Research on Petri Net Based Modeling and Analyzing Methods for Workflow Process

Workflow management is an important aspect in CSCW at present. The elementary knowledge of workflow process is introduced, the Petri nets based process modeling methodology and basic definitions are provided, and the analysis and verification of structural and behavioral correctness of workflow process are discussed. Finally, the algorithm of verification of process definitions is proposed.

An Effective Approach to Verify the Correctness of Workflow Process Models Based on Petri Net

Along with the extensive use of workflow, analysis methods to verify the correctness of the workflow are becoming more and more important. In the paper, we exploit the verification method based on Petri net for workflow process models which deals with the verification of workflow and finds the potential errors in the process design. Additionally, an efficient verification algorithm is given.

A New Methodology for Process Modeling of Workflows

Workflow-based systems are typically said to lead to better use of staff and better management and productivity. The first phase in building a workflow-based system is capturing the real-world process in a conceptual representation suitable for the following phases of formalization and implementation. The specification may be in text or diagram form or written in a formal language. This paper proposes a flow-based diagrammatic methodology as a tool for workflow specification. The expressiveness of the method is appraised though its ability to capture a workflow-based application. Here we show that the proposed conceptual diagrams are able to express situations arising in practice as an alternative to tools currently used in workflow systems. This is demonstrated by using the proposed methodology to partial build demo systems for two government agencies.

OBN地震数据成像处理基本逻辑与关键方法技术

海洋油气勘探逐渐进入深水深层勘探领域,地下地质构造复杂(横向变速剧烈)、目标油藏复杂(由以构造油气藏为主转向构造与地层岩性油气藏并重),同时还可能伴随海底地形及附近岩性的复杂变化,所有因素促使海洋油气地震勘探技术不断变革。提高海洋油气勘探效益的首要问题是发展尽可能满足高精度地震波成像需求的地震数据采集技术及对应的高精度地震波成像技术。当前,无论海上和陆上油气地震勘探,“两宽一高”地震数据采集技术和全波形反演(FWI)/最小二乘逆时偏移(LS_RTM)为代表的地震波成像技术是标志性的领先技术。海上油气地震勘探中,海底节点(OBN)地震数据采集是目前业界公认的、最有可能真正实现“两宽一高”地震数据采集的技术。与拖缆数据采集相比,OBN数据采集具有宽方位照明、数据信噪比高、无检端鬼波、存在实测的(至少一阶自由表面相关)下行波场、四分量观测等优点。尤其是宽方位照明和存在至少一阶自由表面下行波场的特点,使得OBN数据具备了对中深层复杂构造和近海底介质进行高精度成像的能力。着重讨论了高精度地震波成像对地震数据采集的要求,指出OBN数据采集在海洋油气勘探中的必要性;分析了OBN数据采集的地震波场的特点,据此提出OBN数据地震波成像处理的基本逻辑及相应的关键技术;认为海洋油气勘探中地震波成像处理的特殊问题主要由特征反射层引起,海水面、海底面和地下介质中若干强反射层构成了这些特征反射层,提出了模型驱动波动理论特征反射层相关多次波预测与压制的技术路线,并对比了几种代表性的多次波预测的基础理论;指出对应当前的线性化偏移成像算子叠前数据域与叠前成像域是等价的,据此以成像道集后处理为中心,给出期望成像道集的定义,将弱旁瓣、定量的反射系数作为保真高分辨地震波成像的目标,在两个域中尽可能完美实现地下同一反(绕/散)射点、不同炮检距反(绕/散)射子波的同相位叠加,尽可能好地实现保真高分辨带限反射系数的成像;提出最好把带限反射系数成像推进到宽带波阻抗成像的技术路线;结合OBN数据的特点,给出了OBN数据地震波成像处理的基本技术流程,指出各环节的关键方法技术。最后,针对OBN数据四分量观测的特点,指出是实际观测的多波地震波场中的波现象(主要是P_SV波)与地震波传播及模拟理论不匹配导致了当前多波成像结果达不到预期,建议重点研究实际观测的多波地震波场中的波现象与地震波传播及模拟理论不匹配的物理根源,而不是发展更高端的矢量波成像算法。期望本文的思想观点对OBN地震勘探在海洋油气勘探中的进一步应用产生积极的促进作用。

一种基于XML的Workflow过程定义语言

工作流是指一个业务操作从开始到结束的整个过程,是一系列相互衔接、自动进行的业务活动或任务,它在流程管理方面有很重要的应用。由于工作流程和业务规则的变更会经常发生,所以提供一种好的Workflow过程定义方法或语言已经成为目前工作流技术得以进一步发展和广泛应用的关键。在WPDL的基础上提出了一种基于XML的简单易用的Workflow过程定义语言。

