7. Дайте відповіді на запитання.

1. What is a microprocessor unit?

2. What are the chunks of infor­mation reduced to?

3. The MPU can perform only one operation at a time, can't it?

4. How are MPUs measured?

5. What can parallel and serial devices do?

8. Сформулюйте головну ідею тексту.

Контрольна робота № 5

Щоб правильно виконати контрольну роботу № 5, необхідно повторити такі розділи граматики англійської мови.

1. Граматичні функції дієслів should, would.

2. Підрядні речення : додаткові, прислівникові, означальні.

3. Сполучники.

Зразок виконання завдань

Вправа II

Не told us that he felt ill.

Він сказав нам, що почуває себе хворим ( додаткове підрядне речення).

Зразок виконання завдань

Вправа III

І have received a letter and a telegram.

Я одержав листа і телеграму.

ВАРІАНТ I

1. Перепишіть подані речення та перекладіть їх рідною мовою, звертаючи увагу на різне значення дієслів should, would.

1. If they should come, I shall speak to them about it.

2. It is desirable that the agreement should be signed before May.

3. He would go there if he had time.

2. Перепишіть речення та перекладіть рідною мовою. Визначте вид підрядного речення.

1. They laughed at what he said.

2. The man who was here yesterday is a manager.

3. The man that you are speaking about is in the next room.

3. Перепишіть та перекладіть подані речення рідною мовою, звертаючи увагу на виділені сполучники.

1. I sad that he would come in the evening.

2. We have received your telegram as well as your letter of the 20^th May.

3. Ask him whether he can do it tomorrow.

4. After the steamer had left the port, we sent a telegram to the buyers.

4. Прочитайте та перекладіть текст рідною мовою.

THE OPTICAL COMPUTER

The development of the digital computer in the past 40 years is so closely associated with the development of electronic technology that people tend to think of the computer as the inherently electronic device. Actually the operations carried out by a computer are logical and arithmeticones , and they can be done by any of several means. Since the mid-1970’s it has become apparent that the potential exists for constructing a computing device in which signals are transmitted by beams of laser radiation rather than electric currents. There is a powerful incentive for developing such an optical computer it may operate 1,000 times faster an electronic computer. An optical analog of the transistor is the basis element of a computer based on beams of light.

A computer based on beams of light rather than electronic currents might be capable of a trillion operations per second. The crucial component, an optical transistor can be the site of many simultaneous switching operations carried out on parallel laser beams; an electronic device operates on one signal at a time. Moreover the crystals can switch to successively higher levels of transmitted power with successive increases in the incident beam; in contrast an electronic transistor of the kind employed in computers has only two output states. The adoption of devices with more than two stable states may lead to a new system of computer logic.

An experimental version of the optical transistor that is switched by a small change in the intensity of an incident beam of laser radiation has been developed. The optical transistor (called a "transphasor" because its operation is based on controlling the phase of the light within it) has been designed on a property of certain crystals. An increase in the intensity of light causes a change in the crystal's refractive index, a measure of the extent to which light is slowed as it passed through the material. In a new optical transistor switching times of approximately a few picoseconds have been obtained. The starting point of the optical transistor is an ingenious and widely used piece of optical apparatus known as the Fabry -Perot interferometer, invented by the French physicists in 1896 to measure the wavelength of various colours of light. The optical transistor relies on two precisely adjusted laser beams focussed on the front face of a Fabry - Perot interferometer containing a substance with a non-linear refractive index.

The "constant" beam is strong and unvarying. The "probe" beam is weaker and can be modulated. The low transmission or "off - state can stand for the value 0 in the binary logic of the computer; the high transmission or "on"- state can stand for 1. In this respect, the optical transmitter is analogous to the electronic transmitter.

