Showing papers by "City University London published in 1979"
TL;DR: In this paper, an alternative feature-based model of category definitions, using the notion of a Polymorphous concept, can account for the results without making the distinction between defining and characteristic features, on which Smith et al's model relies.
327 citations
TL;DR: The algorithm is shown to perform satisfactorily in a digital simulation study concerned with determining food flow rate and temperature controller set points to maximize the net rate of return from an exothermic chemic...
Abstract: In this paper an algorithm is described which uses a steady-state mode! to determine the optimum operating point of a process. The model, which is not required to be an accurate representation of the real process, contains parameters to be estimated and the algorithm involves an iterative procedure between the two problems of system optimization and parameter estimation. Lagrangian analysis is employed to account for the interaction between the two problems, resulting in a procedure which may be regarded as a modified two-step approach in which the optimization objective index includes an extra term. The extra term contains a comparison between model and real process output derivatives and ensures that the optimal steady-state operating condition is achieved in spite of model inaccuracies. The algorithm is shown to perform satisfactorily in a digital simulation study concerned with determining food flow rate and temperature controller set points to maximize the net rate of return from an exothermic chemic...
238 citations
TL;DR: A critical appreciation of the theory that the recall of an event entails a generation (or search) process followed by a recognition (or decision) process is given in this article. But the results of a large number of studies run counter to its predictions or are otherwise not readily accommodated by it.
124 citations
TL;DR: The effect of auditory as opposed to visual presentation was explored in a free recall paradigm in which each list word was preceded and followed by a period of oral distractor activity.
88 citations
TL;DR: The results may be used to determine corresponding colors for the adaptation conditions studied and be used as the basis for developing mathematical expressions for predictions of corresponding colors under other illumination conditions as well.
Abstract: Chromatic adaptation has been studied by applying methods of direct scaling to color appearances of invariant stimuli seen under different conditions of adaptation. The influence on color appearance of correlated color temperature of illumination, sample luminance factor, illuminance, and surround induction was studied. Perceived hue [expressed as proportions of unitary hues] varies with color temperature of illumination but not significantly with luminance factor or illuminance for the conditions of these experiments. Colorfulness varies with color temperature and also with luminance factor and illuminance, although relative colorfulness does not change significantly with illuminance. Lightness varies with luminance factor but is essentially independent of color temperature and illuminance over the ranges investigated here. Achromatic and chromatic lightnesses for samples of equal luminance differ in systematic ways that depend upon dominant wavelength and excitation purity. Color appearance data for daylight adaptation are highly correlated with Munsell Renotation specifications. The results may be used to determine corresponding colors for the adaptation conditions studied [equivalent to CIE Illuminants D65, D50, A, and dark adaptation]. They may also be used to determine color appearances under those conditions throughout a color solid. It is anticipated that they will be used as the basis for developing mathematical expressions for predictions of corresponding colors under other illumination conditions as well.
63 citations
TL;DR: In this paper, a review of available numerical techniques is presented and this is followed by discussion of a series of models which use finite difference methods to predict the reflected and transmitted signals from wide band pulses of ultrasonic Rayleigh waves incident on various surface-breaking features.
58 citations
TL;DR: Tendon organs of distal tendons of recrus muscles were traced in serial transverse sections using a light microscope and their identity confirmed with an electron microscope and it is argued that tendon organs and myotendinous cylinders might be of common origin.
Abstract: Golgi tendon organs of distal tendons of recrus muscles were traced in serial transverse sections using a light microscope and their identity confirmed with an electron microscope. One or two tendon organs were present in eight of ten muscles taken from four adult rhesus monkeys and none were present in the other two. Tendon organs were unusually small averaging 270 μm in length and 36 μm in maximum width; three of them were bifid, at one or both ends and the remainder were fusiform. Some lay wholly within tendon without direct attachment of muscle fibres and in the others the tip of a single felderstruktur (slow, non-twitch) muscle fibre entered the tendon organ capsule proximally and occupied the full width.
44 citations
TL;DR: In this article, a method of determining the relationship between the shape of a groove type chip breaking tool and the chip curvature is described, and the constants in the relationship vary with workpiece material.
38 citations
TL;DR: In this article, a computer model of the drying process was modified to take account of added solutes and solvents other than water for Co2 NiO4 spinel.
