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Cooperative Target Tracking of Multiple Autonomous Surface Vehicles Under Switching Interaction Topologies

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IEEE/CAA Journal of Automatica Sinica 2023年第3期10卷 673-684页

作者： lang Ma Yu-Long Wang Qing-Long Han Shanghai Key Laboratory of Power Station Automation Technology and the School of Mechatronic Engineering and AutomationShanghai UniversityShanghai 200444China School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia IEEE

This paper is concerned with the cooperative target tracking of multiple autonomous surface vehicles(ASVs)under switching interaction *** the target to be tracked,only its position can be measured/received by some of the ASVs,and its velocity is unavailable to all the ASVs.A distributed extended state observer taking into consideration switching topologies is designed to integrally estimate unknown target dynamics and neighboring ASVs'***,a novel kinematic controller is designed,which takes full advantage of known information and avoids the approximation of some virtual control ***,a disturbance observer is presented to estimate unknown time-varying environmental ***,a distributed dynamic controller is designed to regulate the involved ASVs to cooperatively track the *** enables each ASV to adjust its forces and moments according to the received information from its *** effectiveness of the derived results is demonstrated through cooperative target tracking performance analysis for a tracking system composed of five interacting ASVs.

关键词： Autonomous surface vehicles(ASVs) cooperative target tracking distributed extended state observer switching topologies

Reperfusion after hypoxia-ischemia exacerbates brain injury with compensatory activation of the antiferroptosis system:based on a novel rat model

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Neural Regeneration Research 2023年第10期18卷 2229-2236页

作者： Tian-Lei Zhang Zhi-Wei Zhang Wei Lin Xin-Ru Lin Ke-Xin Lin Ming-Chu Fang Jiang-Hu Zhu Xiao-ling Guo Zhen-lang Lin Department of Pediatrics the Second School of Medicinethe Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhouZhejiang ProvinceChina Second Clinical Medical College Wenzhou Medical UniversityWenzhouZhejiang ProvinceChina Key Laboratory of Children Genitourinary Diseases of Wenzhou the Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhouZhejiang ProvinceChina Key Laboratory of Perinatal Medicine of Wenzhou the Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhouZhejiang ProvinceChina Basic Medical Research Center the Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhouZhejiang ProvinceChina

Hypoxic-ischemic encephalopathy,which predisposes to neonatal death and neurological sequelae,has a high morbidity,but there is still a lack of effective prevention and treatment in clinical *** better understand the pathophysiological mechanism underlying hypoxic-ischemic encephalopathy,in this study we compared hypoxic-ischemic reperfusion brain injury and simple hypoxic-ischemic brain injury in neonatal ***,based on the conventional RiceVannucci model of hypoxic-ischemic encephalopathy,we established a rat model of hypoxic-ischemic reperfusion brain injury by creating a common carotid artery muscle *** we performed tandem mass tag-based proteomic analysis to identify differentially expressed proteins between the hypoxic-ischemic reperfusion brain injury model and the conventional Rice-Vannucci model and found that the majority were mitochondrial *** also performed transmission electron microscopy and found typical characteristics of ferroptosis,including mitochondrial shrinkage,ruptured mitochondrial membranes,and reduced or absent mitochondrial ***,both rat models showed high levels of glial fibrillary acidic protein and low levels of myelin basic protein,which are biological indicators of hypoxic-ischemic brain injury and indicate similar degrees of ***,we found that ferroptosis-related Ferritin(Fth1)and glutathione peroxidase 4 were expressed at higher levels in the brain tissue of rats with hypoxic-ischemic reperfusion brain injury than in rats with simple hypoxic-ischemic brain *** on these results,it appears that the rat model of hypoxic-ischemic reperfusion brain injury is more closely related to the pathophysiology of clinical *** not only aggravates hypoxic-ischemic brain injury but also activates the anti-ferroptosis system.

关键词： ferroptosis hypoxic-ischemic brain injury hypoxic-ischemic encephalopathy hypoxic-ischemic reperfusion brain injury mitochondria model proteomic analysis reperfusion Rice-Vannucci transmission electron microscopy

Novel porous ceramic with high strength and thermal performance using MA hollow spheres

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Progress in Natural Science:Materials International 2022年第6期32卷 732-738页

作者： Anbang Chen lang Li Chong Wang Qingyuan Wang Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan Province College of Architecture and Environment Sichuan University MOE Key Laboratory of Deep Earth Science and Engineering College of Architecture and Environment Sichuan University

