, Fax: 972-4- 8293388, E-mail: [email protected]
4Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-
9901829, Fax: 972-4-9901802, E-mail: [email protected] Keywords: E-learning, self-learning, understanding of a theorem
Nowadays e-learning has become an important part of the educational process. A number of
universities around the world offer online courses. An important benefit of e-learning is that
it encourages students to learn independently. Self-learning is a significant part of the
learning process at university, but it is not a simple task for freshmen students, particularly
future engineers studying Mathematics. Self-learning, furthermore, is an especially difficult
way of learning for students with a poor mathematics background. Many students come to
higher education from schools that emphasize the calculating part of Mathematics and
neglect its theoretical part. A lot of students take a break, long or short, before entering
university and this hiatus may make it that much harder to learn Mathematics on a high level.
We know that students need strong theoretical knowledge in Mathematics in order to
creatively solve practical nonstandard problems. Many students, however, have difficulties in
learning theory, and as a result, are frightened of it. Possible reasons may be the abstractness
of mathematical concepts, and the special language of a theorem or definition. Students
without a profound comprehension of the theory have difficulties in solving problems that
they have not yet seen. We wanted students to become active in their learning and, if
possible, to "discover" concepts and theorems, plus be given the feedback they need, as they
work on their own.
In order to overcome students' problems in learning theory, particularly theorems, we
developed an approach for self-learning a theorem. Usually, a theorem and its proof are
presented to students during the lecture. Students are shown how to apply the theorem to
solving problems. At home, they are expected to study the theorem and its proof and solve
more problems. The question students often ask us is how are they supposed to study a
theorem? We provide students with a set of web based assignments (convenient for self-
learning) that are written in a way that does not appear unusual to students, yet is intended to
teach them how to understand theoretical problems. The given assignments focus on the
following questions: what are the assumptions of a theorem and what are the conclusions?
What happens when one or more of the theorem's assumptions are not fulfilled? Which
assumptions are necessary and which are sufficient? We use theorems from Calculus to show
students how to comprehend a theorem as a set of conditions that are needed to reach the
theorem's conclusions. Normally, we present the proof of a theorem written as a chain of
logical steps in the lecture, following which students receive different types of online
assignments to work on the proof. We applied our approach on several occasions in Calculus
course and received encouraging results.
The ORT Braude College 7th
Interdisciplinary Research Conference
32 | Mathematics
On Linear-Fractional Relations and Images of Angular Operators
Tomas Y. Azizov
1, Victor A. Khatskevich
2, Valerii A. Senderov
3
1Department of Mathematics, Voronezh State University, Universitetskaya Pl. 1, Voronezh, 394000,
Russia, E-mail: [email protected]
2Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Fax: 972-4-
9901801, E-mail: [email protected]; [email protected]
3Pyatnitskoe highway, 23-2-156, Moscow 125430, Russia, E-mail: [email protected]
Keywords: Plus-operator, Banach indefinite space, linear fractional relation, operator ball,
chain rule
For plus-operators in a Banach indefinite space, we consider a linear fractional relation
defined on a subset of the closed unit operator ball. The classes of operators with the empty
domain of definition for such a relation are described. The sufficient (and necessary, in some
means) conditions for the chain rule to be valid are given.
In particular, we consider the special case of linear-fractional transformations.
In the case of Hilbert spaces 1H and 2H , each linear-fractional transformation of the closed
unit ball K of the space 21 , HHL is of the form 1
12112221
KTTKTTKF
and is generated by the plus-operator T.
We consider application of our results to the well-known Krein-Phillips problem of invariant
subspaces of special type for sets of plus-operators acting in Krein spaces.
Acknowledgement: The work of T. Azizov was supported by the Russian Foundation for
Basic Research.
The ORT Braude College 7th
Interdisciplinary Research Conference
Mathematics | 33
Extension Operators via Semigroups
Mark Elin
Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-
9901974, Fax: 972-4-9901802, E-mail: [email protected]
Keywords: Starlike and spirallike mappings, semigroups
The Roper-Suffridge extension operator and its modifications are powerful tools to construct
biholomorphic mappings with special geometric properties.
The first purpose of this work is to analyze common properties of different extension
operators and to define an extension operator for biholomorphic mappings on the open unit
ball of an arbitrary complex Banach space. The second purpose is to study extension
operators for starlike, spirallike and convex in one direction mappings.
We study the problems above and develop a general approach to extension operators, which
enables us to obtain new properties even for known operators. In particular, we show that the
extension of each spirallike mapping is -spirallike for a variety of linear operators.
Our approach is based on a connection of special classes of biholomorphic mappings defined
on the open unit ball of a complex Banach space with semigroups acting on this ball.
The ORT Braude College 7th
Interdisciplinary Research Conference
34 | Mathematics
Robust Tracking Problem:
Linear-Quadratic Differential Game Approach
Valery Glizer
1, Vladimir Turetsky
2
1Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-
9901828, Fax: 972-4-9901802, E-mail: [email protected]
2Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-72-
2463670, Fax: 972-4-9901802, E-mail: [email protected]
Keywords: Trajectory tracking, robust control, linear-quadratic differential game, cheap
control
The problem of tracking a given trajectory under uncertainties (trajectory planning, path
following etc.) is an important practical control problem in different applications. For
example, in guidance, this problem admits several formulations to:
1) intercept the missile,
2) intercept it with zero relative velocity (rendez vous),
3) reach some prescribed points during the engagement
4) track a prescribed relative separation profile, etc.
All these problems can be formulated in terms of some quadratic cost functional.
In this presentation, a general tracking problem is considered. In this problem, a tracking
criterion is chosen as a Lebesgue-Stilties integral G of squared discrepancy between the
system motion and a given vector function (tracked trajectory), calculated over the mixed
discrete-continuous measure. The problem is solved by using an auxiliary zero-sum linear-
quadratic differential game, where the state term of the cost functional is represented by G.
Both the minimizer's and the maximizer's controls in this game are cheap, meaning that
penalty coefficients for their control expenditure are small. Novel, cheap control, solvability
condition is established. It is shown that, subject to some additional conditions, the optimal
cheap control strategy also solves the original tracking problem.
A boundedness of the minimizer's control is also analyzed. Necessary conditions for the
control boundedness in C[t0, tf] and sufficient conditions for the control boundedness in
L2r[t0, tf], are established.
The ORT Braude College 7th
Interdisciplinary Research Conference
Mathematics | 35
On the Euler-Poisson System
Lavi Karp
Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-
9901844, Fax: 972-4-9901802, E-mail: [email protected]
Keywords: Density, equation of state, hyperbolic systems
The motion of gaseous stars can be described by the Euler-Poisson system:
0
4
ρ+ ρu =
t
uρ + ρ u u+ P= ρ Φ
t
ΔΦ= πρ
where ρ is the density, u is a velocity vector in 3R , P is the pressure and Φ is the
Newtonian potential. The unknowns of the system ρ,u,Φ are functions of 3Rx and
0t . The system is closed by an equation of state, and here we consider the polytrophic
type equation of stateγP = Kρ , where1< γ and K is a positive constant. These types of
equations of state serve as a model for perfect gas and the values of the adiabatic exponent γ
correspond to certain physical significances.
Our main interest is existence theorems for the initial value problem which include stationary
solutions. The common way to obtain it is by means hyperbolic systems. However, from
astrophysical context we cannot assume that the density ρ is uniformly strictly positive, and
the vanishing of ρ causes serious difficulties in the transformation of the Euler-Poisson
equations into uniformly hyperbolic systems.
The talk will discuss several mathematical and physical aspects of this system. This is a work
in progress jointly with U. Brauer.
The ORT Braude College 7th
Interdisciplinary Research Conference
36 | Mechanical Engineering
Controlling the Migration of POSS Nano-Particles in Polypropylene
by Computational Modeling
David Alperstein
1, Menachem Lewin
2
1Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901944, Fax: 972-4-9902088, E-mail: [email protected]
2Polymer Research Institute, Polytechnic Institute of NYU, 6 Metrotech Center, Brooklyn, NY 11201
Keywords: Nano-composites, Octaisobutyl POSS, Octamethyl POSS, computational
modeling, solubility parameter
The migration of Octaisobutyl POSS (Oib-POSS) and Octamethyl POSS (Om-POSS) is
compared experimentally, as well as by using computational modeling tools. The migration
of POSS particles in nanocomposites is governed by the following: 1) the Gibbs adsorption
isotherm; 2) entropy considerations; 3) the cohesive energy between the matrix chains and
the additives particles and 4) the kinetic energy imparted to the additives particles by the
relaxation of the chains. The results described in the present paper provide a plausible
explanation for the difference in the migration behavior between Oib-POSS which migrates
freely and Om-POSS which, although of much smaller molecular size, does not migrate at
all. Solubility parameter calculation of the pristine constituents and their blend, enable
judgement whether the Gibbs excess concentration is positive or negative. Pair correlation
function is used to estimate the interaction intensity between the polymeric chains and the
nano-particles. The two systems which were examined in this study represent two extremes:
the non- migrating system – Om-POSS with relatively large carbon-carbon interactions – and
the migrating system Oib-POSS with weak carbon-carbon interactions.
The aim of this research is to explore the characteristics of POSS migration mechanism in
PP, using computational tools and experimental data. The migration of Oib-POSS and
Methyl POSS (m-POSS) is compared using various computational analysis tools.
The interactions of Oib-POSS with the PP chains in all three temperatures are very weak and
probably do not disturb the diffusion in PP. The curve has a shallow wide peak at around 6Å.
The PC curve at 369oK is a little narrower and has a maximum value of more than a unit
indicating that, at this temperature, the carbon carbon interaction is maximal.
On the other hand, the PC results for Om-POSS are different. The curves have pronounced
peaks, they are narrower and they are all above a unit. At 298oK the PC value is more than
1.2. Moreover, the peak distance value is 5Å indicates a much stronger carbon carbon
interaction in Om-POSS.
In this work, the explanation of the reasons for migration or non-migration of the nano-
particles of the nano-composites is elucidated for the first time. Further experimental work is
necessary on nano-composites, based on many polymers and on a large number of nano-
particles. We believe that further work will enable the establishment of general rules by
which migration in nano-composites can be predicted and controlled.
The ORT Braude College 7th
Interdisciplinary Research Conference
Mechanical Engineering | 37
Handling Changes of Performance-Requirements in
Multi Objective Problems
Gideon Avigad
1, Erella Eisenstadt
2, Oliver Schütze
3
1Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901767, Fax: 972-4-9901868, E-mail: [email protected]
2Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901755, Fax: 972-4-9901868, E-mail: [email protected]
3Computer Science Department, CINVESTAV-IPN Departamentode Ingeniería Eléctrica Sección de
Computación, México, D.F. 07300, E-mail: [email protected]
Keywords: Multi objective optimization, evolutionary computation, robustness, family of
designs
A successful product may be attained by scaling the platform in one or more dimensions to
target specific market niches. Yet, considering the fact that as there are more changes needed
in order to meet the new market demands, higher costs are involved, even though the
platform is scaled. Minimizing the needed changes, within a scaled platform, in order to
achieve the new reconfiguration, has not been attempted before
In this study, the need for rapid, low cost changes in a design, in response to changes in
performance requirements, within multi-objective problems, was considered. The purpose is
to design a set of solutions so that once the performance requirements change, the changes
needed in order to adapt the existing product (one member of the set) to the new
requirements, is minimal, while maintaining the aspiration for optimal performances.
In order to design a robust set, a way to search for it, by way of evolutionary multi objective
optimization is suggested. The fitness, which is the competency of the set, is measured with
respect to optimality of the set (in objective space), through the hyper volume measure and
with respect to the distance (in design space) between the members of the set.
It appears that, small distances are gained at the expense of losing optimality within the
original objective space (in the Pareto sense). So the decision maker faces another dilemma,
whether or not to prefer optimality for current markets over meeting future market' demands.
