Showing papers by "Mayank Dave published in 2013"

Network Partitioning Recovery Mechanisms in WSANs: a Survey

Abstract: Wireless sensor and actor networks (WSANs) are more promising and most addressing research field in the area of wireless sensor networks in recent scenario. It composed of possibly a large number of tiny, autonomous sensor devices and resources rich actor nodes equipped with wireless communication and computation capabilities. Actors collect sensors' information and respond collaboratively to achieve an application specific mission. Since actors have to coordinate their operation, a strongly connected inter-actor network would be required at all the time in the network. Actor nodes may fail for many reasons (i.e. due of battery exhaustion or hardware failure due to hash environment etc.) and failures may convert connected network into disjoint networks. This can hinder sometimes not only the performance of network but also degrade the usefulness and effectiveness of the network. Thus, having a partitioning detection and connectivity restoration procedure at the time of failure occurs in the network is crucial for WSANs. In this paper, we review the present network partitioning recovery approaches and provide an overall view of this study by summarizing previous achievements.

A Framework For Handling Local Broadcast Storm Using Probabilistic Data Aggregation In VANET

Abstract: Data aggregation is used to combine correlated data items from different vehicles before redistributing to other vehicles in the vehicular ad hoc networks (VANET). The number of retransmissions and the communication overhead can be reduced considerably by using aggregation. It is a prerequisite for applications that require periodic dissemination of information into a large region so that, drivers can be informed well in advance and can take alternative route in case of traffic congestion. Dissemination of information to vehicles through broadcasting creates a broadcast storm problem in VANET. In this paper a novel framework is proposed for handling the local broadcast storm problem using probabilistic data aggregation which reduces the bandwidth consumption and hence improves the information dissemination. This system exploits the knowledge base and stores the decisions for aggregation and is based on a flexible and extensible set of criteria. These criteria's can be application specific and can enable a dynamic fragmentation of the road according to the various application requirements. The framework is evaluated for VANET based traffic information system through simulation for strictly limited bandwidth and local broadcast problem. The results demonstrate that completely structure-free probabilistic data aggregation reduces the bandwidth consumption by eliminating the local broadcast problem.

Performance evaluation of sequentially combined heterogeneous feature streams for Hindi speech recognition system

Abstract: State-of-the-art automatic speech recognition (ASR) systems follow a well established statistical paradigm, that of parameterization of speech signals (a.k.a. feature extraction) at front-end and likelihood evaluation of feature vectors at back-end. For feature extraction, Mel-frequency cepstral coefficients (MFCC) and perceptual linear prediction (PLP) are the two dominant signal processing methods, which have been used mainly in ASR. Although the effects of both techniques have been analyzed individually, it is not known whether any combination of the two can produce an improvement in the recognition accuracy or not. This paper presents an investigation on the possibility to integrate different types of features such as MFCC, PLP and gravity centroids to improve the performance of ASR in the context of Hindi language. Our experimental results show a significant improvement in case of such few combinations when applied to medium size lexicons in typical field conditions.

Antecedence Graph Approach to Checkpointing for Fault Tolerance in Mobile Agent Systems

Abstract: The flexibility offered by mobile agents is quite noticeable in distributed computing environments. However, the greater flexibility of the mobile agent paradigm compared to the client/server computing paradigm comes at an additional threats since agent systems are prone to failures originating from bad communication, security attacks, agent server crashes, system resources unavailability, network congestion, or even deadlock situations. In such events, mobile agents either get lost or damaged (partially or totally) during execution. In this paper, we propose parallel checkpointing approach based on the use of antecedence graphs for providing fault tolerance in mobile agent systems. During normal computation message transmission, the dependency information among mobile agents is recorded in the form of antecedence graphs by participating mobile agents of mobile agent group. When a checkpointing procedure begins, the initiator concurrently informs relevant mobile agents, which minimizes the identifying time. The proposed scheme utilizes the checkpointed information for fault tolerance which is stored in form of antecedence graphs. In case of failures, using checkpointed information, the antecedence graphs and message logs are regenerated for recovery and then normal operation continued. Moreover, compared with the existing schemes, our algorithm involves the minimum number of mobile agents during the identifying and checkpoiting procedure, which leads to the improvement of the system performance. In addition, the proposed algorithm is a domino-free checkpointing algorithm, which is especially desirable for mobile agent systems. Quantitative analysis and experimental simulation show that our algorithm outperforms other coordinated checkpointing schemes in terms of the identifying time and the number of blocked mobile agents and then can provide a better system performance. The main contribution of the proposed checkpointing scheme is the enhancement of graph-based approach in terms of considerable improvement by reducing message overhead, execution, and recovery times.

