期刊文献+
任意字段
题名或关键词
题名
关键词
摘要
作者
第一作者
机构
刊名
分类号
参考文献
作者简介
基金资助
栏目信息
共找到639篇文章
< 1 2 … 32 >
每页显示 20 50 100
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
显示方式：
Understanding primary and secondary sources of ambient oxygenated volatile organic compounds in Shenzhen utilizing photochemical age-based parameterization method 认领 引用 被引量：22
1
作者 Bo Zhu Yu Han +5 位作者 Chuan Wang Xiaofeng Huang Shiyong Xia Yingbo Niu Zixuan Yin Lingyan He 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2019年第1期105-114,共10页
Oxygenated volatile organic compounds(OVOCs) are key intermediates in the atmospheric photooxidation process. To further study the primary and secondary sources of OVOCs,their ambient levels were monitored using a pro... Oxygenated volatile organic compounds(OVOCs) are key intermediates in the atmospheric photooxidation process. To further study the primary and secondary sources of OVOCs,their ambient levels were monitored using a proton-transfer reaction mass spectrometer(PTR-MS) at an urban site in the Pearl River Delta of China. Continuous monitoring campaigns were conducted in the spring, summer, fall, and winter of 2016. Among the six types of OVOC species, the mean concentrations of methanol were the highest in each season(up to 13–20 ppbv), followed by those of acetone, acetaldehyde and acetic acid(approximately 2–4 ppbv), while those of formic acid and methyl ethyl ketone(MEK) were the lowest(approximately 1–2 ppbv). As observed from a diurnal variation chart, the OVOCs observed in Shenzhen may have been affected by numerous factors such as their primary and secondary sources and photochemical consumption. The photochemical age-based parameterization method was used to apportion the sources of ambient OVOCs. Methanol had significant anthropogenic primary sources but negligible anthropogenic secondary sources during all of the seasons. Acetone, MEK and acetic acid were mostly attributed to anthropogenic primary sources during each season with smaller contributions from anthropogenic secondary sources. Acetaldehyde had similar contributions from both anthropogenic secondary and anthropogenic primary sources throughout the year.Meanwhile, anthropogenic primary sources contributed the most to formic acid. 展开更多
关键词 OVOCs PTR-MS Photochemical age-based parameterization method
暂未订购 下载PDF
Parameter identification of magnetic levitation system based on modulation function method 认领 引用
2
作者 Tingchen Du Xueling Fan Sheng Feng 《Control Theory and Technology》 EI CSCD 2025年第4期602-617,共16页
A novel parameter identification method for magnetic levitation bearing rotor systems is proposed,based on the modulation function method.The fundamental principle of the modulation function method for parameter ident... A novel parameter identification method for magnetic levitation bearing rotor systems is proposed,based on the modulation function method.The fundamental principle of the modulation function method for parameter identification is derived on the basis of the characteristics of the modulation function.The transformation of the differential equation model of a continuous system into a general algebraic equation model is effectively achieved,thereby avoiding the influence of errors introduced by the initial value and differential derivation of the system.Modulation function method parameter identification models have been established for single-degree-of-freedom and multi-degree-of-freedom magnetic levitation bearing rotor systems.The influence of different parameters of Hartley modulation function on the accuracy of system parameter identification has been investigated,thus providing a basis for the design of Hartley modulation function parameters.Simulation and experimental results demonstrate that the modulation function method can effectively identify system parameters despite the presence of system noise. 展开更多
关键词 Modulation function method Hartley modulation function Magnetic levitation system Parameter identification
Dimensional control of turbine blades via RSM-based process parameter optimization in investment casting 认领 引用
3
作者 Sheng-jie Ren Rui-yuan Zhang +4 位作者 Sheng Meng Hang-yu Li Wen-jing Wang Zhong-min Xiao Kun Bu 《China Foundry》 SCIE EI CAS CSCD 2026年第3期451-461,共11页
