M Tech Dissertations

Permanent URI for this collectionhttp://drsr.daiict.ac.in/handle/123456789/3

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Subject: search.filters.subject.Mathematics

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Now showing 1 - 4 of 4
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    New learning based super resolution using contourlet transform
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Singh, Vineet P.; Joshi, Manjunath V.
    new learning based super-resolution reconstruction using contourlet transforms is proposed. contourlet transform provides high degree of directionality. It captures geometrical smoothness along multiple directions and learns the edges present in an image normal to the contour. For learning purpose, training set of low resolution (LR) and high resolution (HR) images, all captured using the same camera, are used. Here two and three level contourlet decomposition for LR images (test image and training image dataset) and HR training images respectively. The comparison of contourlet coeffcients of LR test image from the LR training set using minimum absolute difference (MAD) criterion to obtain the best match contourlet coeffcient. The finer details of test image are learned from the high resolution contourlet coefficients of the training data set. The inverse contourlet transform gives super resolved image corresponding to the test image.
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    On size balanced binary search trees
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2009) Kumar, Anand; Amin, Ashok T.
    History independent data structures are useful when security and privacy are of primary concern. Even if an adversary gets copy of the data structure, he cannot obtain any additional information beyond its content. Important property of history independent data structure is that it has no trace visible in its memory layout about the history of operations performed on it. Buchbinder and Petrank [7] in their paper provided lower bounds for obtaining the Strong History Independence for large class of data structures. They also proposed complementary upper bounds for comparison based models and gave an implementation of Weakly History Independent Heap Abstract data structure. In the paper “A Short Note on Perfectly Balance Binary Tree” by A. P. Korah and M. R. Kaimal [14] an algorithm for insertion of a node in a perfectly balanced binary search tree is presented in which successive data displacement is performed in an inorder fashion to keep the binary tree size balanced. This algorithm has worst case performance linear with the number of nodes in the tree. Binary search tree is a very useful data structure and is used in many applications such as dictionary, priority queue and supports many operations, such as SEARCH, MINIMUM, MAXIMUM, PREDECESSOR, SUCCESSOR, INSERT, and DELETE. Balanced binary trees such as height balanced binary trees, weight balanced binary trees, etc. support these operations in O (lg n) time in worst-case. Size balanced binary search tree is a balanced binary tree in which number of nodes in one subtree cannot exceed by one than the number of nodes in the other sub tree at every node in the tree. In this thesis, Characterizing Size Balanced Binary Search Tree (SB-BST), I determine the number of Size Balanced Binary Search Trees of a given size. I also provide algorithms to insert into and to delete a node from an SB-BST. Delete operation is followed by Maintain in order to maintain the size balance of Binary Search Tree. These operations require O (n) worst-case run time.
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    Multirate signal processing in digital communications
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2008) Arya, Krishna Kumari; Chakka, Vijaykumar
    Fundamentals of multirate signal processing and perfect reconstruction filter banks are revisited. An attempt is made to develop a good understanding of concepts by connecting the filter bank design issues to the concepts of linear algebra. An interpretation of multicarrier systems in the form of transmultiplexers is provided and the notion of resampling of channel is introduced. A pulse shaping filter for the OFDM systems is proposed to remove the constraint of Cyclic Prefix. A comparison of performance of OFDM and filter bank based multicarrier systems in terms of stop band attenuation is provided. Notion of MIMO biorthogonal partners and the conditions for existence of FIR biorthogonal partners are studied. Emphasis is put on finding out the Greatest Right Common Divisor (GRCD) of polynomial matrices.
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    Nonuniform sampling and its reconstruction methodologies
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2008) Bhawsar, Vishal; Chakka, Vijaykumar
    Alias-free DSP (DASP) is a methodology of processing signals digitally inside bandwidth that are wider than the famous nyquist limit of half of the sampling frequency. This topic has benefited from a strong research revival during the past few years. DASP is facilitated by suitable combination of non-uniform sampling and appropriate processing algorithms. In this thesis different stretegies to perform nonuniform sampling and its spectrum analysis are studied. We examine the problem of reconstructing a signal from non-uniform samples. A polynomial interpolation based reconstuction techniques are presented. Its performance are compared with the other previous papers on reconstruction technique on the basis of MSE criteria and Complexity of algorithm.