评估风险的期望损失计算及应用研究

Expected shortfall(ES) is a new method to measure market risk. In this paper, an example was presented to illustrate that the ES is coherent but value-at-risk(VaR) is not coherent. Three formulas for calculating the ES based on historical simulation method,normal method and GARCH method were derived. Further, a numerical experiment on optimizing portfolio using ES was provided.     

Helping Teachers Support Pupils with Mental Health Problems Through Inter-professional Collaboration: A Qualitative Study of Teachers and School Principals

ABSTRACT

A qualitative study conducted in four lower secondary schools in Norway explored teachers’ and school principals’ experiences of collaboration with a variety of extended services (ES). Particular attention was directed to the ways (if any) they perceived collaboration to be relevant to helping teachers support pupils with mental health problems through their everyday social and pedagogic practices. Findings of the study indicated that teachers valued initiatives that could help develop mutual understandings of teachers’ and ES professionals’ roles and responsibilities. Initiatives to build inter-professional relationships were perceived as laying the foundation for more productive collaboration. However, to be able to provide coherent, sustained support in the classroom, teachers needed guidance from ES professionals. This required a shift in collaborative processes away from a focus on individualized pupil support towards helping teachers support pupils through their classroom-based social and pedagogical practices. Implications for policy and practice are discussed.     

嵌入式系统电磁兼容设计研究

介绍了嵌入式系统电磁兼容的定义,提出了电磁干扰模型。分析了嵌入式系统中产生电磁干扰的主要原因,总结了电磁兼容设计的主要方法。最后以嵌入式系统电磁兼容设计为例,以验证主题观点。     

Influence of coherent structures in the gas-particle circular cylinder wake flow

INTRODUCTION Turbulent gas-particle flows are frequently found in natural phenomena and industrial processes.Cases of cylinders in cross flows with particles occur in heat exchange equipment,including the convective zone of a fluidized-bed combustor,and in the primary superheaters,reheaters,and economizers of coal-fired boilers.Coherent structures often occur in the above-mentioned gas-particle flow,and have great effect on such different systems,while some features of tur-bulent multiphas…     

偏振模色散对光副载波复用系统的影响及其抑制

光链路的偏振模色散效应已成为高速 /长距离的传统光时分复用系统和光副载波复用系统的严重阻碍。文章基于一阶近似 ,导出了光副载波系统中 ,偏振模色散效应引起的射频信号功率衰落的一般表达式。并且研究了几种偏振模色散抑制方法的优缺点 ,提出了一种全新的相干检测技术来提高补偿性能。     

Distribution Network Reconfiguration Based on ESA

本文提出了一种新的用于配电网络重构的优化方法－进化策略退火（ＥＳＡ）法,该方法将模拟进化策略法（ＥＳ）与模拟退火法（ＳＡ）进行了有机结合．首先用ＥＳ法选择ＳＡ法的初始温度,然后用改进ＳＡ法搜索重构的全局最优解．为加快寻优速度,本文提出了一种启发式规则用于降温策略,并采用了有效的潮流算法．仿真结果表明了ＥＳＡ法的有效性     

基于进化策略的消防应急救援决策

近年来,随着社会的发展,城市中各种突发事件的发生频率越来越高,因此需要加强对城市应急决策支持系统(Emergency Decision Supports System,EDSS)的研究。进化策略是受自然进化过程启发,并成为求解全局优化问题的重要方法。将进化策略应用于EDSS中的消防救援事件的推理决策过程,提高了EDSS处理复杂问题的决策能力,实验证实了此方法的有效性。     

对CAD技术发展前景的探讨

本文概述了CAD(Computer Aided Design)技术的基本概念及其应用领域的发展状况,认为CAD技术存在缺陷和不足的主要原因是由于缺乏知识表示和推理机制。本文通过阐述专家系统技术的定义、组成及其领域,预示了CAD技术今后的发展方向和趋势。我们分析了我国专家系统技术和CAD技术目前的应用状况,指出在CAD技术中采用专家系统技术不仅是必要的而且是可能的,目的是为了引起人们对专家系统技术的足够重视。     

Precil XC-20型自动血沉仪的应用评价与血沉测定的方法进展

目的:比较Precil XC-20型自动血沉仪测定结果与传统魏氏法的相关性和线性.方法:分别用自动血沉仪法和传统魏氏法测定50例临床病人1h血沉.结果:经统计学处理,两种方法的测定结果相关系数0.84,在正常参考值范围内,二者测定结果一致,但当血沉＞10mm/h后,手工法测定均值高于仪器法,P＜0.01,而且随着测定值增加,二者之间差异越明显.结论:自动血沉仪法对正常标本测定结果与手工法接近,而在血沉升高的标本则手工法结果更可靠.     

