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On-Policy and Off-Policy Value Iteration Algorithms for Stochastic Zero-Sum Dynamic Games

Journal of Systems Science & Complexity 2025年第1期38卷 421-435页

作者： GUO Liangyuan WANG Bing-Chang ZHANG Ji-Feng School of Control Science and Engineering Shandong UniversityJinan 250063China School of Automation and Electrical Engineering Zhongyuan University of TechnologyZhengzhou 450007China Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

This paper considers the value iteration algorithms of stochastic zero-sum linear quadratic games with unkown ***-policy and off-policy learning algorithms are developed to solve the stochastic zero-sum games,where the system dynamics is not *** analyzing the value function iterations,the convergence of the model-based algorithm is *** equivalence of several types of value iteration algorithms is *** effectiveness of model-free algorithms is demonstrated by a numerical example.

关键词： Approximate dynamic programming on-policy off-policy stochastic zero-sum games valueiteration

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Improving aircraft nose wheel steering stability based on control continuation method

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Science China(Technological Sciences) 2025年第3期68卷 258-277页

作者： Qiaozhi YIN Dexu KONG Jiawei WANG Hong NIE Xiaohui WEI National Key Laboratory of Helicopter Aeromechanics Nanjing210016China State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing210016China Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing210016China AVIC Nanjing Engineering Institute of Aircraft Systems Nanjing211106China

Aircraft steering instability during the taxiing process sometimes occurs resulting from the unstable bifurcation phenomena of the nonlinear steering dynamic system,which may lead to severe *** this study,the control parameter design of an aircraft nose wheel steering control system based on the control continuation method is proposed to reduce the number of unstable bifurcation points and enlarge the system stable region area in a certain parameter ***,the aircraft turning performance can be improved ***,a nonlinear aircraft rollout dynamic model is constructed,and the aircraft ground steering bifurcation characteristics are obtained under the open-loop steering control ***,the bifurcation performances under three closed-loop nose wheel steering controllers based on the feedback control method are compared,and the control parameter of the quadratic nonlinear controller with a better bifurcation control effect is selected as a second bifurcation parameter to analyze the directional system stability via two-parameter bifurcation ***,the influence of a crosswind on the aircraft ground steering bifurcation performance is studied for various control parameter ***,the control effects of a traditional proportional-integral-derivative(PID)nose wheel steering control law and the designed feedback controller are compared and ***,a semi-physical experiment of the aircraft nose wheel steering system is carried out,and different control parameter values are selected for test verification,which can further verify the control effect of the designed nonlinear feedback *** results indicate that the feedback control method is unable to vary the system bifurcation types,but appropriate control parameter design can effectively shrink the system instability region and even eliminate the unstable Hopf bifurcation points under some specific working conditions,improving the aircraft ground turning stability re

关键词： aircraft taxiing dynamics and stability nose wheel steering control system control continuation steering bifurcation characteristics quadratic feedback control

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Analysis of the redox environment and genesis of surface sediment in the northeast Indian Ocean at the Ninety-East Ridge

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Journal of Oceanology and Limnology 2025年第1期43卷 57-72页

作者： Zhourong CAI Qianru HUANG Zhengxin YIN Xin SUI Sibo LÜ Meng TANG Juan PENG School of Marine Sciences Sun Yat-sen UniversityZhuhai 519082China Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering Zhuhai 519082China South China Sea Marine Survey Center Ministry of Natural ResourcesGuangzhou 510275China Key Laboratory of Marine Environmental Survey Technology and Application Ministry of Natural ResourcesGuangzhou 510275China

The Ninety-East Ridge(NER)is located in the semioceanic to oceanic region of the southern Bengal Fan in the Northeast Indian *** sedimentary environment,ocean currents,and scientific issues related to climate change have always been the focus of *** well understand the sedimentary environment of the sea area,we studied the modern sedimentary environment of the NER by analyzing the redox-sensitive trace elements(RSEs)and biomarkers in the surface sediments of the northern region and both sides of the NER and the mechanism of their *** ratios of Mo/U(average 2.22),(Cu+Mo)/Zn(average 1.51),and the results ofδCe<1 of the sediment samples,all indicate the reduction of the sedimentary *** addition,the ratio of pristane(Pr)to phytane(Ph),C30diahopane to C30 hopane,and diasterane to sterane were low in all samples,on average of 1.03,0.9,and 0.33,*** analysis of RSE and biomarker data revealed that the sedimentary environment on seabed of the NER is generally a rare low-oxygen reduction *** the analysis of sediment characteristics,material sources,and ocean currents,we preliminarily constructed a genetic model for the low-oxygen reducing environment of surface sediments in the *** believe that the low-oxygen reduction environment of surface sediment in the NER could be influenced by multiple factors,such as terrestrial input of materials,productivity at sea surface,and sediment particle size.

