X-RESTORE: Middleware for XML's Relational Storage and Retrieve

We propose a new approach to store and query XML data in an RDBMS basing on the idea of the numbering scheme and inverted list. O ur approach allows us to quickly determine the precedence, sibling and ancestor/ descendant relationships between any pair of nodes in the hierarchy of XML, and utilize path index to speed up calculating of path expressions. Examples have de monstrated that our approach can effectively and efficiently support both XQuery queries and keyword searches. Our approach is also flexible enough to support X ML documents both with Schema and without Schema, and applications both retrieva l and update. We also present the architecture of middleware for application acc essing XML documents stored in relations, and an algorithm translating a given X ML document into relations effectively.

Fast Computation of Sparse Data Cubes with Constraints

For a data cube there are always constraints between dimensions or among attributes in a dimension, such as functional dependencies. We introduce the problem that when there are functional dependencies, how to use them to speed up the computation of sparse data cubes. A new algorithm CFD (Computation by Functional Dependencies) is presented to satisfy this demand. CFD determines the order of dimensions by considering cardinalities of dimensions and functional dependencies between dimensions together, thus reduce the number of partitions for such dimensions. CFD also combines partitioning from bottom to up and aggregate computation from top to bottom to speed up the computation further. CFD can efficiently compute a data cube with hierarchies in a dimension from the smallest granularity to the coarsest one. Key words sparse data cube - functional dependency - dimension - partition - CFD CLC number TP 311 Foundation item: Supported by the E-Government Project of the Ministry of Science and Technology of China (2001BA110B01)Biography: Feng Yu-cai (1945-), male, Professor, research direction: database system.

A novel face recognition method with feature combination

A novel combined personalized feature framework is proposed for face recognition (FR). In the framework, the proposed linear discriminant analysis (LDA) makes use of the null space of the within-class scatter matrix effectively, and Global feature vectors (PCA-transformed) and local feature vectors (Gabor wavelet-transformed) are integrated by complex vectors as input feature of improved LDA. The proposed method is compared to other commonly used FR methods on two face databases (ORL and UMIST). Results demonstrated that the performance of the proposed method is superior to that of traditional FR ap-

Summarization based on physical features and logical structure of multi documents

With the rapid development of the Internet, multi documents summarization is becoming a very hot research topic. In order to generate a summarization that can effectively characterize the original information from documents, this paper proposes a multi documents summarization approach based on the physical features and logical structure of the document set. This method firstly clusterssimilar sentences into several Logical Topics (LTs), and then orders these topics according to their physical features of multi documents. After that, sentences used for the summarization are extracted from these LTs, and finally the summarization is generated via certain sorting algorithms. Our experiments show that the information coverage rate of our method is 8.83% higher than those methods based solely on logical structures, and 14.31% higher than Top-N method.

Combined Viterbi Detector for a Balanced Code in Page Memories

Based on the two path metrics being equal at a merged node in the trellis employed to describe a Viterbi detector for the detection of data encoded with a rate 6:8 balanced binary code in page-oriented optical memories, the combined Viterbi detector scheme is proposed to improve raw biterror rate performance by mitigating the occurrence of a twobit reversing error event in an estimated codeword for the balanced code. The effectiveness of the detection scheme is verified for different data quantizations using Monte Carlo simulations. Key words holographic data storage - balanced code - modulation code - Viterbi algorithm - path metric CLC number TN 911. 21 Foundation item: Supported by National 973 Research Program of China (G1999033006)Biography: Chen Duan-rong (1960-), male, Lecturer, Ph. D candidate, research direction: coding and signal processing for the recording channel of holographic data storage.

Design and Implementation of Web Services Security Based on Message Layer

Along with the development of Internet, Web Services technology is a new branch of Web application program, and it has become a hotspot in computer science. However, it has not made great progress in research on Web Services security. Traditional security solutions cannot satisfy the Web Services security require of selective protection, end-to-end security and application layer security. Web Services technology needs a solution integrated in Web Services framework to realize end-to-end security. Based on cryptography and Web Services technology and according to W3C, XML encryption specification, XML digital Signature specification and WS-Security, which proposed by IBM and Microsoft, a new Web services security model based on message layer is put forward in this paper. The message layer is composed of message handlers. It is inserted into the message processing sequence and provides transparent security services for Web Services. To verify the model, a Web Services security system is realized on, net platform. The implementation version of the model can provide various security services, and has advantages such as security, scalability, security controllability and end-to-end security in message level. Key words Web services - Web services security - message layer CLC number TP 393.08 Biography: WANG Cui-ru (1954-), female, Professor, research direction: database and information management system.

Data Hiding and Security for XMLDatabase: A TRBAC-Based Approach

In order to cope with varying protection granularity levels of XML(extensible Markup Language) documents, we propose a TXAC (Two-level XML. Access Control) framework,in which an extended TRBAC ( Temporal Role-Based Access Control) approach is proposed to deal withthe dynamic XML data With different system components, LXAC algorithm evaluates access requestsefficiently by appropriate access control policy in dynamic web environment. The method is aflexible and powerful security system offering amulti-level access control solution.

Design Pattern Mining Using Graph Matching

The identification of design pattern instances is important for program understanding and software maintenance. Aiming at the mining of design patterns in existing systems, this paper proposes a subgraph isomorphism approach to discover several design patterns in a legacy system at a time. The attributed relational graph is used to describe design patterns and legacy systems. The sub-graph isomorphism approach consists of decomposition and composition process. During the decomposition process, graphs corresponding to the design patterns are decomposed into sub-graphs, some of which are graphs corresponding to the elemental design patterns. The composition process tries to get sub-graph isomorphism of the matched graph if sub-graph isomorphism of each subgraph is obtained. Due to the common structures between design patterns, the proposed approach can reduce the matching times of entities and relations. Compared with the existing methods, the proposed algorithm is not linearly dependent on the number of design pattern graphs. Key words design pattern mining - attributed relational graph - subgraph isomorphism CLC number TP 311.5 Foundation item: Supported by the National Natural Science Foundation of China (60273075) and the Science Foundation of Naval University of Engineering (HGDJJ03019)Biography: LI Qing-hua (1940-), male, Professor, research direction: parallel computing.

