Conference Papers

Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506

Browse

Author: search.filters.author.Kandasamy, A.

Search Results

Now showing 1 - 10 of 22
  • No Thumbnail Available
    Item
    A phenomic approach to genetic algorithms for reconstruction of gene networks
    (2010) D'Souza, R.G.L.; Chandra Sekaran, K.C.; Kandasamy, A.
    Genetic algorithms require a fitness function to evaluate individuals in a population. The fitness function essentially captures the dependence of the phenotype on the genotype. In the Phenomic approach we represent the phenotype of each individual in a simulated environment where phenotypic interactions are enforced. In reconstruction type of problems, the model is reconstructed from the data that maps the input to the output. In the phenomic algorithm, we use this data to replace the fitness function. Thus we achieve survival-of-the- fittest without the need for a fitness function. Though limited to reconstruction type problems where such mapping data is available, this novel approach nonetheless overcomes the daunting task of providing the elusive fitness function, which has been a stumbling block so far to the widespread use of genetic algorithms. We present an algorithm called Integrated Pheneto-Genetic Algorithm (IPGA), wherein the genetic algorithm is used to process genotypic information and the phenomic algorithm is used to process phenotypic information, thereby providing a holistic approach which completes the evolutionary cycle. We apply this novel evolutionary algorithm to the problem of elucidation of gene networks from microarray data. The algorithm performs well and provides stable and accurate results when compared to some other existing algorithms. © 2010 Springer-Verlag Berlin Heidelberg.
  • No Thumbnail Available
    Item
    Inference of Gene Networks from Microarray Data through a Phenomic Approach
    (2010) D'Souza, R.G.L.; Chandra Sekaran, K.C.; Kandasamy, A.
    The reconstruction of gene networks is crucial to the understanding of cellular processes which are studied in Systems Biology. The success of computational methods of drug discovery and disease diagnosis is dependent upon our understanding of the biological basis of the interaction networks between the genes. Better modelling of biological processes and powerful evolutionary methods are proving to be a key factor in the solution of such problems. However, most of these methods are based on processing of genotypic information. We present an evolutionary algorithm for inferring gene networks from expression data using phenotypic interactions. The benefit of this is that we avoid the need for an explicit objective function in the optimization process. In order to realize this, we have implemented a method called as the Phenomic algorithm and validated it for stability and accuracy in the reconstruction of gene networks. © Springer-Verlag Berlin Heidelberg 2010.
  • No Thumbnail Available
    Item
    LES of flow over a circular cylinder at high Reynolds number
    (Indian Institute of Technology, IIT, Kanpur, 2011) Rajani, B.N.; Kandasamy, A.; Majumdar, S.
    Turbulent flow past a circular cylinder at Re = 1.4 × 105 has been analysed using Large Eddy Simulation (LES) approach solving filtered unsteady 3D NS equations coupled to Smagorinsky and dynamic subgrid scale (SGS) models. These simulations have been carried out using a parallel multiblock structured code which employs an implicit second-order accurate pressure-based finite volume method for solving Navier-Stokes equations for unsteady turbulent incompressible flow situations. The predictions are validated against detailed measurement data for mean as well as turbulence quantities. © IUTAM Symposium on Bluff Body Flows, Blubof 2011.
  • No Thumbnail Available
    Item
    Entrance region flow of casson fluid in a circular tube
    (2012) Kandasamy, A.; Pai, R.G.
    The entrance region flow of a Casson fluid in a tube has been investigated numerically without making prior assumptions on the form of velocity profile within the boundary layer region, which is determined by a cross sectional integration of the momentum differential equation for a given distance from the channel entrance. Using the macroscopic mass and momentum balance equations, the thickness of the core, the entrance length, and the pressure drop have been obtained at each cross section of the entrance region of the tube for specific values of Casson number. © (2012) Trans Tech Publications, Switzerland.
  • No Thumbnail Available
    Item
    Node - Link disjoint multipath routing protocols for wireless sensor networks - A survey and conceptual modeling
    (2012) Muni Venkateswarlu, K.; Chandra Sekaran, K.C.; Kandasamy, A.
    There are different ways to classify the routing protocols that are available. The paper presented here discusses different types of multipath routing protocols for Wireless sensor networks based on the parameter "Disjointedness". In this paper, First, WSN routing issues are discussed then listed the advantages of Multipath routing. Further, comprehensive study of different types of WSN Disjoint-multipath routing protocols is given. Finally, some of the WSN multipath routing on-going research issues are listed. © 2012 Springer-Verlag.
  • No Thumbnail Available
    Item
    A multiobjective phenomic algorithm for inference of gene networks
    (2012) D'Souza, R.G.L.; Chandra Sekaran, K.C.; Kandasamy, A.
