2002 PhD. Core Exam: Part 1MIS Dept, Univ. of Arizona, Tucson, AZ

Tuesday, May 28, 2002Venue: Room 214, McClelland Hall

Time: 9:00 AM – 1:00 PM

INSTRUCTIONS: (Please read them carefully before you begin the exam)

1. The exam will begin promptly at 9:00 a.m. and end promptly at 1:00 p.m. No extensions are allowed.

2. This exam consists of 6 questions. You are required to answer all of them. Please allocate roughly 30 minutes per question and leave some time for checking your answers.

3. Each question is worth 100 points.

4. For each question, state your assumptions clearly.

5. If you are writing by hand in a blue book, please answer each question in a separate blue book. If you are using a word processor, please make sure that you start each new question on a new page. You are allowed to use combinations of the blue book and a word processor file for answering questions.

6. At the top of each question that you answer, please identify two things:

The number of the question that you are answering and

The code name given to you at the beginning of the exam. Do not write your real name anywhere on the exam, and use only your code name.

7. Please make two (2) diskette copies of the files containing your answers if you are using a word processor. Please turn in both diskettes, along with your blue book answers and the exam questions, to the proctor at the end of the exam.

8. You are allowed to take a restroom or lunch break only if no one else is already taking one. You should get the proctor’s consent before taking a break, and also inform him as soon as you return from your break.

9. If you are using a word processor, please make sure that you save your answers frequently. It is your responsibility to ensure that you do not lose work.

10. The exam is CLOSED BOOK. Accessing the web on the computer is NOT allowed and will be severely penalized.

11. Some questions have multiple parts. Make sure you answer all of them and number them properly.

12. You have been provided with MSWORD and POWERPOINT.

GOOD LUCK!!

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Question 1: This question is about various ways to locally interconnect computers. (100 points)

A. (10 points) Consider a set of computers that are connected by communication channels that each connect exactly two computers, and every computer is connected to every other computer. What kind of network is this?

B. (10 points) Describe briefly an advantage of this kind of network vs. an Ethernet LAN which makes use of a Hub or a Switch. Hint: think about security and privacy.

C. (10 points) For N computers, how many connections do you need? Every time you add a new computer to this type of network, how many new connections do you need?

D. (15 points) Explain how LAN technologies, developed in the 1960s and 1970s, reduced the costs from the type of network we are talking about in parts 1A through 1C. Explain what new kind of competition this introduced among the computers and the issues this raises that LAN standards must address.

E. (15 points) Describe collisions in a typical wired Ethernet LAN. What defines a collision? How can they happen given that this LAN uses CSMA? What happens once a collision occurs? How does the standard try to prevent subsequent collisions between the two computers that caused the original collision? What happens if the same two computers collide again?

F. (15 points) Describe the key differences between your answer to IE and the situation with wireless Ethernet LANs broadcasting at 900 MHz. Do the wireless Ethernet LANs use CD (Collision Detect)? If not, how else can they manage collisions?

G. (5 points) What is the wavelength of the broadcast LAN described in Question 1F. Take the speed of light to be 3 * 10^ 10 cm/sec. Make sure to write the units of your answer.

H. (10 points) Suppose you have N computers on an Ethernet LAN which uses a hub, and the probability than any one of the computers might transmit in a given time interval is 0.05. What is the probability that a collision will occur? You do not need to simplify your answer.

I. (10 points) Now consider the case of having exactly 4 computers on this LAN. Solve the problem of 1H considering a Switch instead of a Hub with N = 4. The probability that any of them can transmit is still 0.05. You do not need to simplify your answer.

Question 2: Networking Concepts (100 points)

A. (20 points) What is an Ethernet Repeater? What is the purpose of using it? What layer is this device? If the original effective length of an Ethernet segment is 500 meters, what is the new effective length after we use a repeater? Why can't we extend Ethernet segments indefinitely with repeaters? How many can we use, maximum, between any two Ethernet stations?

