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A physics-informed deep learning framework for spacecraft pursuit-evasion task assessment

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Chinese Journal of Aeronautics 2024年第5期37卷 363-376页

作者： Fuyunxiang YANG Leping YANG Yanwei zhu College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

Qualitative spacecraft pursuit-evasion problem which focuses on feasibility is rarely studied because of high-dimensional dynamics,intractable terminal constraints and heavy computational *** this paper,A physics-informed framework is proposed for the problem,providing an intuitive method for spacecraft threat relationship determination,situation assessment,mission feasibility analysis and orbital game rules *** the first time,situation adjustment suggestions can be provided for the weak player in orbital ***,a dimension-reduction dynamics is derived in the line-of-sight rotation coordinate system and the qualitative model is determined,reducing complexity and avoiding the difficulty of target set presentation caused by individual ***,the Backwards Reachable Set(BRS)of the target set is used for state space partition and capture zone ***-time analysis can eliminate the influence of changeable initial state and enable the proposed framework to analyze plural situations ***,a time-dependent Hamilton-Jacobi-Isaacs(HJI)Partial Differential Equation(PDE)is established to describe BRS evolution driven by dimension-reduction dynamics,based on level set ***,Physics-Informed Neural Networks(PINNs)are extended to HJI PDE final value problem,supporting orbital game rules summarization through capture zone evolution ***,numerical results demonstrate the feasibility and efficiency of the proposed framework.

关键词： Spacecraft pursuit-evasion Qualitative differential game Physics-Informed Neural Networks(PINNs) Reachability analysis Hamilton-Jacobi-Isaacs(HJI) Partial Differential Equations(PDEs)

Optimal Operation Strategy Analysis with Scenario Generation Method Based on Principal Component Analysis,Density Canopy,and K-medoids for Integrated Energy Systems

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 89-100页

作者： Bingtuan Gao Yunyu zhu Yuanmei Li School of Electrical Engineering Southeast UniversityNanjingChina

The operation of integrated energy systems(IESs)is confronted with great challenges for increasing penetration rate of renewable energy and growing complexity of energy *** generation is one of ordinary methods to alleviate the system uncertainties by extracting several typical scenarios to represent the original high-dimensional *** paper proposes a novel representative scenario generation method based on the feature extraction of panel *** original high-dimensional data are represented by an aggregated indicator matrix using principal component analysis to preserve temporal ***,the aggregated indicator matrix is clustered by an algorithm combining density canopy and *** with the proposed scenario generation method,an optimal operation model of IES is established,where the objective is to minimize the annual operation costs considering carbon trading ***,case studies based on the data of Aachen,Germany in 2019 are *** results indicate that the adjusted rand index(ARI)and silhouette coefficient(SC)of the proposed method are 0.6153 and 0.6770,respectively,both higher than the traditional methods,namely K-medoids,K-means++,and density-based spatial clustering of applications with noise(DBSCAN),which means the proposed method has better *** error between optimal operation results of the IES obtained by the proposed method and all-year time series benchmark value is 0.1%,while the calculation time is reduced from 11029 s to 188 s,which verifies that the proposed method can be used to optimize operation strategy of IES with high efficiency without loss of accuracy.

关键词： Scenario generation principal component analysis(PCA) density canopy K-medoids integrated energy system

Literature overview of basic characteristics and flotation laws of flocs

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 943-958页

作者： Wanzhong Yin Yu Xie Zhanglei zhu School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China College of Chemistry and Chemical Engineering Xi’an University of Science and TechnologyXi’an 710054China

Flocculation flotation is the most efficient method for recovering fine-grained minerals,and its essence lies in flotation and recovery of *** physical characteristics of flocs are mainly determined by their apparent particle size and structure(density and morphology).Substantial researches have been conducted regarding the effect of floc characteristics on particle settling and water ***,the influence of floc characteristics on flotation has not been widely *** on the floc formation and flocculation flotation,this study reviews the fundamental physical characteristics of flocs from the perspectives of floc particle size and structure,summarizing the interaction between floc particle size and ***,it thoroughly discusses the effect of floc particle size and structure on floc floatability,further revealing the influence of floc characteristics on bubble collision and adhesion and elucidating the mechanisms of interaction between flocs and ***,it is observed that floc particle size is not the only factor influencing flocculation *** the appropriate apparent particle size range,flocs with a compact structure exhibit higher efficiency in bubble collision and adhesion during flotation,thereby resulting in enhanced flotation *** study aims to provide a reference for flocculation flotation,targeting the development of more efficient and refined flocculation flotation processes in the future.