The objective of this work is to obtain a multifunctional porous ceramic material at low cost with improved properties and that can be used in many applications like:thermal and acoustic insulation,refractory support and hot gas filtration *** that end,a novel facile strategy to fabricate porous ceramics by foaming and poreforming agent methods using magnesia-aluminum spinel hollow spheres(MASHSs) was reported for the first time,in which calcium aluminate cement(CAC) served as high-temperature *** influence of temperature ranging from 1500℃ to 1700℃ on the thermal conductivity,porosity and mechanical strength were *** results show that,the obtained MASHSs ceramic exhibits high porosity(67.2-71.9%) and thermal conductivity(0.18-0.38 W/mK),and compressive strength(6.1-17.1 MPa),which is mainly due to the change in crack directions and microstructure optimization with the prolong of firing *** crack directions changed from the surface of MASHSs to the interior MASHSs,which consumes more crack energy,and thus leading to the excellent mechanical *** is more,the introduction of MASHSs makes it difficult to lose heat at elevated temperature,and thereby improving the thermal conductivity of materials.

关键词： MA hollow Spheres Porous ceramics Thermal conductivity Mechanical property

Task-wise attention guided part complementary learning for few-shot image classification

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Science China(Information Sciences) 2021年第2期64卷 44-57页

作者： Gong CHENG Ruimin LI Chunbo lang Junwei HAN Research and Development Institute of Northwestern Polytechnical University in Shenzhen School of Automation Northwestern Polytechnical University CETC Key Laboratory of Aerospace Information Applications

A general framework to tackle the problem of few-shot learning is meta-learning, which aims to train a well-generalized meta-learner(or backbone network) to learn a base-learner for each future task with small training data. Although a lot of work has produced relatively good results, there are still some challenges for few-shot image classification. First, meta-learning is a learning problem over a collection of tasks and the meta-learner is usually shared among all tasks. To achieve image classification of novel classes in different tasks, it is needed to learn a base-learner for each task. Under the circumstances, how to make the base-learner specialized, and thus respond to different inputs in an extremely task-wise manner for different tasks is a big challenge at present. Second, classification network usually inclines to identify local regions from the most discriminative object parts rather than the whole objects for recognition, thereby resulting in incomplete feature representations. To address the first challenge, we propose a task-wise attention(TWA)module to guide the base-learner to extract task-specific image features. To address the second challenge,under the guidance of TWA, we propose a part complementary learning(PCL) module to extract and fuse the features of multiple complementary parts of target objects, and thus we can obtain more specific and complete information. In addition, the proposed TWA module and PCL module can be embedded into a unified network for end-to-end training. Extensive experiments on two commonly-used benchmark datasets and comparison with state-of-the-art methods demonstrate the effectiveness of our proposed method.

关键词： few-shot learning meta-learning task-wise attention part complementary learning

Event-based optimization with random packet dropping

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Science China(Information Sciences) 2020年第11期63卷 175-194页

作者： Qing-Shan JIA Jing-Xian TANG Zhenning lang Center for Intelligent and Networked Systems Department of AutomationTsinghua University NetEase Inc.

Event-based optimization(EBO) provides a general framework for policy optimization in many discrete event dynamic systems where decision making is triggered by events that represent state transitions with common features. Because the number of events can be defined by the user and usually increases linearly with respect to the system scale, EBO has good potential to address large-scale problems where the state space grows exponentially. However, in many practical systems, sensors are geographically distributed and connected to a central controller through imperfect communication channels. Therefore, events observed by the sensors may not reach the controller. Optimization methods of event-based policies in these cases have not yet been identified. In this paper, we consider this important problem and make three major contributions. First, we formulate a mathematical EBO model in which the communication between sensors and controllers is subject to random packet dropping. Second, we show that this EBO model can be converted to another EBO model with perfect communication. Then, the performance difference equation and the performance derivative equation for event-based policies are straightforward to develop. One gradient-based policy iteration algorithm is developed for problems where the state transition probabilities are explicitly known, while another for problems where they are unknown. Third, the performance of the algorithms and the impact of the packet dropping probability on policy performance are numerically demonstrated on a single-zone occupant level estimation problem in buildings.

关键词： event-based optimization packet dropping discrete event dynamic systems

American Barrier Option Pricing Formulas for Currency Model in Uncertain Environment

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Journal of Systems Science & Complexity 2022年第1期35卷 283-312页

作者： GAO Rong LIU Kaixiang LI Zhiguo lang Liying School of Economics and Management Hebei University of TechnologyTianjin 300401China School of Management Science and Engineering Chongqing Technology and Business UniversityChongqing 400067China Hebei University of Technology Tianjin 300401China

Option pricing problem is one of the central issue in the theory of modern *** currency model has been put forward under the foundation of uncertainty theory as a tool to portray the foreign exchange rate in uncertain finance *** paper uses uncertain differential equation involved by Liu process to dispose of the foreign exchange *** an American barrier option of currency model in uncertain environment is *** important of all,the authors deduce the formulas to price four types of American barrier options for this currency model in uncertain environment by rigorous derivation.

