Conference Papers
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Item Effect of mobility over performance of the ad hoc networks(2006) Geetha, V.; Aithal, S.; ChandraSekaran, K.An ad hoc network is a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. A number of routing protocols like Dynamic Source Routing (DSR), Ad Hoc On-Demand Distance Vector Routing (AODV), Destination-Sequenced Distance-Vector (DSDV) and Temporally Ordered Routing Algorithm (TORA) are normally used in ad hoc networks. In this paper an attempt has been made to compare the effect of mobility in case of on-demand reactive routing protocols for mobile ad hoc networks: AODV with traditional proactive DSDV protocol. The performance is analyzed using varying number of connections in the network, mobility pause and speed of the node. These simulations are carried out using the ns-2 network simulator. © 2006 IEEE.Item Web security: A survey of latest trends in security attacks(2011) Kallapur, P.V.; Geetha, V.Every system used in real time will be having some security threats. Internet has not been exception for it. From as early as 1980s there has been occurrence of several different types of security attacks with Internet being their major target. Internet happens to be main target due to type and amount of information it stores and advancements in computer networks which makes it very easy for accessing the same. Also, at the same time limitations/design flaws in Internet design, programming languages etc. make attack techniques to evolve from day to day. Due to such evolution of new attack mechanisms, at present, we have a big list of different attacks. Further, motivations for making such attacks range from just having fun to sabotaging critical & specific infrastructures at national level. Hence, in this context, it is very necessary and useful to know about latest trends in security attacks. In this connection this paper provides a brief survey of latest security attacks on web. This paper also provides a summarized comparison of discussed attacks against chosen important parameters. In addition, an observational data about attacks via Emails over a period of time is also presented. The paper concludes by mentioning the need of such surveys and research opportunities in this area. © 2011 Springer-Verlag.Item Web security: Research challenges and open issues(2011) Geetha, V.; Kallapur, P.V.It has been observed for a quite long time that Web Security has been one of hot research areas, from point of view of be it either analysis or detection and later developing mitigation plans. Web security threats have undergone much sophistication compared to their initial introduction and they are becoming more & more evolved everyday. The evolution might be in terms of new ways of attack or bringing in resistance to using simulated OS or VM environments. Also, there has been considerable shift in the target of attacks in recent years. Earlier, clients were ignored while choosing targets. But, in recent years client user has become the main target for attacks as the adversary believe that the end user is the weakest link in the security chain. As a result of all these latest developments traditional security tools have been ineffective against these new attacks either for detecting or analyzing the attacks. In this regard this paper presents a brief survey of research challenges and open issues in the area of web security under the suitable subtitles depending upon type of attack associated with the issues. © 2011 Springer-Verlag.Item A survey and comparison of GTS allocation and scheduling algorithms in IEEE 802.15.4 wireless sensor networks(2013) Rao, S.; Keshri, S.; Gangwar, D.; Sundar, P.; Geetha, V.Multimedia applications in the wireless domain require not only contention-based communication, but also reservation based one. The IEEE 802.15.4 standard is widely used for Wireless Sensor Networks (WSNs), and is a standard for low rate, low power and low cost WPANs (Wireless Personal Area Networks). Moreover, it supports the allocation of Guaranteed Time Slot (GTS) to the devices in Contention free period (CFP). With time, many GTS scheduling and allocation algorithms have been proposed with the aim to make maximum the use of GTS. This paper provides a survey and comparison on the current state-of-the-art researches in this important area. We have firstly summarized all the important algorithms proposed till now and then classified and compared them based on various parameters including type, delay, bandwidth, cost, topology, traffic and energy efficiency. © 2013 IEEE.Item Energy efficient LEACH by enhancing the data update procedure of cluster head(2013) Rajan, P.; Geetha, V.There are several modification has been happened in LEACH protocol. Most of modifications are in cluster organization. This paper studies modified LEACH protocol using data update procedure of cluster head. In LEACH protocol frequency of sending data to the base station by smaller cluster is higher than bigger cluster due to that energy dissipation in smaller cluster is more than bigger cluster. This paper studies modified LEACH protocol in which frequency of sending data to the base station by each cluster is same. Simulation has been done in NS2 and simulation result shows that modified LEACH protocol is more energy efficient than LEACH protocol. © 2013 IEEE.Item Enhanced back-off technique for IEEE 802.15.4 WSN