Samiran Chattopadhyay

Optimal gateway selection in sensor-cloud framework for health monitoring

Sensor-cloud computing is envisioned to be one of the key enabling technologies for remote health monitoring. Integration of sensed data into cloud applications in sensor-cloud will help in real-time monitoring of patients over geographically distributed locations. In this study, the authors study the optimal gateway selection problem in sensor-cloud framework for real-time patient monitoring system by using a zero-sum game model. In the proposed model, a gateway acts as the first player, and chooses the strategy based on the available bandwidth, whereas a user request acts as the second player, and follows the strategy chosen by the first player. The authors evaluate the execution time for selecting the optimal gateway through which the sensed data will be fetched to the cloud platform. In addition, the authors show how user requests are serviced by the gateways to access data from cloud platform optimally. The authors also show that by using the proposed approach, the execution time decreases, thereby helping in forming a reliable, efficient and real-time architecture for health monitoring.

Secure Biometric-Based Authentication Scheme Using Chebyshev Chaotic Map for Multi-Server Environment

Multi-server environment is the most common scenario for a large number of enterprise class applications. In this environment, user registration at each server is not recommended. Using multi-server authentication architecture, user can manage authentication to various servers using single identity and password. We introduce a new authentication scheme for multi-server environments using Chebyshev chaotic map. In our scheme, we use the Chebyshev chaotic map and biometric verification along with password verification for authorization and access to various application servers. The proposed scheme is light-weight compared to other related schemes. We only use the Chebyshev chaotic map, cryptographic hash function and symmetric key encryption-decryption in the proposed scheme. Our scheme provides strong authentication, and also supports biometrics & password change phase by a legitimate user at any time locally, and dynamic server addition phase. We perform the formal security verification using the broadly-accepted Automated Validation of Internet Security Protocols and Applications (AVISPA) tool to show that the presented scheme is secure. In addition, we use the formal security analysis using the Burrows-Abadi-Needham (BAN) logic along with random oracle models and prove that our scheme is secure against different known attacks. High security and significantly low computation and communication costs make our scheme is very suitable for multi-server environments as compared to other existing related schemes.

Resource allocation in cloud using simulated annealing

One of the major problems in the domain of cloud computing is to allocate requests to resources maintaining high resource utilization. Many researchers have used heuristic algorithms, statistical methods, stochastic knapsack problem, and soft computing techniques to solve this problem. In this paper, we have utilized a variation of multi dimensional (multi parameter) bin packing to model the problem. We have also presented an efficient resource allocation algorithm using simulated annealing. Our approach can be generalized to solve resource allocation problem in multiple layers of cloud computing. Furthermore, we have carried out experiments to illustrate efficiency of our algorithm with respect to commonly used First Come First Serve (FCFS) resource allocation method.

An efficient GA–PSO approach for solving mixed-integer nonlinear programming problem in reliability optimization

Abstract This paper deals with the development of an efficient hybrid approach based on genetic algorithm and particle swarm optimization for solving mixed integer nonlinear reliability optimization problems in series, series–parallel and bridge systems. This approach maximizes the overall system reliability subject to the nonlinear resource constraints arising on system cost, volume and weight. To meet these purposes, a novel hybrid algorithm with the features of advanced genetic algorithm and particle swarm optimization has been developed for determining the best found solutions. To test the capability and effectiveness of the proposed algorithm, three numerical examples have been solved and the computational results have been compared with the existing ones. From comparison, it is observed that the values of the system reliability are better than the existing results in all three examples. Moreover, the values of average computational time and standard deviation are better than the same of similar studies available in the existing literature. The proposed approach would be very helpful for reliability engineers/practitioners for better understanding about the system reliability and also to reach a better configuration.

Energy-Aware Virtual Backbone Tree for Efficient Routing in Wireless Sensor Networks

Virtual backbone has been proposed recently for provisioning an efficient communication infrastructure in energy constrained wireless sensor network. In this paper, a distributed algorithm is proposed for constructing a energy-aware virtual backbone tree (EVBT) for general-purpose communication in wireless sensor network. What distinguishes our algorithm from others is that it chooses only nodes with adequate energy levels (energy level above threshold) as the member of the virtual backbone. Simulation results show that size of the EVBT is always much smaller compared to other prominent schemes. This will greatly reduce the protocol overhead. It also shows that algorithm performs competitively with others in terms total energy consumption for data delivery along the tree. The use of multiple nodes disjoint EVBTs further improves the robustness of the communication infrastructure.

