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期刊论文 9

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多普勒超声心动图 1

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Reliability and variance-based sensitivity analysis of arch dams during construction and reservoir impoundment

M. Houshmand KHANEGHAHI, M. ALEMBAGHERI, N. SOLTANI

《结构与土木工程前沿（英文）》 2019年 第13卷 第3期   页码 526-541 doi: 10.1007/s11709-018-0495-1

摘要： The static performance of arch dams during construction and reservoir impoundment is assessed taking into account the effects of uncertainties presented in the model properties as well as the loading conditions. Dez arch dam is chosen as the case study; it is modeled along with its rock foundation using the finite element method considering the stage construction. Since previous studies concentrated on simplified models and approaches, comprehensive study of the arch dam model along with efficient and state-of-the-art uncertainty methods are incorporated in this investigation. The reliability method is performed to assess the safety level and the sensitivity analyses for identifying critical input factors and their interaction effects on the response of the dam. Global sensitivity analysis based on improved Latin hypercube sampling is employed in this study to indicate the influence of each random variable and their interaction on variance of the responses. Four levels of model advancement are considered for the dam-foundation system: 1) Monolithic dam without any joint founded on the homogeneous rock foundation, 2) monolithic dam founded on the inhomogeneous foundation including soft rock layers, 3) jointed dam including the peripheral and contraction joints founded on the homogeneous foundation, and 4) jointed dam founded on the inhomogeneous foundation. For each model, proper performance indices are defined through limit-state functions. In this manner, the effects of input parameters in each performance level of the dam are investigated. The outcome of this study is defining the importance of input factors in each stage and model based on the variance of the dam response. Moreover, the results of sampling are computed in order to assess the safety level of the dam in miscellaneous loading and modeling conditions.

关键词： concrete arch dams     reliability     randomness     improved Latin hypercube sampling     variance-based sensitivity analysis     exceedance probability     Sobol′ index    

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The adoption of repeated measurement of variance analysis and Shapiro–Wilk test

《医学前沿（英文）》 2022年 第16卷 第4期   页码 659-660 doi: 10.1007/s11684-021-0908-8

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Answer for questions of repeated measurements of variance analysis and distribution test of data — Authors

《医学前沿（英文）》 2022年 第16卷 第4期   页码 661-664 doi: 10.1007/s11684-021-0907-9

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一种分形图像编码的新方法

王秀妮,姜威,王利村

《中国工程科学》 2006年 第8卷 第1期   页码 54-57

摘要：

由于分形图像编码过程非常费时，因此在前人的基础上，通过分析影响分形图像编码速度的相关因素，提出了使用图像块的改进方差来提高分形压缩性能的思想。在证明迭代函数系统不会改变图像块的改进方差的基础上，给出了基于改进方差的分形图像压缩方法。实验结果说明该方法在保证快速性的同时，重建图像的质量又得到了进一步的提高。

关键词： 分形编码     图像压缩     方差    

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Determination of effective stress parameter of unsaturated soils: A Gaussian process regression approach

Pijush Samui, Jagan J

《结构与土木工程前沿（英文）》 2013年 第7卷 第2期   页码 133-136 doi: 10.1007/s11709-013-0202-1

摘要： This article examines the capability of Gaussian process regression (GPR) for prediction of effective stress parameter ( ) of unsaturated soil. GPR method proceeds by parameterising a covariance function, and then infers the parameters given the data set. Input variables of GPR are net confining pressure ( ), saturated volumetric water content ( ), residual water content ( ), bubbling pressure ( ), suction ( ) and fitting parameter ( ). A comparative study has been carried out between the developed GPR and Artificial Neural Network (ANN) models. A sensitivity analysis has been done to determine the effect of each input parameter on . The developed GPR gives the variance of predicted . The results show that the developed GPR is reliable model for prediction of of unsaturated soil.

关键词： unsaturated soil     effective stress parameter     Gaussian process regression (GPR)     artificial neural network (ANN)     variance    

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Optimization of WEDM process of pure titanium with multiple performance characteristics using Taguchi’s DOE approach and utility concept

Rupesh CHALISGAONKAR, Jatinder KUMAR

《机械工程前沿（英文）》 2013年 第8卷 第2期   页码 201-214 doi: 10.1007/s11465-013-0256-8

摘要：

This paper describes the development of multi response optimization technique using utility method to predict and select the optimal setting of machining parameters in wire electro-discharge machining (WEDM) process. The experimental studies in WEDM process were conducted under varying experimental conditions of process parameters, such as pulse on time(Ton), pulse off time(Toff), peak current (IP), wire feed (WF), wire tension (WT) and servo voltage (SV) using pure titanium as work material. Experiments were planned using Taguchi’s L27 orthogonal array. Multi response optimization was performed for both cutting speed (CS) and surface roughness (SR) using utility concept to find out the optimal process parameter setting. The level of significance of the machining parameters for their effect on the CS and SR was determined by using analysis of variance (ANOVA). Finally, confirmation experiment was performed to validate the effectiveness of the proposed optimal condition.

