Multiple Comparison Procedures: The Practical Solution

A practicing statistician looks at the multiple comparison controversy and related issues through the eyes of the users. The concept of consistency is introduced and discussed in relation to five of the more common multiple comparison procedures. All of the procedures are found to be inconsistent except the simplest procedure, the unrestricted least significant difference (LSD) procedure (or multiple t test). For this and other reasons the unrestricted LSD procedure is recommended for general use, with the proviso that it should be viewed as a hypothesis generator rather than as a method for simultaneous hypothesis generation and testing. The implications for Scheffé's test for general contrasts are also discussed, and a new recommendation is made.     

A Markov regime‐switching model for crude‐oil markets: Comparison of composite likelihood and full likelihood

We use the two‐state Markov regime‐switching model to explain the behaviour of the WTI crude‐oil spot prices from January 1986 to February 2012. We investigated the use of methods based on the composite likelihood and the full likelihood. We found that the composite‐likelihood approach can better capture the general structural changes in world oil prices. The two‐state Markov regime‐switching model based on the composite‐likelihood approach closely depicts the cycles of the two postulated states: fall and rise. These two states persist for on average 8 and 15 months, which matches the observed cycles during the period. According to the fitted model, drops in oil prices are more volatile than rises. We believe that this information can be useful for financial officers working in related areas. The model based on the full‐likelihood approach was less satisfactory. We attribute its failure to the fact that the two‐state Markov regime‐switching model is too rigid and overly simplistic. In comparison, the composite likelihood requires only that the model correctly specifies the joint distribution of two adjacent price changes. Thus, model violations in other areas do not invalidate the results. The Canadian Journal of Statistics 41: 353–367; 2013 © 2013 Statistical Society of Canada     

Generalized estimating equations for mixtures with varying concentrations

A finite mixture model is considered in which the mixing probabilities vary from observation to observation. A parametric model is assumed for one mixture component distribution, while the others are nonparametric nuisance parameters. Generalized estimating equations (GEE) are proposed for the semi‐parametric estimation. Asymptotic normality of the GEE estimates is demonstrated and the lower bound for their dispersion (asymptotic covariance) matrix is derived. An adaptive technique is developed to derive estimates with nearly optimal small dispersion. An application to the sociological analysis of voting results is discussed. The Canadian Journal of Statistics 41: 217–236; 2013 © 2013 Statistical Society of Canada     

Design-based random permutation models with auxiliary information

We extend the random permutation model to obtain the best linear unbiased estimator of a finite population mean accounting for auxiliary variables under simple random sampling without replacement (SRS) or stratified SRS. The proposed method provides a systematic design-based justification for well-known results involving common estimators derived under minimal assumptions that do not require specification of a functional relationship between the response and the auxiliary variables.     

西藏农牧民进城务工的价值引领与法律制度保障

西藏农牧民进城务工有增长之势.职业选择范围窄、劳务工资较低、生活素质较差等问题,折射出西藏农牧民工在劳动技能、职业素质、竞争能力等方面与当下市场经济要求存在一定距离.对此,既要引领农牧民工重视自身素质提高、增强竞争意识,自觉参与劳动技能教育与培训,更要敦促政府完善地方法规,从法律制度上保障各地县的农牧民接受劳动技能培训,建立提升农牧民参与现代化城市建设能力、提高农牧民物质生活的长效机制.     

自由心证的"自由"与"不自由"——民事诉讼自由心证原则解读

自由心证原则是当今世界各国普遍采纳的证据规则,本文在对自由心证原则进行基本概念分析的基础上,讨论了法官自由心证的范围以及在心证客观化趋势下对自由心证的种种限制,并对在我国民事诉讼领域确立自由心证制度进行了分析。     

论公益征收关系人

作为一类征收主体,征收关系人的范围是非常广泛的,但我国现行法规就征收关系人的范围并未做出系统规定,这是我国未来统一征收立法必须解决的一个问题。根据立法通例,登记并非成为适格的征收关系人的必要条件。对于预告登记权利人的关系人地位,应分不同情形作具体分析。     

基于有限差分的化学剂平面运移规律数值模拟

在化学驱中,各种化学剂在地层中的浓度对于驱油是极为关键的,理想的情况是合理设计化学剂注入参数（注入浓度、注入量和注入速度）,使得地层各处化学剂的浓度接近实验室设计的最佳浓度,从而驱油效率最高。化学剂在地层中除正常的对流外,还会发生扩散和吸咐,而平面渗流中,各处渗流速度的不同,使得化学剂在平面的浓度分布比一维情况复杂得多。依据有限差分法和雅可比迭代方法,根据达西渗流定律确定平面渗流速度场和压力场分布,再根据已求得的速度场结合化学剂运移的对流弥散方程,求解得到了化学剂的浓度场。数值模拟结果给出了不同时刻化学剂在地层中的浓度分布,并针对不同的运移滞后系数、弥散系数和化学剂注入量,分析了这些参数对于化学剂分布的影响。     

关于二维小波函数的进一步探讨

对二维小被函数作了进一步分析，讨论了二维频率响应的计算，将二维尺度函数用乘积空间中勒让德正交多项式展开，得到了一些可喜结果。