Abstract:The advanced multimedia and high-speed networks make distributed interactive systems more promising and practical. These systems are distributed systems, which allow many clients located in different locations to concurrently explore and interact with each other. The systems can be built either in the localarea network (LAN), or the wide area network (WAN), such as the Internet. Operations issued at one site are immediately executed at the local sites for a good response time, and are propagated to other sites. One of the challenging issues raised in the systems is consistency maintenance. Such issue in the discrete interactive media has been studied in many literatures. However, the consistency maintenance scheme for discrete interactive media is not suitable for continuous media domain. This paper illustrates a consistency problem in continuous interactive media by a simple example. The absolute consistency model, a strong requirement, is suitable for LAN and results in a bad responsiveness in WAN. To make themodel more practical for WAN, a new consistency model, named delayed consistency model (DCM), is proposed. In this model, if an operation on an object x is issued at site i, every site is required to execute the operation at a specified time. The essential idea behind the proposed model is that other sites are enforced to update the state at a certain amount of time later than site i does. Thus, other sites will finally view the same state of x as that of site i. The DCM model is flexible, since it is unnecessary for all sites to have the identical delayed time. In case that the system is based on a real-time network, another advantage of the model is providing the real-time network scheduling with important timing parameters.

Abstract:When Internet users are browsing the Web, they always have to wait for the next page to come up after selecting the link to the page, even though the Web server is sometimes idle. To reduce the perceived response time, the server is required to predict users' next HTTP request and pre-process the Web page with remaining CPU resources. This paper introduces various methods to predict users' next HTTP request using classified Web page information, user profiles, and Web logs. Sixteen algorithms and methods are analyzed and compared in this paper. Experimental results show that some methods produce highly probable results with the user of user profiles and classified Web page information.

Abstract:In this paper, an algorithm based on the combination of the live wire algorithm and the active contour model is proposed for the semiautomatic segmentation of medical image series. The traditional live wire algorithm is modifiedby integrating with the fuzzy region growing method. Then the improved live wire algorithm is applied to obtain accurate segmentation of one or more slices in a medical image series. Next, the computer will segment the nearby slice automatically using the active contour model. To record the local region characters of the desired object in the segmented slice, a gray-scale model is introduced to the boundary points of the active contour model. Based on the similarity measure of regions in the gray-scale model, a new energy function is defined to replace the external energy of the traditional active contour model. Finally, a simple method based on the idea of the live wire algorithm is introduced for the reparation of the automatic segmentation result to guarantee the reliability of the result. Experiment shows that this algorithm can obtain the boundary of the desiredobject from a series of medical images quickly and reliably with only little user intervention. It has practical value in the medical image analysis.

Abstract:This paper presents the analog macro-cell placement using the novel very fast simulated re-annealing algorithm, which is exponentially faster than the classical Cauchy or Bolzmann annealing. A slide function is applied to convert the absolute placement to relative placement, which greatly decreases the configuration space without degrading the searching opportunity. The cost function is set up deliberately to meet the special requirements of analog integrated circuits. Several net-length estimators are implemented which analog-circuit designers can choose with a trade-off between accuracy and efficiency. The global routing using the minimum Steiner tree is developed, which runs simultaneously duringthe placement configuration searching. This will ease the successive detail routing and greatly decrease the revise of final placement result. The layout example of optional amplifier is given to demonstrate its usability. The application of this algorithm drastically improves the design efficiency.

Abstract:Bézier curve is one kind of the most commonly used parametric curves in CAGD and Computer Graphics. Developing more convenient techniques for desigew method is presented in this paper by constrained optimization based on changing the control points of the curves. By this method, the authors modify control y the shape of the curves optimally. Practical examples are also given.

