Showing papers by "University of Texas at Austin published in 1979"
TL;DR: In this paper, a new basis set, denoted 4-21, is presented for first-row atoms, which is nearly equivalent to the 4-31G set but requires less computational effort.
Abstract: Systematic ab initio gradient calculation of molecular geometries, force constants, and dipole moment derivatives is described. A new basis set, denoted 4-21, is presented for first-row atoms. It is nearly equivalent to the 4-31G set but requires less computational effort. Completely optimized Hartree-Fock geometries of 18 molecules are compared using several basis sets, with and without polarization functions. The question of the best representation of molecular force fields is discussed, and a set of standardized internal coordinates is suggested for future work. Quadratic and the most important cubic force constants and dipole moment derivatives of first-row hydrides are calculated using the 4-21 basis set, and the results are compared with those from other basis sets, including near-Hartree-Fock ones. Force-field calculations on larger molecules with the 4-21 basis are summarized. A general formulation of the rotational correction to dipole moment derivatives is given.
1,973 citations
TL;DR: A package of 38 low level subprograms for many of the basic operations of numerical linear algebra is presented, intended to be used with FORTRAN.
Abstract: A package of 38 low level subprograms for many of the basic operations of numerical linear algebra is presented. The package is intended to be used with FORTRAN. The operations in the package are dot products, elementary vector operations, Givens transformations, vector copy and swap, vector norms, vector scaling, and the indices of components of largest magnitude. The subprograms and a test driver are available in portable FORTRAN. Versions of the subprograms are also provided in assembly language for the IBM 360/67, the CDC 6600 and CDC 7600, and the Univac 1108.
1,788 citations
TL;DR: This work proposes a distributed solution where processes communicate only through messages with their neighbors; there are no shared variables and there is no central process for message routing or process scheduling.
Abstract: The problem of system simulation is typically solved in a sequential manner due to the wide and intensive sharing of variables by all parts of the system. We propose a distributed solution where processes communicate only through messages with their neighbors; there are no shared variables and there is no central process for message routing or process scheduling. Deadlock is avoided in this system despite the absence of global control. Each process in the solution requires only a limited amount of memory. The correctness of a distributed system is proven by proving the correctness of each of its component processes and then using inductive arguments. The proposed solution has been empirically found to be efficient in preliminary studies. The paper presents formal, detailed proofs of correctness.
1,005 citations
TL;DR: In this paper, the principles and applications of semiconductor electrodes in photo-electrochemical (PEC) cells (liquid junction photovoltaic, photoelectro-synthetic, photocatalytic) are described.
886 citations
TL;DR: In this paper, a set of scalar isovists and isovist fields is defined as the set of all points visible from a given vantage point in space and with respect to an environment.
Abstract: The environment is defined as a collection of visible real surfaces in space. An isovist is the set of all points visible from a given vantage point in space and with respect to an environment. The shape and size of an isovist is liable to change with position. Numerical measures are proposed that quantify some salient size and shape features. These measures in turn create a set of scalar isovist fields. Sets of isovists and isovist fields form an alternative description of environments. The method seems relevant to behavioral and perceptual studies in architecture, especially in the areas of view control, privacy, ‘defensibility’, and in dynamic complexity and spaciousness judgements. Isovists and isovist fields also shed light on the meaning of prevalent architectural notions about space. In the latter role it is hoped that an information-field theory such as the one presented can help provide fruitful common ground for designers and researchers.
868 citations
TL;DR: The bispectrum, which is an ensemble average of a product of three spectral components, is shown to be a very useful diagnostic tool in experimental studies of nonlinear wave interactions in random media.
Abstract: The bispectrum, which is an ensemble average of a product of three spectral components, is shown to be a very useful diagnostic tool in experimental studies of nonlinear wave interactions in random media. In particular, it is shown that the bicoherence spectrum may be used to discriminate between nonlinearly coupled waves and spontaneously excited waves and to measure the fraction of wave power due to the quadratic wave coupling in a self-excited fluctuation spectrum. Practical aspects of digital bispectral analysis techniques, such as estimation and statistical variability of the estimator, are also discussed. Finally, applications of bispectral analysis techniques in the analysis and interpretation of plasma fluctuation data are described.
820 citations
TL;DR: In this article, a spin trap was used to detect free-radical intermediates formed during in situ irradiation of TiO/sub 2/ and platinized polysilicon powders in aqueous solution.
