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The application of the orthogonal conditional nonlinear optimal perturbations method to typhoon track ensemble forecasts

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Science China Earth Sciences 2019年第2期62卷 376-388页

作者： Zhenhua HUO Wansuo duan National Meteorological Center China Meteorological Administration State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences

The orthogonal conditional nonlinear optimal perturbations (CNOPs) method, orthogonal singular vectors (SVs)method and CNOP+SVs method, which is similar to the orthogonal SVs method but replaces the leading SV (LSV) with the first CNOP, are adopted in both the Lorenz-96 model and Pennsylvania State University/National Center for Atmospheric Research (PSU/NCAR) Fifth-Generation Mesoscale Model (MM5) for ensemble forecasts. Using the MM5, typhoon track ensemble forecasting experiments are conducted for strong Typhoon Matsa in 2005. The results of the Lorenz-96 model show that the CNOP+SVs method has a higher ensemble forecast skill than the orthogonal SVs method, but ensemble forecasts using the orthogonal CNOPs method have the highest forecast skill. The results from the MM5 show that orthogonal CNOPs have a wider horizontal distribution and better describe the forecast uncertainties compared with SVs. When generating the ensemble mean forecast, equally averaging the ensemble members in addition to the anomalously perturbed forecast members may contribute to a higher forecast skill than equally averaging all of the ensemble members. Furthermore, for given initial perturbation amplitudes, the CNOP+SVs method may not have an ensemble forecast skill greater than that of the orthogonal SVs method, but the orthogonal CNOPs method is likely to have the highest forecast skill. Compared with SVs, orthogonal CNOPs fully consider the influence of nonlinear physical processes on the forecast results; therefore, considering the influence of nonlinearity may be important when generating fast-growing initial ensemble perturbations. All of the results show that the orthogonal CNOP method may be a potential new approach for ensemble forecasting.

关键词： Ensemble forecasts Initial perturbation Conditional nonlinear optimal perturbation Singular vector Typhoon track

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Multi-objective pigeon-inspired optimization for brushless direct current motor parameter design

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Science China(Technological Sciences) 2015年第11期58卷 1915-1923页

作者： QIU HuaXin duan HaiBin Bio-inspired Autonomous Flight Systems(BAFS) Research Group Science and Technology on Aircraft Control Laboratory School of Automation Science and Electrical Engineering Beihang University

Pigeon-inspired optimization(PIO) is a new swarm intelligence optimization algorithm, which is inspired by the behavior of homing pigeons. A variant of pigeon-inspired optimization named multi-objective pigeon-inspired optimization(MPIO) is proposed in this paper. It is also adopted to solve the multi-objective optimization problems in designing the parameters of brushless direct current motors, which has two objective variables, five design variables, and five constraint variables. Furthermore, comparative experimental results with the modified non-dominated sorting genetic algorithm are given to show the feasibility, validity and superiority of our proposed MIPO algorithm.

关键词： brushless direct current (BLDC) motor multi-objective pigeon-inspired optimization (MPIO) electromagnetics mul-ti-objective optimization

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Interference torque of a three-floated gyroscope with gas-lubricated bearings subject to a sudden change of the specific force

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Chinese Journal of Aeronautics 2019年第3期32卷 737-747页

作者： Yan LI Fuhai duan School of Mechanical Engineering Dalian University of Technology

A numerical study is carried out to investigate the influence of a sudden change of the specific force on a three-floated gyroscope with a rotor supported on gas-lubricated *** interference torque is calculated to evaluate the influence by modeling the transient behavior of the rotor-bearing system. In combination with dynamic equations of the rotor displacement,the Reynolds equation is solved on the surface of spiral-grooved conical bearings. It is assumed that a steady state has been obtained with a constant specific force, and then the specific force is suddenly changed and maintained constant after that. Responses of the sudden change are obtained by solving the equations. Numerical results show that the direction of the sudden change of the specific force is the main factor which influences the interference torque curve. With a sudden change along the input direction, the interference torque fluctuation has a constant frequency and a decreasing amplitude. With a sudden change along the output direction, the interference torque fluctuates in a small range. With a sudden change along the spin direction, the change of the interference torque combines a fluctuation and a gradually-changing quasi-equilibrium value. This study provides a supplement to the steady-state error model of the three-floated gyroscope.

