Constraint—Preserving Architecture Transformations：A Graph Rewriting Approach

Architecture transformations are frequently performed during software design and maintenance.However this activity is not well supported at a sufficiently abstract level.In this paper,the authors characterize architecture transformations using using graph rewriting rules,where architectures are represented in graph notations,Architectures are usually required to satisfy certain constraints during evolution.Therefore a way is presented to construct the sufficient and necessary condition for a transformatio to preserve a constraint.The condition can be verified before the application of the transformation.Validated transformations are guaranteed not to violate corresponding constraints whenever applied.     

Similarity-guided streamline placement with error evaluation

Most streamline generation algorithms either provide a particular density of streamlines across the domain or explicitly detect features, such as critical points, and follow customized rules to emphasize those features. However, the former generally includes many redundant streamlines, and the latter requires Boolean decisions on which points are features (and may thus suffer from robustness problems for real-world data). We take a new approach to adaptive streamline placement for steady vector fields in 2D and 3D. We define a metric for local similarity among streamlines and use this metric to grow streamlines from a dense set of candidate seed points. The metric considers not only Euclidean distance, but also a simple statistical measure of shape and directional similarity. Without explicit feature detection, our method produces streamlines that naturally accentuate regions of geometric interest. In conjunction with this method, we also propose a quantitative error metric for evaluating a streamline representation based on how well it preserves the information from the original vector field. This error metric reconstructs a vector field from points on the streamline representation and computes a difference of the reconstruction from the original vector field.     

监控网络系统体系结构与路由算法研究

本文在视频监控系统体系结构的基础上讨论了视频监控系统的扩充和互连方法。提出了数字监控系统中自治系统、视频桥和远程视频代理的概念。并以此为基础,给出了对等体系结构下智能监控系统动态视频路由算法的设计与实现方法。     

不确定时滞系统的稳定条件

利用比较定理、矩阵范数和矩阵测度的有关性质,提出了简单不确定时滞系统及对称组合不确定时滞系统的稳定条件.指出若带有时滞的系统稳定,则去掉时滞时系统一定稳定.在组合系统的情况下给出了时滞相关型的稳定条件.所研究对象的不确定矩阵的范数有一定限制.     

Single machine batch scheduling problem with family setup times and release dates to minimize makespan

In this paper we consider the single machine batch scheduling problem with family setup times and release dates to minimize makespan. We show that this problem is strongly NP-hard, and give an time dynamic programming algorithm and an time dynamic programming algorithm for the problem, where n is the number of jobs, m is the number of families, k is the number of distinct release dates and P is the sum of the setup times of all the families and the processing times of all the jobs. We further give a heuristic with a performance ratio 2. We also give a polynomial-time approximation scheme (PTAS) for the problem.     

Registration using natural features for augmented reality systems

Registration is one of the most difficult problems in augmented reality (AR) systems. In this paper, a simple registration method using natural features based on the projective reconstruction technique is proposed. This method consists of two steps: embedding and rendering. Embedding involves specifying four points to build the world coordinate system on which a virtual object will be superimposed. In rendering, the Kanade-Lucas-Tomasi (KLT) feature tracker is used to track the natural feature correspondences in the live video. The natural features that have been tracked are used to estimate the corresponding projective matrix in the image sequence. Next, the projective reconstruction technique is used to transfer the four specified points to compute the registration matrix for augmentation. This paper also proposes a robust method for estimating the projective matrix, where the natural features that have been tracked are normalized (translation and scaling) and used as the input data. The estimated projective matrix will be used as an initial estimate for a nonlinear optimization method that minimizes the actual residual errors based on the Levenberg-Marquardt (LM) minimization method, thus making the results more robust and stable. The proposed registration method has three major advantages: 1) It is simple, as no predefined fiducials or markers are used for registration for either indoor and outdoor AR applications. 2) It is robust, because it remains effective as long as at least six natural features are tracked during the entire augmentation, and the existence of the corresponding projective matrices in the live video is guaranteed. Meanwhile, the robust method to estimate the projective matrix can obtain stable results even when there are some outliers during the tracking process. 3) Virtual objects can still be superimposed on the specified areas, even if some parts of the areas are occluded during the entire process. Some indoor and outdoor experiments have been conducted to validate the performance of this proposed method.     

基于IBL算法的CBR系统中索引与检索机制研究

文章介绍了基于示例学习算法IBL的概况,并对其加以改进,提出了一个新的算法IBL－Cluster。它主要由概念描述形成算法和概念描述修改算法构成。在此基础上建立了应用在基于事例的推理系统CBR中的基于IBL算法的索引与检索机制。实验表明新算法IBL－Cluster在存储空间及测试正确率方面均有改善。     

圆网印花控制系统中的多机通讯实现

根据分布式圆网印花控制系统的具体情况,设计出基于ＲＳ４８５的简化ＢＩＴＢＵＳ总线通讯方案,实现了主机和各从机之间的通讯,满足了系统协调控制的要求。     

认真深入做好前期工作确保三峡工程顺利兴建

三峡工程建设,无论是防洪,发电、航运其工程规模极其巨大,而且工程建设地处我国人口密集、经济相对较发达的长江干流上游最下部河段上;为此,工程建设的前期工作更应较全面深入周密细致,充分考虑方方面面的利害得失,正确地反映工程建设的经济效益。在开发性移民方针下,做好水库淹没损失的合理补偿和移民安置,不留后患。长江上游年年发生洪水造成灾害,工程设计应考虑在水库调洪运行中给上游带来的洪涝灾害淹没损失应得到相应的赔偿。执行《水法)对水资源的有偿使用经济收益的分配是一个有待探讨的问题。     

Higher order spectral estimation for random fields

This paper is concerned with the nonparametric estimation of the higher order cumulant spectra of vector-valued stationary random fields onZ ^d by smoothing the periodograms, whereZ is the space of integers and the dimensiond1. We derive the asymptotic cumulant properties of the spectral estimates, and consider an application to multidimensional nonlinear systems identification. Numerical examples with simulated data are provided.