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无人机空战的竞争与双重深度强化学习机动对抗决策

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厦门大学学报（自然科学版） 2022年第6期61卷 975-985页

作者：欧洋徐扬张金鹏罗德林厦门大学航空航天学院福建厦门361102 西北工业大学民航学院陕西西安710072 西北工业大学太仓长三角研究院江苏苏州215400 中国空空导弹研究院航空制导武器航空科技重点实验室河南洛阳471009

针对一对一无人机(unmanned aerial vehicle,UAV)空战格斗问题,提出了一种基于竞争与双重深度强化学习的机动对抗方法.建立UAV的状态转移机制和态势奖励模型,将空战态势分为4种基本类型,根据贝叶斯推理计算4种态势的概率,动态地选择不... 详细信息

针对一对一无人机(unmanned aerial vehicle,UAV)空战格斗问题,提出了一种基于竞争与双重深度强化学习的机动对抗方法.建立UAV的状态转移机制和态势奖励模型,将空战态势分为4种基本类型,根据贝叶斯推理计算4种态势的概率,动态地选择不同的权重.在竞争深度Q网络(dueling-DQN)算法和双重深度Q学习网络(double-DQN)算法的基础上结合两者的优点,将网络的输出分为价值函数和优势函数两部分,并通过“双重网络”解耦动作的选择与价值的评估,提出dueling-double-DQN(DDDQN)算法,作为UAV的决策核心,提高了算法的收敛性,改善了Q值被过高估计的问题.仿真结果表明所提出的决策方法的有效性.

关键词：无人机空战决策强化学习竞争与双重网络

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Effects of Number of Bleed Holes on Shock-Wave/Boundary-Layer Interactions in a Transonic Compressor Stator

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Journal of Thermal Science 2024年第2期33卷 611-624页

作者： LI Bai ZHOU Xun luo Lei DU Wei School of Energy Science and Engineering Harbin Institute of TechnologyHarbin150001China

An extensive numerical investigation is conducted to characterize the flow separation control in a transonic compressor cascade with a porous *** bleed holes are arranged on the suction surface in a single row,two staggered rows and three staggered *** each bleed scheme,five bleed pressure ratios are examined at an inlet Mach number of *** results indicate that the aerodynamic performance of the cascade is significantly improved by the porous *** the single-row scheme,the maximum reduction in total pressure losses is 57%.For the two-staggered-row and three-staggered-row schemes,there is an optimal bleed pressure ratio of 1.0,and the maximum reductions in total pressure loss are 68% and 75%,*** low loss in the cascade is due to the well-controlled boundary *** new local supersonic region created by the bleed hole is the key reason for the improved boundary *** vortex induced by side bleeding provides another mechanism for delaying flow *** the bleed holes could create multiple local supersonic regions,which reduce the range of the adverse pressure gradient that the boundary layer needs to *** is the reason why cascades with more bleed holes perform better.

关键词： transonic compressor stator shock wave/boundary layer interaction porous bleed number of bleed holes

Short-time maritime target detection based on polarization scattering characteristics

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Journal of Systems Engineering and Electronics 2024年第1期35卷 55-64页

作者： CHEN Shichao luo Feng TIAN Min LYU Wanghan College of Computer and Information Engineering(College of Artificial Intelligence) Nanjing Tech UniversityNanjing 211816China Hangzhou Institute of Technology Xidian UniversityHangzhou 311200China

In this paper,a detection method combining Cameron decomposition based on polarization scattering characteristics in sea clutter background is ***,the Cameron decomposition is exploited to fuse the radar echoes of full polarization channels at the data *** to the artificial material structure on the surface of the target,it can be shown that the non-reciprocity of the target cell is stronger than that of the clutter ***,based on the analysis of the decomposition results,a new feature with scattering geometry characteristics in polarization domain,denoted as Cameron polarization decomposition scattering weight(CPD-SW),is extracted as the test statistic,which can achieve more detailed descriptions of the clutter scattering characteristics utilizing the difference between their scattering ***,the superiority of the proposed CPD-SW detector over traditional detectors in improving detection performance is verified by the IPIX measured dataset,which has strong stability under short-time observation in threshold detection and can also improve the separability of feature space zin anomaly detection.

