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Communications: from Shakespeare to Virtual Reality Dr. Ronald Pose Faculty of Information Technology Monash University.

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Presentation on theme: "Communications: from Shakespeare to Virtual Reality Dr. Ronald Pose Faculty of Information Technology Monash University."— Presentation transcript:

1 Communications: from Shakespeare to Virtual Reality Dr. Ronald Pose Faculty of Information Technology Monash University

2 Communication What does it mean to ‘communicate’ ? What is required to enable ‘communication’ ? How can one know if ‘communication’ has been achieved ?

3 Communication (2) ‘Communication’ involves at least 2 parties, one of whom communicates ‘something’ to other(s) In order to understand ‘communication’ we need to understand the nature of the communicating parties, and also the nature of the ‘something’

4 Communicating entities The parties that are communicating may be people or may be machines or other artifacts created for some purpose relating to the communication You may hear about communications networks comprising many interconnected computers; Is this communication?

5 What is communicated? Something? Information? Data? Ideas? Bits? We can give many definitions but in essence let us call the ‘something’ that is communicated, ‘information’

6 What is information? Shannon defined ‘information’ in terms related to ‘entropy’, a measure of the ‘disorder’ of the universe This provides a nice analytic definition but let us avoid any mathematical intricacies and instead just consider the gaining of information as equivalent to learning something new, something you did not already know.

7 What is information? (2) I contend that information is ‘physical’ that it cannot exist other than in some physical form that it is not simply an abstraction If this is so, then communication is the transfer of information from one party to other(s) It then follows that communication must take the form of a physical process Not everyone takes this viewpoint

8 Shakespeare’s 18th Sonnet Shall I compare thee to a summer's day? Thou art more lovely and more temperate: Rough winds do shake the darling buds of May, And summer's lease hath all too short a date: Sometime too hot the eye of heaven shines, And often is his gold complexion dimm'd; And every fair from fair sometime declines, By chance or nature's changing course untrimm'd; But thy eternal summer shall not fade Nor lose possession of that fair thou owest; Nor shall Death brag thou wander'st in his shade, When in eternal lines to time thou growest: So long as men can breathe or eyes can see, So long lives this and this gives life to thee.

9 Shakespeare communicating with us Who are the communicating parties? –Shakespeare communicating with us? What is being communicated? –Shakespeare’s 18th sonnet? –The words of the 18th sonnet? –A representation of the 18th sonnet? –A representation of the words of the 18th sonnet? How is the communication taking place?

10 Shakespeare communicating with us (2) Let us take Shakespeare (whoever that may be) as the source of the communication, and ourselves as the recipients Is it important that we know who/what/where the communication originated? Is it important that the originator of the communication knows anything about the recipients? Does communication have to be intentional?

11 Shakespeare Let us assume that Shakespeare was a man If we were to assume otherwise would that affect the nature of the communication of the sonnet? What is a sonnet? Does it matter that we know this ‘information’ is a sonnet? How does one know that communication has taken place? What is the ‘information content’ of the communication?

12 Sonnet A Shakespearean, or English sonnet consists of 14 lines each line contains ten syllables each line is written in iambic pentameter in which a pattern of a non-emphasized syllable followed by an emphasized syllable is repeated five times The rhyme scheme in a Shakespearean sonnet is ABAB CDCD EFEF GG in which the last two lines are a rhyming couplet.

13 Communicating a sonnet We know now that we are dealing with an English sonnet, and how English sonnets are structured We thus are better able to interpret / understand the sonnet What about the language? –English has changed a great deal since Shakespeare Given the changes in language and the general ignorance of what a sonnet is, can we say that the sonnet as Shakespeare conceived it, has been communicated?

14 Communicating a sonnet We know now that we are dealing with an English sonnet, and how English sonnets are structured We thus are better able to interpret / understand the sonnet What about the language? –English has changed a great deal since Shakespeare Given the changes in language and the general ignorance of what a sonnet is, can we say that the sonnet as Shakespeare conceived it, has been communicated?