关键词： flocs basic characteristics particle size and structure flotation laws bubbles

Pixelated non-volatile programmable photonic integrated circuits with 20-level intermediate states

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International Journal of Extreme Manufacturing 2024年第3期6卷 477-487页

作者： Wenyu Chen Shiyuan Liu Jinlong zhu State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074People’s Republic of China Optics Valley Laboratory WuhanHubei 430074People’s Republic of China

Multi-level programmable photonic integrated circuits(PICs)and optical metasurfaces have gained widespread attention in many fields,such as neuromorphic photonics,opticalcommunications,and quantum *** this paper,we propose pixelated programmable Si_(3)N_(4)PICs with record-high 20-level intermediate states at 785 nm *** flexibility in phase or amplitude modulation is achieved by a programmable Sb_(2)S_(3)matrix,the footprint of whose elements can be as small as 1.2μm,limited only by the optical diffraction limit of anin-house developed pulsed laser writing *** believe our work lays the foundation for laser-writing ultra-high-level(20 levels and even more)programmable photonic systems and metasurfaces based on phase change materials,which could catalyze diverse applications such as programmable neuromorphic photonics,biosensing,optical computing,photonic quantum computing,and reconfigurable metasurfaces.

关键词： programmable photonic integrated circuits phase change materials multi-level intermediate states metasurfaces

The role of hydrogen bonding in solubilizing camptothecin in hydrophilic and hydrophobic ionic liquids

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Green Chemical Engineering 2024年第4期5卷 489-500页

作者： Xiaotong zhu Liwen Mu Jiahua zhu Xiaohua Lu Yuanhui Ji Jiangsu Province Hi-Tech Key Laboratory for Biomedical Research School of Chemistry and Chemical Engineering Southeast University State Key Laboratory of Materials-oriented Chemical Engineering College of Chemical Engineering Nanjing Tech University

Utilizing ionic liquid(IL)-water mixtures as selective extraction solvents for raw materials from natural sources represents an efficacious approach; however, elucidating the underlying mechanisms inherent in various types of IL-aqueous solutions continues to pose a significant challenge. In this study, molecular dynamics simulations and density functional theory calculations are employed to illuminate the influence of the functional anion within ILs and the water content on the solvation mechanism and phase separation phenomena observed during the extraction of camptothecin(CPT) using aqueous IL solutions. The simulation results show that the anions in ILs preferentially dissolve CPT through hydrogen bonding at low water concentrations. As the water concentration increases, the hydrophobic IL binds more tightly to CPT, enabling the water to self-aggregate. The anions in hydrophilic IL form hydrogen bonds with water instead, further enhancing the dissolution of CPT. This work reveals the mechanism of phase separation and solvation of different types of IL aqueous solutions, which is helpful in developing new drug extraction and purification technologies.

关键词： Ionic liquids Hydrogen bonding Molecular dynamics simulation Phase separation Quantum chemistry calculations

Bio-inspired Design and Inverse Kinematics Solution of an Omnidirectional Humanoid Robotic Arm with Geometric and Load Capacity Constraints

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Journal of Bionic Engineering 2024年第2期21卷 778-802页

作者： Zhichao zhu Zirong Luo Yiming zhu Tao Jiang Minghai Xia Shanjun Chen Boyu Jin College of Intelligence Science and Technology National University of Defense TechnologyChangshaChina

Inspired by the driving muscles of the human arm,a 4-Degree of Freedom(DOF)concentrated driving humanoid robotic arm is proposed based on a spatial double parallel four-bar *** four-bar mechanism design reduces the inertia of the elbow-driving unit and the torque by 76.65%and 57.81%,*** the human pose regulation strategy that the human arm picks up a heavy object by adjusting its posture naturally without complicated control,the robotic arm features an integrated position-level closed-form inverse solution method considering both geometric and load capacity *** method consists of a geometric constraint model incorporating the arm angle(φ)and the Global Configuration(GC)to avoid joint limits and singularities,and a load capacity model to constrain the feasible domain of the arm ***,trajectory tracking simulations and experiments are conducted to validate the feasibility of the proposed inverse solution *** simulated maximum output torque,maximum output power and total energy consumption of the robotic arm are reduced by up to 2.0%,13.3%,and 33.3%,*** experimental results demonstrate that the robotic arm can bear heavy loads in a human-like posture,effectively reducing the maximum output torque and energy consumption of the robotic arm by 1.83%and 5.03%,respectively,while avoiding joints beyond geometric and load capacity *** proposed design provides a high payload–weight ratio and an efficient pose control solution for robotic arms,which can potentially broaden the application spectrum of humanoid robots.

