Е. В. Тихонова английский язык для самостоятельной работы студентов учебное пособие Омск
|
Скачать 499.12 Kb.
|
IV. Render the information of the text C to your partner. XIV. Read Text В and translate it with a dictionary. Write a short summary: TEXT B. SIX COMPUTER GENERATIONS The first three generations of computers have traditionally been identified as those using vacuum tubes, transistors, and integrated circuits, respectively. The fourth generation was never so clearly delineated, but has generally been associated with the use of large scale integrated circuits that enabled the creation of microprocessor chips. The next major deviation in computer technology, therefore, could be considered (in 1980) to be the fifth generation. The development of the fifth generation of computer systems is characterized mainly by the acceptance of parallel processing. Until this time parallelism was limited to pipelining and vector processing, or at most to a few processors sharing jobs. The fifth generation saw the introduction of machines with hundreds of processors that could all be working on different parts of a single program. The scale of integration in semiconductor continued at an incredible pace - by 1990 it was possible to build chips with a million components - and semiconductor memories became standard on all computers. All of the mainstream commercial computers to date have followed very much in the footsteps of the original stored program computer, the EDVAC, attributed to John von Neumann. Thus, this conventional computer architecture is referred to as "von Neumann". It has been generally accepted that the computers of the future would need to break away from this traditional, sequential, kind of processing in order to achieve the kinds of speeds necessary to accommodate the applications expected to be wanted or required. It is expected that future computers will need to be more intelligent providing natural language interfaces, able to "see" and "hear", and having a large store of knowledge. The amount of computing power required to support these capabilities will naturally be immense. Other new developments were the widespread use of computer networks and the increasing use of single-user workstations. Prior to 19851arge scale parallel processing was viewed as a research goal, but two systems introduced around this time are Meal of the first commercial products to be based on parallel processing. The Sequent Balance 8000 connected up to 20 processors to a single shared memory module (but each processor had its own local cache). The machine was designed the compete with the DEC VAX-780 as a general purpose Unix system, with each processor working on a different user's job. However Sequent provided a library of subroutines that aid allow programmers to write programs that would use more than one processor, and the machine was widely used to explore parallel algorithms and programming techniques. The Intel iPSC-1, nicknamed "the hypercube", took a different approach. Instead of using one memory module, Intel connected each processor to its own memory and used a network interface to connect processors. This distributed memory architecture meant memory was no longer a bottleneck and large systems (using more processors) could be built. The largest iPSC-1 had 128 processors. Toward the end of this period a third type of parallel processor was introduced to the market. In this style of machine, known as a data-parallel or SIMD, there are several thousand very simple processors. All processors work under the direction of a single control unit. Scientific computing in this period was still dominated by vector processing. Most manufacturers of vector processors in this parallel models, but there were very few (two to eight) processors introduced parallel machines. In the area of computer networking, both wide area network (WAN) and local area network (LAN) technology developed at a rapid pace, stimulating a transition from the traditional mainframe computing environment toward a distributed computing environment in which each user has their own workstation for relatively simple tasks (editing and compiling programs, reading mail). One of the most dramatic changes in the sixth generation will be the explosive growth of wide area networking. Network bandwidth has expanded tremendously in the last few years and will continue to improve for the next several years. Tl transmission rates are now standard for regional networks, and the national "backbone" that interconnects regional networks uses T3. Networking technology is becoming more widespread than its original strong base in universities and government laboratories as it is rapidly finding application in K-12 education, community networks and private industry. A little over a decade after the warning voiced in the Lax report, the future of a strong computational science infrastructure is bright. The federal commitment to high performance computing has been further strengthened with the passage of two particularly significant pieces of legislation: the High Performance Computing Act of 1991, which established the High Performance Computing and Communication Program (HPCCP) and Sen. Core's Information Infrastructure and Technology Act of 1992, which addresses a broad spectrum of issues ranging from high performance computing to expanded network access as the necessity to make leading edge technologies available to educators from kindergarten through graduate school. . Read these texts and translate them with a dictionary: TEXTI.FROM CALCULI TO MODERN COMPUTER Although the first modern automatic computers began to work in 1944, the story of the development of ideas, devices, and machines entering into that automatic computer goes back a long time into the past. Problems of calculating with numbers, and recording numbers, lave pressed upon human beings for more than five thousand years. Probably the first of the ideas to deal with numbers is the idea of using small objects, such as pebbles, seeds, or shells, to count with, to supplement the fingers. People, however, find it troublesome to count only in units - it takes too much time and effort. So early a second idea appears: the dea of composing a new unit equal to ten of the old units. The source of this idea is clearly the fact that a man has ten fingers; with this idea you could designate 87 by referring to all the fingers if 8 men, and than 7 more fingers on one