Showing papers on "Conceptual design published in 1994"

Method and system for creating, validating, and scaling structural description of electronic device

Abstract: A methodology for generating structural descriptions of complex digital devices from high-level descriptions and specifications. The methodology uses a systematic technique to map and enforce consistency of the semantics imbedded in the intent of the original, high-level descriptions. The design activity is essentially a series of transformations operating upon various levels of design representations. At each level, the intended meaning (semantics) and formal software manipulations are captured to derive a more detailed level describing hardware meeting the design goals. Important features of the methodology are: capturing the users concepts, intent, specification, descriptions, constraints and trade-offs; architectural partitioning; what-if analysis at a high level; sizing estimation; timing estimation; architectural trade-off; conceptual design with implementation estimation; and timing closure. The methodology includes using estimators, based on data gathered over a number of realized designs, for partitioning and evaluating a design prior to logic synthesis. From the structural description, a physical implementation of the device is readily realized. Techniques for scaling of a model design to provide a scaled design are provided whereby parameters of a model design such as size, circuit complexity, interconnection density, number of I/O connections, etc., can be scaled to produce a scaled version of the design. The scaling techniques employ multi-level hierarchical module replication to produce fully-functional scaled designs which closely match the function of the model design. Test vectors for the scaled designs can be readily obtained by altering test vectors for the model design to account for the replicated modules.

Design Paradigms: Case Histories of Error and Judgment in Engineering

Abstract: 1. Introduction 2. Paconius and the pedestal for Apollo: a paradigm of error in conceptual design 3. Vitruvius's Auger and Galileo's Bones: paradigms of limits to size in design 4. Galileo and the marble column: a paradigm of a design change for the worse 5. Galileo's confirmation of a false hypothesis: A paradigm of logical error in design 6. The design and collapse of the Dee Bridge: a paradigm of success masking error 7. The Britannia Tubular Bridge: A paradigm of tunnel vision in design 8. Failure as a source of engineering judgment: John Roebling as a paradigmatic designer 9. The design climate for the Tacoma Narrows Bridge: a paradigm of the selective use of history 10. Historic bridge failures and caveats for future designs 11. Conclusion References and bibliography Index.

Specification and design of complex digital systems

Abstract: A methodology for generating structural descriptions of complex digital devices from high-level descriptions and specifications is disclosed. The methodology uses a systematic technique to map and enforce consistency of the semantics imbedded in the intent of the original, high-level descriptions. The design activity is essentially a series of transformations operating upon various levels of design representations. At each level, the intended meaning (semantics) and formal software manipulations are captured to derive a more detailed level describing hardware meeting the design goals. Important features of the methodology are: capturing the users concepts, intent, specification, descriptions, constraints and trade-offs; architectural partitioning; what-if analysis at a high level; sizing estimation; timing estimation; architectural trade-off; conceptual design with implementation estimation; and timing closure. The methodology includes using estimators, based on data gathered over a number of realized designs, for partitioning and evaluating a design prior to logic synthesis. From the structural description, a physical implementation of the device is readily realized. The methodology further includes an automated interactive, iterative technique for creating a system-level specification in a directly-executable formal specification language. This technique makes use of formal verification and feasibility analysis techniques to iteratively refine the specification prior to implementation. This iterative refinement eliminates many ambiguities and inconsistencies from the specification, and ensures that there is at least one realizable implementation of the specification. The formal verification techniques are further employed to ensure that as the design progresses, compliance with the specification is maintained, and that any specification change is reflected and accounted for, both system-wide and implementation-wide.