Abstract:This paper focuses on the study of efficient and scalable classification algorithm that tightly integrates classification technology with relational database system technology. In this paper, an approach based on grouping and counting is proposed to build classifier, which uses SQL (structured query language) provided by relational database to implement the major computation tasks. In order to improve the performance, several optimization strategies and a redundant rules'pruning strategy together with a feature selection method integrating with the process of inding classification rules are also proposed.With all methods and strategies,the classification algrthm can find a compact set of classification rules quickly from a large volume of data.In addition the same classification accuracy with current popular classification algorithms and high training speed,the unique features of the classification algorithm also include its linear scalability with respect to the number of training samples and the number of attributes,and the simplicity in implementation.

Abstract:WSD (word sense disambiguation) based on supervised machine learning made a great progress, but it is hard to deal with large-scale WSD because of its 慴ig?labor cost. An unsupervised WSD method is provided in this paper to solve this problem. Only under the knowledge database of sense-words, this method formulates the sense-words and polysemous words in vector space, and based on k-NN (k=1) it calculates the similarity between them to disambiguate polysemous words. The average accuracy is 83.13% for 10 polysemous words in open test by this method.

Abstract:A novel method is proposed to select materialized views of multi-dimensional data called dynamic selection. The idea of dynamic selection is that the system is in charged of collecting the queries to obtain their distribution. The set of materialized views is adjusted dynamically according to the queries?distribution. The method is given in detail including the algorithm of single-step selection and the instant adjusting method. It is also proved that under certain constraints, the performance of the single-step algorithm is guaranteed to be no worse than that of the optimal one by a certain bound.The xeperimental results show that the dynamic selection is more effective than other solutions.

Abstract:In order to support distributed multimedia group communication mechanism description and development, QCGPIPE (QoS controlled group PIPE) is presented as a QoS-based platform multimedia group communication abstraction. The formal definitions of QCGPIPE are introduced and its enforcement procedures are discussed in detail. QCGPIPE has been applied as the guidelines of the development of group communication mechanisms in distributed multimedia information systems, computer conferencing systems and distance edstance education systems successfully.Experimental results show that QCGPIPE can ant as the development guidelines of distributed multimedia group communication mechanisms.

Abstract:In order to support distributed multimedia group communication mechanism description and development, QCGPIPE (QoS controlled group PIPE) is presented as a QoS-based platform multimedia group communication abstraction. The formal definitions of QCGPIPE are introduced and its enforcement procedures are discussed in detail. QCGPIPE has been applied as the guidelines of the development of group communication mechanisms in distributed multimedia information systems, computer conferencing systems and distance edstance education systems successfully.Experimental results show that QCGPIPE can ant as the development guidelines of distributed multimedia group communication mechanisms.

Abstract:Various kinds of application service are used in corporation network; which provide security measures. It isn抰 convenient for users to use and for managers to manage limits of authority. Therefore, a set of once identity authentication system is designed and developed. The system can be well integrated with every application service, and it is convenient for users and managers under ensuring security.

Abstract:In this paper, the algorithms and the computational complexity of Star-Tree phylogeny problem are studied. The Star-Tree phylogeny problem is proved to be NP-complete first. Then it is proved that there is no absolute approximation algorithm for this problem. At last, a polynomial approximation algorithm of ratio 2 is presented to compute the Star-Tree phylogeny problem.

Abstract:A theoretic model and method is proposed to decrease power consumption effectively by reducing execution frequency on multithreaded architecture in this paper. At first, the computation model is studied to recognize the thread which can be executed at lower frequency, and the factor is computed to slow down the frequency. Then, an algorithm and policy of compiler optimization combining with thread partition for low power is given based on the analysis of application program. This model and method can be used to exploit TLP(thread levelparallelism)and decrease the power consumption effectively for the multithreaded multiprocessor architecture with scalable execution frequency.

Abstract:In order to support multicast, efficient multicast routing is crucial. Many present multicast routing algorithms assume that every node in the network support multicast. But in real networks, some nodes may not support multicast, others may limit the number of multicast copies in order to ensure network speed. Thus, the multicast capability of each node is represented in this paper by a degree-constraint. A distributed degree- constrained multicast routing algorithm is proposed which has smaller time complexity and needs smaller number of messages than other existing algorithms.