关键词： Conical bearing Gas lubricated bearings Interference torque Rotor-bearing system Three-floated gyroscope

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The role of initial signals in the tropical Pacific Ocean in predictions of negative Indian Ocean Dipole events

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Science China Earth Sciences 2018年第12期61卷 1832-1843页

作者： Rong FENG Wansuo duan LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Using reanalysis data, the role of initial signals in the tropical Pacific Ocean in predictions of negative Indian Ocean Dipole(IOD) events were analyzed. It was found that the summer predictability barrier(SPB) phenomenon exists in predictions,which is closely related to initial sea temperature errors in the tropical Pacific Ocean, with type-1 initial errors presenting a significant west-east dipole pattern in the tropical Pacific Ocean, and type-2 initial errors showing the opposite spatial pattern. In contrast, SPB-related initial sea temperature errors in the tropical Indian Ocean are relatively small. The initial errors in the tropical Pacific Ocean induce anomalous winds in the tropical Indian Ocean by modulating the Walker circulation in the tropical oceans. In the first half of the prediction year, the anomalous winds, combined with the climatological winds in the tropical Indian Ocean, induce a basin-wide mode of sea surface temperature(SST) errors in the tropical Indian Ocean. With the reversal of the climatological wind in the second half of the prediction year, a west-east dipole pattern of SSTerrors appears in the tropical Indian Ocean, which is further strengthened under the Bjerknes feedback, yielding a significant SPB. Moreover, two types of precursors were also identified: a significant west-east dipole pattern in the tropical Pacific Ocean and relatively small temperature anomalies in the tropical Indian Ocean. Under the combined effects of temperature anomalies in the tropical Indian and Pacific oceans, northwest wind anomalies appear in the tropical Indian Ocean, which induce a significant west-east dipole pattern of SST anomalies, and yield a negative IOD event.

关键词： Negative Indian Ocean Dipole Precursor Initial errors Pacific Ocean

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Verification of monocular and binocular pose estimation algorithms in vision-based UAVs autonomous aerial refueling system

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Science China(Technological Sciences) 2016年第11期59卷 1730-1738页

作者： LI Han duan HaiBin Bio-inspired Autonomous Flight Systems (BAFS) Research Group Science and Technology on Aircraft Control Laboratory School of Automation Science and Electrical Engineering Beihang University

With the high focus on autonomous aerial refueling(AAR), it becomes increasingly urgent to design efficient methods or algorithms for solving the AAR problems in complicated aerial environments. A vision-based technology for AAR is developed in this paper, and five monocular and binocular visual algorithms for pose estimation of the unmanned aerial vehicles(UAVs) are adopted and verified in this AAR system. The real-time on-board vision system is also designed for precise navigation in the UAVs docking phase. A series of out-door comparative experiments for different pose estimation algorithms are conducted to verify the feasibility and accuracy of the vision algorithms in AAR.

关键词： unmanned aerial vehicles(UAVs) autonomous aerial refueling(AAR) pose estimation monocular vision binocular vision

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Two-dimensional ballistic transistors for advanced-node integrated circuits

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National Science Review 2024年第3期11卷 9-10页

作者： Jia Li Xidong duan Hunan Provincial Key Laboratory of Two-Dimensional Materials State Key Laboratory for Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering Hunan University

As the feature size of metal-oxide-semiconductor-field-effect-transistors(MOSFETs) in integrated circuits(ICs)is reduced to sub-10-nm, the traditional channel materials are plagued by enhanced scattering and short-channel effects, leading to the deterioration of switching characteristics and the increase of power consumption.

