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Understanding adversarial attacks on observations in deep reinforcement learning

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Science China(Information Sciences) 2024年第5期67卷 69-83页

作者： You QIAOBEN Chengyang ying Xinning zhou Hang SU Jun zhu Bo ZHANG Department of Computer Science and Technology Beijing National Research Center for Information Science and Technology Tsinghua-Bosch Joint Center for Machine Learning Institute for Artificial Intelligence Tsinghua University Peng Cheng Laboratory

Deep reinforcement learning models are vulnerable to adversarial attacks that can decrease the cumulative expected reward of a victim by manipulating its observations. Despite the efficiency of previous optimization-based methods for generating adversarial noise in supervised learning, such methods might not achieve the lowest cumulative reward since they do not generally explore the environmental ***, a framework is provided to better understand the existing methods by reformulating the problem of adversarial attacks on reinforcement learning in the function space. The reformulation approach adopted herein generates an optimal adversary in the function space of targeted attacks, repelling them via a generic two-stage framework. In the first stage, a deceptive policy is trained by hacking the environment and discovering a set of trajectories routing to the lowest reward or the worst-case performance. Next, the adversary misleads the victim to imitate the deceptive policy by perturbing the observations. Compared to existing approaches, it is theoretically shown that our adversary is strong under an appropriate noise level. Extensive experiments demonstrate the superiority of the proposed method in terms of efficiency and effectiveness, achieving state-of-the-art performance in both Atari and MuJoCo environments.

关键词： deep learning reinforcement learning adversarial robustness adversarial attack

Models to Simulate Effective Coverage of Fire Station Based on Real-Time Travel Times

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 483-513页

作者： Sicheng zhu Dingli Liu Weijun Liu ying Li Tian zhou Department of Engineering Management Changsha University of Science and TechnologyChangsha410114China

In recent years,frequent fire disasters have led to enormous damage in *** firefighting rescues can minimize the losses caused by *** the rescue processes,the travel time of fire trucks can be severely affected by traffic conditions,changing the effective coverage of fire ***,it is still challenging to determine the effective coverage of fire stations considering dynamic traffic *** paper addresses this issue by combining the traveling time calculationmodelwith the effective coverage *** addition,it proposes a new index of total effective coverage area(TECA)based on the time-weighted average of the effective coverage area(ECA)to evaluate the urban fire *** also selects China as the case study to validate the feasibility of the models,a fire station(FS-JX)in ***-JX station and its surrounding 9,117 fire risk points are selected as the fire service supply and demand points,respectively.A total of 196 simulation scenarios throughout a consecutiveweek are ***,1,933,815 sets of valid sample data are *** results showed that the TECA of FS-JX is 3.27 km^(2),which is far below the standard requirement of 7.00 km^(2) due to the traffic *** visualization results showed that three rivers around FS-JX interrupt the continuity of its effective *** proposed method can provide data support to optimize the locations of fire stations by accurately and dynamically determining the effective coverage of fire stations.

关键词： Fire services fire station effective coverage real-time traffic simulation

Enhancing I0/I-Conversion Efficiency by Starch Confinement in Zinc-Iodine Battery

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Energy & Environmental Materials 2024年第1期7卷 118-124页

作者： Danyang Zhao Qiancheng zhu Qiancheng zhou Wenming Zhang ying Yu Shuo Chen Zhifeng Ren Institute of Nanoscience and Nanotechnology College of Physical Science and Technology Central China Normal University National & Local Joint Engineering Laboratory of New Energy Photoelectric Devices College of Physics Science and Technology Hebei University Department of Physics and Tc SUH University of Houston

The redox couple of I0/I-in aqueous rechargeable iodine-zinc（I2-Zn）batteries is a promising energy storage resource since it is safe and costeffective,and provides steady output ***,the cycle life and efficiency of these batteries remain unsatisfactory due to the uncontrolled shuttling of polyiodide（I3-and I5-） and side reactions on the Zn anode.

