425 research outputs found

    A New Scheme for Minimizing Malicious Behavior of Mobile Nodes in Mobile Ad Hoc Networks

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    The performance of Mobile Ad hoc networks (MANET) depends on the cooperation of all active nodes. However, supporting a MANET is a cost-intensive activity for a mobile node. From a single mobile node perspective, the detection of routes as well as forwarding packets consume local CPU time, memory, network-bandwidth, and last but not least energy. We believe that this is one of the main factors that strongly motivate a mobile node to deny packet forwarding for others, while at the same time use their services to deliver its own data. This behavior of an independent mobile node is commonly known as misbehaving or selfishness. A vast amount of research has already been done for minimizing malicious behavior of mobile nodes. However, most of them focused on the methods/techniques/algorithms to remove such nodes from the MANET. We believe that the frequent elimination of such miss-behaving nodes never allowed a free and faster growth of MANET. This paper provides a critical analysis of the recent research wok and its impact on the overall performance of a MANET. In this paper, we clarify some of the misconceptions in the understating of selfishness and miss-behavior of nodes. Moreover, we propose a mathematical model that based on the time division technique to minimize the malicious behavior of mobile nodes by avoiding unnecessary elimination of bad nodes. Our proposed approach not only improves the resource sharing but also creates a consistent trust and cooperation (CTC) environment among the mobile nodes. The simulation results demonstrate the success of the proposed approach that significantly minimizes the malicious nodes and consequently maximizes the overall throughput of MANET than other well known schemes.Comment: 10 pages IEEE format, International Journal of Computer Science and Information Security, IJCSIS July 2009, ISSN 1947 5500, Impact Factor 0.42

    Estimation of Hypsometric Integral and Groundwater Potential Zones of Amarja Reservoir Catchment, Karnataka, India using SRTM Data and Geospatial Tools

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    Hypsometric integral always play a significant role in watershed health condition. It is nothing but the total time taken in reduction of land area to its vile. Drainage network and studies of various landform features always help in the search of groundwater resources. Morphometric parameter of a drainage basin always helps to understand water use and land use of the basin. The present study aims to find out the geological stages through hypsometric integral values and groundwater potential zones using morphometric parameters to classify it into very good, good, moderate and poor zones using GIS tools. The total area of catchment is 544.76 km2, which is surrounded by Deccan traps. The catchment is further separated into 5 sub-basins on the basis of 4th order stream to get the more specific result. The SRTM (Shuttle Radar Topography Mission) data have been generated from USGS website and further analysed to identify the drainage pattern, slope, contours etc. using ArcGIS 10.0 software. The most important parameters like linear, areal and relief for groundwater investigation have been analysed. The analysis revealed that the hypsometric integral value of sub-basin IV of Amarja reservoir catchment is 0.30 which is showing the late mature stage of the basin. Apart from that, the values of sub-basins II, III and V are 0.54, 0.50 and 0.43 respectively, represent the mature stage while sub-basin I has an integral value of 0.67 which represents the young stage of the basin and it is more susceptible for erosion. Drainage pattern of the catchment could be mainly described as sub dendritic to dendritic. Drainage texture was found to vary from 0.41 to 1.16 which is an indicative of massive coarse to granular texture. An average bifurcation ratio of basin is estimated 3.51 which is an indicator of structural control over the basin. Slope values were found to be in a range from 0.71 to 5.73 degree which indicates very gentle to moderate slop

    A New Mathematical Model for Optimizing the Performance of Parallel and Discrete Event Simulation Systems

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    Null message algorithm is an important conservative time management protocol in parallel discrete event simulation systems for providing synchronization between the distributed computers with the capability of both avoiding and resolving the deadlock. However, the excessive generation of null messages prevents the widespread use of this algorithm. The excessive generation of null messages results due to an improper use of some of the critical parameters such as frequency of transmission and Lookahead values. However, if we could minimize the generation of null messages, most of the parallel discrete event simulation systems would be likely to take advantage of this algorithm in order to gain increased system throughput and minimum transmission delays. In this paper, a new mathematical model for optimizing the performance of parallel and distributed simulation systems is proposed. The proposed mathematical model utilizes various optimization techniques such as variance of null message elimination to improve the performance of parallel and distributed simulation systems. For the sake of simulation results, we consider both uniform and non-uniform distribution of Lookahead values across multiple output lines of an LP. Our experimental verifications demonstrate that an optimal NMA offers better scalability in parallel discrete event simulation systems if it is used with the proper selection of critical parameters

    Investigating the Effects of Trees and Butterfly Barriers on the Performance of Optimistic GVT Algorithm

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    The final publication is available at www.springerlink.comThere is two approaches for handling timing constraints in a heterogeneous network; conservatives and optimistic algorithms. In optimistic algorithms, time constraints are allowed to be violated with the help of a time wrap algorithm. Global Virtue Time (GVT) is a necessary mechanism for implementing time wrap algorithm. Mattern [2] has introduced an algorithm for GVT based computation using a ring structure. which showed high latency. The performance of this optimistic algorithm is optimal since it gives accurate GVT approximation. However, this accurate GVT approximation comes at the expense of high GVT latency. Since this resultant GVT latency is not only high but may vary, the multiple processors involve in communication remain idle during that period of time. Consequently, the overall throughput of a parallel and distributed simulation system degrades significantly In this paper, we discuss the potential use of trees and (or) butterflies structures instead of the ring structure. We present our analysis to show the effect of these new mechanisms on the latency of the system.http://link.springer.com/chapter/10.1007%2F978-90-481-3660-5_7

