The sexual abuse of Afro-American and White-American women in childhood

This study examined the prevalence of child sexual abuse in a multi-stage stratified probability sample of Afro-American and white-American women, 18 to 36 years of age, in Los Angeles County. The sample ranged in demographic characteristics by age, marital status, education and the presence of children. Of the total sample of 248 women, 154 (62%) reported at least one incident of sexual abuse prior to age 18, with 57% of Afro-American women and 67% of white-American women having been abused. Sexual abuse before the age of 18 appears to be of equal concern for both ethnic groups, although similarities and differences in the circumstances under which abuse incidents occurred were subtle and deserve attention. The need for identifying contemporary factors that contribute to the prevalence of abuse over the past 40 years is stressed.     

基于Radarsat-1数据的北极海冰SAR图像自动分割研究

基于Radarsat-1数据提出了一种集成Gibbs采样标记步骤的北极海冰SAR图像分割算法,该算法综合考虑了斑点噪声、纹理特征等不确定因素,经由像素到区域再到大尺度区域这一途径,把区域化标识、Gibbs采样标记以及区域合并等操作组合起来,实现对海冰SAR图像的分割,针对S.Laurence Bay和Beaufort海冰图像的测试实验表明,与基于区域的MRF分割算法相比提出的算法可有效提高图像分割的准确性。     

复合二项风险模型破产概率的鞅方法证明

讨论一般情形的复合二项风险模型，首先构造一个离散鞅，应用可选抽样定理和收敛定理，给出该风险模型的最终破产概率公式的简洁证明，并得出最终破产概率一个易于计算的上界表达式．     

What factors influence students’ real-time motivation and engagement? An experience sampling study of high school students using mobile technology

Abstract

Using mobile technology and experience sampling in junior high school, real-time motivation and engagement were explored at four-levels: between lessons (up to 2 lessons per day; Level 1), between days (5 days per week; L2), between weeks (4 weeks; L3), and between students (113 students; L4). Findings for a ‘random effects’ model revealed substantial variance between students (M?=?67%), followed by variance between lessons (M?=?29%), with little variance between days and between weeks (M?=?2%). In a ‘fixed and random effects’ model, we explored the roles of prior general academic motivation and engagement as well as ability and socio-demographics. Findings revealed that prior general academic motivation and engagement played a significant role in students’ real-time motivation and engagement in mathematics and English and reduced between-student variance by about half. Gender (females), ability (high), and socioeconomic status (high) were also associated with higher real-time motivation and engagement.     

基于均值移动重要性采样的粒子滤波人脸跟踪算法

针对condensation目标跟踪算法中用先验转移概率作建议分布函数时没有充分考虑最新观测信息的缺点,提出了一种基于均值移动重要性采样的粒子滤波人脸跟踪算法.算法首先利用均值移动跟踪器粗略定位人脸目标,然后再用此跟踪结果去构造建议分布函数进行粒子传播.由于通过该方法所构造的建议分布函数中包含了最新的观测信息,所以它可以使大多数粒子点都能分布在真实状态区域周围,进而提高了粒子传播的准确性.人脸跟踪结果表明,该算法的跟踪性能明显优于标准condensation方法.     

Statistical Study on Cement-Soil Mixture Strength

This paper presents an investigation on strength of cement deep mixing (CDM) mixture.Four typical works of offshore or land-based projects are introduced. With samples from these projects and laboratory tests, statistical analysis is made on the increment law of the strength of cement-soil mixture with different amount of cement, and strengths under different working conditions are compared. It is found that the amount of cement in the cement-soil mixture is closely related to the unconfined compressive strength of the mixture. At the age of 90 d,the unconfined compressive strength of the cement-soil mixture increased by 0.054 MPa-0.124MPa with each cement increasing 10 kg/m^3 in the cement-soil mixture, averagely increased by 0.085 MPa, while that at the age of 120 d increased by 11% in comparison. The quality of the cement-soil mixture should be comprehensively evaluated in accordance with the trimmed average of strength, coefficient of variation and rock quality designation (RQD) indicators of sampling ratio.     

Student Engagement in U.S. Urban High School Mathematics and Science Classrooms: Findings on Social Organization, Race, and Ethnicity

   This paper reports results of intensive field work in urban high school mathematics and science classrooms based on research with students attending eight high schools located in large, disparate urban sites across the U.S. During the course of our observations and interviews we recorded students’ activities as well as their impressions of classroom processes over the course of a week in each classroom using the Experience Sampling Method (ESM). ESM allows students to record information about their classroom experiences at intervals during daily mathematics and science classroom lessons. We measured levels of student engagement and examined relationships between student engagement and an array of predictors. We take a social organizational approach to interpreting classroom processes, examining the extent to which classroom activities influence student perception of class and communication among students and how these intervening factors affect student engagement during on-going classroom activities. Results suggest that there is variation between group members’ reactions to classroom activities. Specifically, as an example, Latino Students in Chicago, Miami and El Paso were far more engaged and responsive to classroom lessons during the time they spent in small problem-solving groups during class. Student Engagement in High School Mathematics and Science. Kazuaki Uekawa is affiliated with the American Institutes for Research, Washinton DC, USA. Kathryn Borman and Reginald Lee are affilated with the The University of South Florida, Tampa, FL, USA. Address correspondence to Kazuaki Uekawa, American Institutes for Research, Washinton DC, USA; e-mail: kuekawa@air.org     

我国政府网站建设现状研究

本文从全面考察我国政府网站建设情况的思路着手 ,从“网站功能”、“网站服务”和“网站使用效果”三个方面对我国政府网站总体建设情况进行全面的分析 ,并从指标的成熟度、频度分布、差异度等不同角度对中央部委与地方政府之间的情况进行比较。最后结合我国各地区的经济发展状况以及各地区抽样网站样本数目 ,进一步挖掘政务网站建设情况与经济发展状况、地区抽样网站数目之间的相关关系 ,以期获得新的发现。     

深海技术装备研制现状与展望

历经近半个世纪的努力,我国海洋技术与装备取得了长足的进步和发展,尤其是近年来,深海技术与装备的发展为我国海洋科学的创新提供了新的动力。中科院战略性先导科技专项"热带西太平洋海洋系统物质能量交换及其影响"以科学需求为导向,追踪国际前沿,立足我国深海技术装备发展现状,提出研制科学应用目标明确的深海探测与作业装备,形成具备利用自主式观测系统、连续观测与作业系统以及新型海洋传感器及采样设备开展综合性海洋探测与作业的能力。专项执行4年的时间,深海技术装备面向专项科学目标,形成了具有完全自主知识产权的技术装备,形成了一批有影响的成果,为海洋科学研究提供了先进的技术手段,推动了我国深海探测与作业技术的发展,在我国深海技术装备发展中发挥了重要的先导作用。     

Acquisition,Preference and Follow-up Comparison Across Three AAC Modalities Taught to Two Children with Autism Spectrum Disorder

Identifying an augmentative and alternative communication (AAC) method for children with autism spectrum disorder (ASD) might be informed by comparing their performance with, and preference for, a range of communication modalities. Towards this end, the present study involved two children with ASD who were taught to request the continuation of toy play by: (a) signing MORE, (b) exchanging a picture card representing MORE, and (c) touching a MORE symbol from the screen of a speech-generating device. The children were also given opportunities to choose among the three modalities to identify their preferred method of communication. Both children performed better with picture exchange and the speech-generating device than with manual signing, but had variable performance during follow-up. Both children more often chose the speech-generating device, suggesting a preference for that modality. We conclude that concurrent intervention across several communication methods can generate data to inform the selection of an AAC modality.