standard(Springer Verlag service@springer.de, 2014) Vutukuri, A.; Bhattacharya, S.; Raj, T.; Sridhar; Geetha, V.IEEE 802.15.4 is the standard for Low-rate Wireless Personal Area Networks. The CSMA-CA algorithm used in the standard for channel contention causes performance bottlenecks in certain scenarios. We have conducted a performance evaluation of the back-off algorithm with the help of simulations on star networks and identified two parameters which affect the performance of the algorithm - macMinBE and macMaxBE. Further, we have also proposed an enhanced algorithm which involves these two parameters and improves the performance of the back-off algorithm. © 2014 Springer International Publishing Switzerland.Item Performance evaluation of existing wireless TCP variants for high data rate wireless sensor networks(Institute of Electrical and Electronics Engineers Inc., 2016) Geetha, V.; Kallapur, P.V.; Preetham, L.; Darshan, T.K.Wireless Sensor Networks(WSN) are currently being used widely in innumerable types of applications. Each one of these applications may have different data rate, i.e., some applications may have low data rate and others may have high data rate. WSN should be designed to fine tune their performance to meet these varying data rates. Due to the stringent resource constraints and highly application specific nature of WSN, it is very difficult to support these varying data rates. This task of supporting high data rate in WSN becomes very much crucial in case of applications meant for processing heterogeneous sensor data which could be scalar data, still images etc., which may be being generated at very high rate. This paper makes an effort to evaluate the performance of chosen existing wireless TCP variants in case of high data rate WSN. In this regard, this paper presents brief summary of chosen wireless TCP variants, simulations carried out using NS2, results, and the analysis of the results. The paper will be concluded with identification of some major research issues in designing TCP protocols for high data rate WSN. © 2015 IEEE.Item Constructing an enriched domain taxonomy for Hindi using word embeddings(Institute of Electrical and Electronics Engineers Inc., 2017) Keshava, V.; Pravalika, P.; Kamath S․, S.S.; Geetha, V.Domain-specific taxonomies constitute a valuable resource as they offer extensive support in information retrieval related activities like browsing, searching, recommendations and personalization. Such taxonomies can bridge the gap between the lack of domain-specific querying knowledge in potential users and the actual content. In case of multilingual content, taxonomies can play a pivotal role in boosting search performance for content across language barriers. In this paper, a domain-agnostic framework for building an evolving, domain-specific taxonomy for the Hindi, given a set of well-organized data points is proposed. The approach is intended for designing a hierarchical taxonomy enriched with synonyms and other morphological variants using WordNet and Word2vec models respectively. The hierarchical structure acts as a base which binds the taxonomy to a given domain. Such enrichment can improve taxonomy coverage within the given domain. The focus is also on building a taxonomy that can self-evolve over time, with high precision and recall, with minimal manual effort. © 2017 IEEE.Item Survey on routing protocols for Internet of Things(Institute of Electrical and Electronics Engineers Inc., 2017) Bhat, A.; Geetha, V.As Wireless Sensor Network nodes are ID based network, it would be difficult to monitor the status of the same when it is connected to Internet of Things. So gateway is required to connect the network with Internet. In order to access and manage the network remotely, it is good to have IP based devices connected with each other. As IPv4 is being depleted, IPv6 was a solution for much larger address space. IP connectivity in sensor networks mainly depend on two IETF standards: 6LoWPAN and RPL. Routing protocol in 6LoWPAN is very precise due to limited node's potential. Existing protocol of 6LoWPAN does not satisfy Low power Lossy networks. IETF came up with IPv6 routing protocol for low power Lossy networks called RPL. © 2017 IEEE.Item Parallel OpenMP and CUDA Implementations of the N-Body Problem(Springer Verlag service@springer.de, 2019) Gangavarapu, T.; Pal, H.; Prakash, P.; Hegde, S.; Geetha, V.The N-body problem, in the field of astrophysics, predicts the movements of the planets and their gravitational interactions. This paper aims at developing efficient and high-performance implementations of two versions of the N-body problem. Adaptive tree structures are widely used in N-body simulations. Building and storing the tree and the need for work-load balancing pose significant challenges in high-performance implementations. Our implementations use various cores in CPU and GPU via efficient work-load balancing with data and task parallelization. The contributions include OpenMP and Nvidia CUDA implementations to parallelize force computation and mass distribution, and achieve competitive performance in terms of speedup and running time which is empirically justified and graphed. This research not only aids as an alternative to complex simulations but also to other big data applications requiring work-load distribution and computationally expensive procedures. © 2019, Springer Nature Switzerland AG.