Tianwei Xu

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Aiming at the limitations of LEACH, PEGASIS and PEDAP, we present a multi-layer energy-efficient and delay-reducing chain-based data gathering protocol (MEDC) for wireless sensor network, under consideration of the characteristics of wireless sensing traffic monitoring network (WSTMN) such as band monitoring area, high-speed target, long-distance base(More)
The SIFT (Scale Invariant Feature Transform) is a computer vision algorithm that is used to detect and describe the local image features. The SIFT features are robust to changes in illumination, noise, and minor changes in viewpoint. The SIFT features have been used object recognition, image retrieval and matching, and so on.. The research of SIFT(More)
The use of Wireless Sensor Network (WSN) has proved to be a very beneficial in the design of adaptive and dynamic traffic light intersection system that will minimize the waiting time of vehicles and also manage the traffic load at the intersection adaptively. In this paper, we propose an adaptive traffic intersection system based on Wireless Sensor Network(More)
—As a powerful tool, ontology has been widely applied in social science, medicine science and computer science. In computer networks, especially, ontology is used for search extension, thus boost the quality of information retrieval. Ontology concept similarity calculation is an essential problem in these applications. A new method to get similarity between(More)
Curve let transform has been recently proved to be a powerful tool for multi-resolution analysis on images. In this paper we propose a new approach for facial expression recognition based on features extracted via curve let transform. First curve let transform is presented and its advantages in image analysis are described. Then the coefficients of curve(More)
In this paper, after the introduction of ontology-based domain knowledge bases and domain knowledge representation, a formal query model of intelligent search agents that can search over distributed knowledge bases with heterogeneity for Web-based intelligent tutoring systems is proposed; and the searching process of these agents is analyzed. Ontologies are(More)
A graph G is called a fractional (g, f, n)-critical graph if any n vertices are removed from G, then the resulting graph admits a fractional (g, f)-factor. In this paper, we determine the new toughness condition for fractional (g, f, n)-critical graphs. It is proved that G is fractional (g, f, n)-critical if t(G) ≥ b 2 −1+bn a. This bound is sharp in some(More)
A model of a Web-based personalized intelligent tutoring system with a user module, a resource management module, a pedagogical module and a guide module is presented in this paper, and the realization of the system and its properties are discussed. The user module makes use of learnerspsila knowledge levels, psychological characteristics and learning(More)