Managing Engineering Design

Abstract: 0.- 0.1 Terminology.- 0.2 Examples.- 1 The Context.- 1 Ways of Thinking about Engineering Design.- 1.1 Disasters and Failures.- 1.2 Engineering Excellence.- 1.3 New Innovations.- 1.4 Improving Engineering Design.- 1.5 Systematic Approaches to Engineering Design.- 1.6 Systematic Design in Practice.- 1.7 Tips for Management.- 2 The Project Context.- 2.1 Engineering Projects.- 2.2 Engineering Design in the Project Context.- 2.3 The Effect of Influences.- 2.4 Influences at the Macroeconomic Level.- 2.5 Influences at the Microeconomic Level.- 2.6 Influences at the Corporate Level.- 2.7 Design Context Checklist and Work Sheet.- 2.8 Tips for Management.- 2 Task,Team and Tools.- 3 Profiling the Project.- 3.1 Influences at the Project Level.- 3.2 Engineering Design in the Project Context.- 3.3 Design Task.- 3.4 Design Team.- 3.5 Design Tools and Techniques.- 3.6 Design Team Output.- 3.7 Project Profile Checklist and Work Sheet.- 3.8 Tips for Management.- 4 Managing the Design Team.- 4.1 Influences at the Personal Level.- 4.2 Knowledge, Skills, and Attitude.- 4.3 Motivation.- 4.4 Relationships.- 4.5 Personal Output.- 4.6 Personnel Profile Checklist and Work Sheet.- 4.7 Tips for Management.- 3 The Project.- 5 Project Proposal: Getting the Job.- 5.1 Proposals and Briefs.- 5.2 Preparing a Proposal.- 5.3 Negotiations.- 5.4 Debriefing.- 5.5 Project Proposal Checklist and Work Sheet.- 5.6 Tips for Management.- 6 Design Specification: Clarification of the Task.- 6.1 Problem Statement and Design Specification.- 6.2 Defining the Problem.- 6.3 Project Planning.- 6.4 Demands and Wishes.- 6.5 Design Specification.- 6.6 Design Specification Checklist and Work Sheet.- 6.7 Tips for Management.- 7 Feasible Concept: Conceptual Design.- 7.1 Divergent and Convergent Thinking.- 7.2 Generating Ideas.- 7.3 Selecting and Evaluating Concepts.- 7.4 Estimating Costs.- 7.5 Presenting the Final Concept.- 7.6 Conceptual Design Checklist and Work Sheet.- 7.7 Tips for Management.- 8 Developed Concept: Embodiment Design.- 8.1 Abstract Concept to Developed Design.- 8.2 Overall Guidelines for Embodiment Design.- 8.3 Specific Guidelines for Embodiment Design.- 8.4 General Guidelines for Embodiment Design.- 8.5 Embodiment Design Checklist and Work Sheet.- 8.6 Tips for Management.- 9 Final Design: Detail Design for Manufacture.- 9.1 The Importance of Detail Design.- 9.2 The Design Manager and Detail Design.- 9.3 Quality Assurance.- 9.4 Interaction of Shape, Materials, and Manufacture.- 9.5 Manufacturing Drawings and Information.- 9.6 Standard Components.- 9.7 Assembly.- 9.8 Testing and Commissioning.- 9.9 Detail Design Checklist and Work Sheet.- 9.10 Tips for Management.- 10 Users and Customers: Design Feedback.- 10.1 Expectations.- 10.2 Use and Abuse.- 10.3 Maintenance.- 10.4 Litigation.- 10.5 Design Quality Assessment Work Sheet.- 10.6 Tips for Management.- 11 Standards and Codes.- 11.1 General Issues.- 11.2 Basic Definitions.- 11.3 Safety Standards.- 11.4 Some Reference Articles on Safety Standards.- 11.5 Some Reference Articles on International Standards.- 11.6 ISO0 International Standards for Quality Management.- 11.7 National Standards for Engineering Design Management.- 11.8 Tips for Management.- 11.9 Contact Information and URLs for Standards and Codes.- 12 Engineering Design Process: Review and Analysis.- 12.1 Summary.- 12.2 Forensic Analysis of Engineering Design Issues.- 12.3 Analysis of the Engineering Design Process.- 241.- 243.- 247.

