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土石坝沉降的非线性变弹性计算 被引量:4
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作者 王春宁 周琼 刘智杰 《湖南水利水电》 2002年第5期7-8,15,共3页
文章根据土体非线性双曲线应力应变关系的邓肯一张模型,提出了根据常规三轴试验即可计算土石坝沉降的一种实用简便的计算方法,并给出了实际工程算例。该方法不需要用有限元计算整个坝的应力和应变,只要分析坝的控制断面或危险断面即可,... 文章根据土体非线性双曲线应力应变关系的邓肯一张模型,提出了根据常规三轴试验即可计算土石坝沉降的一种实用简便的计算方法,并给出了实际工程算例。该方法不需要用有限元计算整个坝的应力和应变,只要分析坝的控制断面或危险断面即可,并且能够计算断面的不均匀沉降。 展开更多
关键词 土石坝 非线性 双曲线模型 变型模量 沉降计算
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钻孔弹模法应用实例及分析 被引量:3
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作者 祁增云 杨战 《西北水电》 2008年第6期58-59,共2页
结合工程实例阐述了钻孔弹模法的测试原理、技术要求等,并结合声波测试资料进行了综合分析。
关键词 钻孔弹模法 岩石变型试验 变型模量 声波
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Prediction of representative deformation modulus of longwall panel roof rock strata using Mamdani fuzzy system 被引量:7
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作者 Mohammad Rezaei Mostafa Asadizadeh +1 位作者 Abbas Majdi Mohammad Farouq Hossaini 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第1期23-30,共8页
Deformation modulus is the important parameter in stability analysis of tunnels, dams and mining struc- tures. In this paper, two predictive models including Mamdani fuzzy system (MFS) and multivariable regression a... Deformation modulus is the important parameter in stability analysis of tunnels, dams and mining struc- tures. In this paper, two predictive models including Mamdani fuzzy system (MFS) and multivariable regression analysis (MVRA) were developed to predict deformation modulus based on data obtained from dilatometer tests carried out in Bakhtiary dam site and additional data collected from longwall coal mines. Models inputs were considered to be rock quality designation, overburden height, weathering, unconfined compressive strength, bedding inclination to core axis, joint roughness coefficient and fill thickness. To control the models performance, calculating indices such as root mean square error (RMSE), variance account for (VAF) and determination coefficient (R^2) were used. The MFS results show the significant prediction accuracy along with high performance compared to MVRA results. Finally, the sensitivity analysis of MFS results shows that the most and the least effective parameters on deformation modulus are weatherin~ and overburden height, respectively. 展开更多
关键词 Deformation modulusDilatometer testMamdani fuzzy systemMultivariable regression analysis
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Development of a multivariate empirical model for predicting weak rock mass modulus 被引量:2
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作者 Kallu Raj R. Keffeler Evan R. +1 位作者 Watters Robert J. Agharazi Alireza 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第4期545-552,共8页
Estimating weak rock mass modulus has historically proven difficult although this mechanical property is an important input to many types of geotechnical analyses. An empirical database of weak rock mass modulus with ... Estimating weak rock mass modulus has historically proven difficult although this mechanical property is an important input to many types of geotechnical analyses. An empirical database of weak rock mass modulus with associated detailed geotechnical parameters was assembled from plate loading tests per- formed at underground mines in Nevada, the Bakhtiary Dam project, and Portugues Dam project. The database was used to assess the accuracy of published single-variate models and to develop a multivari- ate model for predicting in-situ weak rock mass modulus when limited geoteehnical data are available. Only two of the published models were adequate for predicting modulus of weak rock masses over lim- ited ranges of alteration intensities, and none of the models provided good estimates of modulus over a range of geotechnical properties. In light of this shortcoming, a multivariate model was developed from the weak rock mass modulus dataset, and the new model is exponential in form and has the following independent variables: (1) average block size or joint spacing, (2) field estimated rock strength, (3) dis- continuity roughness, and (4) discontinuity infilling hardness. The multivariate model provided better estimates of modulus for both hard-blocky rock masses and intensely-altered rock masses. 展开更多
关键词 In-situ modulus Weak rock mass Preliminary design Elastic deformation
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Differences in the predictive value of red cell distribution width for the mortality of patients with heart failure due to various heart diseases 被引量:10
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作者 Yang ZHANG Yan WANG +4 位作者 Jin-Suo KANG Jin-Xing YU Shi-Jie YIN Xiang-Feng CONG Xi CHEN 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2015年第6期647-654,共8页
Background Increased red blood cell distribution width (RDW) is associated with adverse outcomes in patients with heart failure (HF). The objective of this study was to compare the differences in the predictive va... Background Increased red blood cell distribution width (RDW) is associated with adverse outcomes in patients with heart failure (HF). The objective of this study was to compare the differences in the predictive value of RDW in patients with HF due to different causes. Methods We retrospectively investigated 1,021 HF patients from October 2009 to December 2011 at Fuwai Hospital (Beijing, China). HF in these patients was caused by three diseases; coronary heart disease (CHD), dilated cardiomyopathy (DCM) and valvular heart disease (VHD). Patients were followed-up for 21 ~ 9 months. Results The RDW, mortality and survival duration were significantly different among the three groups. Kaplan-Meier analysis showed that the cumulative survival decreased significantly with increased RDW in patients with HF caused by CHD and DCM, but not in those with HF patients caused by VHD. In a multivariable model, RDW was identified as an independent predictor for the mortality of HF patients with CHD (P 〈 0.001, HR 1.315, 95% CI 1.122-1.543). The group with higher N-terminal pro-brain natriuretic peptide (NT-proBNP) and higher RDW than median had the lowest cumulative survival in patients with HF due to CHD, but not in patients with HF due to DCM. Conclusions RDW is a prognostic indicator for patients with HF caused by CHD and DCM; thus, RDW adds important information to NT-proBNP in CHD caused HF patients. 展开更多
