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Manipulator-based autonomous inspections at road checkpoints:Application of faster YOLO for detecting large objects

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Defence Technology（防务技术） 2022年第6期18卷 937-951页

作者： Qing-xin Shi Chang-sheng Li Bao-qiao Guo Yong-gui Wang huan-yu tian Hao Wen Fan-sheng Meng Xing-guang Duan School of Mechatronical Engineering Beijing Institute of TechnologyBeijing100081China Beijing Advanced Innovation Center for Intelligent Robots and Systems Beijing Institute of TechnologyBeijing100081China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

With the increasing number of vehicles,manual security inspections are becoming more laborious at road *** address it,a specialized Road Checkpoints Robot(RCRo)system is proposed,incorporated with enhanced You Only Look Once(YOLO)and a 6-degree-of-freedom(DOF)manipulator,for autonomous identity verification and vehicle *** modified YOLO is characterized by large objects’sensitivity and faster detection speed,named“LF-YOLO”.The better sensitivity of large objects and the faster detection speed are achieved by means of the Dense module-based backbone network connecting two-scale detecting network,for object detection tasks,along with optimized anchor boxes and improved loss *** the manipulator motion,Octree-aided motion control scheme is adopted for collision-free motion through Robot Operating System(ROS).The proposed LF-YOLO which utilizes continuous optimization strategy and residual technique provides a promising detector design,which has been found to be more effective during actual object detection,in terms of decreased average detection time by 68.25%and 60.60%,and increased average Intersection over Union(Io U)by 20.74%and6.79%compared to YOLOv3 and YOLOv4 through *** comprehensive functional tests of RCRo system demonstrate the feasibility and competency of the multiple unmanned inspections in practice.

关键词： Robot applications Object detection Vehicle inspection Identity verification You only look once(YOLO)

Predicting bathymetry based on vertical gravity gradient anomaly and analyses for various influential factors

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Geodesy and Geodynamics 2024年第4期15卷 386-396页

作者： huan Xu Jinhai yu Yanyan Zeng Qiuyu Wang yuwei tian Zhongmiao Sun College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijingChina Beijing Institute of Surveying and Mapping BeijingChina National Key Laboratory of Geoinformation Engineering Xi'an 710054China

The prediction of bathymetry has advanced significantly with the development of satellite ***,the majority of its data originate from marine gravity *** this study,based on the expression of vertical gravity gradient(VGG)of a rectangular prism,the governing equations for determining sea depths to invert *** governing equation is solved by linearization through an iterative process,and numerical simulations verify its algorithm and its *** also study the processing methods of different interference *** regularization method improves the stability of the inversion process for errors.A piecewise bilinear interpolation function roughly replaces the low-frequency error,and numerical simulations show that the accuracy can be improved by 41.2%after this *** variable ocean crust density,simulation simulations verify that the root-mean-square(RMS)error of prediction is approximately 5 m for the sea depth of 6 km if density is chosen as the average ***,two test regions in the South China Sea are predicted and compared with ship soundings data,RMS errors of predictions are 71.1 m and 91.4 m,respectively.

关键词： Rectangular prism Vertical gravity gradient Bathymetry Numerical simulation Prediction error

Dynamic response of buildings under debris flow impact

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Journal of Mountain Science 2024年第5期21卷 1581-1597页

作者： LIU huan FAN Xiaoyi tian Shujun DENG Xin School of Mechanical and Electrical Engineering Southwest Petroleum UniversityChengdu 610500China School of Civil Engineering and Geomatics Southwest Petroleum UniversityChengdu 610500China Housing and Urban-Rural Development Bureau of Mingshan District Ya’an 625100China Engineering Safety Assessment and Protection Research Southwest Petroleum UniversityChengdu 610500China School of Civil Engineering and Architecture Southwest University of Science and TechnologyMianyang 621010China

This study employs the smoothed particle hydrodynamics–finite element method(SPH–FEM) coupling numerical method to investigate the impact of debris flow on reinforced concrete(RC)-frame buildings. The methodology considers the variables of debris flow depth and velocity and introduces the intensity index IDV(IDV = DV) to evaluate three different levels of debris flow impact intensity. The primary focus of this study is to investigate the dynamic response and failure mechanism of RC-frame buildings under debris flow impact, including structural failure patterns, impact force and column displacement. The results show that under a highintensity impact, a gradual collapse process of the RCframe building can be observed, and the damage mode of the frame column reflects shear failure or plastic hinge failure mechanism. First, the longitudinal infill walls are damaged owing to their low out-of-plane flexural capacity;the critical failure intensity index IDV value is approximately 7.5 m2/s. The structure cannot withstand debris flows with an intensity index IDV greater than 16 m2/s, and it is recommended that the peak impact force should not exceed 2100 k N. The impact damage ability of debris flow on buildings mostly originates from the impact force of the frontal debris flow, with the impact force of the debris flow body being approximately 42% lower than that of the debris flow head. Finally, a five-level classification system for evaluating the damage status of buildings is proposed based on the numerical simulation and investigation results of the disaster site.

