Bootstrapping the Local Periodogram of Locally Stationary Processes

Abstract. Locally stationary processes are non‐stationary stochastic processes the second‐order structure of which varies smoothly over time. In this paper, we develop a method to bootstrap the local periodogram of a locally stationary process. Our method generates pseudo local periodogram ordinates by combining a parametric time and non‐parametric frequency domain bootstrap approach. We first fit locally a time varying autoregressive model so as to capture the essential characteristics of the underlying process. A locally calculated non‐parametric correction in the frequency domain is then used so as to improve upon the locally parametric autoregressive fit. As an application, we investigate theoretically the asymptotic properties of the bootstrap method proposed applied to the class of local spectral means, local ratio statistics and local spectral density estimators. Some simulations demonstrate the ability of our method to give accurate estimates of the quantities of interest in finite sample situations and an application to a real‐life data‐set is presented.     

Personality and the predisposition to engage in risky or problem behaviors during adolescence.

Longitudinal data from a representative sample of 1,978 Black and White adolescents were used to examine the role of personality in multiple risk or problem behaviors. Results indicate that covariation among diverse behaviors (educational underachievement, delinquent behavior, substance use, sexual behavior) can be adequately modeled by a single higher order factor, and that impulsivity and avoidance coping serve as generalized risk factors for involvement in these behaviors. Whereas none of the personality variables examined explained change in problem behaviors once established, avoidance coping prospectively predicted involvement among a subgroup of adolescents with little or no prior involvement. Results suggest that dysfunctional styles of regulating emotions and emotionally driven behaviors are core features of risky or problem behaviors during adolescence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Scaffolded writing and rewriting in the discipline: A web-based reciprocal peer review system

This paper describes how SWoRD (scaffolded writing and rewriting in the discipline), a web-based reciprocal peer review system, supports writing practice, particularly for large content courses in which writing is considered critical but not feasibly included. To help students gain content knowledge as well as writing and reviewing skills, SWoRD supports the whole cycle of writing, reviews, back-reviews, and rewriting by scaffolding the journal publication process as its authentic practice model. In addition, SWoRD includes algorithms that compute individual reviewer’s review accuracy, which is in turn used to support the various drawbacks of reciprocal peer reviews (e.g., variation in motivation or ability of reviewers). Finally, this paper describes an empirical evaluation showing that the SWoRD approach is effective in improving writing quality in content classes.     

ANOM在质量控制中的应用

ANOM（均值分析）是一种有效的质量工具，可以用来分析实验因素对输出的影响是否显著。可以应用于单因子，双因子的实验设计，无论是计量值数据，还是计数值数据，ANOM检验异常值的能力都很强，介绍了ANOM的基本分析过程，对ANOM和ANOVA进行了检验异常值灵敏度大小的比较，同时给出了实例。     

高职高专现代教育技术管理体制之我见

本文从教育技术的含义和发展的历史出发，分析目前高职高专院校的教育技术管理体制现状，提出应建立完善的教育技术管理体制，以推进教育技术工作的协调发展。     

层状介质中重力,地震联合反演的迭代算法

本文提出一种用于层状介质中重力、地震资料联合反演层速度、层密度及弯曲界面深度的迭代算法。该方法通过引入加权最小平方目标泛函,将层状介质中的重力、地震资料联合反演问题转化成具体的优化问题。为了得到反问题的最优解,文中系统地研究了层状介质中双摄动处理技术,以及层状介质中波场摄动的一阶 Born 近似解与理论重力异常摄动解。并应用 Tarantola 的反演理论,导出了梯度算子的计算公式。然后应用最速下降法给出了求取最优解的具体算法,得到了一种类似于地震偏移与空间更投影的迭代反演方法。对理论模型进行重力、地震联合反演的结果表明,该方法不仅可碱少未知参数的个数,提高反演的收敛速度,而且可减少反演的不适定性,不失为一种可行的多参数反演方法。     

信息与计算科学专业教学团队的建设与实践——以德州学院为例

结合德州学院信息与计算科学专业教学团队建设的实际,阐述了教学团队的内涵与特征、教学团队的梯队建设、教学团队建设的策略,以及教学团队建设已取得的成果。     

Connecting the dots: Understanding the interrelated impacts of type,quality and children's awareness of design features and the mathematics content learning goals in digital math games and related learning outcomes

This study focused on an examination of how type, quality and children's awareness of design features in digital math games, along with an awareness of the mathematics goals of the game, were related to learning outcomes. We conducted a parallel conversion mixed methods study with 45 students in Grades 3 and 4 (ages 9–10). Students participated in clinical interviews using three digital math games. The results suggest a moderated mediation relationship in which the quality of the design features moderated the mediating impact of children's awareness of the game's design features, specifically when the child was aware of the mathematics content learning goal (MCLG) of the game. These findings show how important it is that design features are of high quality in a digital math game, and how this is intertwined with children's awareness of the features and the MCLG. When these variables intertwined in just the right way, the interactions between the children and the digital math game afforded mathematical learning growth.     

现代教育技术在大学物理实验教学中的应用

在信息技术高速发展的今天,现代教育技术在大学物理实验教学中的应用已逐步得到普及。本文从教学实际出发,研究了现代教育技术在大学物理实验课程教学中的应用,并从教学实践角度思考如何有效地运用现代教育技术来调动学生的学习积极性和主动性,提高教学效果。