Secure neighbor discovery is an important element in wireless networking. Several important network functionalities such as routing and localization basically rely on correct neighbor discovery which is the problem concerned in this work. A wormhole attacker can easily tunnel and replay packets from one area of the wireless network to another one, to make the nodes in such typically far awar ar...

In this paper three image steganography methods with variable rate of embedding are proposed. In the first method, called two neighbor method the two neighboring pixels such as upper and left are exploited to take embedding decisions. In three neighbor method the three neighboring pixels such as upper, left and right are exploited to take embedding decisions. In four neighbor method the four ne...

The Neighbor Discovery is a process by which a node identifies its neighbor nodes in its vicinity. We are particular interested in Neighbor Discovery problem in duty-cycle mobile sensor networks in this paper, where a mobile sensor needs to detect its neighbor nodes during its wake-up states. We proposed an algorithm which utilizes the boundary nodes in the communication range of the node to pr...

The first step in graph-based semi-supervised classification is to construct a graph from input data. While the k-nearest neighbor graphs have been the de facto standard method of graph construction, this paper advocates using the less well-known mutual k-nearest neighbor graphs for high-dimensional natural language data. To compare the performance of these two graph construction methods, we ru...

Nearest neighbor search is a powerful abstraction for data access; however, indexing troublesome even approximate indexes. For intrinsically high-dimensional data, high-quality fast searches demand either indexes with impractically large memory usage or preprocessing time. In this paper, we introduce an algorithm to solve nearest-neighbor query q by minimizing kernel function defined the distan...

Reconstructing the evolutionary history of a set of species is an elementary problem in biology, and methods for solving this problem are evaluated based on two characteristics: accuracy and efficiency. Neighbor-joining reconstructs phylogenetic trees by iteratively picking a pair of nodes to merge as a new node until only one node remains; due to its good accuracy and speed, it has been e...