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The Use of Yanai’s Generalized coefficient of Determination to Reduce the Number of Variables in DEA Models

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American Journal of Operations Research 2017年第3期7卷 187-200页

作者： Mauricio Benegas School of Business Accounting and Economics Federal University of Ceará Fortaleza Brazil

This paper proposes a new method to reduce the dimensionality of input and output spaces in DEA models. The method is based on Yanai’s Generalized coefficient of Determination and on the concept of pseudo-rank of a matrix. In addition, the paper suggests a rule to determine the cardinality of the subset of selected variables in a way to gain the maximal discretionary power and to suffer a minimal informational loss.

关键词： DEA Yanai’s Generalized coefficient of Determination Pseudo-Rank Dimension Reduction Improving Discrimination

Magnetic resonance imaging apparent diffusion coefficient before and after neoadjuvant chemotherapy in patients with breast cancer and its correlation with tumor load

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Journal of Hainan Medical University 2018年第9期24卷 52-56页

作者： Si-Qi Wang Ping Jiang Radiology Department Zigong Fourth People's Hospital in Sichuan ProvinceZigongSichuan Province643000

Objective:To study the magnetic resonance imaging apparent diffusion coefficient (ADC) before and after neoadjuvant chemotherapy in patients with breast cancer and its correlation with tumor load.Methods: Patients with stage II-III breast cancer who intended to receive radical operation for breast cancer in our hospital between May 2015 and February 2018 were selected and divided into the experimental group who accepted neoadjuvant chemotherapy and the control group who received surgery directly according to the adoption of preoperative neoadjuvant chemotherapy or not in the history data. Experimental group underwent magnetic resonance imaging before and after neoadjuvant chemotherapy to measure the ADC, and control group underwent magnetic resonance imaging before surgery to measure the ADC;the tumor tissues surgically removed from the two groups of patients were collected to measure the expression of oncogenes and invasion genes.Results:ADC value of experimental group after neoadjuvant chemotherapy was higher than that before neoadjuvant chemotherapy, ADC value of experimental group before neoadjuvant chemotherapy was not significantly different from that of control group whereas ADC value after neoadjuvant chemotherapy was significantly higher than that of control group;MCM3, CyclinD1, TC-1,β-catenin, YAP and MMP2 mRNA expression levels in surgically removed tumor tissues of experimental group were significantly lower than those of control group whereas CCN5, ARID1A and PDCD4 mRNA expression levels were significantly higher than those of control group;MCM3, CyclinD1, TC-1,β-catenin, YAP and MMP2 mRNA expression levels in tumor tissues with high ADC value were significantly lower than those in tumor tissues with low ADC value whereas CCN5, ARID1A and PDCD4 mRNA expression levels were significantly higher than those in tumor tissues with low ADC value.Conclusion:The increase of ADC after breast cancer neoadjuvant chemotherapy is related to the activity of cancer cell proliferation and invasion, and can be used t

关键词： Breast cancer Neoadjuvant chemotherapy Apparent diffusion coefficient Oncogene Invasion gene

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用于颤振分析的影响系数法研究（英文）

风机技术 2019年第1期61卷 54-62,I0009页

作者：刘伟黄秀全王丁喜刘若阳 School of Power and Energy Northwestern Polytechnical University Shaanxi Key Laboratory of Internal Aerodynamics in Aero-engines Northwestern Polytechnical University Aero Engine Academy of China

影响系数法长期以来被用于数值和实验方面的颤振分析研究。在实验研究中,实验装置通常采用3-11个叶片的线性或环形叶栅,并在上下两端放置挡板。实验中仅驱动中间叶片振动,在各叶片表面产生非定常压力,测量各叶片表面的非定常压力并采用... 详细信息

影响系数法长期以来被用于数值和实验方面的颤振分析研究。在实验研究中,实验装置通常采用3-11个叶片的线性或环形叶栅,并在上下两端放置挡板。实验中仅驱动中间叶片振动,在各叶片表面产生非定常压力,测量各叶片表面的非定常压力并采用影响系数法可以得到以行波模式振动时叶片表面的非定常压力。而我们在数值模拟中使用影响系数法时,不需要在上下两端放置挡板,通过采用周期性边界条件就可以保证流场的周期性。有些学者指出,当叶栅中的叶片数至少为9甚至11个时,结果不会随着叶片数的增加而改变。本文采用了谐波平衡法进行非定常流场计算,研究了叶片数目,马赫数以及振动叶片的位置对影响系数法结果的影响。得出结论,对于本文所研究的叶栅,要得到足够精确地结果,在周期性边界条件下需要至少7个叶片,在挡板边界条件下需要至少13个叶片。振动叶片最合适的位置是在叶栅中部。

