工作流环境下数字内容保护系统研究与实现

针对目前工作流系统中对敏感数字内容缺乏有力的安全保护的问题,研究并实现了一种在工作流环境下敏感数字内容流转安全保护系统。该系统基于数字版权管理系统(DRM)紧密结合工作流系统,通过使用并扩展工作流过程定义语言XPDL,使得数字版权管理系统能够充分利用工作流流程信息,解决了数字内容权限与工作流系统动态连接问题,从而实现了在不安全的网络环境下数字内容的安全分发与流转。     

基于组和角色的工作流权限访问控制模型

基于角色的权限控制已经作为国际规范被广泛应用,但是它只能解决用户对某一操作环境的操作权限问题,无法解决相同操作环境下对不同客体子集的访问控制问题,特别是在工作流系统中,对不同对象集、不同节点的权限访问控制尤为重要。针对这个问题,对基于角色的权限控制技术和工作流技术进行了研究,提出了基于组/角色的工作流权限访问控制模型,实现了对操作对象集、操作权限集的二维权限控制,很好地解决了跨区域情况下,多部门基于工作流系统工作时的对象访问控制和权限控制问题。目前该模型已经成功应用于油田作业施工的一体化办公系统中,实践证明该模型的设计是科学合理的、可行的。     

依据角色权限的审批工作流模型构建

为了简化审批工作流建模流程,提高审批流程的柔性与灵活性,以审批流程中的审批对象与审批角色为中心,提出了基于角色的审批权限矩阵,该矩阵定义了当处于某一审批环节时,审批角色对审批对象的操作权限与可以转出到的环节,对审批角色给予更加细粒度的控制。给出了对审批权限矩阵的数学检验方法。依据审批权限矩阵构建了基于Petri网的审批工作流模型,实现了工作流建模与权限控制的结合,以及对不同权限差异化的审批流程管理。     

面向工作流的RBAC模型研究

针对传统的基于角色的访问控制(RBAC)模型存在数据对象划分不清晰、权限分配不够灵活等问题,基于RBAC模型提出了工作流的概念.即将所有数据对象抽象成业务表单,为每个业务表单分配一个工作流,通过工作流的结点及分配的角色来解决用户与数据对象的权限控制问题.实验结果表明,该模型有效地实现了对数据实例的细粒度控制,具有较好实用性与可操作性,较好解决了相同角色对不同数据对象的不同访问权限控制问题.     

基于有限状态机原理的工作流组件实现方法

为了高效地解决传统工作流组件存在的问题,提出了一种基于有限状态机原理的工作流组件实现方法.该工作流原理是通过申请自定义状态机,根据请求路由信息,按照调度命令进行流程处理的模式对第三方权限系统实现内容创建、数据变化和信息迁移的效果.该工作流组件功能设计从用户使用角度出发,维护第三方权限系统,优化自定义数据库的功能,支持父...     

工作流系统中基于任务状态的转授权模型

为了解决工作流系统中多个用户协作完成某个任务时的权限分配问题,提出了工作流系统中用户-用户间基于任务状态的转授权模型,用任务处于某个状态的时间段作为转授权有效期的限制,将任务的部分权限作为转授权对象,在任务的各个状态下为不同的用户分配不同的权限.给出了模型的形式化定义,并提出了模型中转授权约束规则、冲突消解办法和转授权的撤销,最后举例说明该模型在实际工作流系统中的应用.模型能在不增加系统管理员负担的前提下,较好地解决工作流系统中多个用户协作完成某个任务时的授权问题.     

基于角色的适应性工作流系统访问控制模型

现有的一些工作流系统访问控制模型局限于活动执行权限控制,难以满足适应性工作流系统的访问控制需求.针对适应性工作流系统的权限控制需求,对适应性工作流系统的操作行为进行分析和总结,确定操作对象、用户、操作方法为研究对象,对监控和业务过程变更进行细粒度划分,给出了规范化的形式化描述.在此基础上提出基于角色的访问控制的授权模型以及与系统的集成,描述角色、用户和对象等要素之间关系,给出授权方法,保证操作的合理性,有效解决适应性工作流系统中安全控制问题,满足了不同层次人员对监控权限的灵活需求.     

