长输管道建设物流管理新模式——物资配送

长输管道工程是以线路管道与沿途站场为主要内容的建设工程,其物资配送有着不同于一般物流管理的特点,点多线长,且交通不便.文章结合西南成品油管道建设工程的物资配送实践,总结出长输管道物资配送的类型,并从机构设置、计划编制、台账和报表管理等方面介绍了物资配送的管理内容及经验,实践证明,这种物资配送方法不但使业主的物资管理人员大为减少,而且使长输管道工程的物资供应更加及时有序.     

Some results on generalized residual entropy

Shannon’s entropy plays an important role in the context of information theory. Since this entropy is not applicable to a system which has survived for some units of time, the concept of residual entropy has been developed in the literature. Here we generalize the residual entropy by choosing a convex function ? with ?(1) = 0. In this paper, some orderings and aging properties have been defined in terms of the generalized residual entropy function and their properties have been studied. Quite a few results available in the literature have been generalized and some distributions (viz. uniform, exponential, Pareto, power series, finite range) have been characterized through the generalized residual entropy.     

复杂耦合系统的统计能量分析及其应用

文章综合导纳分析法、经典统计能量分析方法和经典功率流理论的各自优点，提出适合复杂耦合系统的统计能量分析方法，为研究实际机械结构之间的振动传递规律、复杂机械系统的声辐射特性提供理论依据，为实际工程结构的振动隔离、噪声治理提供理论指导。文章首次提出统计能量分析参数必须统一定义，将影响实际机械结构相互之间能量传递的若干要素各自分离，并引入相应的参数分别开展研究。利用理论研究的成果，发展后的统计能量分析首次应用于水下航行器振动和噪声特性分析，预报了水下航行器的振动传递规律和辐射噪声级。理论分析与实验测试结果符合较     

长输管道过水面护底的优化设计

长输管道穿越河流时,在河道水流的冲刷下,原来敷设于河床下一定深度的管道有可能暴露漂管,甚至在水流裹携的块状物的撞击作用下,还会发生断管之类的重大事故。为防止河床持续下切造成管道事故,一般对穿越河流的长输管道采取护底措施进行防护。文章根据水力学明渠均匀流理论及相关计算公式,介绍了天然河道的流速计算方法,从水流的裹携能力入手,依据不同地质河床和过水面的抗冲流速,确定相应的过水面护底方案,该计算方法简便,能适应现场设计的需要。     

长输管道不停输防腐层大修技术

东河塘至轮南输油管道,经过12年的运行,钢管外石油沥青玻璃布防腐层已严重老化甚至剥离。在不停输的情况下,对输油管道防腐层大修,特别像东—轮线输油管道,地处沙漠边缘、戈壁地带,没有成熟的施工经验可以借鉴。文章根据东—轮线输油管道防腐层大修的施工实践,详细介绍了长输管道不停输防腐层大修的施工工艺和质量保证措施。     

Effect-Size Indices for Dichotomized Outcomes in Meta-Analysis.

It is very common to find meta-analyses in which some of the studies compare 2 groups on continuous dependent variables and others compare groups on dichotomized variables. Integrating all of them in a meta-analysis requires an effect-size index in the same metric that can be applied to both types of outcomes. In this article, the performance in terms of bias and sampling variance of 7 different effect-size indices for estimating the population standardized mean difference from a 2 × 2 table is examined by Monte Carlo simulation, assuming normal and nonnormal distributions. The results show good performance for 2 indices, one based on the probit transformation and the other based on the logistic distribution. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How Meta-Analysis Increases Statistical Power.

One of the most frequently cited reasons for conducting a meta-analysis is the increase in statistical power that it affords a reviewer. This article demonstrates that fixed-effects meta-analysis increases statistical power by reducing the standard error of the weighted average effect size (T?.) and, in so doing, shrinks the confidence interval around T?.. Small confidence intervals make it more likely for reviewers to detect nonzero population effects, thereby increasing statistical power. Smaller confidence intervals also represent increased precision of the estimated population effect size. Computational examples are provided for 3 effect-size indices: d (standardized mean difference), Pearson's r, and odds ratios. Random-effects meta-analyses also may show increased statistical power and a smaller standard error of the weighted average effect size. However, the authors demonstrate that increasing the number of studies in a random-effects meta-analysis does not always increase statistical power. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

“新时期统计文化建设研讨会”综述

统计文化是一种行业性的亚文化,是科学文化与人文文化的结合。在新的历史时期,统计文化有着丰富的内涵和表现形式,其中深层次的精神文化居于核心地位。统计文化对统计人员的影响往往体现在统计职业道德之中。统计文化建设是一项复杂的系统工程,必须坚持以人为本。     

Methodological Challenges in Union Commitment Studies.

Methodological problems in studies of union commitment were identified and illustrated with data from 4,641 members and 479 stewards in 297 local teachers' unions. Using a 20-item union commitment scale, results confirmed the existence of 3 substantive factors and 1 method factor at the individual level of analysis: loyalty to the union, responsibility to the union, willingness to work for the union, and a factor of negatively worded items. Tests of measurement invariance showed that the scale captured commitment for rank-and-file members but not for union stewards. The authors also found partial measurement invariance between long-time and newer members and full measurement invariance between men and women. Finally, the authors found that violation of the statistical assumption of independence reduced model fit when individual commitment scores were analyzed without attention to the hierarchical nature of the data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

网络电视的发展及其对远程教育的影响

计算机网络技术的发展给电视节目的播出方式带来了巨大的变化，网络电视这一传播媒体应运而生。从而改变了目前广播电视媒体信息单向传播的缺陷。介绍了网络电视的发展，就网络电视对远程教育的影响进行了探讨。