检索结果-南通市图书馆

维普期刊数据库

parameter sensitivity and inversion analysis of a concrete faced rock-fill dam based on HS-BPNN algorithm

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2016年第9期59卷 1442-1451页

作者： SUN PengMing[[ BAO TengFei[[ GU ChongShi[[ JIANG Ming WANG Tian[[ SHI ZhongWen[[ College of Water-conservancy and Hydropower Hohai University Nanjing 210098 China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety Hohai University Nanjing 210098 China Hydrochina Huadong Engineering Corporation Hangzhou 310014 China

Considering the complex nonlinear relationship between the material parameters of a concrete faced rock-fill dam(CFRD) and its displacements, the harmony search(HS) algorithm is used to optimize the back propagation neural network(BPNN), and the HS-BPNN algorithm is formed and applied for the inversion analysis of the parameters of rock-fill materials. The sensitivity of the parameters in the Duncan and Chang's E-B model is analyzed using the orthogonal test design. The case study shows that the parameters φ0, K, Rf, and Kb are sensitive to the deformation of the rock-fill dam and the inversion analysis for these parameters is performed by the HS-BPNN algorithm. Compared with the traditional BPNN, the HS-BPNN algorithm exhibits the advantages of high convergence precision, fast convergence rate, and strong stability.

关键词： parameter sensitivity analysis harmony search algorithm back propagation neural network parameter inversion concrete faced rock-fill dam

维普期刊数据库

DTM2013 model parameter inversion and correlation analysis between its accuracy

在线全文

学校读者我要写书评

暂无评论

DTM2013 model parameter inversion and correlation analysis b...

第十一届中国卫星导航年会

作者： Wenhui Cui Wei Qu Haiyue Li Ning Chen Nan Ye Zhenyu Sun State Key Laboratory of Astronautic Dynamics Aerospace Engineering University Xi’an Satellite Control Center

The framework and the amendment terms of DTM2013 atmospheric model are derived based on the historical DTM series model algorithms. The Legendre polynomial coefficients are derived based on the high-o

关键词： DTM2013 atmospheric model parameter inversion MSIS00 atmospheric model GOCE

Fracture network types revealed by well test curves for shale reservoirs in the Sichuan Basin,China

在线全文

cnki会议

学校读者我要写书评

暂无评论

Energy Geoscience 2024年第1期5卷 264-274页

作者： Yanyan Wang Hua Liu Xiaohu Hu Cheng Dai Sidong Fang State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development Petroleum Exploration and Development Research InstituteSinopecBeijing100083China

Pressure buildup testing can be used to analyze fracture network characteristics and conduct quantitative interpretation of relevant parameters for shale gas wells,thus providing bases for assessing the well productivity and formulating proper development *** study establishes a new well test interpretation model for fractured horizontal wells based on seepage mechanisms of shale reservoirs and proposes a method for identifying fracturing patterns based on the characteristic slopes of pressure buildup curves and curve combination *** pressure buildup curve patterns are identified to represent three types of shale reservoirs in the Sichuan Basin,namely the moderately deep shale reservoirs with high pressure,deep shale reservoirs with ultra-high pressure,and moderately deep shale reservoirs with normal *** on this,the relationship between the typical pressure buildup curve patterns and the fracture network types are put *** effects of three types of shale gas reservoir are compared and *** results show that typical flow patterns of shale reservoirs include bilinear flow in primary and secondary fractures,linear flow in secondary fractures,bilinear flow in secondary fractures and matrix,and linear flow in *** fracture network characteristics can be determined using the characteristic slopes of pressure buildup curves and curve *** linear flow in early secondary fractures is increasingly distinct with an increase in primary fracture ***,the bilinear flow in secondary fractures and matrix and the subsequent linear flow in the matrix occur as the propping and density of secondary fractures *** increase in the burial depth,in-situ stress,and stress difference corresponds to a decrease in the propping of primary fractures that expand along different directions in the shale gas wells in the Sichuan *** pressure buildup curve patterns exist in the Sichuan Basin and it

关键词： Shale gas Fractured horizontal well Well testing interpretation Flow pattern characterization parameter inversion Fracture network characteristics Sichuan basin

Wear monitoring method of water-lubricated polymer thrust bearing based on ultrasonic reflection coefficient amplitude spectrum