Functional understanding of assembly modelling

Abstract: Conceptual design requires the evolution of modelling methodology beyond geometric and feature modelling. The functional understanding of assemblies is a key means to this end. A general top-down assembly model is presented that can provide both a function-oriented view and a module-oriented view of the assembly structure. The former is related to functional and behavioural knowledge, and the latter to manufacturing knowledge. A mixed dimensional geometric-modelling environment is interfaced with the top-down assembly design process. Therefore, assembly models at various levels of detail can be generated and converted to each other. An experimental modelling system, †, illustrates how the modelling scheme can be realized.

Artificial intelligence in design '94

Abstract: Part 1: Conceptual Design. Part 2: Case-Based Design - 1. Part 3: Case-Based Design - 2. Part 4: Configuration Design. Part 5: Design by Generation. Part 6: Theoretical Reasoning in Design. Part 7: Designing with Constraints. Part 8: Shapes and Objects in Design. Part 9: Cognitive Aspects of Design. Part 10: Models of Design. Part 11: Integrated Design. Part 12: Access and Retrieval in Design. Part 13: Design Processes. Part 14: Engineering of Design.

Guiding conceptual design through behavioral reasoning

Abstract: This paper presents a model for conceptual design based on an explicit behavioral reasoning step to guide the design process. Rather than mapping directly from function to form, we treat conceptual design as a two-step process, first transforming functional requirements to a behavioral description and then matching physical artifacts to this behavior. We believe that behavior, in terms of physical principles and phenomena, provides a natural bridge between functional requirements and physical artifacts. Behavioral reasoning breaks preconceived links between functions and artifacts, allowing for innovative solutions to be found. A new representation calledbehavior graphs (derived from bond graphs) has been developed to facilitate behavioral reasoning. This paper discusses behavior graphs and their use in a design synthesis model that generates systems of pre-defined embodiments (e.g., motor, spring, valve) to meet functional requirements given in terms of input and output parameters (e.g., force, pressure, displacement, voltage). An experimental computer program implementing this model is discussed and illustrative examples presented.

An Approach to Functional Synthesis of Solutions in Mechanical Conceptual Design. Part I: Introduction and Knowledge Representation

Abstract: Conceptual design is an early phase in the design process, which involves the generation of solution concepts to satisfy the functional requirements of a design problem. There can be more than one solution to a problem; this means that there is scope for producing improved designs if one could explore a solution space larger than is possible at present. Computer support to conceptual design could be effective to this end, if an adequate understanding of the required design knowledge and subsequent tools for its representation and manipulation were available. This three-part series of articles describes one approach to synthesis of solutions to a class of mechanical design problems; these involve transmission and transformation of mechanical forces and motion, and can be described by a set of inputs and outputs. The approach involves(1) identifying a set of primary functional elements and rules of combining them, and(2) developing appropriate representations and reasoning procedures for synthesising solution concepts using these elements and their combination rules; these synthesis procedures can produce an exhaustive set of solution concepts, in terms of their topological as well as spatial configurations, to a given design problem. Part I provides an overview of the scope and the approach, adopted in the entire series, to identify the design knowledge required for synthesis, and a method for its validation. It specifically focuses on the extraction and representation of this knowledge. Part II describes synthesis of topological (graph structure) descriptions of possible solutions to a given problem. Part III describes a procedure for producing spatial configurations of these solutions.

Conceptual design of multichip modules and systems

Abstract: Preface 1 Introduction 2 Information Modeling and Representation 3 Tradeoff Analysis 4 Design Partitioning 5 Tradeoff Analyses for Multichip Systems List of Symbols Index

The Design of a Tool Kit for Case-Based Design AIDS

Abstract: This paper extends the discussion of Case-Based Design Aids (CBDAs) presented at the 1992 AI in Design Conference (Domeshek and Kolodner, 1992). After reviewing the CBDA concept and its motivation, we discuss progress in implementing such systems, and focus on the generalization of our original CBDA (first developed to support architects with the conceptual design of buildings) into a tool kit applicable to a wide range of design domains. Experience in gathering and organizing case materials, and consideration of more use-scenarios have led us to reorganize and refine many aspects of the original proposal. Here we report our experience building CBDAs for architecture and for jet aircraft subsystem design using the CBDA tool kit Design-MUSE.

