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Motion planning of a quadrotor robot game using a simulation-based projected policy iteration method

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Frontiers of Information Technology & Electronic Engineering 2019年第4期20卷 525-537页

作者： Li-dong zhang Ban WANG Zhi-xiang LIU You-min zhang Jian-liang AI Department of Aeronautics and Astronautics Fudan University Department of Mechanical Industrial and Aerospace Engineering Concordia University

Making rational decisions for sequential decision problems in complex environments has been challenging researchers in various fields for decades. Such problems consist of state transition dynamics, stochastic uncertainties,long-term utilities, and other factors that assemble high barriers including the curse of dimensionality. Recently, the state-of-the-art algorithms in reinforcement learning studies have been developed, providing a strong potential to efficiently break the barriers and make it possible to deal with complex and practical decision problems with decent performance. We propose a formulation of a velocity varying one-on-one quadrotor robot game problem in the threedimensional space and an approximate dynamic programming approach using a projected policy iteration method for learning the utilities of game states and improving motion policies. In addition, a simulation-based iterative scheme is employed to overcome the curse of dimensionality. Simulation results demonstrate that the proposed decision strategy can generate effective and efficient motion policies that can contend with the opponent quadrotor and gather advantaged status during the game. Flight experiments, which are conducted in the Networked Autonomous Vehicles(NAV) Lab at the Concordia University, have further validated the performance of the proposed decision strategy in the real-time environment.

关键词： Reinforcement learning Approximate dynamic programming Decision making Motion planning Unmanned aerial vehicle

Shexiang Tongxin Dropping Pill Allieviates Heart Failure via Extracellula Matrix-Receptor Interaction Pathways Based on RNA-Seq Transcriptomics and Experimental Studies

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Chinese Journal of Integrative Medicine 2023年第7期29卷 600-607页

作者： TAN Ya-fang FU Yu-han zhang min-zhou Intensive Care Research Team of Traditional Chinese Medicine Guangdong Province Hospital of Chinese Medicinethe Second Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou510006China School of Life Sciences and Biopharmaceutics Guangdong Pharmaceutical UniversityGuangzhou510006China

Objective:To investigate the protective mechanisms of Chinese medicine Shexiang Tongxin Dropping Pills(STDP) on heart failure(HF).Methods:Isoproterenol(ISO)-induced HF rat model and angiotensin Ⅱ(Ang Ⅱ)-induced neonatal rat cardiac fibroblast(CFs) model were used in the present *** rats were treated with and without STDP(3 g/kg).RNA-seq was performed to identify differentially expressed genes(DEGs).Cardiac function was evaluated by *** and eosin and Masson’s stainings were taken to assess cardiac *** levels of collagen Ⅰ(Col Ⅰ) and collagen Ⅲ(Col Ⅲ) were detected by immunohistochemical ***8 kit and transwell assay were implemented to test the CFs’ proliferative and migratory activity,*** protein expressions of α-smooth muscle actin(α-SMA),matrix metalloproteinase-2(MMP-2),MMP-9,Col I,and Col Ⅲ were detected by Western ***:The results of RNA-seq analysis showed that STDP exerted its pharmacological effects on HF via multiple signaling pathways,such as the extracellular matrix(ECM)-receptor interaction,cell cycle,and B cell receptor *** from in vivo experiments demonstrated that STDP treatment reversed declines in cardiac function,inhibiting myocardial fibrosis,and reversing increases in Col Ⅰ and Col Ⅱ expression levels in the hearts of HF ***,STDP(6,9 mg/mL) inhibited the proliferation and migration of CFs exposed to Ang Ⅱin vitro(P<0.05).The activation of collagen synthesis and myofibroblast generation were markedly suppressed by STDP,also the synthesis of MMP-2 and MMR-9,as well as ECM components Col Ⅰ,Col Ⅲ,and α-SMA were decreased in Ang Ⅱ-induced neonatal rats’ ***:STDP had anti-fibrotic effects in HF,which might be caused by the modulation of ECM-receptor interaction *** the management of cardiac fibrosis,STOP may be a compelling candidate for improving prognosis of HF.

关键词： Shexiang Tongxin Dropping Pill heart failure RNA-seq extracellular matrix isoproterenol-induced

Fhotocatalytic degradation of polybrominated diphenyl ethers in pure water system

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Frontiers of Environmental Science & Engineering 2016年第2期10卷 229-235页

作者： min zhang Jian LU Yiliang HE P. Chris WILSON School of Environmental Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China Indian River Research and Education Center University of Florida Fort Pierce FL 34945 USA

