Company ABC has 170 personal computers. Each working computer has a 6% probability, independent of all other computers, of encountering a hardware problem on any given day. Most hardware problems require 3/4 of an hour of attention from a computer support technician (CST). Each problem that occurs, however, has a 30% chance of developing into a more serious problem requiring an extra 2 hours of attention from a CST. Each CST can spend up to 6 hours per day fixing problems, and costs the company $300 per day. Every CST hired must be paid their full salary each day, whether or not they have sufficient work to keep them busy. If the company does not have enough CST's to solve all the problems occurring on a given day, it hires an outside firm that charges $110 per hour.

As public pressure for corporate accountability and ethical behavior increases, businesses and industries are putting more emphasis on establishing and publicly sharing their codes of ethics with stakeholders. Businesses adopt these to help guide corporate decision-making, but they can be used against them when businesses stray from their stated codes. Stuart Gilman, president of the Ethics Resource Center in Washington, D.C., said that, for Enron, "ethics was simply a piece of paper with three Psprint, post [in the company lunchroom], and then pray that something is actually going to happen."

In order to complete this discussion assignment, you will need to:

Select a company that you are familiar with as a customer, employee, or investor. Locate a copy of the company's code of ethics. You can generally find this on their Web site in the "About Us" section of the site. Make sure to get the link/URL for the code of ethics when you are there, because you need to include that link in your initial post. Do some general research about the company you selected regarding possible activities by the company or its leadership that either violates or supports this code of ethics. You will use this information to support the position you take in your initial post. For Discussion

Please respond to ALL of the following questions in your initial post:

Share the company you selected, the link/URL to the company's code of ethics, and your reason for selecting the company. Based on your reading of the company's code of ethics, and your research into the activities of the company, what grade would you give them for adhering to their code of ethics? Use the same grading scale you are evaluated by: A, B, C, D, F. Provide your reasoning for assigning them the grade you did. Now, consider the industry in which the company operates (e.g., Disney in the entertainment industry). Are there forces at work in that industry that make it easier or harder to be ethical?

(a) Give a brief description of the three segments that make up the Global Positioning System (GPS), and their main software, hardware and information components. [5 marks] (b) What are the main timing observables from the GPS signals, and how can they be processed to give time, position and velocity? [5 marks] (c) What data is broadcast in the GPS signals, and how is it used by receivers? [5 marks] (d) Explain some of the ways in which an additional communication channel can be used to assist a GPS receiver, and what advantages the user might observe. [5 marks] 3 Digital Communication II (a) Describe the OSI (Open Systems Interconnections) reference model and discuss examples of the networking functions normally associated with each component. [14 marks] (b) What do we mean by layer violation? Discuss some of the reasons that might lead a pragmatic protocol implementer to engage in layer violation and illustrate with an example. [6 marks] 4 Distributed Systems (a) You have been asked to design an event composition and aggregation service to operate above publish/subscribe middleware to be deployed in various environmental monitoring scenarios. Your service is to advertise and publish high-level events of interest to applications. It may subscribe to any published events in the domain of deployment. Your service may itself be distributed. Identify a list of technical design issues you would raise with your client prior to specifying the service in detail. [12 marks] (b) By means of a diagram illustrate the use of vector clocks to implement the delivery in causal order of multicast messages among members of a closed, unstructured process group. Include an explanation of the message delivery algorithm. [8 marks] 3 (TURN OVER) CST.2008.7.4 5 Comparative Architectures (a) Why are multi-level caches often used in preference to a single larger cache? How might the parameters of an L1 and L2 data cache typically differ? [8 marks] (b) What does it mean if a cache memory hierarchy adopts a multi-level inclusion policy? What might influence a decision on whether to adopt a multi-level inclusion or exclusion policy? [6 marks] (c) A processor's multi-level cache hierarchy consists of L1 and L2 caches with the following characteristics: L1 miss rate is 2%, L1 hit time is 2 cycles, local L2 miss rate is 20%, L2 hit time is 10 cycles, L2 miss penalty is 200 cycles. It is suggested that reducing the size of the L1 cache will improve overall performance by reducing the L1 cache's hit time to a single cycle. The reduction in L1 cache size will increase the L1's miss rate to 3%. Will average memory access time actually be improved? Clearly state any formulae you use and show your calculations. [6 marks] 4 CST.2008.7.5 6 Artificial Intelligence II We have a simple, propositionalised planning problem and we suspect that we might be able to solve it using the GraphPlan algorithm. The problem is as follows. Action A has preconditions {X} and effects {X, Z}, action B has preconditions {Y } and effects {X, Y }, and action C has preconditions {X, Y, Z} and effects {W}. The start state for the problem is {W, X, Y, Z} and the goal is {W}. (a) Labelling the start state as level S0 and the first action level as A0, draw the planning graph for this problem up to and including level S2. Use an entire sheet of paper for this diagram. [5 marks] (b) Describe each of the five kinds of mutex link that can appear in a planning graph, and add an example of each to the diagram drawn in part (a), clearly labelling it to show which kind of mutex link it is. [10 marks] (c) What is the level cost of a literal in a planning graph? Explain why this measure of cost might perform poorly as a measure of how hard the literal is to achieve. [2 marks] (d) Will GraphPlan be able to extract a working plan from the diagram you have drawn in parts (a) and (b)? Explain your answer. You may if you wish add further mutex links to your diagram at this stage.

A firm's beta can be estimated from the slope of the characteristic line (best fit line). Following a) to i) to estimate the betas and costs of equity for Polaris and Coca-Cola Inc. 1. Estimate raw beta and adjusted beta () - (Please save Excel file(s) a) Go to finance.yahoo.com, enter the symbol for Polaris (PII), and click on Search. Click on Historical Data; then enter starting and ending dates that correspond to the most recent five years. Download five years of monthly adjusted closing prices for Polaris. Calculate monthly returns for the past 5 years. b) Repeat the process to get comparable data for the S&P 500 Index (symbol ^GSPC). Download the data and copy it into the same spreadsheet as Polaris with dates aligned. Calculate the monthly returns for the past 5 years. c) Run regression using Data Analysis Tool with the monthly return for Polaris as the Input Y Range and the monthly return for S&P 500 as the Input X Range. Report the beta of Polaris. Is this a raw beta or adjusted beta? d) What is the adjusted beta for Polaris using Blume (1971) adjustment?

2. Identify market return (Rm): e) Download monthly adjusted closing prices for S&P 500 index (ticker symbol ^GSPC) for the past 15 years from finance.yahoo.com and calculate monthly returns of S&P 500 index. f) Calculate the average monthly return of S&P 500 index based on the fifteen years' data in e) and annualize the monthly index return to annualized return of the index.