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Improvements of corner frequency and scaling factor for stochastic finite-fault modeling

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Earthquake Engineering and Engineering Vibration 2010年第4期9卷 503-511页

作者： Sun Xiaodan Tao Xiaxin Chen Fu School of Civil Engineering Harbin Institute of Technology Harbin 150090 China School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China

In this paper, three existing source spectral models for stochastic finite-fault modeling of ground motion were reviewed. These three models were used to calculate the far-field received energy at a site from a vertical fault and the mean spectral ratio over 15 stations of the Northridge earthquake, and then compared. From the comparison, a necessary measure was observed to maintain the far-field received energy independent of subfault size and avoid overestimation of the long- period spectra/level. Two improvements were made to one of the three models （i.e., the model based on dynamic comer frequency） as follows：（i） a new method to compute the subfault comer frequency was proposed, where the subfault comer frequency is determined based on a basic value calculated from the total seismic moment of the entire fault and an increment depending on the seismic moment assigned to the subfault; and （ii） the difference of the radiation energy from each suhfault was considered into the scaling factor. The improved model was also compared with the unimproved model through the far-field received energy and the mean spectral ratio. The comparison proves that the improved model allows the received energy to be more independent of subfault size than the unimproved model, and decreases the overestimation degree of the long-period spectral amplitude.

关键词： stochastic finite-fault modeling corner frequency scaling factor far-field received energy long-period spectral amplitude

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几何形状对气垫升力的影响研究

哈尔滨工程大学学报（英文版） 2024年第1期23卷 74-84页

作者： Hamed Petoft Vahid Fakhari Abbas Rahi Faculty of Mechanical and Energy Engineering Shahid Beheshti UniversityTehran ***Iran

One of the crucial and challenging issues for researchers is presenting an appropriate approach to evaluate the aerodynamic characteristics of air cushion vehicles(ACVs)in terms of system design *** of these issues includes introducing a suitable approach to analyze the effect of geometric shapes on the aerodynamic characteristics of *** main novelty of this paper lies in presenting an innovative method to study the geometric shape effect on air cushion lift force,which has not been investigated thus ***,this paper introduces a new approximate mathematical formula for calculating the air cushion lift force in terms of parameters,including the air gap,lateral gaps,air inlet velocity,and scaling factor for the first ***,we calculate the aerodynamic lift force applied to nine different shapes of the air cushions used in the ACVs in the present paper through the ANSYS Fluent *** geometrical shapes studied in this paper are rectangular,square,equilateral triangle,circular,elliptic shapes,and four other combined shapes,including circle-rectangle,circle-square,hexagonal,and fillet *** showed that the cushion with a circular pattern produces the highest lift force among other geometric shapes with the same *** increase in the cushion lift force can be attributed to the fillet with a square shape and its increasing radius compared with the square shape.

关键词： Lift force Air cushion vehicle Geometric shape Simulation Gap Inlet velocity scaling factor

Intercomparison of two trapezoid-based soil moisture downscaling methods using three scaling factors

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International Journal of Digital Earth 2019年第4期12卷 485-499页

作者： Jing Tian Xiangzheng Deng Hongbo Su Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographical Sciences and Natural Resources Research(IGSNRR)Chinese Academy of Sciences(CAS)BeijingPeople’s Republic of China Center for Chinese Agricultural Policy Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingPeople’s Republic of China Department of Civil Environmental and Geomatics EngineeringFlorida Atlantic UniversityBoca RatonFLUSA

This paper compared two soil moisture downscaling methods using three scaling *** 3 soil moisture product of advanced microwave scanning radiometer for EOS(AMSR-E)is downscaled from 25 to 1 *** downscaled results are compared with the soil moisture observations from polarimetric scanning radiometer(PSR)microwave radiometer and field *** results show that(1)the scaling factor of normalized soil thermal inertia(NSTIs)and vegetation temperature condition index(VTCI)are better than soil evaporative efficiency in reflecting soil moisture;(2)for method 1,NSTIS is the best in the downscaling of soil *** method 2,VTCI is the best;(3)no significant differences of the correlation coefficients(R2)and the biases were found between the two methods for the same scaling ***,method 2 shows a better potential than method 1 in the time-series applications of the downscaling of soil moisture;(4)compared with the relationship between the area-averaged soil moisture of AMSR-E and that of PSR,R2 of the 6 sets of the downscaled soil moisture almost do not decrease,which suggests the validity of the downscaling of soil moisture with the two downscaling methods using the three scaling factors.