关键词： SPH–FEM method Debris flow Buildings The intensity index Dynamic response

Introducing sulfur to nickel-iron selenide for high-efficiency alkaline seawater electrolysis

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Science China Chemistry 2024年第8期67卷 2747-2754页

作者： Xuanwa Chen Yanhui yu Xingqi Han huan Wang Yingjie Hua Daoxiong Wu Peilin Deng Juanxiu Xiao Xinlong tian Jing Li School of Marine Science and Engineering Hainan Provincial Key Lab of Fine ChemistrySchool of Chemistry and Chemical EngineeringHainan UniversityHaikou 570228China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071China Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan Province School of Chemistry and Chemical EngineeringHainan Normal UniversityHaikou 571158China

Seawater electrolysis is an effective way to obtain hydrogen(H_(2))in a sustainable ***,the lack of electrocatalysts with high activity,stability,and selectivity for oxygen evolution reaction(OER)severely hinders the development of seawater electrolysis ***,sulfur-doped nickel-iron selenide nanosheets(S-NiFeSe_(2))were prepared by an ion-exchange strategy and served as highly active OER electrocatalyst for alkaline seawater *** overpotential is 367 m V,and it can run stably for over 50 h at 100 m A cm^(-2).Excitingly,the S-NiFeSe_(2)||Pt/C pair exhibits cell voltage of 1.54 V at 10 m A cm^(-2)under alkaline seawater conditions,which can run smoothly for 100 h without decay,and the efficiency of electricity-tohydrogen(ETH)energy conversion reaches more than 80%.Such electrode,with abundant accessible reactive sites and good corrosion resistance,is a good candidate for seawater ***,density functional theory calculations reveal that the surface sulfur atoms can activate the adjacent Ni sites and decrease the free energy changes of the associated intermediates at the adjacent Ni sites for OER,and the step of~*OH→~*O is the potential rate-limiting *** this work,the true reactive site in nickel-iron selenides is the Ni sites,but not the Fe sites as commonly believed.

关键词： S-doping nickel-iron selenide electrocatalysts oxygen evolution reaction alkaline seawater electrolysis

Supramolecular Biomaterials for Cancer Immunotherapy

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Research 2024年第2期2023卷 491-509页

作者： huan Liang Qingqing Lu Jie Yang Guocan yu College of Science Nanjing Forestry UniversityNanjing 210037P.R.China Key Laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology Department of ChemistryTsinghua UniversityBeijing 100084P.R.China

Cancer immunotherapy has achieved tremendous successful clinical results and obtained historic victories in tumor ***,great limitations associated with feeble immune responses and serious adverse effects still cannot be neglected due to the complicated multifactorial etiology and pathologic microenvironment in *** rapid development of nanomedical science and material science has facilitated the advanced progress of engineering biomaterials to tackle critical *** supramolecular biomaterials with flexible and modular structures have exhibited unparalleled advantages of high cargo-loading efficiency,excellent biocompatibility,and diversiform immunomodulatory activity,thereby providing a powerful weapon for cancer *** past decades,supramolecular biomaterials were extensively explored as versatile delivery platforms for immunotherapeutic agents or designed to interact with the key moleculars in immune system in a precise and controllable *** this review,we focused on the crucial role of supramolecular biomaterials in the modulation of pivotal steps during tumor immunotherapy,including antigen delivery and presentation,T lymphocyte activation,tumor-associated macrophage elimination and repolarization,and myeloid-derived suppressor cell *** on extensive research,we explored the current limitations and development prospects of supramolecular biomaterials in cancer immunotherapy.

关键词： biomaterials limitations thereby

Derivatives of Intersection Local Time for Two Independent Symmetricα-stable Processes

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1273-1292页

作者： huan ZHOU Guang Jun SHEN Qian yu Department of Mathematics Anhui Normal UniversityWuhu 241002P.R.China Department of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106P.R.China Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles(NUAA) MIITNanjing 211106P.R.China

In this paper,we consider the derivatives of intersection local time for two independent d-dimensional symmetricα-stable processes X^(α) and X^(α)with respective indices α and α.We first study the sufficient condition for the existence of the derivatives,which makes us obtain the exponential integrability and H?lder *** we show that this condition is also necessary for the existence of derivatives of intersection local time at the ***,we also study the power variation of the derivatives.

