General Design Theory Research Articles

一般設計学の展開(第2報)

一般設計学の展開(第2報)

Formal relationships among governing boards, CEOs, and medical staffs in independent and system hospitals.

This study examines the impact of hospital participation in multi-institutional arrangements on formal relationships between hospital governing boards and chief executive officers (CEOs) and between governing boards and hospital medical staffs. Hypotheses are derived from Mintzberg's general theory of organizational design and are tested using combined data from three American Hospital Association Surveys of nonfederal, short-term hospitals. Analysis results provide considerable support for the study hypotheses. CEOs were found in general to have more formal influence in decisionmaking but also were more likely to be held accountable for performance standards in those hospitals that are part of multi-institutional arrangements. In addition, analyses using both 1976 and 1982 survey data indicate that hospital participation in multi-institutional arrangements is associated with lower levels of formal involvement of the medical staff in institutional decisionmaking. Relationships, for the most part, remain unchanged after the introduction of statistical controls for hospital size. One important issue raised by these findings is the possible impact on hospital performance of less participation by medical staff in the governance of hospitals whose boards are either responsible for multiple hospitals or accountable to higher organizational authority.

On the function of flowers

Most flowers are bisexual in function, but counting secondary allocation to attractive structures such as the corolla as equally male and female leads to the paradoxical conclusion that plants bearing perfect flowers invariably allocate much more to female than to male function. A method of calculating the gender of secondary floral allocation is described, and it is speculated that this allocation is predominantly male. Observations and experiments with natural populations of herbs, designed to test this hypothesis gave the following major results, (i) Insects visit larger flowers more frequently ( Fragaria ), and removal of floral biomass causes a reduction in the frequency of insect visits proportional to the fraction of biomass removed ( Impatiens ). (ii) Removal of attractive structures may cause a decline in the probability that a fruit will be formed but has no effect on the number of seeds set per fruit; thus, mutilation of essentially solitary flowers has no effect on seed-set per fruit ( Impatiens ), while removal of flowers from inflorescences in a species that forms several many-seeded fruits per inflorescence reduces fruit-set per inflorescence but has no effect on seed-set per fruit ( Asclepias ), and removal of sterile flowers from an inflorescence in which the fertile flowers yield one-seeded fruits is effective in reducing seed-set per inflorescence ( Viburnum ), (iii) Larger flowers may disperse a greater fraction of their pollen in unit time ( Impatiens ) and the removal of flowers from inflorescences causes a steep reduction in total pollen exported and a weak decline in the quantity of pollen exported per flower ( Asclepias ). These results are consistent with the hypothesis that a single insect visit (or a very few visits) suffices to fertilize almost all available ovules and is procured by a very small allocation to attractive structures, while much greater allocation is necessary to procure the numerous visits required to disperse a large fraction of the pollen. This inference is supported by a comparative survey of sexually dimorphic plants, in which male flowers are generally larger than female flowers, male inflorescences bear more flowers, and male plants bear more inflorescences. It is concluded that the flower is primarily a male organ, in the sense that the bulk of allocation to secondary floral structures is designed to procure the export of pollen rather than the fertilization of ovules. This conclusion may be sensitive to whether it is the flower or the inflorescence as a whole that represents the primary unit of attraction to insects. It was found that the performance of a given flower was substantially affected by other flowers in the same compact inflorescence ( Asclepias ), though not by other inflorescences on the same plant nor by those borne by nearby plants ( Fragaria, Impatiens ). A general quantitative theory of flower and inflorescence design is outlined, and used to organize the extensive experimental results for Asclepias .

Design Theory for CAD/CAM Integration

Summary It is shown that integration of CAD is necessary for CAD/CAM integration. Present CAD systems aids designers only at final stage of design process, ie production design and drawing, sometimes with optimization. Design does, however, include more abstract thinking process such as concept design and detail design. In this paper, some CAD systems are shown that aid designers at these earlier stages. First, general design theory was established in order to elucidate design process, and then it was applied to develop CAD systems. These CAD systems are, then, integrated. On this integrated CAD, an investigation was made about possibility of automatic generation of manufacturing instructions from the result of design without intervention of engineers. It was shown that, in case of integrated CAD, necessary data can be obtained for manufacturing by tracing backward the process of design, which is preserved in the CAD systems.

一般設計学の展開(第1報)

一般設計学の展開(第1報)

General Differential and Lagrangian Theory for Optimal Experimental Design

The problem of optimal experimental design for estimating parameters in linear regression models is placed in a general convex analysis setting. Duality results are obtained using two approaches, one based on subgradients and the other on Lagrangian theory. The subgradient concept is also used to derive a potentially useful equivalence theorm for establishing the optimality of a singular design and, finally, general versions of the original equivalence theorems of Kiefer and Wolfowitz (1960) are obtained.