Abstract: Spin trapping and ESR detection (with the traps ..cap alpha..-phenyl N-tert-butyl nitrone and ..cap alpha..-(4-pyridyl N-oxide) N-tert-butyl nitrone) were employed to detect free-radical intermediates formed during in situ irradiation of TiO/sub 2/ and platinized TiO/sub 2/ powders in aqueous solutions. Evidence for the production of hydroxyl radical (.OH) (formed in the oxidation of water) and perhydroxyl radical (HO/sub 2/.) (probably formed in a reduction step) is presented. Other spin adducts, attributed to decomposition reactions of the spin traps, were also found. The results suggest an important role for photogenerated .OH in many photocatalytic and photosynthetic processes at TiO/sub 2/ powders.
533 citations
TL;DR: In this paper, a detailed analysis of the double-slit experiment is performed, in which one tries to observe both wave and particle properties of light, and a practically realizable version of this experiment, to which the above analysis applies, is proposed.
Abstract: A detailed analysis of Einstein's version of the double-slit experiment, in which one tries to observe both wave and particle properties of light, is performed. Quantum nonseparability appears in the derivation of the interference pattern, which proves to be surprisingly sharp even when the trajectories of the photons have been determined with fairly high accuracy. An information-theoretic approach to this problem leads to a quantitative formulation of Bohr's complementarity principle for the case of the double-slit experiment. A practically realizable version of this experiment, to which the above analysis applies, is proposed.
523 citations
TL;DR: In both sexes, neuroticism was most highly correlated (in a negative direction) with M+, and acting out behavoir was most strongly correlated with M-.
Abstract: Negatively valued masculinity (M-) and femininity (F-) personality scales were developed to supplement the positively valued Masculinity (M+) and Femininity (F+) scales of the Personal Attributes Questionnaire (PAQ; Spence & Helmreich). M- consisted of traits that had been judged to be (a) more typical of males than females, (b) undesirable in both sexes, and (c ) agentic or instrumental in content. Two F- scales were developed, both containing stereotypically feminine, undesirable traits, one set of traits referring to communionlike characteristics (Fc-) and the other to verbal passive-aggressive qualities (FVA-). Significant sex differences in the predicted direction were found on all scales. In both sexes, low and typically nonsignificant correlations were found between parallel positive and negative scales, but highly significant negative correlations were found between positive and negative cross-sex scales. These findings provide additional evidence for the multidimentionslity of masculinity and femininity. Scores on a self-esteem measure were positively correlated with M+ and F+, uncorrelated with M-, and negatively correlated with the F- scales. Different patterns of scores were associated with two types of problem behaviors. In both sexes, neuroticism was most highly correlated (in a negative direction) with M+, and acting out behavoir was most strongly correlated (in a positive direction) with M-. The next highest correlation in both instances was with FVA-.
506 citations
TL;DR: It is concluded that titin is a structurally conserved myofibrillar component of vertebrate and invertebrate striated muscles.
Abstract: Electrophoretic analyses of protein components of striated muscle myofibril purified from various vertebrate and invertebrate species revealed that proteins much larger than myosin heavy chain are present in significant amounts. To define possible roles of these heretofore unidentified proteins, we purified a combination of two uncommonly large proteins, designated as titin, from chicken breast myofibrils. Chemical and immunological studies indicated that titin is distinct from myosin, actin, and filamin. Specific titin anti body crossreacts with similar protein in both skeletal and cardiac myofibrils of many vertebrate and invertebrate species. Immunofluorescent staining of glycerinated chicken breast myofibrils indicated that titin is present in M lines, Z lines, the junctions of A and I bands, and perhaps throughout the entire A bands. Similar staining studies of myofibrils from other species suggest that titinlike proteins may be organized in all myofibrils according to a common architectural plan. We conclude that titin is a structurally conserved myofibrillar component of vertebrate and invertebrate striated muscles.
500 citations
TL;DR: It is proposed that the common ancestor of the great apes and man displayed rudimentary forms of late sensorimotor and early preoperational intelligence similar to that of one- to four-year-old children, which arose as adaptations for extractive foraging with tools, which requires a long postweaning apprenticeship.