关键词： aqueous battery conversion efficiency iodine–zinc battery starch confinement

In Situ Rutherford Backscattering Spectrometry Analysis of Films by Combination with Sputter Etching

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Chinese Physics Letters 1999年第10期16卷 770-772页

作者： JIANG Lei LIU Bo zhou zhu-ying HE Mian-hong ZHAO Guo-qing ZONG Xiang-fu Accelerator-based Atomic and Nuclear Physics Laboratory Institute of Modem PhysicsFudan UniversityShanghai 200433 National Micro-analysis Center for Microelectronic Materials and Devices Department of Material ScienceFudan UniversityShanghai 200433

We have set up an experimental system consisting of an im gun and a Rutherford backscattering spectro-metry(RBS)analysis *** this system,in situ 2MeV*He+RBS analysis of films is carried out by combination with sputter etching cf low energy Ar+*** an example of the sputtering/RBS method,the analysis of three samples,i.e.,Si/(GexSi_(1-x)/Si)/Si(100),WSi_(x)/SiO_(2)/Si and CoSi_(x)/Si,is presented in this *** an appropriate fraction of the thick layer is removed by sputtering,the back edge of the Ge peak is separated from Si RBS spectmm on the interface and the O peak of the buried S1O2 layer can be *** change cf the doped Ti and W concentrations related to Co on the top surface is *** advantages of this analytical method and its possible applications in film are discussed.

关键词： system removed separated

Surface-induced Microstructure and Performance Changes in P3HT Ultrathin Films

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Chinese Journal of Polymer Science 2024年第6期42卷 805-814页

作者： Hong-Tao Shan Jia-Xin He Bing-Yan zhu Xue-Ting Cao ying-ying Yan Jian-Jun zhou Hong Huo Beijing Key Laboratory of Energy Conversion and Storage Materials College of ChemistryBeijing Normal UniversityBeijing100875China

In this work,poly(3-hexylthiophene)(P3HT)ultrathin films(P3HT-T)were prepared by spin-coating a dilute P3HT solution(in a toluene:o-dichlorobenzene(Tol:ODCB)blend with a volume ratio of 80:20)with ultrasonication and the addition of the nucleating agent bicycle[2.2.1]heptane-2,3-dicarboxylic acid disodium salt(HPN-68L)on glass,Si wafers and indium tin oxide(ITO)*** electrical and mechanical properties of the P3HT-T ultrathin films were investigated,and it was found that the conductivity and crack onset strain(COS)were simultaneously improved in comparison with those of the corresponding pristine P3HT film(P3HT-0,without ultrasonication and nucleating agent)on the same substrate,regardless of what substrate was ***,the conductivity of P3HT-T ultrathin films on different substrates was similar(varying from 3.7 S·cm^(-1)to 4.4 S·cm^(-1)),yet the COS increased from 97%to 138%by varying the substrate from a Si wafer to *** grazing-incidence wide-angle X-ray diffraction(GIXRD),UV-visible(UV-Vis)spectroscopy and atomic force microscopy(AFM),we found that the solid order and crystallinity of the P3HT-T ultrathin film on the Si wafer are highest,followed by those on glass,and much lower on ***,the surface energy and roughness of three substrates were investigated,and it was found that the polar component of the surface energyγp plays a critical role in determining the crystalline microstructures of P3HT ultrathin films on different *** work indicates that the P3HT ultrathin film can obviously improve the stretchability and simultaneously retain similar electrical performance when a suitable substrate is *** findings offer a new direction for research on stretchable CP ultrathin films to facilitate future practical applications.

关键词： P3HT ultrathin film Substrate Crystalline microstructures Polar component of the surface energy Electrical and stretchable performances

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A coupled thermo-mechanical peridynamic model for fracture behavior of granite subjected to heating and water-cooling processes

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2006-2018页

作者： Luming zhou Zhende zhu Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China Jiangsu Research Center for Geotechnical Engineering Technology Hohai UniversityNanjing210098China

Thermal damage and thermal fracture of rocks are two important indicators in geothermal mining *** paper investigates the effects of heating and water-cooling on granite specimens at various *** laboratory uniaxial compression experiments were also ***,a coupled thermo-mechanical ordinary state-based peridynamic(OSB-PD)model and corresponding numerical scheme were developed to simulate the damage of rocks after the heating and cooling processes,and the change of crack evolution process was *** results demonstrate that elevated heating temperatures exacerbate the thermal damage to the specimens,resulting in a decrease in peak strength and an increase in ductility of *** escalating occurrence of thermal-induced cracks significantly affects the crack evolution process during the loading *** numerical results accurately reproduce the damage and fracture characteristics of the granite under different final heating temperatures(FHTs),which are consistent with the test results in terms of strength,crack evolution process,and failure mode.

