Regression models using the LINEX loss to predict lower bounds for the number of points for approximating planar contour shapes

Researchers in statistical shape analysis often analyze outlines of objects. Even though these contours are infinite-dimensional in theory, they must be discretized in practice. When discretizing, it is important to reduce the number of sampling points considerably to reduce computational costs, but to not use too few points so as to result in too much approximation error. Unfortunately, determining the minimum number of points needed to achieve sufficiently approximate the contours is computationally expensive. In this paper, we fit regression models to predict these lower bounds using characteristics of the contours that are computationally cheap as predictor variables. However, least squares regression is inadequate for this task because it treats overestimation and underestimation equally, but underestimation of lower bounds is far more serious. Instead, to fit the models, we use the LINEX loss function, which allows us to penalize underestimation at an exponential rate while penalizing overestimation only linearly. We present a novel approach to select the shape parameter of the loss function and tools for analyzing how well the model fits the data. Through validation methods, we show that the LINEX models work well for reducing the underestimation for the lower bounds.     

中国社会管理创新研究考察\n——以2003～2012年中国知网上CSSCI论文为分析对象

对来自CSSCI期刊上231篇社会管理创新的文章,以内容分析方法来考察论文发表时间、论文作者、作者单位、学术职称、研究层次、学科分类、被引频次、参考文献等,其目的是探明学界对社会管理创新进行研究的现状,并进一步回答哪些学者在研究、从什么维度进行研究和研究质量如何这三个预设问题。尤其指出了在未来研究中应注重政策应用类研究、建立在文献评估和引用基础上的规范研究,以及运用科学方法和经验事实作支撑的实证研究     

基于DEA-FCA的建筑承包商信用\n评价模型研究

建筑承包商信用评价是一个多指标决策问题,有效地对承包商进行信用评价能降低交易成本,约束和规范其行为,促进建筑市场健康稳定发展。针对目前建筑市场承包商信用缺失问题,考虑评价指标的特点,提出了基于DEA交叉评价和模糊综合评价相结合的承包商信用评价方法,采用DEA模型计算定量指标决策单元的平均交叉效率值并将其模糊化,同时利用三角模糊数加权平均算子将专家给出的定性指标的评价意见进行集结,最后通过算例计算了承包商的信用排序,验证了模型的有效性。     

基于结构方程的基层\r\n医疗机构患者满意度研究

基于“主体−事件−客体”分析框架,结合中国60起公共危机典型事件,利用模糊集定性比较分析（fs/QCA）方法来分析影响地方政府公共危机回应有效性的必要条件和组态情况。研究发现：地方政府公共危机回应极具复杂性,不存在促成地方政府公共危机回应有效性的单个必要条件;三种类型构成了地方政府公共危机回应有效性的实现路径,即“主体驱动型”“主体−事件平衡型”“综合型”;实现地方政府公共危机回应的有效性,需要“主体−事件−客体”合力完成。

     

金融危机下汇率变动对失业率变动的相关性研究

在当前国际金融危机下,汇率对经济的影响,已从直接的进出口贸易行业深入到了其他非贸易性的行业;汇率的波动,在一定程度上,也影响到了宏观经济的波动,进而使得国家的投资、产出和消费受到了影响,这种传导机制最终会带来就业的冲击。通过对最新数据的线性回归分析发现,当前主要国家(地区)汇率的波动性对失业产生重要影响。     

Strategic Grading in the Product Acquisition Process of a Reverse Supply Chain

Most recommerce providers have moved to a quality‐dependent process for the acquisition of used products. They acquire the products via websites at which product holders submit upfront quality statements and receive quality‐dependent acquisition prices for their used devices. Motivated by this development of reverse logistics practice, the aim of this study is to analyze the product assessment process of a recommerce provider in detail. To this end, we first propose a sequential bargaining model with complete information which captures the individual behavior of the recommerce provider and the product holder. We determine the optimal strategies of the product holder and the recommerce provider in this game. We find that the resulting strategies lead to an efficient allocation, although the recommerce provider can absorb most of the bargaining potential due to his last mover advantage. In a second step, we relax the assumption of complete information and include uncertainty about the product holder's valuation of the product. We show the trade‐off underlying the recommerce provider's optimal counteroffer decision and analyze the optimal strategy, using a logistic regression approach on a real‐life dataset of nearly 6,000 product submissions. The results reveal a significant improvement potential, compared to the currently applied strategy.     

Rushes in Large Timing Games

We develop a continuum player timing game that subsumes standard wars of attrition and pre‐emption games, and introduces a new rushes phenomenon. Payoffs are continuous and single‐peaked functions of the stopping time and stopping quantile. We show that if payoffs are hump‐shaped in the quantile, then a sudden “rush” of players stops in any Nash or subgame perfect equilibrium. Fear relaxes the first mover advantage in pre‐emption games, asking that the least quantile beat the average; greed relaxes the last mover advantage in wars of attrition, asking just that the last quantile payoff exceed the average. With greed, play is inefficiently late: an accelerating war of attrition starting at optimal time, followed by a rush. With fear, play is inefficiently early: a slowing pre‐emption game, ending at the optimal time, preceded by a rush. The theory predicts the length, duration, and intensity of stopping, and the size and timing of rushes, and offers insights for many common timing games.     

基于TRIZ的复杂系统FMECA分析\n流程和方法研究

大型复杂系统具有结构复杂和功能多样化的特点,严重故障的发生将会造成巨大损失,而现有的故障分析方法和管理手段明显不足。基于传统FMECA方法,结合TRIZ理论和方法,以神光系列激光装置为研究对象,本文提出改进的FMECA分析流程和方法,目的是开展故障模式及影响的多样性分析以及寻找完善的问题纠正措施,从而提高故障归零率,降低系统运行风险     

面向横截面数据的级差最大化灰色指标关联决策模型

针对现有横截面数据灰色关联模型中指标的排序变换影响关联结果的问题,文章从距离的接近性角度,以指数函数的形式表征关联系数;借助TOPSIS思想,并利用级差最大化组合赋权原理分别从正、负理想两个角度对指标进行赋权,集成一种面向横截面数据的级差最大化灰色指标关联决策模型,并对该模型的规范性等性质进行证明。通过实例验证该方法不受指标排序的影响。