Abstract: This paper presents a model for the nature and adaptive significance of intelligence and language in early hominids based on comparative developmental, ecological, and neurological data. We propose that the common ancestor of the great apes and man displayed rudimentary forms of late sensorimotor and early preoperational intelligence similar to that of one- to four-year-old children. These abilities arose as adaptations for extractive foraging with tools, which requires a long postweaning apprenticeship. They were elaborated in the first hominids with the shift to primary dependence on this feeding strategy. These first hominids evolved a protolanguage, similar to that of two-year-old human children, with which they could describe the nature and location of food and request help in obtaining it. The descendents of the first hominids displayed intuitive intelligence, similar to that of four- to seven-year-old children, which arose as an adaptation for complex hunting involving aimed-missile throwing, stone-tool manufacture, animal butchery, food division, and shelter construction. The comparative developmental and paleontological data are consistent with the hypothesis that the stages of development of intelligence and language and their neural substrates in our species recapitulate the stages of their evolution.
TL;DR: Radiotracer studies on three butterfly species showed that nutrients contributed by males through mating are used by females for egg production and possibly for somatic maintenance.
Abstract: Radiotracer studies on three butterfly species showed that nutrients contributed by males through mating are used by females for egg production and possibly for somatic maintenance.
TL;DR: In this article, the need to identify the boundaries of increasingly complex product markets has spawned a number of analytical methods based on customer behavior or judgments, and various methods are compared and compared.
Abstract: The need to identify the boundaries of increasingly complex product-markets has spawned a number of analytical methods based on customer behavior or judgments. The various methods are compared and ...
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01 Jan 1979TL;DR: In this article, the authors investigated the telephone's role as a contributory agent in economic development, using cross-sectional time series data for 60 nations over 13 years to determine how the telephone might make its contribution to economic development.
Abstract: The author investigates the telephone's role as a contributory agent in economic development. Cross-sectional time series data for 60 nations over 13 years were used to determine how the telephone might make its contribution to economic development. Path analysis and cross-lagged correlation techniques indicate that the telephone does contribute to economic development. This contribution appears to come from the telephone's support of the organization of economic activity.
TL;DR: Analysis of a first-order difference picture (FODP) provides a separate estimate for images of moving objects and of stationary scene components that represents the stationary scene component in a TV-image sequence.
Abstract: The count of events where sample areas from the second and subsequent frames of a TV-image sequence are incompatible with the corresponding sample area of the first frame are accumulated in a first-order difference picture (FODP). Analysis of this FODP provides a separate estimate for images of moving objects and of stationary scene components. We start from the hypothesis that the first frame represents the stationary scene component. Once it has been recognized that a subarea of this initial estimate corresponds to the image of a moving object, the grey values in this subarea are replaced by later estimates of the stationary background at this position. No knowledge specific to a particular scene is utilized in the algorithm. The results for two scene sequences are presented.
TL;DR: The primary alcohol dehydrogenases from a variety of methanol-grown bacteria have been purified and compared, and seem to contain a common and novel cofactor which may be more generally associated with the oxidation of single-carbon compounds.
Abstract: METHYLOTROPHIC bacteria are able to use methane derivatives as their sole source of carbon and metabolic energy and so can sustain growth on methane, methanol and other organic compounds which lack carbon–carbon bonds1. They are not autotrophic and, being unable to use carbon dioxide, rely ultimately on their ability to oxidise these substances. Although the primary alcohol dehydrogenases from a variety of methanol-grown bacteria have been purified and compared, and despite the increasing commerical importance of these organisms as sources of ‘single cell protein’, the essential features of these oxidative pathways remain unknown. The dehydrogenases exhibit a rather broad substrate specificity for primary alcohols and formaldehyde, and seem to contain a common and novel cofactor2–6, which may be more generally associated with the oxidation of single-carbon compounds. The structure of the cofactor is reported here.
TL;DR: In this article, an asymptotic series for the renormalized stress-energy tensor is developed as far as the inverse-square term in powers of the distance.
Abstract: Electromagnetic and scalar fields are quantized in the region near an arbitrary smooth boundary, and the renormalized expectation value of the stress-energy tensor is calculated. The energy density is found to diverge as the boundary is approached. For nonconformally invariant fields it varies, to leading order, as the inverse fourth power of the distance from the boundary. For conformally invariant fields the coefficient of this leading term is zero, and the energy density varies as the inverse cube of the distance. An asymptotic series for the renormalized stress-energy tensor is developed as far as the inverse-square term in powers of the distance. Some criticisms are made of the usual approach to this problem, which is via the "renormalized mode sum energy," a quantity which is generically infinite. Green's-function methods are used in explicit calculations, and an iterative scheme is set up to generate asymptotic series for Green's functions near a smooth boundary. Contact is made with the theory of the asymptotic distribution of eigenvalues of the Laplacian operator. The method is extended to nonflat space-times and to an example with a nonsmooth boundary.
