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Senior Science 9.4 Information Systems Section 1 A Variety of Information Systems © P Wilkinson 2002-04 9.4 Section 1 ::: A Variety of Information Systems 9.4.1 Information systems are many and varied and depend on the transfer of energy from place to place 9.4.1.a Outline the basic pattern of the information transfer process as – code common to both parties – message – transmission of coded message – decoder 9.4.1.b Identify a range of information systems used daily 9.4.1.c Classify these systems as – verbal and non-verbal – short distance and long distance – electronic and non-electronic 9.4.1.d Recall phenomena and events where different forms of energy are used 9.4.1.e Identify the transformation of energy at each stage of information transfer in one of the following devices – land connected telephones – mobile phones – television – radios – Compact Disc players 9.4.1.f Discuss the advantages of using a range of information systems 9.4.1.i Gather and process first-hand and secondary information on the basic pattern of the information transfer process in one of the following systems: – land connected telephones – mobile phones – television – radios – Compact Disc players to outline features that the systems have in common and use available evidence to discuss the applications of these systems 9.4.1.ii Gather and process information from secondary sources to develop a timeline of communication systems introduced to society and use the available evidence to analyse the impact these systems have had on society and predict future directions in communication technologies © P Wilkinson 2002-04 2 9.4.1.a Outline the basic pattern of the information transfer process as – code common to both parties – message – transmission of coded message – decoder The Communication Process What is Communication? Communication is the sharing of information. Information can be shared (communicated) in many ways. People can communicate using language. This is one of the main factors responsible for our advanced technological society. It allows people to think abstract thoughts and to communicate these thoughts to others. Communication is the transfer of information from one person to another. It is important to remember that communication is a process - involving several steps. © P Wilkinson 2002-04 3 The Basic Pattern Of Information Transfer What happens when people communicate? What steps are followed (in the communication process)? 1. IDEA: The sender develops an idea or thought. 2. CODE: The idea of the sender is put into a code (some form of message that is understood (and can be decoded) by the sender and receiver) 3. TRANSMISSION: various communication channels transmit the message. Eg. Sound waves - talking Electrical currents - telephone EM radiation - radio, TV 4. DECODE: The receiver decodes the message (since he understands the message) 5. FEEDBACK (RESPONSE): The receiver then has the idea and is able to respond to it, using the same steps. INTERFERENCE (NOISE) IDEA--> CODE--> TRANSMISSION -->DECODE CARRIER / MEDIUM -->IDEA FEEDBACK Interference is any problem that does not assist communication. It is normally called noise. Certain types of communication are more affected by 'noise' than others. Feedback is very important in communication. Communication involves the transfer of energy from place to place. © P Wilkinson 2002-04 4 9.4.1.b Identify a range of information systems used daily 9.4.1.c Classify these systems as – verbal and non-verbal – short distance and long distance – electronic and non-electronic Variety Of Information Systems People communicate in many ways. The method of communication varies. The technologies used are constantly being changed. What to do List as many examples of information or communication systems as you can. These may be: forms of communication or technologies used in communication include The list has been started for you (AT LEAST TWENTY (20) EXAMPLES) * Signs * Braille * Lasers (T) * Bar - codes * Semaphore (flags) * * * Classification Of Communication Systems The various forms of communication can be divided into several groups (of two). What to do COPY and COMPLETE the table below. Certain types of communication can be grouped as either verbal or non-verbal. The telephone would be an example of a verbal communication device. Signs are examples of non-verbal communication devices. GROUP 1 EXAMPLES VERBAL 1. Telephone 2. 3. GROUP 2 EXAMPLES © P Wilkinson 2002-04 1. Signs 2. 3. SHORT DISTANCE OR LONG DISTANCE 1. 2. 3. GROUP 3 EXAMPLES OR NON-VERBAL 1. 2. 3. ELECTRONIC OR NON-ELECTRONIC 1. 2. 3. 1. 2. 3. 