A case-based design aid for conceptual design of aircraft subsystems

Abstract: This paper describes MIDAS (a memory for initial design of aircraft subsystems), a system that applies insights and techniques from case-based reasoning (CBR) to aid engineers in the design of utility subsystems early in the development of a new aircraft concept. Our goal is to demonstrate the usefulness and practicality of a particular approach to building a corporate design memory. MIDAS is an instance of a general class of systems we call Case-Based Design Aids (CBDAs). A CBDA provides a designer with convenient access to multimedia presentations that highlight the outstanding good and bad points of previous designs. MIDAS was developed as a joint project of the Georgia Tech AI Lab and Lockheed Aeronautical Systems Company's Advanced Design Division. It is the first CBDA to be built largely by domain experts; the AI team primarily provided an (evolving) tool kit, and advice. >

Preapplication safety evaluation report for the Power Reactor Innovative Small Module (PRISM) liquid-metal reactor. Final report

Abstract: This preapplication safety evaluation report (PSER) presents the results of the preapplication desip review for die Power Reactor Innovative Small Module (PRISM) liquid-mew (sodium)-cooled reactor, Nuclear Regulatory Commission (NRC) Project No. 674. The PRISM conceptual desip was submitted by the US Department of Energy in accordance with the NRC`s ``Statement of Policy for the Regulation of Advanced Nuclear Power Plants`` (51 Federal Register 24643). This policy provides for the early Commission review and interaction with designers and licensees. The PRISM reactor desip is a small, modular, pool-type, liquid-mew (sodium)-cooled reactor. The standard plant design consists of dim identical power blocks with a total electrical output rating of 1395 MWe- Each power block comprises three reactor modules, each with a thermal rating of 471 MWt. Each module is located in its own below-grade silo and is co to its own intermediate heat transport system and steam generator system. The reactors utilize a metallic-type fuel, a ternary alloy of U-Pu-Zr. The design includes passive reactor shutdown and passive decay heat removal features. The PSER is the NRC`s preliminary evaluation of the safety features in the PRISM design, including the projected research and development programs required to support the design and the proposedmore » testing needs. Because the NRC review was based on a conceptual design, the PSER did not result in an approval of the design. Instead it identified certain key safety issues, provided some guidance on applicable licensing criteria, assessed the adequacy of the preapplicant`s research and development programs, and concluded that no obvious impediments to licensing the PRISM design had been identified.« less

System Sensitivity Analysis Applied to the Conceptual Design of a Dual-Fuel Rocket SSTO

Abstract: This paper reports the results of initial efforts to apply the System Sensitivity Analysis (SSA) optimization method to the conceptual design of a single-stage-to-orbit (SSTO) launch vehicle. SSA is an efficient, calculus-based MDO technique for generating sensitivity derivatives in a highly multidisciplinary design environment. The method has been successfully applied to conceptual aircraft design and has been proven to have advantages over traditional direct optimization methods. The method is applied to the optimization of an advanced, piloted SSTO design similar to vehicles currently being analyzed by NASA as possible replacements for the Space Shuttle. Powered by a derivative of the Russian RD-701 rocket engine, the vehicle employs a combination of hydrocarbon, hydrogen, and oxygen propellants. Three primary disciplines are included in the design - propulsion, performance, and weights & sizing. A complete, converged vehicle analysis depends on the use of three standalone conceptual analysis computer codes. Efforts to minimize vehicle dry (empty) weight are reported in this paper. The problem consists of six system-level design variables and one system-level constraint. Using SSA in a 'manual' fashion to generate gradient information, six system-level iterations were performed from each of two different starting points. The results showed a good pattern of convergence for both starting points. A discussion of the advantages and disadvantages of the method, possible areas of improvement, and future work is included.

