The proliferation of research on target detection and tracking in wireless sensor networks has kindled development of monitoring continuous objects such as fires and hazardous bio-chemical material diffusion. In this paper, we propose an energy-efficient algorithm that monitors a moving event region by selecting only a subset of nodes near object boundaries. The paper also shows that we can effectively reduce report message size. It is verified with performance analysis and simulation results that total average report message size as well as the number of nodes which transmit the report messages to the sink can be greatly reduced, especially when the density of nodes over the network field is high.

Popular Web sites form their Web servers into Web server clusters. The Web server cluster operates with a load-balancing algorithm to distribute Web requests evenly among Web servers. The load-balancing algorithms founded on conventional periodic load-information update mechanism are not scalable due to the synchronized update of load-information. We propose a load-balancing algorithm that the load-information update is not synchronized by exploiting variant execution times of executing scripts in dynamic Web pages. The load-information of each server is updated 'individually' by a new load-information update mechanism, and the proposed algorithm supports high scalability based on this individual update. Simulation results have proven the improvement in system performance through another aspect of high scalability. Furthermore, the proposed algorithm guarantees some level of QoS for Web clients by fairly distributing requests. A fundamental merit of the proposed algorithm is its simplicity, which supports higher throughput of the Web switch.

It is expected that per-user customized services are widely used in next generation Personal Communication Network. To provide personalized services for each call, per-user service profiles are frequently referenced, so efficient service profile management is essentially required. To provide service profile based services, typically two schemes can be employed: One is Intelligent Network based Central scheme and the other is IMT-2000 based full replication scheme, we refer to as Follow-Me Replication Unconditional (FMRU). Since the Central scheme only depends on the service call rate and the FMRU is merely dependent on the movement rate, it is apparent that the FMRU scheme outperforms the Central scheme if the call-to-mobility ratio (CMR) is large, and vice versa. In this paper, we propose a new service profile replication schemes, Adaptive Follow-Me Replication Conditional (AFMRC) that determine replication automatically according to the user's varying CMR in real-time. We compared the performance of the AFMRC with the previous non-adaptive Follow-Me Replication Conditional (FMRC) scheme. Performance results indicate that as the CMR of a user changes, AFMRC adapts well compared to the existing schemes.