Optical switching systems need not be thought of merely as rapid substitutes for electronic devices. On the contrary, the greatest benefits of optical switches may come from applications that cannot be duplicated by other means. Optical fibers which have the capacity to carry prodigious amounts of information, are being utilized increasingly for communications, including communications among computers. Optical switching is a natural candidate to mediate between electronic systems and optical ones. On the other hand, if the computation is done optically to begin with, optical fibers can be employed as direct links between computing systems. In future the capabilities of the optical transistor will transform the architecture of the computer itself.

Constructing an optical computer will require a variety of circuit elements in addition to the optical transistor. Nevertheless many of the elements needed to make an integrated optical circuit have already been demonstrated in experimental form. Formidable technical difficulties must be overcome before such a circuit can be manufactured. However, the optical computer is an intriguing and realistic prospect for the relatively near future once an optical transistor has been constructed. New laser and new non-linear materials will undoubtedly make it possible to improve the speed and efficiency of optical switches. The question of appropriate materials is at the centre of the practical problems of building an optical computing machine.

5. Напишіть короткий зміст тексту.

6. Складіть словник-мінімум до тексту.

ВАРІАНТ II

1. Перепишіть подані речення та перекладіть їх рідною мовою, звертаючи увагу на різне значення дієслів should, would.

1. If he should refuse, they would be greatly disappointed.

2. It was necessary that the question should be settled without delay.

3. He tried to persuade me, but I would not listen to him.

2. Перепишіть подані речення та перекладіть рідною мовою. Визначте вид підрядного речення.

1. Не has just gone away saying that he will return in an hour.

2. The children who live in that house are my son's friends.

3. This is the house that I used to live in.

3. Перепишіть та перекладіть подані речення рідною мову, звертаючи увагу на виділені сполучники.

1. As I was coming here, I met your brother.

2. As long as you insist on these terms, we shall not be able to come to an agreement with you.

3. Не will do it as soon as he comes home.

4. What have you been doing since I last saw you?

4. Прочитайте та перекладіть текст рідною мовою.

IMAGE PROCESSING BY COMPUTER

A digital computer processes information in discrete numerical units: digits. Most images, of course, do not come in such units. An ordinary photograph is an analog representation of a scene, the information is recorded in continuous gradations of tone (and in some cases of colour) across the two dimensional surface of the film. Processing a photograph by means of a computer therefore requires that the analog image first be converted into a digital one. A number ways of digitizing an image are now available, e. g., a photograph image can be sampled by a scanning microdensitomiter by the flying-spot scanner; more avanced image-sampling systems, based on semiconductor technologz have been devised in recent years.

An image that has been reduced to a set of binary numbers can be stored on magnetic tape or transmitted to the computer. The data van then be processed to obtain a new set of digital values, which in turn can generate a revised image. The new image is usually displayed on a tube, where it is either viewed directly or photographed. Once the image has been digitized and transmitted to a computer, various mathematical operations can be carried out on the data in order to enhance the visual quality of the image and thereby allow the information in the image to be more readily and accurately perceived by the human visual system.

When the information in an image is expressed in digital form, it can be manipilated mathematically rather than optically. By mathematical methods a blurred photograph can sometimes be restored to clarity. The digital computer is now an essential tool in many areas of image processing. An out-of-focus photograph or one streaked by movement of the camera can now be digitally processed to improve its resolution and to restore lost details. In many cases the cause of the blur can be determined from the blurred image itself. The techniques for deblurring images can be applied not only in scientific research and medicine but also in fields such as criminology and military intelligence. Investigators are currently working on digital methods for compressing the information in an image, a capability that can lead to greater efficiency in TV transmission.

The greatest application is the automatic recognition of certain recurrent patterns in large number of images, which makes it possible to extract more information from satellite images of the earth. Semiconductor image-sampling devices offer many advantages besides their direct digital output. Accurate and reliable for sampling and quantizing an image or for displaying an image reconstructed from digital data have been commercially available for more than a decade. Without them digital image processing could not become the active field it is today. The increase in the number of companies that specialize in the manufacture of devices for getting images into and out of a computer manifests the growth of the activity.

