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61.
食品安全事件是近年来全球公共安全问题中的热点,由于食品安全的重要性、食品安全事件的公众效应以及基于传媒的属性,媒体常将其作为关注的热点。媒体在食品安全事件中发挥着监测预警、沟通信息、舆论引导等功能,同时也存在关注视角的选择性和职业自律的松懈等不足。作为一种社会公共资源和社会监督力量,基于传媒良知和职业操守,媒体在食品安全事件中必须形成一套良性的应对机制,包括建立信息有效传播机制、建立食品安全事件相关方的沟通协调机制、建立媒体自律机制等。  相似文献   
62.
The estimation of abundance from presence–absence data is an intriguing problem in applied statistics. The classical Poisson model makes strong independence and homogeneity assumptions and in practice generally underestimates the true abundance. A controversial ad hoc method based on negative‐binomial counts (Am. Nat.) has been empirically successful but lacks theoretical justification. We first present an alternative estimator of abundance based on a paired negative binomial model that is consistent and asymptotically normally distributed. A quadruple negative binomial extension is also developed, which yields the previous ad hoc approach and resolves the controversy in the literature. We examine the performance of the estimators in a simulation study and estimate the abundance of 44 tree species in a permanent forest plot.  相似文献   
63.
Categorical longitudinal data are frequently applied in a variety of fields, and are commonly fitted by generalized linear mixed models (GLMMs) and generalized estimating equations models. The cumulative logit is one of the useful link functions to deal with the problem involving repeated ordinal responses. To check the adequacy of the GLMMs with cumulative logit link function, two goodness-of-fit tests constructed by the unweighted sum of squared model residuals using numerical integration and bootstrap resampling technique are proposed. The empirical type I error rates and powers of the proposed tests are examined by simulation studies. The ordinal longitudinal studies are utilized to illustrate the application of the two proposed tests.  相似文献   
64.
探讨中国现实主义文学思潮的接受来源,"日本视野"是不可或缺的视角.近在咫尺的东邻日本,较早接受西方现实主义文学思潮,曾在不同时期给中国现实主义文学思潮的生成与发展产生影响.但中国作家从日本引入的现实主义理论,有不同的内涵与特质,因而也会产生不同的接受效应.  相似文献   
65.
中国货币财政政策有效性的比较检验   总被引:1,自引:0,他引:1  
货币政策和财政政策是政府干预宏观经济最重要、使用最频繁的两大工具。改革开放以来,我国政府综合运用货币政策和财政政策调控经济运行,促进经济增长。为检验中国1978~2006年间经济增长中货币政策和财政政策有效性的差异性特征,应用脉冲响应函数研究它们之间的动态特性后发现:无论是短期还是长期,积极货币政策对于经济增长均有正效应,而积极财政政策仅在短期内有效,长期内呈现负效应且随时间推移逐渐显著。积极财政政策长期失效的原因有多方面,主要是财政支出的供给范围不合理和支出管理失控产生的效率损失。  相似文献   
66.
In recent years, a variety of regression models, including zero-inflated and hurdle versions, have been proposed to explain the case of a dependent variable with respect to exogenous covariates. Apart from the classical Poisson, negative binomial and generalised Poisson distributions, many proposals have appeared in the statistical literature, perhaps in response to the new possibilities offered by advanced software that now enables researchers to implement numerous special functions in a relatively simple way. However, we believe that a significant research gap remains, since very little attention has been paid to the quasi-binomial distribution, which was first proposed over fifty years ago. We believe this distribution might constitute a valid alternative to existing regression models, in situations in which the variable has bounded support. Therefore, in this paper we present a zero-inflated regression model based on the quasi-binomial distribution, taking into account the moments and maximum likelihood estimators, and perform a score test to compare the zero-inflated quasi-binomial distribution with the zero-inflated binomial distribution, and the zero-inflated model with the homogeneous model (the model in which covariates are not considered). This analysis is illustrated with two data sets that are well known in the statistical literature and which contain a large number of zeros.  相似文献   
67.
通过对山东省少年管教所189名男性犯罪青少年人际信任的特点以及与其社会支持、应对方式的关系进行研究发现:(1)男性犯罪青少年人际信任水平比同龄男性中学生低,且差异显著;(2)其社会支持与人际信任水平呈正相关;(3)积极应对方式与人际信任水平呈正相关,消极应对方式与人际信任水平呈负相关;(4)人际信任、社会支持和应对方式之间存在复杂的因果关系;(5)各种客观变量对人际信任的影响甚微.  相似文献   
68.
反讽可以达到戏谑、嘲弄及讽刺的效果,使作品生动幽默,富有艺术感染力。反讽在《傲慢与偏见》中塑造了鲜活的人物形象,使作品妙趣横生,令读者百读不厌。因此,成功的译文必须将其完全再现出来。然而,在阅读三个中文译本的过程中发现存在反讽的欠额翻译现象。从语言学角度分析了其原因,并给出了新的翻译建议,指出译者不仅要具备足够的源语文化和语言知识,还必须具有熟练驾驭目标语的能力,才能避免反讽的欠额翻译,达到译语读者和源语读者反应的对等。  相似文献   
69.
While excess zeros are often thought to cause data over-dispersion (i.e. when the variance exceeds the mean), this implication is not absolute. One should instead consider a flexible class of distributions that can address data dispersion along with excess zeros. This work develops a zero-inflated sum-of-Conway-Maxwell-Poissons (ZISCMP) regression as a flexible analysis tool to model count data that express significant data dispersion and contain excess zeros. This class of models contains several special case zero-inflated regressions, including zero-inflated Poisson (ZIP), zero-inflated negative binomial (ZINB), zero-inflated binomial (ZIB), and the zero-inflated Conway-Maxwell-Poisson (ZICMP). Through simulated and real data examples, we demonstrate class flexibility and usefulness. We further utilize it to analyze shark species data from Australia's Great Barrier Reef to assess the environmental impact of human action on the number of various species of sharks.  相似文献   
70.
Negative binomial regression (NBR) and Poisson regression (PR) applications have become very popular in the analysis of count data in recent years. However, if there is a high degree of relationship between the independent variables, the problem of multicollinearity arises in these models. We introduce new two-parameter estimators (TPEs) for the NBR and the PR models by unifying the two-parameter estimator (TPE) of Özkale and Kaç?ranlar [The restricted and unrestricted two-parameter estimators. Commun Stat Theory Methods. 2007;36:2707–2725]. These new estimators are general estimators which include maximum likelihood (ML) estimator, ridge estimator (RE), Liu estimator (LE) and contraction estimator (CE) as special cases. Furthermore, biasing parameters of these estimators are given and a Monte Carlo simulation is done to evaluate the performance of these estimators using mean square error (MSE) criterion. The benefits of the new TPEs are also illustrated in an empirical application. The results show that the new proposed TPEs for the NBR and the PR models are better than the ML estimator, the RE and the LE.  相似文献   
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