Computer and Number Systems

1. You have been hired to develop a website-based sales system for a large international retail firm. List and describe at least fourfeatures that are specific to the Web design of your system and customer service important to consider if your system is to be successful at attracting and keeping customers living outside of the US. Include not only characteristics of the user interface, but those issues that must be uniquely addressed to successfully service your non-US customers.

The first characteristic concerns the need to understand the critical concept of colors and the potential significance. Red for example in a US environment may signify an error or warning whereas other cultures may use green or black for the same purpose.

Secondly, any symbols or flags should be treated with caution due to certain connotations causing problems in certain cultures – the thumbs up in Iran for example would be highly offensive.

Thirdly payment options should also take into account cultural considerations, with some countries preferring electronic payments while others are using money orders – there should be appropriate payment options for each country that is being served by the website.

It would also be advisable to create different versions of content for each specific culture/region that will be using the site – in this way relevant analogies and formatting of content can be adjusted accordingly.

 

2. In order to receive credit for these problems, you must show all of the steps you took to arrive at your answers.

(c) Convert the following decimal number to binary:

(d) Convert the following binary number to decimal:

(c)Convert the following hexadecimal number to decimal:

(d) Convert the following binary number to hexadecimal:

3. ASCII, Unicode, and EBCDIC are, of course, not the only numeric / character codes. The Sophomites from the planet Collegium use the rather strange code shown in the Figure below. There are only thirteen characters in the Sophomite alphabet, and each character uses a 5-bit code. In addition, there are four numeric digits, since the Sophomites use base 4 for their arithmetic. Given the following Sophomitesequence, what is the corresponding binary message being sent by the Sophomites?

4. Define memory cache write-through and write-back techniques and describe the advantages and disadvantages of each.

Input / Output

5. Answer the follow questions about interrupts.

a. Describe in detail the steps that occur when a system receives an interrupt.

b. Describe how these steps differ in the case when a system receives multiple interrupts

6. Answer the following questions about clusters.

a.Describe how you might use a cluster to provide fault-tolerant computing

b.Describe how you might use a cluster architecture to provide rapid scalability for a Web-based company experiencing rapid growth.

7. Answer the following questions about communication protocols.

a.Using the operations of UDP (User Datagram Protocol) and TCP (Transmission Control Protocol) as a basis, carefully explain the difference between connectionless and connection-oriented communication.

b. If you were ordering a number of items from an online seller, such as amazon.com, which Protocol (TCP or UDP) would you recommend and explain why.

8. In the context of network security,

a.explain the purpose of non-repudiation.

b.How does non-repudiation differ from authentication?

c.(4 pt) Create a business scenario that illustrates the importance of each.

9.Circleor highlight the correct answer to the following questions / statements about data communications:

(a)What characteristic of an analog signal is measured in Hertz, or cycles per second?

a. Amplitude c. Phase

b. Frequency d. Skew

(b)What measurement unit describes the speed and capacity of a communication channel?

a. Throughput c. Response Time

b. Access Time d. Data Transfer Rate

(c)____ can be produced by a variety of sources, including electric motors, radio equipment, and nearby power transmission or communication lines.

a. EMI c. Distortion

b. Attenuation d. Signal/noise (S/N) ratio

(d)A(n) ____ can extend the range of an electrical signal by boosting signal power to overcome attenuation.

a. repeater c. amplifier

b. return wire d. signal wire

(e)Which of the following does not allow multiple messages to be carried on a single channel?

a. time division multiplexing c. packet switching

b. frequency division multiplexing d. half-duplex

10. Answer the following questions about user interfaces:

(a) List and explain at least two of the definite advantages to the use of a command line interface (CLI) over other types of interfaces.

File Management

11. Answer the following:

a.Use the following four processes that have arrived in the ready queue in the sequence shown below and answer the following about process scheduling:

• Process      1 has a total run time of 25 seconds and a priority of 2, but it will      require 15 seconds of I/O after 10 seconds of execution
• Process      2 has a total run time of 30 seconds, a priority of 1, but it will require      10 seconds of I/O after 20 seconds of execution
• Process      3 has a total run time of 15 seconds and a priority of 3
• Process      4 has a total run time of 20 seconds, a priority of 2, but it will require      15 seconds of I/O after 5 seconds of execution

(ii)If the round robinscheduling algorithm is used, which process will finish first? At what time will it complete?

(i)Both shortest job first and non-preemptive priority queue scheduling algorithms will complete all four