Computing and Information Systems - Research Publications

Permanent URI for this collection

Search Results

Now showing 1 - 9 of 9
  • Item
    Thumbnail Image
    A novel document ranking method using the discrete cosine transform
    Park, LAF ; Palaniswami, M ; Ramamohanarao, K (IEEE COMPUTER SOC, 2005-01)
    We propose a new Spectral text retrieval method using the Discrete Cosine Transform (DCT). By taking advantage of the properties of the DCT and by employing the fast query and compression techniques found in vector space methods (VSM), we show that we can process queries as fast as VSM and achieve a much higher precision.
  • Item
    Thumbnail Image
    A taxonomy of data grids for distributed data sharing, management, and processing
    Venugopal, S ; Buyya, R ; Ramamohanarao, K (Association for Computing Machinery (ACM), 2006)
    Data Grids have been adopted as the next generation platform by many scientific communities that need to share, access, transport, process, and manage large data collections distributed worldwide. They combine high-end computing technologies with high-performance networking and wide-area storage management techniques. In this article, we discuss the key concepts behind Data Grids and compare them with other data sharing and distribution paradigms such as content delivery networks, peer-to-peer networks, and distributed databases. We then provide comprehensive taxonomies that cover various aspects of architecture, data transportation, data replication and resource allocation, and scheduling. Finally, we map the proposed taxonomy to various Data Grid systems not only to validate the taxonomy but also to identify areas for future exploration.
  • Item
    Thumbnail Image
    Patterns based classifiers
    Ramamohanarao, K ; Fan, H (SPRINGER, 2007-03)
  • Item
    Thumbnail Image
    Survey of network-based defense mechanisms countering the DoS and DDoS problems
    Peng, T ; Leckie, C ; Ramamohanarao, K (ASSOC COMPUTING MACHINERY, 2007-04)
    This article presents a survey of denial of service attacks and the methods that have been proposed for defense against these attacks. In this survey, we analyze the design decisions in the Internet that have created the potential for denial of service attacks. We review the state-of-art mechanisms for defending against denial of service attacks, compare the strengths and weaknesses of each proposal, and discuss potential countermeasures against each defense mechanism. We conclude by highlighting opportunities for an integrated solution to solve the problem of distributed denial of service attacks.
  • Item
    Thumbnail Image
    Information sharing for distributed intrusion detection systems
    Peng, T ; Leckie, C ; Ramamohanarao, K (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2007-08)
  • Item
    Thumbnail Image
    Incremental maintenance of shortest distance and transitive closure in first-order logic and SQL
    Pang, CY ; Dong, GZ ; Ramamohanarao, K (ASSOC COMPUTING MACHINERY, 2005-09)
    Given a database, the view maintenance problem is concerned with the efficient computation of the new contents of a given view when updates to the database happen. We consider the view maintenance problem for the situation when the database contains a weighted graph and the view is either the transitive closure or the answer to the all-pairs shortest-distance problem ( APSD ). We give incremental algorithms for APSD , which support both edge insertions and deletions. For transitive closure, the algorithm is applicable to a more general class of graphs than those previously explored. Our algorithms use first-order queries, along with addition (+) and less-than (<) operations ( FO (+,<)); they store O ( n 2 ) number of tuples, where n is the number of vertices, and have AC 0 data complexity for integer weights. Since FO (+,<) is a sublanguage of SQL and is supported by almost all current database systems, our maintenance algorithms are more appropriate for database applications than nondatabase query types of maintenance algorithms.
  • Item
    Thumbnail Image
    Approximate clustering in very large relational data
    Bezdek, JC ; Hathaway, RJ ; Huband, JM ; Leckie, C ; Kotagiri, R (WILEY, 2006-08)
  • Item
    Thumbnail Image
    Using emerging patterns to construct weighted decision trees
    Alhammady, H ; Ramamohanarao, K (IEEE COMPUTER SOC, 2006-07)
  • Item