A Hybrid Algorithm for Image Watermarking against Signal Processing Attacks

Abstract: In this paper, we have presented a hybrid image watermarking technique and developed an algorithm based on the three most popular trans form techniques which are discrete wavelet transforms DWT, discrete cosine transforms DCT, and singular value decomposition SVD against signal processing attacks. However, the experimental results demonstrate that this algorithm combines the advantages and remove the disadvantages of these three transform. This proposed hybrid algorithm provides better imperceptibility and robustness against various attacks such as Gaussian noise, salt and pepper noise, motion blur, speckle noise, and Poisson noise etc.

QoS Enabled Probabilistic Routing for Heterogeneous Wireless Sensor Networks

Abstract: There is an increasing research interest in solving routing problems in Wireless Sensor Networks (WSN) and most of the existing routing protocols for WSN consider homogeneous nodes wherein, all sensor nodes have the same capabilities in terms of sensing, communication and computation capabilities. However, deployment of a homogeneous sensor network may suffer from poor performance. In this paper, we present a novel QoS routing scheme that adaptively learns an optimal routing strategy, depending on multiple optimization goals. We base our approach on Ant Colony Optimization (ACO) technique which is insensitive to initial setting, thus ideal in the context of WHSNs. The key feature of the protocol is its ability to meet diverse QoS requirements posed by different kinds of traffic generated due to heterogeneous nature of nodes thus maximizing network performance and utilization. Experimental results suggest a significant gain in the performance of proposed protocol over AODV protocol.

Performance comparison of wavelet filters against signal processing attacks

Abstract: The rapidly growing field of digital contents (image, audio, and video) has incited the need of copyright protection and content authentication, which can be used to verify against any unlawful attempt to either reproduce or juggle them in order to change their identity Digital watermarking is a method providing a best result to the trouble of copyright protection and content authentication of digital contents However, the digital contents can be easily obtained or facsimiled, misrepresented, distributed and stored In this paper, we present the image watermarking method depends on the two most popular transform methods such as discrete wavelet transforms (DWT) and singular value decomposition (SVD) Based on observations, this algorithm combines the advantages and removes the disadvantages of these two transforms techniques Also, we compare the results obtained from different wavelet filters against the number of signal processing attacks This scheme is provides robust watermark without degradation of image quality

Early Handoff mechanism for integrating VANET into Hybrid Wireless Network

Abstract: Hybrid Wireless Network is the integration of more than one type of networks to utilize their benefits and optimize the performance. Vehicular Ad-hoc Networks are the highly dynamic wireless networks formed by vehicles equipped with onboard communication interface. It is difficult to achieve ubiquity in the presence of different types of networks. The proposed mechanism aims to attain ubiquity in Hybrid Wireless Networks by reducing the handoff latency during the handoff procedure and the presence of vehicular nodes removes the power constraint on mobile nodes. The concept of Preferred Access Points has been introduced to achieve fast handoff by using the Early Handoff mechanism. In addition, the mechanism makes use of the knowledge of the network known to access points and GPS (already installed in vehicular nodes) and makes the handoff procedure seamless. The proposed scheme is simulated on the open source simulator OMNeT++ and the delay in registration process of the handoff procedure is the basis for performance evaluation.

Novel Monitoring Mechanism for Distributed System Software Using Mobile Agents

Abstract: As distributed system software gain complexity owing to increasing user needs, monitoring and adaptations are necessary to keep system fit and running. These distributed applications are difficult to manage due to changing interaction patterns, behaviors and faults resulting from varying conditions in the environment. Also the rapid growth in Internet users and diverse services has highlighted the need for intelligent tools that can assist users and applications in delivering the required quality of services. To address these complexities, we introduce mobile agent based monitoring for supporting the self healing capabilities of such distributed applications. We present the novel mobile agent based monitoring technique where the monitor agents constantly collect and update the global information of the system using antecedence graphs. Updating weights of these graphs further help in evaluating host dependence and failure vulnerability of these hosts. These graphs help monitoring mobile agents to detect undesirable behaviors and also provide support for restoring the system back to normalcy.

Performance evaluation of ant based routing protocol for WSNs with Heterogeneous nodes under different radio propagation models

Abstract: The ever-increasing demand for multimedia surveillance and monitoring has led to the deployment of wireless sensor networks capable of capturing multimedia contents along with the scalar data. However, most of the routing protocols designed for wireless sensor networks (WSNs) are meant only for homogeneous sensor networks in which all sensor nodes have same capabilities in terms of communication, computation, energy supply, etc. This paper presents an ant-based QoS routing protocol for Heterogeneous Wireless Sensor Networks consisting of scalar and multimedia sensor nodes with diverse QoS requirements. The proposed protocol proposes different path selection criteria for control traffic and data traffic. The data traffic is further categorized into multimedia traffic and scalar traffic and QoS routes are selected according to the traffic type, thus improving network performance. Further, prior to actual deployment of such networks, an extensive evaluation of the protocols is carried out by making use of simulators. A simulator must replicate realistic conditions and one of the most difficult aspects is the radio signal propagation model. This paper shows that the non-determinism present in some radio propagation models induce randomness which may compromise the performance of many protocols and demonstrates the effectiveness of proposed protocol over AODV under different propagation models.