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Applied Mathematics(A Journal of Chinese Universities) 2023年第4期38卷 475-492页

作者： ZHANG Chun-fang shi yi-min WANG Liang School of Mathematics and Statistics Xidian UniversityXi'an 710126China School of Mathematics and Statistics Northwestern Polytechnical UniversityXi'an 710129China School of Mathematics Yunnan Normal UniversityKunming 650500China

Dependent competing risks model is a practical model in the analysis of lifetime and failure *** dependence can be captured using a statistical tool to explore the re-lationship among failure *** this paper,an Archimedean copula is chosen to describe the dependence in a constant-stress accelerated life *** study the Archimedean copula based dependent competing risks model using parametric and nonparametric *** parametric likelihood inference is presented by deriving the general expression of likelihood function based on assumed survival Archimedean copula associated with the model parameter *** the nonparametric estimation with progressive censoring and the non-parametric copula estimation,we introduce a nonparametric reliability estimation method given competing risks data.A simulation study and a real data analysis are conducted to show the performance of the estimation methods.

关键词： dependent competing risks model accelerated life tests Archimedean copula nonparametric reliability estimation

New Blocking Artifacts Reduction Method Based on Wavelet Transform

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Semiconductor Photonics and Technology 2007年第1期13卷 43-47页

作者： shi min yi Qing-ming Department of Electronic Engineering Jinan University Guangzhou 510632 CHN

It is well known that a block discrete cosine transform compressed image exhibits visually annoying blocking artifacts at low-bit-rate. A new post-processing deblocking algorithm in wavelet domain is proposed. The algorithm exploits blocking-artifact features shown in wavelet domain. The energy of blocking artifacts is concentrated into some lines to form annoying visual effects after wavelet transform. The aim of reducing blocking artifacts is to capture excessive energy on the block boundary effectively and reduce it below the visual scope. Adaptive operators for different subbands are computed based on the wavelet coefficients. The operators are made adaptive to different images and characteristics of blocking artifacts. Experimental results show that the proposed method can significantly improve the visual quality and also increase the peak signal-noise-ratio(PSNR) in the output image.

关键词： block discrete cosine transform(BDCT) blocking artifacts wavelet transform

Novel Efficient De-blocking Method for Highly Compressed Images

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Semiconductor Photonics and Technology 2007年第2期13卷 122-125,145页

作者： shi min yi Qing-ming YANG Liang Department of Electronic Engineering Jinan University Guangzhou 510632 CHN

Due to coarse quantization, block-based discrete cosine transform(BDCT) compression methods usually suffer from visible blocking artifacts at the block boundaries. A novel efficient de-blocking method in DCT domain is proposed. A specific criterion for edge detection is given, one-dimensional DCT is applied on each row of the adjacent blocks and the shifted block in smooth region, and the transform coefficients of the shifted block are modified by weighting the average of three coefficients of the block. Mean square difference of slope criterion is used to judge the efficiency of the proposed algorithm. Simulation results show that the new method not only obtains satisfactory image quality, but also maintains high frequency information.

关键词： block-based discrete cosine transform(BDCT) blocking artifacts image compression

屏蔽数据下BurrXⅡ三部件串联系统的可靠性估计

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系统工程与电子技术 2011年第1期33卷 222-227页

作者：张萌师义民杨扬西北工业大学应用数学系陕西西安710129

在系统失效原因被屏蔽的情形下,讨论三部件串联系统中BurrXⅡ部件的可靠性估计问题。在一般屏蔽情形下,利用迭代法和系统简化法求解极大似然方程组,得到部件参数近似的极大似然估计(maximum likeli-hood estimation,MLE);在完全屏蔽情形... 详细信息

在系统失效原因被屏蔽的情形下,讨论三部件串联系统中BurrXⅡ部件的可靠性估计问题。在一般屏蔽情形下,利用迭代法和系统简化法求解极大似然方程组,得到部件参数近似的极大似然估计(maximum likeli-hood estimation,MLE);在完全屏蔽情形下,直接求解方程组得到参数精确的极大似然估计。同时利用贝叶斯方法分别在平方损失、LINEX损失以及熵损失下推导出部件参数和可靠性指标的贝叶斯估计。最后通过数值仿真说明极大似然估计和贝叶斯估计效果良好,并对二者进行了比较。

关键词：屏蔽数据三部件串联系统 BurrXⅡ分布极大似然估计贝叶斯估计

两参数Weibull分布环境因子的Bayes估计

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系统工程与电子技术 2008年第1期30卷 186-189页

作者：李凤师义民荆源西北工业大学应用数学系陕西西安710072 渭南师范学院数学系陕西渭南714000

基于天地试验环境下Weibull分布形状参数不变的条件,运用Bayes方法对两参数Weibull分布环境因子进行分析,以尺度参数后验密度的商密度作为环境因子的后验密度,给出了在形状参数已知和未知两种情况下,环境因子在平方损失下的Bayes估计。... 详细信息

基于天地试验环境下Weibull分布形状参数不变的条件,运用Bayes方法对两参数Weibull分布环境因子进行分析,以尺度参数后验密度的商密度作为环境因子的后验密度,给出了在形状参数已知和未知两种情况下,环境因子在平方损失下的Bayes估计。最后运用仿真实例与极大似然估计进行比较,结果表明Bayes估计优于极大似然估计。

