Zeng Zhi-wen

Improved Analysis of Energy Hole for Wireless Sensor Networks

Through analysis of energy consumption of wireless sensor networks with uniform node distribution, this paper finds that energy hole in the wireless sensor networks with uniform node distribution can not be avoided. When network lifetime ends, as much as 90% of network energy remains. However, network lifetime can increase several times by selecting different transmission power levels. The main conclusions in this paper are presented is that the energy consumption in the same circular ring is nonuniform if the density of sensor nodes in the same circular ring is uniform.

Heuristic file sorted assignment algorithm of parallel I/O on cluster computing system

A new file assignment strategy of parallel I/O, which is named heuristic file sorted assignment algorithm was proposed on cluster computing system. Based on the load balancing, it assigns the files to the same disk according to the similar service time. Firstly, the files were sorted and stored at the set I in descending order in terms of their service time, then one disk of cluster node was selected randomly when the files were to be assigned, and at last the continuous files were taken orderly from the set I to the disk until the disk reached its load maximum. The experimental results show that the new strategy improves the performance by 20.2% when the load of the system is light and by 31.6% when the load is heavy. And the higher the data access rate, the more evident the improvement of the performance obtained by the heuristic file sorted assignment algorithm.

Analysing three tier C/S application with the LPT algorithm

We discuss how to apply the LPT algorithm to find the database server number and the middle-tier application server number in order to reduce costs. The three tier C/S model is formed when we insert a middle-tier between the client and server named the application server.