Modelling biological behaviours with the unified modelling language: an immunological case study and critique

We present a framework to assist the diagrammatic modelling of complex biological systems using the unified modelling language (UML). The framework comprises three levels of modelling, ranging in scope from the dynamics of individual model entities to system-level emergent properties. By way of an immunological case study of the mouse disease experimental autoimmune encephalomyelitis, we show how the framework can be used to produce models that capture and communicate the biological system, detailing how biological entities, interactions and behaviours lead to higher-level emergent properties observed in the real world. We demonstrate how the UML can be successfully applied within our framework, and provide a critique of UML''s ability to capture concepts fundamental to immunology and biology more generally. We show how specialized, well-explained diagrams with less formal semantics can be used where no suitable UML formalism exists. We highlight UML''s lack of expressive ability concerning cyclic feedbacks in cellular networks, and the compounding concurrency arising from huge numbers of stochastic, interacting agents. To compensate for this, we propose several additional relationships for expressing these concepts in UML''s activity diagram. We also demonstrate the ambiguous nature of class diagrams when applied to complex biology, and question their utility in modelling such dynamic systems. Models created through our framework are non-executable, and expressly free of simulation implementation concerns. They are a valuable complement and precursor to simulation specifications and implementations, focusing purely on thoroughly exploring the biology, recording hypotheses and assumptions, and serve as a communication medium detailing exactly how a simulation relates to the real biology.     

Using Scrum and unified modelling language to analyze and design an automatic course scheduling system

This research used a case study methodology to examine large-scale software projects accomplished despite ambiguous customer requirements. This study adopted Scrum as the agile software development method and used unified modelling language (UML) diagrams to enhance design implementation documents and improve the software development process. This study presented how the case company explored a Scrum-based automatic course scheduling system for elementary and secondary schools. Through interviews, the case company incorporated customers’ requirements by using the corresponding UML diagrams, which helped the project team document the software development process and design the functions to satisfy customer demand. Then, the proposed method was introduced to the automatic elementary and secondary school course scheduling system project undertaken by the case company, verifying the feasibility of the proposed method. A few problems arose in the proposed software development process, and remedies were discussed. Software companies could use these results as a reference when implementing a large-scale software project with ambiguous customer requirements.     

Modelling process platforms based on an object-oriented visual diagrammatic modelling language

Process platforms have been recognised as a promising means of dealing with product variety while achieving a near mass production efficiency. To assist practitioners to better understand, implement and use process platforms, this study addresses the underlying logic for coping with the challenges in high variety production by adopting process platforms. Accordingly, this paper proposes to model process platforms with focus on the application processes. In view of the significance of dynamic modelling and visualisation in shedding light on the logic of any processes, this study introduces a visual diagrammatic modelling language based on object-oriented (OO) techniques, named as OOVDML. With the graphical notations, uniquely shaped symbols, syntax and semantics, control mechanisms and arrangement rules, the OOVDML not only captures the logic of process platform's application but also provides a visualisation of their behaviours in a holistic view. Moreover, incorporating OO modelling allows readers to focus on their own interests. This study approaches to modelling process platform's application with respect to activities pertaining to customer order processing, engineering change control and production job planning. An industrial example of electronics products is also reported. The results of the case study not only show the suitability of the OOVDML but also shed light on the dynamic behaviours of process platforms.     

Managing distributed manufacturing knowledge through multi-perspective modelling for semantic web applications

The development and maintenance of semantic web (SW) means that collaborative manufacturing systems are faced with increasing challenges caused by the growing difficulty in managing distributed manufacturing knowledge. This paper presents a multi-perspective modelling approach to systematically manage distributed manufacturing knowledge on the SW. Considering knowledge engineering as a cyclic and constructive modelling process, a multi-perspective knowledge modelling process is proposed to evolve along knowledge elicitation, engineering modelling, UML-based object modelling, OWL-based ontology modelling, knowledge formalisation and OWL-QL assisted knowledge verification activities. The proposed approach is viewed as a promising knowledge management method that facilitates the implementation of computer supported cooperative work (CSCW) in distributed manufacturing for SW applications by integrating the industrial, UML enabled software engineering techniques into recent ontology-based knowledge engineering process. The feasibility of knowledge management through multi-perspective modelling is manifested using the manufacturing ontology for manufacturing electronic connectors.     

Modelling competence-based virtual organisations using the unified enterprise competence modelling language

Virtual organisations are non-conventional structures aiming at sharing the same goals, developing common practices or creating wealth in a collaborative manner. Accordingly, competence issues are important topics to be addressed in order to ensure coherence between the different objectives of entities taking part in a virtual organisation to guarantee an efficient use of available resources. This paper introduces the principles for modelling competence-based virtual organisations by using a uni?ed enterprise competence modelling language (UECML). Our proposed modelling approach is inspired from previous related works mainly in competence-based enterprise modelling. The language provides a neutral interface to virtual organisation modelling based on competences, taking into account the several roles and entities participating in a virtual organisation. Therefore, providing constructs covering processes, resources, competences, and virtual organisation (VO) entities. A case study of the Swiss virtual network Virtuelle Fabrik with regards to the project Abfallhai is presented and discussed, showing how the developed modelling language is adapted to model virtual organisations.     

