General Electric (Israel)

Journal Article An analysis of variance test for normality (complete samples) Get access S. S. SHAPIRO, S. S. SHAPIRO General Electric Co. and Bell Telephone Laboratories, Inc. Search for other works by this author on: Oxford Academic Google Scholar M. B. WILK M. B. WILK General Electric Co. and Bell Telephone Laboratories, Inc. Search for other works by this author on: Oxford Academic Google Scholar Biometrika, Volume 52, Issue 3-4, December 1965, Pages 591–611, https://doi.org/10.1093/biomet/52.3-4.591 Published: 01 December 1965

A theory of social inequity, with special consideration given to wage inequities is presented. A special case of Festinger's cognitive dissonance, the theory specifies the conditions under which inequity will arise and the means by which it may be reduced or eliminated. Observational field studies s

Beleska o autorima: str. XV-XVI. - Bibliografija uz svako poglavlje. - Registar. - Summaries.

In this review, we discuss the physics underlying the operation of single and multiple heterojunction, vacuum-deposited organic solar cells based on small molecular weight thin films. For single heterojunction cells, we find that the need for direct contact between the deposited electrode and the active organics leads to quenching of excitons. An improved device architecture, the double heterojunction, is shown to confine excitons within the active layers, allowing substantially higher internal efficiencies to be achieved. A full optical and electrical analysis of the double heterostructure architecture leads to optimal cell design as a function of the optical properties and exciton diffusion lengths of the photoactive materials. Combining the double heterostructure with novel light trapping schemes, devices with external efficiencies approaching their internal efficiency are obtained. When applied to an organic photovoltaic cell with a power conversion efficiency of 1.0%±0.1% under 1 sun AM1.5 illumination, devices with external power conversion efficiencies of 2.4%±0.3% are reported. In addition, we show that by using materials with extended exciton diffusion lengths LD, highly efficient double heterojunction photovoltaic cells are obtained, even in the absence of a light trapping geometry. Using C60 as an acceptor material, double heterostructure external power conversion efficiencies of 3.6%±0.4% under 1 sun AM1.5 illumination are obtained. Stacking of single heterojunction devices leads to thin film multiple heterojunction photovoltaic and photodetector structures. Thin bilayer photovoltaic cells can be stacked with ultrathin (∼5 Å), discontinuous Ag layers between adjacent cells serving as efficient recombination sites for electrons and holes generated in the neighboring cells. Such stacked cells have open circuit voltages that are n times the open circuit voltage of a single cell, where n is the number of cells in the stack. In optimized structures, the short circuit photocurrent remains approximately constant upon stacking thin cells, leading to higher achievable power conversion efficiencies, as confirmed by modelling optical interference effects and exciton migration. A 2.5%±0.3% power efficiency under 100 mW/cm2 AM1.5 illumination conditions is obtained by stacking two ∼1% efficient devices. Alternatively, when the contact layers between the stacked cells are eliminated, a multilayer structure consisting of alternating films of donor and acceptor-type materials is obtained. Since the thicknesses of the individual layers (∼5 Å) can be substantially smaller than the exciton diffusion length, nearly 100% of the photogenerated excitons are dissociated, and the resulting free charges are detected. In addition, the ultrathin organic layers facilitate electron and hole transport through the multilayer stack by tunneling. When these devices are operated as photodetectors under applied fields >106 V/cm, the carrier collection efficiency reaches 80%, leading to external quantum efficiencies of 75%±1% across the visible spectrum in cells containing the thinnest layers. We find that due to the fast carrier tunneling process, the temporal response of these multilayer detectors is a direct measure of exciton dynamics. Response times of 720±50 ps are achieved, leading to a 3 dB bandwidth of 430±30 MHz. A summary of representative results obtained for both polymer and small molecule photovoltaic cells and photodetectors is included in this review. Prospects for further improvements in organic solar cells and photodetectors are considered.

The phenomena of stability of synchronous machines under small perturbations is explored by examining the case of a single machine connected to an infinite bus through external reactance.

The polygon remains a popular graphics primitive for computer graphics application. Besides having a simple representation, computer rendering of polygons is widely supported by commercial graphics hardware and software.

The effects of couple stresses in fluids are considered. Linearized constitutive equations are proposed for force and couple stresses. A series of boundary-value problems are solved to indicate the effects of couple stresses as well as for experiments measuring the various material constants. It is found that a size effect comes in which is not present in the nonpolar case (couple stresses absent).