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Analysis of finite-time practical stability for time-varying polytopic systems

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Journal of Systems Engineering and Electronics 2009年第1期20卷 112-119页

作者： Zhong Zhen duan Guangren Harbin Inst. of Technology Harbin 150001 P. R. China

The problem of finite-time practical stability （FTPS） for time-varying polytopic systems is discussed. Three equivalent conditions for FTPS are first proposed. To facilitate the system analysis, a sufficient linear matrix inequality （LMI） criterion on the FTPS is further provided. The definition of finite-time practical boundedness and a sufficient LMI criterion are also provided to overcome the exogenous disturbance. A numerical example is used to illustrate the effect of the proposed approach.

关键词： polytopic systems linear matrix inequality finite-time control practical stability.

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Fostering artificial societies using social learning and social control in parallel emergency management systems

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Frontiers of Computer Science 2012年第5期6卷 604-610页

作者： Wei duan Xiaogang QIU Research Center of Military Computational Experiments and Parallel Systems Technology College of Mechatronics Engineering and AutomationNational University of Defense TechnologyChangsha 410073China

How can we foster and grow artificial societies so as to cause social properties to emerge that are logical, consistent with real societies, and are expected by design- ers？ We propose a framework for fostering artificial soci- eties using social learning mechanisms and social control ap- proaches. We present the application of fostering artificial so- cieties in parallel emergency management systems. Then we discuss social learning mechanisms in artificial societies, in- cluding observational learning, reinforcement learning, imi- tation learning, and advice-based learning. Furthermore, we discuss social control approaches, including social norms, social policies, social reputations, social commitments, and sanctions.

关键词： artificial societies social computing social learning social control agent-based simulation

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Gaussian pigeon-inspired optimization approach to orbital spacecraft formation reconfiguration

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Chinese Journal of Aeronautics 2015年第1期28卷 200-205页

作者： Zhang Shujian duan Haibin School of Automation Science and Electrical Engineering Beihang University

With the rapid development of space technology, orbital spacecraft formation has received great attention from international and domestic academics and industry. Compared with a single monolithic, the orbital spacecraft formation system has many advantages. This paper presents an improved pigeon-inspired optimization（PIO） algorithm for solving the optimal formation reconfiguration problems of multiple orbital spacecraft. Considering that the uniform distribution random searching system in PIO has its own weakness, a modified PIO model adopting Gaussian strategy is presented and the detailed process is also given. Comparative experiments with basic PIO and particle swarm optimization（PSO） are conducted, and the results have verified the feasibility and effectiveness of the proposed Gaussian PIO（GPIO） in solving orbital spacecraft formation reconfiguration problems.

关键词： spacecraft orbital inspired searching verified swarm circle landmark weakness GPIO

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Advancements in pigeon-inspired optimization and its variants

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Science China(Information Sciences) 2019年第7期62卷 5-14页

作者： Haibin duan Huaxin QIU State Key Laboratory of Virtual Reality Technology and Systems School of Automation Science and Electrical Engineering Beihang University Peng Cheng Laboratory

The returning of homing pigeons to their lofts from remote and unfamiliar locations with great accuracy remains a mystery. Pigeon-inspired optimization(PIO), which is a novel mono-objective continuous optimization algorithm, is inspired by the hidden mechanism behind the remarkable navigation capacity of homing pigeons. Since their development, PIO and its variants have been widely applied to various fields ranging from combinatorial optimization to multi-objective optimization in many areas, such as aerospace,medicine, and energy. This study aims to review the modifications of PIO from four aspects of improvement measures, namely, component replacement, operation addition, structure adjustment, and application expansion. It also summarizes the problems of existing research and plots the course of future effort.

关键词： pigeon-inspired optimization homing pigeon bio-inspired computing map and compass operator landmark operator

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