Kaihua Xu

A Routing Strategy Based on Ant Algorithm for WSN

Combined the characteristic of sensor network and the properties of ant algorithm to quickly identify an optimal path, an ant routing algorithm based on deflection angle is proposed. Roulette choosing method is used, combined deflection angle, energy and distance as the elicitation factors, to find an optimal path from source to sink. Aimed at the two conditions of communication and non-communication between artificial ants, simulation and analysis are done separately.

Design and Implementation of Intelligent Vehicle Monitoring and Management System Based on the Multi-Net

In this paper, an intelligent vehicle monitoring and management system (IVMMS) based on the multi-net is designed. First, its architecture and functions are introduced. It uses many technologies fusing GPS, GPRS/CDMA, GIS, RS and Internet, and is composed mainly by two major parts: the Mobile Terminal and the Monitoring Center. Especially, GPRS/CDMA technology is the reliable technical support for wireless communication smooth transition from the 2.5G to the 3G; then, the principles and the key technologies of Mobile Terminal and Monitoring Center are discussed respectively in detail, and figures of their structures are also shown below; finally, a novel vehicle scheduling model based on ant algorithms are proposed and the course of scheduling tasks is also introduced. It is indicated that, the vehicles scheduling efficiency is enhanced greatly. The system not only can be used in the vehicles scheduling, but also in the vessel and other fields, and the solid technical support will be provided for the ITS research

A Novel Hierarchical Clustering Routing Algorithm for Wireless Sensor Networks

Hierarchical clustering is a new clustering scheme in WSN. This paper presents a novel clustering scheme integrating Hierarchical clustering On the basis of classical routing algorithm. Simulation results show that the new scheme efficiently mitigates the hot spot problem in WSN and achieves much improvement in network lifetime and load balance compared to the old algorithm.

A Clustering Algorithm Based on Power for WSNs

This paper computes the optimum number of cluster heads based on power first, and then proposes the clustering algorithm for WSNs, at last estimates its performances by our emulator. On analysis, clustering time complexity is dependent on the network diameter and it is suitable for small or medium networks. The simulation results show that using this clustering algorithm can generate network topology of optimum number of clusters, the nodes energy is reduced greatly and the lifetime of networks is extended.

Model of Controlling the Hubs in P2P Network

Research into the hubs in P2P network, and present a new method to avoid generating the hubs in the network by controlling the logical topology structure of P2P network. We firstly introduce the controlling ideas about hierarchizing the hubs. Then, we disclose and interpret the controlling model, and give out the concrete method to carry it out. Finally, we validate our controlling model via simulations and the simulation results demonstrate that our work is effective to control the hubs in P2P network. Thus, this model can improve the network competence to defend against coordinated attacks, promote the network robustness, and ensure the network would develop continually and healthily.

A Routing Protocol Based on Multi-Path Data Aggregation for Sensor Networks

In this paper, we propose a routing protocol based on multi-path data aggregation (MDA) for sensor network. First, we introduce the techniques, such as data aggregation and so on, then describe the implementation process of this protocol, and finally estimate its performance by our emulator. The simulation results show that because of this protocol, the nodes energy is reduced and the lifetime of network is extended.

Controlling Mechanism for the Hubs in Peer-to-Peer Networks

The hubs could lead to degradation of the system performance and add vulnerability to peer-to-peer (P2P) system. This paper proposes a rank-based controlling mechanism to avoid generating hubs in the P2P networks. In this mechanism, each user has a rank according to its contribution and it can just visit the corresponding rating files with its rank in the system. Users can set and manage the ratings of their sharing files autonomously. The rank structure is pyramidal which enable that the problem of hubs would be solved by user¿s self-management. The simulations validate that this mechanism is effective.

A Genetic Algorithm with Dual-Structure Code and Adaptive Strategy for Link Enhancement Problem

Link enhancement problem is a combinatorial optimization problem, and genetic algorithm is suitable to solve the combinatorial optimization problem. Commonly, the genetic algorithms are adopt one dimension code, this paper adopt the dual-structure code and adaptive probabilities of crossover and mutation to solve the link enhancement problem. In the simulation experiment, we compare the performance of dual-structure code genetic algorithm and one dimension code genetic algorithm

Research of undirected network capacity expansion based on the spanning-tree

This paper gives a mathematical description of the undirected network capacity definitions and theorems of computing capacities towards the network. Prove of the theorem correctness is also given. According to them, the paper proposes an algorithm of computing the undirected network capacities based on spanning tree and even an advanced optimization algorithm. In addition, it. discusses network capacity expansion problems with constraints. And then, the optimization algorithm in the scenario of undirected network with limited costs is outlined, whose feasibility and process are illustrated via examples.

Developing Slow Start over Wireless Networks

In wired networks, congestion is the main reason for most of the packet losses and the original TCP is the best option to implement. However, in wireless networks, these losses will arise for reasons other than congestion. TCPW has been proved to work better in performance and bandwidth utilization than Reno and New Reno in wireless networks. Our research mainly focuses on the slow-start phase of TCPW and develops an algorithm to divide the phase into two parts. In this paper, we propose a simple refinement of slow-start algorithm of TCP Westwood (TCPW), which is a TCP variant focused on to achieve higher performance in wireless and wired networks. We show by results that the new theme could reduce possibility of packet loss in wireless networks. In the first half of slow-start, we use the exponential increase just like the original slow-start. Moreover, we grow the congestion window gradually to decrease packet burstiness in the second half of slow-start.