Student Teaching at a Nature Center

Abstract

A statewide assessment of the status of environmental science (ES) in Texas school districts was conducted in 1985. Respondents were 126 science curriculum supervisors and 278 teachers (grades seven through twelve) representing 339 (38 percent) of those independent school districts (ISDs) (N = 893) having at least one science-certified teacher. The assessment results characterized ES in terms of grade level, subject matter, and implementor; degree to which ES facilities external to the classroom are used and factors preventing their use; ES teaching materials used and needed; levels of emphasis placed on selected teaching strategies; those content areas emphasized in ES; and ES implementation difficulties and needed assistance.     

Economics and violence against children,findings from the Violence Against Children Survey in Nigeria

This study seeks to assess the impact of economic factors on sexual, emotional, and physical violence on Nigerian children and adolescents aged 13–24 years. Data collected from the Nigerian Violence Against Children Survey (VACS), a national, cross-sectional household survey of females and males aged 13–24 years were used to examine sexual, emotional, and physical violence victimization. Data were collected on household economic status, e.g., flooring and roofing materials, transportation. A poverty index was developed using the Simple Poverty Scorecard^™ for Nigeria to determine the impact that economic factors have on these violence measures. Children aged 13–17 years in households with high economic status (ES) were 1.81, 1.78, and 4.91 times, more likely to experience sexual, emotional, and physical violence, respectively, within the last 12 months than those in the lowest ES. Individuals aged 18–24 years in households with high ES were 1.62 and 1.41 times more likely to experience emotional and physical violence, respectively, prior to age 18 than those in the lowest ES. Individuals aged 18–24 years in households with middle or high ES were 1.65 and 1.96, respectively, times more likely to experience physical violence prior to age 18 than those in the lowest ES. Highest tertile ES was significantly associated with sexual, emotional, and physical violence among Nigerians aged 13–24 years. Further research is needed to determine the cause of increased violence amongst high ES households. Targeted interventions towards this ES class are recommended to reduce violence against children in Nigeria.     

Effects of Computer Application on Elementary Schook Student's Achievement: A Meta-Analysis of Students in Taiwan

ABSTRACT

A meta-analysis was performed to synthesize existing research comparing the effects of computer applications (i.e., computer-assisted instruction, computer simulations, and Web-based learning) versus traditional instruction on elementary school students' achievement in Taiwan. Forty-eight studies were located from four sources, and their quantitative data were transformed into Effect Size (ES). The overall grand mean of the study-weighted ES for all 48 studies was 0.449. The results suggest that computer application instruction is more effective than traditional instruction for elementary school students in Taiwan. However, none of the 14 individual variables, conjectured to be related to achievement, had a statistically significant impact on the mean ES.     

The Impact of APA and AERA Guidelines on Effect Size Reporting

Given the long history of effect size (ES) indices (Olejnik and Algina Contemporary Educational Psychology, 25, 241–286 2000) and various attempts by APA and AERA to encourage the reporting and interpretation of ES to supplement findings from inferential statistical analyses, it is essential to document the impact of APA and AERA standards on ES reporting practices. In this paper, we investigated the impact by examining findings from 31 published reviews and our own review of 451 articles published in 2009 and 2010. The 32 reviews were divided into two periods: before and after 1999. A total of 116 journals were reviewed. Findings from these 32 reviews revealed that since 1999, the ES reporting has improved in terms of its rate, variety, interpretation, confidence intervals, and fullness. Yet several inadequate practices still persisted: (1) the dominance of Cohen’s d, and the unadjusted R ²/η², (2) the mere labeling of ES, (3) the under-reporting of confidence intervals, and (4) a lack of integration between ES and statistical tests. The paper concludes with resources on Internet and recommendations for improving ES reporting practices.     

