Westinghouse Electric (Japan)

Consider a signal generator whose instantaneous output voltage V(t) may be written as V(t) = [V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> + ??(t)] sin [2??v <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> t + s(t)] where V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> and v <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> are the nominal amplitude and frequency, respectively, of the output. Provided that ??(t) and ??(t) = (d??/(dt) are sufficiently small for all time t, one may define the fractional instantaneous frequency deviation from nominal by the relation y(t) - ??(t)/2??v <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</inf> A proposed definition for the measure of frequency stability is the spectral density S <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</inf> (f) of the function y(t) where the spectrum is considered to be one sided on a per hertz basis. An alternative definition for the measure of stability is the infinite time average of the sample variance of two adjacent averages of y(t); that is, if y <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</inf> = 1/t ??? <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">tk+r</sup> = y(t <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</inf> ) y(t) dt where ?? is the averaging period, t <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k+1</inf> = t <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</inf> + T, k = 0, 1, 2 ..., t <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> is arbitrary, and T is the time interval between the beginnings of two successive measurements of average frequency; then the second measure of stability is ?? <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</inf> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (??) ??? (y <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k+1</inf> - y <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</inf> ) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> /2 where denotes infinite time average and where T = ??. In practice, data records are of finite length and the infinite time averages implied in the definitions are normally not available; thus estimates for the two measures must be used. Estimates of S <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</inf> (f) would be obtained from suitable averages either in the time domain or the frequency domain.

Topological Sorting is a procedure required for many problems involving analysis of networks. An example of one such problem is PERT. The present paper presents a very general method for obtaining topological order. It permits treatment of larger networks than can be handled on present procedures and achieves this with greater efficiency. Although the procedure can be adapted to any machine, it is discussed in terms of the 7090. A PERT network of 30,000 activities can be ordered in less than one hour of machine time. The method was developed as a byproduct of procedure needed by Westinghouse, Baltimore. It has not been programmed and at present there are no plans to implement it. In regard to the techniques described, Westinghouse's present and anticipated needs are completely served by the Lockheed program, which is in current use.

The purpose of this paper is to introduce the new ASME measurement uncertainty methodology which is the basis for two new ASME/ANSI standards and the ASME short course of the same name. Some background and history that led to the selection of this methodology are discussed as well as its application in current SAE, ISA, JANNAF, NRC, USAF, NATO, and ISO Standards documents and short courses. This ASME methodology is rapidly becoming the national and international standard.

A bstract The fundamental condition for glass formation is the existence of strongly bonded large networks or long chains of atoms in the liquid. Such chains or networks prevent or hinder the orderly orientation of atoms in the chains or networks themselves and also that of atoms, not in the networks in the liquid, near the melting point or liquidus temperature. A liquid structure will persist when the liquid is cooled below the melting point or liquidus temperature and will continue until free, long‐range movement of atoms becomes impossible. In order to obtain such long chains or large networks, it is necessary that (1) the bond strength of atoms in the chains or networks be very strong; (2) the small ring formation of these strongly bonded atoms be at a minimum; and (3) the relative numbers of various atoms in the chains or networks be such that at least a continuous chain is configuratively and structurally possible; at the same time, the coordination numbers of the glassforming atoms should be as small as possible to keep the bond strong. The general treatment is applied to all kinds of glasses, particularly oxide glasses. The bond strengths of all M—O single‐bond linkages in these glasses are calculated and tabulated here for the first time. The bond strength of all the glassformers was found to be greater than 80 kilocalories per Avogadro bond, that of the intermediates between 60 and 80, and that of the modifiers below 60; the transition is continuous, and the division into glassformers, intermediates, and modifiers is arbitrary.

SUMMARY A single-server system with stationary compound Poisson input and general independent service times, the latter being subject to random interruptions of independently but otherwise arbitrarily distributed durations, is studied. For a variety of service-interruption interactions (including the preemptive-repeat) the distributions of busy period duration, of queue length, and of waiting time are characterized by transforms and by moments. Applications are made to priority scheduling problems.

