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Object Helps U-Net Based Change Detectors

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 548-550页

作者： Lan Yan qiang li Kenli li College of Computer Science and Electronic Engineering Hunan UniversityChangsha 410082China State Key Laboratory for Management and Control of Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China

Dear Editor,This letter focuses on leveraging the object information in images to improve the performance of the U-Net based change *** detection is fundamental to many computer vision *** existing solutions based on ... 详细信息

关键词： Net computer networks

Design and heat transfer analysis of a compound multi-layer insulations for use in high temperature cylinder thermal protection systems

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Science China(Technological Sciences) 2018年第7期61卷 994-1002页

作者： CHEN MengJun ZHANG Ping li qiang MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power Engineering Nanjing University of Science & Technology School of Mechanical and Electrical Engineering Guilin University of Electronic Technology

Thermal protection systems are very essential for high temperature thermal conductivity measurement system to reduce the heat loss to environment at the range of 600-1800 K. A compound multi-layer insulations structure which composed of inner carbon fibrous materials and outer alternately arranged alumina fibrous materials and high reflectivity foils is proposed for use in high temperature cylinder thermal protection systems. A coupled conductive and radiation governing equations is presented for heat transfer analysis of the structure. The finite volume method and the discrete ordinate method are used to solve the goveming equations. The optimization structure of the compound multi-layer insulations is investigated by considering the pressure of the gas, the density of the carbon fibrous materials, the density of the alumina fibrous materials, the number of reflective foil layers and the emissivity of reflective foils. The results show that the compound structure has the best thermal insulation performance when the pressure of the gas is below 0.01 kPa, the density of carbon fibrous materials is 180 kg m^-3, the density of alumina fibrous materials is 256 kg m^-3 and the number of reflective foil layers is 39. In addition, the thermal insulation performance is much better when the emissivity of reflective foils is lower.

关键词： compound insulation heat transfer carbon fibrous alumina fibrous

The influence of temperature on flow-induced forces on quartz-crystal-microbalance sensors in a Chinese liquor identification electronic-nose: three-dimensional computational fluid dynamics simulation and analysis

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Applied Mathematics and Mechanics(English Edition) 2019年第9期40卷 1301-1312页

作者： qiang li Yu GU Huatao WANG School of Automation and Electrical Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Beijing 100029 China Department of Chemistry Goethe-University Frankfurt Frankfurt am Main 60438 Germany

An electronic-nose is developed based on eight quartz-crystal-microbalance (QCM) gas sensors in a sensor box, and is used to detect Chinese liquors at room temperature. Each sensor is a highly-accurate and highly-sensitive oscillator that has experienced airflow disturbances under the condition of varying room temperatures due to unstable flow-induced forces on the sensors surfaces. The three-dimensional (3D) nature of the airflow inside the sensor box and the interactions of the airflow on the sensors surfaces at different temperatures are studied by computational fluid dynamics (CFD) tools. Higher simulation accuracy is achieved by optimizing meshes, meshing the computational domain using a fine unstructural tetrahedron mesh. An optimum temperature, 30 ℃, is obtained by analyzing the distributions of velocity streamlines and the static pressure, as well as the flow-induced forces over time, all of which may be used to improve the identification accuracy of the electronic-nose for achieving stable and repeatable signals by removing the influence of temperature.

关键词： computational fluid dynamics (CFD) temperature quartz-crystalmicrobalance (QCM) gas sensor electronic nose identification accuracy

Parameter identification of hysteretic model of rubber-bearing based on sequential nonlinear least-square estimation

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Earthquake Engineering and Engineering Vibration 2010年第3期9卷 375-383页

作者： Yin qiang Zhou li Wang Xinming MOE Key Lab of Structure Mechanics and Control for Aircraft Institute of Structures ＆ Strength Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

In order to evaluate the nonlinear performance and the possible damage to rubber-bearings （RBs） during their normal operation or under strong earthquakes, a simplified Bouc-Wen model is used to describe the nonlinear hysteretic behavior of RBs in this paper, which has the advantages of being smooth-varying and physically motivated. Further, based on the results from experimental tests performed by using a particular type of RB （GZN 110） under different excitation scenarios, including white noise and several earthquakes, a new system identification method, referred to as the sequential nonlinear least- square estimation （SNLSE）, is introduced to identify the model parameters. It is shown that the proposed simplified Bouc- Wen model is capable of describing the nonlinear hysteretic behavior of RBs, and that the SNLSE approach is very effective in identifying the model parameters of RBs.

