Abstract:The feature model has been widely adopted as a domain requirements capturing model by most of the current domain engineering methods. But these methods lack a well formatted framework for the feature models which they use. This has led to the redundancy and confusion in feature model representation between different domain engineering methods, and has made domain analysts difficult to built feature models effectively in practice. In this paper, a uniform framework of feature model is presented from the aspects of basic structure, variability representation and constraint mechanism, and variability binding time. A concrete form of this abstract framework is also given based on the different type of features existing in requirements (service, use case, function, and behavior characteristic), and the relationship among them. Then, combining with a real software domain, the modeling process of the feature model is discussed systematically. This approach will be beneficial to successful domain modeling practices.

Abstract:Based on loop-carried dependence of global schedule, the compiler optimization technology of low power software pipeline scheduling is studied as a kind of ILP formulation for a given loop L under the configuration M with dynamic frequency/voltage scalable multi -function units. A reasonable and effective method of power-aware optimal software pipeline scheduling is proposed. It can make the loop run with minimized power/energy and without performance penalty.

Abstract:Framework is an important approach to large-grained software reuse. Object-Oriented frameworks are widely used through instantiation, but some shortcomings of object-oriented framework were mentioned during related researches and practices. Component-Based software framework (CBSF), which belongs to black-box framework, is adopted to solve these problems. In CBSF, component is chosen to substitute for collaborated class to increase the granularity of framework's element, and hot spot is implemented by component interface calling and components composition. Role extension form of CBSF is discussed, in which role is a special component that need to be instantiated, and can be categorized into abstract component and template. During the CBSF develop process, architecture patterns, design patterns and parameterizations approaches are helpful to design role extension for different domain variability types. Some issues on composing application components based on the role extension form are also discussed in this paper.

Abstract:In recent result, the fault-tolerant scheduling algorithm almost requires that all task's periods are the same and equal to their deadlines, but in fact the periods are not the same in many cases. According to the characteristics of distributed control systems and the technique of primary/backup copies, based on EDF algorithm the novel fault-tolerant scheduling algorithm is proposed in this paper. The algorithm can deal with the different periods of all tasks. By using setting their deadlines the problem that execution times of primary and backup copies are not overlap can be controlled. The method for setting deadlines of primary and backup copies is given and the schedulability of task set is analyzed. The maximal utilization of task set and the minimal number of processor are investigated. The result of simulation shows that the algorithm is effective.

Abstract:To settle the contradictory between convergence speed and precocity and stagnation in ant colony algorithm, an adaptive ant colony algorithm, which is based on the equilibrium of the ant distribution, is presented. By dynamically adjusting the influence of each ant to the trail information updating and the selected probabilities of the paths according to the equilibrium of the ant distribution, the algorithm can keep good balance between accelerating convergence and averting precocity and stagnation. Experimental results on symmetric and asymmetric TSP show that the method presented in this paper has much higher convergence speed and stability than that of classical ant colony algorithm, and is more suitable for solving large scale TSP.

Abstract:A new algorithm for human detection in a static image is proposed in this paper. Human is seen as a model constructed by a torso and four limbs. The torso is fitted by a quadrangle, and each limb is fitted by one or two quadrangles. Detecting human is to search a combination of quadrangles constrained by some geometrical and topological relations. The first step is to detect and fit rectangles in the image, and then try to search some reasonable combinations of rectangles that should satisfy the geometrical and topological relations. If the probability of the combination is more than a fixed threshold, the vertex positions of the rectangles are adjusted to get a compact model of human in that image. At last, the probability of the compact model is recalculated. Experimental results show that this algorithm can be applied in the content-based image retrieval and the analysis of human motion based on video.

Abstract:A method is described to locate eyes accurately in this paper. Eye location is the key step of many face detection methods. After obtaining an eye window, the eye can be located by using projection functions. A novel projection function, i.e. hybrid projection function (HPF), is proposed in this paper. HPF combines integral projection function and variance projection function so that it can reflect the mean and the variance of the pixels in a particular direction of the image. Experimental results show that eyes can be located quite accurately by using hybrid projection function.

Abstract:Trust management model is fundamental for information security in open networks. The fuzzy nature of subjective trust is considered, and the fuzzy set theory has been used to model the issues of trust management. The formalized valuation of subjective trust is given, the definition of trust class and the evaluation of trust are discussed, derivation rules of trust relationships are presented and a subjective trust management model is provided. The formal model proposed in this paper provides a new valuable way for studying trust management in open networks.

