A modeling approach for designing a value chain of virtual enterprise

As the advent of digital economy changes business environment dramatically, virtual enterprise (VE), in general the interactions among business partners in a value chain, has become a key factor to survive under the competitive business environment. VE reveals that more complex and dynamic business processes should be considered as assembled service components in order to integrate the collaborative business processes. Therefore, a formal standard schema for describing and managing the business processes is required. In this paper, we propose a consistent modeling approach that combines enterprise modeling and simulation modeling to design a value chain of a VE. This methodology will provide designers with insight into the business processes of a VE and help identify and resolve unpredictable bottlenecks on the execution of virtual business processes. This paper also illustrates an implemented modeling tool which is based on the generalized model suggested by the working group of the international conference on enterprise integration and modeling technology (ICEIMT) and notations by the object management group (OMG)’s unified modeling language (UML) profile for enterprise distributed object computing (EDOC).     

面向虚拟企业构造的合作企业搜索方法研究

为了解决虚拟企业快速寻找潜在的合作企业问题,提出了一种基于任务特征、企业能力特征描述和自动匹配的合作企业搜索方法。以加工型协作任务为例,提出了基于协作任务特征和企业能力特征的描述方法和模型。这种方法将加工协作任务以特征为单元进行分解,形成子任务,然后以企业的制造资源为约束,在制造协作网中自动搜索能完成某个子任务或全部子任务的所有企业。针对协作任务的多样性,着重研究了面向单一加工任务和多种零件加工任务的合作企业搜索模型及算法。最后,介绍了一个制造协作网系统,给出了合作企业搜索模块的功能和运行实例,以验证合作企业搜索方法和算法的有效性。     

A security-based agent for a virtual enterprise

On the basis of an analysis of the differences between virtual and traditional enterprise including the disadvantages of traditional enterprise, this article addresses the issues of information security and the impact of concurrent events. Because the Internet is an open network, some of the major issues for a virtual enterprise are that they are susceptible to attacks and that concurrent tasks impact each other. We propose a security-based agent for building a safeguard for a virtual enterprise to protect its information, and to reasonably distribute tasks to cooperative objects to solve the issue of concurrent events. The security-policy management and task-scheduling modules are cores of the agent. The agent was developed with Visual C++ 6.0.     

A grid-based scheduling system of manufacturing resources for a virtual enterprise

In this paper, a scheduling system of manufacturing resources for a virtual enterprise is built up based on grid technology. The scheduling system is composed of an exterior grid and an interior grid in the architecture, while the scheduling procedure of manufacturing resources in a virtual enterprise consists of two stages – distributed scheduling and local scheduling. The exterior grid is utilized to implement the distributed scheduling and the interior grid is used to accomplish the local scheduling. This paper illustrates the manufacturing system of a virtual enterprise based on an exterior grid and the manufacturing subsystem of a member enterprise based on an interior grid. Subsequently, the scheduling procedure of manufacturing resources within the virtual enterprise is described for a particular example. Finally, a case of collaborative production of a customized artificial joint (CAJ) in a virtual enterprise is applied to demonstrate the implementation of the scheduling system of manufacturing resources for the virtual enterprise. With grid technology, the efficiency of manufacturing resource scheduling in the virtual enterprise has been improved greatly.     

面向对象的虚拟企业建模方法研究

在组成虚拟企业时,建立具有指导意义的虚拟企业模型.以模型为驱动,实现模拟企业系统建模,是解决当前虚拟企业集成问题普遍认可的方式.利用面向对象的方法,提出了基于构件的虚拟企业构成框架,并以机械制造业为例,给出了虚拟企业工作流对象的构件定义方法.     

An enterprise architecture framework for collaboration of virtual enterprise chains

The competitive power in the dynamically changing business environment has moved from individual enterprises to virtual enterprise chains. The collaboration of enterprises in a virtual enterprise chain requires that all of the enterprise elements should interact efficiently with each other based upon a virtual framework. However, any efficient framework for the collaboration is not introduced yet due to the incompatibility problem which stems from the inherent complexity of diverse enterprise elements. This paper introduces a new framework, the Virtual Enterprise Chain Collaboration Framework (VECCF), to guide enterprises to promote their collaboration efforts by addressing the incompatibility problem of enterprise elements. VECCF focuses on three aspects of enterprise elements which are capturing the different views of the collaboration: business processes, application software, and enabling technologies. In addition, the structure of VECCF conforms to OMG’s metamodel architecture so that the enterprise models can be extended to specific value chains when it is necessary. The enterprise models of a design chain and a supply chain are applied to VECCF and then integrated into a merged value chain to verify the adaptability and the extensibility of the proposed framework.     