基于Daisy的天文卫星数据处理软件系统设计与实现

天文卫星数据处理是开展空间天文学领域科学研究的重要内容,也是当前研究的热点。然而,在大数据背景下,由于需要进行大规模数据处理,传统的数据处理方式已经无法满足当前应用的需求。针对这一问题,本文提出了一种数据处理软件系统,该系统基于Daisy(Data Analysis Integrated Software System)研发,实现天文卫星数据处理流程的自动化和规范化。首先,通过分析卫星数据产品间的依赖关系,采用数据分块处理技术,实现系统内存管理;其次,通过对数据处理算法和工具进行标准化,实现底层代码的统一管理;最后,研发工作流调度平台,实现数据处理流程的自定义配置和实时监控。实验验证了该系统具有有效性和实用性,能够克服传统数据处理方法的不足,实现数据处理流程的自动化和规范化,为相关软件系统的设计提供指导。

基于科学工作流的通用卫星数据处理调度系统

天文卫星产生的海量观测数据下传至地面后,需要经过一系列的处理流程生成可供科学研究人员的数据产品。传统数据处理方式需要耗费大量的时间和人力成本,同时存在缺乏灵活性、任务管理困难及执行效率低下等缺陷。基于上述问题,为实现卫星数据产品生成的自动化和规范化,该文研究并设计了一种基于科学工作流的通用卫星数据处理调度系统。通过封装卫星数据处理算法,结合科学工作流、可视化编辑等相关技术,实现卫星数据处理的自动化和可配置,用户更新需求时无需修改代码,只需重新配置参数;利用可拔插组件设计机制实现系统的通用性,满足不断扩增的卫星的不同数据处理需求。根据已有卫星的数据处理需求进行应用测试,应用实例表明,该系统能够实现卫星数据的自动化处理,并且能够极大地提高处理流程的灵活性、可维护性和执行效率,有利于科学研究人员根据自己的需求获取卫星数据产品。

Dynamic hierarchy description and constraint rules of flexibility workflow

A dynamic hierarchical description method for workflow is presented. The method provides a dynamic hierarchical way to define a workflow with non-determinate or dynamic factors. With this method, the main process defined at build-time can be reified and extended by the principle of the sub-organizations at either the build-time or the run-time. To ensure the consistency and integrity of the description, a series of constraint rules are also discussed to realize seamless integration between a decomposed process and its original one. This approach supports the description of unpredictable uncertainties, the dynamic hierarchy of business process, and the dynamic modification of enterprise organizations, and all of these improve the flexibility and extendability of workflow management systems dramatically.

基于自定义工作流技术的项目管理系统设计

针对传统工作流对流程的定义过于严格,且无法解决企业项目管理中业务流程变更繁多、多层级任务分配等问题,采用了一种三层结构的流程步骤设计方案,该方案保证了流程层级清晰且易灵活配置。同时结合项目管理的前导图法(PDM),提出了一种改进的控制模式。经验证,系统在24小时内完成审批总数量为1157条,在0~4小时内完成485条,0~4小时内处理审批数量占比高达42%。该方案与线下审批处理相比,明显节约了审批时间,为采用自定义工作流技术进行项目管理系统设计提供了新思路。

Lotus Workflow工作机制与应用研究

Dom ino是OAS开发的主力平台,其上的工作流管理系统LotusW orkflow成功地将工作流原理机制引入到开发平台中,很好地适应了OAS开发对安全性、方便性以及动态变化的要求.本文对LotusW orkflow的工作机制进行了详细的剖析,介绍了其工作流的组织方式和引擎工作原理,并在此基础上成功地进行了OA应用系统的设计与实现.

浅析水源山抽水蓄能电站工程砂石料单价计算

砂石料单价对水电工程投资的确定和优化有直接影响,合理计算砂石料单价成为控制及优化投资的重要环节。自产砂石料具有渣料消纳、成品多样、运输方便、价格普遍低于外购砂石料等优势,被广泛应用于抽水蓄能工程中。文章结合水源山抽水蓄能电站上水库砂石料加工系统,梳理了该系统的工艺流程,包括工序划分、设备选用以及皮带输送机流向,通过对各生产工序的分析研究,单价计算过程费用结构清晰,计算成果合理。

工艺工程领域价值分析降成本工作流程探索——以B1B2水性漆切换1K清漆为例

为探索工艺工程领域价值分析降成本工作流程,文章借鉴汽车行业价值分析与价值工程(VAVE)工作经验,通过B1B2水性漆匹配1K清漆价值分析降成本实践,探索出降成本优化点识别、可行性分析、目标设定、方案设计、试行验证、优化调整、总结固化的工作流程,可供国内商用汽车整车及零部件生产企业工艺工程技术人员借鉴参考。

