Yan Chu

Software reliability growth model based on fuzzy wavelet neural network

Back-propagation neural network (BPNN) for software reliability prediction has the problem of network architecture difficult to determine. We want to solve the problem and further increase the prediction accuracy of the model. We use phase space reconstruction technology and the fuzzy wavelet neural network (FWNN), and present the software reliability growth model based on fuzzy wavelet neural network (FWNN-SRGM). The experimental results show that the presented method can easily determine the network architecture according to failure data. The prediction accuracy of FWNN-SRGM is better than that of the widely used BPNN-SRGM.

Research on cooperation communication based-on cross-layer for underwater wireless sensor networks

With the increase of requirements for the ocean information in the world, people begin to put focus on the research on underwater wireless sensor networks. The research on underwater wireless sensor networks is studied by the layer methods in the wireless sensor networks. Although this simplifies the research, the respective layer optimization is not able to guarantee the overall networks optimization. Cross layer can make up for the limitation brought by layer. Its object is to realize the balance between the performance and the design interaction in protocol layer which is not adjacent in logicalness. The cross layer among the physical, data link and networks balances the performance and decreases the transition about the control signal. It realized the maximization of saving energy and the extension of lifetime. This is very important to the underwater wireless sensor networks. The paper combines underwater communications among underwater devices, takes use of the cross layer design, considers the physical layer, modulation and forward error correct interaction, media access control and routing interaction. Based on the research on wireless sensor networks, combined with the characteristics of physical layer, the functionalities and characteristics are considered in a comprehensive way, the cross layer design is studied thoroughly, and the cross layer link transmission algorithm and cross layer link optimization are proposed which makes the scare resource effective utilization. Simulation experiments show that cooperation communication based-on cross layer is fit for underwater wireless sensor network. The algorithm increase the efficiency and throughout. They also have good stability.

Research on data streams publishing of privacy preserving

Data streams contain a lot of client information that need to be carefully managed to protect privacy of clients. Most of existing privacy preserving methods, such as k-anonymity, was designed for static data sets. However these methods can not be applied on data streams directly. Moreover, in dada streams applications, there is a need to offer strong guarantees on maximum allowed delay between incoming data and its anonymous output. This paper presents a novel weak clustering based data streams k-anonymity method for data publishing. Three advantages make its practical: first, little processing time for each tuple of data steam. Second, demand less memory. Last, both privacy preserving and utility of anonymous data are considered carefully. Theoretical analysis and experimental results show that the method is efficient and effective.

A category on the cache invalidation for wireless mobile environments

Wireless computing becomes most popular with the development of mobile computers. Cache technique in wireless computing is crucial because it facilitates the data access at clients for reducing servers’ loading, hence improve the performance. However, conventional cache technique requires coherence between servers and clients because of frequent disconnection. The cache invalidation strategy becomes an ideal method. In this paper, a category on the cache invalidation is proposed. To evaluate system performance, a mathematical model is proposed. It will develop high performance cache technique for practical wireless mobile computing.

Weighted Sub-block Mean-Shift Tracking with Improved Level Set Target Extraction

Mean-shift tracking algorithm is a widely-used tool for efficiently tracking target. However, the background change and shade usually lead to tracking errors and low tracking accuracy. In this paper, we introduce a novel mean-shift tracking algorithm based on weighted sub-block which incorporates the improved level set target extraction. The weight of each sub-block is determined by the similarity of target and candidate sub-blocks, and by the ratio of the target sub-block and overall areas. The target sub-block area is calculated by the means of the narrow band level set combined with a compromise to improve extraction accuracy and operating efficiency. Both of RGB color information in the target region and the pixels position information are taken into consideration while describing the feature model of target and candidate region inside each sub-block. Experimental results demonstrate the methods success for tracking of targets with background change and shade during the dynamic scene, where the basic mean-shift tracking algorithm fails. The proposed method has better tracking performance with higher tracking accuracy and adaptability.

Data Cache Strategy Based on Colony Algorithm in Mobile Computing Environment

In mobile computing environments, the limited bandwidth of wireless communications, the weak capability of mobile computing equipments and the valuable power make it difficult for mobile devices to be maintained with the network all the time. Cache technique caches part of data in the clients to reduce the query of database server, so it solves the problem to some extent. Research on cache strategy for mobile computing environment has become an important research direction. Based on the analysis of existing cache strategy, we studied the cache strategy based on mobile agent further. In order to make Mobile Agents have the real and effective collaboration and not limited reference to the conceptual level, we use the ant colony algorithm to propose the data cache strategy based on ant colony algorithm. Finally, we give the experiment to show the superiority.

An Invalidation Cache Model Based on Ant Colony Algorithm in Mobile Databases

Mobile databases are always the core technique of the dynamic data management. Cache technique, as one of the key techniques in mobile databases, is able to reduce the contention of bandwidth and save the power energy. As the character of ant colony algorithm is choice, update, cooperation mechanism, which is accorded with the mobile agent. An invalidation cache model based on ant colony algorithm is proposed. Mobile agents are looked as different ants which are able to divide the work. Thus, the optimum result is received. The experimental results indicate that the enhancement is practical.