An expert system for preliminary numerical design modelling

This paper is based upon the premise that computers can do more than just ‘number crunching’ to assist a designer in his task. Key features of the design process where traditional computer-aided design (CAD) approaches have had limited success are presented. The approach of expert systems, which shows promise of assisting in these features, is outlined and a system based on this approach, DESIGNER, described. This system can be applied to any numerical design problem and is illustrated through an example from preliminary ship design.     

基于产生式知识表示的铝用炭素煅烧过程专家控制系统的设计

将基于知识的规则模型和解析的数学模型相结合,建立两级结构的实时专家控制系统(ECS)。由具有专家自学习和自适应功能的实时专家系统(ES),以专家优化方式寻找煅烧过程中煅烧带的最优温度、长度和位置,由实时控制系统(RTCS)采用基于CARMA模型和最小二乘法的自校正调节算法和经典PID算法分别进行给料量和负压的控制,保证生产过程在最优生产条件下进行。系统于2003年底正式投入运行,长期运行结果表明系统可靠性高、实用性好,既稳定了生产,又提高了产品质量,实现了节能。     

CAQFD概念设计专家系统模式的研究

质量功能配置(QFD）对满足用户需求的产品概念设计提供了一种切实可行的方法。探讨了计算机辅助QFD概念设计专家系统的设计模型和计算机实现的关键技术。对用户需求信息的获取方法进行了研究,构建了用户需求知识表达的拓扑结构。从知识工程的角度,提出了基于数据库的知识表达模式和推理方式,设计了专家系统的知识推理过程。最后以高速专用磨床的主轴前支承轴承的概念设计为例,进行了系统的应用验证,取得了满意的效果。     

产品设计专家系统研究

介绍了产品设计的目的和任务,信息时代的产品设计发展状况及存在的问题,讨论了将人工智能理论与专家系统技术应用于产品设计领域,提出一个产品设计专家系统的框架结构.利用智能代理技术实现了信息与资料的整理,依据形态分析法实现了辅助创新设计,并提出采用数学建模法进行产品方案的评定.     

Issues in expert system development

The explicit representation of domain knowledge and its separation from the processes which manipulate it and the representation formalism particular to artificial intelligence allow expert systems to solve problems which are characterized by a high combinatoric complexity or which are sufficiently ill defined as to not have reasonable software engineering solutions. The expert system approach to problem-solving differs radically from its conventional system development counterpart. This paper defines the expert system and introduces the production system architecture. The relative strengths and weakenesses of expert system and software engineering approaches to problem solving are discussed. Also addressed are criteria for identifying problems amenable to expert system solution and some justifications for system development.Paper presented at the Ninth International Thermal Expansion Symposium, December 8–10, 1986, Pittsburgh, Pennsylvania, U.S.A.     

An optimal layout of container yards

This study presents a method for designing the layout of container yards where transfer cranes and yard trucks are used for stacking containers in the yard and delivering them between the yard and the quay. A method to determine the layout type, the outline of the yard, and the numbers of vertical and horizontal aisles is suggested. For estimating the effects of the design variables on operational cost terms, formulas for estimating the number of relocations by yard cranes and the expected travel distance of trucks are derived. Numerical examples are provided to illustrate the design procedure. It was also shown that the layout in which blocks are laid out parallel to the side with the gate or the quay outperforms that in which blocks are laid out perpendicular to the side with the gate or the quay.     

专家系统中知识库与工艺曲线动态修改的研究

知识库构建的适当与否直接关系到专家系统的推理效率和使用情况。本文介绍了精密复杂刀具真空热处理专家系统中知识的表示和知识库的构建;总结了影响真空热处理工艺参数的因素,以专家知识的形式存储在知识库中,奠定了坚实的数据基础;论述推理模块的工艺曲线动态修改功能,并给出了精密复杂刀具真空热处理专家系统的具体实例。     

面向创新设计的专题知识库构建与应用

产品创新设计需要大量知识的支持,针对产品设计过程对于产品专题知识的需求,提出了一种面向产品专题设计的知识库构建及应用方法.通过分析专题知识在设计过程中的作用,建立了专题知识的结构与表示方法,设计了一种混合式知识检索模型,并在此基础上开发了面向特定产品的专题知识库原型系统,从而有效辅助设计人员开展产品创新设计.以数控压力机离合器为例验证了该方法和系统的有效性.     

板式阀-插装阀混合的复杂集成块元件布局设计

液压集成块外部元件布局设计与内部油路连通设计的强耦合效应是妨碍其实现自动设计的核心问题.系统归纳总结了2类元件布局经验知识,即隐含于各类标准、技术规范与大量工程实例中文档化设计知识,以及专家在长期工程实践中积累的经验知识.在此基础上提出了一种基于知识和规则推理的板式阀-插装阀混用的液压集成块元件布局设计方法.由于布局经验知识与规则综合考虑了后续油路路径规划,元件的安装、调试与维护等方面的需求,因此极大降低了集成块设计的复杂程度.该方法与虚拟设计技术或智能优化算法相结合,为液压集成块的智能优化设计提供了一条有效途径.     

