in this paper the reflection coefficient of electromagnetic wave incidence on the walls of the buildings and obstacles that occurs in mobile communication path was modified by solving the riccati nonlinear equations. for this purpose, the building walls are assumed inhomogeneous layers where their permittivity changes as function of the wall thickness. using this reflection coefficient, a new p...

The Island is a k nearest neighbor query algorithm of moving objects based on road networks and can effectively balance the performance of query and update. But the algorithm doesn’t consider the direction of moving object which is required in many scenarios. It traverses vertexes from all directions, meaning wasting a lot of time in visiting useless vertexes. Besides, it doesn’t return query p...

Recently, several fully distributed (localized) location-based routing protocols for a mobile ad hoc network were reported in literature. They are variations of directional (DIR), geographic distance (GEDIR) or progress-based (MFR) routing methods. In DIR methods, each node A (the source or intermediate node) transmits a message m to several neighbors whose direction is closest to the direction...

We present a simple, yet effective, approach to Semi-Supervised Learning. Our approach is based on estimating density-based distances (DBD) using a shortest path calculation on a graph. These Graph-DBD estimates can then be used in any distancebased supervised learning method, such as Nearest Neighbor methods and SVMs with RBF kernels. In order to apply the method to very large data sets, we al...

Video-game designers often tessellate continuous 2dimensional terrain into a grid of blocked and unblocked square cells. The three main ways to calculate short paths on such a grid are to determine truly shortest paths, shortest vertex paths and shortest grid paths, listed here in decreasing order of computation time and increasing order of resulting path length. We show that, for both vertex a...

The paper presents an effective strategy for repetitive neighbor finding in binary images which is proper for mobile robot path planning, connected component labeling, etc. It is based on a new neighbor finding method which is universal and generates all the possible and arbitrary sized neighbors (larger, smaller, equal) for any quadtree node using simple algebraic operations. © 1997 Elsevier S...

This paper presents a secure alternate path routing in sensor networks. Our alternate path scheme makes the routing protocol resilient in the presence of malicious nodes that launch selective forwarding attacks. SeRINS (a Secure alternate path Routing IN Sensor networks) detects and isolates the compromised nodes, which try to inject inconsistent routing information, from the network by neighbo...

In this paper, we propose three types of sensorbased path-planning algorithms and compare them as the image-based path-planning algorithm for a huge search space. In the general image-based path-planning, a camera mounted on a tip of a manipulator is seeking for an objective image while the manipulator is controlled in a joint space. As long as the number of degrees-of-freedom of a manipulator ...