A Simple Model of Ballistic Conduction in Multi-Lead Molecular Devices

A fully analytical model is presented for ballistic conduction in a multi-lead device that is based on a π-conjugated carbon framework attached to a single source lead and several sink leads. This source-and-multiple-sink potential (SMSP) model is rooted in the Ernzerhof source-and-sink potential (SSP) approach and specifies transmission in terms of combinations of structural polynomials based on the molecular graph. The simplicity of the model allows insight into many-lead devices in terms of constituent two-lead devices, description of conduction in the multi-lead device in terms of structural polynomials, molecular orbital channels, and selection rules for active and inert leads and orbitals. In the wide-band limit, transmission can be expressed entirely in terms of characteristic polynomials of vertex-deleted graphs. As limiting cases of maximum connection, complete symmetric devices (CSD) and complete bipartite symmetric devices (CBSD) are defined and solved analytically. These devices have vanishing lead-lead interference effects. Illustrative calculations of transmission curves for model small-molecule systems are presented and selection rules are identified.

ENHANCE NETWORK LIFETIME WIRELESS SENSOR WITH MULTIPLE SINK VERSATILITY

Wireless Sensor Networks (WNS) is essential for ubiquitous computing. Sensor networks with variable sensing capabilities have seen applications in a broad range of regulators where correlations with the physical environment are relevant. Thus, the efforts have been made in attempt to detect atmosphere mainly by investigating sensor networks that integrates single wireless collector (i.e., sink). Many examples of WSNs' use are illustrated. It also has a variety of daunting problems such as topology parsing, routing and power management. The research focuses on solution to energy loss in WSN. This is a technical overview of a sensor system and a wireless network. There are still several challenges facing the WSNs.

Distributed Reliable and Efficient Transmission Task Assignment for WSNs

Task assignment is a crucial problem in wireless sensor networks (WSNs) that may affect the completion quality of sensing tasks. From the perspective of global optimization, a transmission-oriented reliable and energy-efficient task allocation (TRETA) is proposed, which is based on a comprehensive multi-level view of the network and an evaluation model for transmission in WSNs. To deliver better fault tolerance, TRETA dynamically adjusts in event-driven mode. Aiming to solve the reliable and efficient distributed task allocation problem in WSNs, two distributed task assignments for WSNs based on TRETA are proposed. In the former, the sink assigns reliability to all cluster heads according to the reliability requirements, so the cluster head performs local task allocation according to the assigned phase target reliability constraints. Simulation results show the reduction of the communication cost and latency of task allocation compared to centralized task assignments. Like the latter, the global view is obtained by fetching local views from multiple sink nodes, as well as multiple sinks having a consistent comprehensive view for global optimization. The way to respond to local task allocation requirements without the need to communicate with remote nodes overcomes the disadvantages of centralized task allocation in large-scale sensor networks with significant communication overheads and considerable delay, and has better scalability.

Energy-Efficient Clustering With Multiple Sink (Eecms) In Wireless Body Area Network

Wireless Body Area Networks is consists of compact bio sensors that implanted in various body areas of human being. WBAN is a new revolution in the field of health sciences. It monitors the health related data like blood pressure (BP), heartbeat, glucose level, electro-cardiogram etc. It passes these data to the health monitoring systems. WBAN is playing main role in the field of sports, entertainment, medical, psychological and social welfare. Till now there are different routing protocols have been outlined to increase its performance, energy efficiency, throughput, packet delivery ratio (PDR), delay and network lifetime. This paper proposes a routing protocol named energyefficient clustering with multiple sink (EECMS) in wireless body area network. Which calculates the fitness function using multiple parameters such as Residual Node Energy, Distance of nodes and Transmission Range for Cluster Head selection. After some interval it keep changing the head to maintain the flow of network.

Performance Evaluation of Distributed Multi Media Wireless Sensor Network

The demand for multimedia services i.e. audio, video and data with improve QoS and optimum utilization of resources in WSN’s has posed new challenges. As the intensity of traffic increases; it demands for higher bandwidth and dedicated resources to reduce packet loss and delay. There have been analytical models proposed where priorities were assigned to video and voice packets to reduce packet loss and optimize resource utilization. In this paper distributed scheme is proposed to handle video, voice and data packets by having multiple sink nodes. There are shared sink nodes where video, voice and data packets are serviced and dedicated sink nodes only for video and voice packets. The proposed scheme has shown that the packet loss for data packets is higher than voice and video packets. The simulation results show that the performance of the network is improved when priorities are assigned to video and voice packets by giving dedicated resources.