In the current algorithm, we resolved this dilemma by introducing the good enough notion to
the problem definition. This means that if a solution is good enough (not necessarily optimal)
it is a satisfying solution, and no further improvements are required.
The suggested approach allows representing a set of optimal solutions that involve tradeoff
between optimal solutions and distance with in sets. It has been highlighted that striving for
small changes might result in that the performances of the adapted solution, are not as good
as if the small distance requirement has not been imposed. Such a tradeoff between
optimality and robustness to changes of performance requirements, which are accounted by
small changes in the design, has been suggested here.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee under Grant number 5000.838.1.4-11.
The ORT Braude College 7th
Interdisciplinary Research Conference
38 | Mechanical Engineering
The Pareto Layer for Multi Objective Games and its Search by Set-
Based Evolutionary Multi Objective Optimization
Gideon Avigad
1, Erella Eisenstadt
1, Miri Weiss Cohen
2
1Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901767, Fax: 972-4-9901868, E-mail: [email protected]
1Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901755, Fax: 972-4-9901868, E-mail: [email protected]
2Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901849, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: Multi objective optimization, evolutionary computation, games
Although games on the one hand and Multi Objective Optimization (MOO) on the other have
been extensively studied, Multi Objective Games (MOGs) are scarcely attended. The existing
studies, mainly deal with the mathematical formulations of the optimum. However, a
definition and search for the representation of the optimal set, in the multi objective space,
has not been attended. Moreover hard MOGs (which involve nonlinear, discrete and concave
spaces), were not solved before.
The aim of this study is to define the solution for MOGs and to suggest a generic set based
multi objective evolutionary algorithm to search for it.
Generally a MOG may be described as choosing a strategy for opponent 1 who aims at
minimizing a set of objectives, while encountering opponent 2 who chooses another strategy,
and aims at maximizing the same objectives. Here, a definition for the representation of the
optimal set in the objective space is suggested. It is related to the way players should be
supported while playing MOGs. In the MOO setting, each strategy taken by one opponent
might be encountered by a set of optimal strategies taken by the other opponent. If this set is
optimized, it is possible to represent an opponent strategy by a Pareto optimality set, which
might be chosen by the other opponent. These representations have now to be evolved in
order to find the best strategies for one opponent by considering all optimal strategies that
might be taken by the other opponent.
The resulting optimality related front, which is shown to be a layer rather than a clear cut
front, may support players in taking decisions on strategies while involved in MOGs. Two
examples are utilized for demonstrating the applicability of the algorithm. The results show
that artificial intelligence may open the way for solving complicated MOGs and moreover,
highlight a new and exciting research direction.
In this study we have made two main contributions to the state of the art of MOGs. The first
involves the definition of the PL, which is a rational representation of optimal strategies for
MOGs. It is rooted in the idea of Pareto in the sense that, for each strategy taken by one
opponent, there might be a set of optimal strategies to encounter it. Moreover, the currently
solved problems are confined to rather simple continuous problems. Thus, the second
contribution is that an initial attempt to solve MOGs by using artificial intelligence tools.
This should open the way for solving hard MOGs.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee under Grant number 5000.838.1.4-11.
The ORT Braude College 7th
Interdisciplinary Research Conference
Mechanical Engineering | 39
Novel Crowding Algorithm for Evolutionary-Based Function
Optimization
Gideon Avigad
1, Alex Goldvard
2, Shaul Salomon
1
1Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901767, Fax: 972-4-9901886, E-mail: [email protected]
2Department of Mathematics, ORT Braude College , P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-
9901844, Fax: 972-4-9901802, E-mail: [email protected]
1Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Fax: 972-4-9901886, E-mail: [email protected]
Keywords: Evolutionary multi-objective, crowding
Optimization of solutions that are associated with transient responses (each solution is
associated with a time dependent function), is scarcely attended. Such an optimization might
evade the need to set auxiliary objectives (e.g. minimization of the square error, overshoot,
etc.) and therefore, tradeoff solutions are not overlooked. In order to find tradeoff functions,
their dissimilarities should be highlighted. In evolutionary based search approaches, this
dissimilarity is related to crowding. To date, there are no adequate crowding methods to
distinguish between different functions that outperform each other, at some instance in time.
In order to preserve elite solutions (for the evolutionary search), which are diversified, we
aim at developing an algorithm that selects an elite group of individuals from a larger group,
in a way that the sub-group represents the original one, while preserving its diversity. The
main research aims are to define and quantify this diversity.
Each function is represented here by its related samples in time. These sampling results in a
function are represented by an ordered set (the set of samples). Therefore, in order to
distinguish between functions, dissimilarity of their samples, serve for assessing their
crowding. Initially the algorithm splits the larger group into sub-groups with individuals as
similar as possible, i.e. individuals that their samples are close by. The division into a specific
number of sub-groups is done by repeatedly splitting one group into two sub-groups, until the
desired number of sub-groups (the size of the elite population) is attained. The group that is
to be split is the one that has the largest span over all sub-groups and samples. Once there are
enough sub-groups, the algorithm chooses one member of each sub-group. Finally, it assigns
each individual with a crowding measure according to the number of members in its sub-
group.
Primary results show that the new method chooses diversified functions from a large group of
functions. It also appears to be very efficient in computations, and is robust with respect to
the number of samples. Apart from the direct utilization of the suggested measure to the
evolution of functions, we envisage its utilization for problems with many objectives. This
would be performed by representing each sample as an objective.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee under Research Grant number 5000.838.1.4-11.
The ORT Braude College 7th
Interdisciplinary Research Conference
40 | Mechanical Engineering
Acoustic Emission as Tool for Identifying the Drill Position in Fiber
Reinforced Plastic and Aluminum Stack
Uri Ben-Hanan
Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901830, Fax: 972-4-9901886, E-mail: [email protected]
Keywords: Composite material, drilling, acoustic emission, signal processing
Drilling a stack of carbon fiber reinforced plastic (CFRP) material and aluminum or titanium
is a common practice in the aircraft industry and is also gaining an important role in the
automotive industry. Making holes in both materials with the same drill under the same
process parameters, causes the need to compromise the quality of the holes and the drilling
performance in the CFRP layer or in the metal part.
The aim of this research is to develop a method for finding the place of the drill in a stack
made of several different layers of materials including CFRP, aluminum and titanium.
There is a good correlation between the force and the AE signals. As it is easier to measure
the AE signal than the force one and the material changes appear better in the AE signal, the
AE signal was used for identifying the position of the drill in the material. The AE signal
was analyzed with a special algorithm developed to find the different shapes in the signals
corresponding to the time the drill enters the first layer, the time it enters the second layer and
the time it exits the stack.
Four drilling experiments in stack made of CFRP and aluminum layers were performed. Two
experiments with a regular drill and two with a step drill. In one experiment, the drilling
started in the CFRP layer and in the second, from the aluminum layer. With the regular drill,
it was found that it is possible to recognize the time when the drill exited the CFRP layer and
entered the aluminum and it is also possible to get an indication when the drill is exiting the
CFRP layer when it was the second one to be drilled. With the step drill there were better
identification capabilities of the changes in the AE signal, because it took a longer time to
change from one layer to the other.
The proposed method seems to be robust and additionally, the training of the system was not
optimal. Using a more sophisticated tool for identifying the changes in the AE signal, as well
as developing a tool for automatically training the system, are the goals of the future work. In
future work, the developed method will be implemented for changing the drilling parameters
and the resulting drill wear out and holes properties will be analyzed and compared to the
regular used drilling method.
Acknowledgment: This work was done during the sabbatical stay of the author at Fraunhofer
IWU, Chemnitz, Germany.
The ORT Braude College 7th
Interdisciplinary Research Conference
Mechanical Engineering | 41
Analyzing the Vibration Signature of Dental Bur
Orit Braun Benyamin1, Uri Ben Hanan
2, Michael Regev
3,
Shmuel Miller4, Rinat Simchon
4
1Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901786, Fax: 972-4-9901886, E-mail: [email protected]
2Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901830, Fax: 972-4-9901886, E-mail: [email protected]
3Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-990134, Fax: 972-4-9901886, E-mail: [email protected]
4Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901905, Fax: 972-4-9580289, E-mail: [email protected]
Keywords: Vibration analysis, dental bur wear
Tooth preparation is affected by a number of factors such as the bur type, handpiece type and
the cooling method. Vibration analysis of dental handpieces as a diagnosis/identification tool
is used for identification of worn out burs. We have found that there is a difference between
the airborne vibration acoustic signals generated by of a new bur and that of a worn out one.
An on-line application of such a method seems to have diagnostic capabilities, alerting the
dentist in real time of a developing wear in the bur.
The aim of this study is to develop procedures for detection and identification of bur wear
based on processing airborne acoustic vibration.
An experimental system, consisting of a pneumatic dental handpiece, was instrumented by
accelerometer and two microphones. The dental handpiece was subjected to a constant feed
rate, for a first order simulation of the actual working conditions of a dental bur. The wear of
the dental bur was monitored by measuring the applied grinding force and the recorded
acoustic signals during the tooth processing. An offline measurement of the bur wear-out was
conducted by means of optical microscopy and Scanning Electron Microscopy. The offline
measurements were used as reference measurements in order to estimate the accuracy of the
online methods and their prediction capabilities. The acceleration and acoustic sensors were
sampled and subjected to various signal processing procedures.
A preliminary frequency analysis showed various spectral peaks with no major differences
between the sensor readings. It was found that the first vibration peak in the frequency
spectrum of the handpiece corresponded to its angular velocity. A qualitative analysis was
conducted on the air-turbine handpiece vibrations to obtain and verify our strategy for
identification of bur wear. The experimental results were compared to the measured drilling
force. Previous studies, conducted with the same experimental apparatus have shown that bur
wear is associated with a sharp increase of the drilling force. The experimental results
indicated that the angular velocity of an air-turbine handpiece shifted with the measured
applied drilling force.
Further data acquisition and analysis are indicated. Repeatability of the results, statistical
robustness and control of results need to be ascertained. Advanced signal processing
procedure should be investigated, in order to study a possible signal generation model. If
successful, this would improve any final detection/classifying system.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
42 | Mechanical Engineering
Improving Functional Performance Neurological and Orthopedic
Trauma: Monitoring the Load Bearing Distribution between the
Lower Extremities
Orit Braun Benyamin
1, Yocheved Laufer
2
1Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901786, Fax: 972-4-9901886, E-mail: [email protected]
2Department of Physical Therapy, University of Haifa, Mount Carmel, Haifa, Israel.
Keywords: Rehabilitation, biofeedback systems, VGRF
Mobility reestablishment is one of the main goals of a rehabilitation program for individuals
after a stroke. Rising from a chair and sitting down are common activities, yet they may turn
into a mechanically demanding functional task. Among the different strategies for training of
these individuals, is the use of biofeedback systems.
The aim of this study is to design of a pressure sensor measuring both ground reaction forces,
and the flexion-extension of the knee joint, including visual feedback. The objective is to
analyze these forces as a function of varying foot positions and knee angles during sit to
stand and stand to sit tasks.
A pressure sensor measuring two vertical ground reaction forces (heal and foot cushion) will
be designed. The flexion – extension angle of the knee joint will be measured by a 2-D
Goniometer (BioPac) during stand up and sit down activities. The end of the Sit to Stand
(SitTS) task and the onset of the Stand to Sit (StandTS) task, will be determined via the knee
angles.
Preliminary experiments were conducted to test the insole pressure sensor and verify its
ability to measure the vertical ground reaction force (VGRF) as the body weight is shifted to
the foot. The sit to stand experiment was conducted according to a study conducted
previously by Roy G. (Montreal University), where twelve subjects with chronic hemiparesis
were asked to stand up and sit down. The following events could be identified: Sit-to Stand
(SitTS) and Stand to sit (StandTS) when the subject is just leaving the seat and is near to
establishing contact with the seat, respectively. The onset of the SitTS task was defined as the
first perceptible change of the VGRF (heel and /or foot cushion), whereas the completion of
this task corresponded with the gaining of stable extension of the knee in the standing
position. The events for the StandTS task were determined by the first observable change in
the knee extension towards flexion and the last perceptible changes in the VGRF (heel and
foot cushion).