B. (20 points) Describe the key similarities and differences between Bridges and Repeaters. At what layer are Bridges? Do they have NIC cards? Do the hosts on the LAN “see” the Bridge or is it invisible to them? Describe how the bridge does “frame filtering”. What kinds of frames does it not pass between Segments? What is the startup behavior of a Filtering Bridge? (hint: at startup, all the Forwarding Tables in the bridges are empty).

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C. (10 points) Describe and define the acronym VPN. Describe a business or university scenario where you would want to use it.

D. (20 points) Describe and define the acronym LDAP and Access Control Lists and how they come into play when considering VPNs. What layer is the LDAP protocol at? How do programming languages make use of LDAP? Describe the basics of the LDAP data structure.

E. (15 points) Distinguish between a Connection-Oriented and Connectionless paradigm. Which one has an analogy to the USA postal system? Give 2 examples of a Connection-oriented Public Switched Data Network (PSDN) and 1 example of a Connectionless PSDN.

F. (15 points) Why does the TCP/IP Protocol software design create a need for DNS? In other words, why do we need DNS; how does the DNS protocol make day-to-day work easier for people? What does the DNS acronym stand for? What layer is it at? What is the name of the special records DNS uses in conjunction with e-mail? What special records alias one domain name to another?

Question 3: Trees for DBMS and data mining: (100 points)

A. Please define a B-tree of Order 2 and draw a B-tree example with sample records. Explain why B-trees are often used in relational DBMS. (30 points)

B. Please present the data structure and algorithm used in the ID3 inductive learning method. (30 points)

C. Please present a business problem that is suited for using ID3. Please explain the characteristics of your problem and the steps (for your business problem) involved to perform your knowledge discovery task. (40 points)

Question 4: Internet Search Engines: (100 points)

A. Please define “spamming” in Internet search engines. Describe one example of spamming and suggest a way to detect it. (30 points)

B. Please present an architecture and its related technical components for creating a B2C (business to customer) product storefront. Choose and describe your own product or service. (30 points)

C. Please describe the similarities and differences between an Internet search engine (e.g., Google) and a B2C product storefront (e.g., Amazon.com). What are the roles of data mining for both applications? (40 points)

Question 5: Relational normalization (100 points)

1. The following relational schema represents the logical design for the Comfort Inn hotel chain. Please examine the functional dependencies and the current table structure. State clearly the highest normal form for each of the current tables. Explain why it is in that normal form and the problems (if any) associated with the current design. Decompose the relations to take care of these anomalies and show the process of your conversions. Remember to mark the primary key in the new tables, and show that the problems you pointed out earlier no longer exist. Please write down any assumptions you make.

Hotels (Phone, HotelNo, HotelName, StreetAddress, City, Zip, State, NumberOfRooms)

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Guests(HotelNo, RoomNo, GLastName, GFirstName, ArriveDate, LeaveDate, NoOfBeds, RatePerDay, OtherCharges)Facilities(HotelNo, Facility, ChargeToUse)Employees(EmpId, SSN, ELastName, EFirstName, Address, StartDate)EmployeePosition(EmpId, Designation, Salary)

HotelNo HotelName, StreetAddress, City, Zip, State, NumberOfRoomsPhone HotelNo HotelNo, RoomNo NoOfBeds, RatePerDay HotelNo, Facility ChargeToUseGuestId GLastName, GFirstNameHotelNo, RoomNo, ArriveDate, LeaveDate GuestId, OtherChargesEmpId SSN, ELastName, EFirstName, AddressSSN EmpId, ELastName, EFirstName, AddressEmpId, StartDate Designation, SalaryEmpId, Designation StartDate, Salary

Question 6: Business rules (100 points)

What are the different types of business rules that can be expressed in an ER model? Give an example of each and clearly explain why it is important to capture these business rules during conceptual design. What is the impact of each rule on the implementation and operation of the database?