To address the dimensional accuracy challenges in investment casting of DD6 nickel-based superalloy hollow turbine blades,a multi-parameter collaborative optimization and deformation response prediction method based o... To address the dimensional accuracy challenges in investment casting of DD6 nickel-based superalloy hollow turbine blades,a multi-parameter collaborative optimization and deformation response prediction method based on response surface methodology was proposed.Using a Box-Behnken design,with pouring temperature,shell temperature,and withdrawal rate as key variables,deformation response data were obtained through numerical simulation,and a second-order model incorporating linear,interaction,and quadratic terms was established to characterize the nonlinear coupling effects of process parameters on dimensional deformation.The results indicate that withdrawal rate is the dominant factor influencing deformation,while shell temperature exhibits a pronounced“U”-shaped nonlinear trend.Significant interactions between process parameters are also observed.The constructed model demonstrates high predictive accuracy,with R2 of 0.978 and an RMSE of 0.0026 mm,and exhibits strong generalization capability,enabling the identification of optimal parameter combinations even beyond the simulated dataset.Compared with conventional orthogonal design methods,the maximum deformation of the optimized process was reduced from 0.2021 mm to 0.1905 mm,achieving an improvement of approximately 5.74%.This work provides a theoretical foundation and practical strategy for dimensional accuracy control and multi-parameter process optimization in the manufacturing of complex thin-walled castings. 展开更多
关键词 response surface method turbine blade process parameter optimization investment casting
暂未订购 下载PDF
Optimization Study on Operating Parameters of Rotary Gas-Gas Heat Exchanger in Low-and Medium-Temperature Denitrification System for Cement Kiln Flue Gas 认领 引用
4
作者 Kaiwen Cheng Yi Sun +2 位作者 Dong Wang Chen Zhu Fuping Qian 《Frontiers in Heat and Mass Transfer》 EI CAS 2026年第3期141-157,共17页
Rotary gas-gas heat exchangers(GGHs)are pivotal for waste heat recovery in low-and mediumtemperature denitrification systems of cement kilns.This study examines the performance of GGHs within such systems by coupling ... Rotary gas-gas heat exchangers(GGHs)are pivotal for waste heat recovery in low-and mediumtemperature denitrification systems of cement kilns.This study examines the performance of GGHs within such systems by coupling computational fluid dynamics(CFD)with the response surface method(RSM),introducing overall system performance(OSP)as the principal optimization criterion.The investigation systematically elucidates the effects of treated flue gas inlet temperature,inlet velocity,and rotor speed on GGH efficiency.Findings reveal that OSP increases with rotor speed but reaches a plateau beyond 1 rpm;it decreases with higher inlet velocity and increases with higher inlet temperature.Response surface analysis identifies treated flue gas inlet temperature as the most influential parameter,highlighting a synergistic effect between rotor speed and inlet temperature,alongside an antagonistic interaction between inlet temperature and inlet velocity.To ensure safe system operation,engineering constraints were incorporated into the optimization framework using a Box-Behnken design.The optimal operational parameters were determined as a treated flue gas inlet temperature of 250℃,inlet velocity of 8 m/s,and rotor speed of 1 rpm,yielding a maximum OSP of 107.74.The integrated CFD-RSM methodology and constraint-aware optimization strategy presented in this study offer a practical reference for enhancing the operational efficiency of industrial waste heat recovery systems,particularly in cement kiln SCR applications. 展开更多
关键词 Waste heat recovery of cement kiln rotary gas-gas heat exchanger response surface method operating parameter optimization
暂未订购 下载PDF
A body-fitted adaptive mesh and Helmholtz-type filter based parameterized level-set method for structural topology optimization 认领 引用 被引量：2
5
作者 Yijie Lu Xueying Chang +3 位作者 Zhengwei Zhang Hui Liu Yanguo Zhou Hao Li 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2025年第5期131-147,共17页
Parameterized level-set method(PLSM)has been proposed and developed for many years,and is renowned for its efficacy in ad-dressing topology optimization challenges associated with intricate boundaries and nucleation o... Parameterized level-set method(PLSM)has been proposed and developed for many years,and is renowned for its efficacy in ad-dressing topology optimization challenges associated with intricate boundaries and nucleation of new holes.However,most pertinent investigations in the field rely predominantly on fixed background mesh,which is never remeshed.Consequently,the mesh element partitioned by material interface during the optimization process necessitates approximation by using artificial interpolation models to obtain its element stiffness or other properties.This paper introduces a novel approach to topology op-timization by integrating the PLSM with body-fitted adaptive mesh and Helmholtz-type filter.Primarily,combining the PLSM with body-fitted adaptive mesh enables