Abstract:The complexity and the dynamic executing behavior of network software add to the difficulties for identifying the precise causes of latency. Using performance monitoring functions provided by the advanced microprocessor and implementation characteristics of network software, NetSlice provides a novel, modular, and extensible way for automated analysis of network software latency. The architecture of NetSlice and its components are introduced at first. Then the performance of NetSlice is studied in detail and the typical application strategy is also given.To demonstrate the utility of NetSlice,the results of analyzing the latency of TCP sending process on linux operating system are presented.The experimental results show NetSilce can shed considerable light on the causes of latency in network software

Abstract:It is very important to evaluate the discovered rules in KDD (knowledge discovery in database). An evaluation method for causal rules is provided in this paper. The new and valid knowledge expression (language field and language value) and the reasoning mechanism (qualitative induction mechanism of causal relation) are used. The method is general and interactive. Its construction and the algorithm are given, and its validity is proved through case. By the comparison with the related work, it is proved to be an advanced method.

Abstract:The combination of concurrency and object orientation is definitely natural except for inheritance. One of the interferences between inheritance and concurrency is inheritance anomaly. Although having been researched extensively, inheritance anomalies are still only vaguely defined and often misunderstood, and no much formal work has been done. A new viewpoint is set forth for understanding inheritance anomalies, in which each subtyping relation has its specific incremental inheritance. Related concepts and definitions are formalized through the language of Category.Some issues are well adapted to distinguish and explin different standpoints about inheritance anomalies,and can serve as guidelines in the modeling of inheritance.

Abstract:The core of choosing a secure elliptic curve for elliptic curve cryptosystems is the calculation of the order of a randomly selected elliptic curve. It is known that SEA (Schoof Elkies Atkin) algorithm is recently the most efficient method to calculate the orders of elliptic curves over Fp. Isogeny cycles method made by Morain is an important local optimized technique to improve SEA algorithm. In this paper, isogeny cycles method is enhanced, and a scheme of more optimal combination of the various techniques in SEA algorithm is provided.Furthermore,some discussions are made on how to speed up the selection of elliptic curves with prime order,and an efficient implementation of SEA algorithm overF_p is described.

Abstract:Unidirectional links brought by many receive-only stations are not suitable for current routing protocols. To solve the unidirectional routing problem, a network model is built for the topology of direct broadcast systems. By simplifying the network model, a link state routing algorithm based on circle discovery and a new protocol SERP (sever-based routing protocol) are proposed. By means of proven convergency of the routing algorithm and simulating results from network simulator tool for the protocol, the correctness of SERP is verified,which has fewer ovwer overheads and supports dynamic routing for integrating broadband satellite networks with high spped Interet.

Abstract:Aiming at the computational complexity resulted from the large amounts of support vectors when the support vector machines (SVMs) are used in function estimation, a simplification algorithm is presented to reduce the number of support vectors and simplify applications. By the adaptation of the simplification algorithm, the LS-SVM (least square support vector machine) algorithm can be combined with SMO (sequential minimal optimization) algorithm to achieve good results with high learning efficiency and a few number of support vectors.

Abstract:IKE (Internet key exchange, RFC2409) describes a suite of Internet key exchange protocols for establishing security associations and obtaining authenticated keying material. A security flaw in these IKE protocols is observed and a simple modification is proposed. In this paper, it is pointed out that there is a neglected security flaw in the amended IKE protocols. And a successful attack on the amended IKE protocols is also provided. A new amendment to IKE protocols is proposed, and the reasons which cause the two security flaws are analyzed by using BAN logic successfully.

Abstract:Traditional data dependence analysis focuses on affine subscript, which is not applicable to detect parallelism in irregular problem. In this paper, two analysis techniques for subscripted subscripts are presented. One takes the property of indirect array into accounts, the other uses runtime test based on the strict array privatization definition. Comparison between the existing methods and the new techniques is also given.