Файл: Н.Н. Курпешко Английский язык Методические указания для обучения студентов II курса (III семестр) специальности 180400.pdf

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I. Which of the listed below statements are true/false. Specify your answer using the text.

1)There are still not so many users of the Internet.

2)There is information on all sorts of topics on the Internet, including education and weather forecasts.

3)People can communicate through e-mail and chat programs only.

4)Internet is tens of thousands of networks which exchange the information in the same basic way.

5)You can access information available on the World Wide Web through the Web browser.

6)You need a computer (hardware) and a special program (software) to be a WWW user.

7)You move from site to site by clicking on a portion of text only.

8)Every time the user wants to move somewhere on the web he/she needs to step by step enter links and addresses.

9)Films and pictures are not available on the Internet.

10)Radio and TV-broadcasting is a future of Internet. They're not available yet.

II. Define the following using the vocabulary:

1)Internet

2)World Wide Web

3)Web browser

4)Internet provider

5)Hyperlinks

III. Find the equivalents:

1)Объем ресурсов и услуг, которые являются частью WWW, растет чрезвычайно быстро.

2)Каждая ссылка, выбранная вами, представляет документ, графическое изображение, видеоклип или аудио файл где-то в Интернет.

3)Интернет может быть также использован для целей развлечения.

4)Вы получаете доступ к ресурсам Интернет через интерфейс или инструмент, который называется веб-браузер.

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5)Вся эта деятельность возможна благодаря десяткам тысяч компьютерных сетей, подключенных к Интернет и обменивающихся информацией в одном режиме.

6)Пользователи общаются через электронную почту, дискуссионные группы, чэт-каналы (многоканальный разговор в реальном времени) и другие средства информационного обмена.

IV: Match the following:

1)You access the information through one interface or tool called a...

2)People connected to the WWW through the local... have access to a variety of information.

3)The user doesn't need to know where the site is, the... follows the...

4)In 1996 there were more than 20 million users of the...

5)Each... provides a graphical interface.

6)Local... charge money for their services to access... resources.

V.Words to match with:

1) web browser, providers, link, WWW,

Questions for group discussion:

1)Some people think that Internet is very harmful, especially for young people, because it carries a lot of information about sex, drugs, violence and terrorism. Do you think that some kind of censorship is necessary on the WWW?

2)World famous authors and publishers say that the Internet violates their copyright because Web-programmers put all kinds of books, pictures, music, films and programs free on the Internet and this reduces their sales and profits.

3)Has anyone in your group experience working on the Internet? Ask

them a) about the difficulties they had; b) useful information retrieved; c) fun they got? Why so few people have experience working on the Internet?

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IV. FAMOUSE PEOPLE OF SCIENCE AND ENGINEERING

Bill Gates

William Henry Gates was born in Seattle, Washington, in 1955.

He is an American business executive, chairman and chief executive officer of the Microsoft Corporation. Gates was the founder of Microsoft in 1975 together with Paul Allen, his partner in computer language development. While attending Harvard in 1975, Gates together with Allen developed a version of the BASIC computer programming language for the first personal computer.

In the early 1980s Gates led Microsoft's evolution from the developer of computer programming languages to a large computer software company. This transition began with the introduction of MS-DOS, the operating system for the new IBM Personal Computer in 1981. Gates also led Microsoft towards the introduction of application software such as the Microsoft Word processor.

Much of Gates' success is based on his ability to translate technical visions into market strategy. Although Gates has accumulated great wealth from his holdings of Microsoft stock, he has been known as a tough competitor who seems to value winning in a competitive environment over money. Gates still continues to work personally in product development at Microsoft.

I. Choose an answer — a or b.

1. A mouse is

a)a small furry animal with a long tail

b)a small box used to operate a computer 2. To surf is

a)to ride on board of the waves of the sea

b)to move around the Internet 3. D bug is

a)a small insect

b)an error in a computer programme 4. A flame is

a)a red or yellow burning gas seen when something is on fire

b)an unfriendly or rude e-mail

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5. To boot is

a)to kick

b)to start a computer 6. A geek is

a)someone who bites the heads off alive chickens as part of a show

d)a person who knows everything about computers

II. Choose an answer — a, b or c.

1.What do you use a modem for? a) to print a document

b) to play music on your computer

c) to send messages along a telephone line

2.What do you use when you want to look for sites on the world wide

web?

a) a browser b) a CD ROM c) a printer

3.What can you use the Internet for?

a)to delete a file from your computer

b)to help you find information and communicate with people

c)to make your computer work faster

4. What do you use a scanner for?

a)to transfer photos and texts to your computer

b)to find certain files on the Internet

c)to clean your computer

5. How much is a gigabyte?

a)1,000 megabytes

b)100 megabytes

c)1000 bytes

III. Match the words (or phrases) to the definitions.

1.chat room

2.e-commerce

3.joystick

4.cyberspace

5.desktop

6.multitasking

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a)the ability of a computer to run several programmes at once

b)the screen you see after you've switched your computer

c)an area on the Internet where people can communicate with each other in 'real time'

d)the business of buying and selling goods and services on the Internet

e)a stick which helps you move In computer games

f)the imaginary place where electronic messages, information pictures, etc. exist when they are sent from one computer to another

IV. True or False?

1.You use the Internet, you need a computer, a radio and a phone line.