TL;DR: A review of the literature in the area of superior-subordinate communication can be found in this article, where the authors classified empirical research into nine topical categories and critically examined the effect of power, status, trust, and semantic-information distance as a source of misunderstand ing in superior sub-ordinate communication.
Abstract: Based on a review of the literature, empirical research in the area of superiorsubordinate communication is classified into nine topical categories and critically examined. Inspection of this literature suggests that researchers have focused the majority of their attention on studying (a) the effects of power and status on superior-subo rdinate communication, (b) trust as a moderator of superior-subo rdinate communication, and (c) semantic-information distance as a source of misunderstand ing in superior-subo rdinate communication. It is concluded that future research should increasingly be developmental and longitudinal in nature and should take into greater consideration the effects situational variables have on communication in the superior-subordinate dyad. Status hierarchy is inherent in the nature of purposeful organizations. As Redding (1972) observes, within organizations "there are 'superiors' and 'subordinates'—even though these terms may not be expressly used, and even though there may exist fluid arrangements whereby superior and subordinates roles may be reversible" (p. 18). How superiors and subordinates interact and communicate to achieve both personal and organizational goals has been an object of investigation by social scientists for most of the 20th century. Empirical research examining superior-subordinate communication is diverse, is strewn across a multitude of disciplines, lacks coherent organization and classification, and in general, has not received sufficient review and interpretation as a body of literature. The present article attempts to alleviate this confusion by reviewing, classifying, interpreting, and providing directions for future research in the area of organizational communication that is loosely termed superior-subordinate communication. This article focuses on empirical research solely in the domain of organizationa l communication. To avoid generalizations from communication research outside of the orga
TL;DR: Patients receiving daily doses of 40 mg of prednisone or its equivalent, are at greater risk for developing steroid psychosis, and tricyclic antidepressants produced an exacerbation or worsening of the clinical state in all patients to whom they were administered.
Abstract: This study suggests that patients receiving daily doses of 40 mg of prednisone or its equivalent, are at greater risk for developing steroid psychosis. Psychotic reactions were twice as likely to occur during the first 5 days of treatment as subsequently. Premorbid personality, history of previous p
TL;DR: In this article, a new approach to texture analysis based on the spatial distribution of local features in unsegmented textures is presented, where textures are described using features derived from generalized co-occurrence matrices (GCM).
Abstract: We present a new approach to texture analysis based on the spatial distribution of local features in unsegmented textures. The textures are described using features derived from generalized co-occurrence matrices (GCM). A GCM is determined by a spatial constraint predicate F and a set of local features P = {(Xi, Yi, di), i = 1,..., m} where (Xi, Yi) is the location of the ith feature, and di is a description of the ith feature. The GCM of P under F, GF, is defined by GF(i, j) = number of pairs, pk, pl such that F(pk, pl) is true and di and dj are the descriptions of pk and pl, respectively. We discuss features derived from GCM's and present an experimental study using natural textures.
TL;DR: In this article, the distribution of fibronectin on human fibroblast surfaces during initial attachment and spreading was studied by indirect immunofluorescence analysis using a monospecific anti-cold-insoluble globulin antiserum.
TL;DR: This approach was tested on a data base consisting of digitized coastlines in various map projections and found that in nearly all cases, all matches except the correct one were eliminated by the relaxation processes.
Abstract: The problem of finding approximate matches of pieces of shapes to parts of larger shapes is investigated. The shapes are represented by polygonal approximations. Initially, figures of merit are assigned to the matches between pairs of angles on the two shapes. Relaxation methods are then used to find acceptable combinations of these matches. This approach was tested on a data base consisting of digitized coastlines in various map projections. In nearly all cases, all matches except the correct one were eliminated by the relaxation processes.
TL;DR: In this article, a direct approach is employed to obtain a general formulation of plate bending problems in terms of a pair of singular integral equations involving displacement, normal slope, bending moment and shear on the plate boundary.
TL;DR: The study shows that the procedures examined indeed exert a powerful influence on solution efficiency, with the identity of the best dependent upon the topology of the network and the range of the arc distance coefficients.
Abstract: : This paper examines different algorithms for calculating the shortest path from one node to all other nodes in a network. More specifically, we seek to advance the state-of-the-art of computer implementation technology for such algorithms and the problems they solve by examining the effect of innovative computer science list structures and labeling techniques on algorithmic performance. The study shows that the procedures examined indeed exert a powerful influence on solution efficiency, with the identity of the best dependent upon the topology of the network and the range of the arc distance coefficients. The study further discloses that the shortest path algorithm previously documented as the most efficient is dominated for all problem structures by the new methods, which are sometimes an order of magnitude faster. (Author)
TL;DR: In this paper, the authors investigate the newly emerging pattern of career aspirations in women, in which both a demanding profession and family life are assumed, within a framework of interrole conflict among major life roles and its correlates.
