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EFFICIENT METHOD FOR MULTIDISCIPLINARY DESIGN OPTIMIZATION BY CONSIDERING UNCERTAINTY
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作者 贺谦 李元生 +2 位作者 敖良波 温志勋 岳珠峰 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2010年第3期213-218,共6页
A new reliability-based multidisciplinary design optimization (RBMDO) framework is proposed by combining the single-loop-based reliability analysis (SLBRA) method with multidisciplinary feasible (MDF) method. Th... A new reliability-based multidisciplinary design optimization (RBMDO) framework is proposed by combining the single-loop-based reliability analysis (SLBRA) method with multidisciplinary feasible (MDF) method. The Kriging approximate model with updating is introduced to reduce the computational cost of MDF caused by the complex structure. The computational efficiency is remarkably improved as the lack of iterative process during reliability analysis. Special attention is paid to a turbine blade design optimization by adopting the proposed method. Results show that the method is much more efficient than the commonly used double-loop based RBMDO method. It is feasible and efficient to apply the method to the engineering design. 展开更多
关键词 multidisciplinary design optimization multidisciplinary feasible method single loop method reliability analysis Kriging approximate model
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Feasibility of central loop TEM method for prospecting multilayer water-fi lled goaf 被引量:9
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作者 Yan Shu Xue Gou-Qiang +2 位作者 Qiu Wei-Zhong Li Hai Zhong Hua-Sen 《Applied Geophysics》 SCIE CSCD 2016年第4期587-597,736,共12页
With deep mining of coal mines, prospecting multilayer water-filled goaf has become a new content that results from geophysical exploration in coalfields. The central loop transient electromagnetic (TEM) method is f... With deep mining of coal mines, prospecting multilayer water-filled goaf has become a new content that results from geophysical exploration in coalfields. The central loop transient electromagnetic (TEM) method is favorable for prospecting conductive layers because of the coupling relationship between its field structure and formation. However, the shielding effect of conductive overburden would not only require a longer observation time when prospecting the same depth but also weaken the anomalous response of underlying layers. Through direct time domain numerical simulation and horizontal layered earth forward modeling, this paper estimates the length of observation time required to prospect the target, and the distinguishable criterion of multilayer water-filled goal is presented with observation error according to the effect of noise on observation data. The observed emf curves from Dazigou Coal Mine, Shanxi Province can distinguish multilayer water-filled goaf. In quantitative inversion interpretation of observed curves, using electric logging data as initial parameters restrains the equivalence caused by coal formation thin layers. The deduced three-layer and two-layer water-filled goals are confirmed by the drilling hole. The result suggests that when observation time is long enough and with the anomalous situation of underlying layers being greater than the observation error, the use of the central loop TEM method to orosoect a multilaver water-filled goaf is feasible. 展开更多
关键词 central loop TEM method prospecting multilayer water-filled goaf conductive shielding layer numerical and theoretical analysis length of observation time observation error distinguishable criterion
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Calculation of all-time apparent resistivity of large loop transient electromagnetic method with very fast simulated annealing 被引量:4
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作者 李建慧 朱自强 +2 位作者 冯德山 肖建平 彭凌星 《Journal of Central South University》 SCIE EI CAS 2011年第4期1235-1239,共5页
In large loop transient electromagnetic method(TEM),the late time apparent resistivity formula cannot truly reflect the geoelectric model,thus it needs to define the all-time apparent resistivity with the position inf... In large loop transient electromagnetic method(TEM),the late time apparent resistivity formula cannot truly reflect the geoelectric model,thus it needs to define the all-time apparent resistivity with the position information of measuring point.Utilizing very fast simulated annealing(VFSA) to fit the theoretical electromagnetic force(EMF) and measured EMF could obtain the all-time apparent resistivity of the measuring points in rectangular transmitting loop.The selective cope of initial model of VFSA could be confirmed by taking the late time apparent resistivity of transient electromagnetic method as the prior information.For verifying the correctness,the all-time apparent resistivities of the geoelectric models were calculated by VFSA and dichotomy,respectively.The results indicate that the relative differences of apparent resistivities calculated by these two methods are within 3%.The change of measuring point position has little influence on the tracing pattern of all-time apparent resistivity.The first branch of the curve of all-time apparent resistivity is close to the resistivity of the first layer medium and the last branch is close to the resistivity of the last layer medium,which proves the correctness of the arithmetics proposed. 展开更多
关键词 very fast simulated annealing (VFSA) large loop transient electromagnetic method rectangular loop all-time apparent resistivity
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Hopping Parameter Expansion Technique in Noise Method for Disconnected Quark Loops
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作者 Jia-Liang Zhou Zhen Cheng +1 位作者 Guang-Yi Xiong Jian-Bo Zhang 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第4期16-19,共4页
We investigate the effectiveness of the hopping parameter expansion(HPE) combined with the Z(2) noise method in the calculation of the trace of the inverse of Wilson's Dirac operator and some other disconnected c... We investigate the effectiveness of the hopping parameter expansion(HPE) combined with the Z(2) noise method in the calculation of the trace of the inverse of Wilson's Dirac operator and some other disconnected contributions.A numerical comparison of the standard deviation for the Z(2) noise method and HPE with the Z(2) noise method is carried out. It is found that there are noise reductions in all the quantities we calculated using the HPE with the Z(2) noise method. For the trace of the inverse of Wilson's Dirac operator, the HPE can reduce the statistical error by about 60%. 展开更多
