Контрольная работа по Английскому языку на тему: "Flicker"

Семестровая контрольная работа

I. Translate the sentences from English into Russian

1. It is desirable that international space cooperation give significant economic advantages for the countries involved.

2. The craft to be launched would essentially be used as a service module for space stations.

3. One should know that the broader the basis for utilizing a space station is the better the prospects for economic efficiency.

4. The applications of laser in industry and science are known to be numerous and varied.

5. The invention of laser was followed by the fabrication of ultrathin silicon fibers capable of servicing as lightweight conductors.

6. Scientists found superconductors to possess thermal, electric and magnetic properties quite different from the non-conducting material.

7. With supersonic planes flying at a speed five to six times above the speed of sound, it will be possible to cover the distance between Tokyo and Moscow in less than two hours.

8. The article deals with microwaves, particular attention being paid to radio location.

9. Were electric motors used, cars would not pollute the air, would be practically noiseless and very easy to control.

10. Provided new composite materials were used, it would be possible to reduce overall aircraft weight.

11. It is possible that a compound become a superconductor even if the chemical elements constituting it are not.

12. The new system developed increased the safety and efficiency of the new devices constructed.

13. Once the user’s position has been determined, the GPS unit can calculate other information such as speed, track, sunrise and sunset time and other data.

14. Lasers appeared to be highly useful for solving the problem of controlled thermonuclear reaction and communication.

15. If I had attended a course of technical translation, I should have been able to read English technical journals.

II. Flicker

1. The first requirement to be met in image analysis is that the reproduced picture shall not flicker, since flicker induces severe visual fatigue. Flicker becomes more evident as the brightness of the picture increases. If flicker is to be unobjectionable at brightness suitable for home viewing during daylight as well as evening hours, the successive illuminations of the picture screen should occur no fewer than 50 times per second. This is approximately twice the rate of picture repetition needed for smooth reproduction of motion. To avoid flicker, therefore, twice as much channel space is needed as would suffice to depict motion.

2. The same disparity occurs in motion picture practice, in which satisfactory performance with respect to flicker requires twice as much film as is necessary for smooth simulation of motion. A way around this difficulty has been found, in motion pictures as well as in television, by projecting each picture twice. In motion pictures, the projector interposes a shutter briefly between film and lens while a single frame of the film is being projected.

3. In television, each image is analyzed and synthesized in two sets of spaced lines, one of which fits successively within the spaces of the other. Thus, the picture area is illuminated twice during each complete picture transmission, although each line in the image is present only once during that time. This technique is feasible because the eye is comparatively insensitive to flicker when the variation of light is confined to a small part of the field of view.

4. It is thus possible to avoid flicker and simulate rapid motion by a picture rate of about 25 per second, with two screen illuminations per picture. The precise value of the picture-repetition rate used in a given region has been chosen by reference to the electric power frequency that predominates in the region.

a) Определите, какое утверждение соответствует содержанию текста.

1. Human vision is completely insensitive to flicker.

2. The exact value of the picture reiteration rate depends on the reproduction place.

3. Flicker doesn’t affect image perception.

4. Flicker influences satisfactory performance in motion picture practice as well as in television.

b) Укажите, в какой части текста (1, 2, 3, 4) содержится ответ на вопрос:

What is the way of avoiding flicker?

c) Укажите, какой части текста (1, 2, 3, 4) соответствует следующая идея:

The ways of avoiding