RIG-A New Management Information System for Railway Transportation

A grid technology together with data warehouse and mediator is used to develop the railway transport management information system （TMIS）, which is aiming at managing and publishing all kinds of enterprise resources among dynamic collections of such information systems with heterogeneous architectures and distributed in geography within Chinese Ministry of Railway. As one logical information integration framework and a uniform interface for accessing resources, a prototype named railway information grid （RIG） is proposed. Its main modules and the key technologies, together with its feasibility, are discussed in detail. RIG can not only provide the integral information service and the interoperability of information at the application level, but also bring us such benefits as： easy use, high efficiency, and reasonable total cost of ownership.

Simulation and reliability analysis of shunt active power filter based on instantaneous reactive power theory

This paper first discusses the operating principle of instantaneous reactive power theory. Then, the theory is introduced into shunt active power filter and its control scheme is studied. Finally, Matlab/Simulink power system toolbox is used to simulate the system. In the simulation model, as the most common harmonic source, 3-phase thyristor bridge rectifier circuit is constructed. The simulation results before and after the shunt active filter was switched to the system corresponding to different firing angles of the thyristors are presented and analyzed, which demonstrate the practicability and reliability of the proposed shunt active filter scheme.

AN EVIDENT SIDELOBE CONTROL METHOD BASED ON NSCT FOR SHIP TARGET IN SAR IMAGES

Evident sidelobe on faint ship target seriously affects the accuracy of the target segmen-tation in Synthetic Aperture Radar(SAR) images.To avoid this problem,a novel sidelobe control method based on NonSubsampled Contourlet Transform(NSCT) for ship targets in SAR images is presented in this paper.This method enhances the SAR images in NSCT domain based on target azimuth estimation and then inhibits the sidelobe directionally in NSCT high-pass frequency subbands.Experimental results on RADARSAT-2 images demonstrate that the proposed method can not only reduce the strong sidelobes effectively,but also enhance the intensity of the objects successfully.Therefore,it gives a good segmentation result on the dark ship images with strong sidelobe,and en-hances the detection rate on these targets.

Domain-oriented data-driven data mining:a new understanding for data mining

Recent advances in computing,communications,digital storage technologies,and high-throughput data-acquisition technologies,make it possible to gather and store incredible volumes of data.It creates unprecedented opportunities for large-scale knowledge discovery from database.Data mining is an emerging area of computational intelligence that offers new theories,techniques,and tools for processing large volumes of data,such as data analysis,decision making,etc.There are many researchers working on designing efficient data mining techniques,methods,and algorithms.Unfortunately,most data mining researchers pay much attention to technique problems for developing data mining models and methods,while little to basic issues of data mining.In this paper,we will propose a new understanding for data mining,that is,domain-oriented data-driven data mining(3DM)model.Some data-driven data mining algorithms developed in our Lab are also presented to show its validity.

VCSW—An RTP/RTCP-Based Video Conferencing System On WAN

This paper chiefly introduces the model of Video Conferencing System, H.323 standard of ITU- T and RTP/RTCP protocol, and realizes a WAN- Oriented Video Conferencing System—VCSW (Video Conferencing System on WAN). In VCSW, RTP/RTCP pro- tocol is used for transporting media data and video conference on WAN can be established, so VCSW has abroad application scope. This paper stresses analyzing RTP/RTCP protocol, realizes it and modifies some details of it according to our device condition: re- duces some fields of RTP and RTCP header, removes some information managed by RTP/RTCP. Consequently in testing of lab, good effect is achieved.

Content Authentication Based on JPEG-to-JPEG Watermarking

A content authentication technique based on JPEG-to-JPEG watermarking is proposed in this paper. In this technique, each 8x8 block in a JPEG compressed image is first processed by entropy decoding, and then the quantized discrete cosine transform （DCT） is applied to generate DCT coefficients： one DC coefficient and 63 AC coefficients in frequency coefficients. The DCT AC coefficients are used to form zero planes in which the watermark is embedded by a chaotic map. In this way, the watermark information is embedded into JPEG compressed domain, and the output watermarked image is still a JPEG format. The proposed method is especially applicable to content authentication of JPEG image since the quantized coefficients are modified for embedding the watermark and the chaotic system possesses an important property with the high sensitivity on initial values. Experimental results show that the tamper regions are localized accurately when the watermarked JPEG image is maliciously tampered.