Студопедия — Text 5. History of television.
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Text 5. History of television.






In its early stages of development, television employed a combination of optical, mechanical and electronic technologies to capture, transmit and display a visual image. By the late 1920s, however, those employing only optical and electronic technologies were being explored. All modern television systems relied on the latter, although the knowledge gained from the work on electromechanical systems was crucial in the development of fully electronic television.

The first images transmitted electrically were sent by early mechanical fax machines, including the pantelegraph, developed in the late nineteenth century. The concept of electrically powered transmission of television images in motion was first sketched in 1878 as the telephonoscope, shortly after the invention of the telephone. At the time, it was imagined by early science fiction authors, that someday that light could be transmitted over copper wires, as sounds were.

The idea of using scanning to transmit images was put to actual practical use in 1881 in the pantelegraph, through the use of a pendulum-based scanning mechanism. From this period forward, scanning in one form or another has been used in nearly every image transmission technology to date, including television. This is the concept of "rasterization", the process of converting a visual image into a stream of electrical pulses.

In 1884 Paul Gottlieb Nipkow, a 23-year-old university student in Germany, patented the first electromechanical television system which employed a scanning disk, a spinning disk with a series of holes spiraling toward the center, for rasterization. The holes were spaced at equal angular intervals such that in a single rotation the disk would allow light to pass through each hole and onto a light-sensitive selenium sensor which produced the electrical pulses. As an image was focused on the rotating disk, each hole captured a horizontal "slice" of the whole image. Nipkow's design would not be practical until advances in amplifiertube technology became available. Later designs would use a rotating mirror-drum scanner to capture the image and a cathode ray tube (CRT) as a display device, but moving images were still not possible, due to the poor sensitivity of the selenium sensors. In 1907 Russian scientist Boris Rosing became the first inventor to use a CRT in the receiver of an experimental television system. He used mirror-drum scanning to transmit simple geometric shapes to the CRT.

 

6. What is a manager?

A number of different terms are often used instead of the term “manager”, including “director”, ”administrator” and “ president”. The term “manager” is used more frequently in profit-making organizations, while the others are used more widely in government and non-profit organizations such as universities, hospitals and social work agencies.

So, whom do we call a “manager”?

In its broad meaning the term “manager” applies to the people who are responsible for making and carrying out decisions within a certain system. A personnel manager directly supervises people in an organizations. Financial manager is a person who is responsible for finance. Sale manager is responsible for selling of goods. A marketing manager is responsible for promotion of goods. A marketing manager is responsible for promotion of products on the market. Almost everything a manager does involves decision-making. When a problem exists a manager has to make a decision to solve it. In decision-making there is always some uncertainty and risk.

Management is a variety of specific activities. Management is a function of planning, organizing, coordinating, directing and controlling. Any managerial system, at any managerial level, is characterized in terms of these general functions.

Managing is a responsible and hard job. There is a lot to be done and relatively little time to do it. In all types of organizations managerial efficiency depends on manager’s direct personal relationships, hard work on a variety of activities and preference for active tasks.

The characteristics of management often vary according to national culture, which can determine how managers are trained, how they lead people and how they approach their jobs.

The amount of responsibility of any individual in a company depends on the position that he or she occupies in its hierarchy. Managers, for example, are responsible for leading the people directly under them, who are called subordinates. To do this successfully, they must use their authority, which is the right to take decisions and give orders. Managers often delegate authority. This means that employees at lower levels in the company hierarchy can use their initiative, that is make decisions without asking their manager.

 







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