The conception of random positive ion velocities corresponding to ion temperatures in a plasma has serious theoretical difficulties and is lacking in direct experimental verification. It is more reasonable to assume that each ion starts from rest and subsequently possesses only the velocity which it acquires by falling through a static electric field which is itself maintained by the balance of electron and ion charges. This new viewpoint thus ascribes motions to the positive ions which, for long free paths, are ordered rather than chaotic, each negative body in contact with the discharge collecting ions from a definite region of the plasma and from it only. The resulting integral ? the plasma-sheath potential distribution have been set up for plane, cylindrical, and spherical plasmas, for long, short and intermediate length ion free paths, and for both constant rate of ionization throughout the plasma and rate proportional to electron density, and these equations have been solved for the potential distribution in the plasma in all important cases. The case of short ion free paths in a cylinder with ion generation proportional to electron density gives the same potential distribution as found for the positive column by Schottky using his ambipolar diffusion theory, with the advantages that ambipolarity and quasineutrality need not appear as postulates. The calculated potential distribution agrees with that found experimentally. The potential difference between center and edge of plasma approximates $\frac{{T}_{e}}{11,600}$ volts in all long ion free path cases. The theory yields two equations. One, the ion current equation, simply equates the total number of ions reaching the discharge tube wall to the total number of ions generated in the plasma, but it affords a new method of calculating the density of ionization. The second, the plasma balance equation, relates rate of ion generation, discharge tube diameter (in the cylindrical case), and electron temperature. It can be used to calculate the rate of ion generation, the resulting values checking (to order of magnitude) those calculated from one-stage ionization probabilities. The potential difference between the center of the plasma and a non-conducting bounding wall as calculated from the ion current equation agrees with that found experimentally.The solution of the general plasma-sheath equation has been extended into the sheath surrounding the plasma to determine the first order correction which is to be subtracted from the discharge tube radius to obtain the plasma radius. The wall sheath in the positive column is several times the thickness given by the simple space charge equation.Actually the ions do not start from rest when formed but have small random velocities corresponding to the gas temperature, ${T}_{g}$. In the long ion free path cases this leads to an error of the order of only $\frac{{T}_{g}}{{T}_{e}}$ in the calculated potential distributions.In the plasma surrounding a fine negatively charged probe wire the potential difference between plasma potential maximum and sheath edge may be so small that the ions generated within the plasma potential maximum are not trapped but can traverse the maximum by virtue of their finite initial velocities. This justifies the use of a sufficiently fine negatively charged wire in the usual way to measure positive ion concentrations, although certain difficulties appear which are thought to be connected with the collector theory rather than the present plasma theory.

Precision methods for measuring the number of caesium atoms adsorbed on tungsten are described. With these methods for determining $\ensuremath{\theta}$ (the fraction of the tungsten surface covered with Cs), the rates of atom, ion and electron emission are measured as functions of $\ensuremath{\theta}$ and $T$, the filament temperature. The rate of atom evaporation, ${\ensuremath{\nu}}_{a}$, increases rapidly with $\ensuremath{\theta}$ and with $T$. At low filament temperatures and high pressures of Cs vapor the concentration of adsorbed Cs atoms approaches a limit 3.563\ifmmode\times\else\texttimes\fi{}${10}^{14}$ atoms ${\mathrm{cm}}^{\ensuremath{-}2}$ of true filament surface (one Cs atom for four tungsten atoms). This film ($\ensuremath{\theta}=1$) exhibits all the characteristics of a true monatomic layer. The formation of a second layer begins only at filament temperatures corresponding to nearly saturated Cs vapor. A theory of the formation of a second and of polyatomic layers is given and experiments supporting it are described. The heat of evaporation (given by the Clapeyron equation) for Cs atoms from clean tungsten is 2.83 volts (65,140 calories), 1.93 volts or 44,473 calories at $\ensuremath{\theta}=0.67, \mathrm{and} 1.77$ volts or 40,757 calories at $\ensuremath{\theta}\ensuremath{\simeq}1$. The adsorbing tungsten surface after proper aging is homogeneous, except that about 0.5 percent of it (active spots) can hold Cs more firmly than the rest. The procedure in obtaining electron (${\ensuremath{\nu}}_{e}$) and ion (${\ensuremath{\nu}}_{p}$) emission for zero field and the large changes in the effect of external field with $\ensuremath{\theta}$ are described. From both ${\ensuremath{\nu}}_{e}$ and ${\ensuremath{\nu}}_{p}$ the contact potential ${V}_{c}$ is calculated, agreeing, except for very concentrated films, with ${V}_{c}$ calculated entirely from data on neutral atom evaporation. At constant temperature the electron emission increases to a maximum at $\ensuremath{\theta}=0.67$ and decreases as $\ensuremath{\theta}=1$ is approached. The positive ion emission increases rapidly to a maximum at $\ensuremath{\theta}\ensuremath{\simeq}0.01$ and then decreases. The work function (exponent in Dushman type equation) for electrons at $\ensuremath{\theta}=0.67$ is 1.70 volts (clean tungsten=4.62 volts). The work function for ions is 1.91 volts at $\ensuremath{\theta}=0, \mathrm{and} 3.93$ volts at $\ensuremath{\theta}=0.67$. It is shown by experiment that the saturated ion current from a clean hot (1200-1500\ifmmode^\circ\else\textdegree\fi{}K) tungsten filament is an accurate measure (experimental error of about 0.2 percent) of the number of atoms striking the filament per second. The condensation coefficient ($\ensuremath{\alpha}$) for atoms striking a tungsten filament is proved by experiment to be unity from $\ensuremath{\theta}=0$ to nearly 1. The important bearing of this fact and of the experimentally observed existence of surface migration or diffusion on the mechanism of evaporation and condensation in dilute and concentrated films is discussed. In addition surface migration is correlated with irregular ion evaporation rates occurring when two phases (dilute and concentrated films of Cs) exist on the tungsten surface. Transient effects in which $\ensuremath{\theta}$ changes with time are studied and entirely explained by the observed rates of evaporation and condensation. This and other facts are used to justify a surface phase postulate according to which all the properties of the adsorbed film are uniquely determined by $\ensuremath{\theta}$ and $T$.

