学校与课堂中的性别公平问题

本文分析了社会对不同性别儿童的角色期待以及学校与课堂中存在的性别刻板印象,揭示了学校与课堂中的性别不公平问题对学生社会化发展及教育公平的深刻影响,并提出了落实性别公平与平等教育的三个层面的策略。     

Female fertility history and mid-late-life health: Findings from China

China’s middle-aged and older women suffer from poorer health than men. Using national baseline data from the China Health and Retirement Longitudinal Study (CHARLS), a survey conducted from 2011 to 2012, this article applies logistic models to investigate the association between female fertility history (parity, early childbearing, late childbearing) and middle-aged and late-life health. We find that parity is related to the mid-late-life health of women. Women with four children or more are more likely to suffer from activities of daily living (ADL) impairment and poorer self-rated health than those with one to three children. Early childbearing is associated with ADL impairment; however, the correlation is mediated by socioeconomic status. Early childbearing is related to self-rated health in later life by an indirect-only mediation effect via educational attainment and personal income.     

Number of children and later-life mortality among Finns born 1938–50

We investigated the association between number of offspring and later-life mortality of Finnish men and women born 1938–50, and whether the association was explained by living conditions in own childhood and adulthood, chronic conditions, fertility timing, and unobserved characteristics common to siblings. We used a longitudinal 1950 census sample to estimate mortality at ages 50–72. Relative to parents of two children, all-cause mortality is highest among childless men and women, and elevated among those with one child, independently of observed confounders. Fixed-effect models, which control for unobserved characteristics shared by siblings, clearly support these findings among men. Cardiovascular mortality is higher among men with no, one, or at least four children than among those with two. Living conditions in adulthood contribute to the association between the number of children and mortality to a greater extent than childhood background, and chronic conditions contribute to the excess mortality of the childless.     

LDPC编码自适应加载MIMO-OFDM系统性能分析

介绍了LDPC校验阵的构造及编译码算法,采用了随机法构造LDPC校验阵,编码基于高斯消去直接进行译码采用无穷阶量化时的置信传播算法;讨论了OFDM自适应加载技术与多输入多输出技术,结合自适应比特功率分配算法与基于多载波调制的比特分配方案实现了该加载分配技术;给出了LDPC编码的自适应加载MIMO-OFDM系统的模型。经仿真分析得出,二元域上非规则LDPC编码的系统性能优于多元域上的,自适应加载MIMO-OFDM技术大大提高了系统传输速率,有效增强了系统抗衰落性。     

从汇率谜团到汇率决定的社会福利平价

汇率及汇率制度之争的根本在于真实汇率的确定,而众多的汇率理论及实证模型得出的结论难以统一,有的甚至背道而驰。汇率及汇率制度理论发展至今,仍然存在诸多谜团。总结汇率理论及理论、实证汇率模型的根本假设在于购买力平价、利率平价和生产力差异。从汇率形成原理和人类经济发展角度以及东西方文明的最高诉求而言,以其作为汇率及汇率制度理论的基本假设,都不甚合理。社会福利平价是我们提出的一个有关汇率及汇率制度的新的基本假设,在此基础上,可以从一个侧面更好地揭示汇率及汇率制度选择的本质,特别是关于新兴市场经济国家汇率确定及汇率制度选择的依据问题。     

购买力平价理论在人民币汇率预测中的应用

购买力平价理论是汇率预测的重要方法。应用协整理论对人民币/美元汇率的购买力平价形式进行检验可以发现,购买力平价理论一定时期内在人民币汇率上不成立。应用神经网络技术构造的非线性协整检验,结果显示其预测的效果要明显优于随机游动模型。因此可以认为在引入了非线性的机制后,基于汇率理论的结构式模型在预测汇率变化的能力上有所提高。     

LDPC编码的最优化HARQ方案研究

使用高斯近似和最优化理论的方法,对基于LDPC码度分布的混合自动重发请求(HARQ)方案的性能进行了研究。研究表明,根据LDPC编码的度分布和初始信道条件,能够确定一个编码码字中各个度数的比特所对应的最优的重发比例,如果按照该比例进行重发,重发功率的效率能够最大化。计算结果显示基于LDPC码度分布的混合自动重发请求方案具有最优的重发比例,是一种最优化方案。     

关于图的并的严格强控制数

图的严格强控制数是图的符号控制数的推广,该文在图的符号控制数的基础上,研究了图的严格强控制数,并且决定了一些图的并的严格强控制数。通过对图的并的严格强控制数的研究,进一步得到了一些图的并的严格强控制数与图的阶数的关系。     

亚式期权在依赖时间的参数下的定价

假定标的资产价格模型中的参数为时间t 的函数(即无风险利率r ( t) ,标的资产的期望 收益率μ( t) ,波动率σ( t) 及红利率g ( t) ) ,利用风险中性定价及随机积分的性质,得到连续几 何平均欧式亚式期权在六种情形下价格的解析公式和一个平价关系,且通过调整执行价格的 形式而得到固定执行价格的连续算术平均欧式亚式期权的渐进公式