    Reconstruction of gene networks has become an important activity in Systems Biology. The potential for better methods of drug discovery and of disease diagnosis hinge upon our understanding of the interaction networks between the genes. Evolutionary methods are proving to be successful in such problems and a number of such methods have been proposed. However, all these methods are based on processing of genotypic information. We have presented an evolutionary algorithm for reconstructing gene networks from expression data using phenotypic interactions, thereby avoiding the need for an explicit objective function. Specifically, we have also extended the basic phenomic algorithm to perform multiobjective optimization for gene network reconstruction. We have applied this novel algorithm to the yeast sporulation dataset and validated it by comparing the results to the links found between genes of the yeast genome at the SGD database. © 2012 ICST Institute for Computer Science, Social Informatics and Telecommunications Engineering.
  • No Thumbnail Available
    Item
    A phenomic algorithm for inference of gene networks using S-systems and memetic search
    (2012) D'Souza G, R.G.L.; Chandra Sekaran, K.C.; Kandasamy, A.
    In recent years, evolutionary methods have seen unprecedented success in elucidation of gene networks, especially from microarray data. We have implemented the Phenomic Algorithm which is an evolutionary method for inference of gene networks based on population dynamics. We have used S-systems to model gene interactions and applied memetic search to fine tune the parameters of the inferred networks. We have tested the novel algorithm on artificial gene expression datasets obtained from simulated gene networks. We have also compared the results to those obtained from two other similar algorithms. Results showed that the new method, which we call as Phenomic Algorithm with Memetic Search (PAMS), is an effective method for inference of gene networks. © 2012 ICST Institute for Computer Science, Social Informatics and Telecommunications Engineering.
  • No Thumbnail Available
    Item
    Core variation in the entrance region flow of casson fluid in an annuli
    (2013) Kandasamy, A.; Pai, R.G.
    The entrance region flow of a Casson fluid in an annular cylinder has been investigated numerically without making prior assumptions on the form of velocity profile within the boundary layer region, which is determined by a cross sectional integration of the momentum differential equation for a given distance from the channel entrance. Using the macroscopic mass balance equation, the thickness of the core has been obtained at each cross section of entrance region of annuli for different values of Casson number and for various values of aspect ratio. © (2013) Trans Tech Publications, Switzerland.
  • No Thumbnail Available
    Item
    Energy-efficient edge-based network partitioning scheme for wireless sensor networks
    (2013) Muni, V.K.; Kandasamy, A.; Chandrasekaran, K.
    The easy use of Wireless Sensor Networks has attracted applications from various fields. Day to day rise in wireless sensor network applications introduce new challenges to researchers. One such critical challenge is, optimal usage of network resources. Energy is one of the most important concerns in wireless sensor networks. Even though there has been an extensive research work done on this issue, the problem is still open with new requirements emerging every day. Exchange of control information consumes most of network resources to carry out network operations. An attempt has been made in the recent past to avoid this wastage of resources, by exploiting the properties of resource abundant sources in the network. Base station is one such source in wireless sensor network. The base station is resource abundant and less constrained network component in wireless sensor networks. The recent research works have focused more in this direction to explore the benefits of base station characteristics. In this perspective, a novel network partitioning mechanism is proposed here, to build energy efficient wireless sensor networks. The system proposed, distributes network load uniformly with little control overhead on energy resources in the network. The uniform distribution of sensor nodes in every part helps the network to distribute the load uniformly. From simulation results, it is noted that, the proposed system elevates the average lifetime of sensor nodes. © 2013 IEEE.
  • No Thumbnail Available
    Item
    Core variation in the entrance region flow of herschel- Bulkley fluid in an annuli
    (Newswood Limited publication@iaeng.org, 2014) Pai, R.G.; Kandasamy, A.
    The entrance region flow in channels constitutes a problem of fundamental interest in engineering applications such as nuclear reactors, polymer processing industries, haemodialyzers and capillary membrane oxygenators. In such installations, the behavior of the fluid in the entrance region may play a significant part in the total length of the channel and the pressure drop may be markedly greater than for the case where the flow is regarded as fully developed throughout the channel. Recently, there has been an increasing interest in problems involving materials with variable viscosity such as Bingham materials, Casson fluids and Herschel-Bulkley fluids which are characterized by an yield value. The entrance region flow of a Herschel- Bulkley fluid in an annular cylinder has been investigated numerically without making prior assumptions on the form of velocity profile within the boundary layer region. This velocity distribution is determined as part of the procedure by cross sectional integration of the momentum differential equation for a given distance z from the channel entrance. Using the macroscopic mass balance equation the core thickness has been obtained at each cross section z of the annuli for specific values of Herschel -Bulkley Number, flow behavior index and various value of aspect ratio.