Multiple hydrogen trapping at monovacancies

Novel structures for multiple hydrogen atoms trapped at a monovacancy are discussed. Using atomistic simulations based on semiempirical interatomic potentials and density functional theory, we find low-energy configurations for four, five, and six hydrogen atoms around a monovacancy different than those that have been previously studied in the literature. The energetics of hydrogen binding are compared to results, both theoretical and experimental, previously published in the literature. We argue that up to four hydrogen atoms may be exothermically bound to monovacancy.     

通货膨胀知觉的认知机制和影响因素

通货膨胀知觉是个体对通货膨胀的主观体验.通货膨胀知觉的认知机制主要体现在体验阶段和整合阶段.体验阶段主要涉及到个体对物价的感受性和记忆,整合阶段主要涉及到个体利用可得性启发式以及锚定和调整启发式完成对通货膨胀的最终估计.通货膨胀知觉的影响因素主要包括通货膨胀预期、框架效应、对价格公平性的认知、社会放大效应以及货币改革等.未来可以从通货膨胀知觉的信息加工方式、认知神经机制、跨文化研究以及具有较高生态效度的测量指标等方面进一步探讨.     

Knowledge does not necessarily make the heart grow fonder: The moderating role of knowledge on accessibility experiences

Accessibility experiences have been a subject of interest since Tversky and Kahneman (1973) published their account of the availability heuristic—specifically, individuals often utilize the phenomenological experience of ease or difficulty of recall in constructing a judgment (Schwarz, 1998). The reported studies contribute further to work in this area by examining the moderating role of knowledge on accessibility experiences and their use in evaluative judgments. We argue that knowledgeable individuals are more likely to experience interference effects in early stages of recall. This would result in a reversal of the usual phenomenon such that while low knowledge individuals would find recalling larger sets effortful, which would lead them to form more negative evaluations when recalling larger amounts of information, high knowledge individuals would find recalling smaller sets effortful and would form more negative evaluations when recalling smaller amounts of information. We discuss potential explanations and draw attention to the distinction between generating a response and the appropriateness of the response in accessibility experiences.     

Temporal coordination between performing musicians

Many common behaviours require people to coordinate the timing of their actions with the timing of others' actions. We examined whether representations of musicians' actions are activated in coperformers with whom they must coordinate their actions in time and whether coperformers simulate each other's actions using their own motor systems during temporal coordination. Pianists performed right-hand melodies along with simple or complex left-hand accompaniments produced by themselves or by another pianist. Individual performers' preferred performance rates were measured in solo performance of the right-hand melody. The complexity of the left-hand accompaniment influenced the temporal grouping structure of the right-hand melody in the same way when it was performed by the self or by the duet partner, providing some support for the action corepresentation hypothesis. In contrast, accompaniment complexity had little influence on temporal coordination measures (asynchronies and cross-correlations between parts). Temporal coordination measures were influenced by a priori similarities between partners' preferred rates; partners who had similar preferred rates in solo performance were better synchronized and showed mutual adaptation to each other's timing during duet performances. These findings extend previous findings of action corepresentation and action simulation to a task that requires precise temporal coordination of independent yet simultaneous actions.     

The Impact of Cognitive Diversity on Crisis Negotiations

This paper reports on a series of experiments designed to assess the impact of grouping decision makers by level of cognitive complexity on the outcomes they attain in crisis negotiations. The participants—University of Maryland undergraduates who took roles in a simulated international hostage crisis—used a computer decision support system and a controlled network environment for communications. The goal of the experiments was to better understand the dynamics that lead certain types of groupings to have greater success in negotiations, and that lead certain groups of adversaries to achieve more mutually beneficial outcomes such as compromise and agreement. The findings point to a positive relationship between the level of homogeneity in cognitive complexity among decision makers and the achievement of positive outcomes in crisis negotiations.     

Regression Mixture Models: Does Modeling the Covariance Between Independent Variables and Latent Classes Improve the Results?