基于基因调优算子的产品平台进化设计研究

市场的发展和技术的进步使得产品平台的衍生产品对需求的匹配度降低,产品竞争力下降。为了维持平台先进性,需适时对平台进行进化。从平台架构和平台元素两个角度,定义了平台DNA和平台基因,提出了实现平台进化的重组、变异、替换、删除、增添五种基因调优算子,构建了基于这5种算子的产品平台进化模型,以平台模块和模块特性的调整优化为手段,形成了具有可实施性和可操作性的平台进化方法。最后应用该方法指导了一种冲压机械手产品平台的进化,验证了该理论的可行性。     

A graphic language based on timing diagrams

We present a new graphic language which can serve, for instance, as models for VLSI and control systems. Its primitives are based on standard timing diagrams, and this is a great advantage over other formalisms since designers can rapidly master it. The semantics is rigorously defined in the formalism of the theory of automata on infinite words. Using this formalism, we are able to give a rather precise upper-bound on the expressive power of our graphic language in terms of a language theoretic measure, theconcatenation level. A detailed example is presented.     

基于优化的产品平台参数规划方法

 为满足客户化和全球竞争的需求,企业要实现大规模定制(mass customization,MC).基于公共产品平台的产品族设计是实现大规模定制的一种有效方式,而平台规划是面向产品族设计方法学的核心内容,也是目前研究中的一个热点问题.基于模型参数的平台设计是其方法之一.针对基于一系列标准可变参数的产品平台,用优化方法对产品平台参数进行规划,以满足各种客户需求.该规划方法无需事先人为指定,而是在满足客户需求的前提下,尽可能提高产品族中设计变量的共性,从而确定最好的产品平台的公共参数及其最优值,以及个性参数及其变化值,并以带式输送机为例验证了该方法.     

基于物理规划的 Stewart 平台多目标优化

应用物理规划方法对500米口径球面射电望远镜(FAST)精调 Stewart 平台进行了多目标优化设计.根据 Stewart 平台的设计准则,将 Stewart 平台的运动精度、重量和工作效率作为目标函数,构造了相应的以目标函数为变量的偏好函数,建立了基于物理规划的多目标优化模型,采用遗传算法对该优化问题进行求解.结果表明,物理规划避免了基于权重的多目标优化方法中权系数难以确定的问题,有效地给出了优化问题的 Pareto 解.     

基于用户模型的产品创新设计服务平台框架

 鉴于目前产品创新设计服务平台的设计用户类型众多、资源形式复杂,不同用户要快速、准确地获取其所需信息比较困难,提出了一种基于用户模型的产品创新设计服务平台框架并实现了相应系统的开发．通过建立基于本体的用户模型以获取用户兴趣,为平台用户提供3种方式获取不同用户的兴趣．基于用户模型构建了包括用户层、应用服务层、个性化操作层及资源层四个层面的平台架构,并为用户提供基于用户需求的特定服务流程,从而能够辅助用户有效获取所需信息,实现对用户设计过程的支持．     

基于LabVIEW的反力式滚筒制动试验台仿真研究

为有效评价反力式滚筒制动试验台的检测性能,该文在建立反力式滚筒制动试验台力学模型的基础上,使用LabVIEW软件对其制动检测过程进行仿真,并通过与实车制动检测试验所得数据的对比,验证该仿真的准确性。通过对台体参数的输入,可反映不同参数制动试验台的使用性能,以验证产品设计或结构优化的效果。     

A framework for fracture modelling based on the material forces concept with XFEM kinematics

A theoretical and computational framework which covers both linear and non‐linear fracture behaviour is presented. As a basis for the formulation, we use the material forces concept due to the close relation between on one hand the Eshelby energy–momentum tensor and on the other hand material defects like cracks and material inhomogeneities. By separating the discontinuous displacement from the continuous counterpart in line with the eXtended finite element method (XFEM), we are able to formulate the weak equilibrium in two coupled problems representing the total deformation. However, in contrast to standard XFEM, where the direct motion discontinuity is used to model the crack, we rather formulate an inverse motion discontinuity to model crack development. The resulting formulation thus couples the continuous direct motion to the inverse discontinuous motion, which may be used to simulate linear as well as non‐linear fracture in one and the same formulation. In fact, the linear fracture formulation can be retrieved from the non‐linear cohesive zone formulation simply by confining the cohesive zone to the crack tip. These features are clarified in the two numerical examples which conclude the paper. Copyright © 2005 John Wiley & Sons, Ltd.     