5 9.4.1.i Gather and process first-hand and secondary information on the basic pattern of the information transfer process in one of the following systems: – land connected telephones – mobile phones – television – radios – Compact Disc players to outline features that the systems have in common and use available evidence to discuss the applications of these systems Communication Systems Information In any communication there is * a step involving coding, * a step involving transmission & * A step involving decoding. For example in a telephone there is * a part for coding (mouthpiece), * a transmission part (wire - electricity) & * A part for decoding (earpiece). At each step there is a change in energy so that energy travels from one place to another. Talking Communication means the message must travel somewhere else. The brain creates a message, coded in a particular language. The voice box then vibrates in a pattern. This causes the surrounding air to vibrate with the same pattern. The air vibrations are called sound waves. These spread out and carry the message through the air. Therefore, the voice box is the coding device and the sound wave is the transmission channel. Since the sound wave must travel through air, the air is called the transmission medium. When the sound wave reaches the ear the pattern in the sound wave is decoded. The ear is called the decoding device. The brain interprets the message. The coding device and the decoding device are energy converters. These devices cause a transformation of energy to occur. In speech, the mechanical energy of the vocal cords is converted into sound energy. The sound energy can then travel (be transmitted) through the air (or other matter). The decoding device, the ear, converts the sound energy back into mechanical energy. This mechanical energy causes the vibrations in the various parts of the ear that allow us to hear. Notes Questions 1. What is the coding device when a person speaks? 2. What is the transmission channel when a person speaks? 3. What is needed for a sound wave to travel? © P Wilkinson 2002-04 6 4. What is the decoding device involved in speaking? 5. Copy and complete the table for talking Communication Code System Coding device Transmission channel Transmission medium Decoding device 6. What happens in a coding device? 7. What energy transformation occurs in the voice box? 8. What energy transformation occurs in the ear? 9. What energy is involved in transmission when a person speaks? 10. Classify talking as a communication system – verbal or non-verbal; electronic?; Land connected telephone The brain develops a message. The vibrations of the voice box are converted into the vibrations of air (sound wave). The sound waves are converted into electrical vibrations by a coding device – the mouthpiece or microphone in the telephone. These electrical vibrations are transmitted along wires (or converted to light to travel in optical fibres). When the electrical vibrations reach their destination they are decoded to become vibrations in the air (sound waves). The ear (the hairs in the cochlea vibrate) decodes the sound waves. The brain interprets the message. In all communication devices the same pattern of vibrations is transmitted through a series of coding and decoding devices. At each of these devices a transformation of energy occurs. This energy transformation occurs so that the pattern can be transmitted. The invention of the telephone involved the development of new technologies. The microphone - the coding device - converts sound energy to electrical energy The earpiece (or loudspeaker) Diagram - the decoding device - converts electrical energy to sound energy The vibrations produced at various stages in a telephone communication Voice box Microphone Electricity Wires © P Wilkinson 2002-04 7 Ear piece Ear Notes Questions 11. Name the two coding devices associated with a telephone communication. 12. Name the two transmission channels associated with a telephone communication. 13. Name one other transmission channel associated with a telephone communication. 14. Name the two coding devices associated with a telephone communication. 15. Identify the main coding device associated with a telephone communication. 16. Identify the main transmission channel associated with a telephone communication. 17. Identify the main decoding device associated with a telephone communication. 18. Copy and complete the flow chart below. Use the groups of words listed below. Vibrations in the Cochlear Electrical vibrations Vibrations of the vocal cords Vibrations in the air – Sound Waves Vibrations in the air – Sound Waves Vibrations of the vocal cords Diagram: Sequence of vibration changes that occur with a telephone communication 19. Copy and complete the table for the telephone connected by wires. Communication System Code Coding device Transmission channel Transmission medium Decoding device 20. Copy and complete the table for the telephone connected by optical fibres. Communication System Code Coding device Transmission channel Transmission medium Decoding device 21. What energy transformation occurs in the microphone? 22. What two energies are used to transmit information in a telephone communication? 23. What other energy is used in a telephone communication? 