Transcript Information
Class 07 - Information What is Information? Class 07 - Information What is Information? • Information arts • Information design • Information society • Information age • Information system • Information theory What is information? Is it information? The next Mark Six result will be, 6, 22, 25, 39, 41, 49 + 13 What is information? Is it information? 你亞媽喺女人 How much information? Which one of the two previous messages contain more information? How to measure information? Any surprise? Clarify any uncertainty? Is information equal to meaning? Describing Information In-formation De-formation Trans-formation Con-formation What is form? What is form? Shape Pattern Relationships of parts in a system Form expresses relationships. Form vs. Information Information is not the same as form. Forming, informing, communicating, detecting, making known, etc. What is information anyway? Information is the transfer of form from one medium to another. Communication of relationships. Information, The New Language of Science, Hans Christian von Baeyer How is it done? When moving from one medium to another, the pattern/form has to be translated. Code Encoding and decoding Remember this And this Coding with fingers We can count from 0 to 1023 with 10 fingers. 1024 numbers are coded with the use of just 10 fingers. It is a kind of digital code, in fact, binary code. Any analog coding? Note that most analog signals are represented and transmitted through some kinds of wave. The most simple wave form is the Sine Wave. Sine wave The formula y = sin (t) Sine wave The general formula y = a*sin (w*t + b) Two sine waves can add together, y1 = a1*sin(w1*t + b1) y2 = a2*sin(w2*t + b2) to form a complex wave form. Fourier Theorem Any periodic function can be approximated by the sum of various sine waves. See the demonstration at http://www.jhu.edu/~signals/fourier2/ y = a1*sin(wt+b1) + a2*sin(2wt+b2) + a3*sin(3wt+b3) + … Fourier Theorem By finding out all the a’s and b’s for the formula, any periodic function can be encoded using these numbers: a1, b1, a2, b2, a3, b3, … y = a1*sin(wt+b1) + a2*sin(2wt+b2) + a3*sin(3wt+b3) + … That is the pre-digital computer age. Pairs of discrete numbers can be used to represent a continuous wave form. Being digital Then comes the digital age where a continuous function is represented by discrete numbers through the process of sampling. Remember the Director self portrait exercise. Analog or Digital Analog or Digital Analog or Digital Analog or Digital Analog or Digital Analog or Digital Analog or Digital Pig Analog or Digital Analog or Digital Analog or Digital Analog or Digital Analog or Digital Familiar coding Morse Code Two symbols, 3 including space, are used to represent all the letters and numbers. Note the number of digits for each characters vary. Another familiar code ASCII Code Note the use of 8 digits of binary code to represent all the characters commonly used in computer. Game • One student writes down the name of another student and hide it. • The other students guess the hidden name by asking questions to the first student. • The student can only answer yes or no. • See who gets it right first and count the number of questions asked. Game answer The amount of information containing in the question ‘who is the student?’ can be measured by the number of questions asked to discover that students. A good question may eliminate half of the students to be considered. Game answer If there are 16 students, one good question will reduce it to half, i.e. 8 students. 4 questions will be required to single out the hidden student. Note, 2 to the power 4 is 16. We need 4 binary digits to encode this piece of information. Information content Which one of the three pictures contain more information? Information content Which one of the three pictures contain more information? Number sequence revisited Take the following number sequences. Which one of them contain more information? 1, 2, 3, 4, 5, 6, 7, 8, 9, … 1, 2, 1, 2, 1, 2, 1, 2, 1, … 4, 7, 3, 1, 2, 1, 9, 6, 5, … 8, 8, 8, 8, 8, 8, 8, 8, 8, … 1, 2, 3, 5, 8, 3, 1, 4, 5, … Randomness A random sequence contains the most information. There is no formula to reproduce the sequence except by listing it out completely. There is no program/algorithm to generate the exact sequence except by copying and listing it out. Randomness and redundancy 4, 7, 3, 1, 2, 1, 9, 6, 5, … 1, 2, 1, 2, 1, 2, 1, 2, 1, … The first sequence seems to be random. The second is obviously not. It contains a lot of redundancy after the first 1, 2. Is it good to have no redundancy then? Redundancy Artworks and communication design contain a lot of redundancy. Redundancy Artworks and communication design contain a lot of redundancy. Redundancy Artworks and communication design contain a lot of redundancy. Redundancy Artworks and communication design contain a lot of redundancy. Every Icon John F. Simon http://www.numeral.com/appletsoftware/eicon.html