This biofeedback system can provide sufficient information concerning weight bearing
shifting during SitTS and StandTS tasks. Implementing this system during the rehabilitation
process may assist patients in regaining these important functions. Following initial testing
this system maybe further developed to assist in gait training as well.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
Mechanical Engineering | 43
Use of Art Media in Engineering Education
Alec Groysman
1, 2
1Department of Mechanical Engineering and Prof. Ephraim Katzir Department of Biotechnology
Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, E-mail:
2Oil Refineries Ltd., P.O. Box 4, Haifa 31000, Israel, Tel: 972-4-8788623, Fax: 972-4-8788371,
E-mail: [email protected]
Keywords: Engineering education, art, science, technology
How many engineers like art? How many engineers are interested in Science and its
achievements? Why is there no progress in art, but there is progress in Engineering and
Science? What is the relationship between Art and Engineering? How can engineers use art
in their inspiration and creativity? Thus, we will explain what Art media and Engineering
education are. In spite of the differences in the terms technology, engineering and industry
we will use one of them Technology or Engineering. Engineering is the ―third culture‖ in
addition to the ―two cultures‖ Art and Science. There is a mutual influence between these
―three cultures‖. What is the general meeting point in them? We speak about interdisciplinary
and humanistic thinking of engineers.
The aim of this study is to show how Art media can help in Engineering education. The
philosophy of our work is establishing of interrelationships between the “three cultures‖,
studying new inspirations and creativity in engineering, searching and determining common
aspects and differences in the ―three cultures‖ in order to show the young generation of
engineers and educators how learning, education and our very existence may be interesting,
fascinating, creative, productive, exciting, attractive, rich, and as a result beautiful.
The examples of use of different arts (music, painting, literature, poetry, sculpture) in
curricula of materials science, thermodynamics, and corrosion of metals are shown.
Analogies, interrelations, metaphors, common aspects and differences between Art and
Engineering disciplines are used in engineering education for the third and fourth year
students. Their understanding is compared with students and engineers who did not receive
such education.
Students and young engineers who received explanations of engineering disciplines in
comparison with humanistic aspects showed more creativity and satisfaction in their job and
life. They have another approach to apprehending engineering disciplines and their very
existence, now seems beautiful.
Humanistic aspects should be included more and more in Engineering education. Namely we
can talk about ―beautifying‖ engineering. Learning and education of students and educators
using art media results in attractiveness of engineering disciplines, their ―beauty‖,
inspirations and creativity of young generation of engineers.
The ORT Braude College 7th
Interdisciplinary Research Conference
44 | Mechanical Engineering
Creep Properties Study of Mg Alloys Friction Stir Welding
Michael Regev
1, Stefano Spigarelli
2, Marcello Cabibbo
2
1Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-990134, Fax: 972-4-9901886, E-mail: [email protected]
2Dipartimento di Meccanica, Università Politecnica delle Marche, I 60131, Ancona, Italy
Keywords: Friction stirs welding, Magnesium alloys, Aluminum alloys
During FSW, the frictional heat that is generated is effectively utilized to facilitate material
consolidation and eventual joining with the aid of an axial pressure. In this process, a non-
consumable rotating tool is inserted into the abutting edges of the material to be joined until
the shoulder of the tool is in direct contact with the two pieces of plates or sheets that are to
be butt-welded. The tool is then progressively traversed along the line of the weld using a
normal load. The highly localized and concentrated heating, aids in softening of the material
around the tool. This coupled with a combination of tool rotation and a gradual translation of
the tool through the material to be joined, results in movement of metallic material from the
front of the rotating pin to the rear of the rotating pin. The process is, therefore, a non-fusion
welding one.
The aim of this research is to study the microstructure and creep properties of a friction stir
welded joint.
A FSW machine has recently been built at the Machining Research Lab of ORT Braude
College and 3.2 mm thick AZ31 plates were successfully welded. Creep specimens were
machined from the welded plates and tested under different loads and temperatures, in
addition to metallographic characterization.
As for non-welded AZ31 specimens - the grain size effect on the high temperature
mechanical properties of the AZ31 Magnesium alloys, has been investigated by comparing
the creep data obtained in the current study with the results available in the literature. The
results of this analysis confirm the existence of a weak but not negligible effect of the grain
size, both in the high stress regime, typical of climb-controlled creep, and in the low stress
region, where deformation is controlled by viscous glide of dislocations in an atmosphere of
solute atoms. The creep response of the welded specimens is still under investigation;
however, creep results of these specimens, indicate that a completely different behavior will
be shown.
Even though the effect of grain size is in general weaker than that of the chemical
composition (in particular of the Al content of the alloy) it deserves the attention of the
investigators; its existence should be related to the occurrence of grain boundary sliding
accommodated by dislocation creep.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
Mechanical Engineering | 45
Applied Nonlinear Optimal-Quadratic Control and Estimation
Moti Shefer
Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-8110646, Fax: 972-4-8110647, E-mail: [email protected]
Keywords: Nonlinear, optimal, quadratic, stochastic, control, hover, maneuver
Optimal nonlinear quadratic stochastic (NLQS) control and estimation methodology for
discrete-time analytic systems has been developed since the 1980‘s and by now has gained a
quite mature and easy to apply and verify status. This methodology was initially made for
digital control, so that with the emerging and further developing of MATLAB, the herein
presented NLQS has become a must-have asset in the tool-box of every system engineer.
Unfortunately, the last 3 decades of control engineering have been characterized by quite
harsh and unjustified abandonment of optimal-control, for all kinds of heuristically generated
control and estimation processes where hyper-intensive online computations with no solid
theoretical basis, replaced rigorous synthesis and analysis.
The main two results of this fashion are:
1) Very expensive control SW solutions that take very long times to develop and
2) No safe way to make a reliable prior performance evaluation and validation of the
solutions, such as statistical moment's analyses.
The aim of this study is to demonstrate the utility and power of digital NLQS by applying it
to case-study projects that have not been attempted so far, in either the literature or the
industry.
The first project case-study selected in OBC is: ―Jumper‖- a small, unmanned flying machine
that can take off and land at any angle between zero and ninety degrees, pass instantaneously
to horizontal flight at over 100 Km/hr, or to a hovering state with about 2g of vertical or
circular maneuvering capability. The main power of the Jumper is provided by 2 electrically
driven tilt able propellers whose optimal control constitutes a highly nonlinear problem.
The typical mission profile of the Jumper is acquisition and transmission of video
intelligence in heavily crowded urban areas and inside deep narrow canyons. The Jumper is
designed to takeoff weight of 10 Kg, including an advanced FLIR and guidance system. Its
goal mission time is 2 hours in a 10 Km radius of operation and 3 Km of service-ceiling. Its
goal production cost is $3,000.
The ORT Braude College 7th
Interdisciplinary Research Conference
46 | Mechanical Engineering
The Kinematics of the Rolling Eccentric Mechanism
Evgeniy Sinenko
1, Olga Konischeva
2
1Prof. Department of Applied Mechanics, Polytechnic Institute of Siberian Federal University,
660074, Kirenskogo st. 26, Krasnoyarsk, Russia, Tel: (3912) 2497-263, E-mail: [email protected]
2Associate Prof. Department of Applied Mechanics, Polytechnic Institute of Siberian Federal
University, 660074, Kirenskogo st. 26, Krasnoyarsk, Russia, Tel: (3912) 2497-263, E-mail:
Keywords: Eccentric mechanism, eccentricity, ratio, efficiency
Usually, known frictionless bearings, roller bearings and ball bushing are used as shafts
bearings in the various mechanisms of machines and devices. However, small structural
changes can make use them as mechanisms.
The aim of this study is to evaluate the nature and effectiveness of the mechanism of rolling
eccentric mechanism, obtained on basis of a standard frictionless bearing.
Using the standard parameters of frictionless bearing dependences for diameters definition of
rolling bodies according to the angle of their location at the given axes shift of cone and outer
race and one of their diameters were obtained. In this case the rolling bodies were given
different sizes and were subjected to certain law. Thus the batch of eccentric mechanism for
converting rotary motion of the driving ring to the reciprocating motion driven ring was
designed and built.
Considering the get device as a mechanism, a mathematical model of which is dependence
),cos1()(u
eS
here e is an eccentricity shift of cone and outer race; is a cone angle of
rotation;
1
21R
Ru is geometrical contact ratio; R1 and R2 are radii of the outer and inner
races. At the result of mechanism research eccentric mechanism contact ratio by speed
equaled to22
2
)sin(2
2sinsin
eR
eeuv
, power transmission coefficient ),ctg( прpu
where is an eccentric lifting angle, пр is a reduced rolling friction angle, efficiency
.tg)ctg( пр
Thus, the analytical dependence and made research allow to judge all the kinematic and
power parameters of the rolling eccentric mechanism: maximum radial shaft of the driven
link is equal to 2e; radial oscillations frequency of the driven link is ,12
u
where
1 is a
driving link angular velocity; ratio by speed can reach uv = 8 at certain values of e and R;
power transfer coefficient reaches up = 25−30, efficiency reaches 0,96−0,98. The results
confirm the feasibility and effectiveness of the using eccentric mechanism as a device for
mixing, grinding, polishing device, roller bearings of armored personnel carrier and others.
Acknowledgement: This design and research were used in the design and manufacture of a
radial piston pump Н-403А.
The ORT Braude College 7th
Interdisciplinary Research Conference
Mechanical Engineering | 47
Mobile Hybrid Kinematic Chain - Utilizing Two Small Robots for
Climbing Stairs
Avi Weiss
1, Gideon Avigad
2, Roee Mizrahi
1
1Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901945, Fax: 972-4-9901886, E-mail: [email protected]
2Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901767, Fax: 972-4-9901868, E-mail: [email protected]
Keywords: Kinematic chain, mobile robot, cooperating robots, climbing robots
One of the main problems in urban robotics is combining fast motion in open areas with the
ability to overcome obstacles, climbing stairs, and maneuvering in indoor limited spaces.
Currently, there is no appropriate solution to the problem. On the one hand, the use of chains
allows for stair climbing but is very limiting when it comes to open spaces. On the other
hand, the use of wheeled robots allows for fast motion in open areas, but stair climbing
abilities are extremely limited. In addition, all of the above are not suitable for indoor
maneuvering in limited spaces.
The aim of this project is to utilize two separate robotic platforms, each allowing for maximal
maneuvering capabilities indoors and in open areas that connect to each other to combine for
a robot with stair climbing abilities.
First, modeling of a complex kinematic chain (robot-manipulator-robot) will be modeled.
Next, optimization of the manipulator kinematics as a function of the robots motion will take
place. Connection trajectory and control using the manipulator will commence. Kinematics
and dynamics of the system during stair climbing will pursue. Finally, a system will be
designed and built to affirm the theoretical results. Several kinematic concepts were
considered for the individual robots, as well as for the connecting arm. It was concluded that
a two-link manipulator arm would provide the desired amount of degrees-of-freedom for the
system, such that a one to one mapping between the control input and system output would
be feasible. In addition, equations of motion for the system were developed for the
benchmark case of climbing stairs with no turns. Conditions for completing climbing were
obtained using a design optimization process and a simulation, which yielded required design
parameters to enable climbing.
Climbing stairs combining two small robots is possible, providing appropriate design
parameters values are used. Since some of the design parameters depend of the shape of the
stairs, configuring them in real time is important. The important parameters that affect the
ability to climb the most were the vertical location of the connection of the manipulator, and
the distance between the wheels. The robots are now in the mechanical design stage, which
allows these two parameters to be controlled during operation.
We plan to build the robots and the arm in order to validate the results. Next, climbing stairs
while turning will be analyzed and tested. Finally, control issues and optimization will be
addressed.