基于LabVIEW平台的信号实时采集与处理系统

基于Lab VIEW平台的信号实时采集与处理系统,相对于传统的基于Visual C++或Vx Works的系统,具有软件开发和修改快捷、可快速实现数据可视化、与通用平台或设备接口方便等优点,使科研人员能够将主要精力集中于实验而非编程。介绍了一种基于Lab VIEW平台的信号实时采集与处理系统。首先介绍了该系统的硬件组成和软件设计方法,之后详细介绍了将不同厂商的硬件板卡集成到Lab VIEW平台上,并由Lab VIEW统一控制的方法——生成动态链接库。该系统已成功应用于某型水声装备的效能评估试验中。     

Variation propagation modelling for multi-station machining processes with fixtures based on locating surfaces

Modelling the dimensional variation propagation in multi-station machining processes (MMPs) has been studied intensively in the past decade to understand and reduce the variation of product quality characteristics. Among others, the Stream-of-Variation (SoV) model has been successfully applied in a variety of applications, such as fault diagnosis, process planning and process-oriented tolerancing. However, the current SoV model is limited to the MMPs where only fixtures with punctual locators are applied. Other types of fixtures, such as those based on locating surfaces, have not been investigated. In this paper, the derivation of the SoV model is extended to model the effect of fixture- and datum-induced variations when fixtures with locating surfaces are applied. Due to the hyperstatic nature of these fixtures, different workholding configurations can be adopted. This will increase the dimension of the SoV model exponentially and thus may make the model-based part quality prediction extremely complex. This paper presents a method of reducing the complexity of the SoV model when fixtures based on locating surfaces are applied and evaluates the worst-case approach of the resulting part quality.     

基于运动平台的海底混响建模与仿真

混响是主动声呐目标检测的主要干扰,混响的建模与仿真对研究水下信号处理具有重要的意义。以海底混响为研究对象,综合考虑发射信号的波形、海底散射体散射特性以及运动平台带来的多普勒频移等影响因素,提出了一种基于运动平台的海底混响仿真方法。该方法同时结合了散射原理与网络模型,具有明确的物理意义,且其仿真实现方法简单高效。最后,通过分析混响仿真信号的瞬时值、包络的概率分布、频谱特性以及时间相关性,验证了该方法对海底混响仿真的有效性。     

A reconfigurable platform in support of one-of-a-kind product development

In recent years, a variety of Internet-based systems has been developed for the purpose of Rapid One-of-a-Kind or customized Product Development (ROKPD). They can be applied in different stages of the product development process such as to rapidly capture customer requirements, and help produce high-quality products at low cost and short lead-time. Many of the systems, however, do not support rapid adaptation or dynamic reconfiguration of systems and tools for supporting ROKPD in a distributed manufacturing environment. To the authors’ knowledge, the infrastructure of such a reconfigurable platform for supporting distributed manufacturing has never been directly studied. This paper proposes an Internet-based reconfigurable ROKP platform that has been prototyped to serve as a substrate for integrating innovative tools and systems for One-of-a-Kind Production (OKP) companies in New Zealand. The main emphasis of this paper is to investigate how to build the Internet-based reconfigurable ROKPD platform and to design appropriate intelligent tools and systems for the purpose of rapidly and economically producing OKP products in the global environment. A number of recent developments are discussed, including the four open-domain infrastructure of the ROKPD platform, Internet-based data management systems, an integrated product data environment and a cost/lead time control tool.     

An implicit unitless error and step‐size control method in integrating unified viscoplastic/creep ODE‐type constitutive equations

A series of numerical analyses are carried out to investigate the difficulties in numerical integration of unified viscoplastic/creep constitutive equations, which are normally represented as a system of ordinary differential equations (ODEs). The problems of numerically integrating the constitutive equations are identified and analysed. To overcome the stiffness problems, implicit methods are used for the numerical integration and a generic technique is introduced to calculate the Jacobian matrix. A normalization technique is introduced in the paper to convert the integration errors for each time increment to unitless errors. Thus, a single tolerance can be used to control the accuracy and step size in integrating a set of unified viscoplastic/creep constitutive equations. In addition, an implicit step‐size control method is proposed and used in the integrations. This method reduces the possibility of rejection of an integration increment due to poor accuracy. Copyright © 2007 John Wiley & Sons, Ltd.     

Potential field based geometric modelling using the method of fundamental solutions

We propose a new geometric modelling method based on the so‐called potential field (PF) modelling technique. The harmonic problem associated with this technique is solved numerically using the method of fundamental solutions (MFS). We investigate the applicability of the proposed approach to parametrically defined curves of varying complexity. Based on the MFS, we also provide definitions of the Boolean operations associated with the geometric modelling. Finally, we give practical applications of the method to computer‐aided design and manufacturing problems. Copyright © 2006 John Wiley & Sons, Ltd.     

基于Web服务的PDC钻头井底流场分析平台研究

为解决常规PDC(polycrystalline diamond compact)钻头井底流场水力性能数值模拟分析时存在的门槛高、耗时长、重复工作量多等问题,建立了基于Web服务的PDC钻头井底流场分析平台。平台框架由上至下分为软件接口层、分析服务层和结果输出层。在服务端通过知识封装技术实现钻头井底流场分析过程的自动化、参数化和集成化;利用Web封装技术对参数化流场分析模板进行封装和管理,从而实现客户端基于Web服务的PDC钻头井底流场的分析研究。实例验证表明,采用该平台分析PDC钻头水力性能可有效降低CFD软件的使用门槛,提高钻头井底流场的分析效率,节约人力与物力,能够为石油装备企业提供规范化的技术支持。