基于JBPM工作流公文流转系统研究与实现

公文流转系统是电子政务系统的重要组成部分,在政府和企事业单位中得到了广泛的使用和普及。本文基于目前业界使用较为普遍的开源工作流引擎JBPM作为研究对象,针对高校的业务模式,提出了面向高校的公文流转系统,并将其应用到高校公文流转系统的开发中。首先,论文介绍了工作流的相关技术,然后研究了JBPM工作流引擎的开发机制,分析了高校公文流转系统的功能需求,并给出了系统主要设计方案,最后,基于JBPM工作流引擎以及高校的业务模式,实现了公文流转系统。该系统的实施提高了工作效率和办公自动化水平。     

面向Web服务工作流系统的访问控制模型

提出了一种面向Web服务工作流系统的访问控制模型（WSWF-RBAC）。在基于角色的访问控制模型基础上引入系统资源的概念,把Web服务对象、属性和其它功能模块当做资源统一管理。引XT资源访问模式的概念,在约束条件下通过与资源的运算生成系统权限,从而实现了对权限的精细管理和动态调整能力。通过扩展web服务访问的角色集和用户集,并引入角色扮演对象,实现了工作流系统中Web服务与其它模块访问控制的一致性。将该模型应用于库房供应链系统中,运行结果表明,该模型能够增强Web服务工作流系统授权的灵活性和安全性。     

基于任务的工作流访问控制模型和实现框架

工作流中角色只有在执行任务时才需要权限,任务与权限密不可分,而现有的基于角色的访问控制不能满足工作流这一特性。提出了基于任务的访问控制模型,该模型根据工作流的具体要求,对任务分配相应的权限,角色执行任务,权限则传递给角色,实现了权限的按需分配,提高了数据访问的安全性,简化了角色系统的管理,最后给出了模型的一个实现框架以及运行过程。     

Systematic planning for digital preservation: evaluating potential strategies and building preservation plans

A number of approaches have been proposed for the problem of digital preservation, and the number of tools offering solutions is steadily increasing. However, the decision making procedures are still largely ad-hoc actions. Especially, the process of selecting the most suitable preservation action tool as one of the key issues in preservation planning has not been sufficiently standardised in practice. The Open Archival Information Systems (OAIS) model and corresponding criteria catalogues for trustworthy repositories specify requirements that such a process should fulfill, but do not provide concrete guidance. This article describes a systematic approach for evaluating potential alternatives for preservation actions and building thoroughly defined, accountable preservation plans for keeping digital content alive over time. In this approach, preservation planners empirically evaluate potential action components in a controlled environment and select the most suitable one with respect to the particular requirements of a given setting. The method follows a variation of utility analysis to support multi-criteria decision making procedures in digital preservation planning. The selection procedure leads to well-documented, well-argued and transparent decisions that can be reproduced and revisited at a later point of time. We describe the context and foundation of the approach, discuss the definition of a preservation plan and describe the components that we consider necessary to constitute a solid and complete preservation plan. We then describe a repeatable workflow for accountable decision making in preservation planning. We analyse and discuss experiences in applying this workflow in case studies. We further set the approach in relation to the OAIS model and show how it supports criteria for trustworthy repositories. Finally, we present a planning tool supporting the workflow and point out directions for future research.     

Digital art: when artistic and cultural muse merges with computer technology.

Digital artifacts or "artistic applications" as they are usually called, aim at displaying information content by materializing concepts in a digital format. In this article the author explains about the concepts and definitions behind digital art and the technological issues related to artistic and cultural heritage applications. Artistic creation begins with a concept or an abstract idea, which is gradually modeled into a form of tangible or intangible digital content that can be both the means and the end product. Digital artists consider computer technology as a way to enhance creativity and as a final artifact. The dual manifestation of artistic and cultural heritage applications results in workflow that differs for each application class. Application constraints identification is one of the most important but often undervalued issues in digital art creation. Displacement is an interactive installation applying augmented reality technology.     

