工作流动态指派参与者模型及应用

本文致力于工作流管理系统中动态指派参与者机制的研究,综合考虑参与者资格适合度、事件优先级、高级约束条件满足性以及参与者状态有效程度等因素提出一个全新的动态指派参与者模型及相应的动态指派方法,并将其应用到保险业工作流管理系统中.基于动态指派参与者机制建设工作流管理系统会更加适应当前的办公环境,提高办事效率.     

基于关系数据库的轻量级工作流引擎

提出了一个基于关系数据库的轻量级工作流引擎模型.深入讨论了采用关系数据库和轻量级理念来设计工作流引擎的原因,并详细地给出了相关各模型的设计原理以及具体的表示和实现方法.与其他类似系统相比,该引擎的过程模型通过屏弃工作项的转出转移列表与转入转移列表简化了引擎的结构,提高了引擎的工作效率;参与者指派模型通过实现同时基于角色与部门的参与者指派增加了工作流的灵活性.     

面向电子政务的工作流模型的研究与应用

文章分析了我国电子政务应用的特点,提出了一种面向电子政务的基于活动网络图的工作流模型,描述了组成工作流的基本实体类型,讨论了模型如何支持电子政务应用中的复杂流程、如何利用已有组织模型、如何与现有系统集成,同时还讨论了工作流模型与XPDL的映射关系,最后介绍了基于该模型的工作流引擎的实现方法.该工作流引擎已经在税务等多个政府信息系统中得到成功应用,应用结果表明所讨论的工作流模型能够满足我国现有电子政务的应用需求.     

接力式协作的工作流控制模型

针对工作流管理系统的描述、构造和实现问题，讨论了工作流的建模原则，分析了工作流要素间的关系，提出了一个描述工作流控制过程和组织结构的模型——接力式协作的工作流控制模型RCW，给出了实现工作流管理系统的理论框架．     

基于任务和角色的工作流访问控制模型

提出一种基于角色和任务的工作流访问控制模型,并描述模型中用户、角色、许可、活动等要素间的指派关系和该模型的静态、动态约束规则,然后以此模型为上下文背景提出一个描述基于角色和任务的工作流授权约束的直观的形式化语言,称为ERCL。它以系统函数、集合一级变量符作为基本元素。最后给出一个该模型在实际工作流系统中的应用。     

基于角色和任务的工作流访问控制模型及其应用*

提出了一种基于角色和任务的工作流访问控制模型RTBWAC,描述了模型中用户、角色、许可、活动等要素间的指派关系和该模型的静态、动态约束规则,最后给出了该模型在实际工作流系统中的应用.     

一种基于同步网的工作流管理系统

作为一类典型的CSCW系统,工作流管理系统主要提供异步、结构化的协同支持。本文从模型入手,介绍了一种基于Petri网的工作流模型——同步网。它采用分层视图描述了过程逻辑、语义及管理,过程模型和管理模型的互动关系用来指导工作流引擎的构造。本文基于同步网开发了工作流管理系统,支持工作流的定义、执行和管理。为了满足CSCW的需要,工作流管理系统中增加了同步协作机制。     

基于风险的工作流系统访问控制优化策略*

在面向服务的工作流访问控制模型中,角色的任务授权随着系统任务状态的变化而变化,一个任务往往有多个不同的角色指派方案。为了确定最优方案,在面向服务的角色访问控制模型基础上,引入了风险的概念,提出了形式化描述风险的方法。通过对不同角色执行任务风险的评估来确定执行角色,使工作流系统具有更好的安全性,同时通过角色风险权值的动态变化有效地平衡了角色间的负载,可以有效提高系统的效率。     

一种支持流程服务集成及协作的工作流描述语言PS-XPDL

在面向服务体系结构和Web服务技术快速发展的条件下，对封装成服务的业务过程集成和协作的支持成为工作流描述语言的发展趋势。通过对流程协作的层次模型和场景模型的分析，提出了一种基于WfMC工作流元模型的扩展元模型，并根据该元模型对XPDL进行了相关元素扩展,得到一种支持流程集成和协作的工作流语言PS-XPDL。该语言对流程服务的协作关系及数据同步具有完备、准确的表达，同时其基于执行支持层标准协议的扩展也使得流程服务的集成及协作易于实现。     

