Материал: Сибирский государственный университет телекоммуникаций и информатики

9. I read a scientific article. I knew that the Global Positioning System (GPS) is a set of 24 satellites, managed by the American armed forces, that constantly send out signals to devices on the ground.

10. In 1994 Tim Berners-Lee left CERN, the particle physics laboratory near Geneva where he created the World Wide Web. He moved to the Massachusetts Institute of Technology (MIT).

VIII. Complete the sentences with Participle I or Participle II.

1. It is of interest to notice the result (obtained, obtaining) on metal which has been deformed by various processes. 2. A more (sophisticated, sophisticating) system might employ an encoder in the transmitter and a decoder in the receiver to give signals suitable characteristics for transmission. 3. Success in one′s work is a (satisfied, satisfying) experience. 4. (Polluted, Polluting) water is not safe for drinking. 5. The experiment (conducted, conducting) at the University of Chicago was successful. 6. A new form of lamp uses microwaves (transformed, transforming) electricity into light. 7. The (defined, defining) characteristic of a crystal is that it is composed of regularly arranged components. 8. The current comprises electrons (flowing, flow) from the negative to the positive terminal of the battery. 9. At the television (transmitted, transmitting) station two carrier waves are modulated, one with the video information and one with the sound information. 10. The npn transistor comprises two p-n junctions which are made up of two diodes (connected, connecting) together.

IX. Translate the sentences paying attention to Absolute Participial Construction.

1. Many informal activities have always been undertaken in the home, the work of housewives being the most important. 2. Around 2.8 billion of mobile phones are already in use, with a further 1.6 million being added every day. 3. The Sun being near the zenith, its rays are nearly vertical. 4. The name electronics is known to be derived from the word “electron”, the electron itself being the basic unit of negative electricity. 5. The work of Polzunov remaining unknown for more than a century, people believed that the inventor of the first engine was James Watt. 6. Electric arc is a discharge accompanied by a temperature of over 3000

C, produced when an electric current flows through a gap between two electrodes, the current being carried by the vapour of the electrode. 7. The first TV sets having been shown in 1939, the news about it spread throughout the world. 8. The young physicist having discovered Newton`s error, other scientists confirmed it. 9. The inventor was demonstrating his new device, with the workers watching its operation attentively. 10. With the current being switched on, the machine automatically starts operating.

X. Join two sentences using Absolute Participial Construction.

Example: a) The electric candle had been invented.

b) The problem of lighting was solved.

The electric candle having been invented, the problem of lighting was solved.

a) Lodygin was the first who thought of tungsten as a material suitable for the purpose.

b) The invention of the incandescent filament lamp belongs to him.

2. a) A series of attempts had been made.

b) He came to a successful solution of the problem.

3. a) Tungsten was used for the filament.

b) Lodygin solved the problem of the incandescent lamp.

4. a) Numerous experiments had been carried out at the orbital stations.

b) It became possible to develop new methods of industrial production of new materials.

5. a) Numerous experiments were over.

b) Newton was able to write his work very quickly.

XI. Read the text. Express the main idea of the text. Translate it.

A new old idea

When most people switch on a desk lamp, they usually want a little extra illumination. But not John Goodey, an engineering student at Oxford University. When he flicks the switch and turns on his lamp, a sensor on his desk downloads music tracks digitally encoded within tiny flickers in the lamp′s light. The music is then relayed through a pair of nearby speakers. This unusual set-up offers a glimpse of a future in which light, rather than radio waves, is used to send information. The concept, known as optical wireless or free-space optics (FSO) promises better security and higher data-transfer rates (up to 10 gigabit per second) than existing radio-based communication technologies. FSO is already used in a few niches: to connect networks in nearby offices. But plans are afoot to extend the idea into a number of new areas. For example, the subtle flickering of car headlights and tail-lights could be used to transmit speed and braking information to other vehicles, to help prevent collisions. Traffic lights could alert cars when they are about to change, or broadcast the latest congestion update to waiting vehicles. At home, FSO could be used together with interior lighting to provide extremely fast internet downloads. Since light does not travel through walls, there would be no need to worry about neighbours snooping on your e-mail, or piggy-backing on your broadband connection. Futuristic though this sounds, FSO is by no means a new idea. Soldiers in ancient Greece used polished shields to send battle orders to each other over vast distances in the form of flashes of sunlight. More recently, so-called “heliographs” have been used to relay military signals in a similar way. And it is only in the past ten years that the British navy has phased out its use of Aldis lamps to convey Morse code signals from ship to ship. These early optical systems could send information at a rate of hundreds of megabits per second (mbps), but customers usually wanted only about 10 mbps. The attraction was not speed but convenience. FSO has the speed of a fiber-optic link and the convenience of a wireless link. It is easy to set-up: simply hook up infra-red laser transceivers on top of two buildings and then align them. The cost to install is very low. In places where transmitters are not allowed on roofs, for example, indoor FSO transceivers can simply send and receive data through closed windows. FSO is secure: the only way to intercept the signal is physically to intercept the beam. City skylines are not criss-crossed with grids of laser beams because it is all done using invisible infra-red light. Telecoms operators are starting to take an interest in the technology as an alternative to the microwave-radio “back-haul” links that are used to link mobile-phone base stations to operators′ core networks. FSO′s main drawback is that bad weather, such as fog or rain, can interrupt the signal. There is no need to worry about bad weather when using FSO indoors. But it is better to use a diffuse light source rather than a laser beam. The natural reflectivity of ceilings and walls, a transmitted infra-red signal can be received by any number of receivers within a room. Dr. O′Brien has been working on a ceiling-based system that tracks where a receiving device is, and sends it a signal using several laser beams from a directional transmitter. A built prototype runs nearly six times faster than today′s typical Wi-Fi links. Wi-Fi is not obsolete, instead, the two technologies may be used together: Wi-Fi as the uplink, and FSO for the much faster downlink. The long-term hope is to transmit data using visible light emitted by indoor lighting. In Japan the Visible Light Communications Consortium, made up of industrial giants such as Sony, Toshiba and NEC, is pursuing that goal. FCO is not possible with existing indoor lighting because incandescent bulbs cannot switch on and off fast enough. But that is not a problem for white light-emitting diodes which are expected to become far more widespread in the coming years, because they use less energy and are more versatile than incandescent bulbs. The combination of LEDs and FSO could then be used to provide internet coverage throughout a home or office. Could it be lights out for radio networking?

Источник: https://tut-files.ru/previewfile/123948

Смотрите также:




17. Введение 18. Линейные программы 19. Ветвления 20. Программирование циклических алгоритмов
Анализ эффективности инвестиций предприятия на примере ООО «СпецПримСтрой»
Сборные железобетонные ребристые плиты перекрытия
_-___-~1
_3 тема - Диффузия
_Роджерс Карл, Брак и его альтернативы
_Штерн Вильям, Дифференциальная психология и ее методические основы

Материал: Сибирский государственный университет телекоммуникаций и информатики

VII. Make sentences beginning with Having ….

Example: We finished our work. We went home.

Having finished our work, we went home.

1. He wrote the letter, then he sent e-mail.

2. The plane was delayed by technical problems. It took off one hour late.

3. I had seen photographs of the place. I had no desire to go there.

4. Marie and Pierre Curie discovered radium. It gave them the possibility to discover other radioactive substances.

5. Lodygin discovered that carbon filaments were not efficient enough, that is why he tried to find some other material, more suitable for the purpose.

6. Teams of physicists, chemists and metallurgists were brought together and materials and theories were improved.

7. The substance was heated and it changed its properties.

8. New features were added and it changed the appearance of mobile phones.