Abstract:Video clip retrieval plays a critical role in the content-based video retrieval. Two major concerns in this issue are: (1) automatic segmentation and retrieval of similar video clips from video database; (2) similarity ranking of similar video clips. In this paper, motivated by the maximal matching and optimal matching in graph theory, a novel approach is proposed for video clip retrieval based on matching theory. To tackle the clip segmentation and retrieval, the retrieval process is divided into two phases: shot-based retrieval and clip-based retrieval. In shot-based retrieval, a shot is temporally partitioned into several sub-shots based on motion content. The similarity among shots is measured according to the color content of sub-shots. In clip-based retrieval, candidates of similar video clips are selected by modeling the continuity of similar shots. Maximal matching based on Hungarian algorithm is then adopted to obtain the final similar video clips. To rank the similarity of the selected video clips, four different factors: visual similarity, granularity, interference and temporal order of shots are taken into consideration. These factors are modeled by optimal matching based on Kuhn-Munkres algorithm and dynamic programming. Experimental results indicate that the proposed approach is effective and efficient in retrieving and ranking similar video clips.

Abstract:In the system on a chip, some cells should be placed along a predefined coordinate within a relatively small region. This constraint comes from the requirement that the data should be ready on the common bus at the same time. In this paper, the module placement problem is studied where some modules have the predefined coordinate alignment (PCA) constraint. The relations are given between constrained modules, from which a necessary condition is induced. A polynomial-time algorithm is developed that can guarantee a feasible placement is always obtainable. The algorithm is implemented and tested on ami33 and ami49. The experimental results show that it is effective.

Abstract:3D object fusion is a new geometric modeling tool. It provides an easy and fast way to generate novel models from two or more existing geometric models by using 3D cutting and pasting operations. A new montage mesh fusion method is proposed based on local harmonic mapping in this paper. The approach first extracts mesh regions to be fused by approximating offset curves on meshes, then parameterizes the regions using harmonic mapping with holes, and the smooth mesh fusion is finally obtained by topology combination and fusion control. Compared with the global harmonic mapping method, this approach has the following advantages. (1) The efficiency of the algorithm is greatly improved. The computational cost involved no longer increases exponentially with the number of vertices of the meshes to be fused. (2) The algorithm is robust as the ambiguity in graph structure combination is alleviated. (3) The detail of the cut mesh is fully kept. (4) The topology restriction of the original algorithm is eliminated. Experimental results show that the new approach can be used to create lots of special exaggerated modeling effects for computer animation, thus it is of import value in film and TV industry.

Abstract:Integer wavelet transform (IWT) and IWT-Based image-compression offer many advantages over traditional wavelet. But every subband coefficients of the IWT-Image have smaller dynamic change value and worse energy compaction than the first generation wavelet. Those reduce efficiency of embedded zerotree wavelet (EZW) coding. This paper proposes "integer square quantization threshold from 1" instead of "2 of integer power quantization threshold" during EZW coding. It shortens the distances of every quantization threshold, reduces probability of the important coefficients in the lower quantization threshold area and increases zerotrees. It reduces the coding signs and does not code the zerotrees of the most high-frequency subbands. The experiments results show that integer square zerotree wavelet (ISZW) coding algorithm solves the low efficiency of EZW based on IWT and improves the performance of compression algorithm. It may be used in still picture compression and transmission.

Abstract:In the geometric shape design, shape preserving interpolation of curve/surface is an important and difficult subject in which both monotonicity-preserving and convexity-preserving interpolation are two basic contents. In this paper, the monotonicity-preserving interpolation of a kind of plane parameter curve with a shape control parameter is investigated. The basic idea is as follows: first, a kind of plane α-B-spline interpolation curve with a shape control parameter a is constructed; then, by converting the first derivatives of the curve into Bernstein polynomial, the positive conditions of Bernstein polynomial can be used to get the necessary and sufficie nt conditions for the monotonicity of α-B-spline interpolation curves, i.e., the range of the parameter a. Therefore, monotone-preserving interpolating curves can be obtained succinctly. Numerical examples illustrate the correctness and the validity of theoretical reasoning. In virtue of its convenience and efficiency, this method is hopeful to be widely applied to engineering and practice.