Approach for workflow modeling using π-calculus

As a variant of process algebra, π calculus can describe the interactions between evolving processes. By modeling activity as a process interacting with other processes through ports, this paper presents a new approach: representing workflow models using π calculus. As a result, the model can characterize the dynamic behaviors of the workflow process in terms of the LTS (Labeled Transition Semantics) semantics of π calculus. The main advantage of the workflow model's formal semantic is that it allows for verification of the model's properties, such as deadlock free and normal termination. Moreover, the equivalence of workflow models can be checked through weak bisimulation theorem in the π calculus, thus facilitating the optimization of business processes.

基于Windows Workflow Foundation技术的软件项目管理系统的实现方法

采用工作流技术构建软件项目管理系统的架构,通过Windows Workflow Foundation技术把系统业务流程的应用逻辑和过程逻辑分离,在不修改具体功能模块的情况下,只需修改过程模型即可改变系统功能,从而实现对系统业务流程的过程化的集成管理。

Behavior Consistency Computation for Workflow Nets With Unknown Correspondence

Consistency degree calculation is established on the basis of known correspondence, but in real life, the correspondence is generally unknown, so how to calculate consistency of two models under unknown correspondence has become a problem. For this condition, we should analyze unknown correspondence due to the influence of different correspondences.In this paper we obtain the relations of transitions based on event relations using branching processes, and build a behavioral matrix of relations. Based on the permutation of behavioral matrix, we express different correspondences, and define a new formula to compute the maximal consistency degree of two workflow nets. Additionally, this paper utilizes an example to show these definitions, computation as well as the advantages.

Artifact-centric workflow management system

Data-centric modeling approach for workflow specification and design has received considerable attention from research and development communities.An architecture for a workflow management system named EZFLOWS was outlined.Key components and research issues associated with the development of EZFLOWS were discussed.

Applying Petri-Net-Based Reduction Approach for Verifying the Correctness of Workflow Models

The correctness of workflow models is one of the major challenges in context of workflow analysis. The aim of this paper is to provide an improved Petri net-based reduction approach for verifying the correctness of workflow models. To the end, how to represent well-behaved building blocks and control structures of business processes by Petri nets is given at first, and then how to build well-structured process nets is presented. According to the structural characteristics of well-structured process nets, a set of legacy reduction rules are improved and extended, and then a complete Petri-net-based verification approach is proposed. The sound ness and the complexity with polynomial time for the improved re duction method are also proven.

Stochastic Model for Multiple Classes and Subclasses Simple Documents Processing

The issue of document management has been raised for a long time, especially with the appearance of office automation in the 1980s, which led to dematerialization and Electronic Document Management (EDM). In the same period, workflow management has experienced significant development, but has become more focused on the industry. However, it seems to us that document workflows have not had the same interest for the scientific community. But nowadays, the emergence and supremacy of the Internet in electronic exchanges are leading to a massive dematerialization of documents;which requires a conceptual reconsideration of the organizational framework for the processing of said documents in both public and private administrations. This problem seems open to us and deserves the interest of the scientific community. Indeed, EDM has mainly focused on the storage (referencing) and circulation of documents (traceability). It paid little attention to the overall behavior of the system in processing documents. The purpose of our researches is to model document processing systems. In the previous works, we proposed a general model and its specialization in the case of small documents (any document processed by a single person at a time during its processing life cycle), which represent 70% of documents processed by administrations, according to our study. In this contribution, we extend the model for processing small documents to the case where they are managed in a system comprising document classes organized in subclasses;which is the case for most administrations. We have thus observed that this model is a Markovian ML×K/ML×K/1 queues network. We have analyzed the constraints of this model and deduced certain characteristics and metrics. In fine, the ultimate objective of our work is to design a document workflow management system, integrating a component of global behavior prediction.

A Reflective Approach for Dynamic Change of BPEL Process

WS-BPEL （Web Service Business Process Execution Language）, as an emerging workflow standard, provides a simple and effective way to construct Web Services-oriented workflows. However, to the best of our knowledge, few effort from the industry and academia has addressed the dynamic change problems of BPEL process. This paper proposes a reflective approach to solve this problem. In this paper, a formal meta-object model of process instance is defined; the behavioral consistency criterion based on this model is proposed; a set of modification primitives are given to modify the meta-object while keeping the change atomic and consistent; and in addition, the MOP is offered to provide the programming interfaces for dynamic BPEL process change.