Writing Engineering Abstracts(45)

8/7/2019 Writing Engineering Abstracts(45)

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Writing Engineering Abstracts(45)

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(1 of 3) (+) As indispensable actuators for auto-focusing (AF) and zooming, stepping motors are extensively adopted indigital video cameras (DVCs). Following rising consumer demand forDVCs in the electronic products market, enhanced properties andelevated functions play an increasing pivotal role in luring newcustomers. Despite their fast dynamic AF access, even the most

advanced DVCs are limited in terms of low power consumption andinadequate operational efficiency to satisfy consumer demand.Conventional AF actuators in DVCs are all stepping motors,subsequently limited by a slow dynamic AF speed, high powerconsumption low power efficiency. Moreover, noise interference from astepping motor in a DVC is easily recorded into the digital films during

AF operation. Therefore, this work describes a sliding motorcontrol (SMC) method based on the position estimation algorithm (PEA)for use in AF of the linear actuator in a DVC to achieve low powerconsumption, high operational efficiency and fast dynamic AF accesscharacteristics.


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(2 of 3)A concrete and linear actuator with low power consumptionand high operational efficiency is manufactured for AF in a DVC.A magneto-resistive (MR) encoder in the linear actuator is thenadopted for use as a position feedback sensor to acquire theposition of the moving part of the linear actuator in AF operation.Next, an interpolation chip is embedded to enhance theresolution of a linear actuator in a DVC, attain an enhancedimage and avoid an increasing prime cost of a DVC. Additionally,the PEA is developed from the MR encoder to determineaccurately the position of the moving part of the linear actuator in

a DVC. Analysis results indicate that theproposed SMC method offers an effective means of positioningand controlling velocity owing to its many advantages, e.g.,insensitivity to parameter variations, disturbance rejection andfast dynamic response.


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(3 of 3)Hence, the SMC based on the PEA written in a single chip enhancesthe control performance in order to increase focusing speed andaccuracy. Additionally, the proposed SMC method can be adopted tomanufacture a linear actuator with low power consumption and highoperational efficiency for AF operation in a DVC. The proposed PEA

also determines accurately the position of a moving part of a linearactuator in a DVC. Moreover, the SMC method based on use of thePEA in AF operation in a DVC reduces AF access time by severalmicroseconds and avoid the recording of acoustic noise interferenceinto the digital films. Importantly, the proposedmethod is highly promising for use in manufacturing an efficient linear

actuator with low power consumption and high operational efficiency forAF operation in DVC rapidly. Furthermore, the AF system with a linearactuator has a fast dynamic AF speed and limited acoustic noiseinterference.


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(1 of 3) (+) Inventory refers to the stock of anyorganizational-related item or resource. All firms maintaining aninventory supply can satisfy demand with respect to product variation.However, a large inventory may incur long product cycle times.

Additionally, the proportion of inventory and setup costs of a productionline to the total operational fund in a company is extremely high,

highlighting the importance of developing a more economic inventoryorder model to satisfy production requirements. The economicproduction quantity (EPQ) model derives an optimal production lot sizethat minimizes overall inventory costs for a single item. However, asituation in which multiple items are scheduled on a single facility doesnot ensure a feasible EPQ solution for each individual item in order toprevent stock depletion during the production cycle. The rotation cyclepolicy assumes that exactly one setup is available for each productduring each cycle. Additionally, all products are manufactured in thesame sequence during each production cycle. Despite its feasibility, therotation cycle approach is not optimal in terms of minimizing overallproduction costs.


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(2 of 3)Therefore, this work presents a process optimization procedure,capable of modifying the production cycle time based on the rotationcycle method. During each cycle, products may have more than onesetup. A solution procedure can determine the appropriate cycle length,number of setups for each item, scheduling constraints and totalinventory cost function. Via this procedure, each item cycle can be

close to the prime solution derived from the EPQ model. Themodel framework is devised in contrast with the rotation cycle policy.The policy is then adjusted to identify how each item is related withrespect to optimal cycle time. Next, feasibility of the proposed model isverified, with desired changes made accordingly. Additionally, a recycletime formula, conditions of model constraints and total cost formula areestablished. Examining the rule by iteration facilitates an analysis of therationality and validity of these models. Moreover, a case studydemonstrates its feasibility, along with a comparison made to thesolution of the primal rotation cycle. Furthermore, sensitivity analysis isperformed to demonstrate how alternation cycle time influences totalcost.


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(3 of 3)Analysis results indicate that the proposed algorithmresolves the EPQ and rotation cycle problem of multiple items for aproduction facility. According to the numerical analysis of a case study,the proposed procedure reduces the overall cost more than the rotationcycle policy does. In doing so, the setup cost and setup time isintegrated into the proposed algorithm. Additionally, production line

facilities are upgraded by centralizing the idle times simultaneously,thus ensuring their efficiency, e.g., routine maintenance and flexibility inproduction scheduling. Importantly, the proposedprocedure resolves problems involving multiple items for a single facility.Consequently, production management can construct a feasiblesolution under multiple items on a single facility. Additionally, a largerratio for multiple production time for one item to another implies morebenefits acquired for the proposed algorithm. Determining productionquintiles is often referred to as a trade-off problem, in which theformulae attempt to minimize cost, reduce inventory costs, enhanceproduct quality and increase corporate profits.


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Writing Engineering Abstracts(45)

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