Kinetics of interstitial segregation in Cottrell atmospheres and grain boundaries

Trapping of interstitial (e.g. carbon) atoms is driven by the reduction in energy in the system. Diffusion of interstitials, together with their trapping in dislocation cores and/or grain boundaries, is studied by the thermodynamic extremal principle. In addition to the total Gibbs energy, a well-established formulation of the total dissipation is applied. Dimension-free evolution equations are derived, whose solution is well approximated by an easy to handle kinetic equation. Cottrell’s power law can be verified in the initial stage.     

Selecting the number of classes under latent class regression: a factor analytic analogue

Recently, the regression extension of latent class analysis (RLCA) model has received much attention in the field of medical research. The basic RLCA model summarizes shared features of measured multiple indicators as an underlying categorical variable and incorporates the covariate information in modeling both latent class membership and multiple indicators themselves. To reduce complexity and enhance interpretability, one usually fixes the number of classes in a given RLCA. Often, goodness of fit methods comparing various estimated models are used as a criterion to select the number of classes. In this paper, we propose a new method that is based on an analogous method used in factor analysis and does not require repeated fitting. Two ideas with application to many settings other than ours are synthesized in deriving the method: a connection between latent class models and factor analysis, and techniques of covariate marginalization and elimination. A Monte Carlo simulation study is presented to evaluate the behavior of the selection procedure and compare to alternative approaches. Data from a study of how measured visual impairments affect older persons’ functioning are used for illustration.This work was supported by National Institute on Aging (NIA) Program Project P01-AG-10184-03. The author wishes to thank Dr. Karen Bandeen-Roche for her stimulating comments and helpful discussions, and Drs. Gary Rubin and Sheila West for kindly making the Salisbury Eye Evaluation data available.     

学习支持对基于计算机模拟的发现学习的影响

研究了针对发现活动的意义性的解释性支持 (IS)、针对其系统逻辑性的实验性支持 (ES)以及学习者的推理能力对基于模拟的科学发现学习的影响。设计开发了关于浮力的模拟软件 ,被试为北京十四中初二学生 80名 ,采用 2 (有 /无IS)× 2 (有 /无ES)× 3(推理能力 )的混合实验设计。结果发现 ,推理能力在原理性知识、直觉性理解测验以及学习者所设计实验的质量上有显著的主效应。IS在原理性知识和灵活应用测验上有显著的主效应。ES与推理能力在原理性知识测验上有显著的交互作用 ,ES在学习者所设计实验的质量上有显著的主效应。这一结果说明 ,发现活动的意义性和系统逻辑性对基于模拟的发现学习有重要的制约作用 ,应该针对这两个侧面设计相应的学习支持     

Residual Normality Assumption and the Estimation of Multiple Membership Random Effects Models

While conventional hierarchical linear modeling is applicable to purely hierarchical data, a multiple membership random effects model (MMrem) is appropriate for nonpurely nested data wherein some lower-level units manifest mobility across higher-level units. Although a few recent studies have investigated the influence of cluster-level residual nonnormality on hierarchical linear modeling estimation for purely hierarchical data, no research has examined the statistical performance of an MMrem given residual non-normality. The purpose of the present study was to extend prior research on the influence of residual non-normality from purely nested data structures to multiple membership data structures. Employing a Monte Carlo simulation study, this research inquiry examined two-level MMrem parameter estimate biases and inferential errors. Simulation factors included the level-two residual distribution, sample sizes, intracluster correlation coefficient, and mobility rate. Results showed that estimates of fixed effect parameters and the level-one variance component were robust to level-two residual non-normality. The level-two variance component, however, was sensitive to level-two residual non-normality and sample size. Coverage rates of the 95% credible intervals deviated from the nominal value assumed when level-two residuals were non-normal. These findings can be useful in the application of an MMrem to account for the contextual effects of multiple higher-level units.     

黎明模拟光照对晨起睡眠惰性的影响

本研究采用单因素被试内设计对清晨唤醒后睡眠惰性对个体主观情绪、警觉性和认知加工的影响，以及利用动态黎明模拟光照能否对睡眠惰性产生有效的对抗作用进行了考察。结果发现：（1）被试的积极情绪、主观警觉性在刚唤醒时显著低于基线水平，之后随时间推移逐渐提升。（2）被试醒后立即进行测试的认知加工成绩最差，随后逐渐提高，且主要表现在加工速度的回升上。（3）黎明模拟光照对被试醒后在积极情绪、主观警觉性、持续性注意和抑制功能的缓解上产生了明显的促进作用。这表明睡眠惰性会对个体的主客观活动产生显著的负性影响，而使用黎明模拟光照可在一定程度上对抗睡眠惰性带来的负性影响。     