The interline power flow controller (IPFC) proposed is a new concept for the compensation and effective power flow management of multi-line transmission systems. In its general form, the IPFC employs a number of inverters with a common DC link, each to provide series compensation for a selected line of the transmission system. Because of the common DC link, any inverter within the IPFC is able to transfer real power to any other and thereby facilitate real power transfer among the lines of the transmission system. Since each inverter is also able to provide reactive compensation, the IPFC is able to carry out an overall real and reactive power compensation of the total transmission system. This capability makes it possible to equalize both real and reactive power flow between the lines, transfer power from overloaded to underloaded lines, compensate against reactive voltage drops and the corresponding reactive line power, and to increase the effectiveness of the compensating system against dynamic disturbances. The paper explains the basic theory and operating characteristics of the IPFC with phasor diagrams, P-Q plots and simulated waveforms.

The development of free convection in a viscous fluid between heated vertical plates is investigated. The basic governing continuity, momentum, and energy equations are expressed in finite difference form and solved numerically on a digital computer. Results are obtained for the variations of velocity, temperature, and pressure throughout the flow field assuming the fluid to enter the channel with ambient temperature and a flat velocity profile. The flow and heat-transfer characteristics of the channel are studied and a development height established. A comparison is made between the results of this theoretical investigation and the experimental work of Elenbaas.

In recent years, there has been a rapid increase in the number of thyristor-controlled shunt compensators used in industrial and utility systems for dynamic power factor correction and terminal voltage stabilization. These thyristor-controlled shunt compensators function as variable reactances operated in both the inductive and capacitive domains.

Analytical models are developed for calculating temperatures, stresses and distortions resulting from the welding process. The models are implemented in finite element formulations and applied to a longitudinal butt weld. Nonuniform temperature transients are shown to result in the characteristic transverse bending distortions. Residual stresses are greatest in the weld metal and heat-affected zones, while the accumulated plastic strain is maximum at the interface of these two zones on the underside of the weldment.

Abstract This paper describes the influence of rate of strain and temperature on the yield stresses of mild steel. Tensile tests are reported for room temperature, 200, 400, and 600 C, at rates of strain which vary from 10−8 to 103 per sec. The results of these tensile tests are plotted to show more clearly the effects of strain-aging on the yield stresses and ultimate stress. The comparison of the yield stress at various strain rates permits an analysis of the influence of strain. The conditions necessary for discontinuous yielding are described and compared with test experiences.

Field orientation has emerged as a powerful tool for controlling ac machines such as inverter-supplied induction motors. The dynamic performance of such a drive is comparable to that of a converterfed four quadrant dc drive. The complex functions required by filed-oriented control may be executed by microprocessors on line, thus greatly reducing the necessary control hardware. It is shown that the flux signals may be derived from sensing coils or, with some compromise in performance, from the stator voltages and currents. The speed signal is obtained from a digital tachometer. Results from a 2-kW experimental drive are given.

A fundamental basis has been developed for the use of a time-shared stored-program digital computer to perform many of the electrical power-system protective-relay functions in a substation. Logic operations are given to detect a fault, locate it, and initiate the opening of the appropriate circuit breakers, whether the fault is in the station or on lines radiating from the station.

A direct tunneling theory is formulated and applied to high-speed thin-oxide complementary metal-nitride-oxide-silicon (MNOS) memory transistors. Charge transport in the erase/write mode of operation is interpreted in terms of the device threshold voltage shift. The threshold voltage shift in the erase/write mode is related to the amplitude and time duration of the applied gate voltage over the full range of switching times. MNOS memory devices ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">X_{o}=25 \Aring, X_{N} = 335 \Aring</tex> ) exhibit a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\Delta V_{th} = \plusmn3</tex> V for an erase/write <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t_{p} = 100</tex> ns, which corresponds to an initial oxide field strength <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E_{ox}= 1.2 \times 10^{7}</tex> V/cm. The direct tunneling theory is applied to the charge retention or memory mode in which charge is transported to and from the Si-SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> interface states. The rate of charge loss to interface states is influenced by electrical stress which alters the interface state characteristics. We discuss the fabrication of complementary high-speed MNOS memory transistors and the experimental test procedures to measure charge transport and storage in these devices.

