Showing papers on "Design tool published in 1986"

A Discrete Fourier-Cosine Transform Chip

Abstract: An 8-point Fourier-cosine transform chip designed for a data rate of 100 Mbits/s is described. The top-down design is presented step by step, including algorithm modification for VLSI suitability, architectural choices, testing overhead, internal precision assignments, mask generation, and finally, verification of the layout. A high-level language (C) design tool was developed concurrently with the layout. This tool allows mimicking exactly the different representations of the algorithm: software, mask, and chip. This provides an automatic cross-checking at all design stages. The VLSI environment created by this tool, as well as existing powerful CAD tools, made a fast design-time possible.

Numerical optimization design of advanced transonic wing configurations

Abstract: A computationally efficient and versatile technique for use in the design of advanced transonic wing configurations has been developed. A reliable and fast transonic wing flow-field analysis program, TWING, has been coupled with a modified quasi-Newton method, unconstrained optimization algorithm, QNMDIF, to create a new design tool. Fully three-dimensional wing designs utilizing both specified wing pressure distributions and drag-to-lift ration minimization as design objectives are demonstrated. Because of the high computational efficiency of each of the components of the design code, in particular the vectorization of TWING and the high speed of the Cray X-MP vector computer, the computer time required for a typical wing design is reduced by approximately an order of magnitude over previous methods. In the results presented here, this computed wave drag has been used as the quantity to be optimized (minimized) with great success, yielding wing designs with nearly shock-free (zero wave drag) pressure distributions and very reasonable wing section shapes.

A simple rigid body algorithm for structural dynamics programs

Abstract: The analysis of low velocity impacts is necessary for designing everything from safe automobiles to safe shipping casks for nuclear material. Although great strides have been made in reducing the cost of impact analysis, the cost must be reduced even more before impact analysis becomes a routine design tool. One approach replaces the mesh outside of the impact zone with a rigid body.

Holdex — Holding Device Expert System

Abstract: Advances in manufacturing technology such as the introduction of FMS and modular fixturing systems, (MPS), have drastically reduced the tooling requirements for the efficient production of components. Also the advent of CAD has given a new design tool for the tooling design process. Unfortunately, although there are many advantages in using CAD systems, such systems are still found to be inadequate, particularly due to the lack of problem solving capability and their inability to embed tolerancing information.

Improved Computer-Aided Synthesis Tools for the Design of Matching Networks for Wide-Band Microwave Amplifiers

Abstract: Network synthesis is a powerful design tool when applied to the design of matching networks for wide-band microwave amplifiers. Significant design improvements have been made in the computer-aided synthesis process, which provides a powerful, efficient, and friendly tool for the microwave amplifier designer. Design methodologies are given, computer automation methods are outlined, and a complete amplifier design example is included.

The optimised design of HVAC systems

Abstract: The workable design of HVAC (Heating Ventilating and Air Conditioning) systems is based upon sizing the components individually to meet a peak duty of a nominal operating point. Growing economic pressure demands more cost effective and efficient designs, but the appraisal of alternative solutions is limited by short design and construction times. The design of HVAC systems can benefit from the application of numerical optimisation methods as these allow the rapid appraisal of alternative schemes and the sizing of the components simultaneously for criteria such as minimum first cost, operating cost, life—cycle cost or primary energy consumption. Optimisation problems can be categorised according to the characteristics of the functions used to appraise the solutions and those of the constraints on the problem. This thesis discusses the formulation of EVAC system design problems in this context and describes the development of an optimisation procedure which is based upon a data base of manufactured components and operating parameters such as controller setpoints, mass flow rates and temperatures. The thesis describes several objective functions used in the appraisal of solutions and describes the use of constraint functions in restricting the solution to a practicable design. UVAC system optimised design problems can be solved using direct search methods. The implementation of three direct search algorithms is described and the limitations of each discussed. Conclusions are drawn and the characteristics of HVAC system optimised design problems used to make recommendations for the future development of an idealized algorithm. The thesis describes the development and structure of the optimised design program and its integration with an existing suite of simulation programs. The application of the program to the design of example heat recovery systems is given and the potential use of the software in other applications described together with proposals for the development of the procedure as a design tool.

Application of expert systems in the design of bridges

Abstract: The principles of artificial intelligence have been used to develop an expert system for the design of bridge superstructures. The expert system developed, a Bridge Design Expert System (BDES), applies the ideas of artificial intelligence to the bridge design process. The result is a practical system capable of aiding any bridge designer. BDES at its preliminary stage considers superstructures of short- to medium-span bridges. It designs for structural steel and prestressed concrete girders. The developed BDES is a valuable design tool, but, more important, it has shown the potential applications of expert systems in bridge design.