24. Identify six features that telephone communication and talking have in common. © P Wilkinson 2002-04 8 Radio The diagram below shows how a radio works. Transmission The coding device for a radio is the radio transmitter. This consists of a set of electric circuits: an audio circuit producing an audio signal, a circuit generating a high frequency carrier signal and a modulating circuit that adds these to currents to produce a modulated signal that can then be transmitted into “space” by the aerial. Reception The decoding device (a diode at its simplest) converts the modulated signal into the original audio signal that can work an amplifier. © P Wilkinson 2002-04 9 The diagram shows that a communication by a radio involves three coding devices involved in transmission. There are also three decoding devices involved in reception. As in all communication devices the same pattern of vibrations is transmitted through this series of coding and decoding devices. At each of these devices a transformation of energy occurs. This energy transformation occurs so that the pattern can be transmitted. The invention of the radio involved the development of new technologies. The modulation circuits The transmitting aerial – converts electrical energy into electromagnetic energy The receiving aerial - converts electromagnetic energy into electrical energy The diode Notes Questions 25. Name the three coding devices associated with radio communication? 26. Name the three transmission channels associated with radio communication? 27. Name the three decoding devices associated with radio communication? 28. Name the main coding device associated with radio communication? 29. Name the main transmission channel associated with radio communication? 30. Name the main decoding device associated with radio communication? 31. Copy and complete the table for the radio. Communication System Code Coding device Transmission channel Transmission medium Decoding device 32. Outline six features that radio and telephone communication have in common. © P Wilkinson 2002-04 10 Television Reception How can electricity carry a visual image? The device used to convert electrical pulses into an image is called a cathode ray tube. The front of a TV screen is one end of a cathode ray tube. The inside surface of this screen is coated with a chemical that will glow when a beam of electrons hits it. An electron gun fires a beam of electrons at the screen. The beam moves in lines across the screen from one side to the other (ie quickly working across, down, across and down the screen). This is similar to how people read a book – one line at a time working down the page. The process is known as scanning. As the beam scans the screen, the intensity of the light produced can be varied producing a picture. The beam and therefore the pattern of light produced is controlled by an electrical signal. This electrical signal has a particular pattern determined by the original picture. Recording A TV camera also has a cathode ray tube. Light from a scene enters the camera and is focused onto the light sensitive screen. An electron gun fires a beam of electrons onto the screen using the same scanning motion as in the TV. By a variety of methods the visual pattern is coded into a stream of electrical impulses. The electrical intensity of the impulses varies according to the amount of light falling on the parts of the screen. That is an electrical pattern of the scene is created. Transmission The electrical pattern is transmitted using wires, radio waves or optical fibres. To make sure the camera scan and the TV scan stay in step with each other, a number of synchronizing pulses are also sent. One pulse is sent at the end of each line. This tells the receiver’s electron gun to move back and start a new line. For colour TV, a minimum of seven signals is needed at the same time. One signal for each of the three primary colours – the blue, red and yellow patterns At least two signals for stereo sound. At least two synchronization signals Notes Questions 33. Draw a flow chart of the sequence of events that occurs for: a. the reception of information by a television. b. the recording of information by a television. EVENT 34. Copy and complete the table for the television. Communication Code Coding Transmission channel System device Transmission medium Decoding device 35. Outline six features that radio and telephone communication have in common. © P Wilkinson 2002-04 11 Research - Mobile telephones Mobile phones combine the technologies of telephones and advances in radio communication to provide people with high speed, private and mobile communication. The Task Gather and process first-hand and secondary information on the basic pattern of the information transfer process in mobile phones to outline features that mobile phones have in common with radio communication and use available evidence to discuss the application of mobile phones What to do 1. Describe how the system of mobile phone telephone communication works. Use one diagram to help with the description. [6 marks] Marking Criteria Uses own words to provide several essential features of a mobile phone system including Cells Variation in frequencies used Connection with traditional telephone system Labeled diagram showing cells Uses own words to provide some features of the system with labeled diagram used Provide some features of the system and / or labeled diagram used 2. Answer true (T) of False (F) for each of the following statements. Marks 5-6 3-4 1-2 [5 marks] a. Mobile phones operate using the same frequency at all times _____ b. Mobile phone communication is completely private _____ c. Mobile phones have