Abstract:Although many clustering algorithms have been proposed so far, seldom was focused on high-dimensional and incremental databases. This paper introduces a grid density-based clustering algorithm GDCA. which discovers clusters with arbitrary shape in spatial databases. It first partitions the data space into a number of units, and then deals with units instead of points. Only those units with the density no less than a given minimum density threshold are useful in extending clusters. An incremental clustering algorithm----IGDCA is also presented, applicable in periodically incremental environment.

Abstract:Today, data are stored in and managed by a DBMS(database management system). Relationaldatabase is the current database technique to solve the problem in the flat-file and hierarchical database model. Inthe application of GIS(geographical information system), it recurs to a mechanism i.e. so-called Spatial Databasefor arranging, analyzing and viewing spatial data. Because spatial database contains many different data formats andstructures, these complex data lead to that spatial data manipulation and process may be very complex and difficultand tend to make mistakes. In this paper, we advise a new method by using relational database to manipulate spatialdata. The scheme is to introduce the concept of RSDD (i.e., Regularly Spatial Discrete Domains), then defineconcepts about RPO (i.e., RSDD_based Primary Object) and RO (i.e., RSDD_based Object). The concept of RSDDcan solve the conflict between the infinite precision real numbers of spatial object and the finite precision numbersystems of computers.

Abstract:An efficient physically based surface sculpting method is presented in this paper for the interactivedeformation of n-sided surfaces. By minimizing an energy functional, the user is able to deform a surface byapplying different forms of forces directly, acting as virtual sculpting tools. The user is also able to define necessarygeometric constraints, so as to further control the surface shape. Compared with the traditional method that asurface is deformed by moving the control points, this method is much more intuitive and still is very efficient.

Abstract:Transaction management is the key component of process-sensitive engineering environments(PSEE). In recent years, several advanced transaction models have been proposed to support long transaction.However, in view of specific characteristic in software process transaction, those models only meet its partialrequirements. Moreover, no commercial or academic results of nested cooperative transaction models have reacheda status stable enough for commercial implementation. It remains a real challenge to the transaction mechanism ofPSEE. In this paper, a criteria-based transaction model E-Process/TM is presented, that may address the keyfeatures of software process, i.e. interactive user control, long-duration activities, iterative approach and multi-usercooperation on shared persistent data. Based on user defined correctness criteria, E-Process/TM offers inherentbenefits in flexibility and openness. By now, this model has been implemented in a commercial PSEE product, andapplied in practice successfully.

Abstract:In order to specify real-time systems, many temporal logics such as Timed Computation Tree Logic, Metric Interval Temporal Logic and Real-Time Temporal Logic have been proposed. Although these logics are good at specifying properties of real-time systems, they are not suitable for describing the implementations of such systems. Thus, the specifications and the implementations are usually described by different languages for real-time systems. In this paper, a new linear temporal logic with clocks, called LTLC,is introduced.It is anextension of Manna and Pnueli's linear temporal logic.It can express both the properties and the implementaions ofreal-time system.With LTLC,systems can be described at many at many levels of abstraction,from high-level requirement specificatons to low-level implementation models,and the conformance between different descriptions can be expressed by logical implication.This aspect of LTLC will be beneficil to the verification and the stepwise refinements of real-time systems.

Abstract:With rapid development of Internet,the line speed of core router has reached 2.5Gbps and even 10Gbps beyond.This speed orders core router to be able to forward ten millions of packets per second.Route lookup is an important step of packet forwarding,so high speed IP address lookup algorithm is the key component of high speed packet forwarding.IP address lookup requires a longest matching prefix search.In the last couple of years,various algorithms for high-performance IP address lookup have been proposed.In this paper,the difficulty of route lookup is analyzed,and a survey of all kinds of lookup algorithms,which are compared indetail,is also presented.At last,some challenging open problems are identified.