Abstract: A solid solution which is sublimed under vacuum during the preparation of a high surface area powder will melt if the temperature of the surface is greater than the eutectic temperature, irrespective of the initial concentration of the solution Three criteria may be used in selecting a suitable solvent for freeze drying: (1) For solvents whose surface temperatures are considerably below the eutectic temperature a small value of the latent heat of sublimation is desirable; or for those whose melting points limit the heat input, a high equilibrium vapour pressure at the melting point is required (2) A low freezing point depression (3) A high solubility of the solute Acetic acid was shown to be a useful solvent for preparing Co2 NiO4 spinel A computer model of the drying process was modified to take account of added solutes and solvents other than water
28 citations
TL;DR: Several variations of Vroom's expectancy-value theory were applied to data obtained from two groups of engineering students, and it was found that intentions to choose certain types of work were better predicted when individual regression weights are applied to belief-value products, and when account was taken of students' beliefs about the attainability of work as discussed by the authors.
Abstract: Several variations of Vroom's expectancy-value theory were applied to data obtained from two groups of engineering students. It was found that intentions to choose certain types of work were better predicted when individual regression weights were applied to belief-value products, and when account was taken of students' beliefs about the attainability of work. Some evidence was found that subjective norms affected choice, but there was no support for a comparative model based on discriminability in preference to the traditional independent additive model. Since different models best predicted the intentions to choose different alternatives, it was concluded that a hierarchy of models rather than a single one should be employed in research on occupational choice.
19 citations
TL;DR: In this paper, a study of the overlap of Canadian and U.S. patent literature and journal literature is presented, and the results confirm the need to search both the journal and the patent literature for comprehensive literature coverage.
TL;DR: The performance of the algorithm is investigated through a theoretical analysis of its application to a linear process, where the optimisation is performed using a quadratic performance index and a mathematical model of incorrect structure.
TL;DR: It is concluded that the model parameters obtained are often of questionable accuracy and there is a clear need for a continuous (or semicontinuous) method of monitoring plasma concentration.
Abstract: The adequacy of present-day measurement techniques for the compartmental modelling of metabolic systems is investigated using numerical examples and analysis of experimentally-obtained plasma clearance curves. It is concluded that the model parameters obtained are often of questionable accuracy. The situation can be improved by careful monitoring of experimental conditions and judicious spacing of data points on the response curve, but the work shows a clear need for a continuous (or semicontinuous) method of monitoring plasma concentration. To resolve ambiguities between models equally plausible on physiological grounds, it is necessary to monitor the dynamics of internal variables, for example, of the concentration in the liver (which is nowadays possible noninvasively).
TL;DR: The concept of relative scientific activity is proposed as the number of papers in a field divided by some function of the size of all fields of science as discussed by the authors, which is a measure of the degree of interest in a given field.
Abstract: Liquid crystal literature is characterised from 1888 (the first paper) to 1975. After an initial peak in 1910, expo nential growth did not occur again until the 1960s. Reviews and especially patents then exhibited very rapid growth with doubling times of less than 1 year for patents in the 1970s. The concept of relative scientific activity is proposed as the number of papers in a field divided by some function of the size of all fields of science. A plot of relative scientific activ ity shows that the 1910 peak in relative activity was not achieved again until 1972 when the actual number of papers per year showed a 20 fold increase. Core journals for the field are identified.
TL;DR: In this paper, a managerial model of the investment decision is presented, which is based on the one presented in this paper. But the model is limited to a single investment decision.
Abstract: (1979). A managerial model of the investment decision. Applied Economics: Vol. 11, No. 1, pp. 1-20.
TL;DR: In this article, a dynamic model of a continuous crystallizer has been attempted as an extension of our work on the continuous freezing of ice from saline solutions and subsequent melting of the ice to give a potable water.
TL;DR: There appears to be a strong case for extending educational activities associated with microprocessors to include bit-slice devices, and working with microprogrammabIe micro Processors seems likely to provide a better understanding of the internal operation of programmed machines.
Abstract: INTRODUCTION The fixed-instruct ion-set single-chip MOS microprocessors (such as the 8080 & 6800)are now commonplace in electrical engineering and in computer science departments of universities and polytechnics, and provision of undergraduate lecture courses and laboratory work on such microprocessors and their applications is increasing rapidly. Although such general-purpose microprocessors have almost unlimited applications and the importance of their impact on electronic system design can hardly be over-emphasized, nevertheless there are some application areas where higher speed, longer wordlengths or other special requirements make the bipolar bit-slice microprogrammable microprocessors (such as the Intel 3000, AMD 2900, and Fairchild 94(0) attractive. Also, working with microprogrammabIe microprocessors seems likely to provide a better understanding of the internal operation of programmed machines, and therefore is of importance from an educational point ofview. The overwhelming majority of microprocessor users have no opportunity to influence the design of microprocessor chips (their creativity is limited to the ways in which they utilize them for applications) whereas the microprogrammable devices permit the user to experiment with different instruction sets and, within limits, to tryout different architectures. There appears, therefore, to be a strong case for extending educational activities associated with microprocessors to include bit-slice devices.