the regeneration of mesh based on the zero level-set interface.This not only precludes the direct traversal of the material interface through the mesh element during the topology optimization process,but also improves the accuracy of calculation.Additionally,the incorporation of a Helmholtz-type partial differential equation filter,relying solely on mesh information essential for finite element discretization,serves to regulate the topological complexity and the minimum feature size of the optimized structure.Leveraging these advantages,the topology optimization program demonstrates its versa-tility by successfully addressing various design problems,encompassing the minimum mean compliance problem and minimum energy dissipation problem.Ultimately,the result of numerical example indicates that the optimized structure exhibits a dis-tinct and smooth boundary,affirming the effective control over both topological complexity and the minimum feature size of the optimized structure. 展开更多
关键词 Topology optimization Parameterized level-set method Helmholtz-type filter Body-fitted adaptive mesh
暂未订购 下载PDF
A Hybrid Simulation-Experimental Method for Deriving Equivalent Dynamic Parameters of O-Ring Support Systems 认领 引用
6
作者 LIU Yi YE He +3 位作者 ZHANG Lingfeng LI Shujia CHEN Ge WANG Yongxing 《Journal of Donghua University(English Edition)》 CAS 2025年第4期425-434,共10页
The high-speed winding spindle employs a flexible support system incorporating rubber O-rings.By precisely configuring the structural parameters and the number of the O-rings,the spindle can stably surpass its critica... The high-speed winding spindle employs a flexible support system incorporating rubber O-rings.By precisely configuring the structural parameters and the number of the O-rings,the spindle can stably surpass its critical speed points and maintain operational stability across the entire working speed range.However,the support stiffness and damping of rubber O-rings exhibit significant nonlinear frequency dependence.Conventional experimental methods for deriving equivalent stiffness and damping,based on the principle of the forced non-resonance method,require fabricating custom setups for each O-ring specification and conducting vibration tests at varying frequencies,resulting in low efficiency and high costs.This study proposes a hybrid simulation-experimental method for dynamic parameter identification.Firstly,the frequency-dependent dynamic parameters of a specific O-ring support system are experimentally obtained.Subsequently,a corresponding parametric finite element model is established to simulate and solve the equivalent elastic modulus and equivalent stiffness-damping coefficient of this O-ring support system.Ultimately,after iterative simulation,the simulated and experimental results achieve a 99.7%agreement.The parametric finite element model developed herein can directly simulate and inversely estimate frequency-dependent dynamic parameters for O-rings of different specifications but identical elastic modulus. 展开更多
关键词 O-ring equivalent dynamic parameter forced non-resonance method inverse parameter estimation dynamic simulation
暂未订购 下载PDF
Similarity transformation-based modeling of the thermally-radiative tetra-hybrid Casson nanofluid flow over a nonlinear stretching sheet using the Clique polynomial collocation method 认领 引用
7
作者 U.L.MANIKANTA K.J.GOWTHAM +1 位作者 B.J.GIREESHA P.VENKATESH 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2026年第1期185-202,共18页
The flow of a tetra-hybrid Casson nanofluid(Al2O3-CuO-TiO2-Ag/H2O)over a nonlinear stretching sheet is investigated.The Buongiorno model is used to account for thermophoresis and Brownian motion,while ther... The flow of a tetra-hybrid Casson nanofluid(Al2O3-CuO-TiO2-Ag/H2O)over a nonlinear stretching sheet is investigated.The Buongiorno model is used to account for thermophoresis and Brownian motion,while thermal radiation is incorporated to examine its influence on the thermal boundary layer.The governing partial differential equations(PDEs)are reduced to a system of nonlinear ordinary differential equations(ODEs)with fully non-dimensional similarity transformations involving all independent variables.To solve the obtained highly nonlinear system of differential equations,a novel Clique polynomial collocation method is applied.The analysis focuses on the effects of the Casson parameter,power index,radiation parameter,thermophoresis parameter,Brownian motion parameter,and Lewis number.The key findings show that thermal radiation intensifies the thermal boundary layer,the Casson parameter reduces the velocity,and the Lewis number suppresses the concentration with direct relevance to polymer processing,coating flows,electronic cooling,and biomedical applications. 展开更多