关键词： Ninety-East Ridge(NER) surface sediment sedimentary environment redox-sensitive trace elements(RSEs) biomarker

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Feature-aided pose estimation approach based on variational auto-encoder structure for spacecrafts

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Chinese Journal of Aeronautics 2024年第8期37卷 329-341页

作者： Yanfang LIU Rui ZHOU Desong DU Shuqing CAO Naiming QI Department of Aerospace Engineering Harbin Institute of TechnologyHarbin 150001China Suzhou Research Institute of HIT Suzhou 215104China Shanghai Institute of Spaceflight Control Technology Shanghai 201109China Shanghai Key Laboratory of Aerospace Intelligent Control Technology Shanghai 201109China

Real-time 6 Degree-of-Freedom(DoF)pose estimation is of paramount importance for various on-orbit *** from the development of deep learning,Convolutional Neural Networks(CNNs)in feature extraction has yielded impressive achievements for spacecraft pose *** improve the robustness and interpretability of CNNs,this paper proposes a Pose Estimation approach based on Variational Auto-Encoder structure(PE-VAE)and a Feature-Aided pose estimation approach based on Variational Auto-Encoder structure(FA-VAE),which aim to accurately estimate the 6 DoF pose of a target *** methods treat the pose vector as latent variables,employing an encoder-decoder network with a Variational Auto-Encoder(VAE)*** enhance the precision of pose estimation,PE-VAE uses the VAE structure to introduce reconstruction mechanism with the whole ***,FA-VAE enforces feature shape constraints by exclusively reconstructing the segment of the target spacecraft with the desired *** evaluation against leading methods on public datasets reveals similar accuracy with a threefold improvement in processing speed,showcasing the significant contribution of VAE structures to accuracy enhancement,and the additional benefit of incorporating global shape prior features.

关键词： Pose estimation Variational auto-encoder Feature-aided Pose Estimation Approach On-orbit measurement tasks Simulated and experimental dataset

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Extension of sound field reconstruction based on element radiation superposition method in a sparsity framework

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Chinese Physics B 2023年第4期32卷 412-422页

作者：高塬杨博全时胜国张昊阳 National Key Laboratory of Underwater Acoustic Technology Harbin Engineering UniversityHarbin 150001China Key Laboratory of Marine Information Acquisition and Security(Harbin Engineering University) Ministry of Industry and Information TechnologyHarbin 150001China College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150001China

Nearfield acoustic holography(NAH)is a powerful tool for realizing source identification and sound field *** wave superposition(WS)-based NAH is appropriate for the spatially extended sources and does not require the complex numerical *** source method(ESM),as a classical WS approach,is widely used due to its simplicity and *** the ESM,a virtual source surface is introduced,on which the virtual point sources are taken as the assumed sources,and an optimal retreat distance needs to be considered.A newly proposed WS-based approach,the element radiation superposition method(ERSM),uses piston surface source as the assumed source with no need to choose a virtual source *** satisfy the application conditions of piston pressure formula,the sizes of pistons are assumed to be as small as possible,which results in a large number of pistons and sampling *** this paper,transfer matrix modes(TMMs),which are composed of the singular vectors of the vibro-acoustic transfer matrix,are used as the sparse basis of piston normal ***,the compressive ERSM based on TMMs is *** with the conventional ERSM,the proposed method maintains a good pressure reconstruction when the number of sampling points and pistons are both ***,the proposed method is compared with the compressive ESM in a mathematical *** simulations and experiments for a rectangular plate demonstrate the advantage of the proposed method over the existing methods.

