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Eu^2＋-doped Sr5(PO4)3Br blue-emitting phosphor with high color purity for near-UV-pumped white light-emitting diodes

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Journal of Rare Earths 2018年第9期36卷 917-923页

作者： Zhiwen Gao Shihua Liu Pengfei Sun Jung hyun jeong Ruijin Yu Bin Deng College of Chemistry and Pharmacy Northwest A&F University Yangling 712100 China College of Chemical Biological and Environmental Engineering Xiangnan University Chenzhou 423043 China Department of Physics Pukyong National University Busan 608-737 Republic of Korea

Eu2＋-doped bromophosphateapatite Sr5（PO4）3 Br phosphors were synthesized by the conventional hightemperature solid-state *** crystal structure and luminescence properties of the phosphors,as well as their thermal stability and CIE chromaticity coordinates were systematically *** spectra of Sr5（PO4）3 Br：Eu2＋ exhibit a single blue emission at 450 nm under the excitation of 345 nm,which is ascribed to the 4 f-5 d transition of Eu2＋.The phosphor shows very good thermal stability; The CIE color coordinates are very close to those of BaMgAl10O17：Eu2＋（BAM）.All the properties indicate that the blue-emitting Sr5（PO4）3 Br：Eu2＋ phosphor has potential application in white LEDs.

关键词： Bromophosphate Luminescence EU^2 + ion Rare earths

Role of two-dimensional shear wave elastography in chronic liver diseases: A narrative review

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World Journal of Gastroenterology 2018年第34期24卷 3849-3860页

作者： Jae Yoon jeong Young Seo Cho Joo hyun Sohn Department of Internal Medicine Hanyang University Guri Hospital Hanyang University College of Medicine Department of Radiology Hanyang University Guri Hospital Hanyang University College of Medicine

Liver biopsy is the gold standard for evaluating the degree of liver fibrosis in patients with chronic liver disease. However, due to the many limitations of liver biopsy, there has been much interest in the use of noninvasive techniques for this purpose. Among these techniques real-time two-dimensional shear wave elastography(2D-SWE) has the advantage of measuring tissue elasticity with the guidance of B-mode images. Recently, many studies have been conducted on the application of 2D-SWE in patients with various liver diseases, and their validity has been confirmed. Here, we briefly discuss the role of 2D-SWE in patients with chronic liver diseases, particularly aspects of the examination techniques and clinical applications.

关键词： Shear wave elastography Liver disease Liver fibrosis Portal hypertension Hepatocelluar carcinoma

Cu^+-incorporated TiO_2 overlayer on Cu_2O nanowire photocathodes for enhanced photoelectrochemical conversion of CO_2 to methanol

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Journal of Energy Chemistry 2018年第1期27卷 264-270页

作者： Kangha lee Seokwon lee hyunjin Cho Sunil jeong Whi Dong Kim Sooho lee Doh C.lee Department of Chemical and Biomolecular Engineering(BK21+program) KAIST Institute for the NanocenturyKorea Advanced Institute of Science and Technology(KAIST)

In this paper, we report photoelectrochemical（PEC） conversion of carbon dioxide（CO_2） using photocathodes based on Cu_2O nanowires（NWs） overcoated with Cu~＋-incorporated crystalline TiO_2（TiO_2–Cu~＋）shell. Cu_2O NW photocathodes show remanent photocurrent of 5.3% after 30 min of PEC reduction of CO_*** coating Cu_2O with TiO_2–Cu~＋ overlayer, the remanent photocurrent is 27.6%, which is an increase by5.2 fold. The charge transfer resistance of Cu_2O/TiO_2–Cu~＋ is 0.423 k/cm2, whereas Cu_2O photocathode shows resistivity of 0.781 k/cm2 under irradiation. Mott–Schottky analysis reveals that Cu~＋ species embedded in TiO_2 layer is responsible for enhanced adsorption of CO_2 on TiO_2 surface, as evidenced by the decrease of capacitance in the Helmholtz layer. On account of these electrochemical and electronic effects by the Cu~＋ species, the Faradaic efficiency（FE） of photocathodes reaches as high as 56.5% when TiO_2–Cu~＋ is added to Cu_2O, showing drastic increase from 23.6% by bare Cu_2O photocathodes.

关键词： Photoelectrochemical CO2 reductionMethanol generation Copper oxide Titanium dioxide Cu+ catalyst

Value of controlled attenuation parameter in fibrosis prediction in nonalcoholic steatohepatitis

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World Journal of Gastroenterology 2019年第33期25卷 4959-4969页

作者： Jung Il lee hyun Woong lee Kwan Sik lee Department of Internal Medicine Gangnam Severance Hospital Yonsei University College of Medicine

BACKGROUND Liver stiffness measurement(LSM)tends to overestimate fibrosis stage in nonalcoholic fatty liver disease(NAFLD).Controlled attenuation parameter(CAP),provided by LSM device,has been introduced for noninvasive quantification of hepatic *** To determine the role of CAP values in predicting liver fibrosis stage by LSM in nonalcoholic steatohepatitis(NASH).METHODS One hundred eighty-four patients with biopsy proven NASH had LSM and CAP evaluated at *** them,130 patients had 1-year follow up LSM and analyzed for the changes of LSM after pioglitazone or ursodeoxycholic acid(UDCA)*** In Kleiner fibrosis stage F0-1,LSM values increased at higher CAP tertile(P=0.001),and in F2,at middle and higher tertiles(P=0.027).No difference across CAP tertiles was noticed in F3-4(P=0.752).Receiver operating characteristic curve for LSM cutoff in diagnosis of F≥2 identified 8.05 kPa for lower CAP tertile,9.35 kPa for middle,and 10.55 kPa for high *** changes in proportion of significant fibrosis(F≥2)were assessed among pioglitazone and UDCA treated patients considering CAP values,pioglitazone treated patients demonstrated decrease in proportion of high *** In patient with NAFLD,interpretation of LSM in association with CAP scores may provide helpful information sparing unnecessary liver biopsy.