工作流资源指派技术的研究与实现*

资源指派是工作流管理系统的一项重要功能,它在运行期将资源模型和过程模型联系起来。对资源指派规则的表达机制进行了分析,并在此基础上研究开发了一个基于指派规则和资源管理服务的资源指派系统,它具有良好的可扩充性,并支持资源模型的共享。     

一种空间上下文感知的提及目标推荐方法

作为一种新兴的社交媒体用户交互服务,提及机制(mention mechanism)正在用户在线交互和网络信息传播方面扮演着重要角色.对用户提及行为的研究能够揭示用户的隐式偏好与其显式行为之间的联系,为信息传播监控、商业智能、个性化推荐等应用提供新的数据支撑.当前,对用户提及机制的探索多集中在其信息传播属性上,缺少从普通用户角度对其用户交互属性的学习.通过对普通用户提及行为的分析和建模构建一个推荐系统,为给定的社交媒体消息生成目标用户推荐.通过对大型真实社交媒体数据集的分析发现,用户的提及行为受其提及活动的语义和空间上下文因素的联合影响.据此,提出一个联合概率生成模型JUMBM(joint user mention behavior model),模拟用户空间关联提及活动的生成过程.通过对用户语义和空间上下文感知的提及行为进行统一建模,JUMBM能够同时发掘用户的移动模式、地理区域依赖的语义兴趣及其对应目标用户的地理聚集模式.此外,提出一种混合剪枝算法,加快推荐系统对在线top-k查询的响应速度.在大型真实数据集上的实验结果表明,所提方法在推荐有效性和推荐效率方面均优于对比方法.     

柔性工作流动态行为建模方法

针对现有工作流动态行为建模柔性差的问题，研究工作流动态行为的柔性定义方法。将活动的动态行为分为自身行为、嵌套行为和协作行为。自身行为实际上是活动的状态转移的过程，通过ECA规则描述活动的状态转移图可实现自身行为的定义；活动间协作行为实质上是参与活动间状态变化关联的过程，通过定义活动间状态的关联关系并用ECA规则描述协作语义，可实现对嵌套和协作行为的细粒度柔性定义。文中提出的可扩展方法适用于复杂或特殊环境下的流程建模。     

Peer profile based trust model for P2P systems using genetic algorithm

The open and anonymous nature of P2P allows peers to easily share their data and other resources among multiple peers, but the absence of a defensible border raise serious security concerns for the users. There is a lack of accountability for the content that is shared by peers and it is hard to distinguish malicious users from honest peers. Establishing Trust relationship between peers can serve as the metric to determine the veracity of the shared content and reliability of the peers. Most of the research work in this area is on Reputation based trust management where trust is determined on the basis of recommendation of other peers. Such recommendations are subjective and can be biased. A number of peers can also collude to provide false testimony for malicious peers. This paper proposes a novel Trust model that combines peer profiling with anomaly detection technique. Each peer can establish trust based on its own prior activities with other peers by comparing the current activity of a peer with its historical data and Genetic Algorithm (GA) has been employed to detect the anomalous behavior. Peer profile is updated dynamically with every transaction using GA operator’s crossover and mutation. This model has been tested using a file sharing application against common attacks and the results obtained are compared with statistical anomaly detection approach.     

Group planning with time constraints

Embedding planning systems in real-world domains has led to the necessity of Distributed Continual Planning (DCP) systems where planning activities are distributed across multiple agents and plan generation may occur concurrently with plan execution. A key challenge in DCP systems is how to coordinate activities for a group of planning agents. This problem is compounded when these agents are situated in a real-world dynamic domain where the agents often encounter differing, incomplete, and possibly inconsistent views of their environment. To date, DCP systems have only focused on cases where agents’ behavior is designed to optimize a global plan. In contrast, this paper presents a temporal reasoning mechanism for self-interested planning agents. To do so, we model agents’ behavior based on the Belief-Desire-Intention (BDI) theoretical model of cooperation, while modeling dynamic joint plans with group time constraints through creating hierarchical abstraction plans integrated with temporal constraints network. The contribution of this paper is threefold: (i) the BDI model specifies a behavior for self interested agents working in a group, permitting an individual agent to schedule its activities in an autonomous fashion, while taking into consideration temporal constraints of its group members; (ii) abstract plans allow the group to plan a joint action without explicitly describing all possible states in advance, making it possible to reduce the number of states which need to be considered in a BDI-based approach; and (iii) a temporal constraints network enables each agent to reason by itself about the best time for scheduling activities, making it possible to reduce coordination messages among a group. The mechanism ensures temporal consistency of a cooperative plan, enables the interleaving of planning and execution at both individual and group levels. We report on how the mechanism was implemented within a commercial training and simulation application, and present empirical evidence of its effectiveness in real-life scenarios and in reducing communication to coordinate group members’ activities.     

