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101.
李贵峰 《石家庄铁道学院学报(社会科学版)》2016,(4):16-20,89
扁平超宽箱梁桥由于具有较大的宽跨比,其受力性能呈现明显的空间效应,通常的单梁模型计算已不能满足设计的精度要求,主要体现在宽箱梁各腹板纵向受力的差异性以及明显的剪力滞效应,同时由于大宽跨比使得横向预应力的作用不仅增加了顶板的压应力,也使得整体箱梁截面下缘出现拉应力,造成边腹板底部纵向裂缝,这些都给宽箱梁的设计带来了不利。因此为研究宽箱梁的空间效应,本文运用ANSYS有限元软件建立了全桥实体模型,计算了各腹板纵向受力差异及剪力滞效应,以及横向预应力对箱梁横向受力的影响,得到了一些有益的结论,为设计人员提供一定的参考。 相似文献
102.
任凤辉 《长春工程学院学报(社会科学版)》2014,(2):33-35
立足于吉林省廉租房政策实施效果的全面调查数据,概述了吉林省廉租房政策实施效果,以独特的视角深入分析了廉租房政策推行过程中出现的一些亟需解决的共性问题,提出了针对性的解决对策。 相似文献
103.
Application of a QMRA Framework to Inform Selection of Drinking Water Interventions in the Developing Context
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S. R. Petterson 《Risk analysis》2016,36(2):203-214
The aim of this study was to develop a modified quantitative microbial risk assessment (QMRA) framework that could be applied as a decision support tool to choose between alternative drinking water interventions in the developing context. The impact of different household water treatment (HWT) interventions on the overall incidence of diarrheal disease and disability adjusted life years (DALYs) was estimated, without relying on source water pathogen concentration as the starting point for the analysis. A framework was developed and a software tool constructed and then implemented for an illustrative case study for Nepal based on published scientific data. Coagulation combined with free chlorine disinfection provided the greatest estimated health gains in the short term; however, when long‐term compliance was incorporated into the calculations, the preferred intervention was porous ceramic filtration. The model demonstrates how the QMRA framework can be used to integrate evidence from different studies to inform management decisions, and in particular to prioritize the next best intervention with respect to estimated reduction in diarrheal incidence. This study only considered HWT interventions; it is recognized that a systematic consideration of sanitation, recreation, and drinking water pathways is important for effective management of waterborne transmission of pathogens, and the approach could be expanded to consider the broader water‐related context. 相似文献
104.
Charles F. Manski 《The American statistician》2019,73(1):296-304
AbstractA central objective of empirical research on treatment response is to inform treatment choice. Unfortunately, researchers commonly use concepts of statistical inference whose foundations are distant from the problem of treatment choice. It has been particularly common to use hypothesis tests to compare treatments. Wald’s development of statistical decision theory provides a coherent frequentist framework for use of sample data on treatment response to make treatment decisions. A body of recent research applies statistical decision theory to characterize uniformly satisfactory treatment choices, in the sense of maximum loss relative to optimal decisions (also known as maximum regret). This article describes the basic ideas and findings, which provide an appealing practical alternative to use of hypothesis tests. For simplicity, the article focuses on medical treatment with evidence from classical randomized clinical trials. The ideas apply generally, encompassing use of observational data and treatment choice in nonmedical contexts. 相似文献
105.
Heid Nøkleby Geir Pedersen Finn Skårderud 《Journal of social work practice in the addictions》2014,14(3):225-238
The aim of this study is to measure and describe symptoms of eating disorders among females in treatment for drug addiction in Norway. Previous clinical and epidemiological studies have revealed coprevalence between eating disorders and substance use or abuse. However, few studies have measured eating disorders in drug-using samples and even fewer within the context of drug treatment. In this study, 29 females with drug use disorder in residential treatment were tested with the Eating Disorder Inventory–2. A subgroup of 9 females (31%) with significant symptoms of eating disorders was identified. The characteristics of this group and possible clinical consequences are discussed. 相似文献
106.
Substance use disorders and referral to treatment in substantiated cases of child maltreatment
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Parents with substance use disorders (SUD) require treatment and support in order to provide children with appropriate care and protection. Using the 2012 National Child Abuse and Neglect Data System (NCANDS), this paper analysed 464 313 substantiated child maltreatment reports to determine (i) the proportion and characteristics of reports involving substance abuse; and (ii) the child and caregiver/perpetrator (C/P) characteristics that predicted referral to treatment as recorded in service plans. Findings indicate that 12% (N = 53 234) of maltreatment reports involved C/P SUD. Yet, of those reports, only (19%) (N = 10 088) were referred to substance abuse treatment as part of their service plan, indicating a large gap between those who need treatment and those who receive it. This finding is important given that parental SUD is consistently linked to poorer child outcomes. Amongst other variables, reports indicate that C/P with co‐occurring emotional disturbance were three times more likely to be referred to treatment for SUD as part of service plans. Additional research is needed regarding the characteristics that distinguish C/P who receive referrals for SUD treatment in substantiated cases of child maltreatment. 相似文献
107.
通过对高校思想政治理论课教学的评价、学生对该课的参与程度,以及该课教学中存在的问题、改进意见和建议等情况进行调查,结果显示,教学内容、教师素质、教学方式是影响当前高校思想政治理论课教学效果的三个主要方面。 相似文献
108.
A comparison of maximum likelihood and least squares for the estimation of a cumulative distribution
《Journal of Statistical Computation and Simulation》2012,82(3-4):229-239
Monte Carlo methods are used to compare the methods of maximum likelihood and least squares to estimate a cumulative distribution function. When the probabilistic model used is correct or nearly correct, the two methods produce similar results with the MLE usually slightly superior When an incorrect model is used, or when the data is contaminated, the least squares technique often gives substantially superior results. 相似文献
109.
本文基于超总体模型研究抽样调查中设计效应的计算问题。首先以随机效应模型为基础,明确了简单随机、二阶段、不等概率和分层抽样对应的超总体模型,进而通过所给模型推导出分层、类集、加权单因素设计效应的计算公式和多因素组合的设计效应计算公式并给出了对应估计量,公式表明:多因素同时存在的组合设计效应等于对应单因素设计效应的乘积。最后,对设计效应的理论值、估计值和真实值之间的关系进行了蒙特卡洛仿真,并利用相对偏倚、相对均方误进行了评价。本文的研究,对复杂抽样设计中正确计算、使用设计效应具有指导意义。 相似文献
110.
《Journal of Statistical Computation and Simulation》2012,82(2):145-187
This paper studies the effects of non-normality and autocorrelation on the performances of various individuals control charts for monitoring the process mean and/or variance. The traditional Shewhart X chart and moving range (MR) chart are investigated as well as several types of exponentially weighted moving average (EWMA) charts and combinations of control charts involving these EWMA charts. It is shown that the combination of the X and MR charts will not detect small and moderate parameter shifts as fast as combinations involving the EWMA charts, and that the performana of the X and MR charts is very sensitive to the normality assumption. It is also shown that certain combinations of EWMA charts can be designed to be robust to non-normality and very effective at detecting small and moderate shifts in the process mean and/or variance. Although autocorrelation can have a significant effect on the in-control performances of these combinations of EWMA charts, their relative out-of-control performances under independence are generally maintained for low to moderate levels of autocorrelation. 相似文献