    A Novel Approach of Using Data Guard for Disaster Recovery & Rolling Upgrades

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    © ASEE 2008Though we already had a standardized way (from Oracle) for Disaster Recovery policy, a major crash of the PLM database made our DBAs to come up with a proposal to execute a procedure using Data Guard together with Oracle Transportable Tablespace which resulted in the successful and timely migration of the PLM Production from Oracle 9.2.0.3 on HP N-Class to Oracle 9.2.0.5 on HP-Superdome in just 8 minutes. This same procedure also gives a fast, reliable way to upgrade from Oracle9i to Oracle Database10g with minimal downtime. And future database upgrades get even easier using Data Guard 10g Rolling Upgrades

    A Mathematical Model for Evaluating the Performance of Multicast Systems

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    © 2008 IEEE. Reprinted, with permission, from Syed S. Rizvi, Aasia Riasat, and Khaled M. Elleith, "A Mathematical Model for Evaluating the Performance of Multicast Systems," The 1st IEEE International Workshop on IP Multimedia Communications (IPMC 2008) August 4 - 7, 2008, St. Thomas U.S. Virgin IslandsThe Internet is experiencing the demand of high-speed real-time applications, such as live streaming multimedia, videoconferencing, and multiparty games. IP multicast is an efficient transmission technique to support these applications. However, there are several architectural issues in this technique that hinder the development and the deployment of IP multicast such as a lack of an efficient multicast address allocation scheme. On the other hand, End System Multicasting (ESM) is a very promising application-layer scheme where all the multicast functionality is shifted to the end-users. Supporting high-speed real-time applications always demand a sound understanding of these schemes and the factors that might affect the end-user requirements. In this paper we attempt to propose both analytical and the mathematical models for characterizing the performance of IP multicast and ESM. Our proposed mathematical model can be used to design and implement a more efficient and robust ESM model for the future networks

    A Novel Approach for Creating Consistent Trust and Cooperation (CTC) among Mobile Nodes of Ad Hoc Network

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    The final publication is available at www.springerlink.comThis paper provides a critical analysis of the recent research wok and its impact on the overall performance of a mobile Ad hoc network. In this paper, we clarify some of the misconceptions in the understating of selfishness and miss-behavior of nodes. Moreover, we propose a mathematical model that based on the time division technique to minimize the node misbehavior by avoiding unnecessary elimination of bad nodes. Our proposed approach not only improves the resource sharing but also creates a consistent trust and cooperation (CTC) environment among the mobile nodes. We believe, that the proposed mathematical model not only points out the weaknesses of the recent research work but also approximates the optimal values of the critical parameters such as throughput, transmission over head, channel capacity etc. The simulation results demonstrate the success of the proposed approach that significantly minimizes the malicious nodes and consequently maximizes the overall throughput of the Ad Hoc network than the other well known schemes.http://link.springer.com/chapter/10.1007/978-1-4020-8737-0_9

    An Efficient Routing Algorithm for Mesh-Hypercube (M-H) Networks

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    Proceedings of the International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA'08, ISBN Set # 1-60132-084-1), Editors: Hamid R. Arabnia and Youngsong Mun, 2008.This paper presents an efficient routing algorithm for the Mesh-Hypercube (M-H) network. The M-H network is one of the new interconnection networking techniques use to build high performance parallel computers. The combination of M-H networks offers high connectivity among multiple nodes, fault-tolerance, and load scalability. However, the performance of M-H networks may degrade significantly in the presence of frequent link or node failures. When a link or node failure occurs, neither the hardware schemes nor point to point and multistage routing algorithms can be used without adding extra links. This paper presents an efficient single bit store and forward (SBSF) routing algorithm for MH network that based on the round robin scheduling algorithm. Simulation and numerical results suggest that the proposed routing algorithm improves the overall performance of M-H network by both reducing the transmission delay and increasing the total data throughput even in the presence of faulty nodes.http://www.world-academy-of-science.org

    Deterministic Formulization of End-to-End Delay for Multicast Systems

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    End-System multicasting (ESM) is a promising application-layer scheme that has been recently proposed for implementing multicast routing in the application layer as a practical alternative to the IP multicasting. Moreover, ESM is an efficient application layer solution where all the multicast functionality is shifted to the end users. However, the limitation in bandwidth and the fact that the message needs to be forwarded from host-to-host using unicast connection, and consequently incrementing the end-to-end delay of the transmission process, contribute to the price to pay for this new approach. Therefore, supporting high-speed real-time applications such as live streaming multimedia, videoconferencing, distributed simulations, and multiparty games require a sound understanding of these multicasting schemes such as IP multicast and ESM and the factors that might affect the end-user requirements. In this paper, we present both the analytical and the mathematical models for formalizing the end-to-end delay efficiency of both IP and ESM multicast systems. For the sake of the experimental verifications of the proposed models, simulation results are presented in this paper. Finally, the proposed formulization can be used to design and implement a more robust and efficient multicast systems for the future networks

    Combining Private and Public Key Encryption Techniques for Providing Extreme Secure Environment for an Academic Institution Application

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    This paper presents the implementation of a secure application for an academic institution that offers numerous services to both students and the faculty. The primary focus of this paper is to provide a technical implementation of a new architecture for encrypting the database. The scope of this paper mainly includes but is not limited to symmetric and public-key cryptography, authentication, key management, and digital signatures. The final results of this paper demonstrate that what security features one should implement in order to achieve a highly secured application. This paper presents the implementation of a stand alone system that can be implemented on any legacy systems, and still operates effectively. In other words, it is self sufficient in terms of the data that it stores
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