more man. In order to deal with numbers in their physical form of counted objects, a third idea appears: a specialized, convenient place upon which to lay out the counted objects. Such a place may be a smooth piece of ground, slab of stone, or a board. It becomes convenient to mark off areas on the slab according to he size of unit you are dealing with - you have one area for ordinary units, one area for tens, one area for hundreds, and so on. These developments gave birth to the abacus, the first computing machine. This device consisted of a slab divided into areas, and a supply of small stones for use as counters or objects to keep track of numbers. The Greek word for slab was abax, and the Latin word for the small stones was calculi, and so the first computing machine, the abacus was invented, consisting originally of a slab and counting stones, and later on, a frame of rods strung with beads,for keeping track of numbers while calculating. The system of numbering and the abacus go hand in hand together. The abacus is still the most widely used computing machine in the world. Then appeared the Arabic positional notation for numerals which reached Western Europe in the 1200's. Just as the small counting stones or calculi could be used in any area on the slab, so the digits 1, 2, 3, 4, 5, 6, 7, 8, 9 could be used in any position of a numeral. Just as the position on the slab answered the question as to whether units, tens, hundreds, etc., were being counted, so the place or column or position of the digit (as in 4786 with its four places) answered the question as to what kinds of units were there being counted. And - this was the final key idea - just as a place on the slab could be empty,so the digit 0 could mark "none" in place or column of a number. That idea, by the way, required centuries to develop. The Romans did not have a numeral for zero; but about 300 B.C. in Babylon a symbol for zero was used. Then the Hindus developed the numerical notation that we call Arabic. The Arabs used the word "sifr" meaning "vacant" about 800 A.D. for "zero". About 1200 A.D. the Arabic word was translated into Latin giving rise subsequently to the two English words "cipher" and "zero". The first machine which would add numbers mechanically was invented by the French mathematician and philosopher Blaise Pascal in 1642. It contained geared counter wheels which could be set at any one of ten positions from 0 to 9. Each gear had a little tooth for nudging the next counter wheel when it passed from 9 to 0 so as to carry 1 into the next column. Some 30 years later, in 1673, another mathematician, G.W. Leibnitz, invented a device which would control automatically the amount of adding to be performed by a given digit, and in this way he invented the first multiplying machine. Pascal's and Leibnitz's machines and their improved successors have given rise to electric-powered but hand-operated adding machines and desk calculating machines which are found throughout offices today. The idea of an automatic machine which would not only add, subtract, multiply, and divide but perform a sequence of steps automatically, was probably first conceived in 1812 by Charles Babbage, a professor of mathematics at Cambridge University, England. Babbage intended that his machine should compute the values of the tabulated mathematical functions and print out the results. No attention would be needed from the human operator, once the starting data and the method of computation had been set into the machine. The construction of this machine was begun with aid from the government. For 20 years however little progress was achieved. In 1833 Babbage changed his plans for another computing machine which he called an analytical engine. This was to consist of three parts: (1) the "store", where numbers were to be stored or remembered; (2) the "mill" where arithmetical operations were to be performed on numbers taken from the store; and (3) the "sequence mechanisms" which would select the proper numbers from the store and instruct the mill to perform the proper operation. Once, Countess of Lovelace, the daughter of the great English poet, Lord Byron, Augusta Ada Byron saw that computing machine. As she was a brilliant mathematician, she was the first who highly appreciated the idea put into the Babbage's automatic computer. She wrote to him later that she was greatly impressed by his invention. They continued to work together for some years. Probably, it was somewhere in 1840, may be later, but they cooperated up to 1850. (She died in 1852 when she was only 37.) Nowadays she considered to be the first programmer in the world. But the first and second Babbage's machines were not completely constructed although small parts of them were. Both Babbage and his son, who also tried to carry out his father's ideas, died without seeing the result of their work. The failure to construct those machines was because of the absence of sufficiently accurate machine tools and of mechanical and electrical devices that finally became available around 1900-1910. Another of the historical developments of automatic machines was about 1886. Dr. Herman Hollerith decided to experiment with cards with punched holes and with electrical devices to detect the holes and count them. He realized that cards bearing human language were not readable by the machine; but cards could be prepared using a machine language, a language of punched holes. Hollerith's experiments and machines were successful, and have led to a great development of machines using punched cards for business, accounting and statistical purposes. These machines, punched card calculating machines, have become a base of business calculations and reports all over the world. The first automatic digital computer that worked was a machine called the Complex Computer, constructed in 1939. Dr. George R. Stibitz, an engineer, noticed around him a lot of troublesomearithmetic multiplying and dividing complex numbers, numbers which electrical engineers find necessary for analyzing alternating electrical circuits. Every multiplication of two complex numbers requires four multiplications and two additions of ordinary numbers. Every division of one complex number by another requires six multiplications, two additions, one subtraction, and two divisions of ordinary numbers. The sequence of the operations with the ordinary numbers is always monotonously the same. Stibitz decided that