Showing papers by "Stanford University published in 1977"

Self-efficacy: toward a unifying theory of behavioral change.

Abstract: The present article presents an integrative theoretical framework to explain and to predict psychological changes achieved by different modes of treatment. This theory states that psychological procedures, whatever their form, alter the level and strength of self-efficacy. It is hypothesized that expectations of personal efficacy determine whether coping behavior will be initiated, how much effort will be expended, and how long it will be sustained in the face of obstacles and aversive experiences. Persistence in activities that are subjectively threatening but in fact relatively safe produces, through experiences of mastery, further enhancement of self-efficacy and corresponding reductions in defensive behavior. In the proposed model, expectations of personal efficacy are derived from four principal sources of information: performance accomplishments, vicarious experience, verbal persuasion, and physiological states. The more dependable the experiential sources, the greater are the changes in perceived selfefficacy. A number of factors are identified as influencing the cognitive processing of efficacy information arising from enactive, vicarious, exhortative, and emotive sources. The differential power of diverse therapeutic procedures is analyzed in terms of the postulated cognitive mechanism of operation. Findings are reported from microanalyses of enactive, vicarious, and emotive modes of treatment that support the hypothesized relationship between perceived self-efficacy and behavioral changes. Possible directions for further research are discussed.

Social learning theory

Abstract: Una exploracion de los avances contemporaneos en la teoria del aprendizaje social, con especial enfasis en los importantes roles que cumplen los procesos cognitivos, indirectos, y autoregulatorios.

The Population Ecology of Organizations

Abstract: Factors impacting the organizational structure of firms have been analyzed often utilizing organizations theory. However, several other theories and perspectives have been proposed as potential alternative means of analyzing organizational structure and functioning. While previous studies regarding organizational structure have utilized such perspectives as adaptation and exchange theory, few studies have utilized population ecology theory, thus leading to the current study. Although population ecology theory is most often used in the biological sciences, many of its principles lend well to organizational analysis. Due to internal structural arrangements (e.g. information constraints, political constraints) and environmental pressures (e.g. legal and fiscal barriers, legitimacy) of an organization, the inflexibility of an organization limits the firm's organizational analysis utilizing an adaptation perspective. The challenges and discontinuities associated with utilizing an ecological perspective are identified, including issues related to the primary sources of change (selection and adaptive learning) and related to differentiating between selection and viability. Utilizing competition theory and niche theory, several models for analyzing organizational diversity are incorporated to address factors not encompassed by ecological theory. By compiling elements of several theories, a population ecology model applicable to business related organizational analyses is derived. (AKP)

CP Conservation in the Presence of Pseudoparticles

Abstract: We give an explanation of the $\mathrm{CP}$ conservation of strong interactions which includes the effects of pseudoparticles. We find it is a natural result for any theory where at least one flavor of fermion acquires its mass through a Yukawa coupling to a scalar field which has nonvanishing vacuum expectation value.

Self-efficacy : Toward a unifying theory of behavioral change

Abstract: The present article presents an integrative theoretical framework to explain and to predict psychological changes achieved by different modes of treatment. This theory states that psychological procedures, whatever their form, alter the level and strength of self-efficacy. It is hypothesized that expectations of personal efficacy determine whether coping behavior will be initiated, how much effort will be expended, and how long it will be sustained in the face of obstacles and aversive experiences. Persistence in activities that are subjectively threatening but in fact relatively safe produces, through experiences of mastery, further enhancement of self-efficacy and corresponding reductions in defensive behavior. In the proposed model, expectations of personal efficacy are derived from four principal sources of information: performance accomplishments, vicarious experience, verbal persuasion, and physiological states. The more dependable the experiential sources, the greater are the changes in perceived selfefficacy. A number of factors are identified as influencing the cognitive processing of efficacy information arising from enactive, vicarious, exhortative, and emotive sources. The differential power of diverse therapeutic procedures is analyzed in terms of the postulated cognitive mechanism of operation. Findings are reported from microanalyses of enactive, vicarious, and emotive modes of treatment that support the hypothesized relationship between perceived self-efficacy and behavioral changes. Possible directions for further research are discussed.

