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81.
本文在浙江省制造业1454家企业大样本调查问卷的基础上,在微观层面研究了企业创新行为以及影响因素。首先利用统计分析的方法考察了企业创新投入的特征、创新投入的行业分布以及创新投入的产出绩效,并且发现了企业规模与R&;D强度之间呈现倒U型关系,这与安同良等人发现的倾斜V型关系的结论不同。其次运用计量分析的方法在有效控制了企业所处行业的技术水平差异、企业产权结构、政府资金扶持、企业品牌和企业设备技术水平后,研究发现:企业规模与企业创新投入之间也呈现较明显的倒U型关系,并且存在规模“拐点”;企业知识产权战略对企业创新投入具有明显的促进作用;出口贸易对企业创新投入并不显著,但发达国家特别是针对发展中国家设置的技术性贸易壁垒的技术标准化要求对企业创新投入有比较明显的促进作用;而企业集聚对企业的创新投入的影响并不确定。 相似文献
82.
Lauren B. Day Jan Faust Ryan A. Black Deborah O. Day Anita Alexander 《Journal of Child Custody》2017,14(2-3):191-208
Factitious Disorder Imposed by Another (FDIA) can be difficult to expeditiously identify. Understanding personality characteristics of FDIA perpetrators via psychological assessment may decrease the time between initial abuse and identification of FDIA. Personality characteristics of FDIA mother-perpetrators were examined through a comparative analysis of MMPI-2 profiles. It was predicted that mother-perpetrators would have significantly higher overall profile elevations on the MMPI-2 and elevations on specific clinical scales than a comparative control group. Results indicated that mother-perpetrators displayed significantly higher, elevations on the Psychasthenia (Pt) and Schizophrenia (Sc) scales and a trend toward significantly higher elevation on the Psychopathic Deviate (Pd) scale than the control group. These findings, along with the demographic information obtained, establish a preliminary foundation for understanding an overall profile of mother-perpetrators. 相似文献
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84.
Łukasz Smaga 《统计学通讯:模拟与计算》2017,46(10):7654-7667
The nonparametric and parametric bootstrap methods for multivariate hypothesis testing are developed. They are used to approximate the null distribution of the test statistics proposed by Duchesne and Francq (2015), resulting in bootstrap testing procedures. In the problem of testing for the mean vector of a multivariate distribution, the asymptotic validity of the bootstrap methods is proved. The finite sample performance of the new solutions is demonstrated by means of Monte Carlo simulation studies. They indicate that for small-sample size, the bootstrap tests provide a better finite sample properties than the asymptotic tests considered by Duchesne and Francq (2015). 相似文献
85.
Yu-Ye Zou 《统计学通讯:理论与方法》2017,46(2):1007-1023
In this article, we study global L2 error of non linear wavelet estimator of density in the Besov space Bspq for missing data model when covariables are present and prove that the estimator can achieve the optimal rate of convergence, which is similar to the result studied by Donoho et al. (1996) in complete independent data case with term-by-term thresholding of the empirical wavelet coefficients. Finite-sample behavior of the proposed estimator is explored via simulations. 相似文献
86.
Perception of peer rank, or how we perform relative to our peers, can be a powerful motivator. While research exists on the effect of social information on decision making, there is less work on how ranked comparisons with our peers influence our behavior. This paper outlines a field experiment conducted with 3896 households in Castro Valley, California, which uses household mailers with various forms of social information and peer rank messaging to motivate water conservation. The experiment tests the effect of a visible peer rank on water use, and how the competitive framing of rank information influences behavioral response. The results show that households with relatively low or high water use in the pre-treatment period responded differently to how rank information was framed. I find that a neutrally-framed peer rank caused a small “boomerang effect” (i.e., an increase in average water use) for low water use households, but this effect was eliminated by competitive framing. At the same time, a competitively-framed peer rank demotivated high water use households, increasing their average water use over the full period of the experiment. This result is supported by evidence that the competitive frame on rank information increased water use for households who ranked “last” in the peer group – a detrimental “last place effect” from competitively-framed rankings. 相似文献
87.
In this experiment, I examine the extent to which competitive social preferences can explain over-bidding in rent-seeking contests. The Human treatment is a standard two-player contest. In the Robot treatment, a single player bids against a computerized player, eliminating potential social preference motives. The results show no difference in bids between treatments at the aggregate level. Further analysis shows evidence of heterogeneous treatment effects between impulsive and reflective subjects. Moreover, impulsive subjects are more likely than reflective subjects to deviate qualitatively from the shape of the theoretical best response function. 相似文献
88.
流行病学研究表明2型糖尿病(type 2 diabetes mellitus T2DM)能够增加患者发生阿尔茨海默病(Alzheimer's disease,AD)的风险。进一步的分子机制研究也表明,胰岛素抵抗以及胰岛素缺乏,这个T2DM特征性和最主要的发病机制也在AD的发病机制中发挥着重要作用。近年来甚至有人提议将AD称作"3型糖尿病"。基于这些研究,降糖药物也许是治疗AD的一个新选择。大量的临床试验研究也已经表明AD患者能够从降糖药物中获益,本文将主要介绍胰岛素、二甲双胍、噻唑烷二酮类药物以及胰升糖素样多肽1类似物。 相似文献
89.
一种基于小波变换和PCA的人脸识别改进方法 总被引:3,自引:0,他引:3
杨绍华 《吉林工程技术师范学院学报》2008,24(9):62-65
针对主成分分析PCA算法中存在的问题,提出了利用小波变换对人脸图像进行预处理,PCA提取图像特征,最近邻法分类的人脸识别改进方法.基于ORL、YALE数据库的相关实验表明,这样的系统能够降低数据维数和克服角度、位移变化对算法的影响,能够取得比传统PCA更好的识别性能。 相似文献
90.
卢晓蕾 《淮海工学院学报(社会科学版)》2012,10(13):77-79
哈代在《德伯家的苔丝》中成功地塑造了女主公苔丝的形象,其文中所描写的苔丝出外谋生和一失足千古恨的悲剧,具有巨大的悲剧研究的社会价值。通过从社会和个人性格两个不同的方面分析了苔丝悲剧产生的原因,使读者在理性地欣赏其作品的同时,更深刻地感受到作品所营造的悲剧效果和艺术感染力。 相似文献