Swapnoneel Roy | University of North Florida (original) (raw)

Papers by Swapnoneel Roy

Abstract—A complex valued neural network is a neural network which consists of complex valued inp... more Abstract—A complex valued neural network is a neural network which consists of complex valued input and/or weights and/or thresholds and/or activation functions. Complex-valued neural networks have been widening the scope of applications not only in electronics and informatics, but also in social systems. One of the most important applications of the complex valued neural network is in signal processing. In Neural networks, generalized mean neuron model (GMN) is often discussed and studied.

Abstract In this work we consider two protocols for performing cryptanalysis and security enhance... more Abstract In this work we consider two protocols for performing cryptanalysis and security enhancement. The first one by Song, is a password authentication scheme based on smart cards. We note that this scheme has already been shown vulnerable to the off-line password guessing attack by Tapiador et al. We perform a further cryptanalysis on this protocol and observe that it is prone to the clogging attack, a kind of denial of service (DOS) attack.

… Systems, 2007. ICAS07. …, Jan 1, 2007

Abstract Various global rearrangements of permutations, such as reversals and transpositions, hav... more Abstract Various global rearrangements of permutations, such as reversals and transpositions, have recently become of interest because of their applications in computational molecular biology, to be more specific, genome rearrangement. Many primitives have been formulated in this regard. These primitives find their applications hugely in the study of the similarity of different organisms. In this paper, we formulate a new primitive for genome rearrangement, the strip exchanges. An approximation algorithm for ...

Arxiv preprint arXiv:1110.0892, Jan 1, 2011

Block Sorting is a well studied problem, motivated by its applications in Optical Character Recog... more Block Sorting is a well studied problem, motivated by its applications in Optical Character Recognition (OCR), and Computational Biology. Block Sorting has been shown to be NP-Hard, and two separate polynomial time 2-approximation algorithms have been designed for the problem. But questions like whether a better approximation algorithm can be designed, and whether the problem is APX-Hard have been open for quite a while now. In this work we answer the latter question by proving Block Sorting to be Max-SN P-Hard (APX-Hard). The APX-Hardness result is based on a linear reduction of Max-3SAT to Block Sorting. We also provide a new lower bound for the problem via a new parametrized problem k-Block Merging.

… (SRII), 2011 Annual, Jan 1, 2011

Abstract In the services domain, the customers raise issues and service requests in the form of t... more Abstract In the services domain, the customers raise issues and service requests in the form of tickets. There is a pool of personnel who work on these tickets and resolve them. The problem at hand is to dispatch these tickets to the most appropriate personnel. Optimality is applied to metrics like the mean service time taken to resolve a ticket, the fair sharing of workload among the personnel, and the size and configuration of the pool. The current state of the art involves a human dispatcher for assigning incoming service requests. Though ...

Abstract—The Block Sorting problem is to sort a given permutation moving blocks. A block is defin... more Abstract—The Block Sorting problem is to sort a given permutation moving blocks. A block is defined as a substring of the given permutation, which is also a substring of the identity permutation. Block Sorting has been proved to be NP-Hard. Until now two different 2-Approximation algorithms have been presented for block sorting. These are the best known algorithms for Block Sorting till date. In this work we present a different characterization of Block Sorting in terms of a transposition cycle graph. Then we suggest a heuristic, which ...

Abstract. The sorting by strip exchanges (aka strip exchanging) problem is motivated by applicati... more Abstract. The sorting by strip exchanges (aka strip exchanging) problem is motivated by applications in optical character recognition and genome rearrangement analysis. While a couple of approximation algorithms have been designed for the problem, nothing has been known about its computational hardness till date. In this work, we show that the decision version of strip exchanging is NP-Complete. We present a few new lower bounds for the problem along with the stated result. The NP-Completeness proof is based on reducing ...

… , 2007. BIBE 2007. Proceedings of the 7th …, Jan 1, 2007

Abstract Genome and other syntenic blocks rearrangements have become a topic of intensive study b... more Abstract Genome and other syntenic blocks rearrangements have become a topic of intensive study by phylogenists, comparative genomicists, and computational biologists: they are a feature of many cancers, must be taken into account to align highly divergent sequences, and constitute a phylogenetic marker of great interest. The mathematics of rearrangements is far more complex than for indels and mutations in sequences. Genome rearrangements have been modeled by a variety of primitives such as reversals, ...

