期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
EPS模陶瓷型精密铸造失模工艺研究 被引量:5
1
作者 米国发 王狂飞 +1 位作者 刘翔宇 贾宝仟 《铸造》 CAS CSCD 北大核心 2007年第8期828-831,共4页
针对EPS陶瓷壳型精铸失模时容易裂壳的现象,对EPS消失模精密铸造工艺进行了研究。利用自制的膨胀率检测设备对不同密度的EPS模试样在不同加热温度下的最大膨胀率进行了测试,研究了壳型膨胀与失模温度之间的关系;对陶瓷壳型中EPS模失模... 针对EPS陶瓷壳型精铸失模时容易裂壳的现象,对EPS消失模精密铸造工艺进行了研究。利用自制的膨胀率检测设备对不同密度的EPS模试样在不同加热温度下的最大膨胀率进行了测试,研究了壳型膨胀与失模温度之间的关系;对陶瓷壳型中EPS模失模时的温度场分布进行测量,发现EPS模试样的密度大小对失模时温度场有着很重要的影响。在试验和分析的基础上,对EPS模失模机制进行了探讨,提出了高温失模机制。高温失模有利于降低失模时对壳型的膨胀作用力,为获得洁净而健全的陶瓷型壳提供了可靠保证。 展开更多
关键词 EPS精密铸造 工艺 裂壳 失模机制
下载PDF
Effect of the computer fuzzy control on coal seam injection
2
作者 宋华岭 杨景才 +3 位作者 王金力 王安 刘淑芹 Cornelis Reiman 《Journal of Coal Science & Engineering(China)》 2003年第2期113-117,共5页
To enhance the technology and efficiency of strata injection is a problem to be solved urgently. Because of effected by the rough and poor production conditions of mining and the changeable bearing condition of strata... To enhance the technology and efficiency of strata injection is a problem to be solved urgently. Because of effected by the rough and poor production conditions of mining and the changeable bearing condition of strata, the technological process of injection can not be controlled automatically.The fuzzy controlling technology of the coal strata injection is applied. This is the good way to ensure the effectiveness and efficiency of coal strata injection and to solve the current problems of production and safety in mining industry. 展开更多
关键词 coal strata injection fuzzy control mining safety
下载PDF
Approximate Conditional Likelihood for Generalized Linear Models with General Missing Data Mechanism 被引量:7
3
作者 ZHAO Jiwei SHAO Jun 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2017年第1期139-153,共15页
The generalized linear model is an indispensable tool for analyzing non-Gaussian response data, with both canonical and non-canonical link functions comprehensively used. When missing values are present, many existing... The generalized linear model is an indispensable tool for analyzing non-Gaussian response data, with both canonical and non-canonical link functions comprehensively used. When missing values are present, many existing methods in the literature heavily depend on an unverifiable assumption of the missing data mechanism, and they fail when the assumption is violated. This paper proposes a missing data mechanism that is as generally applicable as possible, which includes both ignorable and nonignorable missing data cases, as well as both scenarios of missing values in response and covariate.Under this general missing data mechanism, the authors adopt an approximate conditional likelihood method to estimate unknown parameters. The authors rigorously establish the regularity conditions under which the unknown parameters are identifiable under the approximate conditional likelihood approach. For parameters that are identifiable, the authors prove the asymptotic normality of the estimators obtained by maximizing the approximate conditional likelihood. Some simulation studies are conducted to evaluate finite sample performance of the proposed estimators as well as estimators from some existing methods. Finally, the authors present a biomarker analysis in prostate cancer study to illustrate the proposed method. 展开更多
关键词 Asymptotic normality generalized linear model IDENTIFIABILITY missing data mechanism non-canonical link function nonignorable missingness.
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部