a small aerial _____ d. The transmission channel for a mobile phone is an electromagnetic wave _____ e. Mobile phones could be regarded as a long distance communication device f. A coding device used in a mobile phone is an earpiece _____ g. A pattern of vibrations is transmitted by a mobile phone _____ h. Transformations of energy occur in mobile phone communication _____ i. Mobile phones could be classified as non-electronic communication _____ j. Information in mobiles is coded in modulated radio waves _____ © P Wilkinson 2002-04 12 ____ 3. Copy & complete the table to summarize basic pattern of communication for a mobile phone. [5 marks] Communication System 3 H3, H4 Code Coding device 9.4.1.a Transmission channel Transmission medium Not a HSC style question Decoding device Marks Marking Criteria One mark for each part of the table 5 Marks 0-5 4. Outline the features that mobile phones have in common with radio communication [3 marks] 4 H3, H4 9.4.1.i HSC style question Marks Marking Criteria Outlines at least three essential common features of mobile & radio communication Identifies common features 5. Discuss the applications of mobile phones 3 Marks 3 1-2 [6 marks] Use a table like the one below to help structure the answer. Issue 1 Points for Issue 2 Points for 5 H3, H4 Points against Points against 9.4.1.i HSC style question Marking Criteria Identifies at least two issues Provides significant and detailed points for and/or against for each issue Identifies at least two issues Provides some detailed points for and/or against one issue Identifies at one issue Provides points for and/or against one issue © P Wilkinson 2002-04 13 Marks 6 Marks 5-6 3-4 1-2 Compact Discs In a compact disc a physical pattern is recorded. A series of flats and bumps exists on what appears to be the flat disc surface. As the disc spins, laser light is reflected from the disc surface. The reflections are picked up by a photodiode that creates an electric current. As such the photodiode is the decoding device for a CD. Different amounts of light are reflected from the flat areas and the bumps. The electrical pattern produced depends on the amount of laser light reflected to the photodiode. This electrical pattern is digital, and is an exact replica of the original signal used to create the CD recording. To ‘burn’ (or code) a CD the reverse process occurs. A changing electric current controls a laser beam that burns a pattern of flats and bumps on the disc. Since only laser light touches the disc surface there is little or no wear of the CD surface. It is interesting to note that a compact disc spins at several rpm; more than a million pieces of information can be recorded every second; there are about 600 tracks per millimetre on a disc. Notes Questions 36. How is data stored on a Compact disc? 37. What energy change occurs in a photodiode? 38. Research What is meant by digital? 39. Discuss the idea of a transmission channel for a CD. 40. Copy & complete the table to summarize basic pattern of communication for a CD. Communication System © P Wilkinson 2002-04 Code Coding device Transmission channel Transmission medium 14 Decoding device Diagram A diagrammatic summary of the coding devices, decoding devices, transmission channels, transmission media and energy changes in communication systems. Energy Mechanical Changes to Sound Coding device Sound to Electrical Transmission Channel Coding device Electrical to Electromagnetic Transmission Channel Coding device Transmission Channel CD Burner To Storage Radio Wave TV Transmitter Voice Box Sound Waves Microphone Electrical Current Radio Transmitter Radio Wave Ear Sound Waves Loudspeaker Electrical Current Radio Receiver Radio Wave Talking ----------------------------------------- Telephone -------------------------------------------------------------------------------- Radio ---------------------------------------------------------------- Decoding device Energy Sound to Changes Mechanical © P Wilkinson 2002-04 Transmission Channel Decoding device Electrical to Sound 15 Transmission Channel TV Receiver Radio Wave CD Player From Storage Decoding device Transmission Channel Electromagnetic to Electrical 9.4.1.d Recall phenomena and events where different forms of energy are used Using Energy Every day people use several types of energy. The use of energy generally involves the conversion of one type of energy into another. When you switch on a light you used electrical energy to produce light energy. When walking around the house you convert chemical energy into kinetic energy. When using a toaster electrical energy is converted into a type of radiant energy –infra red (felt as heat) When you talk mechanical energy is converted into sound energy. Notes questions 41. What type of energy is stored in petrol? 42. What type of energy is associated with a moving car? 43. What energy conversion occurs in a car? Communication Systems and energy Information systems depend on the transfer of energy from place to place. The coding device and the decoding device used in communication systems are energy converters. These devices cause a transformation of energy to occur. Notes Questions 44. What type of energy is needed to work a loudspeaker? 