What is responsible for the recent surge of activity in digital image processing? First, an image embodies a prodigious amount of information and so most image processing is done with a large powerful computer. As the continuous revolution in microelectronics has reduced the cost of such machines while increasing their capacity they have become more widely available. Second, the same advances in microelectronic technology have also led to the construction of improved devices for converting an image into digital data and vice versa. Third, the development of sophisticated algorithms or mathematical procedures that can be executed by a computer has made it possible to carry out image-processing operations that once had been impossible or impractical.

Scientists are familiar with some of the more spectacular products of digital image processing; enhanced satellite photographs of the planets (including the earth), colourful representations of more distant celestial objects and images assembled from X-ray data to show a cross-section of the human body. Perhaps the most important application of digital image processing is in the area of remote sensing particularly in the analysis of satellite images of the earth. The satellites are equipped with scanning devices that record images of the earth passing under them in a series of strips. Each strip is 185 kilometers wide, and it is usually subdivided (by computer processing on the ground after the data are received) into a series of images 185 kilometers on a side. More і than 90 percent of the earth's surface has been surveyed under cloud-free conditions at this resolution. By combining images made at different wavelengths it is possible to enhance the information display.

The potential of remote sensing for helping to solve human problems is great. For example, the growth of a crop such as wheat is accompanied by predictable changes in its multispectral image. The onset of various crop diseases, such as blight in corn or rust in wheat, can be detected from changes in the multispectral image. Experiments of this kind have led to the suggestion that it might be possible to monitor food crops throughout the world and to predict the world harvest from satellite images. Besides, there is much interest in the development of computer programmes for the recognition of patterns in images. Веcause most deposites of mineral resources are associated with characteristic geological features, efforts are also being made to automatically isolate and extract from remotely sensed images such geological details, as faults and escarpments. The expectation is the automatic extraction of information from such images will some day be one of the most active areas of digital image processing.

5. Напишіть короткий зміст тексту.

6. Складіть словник-мінімум до тексту.

ВАРІАНТ III

1. Перепишіть подані речення та перекладіть їх рідною мовою, звертаючи увагу на різне значення дієслів should; would.

1. Не suggested that the case should be postponed.

2. The sellers demanded that payment should be made within five days.

3. I told him that you would leave Lviv on Monday.

2. Перепишіть подані речення та перекладіть рідною мовою. Визначте вид підрядного речення.

1. Не asked us what we thought of it.

2. The letter that I received from him yesterday is very important.

3. When we arrived at the port, the steamer was being loaded with grain.

3. Перепишіть та перекладіть подані речення рідною мовою, звертаючи увагу на виділені сполучники.

1. Не speaks English perfectly though he has never been to England.

2. It is as warm today as it was yesterday.

3. Whichever day you come, we shall be pleased to see you.

4. Whoever calls, tell them I am out.

4. Прочитайте та перекладіть текст на рідною мовою.

COMPUTER MEMORY

The organization of computer memory has received much attention over the years. There are two general ways of partitioning memory, which can be called vertical and horizontal. The incentive for structuring memory in a vertical or hierarchical manner is that fast memories cost more per bit than slower ones. Moreover, the larger the memory is, the longer it takes to access items that have been stored randomly. The processing units in most large computers communicate directly with a small, very fast memory of perhaps several hundred words. Data can be transferred to or from one of these disk units at a maximum rate of half a million words per second, and in practice it is possible to maintain data flow between central memory and several disk units simultaneously.

The maximum rate of transfer of information to or from a memory device is known as a bandwidth. In order for the average computing speed not to be dominated by the smaller bandwidth of the lower memory levels, programmes must be arranged so that as much computation as possible is done with instruction and data at the higher levels before the need arises to reload the higher level from one below. This is an important consideration in programming vector operations for supercomputers, whose central-memory bandwidth is small in relation to the mega-flop rate that can be sustained for data held in the register set.