Acknowledgement: This study was supported by a grant from the ORT Braude College
Research Committee under Grant number 5000.838.1.2-12.
The ORT Braude College 7th
Interdisciplinary Research Conference
48 | Physics
High Energy Neutrino Sources: Challenges and Prospects
Dafne Guetta
Department of Physics and Optical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982,
Israel, E-mail: [email protected]
Keywords: High energy astrophysics, neutrinos
The fundamental scientific motivation for high-energy neutrino astronomy is that neutrinos
are nearly massless particles that interact very weakly with matter and therefore can peer
into sources that would be opaque to high energy photons and protons. Unlike high energy
photons and protons, neutrinos can travel cosmological distances without being absorbed or
deflected. Therefore neutrinos can provide information on astrophysical sources like
Gamma Ray Bursts that cannot be obtained with high energy photons and charged particles.
However the weak interaction of neutrinos with matter also implies that they are very
difficult to detect, requiring detectors with at least kilo-tons of detecting medium. Neutrino
astronomy has so far been limited to the detection of neutrinos from only two sources, the
sun and supernova SN1987a.
In order to extend neutrino astronomy to the extra-Galactic scale, large volume detectors of
>1 TeV neutrinos have been constructed (Halzen 2005, Phys. Scripta T121, 106).
Four decades ago, researchers first aspired to build a kilometer-scale neutrino detector.
On April 28th, 2011, the Ice Cube Collaboration met in Madison, Wisconsin to celebrate
the completion of the detector that is an extension of the previous detector, AMANDA, able
to reach a 1 Gton effective detector mass. Ice Cube is able to detect >1 TeV neutrinos from
astrophysical sources allowing to reveal and study astrophysical neutrino sources such as
Gamma Ray Bursts (GRBs), Active Galactic Nuclei (AGN) and Microquasars (MQs). Given
the detector Ice Cube at work, it is very timing to carry out research in the neutrino field.
The main aims of this study are to:
1) Solve the long standing problem of the content of the jet of astrophysical sources like
GRBs, AGN and MQs
2) Find the sources of the ultra-high energy cosmic rays
3) Constrain the GRB progenitor and emission mechanism models with neutrinos
We have estimated the flux from individual GRBs observed by the BATSE experiment. The
individual fluxes can be directly compared with coincident observations by the Ice Cube
telescope at the South Pole. Having these observations in mind, we specialize on neutrino
emission coincident in time with the GRB. Because of its large statistics, our predictions are
likely to be representative for future observations with Ice Cube telescope. Individual
neutrino events within the BATSE, Swift and GBM time and angular window are a
meaningful observation.
We estimate a few muons per year in a kilometer-square detector. Fluctuations in fluence and
other burst characteristics enhance this estimate significantly.
The ORT Braude College 7th
Interdisciplinary Research Conference
Physics | 49
Relations between Chaos and Controllability in the Quantum World
Shimshon Kallush
Department of Physics and Optical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982,
Israel, Tel: 972-0722463655, Fax: 972-4-9883429, E-mail: [email protected]
Keywords: Quantum control, quantum chaos, controllability
Control in the quantum world is based upon interferences of several paths to reach a desired
task. In the macroscopic world, the presence of chaos in a system tends to increase the
complexity of its dynamics and decrease the ability to control it. We will ask the question
whether this is also true in the quantum world, if there might be a case where disorder would
be able to ease the way to control the system. Recently, we and others have outlined the
difference between two kinds of control within the quantum regime:
1) Classical-like control in which the system remains localized and similar to classical
distribution throughout the whole process. These systems remain controllable even
when the size of the Hilbert space of the system increases. Control of such processes
can be performed with both local and non-local control operators.
2) Quantum control which make extensive use of interferences. This solution for this
kind of processes is unique for each system's size. The process could be performed
only with non-local operators.
The aim of this study is to demonstrate a quantum system in which the increase of disorder
increases also the controllability.
The model system will be the Hennon-Hilles 2D potential. This potential exhibits chaotic
behavior and a rapid divergence of initially localized distributions, as the initial energy of the
state increase. A control term with varied span over the phase space of the system will be
taken to demonstrate the difference between quantum and classical like control.
Controllability is shown to depend on the locality of the operator that generates the control. A
local operator is characterized by a single control path, and will suffer tremendously from
increase of chaos. Non local operators control the system in a quantum fashion and enjoy an
increase of available paths with the increase of chaos. Thereby, increase the controllability
with the more chaotic behavior.
The ORT Braude College 7th
Interdisciplinary Research Conference
50 | Physics
Measuring the Self-Inductance of a Metal Ring
Eli Raz
Department of Physics and Optical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982,
Israel, Tel: 972-4-9901940, Fax: 972-4-9883494, E-mail: [email protected]
Keywords: Electrodynamics, measurements, laboratory procedures; Physics education
Self- inductance is one of the most difficult physical quantities to measure. If the inductance
is larger than 10 mH, the ordinary AC voltmeter and ammeter can be used. However, in order
to measure inductance of the order of H78 1010 , a method based on direct measurement
of impedance is useless due to the limitations of the measuring devices.
A theoretical formula for the inductance of a ring with circular cross-section is well known,
however, few works were done to measure it and with an accuracy of 10%. Those works
based on measuring the phase difference between induced EMF and induced current in a
ring, when the ring is exposed to an alternating magnetic flux.
The aim of this project is to measure the self-inductance of a metal ring with high accuracy,
by using ordinary students' lab equipment.
Measurement the EMF induced by a coil carrying alternating current on a ring was carried
out, as a function of the distance between the coil and the ring. This was done by using an
identical ring except for a short segment which was removed, making the ring open. In a
second experiment, the force between the coil and a closed ring was measured for the same
distances as done with the open ring. The force was measured by using a scale with a
resolution 0f 0.01 gr.
The metal ring is placed on the polystyrene block, rather than directly on the scale, therefore
the coil is kept at a distance above the scale, to eliminate a direct effect on the scale‘s
reading. The self-inductance can be deduced using magnetic Gauss‘s Law and Faraday‘s
Law. The resistance of the ring‘s material was measured by using the 4 terminal methods.
A linear graph between the force and the derivative of the EMF squared with respect to the
distance between the coil and the ring is obtained with an accuracy of 2%. Analysis of the
graph and taking into account all the uncertainties of the experiment, a value of
H71013.1 for the self-inductance of the ring is obtained with accuracy better than 4%
and in accordance with the known theory.
The ORT Braude College 7th
Interdisciplinary Research Conference
Software Engineering | 51
Combining Height Reduction and Scheduling for VLIW Machines
Enhanced with Three-Argument Arithmetic Operations
Fadi Abboud
1, Yosi Ben-Asher
2, Yousef Shajrawi
3, Esti Stein
4
1Department of Computer Science, Haifa University, Mount Carmel, Haifa 31905, Israel, Tel: 972-4-
8240111, E-mail: [email protected]
2Department of Computer Science, Haifa University, Mount Carmel, Haifa 31905, Israel, Tel: 972-4-
8240338, E-mail: [email protected]
3IBM R&D Labs in Israel, Haifa University Campus, Mount Carmel, Haifa, 31905, Israel, Tel: 972-4-
8296211, E-mail: [email protected]
4Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901740, E-mail: [email protected]
Keywords: Height reduction, VLIW scheduling, MRK algorithm, algebraic circuit, three-
argument operation
Height Reduction (HR) are algebraic transformations used to reduce the height (critical path)
of a given sequence of arithmetic operations. We assume that the computation is represented
as an algebraic circuit (AC). As such, HR can parallelize the computation by transforming an
AC to a "wider'' and shorter circuit. VLIW scheduling is the problem of determining a
minimal sequence of VLIW instructions that, when executed, evaluates a given AC.
Obviously the critical path of the AC bounds from bellow by the number of VLIW
instructions needed to evaluate it. However the number of VLIW instructions for a given AC,
can be larger than the AC's critical path. Typically, compilers apply HR and later on VLIW
scheduling, however as we argue next, these two problems must be combined and solved
"together'' to obtain improved VLIW scheduling.
We consider the need to combine two known optimizations which are usually regarded as
non-related: Height Reduction and VLIW Scheduling.
We consider a technique to automatically extract three-argument instructions from sequential
arithmetic code. The instructions include: multiply and add (MAD), three argument additions
(ADD3) and three argument multiplications (MUL3). The proposed solution combines a
height reduction technique that generates three-argument instructions and a VLIW scheduling
that can benefit from these instructions.
Our results show that for arithmetic benchmarks the proposed technique can improve the
VLIW scheduling, while emitting three-argument instructions. The contribution of this work
includes: the modified MRK algorithm as a new technique for height reduction optimizations
and the study of the potential usefulness of three-argument instructions. Though our results
are for a non-existing hardware they show the usefulness of adding such instructions to
VLIW CPUs.
We show that HR and VLIW scheduling should be combined rather than be executed as two
separate passes. The proposed technique also emits three argument instructions (TAIs), thus
optimizing the resulting VLIW code even further. The method was implemented in the
LLVM compiler and the usefulness of the modified MRK as a height reduction technique
was demonstrated. The experiments showed a clear improvement of the VLIW scheduling
and a significant use of ADD3 and MAD operations.
Acknowledgement: This research was supported by THE ISRAEL SCIENCE FOUNDATION
grant No. 585/09, and by Israel Ministry of Science and Technology (MOST) grant No. 3-
6496.
The ORT Braude College 7th
Interdisciplinary Research Conference
52 | Software Engineering
Acoustic-Phonetic Analysis of Fricatives for Classification using a
SVM Based Algorithm
Alex Frid
1, 2, Yizhar Lavner
1
1Department of Computer Science, Tel-Hai Academic College, Upper Galilee, Israel
2Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901902, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: SVM, phonemes classification, fricatives, audio processing
Classification of phonemes is the process of assigning a phonetic category to a short section
of speech signal. It is a key stage in various applications such as spoken term detection,
continuous speech recognition and music to lyrics synchronization, but it can also be useful
on its own, for example in the professional music industry, and in applications for the hearing
impaired.
In this study we present an effective algorithm for classification of one group of phonemes,
namely the fricatives, which are characterized by a relatively large amount of spectral energy
in the high frequency range. The classification between individual phonemes within this
group is fairly difficult due to the fact that their acoustic-phonetic characteristics are quite
similar.
A three-stage classification algorithm between fricatives, either voiced or unvoiced, is
utilized. In the first stage, the preprocessing stage, each phoneme segment is divided into
consecutive non-overlapping short windowed frames. Each phoneme is then represented by a
15-20 dimensional feature vector. In the second stage, a support vector machine (SVM) is
trained, using radial basis kernel function and an automatic grid search for optimizing the
SVM parameters. Lastly, a tree-based algorithm is used in the classification stage, where the
phonemes are first classified into two subgroups according to their articulation: sibilants (/s/
and /sh/ or /z/, /zh,) and nonsibilants (/f/ and /th/ or /v/ and /dh/). Each subgroup is further
classified using another SVM. This is compared to another procedure in which the frames are
classified to their phoneme groups in one stage.
For the evaluation of the performance of the algorithm, we used more than 11000 phonemes
extracted from the TIMIT speech database. Using a majority vote for the feature vectors of
the same phoneme, the overall accuracy of 85% and 80% is obtained for the unvoiced and
voiced fricatives, respectively. These results are comparable and somewhat better than those
achieved in other studies.
The results shown here indicate that the procedure could be utilized in technologies for the
hearing impaired, for example by differential processing of the unvoiced fricatives, to
improve their discriminability.