Due to the low water solubility of polybromi- nated diphenyl ethers, organic solvent is usually added into the oxidation system to enhance the removal efficiency. In this study the photocatalytic degradation of decabromodi- phenyl ether （BDE209）, a type ofpolybrominated diphenyl ether used throughout the world, in pure water without the addition of organic solvent was investigated. In the pure water system, BDE209 was not dissolved but dispersed as nano-scale particles with a mean diameter of 166 nm. Most of BDE209 （〉 98%） were removed within 4 h and the final debromination ratio was greater than 80%. Although the addition of organic solvent （tetrahydrofuran, THF） could lead to a relatively high BDE209 degradation rate, the final debromination ratio （〈 50%） was much lower than that in pure water system. Major oxidation inter- mediates of tetrahydrofuran, including tetrahydro-2-fura- nol and y-butyrolactone, were detected indicating the engagement of THF in the BDE209 degradation process. The photocatalytic degradation of BDE209 in the pure water system followed first-order kinetics. The BDE209 degradation rate constant increased from 0.0011 to 0.0023 min-1 as the pH increased from 3 to 9.

关键词： polybrominated diphenyl ethers photocataly-tic degradation solvent

A viscoelastic alginate-based hydrogel network coordinated with spermidine for periodontal ligament regeneration

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Regenerative Biomaterials 2023年第1期10卷 510-521页

作者： Songbai zhang Yuanbo Jia Jingyi Liu Fan Feng Zhao Wei min zhang Feng Xu State Key Laboratory of Military Stomatology&National Clinical Research Center for Oral Diseases&Shaanxi International Joint Research Center for Oral Diseases Department of General Dentistry and EmergencySchool of StomatologyFourth Military Medical UniversityXi’an 710032P.R.China The Key Laboratory of Biomedical Information Engineering of ministry of Education School of Life Science and TechnologyXi’an Jiaotong UniversityXi’an 710049P.R.China Bioinspired Engineering and Biomechanics Center(BEBC) Xi’an Jiaotong UniversityXi’an 710049P.R.China

Periodontitis can cause irreversible defects in the periodontal ligament(PDL),the regeneration of which is the major obstacle to the clinical treatment of *** hydrogel for releasing anti-inflammatory drugs is a promising treatment to promote PDL ***,existing hydrogel systems fail to mimic the typical viscoelastic feature of native periodontium,which may have been shown as an important role in tissue ***,the synergistic benefits of mechanical cues and biochemical agents for PDL regeneration remain *** this study,we developed a bi-crosslinking viscoelastic hydrogel(Alg-PBA/Spd)by integrating phenylboronic acid-modified alginate with anti-inflammatory agent(spermidine)through borate ester and B-N coordination bonds,where spermidine will be released with the degradation of the ***-PBA/Spd hydrogel is biocompatible,injectable and can quickly adapt to complex periodontal structures due to the dynamic *** demonstrated in rat models that the viscoelastic Alg-PBA/Spd hydrogel significantly promotes the deposition of periodontal collagen and accelerates the repair of periodontal *** results suggest that the viscoelastic Alg-PBA/Spd hydrogel would be a promising mechano-biochemically synergistic treatment for periodontal regeneration.

关键词： periodontal regeneration viscoelastic hydrogel mechano-biochemically synergistic treatment mechanical microenvironment

Low-temperature heat conduction characteristics of diamond/Cu composite by pressure infiltration method

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Rare Metals 2013年第6期32卷 579-585页

作者： Hong Guo Guang-Zhong Wang Xi-min zhang Fa-zhang Yin Cheng-Chang Jia School of Materials and Engineering University of Science & Technology Beijing

In this paper,diamond/CuCr and diamond/CuB composites were prepared using the pressure infiltration *** physical property measurement system(PPMS)was adopted to evaluate the thermal conductivity of diamond/Cu and MoCu composites within the range of100–350 K,and a scanning electron microscope(SEM)was utilized to analyze the microstructure and fracture appearance of the *** research indicates that the thermal conductivity of diamond/Cu composite within the range of100–350 K is 2.5–3.0 times that of the existing MoCu material,and the low-temperature thermal conductivity of diamond/Cu composite presents an exponential relationship with the *** B element was added to a Cu matrix and a low-temperature binder was used for prefabricated elements,favorable interfacial adhesion,relatively high interfacial thermal conductivity,and favorable low-temperature heat conduction characteristics would be apparent.

关键词： Diamond/Cu composite Low-temperature thermal conductivity Pressure infiltration

Effect of Laser Welding Process Parameters on Microstructure and Mechanical Properties on Butt Joint of New Hot-Rolled Nano-scale Precipitation-Strengthened Steel

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Acta Metallurgica Sinica(English Letters) 2014年第3期27卷 521-529页

作者： min zhang Xiaonan Wang Guangjiang Zhu Changjun Chen Jixin Hou Shunhu zhang Hemin Jing Laser Processing Research Center School of Mechanical and Electrical Engineering Soochow University Shagang School of Iron and Steel Soochow University School of Materials Science & Engineering Anhui University of Technology