2.You can use the Internet to read newspapers and magazines.

3.You cannot use the Internet to play video games.

4.The Internet can help you to do shopping.

5.You can use the Internet to 'chat' with people and make new friends.

6.You need a CD to send e-mail.

7.Multimedia pages with pictures, music and video make downloading

slow.

V. Complete the sentences by using the words in the box below.

INTERNET TV

Is it possible to have a TV set, a (1)_________ and the Internet all in one?

With the advent of Internet TV it has become a reality.

Imagine watching a film on TV and getting (2)________ on the actors in the film at the same time!

To enter (3)_______ addresses and write (4)________ you use a remote control and an (5)____________ keyboard or an optional wireless keyboard.

By clicking a button, you can also read adverts, (6)________ with a friend, plan your holiday and play your favourite (7)________ games.

In the future you'll be able to change the plot of the film you're watching and meddle in the private lives of the characters.

The next (8)__________of Internet TVs will also have a smart-card for shopping, banking and other (9)_____________activities.

Web information interactive e-mail on-screen chat PC generation video

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UNIT VIII

Automation

1.1. Introduction

Engineering is concerned with understanding and controlling the materials and forces of nature for the benefit of mankind. Control system engineers are concerned with understanding and controlling segments of their environment, often called systems, in order to provide useful economic products for society. The twin goals of understanding and control are complementary because, in order to be controlled more effectively, the systems under control must be understood and modeled. Furthermore, control engineering often must consider the control of poorly understood systems such as chemical process systems. The present challenge to control engineers is the modeling and control of modern, complex, interrelated systems such as traffic-control systems, chemical processes, and robotic systems. However, simultaneously, the fortunate engineer has the opportunity to control many very useful and interesting industrial automation systems. Perhaps the most characteristic quality of control engineering is the opportunity to control machines, and industrial and economic processes for the benefit of society.

Control engineering is based on the foundations of feedback theory and linear system analysis, and integrates the concepts of network theory and communication theory. Therefore control engineering is not limited to any engineering discipline but is equally applicable for aeronautical, chemical, mechanical, environmental, civil, and electrical engineering. For example, quite often a control system includes electrical, mechanical, and chemical components. Furthermore, as the understanding of the dynamics of business, social, and political systems increases, the ability to control these systems will increase also.

A control system is an interconnection of components forming a system configuration that will provide a desired system response. The basis for analysis of a system is the foundation provided by linear system theory, which assumes a cause-effect relationship for the components of a system. Therefore a component or process to be controlled can be represented by a block. The input-output relation represents the cause and effect relationship of the process, which in turn represents a processing of the input signal to provide an output signal variable, often with a power amplification. An

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open-loop control system utilizes a controller or control actuator in order to obtain the desired response.

In contrast to an open-loop control system, a closed-loop control system utilizes an additional measure of the actual output in order to compare the actual output with the desired output response. The measure of the output is called the feedback signal.

Figure 1. 3. Closed-loop feedback control system.

A standard definition of a feedback control system is as follows: A feedback control system is a control system that tends to maintain a prescribed relationship of one system variable to another by comparing functions of these variables and uthing the difference as a means of control.

A feedback control system often uses a function of a prescribed relationship between the output and reference input to control the process. Often the difference between the output of the process under control and the reference input is amplified and used to control the process so that the difference is continually reduced. The feedback concept has been the foundation for control system analysis and design.

Due to the increasing complexity of the system under control and the interest in achieving optimum performance, the importance of control system engineering has grown in this decade. Furthermore, as the systems become more complex, the interrelationship of many controlled variables must be considered in the control scheme.

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A common example of an open-loop control system is an electric toaster in the kitchen. An example of a closed-loop control system is a person steering an automobile (assuming his or her eyes are open).

1.2. History of Automatic Control

The use of feedback in order to control a system has had a fascinating history. The first applications of feedback control rest in the development of float regulator mechanisms in Greece in the period 300 to 1 B. C. The water clock of Ktesibios used a float regulator. An oil lamp devised by Philon in approximately 250 B. C. used a float regulator in an oil lamp for maintaining a constant level of fuel oil. Heron of Alexandria, who lived in the first century A. D., published a book entitled Pneumatica, which outlined several forms of water-level mechanisms using float regulators.