The ORT Braude College 7th
Interdisciplinary Research Conference
Software Engineering | 53
Statistical Based Grading of Cipher Texts
Mati Golani
1, Renata Avros
2, Zeev Volkovich
3
1Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-72-2463664, Fax: 972-4-9901852, E-mail: [email protected]
2Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901862, Fax: 972-4-9901852, E-mail: [email protected]
3Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901994, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: Cipher text, encryption, re-sampling, clusters
Various text encryption algorithms use an iterative approach for encrypting text. The quality
of such an algorithm is measured in terms of time complexity and encryption efficiency, i.e.
how difficult it is to decrypt the encrypted text. A cipher-text produced by a good encryption
algorithm should have an almost statistically uniform distribution of characters.
The aim of this study is to measure the randomness and convergence of encryption
algorithms and evaluate their efficiency in terms of clustering metrics.
Two encrypted files are taken. In one scenario, the files are actually different iteration
outcomes of the same file, and in the second scenario, they are outcomes of different
algorithms applied to the same file. Each file is fragmented into 128 bit fragments. A sample
set of size N is generated from each file, by randomly picking a fragment, N times. Each set
is provided to a clustering algorithm, and then a merged set is provided to the same clustering
algorithm. Next, we measure the distance between members of the same cluster. By
employing this re-sampling procedure, we produce a distances' collection which includes the
distance values that are calculated within, and between the samples. Our approach suggests,
that the "between" distances are much longer than the "within" ones, in the case of different
randomness texts.
Better algorithms are expected to converge faster into a uniform distribution across the text
Euclidean space. Thus, our approach suggests that when considering lower graded
algorithms, cipher-text in the preliminary (first few) iteration phases, is expected to provide a
smaller distance between samples. We also expect that each encrypted file is characterized by
a different "location", which means that using the two sample test technique, the distance
between a sample taken from one file, and a sample from the second file is much larger than
the distance between two samples taken from the same encrypted file.
The ORT Braude College 7th
Interdisciplinary Research Conference
54 | Software Engineering
Predicting Fault Location Based on Current and Past Test Results
Katerina Korenblat
1, Avi Soffer
2, Zeev Volkovich
3
1Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901845, Fax: 972-4-9901852, E-mail: [email protected]
2Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901720, Fax: 972-4-9901852, E-mail: [email protected]
3Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901994, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: Software testing, categorization algorithms, software fault correction, debug
Software testing enables achieving a measure of software quality. Although the ultimate goal
of testing is to find software faults, additional measures are taken in order to correct the faults
and achieve the high-quality software systems. Hence, the process known as ―debug‖ -
finding and correcting software faults – is one of the most important components of software
development. Although finding bugs is hard by itself, fixing them is another challenge, which
involves locating the defect that causes the failure. Due to software complexity, the debug
process could be very difficult, especially when the tested software runs concurrent threads.
Typical debugging process includes scope reduction (by scenario simplification), and run-
time tracing to associate each test with related software modules. Ability to predict which
software module is likely to include the bug may reduce the large efforts involved in the
debug process.
One of the approaches to fault root-cause analysis is applying and adjusting categorization
algorithms in the field of testing. Such an algorithm enables, for example, to analyze the
structure of successful tests and to detect differences between them and the given failed test.
That difference may indicate a reason for the test failure and point out the faulty module.
Any set of tests can be non-homogeneous and therefore, describing it becomes a complex
task, which can be simplified by categorizing the test under consideration, and then
comparison only to tests of such type.
The aim of this research is to predict, for a given failed test case, a location of software faults
after capturing the software execution profile and behavior and analyzing together with the
previously gathered test results.
Our research includes two main paths: 1) Developing a testing environment that enables
executing a set of test cases and gathering results for further analysis. In each run, associated
module execution is traced and captured, in order to establish a mapping between the test
steps and the corresponding software modules. 2) Based on known categorization
approaches, developing an algorithm that provides the desired prediction. According to this
algorithm, the run information for failed tests is analyzed together with previously gathered
test data, to identify the software module most likely to be defective.
We intend to show that effective prediction of fault locating is possible.
Our research contributes to enhancing the debug process, which is a major factor in software
quality. Possible future research includes improving the prediction accuracy by further
developing the analysis and prediction algorithm.
The ORT Braude College 7th
Interdisciplinary Research Conference
Software Engineering | 55
A Farthest-Point Approach for Graph Clustering in
Large PPI Networks
Nissan Levtov
1, Zeev Volkovich
2
1Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901902, Fax: 972-4-9901529, E-mail: [email protected]
2Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901902, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: Clustering algorithms, graph clustering, cluster analysis
A protein-protein interaction (PPI) network is generally represented as a graph, with proteins
as nodes and two nodes which are connected by an edge, if and only if the corresponding
proteins interact physically. Protein-protein interactions are fundamental for virtually every
process
in a living cell. Information about these networks improves understanding of diseases and can
provide the basis for new therapeutic approaches. An investigation of PPI mechanisms begins
with the characterization of the PPI graph structure. In particular, clustering is a fundamental
task. Clustering in PPI networks is to group the proteins into sets (clusters) which
demonstrate greater interaction among proteins in the same cluster than in different clusters.
Good clustering methods are necessary to reveal biological relevant functions and cellular
processes.
The aim of this study is to develop a graph clustering algorithm suitable for clustering graphs
which represent large protein-protein interaction networks. The algorithm should also be able
to efficiently decide on the right number of clusters.
Our new clustering algorithm is based on the farthest-point approach of Gonzalez, modified
to deal with large PPI networks. The Gonzalez algorithm provides a clustering of points in a
metric space, aiming to minimize the maximum distance between points in the same cluster.
With the number of desired clusters given, the method attains a 2-approximation ratio for
clustering points in metric spaces. Several issues prevent this approach to be effective for our
data as is. Firstly, we consider PPI networks where the representing graph is not weighted
and therefore one has to define a distance measure between the points in the network.
Another issue to be considered is that some proteins are involved in two or more different
functions, causing several clusters to overlap. Also, we do not assume that the number of
desired clusters is given, but rather would like the algorithm to set the best number of
clusters. Our clustering method takes all these issues under consideration.
The proposed algorithm was tested on real PPI data containing interactions among around
17,000 proteins. During each iteration, the maximum distance of a node to its center was
measured, as well as the amount of change from the last iteration (the distance derivative). If
the measure and algorithm are effective, one would expect to clearly identify the best number
of clusters by a significant decrease in the derivative measure. The results we obtain support
this assumption and the clusters are clearly identified.
The proposed algorithm is effective in identifying (possibly overlapping) clusters in a large
PPI network.
The ORT Braude College 7th
Interdisciplinary Research Conference
56 | Software Engineering
Lower Bounds on the Minimum Average Distance of Codes
Beniamin Mounits
Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901754, Fax: 972-4-9901839, E-mail: [email protected]
Keywords: Code, minimum average distance, association scheme, linear programming
In 1977, Ahlswede and Katona proposed the isoperimetric problem of the extremal
combinatorics of Hamming space of determining the minimum average distance of binary
codes. In 1994, Ahlswede and Althöfer observed that this problem also occurs in the
construction of good codes for write-efficient memories, introduced by Ahlswede and Zhang
at the same time, as a model for storing and updating information on a rewritable medium
with cost constraints. This problem is also equivalent to a cocycle covering problem in graph
theory. In 1998, Xia and Fu developed lower bounds on the minimum average distance of
binary codes. The bounds were obtained using Delsarte's linear programming approach for
bounding the size of cliques in an association scheme. A recent development in this area took
place in 2007 when Xia, Fu and Jiang had considered the problem of bounding minimum
average distance of constant weight codes.
The aim of this study is to find a general framework for obtaining the lower bounds on the
minimum average distance of codes in arbitrary P-polynomial association scheme.
The lower bounds we derive are divided into two types. The first one is combinatorial where
we consider connection between spectrum of the code of interest with the one defined by
"holes" of the code. This technique was recently developed by Mounits, Etzion and Litsyn for
metric association schemes. The second type bounds are linear programming bounds. Being
encouraged by the success of the method in the case of constant weight codes, we try to
generalize the LP approach for a wide class of association schemes, namely P-polynomial
schemes.
By exploiting the connection between the code and its holes we had succeeded in obtaining
an explicit connection between the minimum average distance of a code and that of its
complement, for an arbitrary P-polynomial scheme. As for the optimization bounds, we had
shown that the bounds in binary/non-binary Hamming scheme, as well as in binary/non-
binary Johnson scheme are obtained as particular cases of our generalized approach.
However, we didn't succeed in proving that our approach fits all P-polynomial association
schemes. The work in this direction is still in progress.
The results we obtained so far, especially a generalization of the known bounds and putting
them in to same framework, make us believe that it is possible to reach our aim, or at least to
characterize a class of association schemes suitable to our approach.
The ORT Braude College 7th
Interdisciplinary Research Conference
Software Engineering | 57
Parallel Computations on Decomposable Systems
Elena Ravve
Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901902, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: MSOL, translation Schemes, sum-like systems, Incremental Computation
In many cases, we find the situation, when we do some computation on a system that is
composed from several components. On the other hand, computation systems with several
computation units are widely used, even in personal computers. We try to exploit this
modularity of the systems under consideration as well as the computation tools to make the
computation more effective.
The aim of the present study is to give the precise mathematical definition of the modularity
of the system, as well as to elaborate the computational complexity, in order to measure the
effectiveness of the proposed approach.
We use Monadic Second Order Logic in order to formulate the problem to be solved. We
justify the choice from both an expressive power and a computational complexity point of
view. We use the technique of translation schemes in order to define sum-like systems as the
basic concept of the modularity. In complexity analysis, we consider several scenarios of
computations. For each scenario, we give a complete complexity analysis. We use the
Feferman-Vaught theorem and the technique of translation schemes for the precise definition
of sum-like systems and give several examples of such systems in different fields of
computer science. We also discuss the limitations of the proposed methodology, as well as
the possible directions of further investigations.
Our main result shows that under the used assumptions, the proposed methodology allows to
reduce the complexity of computations on sum-like systems as well as to minimize the
communication between their components. As a negative result, we show some synchronized
systems, where the approach cannot be applied.
We show how the generalization of the Feferman-Vaught theorem may be used for parallel
incremental computation on decomposable systems, which are defined using the notion of
sum-like systems. We give different applications of the methodology in Formal Verification
and in Data Bases. We give complexity analysis, effectiveness and limitations of the
methodology.
The ORT Braude College 7th
Interdisciplinary Research Conference
58 | Software Engineering
Discrete Modeling of Regulation Networks and its Application to
Elucidating Bi-Stability
Amir Rubinstein
1, Yona Kassir
2, Ofir Hazan
3
1Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901902, Fax: 972-4-9901852, E-mail: [email protected]
2Faculty of Biology, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel, Tel:
972-4-8294214, Fax:972-4-8225153, E-mail: [email protected]
3Department of Mathematics, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-50-
9319646, Fax: 972-4-9901802, E-mail: [email protected]
Keywords: Regulation networks, discrete model, meiosis in budding yeast
The modeling and analysis of genetic regulatory networks is essential both for better
understanding their behavior as well as for elucidating and refining open issues. Many
methods for simulating and inspecting the properties of such pathways have been devised,
borrowing from a variety of techniques such as differential equations, algebraic calculi, and
Flux Balance Analysis. Most of these methods are quantitative in nature and require data that
is often not fully revealed; moreover, some of them are computationally intensive, requiring
significant time and resource.
The aim of this research is two-fold:
1) To extend a discrete computational model that allows for qualitative analysis of gene
regulatory pathways, enabling the examination of biological characteristics such as bi-
stability, transient gene expression, robustness, and sensitivity to initial conditions, in an
effective manner. One of the main advantages of this model is its predictive capabilities
to pinpoint missing regulatory elements in a network.
2) To elucidate the mechanism that promotes a bi-stable switch from the cell-cycle to
meiosis in budding yeast.
We apply our model to analyze the manner by which bi-stability is achieved in a
representative developmental pathway, meiosis in budding yeast. Simulation results are
validated with experimental data in the lab. Throughout this process, we are able to both make
predictions as to the mechanism that governs the biological system under research, and
enhance the computational model with abilities that are relevant to similar biological systems.
