An object-oriented database management system for computer-aided design of tall buildings

An effective database and database management system is the key to the success of an integrated approach to software engineering applications in general, and Computer-Aided Design (CAD) for structural applications in particular. Due to the inherent nature of CAD data such as dynamic modeling, a wide range of data types, large data volume, etc., the traditional database models, such as hierarchical, network and relational models, are unable to handle the aforementioned applications satisfactorily. An object-oriented data modeling is known to be the most effective approach. However, many of the commercial object-oriented databases are designed for information management, and they are inadequate for CAD application due to the different features of the object-hierarchy and varying data management objectives during the design cycles. This paper presents a hierarchical index-based object-oriented database management model for CAD applications. To deal with the object hierarchy encountered in CAD for the design of tall buildings, the proposed database consists of several salient features: a hierarchical object model, its related storage structure, a data dictionary, a class factory and an index system. The proposed database management model has been implemented into an integrated CAD system for design application of tall buildings.     

A knowledge support approach for the preliminary design of platform-based products in Engineering-To-Order manufacturing

A product platform is a design approach for meeting the demand for customizable products. Traditional knowledge-based technologies or systems lack flexibility in supporting both configuration and parameter design of platform-based products. In many cases, customers’ requirements and knowledge models both contain incomplete information, and there are complex relations among various solutions, functions and solution parameters in Engineering-To-Order (ETO) products. A knowledge model for the preliminary design of ETO products is presented in this paper, and linkages are established between configuration design knowledge and parameter design procedures. The basis of the knowledge model is the Extended Function-Solutions (EFS) tree, from which design case trees, design modules, constraint checking rules, and module interface templates derive. A corresponding knowledge retrieval and reuse strategy is also presented. It uses an improved fuzzy information axiom to search for the optimal configuration with incomplete information. The parameter design process model of new products then can be generated based on the optimal configuration. The case study demonstrates the knowledge modeling, retrieval and reuse for the preliminary design of open-type crank presses. Moreover, the effectiveness of the methodology is discussed by analyzing the verification approach and the satisfaction of customers’ requirements.     

Micro-computer analysis of three-dimensional tall buildings

A new approximate method of analyzing three-dimensional buildings by micro-computer is presented. It is based on the fact that the deformation pattern at the nodes of a particular floor can be predetermined before loading. These relative displacements are called distribution factors which govern the distribution of displacements. A number of free parameters are to be determined in the global analysis when the loadings are applied. These parameters are called mixing factors. The linear combinations of the distribution factors with mixing factors as weighting factors will give the actual displacements at the nodes. Structural idealizations of coupled shear walls by beams and columns are recommended. Numerical examples are given and the results are encouraging.     

The use of computers in preliminary structural design of buildings

This paper presents a case study of the use of computers for the preliminary structural design of a multi-story office building.First, preliminary structural design is discussed in relation to the entire building design process. Then, specifie computer applications are discussed for the following design activities: system selection, definition of structural elements, modeling of structural systems for analysis, and design of individual elements. Instead of isolated computer programs, this approach to computer usage emphasizes a system capable of creating and maintaining a structural data base for the life of a project.     

A part affordance-based approach for capturing detailed design knowledge

Design knowledge reuse is widely accepted as an effective strategy for designers to develop robust artifacts with less time and lower cost. However, there has been very little research on how to help designers capture detailed design knowledge for reuse. As a result, most detailed design knowledge still has to remain in designers’ memories as tacit knowledge, which can easily get lost due to oblivion or the mobility of designers. Therefore, this paper attempts to develop a part affordance-based approach for externalizing and capturing detailed design knowledge for effective reuse. It first introduces a part model for representing the detailed design-related information. Based on the relational theory for design, the concept, part affordance, is then employed to help designers externalize and capture various lifecycle factors that are implicit in a detailed design. Based on the affordance constraint axiom, a systematic approach is then proposed for deriving tacit design knowledge from captured part affordances through the analysis of extreme working situations. The proposed approach has been implemented as the Design Knowledge-Capturing System (DKCS). A fixture design case has been employed to illustrate the proposed approach.     

