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An improved mask R-CNN example segmentation algorithm based on RGB-D

International Journal of Wireless and Mobile Computing 2024年第3期26卷 302-309页

作者： Li, Gongfa Li, Boao Jiang, Du Tao, Bo Yun, Juntong Key Laboratory of Metallurgical Equipment and Control Technology of Ministry of Education Wuhan University of Science and Technology Hubei Wuhan China Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering Wuhan University of Science and Technology Hubei Wuhan China National Demonstration Centre for Experimental Mechanical Education Wuhan University of Science and Technology Hubei Wuhan China

Combining the characteristics of RGB images and depth images, we propose a reverse fusion instance segmentation algorithm that effectively combines the advantages of RGB and depth information by fusing high-level semantic features with low-level edge detail features. The algorithm uses RGB and depth information in RGB-D images, extracts features from RGB and depth images separately using a Feature Pyramid Network (FPN) and upsamples the high-level features to the same size as the bottommost features. Subsequently, we apply the inverse fusion method to fuse the high-level features with the low-level features. At the same time, a mask optimisation structure is introduced in the mask branch to achieve RGB-D reverse fusion instance segmentation. Experimental results show that this reverse fusion feature model gives satisfactory performance in RGB-D instance segmentation. On the basis of using ResNet-101 as the backbone network, the average accuracy is improved by 10.6% compared with Mask R-CNN without fusing depth information. Copyright © 2024 Inderscience Enterprises Ltd.

关键词： Inverse problems

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Causal reasoning in typical computer vision tasks

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science China(Technological sciences) 2024年第1期67卷 105-120页

作者： ZHANG KeXuan SUN QiYu ZHAO ChaoQiang TANG Yang Key Laboratory of Advanced Control and Optimization for Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China National Key Laboratory of Air based Information Perception and Fusion Luoyang 471000China Luoyang Institute of Electro Optical Equipment of Avic Luoyang 471000China

Deep learning has revolutionized the field of artificial *** on the statistical correlations uncovered by deep learning-based methods,computer vision tasks,such as autonomous driving and robotics,are growing *** being the basis of deep learning,such correlation strongly depends on the distribution of the original data and is susceptible to uncontrolled *** the guidance of prior knowledge,statistical correlations alone cannot correctly reflect the essential causal relations and may even introduce spurious *** a result,researchers are now trying to enhance deep learningbased methods with causal *** theory can model the intrinsic causal structure unaffected by data bias and effectively avoids spurious *** paper aims to comprehensively review the existing causal methods in typical vision and visionlanguage tasks such as semantic segmentation,object detection,and image *** advantages of causality and the approaches for building causal paradigms will be *** roadmaps are also proposed,including facilitating the development of causal theory and its application in other complex scenarios and systems.

关键词： causal reasoning computer vision tasks vision-language tasks semantic segmentation object detection

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Experimental study on permeability evolution of deep high-stressed coal under major horizontal stress unloading paths

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International Journal of Mining science and technology 2024年第11期34卷 1495-1508页

作者： Chao Liu Jiahao Zhang Songwei Wu Jinghua Qi Beichen Yu Liang Wang School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Mining Disaster Prevention and Control Ministry of EducationShandong University of Science and TechnologyQingdao 266590China School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Coal Mine Disaster Prevention and Control China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Theory and Technology on Coal and Rock Dynamic Disaster Prevention and Control National Mine Safety AdministrationChina University of Mining and TechnologyXuzhou 221116China

Both bulk stress(σ_(i i))and stress path(SP)significantly affect the transportation characteristics of deep gas during reservoir pressure ***,the experimental study of horizontal stress unloading on seepage behavior of gas-bearing coal under constantσi i-constraints is *** results show that coal permeability is affected by horizontal stress anisotropy(σ_(H)≠σh),and the contribution of minor horizontal stress to permeability is related to the differential response of horizontal *** slippage phenomenon is prominent in deep high-stress regime,especially in low reservoir pressure.σ_(i i)and SP jointly determine the manifestation of slippage effect and the strength of stress sensitivity(γ)of *** reservoir implies an incremental percentage of slip-based permeability,and SP weakens the slippage effect by changing the elastic–plastic state of ***,γis negatively correlated with slippage *** the Walsh model,narrow(low aspect-ratio)fractures within the coal under unloading SP became the main channel for gas seepage,and bring the effective stress coefficient of permeability(χ)less than 1 for both low-stress elastic and high-stress damaged *** the raise of the effective stress,the effect of pore-lined clay particles on permeability was enhanced,inducing an increase inχfor highstress elastic coal.