TL;DR: In this paper, the authors explored the volumetric energy density picture for nickel-cadmium cells in a single duty cycle application, over the operational temperature range −30 to +55° C.
Abstract: The volumetric energy density picture is explored for nickel-cadmium cells in a single duty cycle application, over the operational temperature range −30 to +55° C. Results are presented showing that fresh, precycled cells easily attain the target specification (40–50 W h dm−3) at temperatures at and above room temperature. Charge acceptance falls sharply at sub-zero temperatures however, and energy density reduces to critical levels below −20° C. The charging characteristics and ability to achieve target performance at −30° C depends markedly on cell origin and the permissibility of allowing some cell venting during the charge. The low temperature limitations can be overcome by means of low wattage heating coils on the cells. Internal temperatures of C and D/2 cells can be raised to 20° C within a few minutes by employing very modest temperature gradients and with heater volumes no greater than the manufacturers label and sleeve. Although the picture is optimistic for fresh precycled cells, major problems are anticipated with stored cells, particularly at temperature extremes, unless steps can be taken to prevent or erase storage effects.
TL;DR: In this paper, a review of factors which govern the effectiveness of materials as adhesives is presented, starting with the forces available for adhesion, the roughness of surfaces, and the wetting and flow properties of liquids.
Abstract: Review of factors which govern the effectiveness of materials as adhesives. Begins with the forces available for adhesion, the roughness of surfaces, and the wetting and flow properties of liquids. Then the necessary phase change is considered and finally these requirements are correlated with actual classes of material.
TL;DR: In this article, the authors describe the long-term future of the universe on the basis of the current "standard models" of cosmology, and present a review of the existing cosmology models.
TL;DR: In this article, the authors investigated the application of goal and model coordination to the decentralized control of a chemical plant consisting of an exothermic reactor, cooler, decanter and distillation column.
Abstract: The paper reports an investigation, performed via computer simulation, into the application of goal and model coordination to the decentralized control of a chemical plant consisting of an exothermic reactor, cooler, decanter and distillation column. Theoretical knowledge of the plant is employed to simplify the mathematical model and produce a decomposed structure consisting of a production subsystem and a separation subsystem with a considerable reduction in the number of interconnection variables. The investigation shows how a feasible control scheme based on model coordination can be implemented where the objective is to maximize the net return per hour. The control scheme contains facilities for overcoming the problem which occurs when the coordination unit specifies non-feasible interconnection variables. Simulation results are presented to illustrate the practicality of the control scheme.
TL;DR: In this paper, it was shown that the two-soliton (antisoliton) solutions of the sine-Gordon equation may be obtained as limiting cases of a separable, two-parameter family of elliptic solutions.
Abstract: We point out that the two-soliton (antisoliton) solutions of the sine-Gordon equation may be obtained as limiting cases of a separable, two-parameter family of elliptic solutions. The solitons are found on the boundary of the parameter space for the elliptic solutions when the latter are considered over their usual complex domain.
01 Jan 1979
TL;DR: This paper will demonstrate that the synthesis of several types of medical documentation is feasible and it is necessary to accept the notion of structure.
Abstract: Medical data is scattered among a variety of documents and the representation of this information makes different demands on available reference languages (Major et al 1978) In this paper we will demonstrate that the synthesis of several types of medical documentation is feasible In order to achieve this it is necessary to accept the notion of structure and to define this at two levels: (i) at the level of the conceptual framework of medicine ie derive a broad model; (ii) at the level of presentation of information — this is the explicit definition of the conceptual steps involved in the unfolding of an information structure
01 Jan 1979
TL;DR: The rate of surplus value is an indicator of exploitation as well as income distribution, measuring the ratio of paid to unpaid labour performed by the working class as discussed by the authors. And it is the one that directly summarises the economic relations between the class antagonists of capitalist society.
Abstract: The first of these ratios, the rate of surplus value, is the most crucial, since it is the one that directly summarises the economic relations between the class antagonists of capitalist society. If we add together surplus value and variable capital for a society for the period of, say a year, we get the annual total of new production. New production is total production less the amount needed to replace used up means of production — what is conventionally called net national income. The ratio of surplus value to variable capital is therefore, first of all, a measure of income distribution between the capitalist class on the one side, and the working class on the other. But new value is entirely the product of living labour which receives only a proportion of it back as wages. Thus the rate of surplus value is an indicator of exploitation as well as income distribution, measuring the ratio of paid to unpaid labour performed by the working class.
TL;DR: A computer program for applying the parameter plane technique to the analysis and design of feedback control systems and how the program may be used to analyse nonlinear control systems, sampled data control Systems and optimal linear control systems is described.