A Knowledge-Based System for Synthesis and Design of Transmission Towers Using Blackboard Architecture

Abstract: This paper describes the development of KASTLE—a knowledge-based system for synthesis and design of steel lattice self-supporting transmission towers. Using inputs such as type of tower, geographical location, the voltage the conductor has to carry and the number of circuits the tower has to support, an experienced designer arrives at an overall configuration of tower. An expert designer basically relies on heuristics to choose parameters, such as base width, tophamper width, type of bracings and sub-bracing pattern, for the tower configuration. The final cost of the tower is sensitive to these initial decisions. Geometric modelling of the configuration is prerequisite for tower analysis. This paper reports an attempt to integrate different types of knowledge-based systems using blackboard architecture. The knowledge system for configuration generation uses theorem proving, whereas in other knowledge-based systems, such as modelling and design heuristics, knowledge has been represented using IF-THEN rules. A sample synthesis and design of a 220 kV and 400 kV tangent tower is included. The system has been implemented on an IBM PC AT with MS-DOS. Prolog, Fortran, and C languages were used.     

A Knowledge-Based System for Concrete Building Structural Design

Abstract: Knowledge representation approaches and knowledge base management strategies in the concrete building structural detail design system KJICAD are described. A load combination algebra system is developed for environmental loads formalization and a code-based problem-solving control structure is established to describe design knowledge sources and their relations. By using compiler techniques, the physical knowledge base is made uniform and simplified for quick access. Finally, a practical design example is included to illustrate the effectiveness of KJICAD.     

Knowledge-Based System Development Tools for Processing Design Specifications

Code-compliance checking in any engineering design process is typically a nonsequential activity that requires extensive data managmenkt and decision making. Knowledge-based system methodology can be applied to solve some of the problems in processing code specifications that could not be addressed by traditional procedural programming languages. Many software development tools are currently available to assist in the development of knowledgte-based systems for specific applications. The characteristics of each tool vary with the knowledge representation and inference methodologies, and differ with the user interface and other features for development. An evaluation of seven knowledge-based system development tools is presented in this paper. The suitability of each development enviornment for design assistance by processing code specifications is investigated by means of prototype design applications. A brief descrioption of the features of each development too, implementation details of prototype applications, and a qualitative comparison of the tools on the basis of suitability to process design code spacifications are presented.     

A Knowledge-Based System for Planning a Construction Operation

Knowledge-based systems can be developed as an educational tool for inexperienced construction managers and students. Microcomputer expert-system shell programs can allow knowledgebased systems to be developed and used on the construction site. Construction experts can provide knowledge which can define the best crew size, expected productivity, and the effects of production bottlenecks. This information can be incorporated in a knowledge-base and used as an aid in determining when production problems are occurring in the field. This information can also be used in the pre-construction period by providing managers and estimators with expert knowledge of expected productivity and required crew size. A prototype expert system was developed for the construction of precast concrete structures. The rules were obtained from construction experts with extensive experience in this type of construction. The system provided advice concerning the best crew size to use based upon the construction site characteristics. The system also provided advice concerning expected productivity and the effects of production problems on productivity. The prototype model was developed using the INSIGHT 2 microcomputer expert-system shell program.     

Modal Logic to Evaluate a Knowledge-Based Bridge Rating System

Knowledge acquisition has been recognized as a major bottleneck in the development of effective knowledge-based systems in recent years. Therefore, many researchers are investigating knowledge-acquisition methodologies to overcome this problem. In this article, a flexible method for expressing empirical knowledge related to bridge rating acquired from questionnaires filled out by bridge rating experts is proposed by relating the knowledge to a membership function based on fuzzy-set theory. In this method, a membership function is regarded as a possibility distribution based on a theory of possibility, and an apparent possibility distribution expressed by an extended II function is transformed into possibility measure distribution and necessity measure distribution utilizing a concept of modal logic. Furthermore, the proposed method has been applied to a questionnaire survey conducted to evaluate the serviceability of an existing bridge. The validity of the method has been verified through comparison between the subjective rating results acquired from application of the method and objective rating results obtained from nondestructive tests conducted for evaluating the serviceability of the same bridge.     