Abstract:Dynamic scheduling algorithms for real-time multiprocessor systems are important components of real-time systems. The most important metric for real-time scheduling algorithms is scheduling success ratio. In this paper, based on the traditional myopic algorithm, a new dynamic scheduling algorithm, called‘hrift algorithm', is proposed for real-time multiprocessor systems. In this algorithm, a new processor selection policy is developed to improve scheduling success ratio. To study the effectiveness of thrift algorithm,an intensive simulation studyis made to analyze the impact of several task parameters on its scheduling success ratio and compare its performance to myopic algorithm.The simulation results show that the scheduling success ratio of our new scheduling algorthm is superior to thet of mypoic algorthm.

Abstract:In this paper, two complete and operational approaches to the revision of a belief set represented by a set of propositional belief set are presented. First, the rules of R-calculus are modified in order to deduce all the minimally consistent subsets. Second, a set of rules is given in order to deduce all the maximally inconsistent subsets. Then, a procedure which can generate all the maximally consistent subsets is presented. They are complete approaches, since all the maximally consistent subsets can be generated.

Abstract:The OLAP (online analytical processing query) queries are ad-hoc, complex queries, as expressed in SQL, these queries include multi-table join and aggregate operation. In this paper, a novel sorting based aggregation algorithm, MuSA (sort-based aggregation with multi-table join), is given for OLAP query evaluation. In this algorithm, by taking the characteristics of star schema into consideration, the aggregation operation is combined with a novel multi-table join algorithm, MJoin, and the key words mapping technique is used to compress the sorting key which can obviously speed up sorting.Further by esting the group number of query result,the proper sorting methods which can optimize the algorithm for different aggregation queries be chosen.Asbeing illustrated by the experimental result,compared with original methods for aggregation query evaluation,theperfmance of the new algorithm can be improved dramatically.

Abstract:Synchronization between processes is one of the main features of concurrent programming. However, under the framework of concurrent object-oriented, the existence of synchronization constraints can cause undesired re-definitions of inherited code. Based on the two kinds of synchronization mechanisms in VDM++, a synchronization model, guard trace structure is presented in this paper to be applied to a wide-spectrum concurrent object-oriented specification language. This model can support not only reuse of general code,but also that of synchronization code effectively.

Abstract:Command history records generated by Unix shell is one of the important sources of system auditing information. But command history does not include sufficient information for intrusion detection and the history records can be easily modified by user themselves. With Linux loadable kernel module technique and system call interception, an extension to security auditing mechanism of Linux shell is implemented in this paper, and then some examples are given for security monitoring with the new mechanism.

Abstract:The performance of a character recognition system depends heavily on what features are being used. In this paper, an optical character recognition method based on match of feature lines is presented. By extracting the feature lines from bitmap of character and detecting the necessary-sufficient condition with templates by baseline superposed, this method carries out the recognition with a very high efficiency. The process of selecting and adjusting the feature lines from template is also described. Then, a new way for collating is proposed. By the hand of dispalaying skeletons of recognized characters that overlap the original bitmap,this method makes finding errors easier.Finally,the performance evaluation based on comparison is given.

Abstract:Jade Bird web component library system (JBWCL) can support the management of software components, thereby facilitating component-based software development in software enterprises. However, the system brings the problem of security and copyright, at the same time it improves openness. To solve these problems, the role-based access control is employed in JBWCL, and the component entity is separated from its description in this paper. The user, role, phrivilege and role hierarchy for the system and those components stored in it are defined.The mechanism meets the requirement of security and copyright,meanwhile ensure the efficency of the system and the support to reuse.

Abstract:The effectiveness and efficiency are two problems in clustering algorithms. DBSCAN is a typical density based clustering algorithm that is very efficient on large databases. In this paper, a recursive density based clustering algorithm that can adaptively change its parameters intelligently is presented. This clustering algorithm RDBC (recursive density based clustering algorithm) is based on DBSCAN. It can be shown that RDBC require the same time complexity as that of the DBSCAN algorithm. In addition, it is proved both analytically and experimentally that this method yields results more superior than that of DBSCAN.

Abstract:In order to solve the real-time synthesis problem in a multi-sample text-to-speech system, the strategy of improving the structure of speech database is discussed and a method of calculating the similarities between two speech units is put forth in this paper. On the basis of these, a mapping address algorithm to locate the address of speech unit is brought up. The experimental results show that mapping address algorithm and reconstruction of speech database improve the real-time performance of text-to-speech system.

