华农-计算机科学导论2011_试卷B_含答案

2011学年第1学期 考试科目：计算机科学导论 考试类型：闭卷 考试时间： 120 分钟

学号 姓名 年级专业 2011(软件学院)软件工程

题 号 得 分 评阅人 1 2

3 总分 1. Fill-in-the-blank / short-answer questions

(45 marks, 15questions. 3 marks each blank/question) 得分 (1) A ________________ is a circuit that produces an output value of _______ or ________, which remains constant until a temporary pulse from another circuit causes it to shift to the other value.

Flip-flop, 0, 1

(2) The result of the operation

11100000

is ___________________.

(3) The equivalent tow’s complement form using eight-bit pattern of the base ten representation -12 is ______________________.

11110100

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(4) A ______________ is a memory area used for the temporary storage of data, usually as a step in ________________ the data.

Buffer, transferring

(5) ASCII is the abbreviations of ______________________________________________.

American Standard Code for Information Interchange

(6) Data compression schemes fall into two categories. Some are ____________, others are _____________. ____________ schemes are those that do not lose information in compression process. ______________ schemes are those that may lead to the loss of information.

lossless, lossy, lossless, lossy

(7) CISC means ______________________________________________.

Complex Instruction Set Computing/Computer

(8) What is the stored program concept?

The idea of storing a computer’s program in its memory or

A program can be encoded as bit patterns and stored in main memory.

(9) A machine’s instruction can be categorized into three groups, what are they?

The data transfer group, the arithmetic/logic group and the control group.

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(10) A machine instruction consists of two parts: the __________, which specifies which

operation to execute; the ___________, which gives more detailed information about the operation.

op-code, operand (11)

An operating system is the software that controls the overall operation of a computer.

It provides the_____________ by which a user can store and retrieve files, provide the _____________ by which a user can request the execution of programs, and provides the _____________ necessary to execute the programs requested.

means, interface, environment. (12)

The need to share____________ and ____________ among different computers has

led to linked computer systems, called networks, in which computers are connected so that data can be transferred from machine to machine. A computer network is often classified as being either a ____________ area network (LAN), a metropolitan area network (MAN), or a wide area network (WAN).

information resources, local (13)

What are the Internet Software Layers?

Link, Network, Transport and Application (14)

What is the difference between a homogeneous array and a heterogeneous array?

All components of a homogeneous array have the same type. (15)

List the classes Θ(n2), Θ(㏒n), Θ(n), and Θ(n3) in decreasing order of efficiency.

The classΘ(㏒n) is most efficient, followed by Θ(n), Θ(n2), and Θ(n3).

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2. Answer the questions by drawing a diagram or a figure.

(25 marks, 5 questions. 5 marks each question) 得分 (1) Draw a diagram to summarize the classification of software.

(2) Draw a diagram to show a conceptual representation of memory-mapped I/O.

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(3) Draw a diagram to show the communication over a bus network.

(4) Draw a diagram to show the software life cycle.

Note: Modification can also be Maintenance.

(5) Give a figure for the conceptual layers of a database implementation

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3. Answer the flowing questions.

(30 marks, 6 questions, 5 marks each question) 得分

(1) What is the definition of an algorithm?

An algorithm is an ordered set of unambiguous executable steps that defines a terminating process.

(2) What are three units of a CPU? What circuitries do they include respectively?

A CPU consists of three parts: the arithmetic/logic unit, which contains the circuitry that performs operations on data; the control unit, which contains the circuitry for coordinating the machine’s activities; and the register unit, which contains data storage cells that are used for temporary storage of information within the CPU.

(3) List Polya’s Problem Solving Steps.

Step 1: Understand the problem

Step 2: Devise a plan for solving the problem Step 3: Carry out the plan

Step 4: Evaluate the solution for accuracy and for its potential as a tool for solving other problems.

(4) What are the characteristics of high-level languages?

1. Each primitive corresponds to a sequence of machine language instructions 2. Machine independent (mostly)

3. Converted to machine language by a program called a compiler

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(5) What is the goal of software engineering?

The goal of software engineering is to find principles that guide the software development process and lead to efficient, reliable software products.

(6) What is difference between the schema and the subschema in a database? What is a DBMS?

A schema is a description of the structure of an entire database, used by database software to maintain the database

A subschema is a description of only that portion of the database pertinent to a particular user’s needs, used to prevent sensitive data from being accessed by unauthorized personnel.

Database Management System (DBMS): A software layer that manipulates a database in response to requests from applications.

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