設計過程モデル論 一般設計学における機械設計へのパイナンバの応用

This paper describes a design process theory by axiomatic approach based on General design theory. Theorems under a hypothesis concerning real designers are deduced, and from it, a production rule type design process model is introduced. In this design process model, the design specification is decomposed into some concepts about physical rules, and the function elements, each of which actualizes the corresponding physical rule as an entity, are selected. The design specification is actualized by the combination of those function elements.In order to operate this design process, a good representation method for functions which enables the decomposition of the specification or the representation of the physical rules, is.required. In the present study, the pai-number method is developed, which is derived from the fact that a machine function can be expressed by the inputoutput energy relation. By using this pal-number method, a guiding principle for the rationalization and the construction of CAD systems of the conceptual design stage of machines is obtained.

実験設計学 一般設計学のための実験的方法

The purpose of this paper is to derive a general theory of design from experimental results of design by the method of structural analysis of them. A specification is given to designers. They discuss it, analyse it, propose tentative design solutions, and finally get to a conclusion which satisfies the specification. The conversation is recorded and reviewed to extract rules governing the thought process by which they converge to the conclusion. This experimental method is found useful to derive the general theory of design. Four models of designing process are extracted : (1) function-attribute transition model, (2) Markovian model, (3) flow diagram model, and (4) logical structure model. These represent characteristic aspects of designer's designing activity respectively. They reveal the merits and demerits of a designer, from which some proposals for improving the design efficiency are obtained, concerning the design process, such as sequence of design steps, amount of information given at each step, distribution of evaluation steps among others, etc. These proposals are useful for practical construction of CAD systems. The models are also compared with deductive models constructed by the axiomatic approach. Good correspondences are found between them.

一般設計過程

Designing process is studied in an axiomatic approach. In the previous paper, the axiomatic approach was found capable of deriving a general design theory which clarifies fundamental principles of human designing activity. In the present paper, the similar method is applied to study dynamic aspects of design, that is designing process. Under the same axioms as the previous paper, the designing process by a real designer is analysed. The real designer is defined as one who deviates from the ideal one by several kinds of imperfections in the memory structure and the thinking process. In case a designer has no imperfections, say an ideal knowledge, it is understood that he reaches a design solution which satisfies the specification given in a mathematical way or algorithmically. A theorem, on the contrary, is deduced which insists that a real designer with some imperfections cannot design unless he is given some specific knowledges which directly link the function to the attribute compensating his imperfections. From the study, four models are proposed by which a real designer can design compensating his imperfections; the catalogue model, the calculation model, the production model and the paradigm model which have correspondences to actual design activities of designers and also have applicability to CAD system constructions.

Optimum design for work-hardening adaptation

Abstract The finite element-linear programming approach and the work-hardening adaptation criterion are used to formulate a general theory of optimum design of rigid-work-hardening structures subjected to loads which vary statically within given limits. Self-weight, as well as some technological constraints, can be introduced into the framework of the optimization problem. The optimality conditions are discussed with the aid of geometrical descriptions as well, and a comparison is made with the standard limit design. Numerical applications are given for a plane truss and a plane frame with axial force-bending moment interaction.

On the synthesis of bandpass filters with bridged topology

This paper presents a general design theory for bridged topology filters exhibiting a Chebyshev characteristic within any wide passband and an arbitrary out-of-band response. The networks proposed consist of LC grounded resonators capacitively coupled to each other. All the inductances have the same value and also negative couplings may be realized by using 1:-1 transformers. One of the most interesting applications is the design of an FDM channel filter working in the 24-28-kHz range. Some experimental results are described.

Producing Designs Of Physical SystemsThrough Model Transmutations

In this paper, engineering design is considered from the point of view of modeling i.e. the construction and manipulation of models of (possible) physical realities. Consequently, the design activity has been analysed in terms of patterns of inference called model transmutations. Three categories of transmutations namely, transformations, combinations and prototype copying, have been discussed with reference to the Multimodeling approach for representing physical systems. The major goal of the paper is to provide a conceptual framework for analysing existing design systems and for addressing questions concerning their competence such as what types of inference patterns underlie different design strategies e.g. case-based, compositional and analogical design; what kind of design solutions a design system is able to generate from what kind of input specification and prior design knowledge; what is the logical relationship between specification and prior design knowledge. A second goal is to provide a basis for the development of a general theory for reactive multistrategy design that aims at combining a range of different design strategies dynamically, in order to take advantage of their respective strengths and address a wider range of practical problems.

