使用倒排索引优化面向组合的语义服务发现

提出为服务库中所有注册服务的输出建立倒排索引,以快速、准确、高效地发现目标服务.即为每个输出维护一个服务列表,用于记录在该服务库中所有能够产生该输出的服务.基于倒排索引机制,提出面向组合的服务发现算法.该方法利用倒排索引的优势,极大地减少了搜索空间,并通过挖掘服务组合提高服务发现的查全率.仿真实验表明,该方法能够在大规模服务库中快速、全面地响应用户请求.     

利用服务聚类优化面向过程模型的语义Web服务发现

如何快速、准确和高效地发现满足用户需求的Web服务是现阶段急需解决的关键问题之一.文中针对现有的Web服务发现机制中存在的效率低下和查准率不高的两个问题,提出了一个新的语义Web服务发现框架.在该框架下,采用Petri网作为Web服务过程描述的形式化工具.首先,利用聚类技术,从服务的功能相似和过程相似两个层面对服务进行聚类预处理,从而在很大程度上降低服务的查找空间,提高服务的查找效率.进一步,针对服务请求中可能潜在的行为约束,建立基于Petri网的过程需求模型,将其与候选服务的过程模型进行比较,对满足功能需求的可行服务进一步筛选,从而提高查找的精确度.最后,利用仿真实验对所提出的方法进行验证.     

用UML建模开发嵌入式软件

针对面向对象开发与C语言的优缺点,提出一种新的方案,用面向对象的思想与开发工具进行软件的设计,用C语言进行编码,给出新方案应用实例,并在此基础上提出几种进一步优化程序性能的方法。新的方案增强了用C语言开发系统软件的可理解性、可移植性和稳定性,同时又保持了C语言高性能与低二进制代码长度的优点。     

问题求解建模：开发对问题求解任务的深入理解

问题求解建模旨在基于ＰＳ的结构化组织去构造ＰＳ过程模型和ＰＳ参考的世界模型。引入知识级分析并使用基于问题归约的分析方法，促进了对ＰＳ组织的开发，尤其是ＰＳ概念模型和深，浅层推理的综合。对于ＰＳ组织的深入理解不仅提高了ＰＳ性能，对启发式联和领域基本知识的获取也具有指导作用。     

Simulation of Procedure Variables Using Ada Tasks

We give a technique for partially simulating procedure variables using Ada tasks. The simulation involves using interface tasks, a technique which may be useful for other problems.     

Using ObjectARX to Realize Feature Modeling

为了满足中小企业实施CAD/CAM集成过程中对产品特征模型的需要,基于特征设计的建模理论,建立了特征的信息模型。研究了在AutoCAD系统上实现特征建模的方法,阐述了特征的参数输入、定位、生成及存储等特征建模的主要步骤。以齿轮泵泵体特征建模为例,证明了基于ObjectARX实现特征建模的可行性,为中小企业实施CAD/CAM集成提供了一种简单而有效的方法。     

Learning Complex Tasks Using a Stepwise Approach

This paper explores a stepwise learning approach based on a system's decomposition into functional subsystems. Two case studies are examined: a visually guided robot that learns to track a maneuvering object, and a robot that learns to use the information from a force sensor in order to put a peg into a hole. These two applications show the features and advantages of the proposed approach: i) the subsystems naturally arise as functional components of the hardware and software; ii) these subsystems are building blocks of the robot behavior and can be combined in several ways for performing various tasks; iii) this decomposition makes it easier to check the performances and detect the cause of a malfunction; iv) only those subsystems for which a satisfactory solution is not available need to be learned; v) the strategy proposed for coordinating the optimization of all subsystems ensures an improvement at the task-level; vi) the overall system's behavior is significantly improved by the stepwise learning approach.     

应用对象过程图扩展UML建模环境

统一建模语言UML存在着面向对象建模的不足,例如,用多个模型表示系统,模型的一致性难以保证.UML的工作主要集中于面向对象的分析和设计阶段,在实现阶段并没有做过多的努力等等,给系统设计带来了不便.提出了在UML建模环境中引入对象过程图(object-process diagram,简称OPD),为多个模型的一致性提供了统一的标准,提高了程序文档的可理解性和可维护性,使得扩展后的UML具备从面向对象分析到程序设计的完全可视化的描述能力.     

Using Performance Modeling to Design Large-Scale Systems

A methodology for accurately modeling large applications explores the performance of ultrascale systems at different stages in their life cycle, from early design through production use.     

Capitalizing on Careabouts to Facilitate Creativity

Low-level knowledge work is work that requires some, but not a great deal, of knowledge to perform. This work sustains the operations of all of our major businesses. As we transform to a knowledge society, it will become increasingly important that this work be performed creatively. Amabile’s well-researched framework for understanding creative action suggests that reward strategies will be successful if knowledge workers are intrinsically motivated, but low-level knowledge work more often than not attracts those who lack intrinsic motivation. As a result, the likelihood of creative action for this group of workers is low. How can “garden variety” creative action be facilitated when knowledge workers lack intrinsic motivation? I introduce the notion of “careabouts,” and suggest ways of linking personal careabouts to incorporate objectives. This linkage provides the hook that can hoist these low-level knowledge workers into creative knowledge work in the knowledge society.     

Robotic Tasks Using Path Control: Two Case Studies

Some robotic tasks usually achieved through motion control – trajectory tracking control – can be also well performed by resorting to path control philosophy. This is the case for applications where motion coordination among the robot joints is more important than joint tracking of a timed desired reference. This paper illustrates this concept by means of two academic case studies – theory and experiments – using a two degrees-of-freedom direct-drive revolute arm.     