ordinary telephone relays could be wired together to do this annoying task. So he represented each decimal digit by a code of l's and O's, so that four relays being energized or not energized could express the code and designate each digit. This machine was completed in 1940 and demonstrated. In 1944 the first general-purpose automatic digital computer was built. This computer ran 24 hours a day, seven days a week and continued to operate for many years. This machine was the first working realization of Ch. Babbage's analytical engine. And it quickly led to more automatic digital computers with numerous improvements. In 1946 an automatic electronic digital computer was built. This machine used instead of relays standard radio tubes and parts, and aimed for high speed. It was ENIAC (Electronic Numerical Integrator and Calculator). It contained 20 registers where numbers of 10 decimal digits could be stored or accumulated. It could add numbers at the rate of 5,000 additions per second. It also contained a multiplier which would carry out from 360 to 500 multiplications per second, a "divider-square-rooter", and other units. From 1952 the addition speed of computers has gone to more than 100,000 additions per second. The multiplication speed has risen to more than 10,000 per second. The amount of storage capacity, or memory, has changed from 72 storage registers to millions of registers. The reliability of automatic computers has increased to the point where a billion and ten billion operations take place between errors. Besides, automatic checking has been built into computers so that no wrong results are allowed out. The description of the history of invention and construction of computers and data processors is only part of the story. What caused this development? There have been two trends in the causes for this development. One is the growth of scientific and engineering knowledge. Take for example astronomy. Isaac Newton and Albert Einstein expressed general lays for the behaviour of heavenly bodies. But the actual calculations for knowing where to look in the sky to see any particular heavenly body at any particular time have to be carried out numerically. Furthermore, the laws were general and in simple form, ignoring many complexities; the actual calculations for particular heavenly bodies were specific and had to take into account many uncomfortable details. Take for example calculating the orbit of the moon: the bulge of the earth at the equator, where the earth is wider than it is at the poles, has an effect on the orbit of the moon, and this has to be calculated in order to predict to the minute and second where the moon will be at any particular time. Such calculations are laborious. Similar laborious calculations occur in electrical engineering, in physics, in chemistry, in nucleonics, and elsewhere. The other main trend is from the world of business. Here enormous quantities of records and calculations are required in order that business may function. The growth of a great civilization has produced an enormous growth in the information to be handled and operated with. This provides the push, the energy, for the development of the electronic computers. |
Похожие:
 |
Учебное пособие для самостоятельной работы студентов заочного отделения... Учебное пособие предназначено для для самостоятельной работы студентов заочного отделения неязыков специальностей вузов, ранее изучавших... |
 |
C. Г. Карамышева английский язык для студентов-экономистов учебное пособие Краснодар Учебное пособие предназначено для аудиторной и самостоятельной работы студентов-бакалавров экономического факультета. Рассчитано... |
|
Пояснительная записка Учебное методическое пособие «Сборник текстов... Методическое пособие предназначено для аудиторной и внеаудиторной самостоятельной работы студентов 1-4 курсов по дисциплине «Иностранный... |
|
Английский язык для ландшафтных дизайнеров Учебное пособие предназначено для аудиторной и самостоятельной работы студентов-магистрантов факультета плодоовощеводства и виноградарства,... |
|
Учебное пособие соответствует дисциплине «Профессиональный английский язык» Учебное пособие предназначено для студентов технических вузов направления подготовки 230100 «Информатика и вычислительная техника»... |
|
Учебное пособие к курсу “Upstream” Уровни А2―В1 Издательство «мгимо-университет» Учебное пособие предназначено для студентов 2 курса факультета мэо, которые изучают английский как второй иностранный язык |
|
Учебное пособие для студентов старших курсов гуманитарных специальностей,... Учебное пособие для студентов старших курсов гуманитарных специальностей, изучающих английский язык |
|
Методические рекомендации по выполнению самостоятельной работы по... Данные Методические рекомендации по выполнению самостоятельной работы по дисциплине огсэ. 03 Иностранный язык (английский) предназначены... |
|
Учебное пособие для студентов 6 курса, обучающихся по специальности... Учебное пособие предназначено для самостоятельной работы студентов 6 курса при подготовке к практическим занятиям |
|
Учебное пособие Тольятти 2011 г. Авторы: Савкин С. А., Рынгач В.... Учебное пособие предназначено для студентов, изучающих предмет «Артиллерийская разведка». Он составлен в соответствии с программой... |
|
Методическое пособие для проведения внеаудиторной самостоятельной... Методическое пособие предназначено для организации эффективной самостоятельной внеаудиторной работы обучающихся, получающих образование... |
|
Учебное пособие подготовлено для самостоятельной внеаудиторной работы... Учебное пособие предназначено для обучающихся по специальности 31. 05. 01 Лечебное дело |
|
Учебное пособие подготовлено для самостоятельной внеаудиторной работы... Учебное пособие предназначено для обучающихся по специальности 31. 05. 01 Лечебное дело |
|
Краткий курс грамматики английского языка учебно-методическое пособие... Учебное пособие предназначено для студентов очного и заочного отделений неязыковых факультетов. Доступное изложение грамматического... |
|
Методические рекомендации для выполнения самостоятельной работы Томск, 2015 Учебное пособие предназначено для студентов средних специальных учебных заведений при выполнении внеаудиторной самостоятельной работы... |
|
Методические указания для самостоятельной внеаудиторной работы студентов... Методические указания предназначены в помощь для Вашей самостоятельной внеаудиторной работы с целью самостоятельного изучения и усвоения... |