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Mastering air combat game with deep reinforcement learning

Defence Technology（防务技术） 2024年第4期34卷 295-312页

作者： Jingyu Zhu Minchi Kuang Wenqing Zhou Heng Shi Jihong Zhu Xu Han Department of Precision Instruments Tsinghua UniversityBeijing 100084China Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China Chengdu Aircraft design&Research Institute Aviation Industry Corporation of ChinaChengdu 610000China

Reinforcement learning has been applied to air combat problems in recent years,and the idea of curriculum learning is often used for reinforcement learning,but traditional curriculum learning suffers from the problem of plasticity loss in neural *** loss is the difficulty of learning new knowledge after the network has *** this end,we propose a motivational curriculum learning distributed proximal policy optimization(MCLDPPO)algorithm,through which trained agents can significantly outperform the predictive game tree and mainstream reinforcement learning *** motivational curriculum learning is designed to help the agent gradually improve its combat ability by observing the agent's unsatisfactory performance and providing appropriate rewards as a ***,a complete tactical maneuver is encapsulated based on the existing air combat knowledge,and through the flexible use of these maneuvers,some tactics beyond human knowledge can be *** addition,we designed an interruption mechanism for the agent to increase the frequency of decisionmaking when the agent faces an *** the number of threats received by the agent changes,the current action is interrupted in order to reacquire observations and make decisions *** the interruption mechanism can significantly improve the performance of the *** simulate actual air combat better,we use digital twin technology to simulate real air battles and propose a parallel battlefield mechanism that can run multiple simulation environments simultaneously,effectively improving data *** experimental results demonstrate that the agent can fully utilize the situational information to make reasonable decisions and provide tactical adaptation in the air combat,verifying the effectiveness of the algorithmic framework proposed in this paper.

关键词： Air combat MCLDPPO Interruption mechanism Digital twin Distributed system

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Application of controlled-release urea increases maize N uptake,environmental benefits and economic returns via optimizing temporal and spatial distributions of soil mineral N

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Pedosphere 2024年第1期34卷 222-235页

作者： Mingxue SUN Juan LI Lili ZHANG Xiaomeng SU Ning LIU Xiaori HAN Songjiang WU Zhentao SUN Xiangdong YANG Institute of Agricultural Resources and Regional planning Chinese Academy of Agricultural Sciences/State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China/Key Laboratory of Plant Nutrition and FertilizerMinistry of Agriculture and Rural AffairsBeijing 100081China Agricultural Development Service Center of Zhuanghe Zhuanghe 116499China Agricultural Technology Extension Center Wafangdian 116300China College of Land and Environment Shenyang Agricultural UniversityShenyang 100866China

The creation of controlled-release urea (CRU) is a potent substitute for conventional fertilizers in order to preserve the availability of nitrogen (N) in soil,prevent environmental pollution,and move toward green *** main objectives of this study were to assess the impacts of CRU’s full application on maize production and to clarify the connection between the nutrient release pattern of CRU and maize nutrient *** order to learn more about the effects of CRU application on maize yields,N uptake,mineral N (N_(min)) dynamics,N balance in soil-crop systems,and economic returns,a series of field experiments were carried out in 2018–2020 in Dalian City,Liaoning Province,*** were 4 different treatments in the experiments:no N fertilizer input (control,CK);application of common urea at 210 kg ha^(-1)(U),the ideal fertilization management level for the study site;application of polyurethane-coated urea at the same N input rate as U (PCU);and application of PCU at a 20% reduction in N input rate (0.8PCU).Our findings showed that using CRU (i.e.,PCU and 0.8 PCU) may considerably increase maize N absorption,maintain maize yields,and increase N use efficiency (NUE) compared to *** grain yield showed considerable positive correlations with total N uptake in leaf in U and 0.8 PCU,but negative correlations with that in PCU,indicating that PCU caused excessive maize absorption while 0.8 PCU could achieve a better yield response to N ***,PCU was able to maintain N fertilizer in the soil profile 0–20 cm away from the fertilization point,and higher N_(min)content was observed in the 0–20 cm soil layer at various growth stages,particularly at the middle and late growing stages,optimizing the temporal and spatial distributions of N_(min).Additionally,compared to that in U,the apparent N loss rate in PCU was reduced by 36.2%,and applying CRU (PCU and 0.8 PCU) increased net profit by 8.5% to 15.2% with less labor and fertilization *** was co