关键词 similarity transformation nonlinear stretching sheet Casson parameter tetra-hybrid nanofluid thermal radiation Clique polynomial collocation method
暂未订购 下载PDF
Modeling of Penicillin Fermentation Process Based on a Multi-stage LHS-EPRCC Method 认领 引用
8
作者 Li Quan Su Peng +5 位作者 Wan Haiying Zhang Chengxi He Zhijian Ni Yiyang Zhao Zhonggai Liu Fei 《系统仿真学报》 EI CAS CSCD 北大核心 2026年第5期1255-1276,共22页
This paper focused on the modeling of microbial fermentation processes under varying production environments and proposed a novel approach.Considering that the dynamic characteristics of microorganisms differ across g... This paper focused on the modeling of microbial fermentation processes under varying production environments and proposed a novel approach.Considering that the dynamic characteristics of microorganisms differ across growth stages,we introduced the concept of multi-stage sensitivity analysis,in which each stage was investigated separately.The fuzzy C-means(FCM)algorithm was employed to cluster process data under nominal conditions,thereby dividing the penicillin fermentation process into distinct growth stages.Based on this division,the Latin hypercube sampling with partial rank correlation coefficient(LHS-EPRCC)method was applied to conduct sensitivity analysis for each stage,identifying an importance parameter set(IPS)that corresponds to the stage-specific growth characteristics.Re-estimation and correction of the IPS were then performed to enhance the predictive accuracy of the model.In a penicillin fermentation process deviating from nominal conditions,the proposed method was applied for model correction.Simulation results demonstrate that the corrected model aligns well with the actual process,thereby verifying the effectiveness of the proposed multistage sensitivity analysis approach in addressing complex fermentation processes and environmental uncertainties. 展开更多
关键词 penicillin fermentation process FCM algorithm LHS-EPRCC method importance parameter set model correction
暂未订购 下载PDF
Simulation of proppant transport in complex fracture networks based on the multiphase particle-in-cell method 认领 引用
9
作者 WANG Qiang YANG Yu +7 位作者 ZHAO Jinzhou ZHUANG Wenlong XU Yanguang HOU Jie ZHANG Yixuan HU Yongquan WANG Yufeng LI Xiaowei 《Petroleum Exploration and Development》 SCIE 2026年第1期249-260,共12页
A three-dimensional multiphase particle-in-cell(MP-PIC)method was adopted to establish a liquid-solid two-phase flow model accounting for complex fracture networks.The model was validated using physical experimental d... A three-dimensional multiphase particle-in-cell(MP-PIC)method was adopted to establish a liquid-solid two-phase flow model accounting for complex fracture networks.The model was validated using physical experimental data.On this basis,the main factors influencing proppant transport in fracture network were analyzed.The study shows that proppant transport in fracture network can be divided into three stages:initial filling,dominant channel formation and fracture network extension.These correspond to three transport patterns:patch-like accumulation near the wellbore,preferential placement along main fractures,and improved the coverage of planar placement as fluid flows into branch fractures.Higher proppant density,lower fracturing fluid viscosity,lower injection rate,and larger proppant grain size result in shorter proppant transport distance and smaller planar placement coefficient.The use of low-density,small-diameter proppant combined with high-viscosity fracturing fluid and appropriately increased injection rate can effectively enlarge the stimulated volume.A smaller angle between the main fracture and branch fractures leads to longer proppant banks,broader coverage,more uniform distribution,and better stimulation performance in branch fractures.In contrast,a larger angle increases the likelihood of proppant accumulation near the branch fracture entrance and reduces the planar placement coefficient. 展开更多
关键词 multiphase particle-in-cell method complex fracture network liquid-solid two-phase flow proppant transport fracturing operation parameter influencing factor
暂未订购 下载PDF
ASYMPTOTIC BEHAVIOR AND PARAMETER ESTIMATION OF A WEIGHTED SELF-REPELLING DIFFUSION DRIVEN BYα-STABLE MOTION 认领 引用
10
作者 Yinmeng CHEN Xiaoyu XIA Litan YAN 《Acta Mathematica Scientia》 SCIE CSCD 2026年第4期1945-1956,共12页
Let Mα={Mtα,t≥0}be anα-stable motion on R with 00.Whenθ>0 and 1/β+1<a<2,we show that the convergence Jtα(0,θ,β):=(1+t)βe-G(t)Xtα→ξ∞α+ν/θand Jtα(n,θ,β... Let Mα={Mtα,t≥0}be anα-stable motion on R with 00.Whenθ>0 and 1/β+1<a<2,we show that the convergence Jtα(0,θ,β):=(1+t)βe-G(t)Xtα→ξ∞α+ν/θand Jtα(n,θ,β):=θ(1+t)β+1(Jtα(n-1,θ,β)λn-1(ξ∞α+ν/θ))→λn(t→∞)hold almost surely for all n≥1,where G(t)=∫0tθ(1+s)βds,ξ∞α=∫0∞(1+s)βe-G(s)d Msαandλn=β(2β+1)...(nβ+n-1).Using least squares method,we study estimators ofθandνand give their asymptotic distributions. 展开更多
