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Multi-UAVs Collaborative Path Planning in the Cramped Environment

IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 529-538页

作者： siyuan feng Linzhi Zeng Jining Liu Yi Yang Wenjie Song School of Automation Beijing Institute of TechnologyNanjing 210039China Nanjing Research Institute of Electronics Technology Nanjing 210039China Yichang Testing Technique Research Institute Yichang 443003China IEEE

Due to its flexibility and complementarity, the multiUAVs system is well adapted to complex and cramped workspaces, with great application potential in the search and rescue(SAR) and indoor goods delivery fields. However, safe and effective path planning of multiple unmanned aerial vehicles(UAVs)in the cramped environment is always challenging: conflicts with each other are frequent because of high-density flight paths, collision probability increases because of space constraints, and the search space increases significantly, including time scale, 3D scale and model scale. Thus, this paper proposes a hierarchical collaborative planning framework with a conflict avoidance module at the high level and a path generation module at the low level. The enhanced conflict-base search(ECBS) in our framework is improved to handle the conflicts in the global path planning and avoid the occurrence of local deadlock. And both the collision and kinematic models of UAVs are considered to improve path smoothness and flight safety. Moreover, we specifically designed and published the cramped environment test set containing various unique obstacles to evaluating our framework performance thoroughly. Experiments are carried out relying on Rviz, with multiple flight missions: random, opposite, and staggered, which showed that the proposed method can generate smooth cooperative paths without conflict for at least 60 UAVs in a few *** benchmark and source code are released in https://***/inin-xingtian/multi-UAVs-path-planner.

关键词： Collision avoidance conflict resolution multi-unmanned aerial vehicles(UAVs)system path planning

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轴压比和面承板厚度对混合节点抗震性能的影响

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浙江大学学报（工学版） 2024年第6期58卷 1185-1197页

作者：冯思远陶宇宸金振奋赵唯坚浙江大学建筑工程学院浙江杭州310058 浙江大学平衡建筑研究中心浙江杭州310028 浙江大学建筑设计研究院有限公司浙江杭州310027

为了研究新型柱全截面隔板式钢筋混凝土柱-钢梁(RCS)混合框架节点形式的抗震性能,考虑不同轴压比和面承板厚度的影响,对2组共6个3/4比例的梁柱节点进行低周往复加载试验研究.试验中所有试件均发生设计预期的节点剪切破坏,滞回曲线呈弓型... 详细信息

为了研究新型柱全截面隔板式钢筋混凝土柱-钢梁(RCS)混合框架节点形式的抗震性能,考虑不同轴压比和面承板厚度的影响,对2组共6个3/4比例的梁柱节点进行低周往复加载试验研究.试验中所有试件均发生设计预期的节点剪切破坏,滞回曲线呈弓型,表明节点具有良好的抗震性能.试件最终因节点区的混凝土开裂剥落而丧失承载力.试验结果表明,当轴压比为0~0.25时,随着轴压比的增大,RCS节点开裂荷载有所增大,峰值荷载前斜裂缝数量减少、宽度减小,试件的承载力、刚度和耗能能力均有所提高.节点域柱纵筋黏结应力随轴压比增大而减小,表明节点域内黏结状况有明显改善.相较于单向面承板试件,双向面承板试件在承载能力、延性和耗能能力方面均表现出显著提高;当双向面承板厚度由6 mm增加至10 mm时,试件峰值承载力和刚度的提升幅度相对有限.

关键词：钢筋混凝土柱-钢梁梁柱节点轴压比面承板抗震性能

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教师的四种角色与五重教育境界——兼论智慧教育时代教育学的挑战与重塑

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现代远程教育研究 2024年第2期36卷 28-35页

作者：李树英冯思圆深圳大学教育学部广东深圳518060

数字化、智慧化教育技术的广泛应用开启了全新的智慧教育时代,变革中的教育模式与场景为教师发展以及教育学建设带来了新的机遇与挑战。从教育与技术演进互动的视角出发,教师角色在不同时期经历了由“讲坛上的圣者”到“学生身旁的指引... 详细信息

数字化、智慧化教育技术的广泛应用开启了全新的智慧教育时代,变革中的教育模式与场景为教师发展以及教育学建设带来了新的机遇与挑战。从教育与技术演进互动的视角出发,教师角色在不同时期经历了由“讲坛上的圣者”到“学生身旁的指引者”再到“翅膀上的幽灵”的转变,并在生成式人工智能技术广泛应用的未来存在“人工智能的竞争者”“人工智能的副驾驶”“机器中的灵魂”等多种可能趋势。教师所能达成的教育境界也从“言传身教”“教书”到“教会学习”“赋能学习”乃至“教育即生活”不断发展。在数字化转型进程中,教师需要积极应对技术环境对固有教育模式所带来的挑战,如利用新技术拓展教育的受众、构建动态知识体系、与学生共同探索与学习、实现精准化的教育赋能等,实现教育境界的数字化重塑。而教师角色与教育境界的变化也意味着教育学迎来了重塑与发展的契机。教育学在智慧教育时代应回归“教育即生活”理念,探索创新教育人才培养模式,培养适应智慧教育场景的教师。教师是危机中的领导者,也是未来的重塑者,如何帮助教师在智慧教育时代发挥重要作用,发挥教育者无法被人工智能替代的教育智慧,将是教育学发展与重塑的重要主题。

