Routing protocols for ad hoc networks with uncertainty in the position of the destination

An ad hoc network comprises a set of computing devices, often mobile, that communicate using wireless transmissions with the devices within their transmission range. These devices or nodes are able to detect the presence of other nodes in their transmission range as well route packets on behalf of other nodes. Hence, the network does not need to depend on any predefined infrastructure. This lack of infrastructure makes the problem of routing and packet forwarding a challenging task in such networks. To carry out this task in an efficient and scalable manner, several authors have proposed position-based routing algorithms. Position-based routing algorithms utilize the position or location of the destination node to inform routing decisions. However, obtaining the accurate position of the destination may not be feasible in some settings. In this thesis, we consider the problem of routing in an ad hoc network where the source node knows the approximate position of the destination node, but is uncertain about its exact current location. We investigate two approaches to this problem: one, based on a traversal of the faces of a planar sub-graph of the graph representing the network, and the second, based on flooding a limited area of the graph that represents the region the destination is likely to be found. We propose several variants of both approaches, and do extensive simulations to analyze the performance of the algorithms. Our results indicate that a simple modification of the basic flooding approach yields the best trade-off for optimizing delivery rate, stretch factor, as well as transmission cost. If however, delivery is required to be guaranteed, then a variant of the face tree traversal approach that we propose has the best performanc

Particle Swarm Optimization and Bacterial Foraging Optimization Techniques for Optimal Current Harmonic Mitigation by Employing Active Power Filter

Conventional mathematical modeling-based approaches are incompetent to solve the electrical power quality problems, as the power system network represents highly nonlinear, nonstationary, complex system that involves large number of inequality constraints. In order to overcome the various difficulties encountered in power system such as harmonic current, unbalanced source current, reactive power burden, active power filter (APF) emerged as a potential solution. This paper proposes the implementation of particle swarm optimization (PSO) and bacterial foraging optimization (BFO) algorithms which are intended for optimal harmonic compensation by minimizing the undesirable losses occurring inside the APF itself. The efficiency and effectiveness of the implementation of two approaches are compared for two different conditions of supply. The total harmonic distortion (THD) in the source current which is a measure of APF performance is reduced drastically to nearly 1% by employing BFO. The results demonstrate that BFO outperforms the conventional and PSO-based approaches by ensuring excellent functionality of APF and quick prevail over harmonics in the source current even under unbalanced supply

Analysis on Checkpointing Scheme Paradigms for Mobile Ad-hoc Network: A Review

Abstract: This paper reviews the performance of various earlier algorithms in Mobile Ad hoc network (MANET) strived to achieve effective fault tolerant technique and subsequently presents a new algorithm keeping in mind all the existing drawbacks which will ensure to have better failure free execution cost and recovery cost. We can't emulate the fault tolerance strategy of general distributed mobile computing system pointing to mobile ad-hoc since this networks limitation and requirement are significantly unlike hence it's quite apparent that surge on tolerance strategy got comprehended. As fault tolerant technique plays vital role in mobile Ad-hoc network which completely depends on the successful process execution on mobile nodes and recovery of nodes state in case of failure. Failure most likely happens when system scales up to have high performance in mobile ad-hoc networks especially when running large and critical applications then the environment needs certain stringent techniques to stand by the fault tolerance. Hence we attempt to provide the current research status of checkpointing schemes pertaining only to ad-hoc network and the analysis, subsequently our proposed schemes i.e. a bolster scheme to this network which can shun the incurred overheads

Effect of vegetation structure on above ground biomass in tropical deciduous forests of Central India

The study aimed to determine the above-ground biomass (AGB) of tropical deciduous forests in Central India using field-based techniques and spaceborne quad-pol ALOS PALSAR-2 L-band and dual-pol Sentinel 1A C-band synthetic aperture radar (SAR). Field sampling based on 73 forested grids exhibited a diverse forest composition in the Satpura Tiger Reserve (STR) with a total of 54 tree species of which 31.48% species were IUCN Red-Listed. The forests were highly diverse (H′=3.22) with a low concentration of dominance (CD = 0.06) and a quite high species evenness (E = 0.81). The sensitivity and correlation between field-based AGB and SAR backscatter in STR were highest in cross-polarization due to its higher sensitivity to the vegetation structure in both L- and C-band SAR, where L-VH based AGB estimates were found more accurate (RMSE:5.17%). The study provided vital information for setting up strategies for biodiversity conservation, enhancing forest productivity, and restoring wildlife habitats

2-Alkyloxazoles as potent and selective PI4KIIIβ inhibitors for the treatment of HCV

Synthesis and SAR of 2-alkyloxazoles as class III phosphatidylinositol-4-kinase beta (PI4KIIIβ inhibitors is described. These compounds demonstrate that inhibition of PI4KIIIβleads to potent inhibition of HCV replication as observed in genotype (GT) 1a and 1b replicon and GT2a JFH1 virus assays in vitro

Discovery of a novel indole pharmacophore for the irreversible inhibition of myeloperoxidase (MPO)

Myeloperoxidase (MPO) activity and subsequent generation of hypochlorous acid has been associated with the killing of host-invading microorganisms (e.g. bacteria, viruses, and fungi). However, during oxidative stress, high MPO activity can damage host tissue and is linked to several chronic inflammatory conditions. Herein, we describe the development of a novel biaryl, indole-pyrazole series of irreversible mechanism-based inhibitors of MPO. Derived from an indole-containing high-throughput screen hit, optimization efforts resulted in potent and selective 6-substituted indoles with good oral bioavailability and in vivo activity