地方高校大学英语课程结构的优化

本文阐述了地方高校大学英语教学长期延用的课程结构体系中存在的一些主要问题,并针对这些问题,提出了建立新型课程结构应该考虑的五个方面。     

基本药物遴选方法的宏观经济效果比较

基本药物遴选的结果与百姓医保报销利益密切相关。我国医改新政关于基本药物遴选的方法学习西方国家，又有所发展。应用比较经济学原理，使用中国统计年鉴数据，测量了世界卫生组织的专家委员会法、中国现行的专家库两轮评审法、循证评价法、药物经济法等四种方法遴选所得基本药物方案的宏观卫生经济数据，得出在医疗卫生体制改革的社会医学领域可以借鉴自然科学统筹优化的组合方法，以获得综合更优的社会期望。     

Bounding Optimal Expected Revenues for Assortment Optimization under Mixtures of Multinomial Logits

We consider assortment problems under a mixture of multinomial logit models. There is a fixed revenue associated with each product. There are multiple customer types. Customers of different types choose according to different multinomial logit models whose parameters depend on the type of the customer. The goal is to find a set of products to offer so as to maximize the expected revenue obtained over all customer types. This assortment problem under the multinomial logit model with multiple customer types is NP‐complete. Although there are heuristics to find good assortments, it is difficult to verify the optimality gap of the heuristics. In this study, motivated by the difficulty of finding optimal solutions and verifying the optimality gap of heuristics, we develop an approach to construct an upper bound on the optimal expected revenue. Our approach can quickly provide upper bounds and these upper bounds can be quite tight. In our computational experiments, over a large set of randomly generated problem instances, the upper bounds provided by our approach deviate from the optimal expected revenues by 0.15% on average and by less than one percent in the worst case. By using our upper bounds, we are able to verify the optimality gaps of a greedy heuristic accurately, even when optimal solutions are not available.     

基于人体膳食均衡视角下的我国果蔬消费趋势预测与结构优化

水果和蔬菜是为人体提供矿物质、维生素、膳食纤维等营养元素的重要农产品,我国居民饮食中普遍存在着能量相对过剩、果蔬摄入量不足的问题。以人体膳食均衡为研究视角,研究我国果蔬消费趋势和结构优化问题,结果表明：按照当前的消费趋势发展,我国居民营养摄入不足与过剩同在的问题依然无法得到解决;我国政府在制定水果和蔬菜战略布局的决策中,应综合考虑人体的膳食营养均衡和未来市场营养需求,以实现我国果蔬产业布局优化;消费者在进行水果和蔬菜消费购买行为时,应在营养膳食均衡的基础上进行合理消费。     

基于灰色系统的小型精密机床热误差模型

为减少热误差对数控机床加工精度的影响,文章利用灰色系统研究热误差建模。初步分析机床热源后,应用灰 色关联度分析结合模糊分类方法优化得到13组关键温度测点,结合小型精密五轴机床处于实际加工状态时的实验数 据,应用GM(I,N)灰色结构进行建模。将实际数据与拟合数据进行对比分析,结果表明此灰色系统模型具有计算方法 成熟、鲁棒性强的特点,适用于机床热误差研究。     

大学生认知方式与德育方法的优化

认知方式划分为场依存和场独立两种类型,大学生认知方式与德育方法实施产生的效果有相关性。笔者认为应构建"以人为本"的德育方法论体系,根据大学生不同的认知方式采取分类指导原则,实施相应的有针对性和实效性的德育方法。     

Does the β-measure make empirical sense? A vignette experiment on humans’ judgment of social dominance

Dominance hierarchies play an important role in governing the social interactions of humans and other species of social animals. In a social group, dominance relations can be inferred from the directed network of matchups between actors. Methodologists have proposed different ways to measure social dominance in directed networks. One such measure, the “β-measure” (van den Brink and Gilles, 2000), emphasizes the quality of defeated opponents in a way that an actor is seen as being more dominant when s/he defeats opponents who are more rarely defeated. While insightful in theory, the validity of the measure in people’s perception remains questionable, considering the cognitive complexity imposed by this measure, compared to a simpler measure that merely counts the number of defeated opponents. We conducted a vignette experiment with human subjects (professional athletes) to test their judgments of the dominance relation in a hypothetical tournament. Fitting our parametric model to peoples’ evaluations in the experiment, we found strong evidence in support of the β-measure: Although, in general, contestants who win more in the tournament are regarded as being more dominant, the contents of the winning records matter, such that those who beat more victorious opponents are further regarded as more dominant than those who defeat less victorious opponents. We also found a gender difference, in that men have a stronger propensity than women to adopt the β-measure when judging social dominance.     

Parametrizing the Kepler exoplanet period-radius distribution with the bivariate normal inverse Gaussian distribution

This paper presents a simple and robust method for obtaining a comprehensive understanding of the joint period and radius distribution in Kepler exoplanets. The proposed method is based on particle swarm optimization and bivariate Normal Inverse Gaussian distribution. Furthermore, in the construction of the probability density function, this study selects planet-host stars with the GK-type. The injecting approach is also employed to solve the survey completeness of sample. The resulting occurrence rate of Earth analogs is 0.025 with a 95% bootstrap confidence interval between 0.023 and 0.032.     

一类稀疏投资组合双层参数估计模型及其应用

带基约束的投资组合问题是近年来投资组合领域的热点问题,但是参数不确定性直接影响了模型的效果。带基约束的投资组合问题所涉及的参数不仅包括以往研究认为非常重要的预期收益率,还包括控制投资组合规模的稀疏度,尤其是最优稀疏度估计方面的专门研究还十分匮乏。为了使带基约束的投资组合模型更好地为投资决策服务,本文从投资者效用出发,用双层规划的思想构建了带基约束的投资组合双层参数估计模型。然后根据模型的特点,设计了无导数优化算法框架,并基于ADMM对算法子问题进行求解。本文实验针对真实的市场数据给出了预期收益率和最优稀疏度的估计,接着通过与等权重策略和含上下界约束的均值-方差模型进行比较,说明了模型及算法的有效性和实用性。最后,将本文提出的双层参数估计模型推广到了更一般的形式。     

新时代侨校思想政治工作的价值定位和路径优化

侨校思想政治工作是高校思想政治工作的有机构成。进入新时代,要准确把握侨校思想政治工作的价值定位,直面当前侨校思想政治工作中所面临的价值观念多元化、工作队伍薄弱化和工作对象差异化的挑战,创新思路,统筹着力,牢牢掌握侨校意识形态工作的话语权,汇聚侨校思想政治工作的强大合力,构建分层化差异化的教育模式,增强侨校思想政治工作的时代性、针对性和实效性。