Several multiprocessing supercomputers currently under development incorporate a number of independent parallel memory modules that linked to an equal number of independent processors through a high-speed programme-controlled switch so that all the memories are equally accesible to all the processors. For pipelines processors still another kind of horizontal partitioning of central memory has been devised: the memory is divided into a number of “phased” memory banks, so described because they operate with their access cycles out of phase with one another. The rationale for the scheme is that random access central memories are relatively slow, requiring the passage of a certain minimum number of clock periods between successive memory references. In order to keep vector operands streaming at a rate of one word per clock period to feed a pipeline, vectors are stored with consecutive operands in different banks. The phase shift that "opens" successively referenced banks is equal to one processor 'clock period. The supercomputers - the Cyber 205 has 16 phased banks; the Cray-1 has 8 or 16, depending on the memory size. In both supercomputers mentioned the bank cycle time is equal to four processor cycles.

The memory of the modem supercomputers - the Cray-1 and Cyber 205 - is organized hierarchically. The two register memories are the smallest, followed in capacity by central memory, extended semiconductor memory and disk memory. The extended semiconductor memory has just begun to appear in supercomputer installations because rotating-disc technology has not kept pace with the increasing speed of processors. The largest such memory, with the capacity of 8 million words is in the Cray-1 supercomputer. Here all the functional units are "pipelined"; meaning that tasks are broken into elements that can be executed at peak speed, and reassembled in a continuous flow, thereby achieving one floating-point operation per clock period: 20 nanoseconds in the Cyber 205 and 12,5 nanoseconds in the Cray-1.

All the functional units can run concurrently, but not all can run at top speed concurrently because they share common resources, such as data paths or memory access cycles. Moreover, conditional branches in the programme interrupt the smooth flow of instructions through the instruction processor. Before the processor issues an instruction, it must wait until it is clear that all the resources needed for the execution of the instruction will be available when they are needed. In the Cray-1 the register memories incorporate further hierarchical structure, and the vector processor holds additional register memory. The vector processors of the Cray-1 and the Cyber-205 also differ significantly in other respects. The disc-based secondary storage systems of both the Cray-1 and the Cyber-205 are too slow to allow any feasible solution of continuous-field simultation whose iterative data base is too large to fit in the machines central memory.

5. Напишіть короткий зміст тексту.

6. Складіть словник-мінімум до тексту.

ВАРІАНТ IV

1. Перепишіть подані речення та перекладіть їх рідною мовою, звертаючи увагу на різне значення дієслів should; would.

1. I am sorry that you should think so.

2. Why should you dislike him so much?

3. I asked him several times to give up smoking, but he wouldn't.

2. Перепишіть подані речення та перекладіть рідною мовою. Визначте вид підрядного речення.

1. Не told us that he felt ill.

2. I know the man whom you mean.

3. The manager of our office, who is a highly educated man, speaks several foreign languages.

3. Перепишіть та перекладіть подані речення рідною мовою, звертаючи увагу на виділені сполучники.

1. І have received a letter and a telegram.

2. The sun has set, but it is still light.

3. Go at once or you will miss your train. I can't do it because I am very busy.

4. Прочитайте та перекладіть текст рідною мовою.

CYBERNETICS

The word "cybernetics" originated from the Greek "kybemetike", the Latin "gubernator" and the English "governor" all meaning, in one sense or another, "control", "management" and "supervision". More recently Norbert Wiener has used the word to name his book, which deals with the activity of a group of scientists engaged in the solution of a wartime problem and some of the mathematical concepts involved. Nowadays the word has become associated with the solution of problems dealing with activities for computers. As such, the discipline must rely on the exact sciences as well as sciences such as biology, psychology, biochemistry and biophysics, neurophysiology and anatomy.