One aspect of long-range planning of electric power systems involves the exploration of various designs for the bulk power transmission network. The use of linear programming for network analysis to determine where capacity shortages exist and, most importantly, where to add new circuits to relieve the shortages is presented. The new method of network estimation produces a feasible transmission network with near-minimum circuit miles using as input any existing network plus a load and generation schedule. An example is used to present the two steps of the method: 1) linear flow estimation and 2) new circuit selection. The method has become a fundamental part of computer programs for transmission network synthesis.

Several polynomial time algorithms finding “good,” but not necessarily optimal, tours for the traveling salesman problem are considered. We measure the closeness of a tour by the ratio of the obtained tour length to the minimal tour length. For the nearest neighbor method, we show the ratio is bounded above by a logarithmic function of the number of nodes. We also provide a logarithmic lower bound on the worst case. A class of approximation methods we call insertion methods are studied, and these are also shown to have a logarithmic upper bound. For two specific insertion methods, which we call nearest insertion and cheapest insertion, the ratio is shown to have a constant upper bound of 2, and examples are provided that come arbitrarily close to this upper bound. It is also shown that for any $n\geqq 8$, there are traveling salesman problems with n nodes having tours which cannot be improved by making $n/4$ edge changes, but for which the ratio is $2(1-1/n)$.

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article Free Access Share on Decimation of triangle meshes Authors: William J. Schroeder General Electric Company Corporate Research and Development, ConSolve, Inc General Electric Company Corporate Research and Development, ConSolve, IncView Profile , Jonathan A. Zarge General Electric Company Corporate Research and Development, ConSolve, Inc General Electric Company Corporate Research and Development, ConSolve, IncView Profile , William E. Lorensen General Electric Company Corporate Research and Development, ConSolve, Inc General Electric Company Corporate Research and Development, ConSolve, IncView Profile Authors Info & Claims ACM SIGGRAPH Computer GraphicsVolume 26Issue 2July 1992 pp 65–70https://doi.org/10.1145/142920.134010Online:01 July 1992Publication History 1,117citation4,229DownloadsMetricsTotal Citations1,117Total Downloads4,229Last 12 Months141Last 6 weeks23 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Polymer film capacitors are critical components in many high-power electrical systems. Because of the low energy density of conventional polymer dielectrics, these capacitors currently occupy significant volume in the entire electrical system. This article reviews recent progress made in the development of polymer dielectrics with high energy storage density, which can potentially lead to significant weight and volume reduction in polymer film capacitors. The increase in energy density is achieved through two approaches, namely (a) the development of novel polymers with high electric polarization and optimized dielectric responses and (b) the development of nanocomposites containing polymer matrixes with high breakdown strength and inorganic nanofillers with high polarization. Promising progress has been made through both strategies, resulting in a maximum energy density of >30 J/cm 3 , which is at least 5 times higher than those of conventional polymer dielectrics. The state-of-the-art manufacturing method for low-cost, high-throughput production of polymer films is also reviewed.