关键词： Soil moisture downscaling trapezoid-based method scaling factor

Adaptive projective synchronization with different scaling factors in networks

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Chinese Physics B 2008年第11期17卷 4067-4072页

作者：过榴晓徐振源胡满峰 School of Science Jiangnan University School of Information Technology Jiangnan University

We study projective synchronization with different scaling factors （PSDF） in N coupled chaotic systems networks. By using the adaptive linear control, some sufficient criteria for the PSDF in symmetrical and asymmetrical coupled networks are separately given based on the Lyapunov function method and the left eigenvalue theory. Numerical simulations for a generalized chaotic unified system are illustrated to verify the theoretical results.

关键词： dynamical networks adaptive control synchronization with different scaling factors (PSDF) scaling factor

A new component maps correction method using variable geometric parameters

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Chinese Journal of Aeronautics 2021年第4期34卷 360-374页

作者： Shaochen LI Hailong TANG Min CHEN School of Energy and Power Engineering Beihang UniversityBeijing 100083China Aircraft Engine Integrated System Safety Beijing Key Laboratory Beijing 100083China

Accurate engine performance models are important for model-based performance evaluation of aero *** accuracy of the model often depends on engine component maps,so there is a need for a method that can accurately correct the component maps of the model over a wide *** this paper,a new method for modifying component maps is proposed,this method combines the correction of the scaling factors with the solution process of the off-design working point,and uses the adjustment of the variable geometric parameters of the engine to change the position of the working line,in order to obtain more correction results and guarantee high accuracy in a wider *** method is validated by taking the main fan of the Adaptive Cycle Engine(ACE),an ideal power unit for a new generation of multi-purpose and ultra-wide working range aircraft,as an *** results show that the maximum error between the corrected component maps and the target maps is less than 1%.New possibility for more precise component maps can be realized in this paper.

关键词： Adaptive cycle engine Component map correction Performance model scaling factor Variable geometric parameter

New analytical imaging algorithm for general case airborne bistatic SAR

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Journal of Systems Engineering and Electronics 2014年第5期25卷 786-793页

作者： Jianyun Zhang Jinhe Ran Yongjun Wu Electronic Engineering Institute

This paper focuses on the general case （GC） airborne bistatic synthetic aperture radar （SAR） data processing, and a new analytical imaging algorithm based on the extended Loffeld＇s bistatic formula （ELBF） is proposed. According to the bistatic SAR geometry, the track decoupling formulas that convert the bistatic geometry to the receiver-referenced geometry in a concise way are derived firstly. Then phase terms of ELBF are decomposed into two independent phase terms as the range phase term and the azimuth phase term in a new way. To get the focusing result, the bistatic deformation （BD） term is compensated in the two-dimensional （2- D） frequency domain, and the space-variances of the range phase term and the azimuth phase term are eliminated by chirp scaling （CS） and chirp z-transform （CZT）, respectively. The effectiveness of the proposed algorithm is verified by the simulation results.

关键词： track decoupling scaling factor general case (GC) bistatic synthetic aperture radar (SAR) imaging algorithm.

Generalized Projective Synchronization Between Rssler System and New Unified Chaotic System

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Communications in Theoretical Physics 2007年第7期 132-136页

作者： LI Xin CHEN Yong1 Nonlinear Science Center and Department of Mathematics,Ningbo University,Ningbo 315211,China2 Institute of Theoretical Computing,East China Normal University,Shanghai 200062,China3 Key Laboratory of Mathematics and Mechanization,the Chinese Academy of Sciences,Beijing 100080,China

Based on symbolic computation system Maple and Lyapunov stability theory,an active control method isused to projectively synchronize two different chaotic systems—Lorenz-Chen-Lü system(LCL)and Rssler system,which belong to different dynamic *** this paper,we achieve generalized projective synchronization between thetwo different chaotic systems by directing the scaling factor onto the desired value *** illustrate our result,numerical simulations are used to perform the process of the synchronization and successfully put the orbits of drivesystem(LCL)and orbits of the response system(Rssler system)in the same plot for understanding intuitively.

关键词： Rssler system Lorenz-Chen-Lü system generalized projective synchronization scaling factor active control

A Modified Differential Evolution Algorithm

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A Modified Differential Evolution Algorithm

Projective Synchronization in Coupled Integer and Fractional Order Liu-Chen Chaotic Systems

第二十九届中国控制会议

作者： GAO Lin School of Automation and Electronic Engineering,Qingdao University of Science and Technology,Qingdao 266042,P.R.China.

Differential Evolution（DE）is a simple and efficient heuristic algorithm for global optimization over continuous *** of its outstanding performance,simplicity and remarkable efficiency,DE has being used widely to deal with real-life *** DE has some problems such as low precision and prematurity if the scaling factor F is not chosen *** this paper a modified DE algorithm（sFDE）is proposed which uses an adaptive scaling factor sF to replace the invariable factor F in basic *** new algorithm performs better than the basic DE over a set of benchmark functions and a practical use for data reconciliation shows its effectiveness also.

关键词： DE Adaptive scaling factor

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Projective Synchronization in Coupled Integer and Fractional...