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2023年第5期11卷 685-703页

作者： Changxiong NING Fei HU Wu OUYANG Xinpin YAN Dongling XU School of Naval Architecture Ocean and Energy Power EngineeringWuhan University of TechnologyWuhan 430063China School of Transportation and Logistics Engineering Wuhan University of TechnologyWuhan 430063China Reliability Engineering Institute National Engineering Research Center for Water Transport SafetyWuhan 430063China Alliance Manchester Business School The University of ManchesterManchester M156PBUK

The water-lubricated thrust bearings of the marine rim-driven thruster(RDT)are usually composed of polymer composites,which are prone to serious wear under harsh working *** is an excellent non-destructive monitoring technology,but polymer materials are characterized by viscoelasticity,heterogeneity,and large acoustic attenuation,making it challenging to extract ultrasonic echo ***,this paper proposes a wear monitoring method based on the amplitude spectrum of the ultrasonic reflection *** effects of bearing parameters,objective function,and algorithm parameters on the identification results are simulated and *** the correlation coefficient and root mean square error as the matching parameters,the thickness,sound velocity,density,and attenuation factor of the bearing are inversed simultaneously by utilizing the differential evolution algorithm(DEA),and the wear measurement system is *** order to verify the identification accuracy of this method,an accelerated wear test under heavy load was executed on a multi-functional vertical water lubrication test rig with poly-ether-etherketone(PEEK)fixed pad and stainless-steel thrust collar as the *** thickness of pad was measured using the high-precision spiral micrometer and ultrasonic testing system,***,the results demonstrate that the thickness identification error of this method is approximately 1%,and in-situ monitoring ability will be realized in the future,which is of great significance to the life prediction of bearings.

关键词： water-lubricated polymer thrust bearings wear monitoring ultrasonic reflection coefficient amplitude spectrum parameter inversion differential evolution

Influence of correlation scale errors on aquifer hydraulic conductivity inversion precision

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Water Science and Engineering 2020年第3期13卷 243-252页

作者： Yun-xiao Mu Lei Zhu Tong-qing Shen Meng Zhang Yuan-yuan Zha School of Civil Engineering and Water Conservancy Ningxia UniversityYinchuan 750021China Engineering Research Center for Efficient Utilization of Modern Agricultural Water Resources in Arid Regions Ministry of EducationYinchuan 750021China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China

In order to investigate the influence of correlation scale error on the inversion precision of the hydraulic conductivity of the aquifer,the successive linear estimator(SLE)was used to invert the hydraulic conductivity field of a heterogeneous aquifer based on synthetic *** increasing the numbers of observation wells and pumping tests,we analyzed the difference between the estimated and true values of hydraulic conductivity with different correlation scale *** relationships between the observation well number and the error in inversion results,and between the pumping test number and the error in inversion results were *** results show that,if the amount of observed head data is insufficient,there will be errors in inversion results with changing correlation *** to the existence of correlation scale error,the improvement of inversion precision gradually slows down with the increase of the amount of observed head data,which indicates that too much observed head data causes data ***,for the synthetic experiments described in this paper,the observation well number should be less than 41,the pumping test number should be less than 17,and a more suitable method should be selected according to the precision requirements of specific situations in practical engineering.

关键词： Hydraulic conductivity parameter inversion Successive linear estimator Correlation scale error Observation well number Pumping test number

维普期刊数据库

在线全文

学校读者我要写书评

暂无评论

非对称分数阶对流弥散的数值模拟及参数反演

高等学校计算数学学报 2013年第4期35卷 309-326页

作者：李新洁李功胜贾现正山东理工大学理学院应用数学所

1引言溶质在多孔介质中的运移一般以对流与机械弥散为主,基于Fick扩散定律的对流弥散方程(ADE)是描述溶质运移行为模式的经典模型[18,24].然而,上世纪90年代以来,有关研究[1,2,6,7,14,19,26]表明,用ADE模型来描述溶质的运移过程时,有时... 详细信息

1引言溶质在多孔介质中的运移一般以对流与机械弥散为主,基于Fick扩散定律的对流弥散方程(ADE)是描述溶质运移行为模式的经典模型[18,24].然而,上世纪90年代以来,有关研究[1,2,6,7,14,19,26]表明,用ADE模型来描述溶质的运移过程时,有时并不能很好的模拟穿透曲线的提前穿透或拖尾现象,同时也不能很好地解释溶质长距离传输中表现出的弥散系数的尺度效应等问题.事实上,ADE模型揭示了溶质运移的瞬时扩散性与对称

关键词： fractional advection-dispersion equation Grǖnwald-Letnikov derivative skewness parameter finite difference scheme parameter inversion numerical simulation

Research on inversion of Soil Water Dynamic parameters by Field Soil Moisture Content

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research on Inversion of Soil Water Dynamic Parameters by Fi...

