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1.
ABSTRACT

This paper considers the characteristics of severe plastic deformation (SPD) to estimate its efficacy and to compare different processing techniques. In contrast to effective strains by von Mises and Hencky, the rotation component of the strain rate is included in the analysis as a mode of deformation, which ranges from simple shear to pure shear. Distortions of material elements during a uniform plane plastic flow are calculated using a kinematic approach. For the fixed deformation mode, the current state is defined by the accumulated shears that are identical to the von Mises effective shear strains. In specific cases of pure shear and simple shear, the accumulated shears match the specific distortions of round or square elements prescribed by Hencky or von Mises approach, respectively. The mode of deformation is important to the structural effects of SPD. In general, two separated characteristics, accumulated shear and the coefficient of deformation mode, are necessary to describe strains during SPD.  相似文献   

2.
One of the first to criticize the verifiability theory of meaning embraced by logical empiricists, Reichenbach ties the significance of scientific statements to their predictive character, which offers the condition for their testability. While identifying prediction as the task of scientific knowledge, Reichenbach assigns induction a pivotal role, and regards the theory of knowledge as a theory of prediction based on induction. Reichenbach’s inductivism is grounded on the frequency notion of probability, of which he prompts a more flexible version than that of Richard von Mises. Unlike von Mises, Reichenbach attempts to account for single case probabilities, and entertains a restricted notion of randomness, more suitable for practical purposes. Moreover, Reichenbach developed a theory of induction, absent from von Mises’s perspective, and argued for the justification of induction. This article outlines the main traits of Reichenbach’s inductivism, with special reference to his book Experience and prediction.  相似文献   

3.
Bayesian theories of perception provide a link between observed response distributions and theoretical constructs from Bayesian decision theory. Using Bayesian psychophysics we derive response distributions for two cases, one based on a normal distribution and one on a von Mises distribution for angular variables. Interestingly, where the theoretical response distribution is always unimodal in the case of normal distributions, it can become bimodal in the angular setting in the case when prior and likelihood are about equally strong.  相似文献   

4.
In the present work, the effect of deformation mode (uniaxial compression, rolling and torsion) on the microstructural heterogeneities in a commercial purity Ni is reported. For a given equivalent von Mises strain, samples subjected to torsion have shown higher fraction of high-angle boundaries, kernel average misorientation and recrystallization nuclei when compared to uniaxially compressed and rolled samples. This is attributed to the differences in the slip system activity under different modes of deformation.  相似文献   

5.
The work of Gustav Theodor Fechner (1801–1887) related to probability and statistics and, in particular, to the treatment of observations is described. From a mathematical point of view his arguments were often insufficient, but his work proved to be highly fruitful, and the relevant comments of such scholars as Pearson and von Mises are presented. As the originator of psychophysics, Fechner opened up a new field for quantification. Subsequent workers rejected some of his findings, while at the same time acknowledging their debt to him.  相似文献   

6.
Aris Spanos 《Synthese》2013,190(9):1555-1585
The main objective of the paper is to propose a frequentist interpretation of probability in the context of model-based induction, anchored on the Strong Law of Large Numbers (SLLN) and justifiable on empirical grounds. It is argued that the prevailing views in philosophy of science concerning induction and the frequentist interpretation of probability are unduly influenced by enumerative induction, and the von Mises rendering, both of which are at odds with frequentist model-based induction that dominates current practice. The differences between the two perspectives are brought out with a view to defend the model-based frequentist interpretation of probability against certain well-known charges, including [i] the circularity of its definition, [ii] its inability to assign ‘single event’ probabilities, and [iii] its reliance on ‘random samples’. It is argued that charges [i]–[ii] stem from misidentifying the frequentist ‘long-run’ with the von Mises collective. In contrast, the defining characteristic of the long-run metaphor associated with model-based induction is neither its temporal nor its physical dimension, but its repeatability (in principle); an attribute that renders it operational in practice. It is also argued that the notion of a statistical model can easily accommodate non-IID samples, rendering charge [iii] simply misinformed.  相似文献   

7.
In this paper, a general perspective on criteria of identity of kinds of objects is developed. The question of the admissibility of impredicative or circular identity criteria is investigated in the light of the view that is articulated. It is argued that in and of itself impredicativity does not constitute sufficient grounds for rejecting a putative identity criterion. The view that is presented is applied to Davidson’s criterion of identity for events and to the structuralist criterion of identity of places in a structure.  相似文献   