关键词： sound field reconstruction nearfield acoustic holography element radiation superposition method sparsity framework

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S-scheme heterojunction construction of Fe/BiOCl/BiVO4 for enhanced photocatalytic degradation of ciprofloxacin

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Progress in Natural Science:Materials International 2024年第2期34卷 290-303页

作者： Guanlong Yu Qifang Sun Yi Yang Si Chen Yuannan Long Yifu Li Shiyong Ge Dian Zheng School of Hydraulic and Environmental Engineering Changsha University of Science & Technology Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province School of Environmental Engineering Wuhan Textile University

With the growing problem of water pollution caused by antibiotics,the development of photocatalysts with high photogenerated carrier separation efficiency is crucial.A high-efficiency microsphere Fe/BiOCl/BiVO4with Sscheme heterojunction was synthesized by solvothermal method and its ciprofloxacin（CIP） degradation performance were investigated under visible ***,FT-IR,SEM,EDS,HRTEM and XPS results show that the photocatalytic have good crystallization,morphology and the formed a *** photocatalytic performance of Fe/BiOCl/BiVO4for CIP was superior to pure BiOCl and BiVO4due to the microsphere and formed heterostructure between BiOCl and *** influencing factors of CIP degradation by Fe/BiOCl/BiVO4were investigated,and the results showed that Fe/BiOCl/BiVO4had high degradation efficiency not only at pH 5-9,but also in the presence of inorganic Cl-,NO3-and metal *** the optimal conditions,the degradation rate of CIP was up to 100% in 75 *** addition to CIP,the Fe/BiOCl/BiVO4photocatalysts degraded other organic pollutants,such as tetracycline,oxytetracycline,chlortetracycline,ofloxacin,levofloxacin,and rhodamine B,by more than 92%.The main active species were photogenerated holes（h+） and superoxide radicals（·O2-）.In addition,possible intermediates and toxicity of intermediates were analyzed and five potential pathways for CIP degradation were proposed.

关键词： BiOCl/BiVO4 Fe3+ doping Organic pollutant Photocatalysis S-scheme heterojunction

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An Energy control Strategy in Hybrid Electric Ships Considering the Battery Life 3

An Energy Control Strategy in Hybrid Electric Ships Consider...

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3rd IEEE International Conference on Industrial Electronics for Sustainable Energy Systems, IESES 2023

作者： Yan, Yucheng Gao, Diju Jiang, Haoyang Shanghai Maritime University Key Laboratory of Transport Industry of Marine Technology and Control Engineering Shanghai China

ISBN: (纸本)9798350324754

Considering the effect of battery life on the full-life-cycle cost of hybrid electric ships (HES), an energy control strategy has been proposed, with the minimization of fuel consumption and battery's health degradation as the optimization objective. Firstly, the double-objectives cost function is established based the diesel engine fuel consumption model, power battery internal resistance model and battery life model. Then, the dynamic programming (DP) algorithm is employed to achieve the global optimization and the optimal weight coefficient is selected according to the optimization results. The experimental results show that, compared with the control strategy based on the single-objective optimization of fuel consumption or the control strategy based on fuzzy logic, the proposed strategy can reduce the fuel consumption and further extend the battery life, and it has good feasibility and practicality. © 2023 IEEE.

关键词： Dynamic programming

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Self-assembly synthesis of phosphorus-doped tubular g-C_(3)N_(4);Ti_(3)C_(2)MXene Schottky junction for boosting photocatalytic hydrogen evolution

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Green Energy & Environment 2023年第1期8卷 233-245页

作者： Kelei Huang Chunhu Li Xiuli Zhang Liang Wang Wentai Wang Xiangchao Meng Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationCollege of Chemistry and Chemical EngineeringOcean University of ChinaQingdao266100China

