Tracking, grading, and student motivation: Using group composition and status to predict self-concept and interest in ninth-grade mathematics.

Assigning students to different classes on the basis of their achievement levels (tracking, streaming, or ability grouping) is an extensively used strategy with widely debated consequences. The authors developed a model of the effects of tracking on self-concept and interest that integrates the opposing predictions of "assimilation" and "contrast" effects, which specifies teacher-assigned grades as a major mediating variable, and tested it in 2 settings in which track level is clearly associated with different status-systematic tracking as a function of school type (Study 1, N = 14,341 German 9th-grade students) and separate streams within a comprehensive school system (Study 2, N = 3,243 German 9th-grade students). The results support predictions that students' math self-concept and math interest differ as a function of the achievement of their reference group, their own achievement, and their teacher-assigned grades. No systematic association between track level and math self-concept was found once individual student achievement, school-/stream-average achievement, and teacher-assigned grades were controlled. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assimilation of problematic experiences.

The assimilation model offers an approach to customizing the therapeutic relationship. Assimilation research has tracked problematic experiences (e.g., destructive relationships or traumatic memories) across therapy sessions and has described a sequence of 8 stages of levels of assimilation of the problematic experience, from being dissociated or unwanted to being understood and integrated. This article reviews some assimilation model research and discusses its limitations. Therapists can use the model in assessing a problem's current level of assimilation and facilitating its movement to the next level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

不同铁矿粉替代澳洲低铝矿粉对烧结黏结相高温行为的影响

澳洲某低铝矿粉具有低Al₂O₃、粗粒度、强同化性等优点,是国内钢铁企业进口矿石的主要来源之一,而该低铝矿粉已濒临枯竭,故寻求其他铁矿粉进行替代现已成为迫切需求。采用微型烧结等方法,考察不同铁矿粉替代该低铝矿粉后黏结相高温行为的变化。研究表明,当配加南美矿粉OA后,黏结相同化性减弱,液相流动性增强,铁酸钙含量降低;当配加北非铁矿OB粉后,黏结相同化性和液相流动性均增强,但硅酸钙含量有所增加;当配加2种澳洲铁矿粉OC和OD后,黏结相的同化性减弱,高铝脆性矿物含量增加。基于此,通过澳洲铁矿粉OC搭配北非铁矿粉OB共同替代该低铝矿粉的方式,增强黏结相同化性和流动性,提高铁酸钙含量,抑制了劣质矿物的生成。     

Transport Map sampling with PGD model reduction for fast dynamical Bayesian data assimilation

The motivation of this work is to address real-time sequential inference of parameters with a full Bayesian formulation. First, the proper generalized decomposition (PGD) is used to reduce the computational evaluation of the posterior density in the online phase. Second, Transport Map sampling is used to build a deterministic coupling between a reference measure and the posterior measure. The determination of the transport maps involves the solution of a minimization problem. As the PGD model is quasi-analytical and under a variable separation form, the use of gradient and Hessian information speeds up the minimization algorithm. Eventually, uncertainty quantification on outputs of interest of the model can be easily performed due to the global feature of the PGD solution over all coordinate domains. Numerical examples highlight the performance of the method.     

Moods as spotlights: The influence of mood on accessibility effects.

Three studies explore the manner in which one's mood may affect the use and impact of accessible information on judgments. Specifically, the authors demonstrated that positive and negative moods differentially influence the direction of accessibility effects (assimilation, contrast) by determining whether abstract traits or concrete actor-trait links are primed. Study 1 investigated the impact of positive versus negative mood on the judgmental impact of trait-implying behaviors and found that positive moods lead to assimilation and negative moods to contrast. In Study 2, this effect was replicated in a subliminal priming paradigm. In Study 3, it was demonstrated that the type of information activated by trait-implying behaviors is indeed mood dependent, such that abstract trait information is activated in a positive mood, whereas specific actor-trait links are activated in a negative mood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ethnic Group Identification and Group Evaluation Among Minority and Majority Groups: Testing the Multiculturalism Hypothesis.