Before studying computer systems it is necessary to distinguish between computers and calculators. These terms have, by connotation, two distinctly different meanings. The term calculator will refer to a machine which (1) can perform arithmetic operations (2) which is mechanical (3) which has a key-board input (4) which has manually operated controls. (Examples: Adding machines, desk calculators). The term computer will refer to automatic digital computers which can (1) solve complete problems, (2) are generally electronic, (3) have various rapid input-output devices, (4) have internally stored control programmes (routines). Speed and general usefulness make a computer equivalent to thousands of calculators and their operators. The ability of electronic computers to solve mathematical and logical problems, thereby augmenting the efficiency and productivity of the human brain, has made the sphere of their application practically boundless.

It is difficult to say what the future holds in store for Cybernetics. Every day learn more and more about the penetration of Cyberbetics into the most widely differing spheres of human activity. The lauching of sputnik and the delivery of our space rockets to their orbits with such high accuracy could have been hardly possible without computers. This, however, does not mean, that a machine can ever become “cleverer” than its creator. The point is that the machine does not replace man, it only increases his work output and multiplies his power over the forces of nature. It should be always remembered that the machine serves man, and not the other way round. Without man, even the most perfect machine would be only a useless heap of metal.

Man's technical progress is reflected in the tools he has invented. From early times he has been ceaselessly creating and improving devices to assist his brain in completing tasks difficult or otherwise impossible. Throughout the centuries man has developed and refined the ability to record, process, and communicate information. With the advent of automatic digital computers, man has created devices that can solve complete problems without the need for human intervention during the course of solution. Although operations performed by computers are the very basic ones (addition, subtraction, multiplication and division) great speed of operation is more than compensation. The principal use of computers has been in the area of applied mathematics. The application of computers to scientific problems has become later than the original business applications. Nowadays computers have become increasingly important as basic tools for analysis. This operation requires highly refined and flexible techniques.

The contributions of the scientists to the progress of Cybernetics consists of the evaluation, measurement and description of the capabilities and of structural 'and functional attributes of living organisms. Such studies involve the methods of communication, feedback and control in the living entity. Hence an important aspect of the work in Cybernetics for mathematicians deals with the mathematical theory of communication.

In terms of computer development Cybernetics is concerned with the design and construction of electrical or electronic analogs capable of performing processes carried out within a living entity, including the selection and evaluation, as well as the storage of information. In terms of understanding the operation of the human nervous system, Cybernetics contributes new insight into a wide range of processes such as learning, regulation and the emotional behaviour of individual human beings as well as societies. Specifically the problems of decision-making, thinking and synthesis, imagination and creative endeavour of people, come under the scrutiny of Cybernetics.

It is anticipated that the future developments of automated industries and societal functions will be based on the theorems developed from Cybernetics which thus far has made significant contribution to the technology of guided missiles, business and scientific computer applications, communications and automatic control. Cybernetics is a young science and yet it is increasingly applied in various branches of industry and research. Invading a wide range of fields in human activity. Cybernetics endeavours to find the answer to two major questions: the best way of controlling this or that process, and the best way of utilizing a machine (if possible) for controlling this process.

5. Напишіть короткий зміст тексту.

6. Складіть словник-мінімум до тексту.

ВАРІАНТ V

1. Перепишіть подані речення та перекладіть рідною мовою, звертаючи увагу на різне значення дієслів should, would.

1. Why should you think that he is not capable of doing this.

2. He said that he would come soon.

3. Would you tell me the time, please?

2. Перепишіть подані речення та перекладіть рідною мовою. Визначте вид підрядного речення.

1. As soon as we received your telegram, we instructed our Kiev office to prepare the goods.

2. I stayed at the custom - house until the goods had been examined.

3. The steamer that we loaded the goods on will leave the port tomorrow.

3. Перепишіть та перекладіть подані речення рідною мовою, звертаючи увагу на виділені сполучники.

1. His English is as good as his French.

2. What have you been doing since I last saw you?

3. After the steamer had left the port, we sent a telegram to the buyers.

4. Ask him whether he can do it tomorrow.

4. Прочитайте та перекладіть текст рідною мовою.