参数和非参数Bootstrap方法的简单中介效应分析比较

采用数据模拟技术比较了(偏差校正和未校正的)参数和非参数Bootstrap方法在简单中介效应分析中的表现。结果表明,1)偏差校正的Bootstrap法的总体表现优于未校正的Bootstrap方法,但在某些条件下会高估第Ⅰ类错误率,导致在 时的置信区间偏差较大。2)参数Bootstrap方法优于非参数Bootstrap方法,偏差校正的参数百分位残差Bootstrap法的综合表现最优,且具有适用范围广,对原始样本依赖性小的优点,最具实用性。     

The impact of September 11 on dreaming

This study focuses on a set of dreams related to the September 11, 2001 terrorist attacks and their aftermath, using content analysis and cognitive psychology to explore the interweaving of external public catastrophe and internal psychological processes. The study tests several recent claims in contemporary dream research, including the central image theory of Hartmann [Hartmann, E., & Basile, R. (2003). Dream imagery becomes more intense after 9/11/01. Dreaming, 13(2), 61-66; Hartmann, E., & Brezler, T. (2008). A systematic change in dreams after 9/11/01. Sleep, 31(2), 213-218], the media exposure factor postulated by Propper [Propper, R. E., Stickgold, R., Keeley, R., & Christman, S. D. (2007). Is television traumatic? Dreams, stress, and media exposure in the aftermath of September 11, 2001. Psychological Science, 18(4), 334-340], the continuity hypothesis of Domhoff [Domhoff, W. G. (1996). Finding meaning in dreams: A quantitative approach. New York: Plenum], the cognitive and metacognitive approach of Kahan [Kahan, T. L. (2001). Consciousness in dreaming: A metacognitive approach. In K. Bulkeley (Ed.), Dreams: A reader on the religious, cultural, and psychological dimensions of dreaming (pp. 333-360). New York: Palgrave], and the threat simulation theory of Revonsuo [Revonsuo, A. (2000). The reinterpretation of dreams: An evolutionary hypothesis of the function of dreaming. Behavioral and Brain Sciences, 23(6), 877-901]. Our findings suggest the terrorist attacks had a tangible impact on the content of many people's dreams, but did not fundamentally alter the cognitive processing features of their dreaming. The 9/11 attacks affected what they dreamed about, but not the way they dreamed.     

Feeling Good,but Lacking Autonomy: Closed-Mindedness on Social and Moral Issues in New Religious Movements

According to previous research, New Religious Movements (NRMs) seem to have a positive effect on the mental health of members who join NRMs with some previous affective, cognitive or other vulnerabilities. The present study investigates the other, less positive, side of the psychology of NRMs, i.e. elements that may be an obstacle to optimal development, such as rigidity and low autonomy. In comparison to non-NRM members, members of various NRMs in Belgium (N = 120) were found to be low in quest religious orientation (Altemeyer and Hunsberger, Int J Psychol Religion 2:113–133, 1992), to privilege conservation values to the detriment of openness to change values (Schwartz, Advances in experimental social psychology (vol 25, pp. 1–65). Orlando, FL: Academic Press, 1992), to show submissiveness to authority in hypothetical situations (projective measure), and to highly moralize judgments of transgression relative to conventional domains (Turiel, The development of social knowledge: Morality and social convention. Cambridge: Cambridge University Press, 1983). Discussion points out the idea that rigidity and restriction of autonomy may be the price to be paid for the structuring role NRMs play with regard to previous vulnerabilities.

具身概念表征的研究及理论述评

具身认知强调认知在本质上是具身的, 身体在认知的实现中发挥着关键作用。传统的符号加工理论认为, 概念表征独立于主体的知觉运动系统并以抽象符号的形式储存于语言记忆中。概念表征的具身理论则认为, 概念表征与知觉运动系统具有共同的神经基础, 概念在本质上是主体经验客体时知觉与运动体验的神经记录, 而概念加工的基本形式则是身体经验的模拟与还原。关于该理论的实证研究主要集中于概念加工引发的知觉动作变化、身体动作对概念加工的影响、抽象概念加工的具身特征等领域。今后的研究应关注符号加工理论与具身理论的整合等。     

分类精确性指数Entropy在潜剖面分析中的表现:一项蒙特卡罗模拟研究

本研究通过蒙特卡洛模拟考查了分类精确性指数Entropy及其变式受样本量、潜类别数目、类别距离和指标个数及其组合的影响情况。研究结果表明:(1)尽管Entropy值与分类精确性高相关,但其值随类别数、样本量和指标数的变化而变化,很难确定唯一的临界值;(2)其他条件不变的情况下,样本量越大,Entropy的值越小,分类精确性越差;(3)类别距离对分类精确性的影响具有跨样本量和跨类别数的一致性;(4)小样本(N=50~100)的情况下,指标数越多,Entropy的结果越好;(5)在各种条件下Entropy对分类错误率比其它变式更灵敏。