关键词： Barrier option currency model option pricing uncertain process

Aerodynamic performance of owl-like airfoil undergoing bio-inspired flapping kinematics

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Chinese Journal of Aeronautics 2021年第5期34卷 239-252页

作者： Xinyu lang Bifeng SONG Wenqing YANG Wenping SONG School of Aeronautics Northwestern Poly technical UniversityXi'an 710072China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518057China Yangtze River Delta Research Institute of Northwestern Polytechnical University Taicang 215400China

Natural flyers have extraordinary flight skills and their prominent aerodynamic performance has attracted a lot of ***,the aerodynamic mechanism of birds’flapping wing kinematics still lacks in-depth *** this paper,the aerodynamic performance of owl-like airfoil undergoing bio-inspired flapping kinematics extracted from a free-flying owl wing has been numerically *** overset mesh technique is used to deal with the large range movements of flapping *** bio-inspired kinematics consist of plunging and pitching movement.A pure sinusoidal motion and a defined motion composed of plunging of sinusoidal motion and pitching of the bio-inspired kinematics are selected for *** other two NACA airfoils are also selected to figure out the advantages of the owl-like *** is found that the cambered owl-like airfoil can enhance lift during the *** bio-inspired kinematics have an obvious advantage in lift generation with a presence of higher peak lift and positive lift over a wider proportion of the flapping ***,the bio-inspired motion is more economical for a lower power consumption compared with the sinusoidal *** sinusoidal flapping motion is better for thrust generation for a higher peak thrust value in both upstroke and downstroke,while the bio-inspired kinematics mainly generate thrust during the downstroke but produce more drag during the *** defined motion has similar lift performance with the bio-inspired kinematics,while it consumes more energy and generates less *** unsteady flow field around airfoils is also analyzed to explain the corresponding *** research in this paper is helpful to understand the flight mechanism of birds and to design a micro air vehicle with higher performance.

关键词： Aerodynamic performance Bio-inspired kinematics Flapping airfoils Low Reynolds number Micro aerial vehicles

Incommensurate Magnetic Order in Sm_(3)BWO_(9)with Distorted Kagome Lattice

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Chinese Physics Letters 2022年第10期39卷 39-44页

作者： Kai-Yue Zeng Fang-Yuan Song lang-Sheng ling Wei Tong Shi-Liang Li Zhao-Ming Tian Long Ma Li Pi Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field LaboratoryChinese Academy of SciencesHefei 230031China Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China School of Physics and Wuhan National High Magnetic Field Center Huazhong University of Science and TechnologyWuhan 430074China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China

We investigate the magnetic ground state of Sm_(3)BWO_(9)with a distorted kagome lattice.A magnetic phase transition is identified at T_(N)=0.75 K from the temperature dependence of specific *** 11B nuclear magnetic resonance measurements,an incommensurate magnetic order is shown by the double-horn type spectra under a c-axis magnetic field,and absence of line splitting is observed for field oriented within the ab-plane,indicating the incommensurate modulation of the internal field strictly along𝑐*** the spin dynamics,the critical slowing-down behavior is observed in the temperature dependence of 1/T_(1)with𝜇_(μ0)H⊥c-axis,which is completely absent in the case with𝜇_(μ0)H||*** on the local symmetry of 11B sites,we analyze the hyperfine coupling tensors and propose two constraints on the possible magnetic *** single ion anisotropy should play an important role in determination of contrasting ground states of Sm_(3)BWO_(9) and Pr_(3)BWO_(9).

关键词： structure incommensurate symmetry

Home visits in brain tumor patient: how nurse and family members cooperate in tumor patient's family self-care

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Chinese Journal of Cancer Research 2013年第6期25卷 729-734页

作者： Liwei lang Zhiyue Yan Hailiang Tang Nursing Department 2Neurosurgery DepartmentHuashan HospitalFudan University Department of Neurosurgery Huashan HospitalFudan UniversityNo.12 Middle Wulumuqi Road

Purposes： We reported the roles and fimctions of nurses in home visits for brain tumor patients using the family health assessment guide in the study. Methods： One patient of brain glioma was chosen as the case illustration. The nurses assessed the patients＇ situation, their families and living environment individually. All these factors were analyzed together. Results： The nurses then implemented their knowledge and skills to adopt different measures in different conditions, investigated the patients＇ health problems and carried out personalized effective actions. Conclusions： Nurses should put effort into community nursing to allow patients to live in a safe environment, to satisfy the health needs of human being and their needs for health knowledge, and enhance their self-care abilities.

关键词： Home visits family care brain tumor