Abstract: Focuses on the problem of engineering design based on the behavior of random variables. Gives numerous examples for determining reliability specifications in which both over- and under-designing can be avoided. Presents design methods that be adapted to nuclear, electrical and mining engineering as well as mechanical engineering specialities.

Abstract: A broad engineering design philosophy and summary is presented as a guide for the safe design of nuclear structures. The manual does not aim to provide specific criteria which are detailed in nature and subject to frequent revision. General considerations, NRC licensing and existing codes, standards and regulations are reviewed. Eight chapters explore the following: (1) probability of failure assessment and rational determination of design requirements, (2) load and behavior criteria, (3) structural design and analysis, (4) seismic analysis and design, (5) design against impluse and impact loads, (6) foundations and buried structures, (7) quality assurance and quality control requirements, and (8) influence of siting concepts in structural design criteria. The procedures described are applicable to large commercial or central station nuclear power plants, and the manual is intended for engineers who are knowledgeable on normal (principally static) loads. Mechanical and electrical aspects of design are treated briefly. The manual was prepared by the editing board and task groups of the committee on nuclear structures and materials of the ASCE Structural Division and it is No. 58 in the ASCE Manuals and Reports on Engineering practice series.

Abstract: A method is presented for the optimum shape design of trusses. This method obtains the optimum locations of the joints while it employs the concept of ground structure. In the formulation of the design problem the displacements of the joints are treated as design variable in addition to member areas and joint coordinates. For the solution of the nonlinear design problem an approximating program is adopted. The proposed design procedure does not require the structural analysis equations to be solved during the design process. Examples are given to demonstrate the flexibility of the method.

Abstract: This article is an account of the development of the Control Data 6600 computer first developed in 1964. Of historical interest is the design team approach adopted by Control Data in which a small staff of engineers was isolated from the main operations of the company. Some review is made of the design process as well as the unique features of the machine. The article also includes some comments in retrospect about the results of certain of the initial design objectives.

Abstract: Data tracking is a software engineering technique for designing and/or documenting a hierarchically structured software system. Its characteristics include a representation of each module in the system as a complete procedural statement, provision for a two part interface of every module in the application hierarchy to a software support system such as a DB/DC system, a method for hiding subfunctions and a development languge mode. Its capabilities include ease of representing DB/DC as well as batch applications, the ability to stage the design process as well as the implementation process, the definitions of independent development units and the capabality of representing many top-down architectural styles.

Abstract: Proper design of fume hoods is a necessary requisite for a clean working environment for many industrial processes. Until recently, the design of these hoods has been rather a trial and error approach and not based on sound engineering design principles. Hatch Associates have developed and applied new techniques to establish hood parameters for different industrial processes. The paper reviews the developed techniques and illustrates practical application of these techniques to the solving of difficult and complex fume hood design and operating performance problems. The scope of the paper covers the following subject areas: definitions and general considerations; evaluation of volume and heat flow rates for emission sources; local capture of process emissions; remote capture of process emissions and case studies of fume hood applications. The purpose of the paper is to detail a coherent approach in the analysis of emission problems which will result in the development of an efficient design of a fume capt...

Abstract: The protection structures of most computers in commercial use today are the results of a haphazard design process. This work represents an attempt to correct this state of affairs by integrating a wide variety of previous work in the areas of programming language design, memory protection, and design methodology. The design process is formalized as a structured walk through the multidimensional computer design space towards an optimal machine. The starting point for this walk is the result of a semantic analysis of the problem to be solved, and the walk ends when no changes to the design result in any improvement. This design approach is used to arrive at a practical general purpose protection architecture from the programming language Ada. This architecture is shown to be comparable in complexity and performance to that of the PDP-11/45. The semantic analysis of Ada required for this effort suggests a number of ways in which Ada or similar languages could be improved, and many of these improvements are anticipated by the proposed protection architecture. In the process of examining problems with Ada, a new protection structure design principle is identified: That the static and dynamic rights transfer mechanisms should parallel each other. Although this principle is violated by Ada and most existing languages, it is obeyed by the proposed architecture. Measures of protection are required in order to identify desirable changes to an architecture or language. A number of existing protection measures are surveyed here, and these are extended to take into account the effects of combining different protection mechanisms, as is commonly done in the process of language implementation. A new overprotection measure is proposed for identifying redundancy in such situations, and this is used as a heuristic to guide the search for an acceptable protection mechanism.