关键词： apparent N loss fertilization management green agriculture maize yield N balance N use efficiency

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Molecular Dynamics Simulation on Friction and Thermal Properties of FCC Copper in Nanoscale Sliding Contacts

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Journal of Harbin Institute of Technology(New Series) 2022年第2期29卷 24-33页

作者： Ruiting Tong Bin Han Tao Zhang Zefen Quan Geng Liu Shaanxi Engineering Laboratory for Transmissions and Controls Northwestern Polytechnical UniversityXi′an 710072China Jiangsu Automation Research Institute Jiangsu Lianyungang 222061China china academy of Launch Vehicle Technology Beijing 100076China Shanghai Aircraft design and Research Institute Shanghai 200232China

In nanoscale sliding contact,adhesion effects and adhesive force are predominant,and high friction force will be *** energy is mainly converted into heat,and the heat will make nanomaterials become soft to affect friction behaviors,so it is important to investigate the friction and thermal properties of the nanoscale sliding contacts.A model of a nanoscale sliding contact between a rigid cylindrical tip and an FCC copper substrate is developed by molecular dynamics *** thermal properties of the substrate and the friction behaviors are studied at different sliding velocities and different tip *** results show that at a low sliding velocity,the friction force fluctuation is mainly caused by material melting⁃solidification,while at a high sliding velocity the material melting is a main factor for the friction *** average friction forces increase at initial phase and then decrease with increasing sliding velocity,and the average temperature of the substrate increases as sliding velocity *** tip radius significantly increases the temperature,while the coupled effects of tip radius and temperature rise make friction force increase slightly.

关键词： molecular dynamics friction property thermal property nanoscale sliding contact

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Core reinforcement design for improving flexural energy-absorption of corrugated sandwich composite structure

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Chinese Journal of Aeronautics 2021年第5期34卷 510-522页

作者： Yiru REN Yabin DENG Hongyong JIANG State Key Laboratory of Advanced design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China College of Mechanical and Vehicle Engineering Hunan UniversityChangsha 410082China

To strengthen Specific Energy-Absorption(SEA)behavior of Sandwich Composite Structure(SCS),a kind of light-weight vertical stiffener is proposed for the corrugated *** vertical stiffener,embedded in the corrugated core,can not only absorb part of energy but also simultaneously enhance Energy-Absorption(EA)of other *** Hashin damage model considering the shear stress and ductile damage model is adopted to predict the failure of carbon fiber face-sheets and aluminum-core,*** perfect bonding is modeled for interfaces between the face-sheet and core due to little realistic *** finite element model is verified by available data of conventional *** obtain more design ideas,several stiffeners with different thicknesses,numbers,and positions are *** the predicted results,both the flexural load and deformation of SCS correlate well with experimental *** is highlighted that the SCSs with different vertical stiffeners exhibit 9.74%-58.48%higher SEA than the SCS without *** complex reinforcement mechanisms are extensively revealed by underlying coupling EA and deformation *** parameter analysis shows that the thickness and number have significant effects on the flexural behavior and SEA of reinforced SCS.

关键词： Energy absorption Finite element Reinforcement Sandwich structure

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Spatial distribution of maize in response to climate change in northeast china during 1980–2010

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Journal of Geographical Sciences 2016年第1期26卷 3-14页

作者：李正国谭杰扬唐鹏钦陈浩张莉刘晗吴文斌唐华俊杨鹏刘珍环 Chinese academy of Agricultural Sciences Key Laboratory of Agri-informaticsMinistry of Agriculture/Institute of Agricultural Resources and Regional Planning Hunan academy of Agricultural Sciences Institute of Agricultural Economics and Regional Planning Sun Yat-sen University School of Geography and Planning

Based on county-level crop statistics and other ancillary information, spatial distri- bution of maize in the major maize-growing areas （latitudes 39°-48°N） was modelled for the period 1980-2010 by using a cross-entropy-based spatial allocation model. Maize extended as far north as the northern part of the Lesser Khingan Mountains during the period, and the area sown to maize increased by about 5 million ha. More than half of the increase occurred before 2000, and more than 80% of it in the climate transitional zone, where the annual ac- cumulated temperature （AAT） was 2800-3400 ℃.d. Regions with AAT of 3800-4000 ℃-d became more important, accounting for more than 25% of the increase after 2000. The ex- pansion of maize was thus closely related to warming, although some variation in the distri- bution was noticed across zones in relation to the warming, indicating that maize in northeast china may have adapted successfully to the warming by adjusting its spatial distribution to match the changed climate.