Simulation - The Design Tool for the Future

Abstract: The capital and operating costs of mineral processing circuits are high. In order to reduce them to a minimum consistent with desired metallurgical performance, the design engineer must be able to predict accurately the metallurgical performance of every circuit which is to be considered for final design, relate performance to costs, and make a choice for detailed design based on these data.

Simulation aids design for flexible automation

Abstract: The widespread use of simulation as an analysis and a design tool has led to the development of a large number of programming languages (more than 600 by the end of 1980). In fact, in corporate planning many analysts opt for simulation in dealing with complex types of problems where analytic methods offer limited scope. In manufacturing the use of simulation has been much less, mainly as a result of a vacuum in model building expertise. Nevertheless, general and special purpose simulations have now been employed increasingly to aid the design and implementation of new manufacturing cells as well as to establish schedules, control inventory, balance production and determine loading capacities. This paper explores the simulation methodology and its applications in a manufacturing environment and highlights its advantages by solving an industrial problem.

Simulation of a flexible manufacturing cell

Abstract: American aerospace manufacturing operations are evaluating and implementing numerous Flexible Manufacturing Systems. Each application is a complex combination of various support systems found in a more traditional production environment. Predicting how these systems will work within the integrated framework of an FMS can be very complicated. Simulation is a valuable tool for not only evaluating a complex system for feasibility, but it can also be incorporated as a design aid. The following paper describes how a simulation model was used to assist in the design and planning of an FMS.A SLAM discrete event simulation model provided many insights into proposed system behavior and how it affected performance. In addition, this model functioned as a design tool during system development. Model development centered around a group participation concept. The model provided statistics for machine tool utilizations, manual station utilizations, inventory levels, product lead times, production levels, and queueing requirements.This particular FMS was dedicated to the machining of a complex product requiring special material handling and quality considerations often associated with high tolerance machining processes. Several simulation runs were dedicated to machine capacity and material handling capabilities. The system design process utilized much of the information obtained via modeling.

Parameter space analysis and design of an adaptive system

Abstract: We investigate the so-called ?-modification scheme which has been proposed for the design of model reference adaptive control systems in the presence of unmodeled dynamics and of disturbances. Limiting attention to first order plants with a single unknown pole and an external disturbance, we verify analytically some of the bifurcations that an example adaptive system has been shown to exhibit via computer simulations. We also construct the parameter space, or bifurcation, diagram which summarizes all possible behaviors of the systems under consideration. Finally, we demonstrate the use of the parameter space as a design tool for the proper implementation of the scheme.

SAM—a computer aided design tool for specifying and analyzing modular, heirarchical systems

Abstract: This paper presents SAM, a computer aided design tool for specifying and analyzing modular, hierarchical systems. SAM is based on Discrete Event System Specification (DEVS) and it uses generic components for specifying coupling relationships among components. The objectives of this design tool are to provide an environment for a user to specify and design systems with ease, and to allow the reuse of previously specified models to build new ones. The later promulgates increased productivity and the applicability of modular approach in the development of complex systems. Furthermore, the design tool analyses a specified system for interface errors which facilitates early testing of the specification before the model is translated into a simulator. The paper discusses how the objectives of SAM are achieved and what are the implementation issues involved. It is envisioned that the specification produced by SAM will be used to map the model onto a network of processors for distributed simulation.

A concept for an advanced computer-based building envelope design tool

Abstract: A review of current daylighting design tools indicates that over 30 tools are now available, including nomographs, protractors, overlays, and programs for micro-, mini-, and mainframe computers. Computer-based tools allow testing and analyzing of more design alternatives under a wider variety of conditions than was previously practical with slower techniques, but they have not fundamentally changed the information available to the design professional. These tools are applicable to certain limited functions of the design process and do not address the varying information needs of the designer at various points in the design process. We describe a concept for a computer-based building envelope design tool that is structured to overcome many of the limitations of the existing tools. The tool would address daylighting design in the context of the overall building envelope design, covering a range of environmental quality issues in addition to quantitative aspects of lighting and energy use. It would be useful throughout the process of design, construction, and occupancy, and is intended to provide important feedback that is often missing between those stages of the building's life cycle. A cost-effective tool with these performance features is not technically feasible using today's hardware technology. However, examination of the developmentmore » of the necessary technologies provides strong evidence for future feasibility; accordingly, we are developing the tool to be used in a 1990+ time frame. To date we have studied the features and capabilities that such a tool should have, as well as several key areas, such as the design process, computer graphics, imaging systems, expert systems, and building science data bases.« less

