http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/437 Sun, 19 May 2013 16:57:46 GMT 2013-05-19T16:57:46Z http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/2009 Antimedian graphs Kannan, Balakrishnan; Changat, Manoj; Klavzar, Sandi; Mathews, Joseph; Peterin, Iztok; Prasanth, G N; Spacapan, Simon Antimedian graphs are introduced as the graphs in which for every triple of vertices there exists a unique vertex x that maximizes the sum of the distances from x to the vertices of the triple. The Cartesian product of graphs is antimedian if and only if its factors are antimedian. It is proved that multiplying a non-antimedian vertex in an antimedian graph yields a larger antimedian graph. Thin even belts are introduced and proved to be antimedian. A characterization of antimedian trees is given that leads to a linear recognition algorithm. Tue, 01 Jan 2008 00:00:00 GMT http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/2009 2008-01-01T00:00:00Z http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/2007 A Cryptosystem Using the Concepts of Algebraic Geometric Code Pramod, K V; Manju, C Cryptosystem using linear codes was developed in 1978 by Mc-Eliece. Later in 1985 Niederreiter and others developed a modified version of cryptosystem using concepts of linear codes. But these systems were not used frequently because of its larger key size. In this study we were designing a cryptosystem using the concepts of algebraic geometric codes with smaller key size. Error detection and correction can be done efficiently by simple decoding methods using the cryptosystem developed. Approach: Algebraic geometric codes are codes, generated using curves. The cryptosystem use basic concepts of elliptic curves cryptography and generator matrix. Decrypted information takes the form of a repetition code. Due to this complexity of decoding procedure is reduced. Error detection and correction can be carried out efficiently by solving a simple system of linear equations, there by imposing the concepts of security along with error detection and correction. Results: Implementation of the algorithm is done on MATLAB and comparative analysis is also done on various parameters of the system. Attacks are common to all cryptosystems. But by securely choosing curve, field and representation of elements in field, we can overcome the attacks and a stable system can be generated. Conclusion: The algorithm defined here protects the information from an intruder and also from the error in communication channel by efficient error correction methods. Fri, 01 Jan 2010 00:00:00 GMT http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/2007 2010-01-01T00:00:00Z http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/2006 On Implementing Joins, Aggregates and Universal Quantifier in Temporal Databases using SQL Standards Pramod, K V; Unnikrishnan, K A feasible way of implementing a temporal database is by mapping temporal data model onto a conventional data model followed by a commercial database management system. Even though extensions were proposed to standard SQL for supporting temporal databases, such proposals have not yet come across standardization processes. This paper attempts to implement database operators such as aggregates and universal quantifier for temporal databases, implemented on top of relational database systems, using currently available SQL standards. Thu, 01 Jan 2009 00:00:00 GMT http://dyuthi.cusat.ac.in:80/xmlui/handle/purl/2006 2009-01-01T00:00:00Z