Automatic design of machining fixtures: Conceptual design

Abstract: Fixtures are used in many manufacturing operations. Owing to the great variety of parts and manufacturing operations, parts may have different sets of fixturing requirements and call for different design strategies. Although there are numerous possibilities for fixture designs, a few basic configurations are clearly identifiable. Based on the belief that it would be more promising to develop one design strategy for each type of fixture than to attempt to develop a general strategy for all types of fixtures, a three-stage design process has been proposed for automatic design of fixtures: conceptual, configuration, and detail design. This paper focuses on the conceptual design stage. A methodology is presented by which the part shape, part features, and cutting force field are analysed to generate conceptual designs of fixtures.

Intelligent Systems in Design and Manufacturing

Abstract: Focuses on solutions to problems in design and manufacturing engineering, presenting a variety of problem solving approaches and practical examples. Covers neural networks and other artificial intelligence tools, computational models for conceptual design, desirable functionalities of intelligent CA

DesignSpace: a manual interaction environment for computer aided design

Abstract: pointing device shifted the paradigm and allowed visualization without explicit numerical references. DesignSpace is a computer-aided-design (CAD) system that facilitates dexterous manipulation of mechanical design representations. The system consists of an interactive simulation programmed with a seamless extended model of the designer's physical environment and driven with continuous instrumentation of the designer's physical actions. The simulation displays consistent visual and aural images of the virtual environment without occluding the designer's sensation of the physical surroundings. Developed at Stanford University's Center for Design Research (CDR), DesignSpace serves as an experimental testbed for design theory and methodology research. DesignSpace includes significant contributions from recent CDR development projects: TalkingGlove, CutPlane, VirtualHand, TeleSign, and VirtualGrasp. The current DesignSpace prototype provides modeling facility for only crude conceptual design and assembly, but can network multiple systems to share a common virtual space and arbitrate the collaborative interaction. The DesignSpace prototype employs three head-tracked rear projection images, head-coupled binaural audio, hand instrumentation, and electromagnetic position tracking. 3D CAD faces similar resistance today while workstation systems channel the design interaction through one and two dimensional interfaces. A design tool should maintain full dimensionality in the design process and not subject the design to unnecessary constraints in the communication between designers, the design media, and the final realized artifact. DesignSpace embraces this ideal by providing facilities for interactive simulation, dexterous manipulation, and remote collaboration. BACKGROUND CDR was founded in 1983 as an industry-academia collaborative and interdisciplinary R&D center to improve the engineering and product design processes. The Center accepts design problems from industry and government, and confronts them with creative design teams, for the purpose of design process observation and study, experimental design practice, and new design tool development. A long-term CDR goal is to aid the design process so that problem complexity does not impede creativity, design knowledge reuse, and human skill. CDR researchers and designers collaborate on projects to study the design process, to develop devices and interfaces to better map manual skills to data operations, to experiment with alternative means of design knowledge storage and retrieval, and to investigate design tool effectiveness. DesignSpace encapsulates technologies from several CDR projects within a conceptual design environment context to serve as a testbed for evaluating their effective application.

A conceptual database design approach based on rules and heuristics

Abstract: Conceptual and logical database design are complex tasks for non-expert designers. Currently, the popular data models for conceptual and logical database design are the entity–relationship (ER) and the relational model, respectively. Logical design methodologies for relational databases have relied on mathematically rigorous approaches which are impractical, or textbook approaches which do not provide the rich constructs to capture real applications. Consequently, designers have to use their intuition to develop their own rules and heuristics. There is a need, therefore, to develop practical rules and heuristics that can be used to handle the complexity of design in real applications. This paper proposes a realistic and detailed approach for conceptual design using the ER model for relational databases. The approach is based on four rules that specify the order in which various types of relationships must be modelled, three rules that pertain to detection of derived relationships, and three heuristics based on observation of constructs in real applications. The approach is illustrated by many examples.

Inferential Design Theory: A Conceptual Outline

Abstract: This paper presents initial ideas toward a new design theory based on the Inferential Theory of Learning, recently developed in artificial intelligence. The theory views engineering design as a process of transforming the initial design specification and design background knowledge into the desired design. This process is performed using certain knowledge operators called ‘knowledge transmutations.’ Nine basic tenets of the theory are provided, and a system of 22 design knowledge transmutations is proposed. Individual transmutations are defined and explained using examples from the area of conceptual design of wind bracings in steel skeleton structures of tall buildings. The paper also contains initial conclusions and a discussion of future research.