Multiple Disjoint Power Aware Minimum Connected Dominating Sets for Efficient Routing in Wireless Ad Hoc Network

Dominating set based routing is emerging as a promising approach for routing in ad hoc wireless networks. A set is dominating if all the nodes in the network are either in the set or neighbors of nodes in the set. Power aware minimum connected dominating set refers to a minimum connected dominating set where energy levels of all dominator nodes are above a predefined threshold level. Usually, nodes in the connected dominating set consume more energy in order to handle various bypass traffics than nodes outside the set. If we want to prolong the life span of each node in the network by balancing their energy consumption, nodes should be alternated in being chosen to form a connected dominating set. With this objective, a distributed algorithm is presented to construct multiple node-disjoint power aware minimum connected dominating sets, based on our initial proposal for single power aware MCDS. Applying existing prominent multipath routing strategies on this multiple dominating set, we show that the new algorithm yields better results in terms of maximizing routing tasks, minimizing average energy consumption per packet, and enhancing lifetime of each node in the network.

A lightweight QRS detector for single lead ECG signals using a max-min difference algorithm

BACKGROUND AND OBJECTIVES Detection of the R-peak pertaining to the QRS complex of an ECG signal plays an important role for the diagnosis of a patients heart condition. To accurately identify the QRS locations from the acquired raw ECG signals, we need to handle a number of challenges, which include noise, baseline wander, varying peak amplitudes, and signal abnormality. This research aims to address these challenges by developing an efficient lightweight algorithm for QRS (i.e., R-peak) detection from raw ECG signals. METHODS A lightweight real-time sliding window-based Max-Min Difference (MMD) algorithm for QRS detection from Lead II ECG signals is proposed. Targeting to achieve the best trade-off between computational efficiency and detection accuracy, the proposed algorithm consists of five key steps for QRS detection, namely, baseline correction, MMD curve generation, dynamic threshold computation, R-peak detection, and error correction. Five annotated databases from Physionet are used for evaluating the proposed algorithm in R-peak detection. Integrated with a feature extraction technique and a neural network classifier, the proposed ORS detection algorithm has also been extended to undertake normal and abnormal heartbeat detection from ECG signals. RESULTS The proposed algorithm exhibits a high degree of robustness in QRS detection and achieves an average sensitivity of 99.62% and an average positive predictivity of 99.67%. Its performance compares favorably with those from the existing state-of-the-art models reported in the literature. In regards to normal and abnormal heartbeat detection, the proposed QRS detection algorithm in combination with the feature extraction technique and neural network classifier achieves an overall accuracy rate of 93.44% based on an empirical evaluation using the MIT-BIH Arrhythmia data set with 10-fold cross validation. CONCLUSIONS In comparison with other related studies, the proposed algorithm offers a lightweight adaptive alternative for R-peak detection with good computational efficiency. The empirical results indicate that it not only yields a high accuracy rate in QRS detection, but also exhibits efficient computational complexity at the order of O(n), where n is the length of an ECG signal.

An Efficient Fingerprint Matching Approach Based on Minutiae to Minutiae Distance Using Indexing with Effectively Lower Time Complexity

Fingerprint matching is the main module of fingerprint-based person authentication system. Accuracy of fingerprint matching is an important objective of this type authentication system. Multiple features are used for better matching accuracy but more features add more computational complexity as well as time and space complexity. In this paper, we proposed an approach of fingerprint based authentication system where fingerprint matching is carried out using spacial information (distance) of minutiae points only. This approach is simple and it needs very small space to store templates. We have used an indexing technique to speed up the matching process. In our experiment, we have used FVC2004 fingerprint data-set as input data and investigated the false non-match ratio and false matching ratio for DB2, DB3 and DB4 also.

Improved performance with novel utility functions in a game-theoretic model of medium access control in wireless networks

This paper presents a novel game-theoretic design to optimize the performance of medium access control (MAC) in wireless networks. The nodes of the network are modeled as selfish and rational players of a non-cooperative game. We define novel utility functions to capture their gain from channel access. We characterize the Nash equilibrium of the game and show that it is unique and non-trivial. This ensures a stable operating point from which no player has an incentive to deviate unilaterally and where every player has an equal non-trivial share of the transmission channel. Thus the selfish behavior of the nodes is used to ensure desirable properties of the network as a whole. The nodes follow a distributed update mechanism to reach the equilibrium. They need no message passing or network-wide information. We implement its asynchronous version in NS-2 and study the dynamics of the game. We compare, via simulations, our game model with the distributed coordination function (DCF) in IEEE 802.11 and a comparable game model in the literature. We observe that our design outperforms both these designs and provides much higher throughput and lower collision overhead over a very wide range of network sizes.

Reconstruction of a digital circle

Abstract Since digitization always causes some loss of information, reconstruction of the original figure from a given digitization is a challenging task. Reconstruction of digital circles has already been addressed in the literature. However, an in-depth analysis of an OBQ image of a continuous circle as well as a solution to its domain construction problem is still lacking. In this paper a detailed analysis of digital circles has been carried out. A modified I_R method is formulated to numerically compute the domain of each digital quarter circle for a given radius. Several properties of the OBQ image of a circle reveal that in many cases it is possible to split a digital circle into four digital quarter circles, such that the domains of the individual quarter circles can be combined to obtain the domain of the full circle. Moreover, the domain of a quarter circle is geometrically characterized.