Arxiv preprint arXiv:1102.4129, Jan 1, 2011

The Lead-Based Multiple Video Transmission (LMVT) problem is motivated by applications in managin... more The Lead-Based Multiple Video Transmission (LMVT) problem is motivated by applications in managing the quality of experience (QoE) of video streaming for mobile clients. In an earlier work, the LMVT problem has been shown to be NP-hard for a specific bit-to-lead conversion function φ. In this work, we show the problem to be NP-hard even if the function φ is linear. We then design a fully polynomial time approximation scheme (FPTAS) for the problem. This problem is exactly equivalent to the Santa Clause Problem on which there has been a lot of work done off-late.

eprint.iacr.org

In this work we consider two protocols for performing cryptanalysis and security enhancement. The... more In this work we consider two protocols for performing cryptanalysis and security enhancement. The first one by Song, is a password authentication scheme based on smart cards. We note that this scheme has already been shown vulnerable to the off-line password guessing attack by Tapiador et al. We perform a further cryptanalysis on this protocol and observe that it is prone to the clogging attack, a kind of denial of service (DOS) attack. We observe that all smart card based authentication protocols which precede the one by Song, and require the server to compute the computationally intensive modular exponentiation, like the one by Xu et al., or Lee at al., are prone to the clogging attack. We then suggest an improvement on the protocol to prevent the clogging attack.

Proceedings of World Academy of …, Jan 1, 2008

Bioinformatics and computational biology involve the use of techniques including applied mathemat... more Bioinformatics and computational biology involve the use of techniques including applied mathematics, informatics, statistics, computer science, artificial intelligence, chemistry, and biochemistry to solve biological problems usually on the molecular level. Research in computational biology often overlaps with systems biology. Major research efforts in the field include sequence alignment, gene finding, genome assembly, protein structure alignment, protein structure prediction, prediction of gene expression and proteinprotein interactions, and the modeling of evolution. Various global rearrangements of permutations, such as reversals and transpositions,have recently become of interest because of their applications in computational molecular biology. A reversal is an operation that reverses the order of a substring of a permutation. A transposition is an operation that swaps two adjacent substrings of a permutation. The problem of determining the smallest number of reversals required to transform a given permutation into the identity permutation is called sorting by reversals. Similar problems can be defined for transpositions and other global rearrangements. In this work we perform a study about some genome rearrangement primitives. We show how a genome is modelled by a permutation, introduce some of the existing primitives and the lower and upper bounds on them. We then provide a comparison of the introduced primitives.

Abstract—A complex valued neural network is a neural network which consists of complex valued inp... more Abstract—A complex valued neural network is a neural network which consists of complex valued input and/or weights and/or thresholds and/or activation functions. Complex-valued neural networks have been widening the scope of applications not only in electronics and informatics, but also in social systems. One of the most important applications of the complex valued neural network is in signal processing. In Neural networks, generalized mean neuron model (GMN) is often discussed and studied.

Abstract In this work we consider two protocols for performing cryptanalysis and security enhance... more Abstract In this work we consider two protocols for performing cryptanalysis and security enhancement. The first one by Song, is a password authentication scheme based on smart cards. We note that this scheme has already been shown vulnerable to the off-line password guessing attack by Tapiador et al. We perform a further cryptanalysis on this protocol and observe that it is prone to the clogging attack, a kind of denial of service (DOS) attack.

… Systems, 2007. ICAS07. …, Jan 1, 2007

Abstract Various global rearrangements of permutations, such as reversals and transpositions, hav... more Abstract Various global rearrangements of permutations, such as reversals and transpositions, have recently become of interest because of their applications in computational molecular biology, to be more specific, genome rearrangement. Many primitives have been formulated in this regard. These primitives find their applications hugely in the study of the similarity of different organisms. In this paper, we formulate a new primitive for genome rearrangement, the strip exchanges. An approximation algorithm for ...

Arxiv preprint arXiv:1110.0892, Jan 1, 2011

Block Sorting is a well studied problem, motivated by its applications in Optical Character Recog... more Block Sorting is a well studied problem, motivated by its applications in Optical Character Recognition (OCR), and Computational Biology. Block Sorting has been shown to be NP-Hard, and two separate polynomial time 2-approximation algorithms have been designed for the problem. But questions like whether a better approximation algorithm can be designed, and whether the problem is APX-Hard have been open for quite a while now. In this work we answer the latter question by proving Block Sorting to be Max-SN P-Hard (APX-Hard). The APX-Hardness result is based on a linear reduction of Max-3SAT to Block Sorting. We also provide a new lower bound for the problem via a new parametrized problem k-Block Merging.