智能虚拟控件在虚拟仪器设计中的实现

提出一种被测试功能触发的智能虚拟控件的新概念。这是测试仪器的一种全新的概念,是测试仪器技术自虚拟仪器之后一次重要的突破。这一概念的提出。将使仪器资源得到更进一步的扩展和延伸。可以认为智能虚拟控件一经实现将从根本上改变测试仪器的设计与生产模式,使仪器可在计算机内进行加工制造。现有的仪器将逐一被具有智能控件特征的虚拟仪器所取代。     

虚拟企业(VE)的使能模式研究

这里分析了敏捷虚拟企业的主要特点，提出了应用核心功能结构(Critical能Function Strutture-CFS)、应用服务提供商(Application service provider-ASP)与敏捷供需链(Agile supply chain-ASC)的虚拟企业使能模式。     

虚拟企业中数字车间与供应链系统的集成与协调

数字车间和供应链系统是虚拟企业的两个重要的功能组织。数字车间与供应链系统的信息集成和功能协调是虚拟企业能够高效运作的基础。Agent技术是构建大型、分布式系统的有效方法。本文研究了基于Agent技术的虚拟企业集成技术和协调机制。     

An extended graph-based virtual clustering-enhanced approach to supply chain optimisation

This paper describes the work that led to the realisation of an extended graph-based virtual clustering-enhanced approach to supply chain optimisation. The Supply-Chain Operations Reference (SCOR) model defined by the Supply-Chain Council in Pittsburgh, PA, USA is used to denote a typical supply chain, which may include geographically distributed suppliers, warehouses, factories, distribution centres (DCs), transportation and customers. A graph representation is proposed to represent and analyse the business processes of the SCOR model from customer orders to suppliers. Furthermore, logical relationships are superimposed onto the graph. This extended graph enables the complex relationships between the nodes of two adjoining layers to be described. By so doing, it is able to model a complex supply chain with multiple level assembly, various types of transportations and a multiple split and merge of orders. In order to handle a large-scale supply chain optimisation problem, the extended graph is enhanced by virtual clustering so as to realise an approach that is able to downscale the optimisation problem and reduce the search space. A case study is used to illustrate the effectiveness of the proposed approach. The details of the SCOR model, the extended graph, the virtual clustering, the proposed approach and the case study are presented in this paper.     

虚拟企业中供应链管理的研究

主要研究虚拟企业和供应链管理的运作原理和技术 ,提出虚拟企业供应链管理运行的生产计划、采购、库存和销售管理模式 ,并分析一具体实例     

面向虚拟企业模型的本体表示方法

针对现有本体表示方法在虚拟企业模型描述方面的不足,通过扩展本体关联语义和约束规则,提出一种适合虚拟企业模型的、图形化的本体表示模式--本体结构图.在分析虚拟企业模型及其特点的基础上,形式化定义了本体结构图的关联和约束规则,给出了虚拟企业模型片段的本体结构图的描述实例,并进一步提出了一种基于可扩展标记语言扩展的本体描述语言,说明了其基本元素和文档结构,描述了本体结构图的关联和约束.最后,通过与其他本体表示方法的比较,阐述了本体表示方法的可行性.     

A virtual environment approach for planning implant placement

This paper presents details of studies on tailor-made design and production of guide templates for osseointegrated implants, which is in progress as a joint research between the Department of Mechanical Engineering and the School of Dentistry at the University of Tokushima. A guide template is used to support the accurate operation to insert implant fixtures into the appropriate site in terms of position and direction as designed before a surgical operation.The procedure in the project includes several basic steps: digital bone modelling based on medical data, planning of implant placement, designing of guide templates to support the operation, implant simulation based on the model, evaluation of the physical model using rapid prototype techniques and the production of guide templates based on the design.This paper focuses on the design issue of implant placement planning in a virtual environment to perform a tailor-made implant treatment. The placement should be designed based on the consideration of where, in which direction, and how deep the fixture should be inserted. This study uses a virtual environment, where a designer can feel the geometry of the bone, along with bone density data to enable an appropriate plan of the implant placement to be made in an intuitive manner. For surgical operation, the tailor-made guide template is used to perform an accurate operation.The paper also describes some of the basic issues regarding the design and production of a tailor-made guide template. The project is not pursuing the technology of standardized template production, but the technology of tailor-made design and production of templates with a goal towards tailor-made implant treatment which satisfies each patient based on individual needs.     