2011 International Conference on New Technology of Agricultural Engineering(ICAE 2011)

作者： Wang Yang-ren Hydraulic Engineering Department Tianjin agricultural university Tianjin China Zhou Qing-yun Hydraulic Engineering Department Tianjin agricultural university Tianjin China Li Yan Hydraulic Engineering Department Tianjin agricultural university Tianjin China Han Na-na Hydraulic Engineering Department Tianjin agricultural university Tianjin China Sun Shu-hong Hydraulic Engineering Department Tianjin agricultural university Tianjin China

The field soil moisture data under different vegetation and irrigation condition were accumulated by many irrigation *** soil water dynamic parameters were acquired or improved by the parameters inversion method and making good use of these *** was significance in monitoring and forecasting soil moisture and field water *** this paper,according to the measured soil moisture of winter wheat from regreening to harvest in 2009 on Tianjin agricultural university agricultural water cycle experimental base,the parameter inversion model was established based on the objective function is the minimum of the relative error square sum between the simulated and measured value of the soil moisture content and the constraint is the diversification range of the water movement parameters acquired from the *** water transport parameters of soil characteristic in experimental site are acquired by use of the interior point method and model *** results showed that the simulation accuracy of the field soil moisture dynamic is significantly improved by the parameter *** changed initial value and step scaling factor are in favor of improving parameter optimization results.

关键词： soil moisture parameter inversion optimization calculation unsaturated soil hydraulic conductivity winter wheat

parameters inversion of Nuclide Migration Based on Accelerating Genetic Algorithm

在线全文

cnki会议

学校读者我要写书评

暂无评论

Parameters Inversion of Nuclide Migration Based on Accelerat...

2011 International Symposium on Water Resource and Environmental Protection(ISWREP 2011)

作者： Yuan Cao Wenke Wang College of Environ mental Science and Engineering Chang’an University Xi’an China Yuan Cao Tieliang Wang Feng Han Fifth Laboratory Northwest Institute of Nuclear Technology Xi’an China

Aiming at the need for model parameters of numerical simulation of nuclide migration at a nuclear waste filed, making use of the observation data of nuclide concentration, taking important parameters like hydraulic conductivity and dispersity for inversion parameters, based on real-coded accelerating genetic algorithm, parameters inversion model of nuclide migration is put forward, algorithm routine is programmed, and values of key computational parameters are obtained. The simulation result accords with the observation result on the whole. A contrast with manual adjustment method and traditional genetic algorithm shows that this algorithm has advantages of overall convergence ability, fast convergence rate, high computational precision and quantitative ability for inversion effect. The algorithm has well feasibility and validity in application to numerical simulation of nuclide migration.

关键词： dispersity genetic algorithm hydraulic conductivity nuclide migration parameter inversion

AN IMPROVED METHOD OF STRUCTURAL DAMAGE DETECTION BASED ON FREQUENCY RESPONSE FUNCTION

在线全文

cnki会议

学校读者我要写书评

暂无评论

AN IMPROVED METHOD OF STRUCTURAL DAMAGE DETECTION BASED ON F...

第六届国际振动工程会议

作者： H.F. Yang* Y.J. Yan Z.Y. Wu (School of Mechanics Civil and Architecture Northwestern Polytechnical University XI’AN 710072)

This paper presents a improved method to measure the location and degree of structural damage based on frequency response *** method can refine dynamic model’s stiffness matrix by using a subset vectors from the full set of frequency response functions that are extracted from test data and calculated from analytical *** a result,frequency response functions obtained from the updated analytical model are coinciding with those *** location and degree of structural damage can be found through the *** method has definite physical meaning,avoid modal analysis, and can come into being the on-line monitor system. One numerical example checks the method’s validity and precision.

关键词： structural damage detection frequency response function parameter inversion