Adaptive tracking controller using BP neural networks for a class of nonlinear systems

An BP neural-network-based adaptive control (NNAC) design method is described whose aim is to control a class of partially unknown nonlinear systems. Making use of the online identification of BP neural networks, the results of the identification could be used into the parameters of the controller. Not only the strong robustness with respect to uncertain dynamics and nonlinearities can be obtained, but also the output tracking error between the plant output and the desired reference output can asymptotically converge to zero by Lyapunov theory in the process of this design method. And a simulation example is also presented to evaluate the effectiveness of the design.

Authorization Administration in a Distributed Multi-application Environment

To meet the authorization administration requirements in a distributed computer network environment, this paper extends the role-based access control model with multiple application dimensions and establishes a new access control model ED-RBAC(Extended Role Based Access Control Model) for the distributed environment. We propose an extendable hierarchical authorization assignment framework and design effective role-registering, role-applying and role-assigning protocol with symmetric and asymmetric cryptographic systems. The model can be used to simplify authorization administration in a distributed environment with multiple applications.

The Response Time Analysis of Digital Broadcasting System

Digital broadcasting system has become a high-light of research on computer application. To respond to the changes of the playbill in the broadcasting system in real time, the response time of the system must be studied. There is scarcely the research on this area currently. The influence factors in the response time are analyzed; the model on the response time of the system service is built; how the influence factors affect the response time of the system service is validated; and four improvement measures are proposed to minimize the response time of system service.

A High-Speed Information Retrieval System

We cleveloped a high-speed information retrieval system. The system hased on the IXP 2800 is one of the dedicute device. The velocity of the information retrieval is 6.8 Gb/s. The protocol support Telnet, FTP, SMTP, POP3 etc. various networks protocols. The information retrieval supports the key word and the natural language process. This paper explains the hardware system, software system and the index of the performance. Key words network processor - IXP2800 - information retrieval - IXA CLC number TP 309 Foundation item: Supported by the National Natural Science Foundation of China (69873016 & 69972017) and the National High Technology Development Program of China (863-301-06-1)Biography: SHI Shu-dong (1963-), male, Ph. D. candidate, research direction: network & information security.

Ontology Based Resolution of Semantic Conflicts in Information Integration

Semantic conflict is the conflict caused by using different ways in heterogeneous systems to express the same entity in reality. This prevents information integration from accomplishing semantic coherence. Since ontology helps to solve semantic problems, this area has become a hot topic in information integration. In this paper, we introduce semantic conflict into information integration of heterogeneous applications. We discuss the origins and categories of the conflict, and present an ontology-based schema mapping approach to eliminate semantic conflicts. Key words ontology - CCSOL - semantic conflict - schema mapping CLC number TP 301 Biography: LU Han (1980-), male, Master candidate, research direction: ontology and information integration.

An Improved Direction Relation Detection Model for Spatial Objects

Direction is a common spatial concept that is used in our daily life. It is frequently used as a selection condition in spatial queries. As a result, it is important for spatial databases to provide a mechanism for modeling and processing direction queries and reasoning. Depending on the direction relation matrix, an inverted direction relation matrix and the concept of direction pre- dominance are proposed to improve the detection of direction relation between objects. Direction predicates of spatial systems are also extended. These techniques can improve the veracity of direction queries and reasoning. Experiments show excellent efficiency and performance in view of direction queries.

Approach in High Precision Topic-Specific Resource Discovery on the Web

The Internet presents numerous sources of useful information nowadays. However, these resources are drowning under the dynamic Web, so accurate finding user-specific information is very difficult. In this paper we discuss a Semantic Graph Web Search (SGWS) algorithm in topic-specific resource discovery on the Web. This method combines the use of hyperlinks, characteristics of Web graph and semantic term weights. We implement the algorithm to find Chinese medical information from the Internet. Our study showed that it has better precision than traditional IR (Information Retrieval) methods and traditional search engines.

A Dynamic XML-NS View Based Approach for the Extensible Integration of Web Data Sources

We propose a three-step technique to achieve this purpose. First, we utilize a collection of XML namespaces organized into hierarchical structure as a medium for expressing data semantics. Second, we define the format of resource descriptor for the information source discovery scheme so that we can dynamically register and/or deregister the Web data sources on the fly. Third, we employ an inverted-index mechanism to identify the subset of information sources that are relevant to a particular user query. We describe the design, architecture, and implementation of our approach—IWDS, and illustrate its use through case examples. Key words integration - heterogeneity - Web data source - XML namespace CLC number TP 311.13 Foundation item: Supported by the National Key Technologies R&D Program of China(2002BA103A04)Biography: WU Wei (1975-), male, Ph.D candidate, research direction: information integration, distribute computing

Modeling and software implementation of flight system for simulator of a new fighter

Real-time modeling and simulation of flight system are the key parts of simulator. After describing the architecture of simulator for a newer fighter, author presents the composition of flight system and its mathematic models. In this paper, aircraft is regarded as an elastic flight body. And a new integrated algorithm which can remedy the shortcoming of Euler method and four-element method is used to calculate the Eulerian angles of aircraft. Finally, the software implementation of the flight system is given in the paper.