Screening lambdagt recombinant clones by hybridization to single plaques in situ

Abstract: A rapid, direct method for screening single plaques of Agt recombinant phage is described. The method allows at least 10(6) clones to be screened per day and simplifies physical containment of recombinants.

The Intuitive Psychologist And His Shortcomings: Distortions in the Attribution Process1

Abstract: Publisher Summary Attribution theory is concerned with the attempts of ordinary people to understand the causes and implications of the events they witness. It deals with the “naive psychology” of the “man in the street” as he interprets his own behaviors and the actions of others. For man—in the perspective of attribution theory—is an intuitive psychologist who seeks to explain behavior and draw inferences about actors and their environments. To better understand the perceptions and actions of this intuitive scientist, his methods must be explored. The sources of oversight, error, or bias in his assumptions and procedures may have serious consequences, both for the lay psychologist himself and for the society that he builds and perpetuates. These shortcomings, explored from the vantage point of contemporary attribution theory, are the focus of the chapter. The logical or rational schemata employed by intuitive psychologists and the sources of bias in their attempts at understanding, predicting, and controlling the events that unfold around them are considered. Attributional biases in the psychology of prediction, perseverance of social inferences and social theories, and the intuitive psychologist's illusions and insights are described.

An Algorithm for Finding Best Matches in Logarithmic Expected Time

Abstract: An algorithm and data structure are presented for searching a file containing N records, each described by k real valued keys, for the m closest matches or nearest neighbors to a given query record. The computation required to organize the file is proportional to kNlogN. The expected number of records examined in each search is independent of the file size. The expected computation to perform each search is proportional to logN. Empirical evidence suggests that except for very small files, this algorithm is considerably faster than other methods.

Toeplitz and circulant matrices

Abstract: The fundamental theorems on the asymptotic behavior of eigenvalues, inverses, and products of banded Toeplitz matrices and Toeplitz matrices with absolutely summable elements are derived in a tutorial manner. Mathematical elegance and generality are sacrificed for conceptual simplicity and insight in the hope of making these results available to engineers lacking either the background or endurance to attack the mathematical literature on the subject. By limiting the generality of the matrices considered, the essential ideas and results can be conveyed in a more intuitive manner without the mathematical machinery required for the most general cases. As an application the results are applied to the study of the covariance matrices and their factors of linear models of discrete time random processes.

Constraints imposed by CP conservation in the presence of pseudoparticles

Abstract: We elaborate on an earlier discussion of CP conservation of strong interactions which includes the effect of pseudoparticles. We discuss what happens in theories of the quantum-chromodynamics type when we include weak and electromagnetic interactions. We find that strong CP conservation remains a natural symmetry if the full Lagrangian possesses a chiral U(1) invariance. We illustrate our results by considering in detail a recent model of (weak) CP nonconservation.

Determination of the Kinetic Parameters of Mixed‐Conducting Electrodes and Application to the System Li3Sb

Abstract: An electrochemical galvanostatic intermittent titration technique (GITT) is described which combines both transient and steady‐state measurements to obtain kinetic properties of solid mixed‐conducting electrodes, as well as thermodynamic data. The derivation of quantities such as the chemical and component diffusion coefficients, the partial conductivity, the mobility, the thermodynamic enhancement factor, and the parabolic rate constant as a function of stoichiometry is presented. A description of the factors governing the equilibration of composition gradients in such phases is included. The technique is applied to the determination of the kinetic parameters of the compound which has a narrow composition range. For the chemical diffusion coefficient is at 360°C. This value is quite high, due to a large thermodynamic enhancement factor of . The lithium component diffusion coefficient is comparatively small at this composition, . The partial conductivity and electrical mobility of lithium are and , respectively, at the same stoichiometry and temperature. Because of the very large values of the chemical diffusion coefficient and the fact that 3 moles of lithium can react per mole of antimony, this system may be of interest for use in new types of secondary batteries.