关键词： parameter identification rubber-bearing hysteretic behavior Bouc-Wen model sequential nonlinear least- square estimation

Image decomposing for inpainting using compressed sensing in DCT domain

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Frontiers of Computer Science 2014年第6期8卷 905-915页

作者： qiang li Yahong HAN Jianwu DANG School of Computer Science and Technology Tianjin University Tianjin 300072 China Tianjin Key Laboratory of Cognitive Computing and Application Tianjin University Tianjin 300072 China School of Information Science Japan Advanced Institute of Science and Technology Ishikawa 923-1192 Japan

Inpainting images with occlusion or corruption is a challenging task. Most existing algorithms are pixel based, which construct a statistical model from image features. However, in these algorithms, the frequency component is not sufficiently addressed. In this paper, we propose a novel algorithm that utilizes compressed sensing （CS） in frequency domain to reconstruct corrupted images. In order to reconstruct image, we first decompose the image into two functions with different basic characteristics - structure component and textual component. We seek a sparse representation for the functions and use the DCT coefficients of this representation to generate an over-complete dictionary. Experimental results on real world datasets demonstrate the efficacy of our method in image inpainting. We compare our method with three state-of-the-art inpalnting algorithms and demonstrate its advantages in terms of both quantitative and qualitative aspects.

关键词： image inpainting compressed sensing image decomposing discrete cosine transform

A Signal Based “W” Structural Elements for Multi-scale Mathematical Morphology Analysis and Application to Fault Diagnosis of Rolling Bearings of Wind Turbines

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International Journal of Automation and computing 2021年第6期18卷 993-1006页

作者： qiang li Yong-Sheng Qi Xue-Jin Gao Yong-Ting li li-qiang liu Institute of Electric Power Inner Mongolia University of TechnologyHohhot 010080China Inner Mongolia Key Laboratory of Electrical and Mechanical Control Hohhot 010051China Faculty of Information Beijing University of TechnologyBeijing 100124China

Working conditions of rolling bearings of wind turbine generators are complicated, and their vibration signals often show non-linear and non-stationary characteristics. In order to improve the efficiency of feature extraction of wind turbine rolling bearings and to strengthen the feature information, a new structural element and an adaptive algorithm based on the peak energy are proposed,which are combined with spectral correlation analysis to form a fault diagnosis algorithm for wind turbine rolling bearings. The proposed method firstly addresses the problem of impulsive signal omissions that are prone to occur in the process of fault feature extraction of traditional structural elements and proposes a "W" structural element to capture more characteristic information. Then, the proposed method selects the scale of multi-scale mathematical morphology, aiming at the problem of multi-scale mathematical morphology scale selection and structural element expansion law. An adaptive algorithm based on peak energy is proposed to carry out morphological scale selection and structural element expansion by improving the computing efficiency and enhancing the feature extraction ***, the proposed method performs spectral correlation analysis in the frequency domain for an unknown signal of the extracted feature and identifies the fault based on the correlation coefficient. The method is verified by numerical examples using experimental rig bearing data and actual wind field acquisition data and compared with traditional triangular and flat structural elements. The experimental results show that the new structural elements can more effectively extract the pulses in the signal and reduce noise interference,and the fault-diagnosis algorithm can accurately identify the fault category and improve the reliability of the results.

