浅谈工作流在OA设计中的要点

三作流技术是办公自动化系统的关键技术之一。正确使用工作流技术，可以提高办公效率，我们就工作流技术在oA中的应用，特别是复杂的子工作流流程的设计，结合实际工作提出我们的观点和看法．     

基于微内核的工作流引擎技术

工作流技术是企事业单位信息化的一个重要技术,工作流管理系统的核心是工作流引擎。但传统工作流引擎大多采用宏内核结构,即内核要同时完成调度和服务功能,这种结构造成了工作流引擎重构和维护的困难。本文提出基于微内核结构的工作流引擎技术,从而降低了工作流引擎重构和维护的难度。     

基于工作流管理技术的研究

本文针对工作流技术的起源,对工作流的概念、研究的技术内容及工作流管理系统作了深入的介绍,对工作流管理这个研究领域建立了一个全局的概述,介绍了工作流管理系统的参考模型,并具体介绍了企业工作流管理系统的实施过程。     

工作流技术综述

工作流技术是进入90年代以后计算机应用领域的一个新的研究热点.对工作流技术进行深入的研究对于提高我国企业的信息化程度、运行效率以及竞争能力都有着重要的意义.该文首先介绍了工作流技术的起源与发展;然后对工作流的研究现状进行综述,主要包括工作流定义、工作流模型、工作流实现方案以及工作流事务管理这4个方面;同时分析了目前工作流技术中所存在的不足以及造成这些不足的根本原因;最后指出了工作流技术的未来发展趋势.     

企业动态联盟中柔性工作流的研究与实现

柔性问题是工作流管理系统在应用中面临的一个重要问题，目前已成为工作流技术领域的研究热点之一，在本文中，我们在对工作流的基本概念进行介绍之后从几个方面讨论柔性在工作流管理中的必要性，随后对柔性作出大体的分类与讨论，DyFxWF是一个基于面向对象技术开发的工作流管理系统的原型系统，客户可以在工作流的执行过程中根据具体情况修改执行路径，调整任务及其它参数，实现了动态的柔性。     

工作流管理系统及其在邮电号线管理中的应用

由于使用工作流技术构建的信息系统具有很好的灵活性、良好的可扩展能力等,工作流技术的研究与应用已成为目前的一个热点。文章首先详细介绍了工作流的相关概念、工作流的参考模型和工作流的分类,然后介绍了一个工作流技术支持的邮电号线管理系统的实现,并对采用工作流技术而为系统带来的优点作了详细的分析。实践证明了该系统的设计思想是有意义的,并对开发同类系统具有一定的参考价值。     

基于UML的工作流引擎的设计与研究

由于工作流技术具有在异构环境中处理复杂事务的能力,所以在科学研究、电子政务和商务等方面引起了广泛的关注,工作流引擎是工作流管理系统的核心,本文以工作流管理联盟的工作流参考模型为基础,主要使用UML建模技术对工作流引擎进行分析与设计。     

工作流技术在办公自动化系统中的应用研究

工作流技术是办公自动化系统中的核心技术之一.文章对工作流、工作流管理系统的概念和模型做了详细的介绍.提出了一个基于工作流模型的OA系统模型,在此基础上介绍了一个已完成的公文流转子系统中采用的相应技术.     

基于Agent的WfMS的设计及应用

工作流及工作流管理系统是CSCW领域研究的热点之一,Agent技术也是人工智能领域的新兴课题。把A- gent技术结合到工作流管理中,利用Agent智能、易于扩展的特点,可以使工作流管理系统更加灵活,适应性更强。本文提出了一种基于Agent的工作流模型,并给出了该模型的一个实际应用。     

工作流管理系统及其建模研究

对工作流技术发展情况进行概述,介绍由国际工作流管理联盟所定义的工作流管理系统的体系结构和参考模型,并简单介绍分析现今常用的几种工作流模型。在工作流建模方面,参考结合曾参与开发的工作流开发平台项目,详细地论述工作流模型建立阶段的一些技术要点和本系统建模工具的元模型元素架构及模型的两种存储方案。详细介绍工作流开发平台建模工具的功能和实现,并演示一个利用此建模工具所开发的模型实例。     

烟草在线异物剔除系统

介绍一种基于智能模式识别方法的烟草在线异物剔除系统，论述了该系统的工作原理，特点和构成，对系统硬件的设计和软件的功能也作了说明。     

Sobolev Active Contours

All previous geometric active contour models that have been formulated as gradient flows of various energies use the same L ²-type inner product to define the notion of gradient. Recent work has shown that this inner product induces a pathological Riemannian metric on the space of smooth curves. However, there are also undesirable features associated with the gradient flows that this inner product induces. In this paper, we reformulate the generic geometric active contour model by redefining the notion of gradient in accordance with Sobolev-type inner products. We call the resulting flows Sobolev active contours. Sobolev metrics induce favorable regularity properties in their gradient flows. In addition, Sobolev active contours favor global translations, but are not restricted to such motions; they are also less susceptible to certain types of local minima in contrast to traditional active contours. These properties are particularly useful in tracking applications. We demonstrate the general methodology by reformulating some standard edge-based and region-based active contour models as Sobolev active contours and show the substantial improvements gained in segmentation.     

A Robust Spectral Element Method for Simulations of Time-Dependent Viscoelastic Flows, Derived from the Brownian Configuration Field Method

This paper is an extension of previous work [4], where a robust numerical method derived from the Brownian configuration field method [8] was introduced in order to simulate the flows of dilute polymeric solutions. In [4], we limited our study to solutions of dumbbells having infinite extensibility (Oldroyd-B model), whereas in this paper, we tackle the more difficult problem of dumbbells having finite extensibility (FENE-P model).     