基于密码技术的Android平台数字媒体版权管理系统

针对电子商务领域数字媒体版权保护的需求,给出一种数字媒体版权管理（DRM）系统框架。基于Android平台,对版权管理系统涉及的DRM内容格式及权利对象文件进行设计,给出系统的工作流程。最后,给出了系统的测试结果,并分析了系统的主要特点。     

A model, design, and implementation of an efficient multithreaded workflow execution engine with data streaming, caching, and storage constraints

The paper proposes a model, design, and implementation of an efficient multithreaded engine for execution of distributed service-based workflows with data streaming defined on a per task basis. The implementation takes into account capacity constraints of the servers on which services are installed and the workflow data footprint if needed. Furthermore, it also considers storage space of the workflow execution engine and its cost. Caching service output data is implemented to speed up the execution of the workflow. Input data is partitioned into data packets, which are passed and processed by services previously selected for workflow tasks so that the aforementioned constraints are met. Performance impact of the proposed mechanisms is investigated for workflow structures common in acyclic directed graph workflow applications. It is shown for a real workflow with distributed processing of digital media content that the initial budget needs to be properly distributed between both the cost of services, but also the cost of intermediate storage to obtain good workflow execution times.     

基于Web和工作流的冲印管理系统的设计

网络冲印已成为数码影像业中的重要经营方式,但目前人工冲印业务复杂、工作流程混乱,给用户和冲印店都带来了很大的不便。因此,在冲印管理系统中引入了工作流的概念,对冲印管理系统中的工作流程进行了探讨,建立了冲印管理系统的工作流模型,并设计实现了一个基于Web的冲印管理系统。     

Workflow Business Template for Application Processes in Administration Department

The reuse of business-process and information specifications can reduce the cost of business design by helping to alleviate bottlenecks in the development of workflow systems. Using a new concept we call workflow design pattern, we create a library of standard business-process and information specifications to be used as workflow business template. Business design and system design are done by customizing the standard specifications. New support tools are used to implement the design result. By using this proposed method, the cost of system development can be reduced.     

基于对象状态的工作流系统访问控制机制的研究

针对访问控制机制中仅考虑对象层次的不足,在基于任务和角色的访问控制模型中加入对象层次的访问控制,并考虑对象状态对使用者访问权限变化的影响,使访问控制的粒度精确到以个别对象状态为单位。在设计访问控制机制时,将不同状态下的访问规则从权限管理的架构中分离,通过这种方式可以使访问控制机制运用在不同工作流程中。系统实现时采用面向对象的设计模式,将此访问控制机制应用在具有多种素材的在线数字化博物馆内容审核流程上,通过内容管理以及访问控制机制的引入,确保数字化内容的正确性与适用性。     

A workflow management system to feed digital libraries: proposal and case study

Building a digital library of antique documents involves not only technical implementation issues, but also aspects related to the digitization of large collections of documents. Antique documents are usually delicate and need to be handled with care. Also, a poor state of preservation and the use of unrecognizable font types make automatic text recognition more difficult, hence requiring a further human revision to perform text corrections. This makes the participation of experts in the digitization process mandatory and, therefore, costly. In this paper, we present a framework for managing the workflow of the digitization of large collections of antique documents. We describe the digitization process, and a tool supporting all of its phases and tasks. We also present a case study in which we describe how the workflow management system was applied to the digitization of more than 10,000 documents from journals of the 19th century. In addition, we describe the resulting digital library, focusing on the most important technological issues.     

ERP工作流引擎中的数字签名技术

论述了工作流引擎在企业资源规划(ERP)系统中的主要功能后,为了能解决工作流运行过程中可能遇到的网络安全、法律效力等问题,提出了结合数字证书与数字签名技术的B/S解决方案,并结合Java授权与认证服务(Java Authentication and Authorization Service,JAAS)保证了工作流引擎更加安全可靠地运行.