2. Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/1/7
Browse
12 results
Search Results
Item Memetic NSGA - A multi-objective genetic algorithm for classification of microarray data(2007) Kumar, K, P.; Sharath, S.; D'Souza, G, R.; Sekaran, K.C.In Gene Expression studies, the identification of gene subsets responsible for classifying available samples to two or more classes is an important task. One major difficulty in identifying these gene subsets is the availability of only a few samples compared to the number of genes in the samples. Here we treat this problem as a Multi-objective optimization problem of minimizing the gene subset size and minimizing the number ofmisclassified samples. We present a new elitist Non-dominated Sorting-based Genetic Algorithm (NSGA) called Memetic-NSGA which uses the concept of Memes. Memes are a group of genes which have a particular functionality at the phenotype level. We have chosen a 50 gene Leukemia dataset to evaluate our algorithm. A comparative study between Memetic-NSGA and another Non-dominated Sorting Genetic Algorithm, called NSGA-II, is presented. Memetic-NSGA is found to perform better in terms of execution time and gene-subset length identified. � 2007 IEEE.Item Executable specification and prototyping of network protocols using UML and Java(2009) Sekaran, K.C.; Gnanamurthy, R.K.Network protocols are often implemented in software and / or hardware, and, it becomes essential to design and test them in an efficient manner. This paper explores a dual phase approach for developing network protocols: in the first phase protocols are modeled using UML (Unified Modeling Language) as the formalism, and, in the second phase, use of executable specification and prototyping of protocols based on Java is supported. The prototyping of a protocol is useful for further investigations such as verification ofprotocol properties, test case generation etc. Once the second phase provides a satisfied result, the developers can go ahead in developing and deploying the protocol in the real environment. Yet another objective in this work is to design executable constructs in Java to specify protocols and prototyping them. The protocols designed using this approach ensures sustenance of the models already developed. Illustration of using executable constructs in Java to specify and prototyping ofprotocols, and comparison with native implementations is presented in this paper. �2009 IEEE.Item Implementation of an adaptive buffering algorithm to improve QoS in VoIP(2005) Nagesh, H.R.; Sekaran, K.C.; Kordcal, A.R.The Internet has evolved into a worldwide communication infrastructure and it now provides various services including Voice over IP (VoIP) or Internet Telephony [7]. VoIP involves transmission of voice packets across the IP network known as IP telephony. Internet Protocol (IP) Telephony has many issues that have to be overcome before it can be considered a rival to the existing telephony infrastructure. One such issue is the Quality of service (QoS). The use of play-out buffering at the receiver helps to improve the quality of Voice over IP (VoIP). There exists a buffering algorithm, which uses a dynamic adaptive approach. In this algorithm the playout times of voice packets are calculated using adaptive estimation of the network delays. In contrast to previous solutions, weighting factor that controls the estimation process is dynamically adjusted according to the observed delay variations. This results in higher quality estimates of network delay. The contribution of this paper is to analyze, implement and incorporate one such adaptive buffering algorithm into the Session Initiation Protocol (SIP) through which one can achieve better delay/loss trade-off and thus better call quality.Item Distributed multi level security token based authentication for ubiquitous objects -DMSA(2006) Kulkarni, U.P.; Vadavi, J.V.; Joshi, S.M.; Sekaran, K.C.; Yardi, A.R.Ubiquitous computing technology provides an environment where users expect to access resources and services anytime and anywhere. The serious security risks and problems arise because resources can now be accessed by almost anyone with a mobile device in such an open model. This paper explores security in ubiquitous computing with focus on authentication. We propose a new model, which uses distributed hierarchical tree based approach for authenticating ubiquitous objects which overcomes the problems associated with centralized source of information. � 2006 IEEE.Item Development of a link layer protocol using UML(2001) Sekaran, K.C.This paper presents a report on the development of a link layer protocol using an object oriented formal method. It describes the steps involved in the conceptualization, analysis and design of the L2CAP (Logical Link Control and Adaptation Layer Protocol) of the Bluetooth architecture. UML (Unified