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Prediction and Control of Thermal Scratch Defect on Surface of Strip in Tandem Cold Rolling

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Journal of Iron and Steel Research International 2015年第2期22卷 106-114页

作者： jin-shan CHEN chang-sheng LI State Key Laboratory of Rolling and Automation Northeastern University

The thermal scratch significantly influences the surface quality of the cold rolled stainless steel strip. In or der to establish a precise mathematical model of oil film thickness in deformation zone, the lubrication in cold rolling process of B443NT stainless steel strip was studied in the laboratory. According to the principle of statistics, a math- ematical model of critical oil film thickness in deformation zone for thermal scratch was built, with fitting and regres- sion analytical method, and then based on temperature comparison method, the criterion for deciding thermal scratch defect was put forward. Storing and calling data through SQI. Server 2005, a software on thermal scratch control was developed in the Microsoft Visual Studio 2008 environment by MFC technique for stainless steel in tandem cold roll- ing, and then it was used into the practical production. Statistical results demonstrated that the hit rate of thermal scratch arrives at 91.47%, the occurrence rate of thermal scratch is decreased by 87.81%, and rolling speed is in- creased by 7.3%. The developed software is of significance to the control of products quality of stainless steel strips, and the analysis and solution to the problem of thermal scratch defects in tandem cold rolling.

关键词： thermal serateh software design tandem cold rolling temperature stainless steel

Model Simulation and Eigen-Analysis for Polarimetric Scattering from Tree Canopy in SAR Imagery

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Journal of Systems Engineering and Electronics 2000年第2期11卷 48-54页

作者： jin, Yaqiu Zhan, Nanxiong chang, Mei Fudan Univ Shanghai China

In this paper, a theoretical model of multi-level, non-spherical scatterers is developed for fully polarimetric scattering from tree canopy in SAR imaging at C band. The amplitude functions of non-spherical particles with randomly spatial orientation are derived by the generalized Rayleigh-Gans (GRG) approximation. The non-diagonal extinction matrix and the Mueller matrix solution are constructed. Numerical solutions of polarimetric scattering of four Stokes parameters from random, non-spherical scatterers are obtained. To physically identify polarimetric scattering of the Mueller matrix solution, the coherency matrix and its eigen-analysis are discussed. Functional dependence of the coherency matrix and entropy upon various parameters are obtained. As an application, the analysis of AirSAR images at P, L, C bands is discussed.

关键词： Approximation theory Eigenvalues and eigenfunctions Light scattering Matrix algebra Random processes Synthetic aperture radar Trees (mathematics)

New Differential Properties of Sup-type Functions

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Acta Mathematicae Applicatae Sinica 2009年第2期25卷 243-254页

作者： jin-chuan Zhou chang-yu Wang Department of Mathematics School of Science Beijing Jiaotong University Beijing 100044 China Institute of Operations Research Qufu Normal University Qufu 273165 China

In this paper, we study the directional derivative, subderivative, and subdifferential of sup-type functions without any compactness assumption on the index set. As applications, we provide an estimate of the Lipschit... 详细信息

关键词： sup-type function subderivative subdifferential Lipschitz modulus

Surface properties of Al-doped ZnO thin film before and after CF_4/Ar plasma etching

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Plasma Science and Technology 2022年第7期24卷 194-200页

作者： Young-hee JOO Gwan-Ha KIM Doo-Seung UM chang-Il KIM School of Electrical and Electronics Engineering Chung-Ang UniversitySeoul 06974Republic of Korea Department of Semiconductor Materials and Applications Korea PolytechnicSeongnam 13122Republic of Korea Department of Electrical Engineering Sejong UniversitySeoul 05006Republic of Korea

Al-doped ZnO(AZO) is considered as an alternative to transparent conductive oxide *** and achieving a stable surface are important challenges in the development and optimization of dry etching processes, which must be overcome for the application of AZO in various devices. Therefore, in this study, the etch rate and surface properties of an AZO thin film after plasma etching using the adaptive coupled plasma system were investigated. The fastest etch rate was achieved with a CF_(4)/Ar ratio of 50:50 sccm. Regardless of the ratio of CF_(4) to Ar,the transmittance of the film in the visible region exceeded 80%. X-ray photoelectron spectroscopy analysis of the AZO thin film confirmed that metal-F bonding persists on the surface after plasma etching. It was also shown that F eliminates O vacancies. Consequently, the work function and bandgap energy increased as the ratio of CF-4 increased. This study not only provides information on the effect of plasma on AZO thin film, but identifies the cause of changes in the device characteristics during device fabrication.