A Specialized Silicon Compiler and Programmable Chip for Language Recognition

Abstract: Publisher Summary This chapter discusses the construction of specialized silicon compilers, using a regular expression compiler as an example. To reduce the complexity of custom very large scale integrated (VLSI) design, a design tool is needed that automatically lays out an efficient custom chip from its behavioral specification. Such tools, often called silicon compilers, already exist; however, while they fulfill the requirement of performing automatic layout from a behavioral specification, they fail to produce chips that are efficient. Using these tools, the behavioral specification for a chip can be written in a high level programming language and can be checked and modified before the chip is laid out. The automation of the layout process ensures that the chip and the program have the same behavior. This eases the design of custom chips in two ways: (1) circuit design, layout, and similar low-level design tasks are eliminated and (2) the number of design iterations is reduced as finished chips are likely to meet their behavioral specifications. Specialized silicon compilers can be useful and feasible. The usefulness of the compiler comes from its ability to produce efficient chips automatically, while feasibility is shown by the construction of both the compiler and a programmable layout that serves as a target for the compiler.

Overhead distribution lines - some reflections on design

Abstract: While existing regulations regarding the design of overhead lines have served well the electricity supply industry, recent happenings, when many networks suffered damage in Europe, have highlighted the need for a critical review of design practices. It is argued that, provided some statistical data on meteorological phenomena are available, attempts could be made to design overhead lines to suit subsequent performance requirements. The ultimate load design concept is favoured, in which an anticipated load with a quantified probability of occurrence is compared with the strength of a component having a selected probability of being achieved. Besides, it is suggested that, by the use of suitable coefficients, a preconceived coordination of strengths of the components can be obtained. Due to electrical constraints, there is a limit on conductor sizes, beyond which there is no measurable improvement in electrical performance. There is obviously an economic impact which must be appreciated. For a rapid assessment of a suitable voltage and conductor size the technique of kVA-km is a handy design tool. Analysis of many km-years of performance of overhead lines in general has proved useful in defining guidelines for insulation selection. A similar exercise on the lightning performance of distribution lines seems to indicate the beneficial influence of earthwires, although some simplified theoretical considerations would have led to a somewhat different conclusion. Notwithstanding the many efforts by various suppliers to provide alternative types of materials for the supports, these are normally made of either wood or steel. To satisfy specific requirements they can take many shapes to obtain a variety of conductor configurations. Foundations designed for overturning are most commonly used for distribution lines, although the design techniques are seldom taught to students. Designing foundations for overhead lines should remain a challenge to civil engineers.

Pc-based pedestrian flow simulation model for grand central terminal

Abstract: A pedestrian flow simulation model was developed to test and evaluate the proposed underground pedestrian network for Grand Central Terminal's North End Access Improvements. The simulation model runs on a personal computer (PC) using the LOTUS 1-2-3 spreadsheet program. Based on the results of the simulation, planners modified the design to increase the capacities of certain passageways and to develop a more cost-effective design solution. Also, the model was used to test nearly a dozen construction-phasing options to respond to capital funding availability and passenger flow needs. The model, although not as sophisticated as some previous simulation programs, proved to be a useful and cost-effective tool in the design process. It uses widely available, inexpensive personal computer hardware and software. The pedestrian flow simulation model, its essential components, and how it was used as a design tool are described in this paper. The advantages and disadvantages of this type of approach are discussed in the conclusion.

Energy Signatures: a proposed new design tool

Abstract: Energy Signatures is a proposed new technique for aiding a designer in selecting and sizing passive solar elements on a building. Hourly heat flux profiles for each candidate design element are determined. These profiles are then matched to the hourly energy requirement of the space accounting for weather conditions, internal heat profiles of the space, and the mass characteristics of the building. Simulation analysis techniques are used to determine the Energy Signatures, the load profiles, and check the final result. Least-squares techniques are used to determine the optimum mix of strategies. Examples are given to illustrate development of the method up to the present. Future directions and possibilities are outlined.