8.
THE CONCEPT OF DYNAMIC CRITERIA: A CRITICAL REANALYSIS   总被引:2,自引:0,他引:2  
Discussions of "the criterion problem" stress the assumedly frequent incidence of dynamic criteria. However, different concepts of dynamic criteria have not been distinguished. Three views of dynamic criteria are clarified in this paper. These are dynamic criteria conceptualized as (a) changes in group average performance over time, (b) changes in validity over time, and (c) changes in the rank-ordering of scores on the criterion over time. The evidence cited for each concept of dynamic criteria is critically analyzed and submitted to significance tests. The results of analyses of 735 r 's and 532 paired r 's across time from studies pertinent to dynamic criteria are reported. It is concluded that dynamic criteria are rare phenomena, with the significant changes found in key studies explainable by methodological artifacts. Though many sources suggest that dynamic criteria have dire consequences for the overall selection process, we argue that the phenomena have been over-emphasized in the literature, and that practitioners' concern should focus instead on removing sources of criterion unreliability.  相似文献   

9.
规范性分析详细描述了一个理想的、完美的内隐测验所应当具有的一系列标准和特征。通过对内隐联想测验的三个新变式在多大程度上符合这些规范性特征和标准的检验, 发现相对于简式内隐联想测验而言, 无再编码和单区组内隐联想测验更符合What标准和How标准, 未来的研究应更多关注内隐标准。  相似文献   

10.
Exploratory factor analysis (EFA) is a commonly used statistical technique for examining the relationships between variables (e.g., items) and the factors (e.g., latent traits) they depict. There are several decisions that must be made when using EFA, with one of the more important being choice of the rotation criterion. This selection can be arduous given the numerous rotation criteria available and the lack of research/literature that compares their function and utility. Historically, researchers have chosen rotation criteria based on whether or not factors are correlated and have failed to consider other important aspects of their data. This study reviews several rotation criteria, demonstrates how they may perform with different factor pattern structures, and highlights for researchers subtle but important differences between each rotation criterion. The choice of rotation criterion is critical to ensure researchers make informed decisions as to when different rotation criteria may or may not be appropriate. The results suggest that depending on the rotation criterion selected and the complexity of the factor pattern matrix, the interpretation of the interfactor correlations and factor pattern loadings can vary substantially. Implications and future directions are discussed.  相似文献   

11.
This article examines two criteria for a definition of applied behavior analysis. The criteria are derived from a 19th century attempt to establish medicine as a scientific field. The first criterion, experimental determinism, specifies the methodological boundaries of an experimental science. The second criterion, philosophic doubt, clarifies the tentative nature of facts and theories derived from those facts. Practices which will advance the science of behavior are commented upon within each criteria. To conclude, the problems of a 19th century form of empiricism in medicine are related to current practices in applied behavior analysis.  相似文献   

12.
Measures of test parsimony and factor parsimony are defined. Minimizing their weighted sum produces a general rotation criterion for either oblique or orthogonal rotation. The quartimax, varimax and equamax criteria are special cases of the expression. Two new criteria are developed. One of these, the parsimax criterion, apparently gives excellent results. It is argued that one of the most important factors bearing on the choice of a rotation criterion for a particular problem is the amount of information available on the number of factors that should be rotated. This research was supported by the National Research Council of Canada research grant 291-13 to Dr. G. A. Ferguson.  相似文献   

13.
Editorial     
Austrian economics ‐ the school of thought associated with Carl Menger, Frederick von Weiser, Eugen von Bohm‐Bawerk, and in this century, Ludwig von Mises, Friedrich Hayek, Murray N. Rothbard, and Israel Kirzner ‐ is based on a framework of methodological principles and assumptions much at variance with those of traditional or ‘orthodox’ economists. Robert Nozick, in his ‘On Austrian Methodology’, focuses attention on the most fundamental features of this framework, and subjects them to a thoroughgoing and scathing analysis. Singled out for detailed and critical review are: (1) the praxeological concepts of methodological individualism; (2) the claim that economics is an a priori science of human action; (3) the nature of preference and its relation to choice and action; and (4) the assumptions of time‐preference theory. Although Nozick does not consider Austrian views on business cycles, market process analysis, the coordinative and informational effects of the price system, competition, and several other fundamental aspects of praxeology, his criticism strikes at the very root of the praxeological school. This paper attempts to refute each criticism made of the praxeological school by Nozick on a point‐by‐point basis. It thus follows the same pattern as the original paper, and scrutinizes in detail the arguments made by its author.  相似文献   