The Kondo lattice and weak antiferromagnetism

Abstract: By considering a one-dimensional analog of a system of conduction electrons exchange coupled to a localized spin in each cell of a lattice, it is suggested that a second-order transition from an antiferromagnetic to a Kondo spin-compensated ground state will occur as the exchange coupling constant J is increased to a critical value Jc For systems in which J ≲ Jc, a very weak sublattice magnetization may occur as a result of nearly complete spin-compensation

Analysis of self-efficacy theory of behavioral change

Abstract: This article reports the findings of two experimental tests of self-efficacy theory of behavioral change. The first study investigated the hypothesis that systematic desensitization effects changes in avoidance behavior by creating and strengthening expectations of personal efficacy. Thorough extinction of anxiety arousal to visualized threats by desensitization treatment produced differential increases in self-efficacy. In accord with prediction, microanalysis of congruence between self-efficacy and performance showed self-efficacy to be a highly accurate predictor of degree of behavioral change following complete desensitization. The findings also lend support to the view that perceived self-efficacy mediates anxiety arousal. The second experiment investigated the process of efficacy and behavioral change during the course of treatment by participant modeling. Self-efficacy proved to be a superior predictor of amount of behavioral improvement phobics gained from partial mastery of threats at different phases of treatment.

Cosmological lower bound on heavy-neutrino masses

Abstract: The present cosmic mass density of possible stable neutral heavy leptons is calculated in a standard cosmological model. In order for this density not to exceed the upper limit of 2\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}29}$ g/${\mathrm{cm}}^{3}$, the lepton mass would have to be greater than a lower bound of the order of 2 GeV.

The Efficiency of Cox's Likelihood Function for Censored Data

Abstract: D.R. Cox has suggested a simple method for the regression analysis of censored data. We carry out an information calculation which shows that Cox's method has full asymptotic efficiency under conditions which are likely to be satisfied in many realistic situations. The connection of Cox's method with the Kaplan-Meier estimator of a survival curve is made explicit.

Bargains and Ripoffs: A Model of Monopolistically Competitive Price Dispersion

Abstract: Bargains and Ripoffs: A Model of Monopolistically Competitive Price DispersionAuthor(s): Steven Salop and Joseph StiglitzSource: The Review of Economic Studies, Vol. 44, No. 3 (Oct., 1977), pp. 493-510Published by: The Review of Economic Studies Ltd.Stable URL: http://www.jstor.org/stable/2296903Accessed: 15/09/2009 15:43

Technology transfer by multinational firms : The resource cost of transferring technological know-how

Abstract: The following sections are included:IntroductionTechnology Transfer and the Production of KnowledgeThe SampleDefinition of Technology Transfer CostsTransfer Costs: Data and HypothesesThe Level of Transfer CostsTechnology/Transferor CharacteristicsTransferee and Host Country CharacteristicsDeterminants of the Cost of International Technology Transfer: Tests and ResultsThe ModelStatistical Tests: Phase IStatistical Tests: Phase IIDefferences between International and Domestic Technology TransferConclusionReferences

Cognitive processes mediating behavioral change.

Abstract: The present experiment was designed to test the theory that psychological procedures achieve changes in behavior by altering the level and strength of self-efficacy. In this formulation, perceived self-efficacy. In this formulation, perceived self-efficacy influences level of performance by enhancing intensity and persistence of effort. Adult phobics were administered treatments based upon either performance mastery experiences, vicarious experiences., or they received no treatment. Their efficacy expectations and approach behavior toward threats differing on a similarity dimension were measured before and after treatment. In accord with our prediction, the mastery-based treatment produced higher, stronger, and more generalized expectations of personal efficacy than did the treatment relying solely upon vicarious experiences. Results of a microanalysis further confirm the hypothesized relationship between self-efficacy and behavioral change. Self-efficacy was a uniformly accurate predictor of performance on tasks of varying difficulty with different threats regardless of whether the changes in self-efficacy were produced through enactive mastery or by vicarious experience alone.

Absorbing boundary conditions for acoustic and elastic wave equations

Abstract: Boundary conditions are derived for numerical wave simulation that minimize artificial reflections from the edges of the domain of computation. In this way acoustic and elastic wave propagation in a limited area can be efficiently used to describe physical behavior in an unbounded domain. The boundary conditions are based on paraxial approximations of the scalar and elastic wave equations. They are computationally inexpensive and simple to apply, and they reduce reflections over a wide range of incident angles.

