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Search Results: 1 - 10 of 33921 matches for " 冯三营 "
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Empirical Likelihood Confidence Regions of the Parameters in Nonlinear Semiparametric Regression Models
非线性半参数回归模型中参数的经验似然置信域

,薛留根,范承华
数学物理学报(A辑) , 2009,
Abstract: In this paper, we consider the nonlinear semiparametric regression model, and construct the empirical log-likelihood ratio statistic for the unknown parameter. It is shown that the proposed statistics have the asymptotic standard chi-square distribution, and hence it can be used to construct the confidence region of the parameter. In addition, the least squares estimator of unknown parameter is constructed, and its asymptotic behavior is proved. A simulation study is carried out to compare the proposed methods with the least-squares method in terms of the confidence regions and its coverage probabilities.
部分函数线性模型的经验似然推断
胡玉萍,,薛留根
应用概率统计 , 2015,
Abstract: 本文考虑部分函数线性回归模型,研究了回归系数的经验似然推断,证明了所提出的经验对数似然比渐近于分布,此结果可以用来构造了相应兴趣参数的置信域.另外,本文也给出了系数函数的极大经验似然估计,并在适当条件下给出了所提出估计量的收敛速度.仅就置信域精度及其覆盖概率大小方面,通过模拟研究和实例分析比较了经验似然方法与最小二乘方法的优劣.
变系数EV模型的局部纠偏经验似然
,牛惠芳,薛留根
应用概率统计 , 2010,
Abstract: 本文研究变系数EV模型,构造了未知系数函数的局部纠偏经验对数似然比统计量,在适当条件下,证明了所提出的统计量都具有渐近$\chi^{2}$分布,所得结果可以用来构造未知系数函数的逐点置信域.通过模拟研究比较了经验似然方法与正态逼近方法在逐点置信域构造方面的优劣.
纵向数据单指标模型中参数的经验似然置信域
李高荣,,薛留根
应用概率统计 , 2010,
Abstract: 考虑纵向数据单指标模型,针对纵向数据组间独立的特点,提出了模型中未知参数的三种经验对数似然比统计量.在适当条件下,证明了所提出的统计量依分布收敛于$\chi^{2}$分布,所得结果可以构造未知参数的置信域.进一步证明了所提出的纠偏的经验对数似然比有许多优良的性质.通过模拟研究对所提方法进行了说明.
半函数部分线性模型的经验似然推断
胡玉萍,薛留根,
- , 2017,
Abstract: 考虑了半函数部分线性回归模型的估计问题.在函数型数据下发展了经验似然方法.构造了参数分量的经验似然比函数,得到提出的经验对数似然比渐近于χ2分布,可用此结果构造兴趣参数的置信域.同时,也给出了非参数函数的估计,在一定的正则条件下给出了其收敛速度.
达州市环境空气污染特征及其与气象要素的关系
Characteristics of Environmental Air Pollution in Dazhou and Its Relationship with Meteorological Elements
 [PDF]


Climate Change Research Letters (CCRL) , 2019, DOI: 10.12677/CCRL.2019.86094
Abstract:
本文利用达州市2015~2016年的污染数据和同期的气象数据,对达州市的污染特征进行分析,结果表明:达州市总体上空气质量较好,空气优良率达到了70%,主要的污染天数集中在冬季,这期间以细颗粒物PM2.5的污染最为严重。污染物SO2、NO2、CO、PM10和PM2.5浓度的季节变化特征都是冬高夏低,但O3浓度的季节变化却是夏高冬低;CO、PM10和PM2.5浓度的逐月变化图呈明显的“U”型特征,O3浓度的逐月变化特征呈倒“U”型。最后,用6种主要污染物浓度与同期6种气象要素做相关性分析,得到气压、气温、降水量和风速这4种气象要素与各种污染物浓度的相关程度较高,其中O3和4种气象要素的相关性与另外5种污染物的相关性完全相反。
Based on the pollution data of Dazhou from 2015 to 2016 and the meteorological data of the same period, this paper analyzes the pollution characteristics of Dazhou and the results show: Dazhou has better air quality overall, and the excellent rate has reached 70%; the main days of pollution are concentrated in the winter, during which time the pollution of fine particulate matter PM2.5 is the most serious. The seasonal variation characteristics of pollutants SO2, NO2, CO, PM10 and PM2.5 are low in winter and high in summer, but the seasonal variation in O3 concentration is low in summer and high in winter. The monthly change of CO, PM10 and PM2.5 concentrations also showed obvious U-shaped features, and the monthly variation of O3 concentration was inverted U-shaped. Finally, the correlation analysis between the six main pollutant concentrations and the six meteorological elements in the same period shows that the correlation between the four meteorological elements of air pressure, temperature, precipitation and wind speed with the concentration of various pollutants is higher, the correlation of O3 and four meteorological elements associated is completely contrary with the other five pollutants.
高校官方微信公众号传播效果影响因素的实证研究——基于启发-系统模型
An Empirical Study on Influential Factors of the Effects of University Official WeChat Public Accounts——Based on Heuristic-Systematic Model