Fixture knowledge model development and implementation based on a functional design approach

The development of a knowledge model applied to fixture design is a complex task. The main purpose of such model is the development of a knowledge-based application to assist fixture designers. It comprises a detailed specification of the types and structures of data involved in the execution of the inference process needed to create a fixture solution for machining a raw part. A development method together with a knowledge model for automating fixture design is proposed. The development was divided into three parts: Design Process Model, definition of Top-level functional functions and Product Knowledge Model. Adopting a functional design approach, the fixture design solution was created in two levels: functional and detailed. The functional level is based on fixture functional elements and the detailed one is based on fixture commercial elements. The definitions and concepts used in the application are specified in several Units of Knowledge (UoK) that comprises the Fixture Knowledge Model. Common Knowledge Analysis and Design Structuring (CommonKADS), Methodology and software tools Oriented to KBE Applications (MOKA), Integrated DEFinition for Function Modelling (IDEF0) and Unified Modelling Language (UML) are the methodologies and techniques used in the proposed method. Finally, a prototype KBE application for fixture design was developed.     

Semantic Web based innovative design knowledge modeling for collaborative design

This paper describes a study about how to use the Semantic Web technologies for innovative design knowledge modeling in a multi-agent distributed design environment. Semantic Web based knowledge modeling for innovative design is proposed as prelude to the meaningful agent communication and knowledge reuse for collaborative work among multidisciplinary organizations. A model for innovative design is proposed at first, based on which a knowledge schema is brought forward. For sharing the design knowledge among an internet-based or distributed work team, even globally, A RDF-based knowledge model is presented to realize its representation on Semantic Web. A Semantic Web based repository for innovative design and its API for topper Semantic Web applications have been also constructed. The proposed knowledge modeling extends traditional product modeling with capabilities of innovative design, knowledge sharing and distributed problem solving, and is employed as a content language within the messages in the proposed multi-agent system architecture. The proposed approach is viewed as a promising knowledge management method that facilitates the implementation of computer supported cooperative work in innovative design of Semantic Web applications.     

Human-centred knowledge based systems design

It is held that the quality of the working environment afforded to an individual critically affects the health and well-being of that individual. This has consequences for both the quality of work which that individual can actually perform, and for the quality of the society in which that individual has a place. Conceptions of a fit working environment have led to the idea of a human-centred system, and this idea is applicable to the area of knowledge-based systems (KBS). A system structure is discussed, which permits a human-centred approach to be adopted towards KBS design. It is held that the performance of such a system will generally exceed that of unaided KBS operation.     

A hypernetwork-based context-aware approach for design lesson-learned knowledge proactive feedback in design for manufacturing

Design lesson-learned knowledge (DLK) clearly describes various design quality problems exposed in past manufacturing stages, solutions and preventive measures. If knowledge management system could proactively feed DLK back into design process, many previous quality problems would be avoided, thus helping designers better implement design for manufacturing (DFM) in a smarter manner. However, since design quality problems are not pointed out in design process, problem-relevant information extracted from design contexts might be inaccurate. In this situation, traditional context-aware approach is prone to acquire design quality problems that designers do not need. Facing these challenges, a hypernetwork-based context-aware DLK proactive feedback approach is proposed to construct hypernetwork-based DLK representation model and predict possible design quality problems in the design process, thus providing corresponding DLK and helping designers reduce the reoccurrence of previous quality problems in DFM. Specifically, hypernetwork-based DLK representation model is first constructed, which consists of designer context network, task context network and DLK network. Based on this model, a context-aware collaborative reason strategy is constructed to predict possible design quality problems according to complex design contexts. To validate the proposed approach, a practical product development case on the shipbuilding design is implemented, and some comparative experiments are conducted. Experiment results show the proposed approach is effective and has a positive performance in DFM. It is anticipated this work opens up a promising way to help designers reuse DLK for reducing the reoccurrence of previous design quality problems in a smarter manner, thus better implementation of DFM.     

