• / 4
  • 下载费用:10 金币  

零膨胀模型论文:零膨胀模型的若干问题研究.doc

关 键 词:
零膨胀模型论文:零膨胀模型的若干问题研究.doc
资源描述:
零膨胀模型论文:零膨胀模型的若干问题研究【中文摘要】在相关应用科学研究领域,计数资料有时会表现出较大的变异性。当变量的方差远大于其均值时,便存在过离散现象。过离散的一种特殊情形就是零膨胀,是由于数据中含有大量的零值而造成方差和均值之间的差异,在建模时忽略这种现象,会导致参数的错误估计从而做出不合理的推论和预测。针对上述情形,国外学者们提出多个处理零膨胀现象的模型,比如零膨胀泊松模型、零膨胀负二项模型和零膨胀广义泊松模型。但在实践中,传统的零膨胀模型在小样本量的参数估计上出现较大的偏差。故本文在传统零膨胀模型的基础上,探讨了源于 Beta-Binomial 混合分布的零膨胀模型,并对新模型和上述三种模型做了模拟对比研究,结果显示在小样本、较低程度的过离散情形下,新模型比其它三个模型对参数和 0 概率的估计精度更高;另外,考虑到某些现实问题的复杂性,将空间和时间因素引入到零膨胀数据的建模之中,着重论述了具有时空效应的零膨胀模型及模型的 MCMC 实现,并通过实例分析表明时空效应-零膨胀泊松模型在对 0 概率预测优于传统零膨胀泊松模型,进一步说明了时空效应-零膨胀模型的可行性和有效性。【英文摘要】In the relevant field of applied science research,discrete data sometimes shows a bigger variability. When the variance of variable is far larger than its mean value, the over-dispersion phenomenon exists, especially when there is a great deal of zeros in the sample. If neglecting this kind of phenomenon, it will cause the mistake of parameter estimate to make a false reasoning and forecast.As is stated above, the foreign scholars proposed several models to deal with the problem, for example Zero-Inflated Poisson model, Zero-Inflated Negative Binomial model and Zero-Inflated General Poisson model. But in the practice, there is a certain deviation on parameter estimate when modeling with small samples using these models. Based on the current situation of traditional models, this paper investigates Zero-Inflated model with small samples which are from Beta-Binomial distribution and contrast the new model with the above three models under the simulation experiment. The results show the new model has better estimations on parameters and zero probability than other three models under the situation of small samples and lower over-dispersion. At the same time, considered the complexity of some practical problems, time-space effect is imported into the modeling of Zero-Inflated model. The Zero-Inflated model with time-space effect and the detailed MCMC implementation procedure are described in detail in the paper. And the analysis of the example show
展开阅读全文
  微传网所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。
0条评论

还可以输入200字符

暂无评论,赶快抢占沙发吧。

关于本文
本文标题:零膨胀模型论文:零膨胀模型的若干问题研究.doc
链接地址:https://www.weizhuannet.com/p-9503453.html
微传网是一个办公文档、学习资料下载的在线文档分享平台!

微传网博客

网站资源均来自网络,如有侵权,请联系客服删除!

 网站客服QQ:80879498  会员QQ群:727456886

copyright@ 2018-2028 微传网络工作室版权所有

     经营许可证编号:冀ICP备18006529号-1 ,公安局备案号:13028102000124

收起
展开