Our model is a state-graph, in which nodes represent proteins/mRNA, and may assume
discrete states from a finite range {0,…,N}; edges represent regulation effects; hyper-edges
(edges from nodes to other edges) represent conditional regulation. A transition function
determines the states of all nodes in the next time steps in a synchronous fashion.
To this end, we have examined several hypothesized regulation networks with our
computational model. Simulations suggest a few biological insights, one of which is that the
regulation on Ime2, a key player in meiosis in budding yeast, is conducted through its activity
and not quantity. Throughout this process we identified a meaningful extension to the
transition function of the computational model.
The ORT Braude College 7th
Interdisciplinary Research Conference
Software Engineering | 59
A Comparative Assessment of Outlier Detection Methods in Wireless
Sensor Networks (WSN)
Peter Soreanu
1, Zeev Volkovich
2
1Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901845, Fax: 972-4-9901852, E-mail: [email protected]
2Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901994, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: Wireless sensor networks, WSN, outliers, outlier detection methods
Wireless sensor networks consist of small processing and communication units with sensing
capabilities, deployed in a field to be monitored. The gathered data is transmitted using ad
hoc wireless links, without a fixed infrastructure, ultimately reaching a remote computer
outside the field. This data has to be interpreted, with one of the main tasks being the
detection of significant events. This detection is based on measurements reported by sensors,
where deviations of successive measurement are tested towards a threshold and the history of
previous received data. However, these techniques cannot distinguish between a real event
and a local anomaly, possible due to a sensor failure or a malicious attack. Various methods
have been proposed to deal with this problem, generally looking at sensed data in a spatial-
temporal manner. Every proposed method works better under certain assumptions, and no
method is suitable to every outlier scenario found.
The aim of this study is to evaluate the efficiency of different outlier detection methods in
various real-world scenarios, and find out which ones are best suited for classes of possible
outliers detected by the WSN.
Six outlier detection methods were implemented, each one simulating basically the same
scenarios. The following methods have been used: Gaussian distribution assumption, kernel-
based algorithm, K-nearest neighbors, Support Vector Machine, Bayesian belief networks
and Kalman filtering. Each implementation developed a different simulator, so the final
results were normalized for comparative analysis.
We have found that the least efficient was the algorithm based on the assumption of Gaussian
distribution of the measurements' values, that the Support Vector Machine-based algorithm
was sensible to the parameters chosen, and the Kalman filter acted very efficiently on some
scenarios, and was practically ineffective in others.
The specific suitability of various outlier detection methods in a sensed field suggest two
kinds of uses: if the outliers behavior may be predicted, the best detection method found in
our research for this scenario may be recommended for implementation; if no outlier
behavior may be predicted, a possible solution would be the parallel implementation of more
than one algorithm. The later approach seems very promising in real-time situations, and may
be the object of our further research.
The ORT Braude College 7th
Interdisciplinary Research Conference
60 | Software Engineering
A K-NN Approach for Cluster Configuration Assessment
Dvora Toledano-Kitai
1, Zeev Volkovich
2
1Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901862, Fax: 972-4-9901852, E-mail: [email protected]
2Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901862, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: Clustering, cluster stability, K-Nearest Neighbours
Cluster analysis is a tool for discovering hidden ‘groups‘ or ‘clusters‘ in collections of items
commonly described by numerical, linguistic or structural features. The elements of each
cluster are highly similarly to each other in their behaviour (with respect to the given data)
and the groups are expectantly well separated. A key and effectively unsolved ―ill posed‖
cluster analysis problem is the estimation of the appropriate ―true‖ number of clusters. The
conclusion can be influenced by the data scale chosen. Although many methods were
proposed over the years to overcome the aforementioned problem, none have been agreed to
be superior.
In the current talk we present a new viewpoint to the cluster validation problem founded on
the K-Nearest Neighbours (K-NN) approach which is based on the stability of the partitions'
geometrical configuration which is estimated within a resampling procedure.
Triples disjoint subsets of the data under investigation are randomly drawn, and presented to
a cluster algorithm in two unions of samples‘ pairs. We estimate the partition‘s readiness
using probabilistic features of the K Nearest Neighbors (K-NN) approach, focusing on at the
portion of the K-NN belonging to its own sample for each point from the mutual part in the
pairs. We presume that the cited K-NN fractions appear to be independent realizations of the
same random variable in the case of the ‖true‖ number of clusters. These actualizations are
compared by means of a simple probabilistic metric, such that the empirical distributions of
the distance magnitudes and their observed p-values are created. Suitably, concentrated
distribution indicates the true number of clusters.
In order to validate the proposed model, several numerical experiments on synthetic and on
real data were performed. In each experiment, the computations are performed on a
substantial quantity of samples to allow achieving accurate conclusions. Empirical
distributions of the distortion function are formed for several possible numbers of clusters in
the purpose of determining the ―true‖ quantity of clusters by means of the one most suitably
concentrated distribution. In all of the experiments the suggested model succeeds in detecting
the ―true‖ numbers of clusters.
The proposed novel manner demonstrates high abilities in handling the detection of the true
number of clusters.
Acknowledgement: This study is supported by a grant from the ORT Braude College
Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
Software Engineering | 61
An Information Criterion for Selecting the
Optimal Number of Components
Zeev Volkovich
1, Zeev Barzily
2, Gerhard-Wilhelm Weber
3
1Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901862, Fax: 972-4-9901852, E-mail: [email protected]
2Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel,
Tel: 972-4-9901862, Fax: 972-4-9901852, E-mail: [email protected]
3Institute of Applied Mathematics, Middle East Technical University, 06531 Ankara, Turkey
University of Siegen (Germany), University of Aveiro (Portugal), Universiti Teknologi Malaysia,
Skudai, E-mail: [email protected]
Keywords: Clustering, cluster stability, Gaussian Mixture Model
Cluster analysis is a tool for discovering hidden ‘groups‘ or ‘clusters‘ in items or collections
commonly described by numerical, linguistic or structural features. The estimation of the
suggested number of clusters in dataset is an ‗ill posed‘ problem of essential relevance in
cluster analysis. A group (cluster) is characterized by relatively high similarity among its
elements in addition to a relatively low similarity to elements of other groups. We claim that
sequences of samples can be interpreted as Gaussian distributed i.d. samples drawn from the
same source. Consequently, mixture, especially Gaussian, cluster models are an essential
statistical modeling instrument at the heart of many applications in computer vision, machine
learning and text classification.
In this paper, we present a novel efficient algorithm for selecting the optimal number of
components for a Gaussian Mixture Model. Efficiency is an important attribute here, since
clustering serves as a preprocessor in many data mining applications and clustering
algorithms tends to require long computing times.
We formulate the criterion as an optimization problem of minimizing the information learned
distance, between two partitions, obtained for disjoint samples. The problem is resolved by
constructing the distance empirical distributions such that the one concentrated at the origin
depicts the optimal components quantity. Our procedure can, now, roughly be described as a
generation of an empirical distribution of the test statistic with the application of a
concentration test.
A new efficient methodology for the number of components estimation is offered and
evaluated across synthetic and real-world data. The results obtained demonstrate high
capability of the proposed approach.
The new method exhibits the potentiality of the applications of the distance learning
methodology in the cluster validation problematic.
The ORT Braude College 7th
Interdisciplinary Research Conference
62 | Software Engineering
An Efficient Way for Determining the Number of Clusters
in a Graph
Orly Yahalom
1, Zeev Volkovich
2
1Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901845, Fax: 972-4-9901852, E-mail: [email protected]
2Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901994, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: Graph clustering, cluster validation
Cluster analysis is a central task in machine learning, aimed to identify meaningful,
homogenous data groups, named clusters. Cluster analysis includes two main tasks:
clustering and validation. Clustering methods deal with finding a partition in the data
elements into a given number of clusters. No additional external information in the clusters
process is available. Validation methods deal with determining the optimal (―true‖) number
of clusters in a dataset. Here, the clustering solutions are compared according to the
predefined rule and the optimal number of clusters is chosen as the one which yields the
optimal quality.
Our research is devoted to cluster validation in graphs, which has various applications in the
study of natural and manmade networks. Graph clustering is normally done by applying
spectral algorithms, using the eigenvectors of matrices derived from the graph.
The aim of this study is to determine the optimal number of clusters in graphs in order to
fully utilize graph clustering algorithms.
Given a graph G and a number of clusters k, we sample two sub graphs G1 and G2 (using
existing sampling methods based on the random walk technique) and compute partitions 1
and 2 of G1 and G2, respectively. If k is indeed the correct number of clusters, we expect to
obtain "similar" partitions, in the sense that every cluster in the natural partition would have a
corresponding sub cluster in 1 as well as in 2.
For a vertex u and a cluster C we define d(u,C) as the average graph distance between u and
vertices in C. Now, for any vertex u of G1, let C1(u) and C2(u) be the "closest" and "second
closest" clusters to u in 2, with respect to the aforementioned distance function.
Equivalently, for any vertex u of G2, let C1(u) and C2(u) be the "closest" and "second closest"
clusters to u in 1. If the partitions 1 and 2 are of high quality, then for every cluster C in
either of the partitions, we expect C1(u) to be a subset of the cluster to which u belongs, and
thus d(u, C1(u)) should be significantly smaller than d(u, C1(u)). Hence, we define the
average of ratio between d(u, C1(u)) and d(u, C2(u)) as an index for the clustering quality,
where a minimum value of the index should indicate the correct value of k.
Currently we are building an application to employ our method. Once done, we will perform
our method on various synthetic and real world datasets, to test its efficiency and robustness.
Acknowledgement: This study is supported by a grant from the ORT Braude College
Research Committee.
The ORT Braude College 7th
Interdisciplinary Research Conference
Teaching and Learning | 63
Chemistry: From the Nano-Scale to Microelectronics
Learning Quantum Chemistry via Visual-Conceptual Approach
Vered Dangur
1, Yehudit Judy Dori
1, 2, Uri Peskin
3
1Department of Education in Technology and Science Technion - Israel Institute of Technology,
Technion City, Haifa 32000, Israel;Teaching and Learning Center, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901724, Fax: 972-4-9901738 , E-mail: [email protected].
2Division of Continuing Education and External Studies, Technion - Israel Institute of Technology,
Technion City, Haifa 32000, Israel. Tel: 972-4-8294524, Fax: 972-4-8236022, E-mail:
3Schulich Faculty of Chemistry, Technion -Israel Institute of Technology, Technion City, Haifa 32000,
Israel Tel: 972-4-8292137, Fax: 972-4-829570, E-mail: [email protected]
Keywords: Quantum chemistry, thinking skills, visualization, chemistry understanding
levels
In the last decade, a new chemistry curriculum for Israeli High School students was
developed. The focus of most of the learning units was the development of higher order
thinking skills and conceptual understanding. Along these lines, one of the new learning units
which focused on Quantum Chemistry, was developed at the Technion. The title of this unit
is Chemistry – From “the hole” to “the whole”: From the nano-scale to Microelectronics.
Undergraduate Quantum Mechanics courses are taught mostly via a mathematics-oriented
approach. Our unit aims at 12th grade students, and is based on a more qualitative approach
which integrates real-life applications and visualization - the visual-conceptual approach. The
unit was also partially implemented in an undergraduate Quantum Chemistry course.
The research objectives were to investigate the effect of the unit on undergraduate and High
School Chemistry students' understanding of Quantum Mechanical concepts, as well as
visual and textual chemical understanding.
Research participants were 198 High School students who studied the unit, and 82
undergraduate students who learned Quantum Mechanics and volunteered to participate in
the study. About a third of the undergraduates participated in a short-term enrichment
workshop that included the topics of the learning unit.