关键词： Symmetric stable processes intersection local time exponential integrability power variation

Prediction of ball-on-plate friction and wear by ANN with data-driven optimization

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Friction 2024年第6期12卷 1235-1249页

作者： Alexander KOVALEV yu tian Yonggang MENG State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China

For training artificial neural network(ANN),big data either generated by machine or measured from experiments are used as input to"learn"the unspecified functions defining the *** experimental data are fed directly into the optimizer allowing training to be performed according to a predefined loss *** predict sliding friction and wear at mixed lubrication conditions,in this study a specific ANN structure was so designed that deep learning algorithms and data-driven optimization models can be *** ball-on-plate friction and wear data were analyzed using the specific training procedure to optimize the weights and biases incorporated into the neural layers of the ANN,and only two independent experimental data sets were used during the ANN optimization *** the training procedure,the ANN is capable to predict the contact and hydrodynamic pressure by adapting the output data according to the tribological condition implemented in the optimization algorithm.

关键词： machine learning deep learning artificial neural network mixed lubrication

Use of Evidence-Based Research Approach in RCTs of Acupuncture-Related Therapies for Primary Dysmenorrhea: A Meta-Research

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Chinese Journal of Integrative Medicine 2024年第6期30卷 551-558页

作者： HU Xiao-yi tian Zi-yu CHEN huan HU Xiang-yu MING tian-yu PENG Hao-xuan JIAO Rui-min SHI Lan-jun XIU Wen-cui YANG Ji-wei GANG Wei-juan JING Xiang-hong Institute of Acupuncture and Moxibustion China Academy of Chinese Medical SciencesBeijingChina Department of Traditional Chinese Medicine Beijing Puren HospitalBeijing100062China

Objective To assess the use of evidence-based research(EBR)approach in randomized controlled trials(RCTs)of acupuncture-related therapies for primary dysmenorrhea(PD).Methods PubMed,EMBASE,Cochrane Library,China National Knowledge Infrastructure,Wanfang Database,Chinese Biomedical Database,and China Science and Technology Journal Database were searched from January 2013 to December 2022 for RCTs of acupuncture on *** full text and references of each RCT were read to assess whether systematic reviews(SRs)or other types of studies with similar research questions and end-users’perspectives were cited to justify and design the *** addition,the discussion section were analyzed to evaluate whether trials placed the new result in the existing SRs to draw a *** logistic regression was used to find variables that associated with 3 aspects of EBR approach:(1)citing clinical studies for justification,(2)citing relevant studies that obtain the perspectives of end users,and(3)citing clinical studies for results *** Of 473 RCTs included,45.67%(216)of the trials cited relevant similar studies,21.56%(102)referenced to the studies that collected end-users’perspectives,and 10.99%(52)placed result in the context of the previous *** RCTs appropriately applied EBR *** all the included studies,3.17%(15)of the trials used SRs to inform study questions but none of them used updated SRs with acceptable quality;1.05%(5)of the trials cited SRs of end-user’s perspectives in the justification and design of the study,and only 1 trial added results in existing SR to draw a *** of publication,language,funding,registration,ethical approval and number of sites were significantly associated with 1 of the 3 aspects of EBR *** Few RCTs in acupuncture-related therapies for PD used the EBR approach to minimize research ***,research institutes,funding agencies,ethics committees,journals and peer

关键词： evidence-based research acupuncture therapy primary dysmenorrhea randomized controlled trial systematic review end-usersperspective meta-research

First Passage Density of Brownian Motion with Two-sided Piecewise Linear Boundaries

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1505-1520页

作者： Zhen yu Mao Zai tian Center for Applied Statistics School of StatisticsRenmin University of ChinaBeijing 100872P.R.China School of Mathematics and Data Science Changji UniversityChangji 831100P.R.China

The first passage time has many applications in fields like finance,econometrics,statistics,and ***,explicit formulas for the first passage density have only been obtained for a few *** paper derives an explicit formula for the first passage density of Brownian motion with twosided piecewise continuous boundaries which may have some points of *** are used to obtain a simplified formula for estimating the first passage ***,the results are also generalized to the case of two-sided general nonlinear *** can be easily carried out with Monte Carlo method and it is demonstrated for several typical two-sided boundaries that the proposed approximation method offers a highly accurate approximation of first passage density.

关键词： Boundary non-crossing probability first density passage density two-sided piecewise continuous boundaries Brownian motion