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61.
校园暴力的成因分析及预防策略探究   总被引:4,自引:0,他引:4  
校园暴力看似一种个别的、简单的社会现象,其实却具有复杂的社会心理背景,它是家庭结构或功能不健全、学校管理理念落后、教师管教失当、接受大众传媒负面影响、结交不良同伴等相互作用的混合产物.对校园暴力的预防应充分运用政府、社会、学校、家庭等各方面的资源,职责明确、责任到位,形成校园暴力治理的合力,才能为青少年学生全面和谐发展提供良好的条件.  相似文献   
62.
中国行政效率的公共选择理论分析   总被引:1,自引:1,他引:0  
从公共选择理论看来,政府在弥补市场失灵的同时,自身也会产生失灵。但是,中国在从计划经济向市场经济转型过程中,政府行政低效问题主要原因在于自身制度不够完善,如组织的约束机制和组织监控机制的不完善等。主要表现为政府决策达不到帕累托最优、无法评价市场机制与政府干预,何者的作用更大等。因此,必须通过引入竞争机制、进行成本-受益分析和加强监督等措施加以解决。  相似文献   
63.
技术和消费的“双升”加快了新零售服务供应链的形成和产生,同时也通过驱动其质量系统的协同改进及动态演化实现持续的发展。本文从创新驱动质量的动态视角,分析创新驱动下新零售服务供应链中多主体协同质量改进的运行机制和动态演化过程,运用演化博弈方法分析构建多主体协同的动态演化博弈模型,以此分析新零售服务供应链协同质量改进中各参与主体的博弈策略选择,并利用雅克比矩阵判断其策略稳定性。研究表明:在多元参与主体利益诉求得到满足的前提下,多主体协同质量改进能够保持系统稳定状态;多主体间的质量势差与协同质量改进稳定性呈现出反比关系;良好的质量协同效应、独立的内部监督机制等能有效的促进协同质量改进系统稳定。  相似文献   
64.
Consider a randomized trial in which time to the occurrence of a particular disease, say pneumocystis pneumonia in an AIDS trial or breast cancer in a mammographic screening trial, is the failure time of primary interest. Suppose that time to disease is subject to informative censoring by the minimum of time to death, loss to and end of follow-up. In such a trial, the censoring time is observed for all study subjects, including failures. In the presence of informative censoring, it is not possible to consistently estimate the effect of treatment on time to disease without imposing additional non-identifiable assumptions. The goals of this paper are to specify two non-identifiable assumptions that allow one to test for and estimate an effect of treatment on time to disease in the presence of informative censoring. In a companion paper (Robins, 1995), we provide consistent and reasonably efficient semiparametric estimators for the treatment effect under these assumptions. In this paper we largely restrict attention to testing. We propose tests that, like standard weighted-log-rank tests, are asymptotically distribution-free -level tests under the null hypothesis of no causal effect of treatment on time to disease whenever the censoring and failure distributions are conditionally independent given treatment arm. However, our tests remain asymptotically distribution-free -level tests in the presence of informative censoring provided either of our assumptions are true. In contrast, a weighted log-rank test will be an -level test in the presence of informative censoring only if (1) one of our two non-identifiable assumptions hold, and (2) the distribution of time to censoring is the same in the two treatment arms. We also extend our methods to studies of the effect of a treatment on the evolution over time of the mean of a repeated measures outcome, such as CD-4 count.  相似文献   
65.
A Multivariate Model for Repeated Failure Time Measurements   总被引:1,自引:1,他引:0  
A parametric multivariate failure time distribution is derived from a frailty-type model with a particular frailty distribution. It covers as special cases certain distributions which have been used for multivariate survival data in recent years. Some properties of the distribution are derived: its marginal and conditional distributions lie within the parametric family, and association between the component variates can be positive or, to a limited extent, negative. The simple closed form of the survivor function is useful for right-censored data, as occur commonly in survival analysis, and for calculating uniform residuals. Also featured is the distribution of ratios of paired failure times. The model is applied to data from the literature  相似文献   
66.
A central part of probabilistic public health risk assessment is the selection of probability distributions for the uncertain input variables. In this paper, we apply the first-order reliability method (FORM)(1–3) as a probabilistic tool to assess the effect of probability distributions of the input random variables on the probability that risk exceeds a threshold level (termed the probability of failure) and on the relevant probabilistic sensitivities. The analysis was applied to a case study given by Thompson et al. (4) on cancer risk caused by the ingestion of benzene contaminated soil. Normal, lognormal, and uniform distributions were used in the analysis. The results show that the selection of a probability distribution function for the uncertain variables in this case study had a moderate impact on the probability that values would fall above a given threshold risk when the threshold risk is at the 50th percentile of the original distribution given by Thompson et al. (4) The impact was much greater when the threshold risk level was at the 95th percentile. The impact on uncertainty sensitivity, however, showed a reversed trend, where the impact was more appreciable for the 50th percentile of the original distribution of risk given by Thompson et al. 4 than for the 95th percentile. Nevertheless, the choice of distribution shape did not alter the order of probabilistic sensitivity of the basic uncertain variables.  相似文献   
67.
对行政强制措施实行检察监督是十八届四中全会赋予检察机关的改革任务。在全面依法治国和监察体制改革背景下,检察机关履行行政强制措施检察监督职能既有必要性,也有可行性。在下一步检察改革过程中,应当坚持有限监督、适时监督、行政先行救济原则,探索采用检察建议、支持起诉、督促纠正违法、提请责任追究等方式对违法行政强制措施进行监督。  相似文献   
68.
Classifying several regression models fitted on a dataset is one of the most problems in data analysis. In other words, scientists are interested in comparing several regression models that can be used for a dataset. In this paper, an approach will be used to compare and classify several dependent regression models. Then the performance of the proposed method is investigated using simulation study and real example.  相似文献   
69.
Having demonstrated its credentials as one of the more elegant and robust conceptualisations of human relationships, attachment theory has considerable relevance to social work. Attachment‐based research has flourished over the past few years and it now includes an impressive array of studies across the lifespan. This article considers four different measures used in attachment‐based research, although more discussion is devoted to interview and projective measures because they specifically embrace a psychodynamic approach in their design and analytic focus. The aim of the article is to provide a brief overview of each measure and to offer some illustrative examples using practice‐related material.  相似文献   
70.
This paper develops a test for comparing treatment effects when observations are missing at random for repeated measures data on independent subjects. It is assumed that missingness at any occasion follows a Bernoulli distribution. It is shown that the distribution of the vector of linear rank statistics depends on the unknown parameters of the probability law that governs missingness, which is absent in the existing conditional methods employing rank statistics. This dependence is through the variance–covariance matrix of the vector of linear ranks. The test statistic is a quadratic form in the linear rank statistics when the variance–covariance matrix is estimated. The limiting distribution of the test statistic is derived under the null hypothesis. Several methods of estimating the unknown components of the variance–covariance matrix are considered. The estimate that produces stable empirical Type I error rate while maintaining the highest power among the competing tests is recommended for implementation in practice. Simulation studies are also presented to show the advantage of the proposed test over other rank-based tests that do not account for the randomness in the missing data pattern. Our method is shown to have the highest power while also maintaining near-nominal Type I error rates. Our results clearly illustrate that even for an ignorable missingness mechanism, the randomness in the pattern of missingness cannot be ignored. A real data example is presented to highlight the effectiveness of the proposed method.  相似文献   
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