15 Representation No matter what a sonnet is, I contend that what is communicated is at most a representation of a sonnet A sonnet may be represented in many ways: –Text –Sound recording of a person reciting the sonnet The key thing is that a representation purposefully includes a selection of the information content of the sonnet –Note that a representation has a purpose and that the purpose influences the selection of the information to be included

16 Representation as the thing that is communicated I contend that what is actually communicated is a ‘representation’ rather than the actual thing I contend that depending on the purpose of the communication, different representations may be used, perhaps emphasizing different information I contend that the representation is encoded into a convenient form for communication under the assumption that a suitable decoder is employed by the recipient I contend that there is usually an assumption that the recipient can use the representation to be informed about the original thing

17 Communication schematic Sonnet

18 Communication processes Thing is created Representation of ‘thing’ is created for a particular purpose incorporating information relevant to that purpose The representation is encoded in a language or form understandable by the intended recipients The encoded representation is sent to the recipient Recipient decodes the representation Information obtained via the representation gives the recipient some notion of the original thing

19 Observations The ‘thing’ may or may not exist as a physical object but must have information content, hence must in some way have a physical existence The representation must at best contain a subset of the content of the ‘thing’ –It is not the ‘thing’ otherwise communication would be akin to cloning The representation may involve a language such as English, or a more formal language such as Fortran or mathematical notations, or be pictorial, or of other forms The representation may be encoded into binary, compressed, or otherwise transformed for convenience in transfering to the recipient

20 Observations (2) Not all representations are equal –Some representations may be better at preserving the information that they are intended to convey A representation in essence reflects a model of the ‘thing’ in which salient aspects are preserved The mapping between the ‘thing’ and a ‘representation’ of the thing is not intrinsic in the representation or the thing, hence it may be necessary to communicate not only the representation but also more details of the model that links it back to the ‘thing’ –i.e. beware of assuming that the recipient can understand the language of the representation The encoding of the representation, whether it be a language text, a picture, or some other form, often ends up as a binary stream in modern digital communications technology –This has to be decoded to recover the representation, so knowledge of the encoding/decoding process may also have to be communicated

21 Back to Computer Science How does this seemingly esoteric discussion of representation, encoding and communication relate to Computer Science or Software Engineering? Well, in fact this is the essence of Computer Science What do we do with computers? –We model aspects of the natural or man-made world and derive information from that model that we can use to help us manage or manipulate the world A computer system may be used by a bank to manage its assets, loans, borrowers and lenders –A model is made of the relevant features of those parts of the banking world that are of interest –Borrowers and lenders may be represented by name, address, age, some view of their financial and other assets, etc. –At the base level these may come down to character strings, integers, etc. –The banking transactions are in effect communications among these represented entities in which information is transferred appropriately, perhaps within the computer system, perhaps between networked computer systems –There is also communication between the bank’s computer systems and its users, both staff and customers, in branches and at ATMs

22 Forms of representation Our banking example used mostly textual and numeric representational forms Other applications may use graphical forms –Radar images representing rainfall –Synoptic charts depicting isobars of air pressure –Charts depicting population density –Architectural plans –Pert charts –Flow charts –Anatomical or botanical illustrations What about sound and music recordings as representations? There are many choices of representations available –The ‘correct’ choice depends on the purpose for the representation The richness and complexity of the representation will impose demands on the encoding and transmission components of the communication system

23 Pictorial representation

24 Pictorial representation(2) Picasso using a cubist representation of a woman enables us to see the nose and mouth in profile and the eyes from the front We can see so much more in this representation than would be possible if one took a photograph with a conventional camera

25 Pictorial representation(3) Drawing plants is often a better way to record them than photography because through drawing it is possible to highlight on a single page important features as well as to show different stages of development

26 Pictorial representation(4) One-point perspective

27 Pictorial representation(5) two-point perspective three-point perspective

28 Pictorial representation(6) Note that none of these pictorial representations is a complete description of the underlying ‘thing’ being represented The various views expose different aspects of the thing being represented Different information is being presented Thus as in textual, poetic or other representations there is no true representation Somewhat arbitrary choices are made, and the only real indication of quality is whether it serves its purpose in conveying the required information

29 Virtual Reality (representation) In our human experience we employ all our senses to gather information about the environment in which we live Our interactions with computer-based models generally are textual or graphical Virtual Reality systems attempt to engage more of the human user’s senses to try to convey more information, or perhaps different aspects or perspectives of the world being represented Such systems can use stereoscopic moving images, stereophonic sound, perhaps some haptic feedback, even more exotic things such as temperature

30 Virtual Reality (representation) In our human experience we employ all our senses to gather information about the environment in which we live Our interactions with computer-based models generally are textual or graphical Virtual Reality systems attempt to engage more of the human user’s senses to try to convey more information, or perhaps different aspects or perspectives of the world being represented Such systems can use stereoscopic moving images, stereophonic sound, perhaps some haptic feedback, even more exotic things such as temperature

31 Casey Chow modelling a Vector Research V8 with a mechanically coupled tracker

32 Communication revisited Let us assume human-human communication I assume that you function as sentient beings in some way similarly to the way I do I have a mental model, a representation perhaps encapsulated as part of the state of my brain, that I wish to communicate to you Thus as an outcome of the communication process I wish to change the state of your brain to incorporate a mental model of the ‘thing’ I am communicating How presumptuous of me to want to change your brain, to want to change the very essence of your being How do I know that I have achieved this? Can I ever achieve such communication? What has this to do with computer science or software engineering?