Parallel Godunov smoothed particle hydrodynamics (SPH) with improved treatment of Boundary Conditions and an application to granular flows

Smoothed Particle Hydrodynamics has been successfully used for various fluid-dynamics problems, such as breaking-waves, flooding etc., since it was originally proposed. While the Lagrangian approach is naturally suitable for free-surface flows, enforcing boundary conditions and poor approximations in the presence of discontinuities in the solution are major difficulties with the method. In this paper we present an enhanced conservative Godunov SPH based on the work of Inutsuka [S. Inutsuka, Reformulation of smoothed particle hydrodynamics with Riemann solver, Journal of Computational Physics 179 (2002) 238–267] that accurately resolves discontinuities without the need to use artificial viscosity, preserves partition of unity everywhere in the domain, correctly and flexibly enforces necessary essential and frictional slip boundary conditions to approximately solve free-surface granular flows. The development is motivated by the need to improve upon depth averaged grid based models of large scale debris flows and avalanches often characterized as granular flows. Simple validation of the results is obtained by comparison to table-top experiments.     

New Possibilities with Sobolev Active Contours

Recently, the Sobolev metric was introduced to define gradient flows of various geometric active contour energies. It was shown that the Sobolev metric outperforms the traditional metric for the same energy in many cases such as for tracking where the coarse scale changes of the contour are important. Some interesting properties of Sobolev gradient flows include that they stabilize certain unstable traditional flows, and the order of the evolution PDEs are reduced when compared with traditional gradient flows of the same energies. In this paper, we explore new possibilities for active contours made possible by Sobolev metrics. The Sobolev method allows one to implement new energy-based active contour models that were not otherwise considered because the traditional minimizing method render them ill-posed or numerically infeasible. In particular, we exploit the stabilizing and the order reducing properties of Sobolev gradients to implement the gradient descent of these new energies. We give examples of this class of energies, which include some simple geometric priors and new edge-based energies. We also show that these energies can be quite useful for segmentation and tracking. We also show that the gradient flows using the traditional metric are either ill-posed or numerically difficult to implement, and then show that the flows can be implemented in a stable and numerically feasible manner using the Sobolev gradient. Sundaramoorthi and Yezzi were supported by NSF CCR-0133736, NIH/NINDS R01-NS-037747, and Airforce MURI; Sapiro was partially supported by NSF, ONR, NGA, ARO, DARPA, and the McKnight Foundation.     

Large-eddy simulations in mixed-flow pumps using an immersed-boundary method

Computations of turbulent and transitional flows in rotating machinery applications are very challenging due to complexity of the geometry, which usually consists of multiple rotating and stationary parts. The application of well-established, body-fitted methods frequently utilizes overset grids and different reference frames, which have an adverse impact on the overall accuracy and cost-efficiency of the method. In the present work we explore the feasibility of performing computations of such flows using a single reference frame and an immersed-boundary approach. In particular, we report one of the first large-eddy simulation in this class of flows, where a structured cylindrical coordinate solver with optimal conservation properties is utilized in conjunction with an immersed-boundary method. To evaluate the accuracy of the computations the results are compared to the experimental measurements in [1]. Results using the standard Smagorinsky model and the Filtered Structured Function model are presented. We demonstrate that the overall approach is well suited for the flow under consideration and the results with the more advanced subgrid scale model are in good agreement with the experiment. We also briefly discuss some of the features of the instantaneous flow dynamics, to provide a glimpse of the wealth of information that can be extracted from such computations.     

Study of a Jacobian-free approach in the simulation of compressible fluid flows in porous media using a derivative-free spectral method

The development of Jacobian-free software for solving problems formulated by nonlinear partial differential equations is of increasing interest to simulate practical engineering processes. For the first time, this work uses the so-called derivative-free spectral algorithm for nonlinear equations in the simulation of flows in porous media. The model considered here is the one employed to describe the displacement of miscible compressible fluid in porous media with point sources and sinks, where the density of the fluid mixture varies exponentially with the pressure. This spectral algorithm is a modern method for solving large-scale nonlinear systems, which does not use any explicit information associated with the Jacobin matrix of the considered system, being a Jacobian-free approach. Two dimensional problems are presented, along with numerical results comparing the spectral algorithm to a well-developed Jacobian-free inexact Newton method. The results of this paper show that this modern spectral algorithm is a reliable and efficient method for simulation of compressible flows in porous media.     

基于近似方法的抽样报文流数估计算法

维护每个报文的流记录需要占用大量测量资源.目前已有多种抽样技术估计网络流统计信息,然而精确地估计出流数统计信息是目前的研究难点.提出了Integral和Iteration 两种基于报文抽样样本估计网络流数的算法.Integral算法只需使用抽样流长为1的流数信息就可以近似推导出未抽样的流数.Iteration算法通过建立迭代函数估计未抽样流数,然后根据未抽样流数和已抽样的流数推断出原始流量的流数.采用CERNET(China education andresearch network)骨干网络链路数据将这两种算法与EM(expectation maximization)算法进行对比,表明Iteration算法具有较好的精度和性能.     

一种非TCP友好流惩罚算法

为了改善Internet中各流量带宽分配的不公平性,提出一种适于缓存管理的非TCP友好流的惩罚算法（NFTFP算法）。通过在缓冲区记录每个连接所占用的带宽,对于非TCP友好流量进行识别和惩罚,从而提高不同数据流享用带宽的公平性。仿真实验表明在标准TCP流量和非TCP友好流共存的环境下,NFTFP算法能提高对非TCP友好流的惩罚力度,在保持较高的链路利用率的同时,获得比RED算法更好的公平性。