关键词：教师角色教育境界教师发展智慧教育生成式人工智能

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国土空间治理体系和治理能力现代化的思考

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中国行政管理 2024年第4期40卷 129-140页

作者：严金明冯思远夏方舟中国人民大学公共管理学院北京100872

国土空间治理是国家治理体系和治理能力现代化建设的重要组成部分,如何全面提升国土空间治理体系和治理能力现代化水平是当前理论和实践面临的重大议题。本文以“制度分析与发展”框架为基础构建了治理现代化理论框架,探讨了国土空间治... 详细信息

国土空间治理是国家治理体系和治理能力现代化建设的重要组成部分,如何全面提升国土空间治理体系和治理能力现代化水平是当前理论和实践面临的重大议题。本文以“制度分析与发展”框架为基础构建了治理现代化理论框架,探讨了国土空间治理体系和治理能力现代化的核心内涵。研究提出,国土空间治理体系是以政府、市场、社会治理主体形成的一整套紧密相连、相互协调的国土空间开发利用保护相关的体制机制、法律法规安排,其现代化内涵即要建立符合制度化、法治化、高效化、科学化、民主化等现代化准则要求的“三元四体系”;国土空间治理能力是多元主体基于治理体系、运用相关治理工具开展国土空间治理各方面事务的能力,其现代化内涵是治理主体按照系统化、创新化、标准化、精细化和持续化等现代化准则的要求,不断推进“三元九能力”提升和重构的过程。

关键词：国土空间治理治理体系治理能力现代化

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Effects of 3-D deformation of elastic wings on aerodynamic performance of an aircraft model

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Science China(Technological Sciences) 2023年第5期66卷 1365-1377页

作者： GUO Qinfeng feng siyuan WANG JinJun Fluid Mechanics Key Laboratory of Education Ministry Beijing University of Aeronautics and AstronauticsBeijing 100191China

The wind tunnel experiment is conducted on a simplified aircraft model with rigid and two kinds of elastic wings to investigate the effect of wing 3-D deformation on the aircraft aerodynamic *** results show that two elastic wings exhibit different aerodynamic performances,which are classified as the lift-enhancement wing and the drag-reduction *** the liftenhancement wing,the stall angle is delayed from 8°to 15°with a corresponding lift increment of 64.3%compared with the rigid *** is shown that the lift enhancement of the aircraft model is accompanied by the torsional vibration mode of the wing,which results in the significant improvement of wing *** the drag-reduction wing,the aerodynamic performance is dominated by the time-averaged deformation,which couples the bending and *** wing twist reduces the effective angle of attack,as well as the frontal area,and contributes to the decreased wake ***,the bent wings function as barriers to the cross flow resulting in a reduction of lift-induced *** a result,the drag coefficient is reduced from 0.115 to 0.098 with a reduction of 14.8%at angle of attack of 12°.

关键词： wind tunnel experiment elastic wing aerodynamic force wing deformation wake flow field

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仙林大学城空间生产过程与机制研究

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现代城市研究 2024年第2期39卷 24-28,35页

作者：管曼玲张艺凡冯思源孙世界东南大学建筑学院

文章以“权力—资本—效益”分析框架研究南京仙林大学城的空间生产过程与作用机制。仙林大学城的发展包括3个阶段:多重效益驱使的选址阶段、权力与资本博弈下的开发阶段、多方主体合作发展的运营阶段。需求驱动和资本增值是大学城空间... 详细信息

文章以“权力—资本—效益”分析框架研究南京仙林大学城的空间生产过程与作用机制。仙林大学城的发展包括3个阶段:多重效益驱使的选址阶段、权力与资本博弈下的开发阶段、多方主体合作发展的运营阶段。需求驱动和资本增值是大学城空间生产的机制。政府统筹下的城市建设加上多方参与的城市实践有利于调节市场运行规律,避免投资风险,促进空间生产的良性循环。文化效益和环境效益是大学城开发建设过程中提升城市品质、促进转型发展的关键。

关键词：空间生产权力与资本资本增值仙林大学城南京

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Influence of membrane wing active deformation on the aerodynamic performance of an aircraft model

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Science China(Technological Sciences) 2022年第10期65卷 2474-2484页

作者： feng siyuan GUO Qinfeng WANG JinJun XU Yang Fluid Mechanics Key Laboratory of Education Ministry Beijing University of Aeronautics and AstronauticsBeijing 100191China

The aerodynamic performance of a simplified aircraft model with a pair of actively deformed membrane wings is investigated experimentally in this work. The active deformation is achieved with Macro fiber composite(MFC) actuators, which are attached to the upper surface of the wings and occupied 13.7% of the wing surface area. Wind tunnel experiments are conducted to evaluate the influence of membrane active deformation on the aerodynamic performance of the aircraft. The results show that the membrane deforms and vibrates under the actuation which can effectively suppress the leading-edge separation and facilitate the reattachment. Therefore, compared with the rigid wing model, the lift coefficient of the actively deformed membrane wing model is enhanced remarkably from the angle of attack of 7° to 22°. The stall angle is delayed by 2°, and a maximum lift coefficient enhancement of 32.5% is reached, which shows a wide potential application in improving the aerodynamic performance of modern aircraft.