关键词： Al-doped ZnO plasma etching F-based plasma surface characteristics X-ray photoelectron spectroscopy ultraviolet photoelectron spectroscopy

Two-stage dynamic recrystallization and texture evolution in Al-7Mg alloy during hot torsion

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1900-1911页

作者： Kwang Tae Son chang hee Cho Myoung Gyun Kim Ji Woon Lee School of Mechanical Industrialand Manufacturing EngineeringOregon State UniversityCorvallis OR 97331USA Department of Materials Science Engineering Northwestern UniversityEvanston IL 60208USA Research Institute of Industrial Science and Technology(RIST) Pohang 37673Rep.of Korea Division of Advanced Materials Engineering Kongju National UniversityCheonan 31080Rep.of Korea Center for Advanced Materials and Parts of Powders Kongju National UniversityCheonan 31080Rep.of Korea

Hot torsion tests were performed on the Al-7Mg alloy at the temperature ranging from 300 to 500℃ and strain rates between 0.05 and 5 s^(-1) to explore the progressive dynamic recrystallization(DRX)and texture *** DRX behavior of the alloy manifested two distinct stages:Stage 1 at strain of≤2 and Stage 2 at strains of≥*** Stage 1,there was a slight increase in the DRXed grain fraction(X_(DRX))with predominance of discontinuous DRX(DDRX),followed by a modest change in X_(DRX) until the transition to Stage *** 2 was marked by an accelerated rate of DRX,culminating in a substantial final X_(DRX) of~*** backscattered diffraction(EBSD)analysis on a sample in Stage 2 revealed that continuous DRX(CDRX)predominantly occurred within the(121)[001]grains,whereas the(111)[110]grains underwent a geometric DRX(GDRX)evolution without a noticeable sub-grain ***,a modified Avrami’s DRX kinetics model was utilized to predict the microstructural refinement in the Al-7Mg alloy during the DRX *** this kinetics model did not accurately capture the DDRX behavior in Stage 1,it effectively simulated the DRX rate in Stage *** texture index was employed to assess the evolution of the texture isotropy during hot-torsion test,demonstrating significant improvement(>75%)in texture randomness before the commencement of Stage *** initial texture evolution is attributed to the rotation of parent grains and the substructure evolution,rather than to an increase in X_(DRX).

关键词： Al-7Mg alloys hot deformation hot torsion tests dynamic recrystazlliation microstructure texture

Bifurcation Control for a Duffing Oscillator with Delayed Velocity Feedback

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International Journal of Automation and computing 2016年第6期13卷 596-606页

作者： chang-jin Xu Yu-Sen Wu Guizhou Key Laboratory of Economics System Simulation Guizhou University of Finance and Economics Guiyang 550004 China School of Mathematics and Statistics Henan University of Science and Technology Luoyang 471023 China

In this paper, a Duffing oscillator model with delayed velocity feedback is considered. Applying the time delayed feedback control method and delayed differential equation theory, we establish some criteria which ensure the stability and the existence of Hopf bifurcation of the model. By choosing the delay as bifurcation parameter and analyzing the associated characteristic equation,the existence of bifurcation parameter point is determined. We found that if the time delay is chosen as a bifurcation parameter,Hopf bifurcation occurs when the time delay is changed through a series of critical values. Some numerical simulations show that the designed feedback controllers not only delay the onset of Hopf bifurcation, but also enlarge the stability region for the model.

关键词： bifurcation oscillator Feedback asymptotically dynamical Velocity enlarge perturbation imaginary unstable

Earthquake Risk Assessment Approach Using Multiple Spatial Parameters for Shelter Demands

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Computers, Materials & Continua 2022年第2期70卷 3763-3780页

作者： Wenquan jin Naeem Iqbal hee-Cheal Kang Dohyeun Kim Big Data Research Center Jeju National UniversityJeju63243Korea Department of Computer Engineering Jeju National UniversityJeju63243Korea Infomind Jeju63243Korea