关键词： climate warming regional response spatial pattern Zea mays china

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Improving Investment and Financing Mechanism, Speeding up the Energy Reform Process-Interpretation to Implementing Opinions on Deepening Reform of Investment and Financing System in Energy Industry

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china Oil & Gas 2018年第2期25卷 11-16页

作者： Xu Huiwen Wang Zhen academy of Chinese Energy Strategy China University of Petroleum-Beijing Petrochina planning & Engineering Institute

Under the context of economic transformation and upgrading and the continued advancement of supplyside reforms in china, the development of the energy industry is confronted with many problems and challenges, such as insufficient energy investment, a shortage of financing channels,and the low participation of social capital. In order to fully mobilize social capital to invest in energy, enhance energy investment efficiency, expand energy financing channels,and increase the vitality of the energy industry, the state has recently issued the Implementing Opinions on Deepening the Reform of Investment and the Financing System in the Energy Industry( "Opinions"). This paper provides a deep interpretation of this document from the perspectives of the background for the investment and financing system reform in the energy industry,the main content of the reform, the problems and challenges confronting the reform,and the expected effects from the reform, and analyzes the objectives, ideas and problems of the reform, in order to effectively promote the investment and financing system reform in the energy industry.

关键词： Energy industry Investment and financing System reform

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Research on Multi-Objective Optimization Model of Industrial Microgrid Considering Demand Response Technology and User Satisfaction

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Energy Engineering 2023年第4期120卷 869-884页

作者： Junhui Li Jinxin Zhong Kailiang Wang Yu Luo Qian Han Jieren Tan Dongguan Power Supply Bureau Dongguan523000China Guangdong Electric Power design and Research Institute Guangzhou510000China

In the process of wind power,coal power,and energy storage equipment participating in the operation of industrial microgrids,the stable operation of wind-storage industrial microgrids is guaranteed by considering demand response technology and user *** paper firstly sorts out the status quo of microgrid operation optimization,and determines themain requirements for user satisfaction considering three types of load characteristics,demand response technology,power consumption benefit loss,user balance power purchase price and wind power consumption evaluation indicators in the ***,the operation architecture of the windstorage industrialmicrogrid is designed,and themulti-objective optimizationmodel of the wind-storage industrial microgrid is established with the comprehensive operating cost and user satisfaction as the target variables,and the corresponding solution method is ***,a typical wind-storage industrial microgrid is selected for simulation analysis,and the results showthat,(1)Considering the demand response technology,the comprehensive operating cost of the wind-storage industrial microgrid per day is 5292.63 yuan,the user satisfaction index is 0.953,and the wind power consumption rate reaches 100%.(2)By setting four scenarios,it highlights that the grid-connected operation mode is superior to the off-grid operation *** the demand response technology,the load curve can be optimized,and the time-of-use electricity price can be fully used to coordinate the operation of each unit,which enhances the wind power consumption *** compromise solution of the system comprehensive operating cost and user satisfaction under the confidence level of 0.95 is obtained,namely(5343.22,0.94).(3)The frontier curve shows that in the process of model solving,it is impossible to optimize any sub-objective by changing the control variables,which proves that there is a close relationship between the comprehensive operating

关键词： Wind storage industrial microgrid demand response user satisfaction

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Athermal design of the mirror support with flexure hinges for the laser communication terminal

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Optoelectronics Letters 2019年第6期15卷 454-458页

作者： YANG Feng-fu TIAN Hai-ying YAN Chang-xiang WU Cong-jun MU De-qiang Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China University of Chinese academy of Sciences Beijing 100049China Center of Materials Science and Optoelectrics Engineering University of Chinese Academy of ScienceBeijing 100049China Changchun University of Technology Changchun 130012China

In order to suppress the effect of the temperature variation on the wavefront of the laser communication terminal, the secondary mirror support with flexure hinges is designed. The series-wound straight-circle flexure hinge is designed to achieve the maximal variation range of the flexibility or stiffness with the limit of flexure hinges' geometrical size. The position and quantity of the flexure hinges are determined to control the deformation direction of the secondary mirror. In order to search the direction in which the wavefront aberration is minimum, the flexure hinges' parameters are optimized with the system wavefront aberration as the optimization objective. The prototype of the laser communication terminal is constructed and the value of the wavefront aberration is measured under the condition of 20±2°C. Experimental results show that the value of the wavefront aberration root mean square(RMS) is reduced from 0.066λ to 0.042λ, meeting the requirement of RMS less than 1/20λ(λ=632.8 nm). The athermal design method presented in this paper provides a novel way for the athermal design of the small aperture mirror support in off-axis optical systems.

