Tuesday, May 29, 2007

Seminar Topics - Brain Computer Interface

Brain-Computer interface is a staple of science fiction writing.  Init's earliest  incarnations nomechanism was thought necessary, as the  technology seemed so far fetched that no explanation was likely.   As more became known about the brain however, the possibility has become more real and the science fiction more technically sophisticated.  Recently, the cyberpunk movement has adopted the idea of 'jacking in', sliding 'biosoft' chips into slots implanted in the skull (Gibson, W. 1984).  

                              Although such  biosofts are still science fiction, there have been several recent steps toward interfacing the brain and computers.  Chief among these are techniques for stimulating and recording from areas of the brain with   permanently implanted electrodes and using conscious control of EEG to control computers. 

                                         

                                        Some preliminary work is being done on synapsing neurons on silicon transformers and on growing neurons into neural networks on top of computer chips.The most advanced work in designing a brain-computer interface has stemmed   from the evolution of traditional electrodes.  There are essentially two main problems, stimulating the brain (input) and recording from the brain (output).

                             

                                        Traditionally, both input and output were handled by electrodes pulled from metal wires and glass tubing.Using conventional electrodes, multi-unit recordings can be constructed from mutlibarrelled pipettes.   In addition to being fragile and bulky, the electrodes in these arrays are often too far apart, as most fine neural processes are only .1 to 2 µm apart.

                                   

 

                      Pickard describes a new type   of electrode, which circumvents many of the problems listed above.  These printed circuit micro-electrodes (PCMs) are manufactured in the same manner of computer chips.  A design of a chip is photoreduced to produce an image on a photosensitive glass plate. This is used as a mask, which covers a UV sensitive glass or plastic film.

   A PCM has three essential elements:

                           1) the tissue terminals,

                           2) a circuit board controlling or reading from the terminals      

                           3) a Input/Output controller-interpreter,  such as a computer.                                     

Engineering Seminar Topics

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For Seminar topics
log on to http://www.seminartopics.net

Saturday, May 26, 2007

Choreography

Choreography, in a Web services context, refers to specifications for how messages should flow among diverse, interconnected components and applications to ensure optimum interoperability. The term is borrowed from the dance world, in which choreography directs the movement and interactions of dancers.

Web services choreography can be categorized as abstract, portable or concrete:

  • In abstract choreography, exchanged messages are defined only according to the data type and transmission sequence.
  • Portable choreography defines the data type, transmission sequence, structure, control methods and technical parameters.
  • Concrete choreography is similar to portable choreography but includes, in addition, the source and destination URLs as well as security information such as digital certificates.