The first feedback system to be invented in modern Europe was the temperature regulator of Cornelis Drebbel (1572-1633) of Holland. Dennis Papin [1647-1712] invented the first pressure regulator for steam boilers in 1681. Papin's pressure regulator was a form of safety regulator similar to a pressure-cooker valve.

The first automatic feedback controller used in an industrial process is generally agreed to be James Watt's flyball governor developed in 1769 for controlling the speed of a steam engine. The all-mechanical device, measured the speed of the output shaft and utilized the movement of the flyball with speed to control the valve and therefore the amount of steam entering the engine. As the speed increases, the ball weights rise and move away from the shaft axis thus closing the valve. The flyweights require power from the engine in order to turn and therefore make the speed measurement less accurate.

The first historical feedback system claimed by the Soviet Union is the water-level float regulator said to have been invented by I. Polzunov in 1765 [4]. The level regulator system is shown in Fig. 1. 7. The float detects the water level and controls the valve that covers the water inlet in the boiler.

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Figure 1. 6. Watt flyball governor.

Figure 1. 7. Water-level float regulator.

The period preceding 1868 was characterized by the development of automatic control systems by intuitive invention. Efforts to increase the accuracy of the control system led to slower attenuation of the transient oscillations and even to unstable systems. It then became imperative to develop a theory of automatic control. J. C. Maxwell formulated a mathematical theory related to control theory using a differential equation model of a governor. Maxwell's study was concerned with the effect various system parameters had on the system performance. During the same period, I. A. Vyshnegradskii formulated a mathematical theory of regulators.

Prior to World War II, control theory and practice developed in the United States of America and Western Europe in a different manner than in

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the USSR and Eastern Europe. One main impetus for the use of feedback in the United States was the development of the telephone system and electronic feedback amplifiers by Bode, Nyquist, and Black at the Bell Telephone Laboratories. The frequency domain was used primarily to describe the operation of the feedback amplifiers in terms of bandwidth and other frequency variables. In contrast, the eminent mathematicians and applied mechanicians in Russia inspired and dominated the field of control theory. Therefore, the Russian theory tended to utilize a time-domain formulation using differential equations.

A large impetus to the theory and practice of automatic control occurred during World War II when it became necessary to design and construct automatic airplane pilots, gun-positioning systems, radar antenna control systems, and other military systems based on the feedback control approach. The complexity and expected performance of these military systems necessitated an extension of the available control techniques and fostered interest in control systems and the development of new insights and methods. Prior to 1940, for most cases, the design of control systems was an art involving a trial-and-error approach. During the decade of the 1940s, mathematical and analytical methods increased in number and utility, and control engineering became an engineering discipline in its own right.

Frequency-domain techniques continued to dominate the field of control following World War II with the increased use of the Laplace transform and the complex frequency plane. During the 1950s, the emphasis in control engineering theory was on the development and use of the. y-plane methods and, particularly, the root locus approach. Furthermore, during the 1980s, the utilization of digital computers for control components became routine. These new controlling elements possessed an ability to calculate rapidly and accurately that was formerly not available to the control engineer. There are now over ninety thousand digital process control computers installed in the United States. These computers are employed especially for process control systems in which many variables are measured and controlled simultaneously by the computer.

With the advent of Sputnik and the space age, another new impetus was imparted to control engineering. It became necessary to design complex, highly accurate control systems for missiles and space probes. Furthermore, the necessity to minimize the weight of satellites and to control them very accurately has spawned the important field of optimal control. Due to these requirements, the time-domain methods due to Liapunov, Minorsky, and

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others have met with great interest in the last decade. Furthermore, new theories of optimal control have been developed by L. S. Pontryagin in Russia and R. Bellman in the United States. It now appears that control engineering must consider both the time-domain and the frequency-domain approaches simultaneously in the analysis and design of control systems.

The selected history of control system development is summarized in Table 1.1.

Table 1. 1. Selected Historical Developments of Control Systems

1769 James Watt's steam engine and governor developed. The Watt steam engine is often used to mark the beginning of the Industrial Revolution in Great Britain. During the industrial revolution, great strides were made in the development of mechanization, a technology preceding automation.

1800 Eli Whitney's concept of interchangeable parts manufacturing demonstrated in the production of muskets. Whitney's development is often considered as the beginning of mass production.

1868 J. C. Maxwell formulates a mathematical model for a governor control of a steam engine.

1913 Henry Ford's mechanized assembly machine introduced for automobile production.

1927 H. W. Bode analyzes feedback amplifiers.

1932 H. Nyquist develops a method for analyzing the stability of systems.

1952 Numerical control (NC) developed at Massachusetts Institute of Technology for control of machine-tool axes.

1954 George Devol develops "programmed article transfer," considered to be the first industrial robot design.

1960 First Unimate robot introduced, based on Devol's designs. Unimate installed in 1961 for tending die-casting machines.