33 Computation What do we mean by computation? What does a computer program do? Typically computer programs model real-world phenomena, processes, things In order to do this a representation or model is created that incorporates salient features of aspects of the real world that are relevant This is represented in the form of data structures and algorithms encoded in various formal computer languages These representations take the physical form of state in some computational machinery Doesn’t this seem like an analogous situation to the case of communication we have been exploring?

34 Computation (2) Consider the execution of a typical computer program on a von Neumann computer or if you prefer in a Turing machine Typically the algorithm will comprise a number of ‘assignment statements’ which copy values (perhaps modified) from one memory location to another –Surely this is an instance of communication –Values moving from one place to another is communication Is there a difference between computation and communication?

35 Computation (3) Our representation of the aspects of the world we are modelling with our computer program may be expressed in a computer programming language In one sense we can consider a computer programmer as communicating his model of the world of interest to the computer system using a language such as Java The computer system interprets this program and so may manipulate the representation of the world of concern

36 Computation (4) OK, so a computer programmer communicates to the computer using a programming language to express the representation of the model The computer system communicates with its users via its input/output system whereby it can obtain data to feed its representation of the world and it can provide output to the users or perhaps to other computer systems

37 Computation versus Communication When I claim that communication and computation are essentially equivalent, in fact two ways of viewing the same phenomenon, I speak not of a highly abstract, mathematically equivalent model in which communication and computation have the same forms, rather I know this through experience of seeing and building communications networks and computer hardware The physical structures of communications networks and of computers are the same

38 Communications Network A computer communications network comprising computers interconnected with wires and switches

39 Inside a computer A 14 transistor circuit that forms a full adder A+B+Carry-in -> Sum, Carry-out A modern digital electronic computer can be made entirely of wires and switches (transistors)

40 Computers versus communication networks Computers and communications networks can both be made from wires of various quality (to conduct electricity) and switches of various quality (e.g. transistors) Both simply require some energy (e.g. electricity) Both do communications in that information is moved around along the wires and through switches There seems to be an arbitrary boundary between the computers and the communications network that interconnects them When one looks closely all one sees is a richly interconnected set of switches We view such a set of interconnected switches as a computer when we interpret the information flows and transformations happening with such a system as a computation I contend we can do computation in an analogous way in a communications network

41 Computation versus communication OK, so we can see that computers and communications networks, the physical devices in which computation and communication are performed, have the same structure and form of operations Can we relate the more theoretical descriptions of computation (Turing) and communication (Shannon)? The answer is yes, but it is a much more subtle and abstract path to take If one does it carefully one will reach the same conclusion, that the distinction between computation and communication is simply where one draws the boundary between the computer and the interconnection network over which computers communicate Another way to view it would be as a single distributed computer system, or as a network of individual computers

42 Summary We have looked at communication, human-human and human- computer and computer-computer We discovered that communication involves representation and encoding of the representation using some language or notation The encoded representation is transferred to the recipient Communication is only successful if the recipient knows how to decode the representation and can also relate the representation to the intended informational domain We also discovered that our computational systems also involve an analogous representational and encoding process When we examine the computer and communications hardware we find similar structures in both and the same principles of operation We conclude that communication and computation are essentially the same thing, or perhaps two ways of looking at the same thing One can take Turing’s computational model and Shannon’s communicational model and demonstrate the same thing in a more mathematical way

43 Further exploration In preparing this talk I looked for documents exploring the relationship of communication and computation I also looked for documents describing representation There is a long history of study of what the essence of an object or of the world really is, going back to the ancient Greeks and beyond This notion of ‘being’ or if you like, what something ‘is’ is the realm of ONTOLOGY, not to be confused with the current hijacking of the word to mean a controlled vocabulary enabling discourse about a domain The representation of something and its description and encoding via language must have ways of signifying what is being represented. This is the realm of SEMIOTICS and its branch called SEMANTICS What we know about the world is often communicated in various ways so one may also be interested in EPISTEMOLOGY, the study of knowledge

44 Another presentation For those that feel inclined to another episode of unusual and ‘politically incorrect’ thinking about computation and communication, let me invite you to another talk, focusing on Human-Computer Interaction (HCI), where we will explore in some detail the use of Virtual Reality systems as the ultimate HCI, and whether it is a good thing Is Virtual Reality the ultimate HCI for all computer usage, work and play? Dr. Ronald Pose Tuesday 2nd June 2009, Lecture Theatre H3 Monash University, Clayton Campus


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