SUPERCOMPUTERS

American computers now reaching the market in volume can perform a few hundred arithmetic operations per second. At the other end of the are the powerful machines known as Supercomputers, of which there are now only several dozen in the world, whose peak computing speeds exceed 100 million operations per second. For a machine to be qualified as a supercomputer in 1982, it should be able to sustain average rates of 20 megaflops (the megaflop - one million floating-point operations per second) for a range of typical iterative problems that have a data base of a million or more words. The first commercial electronic computer Univac I (1951), was about three times faster than today's home computers and thousands of times more massive. Since Univac the speed of large-scale scientific computers has doubled on the average every two years. These increases of speed have entailed large increases in memory capacity, necessary for storing data and results. The latest supercomputers are the Cray-1 and the Cyber-205, they are fully operational arid offered for sale.

The doubling and redoubling of computer speeds in recent years has been made possible in large part by the steady decrease in size of micro-electric circuits. The number of transistors that can be fabricated on a chip of solicon measuring a fraction of an inch on a side increased from a dozen or so in the early 1960s, to several thousand in the early 1970s and has now reached several hundred thousand. These strides in semiconductor technology made it possible for the first time to build large, fast memories at tolerable cost. A second benefit of increased circuit density has been a reduction in the time needed for each cycle of logic operations. Concentrating, however, a large amount of circuitry into a small volume to minimize the length of wires creates a serious problem: the removal of the waste heat generated by electrical energy conversions.

Digital circuits are subject to errors caused by the failure of components and by random electrical noise. Even though chips have become' increasingly reliable, error rates grow as supercomputers evolve, because the error rates of a complex system are at least proportional to the number of its parts. In order to protect the user from flawed results super­computers incorporate mathematical codes capable of detecting and correcting errors. This is done by adding redundant bits of information to the minimum word length required. Circuitry for generating and checking; the redundancy bits must be included at several error-control points in the machine. All supercomputers of the current generation incorporate error-control systems. To be sure, error control adds appreciably to machine cost and does not eliminate the possibility of undetected errors (errors of three bits or more), although it does reduce their rate to acceptable levels.

Although the current performance levels of such machines owe much to the rapid advance of microelectronics, new concepts in computer architecture have been equally important. The term architecture refers to-the logical organization of the computer as it is seen by the programmer. The architectural innovations of greatest significance are those that enable the machine to carry out many similar operations in parallel, or concurrently. Whereas early computers obliged the programmer to break his computational problem down into a sequence of elementary steps, which are to be executed one at a time, the latest supercomputers allow him to specify that many different elementary steps be executed simultaneously.

A modern American supercomputer can be regarded as simplified model of both the Cray-1 and the Cyber-205. Although supercomputers-are still few in number, they are to become widely available with the development of national and international high-speed data networks that link the scientific centres. Some major centres of scientific computation have developed elaborate data-communications networks linking several supercomputers, front-end processor (input-output systems), other general-purpose computers, mass-storage data banks and graphic-display stations so that each user has rapid access to the most suitable resources for his problem: Supercomputer users demand ever increasing power for attaching the computational problems at the frontiers of their various disciplines. Computer architects have differing ideas for satisfying user demands.

It is not unreasonable to ask why anyone wants a computer 50 times faster than most of the fastest computers that are being manufactured today. There are some computational tasks in which speed is important, viz., long-range weather predictions, also cryptology demands can benefit directly from higher speed. To attain higher speed a new-microelectronic technology replaces transistors with superconducting switches. These computers can carry out a billion elementary operations per second. Such an ultrafast supercomputer can and will be employed for the routine processing of insurance premiums, tax returns and payroll records. It will serve multiple users and multiple functions in the central computing departments of universities. In most such applications it makes, no difference whether a task that takes a million machine cycles is completed in one milliseconds or 50 milliseconds.The point is that a computer running 50 times faster can do 50 times more, perhaps per the same cost.