Multiquark hadrons. I. Phenomenology of Q 2 Q̄ 2 mesons

Abstract: The spectra and dominant decay couplings of ${Q}^{2}{\overline{Q}}^{2}$ mesons are presented as calculated in the quark-bag model. Certain known ${0}^{+}$ mesons [$\ensuremath{\epsilon}(700),{S}^{*},\ensuremath{\delta},\ensuremath{\kappa}$] are assigned to the lightest cryptoexotic ${Q}^{2}{\overline{Q}}^{2}$ nonet. The usual quark-model ${0}^{+}$ nonet ($Q\overline{Q} L=1$) must lie higher in mass. All other ${Q}^{2}{\overline{Q}}^{2}$ mesons are predicted to be broad, heavy, and usually inelastic in formation processes. Other ${Q}^{2}{\overline{Q}}^{2}$ states which may be experimentally prominent are discussed.

First Operation of a Free-Electron Laser

Abstract: A free-electron laser oscillator has been operated above threshold at a wavelength of 3.4 \ensuremath{\mu}m.

Calabi's conjecture and some new results in algebraic geometry

Abstract: We announce a proof of Calabi's conjectures on the Ricci curvature of a compact Kahler manifold and then apply it to prove some new results in algebraic geometry and differential geometry. For example, we prove that the only Kahler structure on a complex projective space is the standard one.

Cryptographic apparatus and method

Abstract: A cryptographic system transmits a computationally secure cryptogram over an insecure communication channel without prearrangement of a cipher key. A secure cipher key is generated by the conversers from transformations of exchanged transformed signals. The conversers each possess a secret signal and exchange an initial transformation of the secret signal with the other converser. The received transformation of the other converser's secret signal is again transformed with the receiving converser's secret signal to generate a secure cipher key. The transformations use non-secret operations that are easily performed but extremely difficult to invert. It is infeasible for an eavesdropper to invert the initial transformation to obtain either conversers' secret signal, or duplicate the latter transformation to obtain the secure cipher key.

Dynamic equations in descriptor form

Abstract: This paper studies a general form of sets of equations that is often the product of problem formulation in large-scale systems, especially when the equations are expressed in terms of the natural describing variables of the system. Such equations represent a broad class of time-evolutionary phenomena, and include as special cases ordinary static equations of arbitrary dimension, ordinary state-space equations, combinations of static and dynamic equations, and noncausal systems. The main thrust of the paper is to show (for sets of linear equations) that familiar concepts of dynamic system theory can be extended to this more general class, although sometimes with significant modification. Two new (and essentially dual) concepts, that of solvable and conditionable sets of equations, are found to be fundamental to the study of equations of this form. The notion of initial conditions, although not directly related to a state, is used as a general solution method for equations of this type. In addition a set of necessary and sufficient conditions for a set of dynamic equations to contain an embedded state-space representation is derived.

A fast algorithm for computing longest common subsequences

Abstract: Previously published algorithms for finding the longest common subsequence of two sequences of length n have had a best-case running time of O(n2). An algorithm for this problem is presented which has a running time of O((r + n) log n), where r is the total number of ordered pairs of positions at which the two sequences match. Thus in the worst case the algorithm has a running time of O(n2 log n). However, for those applications where most positions of one sequence match relatively few positions in the other sequence, a running time of O(n log n) can be expected.

Natural History of Sudden Sensorineural Hearing Loss

Abstract: This is a prospective in-depth study of patients with sudden idiopathic sensorineural hearing loss. We found that 65% recover completely to functional hearing levels spontaneously and independent of any type of medical treatment. The majority do so within 14 days and many within the first few days. Prognosis can be predicted according to the slope of the initial audiogram (low-frequency losses do better than high-frequency losses), hearing at 8 kHz, erythrocyte sedimentation rates, in some select instances spatial disorientation symptoms, and speech discrimination scores. There was a very poor correlation between hearing and vestibular test abnormalities, except hypoactive calories. There were no correlations with age (excepting the very elderly), with antecedent respiratory infections, hypertension, diabetes, or other chronic diseases. We conclude that there is a fundamental difference in the behavior of apical and basal cochlea losses, that hearing recovery is always better at low than at high frequencies, that because of the high spontaneous recovery rates, tympanotomies seeking peri-lymph fistulas should be delayed ten days unless there is a progressive hearing loss, and that none of the current recommended treatments, especially histamine, have any effect on the outcome.