An approach to capturing and reusing tacit design knowledge using relational learning for knowledge graphs

Tacit design knowledge plays an important role in the process of product design and is a valuable knowledge asset for enterprises. In terms of the characteristics of tacit rational design knowledge, this paper puts forward a scientific hypothesis and approach on capturing and reusing tacit rational design knowledge. The presented approach represents the observable design result facts of products using design knowledge graphs. A design issue-solving oriented knowledge graph model is presented, where directed relation edges represent design issues, and nodes stand for design solutions. When a new design solutions requirement needs to be searched, tacit design knowledge can be reused by relational learning for the constructed design knowledge graphs. In relational learning, the design knowledge graph is converted into a three-order tensor, where two modes are solution nodes, and the third mode holds the issue relations. Then, a tensor factorization approach is employed to calculate the latent features between design solutions for an issue relation. As a result, a score vector to represent the existence of issue-solution relations can be obtained. By sorting the scores in descending order, we may select the solution node with the highest score as the design solution to be searched. Finally, a stamping die design case study is provided. The case study shows that the proposed approach is feasible, and effective, and has better flexibility, scalability and efficiency than CBR methods.     

Agent based approach for organization and personal knowledge modelling: knowledge management perspective

The paper tries to bridge gap between knowledge management and artificial intelligence approaches proposing agent-based framework for modelling organization and personal knowledge. The perspective of knowledge management is chosen to develop two conceptual models—one describes the intelligent enterprise memory, another models an intelligent organization’s knowledge management system. The concept of an agent-based environment of the knowledge worker for personal and organizational knowledge management support is introduced.     

基于知识融合技术的产品设计知识模型研究*

为解决机械产品设计中知识融合的问题,建立了一种基于本体的产品设计知识模型。基于此,提出了一种基于模糊证据理论的融合推理方法,这种方法将模糊集引入证据识别空间中,利用证据合成与决策规则得出知识融合的结果,这种方法弥补了本体建模时的不足并解决了不确定性知识的推理。最后,将该知识模型应用于制造行业产品设计中,帮助制造企业缩短产品设计周期和提高开发质量,同时也有利于产品设计知识的共享和重用。     

A generalized coordinate method for the analysis of 3D tall buildings

A generalized coordinate method (GCM) is proposed for the reduction of unknowns in the 3D analysis of tall buildings when the displacement method is employed. The number of variables is reduced by the assumption of in-plane rigid floors and by use of a 2D polynomial approximation for the out-of-plane displacements of floors, and a 1D polynomial approximation of the displacements with the height of building. The overall stiffness equation is obtained in generalized coordinates. The transformations are performed at the member level so that calculations involving large matrices are avoided. The GCM might be considered as a reduction technique based on a combination of the FEM at member level and the Rayleigh-Ritz method at the structure level. The GCM has the advantages that (1) the number of unknowns is significantly reduced and is independent of the number of storeys: (2) the accuracy can be adjusted by selecting the number of terms of the displacement function. The storage needed, the required number of operations and the possibility of choosing hierarchical displacement functions to make the calculation adaptive are discussed. The method presented can easily be extended to nonlinear and dynamic analysis. However, the derivation in this paper is confined only to the linear elastic analysis of frame and frame-shear wall structures. Numerical examples are given to show the efficiency of the proposed method.     

Data-driven performance-based topology optimization of uncertain wind-excited tall buildings

Topology optimization is traditionally framed in a static and deterministic setting notwithstanding the uncertain dynamic nature of many problems. This paper presents a new data-driven simulation-based framework for the effective topology optimization of uncertain and dynamic wind-excited tall buildings. The performance of the system is described through probabilistic performance integrals that encapsulate state-of-the-art performance-based design driven by climatological, aerodynamic and fragility data sets for describing the site-specific hazard, aerodynamic response and damage susceptibility of the system. To solve the resulting probabilistic topology optimization problem, a sequential optimization strategy is developed that is based on solving a series of high quality approximate sub-problems. A suite of case studies demonstrate the effectiveness of the approach.     