Abstract: This paper describes an information processing approach to forming accurate construction cost estimates durning the design process. The process contains three major phases comprising 19 stages which cover the multiple facets of factors which affect such an estimate. Also presented are some general concepts, strategies, conclusion, and generalized flow charts of the overall process. The contents of the paper were derived from heuristic analyses of two such estimates carried out by the author which produced results very close to the amounts of subsequent construction bids for a hospital alteration project and a school addition and alteration project in the $5,000,000 to $10,000,000 range. The purpose of the paper is to methodology a generalized mothodology and consideration of the many factors which can lead to high accuracy in carrying out construction cost estimating in the design process.

Abstract: The design process is one of the sources used to produce requirements for a computer system to integrate and manage product design data, program management information, and technical computation and engineering data management activities of the aerospace design process. Design activities were grouped chronologically and explored for activity type, activity interface, data quantity, and data flow. The work was based on analysis of the design process of several typical aerospace products, including both conventional and supersonic airplanes and a hydrofoil design. Activities examined included research, preliminary design, detail design, manufacturing interface, product verification, and product support. The design process was then described in an IPAD environment--the future.

Abstract: This dissertation describes research into an experimental interactive knowledge-based system whose domain of expertise is digital electronics. The system is named SADD for Semi-Automatic Digital Designer. The goals of the research are (1) to represent the working knowledge that humans have of digital electronics and (2) to utilize this knowledge in a useful design environment. This requires both a digital problem solver and an intelligent bookkeeping mechanism. In the SADD environment, design is a four phase process: Specification Acquisition, Implementation, Integration and Analysis. In each phase the user can play an integral role in the design (hence the term semi-automatic). In the Specification Acquisition phase, the user can describe the circuit in an English-like language. This usually entails identifying the digital components and their characteristics, defining connections between these components, and describing how and when signals propagate between the components. Each input sentence is mapped into a set of directives for manipulating the conceptual model of the circuit, maintained as a semantic net. The Implementation phase is used to select a strategy for refining a function into a chip-level implementation. The selection process is based on the characteristics of the function: both the explicit characteristics provided by the designer and the implicit characteristics inferentially determined by the function's context. SADD performs this implementation one function at a time, aided minimally by the user. The Integration phase maps the conceptual connections between the individually implemented functions into actual wires, the result being a constructable circuit schematic. The Analysis phase (which is described, but not implemented) allows for simulation of both the conceptual model in terms similar to those of the designer and the implemented model where timing information is crucial. This analysis can be performed on a partial or complete circuit. The SADD system uses a sophisticated TV display circuit known as the Screensplitter for its case study. The circuit is described in 41 sentences. Since SADD is designed as an intelligent bookkeeping system this description is intentionally incomplete to illustrate how SADD will detect and fill in missing concepts and connections that are necessary for a function to perform properly. Examples using the Screensplitter illustrate each of SADD's phases. The future plans for SADD are to expand its digital knowledge base, to provide a graphic display environment for the design process, and to implement the analysis package.

Abstract: The basic goal in the design of computer control units is the efficient, high-speed allocation, orchestration, and synchronization of the computer resources. The key concept to meeting the above requirements is the continual optimization of the control structure during the design process. This paper defines an approach to control optimization which is independent of the particular control structure.

Abstract: Maintaining productivity levels while assuring the quality of engineering products grows increasingly more difficult and costly for industries such as the energy industry which are heavily committed to product design. The man/machine interface made possible through the development of computer-aided design/computer-aided manufacturing (CAD/CAM) technology can be applied to the design process as a tool for increased control to assure the quality of the final engineering product. The quality-control aspects of CAD/CAM technology are addressed in this presentation.

Abstract: A joint NASA/industry project called Integrated Programs for Aerospace-vehicle Design (IPAD) is described, which has the goal of raising aerospace-industry productivity through the application of computers to integrate company-wide management of engineering data. Basically a general-purpose interactive computing system developed to support engineering design processes, the IPAD design is composed of three major software components: the executive, data management, and geometry and graphics software. Results of IPAD activities include a comprehensive description of a future representative aerospace vehicle design process and its interface to manufacturing, and requirements and preliminary design of a future IPAD software system to integrate engineering activities of an aerospace company having several products under simultaneous development.

