Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
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Item Development of a link layer protocol using UML(Institute of Electrical and Electronics Engineers Inc., 2001) Chandra 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 Implementation of an adaptive buffering algorithm to improve QoS in VoIP(2005) Nagesh, H.R.; Chandra 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 Design and development of proactive solutions for mitigating denial-of-service attacks(2006) Nagesh, H.R.; Chandra 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 Detection of reticulation events - A character based method(2006) Navada, K.C.; Chandra 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 Ubiquitous object categorization and identity(2006) Kulkarni, U.P.; Vadavi, J.V.; Joshi, S.M.; Chandra Sekaran, K.C.; Yardi, A.R.Ubiquitous computing technology provides an environment where users expect to access resources and services anytime and anywhere. Everyday objects communicate with each other and also with the Internet objects available today. People have an increasing desire for such ubiquitous access to information, anywhere, anyplace, and anytime. As ubicomp occurs everywhere, there may be a very large number of users/objects interacting with each other simultaneously in future. This necessitates the question of how to uniquely provide identity to infinitely growing objects and standard towards the uniformity of the data being exchanged by the various objects. 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. In this paper, author proposes the way of providing uniqueness in scalable object identity, object categorization and standard in data being exchanged by various ubicomp compliant objects and explore the security issue in ubiquitous computing with a focus on authentication. © 2006 IEEE.Item Active probing based end to end internet path metrics estimation tool(2006) Suryanarayana, V.; Chandra 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 Distributed multi level security token based authentication for ubiquitous objects -DMSA(2006) Kulkarni, U.P.; Vadavi, J.V.; Joshi, S.M.; Chandra 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 Autonomous data replication using Q-learning for unstructured P2P networks(2007) Thampi, S.M.; Chandra Sekaran, K.C.Resource discovery is an important problem in unstructured peer-to-peer networks as there is no centralized index where to search for information about resources. The solution for the problem is to use a search algorithm that locates the resources based on the local information about the network. Efficient data sharing in a peer-to-peer system is complicated by uneven node failure, unreliable network connectivity and limited bandwidth. A well-known technique for improving availability is replication. If multiple copies of data exist on independent nodes, then the chances of at least one copy being accessible are increased. Replication increases robustness. In this paper, we present a novel technique based on Q-learning for replicating objects to other nodes. © 2007 IEEE.Item Technology driven high-level synthesis(Institute of Electrical and Electronics Engineers Inc., 2007) Joseph, M.; Bhat Narasimha, N.B.; Chandra Sekaran, K.C.Technology driven High-Level Synthesis make the present High-Level Synthesis knowledgeable of the target Field Programmable Gate Array. All the functions of High-Level Synthesis become aware of target technology since parsing. It makes right inference of hardware, by attaching target technology specific attributes to the parse tree. This right inference will guide to generate optimized hardware. © 2007 IEEE.Item Memetic NSGA - A multi-objective genetic algorithm for classification of microarray data(Institute of Electrical and Electronics Engineers Inc., 2007) Kumar K, P.; Sharath, S.; D'Souza G, R.; Chandra 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.