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2002 PhD. Core Exam: Part 2MIS Dept, Univ. of Arizona, Tucson, AZ

Wednesday, May 29, 2002Venue: Room 214, McClelland Hall

Time: 9:00 AM – 1:00 PM

INSTRUCTIONS: (Please read them carefully before you begin the exam)

13. The exam will begin promptly at 9:00 a.m. and end promptly at 1:00 p.m. No extensions are allowed.

14. This exam consists of 6 questions. You are required to answer all of them. Please allocate roughly 30 minutes per question and leave some time for checking your answers.

15. Each question is worth 100 points.

16. For each question, state your assumptions clearly.

17. If you are writing by hand in a blue book, please answer each question in a separate blue book. If you are using a word processor, please make sure that you start each new question on a new page. You are allowed to use combinations of the blue book and a word processor file for answering questions.

18. At the top of each question that you answer, please identify two things:

The number of the question that you are answering and

The code name given to you at the beginning of the exam. Do not write your real name anywhere on the exam, and use only your code name.

19. Please make two (2) diskette copies of the files containing your answers if you are using a word processor. Please turn in both diskettes, along with your blue book answers and the exam questions, to the proctor at the end of the exam.

20. You are allowed to take a restroom or lunch break only if no one else is already taking one. You should get the proctor’s consent before taking a break, and also inform him as soon as you return from your break.

21. If you are using a word processor, please make sure that you save your answers frequently. It is your responsibility to ensure that you do not lose work.

22. The exam is CLOSED BOOK. Accessing the web on the computer is NOT allowed and will be severely penalized.

23. Some questions have multiple parts. Make sure you answer all of them and number them properly.

24. You have been provided with MSWORD and POWERPOINT.

GOOD LUCK!!

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QUESTIONS 7 and 8 BELOW ARE BASED ON THE FOLLOWING NARRATIVE OF A BUSINESS PROCESS SYSTEM

The following is a description of a TO-BE process for a music store planning to sell CDs online. The Internet Sales System will have a database of basic information about the CDs that it can sell over the Internet similar to the CD database at each of the retail stores. Everyday the Internet sales system will receive an update from the distribution system that will be used to update this CD database. Some new CDs will be added, some will be deleted and others will be revised (such as have a new price). The electronic marketing (EM) Manager will also have the ability to create and update the information. The sales system will also maintain a marketing database of materials about each CD that will enable online users to learn more about them. Vendors will be encouraged to email marketing materials (music reviews, links to Web sites, artist info, sound clips) that promote their CDs. The EM manager will go through the emails and determine what information to place on the web. He or she will add this information to a marketing materials database (or revise it or delete old information) that will be linked to the Website. Customers will access the Internet Sales System to look for CDs of interest. Some customers will search for specific CDs or CDs by specific artists whereas other customers want to browse for interesting CDs in certain categories (e.g. rock, jazz, classical). When the customer has found all the CDs he or she wants, the customer will check out by providing personal information (including credit card) and order information. The system will verify the customers credit card info with an online credit card center and either accept the order or reject it. Every hour or so, the orders will be pulled out of the order database and sent to the distribution system. The distribution system will handle the actual sending of the CDs to customers; however, when CDs are sent to customers (via UPS or mail), the distribution system will notify the Internet sales system, which in turn will email the customer. Weekly reports can be run by the EM manager to check the order status.

Question 7: (100 points)Context Diagram

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Functional Decomposition Diagram (Shown are 2 levels below Level 0)

A. Draw the Level 1 DFD showing interaction between processes in Level 1 of the diagram above. (30 points)

B. Illustrate the Control Flow on the above DF diagram for the following scenario: (NOTE: You may need to develop additional levels of DFDs or integrate multiple ones for the following)a. Processing a Customer order – (order placement through to order management)

(8 points)b. Failure notification to Manager & Customer (Non-availability of CD in

inventory) (7 points)

C. Convert the above analysis into the following:

a. Identify Key objects, their methods. (at least 2 for each) (25 points)b. What is the relationship between the above methods and the processes in the

