Buffon's needle and the estimation of migration distances

A procedure is suggested for estimating migration distances from data on the proportion of migrants crossing regional boundaries. The method makes use of Buffon's needle, a problem in geometrical probability from the eighteenth century that was originally used as an empirical means of estimating π. The procedure is described for various scenarios that differ in their assumptions about region shape, the spatial distribution of population, and the distribution of migration distances. An application to migration distances in the United States is given, and additional attention is given to the estimation of intraregional migration distances.     

Inferences on regression coefficients in a regression model under heteroscedasticity and robustness with respect to departure from normality

In this paper we consider a simple linear regression model under heteroscedasticity and nonnormality. A statistical test for testing the regression coefficient is then derived by assuming normality for the random disturbances and by applying Welch's method. Some Monte Carlo studies are generated for assessing robustness of this test. By combining Tiku's robust procedure with the new test, a robust but more powerful test is developed.     

Evaluation of the parameters of su by rational fractions

A rational fraction approximation is given for a function of one of the parameters defining Johnson's S_UError assessment for a segment of the domain of validity shows remarkable accuracy.     

Xinhai remembered: from Han racial revolution to great revival of the Chinese nation

This article turns three different analytical mirrors onto the Xinhai Revolution – 1911, 1961, 2011 – in order to interrogate its evolving significance in the minds of China's Han ethnic and ruling elite. In particular, it seeks to demonstrates the discursive appropriation of the Qing nomadic frontier in the ways in which the 1911 Revolution is remembered and commemorated, exploring both the temporal and spatial dimensions of this appropriation, and how the revolution shifted from a bloody Han racial insurrection against Manchu power and privilege to a heroic celebration of the revival of a multiethnic Chinese nation-state in the face of foreign imperialism and oppression.     

中国特色社会主义文艺理论研究亟待加强

要高度重视和深入研究中国特色社会主义文艺理论,这种文艺理论研究不是从理论教条出发剪裁客观对象,而是从客观对象本身出发得出的科学结论。中国特色社会主义文艺理论不但要促进当代中国文艺的多样化发展,而且要在正确地把握中国特色社会主义文艺的发展方向的基础上引领多样化文艺的科学发展。     

书号实名申领制探析——以湖北省为例

鉴于先前较为混乱的书号管理秩序及其给出版业带来的消级影响，书号实名中领制应运而生，它对于国家整合出版资源、加强宏观调控、规范市场秩序，出版社加快出版节奏、提高市场竞争都有一定的成效，但书号实名申领制在具体的运物过程中，也还存在一些弊端，因此，它还有待于进一步改进。     

20世纪30年代北平大学中的左翼思潮

20世纪30年代左翼思潮在大学生中相当流行,不过由于学校立场、师生关系等各种因素,其在不同学校表现的强度和形式亦有所不同。本文以大学较为集中的北平为对象,考察左翼思潮在各校中的分布情况,认为在左翼思潮兴盛的学校,学生占据着主导地位,这一点亦有助于我们理解左翼学生从事文化运动时所采取的策略。     

A Risk Analysis Model in Concurrent Engineering Product Development

Concurrent engineering has been widely accepted as a viable strategy for companies to reduce time to market and achieve overall cost savings. This article analyzes various risks and challenges in product development under the concurrent engineering environment. A three‐dimensional early warning approach for product development risk management is proposed by integrating graphical evaluation and review technique (GERT) and failure modes and effects analysis (FMEA). Simulation models are created to solve our proposed concurrent engineering product development risk management model. Solutions lead to identification of key risk controlling points. This article demonstrates the value of our approach to risk analysis as a means to monitor various risks typical in the manufacturing sector. This article has three main contributions. First, we establish a conceptual framework to classify various risks in concurrent engineering (CE) product development (PD). Second, we propose use of existing quantitative approaches for PD risk analysis purposes: GERT, FMEA, and product database management (PDM). Based on quantitative tools, we create our approach for risk management of CE PD and discuss solutions of the models. Third, we demonstrate the value of applying our approach using data from a typical Chinese motor company.     

基于加权组合和最小二乘法改进的GM(2,1)模型

文章通过分析指出了GM(2,1)模型存在灰微分方程与白化方程无法匹配以及默认经过初始值点的缺陷;利用权值p1、p2对一阶灰导数和背景值进行加权组合,建立了GM(2,1)模型的一种改进形式--GM(2,1,p1,p2模型,利用最小二乘法确定系统最终参数.实例验证结果表明,改进GM(2,1)模型具有更高的预测精度.