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William A. Edmonds Gershon Tenenbaum Derek T. Y. Mann Michael Johnson Akihito Kamata 《Journal of sports sciences》2013,31(7):761-773
Abstract In this study, we wished to investigate the factors that determine the direction of the spin axis of a pitched baseball. Nineteen male baseball pitchers were recruited to pitch fastballs. The pitching motion was recorded with a three-dimensional motion analysis system (1000 Hz), and the orientations of the hand segment in a global coordinate system were calculated using Euler rotation angles. Reflective markers were attached to the ball, and the direction of the spin axis was calculated on the basis of their positional changes. The spin axis directions were significantly correlated with the orientations of the hand just before ball release. The ball is released from the fingertip and rotates on a plane that is formed by the palm and fingers; the spin axis of the ball is parallel to this plane. The lift force of the pitched baseball is largest when the angular and translational velocity vectors are mutually perpendicular. Furthermore, to increase the lift forces for the fastballs, the palm must face home plate. 相似文献
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The present experiment examined whether predictability of food acquisition would eliminate the impairment of subsequent escape performance that otherwise resulted from uncontrollability over food acquisition. In pretreatment, the yoked and the yoked-signal groups received response-independent food at the same times as the experimental group acquired it on an FR 5/20 lever-press schedule. However, a pellet presented for the yoked-signal group followed a 1.5-sqc tone, which served as a predictive signal of food. The naive control group received the same clumber of pellets in their home cages in this phase. Results of the escape latency in the subsequent FR 2 shuttling shock-escape test indicated that the predictability of outcome eliminated the escape deficits showed by the yoked-non signal group. This modulating effect of a predictive signal is hypothesized to be due to an overshadowing of uncontrollability by predictability. 相似文献
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In two experiments, we examined whether or not a loss of control over food availability would interfere with subsequent two-way shuttle-escape learning. Rats that had experienced loss of control over food delivery were impaired in their acquisition of a shuttle-escape response, relative to the response-contingent and the continuous-reinforcement control rats (in Experiments 1 and 2) and to the lack-of-control and home cage control rats (in Experiment 2). Rats that had received noncontingent food delivery without a prior history of control over food exhibited poorer performance than did the home cage control rats. Moreover, loss of control resulted in a larger interference effect than did lack of control, supporting the view that the learning of response-outcome noncontingency is the main determinant of the interference effect. 相似文献
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Hong Jiao Akihito Kamata Shudong Wang Ying Jin 《Journal of Educational Measurement》2012,49(1):82-100
The applications of item response theory (IRT) models assume local item independence and that examinees are independent of each other. When a representative sample for psychometric analysis is selected using a cluster sampling method in a testlet‐based assessment, both local item dependence and local person dependence are likely to be induced. This study proposed a four‐level IRT model to simultaneously account for dual local dependence due to item clustering and person clustering. Model parameter estimation was explored using the Markov Chain Monte Carlo method. Model parameter recovery was evaluated in a simulation study in comparison with three other related models: the Rasch model, the Rasch testlet model, and the three‐level Rasch model for person clustering. In general, the proposed model recovered the item difficulty and person ability parameters with the least total error. The bias in both item and person parameter estimation was not affected but the standard error (SE) was affected. In some simulation conditions, the difference in classification accuracy between models could go up to 11%. The illustration using the real data generally supported model performance observed in the simulation study. 相似文献
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In this article, we discuss and illustrate two centering and anchoring options available in differential item functioning (DIF) detection studies based on the hierarchical generalized linear and generalized linear mixed modeling frameworks. We compared and contrasted the assumptions of the two options, and examined the properties of their DIF estimates with a simulation study. For reference purposes, the results were compared to those obtained from using the Mantel-Haenszel procedure as well. Finally, we discuss some implications regarding the choice of model parameterizations for DIF detection using these frameworks. 相似文献
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The relations among several alternative parameterizations of the binary factor analysis model and the 2-parameter item response theory model are discussed. It is pointed out that different parameterizations of factor analysis model parameters can be transformed into item response model theory parameters, and general formulas are provided. Illustrative data analysis is provided to demonstrate the transformations. 相似文献
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OBJECTIVES: Children are often considered a primary motivator for women seeking substance abuse treatment. This study tested a model predicting treatment motivation in substance-abusing mothers. METHODS: This study was a secondary analysis of the Drug Absue Treatment Outcome Study (DATOS). It used structural equation modeling to describe factors influencing motivation for treatment. DATOS is a national study of substance abusers entering treatment. Treatment was provided by a sampling of community-based programs, free-standing hospitals, hospital units, county-funded programs, modified therapeutic communities, and criminal justice programs. The subsample of women with children under the age of 18 for whom custody of children could be determined was selected (n=1371). The variables comprising each factor were based on self-report, and standardized scales measuring level of drug involvement, psychological functioning, children, and a desire to stop using drugs were used. RESULTS: Drug involvement was positively related to poorer psychological functioning, child custody issues, and the desire to stop using drugs. Child custody issues had a negative influence, while poorer psychological functioning and a desire to stop using drugs positively influenced treatment motivation. CONCLUSIONS: The negative influence that children have on treatment motivation may reflect the practical or emotional difficulties of having to leave children behind or in some instances having children placed in foster care. Specifically, losing custody of children, particularly with little expectation they will be reunified, may serve as a detriment to motivation. Popular beliefs hold that children serve as a primary source of a mother's treatment motivation; however this study found the opposite was true. Children should not automatically be considered a primary source of motivation for participation in treatment. 相似文献
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The foundation of this study was based on an idiosyncratic concept, which uses probabilistic determinations (Kamata, Tenenbaum, & Hanin, 2002) to verify the utility and effectiveness of a biofeedback intervention by manipulating affective performance states in a race-car simulator. Nine males completed five separate time-trials of a simulated racing task and were then randomly assigned to one of three arousal regulation treatment conditions: (1) optimal, (2) poor, and (3) attention control. Following the biofeedback intervention, participants underwent another series of race trials to determine the effectiveness of the arousal regulation intervention. The results indicated that there were relative similarities in the strength and direction of the perceived and physiological states between the participants; however, the subtle details of the participants' unique performance zones and the probability of achieving each zone were revealed to be unique among the participants. The results also indicated that: (a) the biofeedback manipulation resulted in the expected changes for each participant, and (b) there were some large individual differences among the participants, necessitating the idiosyncratic approach. Limitations and future directions are also addressed. 相似文献
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Akihito Kamata 《Journal of Educational Measurement》2001,38(1):79-93
The hierarchical generalized linear model (HGLM) is presented as an explicit, two-level formulation of a multilevel item response model. In this paper, it is shown that the HGLM is equivalent to the Rasch model and that, characteristic of the HGLM, person ability can be expressed in the form of random effects rather than parameters. The two-level item analysis model is presented as a latent regression model with person-characteristic variables. Furthermore, it is shown that the two-level HGLM model can be extended to a three-level latent regression model that permits investigation of the variation of students' performance across groups, such as is found in classrooms and schools, and of the interactive effect of person-and group-characteristic variables. 相似文献
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The goal of this study was the development of a procedure to predict the equating error associated with the long-term equating method of Tate (2003) for mixed-format tests. An expression for the determination of the error of an equating based on multiple links using the error for the component links was derived and illustrated with simulated data. Expressions relating the equating error for single equating links to relevant factors like the equating design and the history of the examinee population ability distribution were determined based on computer simulation. Use of the resulting procedure for the selection of a long-term equating design was illustrated. 相似文献
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