关键词： sea clutter small target radar detection Cameron decomposition characteristics analysis

Gear walk instability caused by brake-disc friction characteristics

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Chinese Journal of Aeronautics 2024年第2期37卷 343-359页

作者： Xiaoqiong DU Bin LI Wen CAI Linyin luo School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Department of Mechanical Engineering University of MichiganAnn Arbor 48109USA AVIC General Huanan Aircraft Industry Co.Ltd. Zhuhai 519040China

A multi-body dynamic rigid-flexible coupling model of landing gear is established to study the gear walk instability caused by the friction characteristics of the brake *** validating the model with the experimental results,the influence of the landing gear structure and braking system parameters on gear walk is further *** the above factors,the slope of the graph for the friction coefficient of the brake disc and the relative velocity of brake stators and rotors is the most influential factor on gear walk *** trajectory analysis verifies that gear walk occurs when the coupling of multiple factors causes the system to exhibit an equivalent negative damping *** consider a more realistic braking case,a back propagation neural network method is employed to describe the nonlinear behavior of the friction coefficient of the brake *** the realistic nonlinear model of the friction coefficient,the maximum error in predicting the braking torque is less than 10%and the effect of the brake disc temperature on gear walk is *** results reveal that a more negative friction slope may contribute to a more severe unstable gear walk,and reducing the braking pressure is an effective approach to avoid gear walk,which provides help for future braking system design.

关键词： Gear walk Friction characteristics of brake disc Brake-induced vibration Negative damping Rigid-flexible coupling Negative slope of braking torque

AWells-Riley/based COVID-19 infectiousrisk assessment model combining both short rangeandroom scale effects

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Building Simulation 2024年第1期17卷 93-111页

作者： Yinshuai Feng Yifan Fan Xiaoyu luo Jian Ge College of Civil Engineering and Architecture Zhejiang UniversityHangzhouChina Center for Balance Architecture Zhejiang UniversityHangzhouChina International Research Center for Green Building and Low-Carbon City International CampusZhejiang UniversityHainingChina

There is growing evidence of the high transmission potential of COVID-19 through virus-laden *** aerosols are inhaled in various concentrations,an overall assessment of transmission risks at different indoor scales is ***,a comprehensive risk assessment method that evaluates the direct link between short-range and room-scale zones is stl *** this paper,a risk assessment model combining both short-range and room-scale effects is developed to obtain effective reproduction number in confined indoor environments,called Turbulent Jet Wells Riley(TJWR)*** with the viral load data and aerosol generation data of different human respiratory activities,the Monte Carlo simulation method is applied to calculate the quanta emission rate,which further provides the input parameters of the TJWR *** known outbreaks(Hangzhou banquet hall X,Guangzhou restaurant Y,and Hong Kong restaurant Z,China)are chosen to validate the TJWR *** show that the TJWR model is more efficient than the original Wells-Riley *** average relative error of the TJWR model ranges between 9%and 44%,while for the Wells-Riley model,it ranges between 57%and 78%.The TJWR model also proves that infection risk assessments using the well-mixed assumption can systematically underestimate the transmission risk for those close to the ***,there is a significant positive linear correlation between the total number of exposed individuals at the short-range and the effective reproduction *** newly developed TJWR model has great potential for rapid and real-time overall airborne transmission risk assessment in buildings and cities.

关键词： COVID-19 airborne transmission infection risk Wells-Riley model Monte Carlo simulation

An anonymous authentication and secure data transmission scheme for the Internet of Things based on blockchain

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Frontiers of Computer Science 2024年第3期18卷 183-197页

作者： Xingxing CHEN Qingfeng CHENG Weidong YANG Xiangyang luo State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou Institute of Information Science and TechnologyZhengzhou 450001China Henan Key Laboratory of Grain Photoelectric Detection and Control Henan University of TechnologyZhengzhou 450001China Henan Province Key Laboratory of Cyberspace Situation Awareness Zhengzhou Institute of Information Science and TechnologyZhengzhou 450001China

With the widespread use of network infrastructures such as 5G and low-power wide-area networks,a large number of the Internet of Things(IoT)device nodes are connected to the network,generating massive amounts of ***,it is a great challenge to achieve anonymous authentication of IoT nodes and secure data *** present,blockchain technology is widely used in authentication and s data storage due to its decentralization and ***,Fan et *** a secure and efficient blockchain-based IoT authentication and data sharing *** studied it as one of the state-of-the-art protocols and found that this scheme does not consider the resistance to ephemeral secret compromise attacks and the anonymity of IoT *** overcome these security flaws,this paper proposes an enhanced authentication and data transmission scheme,which is verified by formal security proofs and informal security ***,Scyther is applied to prove the security of the proposed ***,it is demonstrated that the proposed scheme achieves better performance in terms of communication and computational cost compared to other related schemes.