关键词： fluid-structure interaction flexible membrane wing active control force measurement flow field measurement

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Design of multi-section luffing apple pruning equipment and cutting test of the key components

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 109-117页

作者： siyuan Tong Wenbin Li Yaxiong Wang Lei Zhang feng Kang School of Technology Beijing Forestry UniversityKey Lab of State Forestry and Grassland Administration for Forestry Equipment and AutomationBeijing 100083China

In order to reduce the labor intensity and improve the efficiency of pruning,this study designed a multi-section luffing apple pruning equipment suitable for apple orchards in hilly and mountainous areas of *** the essay,the structure and working principle of the equipment are expounded,the cutter was analyzed,and the parameters were *** the self-made test bench to simulate the field experiment,this study selected the ratio of cutting speed to feeding speed and feeding speed as the influencing factors and took the cut-off rate,cutting efficiency and cutting power as the objectives to carry out single factor experiment and quadratic regression orthogonal *** test results show that the cutting power increases with the increase of ratio of cutting speed to feeding speed,and the cut-off rate and cutting efficiency first increase and then *** the feeding speed increases,the cutting efficiency and power increase,and the cut-off rate *** the cutoff rate was greater than 80%,the optimal combination of operating parameters was the feeding speed of 0.55 m/s and ratio of cutting speed to feeding speed of *** this combination,the cut-off rate was 84.9%,the cutting efficiency was 13.1,and the cutting power was 175.7 *** error between the predicted target value of the model and the average measured target value was less than 7%,so the test results are *** to the obtained optimal operating parameters,the actual cutting experiment of the pruning equipment in the field was carried out,and the cutting rate was 96.3%,which meet the design *** study can also meet the needs of mechanized pruning of fruit trees with different crown shapes,improve the applicability of pruning equipment,and provide support for the development of mechanized pruning equipment in China.

关键词： apple pruning equipment cutting test optimal parameters regression analysis

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高温与冷却方式对纤维混凝土影响研究

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新型建筑材料 2024年第1期51卷 25-28页

作者：孙传武王学志任莉莉冯思源辛明贺晶晶辽宁工业大学土木建筑工程学院辽宁锦州121001 辽宁铁道职业技术学院铁道工程学院辽宁锦州121001 中国电建集团西北勘测设计研究院有限公司陕西西安710065

研究了高温对玻璃-聚丙烯混杂纤维混凝土的影响,对比了不同的冷却方式对混凝土强度的影响,基于试验结果分析了高温损伤机理和纤维增强机理。研究表明:喷水冷却对混凝土强度损伤大,玻璃纤维和聚丙烯纤维混掺掺量分别为0.4%和0.1%时,能够... 详细信息

研究了高温对玻璃-聚丙烯混杂纤维混凝土的影响,对比了不同的冷却方式对混凝土强度的影响,基于试验结果分析了高温损伤机理和纤维增强机理。研究表明:喷水冷却对混凝土强度损伤大,玻璃纤维和聚丙烯纤维混掺掺量分别为0.4%和0.1%时,能够显著提高混凝土的耐火性能,在400℃下,自然冷却时,抗压和抗折强度较基准组分别提高了15.3%和30.9%;喷水冷却时,抗压和抗折强度较基准组分别提高了21.3%和30.3%。

关键词：高温冷却方式玻璃纤维聚丙烯纤维混凝土

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Nano-scale Reinforcements and Properties of Al-Si-Cu Alloy Processed by High-Pressure Torsion

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1253-1259页

作者： DONG Ying WU siyuan HE Ziyang LIANG Chen CHENG feng HE Zuwei QIAN Chenhao School of Mechanical Engineering Jiangnan UniversityWuxi 214122China Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology Wuxi 214122China School of International Studies Renmin University of ChinaBeijing 100872China School of Engineering University of LiverpoolLiverpool L693GHUnited Kingdom

To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu alloy was *** results show that the reinforcements(β-Si andθ-CuAl_(2)phases)of the Al-Si-Cu alloy are dispersed in theα-Al matrix phase with finer phase size after the *** processed samples exhibit grain sizes in the submicron or even nanometer range,which effectively improves the mechanical properties of the *** hardness and strength of the deformed alloy are both significantly raised to 268 HV and 390.04 MPa by 10 turns HPT process,and the fracture morphology shows that the material gradually transits from brittle to plastic before and after *** elements interdiffusion at the interface between the phases has also been effectively *** addition,it is found that the severe plastic deformation at room temperature induces a ternary eutectic reaction,resulting in the formation of ternary Al+Si+CuAl_(2)eutectic.

关键词： Al-Si-Cu alloy high-pressure torsion nano-scale reinforcements ternary eutectic

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