Case studies offer a practical problem for which you supply a written solution. There is not always a specific right or wrong answer to these cases. They are intended to encourage you to review the chapter material and delve deeper into the topics you have learned.

One of the primary reasons networks were built was to facilitate the sharing of information. Organizations want to share files and printers in Windows, Linux,and Mac OS X. However, organizations need to ensure they maintain secure access to shared files. This is often accomplished using user and group accounts, with assigned permissions. These permissions determine who can access the shared resources and what type of access they have.

Consider a GaAs p-n junction diode. The p-type acceptor is Zn, with a dopant concentration of 2 x 10^17 cm^-3 and the n-tpye donor is Si, with a dopant concentration of 5 x 10^16 cm^-3. Working at temp= 300 K.

a) Calculate the Fermi Level in the p-type material. Assume that the hole density is equal to the density of the p-dopant atoms.

b) Performing the same calculation for the n-type material gives a fermi level of 1.363 eV. What is the zero-bias built- in potential at the junction?

c) Calculate the width of the depletion zone for this case

A craftsman builds two kinds of birdhouses, one for wrens and one for bluebirds. Each wren birdhouse takes 3 hours of labor and 4 units of lumber. Each bluebird house requires 2 hours of labor and 10 units of lumber. The craftsman has available 80 hours of labor and 100 units of lumber, and he wants to build at least 6 wren houses. Wren houses profit $8 each and bluebird houses profit $16 each. How many of each kind of birdhouses should be built in order to maximize total profit?  Formulate this as a linear programming problem (i.e., DO NOT solve it.)

Write a program that takes a string from the user, identifies and counts all unique characters in that given string. You are bound to use only built-in string functions where necessary. For identification of unique characters and for counting of the characters make separate functions.

For character identification

Develop a program that takes a string argument, and returns an array containing all unique characters.

For character counting

Develop a program that takes an array returned from above function as an argument along with the given string and return an array containing the total count of each uniquely identified character present in the argument array.

(Dev Cpp +Multifing )

Consider a GaAs p-n junction diode. The p-type acceptor is Zn, with a dopant concentration of 2 x 10^17 cm^-3 and the n-tpye donor is Si, with a dopant concentration of 5 x 10^16 cm^-3. Working at temp= 300 K.

a) Calculate the Fermi Level in the p-type material. Assume that the hole density is equal to the density of the p-dopant atoms.

b) Performing the same calculation for the n-type material gives a fermi level of 1.363 eV. What is the zero-bias built- in potential at the junction?

c) Calculate the width of the depletion zone for this case

Over the past several years, decommissioned U.S. warships have been turned into artificial reefs in the ocean by towing them out to sea and sinking them. The thinking was that sinking the ship would conveniently dispose of it while providing an artificial reef environment for aquatic life. In reality, some of the sunken ships have released toxins into the ocean and have been costly to decontaminate. In the late 1990s, at least two international conventions have made it all but impossible to export used warships for salvage without removing all military equipment, conducting a complete cleanup and cutting the ship into such comparatively small pieces as to make the entire exercise relatively expensive.

The new environmental regulations have made disposal of ships an expensive project. The United States has hundreds of mothballed warships, presenting an extremely expensive problem for military authorities and the government. Now the U.S. government is taking bids to instead dismantle and recycle ships that have recently been decommissioned (but have not been sunk yet.)

Assume that a recently decommissioned aircraft carrier, the USS Blaze, is estimated to contain 40 tons of recyclable materials able to be sold for approximately $32.8 million. About 90% of the value in old ships is the metals, including steel, copper, copper alloys, and lead that can be removed, sold for remelting, and reformed into new metal products. There are also some high-value metals; such as, nickel alloys, stainless steel, and titanium that can be found in some parts of all warships but may be present is such small quantities that recovery and resale may not be cost effective. The low bid for dismantling and transporting the ship materials to appropriate facilities is $34.5 million. Recycling and dismantling the ship would create about 500 jobs for about a year on the West Coast area. This geographic area has been experiencing record-high unemployment rates in recent years.

As an alternative, reefing these ships would create new habitats for underwater life and can be done using newer environmentally safe methods. These new artificial reefs would enhance fishery resources and facilitate the access and utilization by recreational and commercial fishermen. Artificial reefs can also increase tourism by attracting sport divers for recreational purposes. Academic organizations may be interested in using the site to study fish and other marine life which may open the door for more funding from these research activities. Research has shown that a new reef will attract 60,000 – 70,000 divers and add more than 10 million to the local tourism industry. Research has also shown that artificial reefs can substantially increase the population of reef-associated species. Within months the G. B. Church artificial reef in British Columbia had hundreds of encrusted individuals on its hull and within 2.5 years had seen an increase of nearly 100 species.