关键词： True triaxial stress path Constant bulk stress Horizontal stress Effective stress coefficient of permeability Slippage effect

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Effect of Free-End Torsion on the Corrosion and mechanical Properties for Mg-3Zn-0.2Ca Alloy

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Acta Metallurgica Sinica(English Letters) 2025年第1期38卷 59-70页

作者： Li-Lan Gao Jiang Ma Yan-Song Tan Xiao-Hao Sun Qi-Jun Gao De-Bao Liu Chun-Qiu Zhang Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin300384China School of Materials Science and Engineering Tianjin University of TechnologyTianjin300384China

Magnesium alloys with excellent degradability and biocompatibility are promising materials for biomedical implants,saving patients the burden of second ***,their mechanical properties and corrosion resistance are significantly below the requirements for implant *** study aims to improve the mechanical and corrosion resistance properties of Mg-3Zn-0.2Ca alloy by pre-torsion treatment,and find out the optimal shear *** rod-shaped Mg-3Zn-0.2Ca alloy specimens were pre-torsion treated at different torsion *** effect of free-end torsion on Mg-3Zn-0.2Ca alloy was characterized through microstructure analysis,mechanical testing,and corrosion ***-torsion treatment can refine grain and induce twins and dislocations in Mg-3Zn-0.2Ca *** surface hardness increases with the increase in torsion *** yield strength and ultimate strength initially increase and then decrease with increasing torsion angle,while ductility decreases with increasing torsion *** with a shear strain of 30%exhibit the highest tensile strength,reaching 284.78±10.62 MPa,with an elongation of 19.37±1.66%.Furthermore,they show a significant improvement in fatigue lives both before and after *** the stress amplitude is 120 MPa,the fatigue lives for specimens without pre-torsion treatment are 54,275 cycles and 4324 cycles before and after pre-corrosion,while they increased significantly to 92,015 cycles and 5050 cycles with the 30%shear strain,***,the 30%shear strain specimens show a significant reduction in corrosion *** conclusion,pre-torsion treatment can effectively modify the microstructure of Mg-3Zn-0.2Ca alloy,enhancing both mechanical properties and corrosion *** optimal shear strain for this improvement is 30%.This study provides a practical method to enhance the mechanical properties and corrosion resistance of Mg-3Zn-0.2Ca alloy,making it more suitable for biomedical implan

关键词： Magnesium alloy Pre-torsion Microstructure mechanical property Corrosion resistance

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Method for Evaluating the Performance of Aircraft Collaborative Decision-Making Based on dynamic Bayesian Network

Method for Evaluating the Performance of Aircraft Collaborat...

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2024 International Conference on electronics and Devices, Computational science, ICEDCS 2024

作者： Zhang, Wenbo Yu, Boxiao Tong, Jiahui Li, Jing Beijing Electro-Mechanical Engineering Institute National Key Laboratory of Complex System Control and Intelligent Agent Cooperation Beijing China Beijing Institute of Technology School of Computer Science and Technology Beijing China

ISBN: (纸本)9798331527624

This research addresses the challenge of assessing equipment decision-making effectiveness in environments characterized by uncertainty and multiple influencing factors. We propose a novel approach involving the creation and optimization of a dynamic Bayesian network-based model tailored for equipment decision-making processes. The model facilitates a systematic evaluation of decision-making effectiveness by incorporating various factors, including equipment performance, environmental conditions, and enemy defensive capabilities. A comprehensive assessment system has been developed to simulate the penetration capabilities of different equipment through enemy defenses. Moreover, this study identifies potential errors in the effectiveness evaluation model by analyzing its performance in typical scenarios, pinpointing areas for enhancement. © 2024 IEEE.

关键词： Decision-making dynamic Bayesian networks Equipment Simulation Uncertainty Management

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dynamics and stability analysis of unbalance responses in mid-positioned electrically assisted turbocharger rotor

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International Journal of mechanical System dynamics 2024年第4期4卷 515-535页

作者： Mingyue Hu Shuqian Cao Xiaolin Cao Zhiyong Zhang Rixiu Men Zhenzhen You Tianyou Wang School of Mechanical Engineering Tianjin UniversityTianjinChina Tianjin Key Laboratory of Nonlinear Dynamics and Control TianjinChina National Key Laboratory of Vehicle Power System TianjinChina Science and Technology on Diesel Engine Turbocharging Laboratory China North Engine Research InstituteTianjinChina