关键词 Coronary heart disease Dilated cardiomyopathy Heart failure Red blood cell distribution width Valvular heart disease
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Strong Consistency of Estimators of a Semiparametric Regression Model under Fixed Design
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作者 TIAN Ping XUE Liu-gen 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2006年第2期202-209,共8页
In this paper, we consider the following semipaxametric regression model under fixed design: yi = xi′β+g(xi)+ei. The estimators of β, g(·) and σ^2 axe obtained by using the least squares and usual nonp... In this paper, we consider the following semipaxametric regression model under fixed design: yi = xi′β+g(xi)+ei. The estimators of β, g(·) and σ^2 axe obtained by using the least squares and usual nonparametric weight function method and their strong consistency is proved under the suitable conditions. 展开更多
关键词 semiparametric regression model least square estimation weight function strong consistency
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Probability modeling for robustness of multivariate LQG designing based on ship lateral motion
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作者 ZHAO Xi-ren PENG Xiu-yan YIN Zhong-feng 《Journal of Marine Science and Application》 2005年第4期18-22,共5页
The robustness of LQG designing for latitudinal movement of ship is mainly discussed, when its hydrodynamic parameters fluctuate around criterion value at random on the proportional distributing. When a given ship sta... The robustness of LQG designing for latitudinal movement of ship is mainly discussed, when its hydrodynamic parameters fluctuate around criterion value at random on the proportional distributing. When a given ship state at the speed of 18 kn and the course of 45° under Rank 5 state of sea, and the hydrodynamic parameters of the ship fluctuate at random on the proportional distributing with a range of ± 10% , ± 20% , ± 30% , the robustness of muhivariate LQG designing for ship is analyzed with applying the probability modeling of relative controlling effect, The result of simulating shows that when the hydrodynamic parameters of ship fluctuates the relative controlling effect of the LQG designing submit to normal distribution and the mean value of relative controlling effect has no remarkable changes comparing to that without perturbation of hydrodynamic parameter, 展开更多
关键词 hydrodynamic parameters PERTURBATION LQG designing statislic modeling
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Substantial study on the occupation development of gender equality
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作者 Zhang Xiaoyan 《International Journal of Mining Science and Technology》 SCIE EI 2012年第5期625-628,共4页
Men and women participate in many social activities through professional roles.The main content of this study is the occupation development gender equality,which is a recessive change of quantity.Therefore,we cannot c... Men and women participate in many social activities through professional roles.The main content of this study is the occupation development gender equality,which is a recessive change of quantity.Therefore,we cannot concretely measure it to some extent,but through the structure square distance model and employees' feeling about the process,we can reflect its difference.The results of studying the feelings of male and female employees show that the gender equality is a problem,and there is a difference for men and women in career development. 展开更多
关键词 Occupation development Equality Substantial evidence research
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Limiting stand density and basal area projection models for even-aged Tecomella undulata plantations in a hot arid region of India
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作者 Vindhya Prasad Tewari 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第1期13-18,I0001,共7页
This paper presents equations for estimating limiting stand density for Z undulata plantations grown in hot desert areas of Raj asthan State in India. Five different stand level basal area projection models, belonging... This paper presents equations for estimating limiting stand density for Z undulata plantations grown in hot desert areas of Raj asthan State in India. Five different stand level basal area projection models, belonging to the path invariant algebraic difference form of a non-linear growth function, were also tested and compared. These models can be used to predict future basal area as a function of stand variables like dominant height and stem number per hectare and are necessary for reviewing different silvicultural treatment options. Data from 22 sample plots were used for modelling. An all possible growth intervals data structure was used. Both, qualitative and quantitative criteria were used to compare alternative models. The Akaike's information criteria differ- ence statistic was used to analyze the predictive ability of the models. Results show that the model proposed by Hui and Gadow performed best and hence this model is recommended for use in predicting basal area development in 12 undulata plantations in the study area. The data used were not from thinned stands, and hence the models may be less accurate when used for predictions when natural mortality is very significant. 展开更多
关键词 model evaluation path invariant algebraic difference form growth function potential density qualitative and quantitative criteria RAJASTHAN
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