面向结构化布局设计的产品布局多色模型

为实现产品原理方案向结构化布局映射,提出产品布局元层次关系网及产品布局多色模型.首先在布局模块及其属性关系网的基础上构建布局元层次关系网;然后应用多色集合的个人颜色、统一颜色,给出产品布局元层次关系网的数学描述,形成产品布局多色模型,并提出推理算法;再利用个人颜色、统一颜色之间的围道布尔矩阵推理原理,进行产品结构布局设计过程中功能—运动分配—布局模块之间映射过程的形式化描述.应用该模型进行结构化布局设计,可有效地支持产品结构布局设计的公理化;最后在Pro/E平台中利用VC.net 2003工具进行二次开发,并以数控机床结构布局设计为例验证了文中模型和设计方法的可行性和有效性.     

Local Search Algorithms for the Maximal Planar Layout Problem

The problem of laying out facilities is practically important in a modern manufacturing environment. This problem can be formulated as a weighted maximal planar graph in which vertices represent facilities and edge weights represent desirability measures between facilities. The objective is to find a planar graph that can be drawn on a plane without any edges intersecting with the highest sum of edge weights. Exact solution method can only solve small sized problems. In this paper, local search algorithms based on steepest ascent, hybrid simulated annealing and tabu search with a non-monotonic cooling schedule, and tabu search with a hashing function are developed to obtain near-optimal solutions. Different search strategies are investigated. All the developed algorithms are compared with existing construction methods and a branch and bound exact algorithm on a set of practical size problems. The proposed algorithms performed very well in terms of solution quality and computation time.     

自动布局布线及验证研究

介绍了在超大规模集成电路版图设计过程中,布局布线时电源、时钟、总线和信号线的布线要点,针对电源的布局设计和时钟网络的设计进行重点讨论;同时讨论了几何设计规则检查、电学设计规则检查和版图/电路图网表匹配检查三种版图验证手段。     

一种改进遗传算法在生产车间设备布局中的应用

生产系统的设备布局设计是一个组合优化的问题。具有非线性,N P难等特性,常规方法较难以求解。文章通过创建生产系统设备布局的数学优化模型。引入了小生境技术,保持了种群的多样性。并且利用精英选择机制,自适应交叉和变异概率等手段,在使种群保持多样化的同时,增强了算法的全局和局部搜索能力,协调了遗传算法大范围粗糙搜索和小范围精细搜索之间的平衡,有效改善了早熟和过早收敛问题,并通过实例验证了其有效性。     

Container spaces and functional features for top-down 3D layout design

Although there have been many advances in computer-aided modelling techniques and representations of mechanical parts, there are areas where exact modelling is a handicap. One of these is 3D layout design. Here, simpler models are useful for initial design sketches to verify kinematic behaviour and organise product structure before the detailed component design phase begins. A commitment to exact, or close approximational geometry too early can imply a commitment to form before functionality has been finalised. This paper describes a system for top-down 3D layout design based on simple conceptual elements which can be used as a basis for visualisation, discussion, definition of product structure and kinematic functionality in the conceptual design phase before the embodiment or detailing begins. This tool forms a bridge between the abstract nature of the conceptual design phase and the geometric nature of the embodiment phase. The 3D layout module uses design spaces with simple geometry and kinematic connections to represent a product. The design spaces act as containers or envelopes within which the final component design is to be realised. The kinematic connections allow the behaviour of the product to be simulated to gain more information (such as overall component dimensions and areas of potential collisions) for the detailed design phase. In addition the paper describes the design process based on the proposed 3D layout design system and contrasts this with the traditional design process. An industrial case study is presented to illustrate the following advantages of the proposed approach: (i) the design process proceeds faster because unnecessary layout parameter and constraint modifications are avoided since kinematic functionality verification precedes the detail design, (ii) the design process can produce better designs since alternative solution principles can be explored early in the design process. Theoretical issues are discussed concerning kinematic constraint inheritance during design space decomposition and concerning computer support for non-rigid design spaces.     

SLP和遗传算法结合在车间设备布局中的应用

用经典的系统布置设计结合遗传算法求解车间设备布局,以高效率获得满意的设计结果,弥补传统SLP设计过程中手工操作的繁琐迭代、易受主观影响、结果不稳定等缺点。并且通过对遗传算法的改进,增强了算法的全局和局部搜索能力。最后,通过实例验证了其有效性。     

工程布局CAD系统设计与实现

针对工程布局设计的复杂性,提出了开放式的工程布局设计CAD系统的结构框架,讨论了实现该系统的关键方法,包括自动化设计进程建模、基于功能特征的待布物和布局空间几何近似建模、布局知识和布局约束的表达、布局方法应用.基于该系统框架,实现了计算机辅助工程布局设计原型系统,并以车辆动力舱布局设计为背景,对原型系统的有效性进行了验证.     