关键词： WeibuU分布环境因子 Bayes估计极大似然估计

Empirical Bayes Test for Two-parameter Exponential Distribution under Type-Ⅱ Censored Samples

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Chinese Quarterly Journal of Mathematics 2012年第1期27卷 54-58页

作者： WANG Liang shi yi-min CHANG Ping Department of Applied Mathematics Northwestern Polytechnical UniversityXi’an 710072China College of Medicine Xi’an Jiaotong UniversityXi’an 710061China

The empirical Bayes test problem is considered for scale parameter of twoparameter exponential distribution under type-II censored *** using wavelets estimation method,the EB test function is constructed,of which the ... 详细信息

关键词： two-parameter exponential distribution wavelets estimation empirical Bayes test asymptotic optimality convergence rates

Asymptotically Optimal and Admissible Empirical Bayes Estimation of Normal Parameter

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Chinese Quarterly Journal of Mathematics 2007年第1期22卷 1-6页

作者： LIU Huan-xiang shi yi-min ZHANG Su-mei ZHOU Bing-chang Department of Mathematica Shaoxing College of Arts and Science Shaoxing 312000 China Department of Applied Mathematics Northwestern Polytechnical University Xi＇an 710072 China

Under square loss, this paper constructs the empirical Bayes（EB） estimation for the parameter of normal distribution which has both asymptotic optimality and admissibility. Moreover, the convergence rate of the EB e... 详细信息

关键词： empirical Bayes estimation asymptotic optimality admissibility

Protein A immunoadsorption therapy in the highly sensitized kidney transplant candidates

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Chinese Medical Journal 2011年第5期124卷 780-782页

作者： JIN Qing LIU Hang SONG Lin-yan HUANG Jing CHANG Yan ZHANG Mei shi yi-min Department of Urology Beijing Chaoyang Hospital Capital Medical University Beijing 100020 China

Background Sensitization in transplant candidates increases risk of irreversible immunologic injury of graft in the early period postoperatively. Elimination of anti-human leukocyte antigen （HLA） antibodies using protein A immunoadsorption （IA） might benefit these *** Protein A IA was used in 21 patients with high panel reactive antibody （PRA）. The patients had IA 1-6 times （median 5 times） with the interval period was 2-5 days （median 2.5 days）.Results Total 67 IA procedures were carried out smoothly in all patients. IA treatment reduced PRA I （pre （31.4±3.8）% vs. post （24.4±3.4）%, P 〈0.01） and II （pre （37.1±4.3）% vs. post （34.1±3.9）%, P 〈0.01）. However, PRA did not change in some patients after the treatment. The serum immunoglobulin （IgG, IgM and IgA） and complement C3, C4 level were decreased significantly. Hemoglobin and albumin levels were slightly decreased associated with IA procedures. Flu-like symptoms were observed in a few of cases during the procedure but generally mild and *** Protein A IA is capable to efficiently remove serum immunoglobulin and complement, reduce HLA class I and class II PRA in high sensitized transplant candidates, which is likely to benefit the kidney transplantation in these patients.

关键词： protein A immunoadsorption sensitization," transplant candidates

Burr-XII分布在具有随机移走逐步增加截尾模型下可靠性指标的Bayes估计

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系统工程理论与实践 2012年第7期32卷 1476-1484页

作者：孙天宇师义民王亮西北工业大学应用数学系西安710072 西安电子科技大学理学院西安710071

在具有随机移走的逐步增加Type-Ⅱ截尾模型下,假定每一个失效时刻移走的未失效样本数都服从二项分布,当Burr-XⅡ分布中两个形状参数均未知时,分别在q-对称损失函数和LINEX损失函数下给出了两个未知形状参数、移走概率以及可靠性指标的Ba... 详细信息

在具有随机移走的逐步增加Type-Ⅱ截尾模型下,假定每一个失效时刻移走的未失效样本数都服从二项分布,当Burr-XⅡ分布中两个形状参数均未知时,分别在q-对称损失函数和LINEX损失函数下给出了两个未知形状参数、移走概率以及可靠性指标的Baves估计和Bayes后验区间估计,并给出了参数估计的容许性证明.最后利用Monte Carlo方法对各种估计结果进行了模拟分析.

关键词：随机移走 Burr-X11分布 q-对称熵损失 LINEX损失 Bayes估计

Parameter Estimations in BurrⅫ Model Using Masked Data

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Chinese Quarterly Journal of Mathematics 2011年第2期26卷 251-255页

作者： HOU Hua-lei JIANG Yao-wei shi yi-min Department of Microwave Sichuan Jiuzhou Electric Group Corporation Mianyang 621000 China First Research Institute Sichuan Jiuzhou Electric Group Gorporation Mianyang 621000 China Department of Applied Mathematics Northwestern Polytechnical University Xi＇an 710072 China

We consider a series system of two independent and non-identical components which have different BurrⅫ distributed *** maximum likelihood and Bayes estimators of the parameters of the system＇s components are obtained based on masked system life test *** conclusion is that the Bayes estimates are better than the maximum likelihood estimates in the sense of having smaller mean squared errors.

关键词： masked data BurrⅫ distribution Bayes estimation