Establishing highly effective charge transfer channels in carbon nitride(g-C_(3)N_(4)) to enhance its photocatalytic activity is still a challenging ***,the delaminated 2D Ti_(3)C_(2) MXene nanosheets were employed to decorate the P-doped tubular g-C_(3)N_(4)(PTCN)for engineering 1D/2D Schottky heterojunction(PTCN/TC)through electrostatic *** optimized PTCN/TC exhibited the highest hydrogen evolution rate(565 μmol h^(-1)g^(-1)),which was 4.3 and 2.0-fold higher than pristine bulk g-C_(3)N_(4) and PTCN,*** enhancement may be primarily attributed to the phosphorus heteroatom doped and unique structure of 1D/2D g-C_(3)N_(4)/Ti_(3)C_(2) Schottky heterojunction,enhancing the light-harvesting and charges’***-dimensional pathway of g-C_(3)N_(4) tube and built-in electric field of interfacial Schottky effect can significantly facilitate the spatial separation of photogenerated charge carriers,and simultaneously inhibit their recombination via Schottky *** this composite,metallic Ti_(3)C_(2) was served as electrons sink and photons ***,ultrathin Ti_(3)C_(2) flake with exposed terminal metal sites as a co-catalyst exhibited higher photocatalytic reactivity in H2 evolution compared to carbon materials(such as reduced graphene oxide).This work not only proposed the mechanism of tubular g-C_(3)N_(4)/Ti_(3)C_(2) Schottky junction in photocatalysis,but also provided a feasible way to load ultrathin Ti_(3)C_(2) as a co-catalyst for designing highly efficient photocatalysts.

关键词： Tubular g-C_(3)N_(4) Ti_(3)C_(2)MXene Schottky junction Photocatalyst Hydrogen evolution

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Design of the rare-earth-containing materials based on the micro-alloying phase equilibria, phase diagrams and phase transformations

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Journal of Materials Science & technology 2023年第20期151卷 119-149页

作者： Kai Xu Chengcheng Zhan Ming Lou Xuelian Xiao Ruonan Zhou Fangming Wang Xiaofei Hu Yuan Yuan Keke Chang Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Rare-earth(RE)elements,known as“industrial vitamins”,have permeated modern lives,especially in high-tech *** the RE elements possess close chemical similarities and have been treated as“one element”in the periodic table,their characteristics differ from each *** RE microalloying effect is the crux to ameliorate the physicomechanical and thermochemical properties of materials,thereby the study of RE-related phase diagrams becomes indispensable to the design and optimization of RE-containing ***,in reality,the knowledge base in this area is considerably scarce compared with that of other commonly-used *** this work,the phase equilibria,phase diagrams,phase transformations,and some recent examples of RE-containing materials design are summarized,with which one can predict the RE solubilities,the RE precipitates,as well as the corresponding service *** attainment of enhanced materials’properties suggests that the thermodynamic rules extracted from the phase diagrams could serve as fundamental criteria for the successful development of novel RE-containing materials.

关键词： Rare-earth elements Phase diagrams CALPHAD Phase transformations Materials design

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Simulation of Horizontal-Two-Dimension Focused Waves Using A Two-Layer Boussinesq-Type Model

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China Ocean engineering 2023年第5期37卷 725-737页

作者： ZOU Wen-feng WANG Ping LIU Zhong-bo FANG Ke-zhao SUN Jia-wen ZHANG Ning-chuan Key Laboratory of coastal and offshore engineering Dalian University of TechnologyDalian 116024China State Environmental Protection Key Laboratory of Marine Ecosystem Restoration National Marine Environmental Monitoring CenterDalian 116023China Dalian Maritime University College of Transportation EngineeringDalian 116024China

Accurate simulation of the horizontal-two-dimension(H2D)focused wave group in deep water requires high accuracy of a numerical *** two-layer Boussinesq-type model(Liu and Fang,2016;Liu et al.,2018)with the highest spatial derivative of 2 has high accuracy in both linear and nonlinear *** on the further development of the velocity equations(Liu et al.,2023),the H2D numerical model for water waves is established with the prediction-correction-iteration model in the finite difference method,and a composite fourth-order Adams-Bashforth-Moulton scheme is used for time *** wave generation method proposed by Hsiao et al.(2005)is applied and calibrated in this H2D *** numerical calculations lead to the following three main conclusions:First,compared with the analytical solution of Stokes linear waves,the calculated velocity profiles show higher accuracy by using the improved velocity ***,the simulations of the focused multidirectional wave group are carried out,and good agreements are found,demonstrating that the present H2D numerical model shows high accuracy in simulating focused multidirectional wave groups,and the effectiveness of the improved velocity formulas is also ***,the velocity profiles throughout the computational domain at the time of maximum wave crest are ***,the FFT method is used to obtain the amplitude with different frequencies for several locations,and the changes of the wavelet energy spectrum at different locations are presented for several cases.

关键词： focused wave horizontal-two-dimension model finite difference method nonlinear property

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