关键词 asymptotic behavior least squares method stable motion weighted self repelling diffusion parameter estimation large time behaviors
暂未订购 下载PDF
A strength reduction method based on double reduction parameters and its application 认领 引用 被引量：59
11
作者 袁维 白冰 +1 位作者 李小春 汪海滨 《Journal of Central South University》 SCIE EI CAS 2013年第9期2555-2562,共8页
In the traditional strength reduction method,the cohesion and the friction angle adopt the same reduction parameter,resulting in equivalent proportional reduction.This method does not consider the different effects of... In the traditional strength reduction method,the cohesion and the friction angle adopt the same reduction parameter,resulting in equivalent proportional reduction.This method does not consider the different effects of the cohesion and friction angle on the stability of the same slope and is defective to some extent.Regarding this defect,a strength reduction method based on double reduction parameters,which adopts different reduction parameters,is proposed.The core of the double-parameter reduction method is the matching reduction principle of the slope with different angles.This principle is represented by the ratio of the reduction parameter of the cohesion to that of the friction angle,described as η.With the increase in the slopeangle,ηincreases; in particular,when the slope angle is 45°,tηis 1.0.Through the matching reduction principle,different safety margin factors can be calculated for the cohesion and friction angle.In combination with these two safety margin factors,a formula for calculating the overall safety factor of the slope is proposed,reflecting the different contributions of the cohesion and friction angle to the slope stability.Finally,it is shown that the strength reduction method based on double reduction parameters acquires a larger safety factor than the classic limit equilibrium method,but the calculation results are very close to those obtained by the limit equilibrium method. 展开更多
关键词 double reduction parameter strength reduction method matching reduction principle slope stability
暂未订购 下载PDF
Drilling-based measuring method for the c-φ parameter of rock and its field application 认领 引用 被引量：13
12
作者 Bei Jiang Fenglin Ma +5 位作者 Qi Wang Hongke Gao Dahu Zhai Yusong Deng Chuanjie Xu Liangdi Yao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第1期65-76,共12页
The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(R... The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters. 展开更多
关键词 Digital drilling Rock crushing zone c-u parameter Measurement method Field application
暂未订购 下载PDF
Study of probability integration method parameter inversion by the genetic algorithm 认领 引用 被引量：7
13
作者 Li Peixian Peng Di +1 位作者 Tan Zhixiang Deng Kazhong 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2017年第6期1073-1079,共7页
In order to obtain accurate probability integration method(PIM) parameters for surface movement of multi-panel mining, a genetic algorithm(GA) was used to optimize the parameters. As the measured surface movement is a... In order to obtain accurate probability integration method(PIM) parameters for surface movement of multi-panel mining, a genetic algorithm(GA) was used to optimize the parameters. As the measured surface movement is affected by more than one mining panel, traditional PIM parameter inversion model is difficult to ensure the reliability of the results due to the complexity of rock movement. With crossover,mutation and selection operators, GA can perform a global optimization search and has high computation efficiency. Compared with the pattern search algorithm, the fitness function can avoid falling into local minima traps. GA reduces the risk of local minima traps which improves the accuracy and reliability with the mutation mechanism. Application at Xuehu colliery shows that GA can be used to inverse the PIM parameters for multi-panel surface movement observation, and reliable results can be obtained. The research provides a new way for back-analysis of PIM parameters for mining subsidence under complex conditions. 展开更多
关键词 Probability integration method GA Mining subsidence Parameter inversion Multiobjective optimization
暂未订购 下载PDF
Physical Parameter Identification Method Based on Modal Analysis for Two-axis On-road Vehicles:Theory and Simulation 认领 引用 被引量：5
14
作者 ZHENG Minyi ZHANG Bangji +1 位作者 ZHANG Jie ZHANG Nong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第4期756-764,共9页