Abstract:Surfaces reconstruction from serial section images is a mature research in visualization of medical imaging. Traditional methods always adopt the process that starts on mesh reconstruction or isosurfaces extraction, then data simplification. Since the volumetric datasets are huge and segmented. Most of the existing algorithms that use large in-core data structures might be too large to off-load to disk. In this paper, an algorithm is presented that has been designed to reconstruct 3D surfaces from huge and segmented volumetric datasets. Approximate mesh can be reconstructed and simplified layer by layer. And user can control mesh complexity by parameters. Because memories are used rationally, some surfaces reconstruction from large datasets can work on PC using the algorithm.

Abstract:Commonly, surface/surface intersect algorithm is repeatedly used to solve the offset surface/surface intersections. It doesn't make full use of similarity of intersect curve topology to simple offset surface/surface intersection problem. The algorithm presented in this paper pre-processes two parametric surfaces to achieve points, called topology transition points, which produce an effect on intersect curve structure, number and location. According to topology transition points distribution graph, initial point search strategy and intersect curve topology can be fixed. The algorithm is tested, and can be proved to overcome the degenerate conditions such as loop leaking, singularity leaking and can calculate the initial point effectively.

Abstract:Dj. Golic applied linear sequential circuit approximation (LSCA) method to analyze the summation generator with an arbitrary number of inputs. He conjectured that he could obtain all pairs of mutually correlated input and output linear functions with the maximum possible absolute value of the correlation coefficient by this method, but he did not give any proof. By using Walsh Transformation technique, the conjecture is proved for even n in this paper. The "total correlation" of summation generator is studied which is very similar to that of combiners with one bit memory.

Abstract:Mobile Agent is thought to be the popular computing model for the next-generation distributed system. Collaboration and communication are essential for mobile Agent systems. However, there still exists some deficiency in the current communication mechanism for mobile Agents especially when communication reliability and efficiency are emphasized. In this paper, an efficiently message forwarding scheme (EMFS) for mobile Agents is introduced. This scheme adopts a novel addressing mechanism, which combines the pointer forwarding and central addressing approaches. At the same time, the problem of communication failure can be settled by checking approach with the aid of synchronization. Thus, the performance of the whole communication system can be greatly improved. Meanwhile, besides discussing of setting main parameters of the protocol, the performance of EMFS is analyzed in theory and simulation data is also provided, which illuminates the correctness and the efficiency of EMFS.

Abstract:Barnet, an infrastructure for attribute addressable P2P network, is brought forward in this paper. This infrastructure aims to provide high availability, collaborative, large-scale wide area information service. The architecture, information organization and access model of Barnet are described in this paper. NetShot is a peer-to-peer based Naming, Locating and Lookup algorithm. As proof that NetShot is useful in developing decentralized applications. After discussing the naming, joining, departing and neighboring model of NetShot, this paper proposes the concept of attribute addressable P2P network, and describes the details of lookup and location strategy which is adopted in Barnet.

Abstract:In the distributed computing environments such as wireless network, the key exchange protocol with mutual authentication is critical to the following secure sessions between communicators and more attentions are paid to the provability of the protocol security. A mutual authentication key agreement protocol, MAKAP (mutual authenticated key agreement protocol) is proposed. The security of the protocol is proved in Bellare-Rogaway's model and its computation cost is also analyzed. MAKAP has advantages over other protocols in its security provability and only spends moderate computation cost, so it is quite practical.

Abstract:Bluetooth ad hoc personal area network is one independent wireless network composed of Bluetooth enabled mobile devices, which can freely communicate and collaborate with each other in some area without extra infrastructure. Some nodes in Bluetooth ad hoc personal area networks participate in multiple piconets in time division duplex and forward network traffic. It needs one inter-piconet or scatternet scheduling algorithm since at a time the node presents in only one of the piconets it participates. Sniff mode provides a flexible method to support inter-piconet scheduling scheme without protocol modification. A self-adaptive scatternet scheduling algorithm is presented based on sniff mode to efficiently deal with the challenging issue in this paper. According to the supervised dynamic traffic of the physical links, the algorithm adjusts in real time the allocation ratio of the node's time slots to its connected links. With the comparison and analysis of the results of the simulation in various flow models, it validates that the algorithm can enhance the throughput of the system, lower the delay of the system and then improve the performance of the network.