A Knowledge-Based System for Construction-Site Organization

Abstract: This paper presents an example of a knowledge-based system application in the domain of building design, specifically for construction-site management. This type of system is a reasonable approach for providing a design aid to engineers. The object-oriented representation that is the base of the prototype GRAM_V2 was developed by the authors from an analysis of the specific needs for a building computer-aided design (CAD) system. This hybrid language integrates several functionalities such as multiple representation, delegation, and a set of graphic classes. The system architecture promotes adaptability, ease of use, and evolution of the system over time. GRAM_V2 utilizes AUTOCAD as a graphic interface and an object-oriented language developed in LISP. This paper emphasizes the formalism and explains the utility of the different functionalities of GRAM_V2 through this specific application.     

A Knowledge-Based Design Tool to Assist in Preliminary Seismic Design

Abstract: Many structural engineers only rarely need to be concerned with seismic design. It is a relatively difficult process that can involve advanced analytical techniques and concepts such as ductility which are not normally encountered except in this context. A prototype Seismic Design Assistant (SDA) has been developed specifically to assist, advise, and guide design engineers engaged in the preliminary seismic design of reinforced concrete buildings (with coupled shear walls). Available seismic design methods are reviewed, and a particular method is outlined that incorporates sophisticated analytical procedures to enable ductility requirements to be satisfied. This method provides the basis of the knowledge base employed within the SDA. The prototype design tool has been implemented on a Sun workstation using Quintec-Prolog, Quintec-Flex, and Fortran 77. Details are presented of the architecture of the SDA, of the knowledge representation that has been employed, and of the integration of traditional procedural software within a knowledge-based approach.     

Graffiti: A Computer-Aided Construction Process Knowledge-Based System

Abstract: This paper presents a computer-aided construction process program based on a heuristic research knowledge-based system, logical procedures for constraints propagation, as well as on operational research algorithms. The system is interactive: it is the user, not the program, who controls the heuristic research. Furthermore, it is graphics oriented: a reflexive architecture between the knowledge-based system and a geometrical modeller allows permanent graphic visualization of the work in progress. The application presented includes a variety of operations, ranging from the geometric modelling of the architectural project to the intelligent analysis of its structure, its division into component types (e.g. shuttering posts, beams, floors, walls) and the planning of the construction process (production cycles, tasks scheduling).
Tested by engineers of a private international building company, the system has now received new implementations, which allow us to simulate different technologies and modify very rapidly many various parameters, thus giving to the users a real computer-aided construction process environment.     

A Knowledge-Based Expert System for Innovative Transportation Financing Techniques

Abstract: This paper discusses the development of a medium-sized knowledge-based expert system for selection of appropriate innovative financing technique(s) for transportation projects by several state and local governments. The steps involved in the development of the expert system, namely, problem identification, conceptualization, knowledge acquisition, knowledge representation, implementation, and testing and evaluation, are discussed. The process of organizing the available knowledge of innovative financing techniques, as well as the process leading to the selection of one or more of them for a particular project, is encoded in the knowledge base of the expert system developed for the purpose. The working system was tested and validated by comparing the output of the system against the recommendations made by transportation professionals in counties and cities in various states. The tests indicate favorable results for the system. The operational system can be used as a decision support system as well as a teaching tool for transportation engineers, planners, private developers, and government officials.     

体系能力设计法与基于性态/位移抗震设计

首先论述了基于性态 /位移抗震设计方法的发展及其需解决的问题 ,综合了结构抗震耗能原理、破坏机制控制概念、抗震体系和能力设计法等结构抗震原理 ,提出了体系能力设计法思想。体系能力设计法要求结构具有多重抗侧力抗震体系 ,并对不同子抗侧力结构采用不同的抗震能力 ,通过对抗侧力体系间能力差的控制 ,以实现主体抗侧力结构对整体结构在地震作用下的位移模式和破坏机制控制 ,进而使得整体结构的弹塑性地震响应和耗能分布的规律便于把握和确定 ,从而解决了基于性态 /位移抗震设计方法中的一些难以确定和计算的关键问题。最后通过一实例介绍了体系能力设计法的应用 ,并讨论了实现体系能力设计法基本概念和需进一步研究的问题     

A Knowledge-Based System for Seismic Vulnerability Assessment of Masonry Buildings

Abstract: A specific class of structures, masonary, is considered. For its analysis a great expertise is available. The 'state of health' of a single existing building is assissed by an expert system which incorporates this expertise. The paper illustrates a knowledge-based expert system for the seismic vulneraility assesment of masonry buildings.     