The earthquake is considered one of the most devastating disasters in any area of the world due to its potentially destructive *** on the various earthquake-related parameters,the risk assessment is enabled in advance to prevent future earthquake *** this paper,for providing the shelter space demands to reduce the damage level and prevention costs,an earthquake risk assessment approach is proposed for deriving the risk index based on multiple spatial parameters in the gridded *** proposed assessment approach is comprised of pre-processing,methodologymodel,and data *** risk index model derives the earthquake risk index by multiple spatial parameters including indexes of earthquake,danger,shelter,and building for blocks in the quantitative gridded *** parameters are provided based onmathematicalmodels and combinedwith the risk index that presents the earthquake risk assessment result for each ***,the gridding approach is proposed to provide the elements of the risk assessment area that are used in the spatial *** gridded map is developed for the selected area to visualize risk index parameters associated with each risk *** on the derived result of the proposed earthquake risk indexmodel,emergency shelter requirements are provided according to the risk index for each location,which supports safety measures in advance to prevent future earthquake disasters.

关键词： Risk analysis risk index earthquake shelter demand data analysis

Shadow Detection and Removal From Photo-Realistic Synthetic Urban Image Using Deep Learning

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Computers, Materials & Continua 2020年第1期62卷 459-472页

作者： hee-jin Yoon Kang-Jik Kim Jun-Chul Chun Department of Computer Science Kyonggi UniversityGyeonggi-do16227Korea

Recently,virtual reality technology that can interact with various data is used for urban design and ***,one of the most important elements in virtual reality technology,means visual expression so that a person can experience three-dimensional space like *** obtain this realism,real-world data are used in the various *** example,in order to increase the realism of 3D modeled building textures real aerial images are utilized in 3D ***,the aerial image captured during the day can be shadowed by the sun and it can cause the distortion or deterioration of *** resolve this problem,researches on detecting and removing shadows have been conducted,but the detecting and removing shadow is still considered as a challenging *** this paper,we propose a novel method for detecting and removing shadows using deep *** this work,we first a build a new dataset of photo-realistic synthetic urban data based on the virtual environment using 3D spatial information provided by *** detecting and removing shadow from the dataset,firstly,the 1-channel shadow mask image is inferred from the 3-channel shadow image through the ***,to generate a shadow-free image,a 3-channel shadow image and a detected 1-channel shadow mask into the GAN is *** the experiments,we can prove that the proposed method outperforms the existing methods in detecting and removing shadow.

关键词： Deep-learning shadow detection shadow removal synthetic data

Comparison of intra peritoneal anti-adhesive polysaccha rides derived from Phellinus mushrooms in a rat peritonitis model

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World Journal of Gastroenterology 2005年第6期11卷 810-816页

作者： Jae-Sung Bae Kwang-Ho Jang hee-Kyung jin Department of Surgery Department of Laboratory Animal Medicine

AIM: To assess the adhesion- and abscess-reducing capacities of various concentrations of polysaccharides derived from fungus, Phellinus gilvus (PG) or Phellinus linteus (PL) in a rat peritonitis ***: In 96 SD rats, experimental peritonitis was induced using the cecal ligation and puncture model (CLP).Rats were randomly assigned to 8 groups; Ringer's lactate solution (RL group), hyaluronic acid (HA group), 0.025%,0.25%, and 0.5% polysaccharides from PG (PG0.025, 0.25,and 0.5 groups), and PL (PL0.025, 0.25, and 0.5 groups).Adhesions and abscesses were noted at 7 d after ***-PCR assay was performed to assess the cecal ***: Adhesion formation was significantly reduced in PG0.25, 0.5, PL0.25, 0.5, and HA groups (2.5±0.7,2.4±0.7, 3.8±1.0, 3.6±0.8, and 2.7±1.1, P＜0.05). The incidence of abscesses was significantly reduced in all treated groups compared to RL group (58%, P＜0.05). The urokinase-type plasminogen activator (uPA) gene expression was greatly up-regulated by increasing the concentration of polysaccharides. The urokinase-type plasminogen activator receptor (uPAR) and tumor necrosis factor (TNF)-α mRNA were highly expressed in PG0.25, 0.5, PL0.25, and ***: We concluded that 0.5% polysaccharide derived from PG and PL was the optimal concentration in preventing adhesion and abscess formation and may act by modulating activity of uPA and TNF-α in a rat peritonitis model.

关键词： Adhesion Abscess Phellinus gilvus, Phellinus linteus Polysaccharides