14.
This study sought to investigate the coherence of changes observed in diagnostic criteria for borderline, schizotypal, obsessive-compulsive, and avoidant personality disorders. Five hundred, forty-nine patients were independently evaluated 2 years apart, and correlations of observed changes in each diagnostic criterion with changes in other criteria were examined to determine if there was within-syndrome consistency in these changes. The observed changes in criteria were consistent within syndrome (median alpha = 0.72 across 4 disorders), and reasonably specific to that syndrome relative to the other disorders. The results support the validity of these criterion sets as representing coherent syndromes.  相似文献   

15.
In this study, we manipulated mastery criterion form (rolling or block) and stringency (across 6 or 12 trials) and measured the emergence of derived relations. College students learned neuroanatomy equivalence classes and experienced one of two rolling mastery criteria (6 or 12 consecutive correct responses) or a block mastery criterion (12 trials in a block) during training. The study found that block and rolling mastery criteria produced similar outcomes. Effectiveness was hampered when the criterion was less stringent.  相似文献   

16.
The authors examined whether participants can shift their criterion for recognition decisions in response to the probability that an item was previously studied. Participants in 3 experiments were given recognition tests in which the probability that an item was studied was correlated with its location during the test. Results from all 3 experiments indicated that participants' response criteria were sensitive to the probability that an item was previously studied and that shifts in criterion were robust. In addition, awareness of the bases for criterion shifts and feedback on performance were key factors contributing to the observed shifts in decision criteria. These data suggest that decision processes can operate in a dynamic fashion, shifting from item to item.  相似文献   

17.
This study examined what Greek adolescents believe are the most important criteria of personal, boys', and girls' popularity in their age group. Participants were 364 students aged between 12 and 15 years. Seven main criteria of popularity were identified: sport competence, physical appearance, academic ability, being a good friend, being sociable, having a good sense of humor, and having the 'right circle of friends'. With regard to personal popularity, being a good friend and being sociable were the two most highly ranked criteria for both boys and girls across all ages. Boys and girls perceived differently the most important criteria of boys' and girls' popularity. Specifically, for same-sex popularity, being a good friend was the most highly ranked criterion, whereas for other-sex popularity, physical attractiveness was the most highly ranked criterion. The findings imply that friendship and social affiliation are the most important criteria of popularity in Greek adolescents.  相似文献   

18.
Research has consistently identified poor interrater agreement among multiple assessments of managerial performance. Three alternative sources of dissensus in the effectiveness ratings were examined: rating errors, selective perceptions, and variations in criteria type or weight. As the available empirical evidence and theoretical analysis show, all three causes provide plausible reasons—though in varying degrees—for the low agreement coefficient. However, an empirical study designed to test three specific hypotheses on criterion type and criterion weights found consensus in the effectiveness models of superiors, subordinates, and peers. Consensus among different raters was high on both the role behaviors and on the personal traits of the managers as criteria for effectiveness. While these findings supported Biddle's role theory (1979), disagreement on the relative weights of these criteria was evident. These observations underscore the need for further conceptualization on the preference functions of raters as a primary source of the low convergent validity coefficients among multiple raters. Further research is also desirable on contextual and cognitive factors that may lead to shifts in criterion type and criterion weight, as well as on actual rating error tendencies among different raters.  相似文献   

19.
Significant job-relatedness was found for a posttraining job knowledge test criterion using an application of Lawshe's content validity method. The aide test was used as a criterion to assess the predictive validity of a vocabulary test and a civil service test with samples of black ( N = 43) and white ( N = 62) psychiatric aides. Significant validities were found on both tests, but a vocabulary test proved to be the better predictor of the criterion in both samples. The obtained validities were discussed in terms of differential validity, test fairness, and sample size. This study demonstrated that a content validity method could be applied to criteria as well as selection tests. It was concluded that content validity methods may be able to help solve the problem of criterion relevance in validation research by providing quantitative evidence of the job-relatedness of criteria.  相似文献   

20.
This study examined the diagnostic efficiency of the DSM-IV criteria for obsessive compulsive personality disorder (OCPD) in patients with binge eating disorder (BED). Two hundred and eleven consecutive adult patients with axis I diagnoses of BED were reliably assessed with semi-structured diagnostic interviews. Conditional probabilities-sensitivity, specificity, positive predictive power (PPP), and negative predictive power (NPP)-were calculated for each of the eight criteria for OCPD, using the 'best-estimate' OCPD diagnosis as the standard. The diagnostic efficiencies of the OCPD criteria were variable, with three criteria failing to have predictive value (PPP<0.50). The best inclusion criterion (highest PPP) was 'Perfectionism,' which was also the overall most predictive criterion. The findings suggest ordering of the DSM-IV criteria for OCPD based on performance and call into question the utility of some criteria.  相似文献   

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