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Large Displacement Optical Flow with Adaptive Feature Match
Xiaoping Zhang,Guoxin Li 보안공학연구지원센터(IJSIP) 2014 International Journal of Signal Processing, Image Vol.7 No.6
This paper presents an accurate large displacement optical flow estimation approach by adaptively integrate the local feature match. Despite coarse-to-fine warping approach can handle large displacement optical flow; however, there is inherent limit for small object with large motion. And recently integration of feature match to the variational framework has relaxed the limit, but raised another problem of ambiguous feature matching due to poor feature descriptor. Address the aforementioned problem, in this paper we propose an adaptive integration approach of local feature match. The essence is that we only keep the robust feature and remove those unstable features (e.g, textureless region) to improve the flow accuracy. The adaptive approach substantially decreases the computational cost by remove uncertain features and leads to more robust performance by excluding unreliable matches. We qualitatively and quantitatively compared to the conventional flow methods on Middlebury and Sintel benchmark and show that we achieve more accurate and promising results.
( Xiaoping Zhang ),( Bo Zhang ),( Renyun Miao ),( Jie Zhou ),( Lei Ye ),( Dinghong Jia ),( Weihong Peng ),( Lijuan Yan ),( Xiaoping Zhang ),( Wei Tan ),( Xiaolin Li ) 한국균학회 2018 Mycobiology Vol.46 No.3
Temperature is an important environmental factor that can greatly influence the cultivation of Auricularia cornea. In this study, lignin peroxidase, laccase, manganese peroxidase, and cellulose in A. cornea fruiting bodies were tested under five different temperatures (20℃, 25℃, 30℃, 35℃, and 40℃) in three different culture periods (10 days, 20 days and 30 days). In addition, the V4 region of bacterial 16S rRNA genes in the substrate of A. cornea cultivated for 30 days at different temperatures were sequenced using next-generation sequencing technology to explore the structure and diversity of bacterial communities in the substrate. Temperature and culture days had a significant effect on the activities of the four enzymes, and changes in activity were not synchronized with changes in temperature and culture days. Overall, we obtained 487,694 sequences from 15 samples and assigned them to 16 bacterial phyla. Bacterial community composition and structure in the substrate changed when the temperature was above 35℃. The relative abundances of some bacteria were significantly affected by temperature. A total of 35 genera at five temperatures in the substrate were correlated, and 41 functional pathways were predicted in the study. Bacterial genes associated with the membrane transport pathway had the highest average abundance (16.16%), and this increased at 35℃ and 40℃. Generally, different temperatures had impacts on the physiological activity of A. cornea and the bacterial community in the substrate; therefore, the data presented herein should facilitate cultivation of A. cornea.
Surface polished of bulk methylammonium lead tribromide single crystal
Zhang Hang,Zhang Bohao,Wang Xiang,Shao Wenyi,Nie Jing,Liu Jun,Ouyang Xiaoping,Xu Qiang 한국물리학회 2020 Current Applied Physics Vol.20 No.10
Organic-inorganic halide perovskite materials have been demonstrated with wide applications in optoelectronics and ionization radiation detection. For bulk as-grown crystals, the existence of surface cracks and defects can significantly increase charges recombination and reduce the performance of the device. Herein, we polished the crystal surfaces with both mechanical and chemical mechanical methods at room temperature. After been chemical-mechanical polished, the crystal surface with root mean square roughness about 0.5 nm was obtained. Optical transmission and photoluminescence spectra indicate that chemical mechanical polishing technology can effectively reduce the density of crystal surface defects. The achieved low leakage current density on the surface and bulk crystal is 0.05 nA mm 2 and 0.07 nA mm 2, respectively. Furthermore, the current-voltage curve under visible photons and X-ray photons reveals that surface polishing treatment can suppress the charges recombination and increase the charges transportation.
An Adaptive Fault-tolerant Control Method for Robot Manipulators
Wenjie Zhang,Xiaohui Yang,Zhenghong Xu,Wei Zhang,Li Yang,Xiaoping Liu 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.12
This paper presents a new method for adaptive continuous nonsingular fast terminal sliding mode control (ACNFTSMC) based on a novel structure-improved extended state observer (SIESO) for fault-tolerant control (FTC). In response to the initial peaking phenomenon in traditional ESO (TESO), which can severely degrade the accuracy and stability of the control system, The SIESO is designed to replace TESO to estimate the lump disturbances/faults. Besides, to address the problem of the unknown estimation error of ESO, an adaptive technique is applied to compensate for the observation error in real-time. To guarantee fast convergence and chattering-free, the CNFTSMC method is employed. Afterward, the stability and rapid convergence of the control system is demonstrated using Lyapunov theory. Finally, the simulation results verify the superiority of the proposed control strategy compared to the other existing advanced control techniques.