唐亚阳,
- , 2018,
Abstract: 高校官方微信公众号是高校宣传形象,与学生联络情感的重要平台,对高校官微传播效果进行影响因素分析,有助于官微运营者改进推送策略,提升传播效果。文章借鉴社会心理学的启发-系统模型,采用内容分析法对7个层次42所高校的1024篇官方微信公众号文章样本进行编码分析。分层回归模型结果显示,大学生主要通过启发模式处理高校官微信息,学校名气、推送时间、文章位置、编排形式等是影响传播效果的关键因素;推送内容对传播效果作用有限,能引起情感共鸣的内容更受欢迎。
University official WeChat public account is an important platform of image promotion and affection connection with students in college. It is conducive to the administrators of the university official WeChat public accounts to improve delivering strategies and promoting effects through analyzing the impact factors. Based on Heuristic-Systematic Model of Social Psychology, content analysis is used to encode samples of 1024 official WeChat public articles in 7 levels and 42 colleges and universities.It reveals that university students process university official WeChat public accounts’ information mainly by heuristic mode. The university fame, issuing time, article rank, layout form, and so forth are essential factors influencing the effects. Content types slightly impact the effects and however, the affective content is more popular.
消毒机程序与不同定时消毒对消毒效果的比较
Comparison of Disinfection Machine Procedures and Different Regular Disinfections on Disinfection Effect
 [PDF]

丽燕, 白静,, 陈立
Nursing Science (NS) , 2016, DOI: 10.12677/NS.2016.52004
Abstract:
目的:观察消毒机程序消毒与定时消毒对较高值2类医用品的消毒效果。方法:利用麻醉机呼吸回路消毒机对医用品进行程序消毒,与定时45 min、60 min两种不同时间对医用品进行消毒,检验三种方法的消毒效果,进行临床对比。结果:消毒机程序消毒与单项定时60 min进行医用品消毒,两种方法均达到高水平的消毒效果,细菌培养均阴性。单项定时45 min消毒时间,医用品消毒表面有细菌生长。结论:使用消毒机自身设计的程序消毒和单项定时60 min进行医用品消毒,均能达到高水平的消毒效果,安全可靠。单项定时45 min消毒时间,医用品消毒表面有细菌生长,达不到高水平的消毒效果。
Aim: To observe the disinfection effect of disinfection machine procedure and regular disinfection on 2 kinds of high-value medical supplies. Methods: The anesthetic machine breathing circuit disinfector in terms of program, and two different time of 45 min as well as 60 min were used in disinfection of medical supplies; the disinfection effect of these above three methods was tested and compared clinically. Result: Disinfection using disinfection machine procedure and single timing of 60 min all reached high-level effect, and bacterial cultures were negative. While when the single timing was 45 min, bacteria grew on the medical supplies’ disinfection surface. Conclusion: Using disinfection machine procedure and single timing of 60 min for disinfection of medical supplies can reach high-level disinfection effect, and these two methods are safe and reliable. Nevertheless disinfection of 45 min single timing results in bacteria growth on medical supplies’ disinfection surface, which cannot get high-level disinfection effect.
基于傅里叶描述子的稻飞虱形状识别
,丁为民,刘德
农业机械学报 , 2009,
Abstract: 分析了具有旋转、平移和尺度变换不变性,并且与边界的起点位置无关的归一化傅里叶描述子,并把傅里叶描述子及欧氏距离应用于稻飞虱的形状识别中,通过计算同一形状和不同形状的平均离散度检验了归一化傅里叶描述子系数的稳定性,从而确定形状系数基准值。对191张样本图像进行了测试,当相似度差异小于0.0123时,稻飞虱误判率为7.85%。结果表明,归一化傅里叶描述子具有高效的识别性能。
边界点数量对傅里叶描述子识别精度的影响
,刘德,丁为民,申宝
农业机械学报 , 2014, DOI: 10.6041/j.issn.1000-1298.2014.09.049
Abstract: 以傅里叶描述子(FDs)为形状边界的特征识别时,边界点数量(N)是影响其识别精度的唯一不确定参数。为合理选择该参数,以圆、椭圆、稻飞虱前翅边界为研究对象,以复数傅里叶描述子(CFD)、椭圆傅里叶描述子(EFD)为边界特征,以类内相似度、类间相似度为评价指标,对边界点数量影响识别精度的实质进行试验分析和验证。结果表明,边界点数量是以改变类内相似度/圆形边界信息量达到傅里叶描述子识别精度的改变,而且,一次采样的边界点数量N≥64时,CFD可以用较少的重采样的边界点数量(N≥16)来描述边界的整体形状;一次采样和重采样的边界点数量对EFD的识别精度均有影响,该描述子需要较多的边界点数量(N≥128)来表达边界的细节信息,尤其适用于边界形状极其相似的场合。
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