Three optimal cut-point selection criteria based on sensitivity and specificity with user-defined weights

Methods: Based on the index S (S = SENSITIVITY (SEN) × SPECIFICITY (SPE)), the new weighted product index S_w is defined as S_w = (SEN)^2w × (SPE)^2(1-w), where (0≤w≤1). The S_w is developed to be a new tool to select the optimal cut point in ROC analysis and be compared with the other two commonly used criteria.

Results: Comparing the optimal cut point for the three criteria, the wave range of the optimal cut point for the maximized weighted Youden index criterion is the widest, the weighted closest-to-(0,1) criterion is the narrowest and the weighted product index S_w criterion lays between the ranges of the two criteria.     

On the maximum of periodic integer-valued sequences with exponential type tails via max-semistable laws

In this work we study the limiting distribution of the maximum term of periodic integer-valued sequences with marginal distribution belonging to a particular class where the tail decays exponentially. This class does not belong to the domain of attraction of any max-stable distribution. Nevertheless, we prove that the limiting distribution is max-semistable when we consider the maximum of the first k_n observations, for a suitable sequence {_kn}$\{k_n\}$ increasing to infinity. We obtain an expression for calculating the extremal index of sequences satisfying certain local conditions similar to conditions D^(m)(_un)$D^{(m)}(u_n)$, m∈N$m\in \mathbb{N}$, defined by Chernick et al. (1991). We apply the results to a class of max-autoregressive sequences and a class of moving average models. The results generalize the ones obtained for the stationary case.     

Urbanization and warming of Phoenix (Arizona,USA): Impacts,feedbacks and mitigation

This paper examines the impacts, feedbacks, and mitigation of the urban heat island in Phoenix, Arizona (USA). At Sky Harbor Airport, urbanization has increased the nighttime minimum temperature by 5°C and the average daily temperatures by 3.1°C. Urban warming has increased the number of misery hours per day for humans, which may have important social consequences. Other impacts include (1) increased energy consumption for heating and cooling of buildings, (2) increased heat stress (but decreased cold stress) for plants, (3) reduced quality of cotton fiber and reduced dairy production on the urban fringe, and (4) a broadening of the seasonal thermal window for arthropods. Climate feedback loops associated with evapotranspiration, energy production and consumption associated with increased air conditioning demand, and land conversion are discussed. Urban planning and design policy could be redesigned to mitigate urban warming, and several cities in the region are incorporating concerns regarding urban warming into planning codes and practices. The issue is timely and important, because most of the world's human population growth over the next 30 years will occur in cities in warm climates.     

上海“创新驱动,转型发展”评价指标体系研究

构建上海"创新驱动,转型发展"评价指标体系,应遵循体现"创新驱动,转型发展"的特点、兼顾区域比较、结合当前重点和着眼长远需要4个原则,从多个维度展开分析和研究:一是经济结构合理化,主要从产业结构、投资与消费结构、收入分配结构、企业所有制结构等的优化方面加以考察;二是创新驱动和经济运行质量提升,主要从创新成果、节能减排、经济效益、居民收入、就业等方面加以考察;三是社会生态环境优化,主要从生态环境、社会环境等方面加以考察。上海的"创新驱动,转型发展"评价指标体系应包含"创新驱动""转型发展"和"民生改善"3个子指标体系和30个具体的评价指标。     

会展产业综合效益评价指标体系初探

随着市场经济的蓬勃发展,会展业应运而生,并逐步成为经济发展的重要产业.会展业在取得直接效益的同时,还促进相关产业如宾馆业、餐饮业、交通运输业等蓬勃发展,促进经济贸易合作、城市建设、各经济部门和事业部门及消费者之间的沟通与交流,起到传播信息、知识、观念的作用.根据会展产业特点,文章在参考相关资料的基础上,从六个方面入手,综合考虑,选取相关指标,构建会展产业综合效益评价的指标体系.     

农业地质调查项目技术评价指标体系初探

通过分析浙江省农业地质调查活动流程,确定调查活动涉及到的设备清单,从而为技术评价做好准备。对农业地质调查项目进行技术评价可以从先进性、适用性、可靠性、可维护性、技术效率和技术人员的水平六个方面进行。     

基于全球经济一体化的当前通货紧缩研究

自从 1 997年下半年以来 ,我国物价指数增幅连续二十多个月为负数 .这一建国后罕见的物价低迷现象引出了一场关于通货紧缩的热烈讨论 .在这些讨论中 ,认为我国正处于通货紧缩的论点占绝对主导地位 .本文认为 ,由于全球经济的一体化浪潮 ,国家与国家之间经济边界的淡化以及经济系统边界的扩大 ,经济系统中突现出许多本质不同的性质和特征 ,这些变化不仅导致各国经济变化存在很大相关性 ,甚至连政策变化也存在一定相关性 ,因此基于孤立的一个国家视角的通货紧缩理论具有很大的局限性 .本文立足于全球经济一体化的观点和“一篮子货币”思想 ,通过选择不同的参照系 ,考虑人民币 /美元汇率 ,以及考虑其它重要经济因素——日元 /美元汇率 ,世界原油价格 ,有色金属价格以及东南亚金融危机的影响 ,定量地考察了我国近年物价变化的实质原因 ,从而阐明了我国近两年的物价下跌基本上是正常的物价回落 ,同时也证明了近两年国家刺激经济增长的财政政策和货币政策已经发挥了巨大的作用 .最后 ,本文从几个重要经济指标的走势变化指出了全球经济形势的新变化 ,运用世界经济和我国经济滞后影响原理 ,提出了目前应该进入仔细观察和深入定量分析国际和国内经济形,谨慎出台刺激物价上涨政策的阶段,以便寻求一系列更适合和安全的政策．     

Body Mass Index, Perceived Health, and Happiness: Their Determinants and Structural Relationships

The structural relationships between body mass index, perceived health and happiness have been studied in a survey of 700 native Dutch citizens. We found an indirect effect of body mass index on happiness, via perceived health. Age had an inverted U-shaped relationship with body mass index, and both education and smoking had a negative effect on body mass index. Being married, doing paid work, owning a house, and doing sports had positive effects on perceived health, suggesting that living a regular life may lead to a better perceived health. Being married positively affected happiness. The other socio-demographic variables either had no effects on happiness or indirect effects via body mass index and perceived health.     

氢键对有机化合物性质的影响

该文从氢键的概念出发，分析讨论了氢键的形成对有机化合物的熔沸点、水溶性、结构平衡、酸性、反应活性及红外光谱产生的影响．     

高职高专教育课程评价的探讨

我国高职高专教育课程评价工作还未真正起步 ,因之对此问题的探讨具有重要意义。在评价标准和指标体系的设计中应坚持突出科学性和导向性、注重整体优化、注意简易性和可测性等指导思想 ,合理确定与使用权重。综合考虑以上因素 ,本文给出了高职高专教育课程评价指标体系。