Estimation of non-parametric regression for dasometric measures

The aim of this paper is to describe a simulation procedure to compare parametric regression against a non-parametric regression method, for different functions and sets of information. The proposed methodology improves lack of fit at the edges of the regression curves, and an acceptable result is obtained for the no-parametric estimation in all studied cases. Larger differences appear at the edges of the estimation. The results are applied to the study of dasometric variables, which do not fulfil the normality hypothesis needed for parametric estimation. The kernel regression shows the relationship between the studied variables, which would not be detected with more rigid parametric models.     

Determinants of Contraceptive Use in Egypt: A Multilevel Approach

The increasing use of family planning methods seems to be the intermediate determinant which mostly influences the fertility decline in developing countries, and in particular in those countries which are in an advanced phase of demographic transition such as Egypt. Moreover large countries, like Egypt, are characterized by very different geographical realities and even by strong regional heterogeneities. The aim of this study is the analysis of the determinants of contraceptive use in Egypt, with particular reference to the differentials due to the socio-economic context and to the area of residence. To estimate each individual and regional factors’ effect on contraceptive use, a logistic two-level random intercept model is fitted to EDHS 2000 data; the use of a multilevel analysis is suggested by the two-level data structure: the first level units are the women, the second level units are their regions of residence.     

Rejoinder to 'Ahmed, M.S. (1998). A note on regression-type estimators using multiple auxiliary information.'

In the estimators t ₃ , t ₄ , t ₅ of Mukerjee, Rao & Vijayan (1987), b _{y x} and b _{y z} are partial regression coefficients of y on x and z , respectively, based on the smaller sample. With the above interpretation of b _{y x} and b _{y z} in t ₃ , t ₄ , t ₅ , all the calculations in Mukerjee at al. (1987) are correct. In this connection, we also wish to make it explicit that b _{x z} in t ₅ is an ordinary and not a partial regression coefficient. The 'corrected' MSEs of t ₃ , t ₄ , t ₅ , as given in Ahmed (1998 Section 3) are computed assuming that our b _{y x} and b _{y z} are ordinary and not partial regression coefficients. Indeed, we had no intention of giving estimators using the corresponding ordinary regression coefficients which would lead to estimators inferior to those given by Kiregyera (1984). We accept responsibility for any notational confusion created by us and express regret to readers who have been confused by our notation. Finally, in consideration of the above, it may be noted that Tripathi & Ahmed's (1995) estimator t ₀ , quoted also in Ahmed (1998), is no better than t ₅ of Mukerjee at al. (1987).     

企业家、企业家资源分布及其评价指标体系 ——结合浙江的实证分析

市场经济发展的主要动力来自企业家的创新.对于转型发展中国家来说,能否在转型过程中形成以企业家为中心的动力机制是实现转型成功和经济发展的关键.企业家作为一种重要的生产要素,也和资本、技术一样是一种稀缺资源,企业家资源分布的差异是导致经济发展和体制转型绩效差异的重要原因.从非国有经济份额、个私经济数量、市场化进展水平、发展绩效和经济内生化程度等5个方面建立的企业家资源评价指标体系,可以证明企业家资源的丰盈程度和经济绩效之间的正相关关系.     

教育对经济增长影响的实证分析——以陕西省为例

运用菲德模型,以陕西省为例,测定教育部门对经济增长的全部作用和教育对经济中其他部门的外溢作用。结果表明,陕西省教育部门的边际生产力高于经济部门的边际生产力,但仍是相当的低。陕西省教育目前主要是通过外溢作用间接对经济发展发挥作用,其直接作用远远没有发挥出来,甚至表现为负的作用,教育部门的效率有待发挥。基于此,提出加大教育投入力度,深化教育部门内部改革,加快建设市场经济体制以充分发挥教育对经济的促进作用。     

计算机辅助英语阅读课程设计的若干问题

本文从计算机辅助语言学习（ Ｃ Ａ Ｌ Ｌ） 课程的设计思想出发,分析和讨论有关机助英语阅读课程设计的若干问题,如阅读能力,教学方法,学习的评价等,以揭示机助英语阅读课程乃至机助语言学习课程设计的一些规律和原则     

高师学生职业素质发展测评系统

本文以国内外有关教师素质的最新理论为指导,在经过广泛调查和统计分析的基础上,提出了一个包含学科知识与能力、教育教学能力、职业基础知识与能力、职业人格、基础心理素质和教育实习行为表现等内容的高师学生职业素质发展测评系统,该系统结构合理、可操作性强,能较好地满足高师教育改革的需要     

水力发电企业整体效益评价及实例

针对水力发电企业的整体经济效益难以进行评价的问题,提出了以灰色关联度技术为支撑,选择数量模型评价方法,应用层次分析法的有关技术和思想,建立起具有可操作性的评价模型及评价体系。     

Accelerated test system strength models based on Birnbaum–Saunders distribution: a complete Bayesian analysis and comparison

Several models for studies related to tensile strength of materials are proposed in the literature where the size or length component has been taken to be an important factor for studying the specimens’ failure behaviour. An important model, developed on the basis of cumulative damage approach, is the three-parameter extension of the Birnbaum–Saunders fatigue model that incorporates size of the specimen as an additional variable. This model is a strong competitor of the commonly used Weibull model and stands better than the traditional models, which do not incorporate the size effect. The paper considers two such cumulative damage models, checks their compatibility with a real dataset, compares them with some of the recent toolkits, and finally recommends a model, which appears an appropriate one. Throughout the study is Bayesian based on Markov chain Monte Carlo simulation.     

A case–control study relating railroad worker mortality to diesel exhaust exposure using a threshold regression model

A case–control study of lung cancer mortality in U.S. railroad workers in jobs with and without diesel exhaust exposure is reanalyzed using a new threshold regression methodology. The study included 1256 workers who died of lung cancer and 2385 controls who died primarily of circulatory system diseases. Diesel exhaust exposure was assessed using railroad job history from the US Railroad Retirement Board and an industrial hygiene survey. Smoking habits were available from next-of-kin and potential asbestos exposure was assessed by job history review. The new analysis reassesses lung cancer mortality and examines circulatory system disease mortality. Jobs with regular exposure to diesel exhaust had a survival pattern characterized by an initial delay in mortality, followed by a rapid deterioration of health prior to death. The pattern is seen in subjects dying of lung cancer, circulatory system diseases, and other causes. The unique pattern is illustrated using a new type of Kaplan–Meier survival plot in which the time scale represents a measure of disease progression rather than calendar time. The disease progression scale accounts for a healthy-worker effect when describing the effects of cumulative exposures on mortality.