体系能力设计法在消能减震结构设计中的应用

结合基于性能抗震设计概念,介绍了体系能力设计法在消能减震结构中的应用。依据体系能力设计法建议了消能减震结构抗震设防目标,并通过算例分析给出了满足体系能力设计方法所需具备的条件。在此基础上,给出了消能减震结构设计中阻尼器分布、阻尼器参数和等效阻尼比等有关计算方法。     

太阳能集中供热水系统电气设计

太阳能作为一种绿色、环保的新型能源,正越来越广泛地受到重视和应用。本文分析介绍了太阳能集中供热水系统的构成,以及电气和智能化设计的要求。并针对太阳能供热水系统的特点．结合实际工程,从防雷保护、等电位联结的布置、变配电系统负荷分配的特点等方面,阐述设计中需要注意的问题．并对设计中产生的一些新问题进行了探讨分析。     

市场主体分类监管的系统方法与制度设计 ——以厦门市建安信用监管制度为例

运用基于灰色系统理论与政策方法论的市场主体信用监管评价曲线,介绍了基于整体信息的信用监管分级与分类方法,阐述了实施分类监管后的信息收集与处理的技术路线和方法,论证了分类监管操作的可行性、可靠性和公正性,并做出制度设计与政策规范,讨论了有关应用问题.     

基于AutoCAD的燃气管网水力计算软件开发

以AutoCAD为平台,采用AutoCAD Object ARX二次开发技术实现对燃气管网水力计算的数据自动化处理,包括建立管网节点和管段的拓扑关系、读取Excel表中的管网数据并显示到图中,以获得管网的可视化;采用C#语言,编制了中低压燃气管网水力计算软件。     

燃气热水器地板辐射供暖系统的设计

对以壁挂式燃气热水器作为热源的地板辐射供暖系统设计中供回水温度的选取、燃气热水器热功率的确定、阻力计算、循环泵的选择进行了探讨。     

"城市总设计师制" ——城市设计实施的协作化管理路径

AT:目前"城市总设计师制"(以下简称"总师制度")受到很多关注,请谈谈您理解的总师制度?如何看待"总师制度成为关注热点"这一现状? 匡晓明:城市总设计师制是在我国城市设计的发展过程中暴露出编制与实施时空分离问题之后,试图从机制角度加强规划编制与实施之间连续性而采取的一种设计治理方式.类似的城市总设计师制度在国际上已有诸多实践探索,如奥斯曼主持的巴黎改造、培根主持的旧金山城市设计、巴奈特参与的纽约城市设计等,这个时期的总设计师还没有"正名".1951年,美国建筑师格罗皮乌斯提出了建筑师协作概念,是总师制度的早期构想.随着实践发展,法国、日本、德国等国推行了协调建筑师、主管总设计师、专家顾问团等制度,以保障城市设计成果落地.法国的"协调建筑师"制度,从工作内容和工作方式方面,特别是从城市规划中所行使的权力及承担事项的视角来看,都无疑是典型意义上总师制度的实践."协调建筑师"在法国的城市开发建设控制体系中起到了十分重要的作用,旨在衔接开发控制和建筑形态设计之间的断层,在城市设计项目实施与设计管控一体化及组织协调方面起到了重要的作用.     

生态设计方法

文中以生态设计的技术与理论为基础,建立了建成环境与生态环境的互动框架,阐述了其相互作用的内部关系,列表对各种有关生态系统层次作用的要素进行了评估,提出了建筑物及环境的生态设计的目标和控制方法。     

理性的城市设计新策略

本文以英国的两个城市设计项目为例——新城区的大规模开发设计和旧城更新的总体规划，阐释空间句法理论在城市设计中的实践空间句法基于对空间结构与社会活动本质联系的理解，对原设计方案进行理性的分析，最终提出截然不同的空间结构排布。本文通过对案例设计背景、方案评价及修改过程的描述，力图为中国大规模的城市设计提供运作机制上的借鉴。