Following social identity theory, the author hypothesized that members of minority groups are more likely than majority group members to endorse multiculturalism more strongly and assimilationist thinking less strongly. In addition, the multiculturalism hypothesis proposes that the more minority groups endorse the ideology of multiculturalism (or assimilationism), the more (or less) likely they will be to identify with their ethnic in-group and to show positive in-group evaluation. In contrast, the more majority group members endorse multiculturalism (or assimilationism), the less (or more) likely they are to identify with their ethnic group and to show negative out-group evaluation. Results from 4 studies (correlational and experimental) provide support for this hypothesis among Dutch and Turkish participants living in the Netherlands. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assimilation for Affiliation and Contrast for Control: Complementary Self-Construals.

People have knowledge about relationships (i.e., relational schemas) that is based on their experiences. Because most people have experience with complementary behavior (interaction partners behaving similarly in terms of affiliation but oppositely in terms of control), they expect complementary behavior in their relationships. Like other beliefs about relationships, expectations of complementarity affect self-construal. The authors provide evidence for complementary self-construal; people assimilate to relevant relationship partners on the affiliation dimension and contrast on the control dimension. Consistent with the proposed role of relationship knowledge in these effects, complementary self-construal was moderated by the familiarity of the target, whether people focused on their relationship with or the appearance of the target, and whether the context was relevant for the interpersonal dimension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Categorization and communication in the face of prejudice: When describing perceptions changes what is perceived.

In the face of prejudice against an ingroup, common ground for communication exists when people use similar social categories to understand the situation. Three studies tested the hypothesis that describing perceptions of prejudice can fundamentally change those perceptions because communicators account for the common ground in line with conversational norms. When women (Study 1), African Americans (Study 2), and Americans (Study 3) simply thought about suspected prejudice against their ingroup, categorization guided their perceptions: Participants assimilated their views of the prejudiced event toward the perceptions of ingroup members but contrasted away from the perceptions of outgroup members. Conversely, when participants described their perceptions, they contrasted away from the given category information and actually arrived at the opposite perceptions as those who merely thought about the prejudiced event. Study 3 identified an important qualification of these effects by showing that they were obtained only when participants could assume their audience was familiar with the common ground. Implications are discussed for understanding the role of communication in facilitating and inhibiting collective action about prejudice. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

迭代集合卡尔曼滤波方法的性能比较研究

针对数据同化过程中模型的非线性问题,通过分析对比得出了一种适合强非线性系统的迭代集合Kalman滤波(IEnKF)。在Lorenz\|63模型的框架内,比较分析集合Kalman滤波(EnKF)、迭代集合Kalman滤波(IEnKF)和迭代扩展卡Kalman滤波(IEKF)在集合数、观测误差方差、放大因子和模型步长不同时同化性能差异,由此探讨这3种方法的优劣。研究结果表明:随着集合数的增加,3种算法的同化性能都得到了一定的改善;放大因子的增大,使其同化性能变差且EnKF呈现出多重波峰波谷的现象;3种方法的均方误差(RMSE）随观测误差方差和模型步长的增大而增大,其同化精度都变差;而IEnKF同化性能最优,更具有鲁棒性。     

WRF-LTNGDA: A lightning data assimilation technique implemented in the WRF model for improving precipitation forecasts

This study introduces WRF-LTNGDA, a lightning data assimilation technique implemented in the Weather Research and Forecasting (WRF) model. This technique employs lightning for improving the representation of convection by means of controlling the triggering of the model's convection parameterization scheme. The development and implementation of WRF-LTNGDA was carried out in a framework that could easily allow for its exploitation in real-time forecasting activities. The assimilation algorithm was evaluated over eight precipitation events that took place in Greece in the years 2010–2013. Results clearly show that lightning forcing has a positive impact on model performance. The conducted analysis revealed that the employment of WRF-LTNGDA induces statistically significant improvements in precipitation verification scores, especially for high rainfall accumulations. Separate examination of one of the eight case studies highlighted the overall better agreement between the modelled and observed spatial distribution of precipitation when lightning data assimilation was applied, than in the control simulation.