使用NetBeans IDE实现UML建模

NetBeans IDE是当前市场上最流行的、开源且免费的集成开发工具。使用NetBeans不仅可以开发Java程序,还提供了对UML的全面支持。利用NetBeans UML建模模块,可以创建八种类型的UML图,极大地方便了开发人员编写程序。本文首先介绍了NetBeans和UML的基本知识;其次着重介绍了如何在NetBeans IDE中实现UML建模;最后,通过创建一个酒店系统的用例图实例加深理解。     

使用NetBeans IDE实现UML建模

NetBeans IDE是当前市场上最流行的、开源且免费的集成开发工具。使用NetBeans不仅可以开发Java程序．还提供了对UML的全面支持。利用NetBeans UML建模模块,可以创建八种类型的UML图,极大地方便了开发人员编写程序。本文首先介绍了NetBeans和UML的基本知识;其次着重介绍了如何在NetBeans IDE中实现UML建模;最后,通过创建一个酒店系统的用例图实例加深理解。     

The Advantages of Designing Adaptive Business Agents Using Reputation Modeling Compared to the Approach of Recursive Modeling

Adaptive business agents operate in electronic marketplaces, learning from past experiences to make effective decisions on behalf of their users. How best to design these agents is an open question. In this article, we present an approach for the design of adaptive business agents that uses a combination of reinforcement learning and reputation modeling. In particular, we take into account the fact that multiple selling agents may offer the same good with different qualities, and that selling agents may alter the quality of their goods. We also consider the possibility of dishonest agents in the marketplace. Our buying agents exploit the reputation of selling agents to avoid interaction with the disreputable ones, and therefore to reduce the risk of purchasing low value goods. We then experimentally compare the performance of our agents with those designed using a recursive modeling approach. We are able to show that agents designed according to our algorithms achieve better performance in terms of satisfaction and computational time and as such are well suited for the design of electronic marketplaces.     

Designing E-Collaboration Technologies to Facilitate Compensatory Adaptation

This article argues that e-collaboration technologies often pose obstacles to effective communication in complex collaborative tasks. The reason presented is that typically those technologies selectively suppress face-to-face communication elements that human beings have been designed by evolution to use extensively while communicating with each other. It is argued that technology users invariably react to those obstacles by engaging in compensatory adaptation, whereby they change their communicative behavior in order to compensate for the obstacles. The article concludes with a call for more research on how e-collaboration technologies can be designed to facilitate compensatory adaptation.     

Using Bayesian Networks to Manage Uncertainty in Student Modeling

When a tutoring system aims to provide students with interactive help, it needs to know what knowledge the student has and what goals the student is currently trying to achieve. That is, it must do both assessment and plan recognition. These modeling tasks involve a high level of uncertainty when students are allowed to follow various lines of reasoning and are not required to show all their reasoning explicitly. We use Bayesian networks as a comprehensive, sound formalism to handle this uncertainty. Using Bayesian networks, we have devised the probabilistic student models for Andes, a tutoring system for Newtonian physics whose philosophy is to maximize student initiative and freedom during the pedagogical interaction. Andes’ models provide long-term knowledge assessment, plan recognition, and prediction of students’ actions during problem solving, as well as assessment of students’ knowledge and understanding as students read and explain worked out examples. In this paper, we describe the basic mechanisms that allow Andes’ student models to soundly perform assessment and plan recognition, as well as the Bayesian network solutions to issues that arose in scaling up the model to a full-scale, field evaluated application. We also summarize the results of several evaluations of Andes which provide evidence on the accuracy of its student models.This revised version was published online in July 2005 with corrections to the author name VanLehn.     

采用遗传-退火算法的网格依赖任务可信调度

针对异构网格环境下的依赖任务调度问题面临的安全性挑战,综合考虑网格资源节点的固有安全性和行为安全性,构建一个网格资源节点身份可靠性度量函数和行为表现信誉度评估策略;同时为了确立任务安全需求与资源节点安全属性之间的隶属关系,定义了安全效益隶属度函数,从而建立了一个网格任务调度的安全可信模型.以此为基础,定义任务需求表示模型和网格资源拓扑模型,提出一种安全可信的网格任务调度新模型.为求解该模型,在遗传算法的基础上,设计新的进化算子即改进的交叉算子、内部交叉算子及作为变异的迁移算子,同时引入模拟退火算法增加搜索精度,从而提出了一种新的遗传-退火算法.仿真实验表明,在相同条件下,该算法比同类算法在调度长度、安全可信值及收敛性等方面具有更好的综合性能.     

基于Petri网和并发调度标识图的并发任务调度的建模与分析

在云计算及网格计算环境下,由于资源具有分布、异构、动态、自治等特点,其并发任务的调度更加复杂,迫切需要强有力的图形与数学工具对其进行建模与分析。Petri网是描述与分析并发、异步、动态等事件的理想的图形与数学工具。给出了并发任务调度的加权时延Petri网模型。可达标识图是分析Petri网动态特性的一个重要工具,但它不能表达Petri网中变迁的并发关系,尤其是不便于分析被描述系统的时间特性。提出了并发调度标识图的概念,给出了构造时延Petri网的并发调度标识图的算法。最后,利用并发调度标识图分析了并行下载的时间特性。     

Precompilation of Fortran Programs to Facilitate Array Processing

The automatic recognition of array operations in Fortran programs can now be applied to attached array processors using vectorizing precompiler software.