A 4 kW fiber laser was chosen to weld the new hot-rolled nano-scale precipitation-strengthened steel with a thickness of 4.5 mm. The effect of laser power, defocusing distance, and welding speed on the welded joint appearance was examined, and the microstructure and mechanical properties on the typical butt joints were investigated. Results showed that increasing laser welding power may cause faster downward flow of molten metal to produce greater root humping. With the welding speed increasing, the average welding seam （WS） width decreased, and the average WS and heat-affected zone （HAZ） hardness increased. The microstructures of WS, fusion line, and coarse grain heat-affected zone were lath martensite, but the growth direction of the original austenite grain boundaries was significantly different. The microstructures of fine grain heat-affected zone were ferrite and martensite, and the microstructure of mixed grain heat- affected zone contained ferrite, massive M/A island, and a small amount of martensite. The micro-hardness values of WS, HAZ, and base metal （BM） were 358, 302, and 265 HV, respectively. The butt joint fracture at the BM far from the WS and the welded joint tensile strength are observed to follow proportional relationship with hardness.

关键词： Laser welding Microstructure Mechanical properties Microalloyed steel

Active fault-tolerant tracking control of a quadrotor with model uncertainties and actuator faults

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Frontiers of Information Technology & Electronic Engineering 2019年第1期20卷 95-106页

作者： Yu-jiang ZHONG Zhi-xiang LIU You-min zhang Wei zhang Jun-yi ZUO School of Aeronautics Northwestern Polytechnical University Department of Mechanical Industrial and Aerospace Engineering Concordia University

This paper presents a reliable active fault-tolerant tracking control system(AFTTCS) for actuator faults in a quadrotor unmanned aerial vehicle(QUAV). The proposed AFTTCS is designed based on a well-known model reference adaptive control(MRAC) framework that guarantees the global asymptotic stability of a QUAV system. To mitigate the negative impacts of model uncertainties and enhance system robustness, a radial basis function neural network is incorporated into the MRAC scheme for adaptively identifying the model uncertainties online and modifying the reference model. Meanwhile, actuator dynamics are considered to avoid undesirable performance degradation. Furthermore, a fault detection and diagnosis estimator is constructed to diagnose lossof-control-effectiveness faults in actuators. Based on the fault information, a fault compensation term is added to the control law to compensate for the adverse effects of actuator faults. Simulation results show that the proposed AFTTCS enables the QUAV to track the desired reference commands in the absence/presence of actuator faults with satisfactory performance.

关键词： Model reference adaptive control Neural network Quadrotor Fault-tolerant control Fault detection and diagnosis

Cognition-driven multimodal personality classification

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Science China(Information Sciences) 2022年第10期65卷 164-177页

作者： Xiaoya GAO Jingjing WANG Shoushan LI min zhang Guodong ZHOU School of Computer Science and Technology Soochow University

In this paper, we address a novel task, namely, cognition-driven multimodal personality classification(CMPC), aiming to infer personality traits(e.g., romantic, humorous, and gloomy) shown in real time by a human being from the perspective of cognitive psychology. Specifically, this task is motivated by a cognitive difference phenomenon that humans with different personality traits tend to give different personality-oriented textual descriptions when observing an image. In particular, to tackle the inherent noise challenges in this CMPC task, we propose a tailored reinforcement learning approach, namely, multi-agent Select Net, aiming to integrate the opinion-word and image-region selection strategies to select informative opinion-word and image-region features for CMPC. To justify the effectiveness of our approach, we construct six kinds of multimodal personality classification datasets and conduct extensive experiments on the *** results demonstrate that our approach can significantly outperform other strong competitors,including the state-of-the-art unimodal and multimodal approaches.

关键词： cognitive psychology personality classification multimodal analysis multi-agent reinforcement learning agent-sharing mechanism

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Fabrication of fine spongy nanoporous Ag-Au alloys with improved catalysis properties

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Progress in Natural Science:Materials International 2017年第6期27卷 658-663页

作者： Cuiting Li Tao zhang min zhang Yu Jin Lei Zuo Hongjie Xu Ran Li Key Laboratory of Aerospace Materials and Performance (ministry of Education) School of Materials Science and Engineering Beihang University Materials Science and Engineering Research Center School of Mechanical Electronic and Control Engineering Beijing Jiaotong University

Fine NP-AgAu（nanoporous AgAu） alloys with spongy structure was fabricated by chemical dealloying from rapidly solidified amorphous precursors Ag;Cu;Si;Au;（x=0, 0.5, 1 and 5）. The results indicate that the addition of small content Au in precursor can refine both the ligaments and pores obviously. Among the present components of the precursors, NP-AgAu alloys dealloying from Ag;Cu;Si;Au;had the finest spongy structure. The size of pores was 5–10 nm and the grain size of ligaments was 10–20 nm. It also had the highest surface area of 106.83 m;g;and the best catalytic activity towards electro-oxidation of formaldehyde with the peak current of 665 mA mg;.

关键词： Nanoporous Ag-Au Dealloying Formaldehyde electro-oxidation Catalysis Amorphous