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Frame Relay

Frame Relay is a virtual circuit technology that provides low-level (physical and data link layers) services in response to following demands:
o Higher data rate at lower cost
o Bursty data—bandwidth on demand—bursty data requires different bandwidth allocation at different times.
o Less overhead due to improved transmission media
• The most technical innovation to come out of the standardization work on narrowband ISDN is the frame relay.
• Frame relay is a streamlined technique for packet switching that operates at the data link layer with much less overhead than packet switching X.25
• Standardization of the frame-mode bearer service, or frame relay, was done by both ITU-T and ANSI.

View / Download: Frame Relay (Size 928KB)

 

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Data Link Protocol

Data Link protocols
• Asynchronous Protocols
• Not complex and inexpensive to implement
• Data unit is transmitted with no timing co-ordination between sender and receiver.
• Receiver does not know when data unit is sent- only recognizes the beginning and    ending of frame-accomplished by start and stop bit.
• Used primarily in modem, features start and stop bits and variable length gaps between    characters.
• Synchronous Protocols

View / Download: Data Link Protocol (Size 1.24 MB)

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Data Link Layer Functions

Line Discipline: co-ordinates the link system-determines which device can send and when it can send.
• Flow Control: co-ordinates the amount of data that can be sent before receiving ack.
• Error Control: error detection/correction-allows receiver to inform the sender of any frame lost or damaged and co-ordinate the retransmission

View / Download : Data Link Layer Functions  (Size 988 KB)

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UBICOM: Applications

Ubiquitous computing is changing our daily activities in a variety of ways. When it comes to using today’s digital tools users tend to….

  • communicate in different ways
  • be more active
  • conceive and use geographical and temporal spaces differently
  • have more control

In addition, ubiquitous computing is…

  • global and local
  • social and personal
  • public and private
  • invisible and visible

an aspect of both knowledge creation and information dissemination.

View / Download: Ubiquitous Computing_Applications (size 1.28MB}

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Digital Communication Systems

Learning material by

Prof.H. S. Jamadagni, CEDT, IISc, Bangalore

Topics in Digital Communications

  1. Digital communication system advantages and disadvantages
  2. Digital communication system classification
  3. Digitization of analog signals
  4. Digital transmission systems
  5. Data communication systems
  6. Integrated Services Digital Network and other advanced digital communication systems

View / download : DCN-LearningMaterial (size 1.44MB)

 

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Optimize visual image search for semantic web

Abstract: In today’s web image search engines find more irrelevances in the search result. By adding semantic meaning to the document this irrelevance can be reduced. SIEVE image search algorithm combine the text based and content based method and shows the result. Also “IN-Picture” search algorithm mixing the images higher level and lower level contents. In this paper it shows some image searching framework like “SAFE” describe how image are searched using its attributes. Also describes some semantic web technology, which helps in image search and shows how detailed indexing system can use SPARQL query and ontology of an image to build semantic web based framework.

View Full Paper : ijcsit_survey optimize visual image search for semantic web (size 375 KB)

 

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Optimizing Query execution over Linked Data

Abstract— Linked open data also known as web of linked data is a globally distributed database. The four fold increase in the use of linked open data shows its need in the future. This linked data can be queried with SPARQL protocol and RDF query language also known as SPARQL. Various optimization techniques have been proposed but just a couple implemented as yet. In this paper two most feasible query optimization methods are proposed. Solution one is applying federation and query rewriting. Solution two is expressing the RDF structure as a context graph and pruning intermediate results based on probability or selectivity of the result. The paper gives a brief understanding for both solutions.

View Full Paper: IJETAE_Optimizing Query execution over Linked Data (size 354 KB)

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SEMANTIC WEB and COMPARATIVE ANALYSIS of INFERENCE ENGINES

Abstract— Semantic Web is an emerging technology for efficient reasoning support over the knowledge represented on the Web. This paper presents the semantic web standards and survey a number of Inference Engines that supports reasoning with OWL. Also analyzed the reasoner with set of ontologies and based on supported features.

View Full paper: Survey Paper on Semantic Web and Inference Engine  (Size 567KB)

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UBICOM: Basics and Vision

Ubiquitous computing (ubicomp) is a post-desktop model of human-computer interaction in which information processing has been thoroughly integrated into everyday objects and activities. In the course of ordinary activities, someone “using” ubiquitous computing engages many computational devices and systems simultaneously, and may not necessarily even be aware that they are doing so.

Download: Ubiquitous Computing_Basic and Vision (size 1.34 MB)

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