基于改进蚁群算法的数据仓库多连接查询优化

传统蚁群算法在解决数据仓库查询优化问题时存在过早收敛、收敛速度慢的缺点。为此,对传统蚁群算法进行改进,将伪随机状态转移规则引入最大最小蚁群系统,在每次迭代结束后进行迭代局部搜索。实验结果表明,改进算法在多表连接查询优化中具有较快的收敛速度,能提高最优解的质量。     

基于插件技术的VWESA平台的研究与设计

针对当前企业资源计划(ERP)系统在中小型企业实施成本高、失败率高、个性化需求无法得到满足的问题,提出了基于Eclipse插件技术的ERP系统开发平台—VWESA.该平台按照面向服务架构(SOA)规范对企业业务流程及其功能进行小粒度服务抽取,并使用页面编辑环境和ERP-BPEL(业务流程执行语言)进行业务流程建模,最终由平台的解释引擎解释、生成基于Web service的ERP Web系统.经实践证明,采用本平台来构建符合企业个性化需求的ERP系统所需的开发时间比传统开发方式大幅度减少、开发效率大幅度提高,开发的灵活性更强;本平台适合用于个性化需求多变的中小型企业的ERP系统开发.     

Object-Action Complexes: Grounded abstractions of sensory-motor processes

This paper formalises Object-Action Complexes (OACs) as a basis for symbolic representations of sensory-motor experience and behaviours. OACs are designed to capture the interaction between objects and associated actions in artificial cognitive systems. This paper gives a formal definition of OACs, provides examples of their use for autonomous cognitive robots, and enumerates a number of critical learning problems in terms of OACs.     

A survey on algorithmic debugging strategies

Algorithmic debugging is a debugging technique that has been extended to practically all programming paradigms. Roughly speaking, the technique constructs an internal representation of all (sub)computations performed during the execution of a buggy program; and then, it asks the programmer about the correctness of such computations. The answers of the programmer guide the search for the bug until it is isolated by discarding correct parts of the program. After twenty years of research in algorithmic debugging many different techniques have appeared to improve the original proposal. Surprisingly, no study exists that joins together all these techniques and compares their advantages and their performance. This article presents a study that compares all current algorithmic debugging techniques and analyzes their differences and their costs. The research identifies the dimensions on which each strategy relies. This information allows us to combine the strong points of different strategies.     

基于扩展同步Petri网的BPEL建模

使用业务流程执行语言(BPEL)描述复杂业务流程时容易出错。针对以上问题,通过对同步Petri网进行扩展,设计一个更适合BPEL建模的模型SPN-NET,给出各种BPEL结构化活动到SPN-NET的转换,提出一种具有一般性的相似性化简算法。合理性验证和性能分析表明,该模型简洁紧凑,可理解性好。     

面向服务架构的流程状态保存与恢复方法

以业务流程执行语言(BPEL)为基础,选取无状态的Web服务,采用有色Petri网模型描述业务流程,设计一种多输入多输出、引擎集中式的流程执行结构,使用关联矩阵和消息的双向传递实现应用级的状态保存。当流程异常中断时,提供恢复执行所需的最小状态集合,保证基于Web服务BPEL的面向服务架构应用的正确性和连续性。实例分析表明,该方法实用性强、可靠性高。     

MapReduce框架下一种负载均衡的Top-k连接查询算法

针对传统Top-k连接查询算法在处理海量数据时的时效问题,提出一种基于MapReduce框架的负载均衡的并行Top-k连接查询算法(P-TKJ)。使用直方图形式来存储数据,有助于提高CPU的利用率。同时融入了提前终止策略和磁盘数据的选择性访问,以便提高对HDFS数据访问的性能。另外,提出了一种基于最长处理时间优先(LPT)算法的负载均衡策略来均衡Reduce任务,以此设计出高效的并行Top-k连接算法。一个集群实验结果表明,该方法能够有效缩短算法的执行时间。     

信息系统分析设计与建模方法

应用钱学森先生的以人为主、人机结合,从定性到定量综合集成法,探讨信息系统及其求解过程的内在特性,纠正其中的错误认识,并提出现实业务、信息系统的分析设计是反复递归构造上游模型、下游职能模型、功能模型、执行模型、物理模型的过程。这5层模型依序为上下游推导关系,稳定性逐次减弱,反对忽略上游模型直接构造下游模型。通过5种上下游模型法,可有效提高信息系统质量与成效。     

Execution trace analysis through massive sequence and circular bundle views

An important part of many software maintenance tasks is to gain a sufficient level of understanding of the system at hand. The use of dynamic information to aid in this software understanding process is a common practice nowadays. A major issue in this context is scalability: due to the vast amounts of information, it is a very difficult task to successfully navigate through the dynamic data contained in execution traces without getting lost.In this paper, we propose the use of two novel trace visualization techniques based on the massive sequence and circular bundle view, which both reflect a strong emphasis on scalability. These techniques have been implemented in a tool called Extravis. By means of distinct usage scenarios that were conducted on three different software systems, we show how our approach is applicable in three typical program comprehension tasks: trace exploration, feature location, and top-down analysis with domain knowledge.     

Systematic Component-Oriented development with Axiomatic Design

A form of design guidance is offered through a process that applies Axiomatic Design Theory to Component-Orientation. Axiomatic Design has been proposed by Do and Suh for object-oriented software development. Our approach leverages divide-and-conquer and find-integrate techniques that support service-based development as an alternative to developing code from scratch. Using this process, missing or conflicting components can be identified, and missing components can be defined. The effectiveness of our proposed system is demonstrated through an example based on High Level Architecture (HLA) simulations. Our Component-Oriented approach utilizing axiomatic design theory has been adapted to HLA Federation Development and Execution Process (FEDEP). As one of the Component-Oriented approaches proposed, FEDEP is able to obtain interoperability and reusability of available components, namely federates.