Optimal design of elastic structures for maximum stiffness

The purpose of this paper is to establish a general theory of optimal design of elastic structures such that the structure with a given volume would have maximum stiffness. A sufficient condition of optimality is derived from the principle of minimum potential energy. This optimality condition is proven by the variationa! method to be a necessary one under the condition that the optimal structure has certain continuity and differentiability properties. Physical interpretations of the optimality condition are discussed for problems of beams, plates and trusses. An application of the theory is illustrated in a problem of optimal design of a simply supported circular plate under uniform pressure. Detailed description of the numerical procedure for the solution of the plate problem is presented.

Narrow-Band Self-Filtering Junction Detectors

The general principles and design theory of p-n junction detectors with narrow spectral responses are described. These detectors do not require the use of external filters and are capable of maintaining their narrow spectral response over large fields of view. Use of zinc diffusion in n-type gallium arsenide has produced detectors peaking in the neighborhood of 8850 Å with characteristic bandwidths on the order of 200 Å and quantum efficiencies from 0.2–0.3 electrons per photon. The principle has been experimentally extended to a second material, indium-arsenide—phosphide, whose composition is tuned to provide a narrow spectral response peaking at 1.06 μ. The experimental results are compared with theoretical predictions.

A General Theory of Optimal Plastic Design

The method of optimal plastic design used by Marc¸al and Prager [1] is reviewed and generalized to arbitrary one and two-dimensional plastic structures, and the uniqueness of optimal designs is discussed.

Design of bidirectional coherent counters

The general design theory of coherent parallel counters is described and illustrated by the design of a 5421 BCD counter. The method shows how the counter can be steered to operate bidirectionally. Details of design data for a number of differently coded bidirectional decade counters are also given. The circuits described use JK flip flops and have been fabricated using silicon integrated circuits in order to prove the theory. (In this paper, as in current usage, flip flops are bistable elements.)

GaAs—Si photon-activated switch

A light-activated low-level switch (LAS) has been developed for multiplexing applications. The switch consists of an electroluminescent GaAs p-n diode and a double-emitter silicon transistor. (Both NPN and PNP units have been made.) The two, light emitter and detector, are coupled optically. The switch is a substantial improvement over existing switching devices used in multiplexers. A general design theory based on the Ebers & Moll [1] low-level transistor model is given, with special emphasis on breakdown voltage, ON impedance, offset voltage, and switching speed. It is shown how the design considerations lead to a specific geometry for the detector. Results of extensive testing are reported.

A method of constructin g balanced incomplete block desi gns

Dr Eric-Roy Muller was a research student in the Department of Statistics, University of Aberdeen from 1959 to 1962. A scientist of great promise, he received the degree of Ph.D. in June 1962 for his thesis ‘On Confounding of Asymmetrical Factorial Designs’. Shortly afterwards, he returned to his position in the Department of Statistics, University of Natal. In January 1963, he and his wife were killed tragically when their car was hit by a train at a level crossing. Roy Muller's thesis included critical discussion of the problems that arise in confounding factorial arrangements, in such a way as to conserve information on the most important contrasts, when the combinations of factor levels and block size present difficulties not encountered in the classical factorial designs. His pseudo-factors and related devices provide new methods of construction and some new designs. In the belief that this work is of value to the general theory of experimental design, and as a tribute to our friend and fellow statistician, my colleagues and I hope to condense parts of the thesis for publication. This first paper, though a digression from the main theme, develops a method that is to be used later.

Approximation Theory for Filter-Networks

This paper presents a general design theory for filter-networks constructed on the basis of theory of the Abelian Integral. An ideal transmission function is defined to be an Anbelian Integral w(\lambda) with the following properties: 1) Re w(\lambda) = u(\lambda) = A_k in given regions B_k , 2) \{u(\lambda) - \log | \lambda + a_i|\} is regular at any given point a_i , and 3) otherwise u(\lambda) is a harmonic function. The application of appropriate analytic transformation techniques to w(\lambda) leads to a generalized characteristic function \phi(\lambda)) . All kinds of realizable transfer functions can be derived by the use of linear transformations of \{\phi(\lambda)\}^2 with respect to \lambda^2 . Further, this treatise gives the design methods for filter-networks having one or two pass bands, in which they exhibit the Tchebycheff performance. Besides the method is also established to synthesize a reactance band-pass network with the order N using only [(N - 1)/2] coils. Three design examples, such that the band-pass filter comprising only 6 coils for N = 13 and 4 coils for N = 10 , and the double-pass-band filters with N = 8 and 4 coils, are described in quite detail. All of the examples have the Tchebycheff performance in their pass bands.

The Theory of the Ideal Design of a Compound Vessel

A general theory for the elastic design of a compound cylinder made by shrinking together many concentric cylinders is described. Each cylinder may have entirely different strength and operate at any temperature under any pressure, internal or external. The only assumptions, in addition to the usual homogeneity and isotropy in each member, are that they have the same Young’s modulus, although even different elastic moduli could be accommodated, and that they are not so thin that stability becomes a problem.