V. Tejaswi

QoS driven distributed multi-channel scheduling MAC protocol for multihop WSNs

Multi-Channel Dynamic Scheduling has been centric stage of research in WSNs in recent years. In this paper, we propose a Distributed Multi-Channel Scheduling MAC communication protocol (DMS-MAC) to improve the network performance of WSNs, which selects the best channel for an individual wireless sensor node. DMS-MAC supports dynamic channel assignment mechanism where each sensor node is equipped with a directional antennas. The proposed protocol helps to decrease the probability of collision, interferences and improves the overall network performance of Wireless Sensor Networks (WSNs). The protocol is most suitable for short packet transmission under low traffic networks and has ability to utilize parallel transmission among neighboring nodes and achieves increased energy efficiency when multi-channels are available. Simulation result shows that the proposed protocol improves the performance of aggregate throughput, probability of successful transmission, packet delivery ratio, energy consumption and average end-to-end delay.

PCVOS: Principal component variances based off-line signature verification

Offline signature verification system is widely used as a behavioral biometric for identifying a person. This behavioral biometric trait is a challenge in designing the system that has to counter intrapersonal and interpersonal variations. In this paper, we propose a novel technique PCVOS: Principal Component Variances based Off-line Signature Verification on two critical parameters viz., the Pixel Density (PD) and the Centre of Gravity (CoG) distance. It consists of two parallel processes, namely Signature training which involves extraction of features from the samples of database and Test signature analysis which performs extraction of features from the test samples. The trained values from the database are compared with the features of the test signature using Principal Component Analysis (PCA). The PCVOS algorithm shows a notable improvement over the algorithms in [21], [22] and [23].

Efficient Retransmission QoS-Aware MAC Scheme in Wireless Sensor Networks

In this paper, an Efficient Retransmission Random Access Protocol (ERRAP) is designed that combines scheme of collision avoidance and energy management for low-cost, short-range wireless radios and low-energy sensor nodes applications. This protocol focuses on efficient Media Access Control (MAC) schemes to provide autonomous Quality of Service (QoS) to the sensor nodes in one-hop QoS retransmission group in WSNs where the source nodes do not have receiver circuits. These sensor nodes can only transmit data to a destination node, but cannot receive acknowledgement or control signals from the destination node. The proposed scheme ERRAP provides QoS to the nodes which work independently on predefined time by allowing them to transmit each packet an optimal number of times within a given period. Our simulation results demonstrate the superiority of ERRAP scheme which increases the delivery probability and reduces the energy consumption.

PCF-Engine: A Fact Based Search Engine

The World Wide Web (WWW) is the repository of large number of web pages which can be accessed via Internet by multiple users at the same time and therefore it is Ubiquitous in nature. The search engine is a key application used to search the web pages from this huge repository, which uses the link analysis for ranking the web pages without considering the facts provided by them. A new application called Probability of Correctness of Facts(PCF)-Engine is proposed to find the accuracy of the facts provided by the web pages. It uses the Probability based similarity (SIM) function which performs the string matching between the true facts and the facts of web pages to find their probability of correctness. The existing semantic search engines, may give the relevant result to the user query but may not be 100% accurate. Our algorithm probes for the accuracy among the facts to rank the web pages. Simulation results show that our approach is efficient when compared with existing Voting [1] and Truthfinder [1] algorithms with respect to the trustworthiness of the websites.