Modeling Language) is the formal modeling language used in this work. It has been shown how the static, dynamic and operational aspects of the system are captured using various UML diagrams. � 2001 IEEE.Item Detection of reticulation events - A character based method(2006) Navada, K.C.; Sekaran, K.C.It is observed that during the evolution of species, reticulation is an important event and is very prevalent in several organisms. However, the analytical tools for the representation of these events are still under development. This is primarily because of the difficulty involved in detecting these reticulation events that have taken place during the evolution using the sequences that are currently available in some form. Since it is not possible to get each sequence starting from the root (beginning of the evolution process), inferring the history has to be based on a few assumptions, which are biologically valid. In this paper, we propose an algorithm which, we feel, is a step in this direction. The algorithm detects the sequences which require reticulation events for their formation and returns the count of such sequences. � 2006 IEEE.Item Design and development of proactive solutions for mitigating denial-of-service attacks(2006) Nagesh, H.R.; Sekaran, K.C.Denial of Service attacks, orchestrated by a single host or multiple hosts in a coordinated manner, has become an increasingly frequent disturbance in today's Internet. Generally, attackers launch DDoS attacks by directing a massive number of attack sources to send useless traffic to the victim. The victim's services are disrupted when its host or network resources are occupied by the attack traffic. The threat of DDoS attacks has become even more severe as attackers can compromise a huge number of computers using vulnerabilities in popular operating systems [4].This paper deals with Denial of service (DoS) and Distributed DoS (DDoS) attacks. In the first part, we categorize existing defense mechanisms, and analyze their strengths and weaknesses. In the second part of our investigation, we develop and evaluate two defense models for DoS attacks: the Secure Overlay Services (SOS) Model and the Server Hopping Model using distributed firewalls. Each of these models provide defense in a different part of the network, and has different resource requirements. In the third part of our investigation, we assess the effectiveness of our defense models for different types of DoS attack. � 2006 IEEE.Item Active probing based end to end internet path metrics estimation tool(2006) Suryanarayana, V.; Sekaran, K.C.This paper considers the problem of measuring the various network path metrics such as Connectivity, Capacity, bandwidth, available bandwidth etc. of a network path using probing-based methods. To that end, we propose a new model called an Integrated Metrics Measurement Model (IMMM) to measure all possible performance metrics. It will be designed to probe the network non-intrusively so that the measurements will not disturb the stability of the network. The experimental results of our partial implementation of the proposed model are presented. � 2006 IEEE.Item Simulation environment for a fuzzy controller based Autonomic Computing system(2009) Harish, S.V.; Sekaran, K.C.eCommerce is an area where an Autonomic Computing system could be very effectively deployed. eCommerce has created demand for high quality information technology services and businesses seek ways to improve the quality of service in a costeffective way. Properly adjusting tuning parameters for best values is time-consuming and skills-intensive. This paper describes a simulation environment to implement an approach to automate the tuning of MaxClients parameter of Apache web server using a fuzzy controller and knowledge of the affect of the parameter on quality of service. This is an illustration of the self-optimizing characteristic of an autonomic computing system. � 2008 IEEE.Item Simulation environment for maximizing profits in an autonomic computing system using fuzzy control(2009) Venkatarama, H.S.; Sekaran, K.C.eCommerce is an area where an Autonomic Computing system could be very effectively deployed. The growth of eCommerce has created demand for services with financial incentives for service providers. Revenues accrue if the admitted requests are processed within the specified deadline and costs are incurred if the admitted requests are not processed within the deadline. The number of requests to be admitted depends oil system capacity and workload. This paper describes a simulation environment to implement an approach to automate the admission control decisions in an Apache web server for maximizing profits. A fuzzy controller that implements hill climbing logic is used. This is an illustration of the self-optimizing characteristic of an autonomic computing system. Copyright � 2009 by IICAI.