Zhenghong Xu,Xiaohui Yang,Wenjie Zhang,Wei Zhang,Liufang Zhang,Peter Xiaoping Liu 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.6
In this paper, we propose a backstepping integral nonsingular fast terminal sliding mode control approach based on an extended state observer to the trajectory tracking control of robotic manipulators with LuGre friction. In order to improve convergence speed and tracking precision, an integral fast terminal sliding surface is introduced. An appropriate saturation function is designed in the control input to avoid singularity. An extended state observer is employed to estimate the uncertainties and disturbances, and they are compensated by the control laws, for which the chattering can be effectively eliminated. The backstepping method is used to design the control input of the system to ensure the globally asymptotic stability based on the Lyapunov criterion. In comparison with other control methods, simulation results show effectiveness and superiority of this proposed control scheme.
Zhang, Zhan,Lim, Jong Min,Ishida, Masatoshi,Roznyatovskiy, VladimirV.,Lynch, Vincent M.,Gong, Han-Yuan,Yang, Xiaoping,Kim, Dongho,Sessler, Jonathan L. American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.9
<P>Novel hybrid cyclo[<I>m</I>]pyridine[<I>n</I>]pyrroles have been synthesized using Suzuki coupling.Their NMRand optical spectroscopic features and solid state structural parametersprovide support for the proposal that these species are best describedas locally aromatic compounds devoid of long-range intersubunit conjugation.However, an extension of the π-conjugation in the macrocyclescan be realized through protonation, as inferred from optical spectroscopicand X-ray diffraction-based structural studies.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2012/jacsat.2012.134.issue-9/ja211985k/production/images/medium/ja-2011-11985k_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja211985k'>ACS Electronic Supporting Info</A></P>
Xiaoping Chen,Wenjin Zhang,Shaolong Wang,Zu-chao Zhu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.12
On the basis of the weakly compressible assumption, large-eddy simulation of a high-speed centrifugal pump is performed at a rotational speed of 9685 r/min and flow rate of approximately quarter load (0.23 Qd). Three cryogenic media, namely, liquid methane (MM), liquid nitrogen (MN), and liquid oxygen (MO), are used. Results show that many of the internal flow characteristics derived and validated for normal-temperature water still hold for cryogenic media. Pump efficiency, maximum density deviation, and total entropy generation rate increase with the increase in the reference density. The dominant frequencies of the pressure spectrum are 12 and 6 times the rotation frequency and insensitive to the cryogenic media. The average amplitude of the first-order dominant frequency between MN and MO deviates from that of MM by approximately 10 %. The maximum deviations of the average amplitudes of second-order dominant and axial frequencies are 34.9 % and 32.3 %, respectively. The variation in standard deviation exceeds 40 % for all cryogenic media.
Xiaoping Li,Zongping Zhang,Jiangnan Huang,Lijie Su,Mengjin Zhu,Mei Yu 한국유전학회 2013 Genes & Genomics Vol.35 No.3
In pigs, complex molecular cross-talk between the mother and embryo(s) especially maternal immunotolerance at the maternal-fetal interface has been postulated to play important roles on embryo/fetal loss during the peri-implantation and midgestation. In this study, we collected the endometrium samples in implantation sites at gestational day 15 (gd15), 26 (gd26)) and 50 (gd50)from Meishan pigs to evaluate the contribution of the genes participating in immune response by using porcine Affymetrix GeneChip.The results showed that totally 68immune related genes showed significantly differential expression at three stages, and the expression of these genes underwent drastic changes during the peri-implantation period (between gd15 and gd26). The identified genes including IL6 proinflammatory cytokine family,inflammatory chemokines (CCL28), IGF/IGFBP system,growth factors (FGF7) and adhesion molecules (ITGB3,PCDH15) may prove valuable for further investigations of porcine prenatal mortality.
Xiaoping Wang,Jianghua Du,Xin Zhang,Deming Jia 한국고분자학회 2018 Macromolecular Research Vol.26 No.5
A mechano-chemical modification process for waste rubber powder (WRP) was investigated in this paper. 2-Mercatobenzothiozole (accelerator M) was introduced as a peptizer to improve plasticity of WRP, and 3-aminopropyltriethoxysilane (silane coupling agent KH550) was used as a surfactant to further modify the surface of plasticized rubber powder (PRP) to improve interfacial bonding with epoxidized natural rubber (ENR). Infrared spectrums showed that the WRP generated more oxygen-containing groups by mechanical forces in the presence of accelerator M and then grafted amino groups with KH550. The mechano-chemical process with accelerator M changed the structure of WRP obviously shown by sol fraction and microstructure of PRP, which increased the mechanical properties and crosslink density of full rubber powder vulcanizates. After further modified by KH550, the modified rubber powder (MRP) had a positive chemical interfacial bonding with ENR, changing the fracture surface and improving the mechanical properties of vulcanizates. The cure characteristics of the vulcanizates also illustrated that accelerator M and KH550 participated in the vulcanization process increasing the curing efficiency. The best mechanical properties of ENR/MRP vulcanizates were better than the neat ENR vulcanizates. It indicated that the mechano-chemical process with accelerator M and KH550 will be a potential method to reclaim WRP.