ASURVEY ON CLUSTER BASED LOAD BALANCINGAPPROACHESFOR WIRELESSSENSOR NETWORK

Wireless sensor network (WSN) is becoming a very interesting field of research in recent days. It has wide area of research due to various issues caused by the hardware capabilities of sensing nodes such as memory, power, and computing capabilities. One of the major issues is to concentrate on the energy consumption of the sensing node which determines the lifetime of the network. One of such problem is called Hot-spot problem, in which the best channel to the sink are overloaded with traffic and thus causing the nodes to deplete their energy quicker than the energy of other nodes in the network. Clustering algorithms along with sink mobility widely support for equal distribution of the load in the network. In order to overcome this problem various load balancing algorithms are discussed for improving the lifetime of the network

ENERGY EFFICIENT RADIO ACCESS TECHNOLOGIES AND NETWORKING WIRELESS ACCESS NETWORK

LEACH (Low Energy Adaptive Clustering Hierarchy) is the first network protocol that uses hierarchical routing for Wireless Sensor Networks (WSN) to increase the life time of network. Research on WSN has recently received much attention as they offer an advantage of monitoring various kinds of environment by sensing physical phenomenon, such as in-hospitable terrain, it is expected that suddenly active to gather the required data for some times when something is detected, and then remaining largely inactive for long periods of time. So, efficient energy saving schemes and corresponding algorithms must be developed and designed in order to provide reasonable energy consumption and to improve the network lifetime for WSN. WSN are networks consist of large number of tiny battery powered sensor nodes having limited on-board storage, processing, and radio capabilities. Nodes sense and send their reports toward a processing center which is called sink node or Base Station (BS). Since the transmission and reception process consumes lots of energy for data dispensation, it is necessary to designing protocols and applications for such networks has to be energy aware in order to prolong the lifetime of the network. The proposed, LEACH-PR (Low Energy Adaptive Clustering Hierarchy - Power Resourceful) protocol includes clustering, routing and radio propagation technique by balancing the energy consumption of sensor nodes to improve the efficiency of data transmission and prolonging the network lifetime. The goals of this scheme are, increase the stability period of network, and minimize the energy consumption. The performance analysis of proposed LEACH-PR is compared with ILEACH (Improved LEACH), EHE-LEACH (Enhanced Heterogeneous LEACH), and EEM-LEACH (Energy Efficient Multihop LEACH) protocols and concluded that, the LEACH-PR has significant improvement over in terms of lifetime of network, both in homogeneous and heterogeneous environments

Characterizing the scent and chemical composition of Panthera leo marking fluid using solid-phase microextraction and multidimensional gas chromatography–mass spectrometry-olfactometry

Lions (Panthera leo) use chemical signaling to indicate health, reproductive status, and territorial ownership. To date, no study has reported on both scent and composition of marking fluid (MF) from P. leo. The objectives of this study were to: 1) develop a novel method for simultaneous chemical and scent identification of lion MF in its totality (urine + MF), 2) identify characteristic odorants responsible for the overall scent of MF as perceived by human panelists, and 3) compare the existing library of known odorous compounds characterized as eliciting behaviors in animals in order to understand potential functionality in lion behavior. Solid-phase microextraction and simultaneous chemical-sensory analyses with multidimensional gas-chromatography-mass spectrometry-olfactometry improved separating, isolating, and identifying mixed (MF, urine) compounds versus solvent-based extraction and chemical analyses. 2,5-Dimethylpyrazine, 4-methylphenol, and 3-methylcyclopentanone were isolated and identified as the compounds responsible for the characteristic odor of lion MF. Twenty-eight volatile organic compounds (VOCs) emitted from MF were identified, adding a new list of compounds previously unidentified in lion urine. New chemicals were identified in nine compound groups: ketones, aldehydes, amines, alcohols, aromatics, sulfur-containing compounds, phenyls, phenols, and volatile fatty acids. Twenty-three VOCs are known semiochemicals that are implicated in attraction, reproduction, and alarm-signaling behaviors in other species