关键词： Humanoid robotic arm Bio-inspired design Inverse kinematics solution Load capacity constraint Geometric constraint

An Improved Bounded Conflict-Based Search for Multi-AGV Pathfinding in Automated Container Terminals

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2705-2727页

作者： Xinci Zhou Jin zhu Shanghai Maritime University Logistics Science and Engineering Research InstituteShanghai200000China

As the number of automated guided vehicles(AGVs)within automated container terminals(ACT)continues to rise,conflicts have becomemore *** point and edge conflicts ofAGVs,amulti-AGVconflict-free path planning model has been formulated to minimize the total path length of AGVs between shore bridges and *** larger terminalmaps and complex environments,the grid method is employed to model AGVs’road *** improved bounded conflict-based search(IBCBS)algorithmtailored to ACT is proposed,leveraging the binary tree principle to resolve conflicts and employing focal search to expand the search *** experiments involving 60 AGVs indicate a reduction in computing time by 37.397%to 64.06%while maintaining the over cost within 1.019%.Numerical experiments validate the proposed algorithm’s efficacy in enhancing efficiency and ensuring solution quality.

关键词： Automated terminals multi-AGV multi-agent path finding(MAPF) conflict based search(CBS) AGV path planning

2-local unstable homotopy groups of indecomposable A3～2-complexes

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Science China Mathematics 2024年第3期67卷 607-626页

作者： Zhongjian zhu Jianzhong Pan College of Mathematics and Physics Wenzhou University Hua Loo-Keng Key Laboratory of Mathematics Institute of MathematicsAcademy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences

In this paper,we calculate the 2-local unstable homotopy groups of indecomposable A3～*** main technique used is analysing the homotopy property of J（A,X）,defined by Gray（1973） for a CW-pair（X,A）,which is homoto... 详细信息

关键词： homotopy groups A 2 n -complexes fibration sequence relative James construction 55P15

YOLO-MFD:Remote Sensing Image Object Detection with Multi-Scale Fusion Dynamic Head

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Computers, Materials & Continua 2024年第5期79卷 2547-2563页

作者： Zhongyuan Zhang Wenqiu zhu School of Computer Science Hunan University of TechnologyZhuzhou412007China

Remote sensing imagery,due to its high altitude,presents inherent challenges characterized by multiple scales,limited target areas,and intricate *** inherent traits often lead to increased miss and false detection rates when applying object recognition algorithms tailored for remote sensing ***,these complexities contribute to inaccuracies in target localization and hinder precise target *** paper addresses these challenges by proposing a solution:The YOLO-MFD model(YOLO-MFD:Remote Sensing Image Object Detection withMulti-scale Fusion Dynamic Head).Before presenting our method,we delve into the prevalent issues faced in remote sensing imagery ***,we emphasize the struggles of existing object recognition algorithms in comprehensively capturing critical image features amidst varying scales and complex *** resolve these issues,we introduce a novel ***,we propose the implementation of a lightweight multi-scale module called *** module significantly improves the model’s ability to comprehensively capture important image features by merging multi-scale feature *** effectively addresses the issues of missed detection and mistaken alarms that are common in remote sensing ***,an additional layer of small target detection heads is added,and a residual link is established with the higher-level feature extraction module in the backbone *** allows the model to incorporate shallower information,significantly improving the accuracy of target localization in remotely sensed ***,a dynamic head attentionmechanism is *** allows themodel to exhibit greater flexibility and accuracy in recognizing shapes and targets of different ***,the precision of object detection is significantly *** trial results show that the YOLO-MFD model shows improvements of 6.3%,3.5%,and 2.5%over the original YOLOv8 model in Precision,map@0.5 a

关键词： Object detection YOLOv8 multi-scale attention mechanism dynamic detection head