… (SRII), 2011 Annual, Jan 1, 2011

Abstract In the services domain, the customers raise issues and service requests in the form of t... more Abstract In the services domain, the customers raise issues and service requests in the form of tickets. There is a pool of personnel who work on these tickets and resolve them. The problem at hand is to dispatch these tickets to the most appropriate personnel. Optimality is applied to metrics like the mean service time taken to resolve a ticket, the fair sharing of workload among the personnel, and the size and configuration of the pool. The current state of the art involves a human dispatcher for assigning incoming service requests. Though ...

Abstract—The Block Sorting problem is to sort a given permutation moving blocks. A block is defin... more Abstract—The Block Sorting problem is to sort a given permutation moving blocks. A block is defined as a substring of the given permutation, which is also a substring of the identity permutation. Block Sorting has been proved to be NP-Hard. Until now two different 2-Approximation algorithms have been presented for block sorting. These are the best known algorithms for Block Sorting till date. In this work we present a different characterization of Block Sorting in terms of a transposition cycle graph. Then we suggest a heuristic, which ...

Abstract. The sorting by strip exchanges (aka strip exchanging) problem is motivated by applicati... more Abstract. The sorting by strip exchanges (aka strip exchanging) problem is motivated by applications in optical character recognition and genome rearrangement analysis. While a couple of approximation algorithms have been designed for the problem, nothing has been known about its computational hardness till date. In this work, we show that the decision version of strip exchanging is NP-Complete. We present a few new lower bounds for the problem along with the stated result. The NP-Completeness proof is based on reducing ...

… , 2007. BIBE 2007. Proceedings of the 7th …, Jan 1, 2007

Abstract Genome and other syntenic blocks rearrangements have become a topic of intensive study b... more Abstract Genome and other syntenic blocks rearrangements have become a topic of intensive study by phylogenists, comparative genomicists, and computational biologists: they are a feature of many cancers, must be taken into account to align highly divergent sequences, and constitute a phylogenetic marker of great interest. The mathematics of rearrangements is far more complex than for indels and mutations in sequences. Genome rearrangements have been modeled by a variety of primitives such as reversals, ...

Arxiv preprint arXiv:1102.4129, Jan 1, 2011

The Lead-Based Multiple Video Transmission (LMVT) problem is motivated by applications in managin... more The Lead-Based Multiple Video Transmission (LMVT) problem is motivated by applications in managing the quality of experience (QoE) of video streaming for mobile clients. In an earlier work, the LMVT problem has been shown to be NP-hard for a specific bit-to-lead conversion function φ. In this work, we show the problem to be NP-hard even if the function φ is linear. We then design a fully polynomial time approximation scheme (FPTAS) for the problem. This problem is exactly equivalent to the Santa Clause Problem on which there has been a lot of work done off-late.

eprint.iacr.org

In this work we consider two protocols for performing cryptanalysis and security enhancement. The... more In this work we consider two protocols for performing cryptanalysis and security enhancement. The first one by Song, is a password authentication scheme based on smart cards. We note that this scheme has already been shown vulnerable to the off-line password guessing attack by Tapiador et al. We perform a further cryptanalysis on this protocol and observe that it is prone to the clogging attack, a kind of denial of service (DOS) attack. We observe that all smart card based authentication protocols which precede the one by Song, and require the server to compute the computationally intensive modular exponentiation, like the one by Xu et al., or Lee at al., are prone to the clogging attack. We then suggest an improvement on the protocol to prevent the clogging attack.

Proceedings of World Academy of …, Jan 1, 2008

Bioinformatics and computational biology involve the use of techniques including applied mathemat... more Bioinformatics and computational biology involve the use of techniques including applied mathematics, informatics, statistics, computer science, artificial intelligence, chemistry, and biochemistry to solve biological problems usually on the molecular level. Research in computational biology often overlaps with systems biology. Major research efforts in the field include sequence alignment, gene finding, genome assembly, protein structure alignment, protein structure prediction, prediction of gene expression and proteinprotein interactions, and the modeling of evolution. Various global rearrangements of permutations, such as reversals and transpositions,have recently become of interest because of their applications in computational molecular biology. A reversal is an operation that reverses the order of a substring of a permutation. A transposition is an operation that swaps two adjacent substrings of a permutation. The problem of determining the smallest number of reversals required to transform a given permutation into the identity permutation is called sorting by reversals. Similar problems can be defined for transpositions and other global rearrangements. In this work we perform a study about some genome rearrangement primitives. We show how a genome is modelled by a permutation, introduce some of the existing primitives and the lower and upper bounds on them. We then provide a comparison of the introduced primitives.