Regression mixture models are increasingly used as an exploratory approach to identify heterogeneity in the effects of a predictor on an outcome. In this simulation study, we tested the effects of violating an implicit assumption often made in these models; that is, independent variables in the model are not directly related to latent classes. Results indicate that the major risk of failing to model the relationship between predictor and latent class was an increase in the probability of selecting additional latent classes and biased class proportions. In addition, we tested whether regression mixture models can detect a piecewise relationship between a predictor and outcome. Results suggest that these models are able to detect piecewise relations but only when the relationship between the latent class and the predictor is included in model estimation. We illustrate the implications of making this assumption through a reanalysis of applied data examining heterogeneity in the effects of family resources on academic achievement. We compare previous results (which assumed no relation between independent variables and latent class) to the model where this assumption is lifted. Implications and analytic suggestions for conducting regression mixture based on these findings are noted.     

Optimisation of phase ratio in the triple jump using computer simulation

The triple jump is an athletic event comprising three phases in which the optimal proportion of each phase to the total distance jumped, termed the phase ratio, is unknown. This study used a whole-body torque-driven computer simulation model of all three phases of the triple jump to investigate optimal technique. The technique of the simulation model was optimised by varying torque generator activation parameters using a Genetic Algorithm in order to maximise total jump distance, resulting in a hop-dominated technique (35.7%:30.8%:33.6%) and a distance of 14.05 m. Optimisations were then run with penalties forcing the model to adopt hop and jump phases of 33%, 34%, 35%, 36%, and 37% of the optimised distance, resulting in total distances of: 13.79 m, 13.87 m, 13.95 m, 14.05 m, and 14.02 m; and 14.01 m, 14.02 m, 13.97 m, 13.84 m, and 13.67 m respectively. These results indicate that in this subject-specific case there is a plateau in optimum technique encompassing balanced and hop-dominated techniques, but that a jump-dominated technique is associated with a decrease in performance. Hop-dominated techniques are associated with higher forces than jump-dominated techniques; therefore optimal phase ratio may be related to a combination of strength and approach velocity.     

Connecting the dots between fantasy and reality: The social psychology of our engagement with fictional narrative and its functional value

This essay provides an overview of research and theory on narrative and its important, functional role in human experience, including the ways people use media to interrogate their own beliefs and feelings, and derive social meaning. Thought‐provoking film, television, and books can help us make meaning of our lives and grow in ways that are important for our successful social functioning. Research reviewed here demonstrates that exposure to fiction can increase empathy and social skills and reduce prejudice. Our connection to characters and stories has been studied in various ways as extensions of the self into another, while at the same time bringing the other into the self. Bringing together disparate perspectives, we propose that connecting to story worlds involves a process of “dual empathy”—simultaneously engaging in intense personal processing while also “feeling through” characters, both of which produce benefits. Because the value of entertainment narratives may not always be well understood, we explain how those experiences can be personal, social, and can serve important adaptive functions.     

Is the “hot‐hands” phenomenon a misperception of random events?

T. Gilovich, R. Vallone, and A. Tversky (1985) asked whether the so-called hot-hands phenomenon – a temporary elevation of the probability of successful shots – actually exists in basketball. They concluded that hot-hands are misperceived random events. This paper re-examines the truth of their conclusion. The present study's main concern was the sensitivity of the statistical tests used in Gilovich et al.'s research. Simulated records of shots over a season were used. These represented many different situations and players, but they always contained at least one hot-hand period. The issue was whether Gilovich et al.'s tests were sensitive enough to detect the hot-hands embedded in the records. The study found that this sensitivity depends on the frequency of hot-hand periods, the total number of shots in all hot-hand periods, the number of shots in each hot-hand period, and the size of the increase in the probability of successful shots in hot-hand periods. However, when the values of those variables were set realistically, on average the tests could detect only about 12% of the hot-hands phenomena.     

Quantified Propositional Logic and the Number of Lines of Tree-Like Proofs

There is an exponential speed-up in the number of lines of the quantified propositional sequent calculus over Substitution Frege Systems, if one considers proofs as trees. Whether this is true also for the number of symbols, is still an open problem. This revised version was published online in June 2006 with corrections to the Cover Date.