异形盒交互设计系统的研究

从立体构成原理出发对异形盒设计进行了分析,提出了以纸面为对象的立体构成原理进行异形盒设计的方法,从而使异形盒设计有规律可循,开发了异形盒交互系统的设计,就交互系统的功能框架、系统的设计流程、系统的操作界面等作了分析,并以实例证明了系统的实用性。     

Polyoptimal design of sandwich cylindrical panels with the application of an expert system

Thin-walled sandwich structures have become extremely useful because of their high strength-to-mass and stiffness-to-mass ratios. The results of the bicriteria optimization of thin-walled sandwich cylindrical panels under combined loads are presented in this article. Panel mass and panel deformability are two objective functions, where panel deformability is defined with the help of bending rigidity. A set of constraints includes stability and stress conditions, a constraint connected with the importance of applied theoretical models, and technological and constructional requirements. The optimization problem was solved using the Pareto concept of optimality and application of the OPTIKON computer program, which implements elements of an expert system. The OPTIKON program was designed to solve multicriteria optimization problems for non-linear engineering models with discrete and continuous sets of design variables. The results of numerical calculations are presented as tables and diagrams.     

The constraints satisfaction problem approach in the design of an architectural functional layout

A design support system with a new strategy for finding the optimal functional configurations of rooms for architectural layouts is presented. A set of configurations satisfying given constraints is generated and ranked according to multiple objectives. The method can be applied to problems in architectural practice, urban or graphic design—wherever allocation of related geometrical elements of known shape is optimized. Although the methodology is shown using simplified examples—a single story residential building with two apartments each having two rooms—the results resemble realistic functional layouts. One example of a practical size problem of a layout of three apartments with a total of 20 rooms is demonstrated, where the generated solution can be used as a base for a realistic architectural blueprint. The discretization of design space is discussed, followed by application of a backtrack search algorithm used for generating a set of potentially ‘good’ room configurations. Next the solutions are classified by a machine learning method (FFN) as ‘proper’ or ‘improper’ according to the internal communication criteria. Examples of interactive ranking of the ‘proper’ configurations according to multiple criteria and choosing ‘the best’ ones are presented. The proposed framework is general and universal—the criteria, parameters and weights can be individually defined by a user and the search algorithm can be adjusted to a specific problem.     

Optimization of the process variables of roller compaction,on the basis of granules characteristics (flow,mechanical strength,and disintegration behavior): an application of SeDeM-ODT expert system

The objective of the study was application of SeDeM-ODT expert system for optimization of process variables for roller compaction and for the preparation of granules with better flow, compressibility, and disintegration behavior. In the present study, granules were prepared at pre-determined (on the basis of factorial design) process variables and characterized using SeDeM-ODT expert system. Compatibility of ribavirin with excipients (microcrystalline cellulose, tablettose-80, cross carmellose sodium, and magnesium stearate) was evaluated by binary mixture approach, using FTIR. According to the SeDeM-ODT expert system, granules were characterized for various parameters related to flow, compressibility and disintegration behavior and Index of Good Compressibility and Buccodispersibility (IGCB) was calculated. The process variables resulting in highest IGCB value were considered as optimum. Ribavirin was found compatible with all the excipients used in the study and characteristics peaks were present in FTIR spectra after subjecting to stress conditions (75% relative humidity at 45?±?5?°C) for 30?days. Both Ribavirin powder and Ribavirin containing powder blend had poor flow and compressibility while disintegration behavior was good due to higher water solubility. Screw speed of 35?rpm and roller speed at 12?rpm resulted in granules with acceptable characteristics. The IGCB value (5.63) of the granules was highest of all, indicating its better characteristics. SeDeM-ODT expert system presents a more practical picture of the granules and also predicts the mechanical strength and disintegration behavior of the tablets prepared from the granules. By proper optimization of screw and roller speed, efficiency of the process can be improved.     

Integrated layout design of multi‐component system

A new integrated layout optimization method is proposed here for the design of multi‐component systems. By introducing movable components into the design domain, the components layout and the supporting structural topology are optimized simultaneously. The developed design procedure mainly consists of three parts: (i) Introduction of non‐overlap constraints between components. The finite circle method (FCM) is used to avoid the components overlaps and also overlaps between components and the design domain boundaries. (ii) Layout optimization of the components and supporting structure. Locations and orientations of the components are assumed as geometrical design variables for the optimal placement while topology design variables of the supporting structure are defined by the density points. Meanwhile, embedded meshing techniques are developed to take into account the finite element mesh change caused by the component movements. (iii) Consistent material interpolation scheme between element stiffness and inertial load. The commonly used solid isotropic material with penalization model is improved to avoid the singularity of localized deformation in the presence of design dependent loading when the element stiffness and the involved inertial load are weakened by the element material removal. Finally, to validate the proposed design procedure, a variety of multi‐component system layout design problems are tested and solved on account of inertia loads and gravity center position constraint. Solutions are compared with traditional topology designs without component. Copyright © 2008 John Wiley & Sons, Ltd.     

舰艇武器布置问题的一种协同优化算法

针对舰艇武器布置问题的特点，提出了一种基于粒子群优化和分类器系统的协同优化算法，以粒子群优化进行优化计算，用分类器系统消除约束．计算实例表明，该算法能较好地实现优化计算，并能节省大量的计算时间．     

一种用于功率IC中高性能PNP管的版图设计

在对传统横向PNP管版图和晶体管寄生效应分析的基础上,提出了一种基于双极工艺的横向PNP管设计方案,并给出了一个适用于功率集成电路中高性能横向PNP输出管的版图设计.     

Advances in discrete material handling system design

The paper presents an outline of the research done in the area of facility layout and discrete material handling system design. The objective of this paper is to observe the trend in the literature in the area of manufacturing system design and predict the direction of future research in this area. The paper attempts to link the areas of facility layout design and material flow network design. A methodology for solving the integrated design problem is presented. An algorithm which aids in solving the combined pick-up/drop-off point location and material handling flowpath problem is outlined.