Electrically assisted turbochargers(EAT)improve intake efficiency by motor-assisted compressor impeller rotation,enhancing the system's transient ***,the addition of motor rotor components has increased the number of unbalanced positions in the shaft system,leading to problems such as excessive compressor end vibration and complex changes in oil film *** evaluate the effects of unbalance in the motor rotor,along with the parameters of floating ring bearings(FRB),on the dynamic response of EAT,a finite element model of an EAT rotor supported by nonlinear FRB is developed,and the vibration response of the compressor end bearing is obtained by numerical *** results indicate:(1)In contrast to the effect of compressor and turbine unbalance,proper motor rotor unbalance is more effective in suppressing oil whirl instability in the high-speed operating ***,a new inner oil film whirl“instability interval”is also induced in the low-speed operating range,leading to an increase in the Y1 compressor-end amplitude at low and medium speeds,and this“instability interval”increases with the amount of unbalance.(2)When an oil whirl occurs in the oil film,the maximum eccentricity of the bearing surges and is greater than 0.3,which can be used as an effective threshold for determining whether the oil film is unstable in engineering applications.(3)A suitable outer oil-film clearance range should be 35–40μm,otherwise,a wide range of outer oil-film whirl instability *** the amount of unbalance and oil-film clearance to suppress the subsynchronous vibration of the EAT,provides a theoretical basis for the design of the dynamics of the nonlinear rotor bearing system and improves the stability of the turbocharger's operation.

关键词： electrically assisted turbocharger motor unbalance oil-film clearance rotor dynamics nonlinear vibration

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High-precision colorimetric-fluorescent dual-mode biosensor for detecting acetylcholinesterase based on a trimetallic nanozyme for efficient peroxidase-mimicking

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Journal of Materials science & technology 2024年第24期191卷 168-180页

作者： Meie Zheng Mingxing Liu Zichen Song Fei Ma Hongda Zhu Huiling Guo Hongmei Sun Cooperative Innovation Center of Industrial Fermentation(Ministry of Education&Hubei Province) National“111”Center for Cellular Regulation and Molecular PharmaceuticsKey Laboratory of Fermentation Engineering(Ministry of Education)Hubei Key Laboratory of Industrial MicrobiologyHubei University of TechnologyWuhan 430068China Hubei Key Laboratory of Quality Control of Characteristic Fruits and Vegetables College of Life Science and TechnologySchool of Mechanical EngineeringHubei Engineering UniversityXiaogan 432000China

Highly sensitive and stable acetylcholinesterase detection is critical for diagnosing and treating various neurotransmission-related *** this study,a novel colorimetric-fluorescent dual-mode biosensor based on highly dispersive trimetal-modified graphite-phase carbon nitride nanocomposites for acetylcholinesterase detection was designed and synthesized by phosphorus doping and a mixed-metal MOF *** specific surface area of trimetal-modified graphite-phase carbon nitride nanocomposites increased from 15.81 to 96.69 g m^(-2),and its thermal stability,interfacial charge transfer,and oxidation-reduction capability were enhanced compared with those of graphite-phase carbon ***-principles density functional theory calculations and steady-state kinetic analysis are applied to investigate the electronic structures and efficient peroxidase-mimicking properties of trimetal-modified graphite-phase carbon nitride *** oxidation of 3,3',5,5'-tetramethylbenzidin was inhibited by thiocholine,which originates from the decomposition of thiocholine iodide by Acetyl-cholinesterase(AChE),resulting in changes in fluorescence and absorbance *** to the independence and complementarity of the signals,a highly precise colorimetric-fluorescent dual-mode biosensor with a linear range for detecting AChE of 4-20μU mL^(-1) and detection limits of 0.13μU mL^(-1)(colorimetric)and 0.04μU mL^(-1)(fluorescence)was *** spiking recovery of AChE in actual samples was 99.0%-100.4%.Therefore,a highly accurate,specific,and stable dual-mode biosensor is available for AChE detection,and this biosensor has the potential for the analysis of other biomarkers.

关键词： Graphitic carbon nitride Zeolitic imidazolate framework-8 Colorimetric-fluorescent dual-mode sensor Density functional theory calculations Acetylcholinesterase

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Safe Efficient Policy Optimization Algorithm for Unsignalized Intersection Navigation

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IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 2011-2026页

作者： Xiaolong Chen Biao Xu Manjiang Hu Yougang Bian Yang Li Xin Xu State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body the College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body the College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082 Wuxi Intelligent Control Research Institute(WICRI)of Hunan University Wuxi 214115China College of Intelligence Science and Technology Institute of Unmanned SystemsNational University of Defense TechnologyChangsha 410073China

