“倒按揭”养老模式的精算模型构建与应用

为了推进“倒按揭”养老模式在我国的发展,本文通过对“倒按揭”进行概念解析,构建了个体“倒按揭”精算模型和家庭“倒按揭”精算模型;利用两个模型,测算了固定房产值时的给付标准和固定给付标准时对房产值的要求,研究发现,实行“倒按揭”养老的警戒线为房产净价值136576元;当拥有房产价值227627元时,给付标准可达到城镇居民人均可支配收入水平。     

甲骨文中农作物“稻”“黍”“来(■)”“榖”“稬”的考辨

本文对甲骨文农作物“稻”、“黍”、“来”、“■”、“■”等字着重就甲、金文直至隶、楷,参照传世文献进行了共时的、历时的综合分析,理 清它们的演变情况,作出新的考定。     

宋代文化政策宽明原因新探

宋代文化政策之宽明,作为一种历史现象,是由多种历史条件交合作用而形成的。首先是宋以前中国多元文化格局及宽明文化政策历史传承的结果;其次是宋代抑武重文集权措施之偏倚所造成;另外,“皇帝与士大夫共治天下”的政治格局,使士大夫思想自由、精神独立,对皇权进行约束,是宽明文化政策之保障。     

价值观视野中的可持续发展

可持续发展理论是人类以新的价值观和伦理观审视自己的行为 ,从而作出的人与自然、人与社会、人与人相协调的发展战略。在价值观层面上 ,它蕴含了由于情感之维、理性的僭越、生态伦理、和谐理念等观念的介入而形成的自然价值观 ,包含整体价值观、平等价值观、协调价值观、科技价值观、制度价值观在内的社会价值观以及对近代人类中心价值观辩证扬弃而形成的现代人类中心价值观。     

How Many More Missing Women? Excess Female Mortality and Prenatal Sex Selection, 1970–2050

Sex‐based discrimination has resulted in severe demographic imbalances between males and females, culminating in a large number of “missing women” in several countries around the world. We provide new estimates and projections of the number of missing females and of the roles played by prenatal and postnatal factors in this imbalance. We estimate time series of the number of missing females, the number of excess female deaths, and the number of missing female births for the world and selected countries. Estimates are provided for 1970–2010 and projections are made from 2010 to 2050. We show that the estimates of these different indicators are consistent with one another and account for the dynamics of the population of missing females over time. We conclude that the number of missing females has steadily risen in the past decades, reaching 126 million in 2010, and the number is expected to peak at 150 million in 2035. Excess mortality was the dominant cause of missing females in the past, and this is expected to remain the case in future decades in spite of the recent rise of prenatal sex selection. The annual number of newly missing females reached 3.4 million in 2010 and is expected to remain above 3 million every year until 2050.     

多元文化背景下大学生文化自觉缺失现状及影响因素分析

以高度的文化自觉和文化自信推进社会主义文化大发展大繁荣是中国特色社会主义建设的重要战略任务。而多元文化背景下大学生文化自觉问题已经成为关乎中国未来文化安全、关乎中国人才成长、关乎中华民族伟大复兴和世界和谐发展的重大问题。当前大学生文化自觉的现状不容乐观,存在诸多值得关注的问题。影响大学生文化自觉的因素很多,既有外源性的客观因素,也有内源性的主观因素。客观分析当前大学生文化自觉缺失现状及其主、客观影响因素,是深入研究大学生文化自觉培养问题的重要前提。     

Moving targets: determinants of nutritional preferences and habitat use in an urban ant community

Urban environments are often associated with reduced biodiversity, presumably because they are typically more fragmented, warmer, and drier than nearby non-urban environments. However, urban landscapes offer significant complexity that have allowed some taxonomic groups to flourish. Understanding how urban-exploiting animals navigate this spatiotemporal heterogeneity is important given the continued global urban land expansion. Here, we examined the factors influencing resource-use in an urban community of ants, which represent a widespread and important taxon in urban ecosystems. In particular, we sought to integrate ants’ nutritional, thermal, and spatial niches to better understand how urban animals successfully access critical resources throughout their active season. Meteorological season (spring, summer, and fall) and/or species (n?=?9) influenced ants’ preferences for nutrition (ratio of ingested protein-to-carbohydrate ratio), as well as the temperature, type (impervious vs. non-impervious), and shade status (shaded vs. non-shaded) of surfaces used during activity. Our data also indicate links among habitat variables, as well as between nutritional preferences and habitat use. Together, our results suggest that species and seasonality influence ecological (combined nutritional, thermal, and spatial) niches in an urban community. We encourage future work in urban ecosystems that continues to integrate more features of the ecological niche, and to examine the outcomes of variation in niches (e.g., non-overlapping niches may explain both the persistence of some native animals and the success of invaders).     

属性关系与诊断测验分类影响的探讨

认知诊断模型-DINA模型假定属性之间是相互独立、非补偿的关系,但在实际应用中,属性之间有可能存在补偿关系.文章探讨了在不同的被试总体下,DINA模型在属性之间独立和存在补偿关系时作答数据上的表现,结果表明,当测验中有部分属性间存在补偿关系时,会给DINA模型诊断分布带来较大的影响,在固定其他条件(被试人数、随机因子)条件下,存在和不存在补偿作用所导致的诊断分类率之间有显著差异,且在不同大小补偿作用下,诊断分类率之间的差异显著;随着随机因子的增加,不同大小的补偿因子所导致的诊断分类率之间的差异会变小,补偿因子和随机因子之间存在着显著的交互作用.     

Vine copula constructions of higher-dimensional dependent reliability systems

Copulas have proved to be very successful tools for the flexible modeling of dependence. Bivariate copulas have been deeply researched in recent years, while building higher-dimensional copulas is still recognized to be a difficult task. In this paper, we study the higher-dimensional dependent reliability systems using a type of decomposition called “vine,” by which a multivariate distribution can be decomposed into a cascade of bivariate copulas. Some equations of system reliability for parallel, series, and k-out-of-n systems are obtained and then decomposed based on C-vine and D-vine copulas. Finally, a shutdown system is considered to illustrate the results obtained in the paper.     

Local influence in seemingly unrelated regression model with ridge estimate

Local influence is a well-known method for identifying the influential observations in a dataset and commonly needed in a statistical analysis. In this paper, we study the local influence on the parameters of interest in the seemingly unrelated regression model with ridge estimation, when there exists collinearity among the explanatory variables. We examine two types of perturbation schemes to identify influential observations: the perturbation of variance and the perturbation of individual explanatory variables. Finally, the efficacy of our proposed method is illustrated by analyzing [13 A. Munnell, Why has productivity declined? Productivity and public investment, New Engl. Econ. Rev. (1990), pp. 3–22. [Google Scholar]] productivity dataset.