Reefing the ship would cost an estimated 800K (or $0.8 million) which includes cleaning of the vessel of toxics, oils and greases, PCB containing electrical and electronic equipment and other readily removable PCB containing equipment, local towing and docking, preparation (unspecified) and other incidental overhead items, insurance, and making the vessels safe for divers (diverizing). There will also be yearly maintenance costs in perpetuity.

1. Is it more financially advantageous to sink the ship or to dismantle and recycle it? Show your calculations. (Worth 4 pts.)

Recycling=$32,800,000

Dismantle and transport=$34,500,000

Reefing the ship= $800,000

To dismantle and recycle the ship would cost, 34,500,000-32,800,000=$1,700,000, while sinking/reefing the ship would cost $800,000. This means that it would be more financially advantageous to sink or reef the ship because it would save a total of $900,000.

2. From a sustainability standpoint, what should be done with the decommissioned aircraft carrier? (Worth 4 pts.)

3. List some of the other quantitative and qualitative factors that should enter into this analysis. (Worth 10 pts.)

4. As a taxpayer(s), which action would you prefer (sink or recycle)? Defend your answer. (Worth 4 pts.)

You would like to setup a website to sell towels, linens, pottery, and tableware from Portugal and are examining services for hosting small business internet storefronts. Your website should be able to take secure credit card payments and calculate shipping costs and taxes. Initially, you would like to display photos and descriptions of 40 products. Visit Yahoo! Small Business, GoDaddy, and iPage and compare the range of e-commerce hosting services they offer to small businesses, their capabilities and their costs.

Examine the tools they provide for creating an e-commerce site.

Compare these services and decide which you would use if you were actually establishing a web store.

Write a brief report indicating your choice and explaining the strengths and weaknesses of each service.

Internal Control : Performance Measures

Essex Engineering

Topic: Performance measures,

Essex is an industrial company with three divisions. Both the Midland Division and the North Division are long established. Senior managers are concerned that these divisions have a high percentage of products that are near the end of their product life-cycle. Forecast sales increases over the next 5 years is expected to be in the region of 4-5% per annum.

The East Division was acquired in 1999 and senior managers are optimistic that this division has very good growth potential. Most of the senior managers at this division have experience of working at the other divisions.

Since 1999 the head office has ranked all divisions according to return on investment (ROI) and residual income (RI). All managers believe that the rankings are important for future promotions and career development.

A small number of other performance measures are also used by managers. These include

These performance measures were agreed by all managers in 1999. At the time it was thought that managers should focus on only a small number of measures.

2002

The managers at the divisions provided the following information for the head office.

Selected data from the budgeted Management Accounts to 31 December 2002

Other measures

The head office has estimated that the group cost of capital is 10%

Ranking divisions in 2000

In 2000 the data on controllable and non-controllable costs and investments will be used to rank divisions.

Questions

Question 1

Based on the data provided comment on the relative financial performance of the two divisions and discuss how the ranking of the divisions changes if controllable and non-controllable costs and capital employed are analysed. (provide the calculation to prove your standpoint)

Question 2

Evaluate the choice of performance measures for the 3 divisions

Question 3

Identify and evaluate the difficulties faced by managers when measuring capital employed for a division.

Question 4

Discuss how using ROI can result in managers making poor investment decisions.

ROI has some built in biases that can lead managers to make poor decisions. First, ROI requires that all costs and benefits be stated in dollars. Because it is usually easier to quantify costs than benefits, ROI measurements can be biased in a way that gives undue weight to costs. Second, ROI focuses on benefits that can be predicted. It also tends to emphasize short run benefits over long run benefits. This biases ROI calculations to weigh short term costs and benefits more heavily than long term costs and benefits.

Question 5

Discuss the particular problems multinational companies have when evaluating the performance of divisions.   

8. You are tasked with trying to restore the biodiversity in a national park. How might your understanding of keystone species affect your management plans?

9. Earth can support more people who are vegetarians than people who regularly consume meat. Why do you think this is?

10. If only 10% of the energy available in a plant is turned into body tissue of a cow, what happens to the other 90%?

11. Which do you think would be a more stable ecosystem: one where each species has only one connection to another species, or one where each species has five connections to other species? Explain your answer.

12. Which community would support the greatest diversity of species—a community composed of species with broad ecological niches or a community composed of species with narrow, specialized ecological niches? Explain your answer.