关键词： Fault diagnosis structural element multi-scale mathematical morphology rolling bearing correlation analysis

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The role of hydrated anions in hydration lubrication

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Nano Research 2023年第1期16卷 1096-1100页

作者： Zibo li Qian liu qiang li Mingdong Dong Key Laboratory of Colloid and Interface Chemistry of the Ministry of Education School of Chemistry and Chemical EngineeringShandong UniversityJinan 250100China Interdisciplinary Nanoscience Center(iNANO) Aarhus UniversityAarhus C DK-8000Denmark

Hydration lubrication has long been invoked to account for the ultralow sliding friction between charged surfaces in aqueous environments,but still not well understood at ***,we explored the lubrication effect of hydrated halogen anions on positively charged surface at the atomic scale by using three-dimensional atomic force microscopy and friction force *** resolved three-dimensional imaging revealed that the anion layer was topped by a few hydration *** mechanical properties of the hydration layers were found mainly dependent on the concentration of electrolyte solutions and independent of the species of hydrated ***-scale friction experiments showed that the hydration friction coefficient and friction dissipation at low concentrations were orders of magnitude lower than that at high concentrations and in pure *** can be achieved in low concentration electrolyte *** results indicated that the changes of electrolyte solution concentrations led to different adsorption state of anions on the positively charged surface which gave rise to the difference of the friction *** findings in this study reveal the role of hydrated anions in hydration lubrication and provide deep insights into the origins of hydration lubrication.

关键词： hydration lubrication hydration structures anions friction three-dimensional atomic force microscopy(3D-AFM)

Dynamic Optimization Method on Electromechanical Coupling System by Exponential Inertia Weight Particle Swarm Algorithm

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Chinese Journal of Mechanical Engineering 2009年第4期22卷 602-607页

作者： li qiang WU Jianxin SUN Yan College of Mechanical and Electrical Engineering North China University of Technology Beijing 100144 China College of Mechanical Engineering lnner Mongolia University of Technology Hohhot 010051 China

Dynamic optimization of electromechanical coupling system is a significant engineering problem in the field of mechatronics. The performance improvement of electromechanical equipment depends on the system design parameters. Aiming at the spindle unit of refitted machine tool for solid rocket, the vibration acceleration of tool is taken as objective function, and the electromechanical system design parameters are appointed as design variables. Dynamic optimization model is set up by adopting Lagrange-Maxwell equations, Park transform and electromechanical system energy equations. In the procedure of seeking high efficient optimization method, exponential function is adopted to be the weight function of particle swarm optimization algorithm. Exponential inertia weight particle swarm algorithm（EPSA）, is formed and applied to solve the dynamic optimization problem of electromechanical system. The probability density function of EPSA is presented and used to perform convergence analysis. After calculation, the optimized design parameters of the spindle unit are obtained in limited time period. The vibration acceleration of the tool has been decreased greatly by the optimized design parameters. The research job in the paper reveals that the problem of dynamic optimization of electromechanical system can be solved by the method of combining system dynamic analysis with reformed swarm particle optimizati on. Such kind of method can be applied in the design of robots, NC machine, and other electromechanical equipments.

关键词： particle swarm algorithm electromechanical coupling system dynamic optimization

Mean-square Stability of Stochastic Age-dependent Delay Population Systems with Jumps

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Acta Mathematicae Applicatae Sinica 2018年第1期34卷 145-154页

作者： qiang li Qi-min ZHANG Bo-qiang CAO School of Mathematics and Statistics Ningxia University Yinchuan 750021 China School of Mathematics and Information Sciences Beifang University of Nationalities Yinchuan 750021 China

In this paper, we present the compensated stochastic θ method for stochastic age-dependent delay population systems（SADDPSs） with Poisson jumps. The definition of mean-square stability of the numerical solution is given and a sufficient condition for mean-square stability of the numerical solution is derived. It is shown that the compensated stochastic θ method inherits stability property of the numerical solutions. Finally,the theoretical results are also confirmed by a numerical experiment.

关键词： stochastic age-dependent delay population systems compensated stochastic θ method poisson jumps mean-square stability