关键词： Internet of Things blockchain authentication data transmission

Progress in research on the exploration and evaluation of deep geothermal resources in the Fujian-Guangdong-Hainan region,China

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Energy Geoscience 2024年第2期5卷 1-13页

作者： Herong Zheng Jun luo Petroleum Exploration and Production Research Institute SINOPECBeijing 102206China

Deep geothermal resources in the Fujian-Guangdong-Hainan region,China,offer significant potential for sustainable *** diverse igneous rock formations along the southeast coast present intricate geological challenges that impede exploration and evaluation *** this study,we address critical concerns related to the Fujian-Guangdong-Hainan region's deep geothermal resources,encompassing heat source composition,formation conditions,strategic favorable areas,and exploration *** methods involve the analysis of regional geothermal reservoirs and cap *** findings include:the primary heat sources in the Fujian-Guangdong-Hainan region consist of the radioactive heat generation from granites in the crust,heat conduction in the mantle,and,in specific areas like Yangjiang and Shantou,melts within the middle and lower crust;the deep,high-temperature geothermal resources in the region predominantly reside in basins'depressed *** areas are characterized by the confluence of triple heat sources:heat from the Earth's crust,mantle,and other supplementary sources;our analysis led to the identification of three strategic areas favorable for deep geothermal resources in the Fujian-Guangdong-Hainan *** are the Beibu Gulf Basin's continental area,the Yuezhong Depression,and the Fuzhou-Zhangzhou area.

关键词： Deep geothermal resources Geology of geothermal energy Strategic selection

A universal and ultrafast method for fabricating a library of nanocellulose-supported metal nanoparticles

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Progress in Natural Science:Materials International 2024年第2期34卷 389-395页

作者： Ziyi luo Xiaoyang Wang Baihua Cui Hao luo Tao Zhang Jia Ding Yanan Chen Yida Deng Wenbin Hu School of Materials Science and Engineering Tianjin University Department of Chemistry National University of Singapore State Key Laboratory of Marine Resource Utilization in South China Sea School of Materials Science and Engineering Hainan University

Using nanocatalysts to catalyze water electrolysis for hydrogen production is an ideal solution to address the energy *** most well-adopted fabrication methods for nanocatalysts are tube furnace annealing,Hydrothermal method,etc.,hardly satisfying the trade-off among coarsening,dispersity,and particle size due to mutual ***,a universal,ultrafast and facile cellulose nanometer whiskers-high temperature shock（CNWHTS） method was reported for fabricating a library of ultrafine metal nanoparticles with uniform dispersion and narrow size *** metal-anchor functional groups in CNW（i.e.,-OH and-COOH） and the characteristics of the HTS method for ultrafast heating and powerful quenching synergistically contribute to the successful synthesis of metal *** an initial demonstration,the as-prepared Pt nanocatalyst(η10 mA cm-2=51.8 mV) shows more excellent catalytic hydrogen evolution reaction（HER） performance than the Pt catalyst prepared in the tubular furnace(η10 mA cm-2=169.4 mV).This rapid and universal CNW-HTS method can pave the way for nanomanufacturing to produce high-quality metal nanoparticles,thereby expanding applications of energy conversion and electrocatalysis.

关键词： Electrocatalysis High-temperature shock Hydrogen evolution reaction (HER) Nanocellulose Nanomanufacturing Nanoparticles

Role of inflammatory lipid and fatty acid metabolic abnormalities induced by plastic additives exposure in childhood asthma

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Journal of Environmental Sciences 2024年第3期137卷 172-180页

作者： Zhiyu Chen Fang Li Lei Fu Yu Xia Ying luo Ang Guo Xiaona Zhu Huifang Zhong Qian luo Institute of Biomedical and Health Engineering Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China Rheumatology&Immunology Department of Shenzhen Children’s Hospital Shenzhen 518038China Hubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances Institute of Environment and HealthJianghan UniversityWuhan 430056China

Lipid metabolism play an essential role in occurrence and development of asthma,and it can be disturbed by phthalate esters(PAEs)and organophosphate fame retardants(OPFRs).As a chronic infammatory respiratory disease,the occurrence risk of childhood asthma is increased by PAEs and OPFRs exposure,but it remains not entirely clear how PAEs and OPFRs contribute the onset and progress of the *** have profiled the serum levels of PAEs and OPFRs congeners by liquid chromatography coupled with mass spectrometry,and its relationships with the dysregulation of lipid metabolism in asthmatic,bronchitic(acute infammation)and healthy(non-infammation)*** PAEs and nine OPFRs congeners were found in the serum of children(1–5 years old)from Shenzhen,and their total median levels were 615.16 ng/m L and 17.06 ng/m L,***,the serum levels of mono-methyl phthalate(MMP),tri-propyl phosphate(TPP)and tri-n-butyl phosphate(TNBP)were significant higher in asthmatic children than in healthy and bronchitic children as ***-one characteristic lipids and fatty acids of asthma were screened by machine-learning random forest model based on serum lipidome data,and the alterations of infammatory characteristic lipids and fatty acids including palmitic acids,12,13-Di HODE,14,21-Di HDHA,prostaglandin D2 and Lyso PA(18:2)showed significant correlated with high serum levels of MMP,TPP and *** results imply PAEs and OPFRs promote the occurrence of childhood asthma via disrupting infammatory lipid and fatty acid metabolism,and provide a novel sight for better understanding the effects of plastic additives on childhood asthma.

关键词： Phthalate esters Organophosphate fame retardants Childhood asthma Lipid and fatty acid metabolism Machine-learning random forest model Chronic airway infammation