Unsignalized intersections pose a challenge for autonomous vehicles that must decide how to navigate them safely and *** paper proposes a reinforcement learning(RL)method for autonomous vehicles to navigate unsignalized intersections safely and *** method uses a semantic scene representation to handle variable numbers of vehicles and a universal reward function to facilitate stable learning.A collision risk function is designed to penalize unsafe actions and guide the agent to avoid them.A scalable policy optimization algorithm is introduced to improve data efficiency and safety for vehicle learning at *** algorithm employs experience replay to overcome the on-policy limitation of proximal policy optimization and incorporates the collision risk constraint into the policy optimization *** proposed safe RL algorithm can balance the trade-off between vehicle traffic safety and policy learning *** intersection scenarios with different traffic situations are used to test the algorithm and demonstrate its high success rates and low collision rates under different traffic *** algorithm shows the potential of RL for enhancing the safety and reliability of autonomous driving systems at unsignalized intersections.

关键词： Autonomous driving decision-making reinforcement learning(RL) unsignalized intersection

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Reliability analysis of arresting hook engaging arresting cable for carrier-based aircraft influenced by multifactors

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Chinese Journal of Aeronautics 2023年第1期36卷 311-323页

作者： Yiming PENG Yin YIN Pengpeng XIE Xiaohui WEI Hong NIE State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing University of Aeronautics and AstronauticsNanjing 210016China Shanghai Institute of Spacecraft Equipment Shanghai 200240China

The carrier-based aircraft landing and arrest process is complex and nonlinear,and includes the coupling effect between the aircraft and arresting *** has many uncertain factors,which lead to difficulty in the reliability *** make the reliability analysis more accurate and effective,this paper presents some *** a certain type of carrier-based aircraft as the research object,a dynamic model of the landing and arrest cable was established,and the accuracy of the model was verified using laboratory test *** on the model,this paper shows how the key parameters,including the sinking velocity,pitch angle and horizontal velocity,affect the collision rebound performance of the arresting *** that,a limit state equation of the arresting hook system’s reliability was *** the implicit limit state equation,a surrogate model of the reliability of the arresting hook was established using the Support Vector Machine(SVM)method,and then reliability analysis was carried out using the Monte Carlo ***,it was explained in detail how the key parameters affect the reliability of the hook engaging the arresting cable,and some meaningful conclusions were *** analysis method and its results can provide a reference for the top-level parameter design of carrier-based aircraft and reliability research on the arresting systems.

关键词： Arresting cable Arresting devices dynamics Reliability Support Vector Machines

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Real-time monitoring and analysis of hydraulic fracturing in surface well using microseismic technology:Case insights and methodological advances

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International Journal of Mining science and technology 2025年第4期35卷 619-638页

作者： Yanan Qian Ting Liu Cheng Zhai Hongda Wen Yuebing Zhang Menghao Zheng Hexiang Xu Dongyong Xing Xinke Gan State Key Laboratory of Coal Mine Disaster Prevention and Control China University of Mining and TechnologyXuzhou 221116China Yunlong Lake Laboratory of Deep Underground Science and Engineering Xuzhou 221003China Key Laboratory of Theory and Technology on Coal and Rock Dynamic Disaster Prevention and Control National Mine Safety AdministrationChina University of Mining and TechnologyXuzhou 221116China School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China School of Emergency Management Chengdu UniversityChengdu 610106China School of Safety Science and Engineering Anhui University of Science and TechnologyHuainan 232001China Xinjiang Yaxin Coalbed Methane 156 Exploration Co. Ltd.Urumqi 841100China

Through a case analysis,this study examines the spatiotemporal evolution of microseismic(MS)events,energy characteristics,volumetric features,and fracture network development in surface well hydraulic fracturing.A total of 349 MS events were analyzed across different fracturing sections,revealing significant heterogeneity in fracture *** scanning results showed that cumulative energy values ranged from 240 to 1060 J across the sections,indicating notable *** reservoir volume(SRV)analysis demonstrated well-developed fracture networks in certain sections,with a total SRV exceeding 1540000 m^(3).The hydraulic fracture network analysis revealed that during the midfracturing stage,the density and spatial extent of MS events significantly increased,indicating rapid fracture propagation and the formation of complex *** the later stage,the number of secondary fractures near fracture edges decreased,and the fracture network *** comparing the branching index,fracture length,width,height,and SRV values across different fracturing sections,Sections No.1 and No.8 showed the best performance,with high MS event densities,extensive fracture networks,and significant energy ***,Sections No.4 and No.5 exhibited sparse MS activity and poor fracture connectivity,indicating suboptimal stimulation effectiveness.

关键词： Hydraulic fracturing Microseismic Source location Energy scanning Fracture network

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