粒子群算法及其在布局优化中的应用

复杂工程布局(如卫星舱布局)方案设计问题,在理论上属带性能约束的布局优化问题(NPC问题),很难求解。论文以卫星舱布局为例,将粒子群算法(PSO)应用于布局问题,构造此类问题的粒子表达方法,建立了此类问题的粒子群算法。文中通过3个算例(其中一个为已知最优解的算例)的数值计算,验证了该算法的可行性和有效性。     

MEMS版图抽取及系统级模型自动构建技术

研究了一种抽取版图信息构建系统级模型的技术,即从标准版图文件中提取结构的几何信息和拓扑信息,将其转换对应于系统级中的参数化元件库,并按原始版图拓扑互连,从而生成基于saber仿真平台的系统级模型文件,实现了MEMS工艺级到系统级的数据传递,使用C 编程语言开发了相应的转换接口。通过典型器件——微加速度计和微变形镜的多种结构验证了转换方法的可行性。     

通信机房布局优化的数学模型与分析

本文通过对现有通信机房布局方式的分析,通过理论模型与实例分析的不断完善和修正,建立通信机房布局优化的数学模型,对今后的通信机房布局提供理论参考.     

商业画册版式设计略谈

平面设计是一门应用性很强的学科,当设计师面对各种类型的商业画册设计项目时,设计师应灵活的将版式设计的原理运用到商业画册的设计中,以一定的理论作为基础和标准,充分考虑市场需求,设计出兼顾艺术性和实用性的商业画册。     

求解装填布局问题的膨胀方法

介绍了膨胀装填布局的思想原理与算法实现。膨胀装填布局通过对缩小了的装填物体系统地施加膨胀－排斥操作而实现被装填物体布局位置的自动产生,具有直观性强、聚集性好、几何形状适应性广、便于工程推广等优点。作为算例,使用膨胀装填算法对几种与平面圆相关的装填布局问题给出了计算结果。     

Ontologies for conceptual modeling: their creation, use, and management

Although ontologies have been proposed as an important and natural means of representing real world knowledge for the development of database designs, most ontology creation is not carried out systematically. To be truly useful, a repository of ontologies, organized by application domain is needed, along with procedures for creating and integrating ontologies into database design methodologies. This research proposes a methodology for creating and managing domain ontologies. An architecture for an ontology management system is presented and implemented in a prototype. Empirical validation of the prototype demonstrates the effectiveness of the research.     

改进的蚂蚁算法在矩形优化排料中的应用

矩形件优化排料问题是一类具有NP完全难度的组合优化问题.将改进的蚂蚁算法应用到矩形件优化排料问题求解中,优化试验结果表明可获得比基本蚂蚁算法更好的效果,为矩形件优化排料这类NP完全问题提供了新的思路和方法.     

A heuristic procedure for the integrated facility layout design and flow assignment problem

We present an efficient iterative heuristic procedure for solving the integrated layout design and product flow assignment problem. The layout design decisions involve planar location of unequal-area machines with duplicates. The product flows are assigned to machines according to the product processing routes. The integrated decision problem is a nonlinear mixed integer model which cannot be efficiently solved using classical methods for large problems. We propose a novel integrated heuristic procedure based on the alternating heuristic, a perturbation algorithm and sequential location heuristic. Since the alternating heuristic between facility layout design and product-machine assignment sub-problems terminates with local optima, we developed a perturbation algorithm based on assignment decisions. The results of an experimental study show that proposed procedure is both efficient and effective in identifying quality solutions for small to very large-sized problems.     

Feature-based design and material blending for free-form heterogeneous object modeling

In this paper, a new feature-based method is proposed to represent and design heterogeneous objects. Material governing features are defined to control material composition inside the objects. Interrelations between the material governing features and material attributes are established in the design process and retained in the object model. Free-form B-spline functions are used to represent complex shapes of geometry and material features. A new material feature blending method is used to determine continuous material variation. To obtain the best material features, an optimization problem is constructed based on the object's functional requirements. Variant models are easily generated by changing the geometric and material features using the constraints between them. Implementation and examples are also presented in this paper.     

A tabu search procedure based on a random Roulette diversification for the weighted maximal planar graph problem

An efficient and effective tabu search implementation for the weighted maximal planar graph problem is proposed. The search incorporates a number of novel features including: the introduction of a new set of two-move operators; a move-cache-memory structure for efficiently searching the neighbourhood space; and a random roulette selection from a ranked list of best moves for diversification. The effects of these and other features on solution quality are investigated. Computational results are reported on a set of 100 benchmark instances of sizes varying from 20 to 100 vertices. The results demonstrate that the new probabilistic tabu search algorithm is very competitive with state of the art algorithms in the literature in terms of both solution quality and computational effort.Scope     

Procedural modeling of urban zone by optimization

Procedural modeling technology may be applied for constructing a large‐scale urban scene. Most of the previous studies have exploited a grammar‐based modeling method to generate models. Nevertheless, we formulate the urban planning as a constrained layout optimization problem, propose an algorithm to solve the problem, and procedurally generate models of the urban zone. It produces an extensive urban virtual environment for computer games and simulations at low cost. We optimize a cost function to distribute buildings and roads subject to some urban planning constraints. We employ particle swarm optimization and two‐step path planning to find the optimal solution, which is further interpreted as the 2D blueprint of the urban zone. During the optimization, we adopt the spatial pattern tree structure to reduce the combinational search space greatly. 3D city models in large scale are then assembled according to the 2D blueprints. Experimental results prove that our method can efficiently produce the virtual urban scene similar to that designed by urban planners. Copyright © 2008 John Wiley & Sons, Ltd.