We present the detailed planning and execution of the Insight Toolkit (ITK), an application programmers interface (API) for the segmentation and registration of medical image data. This public resource has been developed through the NLM Visible Human Project, and is in beta test as an open-source software offering under cost-free licensing. The toolkit concentrates on 3D medical data segmentation and registration algorithms, multimodal and multiresolution capabilities, and portable platform independent support for Windows, Linux/Unix systems. This toolkit was built using current practices in software engineering. Specifically, we embraced the concept of generic programming during the development of these tools, working extensively with C++ templates and the freedom and flexibility they allow. Software development tools for distributed consortium-based code development have been created and are also publicly available. We discuss our assumptions, design decisions, and some lessons learned.

Auditory masking of one pure tone by another.---Using an air damped telephone receiver supplied with current with a proper combination of two frequencies, as source, the amount of masking by tones of frequency 200 to 3500 was determined for frequencies from 150 to 5000 per sec. The magnitude of a tone is taken as the logarithm of the ratio of its pressure to the threshold value, and masking is taken as the logarithm of its threshold value with masking to that without. The curves of masking as function of magnitude are approximated straight lines as a rule except for rounded feet, of slope $s$ intersecting the magnitude axis at minimum masking magnitude $m$. For a given masking frequency $n$ the slope increases from zero through nearly 1.0 for a frequency near $n$, then more slowly, approaching about 3 to 4 for the highest frequencies measured. The intercept is small or zero below $n$, then increases rapidly, approaching the value 3 for high frequencies. Except when the frequencies are so close together as to produce beats, the masking is greatest for tones nearly alike. When the masking tone is loud it masks tones of higher frequency better than those of frequency lower than itself. When the masking tone is weak, there is little difference. If the masking tone is introduced into the opposite ear, no appreciable masking occurs until the intensity is sufficient to reach the listening ear through the bones of the head. At intensities considerably above minimum audibility, there is no longer a linear relation between the sound pressure and the response of the ear. Data are given showing combinational tones resulting from this non-linearity when two tones are simultaneously introduced in the ear. The presence also of subjective overtones in a loud tone accounts for the large amount of masking of tones higher than itself by a loud masking tone.Dynamics of inner ear.---The data on masking together with Knudson's data on frequency sensibility are interpreted in terms of the dynamical theory of the cochlea which ascribes its frequency selectivity to a passing of vibrations along the basilar membrane and a shunting through narrow regions of the membrane at points depending on the frequency. Conjectured curves are given for a few single frequencies of the amplitude of vibration of this membrane as a function of the distance along it.

Hexagonal, graphitelike boron nitride may be changed directly into the zincblende cubic form reported earlier or into a new wurtzite form by the application of static high pressures. No catalyst appears to be necessary. At high temperatures, between about 2500° and 4000°K, the zincblende form is favored; at lower temperatures, down to 300°K, the wurtzite form is favored; frequently both forms appear together. The minimum pressure required for the transformations is about 115 kbar at 2000°K; somewhat higher pressures, of the order of 130 kbar, suffice at higher and lower temperatures. The crystallites of the dense phases are small but give good x-ray diffraction patterns from which the crystal structures can be determined.

We propose a method for comparing density forecasts that is based on weighted versions of the continuous ranked probability score. The weighting emphasizes regions of interest, such as the tails or the center of a variable’s range, while retaining propriety, as opposed to a recently developed weighted likelihood ratio test, which can be hedged. Threshold- and quantile-based decompositions of the continuous ranked probability score can be illustrated graphically and provide insight into the strengths and deficiencies of a forecasting method. We illustrate the use of the test and graphical tools in case studies on the Bank of England’s density forecasts of quarterly inflation rates in the United Kingdom, and probabilistic predictions of wind resources in the Pacific Northwest.

This note treats the existence of connected, undirected graphs homogeneous of degree d and of diameter k, having a number of nodes which is maximal according to a certain definition. For k = 2 unique graphs exist for d = 2,3,7 and possibly for d = 57 (which is undecided), but for no other degree. For k = 3 a graph exists only for d = 2. The proof exploits the characteristic roots and vectors of the adjacency matrix (and its principal submatrices) of the graph.

It is shown in this paper that the discrete equivalent of a chirp filter is needed to implement the computation of the discrete Fourier transform (DFT) as a linear filtering process. We show further that the chirp filter should not be realized as a transversal filter in a wide range of cases; use instead of the conventional FFT permits the computation of the DFT in a time proportional to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N \log_{2} N</tex> for any <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N, N</tex> being the number of points in the array that is transformed. Another proposed implementation of the chirp filter requires N to be a perfect square. The number of operations required for this algorithm is proportional to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N^{3/2}</tex> .