关键词： wire electro-discharge machining (WEDM)     Taguchi method     analysis of variance (ANOVA)     utility concept     cutting speed (CS)     surface roughness (SR)    

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Application of grey-taguchi method for optimization of dry sliding wear properties of aluminum MMCs

Rajesh SIRIYALA, Gopala Krishna ALLURU, Rama Murthy Raju PENMETSA, Muthukannan DURAISELVAM

《机械工程前沿（英文）》 2012年 第7卷 第3期   页码 279-287 doi: 10.1007/s11465-012-0329-0

摘要：

Through a pin-on-disc type wear setup, the dry sliding wear behavior of SiC-reinforced aluminum composites produced using the molten metal mixing method was investigated in this paper. Dry sliding wear tests were carried on SiC-reinforced metal matrix composites (MMCs) and its matrix alloy sliding against a steel counter face. Different contact stresses, reinforcement percentages, sliding distances, and sliding velocities were selected as the control variables, and the responses were selected as the wear volume loss (WVL) and coefficient of friction (COF) to evaluate the dry sliding performance. An L25 orthogonal array was employed for the experimental design. Initially, the optimization of the dry sliding performance of the SiC-reinforced MMCs was performed using grey relational analysis (GRA). Based on the GRA, the optimum level parameters for overall grey relational grade in terms of WVL and COF were identified. Analysis of variance was performed to determine the effect of individual factors on the overall grey relational grade. The results indicated that the sliding velocity was the most effective factor among the control parameters on dry sliding wear, followed by the reinforcement percentage, sliding distance, and contact stress. Finally, the wear surface morphology and wear mechanism of the composites were investigated through scanning electron microscopy.

关键词： aluminum     ANOVA (analysis of variance)     grey relational analysis     metal matrix composites     SiC particulates     Taguchi    

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Indoor thermal comfort research on the hybrid system of radiant cooling and dedicated outdoor air system

Weiliang WANG, Zhe TIAN

《能源前沿（英文）》 2013年 第7卷 第2期   页码 155-160 doi: 10.1007/s11708-013-0244-z

摘要： The radiant cooling system generally operates with the dedicated outdoor air system (DOAS). Air supply modes and the corresponding setting parameters of the hybrid system may substantially influence the indoor thermal comfort. With target indexes of air diffusion performance index (ADPI) and predicted mean vote (PMV), the Taguchi method was used to choose the optimal air supply mode and to analyze the significance of different factors on the thermal comfort. The results are expected for conducting the future design and regulation of the hybrid system. Computation fluid dynamics (CFD) simulation as well as verified experiments was performed during the research. Based on the ADPI studies, it is found that the air supply mode of ceiling delivery with ceiling exhaust is an optimized option to apply in DOAS of the hybrid system. Variance analysis results show that influence fact of air supply temperature is the most dominant one to impact the indoor thermal comfort index of PMV.

关键词： radiant cooling system     dedicated outdoor air system (DOAS)     thermal comfort     Taguchi method     variance analysis    

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基于一种全新的优化多变量非等距模型对中国汉族成人左心室多普勒超声心动图测值生理性变异的校正方法 Article

姚桂华, 陈湘云, 杨文静, 张青, 刘静, 梁欢, 孙慧, 许耀, 王丽, 徐金锋, 张澄, 孙丰荣, 张梅, 曾雪迎, 张运

《工程（英文）》 2022年 第16卷 第9期   页码 115-122 doi: 10.1016/j.eng.2021.05.007

摘要：

多数左心室（LV）多普勒超声心动图参数测值随年龄和性别显著变化，因此有必要对其生理性差异进行校正。本研究旨在验证：不同的多普勒参数测值与生物学特征变量间呈异速非线性相关，且其校正常数与校正指数各不同。共测量了1224名健康成人的23个LV多普勒参数。随机选择70%数据（A组）建立优化多变量非线性模型（OMAM），在30%数据（B组）和183名超重人群数据（C组）中验证OMAM的可靠性，并与基于体表面积（BSA）的单变量等距模型（SVIM）进行比较。结果显示，校正前，23个LV多普勒参数均与一个或多个生物学特征变量显著相关，B组中47.8% (11/23)的参数存在性别间差异，经OMAM校正后，81.8% (9/11)的参数消除了性别间差异。OMAM对B组和C组数据的校正成功率分别为100% (23/23)和82.6% (19/23)，建立了独立于生物学特征变量的多普勒参数的OMAM参考值，而基于BSA的SVIM校正成功率为零。不同的LV多普勒参数与一个或多个生物学特征变量呈异速非线性相关；本研究建立的OMAM成功校正了因生物学特征变量差异对健康和超重人群多普勒测值的生理性影响，其校正效果显著优于传统的SVIM。然而，OMAM针对其他种族、肥胖和疾病状态人群的适用性仍需进一步探究

关键词： 多普勒超声心动图     生理性变异     非等距模型     正常参考值    

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标题 作者 时间 类型 操作

Reliability and variance-based sensitivity analysis of arch dams during construction and reservoir impoundment

M. Houshmand KHANEGHAHI, M. ALEMBAGHERI, N. SOLTANI

期刊论文

The adoption of repeated measurement of variance analysis and Shapiro–Wilk test

期刊论文

Answer for questions of repeated measurements of variance analysis and distribution test of data — Authors

期刊论文

一种分形图像编码的新方法

王秀妮,姜威,王利村

期刊论文

Determination of effective stress parameter of unsaturated soils: A Gaussian process regression approach

Pijush Samui, Jagan J

期刊论文

Optimization of WEDM process of pure titanium with multiple performance characteristics using Taguchi’s DOE approach and utility concept

Rupesh CHALISGAONKAR, Jatinder KUMAR

期刊论文

Application of grey-taguchi method for optimization of dry sliding wear properties of aluminum MMCs

Rajesh SIRIYALA, Gopala Krishna ALLURU, Rama Murthy Raju PENMETSA, Muthukannan DURAISELVAM

期刊论文

Indoor thermal comfort research on the hybrid system of radiant cooling and dedicated outdoor air system

Weiliang WANG, Zhe TIAN

期刊论文

基于一种全新的优化多变量非等距模型对中国汉族成人左心室多普勒超声心动图测值生理性变异的校正方法

姚桂华, 陈湘云, 杨文静, 张青, 刘静, 梁欢, 孙慧, 许耀, 王丽, 徐金锋, 张澄, 孙丰荣, 张梅, 曾雪迎, 张运

期刊论文