Additive mixed effect model for recurrent gap time data

Gap times between recurrent events are often of primary interest in medical and observational studies. The additive hazards model, focusing on risk differences rather than risk ratios, has been widely used in practice. However, the marginal additive hazards model does not take the dependence among gap times into account. In this paper, we propose an additive mixed effect model to analyze gap time data, and the proposed model includes a subject-specific random effect to account for the dependence among the gap times. Estimating equation approaches are developed for parameter estimation, and the asymptotic properties of the resulting estimators are established. In addition, some graphical and numerical procedures are presented for model checking. The finite sample behavior of the proposed methods is evaluated through simulation studies, and an application to a data set from a clinic study on chronic granulomatous disease is provided.     

环境公共治理政策的效果评价与优化组合研究

本文构建了包含环境治理体系的动态一般均衡模型,基于模型的研究发现,在经济增长方面生产者补贴较为有效;而技术研发补贴在技术进步中的作用十分显著,其通过“研发投入→绿色技术提升→降低污染物排放”的路径可以实现环境质量的改善.此外,本文还模拟了生产者补贴和技术研发补贴的政策组合对社会福利和污染排放的影响,结果显示,政府可以采用生产者价格补贴或技术研发补贴促进产出水平增长进而提高社会福利水平,同时增大生产者价格补贴和技术研发补贴的幅度则能够通过提高技术水平促使污染水平不断下降.最后,本文给出了社会福利增进与环境质量改善双重目标下生产补贴和技术研发补贴政策的可行性区域,进行了环境公共治理政策的优化组合研究.     

基于化学反应算法的鲜活农产品配送路径优化

文章通过引入时间价格因子考虑在鲜活农产品配送过程的损耗并结合运输成本和惩罚成本构建数学模型.从实际的运用环境出发,考虑到未在期望获得时间内达到运输地点的成本消耗,并且随着时间的推移,鲜活农产品本身也有成本损耗构建目标函数.根据该模型的特点设计化学反应的最小单元分子结构和算法步骤.运用化学反应算法可以很好地解决模型算法过早收敛于局部最优问题.通过实例验证了模型和算法的有效性和科学性.     

基于累积和控制图改进的累积得分控制图

文章针对双边的区域控制图的累积得分思想,设计单边累积得分控制图.利用马尔科夫链的方法计算其平均链长,并与传统的控制图比较.结合快速初始响应方法,设置改进控制图的初始响应值,与带有初始响应的累积和控制图进行过程失控的平均链长的对比.在存在偶然性因素下,改进控制图与传统累积和控制图比较.     

广州市非遗数字化保护的困境与对策研究

广州市现有市级以上非物质文化遗产180余项,其数字化保护方面存在着制度不完善、人才匮乏、技术规则无统一标准等困境,课题组调研后建议从三个方面推动非遗数字化保护:一是制定平台建设、非遗信息采集、传承人知识产权保护、非遗产业化开发等方面的操作制度,推动非遗数字化进程;二是编制科学规划,分阶段实现非遗项目的深度数字化;三是加强与大、中小学合作,尤其是加强与职业类院校合作,推动非遗传承人走进职业院校成立"技能大师工作室",发掘培养潜在传承人,建立专业人才队伍.     

Developmental Latent Patterns of Identification as Mostly Heterosexual Versus Lesbian,Gay, or Bisexual

Scant research exists on the development of mostly heterosexual identity, the largest sexual orientation minority subgroup. We used longitudinal latent class analysis to characterize the patterns of identification with lesbian, gay, bisexual (LGB), or mostly heterosexual identities from ages 12 to 23 in 13,859 youth (57% female) in a U.S. national cohort. Three classes emerged: completely heterosexual (88.2%), mostly heterosexual (9.5%), and LGB (2.4%). LGB class youth generally identified with sexual minority identities by ages 12–17. In contrast, mostly heterosexual class youth identified with sexual minority identities gradually, with steady increases in endorsement starting at the age of 14. Developmental implications of these differential patterns are discussed.     

The reproductive health indices and sex hormone levels in middle-aged and elderly Chinese men

Objective: The aim of this study was to analyze the age-related recession trajectory of reproductive health indices in middle-aged and elderly Chinese men.

Methods: A population-based cross-sectional study was conducted in Jiashan County, Zhejiang in 2012. Healthy men between 40 and 80 years of age were considered eligible for the study. Physical examination and the sex hormones were measured. The subjects were assessed based on the 5-item version of the International Index of Erectile Function (IIEF-5) for Erectile Dysfunction (ED), and Aging Males’ Symptoms (AMS) scale for Symptomatic Late-Onset Hypogonadism (SLOH).

Results: TG showed a decrease at age 60 years. Testis volume and TT did not show significant difference among the four age groups; cFT began to decrease at age 50 years and Bio-T decreased faster at age 50 years. SHBG and LH increased faster at age 50 and 70 years, respectively. IIEF5 score decrease faster at age 60 years. AMS scores increased faster at age 70 years. With the increase in age, the symptoms of ED and SLOH became severer.

Conclusion: Different indices on reproductive health of men showed turning points at different ages. At first, androgenic sex hormones decreased faster, and then erectile dysfunction got severer, and the last overall male syndromes declined.     

Culturally responsive teaching in China: instructional strategy and teachers’ attitudes

The aim of this study was to investigate the manner in which teachers facilitate the pedagogical process within a culturally diverse student population. The study focused on two primary schools in China; one located in a more fully developed city in eastern China (Case A), while the other was in a less developed city in rural western China (Case B). This allowed the researchers to compare and analyse the different instructional practices by means of semi-structured interviews and questionnaires. The findings indicate that: the teachers in Case A demonstrated overall affirmative attitudes towards ethnic minority cultures, as well as towards the students belonging to those cultures. However, the teachers also chose not to mention the specific ethnic identities and cultural differences of the students during the course of their instruction in order to ensure equal treatment for everyone. This leads to a kind of ‘cultural blindness’ in the classroom. In Case B, opinions regarding minority cultures were more varied. Compared with the teachers in Case A, more teachers in Case B found minority cultures to be inferior to the dominant Han culture. Some teachers also, counter intuitively, were of the opinion that the minority cultures were even superior. At the instructional level, school leadership developed courses on local culture and ethnicity for the teaching staff. This was done for a variety of reasons. The strongest evidence to support culturally responsive teaching in Case A does not stem from teaching and learning demands but from the necessity to pursue characteristics that make them distinctive from other schools at the same time, Case B’s practice of culturally responsive teaching was strongly supported by the government and UNICEF. Teachers in both schools indicated that they had integrated their knowledge of ethnic minority groups into the subject matter when it was necessary.