Physical parameters are very important for vehicle dynamic modeling and analysis.However,most of physical parameter identification methods are assuming some physical parameters of vehicle are known,and the other unkno... Physical parameters are very important for vehicle dynamic modeling and analysis.However,most of physical parameter identification methods are assuming some physical parameters of vehicle are known,and the other unknown parameters can be identified.In order to identify physical parameters of vehicle in the case that all physical parameters are unknown,a methodology based on the State Variable Method(SVM)for physical parameter identification of two-axis on-road vehicle is presented.The modal parameters of the vehicle are identified by the SVM,furthermore,the physical parameters of the vehicle are estimated by least squares method.In numerical simulations,physical parameters of Ford Granada are chosen as parameters of vehicle model,and half-sine bump function is chosen to simulate tire stimulated by impulse excitation.The first numerical simulation shows that the present method can identify all of the physical parameters and the largest absolute value of percentage error of the identified physical parameter is 0.205%;and the effect of the errors of additional mass,structural parameter and measurement noise are discussed in the following simulations,the results shows that when signal contains 30 d B noise,the largest absolute value of percentage error of the identification is 3.78%.These simulations verify that the presented method is effective and accurate for physical parameter identification of two-axis on-road vehicles.The proposed methodology can identify all physical parameters of 7-DOF vehicle model by using free-decay responses of vehicle without need to assume some physical parameters are known. 展开更多
关键词 Parameter identification free-decay response state variable method modal parameter physical parameter
暂未订购 下载PDF
Research on likelihood ratio evaluation method of fingerprint evidence based on parameter estimation method 认领 引用 被引量：6
15
作者 Kang Li Yishi Han Yaping Luo 《Forensic Sciences Research》 CSCD 2024年第1期66-83,共18页
Fingerprints with similar morphological characteristics but from different individuals can lead to errors in individual identification,especially when dealing with large databases containing millions of fingerprints.T... Fingerprints with similar morphological characteristics but from different individuals can lead to errors in individual identification,especially when dealing with large databases containing millions of fingerprints.To address this issue and enhance the accuracy of similar fingerprint identification,the use of the likelihood ratio(LR)model for quantitative evaluation of fingerprint evidence has emerged as an effective research method.In this study,the LR fingerprint evidence evaluation model was established by using mathematical statistical methods,such as parameter estimation and hypothesis testing.This involved various steps,including database construction,scoring,fitting,calculation,and visual evaluation.Under the same-source conditions,the optimal parameter methods selected by different number of minutiae are gamma and Weibull distribution,while normal,Weibull,and lognormal distributions were the fitting parameters selected for minutiae configurations.The fitting parameters selected by different number of minutiae under different-source conditions are lognormal distribution,and the parameter methods selected for different minutiae configurations include Weibull,gamma,and lognormal distributions.The results of the LR model showed increased accuracy as the number of minutiae increased,indicating strong discriminative and corrective power.However,the accuracy of the LR evaluation based on different configurations was comparatively lower.In addition,the LR models with different numbers of minutiae outperformed those with different minutiae configurations.Our study shows that the use of LR models based on parametric methods is favoured in reducing the risk of fingerprint evidence misidentification,improving the quantitative assessment methods of fingerprint evidence,and promoting fingerprint identification from experience to science. 展开更多
关键词 fingerprints likelihood ratio parameter estimation hypothesis testing quantitative method evidence evaluation
暂未订购 下载PDF
Differences in parameter estimates derived from various methods for the ORYZA(v3) Model 认领 引用 被引量：2
16
作者 TAN Jun-wei DUAN Qing-yun +1 位作者 GONG Wei DI Zhen-hua 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2022年第2期375-388,共14页