Abstract:Active rules and its processing mechanism have been the weaknesses in the research area of active database for a long time. The weaknesses were mainly represented: (1) The semantic of rules is not rich enough; (2) Lack of fundamental semantic; (3) Lack of hierarchical and structural description of rule processing. In this paper, in order to make up the above weakness, a rich extending semantic is given to the rule processing mechanism. A rule processing tree is represented to describe the influence of rule processing to the state of system structurally.and hierarchically.Based on the new system executing model and the extended transaction model,a rule processing algorithm the supports rich rule semantic can be represented.Comparing with othr similar algorithm,thealgorithm implements the new semantic.The using of recursive techursive technique makes the algorithm coincide with the rule processing.

Abstract:Parallel computing is about 20 years old. Till now, there is a lack of effective parallel programming methods and tools in high performance computing as a result that it is very difficulty to parallel programming, understanding behaviors of parallel program, debugging parallel codes and optimizing performance. In this paper, the reasons why so difficulty parallel programming is are analyzed, while the issues about parallel programming methods existing in recent high performance parallel machines are addressed,the current status of parallel programming models and languages are surveeyed,the view of the criteria is offered to evaluate parallel programming models,the challenge problems in this area are brought forward,and some future research directions are pointed out.

Abstract:There are a lot of continuous values and various kinds of cognitive information (knowledge). Firstly, for describing and handling the knowledge, in this paper, they are divided into two parts: a continuous cognitive result and its cognitive structure. Secondly, a cognitive structure and a cognitive inference network are put forward, and they are integrated into a continuous cognitive structure. Thirdly, a continuous cognitive inferential network based on continuous cognitive structure is proposed. Fourthly,a set of inference approaches are discussed utilizing the continuous cognitive structure.The inference is non-monotonous upon incomplete inference network.The most simplified computational complexity of inference is linear is linear to the inferential nodes under the most complex condition.Finally,the suitability of the approach in practical problem is shown by an example.

Abstract:Based on the analysis of the current mobile agent systems and MASIF (mobile agent system interoperability facility), a template architecture for mobile agent system of high security called Jamogents including the architectures of both mobile agent itself and its supporting environment (MASE) are proposed in this paper. The working flow of Jamogents is also described. To make Jamogents secure, an algorithm called RIM, which implements both encryption and digital signature, is also discussed and implemented.

Abstract:As an increasing number of users access information on the Web, there is a great opportunity to learn about the users?probable actions in the future from the server logs. In this paper, an n-gram based model is presented to utilize path profiles of users from very large data sets to predict the users?future requests. Since this is a prediction system, the recall cannot be measured in a traditional sense. Therefore, the notion of applicability is presented to give a measure of the ability to predict the next document.The new model is based on a simple extension of existing point-based models for such predictions,but the results show that by sacrificing the applicability somewhat one can gin a great deal in prediction precision.The result can potentially be applied to awide range of applications on the Web,including pre-sending,pre-fetching,enhancement of recommendation systems as well as Web caching po;icies.The tests are based on three realistic Web logs.The new algorithm shows a marked improvement in precision and applicability over previous approaches.

Abstract:Data-Intensive Web sites refer to the Web sites which integrate data from multiple heterogenous data sources. Building data-intensive Web sites is a data-management problem. Generally speaking, this process consists of three main programming tasks: accessing and integrating the data available in the site, building the structure of the site, i.e., specifying the data in each page and the links between pages, and generating the HTML representation of pages. In this paper, a Web page definition language named WPDL is proposed on XML techniques and related recommendations from W3C.A brief EBNF grammar rule of WPDL is given,and the key features of WPDL are described with wieh a couple of examples.It is argued that the three tasks can be separated with that kind of declarative query language.Thereby it is possible to maintain a data-intensive Web site with restructuring,reusability and integrityconstraint enforcement.

Abstract:In this paper, a new full-text index model, subsequence array model, is put forward. It has the advantages of many popular full-text index model, such as inverted-list model and Pat array model, and improves the efficiency of the space and time, which is proved by theory and experiment.