基于SWOT分析和价值链理论的创业教育模型研究

基于目前大学生创业教育研究成果,引入优势/劣势/机会/威胁(SWOT)分析理论,分析当今大学生创业教育的重要性和必要性;运用价值链理论,分析我国高等创业教育的竞争力,为我国大学生创业教育改革提出有实用价值的建议;并在对大学生创新链条进行改造的基础上提出环形创新链.     

基于自适应遗传算法的虚拟企业伙伴选择求解

针对虚拟企业合作伙伴的选择问题,根据虚拟企业的市场目标,采用层次分析算法确定评价因子的权重,然后建立多目标的虚拟企业伙伴选择优化模型.为简化模型,以最短的完工时间、最低的成本和最高的信誉度为目标.在遗传过程中对各个单目标进行排序选择,通过对交叉、变异算子进行自适应改进,采用最优保存策略迭代求出最佳合作伙伴及分配的具体工作量.通过与普通遗传算法的对比,仿真算例验证了改进后的算法的优越性.     

A hybrid supervisory control approach for virtual production systems

With the development of computer technology, the anticipated extensive use of virtual production systems (VPSs) in the future has encouraged its intensive research recently. However, a limited amount of research has been made on its efficient control. In this paper, a hybrid supervisory control approach based on autonomy and coordination is proposed for VPSs to enhance the efficiency of control. Its three primary advantages are: (1) application of supervisory control theory, which can efficiently obtain the desired property through closed-loop feedback; (2) use of hybrid control structure combining hierarchical and distributed ones, which can avoid the exponential explosion of state space due to synthesis of models; and (3) utilization of autonomous and coordination mechanisms, which can keep the balance of local quick response and global optimization. A case study is used to illustrate how to implement the proposed approach, and is finally analyzed and simulated by an integrated tool named UPPAAL.     

基于CIMOSA的虚拟企业多维建模方法研究

虚拟企业建模是虚拟企业组建与运营的重要步骤.虚拟企业建模主要涉及虚拟企业组建时合作伙伴选择的建模和企业构成与运营过程的建模.阐述了虚拟企业从组建到解散的一般过程,从虚拟企业建模原则的角度,分析了CIMOSA建模规范在企业建模中的作用,提出了基于CIMOSA的虚拟企业建模方法.     

敏捷虚拟企业环境下伙伴企业产品过程再设计

在敏捷虚拟企业环境下,怎样根据联盟的需要对伙伴企业的产品过程进行重新设计是关系到敏捷虚拟企业实施成败的关键。本文建立了敏捷虚拟企业产品过程设计的基本框架,给出了进行过程再设计的核心过程确定方法,并提出了一些进行过程结构优化的方法。     

A reverse engineering approach to generate a virtual plant model for PLC simulation

A reverse engineering approach to generate a virtual plant model is proposed. The model can be used for programmable logical controller (PLC) simulation. The virtual plant model for the PLC simulation consists of virtual device models and must interact with the input and output signals of a PLC. The behavior of a virtual device model should be the same as that of real device. Conventionally, the discrete event system specifications (DEVS) formalism has been used to represent the behavior of a virtual device model. Modeling using DEVS formalism, however, requires in-depth knowledge of the simulation area, as well as a significant amount of time and effort. One of the key ideas of the proposed methodology is to provide a method to generate a virtual plant model using both log data (time-stamped signal history) and a PLC I/O signal table extracted from the existing production system. The proposed reverse engineering approach provides two major benefits: (1) significant reduction in the time and effort for the construction of a reliable virtual plant model of a current production system, which can be referenced for newly planned production systems, and (2) reduction in the stabilization time of a production system through PLC simulation. The proposed approach was implemented and applied to an automated production line.     

基于信任的虚拟企业伙伴选择模型构建及仿真

针对现有虚拟企业伙伴选择研究以时间、成本、风险等定量指标为准则,优化伙伴选择过程,但未考虑信任这一重要协作因素的缺陷,结合虚拟企业特征,给出能力、动机、持续性三个维度的指标体系;采用模糊认知图理论,设计了实时编码遗传算法和非线性Hebbian学习算法,构建了基于信任的虚拟企业伙伴选择模型;对模型及算法进行了仿真实验。实验表明,模型结果与历史数据拟合较好,具有较好的有效性和可行性。