关键词： communication laser mirror

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Cognitive J^(2)SAC:Joint Jamming,Sensing,and Communication Under Antagonistic Environment

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china Communications 2023年第9期20卷 78-95页

作者： Jiangchun Gu Guoru Ding Yizhen Yin Haichao Wang Yitao Xu Yehui Song College of Communications Engineering Army Engineering UniversityNanjing 210007China College of Joint design and Innovation Xi’an Jiaotong UniversityXi’an 710049China

Integrated sensing and communication(ISAC)is regarded as a recent advanced technology,which is expected to realize the dual functions of sensing and communication simultaneously in one ***,it still faces the challenges of the information security and transmission robustness caused by the openness of wireless channel,especially under antagonistic ***,this article develops a generalized framework,named cognitive joint jamming,sensing and communication(cognitive J2SAC),to empower the current sensing/communication/jamming system with a“brain”for realizing precise sensing,reliable communication and effective jamming under antagonistic *** kinds of gains can be captured by cognitive J2SAC,including integrated gain,cooperative gain and cognitive ***,we highlight the enabling mechanism among jamming,sensing,and communication,as well as illustrating several typical use cases of cognitive ***,several key enabled technologies are analyzed and a typical sensing enhance integrated communication and jamming case study is discussed to verify the effectiveness of the proposed *** but not the least,the future directions are listed before concluding this *** sensing and communication(ISAC)is regarded as a recent advanced technology,which is expected to realize the dual functions of sensing and communication simultaneously in one ***,it still faces the challenges of the information security and transmission robustness caused by the openness of wireless channel,especially under antagonistic ***,this article develops a generalized framework,named cognitive joint jamming,sensing and communication(cognitive J2SAC),to empower the current sensing/communication/jamming system with a“brain”for realizing precise sensing,reliable communication and effective jamming under antagonistic *** kinds of gains can be captured by cognitive J2SAC,including integrated gain

关键词： integrated sensing and communication(ISAC) information security joint jamming,sensing and communication(J2SAC) cognition theory

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Optimization research on supply and demand system for water resources in the Chang-Zhu-Tan urban agglomeration

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Journal of Geographical Sciences 2015年第11期25卷 1357-1376页

作者： XIONG Ying LI Jingzhi JIANG Dingling Department of Resources and Environmental Sciences Changsha University of Science and TechnologyChangsha 410114 China Research Center of Resource Environment and urban planning Changsha University of Science & Tech-nology Changsha 410114 China

Using system analysis theory and methods, a dynamic model of a water resource supply and demand system was built to simulate trends in the supply and demand of water in the Changsha-Zhuzhou-Xiangtan （Chang-Zhu-Tan） urban agglomeration for the period 2012 to 2030. Four scenarios were examined; namely, a traditional development model, an economic development model, a water-saving model, and a coordinated development model. （i） The problem of balancing water resource supply and demand is becoming increasingly conspicuous with a growing population and a rapidly developing economy. （ii） By 2030, water demand is set to reach a total of 105.1 × 10^8 m^3, with a water supply of 5.4 × 10^8 m^3. A coordinated development model for water resource supply could meet the growing demands of socio-economic development, and generate huge comprehensive benefits. This will be the best solution for the development and utilization of a water resource supply and demand system in the Chang-Zhu-Tan urban agglomeration. （iii） We should accelerate the construction of water conservation projects, strengthen the management of water conservation, optimize economic structures, enhance our awareness of the importance of protecting water resources, hasten the recycling of waste water and environmental improvement, and promote utilization efficiency, and support the capabilities of water resources to meet our expectations.

关键词： water resource supply and demand system analog simulation optimization decision-making system dynamics Chang-Zhu-Tan (Changsha-Zhozhoa-Xiangtan) urban agglomeration

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