45. What type of energy is heard when listening to a loudspeaker? 46. What energy transformation occurs in a loudspeaker 47. What type of energy is transmitted by a radio? 48. What type of energy is produced in a receiving aerial? 49. Identify the energy transformation that occurs in three coding or decoding devices. © P Wilkinson 2002-04 16 9.4.1.e Identify the transformation of energy at each stage of information transfer in one of the following devices – Land connected telephones – Mobile phones – Television – Radios – Compact Disc players Energy changes in a mobile phone. The flow chart shows the events in the transfer of information for a mobile phone. Identify the transformation of energy that occurs at various points in the flow chart. Possible energies include: mechanical, sound, electrical, radiant. ENERGY TRANSFORMATION??? EVENT Brain develops an idea Electrical impulses travel from brain to voice box via nerves. Electrical impulses converted into sound wave by the voice box Sound travels through the air and reaches microphone in the mobile Microphone converts sound wave into an electrical signal Electrical signal from microphone is added to a high frequency alternating current to produce a modulated high frequency signal This HF signal can be transmitted by aerial in the form of a microwave Microwave travels through air or space to microwave dish that collects, cleans, amplifies and then retransmits the wave to another mobile. Aerial of second mobile detects and then converts the microwave into a high frequency electrical current. Circuit in the phone separates the original electrical signal from the HF alternating current Ear piece converts electrical signal into sound wave Sound wave travels to persons ear Ear converts the sound Into electrical impulses Electrical impulses travel to brain via nerves where the message is interpreted © P Wilkinson 2002-04 17 9.4.1.ii Gather and process information from secondary sources to develop a timeline of communication systems introduced to society and use the available evidence to analyse the impact these systems have had on society and predict future directions in communication technologies Communication technologies and benefits to society - Comprehension Animals communicate using facial expressions, sounds, body positions and body features. Early people probably communicated in a similar way to animals - by facial expressions and sounds. Over a long period of time, people developed (invented) language (words). The benefit to society was that language allowed ideas to be expressed more easily. Quality Writing was an important technological development in communication. Society benefited from writing because it improved the quality of communication. It allowed complicated messages to be sent over long distances. The memory of the messenger was no longer important. Such written information was important for business people and military leaders. Writing also allowed information to be stored for later use. Writing required materials. People throughout history developed materials on which to write. Such materials included papyrus, parchment, velum and Paper. Cai Lun invented paper in China in AD 105. Quantity A major advance in written communication occurred with the development of printing. Printing benefited society because it allowed more books to be made. This resulted in a much wider spread of knowledge (to many people). Before the invention of printing, books were hand copied - therefore very few books were produced. The invention of movable type was an important technological development in printing. It allowed the same carved letters to be used, separated and used over and over again. Movable type made printing much faster. This allowed many, many more books to be produced. Other technological advances further improved written communication. These also improved the quantity of information communicated. © P Wilkinson 2002-04 18 * * * In 1811 a steam engine was used to drive a printing press. This made printing much faster. In 1868 the first practical typewriter was patented. Photography was invented in 1826. Speed Writing and printing improved the quality and quantity of communication. They had no effect on the speed of communication. Over long distances communication was quite slow. For example, the first European settlers to reach Australia could wait for as long as three years to receive replies to letters sent `home' to England, by boat. Science discovered and developed electricity. This allowed great advances in communication. An important technological advance, using electricity, occurred in 1840. Samuel Morse developed the telegraph. The telegraph increased the speed of communication over large distances. It used a system of dots and dashes (Morse Code) to code messages. Submarine telegraph cables were laid to link people separated by water. Using a series of manned repeater stations the first telegram was sent 20 000 miles from London to Australia in 1872. Telegraph communication was much quicker than sending a letter by boat. Laying submarine cables (wires) is very expensive. An Italian scientist, Guglielmo Marconi, developed wireless communication