The research tools included pre and post-questionnaires designed to assess conceptual and
visual understanding, as well as feedback questions. The High School students' responses to
the post-questionnaire showed a better understanding of the quantum models in comparison
to the pre-questionnaire. However, few of them still demonstrated misconceptions, such as
previous naïve and hybrid models. Both High School and undergraduate students improved
their scores in visual and textual chemical understanding. Comparison between the sub-
groups which participated in the research revealed that in questions related to the visual and
textual chemical understanding of the unit‘s topics, the 12th graders improved their scores
more than undergraduate students who participated in the enrichment course that included the
topics of the learning unit. In addition, students who took the enrichment workshop that had
exposed them to the unit, improved their scores significantly more than students who
participated in a short mathematical-oriented enrichment workshop.
The research emphasizes the contribution of a visual-conceptual approach to the teaching and
learning of Quantum Mechanics at both High School and undergraduate levels. It also
contributes to the body of knowledge of the four chemistry understanding levels-
macroscopic, microscopic, symbol and process, via the addition of the Quantum Mechanical
level as a fifth level of Chemistry understanding.
The ORT Braude College 7th
Interdisciplinary Research Conference
64 | Teaching and Learning
"Personal Coaching" Program -
Students' Academic Achievements and Lecturers' Experience
Ita Donner
1*, Miri Shacham
2, Rivka Weiser Biton
3, Orit Herscovitz
4
1Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901907, Fax: 972-4-9901886, E-mail:[email protected] 2Department of Teaching, Teaching and Learning Center, ORT Braude College, P.O. Box 78,
Karmiel, 21982 Israel, Tel: 972-4-9901895, E-mail: [email protected]
3Prof. Ephraim Katzir Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901875, Fax: 972-4-9901886, E-mail:[email protected]
4Department of Teaching, Teaching and Learning Center, ORT Braude College, P.O. Box 78,
Karmiel, 21982 Israel and the Department of Education in Technology and Science, Technion- Israel
Institute of Technology, Technion City, Haifa, Israel, 32000, Tel: 972-4-9901750, Fax: 972-4-
9987839, E-mail: orither@ technion.ac.il
Keywords: "Personal Coaching", "under achieving" academic status, lecturers experience
During the last three academic years, project MALAT at ORT Braude College has been
focusing on assisting students who are in "under- achieving" academic status by the end of
their first year in the College. As a part of the project, the students undergo an interview with
a psychologist at the Teaching and Learning Center and some of them are recommended to
have "Personal Coaching" carried out by a trained lecturer from the College.
The goals of the "Personal Coaching" are twofold: on the personal level - to promote
students' learning skills, self-efficacy and academic achievements, and on the College level -
to decrease the amount of learning failures and drop outs in the first academic year. The
coaching process includes a one hour meeting between the student and his/her coacher every
week during the semester. The main issues which are discussed during the coaching process
includes: setting goals, time management, coping with academic tasks, stress management
and personal learning style. The coaching process is accompanied by a longitudinal research.
This part of the research examines the students' academic achievements in the end of the
coaching process, after a year and after two years. The research also focuses on the effect of
the "Personal Coaching" on the lecturers - has the experience of being a coacher for College
students contributed to the professional development of the lecturers?
During the 2009-2011 academic years, 30 students received personal coaching by lecturers
from ORT Braude College. The lecturers participated in a 120 hour training course for a
"Personal Coachers‖ diploma with a special focus on under-achieving students.
Questionnaires and in-depth interviews were held with 15 lecturers who were coachers for
students.
In this presentation we will present our findings regarding the students and the lecturers.
*Deceased
The ORT Braude College 7th
Interdisciplinary Research Conference
Teaching and Learning | 65
Moving Towards Distance Learning - Literature Review and Two
Examples of Using Interactive Forums in Science Education Courses
Orit Herscovitz
Department of Teaching, Teaching and Learning Center, ORT Braude College, P.O. Box 78, Karmiel,
21982 Israel and the Department of Education in Technology and Science, Technion- Israel Institute
of Technology, Technion City, Haifa, Israel, 32000, Tel:972-4-9901750, Fax: 972-4-9987839, E-
mail: orither@ technion.ac.il
Keywords: Distance learning, forums, Moodle environment
The nature of the 21st century classroom is changing rapidly. Online education is growing at
about 30 percent annually. Distance learning is defined as an interactive teaching-learning
process, of which at least part is carried out online via text, audio, and/or video. Distance
learning occurs when the student and the teacher are physically separated and technology is
used to connect them.
Distance learning is conducted synchronously or asynchronously. Synchronous learning can
take place when the learner has the possibility to interact with the instructor and/or other
learners in real time. Asynchronous learning takes place when the learner is not in real-time
communication with the instructor or with other learners, and learners control the rhythm and
rate of their responses and the pace at which they assimilate the learning materials.
Distance learning provides for life-long learning. It enables the learner to be flexible with
respect to time and distance and for individual adaptation of the domains of interest, the pace,
and the academic level. For the institution administering the teaching, distance learning
enables catering to a large number of learners of diverse backgrounds, offering a variety of
learning subjects, and employing a large team of experts at relatively low costs. Research has
shown that most of the difficulties associated with distance learning are related to reading
text in digital formats, a sense of loneliness, social disconnect and lack of cognitive skills for
effective use of technology for learning. This might lead to ineffective use of technologies for
distance learning and to lack of pedagogical approaches to distance learning and teaching
processes.
Teaching online is different from teaching face-to-face and needs its own set of pedagogies.
In order to explore these pedagogies, interactive forums were integrated in two courses in
Science Education. The first course was "Action Research" conducted at the Technion,
including 12 undergraduate and graduate students. The second course was "Teaching
Methods" conducted at ORT Braude College, including 23 undergraduate students. In each of
the courses, the forums were managed in a Moodle environment and the activity was part of
the graded assignments in the course. In both cases, the students were divided into small
working groups, received a set of instruction and a specific period of time for the activity, in
which the face-to-face meeting in the course was converted to a virtual meeting. The
Technion forum was based on free discussion between the groups on preparing a research
proposal. The lecturer was actively involved in the dissections. The ORT Braude College
forum was based on posing questions by each one of the groups (after reading articles) and
managed the discussion with their colleagues on these questions. The lecturer was not
actively involved in the discussions.
The research tools included an open ended attitudes questionnaire given at the end of the
activity and full documentation of the activity in the forums. A preliminary analysis of the
questionnaire reveals mixed attitudes towards the importance and effectiveness of usage of
forums. The full analysis of the attitudes questionnaire and the content analysis of the
discussion in the forums will be presented at the conference.
The ORT Braude College 7th
Interdisciplinary Research Conference
66 | Teaching and Learning
Program for Supporting Underachieving Students - Continuous
Evaluation
Orna Muller
1, Vered Dangur
1, 2, Daud Daud
1, Merav Rosenfeld
1
1Teaching and Learning Center, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-
4-9901724, Fax: 972-4-9901738, E-mail: [email protected]; [email protected];
2Department of Education in Technology and Science, Technion – Israel Institute of Technology,
Technion City, Haifa 32000, Israel;Teaching and Learning Center, ORT Braude College, P.O. Box 78,
Karmiel 21982, Israel, Tel: 972-4-9901724, Fax: 972-4-9901738, E-mail: [email protected].
Keywords: Underachieving students, supporting tools for learning, learning skills
A student in an academic underachieving status is identified at ORT Braude College (OBC)
as a student who accumulated three failures in courses or achieved a low average grade (less
than 65) over two consecutive semesters; according to College policy, the termination of this
student's studies is considered . OBC tries on one hand, to cut down the percentage of failing
students in advanced stages of their studies in the College, and on the other hand, to lower the
drop-out rate.
The program for supporting underachieving students (called MALAT) was design by the
Teaching and Learning Center (TLC), to provide support to students which their departments
evaluated as having a good chance to overcoming their difficulties, to improve their academic
status and to succeed in their studies.
The MALAT program includes two main stages: 1) Student‘s difficulties and possible
reasons for their failures are revealed through collection of personal information and an
extensive personal interview with a psychologist. 2) The student is offered several
supporting tools that may help them overcome difficulties and improve their achievements.
Among the tools offered are: tutoring by a peer-student, coaching by College lecturers
(trained and certified), emotional counseling, group meetings for time management, personal
counseling to improve learning skills, courses for learning strategies and team-leaders‘
workshops.
The MALAT program is documented and evaluated for the purpose of both assessing the rate
of success and evaluating the process of supporting the students. The main questions that are
evaluated are: What are the sources of difficulties and the reasons for failure among students
who participated in the MALAT program? What is the rate of students that improved their
academic status after participating in the program? What is the correlation between a
supporting tool, the degree of implementation of a recommended tool and students'
achievement during the 3rd
semester? Which supporting tools are most effective?
Research tools include continuous documentation of students' participation in supporting
activities, and interviews with students who have completed the program.
This is the third year of evaluating the program. Analysis of data collected on 125 students
who participated in the MALAT project during the winter semesters of 2009-2010 and 2010-
2011 academic years, shows that 50% of them moved to a satisfactory academic status.
Other results will be described in our presentation.
The ORT Braude College 7th
Interdisciplinary Research Conference
Teaching and Learning | 67
Enriching the Quality of Personal-Social Expression in
Digital Environment
David Pundak
1, Miri Shacham
2
1Web-Learning Unit, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901843,
Fax: 972-4-9901886, E-mail: [email protected]
2Department of Teaching, Teaching and Learning Center, ORT Braude College, P.O. Box 78,
Karmiel, 21982 Israel, Tel: 972-4-9901895, E-mail: [email protected]
Keywords: Personal-social discourse, WIKI, peer feedback, meaningful learning
Research has indicated that attempts to promote on-line collaboration between students via
web in academic courses, encounter many difficulties. One of them is the difficulty in
managing a meaningful discussion between the students during the preparation of conceptual
framework. The research tracks the computerized discourse in a WIKI environment over a
period of three years in a "Technology in Education" course. During the period of the
research, alterations were applied in order to deepen the student's personal expression on the
net, as a preliminary stage for their social discussion. Findings indicate an improvement in
students' involvement in the editing of their personal site and a reduction in the percentage of
meaningless feedback. It would be valuable to examine these research directions in larger
and broader populations.
The research focused on the bonding of personal and group knowledge in the WIKI
environment, including the influence of a personal site on constructing a conceptual
framework.
During the three years in which the WIKI environment was examined in the studied course,
efforts were made to enhance the student's involvement: in writing their personal site,
improving willingness to accept and provide feedback and accepting responsibility to write a
concept related to their knowledge and construct it according to accepted criteria. Difficulties
in attainment of these goals were described in detail in previous studies. In brief, these
include: reticence regarding exposure on the net, fear of criticism, avoiding the presentation
of criticism, resistance to intervention in personal products, providing meaningless feedback,
a long period of assimilation to the new environment and a tendency to invest minimal
efforts. In order to cope with these difficulties, each year, alterations were introduced in the
instructions given to the students when they dealt with the tasks in the WIKI environment.
The findings and conclusions of the research will be presented at the conference.
The ORT Braude College 7th
Interdisciplinary Research Conference
68 | Teaching and Learning
A New Skills Course - Logical Thinking and Argumentation
Amir Rubinstein
Department of Software Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel:
972-4-9901902, Fax: 972-4-9901852, E-mail: [email protected]
Keywords: Logical thinking, argumentation skills
Computer Science and Software Engineering curricula require, among other skills, high
logical reasoning ability. Insufficient logical thinking skills result in poor and illogical
argumentation processes, disconnected, imprecise and ambiguous statements, and incorrectly
used terms. Logical thinking is essential for handling abstractions in a precise manner, which
is fundamental in Computer Science and Software Engineering. However, introductory
Mathematics and programming courses frequently emphasize mastering specific
Mathematics content and a programming language, while thinking processes are dealt with in
an unstructured and implicit manner.
This study proposes that logical thinking needs to be introduced separately from Mathematics
and Computer Science courses, but in parallel to them; consequently, connections and the
implementation of ideas can constantly be made. The Logical Thinking and Argumentation
course has two main goals: 1) to develop logical and precise thinking and 2) to enhance
students' skills in formal argumentation techniques. The primary theme of proof and disproof
is always in the spotlight. Topics are taught not in a less formal manner, subtle issues are
discussed to enhance students' awareness of them and raising difficulties and examples for
discussion is encouraged.