关键词： Influence coefficient Method Flutter Linear Cascade Travelling Wave Method

Regularization Method to the Parameter Identification of Interfacial Heat Transfer coefficient and Properties during Casting Solidification

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Journal of Shanghai Jiaotong university(Science) 2007年第4期12卷 511-516页

作者：隋大山崔振山 National Die & Mould CAD Eng.Research Center Shanghai Jiaotong Univ.

The accurate material physical properties, initial and boundary conditions are indispensable to the numerical simulation in the casting process, and they are related to the simulation accuracy directly. The inverse heat conduction method can be used to identify the mentioned above parameters based on the temperature measurement data. This paper presented a new inverse method according to Tikhonov regularization theory. A regularization functional was established and the regularization parameter was deduced, the Newton-Raphson iteration method was used to solve the equations. One detailed case was solved to identify the thermal conductivity and specific heat of sand mold and interfacial heat transfer coefficient (IHTC) at the meantime. This indicates that the regularization method is very efficient in decreasing the sensitivity to the temperature measurement data, overcoming the ill-posedness of the inverse heat conduction problem (IHCP) and improving the stability and accuracy of the results. As a general inverse method, it can be used to identify not only the material physical properties but also the initial and boundary conditions' parameters.

关键词： casting inverse heat conduction problem parameter identification regularization method interfacial heat transfer coefficient

Observation and Numerical Experiments for Drag coefficient Under Typhoon Wind Forcing

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Journal of Ocean University of China 2017年第1期16卷 35-41页

作者： CAO Huiqiu ZHOU Liangming LI Shuiqing WANG Zhifeng College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100P.R.China Institute of Oceanology Chinese Academy of SciencesQingdao 266100P.R.China College of Engineering Ocean University of ChinaQingdao 266100P.R.China

This paper presents a study on drag coefficients under typhoon wind forcing based on observations and numerical experiments. The friction velocity and wind speed are measured at a marine observation platform in the South China Sea. Three typhoons: SOULIK(2013), TRAMI(2013) and FITOW(2013) are observed at a buoy station in the northeast sea area of Pingtan Island. A new parameterization is formulated for the wind drag coefficient as a function of wind speed. It is found that the drag coefficient(Cd) increases linearly with the slope of 0.083′10^(-3) for wind speed less than 24 m s^(-1). To investigate the drag coefficient under higher wind conditions, three numerical experiments are implemented for these three typhoons using SWAN wave model. The wind input data are objective reanalysis datasets, which are assimilated with many sources and provided every six hours with the resolution of 0.125?×0.125?. The numerical simulation results show a good agreement with wave observation data under typhoon wind forcing. The results indicate that the drag coefficient levels off with the linear slope of 0.012′10^(-3) for higher wind speeds(less than 34 m s^(-1)) and the new parameterization improvese the simulation accuracy compared with the Wu(1982) default used in SWAN.

关键词： drag coefficient SWAN high wind speed typhoon

Method for acquiring part load distribution coefficient of air conditioning system

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Journal of Central South University 2009年第S1期16卷 95-99页

作者：丁勇李百战谭颖 Key Laboratory of Three Gorges Reservoir Region's Eco-Environment Ministry of EducationChongqing University Faculty of Urban Construction and Environmental Engineering Chongqing University

This paper presents a method to acquire runtime distribution ratio of building air conditioning system under part load condition (part load coefficient of system) through practical energy consumption data. By utilizing monthly energy consumption data of the entire year as the analysis object,this paper identifies data distribution,verifies distribution characteristics and analyzes distribution probability density for the issue of running time distribution ratio of air conditioning system in part load zones in the whole operation period,thus providing a basic calculation basis for an overall analysis of energy efficiency of air conditioning system. In view of the general survey of public building energy consumption carried by the government of Chongqing,this paper takes the governmental office building as an example,the part load ratio coefficient corresponding to practical running of air conditioning system of governmental office building in Chongqing is obtained by utilizing the above probability analysis and the solving method of probability density function. By utilizing the ratio coefficient obtained using this method,the part load coefficient with any running ratio of air conditioning system can be obtained according to the requirement of analysis,which can be used in any load ratio for analyzing running energy efficiency of air conditioning system.

