Abstract:XYZ is a software engineering system consisting of a temporal logic language XYZ/ E and a set of CASEtools.The temporal logic language XYZ/ E is based on Manna- Pnuli's Linear- Time Temporal L ogic.It canrepresent both high level and low level specifications in the same frame work,so that the specification andimplementation of software systems are very convenient.XYZ/ E is simple yet expressive enough to be acceptedby engineers.Besides,the formal nature of this language makes it capable of programming verif...

Abstract:An advanced transaction model for CSCW applications—FCFM (flexible cooperative transaction model) is presented in this paper. Firstly, the definition of cooperative transactions is given and the states of them are specified. Secondly, the dependencies among cooperative transactions and those between cooperative transactions and outside environments are specified in terms of states of cooperative transactions. Finally, the serializability correctness criterion for the presented model is specified by state dependencies of cooperative transactions.The main advantage of FCTM is that users can customize the states and state dependencies of cooperative transactions to reflect the different requirements of CSCW applications.

Abstract:Abstracttest method aims to enable test suite designers to use the most appropriate methods for their circumstances. Most existing methods are end system oriented, rather than relay system concerned. This paper discusses the abstract test methods for relay system testing, introduces the model of the R SUT (relay system under test), gives the conceptual architecture of relay system testing, and proposes several abstract test methods. Finally, some practical experience for testing the relay system, such as IP router,SMTP email server,and Packet Assembly/Disassembly(PAD),is illustrated with the methods presented.These methods could be used for testing ATM switch too.

Abstract:Clustering is an important application area for many fields including data mining, statistical data analysis, pattern recognition, image processing, and other business applications. Up to now, many algorithms for clustering have been developed. Contributed from the database research community, DBSCAN algorithm is an outstanding representative of clustering algorithms for its good performance in clustering spatial data. Relying on a density based notion of clusters, DBSCAN is designed to discover clusters of arbitrary shape.It requires only one input parameter and supports the user in determining an appropriate value of it.In this paper,a fast DBSCAN algorithm (FDBSCAN) is developed which considerably speeds up the original DBSCAN algorithm.Unlike DBSCAN,FDBSCAN uses only a small number of representative points in a core point's neighborhood as seeds to expand the cluster such that the execution frequency of region query and consequently the I/O cost are reduced.Experimental results show that FDBSCAN is effective and efficient in clustering large-scale databases,and it is faster than the original DBSCAN algorithm by several times.

Abstract:It is proved that there are r.e. degrees a and c such that ［c］<［a］ and ［b］≠［c］ for any r.e. degree b≤_T a, where ［a］ is an element of R/M, the quotient of the recursively enumerable degrees R modulo the cappable degrees M.

Abstract:In the field of traditional computer vision, the theory, in which the visual interpretation task comprises several levels that can be managed independently, has great influence on researchers. It presents that the information for accomplishing low level visual task can only be obtained from image itself. Kass et al. challenged the theory by developing an active contour model called Snake in 1987. Since then, this model has been enjoying a wide range of applications in the field of computer vision and significant advances have been made. The paper reviews the research, development and applications of the active contour model, and presents possible future research orientations.

Abstract:In this paper, the authors give a transition system for those abstractive knowledge bases with the form of so-called assertion set, which plays an important role in knowledge representation and processing, so that each such knowledge base possibly with contradictions can be eventually transferred into a consistent version of it. This leads to a calculus-like mechanism for producing R-reconstruction. This transition system is proved to be sound and complete.

Abstract:In this paper, the authors give a transition system for those abstractive knowledge bases with the form of so-called assertion set, which plays an important role in knowledge representation and processing, so that each such knowledge base possibly with contradictions can be eventually transferred into a consistent version of it. This leads to a calculus-like mechanism for producing R-reconstruction. This transition system is proved to be sound and complete.

Abstract:Parallel string matching algorithms are mainly based on PRAM (parallel random access machine) computation model, while the research on parallel string matching algorithm for other more realistic models is very limited. In this paper, the authors present an efficient and scalable distributed string-matching algorithm is presented by parallelizing the improved KMP (Knuth-Morris-Pratt) algorithm and making use of the pattern period. Its computation complexity is O(n/p+m) and communication time is O(ulogp), wheren is the length of text, m the length of pattern, p the number of processors and u the period length of pattern.

Abstract:One of the most challenging problems in managing large computer software systems on global network is the complexity of security administration. The RBAC (role-based access control) method shows powerful capability on access control by realizing logical separation between users and permissions and constructing role hierarchies. This paper presents a role hierarchy model EHRBAC (extended hierarchy role-based access control) based on RBAC96, which defines common permissions and private permissions and imports normal inheritance and extended inheritance. Based on EHRBAC, the authors realize the security administration for the Petrochemical Market Information System. The EHRBAC model can specify the complex inheritance of roles and simplify their relation hierarchies. It minimizes the role access permissions by the separation of private permissions from common permissions.

Abstract:Shadow generation plays an important role in realistic image synthesis, but with the old algorithms, generation of shadows is quite time-consuming and can't be used in a real-time interactive environment. The authors present a new method to produce the real-time shadows for the point light sources in this paper. The algorithm takes advantage of the fact that in many cases, only a small number of polygons in the complex virtual environment change their shape relative to the lights resulting in a corresponding change to the shadow calculation while most of the polygons remain static relative to the lights. So it is possible to process the static and dynamic objects separately and thus make the number of polygons to be calculated as less as possible. The main idea is to prepocess the static scene with “Tiling” method and decide the precise shadow-relative sets, and then use SVBSP method to calculate the dynamic shadows. All the algorithms in this paper are realized in C++, and run on the microcomputer platform of Intel Pentium Ⅱ 400. The experimental results are satisfactory.