关键词： Peridynamics(PD) Granite Heating and cooling Damage and fracture Uniaxial compression

Deep-reinforcement-learning-based UAV autonomous navigation and collision avoidance in unknown environments

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Chinese Journal of Aeronautics 2024年第3期37卷 237-257页

作者： Fei WANG Xiaoping zhu zhou zhou Yang TANG School of Astronautics Northwestern Polytechnical UniversityXi’an 710072China School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China

In some military application scenarios,Unmanned Aerial Vehicles(UAVs)need to perform missions with the assistance of on-board cameras when radar is not available and communication is interrupted,which brings challenges for UAV autonomous navigation and collision *** this paper,an improved deep-reinforcement-learning algorithm,Deep Q-Network with a Faster R-CNN model and a Data Deposit Mechanism(FRDDM-DQN),is proposed.A Faster R-CNN model(FR)is introduced and optimized to obtain the ability to extract obstacle information from images,and a new replay memory Data Deposit Mechanism(DDM)is designed to train an agent with a better *** training,a two-part training approach is used to reduce the time spent on training as well as retraining when the scenario *** order to verify the performance of the proposed method,a series of experiments,including training experiments,test experiments,and typical episodes experiments,is conducted in a 3D simulation *** results show that the agent trained by the proposed FRDDM-DQN has the ability to navigate autonomously and avoid collisions,and performs better compared to the FRDQN,FR-DDQN,FR-Dueling DQN,YOLO-based YDDM-DQN,and original FR outputbased FR-ODQN.

关键词： Faster R-CNN model Replay memory Data Deposit Mechanism(DDM) Two-part training approach Image-based Autonomous Navigation and Collision Avoidance(ANCA) Unmanned Aerial Vehicle(UAV)

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Long-term clinical outcomes and health-related quality of life in patients with isolated methylmalonic acidemia after liver transplantation:experience from the largest cohort study in China

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World Journal of Pediatrics 2024年第8期20卷 809-821页

作者： Yi-zhou Jiang Guang-Peng zhou Lin Wei Wei Qu Zhi-Gui Zeng ying Liu Yu-Le Tan Jun Wang Zhi-Jun zhu Li-ying Sun Department of Critical Liver Diseases Liver Research CenterBeijing Friendship HospitalCapital Medical UniversityNo.101 Lu Yuan Dong RoadTong-Zhou DistrictBeijing110112China Liver Transplantation Center National Clinical Research Center for Digestive DiseasesBeijing Friendship HospitalCapital Medical UniversityBeijingChina Clinical Center for Pediatric Liver Transplantation No.101 Lu Yuan Dong RoadTong-Zhou DistrictCapital Medical UniversityBeijing110112China

Background Liver transplantation(LT)has been proposed as a viable treatment option for selected methylmalonic acidemia(MMA)***,there are still controversies regarding the therapeutic value of LT for *** systematic assessment of health-related quality of life(HRQoL)-targeted MMA children before and after LT is also *** study aimed to comprehensively assess the long-term impact of LT on MMA,including multiorgan sequelae and HRQoL in children and *** We retrospectively evaluated 15 isolated MMA patients undergoing LT at our institution between June 2013 and March ***-and post-transplant data were compared,including metabolic profiles,neurologic consequences,growth parameters,and *** further assess the characteristics of the HRQoL outcomes in MMA,we compared the results with those of children with biliary atresia(BA).Results All patients had early onset MMA,and underwent LT at a mean age of 4.3 *** 1.3–8.2 years of follow-up,the patient and graft survival rates were 100%.Metabolic stability was achieved in all patients with liberalized dietary protein *** was a significant overall improvement in height Z scores(P=0.0047),and some preexisting neurological complications remained stable or even improved after *** the Pediatric Quality of Life Inventory(PedsQL™)generic core scales,the mean total,physical health,and psychosocial health scores improved significantly posttransplant(P<0.05).In the family impact module,higher mean scores were noted for all subscales post-LT,especially family function and daily activities(P<0.01).However,the total scores on the generic core scales and transplant module were significantly lower(Cohen’s d=0.57–1.17)when compared with BA *** particular,social and school functioning(Cohen’s d=0.86–1.76),treatment anxiety,and communication(Cohen’s d=0.99–1.81)were far behind,with a large effect *** This large single-center study of the mainland of China sh

关键词： Health-related quality of life.Inborn error of metabolism Isolated methylmalonic acidemia Liver transplantation:Outcomes

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