Abstract:Free-form deformation is an important geometric shape modification method in computer animation and geometric modeling. The authors explore it by means of functional composition via shifting operators in this paper. When the object to be deformed is represented by triangular meshes and the deformation tool is a B-spline volume, the deformed object can be accurately described as a set of triangular Bzier patches, whose degree is the sum of three directional degrees of the B-spline volume. The proposed method also solves the sample problem of free-form deformation, because free-form deformation acts on triangular meshes rather than points.

Abstract:This is a review paper on recent works about quality of service (QoS) of multimedia information networks. A brief of the technologies considered in the literatures is given in this paper. These technologies include admission control, traffic shaping, QoS routing, resource reservation, QoS based scheduling, and QoS control for integrated services. A few of methodologies, research directions and open problems in this area are discussed in this paper.

Abstract:Java Beans is a standard for software components. For checking the consistency of the Java Beans semantic constraints with its implementation, a formal Java Beans description language (JBDL) and a dynamic model checking method are proposed in this paper. The authors contribute an efficient symbolic model checking approach using T³BDD. The approach is based on three valued semantics for JBDL formulas and a kind of abstract model which is dynamically established and evolved during Bean’s execution.

Abstract:Process migration is an important tool on NOWs (network of workstations) for load-balancing and high availability. In this paper, the authors present a log-based approach to provide process migration for parallel applications. Because this approach is implemented on top of PVM (parallel virtual machine), it is transparent to users and portable. This approach has been used in the ChaRM (checkpointing-based rollback recovery and process migration system) system. The experiments show that the overhead is low.

Abstract:Optimum degree of parallelism-based task dependence graph scheduling scheme fully utilizes the global information collected at compile-time, employs the techniques such as task merging in horizontal and vertical directions, processors pre-allocation, combination of static and dynamic scheduling, and integration of centralized scheduling and layer-scheduling. It is a simple, practical and effective scheduling method which addresses the problem of how to both reduce the execution time of programs and economize on processor resources.

Abstract:Packet scheduling algorithm controls the order of packet service, which is crucial in the design of a QoS network. In this paper, the authors first give a virtualclock difference-bounded framework (VDBF), then present a new scheduling algorithm——DFQR (difference-based fair queueing by re-calibration), in which they use a hierarchical structure, recalibrate the system virtual clock periodically, compromise network delay with fairness and implementation complexity. Finally, they demonstrate the performance benefit of DFQR by analysis and simulation.

Abstract:A new run-time pointer aliasing disambiguation method, SHRTD, combined with software and hardware techniques, can be used for irreversible code and has very limited compensation code space and no serious rerollability problem. In this paper, instruction-level parallel speedups of the SHRTD method are analyzed in detail. Speedups and mean speedups where address conflicts occurred and speedups where address conflicts will occur according to their probabilities are given. Three theoretical speedups introduced in this paper are very useful for studying and evaluating instruction-level parallel compiling techniques.

Abstract:In this paper, three tasks division strategies of load-balancing are given, which include a round-robin fashion, a domain partitioning fashion and a fashion of round-robin combining with domain partitioning, and a comparison is made. Then tasks division methods are proposed which can reduce solving times and benefit load-balancing and increases parallel efficiency for a simulation of reservoir of multiple layers two-dimension two-phase flow numerical problems on distributed memory parallel systems. This approach is applied to a large scale reservoir simulation which has over 720 000 grid points. The practical results show that the tasks generated by the strategy are well-balanced and benefit to improve speedup. This approach is apt to the problems for domain parallel or data parallel.

Abstract:Distributed interactive simulation requires high network bandwidth and computation capacity which caused by redundant data when the system’s scale increases. This situation can be alleviated by data filtering to great extent. But the effective filtering scheme requires simulation hosts receiving accurate filtering information and high processing capability, this consumes too much computation resources when systems grow. In this paper, the authors propose a server-based hierarchical filtering scheme. New scheme frees the simulation hosts from the filtering processing and avails system’s scalability. New scheme also exploits the potential locality of distributed interactive simulation, which reduces the amounts of filtering messages exchanged and filtering computation.

Abstract:Job oriented scheduling (JOS) has been the most commonly used technique in actual job shop scheduling. It loads jobs one by one onto machines. In this paper, the authors present a fast scheduling algorithm of computer-based JOS system, the algorithm assigns feasible schedule start and finish times to the operations of a job by loading them forward or backward onto the capacity constrained machines. The computation time to find the feasible time slot on the machine is reduced by log and modify each machine’s feasible time slot. Thus, the computational efficiency is substantially improved. Experimental testing shows that the algorithm has significant merits for large size problems.

Abstract:In this paper, the author analyzes the incremental updating algorithm (IUA) on association rules, points out its existing problems, and presents an improved algorithm, NEWIUA (new IUA), which takes full use of already existing and the current updated new frequent itemsets, therefore the efficiency is increased besides guaranteeing the validity of the algorithm. Three parallel algorithms for data mining on association rules are presented, the analysis and discussion on each algorithm are also presented.

Abstract:Based on the usage frequency of the data in temporal database, the storage method with three historical segments is proposed in this paper. The object history is divided into three segments, and stored in different media with various chronons. The special data structure for segmented storage is discussed, the age transfer algorithm and the compress sampling algorithm are proposed. The performance study shows that the time and space efficiency are promoted one magnitudes.

Abstract:In this paper, the authors introduce a monitoring and profiling tool which is used in a high performance Fortran (HPF) compilation system. A brief overview of the HPF compilation system is given first, then the importance and main tasks of performance analysis are discussed, the method of performance profiling and monitoring and the method of performance data collecting are given in detail. The paper is concluded with a description of the tool’s role in the HPF compilation system.

Abstract:Taking the layout problem of satellite cabins as background, the authors make a study of the optimal layout problem of circle group in a circular container with performance constraints of equilibrium etc. in this paper, which belongs to NP-complete problem. A modified genetic algorithm called decimal coded adaptive genetic algorithm (DAGA) is presented to solve the problem. In this way, the algorithm relaxes the combinatorial explode and the premature convergence of genetic algorithm. Two examples are provided (one of them is proposed by the authors, and its optimal solution is known). The numerical results show that the DAGA is effective and superior to multiplicator algorithm. The DAGA can be developed to solve other layout optimization problems.

Abstract:Formal methods and tools are key aspects for the analysis of cryptographic protocols. In this paper, a formal language PEP (principals+environment=protocol) for the specification of cryptographic protocols is proposed. For some cryptographic protocols, their PEP specifications can be translated into finite basic CCS processes, so it is possible to analyze the security properties using CCS-based tools such as CWB (concurrency workbench). The advantage of the mothod proposed in this paper is that the actions of the attacker can be implicitly specified, and if the potential back door of the protocol analyzed exists, the attacking action trace can be explicitly found out by model checker.

Abstract:The dynamics of discrete neural network with delay are studied in this paper using a matrix inequality which is shown to be equivalent to the state transition equation of the network. For the network with arbitrary weight matrix, the conditions for the existence of cycle of length 1 and 2 are presented. Also, the conditions for the existence of special cycle of length 1, 2 and 4, for having no any stable states are achieved. Computer simulations demonstrate that the theoretical analysis is correct.

Abstract:The differences between traditional applications and hypermedia applications are compared in this paper. The main features of hypermedia system and the attraction for non-hypermedia application users are introduced. A model of dynamic hypermedia mapping engine is built, which can enhance non-hypermedia application with hypermedia features with minimal or no changes to it. A prototype of DhyME (dynamic hypermedia mapping engine) is also presented in this paper.