Abstract:Many applications need IP multicast. In order to support large-scale multicast applications in Internet, effective multicast routing is crucial. These multicast routing protocols must possess efficacy, scalability and incremental deployment capability. But the existing multicast routing protocols are performance insensitive and cannot deal with traffic load balancing and congestion-oriented routing. Many multicast routing protocols not only take charge of data forwarding but also participate in routing control algorithms, which results in more complexity for routers. Furthermore, large-scale deployment of these multicast routing protocols in Internet is a manual, costly process. In this paper, the authors present a novel Active Hierarchical Multicast Routing scheme (AHMR) based on active network technologies by separating data forwarding and routing control protocol. Based on link-state protocol, it uses active packet to set up multicast routing as an efficient, automatically upgrading routing scheme for large-scale multicast applications in Internet. The architecture, control protocol, the proof of its correctness and its advantages over other schemes are demonstrated.

Abstract:In this paper, a novel adaptive text-independent speaker verification method is proposed. This adaptive method is based on the previous work, which uses global speaker model to normalize the likelihood score, and solves one problem of the previous method, i.e., the training time is to long. As a consequence, the waiting time for a new registration is shortened so that a new user can use the system in a short period. The experimental results fully demonstrate the effectiveness of this novel method. When the system has 30 users, the registration time for a new user is accelerated 12 times.

Abstract:In this paper, the conception of Chinese character's corresponding curve feature is proposed, and three kinds of statistical features of Chinese characters, which can be represented by curve, are discussed. Applying P-Fourier operator to them, the final features for character recognition are extracted. Experimental results indicate that the proposed method is very promising for the recognition of handwritten Chinese characters, and is especially suitable for the fine classification.

Abstract:Commonsense and temporal reasoning are two main research topics in artificial intelligence. Temporal reasoning proposed by Allen and others lacks a unified representative network about time point, interval and duration, overemphasizes computation while lacking rule inference, is difficult to apply in multiagent setting, and does not consider inconsistency in common sense. In this paper, the authors present a unified representative network about time information, analyze the inference rules among constraints, and propose the multiagent cooperative method satisfying weak path consistency to solve commonsense temporal task. The work of this paper improves the work of Meiri as well as that of Wetprasit and Sattar, provides viable scheme for temporal reasoning to combine commonsense property and to fit the cooperative multiagent setting.

Abstract:Based on the perspective of dividing the total QoS requirement of delay bound into local QoS requirements among links along the path, the authors examine the constraint conditions of resource reservation for satisfying end-to-end delay bound, present a new cost function for resource allocation and a method of the resource allocation for the links according to the principle of cost minimization, and give a distributed three-phase resource reservation algorithm in this paper. The purpose is to make the use of network resources more balanced and more reasonable in order that more call requests can be admitted in future. Furthermore, also discusse resource reservation processing for multicast connection establishment to which the method is applied. Finally, the results of simulations for the method are given and the effectiveness of the method is confirmed.

Abstract:Having no distinctly guided tendency is one of the main weaknesses of Evolutionary Algorithms. In reference to the individuals' life periodicity, an ecological evolution model guided by life period is proposed in this paper. In the model, the guiding sectors are set up at each phase of the life period, and the individuals' evolution is guided by their ecological features within the whole life period. The experimental results show the model's effectiveness.

Abstract:A real-time database (RTDB) requires a main memory database (MMDB) to support it as its base. The vulnerability of an MMDB makes its loading (including initial loading and reloading) very frequent, which has a large influence on system performance. Traditional database loading approaches are not suitable for Real-Time MMDBs. In this paper, the authors first give the properties of real-time transactions and data which have influence on the loading of a database, then present a strategy and algorithm for DB loading.

Abstract:Tasks are the basic facilities of concurrent programming in Ada, which provides a good mechanism of synchronization and communication. However, there exists a kind of serving tasks that are passive and are used as servers. The existence of serving tasks makes systems have a little overhead and degrades system performance. When serving tasks are transformed to protected objects, the performance of systems can be improved. In this paper, the authors propose a method of transforming Ada83 serving tasks to Ada95 protected objects at the source code level. First, conditions that a serving task must satisfy are discussed. Then the methods of identifying and transforming serving tasks are discussed, followed by discussions on the feasibility of the methods. Compared with other methods, the proposed methods have less hypotheses and higher efficiency and are easier to verify.

Abstract:Current methods for disseminating and accessing database data or information have a few drawbacks. This paper proposes a new way, which is called MOAT (movable operations as texts) model. The model differs from the traditional ones in the representation of the database accessing operation across the network. MOAT represents the operation as a kind of text description while the traditional methods use a segment of programs (such as Java applets) to represent data accessing operations. MOAT model makes the transference of operations more succinct, visualized and modifiable. Users can easily modify or integrate the existing operations in text formats to form new database operations, which can also be disseminated again across the network. This paper also introduces an implementation architecture of MOAT model. Some further work is given finally.