基于PHP技术网络考试系统的开发

介绍了基于PHP技术开发的网上考试系统,该系统以PHP作为开发工具,采用win2003+IIS6.0作为WEB服务器,Mysql作为数据库搭建B/S系统平台。详细分析了系统运行环境、功能模块的设计与实现方法,分析了试题结构、和组卷分析。该系统灵活通用,便于操作和移植,并在高校大学英语课程教学中得到实现,实现了考教分离,无纸考试。     

以序列特征值预测酶和非酶蛋白及内含肽

利用生物信息学快速准确鉴别酶、非酶蛋白及内含肽能极大提高实验效率,而测序数量的指数型增长使酶、非酶蛋白及内含肽的自动分类尤显重要。本文获取了同一性小于25%的序列共计3853条,采用Z标度的伪氨基酸组成和氨基酸组成分布提取序列特征值识别酶、非酶蛋白及内含肽。结果表明,该特征值提取方法经参数优化后,即当λ=5,w=0.15时,以支持向量机为分类器,其10倍交叉验证的精度可达81.3%,ROC曲线下面积为0.83;其精度高于其它方法0.5%到12.9%不等;独立样本测试的预测精度可达71.2%,ROC曲线下面积为0.782,其精度高于其它方法0.4%到6.4%不等,效果均优于其它常见的序列特征值方法。本文结果说明从序列出发判断其归属是可行的,3种不同功能的分子在序列特征上存在一定的差异,所建立的Z标度的伪氨基酸组成和氨基酸组成分布法可用于其它类似的生物信息学问题。建立了从序列出发预测酶、非酶蛋白及内含肽的新方法。     

An algebraic foundation for automatic feature-based program synthesis

Feature-Oriented Software Development provides a multitude of formalisms, methods, languages, and tools for building variable, customizable, and extensible software. Along different lines of research, different notions of a feature have been developed. Although these notions have similar goals, no common basis for evaluation, comparison, and integration exists. We present a feature algebra that captures the key ideas of feature orientation and that provides a common ground for current and future research in this field, on which also alternative options can be explored. Furthermore, our algebraic framework is meant to serve as a basis for the development of the technology of automatic feature-based program synthesis and architectural metaprogramming.     

如何在设计教学中加强色彩构成的重要性

目前我国的艺术院校的色彩构成教学有明显的几个弊端:一是注重对色彩理论的试验分析,偏重已有理论成果的再现,不注重对色彩运用的感性分析;二是缺乏主题性设计的引入,缺乏色彩研究的创新思路,不注重研究民族传统色彩。因此,针对色彩构成教学几十年来几乎一成不变的教学体系与模式,需要进行改革和深化。为了实现这一目标,首先要对现有色彩构成的概念进行反思和追溯。     

信任感知的组合服务动态选择方法

把信任概念和信任度引入到服务组合中来,讨论了信任感知的服务组合选择问题,分别基于两种观点建立了其数学模型.并基于观点1,深入地研究了服务组合的动态选择问题,分别采用蚁群系统作为优化工具设计了两种动态选择方法:方法1针对服务在上限阈值的范围内提供优质服务,服务质量保持不变,超过阈值则拒绝服务的情况;方法2针对服务无限制地接受请求,但随着请求数量的增多,其服务质量下降的情况.通过对方法1和方法2的仿真实验结果分析表明,两种方法具有很好的效果.     

Minimizing a nonlinear function under a fuzzy max-t-norm relational equation constraint

This work studies a nonlinear optimization problem subject to fuzzy relational equations with max-t-norm composition. Since the feasible domain of fuzzy relational equations with more than one minimal solution is non-convex, traditional nonlinear programming methods usually cannot solve them efficiently. This work proposes a genetic algorithm to solve this problem. This algorithm first locates the feasible domain through the maximum solution and the minimal solutions of the fuzzy relational equations, to significantly reduce the search space. The algorithm then executes all genetic operations inside this feasible domain, and thus avoids the need to check the feasibility of each solution generated. Moreover, it uses a local search operation to fine-tune each mutated solution. Experimental results indicate that the proposed algorithm can accelerate the searching speed and find the optimal solution.     

一种Web服务组合的可信评估方法

软件可信性日益成为软件工程研究中的热点问题,作为软件资源主要形态的Web服务的可信性也受到了越 来越多的关注。目前对于Web服务可信性的研究主要集中在单一服务QoS属性的可信评价,而针对服务组合的可信 性研究较少。提出了一种通用的原子服务可信评佑模型,并结合原子服务在服务组合执行时的权重,给出了一种基于 结构分析的服务组合可信性的评估方法。最后,结合网络购物实例描述了服务组合可信性评估方法的实验过程。     

Minimizing a linear objective function under a fuzzy max-t norm relation equation constraint

The work examines the feasibility of minimizing a linear objective function subject to a max-t fuzzy relation equation constraint, where t is a continuous/Archimedean t-norm. Conventional methods for solving this problem are significantly improved by, first separating the problem into two sub-problems according to the availability of positive coefficients. This decomposition is thus more easily handled than in previous literature. Next, based on use of the maximum solution of the constraint equation, the sub-problem with non-positive coefficients is solved and the size of the sub-problem with positive coefficients reduced as well. This step is unique among conventional methods, owing to its ability to determine as many optimal variables as possible. Additionally, several rules are developed for simplifying the remaining problem. Finally, those undecided optimal variables are obtained using the covering problem rather than the branch-and-bound methods. Three illustrative examples demonstrate that the proposed approach outperforms conventional schemes. Its potential applications are discussed as well.     

A novel heuristic algorithm for QoS-aware end-to-end service composition

Many works have been carried out to find the efficient algorithms for QoS-aware service composition in recent years. Nevertheless, on one hand, some of these works only consider the local QoS attributes in Web services composition; on the other hand, some ideas derived from QoS selection algorithms for network routing are directly applied in service composition without any adaption. A service composition model with end-to-end QoS constraints has been presented in this paper. An improved heuristics HCE based on the observation of characteristic of end-to-end service composition is proposed as a novel solution. Simulation results reveal the better performance of proposed heuristic compared to the other two heuristics, HMCOP and generic CE algorithm.