Engineering mobile agent applications via context-dependent coordination

The design and development of Internet applications requiring dynamic and possibly mobile access to Internet resources can take advantage of an approach based on autonomous mobile agents. However, mobility introduces peculiar issues related to the modeling and management of the agents' coordination activities. This paper introduces context-dependent coordination as a framework for the design and development of Internet applications based on mobile agents, and shows how it can be supported by a proper coordination infrastructure. Context-dependent coordination is centered on the notion of programmable coordination media, as the software abstraction via which an agent in an Internet site can access to local resources and coordinate with local agents. Programmability stems from the fact that the behavior of the media can be fully configured to influence agents' coordination activities. This enables local administrators to configure coordination media so as to enact site-dependent coordination policies, and mobile agents to configure the accessed coordination media to obtain an application-dependent behavior of the media themselves. Several application examples shows that exploiting context-dependent coordination promotes a clear separation of concerns in design and development, and can make applications more modular and easier to be maintained. The MARS system is assumed as an exemplar coordination infrastructure to clarify the concepts expressed and to show their actual implementation.     

基于完全有限前缀展开的行为等价过程树生成算法

过程树能够兼具过程模型的行为和结构，对简化模型结构的复杂度方面具有重要意义.现有过程树转化仅能将基于块结构的简单过程模型转化为过程树，但是无法将具有复杂结构的过程模型转化过程树.为此，提出了一种基于完全有限前缀展开的行为等价过程树生成算法，用于将与过程树行为等价的过程模型转化为行为等价过程树.该方法首先利用完全有限前缀展开技术分析过程模型，抽取模型的活动关系;其次通过分析活动关系，进而对模型进行重构.最终通过活动关系判断和模型重构的不断迭代操作，构建行为等价过程树.在实验部分通过在测试模型上的实验，验证了该算法在行为等价过程树生成方面的正确性和可行性.     

基于函数型数据时间序列建模的单传感器日常行为识别

在基于惯性传感器的人体行为识别中,传统算法常忽略行为的周期性与时序性,对提取特征的滑动窗口大小也有相应要求.文中基于单个腰部传感器分析人体日常行为,提出面向周期行为的函数型数据分析方法和隐马尔可夫模型结合的行为识别算法.首先,使用函数型数据分析方法,拟合周期性日常行为的动作捕捉数据,提取拟合后的单个周期数据.然后基于此周期时间序列数据建立描述各个日常行为过程的隐马尔可夫模型.最后,使用最大似然估计判别行为,得到识别结果.该算法通过单个腰部传感器即可快速有效地识别8种日常行为,在基于用户依赖策略和用户独立策略时识别率较高.     

Disentangling utilitarian and hedonic consumption behavior in online shopping: An expectation disconfirmation perspective

Increasingly, researchers have come to acknowledge that consumption activities entail both utilitarian and hedonic components. Whereas utilitarian consumption accentuates the achievement of predetermined outcomes typical of cognitive consumer behavior, its hedonic counterpart relates to affective consumer behavior in dealing with the emotive and multisensory aspects of the shopping experience. Consequently, while utilitarian consumption activities appeal to the rationality of customers in inducing their intellectual buy-in of the shopping experience, customers’ corresponding emotional buy-in can only be attained through the presence of hedonic consumption activities. The same can be said for online shopping. Because the online shopping environment is characterized by the existence of an IT-enabled web interface that acts as the focal point of contact between customers and vendors, its design should embed utilitarian and hedonic elements to create a holistic shopping experience. Building on Expectation Disconfirmation Theory (EDT), this study advances a research model that not only delineates between customers’ utilitarian and hedonic expectations for online shopping but also highlights how these expectations can be best served through functional and esthetic performance, respectively. Furthermore, we introduce online shopping experience (i.e., transactional frequency) as a moderator affecting not only how customers form utilitarian and hedonic expectations but also how they evaluate the functional and esthetic performances of e-commerce sites. The model is then empirically validated via an online survey questionnaire administered on a sample of 303 respondents. Theoretical contributions and pragmatic implications to be gleaned from our research model and its subsequent empirical validation are discussed.