Reflective written questionnaires were presented to the students at the end of the course. The
questionnaires which consist of open questions, allow learning about students‘ attitudes
regarding the influence of the course on their argumentation skills and changes in their
perception of argumentation in general. Students were also asked to submit a summary of the
course rationale in their eyes and give personal feedback.
Since Logical Thinking and Argumentation is only being taught in our College for the second
time, we have relatively few impressions at the moment (but will have more at the end of the
current semester). In general, students report improvement in their confidence in the
rationality of logical argumentations. Many of them feel that they became more aware of
vague statements made by themselves or others, and therefore can make an effort to avoid
them. Some also find proofs they encounter "more familiar" and less threatening. Students
mentioned that in this course there was time and legitimacy to expose, argue about and iron
out subtle logical issues, which caused difficulties in other first year courses they took (e.g.:
the fact that in some universal statements the "for all" quantifier is omitted, the right way to
disprove an 'if a then b' statement, the rationale of proof by contradiction, etc.).
This feedback implies that an efficient, separate, introductory unit that explicates the
principles of logical reasoning and argumentation is of importance for freshmen in Science
and Engineering.
The ORT Braude College 7th
Interdisciplinary Research Conference
Teaching and Learning | 69
Evaluation of the Preparatory Semester Program
Miri Shacham
1, Orna Muller
2
1Department of Teaching, Teaching and Learning Center, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901895, E-mail: [email protected]
2Department of Teaching, Teaching and Learning Center, Department of Software Engineering, ORT
Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901895, E-mail:
Keywords: Preparatory semester, first academic year, algorithmic thinking
Numerous students, though eligible for academic studies, take up engineering without being
adequately prepared for academic studies, often occurring years after High School
graduation. The sharp entry into the intensive academic world is highly demanding and
challenging to students who lack learning and thinking skills, as well as solid scientific
grounds in Mathematics, Physics and Computer Science. Consequently, many students
experience difficulties and failure, have to re-attend courses and even drop out. In 2010-2011,
the Departments of Mechanical and Software Engineering offered a unique first semester
curriculum ("Preparatory Semester") seeking to enable a gradual adjustment to the studies
and decrease failure rates in the first year. The program‘s principles are:
Decreasing the number of required courses compared to the ―recommended‖
program
Providing introductory courses preparing the students for their studies in the
Department
Adding learning and thinking skills courses
Increasing the number of hours in basic courses considered ―difficult‖
Teaching in small groups giving more attention to each student
Option to complete the studies in four years by offering summer complementary
courses
Accompanying the program with research
The aims of this study are:
1) Examining the students‘ achievements after the Preparatory Semester versus those of
the other students in the Department
2) Examining the students‘ satisfaction with the program
In the first and second semesters of 2010-2011, the research population consisted of 14
Mechanical Engineering and 34 Software Engineering students. Participants filled out a
questionnaire examining their perceptions of the program and their first semester
achievements were compared to those of the other students in the faculty.
Analysis of the data reveals that most students feel their expectations of the "Preparatory
Semester" were met. The students explained their feelings by stating that they got good
grounds for their studies, as well as personal treatment, learning and thinking tools. The
"Preparatory Semester" enhanced their personal abilities and allowed for ―a smooth landing‖
and the development of learning and thinking skills required for academic studies.
The students have faith in their ability to cope with the academic demands and believe the
program is important mainly for students with no previous knowledge and those who have
enrolled in College long after their high school studies.
The participants‘ achievements will be presented and compared to those of the entire student
body, after one semester/two semesters. Their perceptions of the program‘s contribution will
also be presented.
The ORT Braude College 7th
Interdisciplinary Research Conference
70 | Teaching and Learning
Intercultural Doctoral Learning
Yehudit Od-Cohen
1, Miri Shacham
2
1The English Department, Ohalo College of Katzrin, P. O. Box 222, Katzrin 12900, Israel, Tel: 972-4-
6825000, Fax: 972-4-6825011, E-mail: [email protected]
2Department of Teaching, Teaching and Learning Center, ORT Braude College, P.O. Box 78, Karmiel
21982, Israel, Tel: 972-4-9901895, Fax: 972-4-9901839, E-mail: [email protected]
Keywords: Intercultural learning, lifelong learning, adult education, academic discourse,
conceptual thinking
The research examined the learning experiences of social sciences doctoral students in the
international program in ARU University in the UK.. This research focused on learning
characteristics in a cultural and a community context, both during Ph.D. studies and after
completion. It draws on theories of communities of practice, intercultural learning, adult
learning and lifelong learning. We will present a part of a longitudinal research that was
conducted during the years 2005-2010.
The aim of the present study is to examine the learning experiences and the professional
development of the program graduates beyond their Ph.D.'s, and their transition from field
experts to researchers and theorists.
The research methods included interviews with open-ended questions that were conducted
with 30 graduates who completed their doctorates in the past five years. Interviews were
conducted both face to face and using E-mail. Rate of response was 85%. The research
population included adults aged 40-50, in their mid-career, most of them not affiliated with
academic institutions. Additionally, the research population field of expertise pertained to
Education and Business Management, Psychology, Nursing, History, and Law.
The content analysis yielded four elements that characterize learning and development after
completing the doctorate: Cognitive, Emotional, Interpersonal and Professional
Development. Additional findings show that the transition from field experts into researchers,
continuing their research beyond their Ph.D.'s and developing academic discourse.
Intercultural learning within cross-cultural supervision emerges from this study as an
interaction between the supervisor‘s and the Ph.D. student‘s cultures. As thinking is
expressed through language, the student‘s level of linguistic and socio-linguistic competence
on the one hand and the supervisor‘s recognition of this competence on the other hand, can
enhance conceptual thinking. Beyond Ph.D., conceptual thinking is used for more theory,
more research, more development as a researcher, and more contribution to society.
The ORT Braude College 7th
Interdisciplinary Research Conference
Teaching and Learning | 71
Content and Language Integrated Learning – the Implications for
College Teachers and Students
Linda Weinberg
1, Suzy Esquenazi Cohen
2
1English Studies Unit, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901985,
Fax: 972-4-9901832, E-mail: linda @braude.ac.il
2English Studies Unit, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: 972-4-9901985,
Fax: 972-4-9901832, E-mail: suzycohen @braude.ac.il
Keywords: English, content courses, policy, proficiency, CLIL, CEFR
Content courses taught in English at Israeli institutions of higher learning are usually found in
programs for overseas students and are not generally intended for local students. More
recently, local students have been able to consider taking a degree in English at Bar Ilan
University or at the Interdisciplinary Center in Herzliya. Although only at Bar Ilan University
are the degree courses advertised as an opportunity for the students to improve their language
skills and their ability to compete in the global community. In the past, the institutional
objection to teaching in English was largely based on fear of the English language usurping
the prestige of Hebrew as the revitalized and national language of Israel. More recently
however, an increasing number of institutions have begun to offer occasional courses in
English to Israeli students. The motivation for this is less clear than such initiatives in
Europe, where there is a clearly defined policy aimed at improving proficiency in English
with the aim of facilitating academic and professional mobility within the European Union
(E.U.) and the wider global market. Consequently, in Europe there is a Common European
Framework of Reference for language learning (CEFR) which is applicable throughout the
E.U., and which clarifies learners‘ objectives and achievements in language learning. At the
same time, there is a growing body of research into Content and Language Integrated
Learning (CLIL). While a variety of courses have been given in English at ORT Braude
College (OBC) over the last 15 or so years, within the college‘s U.S. exchange and semester
abroad programs, student and lecturer needs for learning and teaching in English have not yet
been systematically addressed and a consistent policy regarding the necessary preparation
and support within the curriculum have yet to be developed.
The aim of this study is to investigate the impact of teaching in English both on students and
on lecturers and to clarify the extent to which existing English language courses need to be
adapted in order to address new needs.
Within the framework of the TEMPUS-EFA project, in which OBC is a participant, we are
observing preparations for and implementation of, courses in English for our students. We
are collating feedback from students and lecturers who have been involved in content courses
taught in English, and we are examining current policies on English language learning at the
tertiary level in Israel, comparing outcomes of these courses with those of students at the
tertiary level in the E.U.
The ORT Braude College 7th
Interdisciplinary Research Conference
Authors' Index
17
27,67
28
57
50
41,44
66
17
58,68
11,18
5
16
39
12,17
10
17
23
64,67,69,70
51
6
45
29
37
31
41
46
54
59
44
51
30
60
7
18
34
53-55,59-62
7
61
71
46
47
38
8,9
62
24
30
Pozner R.
Pundak D.
Ravid R.
Ravve E.
Raz E.
Regev M.
Rosenfeld M.
Rosenwaks Y.
Rubinstein A.
Sabag N.
Sabbah I.
Sabban A.
Salomon S.
Sarfaty R.
Schechner P.
Segev G.
Senderov V.A.
Shacham M.
Shajrawi Y.
Shakhrai S.G.
Shefer M.
Shnits B.
Shutze O.
Shvartsman L.
Simchon R.
Sinenko E.
Soffer A.
Soreanu P.
Spigarelli S.
Stein E.
Tahan M.
Toledano-Kitai D.
Toubi A.
Trotskovsky E.
Turetsky V.
Volkovich Z.
Wasser S.P.
Weber G.W.
Weinberg L.
Weiser-Biton R.
Weiss A.
Weiss-Cohen M.
Weitz I.S.
Yahalom O.
Yedidsion L.
Yuval E.
.
4
43
2,8
48
58
65
5
49
23
4,6
4
35
58
23
3
46
54
4,6
14
17
1
30
42
52
26
55
36
27
2,9
23
5
24
15,41
3
47
9
56
66,69
3
24,25
5
70
26
28
63
Gron V.A.
Groysman A.
Grozovsky M.
Guetta D.
Hazan O.
Herscovitz O.
Jiryes M.
Kallush S.
Kaner M.
Kaplichenko N.M.
Kaplichenko E.G.
Karp L.
Kassir Y.
Khatskevich V. A.
Knani D.
Konischeva O.
Korenblat K.
Korostovenko V.V.
Kosolapov S.
Kribus A.
Kroll E.
Kuflik T.
Laufer Y.
Lavner Y.
Levi A.
Levtov N.
Lewin M.
Maharshak A.
Maoz M.
Marmor Y.
Masalha N.
Mikhaylidi Y.
Miller S.
Mironi-Harpaz I.
Mizrahi R.
Morell J.J.
Mounits B.
Muller O.
Narkis M.
Naseraldin H.
Nujedat A.
Od-Cohen Y.
Peretz H.
Perry D.
Peskin U.
.
51
31
3,36
2
37-39,47
35
1
32
5
8
25
61
19
51
20
40,41
31
31
1
28
41,42
10
44
63,66
66
46
63
23
37,38
33
71
10
21
7
11,12
9
52
26
19,23
22
13
34
35
20
39
Abboud F.
Abramovitz B.
Alperstein D.
Assy N.
Avigad G.
Avros R.
Azhari R.
Azizov T. Y.
Baransi K.
Bar Guy N.
Baron O.
Barzily Z.
Bashkansky E.
Ben Asher Y.
Bendavid I.
Ben Hanan U.
Berezina M.
Berman A.
Bonshtein I.
Boxma O.J.
Braun-Benyamin O.
Bubis E.
Cabibbo M.
Dangur V.
Daud D.
Donner I.*
Dori Y.J.
Dror S.
Eisenstadt E.
Elin M.
Esquenazy–Cohen S.
Faiger H.
Faran D.
Fares F.
Florescu R.
Freitag C.
Frid A.
Fried Y.
Gadrich T.
Gavish N.
Gladshtein M.
Glizer V.
Golani M.
Golany B.
Goldvard A.
*Deceased