Abstract: This paper presents GLIDE, an integrated design database facility, that supports implementation of systems capable of incorporating all the information needed for the design and construction of large engineering projects. GLIDE is a computer language incorporating database, geometric modeling, graphics and command processor facilities. Some facilities have been described and others suggested that seem to be desirable for a general purpose engineering design database. In most facilities the importance of maintaining generality and flexibility are described, partly because of the great diversity of engineering practices, but partly also because of the lack of understanding of the design process. The ability to develop practical applications based on such systems will be strongly dependent on the development of better models of designing. It is for this reason that a section on the notion of abstraction hierarchies is included, as an indication of the kind of conceptual models that may be required. The development of a new generation of CAD applications must go hand in hand with the development of a better understanding of the design process.

Abstract: The design methodology for the determination of the optimal heliostat field designs is presented in detail for a small solar central receiver. The optimization process is reviewed. Cost and performance models are discussed. To illustrate the design process, a representative small solar central receiver system is optimized. Cost factors were developed from current prices. The individual heliostat design and cost data were taken from the design of the ten megawatt-electric Barstow Pilot Plant design. A north field configuration, steel guyed tower and a tilted, circular aperture, cavity receiver were utilized. It is demonstrated that solar central receiver systems are more cost effective at higher power levels, above those considered here. But this fact has nothing to do with relative cost effectiveness of competing small, stand-alone, power systems.

Abstract: This paper describes a new sophomore course being offered at Purdue University in the area of aerospace design. While the course and the examples used in this presentation deal with aerospace engineering, the overall structure is presented as being applicable in other engineering areas as well. The basic idea is that, with time, more of the design processes will involve the use of a computer and this necessarily will force the design process towards a higher degree of organization. The course is a simple illustrative example within this viewpoint. The basic modules of aerospace engineering of flight mechanics, aerodynamics, structures, propulsion, weights, air transportation, stability and control, and performance are used to formulate a set of constraints, which, in the particular example, are positive static stability, trim, structural integrity, and range. A (paper) aircraft is defined as an element of the set of feasible values of design parameters (geometry, altitude, speed). Then, given the subset of aircraft which satisfies all the constraints, the aircraft, with the optimum index of performance, is defined to be the best aircraft.

Abstract: The intent of this paper is to describe a major Department of Energy (DOE) thrust to bring line-focus solar thermal technology to commercial readiness. This effort is referred to as the MISR Project. The project is based upon the premise that thermal energy is the basic solar thermal system output and that low-temperature, fossil fuel applications are technically the first that should be retrofitted. Experience has shown that modularity in system design and construction offers potential for reducing engineering design costs, reduces manufacturing costs, reduces installation time and expense, and improves system operational reliability. The modular design effort will be sponsored by Sandia National Laboratories with industry doing the final designs. The operational credibility of the systems will be established by allowing selected industrial thermal energy users to purchase MISR systems from suppliers and operate them for two years. Industries will be solicited by DOE/Albuquerque Operations Office to conduct these experiments on a cost sharing basis. The MISR system allowed in the experiments will have been previously qualified for the application. The project is divided into three development phases which represent three design and experiment cycles. The first cycle will use commercially available trough-type solar collectors and will incorporate 5more » to 10 experiments of up to 5000 m/sup 2/ of collectors each. The project effort began in March 1980, and the first cycle is to be completed in 1985. Subsequent cycles will begin at 3-year intervals. The project is success oriented, and if the first cycle reaches commercial readiness, the project will be terminated. If not, a second, and possibly a third, development cycle will be conducted.« less

Abstract: This paper discusses the Interactive Graphics System used by the General Electric Company, Medium Steam Turbine Department (Engineering & Manufacturing) for designing, drafting, and manufacturing applications. A brief overview of the hardware malting up the system is described, followed by a more detailed description of the actual applications. Two-dimensional applications described include a Heat Balance Analysis, Flow Diagrams, and Electrical Schematics. A more fruitful area for increased productivity gains is described in the three-dimensional or mechanical applications including turbine design & layout and bucket design. coordination of the design with manufacturing for numerical control tape generation is described through CAM and Plate Frame Cutting applications. Finally, a short review of the engineering design work using Interactive Graphics is discussed. Productivity gains of 2.6 to 1 are being realized, and the overall savings to the Medium Steam Department are outlined.