Parameter estimation is always a difficult issue for crop model users, and inaccurate parameter values will result in deceptive model predictions. Parameter values may vary with different inversion methods due to equi... Parameter estimation is always a difficult issue for crop model users, and inaccurate parameter values will result in deceptive model predictions. Parameter values may vary with different inversion methods due to equifinality and differences in the estimating processes. Therefore, it is of great importance to evaluate the factors which may influence parameter estimates and to make a comparison of the current widely-used methods. In this study, three popular frequentist methods(SCE-UA, GA and PEST) and two Bayesian-based methods(GLUE and MCMC-AM) were applied to estimate nine cultivar parameters using the ORYZA(v3) Model. The results showed that there were substantial differences between the parameter estimates derived by the different methods, and they had strong effects on model predictions. The parameter estimates given by the frequentist methods were obviously sensitive to initial values, and the extent of the sensitivity varied with algorithms and objective functions. Among the frequentist methods, the SCE-UA was recommended due to the balance between stable convergence and high efficiency. All the parameter estimates remarkably improved the goodness of model-fit, and the parameter estimates derived from the Bayesian-based methods had relatively worse performance compared to the frequentist methods. In particular, the parameter estimates with the highest probability density of posterior distributions derived from the MCMC-AM method(MCMC_Pmax) led to results equivalent to those derived from the frequentist methods, and even better in some situations. Additionally, model accuracy was greatly influenced by the values of phenology parameters in validation. 展开更多
关键词 parameter estimation frequentist method Bayesian method crop model calibration
暂未订购 下载PDF
Discussion of Muskingum method parameter X 认领 引用 被引量：4
17
作者 Rui Xiaofang Liu Fanggui Yu Mei 《Water Science and Engineering》 CAS 2008年第3期16-23,共8页
The parameter X of the Muskingum method is a physical parameter that reflects the flood peak attenuation and hydrograph shape flattening of a diffusion wave in motion. In this paper, the historic process that hydrolog... The parameter X of the Muskingum method is a physical parameter that reflects the flood peak attenuation and hydrograph shape flattening of a diffusion wave in motion. In this paper, the historic process that hydrologists have undergone to find a physical explanation of this parameter is briefly discussed. Based on the fact that the Muskingum method is the second-order accuracy difference solution to the diffusion wave equation, its numerical stability condition is analyzed, and a conclusion is drawn： X ≤ 0.5 is the uniform condition satisfying the demands for its physical meaning and numerical stability. It is also pointed out that the methods that regard the sum of squares of differences between the calculated and observed discharges or stages as the objective function and the routing coefficients C0, C1 and C2 of the Muskingum method as the optimization parameters cannot guarantee the physical meaning of X. 展开更多
关键词 Muskingum method parameter X physical meaning numerical analysis stability condition parameter calibration
暂未订购 下载PDF
Modal Parameter Identification Method of Jacket Platform Structure Based on AFDD and Optimized FBFFT 认领 引用 被引量：2
18
作者 LENG Jian-cheng MA Jin-yong +2 位作者 FAN Zong-heng QIAN Wan-dong FENG Hui-yu 《China Ocean Engineering》 SCIE EI CSCD 2023年第3期393-407,共15页
Offshore platforms are susceptible to structural damage due to prolonged exposure to random loads,such as wind,waves,and currents.This is particularly true for platforms that have been in service for an extended perio... Offshore platforms are susceptible to structural damage due to prolonged exposure to random loads,such as wind,waves,and currents.This is particularly true for platforms that have been in service for an extended period.Identifying the modal parameters of offshore platforms is crucial for damage diagno sis,as it serves as a prerequisite and foundation for the process.Therefore,it holds great significance to prioritize the identification of these parameters.Aiming at the shortcomings of the traditional Fast Bayesian Fast Fourier Transform(FBFFT) method,this paper proposes a modal parameter identification method based on Automatic Frequency Domain Decomposition(AFDD) and optimized FBFFT.By introducing the AFDD method and Powell optimization algorithm,this method can automatically identify the initial value of natural frequency and solve the objective function efficiently and simply.In order to verify the feasibility and effectiveness of the proposed method,it is used to identify the modal parameters of the IASC-ASCE benchmark model and the j acket platform structure model,and the Most Probable Value(MPV) of the modal parameters and their respective posterior uncertainties are successfully identified.The identification results of the IASC-ASCE benc hmark model are compared with the identification re sults of the MODE-ID method,which verifies the effectivene ss and accuracy of the proposed method for identifying modal parameters.It provides a simple and feasible method for quantifying the influence of uncertain factors such as environmental parameters on the identification results,and also provide s a reference for modal parameter identification of other large structures. 展开更多
