动态进化导向的系统分析与设计

信息系统的动态进化是其适应IT发展、组织业务和环境变化需求的一种重要能力,特别是在实时系统和分布式系统当中,正引起学者的广泛关注和深入研究。综述了相关领域的研究成果,并提出用系统化的建模方法,从信息系统动态进化的行为连续性、触发机制、系统化的抽象层次三个角度来研究信息系统的动态进化。这一系列的信息系统动态进化理论和提出的系统建模方法、建议的工具、系统构架构成了一定的动态进化导向的信息系统分析和设计的方法论,推动当前相关领域的理论研究和实践探索。     

Formality Considered Harmful: Experiences, Emerging Themes, and Directions on the Use of Formal Representations in Interactive Systems

This paper reflects on experiences designing, developing, and working with users of a variety of interactive computer systems. The authors propose, based on these experiences, that the cause of a number of unexpected difficulties in human-computer interaction lies in users' unwillingness or inability to make structure, content, or procedures explicit. Besides recounting experiences with system use, this paper discusses why users reject or circumvent formalisms which require such explicit expression, and suggests how system designers can anticipate and compensate for problems users have in making implicit aspects of their tasks explicit. The authors propose computational approaches that address this problem, including incremental and system-assisted formalization mechanisms and methods for recognizing and using undeclared structure; they also propose non-computational solutions that involve designers and users reaching a shared understanding of the task situation and the methods that motivate the formalisms. This paper poses that, while it is impossible to remove all formalisms from computing systems, system designers need to match the level of formal expression entailed with the goals and situation of the users -- a design criteria not commonly mentioned in current interface design.     

冶金冷轧薄板企业生产计划调度体系结构及方法研究

本文在三层企业集成模型的基础上,针对冷轧薄板企业的产品、经营、生产及设备等特点,提出了冷轧薄板企业的多级计划与调度体系结构,并引入了以生产线控制机制为核心的企业经营生产全过程闭环优化集成模式.同时还对企业生产组织中的各级优化问题及方法进行了全面的分类研究,为进一步的研究和冷轧薄板企业集成应用系统的开发奠定了基础.􀁽     

Modeling, Analysis, and Optimal Control of a Class of Hybrid Systems

We propose a modeling framework for a class of hybrid systems which arise in many manufacturing environments and study related optimal control problems. In this framework, discrete entities have a state characterized by a temporal component whose evolution is described by event-driven dynamics, and a physical component whose evolution is described by time-driven dynamics. As a first step towards developing an optimal control theory for such hybrid systems, we formulate a problem consisting of a single-stage manufacturing process and use calculus of variations techniques to obtain structural properties and an explicit algorithm for deriving optimal policies.     

支持动态变型设计的多领域系统知识建模与推理求解

基于Modelica语言的多领域系统建模关注物理建模和参数优化等问题,缺乏对产品变型设计的支持.通过扩展多领域基本仿真模型,提出一种结构待定和参数待定的变型产品结构模型.该模型按照参数约束、部件约束和模型约束等知识表达规范融入产品设计知识和经验,采用推理机推理确定产品的结构和参数,实现了基于仿真的动态变型设计.最后以实例验证了动态变型设计方法的实用价值.     

Specifications in Context: Stakeholders, Systems and Modelling of Conflict

This paper looks from an ethnographic viewpoint at the case of two information systems in a multinational engineering consultancy. It proposes using the rich findings from ethnographic analysis during requirements discovery. The paper shows how context – organisational and social – can be taken into account during an information system development process. Socio-technical approaches are holistic in nature and provide opportunities to produce information systems utilising social science insights, computer science technical competence and psychological approaches. These approaches provide fact-finding methods that are appropriate to system participants’ and organisational stakeholders’ needs.  The paper recommends a method of modelling that results in a computerised information system data model that reflects the conflicting and competing data and multiple perspectives of participants and stakeholders, and that improves interactivity and conflict management.     

Analysis, design, and development model: a case study of an internet-based system for insert and parameter selection

Abstract. The analysis, design, and development model (ADDM) is based on the systems lifecycle process (SLCP) in which analysts begin to understand external client requirements and internal client specifications as they are designing and developing a complex system. In the ADDM, clients and system analysts (SA) continuously interact as the system is being designed, developed, tested and maintained. In the design phase, system development can be altered when it is most cost‐effective. Depending on the type of environment and SA preference and expertise, various interfaces and software and hardware configurations are created during the SLCP. The SLCP ensures effective standardization and continuous quality improvements throughout development. The model follows modern information technology principles to integrate and monitor SLCP phases. A case is presented that describes an application of the ADDM. This case outlines the architecture of an e‐commerce production system (ECPS). The system has a three‐tier structure consisting of the client interface, Java server page (JSP) and database module. The model assists in designing economic production operations in an industrial setting by allowing a client to retrieve current production data needed for operations through the internet.     

Stability Analysis,Chaos Control of Fractional Order Vallis and El-Nino Systems and Their Synchronization

In this article the authors have studied the stability analysis and chaos control of the fractional order Vallis and El-Nino systems. The chaos control of these systems is studied using nonlinear control method with the help of a new lemma for Caputo derivative and Lyapunov stability theory. The synchronization between the systems for different fractional order cases and numerical simulation through graphical plots for different particular cases clearly exhibit that the method is easy to implement and reliable for synchronization of fractional order chaotic systems. The comparison of time of synchronization when the systems pair approaches from standard order to fractional order is the key feature of the article.      

Analysis of Over- and Underdetermined Nonlinear Differential-Algebraic Systems with Application to Nonlinear Control Problems

 We study over- and underdetermined systems of nonlinear differential-algebraic equations. Such equations arise in many applications in circuit and multibody system simulation, in particular when automatic model generation is used, or in the analysis and solution of control problems in the behavior framework.?We give a general (local) existence and uniqueness theory and apply the results to analyze when nonlinear implicit control problems can be made regular by state or output feedback.?The theoretical analysis also leads immediately to numerical methods for the simulation as well as the construction of regularizing feedbacks. Date received: February 21, 2000. Date revised: November 14, 2000.