Energy efficiency performance improvements for ant-based routing algorithm in wireless sensor networks

The main problem for event gathering in wireless sensor networks (WSNs) is the restricted communication range for each node. Due to the restricted communication range and high network density, event forwarding in WSNs is very challenging and requires multihop data forwarding. Currently, the energy-efficient ant based routing (EEABR) algorithm, based on the ant colony optimization (ACO) metaheuristic, is one of the state-of-the-art energy-aware routing protocols. In this paper, we propose three improvements to the EEABR algorithm to further improve its energy efficiency. The improvements to the original EEABR are based on the following: (1) a new scheme to intelligently initialize the routing tables giving priority to neighboring nodes that simultaneously could be the destination, (2) intelligent update of routing tables in case of a node or link failure, and (3) reducing the flooding ability of ants for congestion control. The energy efficiency improvements are significant particularly for dynamic routing environments. Experimental results using the RMASE simulation environment show that the proposed method increases the energy efficiency by up to 9% and 64% in converge-cast and target-tracking scenarios, respectively, over the original EEABR without incurring a significant increase in complexity. The method is also compared and found to also outperform other swarm-based routing protocols such as sensor-driven and cost-aware ant routing (SC) and Beesensor

Layers of Metal Nanoparticles on Semiconductors Deposited by Electrophoresis from Solutions with Reverse Micelles

Pd nanoparticles were prepared with reverse micelles of water/AOT/isooctane solution and deposited onto silicon or InP substrates by electrophoresis. A large change of capacitance-voltage characteristics of mercury contacts on a semiconductor was found after Pd deposition. This change could be modified when the Pd deposition is followed by a partial removal of the deposited AOT. The deposited Pd nanoparticles were investigated by optical mictroscopy, SIMS and SEM. Finally, Schottky diodes with barrier height as high as 1.07 eV were prepared by deposition of Pd nanoparticles on n-type InP and by a partial removal of superfluous AOT. These diodes are prospective structures for further testing as hydrogen sensors

Baker's asthma: a case report.

Annals of the Academy of Medicine Singapore193407-40

The ECG "lead I sign" in cardiac disease - An indicator of coexisting obstructive pulmonary disease

Singapore Medical Journal404281-283SIMJ

Choices and preferences in asthma management

Singapore Medical Journal336590-594SIMJ

Analysis of P wave and P dispersion in children with secundum atrial septal defect

Annals of Noninvasive Electrocardiology64305-309ANEL

Development of Ni80Fe20/Cu nanocrystalline composite wires by pulse-reverse electrodeposition

10.1016/j.jallcom.2006.02.104Journal of Alloys and Compounds4491-2279-283JALC

Magnetic properties of pulse-reverse electrodeposited nanocrystalline NiFe/Cu composite wires in relation to the anodic current

10.1088/0031-8949/2007/T129/038Physica Scripta TT129165-169PHST