关键词 HPE Hopping Parameter Expansion Technique in Noise method for Disconnected Quark Loops
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Three-Dimensional Phase Field Simulations of Hysteresis and Butterfly Loops by the Finite Volume Method
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作者 席丽莹 陈焕铭 +3 位作者 郑富 高华 童洋 马治 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第9期128-131,共4页
Three-dimensional simulations of ferroelectric hysteresis and butterfly loops are carried out based on solving the time dependent Ginzburg-Landau equations using a finite volume method. The influence of externally mec... Three-dimensional simulations of ferroelectric hysteresis and butterfly loops are carried out based on solving the time dependent Ginzburg-Landau equations using a finite volume method. The influence of externally mechanical loadings with a tensile strain and a compressive strain on the hysteresis and butterfly loops is studied numerically. Different from the traditional finite element and finite difference methods, the finite volume method is applicable to simulate the ferroelectric phase transitions and properties of ferroelectric materials even for more realistic and physical problems. 展开更多
关键词 Three-Dimensional Phase Field Simulations of Hysteresis and Butterfly Loops by the Finite Volume method
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Nonlinear adaptive optimal control for vehicle handling improvement through steer-by-wire system 被引量:8
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作者 Vahid Tavoosi Reza Kazemi Atta Oveisi 《Journal of Central South University》 SCIE EI CAS 2014年第1期100-112,共13页
A control algorithm for improving vehicle handling was proposed by applying right angle to the steering wheel,based on the nonlinear adaptive optimal control(NAOC).A nonlinear 4-DOF model was initially developed,then ... A control algorithm for improving vehicle handling was proposed by applying right angle to the steering wheel,based on the nonlinear adaptive optimal control(NAOC).A nonlinear 4-DOF model was initially developed,then it was simplified to a 2-DOF model with reasonable assumptions to design observer and optimal controllers.Then a simplified model was developed for steering system.The numerical simulations were carried out using vehicle parameters for standard maneuvers in dry and wet road conditions.Moreover,the hardware in the loop method was implemented to prove the controller ability in realistic conditions.Simulation results obviously show the effectiveness of NAOC on vehicle handling and reveal that the proposed controller can significantly improve vehicle handling during severe maneuvers. 展开更多
关键词 HANDLING vehicle STEER-BY-WIRE CONTROLLER nonlinear adaptive optimal control hardware loop method
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Preparation and Application of the Sol–Gel Combustion Synthesis-Made CaO/CaZrO_3 Sorbent for Cyclic CO_2 Capture Through the Severe Calcination Condition 被引量:5
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作者 王保文 宋小勇 +1 位作者 王宗华 郑楚光 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第9期991-999,共9页
Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the se... Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the severe calcination condition so as to obtain the concentrated C02 stream. In this research, CaO/CaZrO3 sorbents were synthesized using the sol-gel combustion synthesis (SGCS) method with urea as fuel. The cyclic reaction performance of the synthesized sorbents was evaluated on a lab-scaled reactor system through calcination at 950 ℃ in a pure C02 atmosphere and carbonation at 650 ℃ in the 15% (by volume) C02. The mass ratio of CaO to CaZr03 as 8:2 (designated as CasZr2) was screened as the best option among all the synthesized CaO sorbents for its high CO2 capture capacity and carbonation conversion at the initial cycle. And then a gradual decay in the C02 capture capacity was observed at the following 10 successive cycles, but hereafter stabilized throughout the later cycles. Furthermore, structural evolution of the carbonated CasZr2 over the looping cycles was investigated. With increasing looping cycles, the pore peak and mean grain size of the carbonated CasZr2 sorbent shifted to the bigger direction but both the surface area (SA) ratio and surface fractal dimension Ds decreased. Finally, morphological transformation of the carbonated CasZr2 was observed. Agglomeration and edge rounding of the newly formed CaC03 grains were found as aggravated at the cyclic carbonation stage. As a result, carbonation of CasZr2 with C02 was observed only confined to the external active CaO by the fast formation of the CaC03 shell outside, which occluded the further carbonation of the unreacted CaO inside. Therefore, enough attention should be paid to the carbonation stage and more effective activation measures should be explored to ensure the unreacted active CaO fully carbonatPd river the extended Ioonin cycles. 展开更多
关键词 C02 captureCalcium looping cyclesCaO/CaZr03 sorbentSol-gel combustion synthesis method
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Single-phase earth fault current distribution between optical fiber composite overhead ground wire and ordinary ground wire in transmission system
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作者 许高雄 《Journal of Chongqing University》 CAS 2011年第2期78-83,共6页
It is important for the safety of transmission system to accurately calculate single-phase earth fault current distribution.Features of double sided elimination method were illustrated.Quantitative calculation of sing... It is important for the safety of transmission system to accurately calculate single-phase earth fault current distribution.Features of double sided elimination method were illustrated.Quantitative calculation of single-phase earth fault current distribution and case verification were accomplished by using the loop method.Influences of some factors,such as single-phase earth fault location and ground resistance of poles,on short-circuit current distribution were discussed.Results show that:1) results of the loop method conform to those of double sided elimination method;2) the fault location hardly influences macro-distribution of short-circuit current.However,current near fault location is evidently influenced;and 3) the short-circuit current distribution is not so sensitive to the ground resistance of poles. 展开更多
关键词 loop method single-phase earth fault short-circuit current distribution optical fiber composite overhead ground wire ordinary ground wire
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