关键词： air conditioning system monthly energy consumption probability density distribution part load coefficient of system

Correlation of MRI apparent diffusion coefficient of invasive breast cancer with tumor tissue growth and angiogenesis

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Journal of Hainan Medical University 2017年第16期23卷 134-137页

作者： Ze-Hong Fu Hong-Fang Xu Jun-Yan Wang Department of Radiology Wuhan No.6 Hospital Affiliated to Jianghan University in Hubei ProvinceWuhan CityHubei Province430015

Objective: To study the correlation of MRI apparent diffusion coefficient (ADC value) of invasive breast cancer with tumor tissue growth and angiogenesis. Methods: Patients with breast mass who were treated in Wuhan No. 6 Hospital between March 2014 and May 2017 were selected as the research subjects and divided into group A with invasive ductal carcinoma, group B with intraductal carcinoma and group C with benign lesion according to the biopsy results, magnetic resonance diffusion-weighted imaging was conducted to determine ADC values, and biopsy tissue was taken to determine the expression of proliferation genes and angiogenesis genes. Results: USP39, CyclinD1, VEGF, bFGF, Angplt-2, Angplt-3 and Angplt-4 protein expression levels in lesions of group A and group B were significantly higher than those of group C while ADC value as well as ALEX1 and Bax protein expression levels were significantly lower than those of group C;USP39, CyclinD1, VEGF, bFGF, Angplt-2, Angplt-3 and Angplt-4 protein expression levels in lesions of group A were significantly higher than those of group B while ADC value as well as ALEX1 and Bax protein expression levels was significantly lower than those of group B;USP39, CyclinD1, VEGF, bFGF, Angplt-2, Angplt-3 and Angplt-4 protein expression levels in invasive breast cancer tissue with high ADC value were significantly lower than those in invasive breast cancer tissue with low ADC value while ALEX1 and Bax protein expression levels were significantly higher than those in invasive breast cancer tissue with low ADC value. Conclusion: The decrease of ADC value of invasive breast cancer is closely related to cancer cell proliferation and angiogenesis.

关键词： Invasive breast cancer Magnetic resonance diffusion-weighted imaging Apparent diffusion coefficient Proliferation Angiogenesis

改进的BP网络模型在确定河流纵向离散系数中的应用

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水电能源科学 2010年第9期28卷 19-21页

作者：马海波崔广柏常文娟河海大学水文水资源与水利工程科学国家重点实验室江苏南京210098

针对当前河流纵向离散系数计算方法的缺陷,提出了一种利用改进的BP神经网络模型计算河流纵向离散系数的新方法。实例应用结果表明,该法增强了BP网络预测的精度和泛化能力,可简单、有效地预测河流纵向离散系数。

关键词：改进网络模型河流纵向离散系数 Dispersion coefficient Determination of Network Model Improved 网络预测应用结果神经网络模型计算计算方法泛化能力新方法增强缺陷精度

The Relation between the coefficient of Friction and Pressure Drop by Using the Different Reynolds Number in a Circular Tube

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Open Journal of Fluid Dynamics 2015年第2期5卷 99-105页

作者： Abdulmagid A. Khattabi Ahmed A. Hablous Mofied M. Elnemry Department of Mechanical Engineering Higher Institute of Marine Sciences Techniques and Fisheries Sabrata Libya Department of Mechanical Engineering Higher Institute of Industrial Technology Tripoli Libya College of Engineering Technology Janzor Libya

This study explains the relationship between friction coefficient and pressure change at a range of Reynolds (21,056 - 28,574) and (0 - 1.4) solid loading ratio of two-phase flow (gas-solid) inside a circular copper pipe by using laboratory apparatus and solving the equations mathematically. An experimentally relationship of friction coefficient and pressure change with Reynolds number and flow velocity obtained also the relationship between the Solid loading ratio with friction coefficient and pressure change has been done for a Limit range of Reynolds number. It was noticed that the increase in friction coefficient and pressure change for two-phase flow was occurred when solid loading ratio increased. Also the relationship between pressure change and Reynolds number was direct proportion while the relationship between friction coefficient and Reynolds Number was inversely related.

关键词： Two-Phase Flow Pressure Drop Reynolds Number Loading Ratio Friction coefficient