Showing papers on "Design tool published in 1978"

Programming Viewed as an Engineering Activity

Abstract: : It is profitable to view the process of writing programs as an engineering activity. A program is a deliberately contrived mechanism constructed from parts whose behaviors are combined to produce the behavior of the whole. One proposes to develop a notion of understanding a program which is analogous to similar notions in other engineering subjects. Understanding is a rich notion in engineering domains. It includes the ability to identify the parts of a mechanism and assign a purpose to each part. Understanding also entails being able to explain to someone how a mechanism works and rationalize its behavior under unusual circumstances. Part of the methodology for investigating these ideas is to build a computer-aided design tool for computer programs. The construction of this tool will serve both as a concrete realization of the theoretical ideas and as a testbed for our practical techniques.

A Case Study of Simulation as a Computer System Design Tool

Abstract: Simulation can be a powerful design tool, allowing system architects and programmers to optimize both hardware and software before a final design is chosen.

Augmented Transition Networks as a design tool for personalized database systems

Abstract: This paper illustrates the use of Augmented Transition Networks (ATNs) as a design tool for constructing document retrieval systems for those personalized applications which are too small or specialized to attract a commercial vendor. ATNs, which are explained in the context of this application, are used not only to improve the human/computer interface with the retrieval system but also to conceptually organize its structure.

Prediction of load characteristics of turbogenerators

Abstract: A method is described for the determination of the excitation requirement of a turbogenerator, on load at any power factor, from the dimensions of a design and from the magnetic properties of the stator and rotor cores. As a test of the accuracy of the method, magnetisation curves have been computed for a large generator and compared with test results. The comparison shows that the prediction is sufficiently accurate for all practical purposes. For a typical design of large generator, the effect of design changes is explored with a view to design optimisation. This gives results which are of practical significance and which demonstrate the use of the program as a design tool.

Towards the performance evaluation of distributed computing systems

Abstract: The aims of this paper are twofold. Firstly, it aims to describe progress towards the development of a performance modelling technique which is appropriate to problems involving communicating parallel activities. Secondly, in doing this, it aims to provide an example of how differing areas of research may be related to their mutual benefit, and to indicate how facets of them may be combined to provide a valuable design tool. We draw on two current areas of research: a method of expression of concurrent activities in a programming language called EPL; and analytical performance modelling techniques based on probabilistic grammars, finite state machines and computation structures. These two areas are brought together by re-casting salient features in Petri net form. Only a sub-class of Petri nets is needed, giving valuable properties which are exploited in determining the extent to which current analytical techniques can be used. A method of modelling using these techniques in combination with simulation techniques is proposed.

CYBERMAN - A Human Factors Design Tool

Abstract: In automotive packaging the utility of te design is of prime importance. The end product--the automobile--must not only be usable by all shapes and sizes of people, it must be so designed that it encourages correct use of its controls and devices. The driver should experience no obstructions, distractions or surprises in operating his car. The purpose of this paper is to show how computer methods can assist in solving problems of automotive packaging design in a 3D environment --prior to the construction of full-size mockups. /SAE/

Comprehensive, yet computationally simple, direct digital control-system design technique

Abstract: As a result of the enormous impact of microprocessors, electronic engineers, with sometimes only a cursory background in control theory, are being involved in direct-digital-control (d.d.c.) system design. There appears to be a real need for an easily understood and simply implemented comprehensive design technique for single-input d.d.c. systems. This is the objective of this largely tutorial paper, which assembles for the first time information that is widely scattered in the control-engineering literature. The proposed design technique provides, first of all, a simple calculation that ensures that the data sampling rate is consistent with the control system's accuracy specification or the fatigue life of its actuators. Pulsed transfer-function design for a plant controller is based on two simple rules and a few standard frequency-response curves, which are easily computed once and for all time. Structural resonances are eliminated by digital notch filters, the pole-zero locations of which are directly related to the frequency and bandwidth of an oscillatory mode; this is exactly as with analogue networks. In addition a computationally simple formula gives an upper bound on the amplitude of the control error (deviation) component due to multiplicative rounding effects in the digital computer; this thereby enables the selection of a suitable machine wordlength or machine. A distinct advantage of the proposed design technique is that its implementation does not necessarily involve a complex computer-aided-design facility. This aspect is confirmed by a class-2 design example in the text. Furthermore, the frequency-domain design curves are a versatile design tool in that they can also be used to design conventional 3-term digital controllers, or to translate a working analogue controller into its digital counterpart.

An APL Laboratory for Power System Engineering Education

Abstract: Supplementary use of the digital computer in power-system engineering education can provide an effective learning environment for introductory as well as advanced studies. In addition, sufficient exposure to the computer as a design tool is consistent with the expanding application of these devices in power-system planning. Presented is an approach to the creation of such a learning situation through application of an APL interactive programming system. Present instructional modules are oriented towards load-flow, fault, and transient-stability analyses, but may also be applied to other system problems which can be formulated in a bus frame of reference. Students utilizing this system in a computation session are required to define or set-up a problem, analyze results and to decide upon and evaluate any proposed system modifications. A portion of the material presented was developed with the support of the U.S. Department of Interior's Bureau of Mines under USBM Grant G0155003.

DOE-1 verification program plan

Abstract: This program plan has been prepared to provide a scheduled, comprehensive technique for verifying the DOE-1 computer program. The DOE-1 building energy analysis computer program is a very flexible design tool for architect/engineers to use in the efficient design and analysis of new or retrofitted buildings. Tasks to be performed, the interaction of the individual tasks, and the philosophy governing the performance of these tasks are described in the plan. A time schedule for initiation and completion of each task is shown, as well as the approximate date that results will be available. The successful verification of DOE-1 will provide government and the private sector with a building design analysis tool that can be used with confidence.

Interactive Composite Joint Design. Part 1

Abstract: : A computing technique was developed to determine the feasibility of combining the several batch computer programs for the analysis of composite joints into one interactive computer program utilizing graphics display This approach proved successful and produced a design tool for the analysis of bolted or bonded composite joints The program utilizes the software package provided by TEKTRONIX for the graphics display The user works at the remote on-line graphics terminal in conjunction with the main computing facilities which contain the program The final report discusses the summary, conclusion, and recommendations of the work performed The User's Manual and Programming Manual discusses the input, output, and function of the program

SPEED - an early design tool for building services

Abstract: An interactive program SPEED has been produced to assist in the sketch-plan stage of building design. It will allow an architect and building services engineer to examine the interaction between the building envelope and the internal thermal and visual environment. The program is simple to use and follows a design philosophy which will be familiar to users. The amount of data that must be provided by the user is small and use is made of data files within the program. The program is fast in execution, permitting many different design solutions to be appraised at low cost.

System Engineering In Haze, Fog, Rain And Smoke

Abstract: The simulation of the operational performance of systems utilizing optical subsystems is a design tool that is evolving with the rising cost of hardware development. The scope of existing individual sensor models and broad scope operational simulations is reviewed in terms of their suitability for use by the design engineer. The philosophy of an interemdiate category of models is presented in terms of an existing, evolutionary small scale operational model, PERTAM. The structure of PERTAM is described in terms of the integration of the individual sensor phenomenological simulations with the operational aspects of utilization. An example of the execution of the model is presented.© (1978) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.