电动两轮车侧翻倒地滑动摩擦系数实验研究

目的两轮车侧翻倒地后的滑行摩擦系数是利用两轮车碰撞后倒地滑行距离进行速度计算的关键参数,论文通过试验研究提出用于道路交通事故速度计算的电动两轮车侧翻倒地滑动摩擦系数。方法在综合分析电动两轮车侧倒滑行摩擦系数影响因素的基础上,利用正交试验设计摩擦系数实验方案,并采用实车牵引的方法,在不同速度条件下,分别在干燥、潮湿的沥青混凝土路面及水泥混凝土路面上进行实验。结果实验所得数据显示,电动两轮车侧翻倒地滑动摩擦系数的范围为0.40～0.60。结论通过对所得数据进行处理,提出适用于电动两轮车交通事故再现的摩擦系数范围。     

Individual Camera Identification Using Correlation of Fixed Pattern Noise in Image Sensors

Abstract:  This paper presents results of experiments related to individual video camera identification using a correlation coefficient of fixed pattern noise (FPN) in image sensors. Five color charge-coupled device (CCD) modules of the same brand were examined. Images were captured using a 12-bit monochrome video capture board and stored in a personal computer. For each module, 100 frames were captured. They were integrated to obtain FPN. The results show that a specific CCD module was distinguished among the five modules by analyzing the normalized correlation coefficient. The temporal change of the correlation coefficient during several days had only a negligible effect on identifying the modules. Furthermore, a positive relation was found between the correlation coefficient of the same modules and the number of frames that were used for image integration. Consequently, precise individual camera identification is enhanced by acquisition of as many frames as possible.     

车辆碰撞护栏事故车速分析的方法

车辆碰撞护栏是高速公路上常见的一类事故,主要有两种常用的车速分析方法,即法向弹性恢复系数法和切向摩擦系数法。但是由于高速公路上,车速较快,经常有车辆冲出道路,在此情况下,提出一种基于护栏变形能量的车速分析方法,用来计算车辆碰撞护栏时的最低速度,并通过实例进行了验证。     

The Forward Specialization Coefficient: Distributional Properties and Subgroup Differences

For both public policy and theoretical reasons, criminologists have been interested in the degree to which criminal offenders specialize in particular crimes. Traditionally, offense specialization has been measured with the forward specialization coefficient (FSC). Recently, the FSC has been criticized for being interpretationally obtuse and having no known sampling distribution. In this paper we examine both the interpretational and the statistical properties of the FSC. We conclude that (1) it has an intuitive interpretation that is no less useful than either a standard correlation coefficient or its competitors, (2) its sampling distribution is approximately normal, and (3) the conventional formula for the estimated standard error of the FSC may underestimate the true standard error in some circumstances. With these results behind us, we propose and illustrate both a parametric statistical test for the difference between two independent FSCs and two nonparametric alternatives.     

陕西产业结构变迁对就业的影响分析

产业结构是生产要素在产业部门之间的分配状况及关联方式,它决定了一个国家或地区的经济增长状况,尤其是决定了就业结构的状况。陕西产业结构从整体上讲正朝着合理的方向发展,但就业结构的变动明显滞后于产业结构,并且二者发展不平衡。为了缓解就业形势,陕西应在保证国民经济快速增长的同时,保持第一产业的基础地位,巩固第二产业的支柱地位,积极和大力发展第三产业,调整就业结构。     

Towards a Realignment of the Mind: Compass Lecture,Commonwealth Club,London, 10 February 2011

Britain urgently needs a national conversation about the economic, political and moral predicament it now faces. It should start with the economic crisis of 2008–09. Keynesians and neoliberals alike still seek to return to pre‐crisis business as usual, albeit with modifications. But the untamed capitalism that came to grief in 2008 had three major flaws. First, it undermined the public domain of equity, citizenship and civic virtue, whose creation was one of the great achievements of the late‐nineteenth and early‐twentieth centuries, exposing it to invasion by the market domain. Second, it led to a remorseless rise in inequality of resources and life chances, rendering British society one of the most dysfunctional in Europe. Third, it encouraged the emergence of a debased form of democracy, best called ‘market populism’, that mocks the dream of political equality that lies at the heart of the democratic ideal. Yet growth points of a better society can be detected amidst the gloom. Informal institutions and social movements like London Citizens and the burgeoning environmental movement show that the notion of the public good is still alive. So do the survival of Edmund Burke's communitarianism in the conservative tradition, of John Stuart Mill's social liberalism in the liberal tradition and of ethical socialism in the social‐democratic tradition.     

A statistical methodology for the comparison of blue gel pen inks analyzed by laser desorption/ionization mass spectrometry

A statistical methodology for the objective comparison of LDI-MS mass spectra of blue gel pen inks was evaluated. Thirty-three blue gel pen inks previously studied by RAMAN were analyzed directly on the paper using both positive and negative mode. The obtained mass spectra were first compared using relative areas of selected peaks using the Pearson correlation coefficient and the Euclidean distance. Intra-variability among results from one ink and inter-variability between results from different inks were compared in order to choose a differentiation threshold minimizing the rate of false negative (i.e. avoiding false differentiation of the inks). This yielded a discriminating power of up to 77% for analysis made in the negative mode. The whole mass spectra were then compared using the same methodology, allowing for a better DP in the negative mode of 92% using the Pearson correlation on standardized data. The positive mode results generally yielded a lower differential power (DP) than the negative mode due to a higher intra-variability compared to the inter-variability in the mass spectra of the ink samples.     

道路交通事故成因的综合分析

本文在引入交通事故地点危险系数及其计算公式的基础上 ,建立了一种基于事故成因地点危险系数概率单元分析的事故成因综合分析方法 ,并采用 10 7国道 174 1公里的交通事故数据进行了分析验证。     

大学生就业问题的人口经济学分析

对目前我国高校人才培养结构现状及高校人才培养结构与产业人才需求的匹配状况做了比较深入的定量分析,并通过对分行业(部门)人才就业弹性系数和人才就业产出弹性系数的计算,结果显示出目前高校大学生就业潜力较大与较小的专业,这应引起有关部门和社会各界注意.     

Paternity probability when a relative of the father is an alleged father

When scientists use DNA evidence in court, coancestry effects such as population structure and relatedness are usually ignored. In paternity cases, only if a particular man has the child's paternal allele at a certain locus, can he not be excluded in the paternity dispute. However, it is certainly true that close relatives will be far more likely to have the child's paternal allele than will random members of the reference population. In particular, the probability that the true father's brother has the paternal allele is very much greater than that for any other relationship. In this paper, the authors describe a method for inference in a case where the true father may be a relative of the alleged father. This paper also reports that most current methods overstate the probability that the alleged father is the father.