(2+1)-维反对称Nizhnik-Novikov-Veselov方程的Bcklund变换和局域相干结构

This article is concerned with the extended homogeneous balance method for studying the abundant localized solution structure of the (2 + 1)-dimensional asymmetric Nizhnik-Novikov-Veselov equation. A Backlund transformation was first obtained, and then the richness of the localized coherent structures was found, which was caused by the entrance of two variable-separated arbitrary functions, in the model. For some special choices of the arbitrary functions, it is shown that the localized structures of the model may be dromions, lumps, and ring solitons.     

Baecklund Transformation and Localized Coherent Structure for the （2＋1）—Dimensional Asymmetric Nizhnik—Novikov—Veselov Equation

This article is concerned with the extended homogeneous balance method for studying the abundant lacalized solution structure of the (2 1)-dimensional asymmetric Nizhnik-novikov-Veselov equation.A Baecklund transformation was first obtained.and then the richness of the localized coherent structures was found,which was caused by the entrance of two variable-separated arbitrary functions,in the model.For some spectial choices of the arbitrary functions,it is shown that the localized structures of the model may be dromions,lumps,and rinmg solitons.     

二周期驱动及弱耦合玻丝-爱因斯坦凝聚模型的动力学性质

1Introduction Theinvestigationsontheexistenceofthequantum chaoshavebeenconductedforalongtimeandthere havebeenaincreasingnumberofpeopleinterestedin thefield[29].Thedifficultyoftheproblemisthatthere existsthephenomenonofso calledbreakdownofthe correspondentprincipleforthechaoticsystem[5,8].A reasonofthequantumbreakdownofchaosisthatthe classicalchaosgenerallyappearsinsomenonlinear systemsandthecorrespondingquantumSchr¨odinger equationssupplysuchsystemsforus[10].Sincetheex perimentalobservationo…     

Promoting Acceleration of Comprehension and Content Through Text in High School Social Studies Classes

Abstract:

The purpose of this study was to evaluate the efficacy of Promoting Acceleration of Comprehension and Content Through Text intervention implemented with 11th-grade students enrolled in U.S. History classes. Using a within-teacher randomized design, the study was conducted in 41 classes (23 treatment classes) with 14 teachers providing the treatment. Students in the treatment condition performed significantly better than students in the typical instruction comparison condition on a measure of content acquisition at posttest (ES = 0.36), as well as 4 (ES =.22) and 12 (ES =.24) weeks following treatment. There were no differences between treatment and comparison groups on measures of social studies reading comprehension or more general reading comprehension.     

Effects of Technology-Mediated Vocabulary Intervention for Third-Grade Students with Reading Difficulties

Abstract

In this experimental study, we examined the effects of a technology-mediated intervention to improve students’ understanding of academic vocabulary and its impact on measures of vocabulary and comprehension. The Vocabulators program was implemented in two states involving 24 teachers and 200 third-grade students identified as in need of supplemental vocabulary instruction. Individual students within each classroom were randomly assigned to treatment (n?=?100) or typical instructional practices (n?=?100) conditions. In the treatment condition, students received, on average, 29 lessons on vocabulary and comprehension. Results of linear regression analyses showed statistically significant and practical effects on experimenter-developed proximal measures of decoding (ES = 0.52), expressive vocabulary (ES = 0.78), receptive vocabulary (ES = 0.51), and near transfer measures of understanding vocabulary in sentences (ES = 0.65), and informational text comprehension (ES = 0.28). Group performance did not differ statistically on near transfer measures of sentence verification with vocabulary and narrative text comprehension as well as distal standardized measures of general vocabulary or reading comprehension. Findings suggest the potential impact of technology-based vocabulary/comprehension lessons to supplement typical instruction.     

SU(1,1)广义相干态中的高阶涨落和SU(1,1)高阶压缩

The higher-order fluctuations in the SU(1,1)generalized coherent states are discussed.The definition of higher-order SU(1,1)squeezing is introduced in terms of higher-order uncertainty relation.For two possible bosonic realizations of SU(1,1)Lie algebra,the second-,fourth-and sixth-order SU(1,1)squeezing are examined in detail.It is shown that the SU(1,1)generalized coherent states can be squeezed to not only second-order,but also fourth-and sixth-order.Hence,it follows that the higher-order squeezing will occur for the fluctuations of the square of amplitude in squeezed vacuum.SU(1,1)higher-order squeezing is a kind of non-classical property which is independent of second-order squeezing.