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Computer Networks/Networks




                    Notes              milliseconds. So, jitter of only a few milliseconds during a multimedia transmission
                                       affects the perceived sound quality more than it affects the perceived image quality.
                                   5.  Video: The human eye has the property that when an image is flashed on the retina, it is
                                       retained for a few milliseconds before decaying. If a sequence of images is flashed at 50 or
                                       more images/sec, the eye does not notice that it is looking at discrete images. All TV
                                       systems exploit this property to produce moving pictures.
                                       Currently, video is good for:
                                       (i)  Promoting television shows, films, or other non-computer media that traditionally
                                            have used trailers in their advertising.
                                       (ii)  Giving users an impression of a speaker’s personality.
                                       (iii)  Showing things that move. For example, a clip from a motion picture. Product
                                            demos of physical products are also well suited for video.

                                   12.4.2 Uses of Multimedia

                                   Placing the media in a perspective within the instructional process is an important role of the
                                   teacher and library professional. Following are the possible areas of application of multimedia:
                                       Can be used as reinforcement
                                       Can be used to clarify or symbolize a concept
                                       Creates the positive attitude of individuals toward what they are learning and the learning
                                       process itself can be enhanced.
                                       The content of a topic can be more carefully selected and organized
                                       The teaching and learning can be more interesting and interactive

                                       The delivery of instruction can be more standardized.
                                       The length of time needed for instruction can be reduced.
                                       The instruction can be provided when and where desired or necessary.

                                   12.5 Summary


                                       The uppermost layer of OSI models provides a number of services to the users using the
                                       TCP/IP protocol. The Socket interface is used to provide a standard, well-documented
                                       approach to access kernel network resources.

                                       TCP/IP applications operate at the application or process layer of the TCP/IP hierarchy
                                       and split an application into server and client components.
                                       Domain Name System (DNS) provides the quick translation of text of the IP addresses
                                       within fraction of seconds from a directory of billions of such addresses. This could be
                                       made possible by using Domain concepts, which uses hierarchical arrangements of text
                                       addresses translation. The servers maintaining addresses are distributed and have locations
                                       throughout the world.

                                       Electronic mail is one of the most popular network services and uses user agent and message
                                       transfer agent to transport messages created by a user to destination mailboxes possibly on
                                       remote machines. Multimedia applications have enthused life in webpages making them
                                       interactive. The convergence of different media such as text, pictures, video and sound into
                                       a single media has contributed enormously for the growth of Internet and www.



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