around 1895. Wireless communication was much cheaper than the telegraph using wires. Wireless telegraph was much faster and it allowed ship-to-ship communication. Private Communication One problem with the telegraph, either cable or wireless was that it required skilled operators. As such it was not private since all communications passed through the hands of these operators. The telephone, invented by Alexander G. Bell in 1876, removed this problem. The advantages of the telephone were that it was simple to use, and allowed rapid, private and long distant communication. Mass Communication To communicate a message to a large number of people can be a difficult task. Many, many years ago town criers were employed. With the invention of rapid printing presses, leaflets and newspapers could spread information widely. Today, however, the task of mass communication is occurs by using radio and TV. © P Wilkinson 2002-04 19 What to do 1 2 Copy and complete the table below by a) Listing all the technological or scientific advances mentioned b) Outlining how these advances benefited society. SCIENTIFIC OR TECHNOLOGICAL ADVANCE BENEFIT TO SOCIETY Invention of language * allowed ideas to be expressed more easily Invention of writing * * Copy and complete Steam engine, Speed, Telephone, Thousands, typewriter, Quantity, Television, Paper, Radio, Radio, Quality, Television, a. Writing increased the _____ of communication. b. Printing increased the _____ of communication. c. The discovery of electricity led to an increase in the _____ of long distance communication. d. Private, rapid long distance communication became possible with the _____. e. The invention of the ______ and _____ helped speed up printing and contributed to an increase in the quantity of communication. f. Rapid, long distance communication with ships was possible with the invention of the _____. g. Long distance communication has been possible for _____ of years. h. The most modern form of mass communication is _____. i. Paper had to be invented before writing was developed. j. One advantage of _____ communication is that it does not need a physical link for communication to occur. © P Wilkinson 2002-04 20 9.4.1.ii Gather and process information from secondary sources to develop a timeline of communication systems introduced to society and use the available evidence to analyse the impact these systems have had on society and predict future directions in communication technologies 9.4.1.f Discuss the advantages of using a range of information systems ASSIGNMENT A History Of Communication What to do 1. For a disaster situation (eg bush fire danger), discuss advantages of using a range of communication devices. [5 marks] Marking Criteria Identifies at least two issues Provides significant and detailed points for and/or against for each issue Identifies at least two issues Provides some detailed points for and/or against one issue Identifies at one issue Provides points for and/or against one issue 2. Develop a time line of the communication systems or technologies Marks 5 3-4 1-2 [5 marks] The time line must contain a minimum of twelve and a maximum of fifteen communication systems or devices. One communication advance for each of the following time periods must be included: Before 1900. Between 1940 and 1980 After 1985 Information from the web site www.phonetics.com.au must be used. information from this site must also be identified. World Book Encyclopaedia – Communication has a useful time line. Marking Criteria Timeline contains all the following features Set out as a timeline At least 12 systems or technologies Mandatory dates covered Specified web site used and identified Marks 5 Some of the features incomplete © P Wilkinson 2002-04 The 1-4 21 3. Analyse the impact two of these systems or technologies have had on society [10 marks – 2 x 5 marks] The following format must be used for each system or technology Maximum of 250 words for each system or technology Use the comprehension exercise for ideas – quantity, quality, speed, mass communication, private communication Communication system or technology This section carries the least weight for marks – 1 to 2 marks Date discovered / developed Brief description of the communication device / system Analyse the impact of the communication system on society. If possible, name the system replaced by new development List benefits to society and or list problems created (if any) Other Marking Criteria – for each system Identify date discovered Brief description of the communication device/system Identify several general impacts on society Add detail by outlining specific examples of impact Outline benefits and problems of communication technology Identify date discovered Brief description of the communication device/system Identify a few general impacts on society Outline some examples of impact Outline benefits and/or problems of communication technology Identify date discovered Brief description of the communication device/system Identify one or two general impacts on society Identify benefits and/or problems of communication technology © P Wilkinson 2002-04 22 This section carries the most weight for marks – 3 to 4 marks Marks 5 3-4 1-2