In Wireless sensor networks (WSNs), All communications between different nodes are sent out in a broadcast fashion. These networks are used in a variety of applications including military, environmental, and smart spaces. Sensors are susceptible to various types of attack, such as data modification, data insertion and deletion, or even physical capture and sensor replacement. Hence security bec...

The Helmholtz equation governing wave propagation and scattering phenomena is difficult to solve numerically. Its discretization with piecewise linear finite elements results in typically large linear systems of equations. The inherently parallel domain decomposition methods constitute hence a promising class of preconditioners. An essential element of these methods is a good coarse space. Here...

This paper provides the knowledge about different techniques for speckle noise removal from different types of images like synthetic, photographic, ultrasound and Synthetic Aperture Radar images. Although many filters are available for speckle reduction, some filters are best suited for some particular class of images i.e., some filters are best suited for SAR images and others are best suited ...