Spreadsheets: A New Design Tool

Abstract: New techniques are developing which make computer programming easier. One new technique is spreadsheet programming for microcomputers. Two programs are presented which give a quick overall look at different applications (steel beam design template, and biaxial loading footing design). There are other programs for applications such as retaining walls, reinforced concrete beam design, steel moment connections, etc. All these applications solve common everyday problems. As the trend increases toward the use of spreadsheet programming in lieu of conventional programming languages, more elaborate worksheets will include steps for more involved applications. The author encourages the use of spreadsheet programs because they not only speed up the calculations but also allow the engineer to get a direct feeling for his own design.

Improved Computer-Aided Synthesis Tools for the Design of Matching Networks for Wideband Microwave Amplifiers

Abstract: Network synthesis is a powerful design tool when applied to the design of matching networks for wideband microwave amplifiers. Significant design improvements have been made in the computer-aided synthesis process which provides a powerful, efficient and friendly tool for the microwave amplifier designer. Design methodologies are given, computer automation methods outlined and a complete amplifier design example is included.

Simulation - the design tool for the future

Abstract: The capital and operating costs of mineral processing circuits are high. In order to reduce them to a minimum consistent with desired metallurgical performance, the design engineer must be able to predict accurately the metallurgical performance of every circuit which is to be considered for final design, relate performance to costs, and make a choice for detailed design based on these data. Techniques currently used for design accurately the total performance of a simulation techniques are suitable for this that the unit models are valid. It is for simulation is such an important design tool. for accurate simulation are: cannot predict circuit whereas purpose provided this reason that The requirements -valid mathematical models of each unit in the circuit, -experimental data which can be used for the calculation of the parameters for use in the models. The simulation of mineral processing circuits has been a popular subject for research for many years and considerable progress has been made. Size reduction circuits containing crushers, vibrating screens, rod mills, ball mills and hydrocyclones, can be modelled accurately, and accurate predictions of circuit performance at different operating conditions can be made based on laboratory or plant data. Consequently, simulation is a valuable aid in the design of these circuits. An example is given of the use of simulation for this purpose. Progress is not as other units in mineral is given of the status

Computational fluid dynamics as a design tool for the hot gas manifold of the Space Shuttle Main Engine

Abstract: The paper discusses the application of computational fluid dynamics as a design tool for the Hot Gas Manifold of the Space Shuttle Main Engine. An improved Hot Gas Manifold configuration was arrived at computationally. This configuration was then built and air flow tested. Testing verified this configuration to be a substantial improvement over existing flight designs.

An Interactive, Graphical, CAD Integrated Tool for Stray Radiation Analysis

Abstract: The stray radiation analysis tool presented here is based on a general ray tracing program which is integrated with the "Euclid" 3-D solid modeling CAD system. It is an analysis/design tool whose main features are its highly accurate representation of mechanical structures, its interactivity, its visualization capability and the understanding it gives the user about the paths by which stray radiation propagates through the opto-mechanical system.

CAE: A Tool for the Engineer--A Dilemma for the Academic.

Abstract: This paper considers the impact of Computer Aided Engineering (CAE) on traditional engineering teaching philosophy and methodology. The nature of CAE is discussed and the problems associated with its inclusion within existing curricula examined. The integrative potential available is seen in terms of a challenge to engineering education. The academic dilemma posed by the challenge of CAE is presented and a new educational approach based on CAE as the teaching vehicle advocated. The introduction of CAE is seen to provide an opportunity to re–appraise teaching philosophy, devise new objectives and fundamentally revise teaching methods to take full advantage of the potential available. One academic response to the challenge of CAE is discussed and illustrated with reference to several documented examples. The use of CAE as a design tool for problem simulation and solution is advocated. The paper concludes by observing the need to change traditional teaching philosophy, methodology and practices.

Preliminary design methods for fiber reinforced composite structures employing a personal computer

Abstract: The objective of this project was to develop a user-friendly interactive computer program to be used as an analytical tool by structural designers. Its intent was to do preliminary, approximate stress analysis to help select or verify sizing choices for composite structural members. The approach to the project was to provide a subroutine which uses classical lamination theory to predict an effective elastic modulus for a laminate of arbitrary material and ply orientation. This effective elastic modulus can then be used in a family of other subroutines which employ the familiar basic structural analysis methods for isotropic materials. This method is simple and convenient to use but only approximate, as is appropriate for a preliminary design tool which will be subsequently verified by more sophisticated analysis. Additional subroutines have been provided to calculate laminate coefficient of thermal expansion and to calculate ply-by-ply strains within a laminate.