DFDs? (10 points)c. Draw Activity (and/or) State diagrams to illustrate the scenarios in B and also

highlight which key objects may be involved. (20 points)

Question 8: (100 points)

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A. Suggest a possible architecture to convert the above analysis into an implementation. For the architecture, You need to show the following:

a. A list of components and for each component outline the elements of analysis that they may contain and their functionality. (18 points)

b. A layout of the components – illustrate the control flow between the components (20 points)

c. List four qualitative properties that may be required for the overall sales system. (12 points)

d. Evaluate the style on the above properties by considering the Order processing scenario described above. (10 points)

B. The CIO of the Music company requires the development of a strategy to implement the system with the ability to innovate in the future, accommodate new technology, low cost overall and minimize risk if possible. Suggest a lifecycle using one of the architectures you describe above. For each lifecycle phase, say in a couple of lines what happens. (40 points)

Question 9: Case Study (100 points)

Assume you have just been given an opportunity to do a case study to answer some of the research questions you posed in your 611b paper, or a phenomenon that you would like to investigate.

a) Give three (3) examples of different kinds of case studies and briefly describe the differences between them. (10 pts)

b) Describe your case study. (40 pts)

c) What kind of sample would you select for you study and why? (10 pts)

d) Describe how you would go about building a theory using case study? What steps would you take to ensure that your research is of high quality? (30 pts)

e) What are the strengths and weaknesses of doing case research? (10 pts)

Question 10: Empirical research (100 points)

a) Why is it so important to have comparisons when conducting empirical research? Give an example of what happens when you do not have a comparison. (35 pts)

b) According to Martin ("Doing Psychology Experiments") and others, the major advantage of a factorial experiment is that we can study interactions. What is an interaction? Why do interactions help in theory building? (30 pts)

c) Having read and discussed Baron & Kenny ("The Moderator-Mediator Variable Distinction in Social Psychological Research"), what is a moderator variable? What is a mediator variable? Give an example of each. (35 pts)

Question 11: (100 points)

A. (40 Pts.) Describe your dissertation topic or preliminary paper even if it is hypothetical. The write-up should be in the form of an elevator speech. It should be no longer than about 30 seconds or 1 page in

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length. The speech should include a description of the overall or general problem and the specific problem you are going to solve. Your answer should reflect that you understand what makes up a good research problem and you know how to present what you are researching.

In the 696A class we discussed the importance of having a good chart, figure or graphic.

B. (20 Pts.) Why is a good chart, figure or graphic important?

C. (20 Pts.) List the characteristic of a good chart, figure or graphics.

D. (20 Pts.) Give an example of an effective graphic, chart or figure. You can use a graphic from your dissertation topic or your favorite graphic from another class.

Question 12: (100 Points)

A. (42 Pts.) Listed below are biases that often occur in experiments and research projects. Define (4 Pts.) and give an example (3 Pts.) of:

(1.) Truth Bias(2.) Hindsight Bias(3.) Visual Bias(4.) Availability Bias(5.) Recency Bias(6.) Order Bias

B. (28 Pts.) The following statement is based upon the book Fortune Sellers by William Sherden:

Predicting the future is easy if it is done right! Why? Discuss.

C. (30 points) All of the names listed in the chart below are well known contributors to the field of MIS, Computer Science, Management or Economics. What is each researcher known for (be specific); what organization is he/she affiliated with; also, where did he/she receive his/her graduate education? An example is provided for you. (30 points).

Person Research Area Current Organization Graduate Education(Example) Sudha Ram Data Base Systems University of Arizona University of IllinoisPoints per name = 2 1 point ½ point ½ point1. Lynda Applegate

2. Peter Chen

3. Eric Clemons

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4. Gordon Davis

5. Gerry Desanctis

6. Sarah Kiesler

7. John King

8. Don Knuth

9. Stuart Madnick

10.Wanda Orlikowski

11. Herb Simon

12. Hal Varian

13. Andy Whinston

14. Joe Valacich

15. Robert Zmud

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