IN THE BRIEF SPAN of years since the closing days of World War II, we have witnessed a technological development in computers of such broad proportions that it is still impossible to appraise its far reaching effects adequately. Perhaps, the best way to express the enormous influence of this revolution is simply to point out that practically all of man's actions in producing the necessities and luxuries of life fall into two categories, namely his mental and his physical work. All of his mental work has to do with the processing of information in some form or other, and the close relationship of the computer to the human brain and its functioning needs no elaboration here. It should have been expected that nearly all of the operations of the civilized world, in which the human brain is involved to a greater or lesser extent in carrying out the task, could be aided by a technological development which performs accurately and at high speed, some of the functions of the brain. This is variously called computing, or information- or data-processing. Its field of application is as broad as human knowledge and is far beyond the comprehension of any one individual. However, large teams of scientists and engineers are currently at work in many of these compartmented fields of knowledge, learning how to adapt and develop the automatic processing methods of the computer to the needs of their particular fields.

A primary feeder model using small area demand locations to represent nonuniform loads, and feeder segments having variable distribution costs and limited capacities is formulated. The solution of problems having 1000 demand locations and 100 substations can be found in a fraction of a second by using a current fast upper bounded transshipment code. The problem of restructuring the solution to satisfy other kinds of constraints is also discussed.

Summary A technique is described for the identification of clay minerals, the layers of which are difficult to expand or collapse by the usual treatment with glycerol and KCl. Samples are extracted for 3 to 6 hours in normal sodium citrate at pH 7–3 and 100° C. The citrate is renewed hourly. After the citrate extraction the inter‐ layer spaces of some minerals can be expanded with glycerol and CaCl 2 Basal spacings of minerals previously identified as ‘dioctahedral vermiculite’ expand to 16–18 A. after this treatment; hence, their identity is questioned. The widespread occurrence in the north‐eastem United States of clay minerals with 14‐A. spacing necessitates this extraction for correct identification.

During severe emergencies which result in insufficient generation to meet load, an automatic load shedding program throughout the affected area can prevent total area collapse. It also helps to achieve fast restoration of all affected loads. This paper describes the factors involved in applying underfrequency relays to achieve a desired "deficient generation" protection level and a calculating method to achieve optimum relay settings.

Four fluorescent lamps of daylight chromaticity, and with varying Color-Preference Index (CPI), illuminated an array of fruit, vegetables, breads and meat. The lamps were rated in order of preference for the coloration of this array by 267 observers. Excellent correlation of observer preference with CPI, as well as with the prime-color content of the spectral power distributions of the lamps, served to validate the CPI and Judd's assignment of preferred chromaticities of identifiable objects.

Abstract Diffusion measurements in pure iron have been made in the temperature ranges 683 to 884°c and 1428 to 1521°c. The following expressions for diffusion coefficients, D, are deduced from least mean squares analyses of the results: A single Arrhenius equation describes the diffusion data obtained above the Curie temperature. Alternative corrections for absorption of radiation in the residual activity technique are compared and the origin of diffusion ‘tails’ is discussed.

Description In recent years the development of new scientific instruments and techniques has made microanalysis an essential and powerful tool for the materials scientist. The ability to chemically characterize small, included particles or second-phase materials down to one micrometer (1 &amp;#181m) in diameter and to determine the nature of surfaces with a depth resolution below 100A has led to the solution of serious materials problems and the development of new products and processes. This article, which is a review of the many techniques available, illustrates how the various techniques are related, when they can be most appropriately used and when they can be successfully combined in a single instrument. Such a review should: 1) aid the materials scientist in selecting the proper technique and instrument for his particular problem; 2) guide the novice in his initial efforts in the field of microanalysis; and 3) provide the expert with a critical review and state-of-the-art description of the field. Particular emphasis is placed on the quantitative capabilities of the various techniques so that the reader may obtain a full understanding of the capabilities and limitations of each. The problems associated with accuracy and precision in electron beam microanalysis are discussed so the investigator or user will be aware of potential problems. The following instruments and techniques or combinations thereof are discussed: electron probe analyzer, transmission electron microscope, scanning electron microscope, Auger electron spectroscopy, energy dispersive spectrometer, ion mass analyzer, automated instruments and quantitative metallography. Finally applications in many disciplines are presented to illustrate the vast potential of the techniques.