关键词 jacket platform uncertain modal parameter identification FBFFT method environmental excitation AFDD method Powell optimization
暂未订购 下载PDF
Investigation on charge parameters of underwater contact explosion based on axisymmetric SPH method 认领 引用 被引量：9
19
作者 明付仁 孙鹏楠 张阿漫 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2014年第4期453-468,共16页
This paper investigates the effects of charge parameters of the underwater contact explosion based on the axisymmetric smoothed particle hydrodynamics （SPH） method. The dynamic boundary particle is proposed to impro... This paper investigates the effects of charge parameters of the underwater contact explosion based on the axisymmetric smoothed particle hydrodynamics （SPH） method. The dynamic boundary particle is proposed to improve the pressure fluctuation and numerical accuracy near the symmetric axis. An in-depth study is carried out over the influence of charge shapes and detonation modes on the near-field loads in terms of the peak pressure and impulse of shock waves. For different charge shapes, the cylindrical charge with different length-diameter ratios may cause strong directivity of peak pressure and impulse in the near field. Compared with spherical charge, the peak pressure of cylindrical charge may be either weakened or enhanced in different directions. Within a certain range, the greater the length-diameter ratio is, the more obvious the effect will be. The weakened ratio near the detonation end may reach 25% approximately, while the enhanced ratio may reach around 20% in the opposite direction. However, the impulse in different directions seems to be uniform. For different detonation modes, compared with point-source explosion, the peak pressure of plane-source explosion is enhanced by about 5%. Besides, the impulse of plane-source explosion is enhanced by around 5% near the detonation end, but close to those of the point-source explosion in other directions. Based on the material constitutive relation in the axisymmetric coordinates, a simple case of underwater contact explosion is simulated to verify the above conclusions, showing that the charge parameters of underwater contact explosion should not be ignored. 展开更多
关键词 underwater contact explosion charge parameter axisymmetric smoothedparticle hydrodynamics （SPH） method symmetric axis
暂未订购 下载PDF
Numerical and experimental evaluation on methods for parameter identification of thermal response tests 认领 引用 被引量：3
20
作者 王沣浩 冯琛琛 +1 位作者 颜亮 王新轲 《Journal of Central South University》 SCIE EI CAS 2012年第3期816-823,共8页
Several parameter identification methods of thermal response test were evaluated through numerical and experimental study.A three-dimensional finite-volume numerical model was established under the assumption that the... Several parameter identification methods of thermal response test were evaluated through numerical and experimental study.A three-dimensional finite-volume numerical model was established under the assumption that the soil thermal conductivity had been known in the simulation of thermal response test.The thermal response curve was firstly obtained through numerical calculation.Then,the accuracy of the numerical model was verified with measured data obtained through a thermal response test.Based on the numerical and experimental thermal response curves,the thermal conductivity of the soil was calculated by different parameter identification methods.The calculated results were compared with the assumed value and then the accuracy of these methods was evaluated.Furthermore,the effects of test time,variable data quality,borehole radius,initial ground temperature,and heat injection rate were analyzed.The results show that the method based on cylinder-source model has a low precision and the identified thermal conductivity decreases with an increase in borehole radius.For parameter estimation,the measuring accuracy of the initial temperature of the deep ground soil has greater effect on identified thermal conductivity. 展开更多
关键词 ground source heat pump thermal response parameter identification method numerical simulation
暂未订购 下载PDF
已选0条
引用分析
参考文献
引证文献
 统计分析
检索结果
已选文献
上一页 1 2 … 32 下一页 到第 页
在线咨询 使用帮助 返回顶部 意见反馈