Abstract: An investigation of the newly emerging pattern of career aspirations in women, in which both a demanding profession and family life are assumed, was conducted within a framework of interrole conflict among major life roles and its correlates. Subjects were 28 dual career couples who responded to an anonymous questionnaire. Of specific interest were the areas and degree of interrole conflict, in addition to their relationship to gender, parent hood, level of career aspirations, spouse's emotional support of career pursuit, and attitudes toward the roles of women. Surprisingly, the prediction of gender differences in regard to areas and correlates of interrole conflict were not supported. The one exception was level of career aspiration, where high aspirations were negatively related to role conflict for men but positively related to role conflict for women. Strikingly different patterns of conflict, however, were found as a function of the presence or absence of children.
TL;DR: The analysis of quasars' emission-line spectra has become an intricate subject which differs considerably from traditional, low-density nebular astrophysics as mentioned in this paper, and a review is intended to explain our present understanding of the situation, including some aspects of galactic nuclei whose luminosities are more modest than quasar.
Abstract: Much of our information about quasars is derived from their emission-line spectra. The analysis of such spectra has become an intricate subject which differs considerably from traditional, low-density nebular astrophysics. This review is intended to explain our present understanding of the situation, including some aspects of galactic nuclei whose luminosities are more modest than quasars. Quasars' line-emitting regions are probably photoionized (even if supplementary heating processes also occur). So far, models have been constructed which include ionization and thermal equilibria, the transfer of resonance-line and related photons, and the likely effects of absorption and scattering by dust grains. From comparisons between emission-line intensities produced in these models and observed quasars' spectra, it appears that certain densities and pressures and size scales occur in or around quasars. The relative abundances of elements are not very far from solar values, although it is suspected that heavy elements---carbon, nitrogen, and oxygen in particular---are moderately "overabundant" in quasars. The emission-line intensities also provide indirect information about quasars' ultraviolet and soft-x-ray continua; there are hints that photons with energies between 20 and 300 eV---which are not directly observable---may even represent the peak of the luminous output of a typical quasar. Finally, some gas-dynamical questions, while extremely important, are very difficult to answer, because of a lack of observables.
TL;DR: It is shown that the mean-square difference between the probability of error for the nde and its deleted estimate is bounded by A/ \sqrt{n} where A is an explicitly given constant depending only on M and the potential function.
Abstract: In the discrimination problem the random variable \theta , known to take values in {1, \cdots ,M} , is estimated from the random vector X . All that is known about the joint distribution of (X, \theta) is that which can be inferred from a sample (X_{1}, \theta_{1}), \cdots ,(X_{n}, \theta_{n}) of size n drawn from that distribution. A discrimination nde is any procedure which determines a decision \hat{ \theta} for \theta from X and (X_{1}, \theta_{1}) , \cdots , (X_{n}, \theta_{n}) . For rules which are determined by potential functions it is shown that the mean-square difference between the probability of error for the nde and its deleted estimate is bounded by A/ \sqrt{n} where A is an explicitly given constant depending only on M and the potential function. The O(n ^{-1/2}) behavior is shown to be the best possible for one of the most commonly encountered rules of this type.
01 Jan 1979
TL;DR: In this paper, the results of approximately 4000 published and unpublished tensile tests on deformed reinforcing bars are studied to obtain statistical relationships for various mechanical properties, including the mean and coefficients of variation of the mill test yield strength.
Abstract: The results of approximately 4000 published and unpublished tensile tests on deformed reinforcing bars are studied to obtain statistical relationships for various mechanical properties. The sample included No. 3 through No. 18, Grades 40 and 60, bars. The means and coefficients of variation of the mill test yield strengths were found to be 48.8 ksi (337 MN/sq m) and 10.7% for Grade 40 and 71 ksi (MN/sq m) and 9.3% for Grade 60 bars. Beta distributions were used to represent both of these sets of data. The static yield strength was found to be 3.5 ksi (24 MN/sq m) lower on the average than the mill test yield strength in both cases, with a coefficient of variation of 13.4%. The trend to lower yield strengths with increased bar sizes observed early in the 1970's was not present in more resent test data, apparently due to more stringent production control in recent years. /Authors/