What is the best way to set up the information to be transmitted to give the maximum information transfer across a given channel?

This is of interest in many applications; an example is sending a large document by email. The document may be several hundred kilobytes in size and to send it by email over a telephone line using a modem operating at 28.8 kbps may take a considerable time. If the data are compressed, the file can in certain cases be reduced in size by a factor of over 10, which would reduce the time taken to transmit the file, thus improving the convenience and minimizing cost. If the source information contains redundant information, data compression can shorten the message by removing redundancy. An example would be sending a text file over a communications link where the source device removes redundant characters before transmission. If the file contains sequences that are repeated, such as several space characters in a row, then instead of transmitting each of them the number of spaces could be transmitted. At the receiver the reverse process would allow the original document to be recovered. This process can be done with any character and can be used on simple binary data. This is termed run length encoding and is widely used in a variety of applications including fax machines. Try sending a fax of plain paper and compare the time taken with that taken for a page of typed notes.

More powerful algorithms are available but they all work by identifying redundancy and removing it. Note that the information content of the message is not altered and these techniques are termed compaction. Data compression may lose some information, which is acceptable in certain situations such as digital TV. The term data compression is used both for those processes that may lose information and for those that do not (i.e. compaction). Another example of coding source information is the Morse code.

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How Energy conversion from coal is done?

Single generator sets of over 600 MW are now used in the UK, though there are many smaller generators in use. A 600 MW generator can supplythe average needs of over 1 million UK households. Three or four such generators are typically installed in a single large coal-fired station which isoften sited close to a coal mine, away from the city dwellers who consume the electricity. Such generators are usually driven by a compound arrangement of highpressure, intermediate-pressure and low-pressure turbines, increasing in size as the pressure decreases. Modern turbines rotate in a speed range from 1500 to 3500 r.p.m., usually 3000 r.p.m. for the UK’s 50 Hz system. For large coal-fired plant the steam pressure could be 25 megapascals (MPa) with steam temperatures of 500–600 °C to improve the thermodynamic efficiency. In nuclear reactors, which operate under less demanding conditions, the steam is superheated to about 5 MPa and 300 °C. Modern water tube boilers are complex and have ...

All about Electronics & Instrumentation Engineering)(EI)

Vision : To be globally recognized as a seat of learning and innovation in Electronics for application to Communication, Transportation, Defence, Industry, Health Care, Entertainment, and many other consumer products. Mission : 1). To produce quality engineers in the field of Electronics and related domains. 2) To conduct research and develop products in the fields of Chip design, Communication Systems, Electronics Instrumentation, Signal Processing and other related areas with strong emphasis on critical state of the art applications. 3) To grow in the area of Design and Manufacturing of chips, boards and systems. Program Educational Objectives : I. To provide students a successful career in industry that meets the needs of national and multinational companies. II. To develop the ability among students to synthesize data and technical concepts for application to electronic product design and to solve real...

5 TOP FACTS LIGHTHOUSES

1 The builder of the Lighthouse of Alexandria, Sostratus – disobeying orders from the pharaoh Ptolemy – engraved his name and a dedication to the sea gods on the tower base. Fame 2 The technical term for the study of lighthouses is ‘pharology’, a word derived from Pharos, the island upon which the great Lighthouse of Alexandria once stood. Academia 3 George Meade built many notable lighthouses in the US during the classical lighthouse period. He is remembered in history as the winning general in the Battle of Gettysburg. War 4 The tallest lighthouse in the world is the Yokohama Marine Tower in Yokohama, Japan. The structure ﬂ ashes alternately green and red every 20 seconds. Tallest 5 Originally lighthouses were lit merely with open ﬁ res, only later progressing through candles, lanterns and electric lights. Lanterns tended to use whale oil as fuel.

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