A functional approach to redesign

Abstract: This paper describes a methodology to assist in the identification of possible conceptual design variants during redesign. The approach is based on functional reasoning and involves: (1) the structural and functional analysis of an existing design; (2) the production of abstract representations of functions and design entities using conceptual graphs; and (3) design interrogation based on a functional tree approach. The research reported in this paper also focuses on the definition and the representation of elementary mechanical functions. Extended Backus-Naur Form (EBNF) notations are used to structure in a computable form, the relevant information (or design knowledge) conceptualised in either the conceptual graphs or the functional trees. EBNF syntax is also used to formulate rules which aid the partial automation of the reasoning process. The EBNF notations can be mapped to any programming language. A diaphragm valve is used as a case study to demonstrate the approach.

Computational proxies: modeling scientific applications in object databases

Abstract: This paper addresses problems of data management and interoperability for computational science applications. We recount efforts to design and implement a framework for computational experiment management that encapsulates computationally intensive programs in an object-oriented database. The mechanism we designed and implemented, dubbed "computational proxy", is defined, and a conceptual design for it rendered. We also describe the functional components of the proxy, i.e. the ability to start up and control application invocations and to capture experimental results into the database. We specifically address applications in computational chemistry, but believe our work is applicable to other computational sciences. >

Automation Based Creative Design: Research and Perspectives

Abstract: Introduction (A. Tzonis, I. White). Case-based design and creativity (G. Schmitt). Remembrance of things past: design precedents in libraries (R. Oxmna, R. Oxman). Modelling the representation of architectural design cases (C. Kuhn, M. Herzog). The 98% solution (F. Jules). The image and the model (P. Quintrand). The future of visual design representations in architecture (A. Koutamanis). A multi-level primitive generic components model (L.K. Alberts, P.M. Wognum, N.J.I. Mars). The pedagogical grammar (G. Stiny). Artifact grammars and architectural invention (W.J. Mitchell). The design of prismatic and crystalline building shapes with the help of computer techniques (P. Huybers). System architecture for computer integration of design and construction knowledge (C.M. Eastman et al.). Integrated use of building design tools: results from the combine project (G. Augenbroe). Computational support for shared memory in design (E. Subrahmanian et al.). Design as a collaborative process (D. Sriram). Deliberation and aggregation in computer aided performance evaluation (Q. Cao, J.-P. Protzen). Iconographic thesaurus: a key to subject retrieval in pictorial information systems (J. van den Berg, H. Brandhorst, P. van Huisstede). Tracing architectural history (R. Stenvert). A database of the non-domestic building stock of Britain (P. Steadman). Desktop design: a toolkit approach on cost and planning modelling (T.-H. Lin, J.-P. Protzen). A model of the architectural design process, and some implications (R. Hamel). The ideate project: exploring computer enhancements for conceptualizing (J.M. Hennessey). Mixtures of simples: towards a technology for designing (P. Papazian). Towards the automation of conceptual design (S.N. Pollalis). Critical issues in automation based creative design education (D.L. Schodek). Name Index. Subject Index.

Machine Learning of Design Rules: Methodology and Case Study

Abstract: This paper describes a methodology for applying machine learning to problems of conceptual design, and presents a case study of learning design rules for wind bracings in tall buildings. Design rules are generated by induction from examples of minimum weight designs. This study investigates the applicability of machine learning methods that are capable of \Iconstructive induction\N, that is of automatically searching for and generating problem-relevant attributes beyond those originally provided. The decision rules generated by machine learning programs specify design configurations that are recommended, typical, infeasible, or those that are to be avoided. The learned rules captured some of the essential expert’s understanding of the design characteristics involved in selecting wind bracings for tall buildings. These results are promising and demonstrate a potential practical usefulness of the proposed methodology for automated generating of design rules.