An object-oriented knowledge based Petri net approach to intelligent integration of design and assembly planning

Artificial intelligence can play an important role in the reduction of manufacturing costs and the enhancement of production efficiency and product quality. In order to assist designers in the early stages of a product development this paper develops an intelligent methodology for integration of design and assembly planning processes, including product design, assembly evaluation and redesign, assembly process planning, design of assembly system and assembly simulation, subjected to both econo-technical and ergonomic evaluations. A new unified class of object-oriented knowledge based Petri nets called OOKPNs, incorporating knowledge based expert systems and fuzzy logic into ordinary place–transition Petri nets, is defined and used for the representation and modeling of the distributed design processes. A prototype intelligent integrated design and assembly planning system (IIDAP) is implemented through distributed blackboard structure with concurrent integration of multiple cooperative knowledge sources and software. It consists essentially of the networked agents and the meta-system, each of which is a knowledge Petri net system with the capabilities of problem solving, learning and conflict resolution, and can be obtained through the inheritance, polymorphism and dynamic binding of instances of OOKPNs. In IIDAP system, both C/C++ language and COOL (CLIPS object-oriented language) are used to incorporate a Petri net tool, a geometric modeling and design tool, a planner and simulator and an evaluation tool. By use of this system, product design and assembly planning can be carried out simultaneously and intelligently in an entirely computer-aided concurrent design and assembly planning system. The design of manufacturable, cost-effective, usable products can therefore be achieved rapidly and flexibly. The developed methodology and system have been successfully applied to assembly design and planning of a micro switch.     

Answer set based design of knowledge systems

The aim of this paper is to demonstrate that A-Prolog is a powerful language for the construction of reasoning systems. In fact, A-Prolog allows to specify the initial situation, the domain model, the control knowledge, and the reasoning modules. Moreover, it is efficient enough to be used for practical tasks and can be nicely integrated with programming languages such as Java. An extension of A-Prolog (CR-Prolog) allows to further improve the quality of reasoning by specifying requirements that the solutions should satisfy if at all possible. The features of A-Prolog and CR-Prolog are demonstrated by describing in detail the design of USA-Advisor, an A-Prolog based decision support system for the Space Shuttle flight controllers.     

基于时事折换图的因果知识量化分析方法

针对目前协同因果事件族的知识分析缺乏时态信息和量化手段等问题，提出基于时事折换图的因果知识量化分析方法。 首先运用时事折换思想建立包含时态信息的因果知识事件域描述机制，然后考虑原因事件对结果事件发生冲击影响和时间累积影响，提出因果度、依赖度、影响度三种指标并推出其计算公式，实现了对因果知识的量化描述和双向推理。 应用实例表明该方法具有高效、细致、直观优点。     

User-centric knowledge representations based on ontology for AEC design collaboration

Fostering collaboration in the AEC (Architecture/Engineering/Construction) field is difficult, due to the differing educational and disciplinary backgrounds of the participants. Current approaches to managing such collaboration in the AEC industry often fail to overcome the disciplinary differences among the participants, resulting in cost overruns, missed schedules, and diminished satisfaction of the clients or society. Their failure is due to the lack of understanding of the nature of multi-disciplinary design and the lack of tools that can support them. The primary objective of this research is to establish a suitable model for machine-mediated collaboration. In contrast to the monolithic model, which is insensitive to changes, we propose to develop a distributed and flexible model, where each domain of expertise retains its own data in the form most appropriate for its needs, and where ontology-based, intelligent filters translate neutral design data into domain-specific ones. The filtered data appear semantically-rich to the participant, even when it was generated by another participant. To verify the feasibility of the proposed filter-based communication model, we developed and tested a prototype. The result of the prototype test demonstrates that the proposed model can enable designers from different disciplines participating in an AEC project to better understand the dynamic process of design and achieve a high level of shared understanding.