关键词： Fibroscan Controlled attenuation parameter Liver stiffness Nonalcoholic steatohepatitis Liver fibrosis

Multi-stage optimum design of magazine type automatic tool changer arm

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Journal of Central South University 2012年第1期19卷 174-178页

作者： KIM Jae-hyun lee Choon-Man School of Mechatronics Changwon National UniversityChangwon 641-773Korea

To enhance machining efficiency,tool change time has to be ***,for an automatic tool changer attached to a machining center,the tool change time is to be *** the automatic tool changer is a main part of the machining center as a driving *** static attributes of the automatic tool changer using the commercial code,ANSYS Workbench V12,were tried to *** the optimum design of automatic tool changer arm was proposed by performing the multi-stage optimum *** shape optimization of the automatic tool changer was proposed and the result was verified to obtain acceptable *** is possible to obtain an optimized model in which the maximum deformation,maximum stress,and mass are reduced by 10.46%,12.89% and 9.26%,respectively,compared with those of the initial ***,the results between conventional method by the design of experiments and proposed method by the multi-stage optimum design method were compared.

关键词： automatic tool changer optimum design structural analysis exchange arm

Aqueous-processable,naphthalene diimide-based polymers for eco-friendly fabrication of high-performance,n-type organic electrolyte-gated transistors

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Science China Chemistry 2022年第5期65卷 973-978页

作者： Dahyun jeong Min Je Kim Seungjin lee Jin-Woo lee Youngwoong Kim Hyeong Jun Kim jeong Ho Cho Bumjoon J.Kim Department of Chemical and Biomolecular Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea Department of Chemical and Biomolecular Engineering Yonsei UniversitySeoul 03722Republic of Korea Department of Chemical and Biomolecular Engineering Sogang UniversitySeoul 04107Republic of Korea

Organic electrolyte-gated transistors(OEGTs) have the benefits of low power consumption and large current ***,the electrical performance of n-type OEGTs lags far behind that of p-type *** this study,we design a series of polymers,P(NDITEG-T) and P(NDIMTEG-T),comprising a naphthalene diimide backbone for n-type charge transport and oligo(ethylene glycol)(OEG) side chains for high ionic conductivity and eco-friendly solution *** incorporation of the OEG chain facilitates the electrochemical doping of the semiconductor by ions to realize high-performance,n-type ***,in OEGTs,P(NDITEG-T) achieves a high electron mobility of 1.0 × 10^(-1) cm^(2) V^(-1) s^(-1),which represents the highest value reported for solution-processed,n-type *** is noted that the fabrication of the OEGTs is achieved by solution processing with eco-friendly ethanol/water mixtures in virtue of the hydrophilic OEG *** work demonstrates the molecular design of the P(NDITEG-T) polymer and its significant ability to produce aqueous-processable,high-performance,and n-type OEGTs.

关键词： organic electrolyte-gated transistors n-type transistors oligo(ethylene glycol)polymers eco-friendly solution process high electron mobility

Development of vehicle-recognition method on water surfaces using LiDAR data:SPD^(2)(spherically stratified point projection with diameter and distance)

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Defence Technology（防务技术） 2024年第6期36卷 95-104页

作者： Eon-ho lee Hyeon Jun Jeon Jinwoo Choi hyun-Taek Choi Sejin lee The Department of Mechanical Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea Ocean System Engineering Research Division Korea Research Institute of Ships and Ocean Engineering(KRISO)Daejeon 34103Republic of Korea The Division of Mechanical&Automotive Engineering Kongju National University1223-24 Cheonan-daeroCheonan 31080Republic of Korea

Swarm robot systems are an important application of autonomous unmanned surface vehicles on water *** monitoring natural environments and conducting security activities within a certain range using a surface vehicle,the swarm robot system is more efficient than the operation of a single object as the former can reduce cost and save *** is necessary to detect adjacent surface obstacles robustly to operate a cluster of unmanned surface *** this purpose,a LiDAR(light detection and ranging)sensor is used as it can simultaneously obtain 3D information for all directions,relatively robustly and accurately,irrespective of the surrounding environmental *** the GPS(global-positioning-system)error range exists,obtaining measurements of the surface-vessel position can still ensure stability during platoon *** this study,a three-layer convolutional neural network is applied to classify types of surface *** aim of this approach is to redefine the sparse 3D point cloud data as 2D image data with a connotative meaning and subsequently utilize this transformed data for object classification ***,we have proposed a descriptor that converts the 3D point cloud data into 2D image *** use this descriptor effectively,it is necessary to perform a clustering operation that separates the point clouds for each *** developed voxel-based clustering for the point cloud ***,using the descriptor,3D point cloud data can be converted into a 2D feature image,and the converted 2D image is provided as an input value to the *** intend to verify the validity of the proposed 3D point cloud feature descriptor by using experimental data in the ***,we explore the feasibility of real-time object classification within this framework.

关键词： Object classification Clustering 3D point cloud data LiDAR(light detection and ranging) Surface vehicle

Comparative study on discharge conditions in micro-hole electrical discharge machining of tungsten carbide (WC-Co) material

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中国有色金属学会会刊：英文版 2009年第B09期19卷 114-118页

作者： hyun-Seok TAK Chang-Seung HA Dong-hyun KIM Ho-Jun lee Hae-June lee Myung-Chang KANG National Core Research Center for Hybrid Materials Solution Pusan National University Department of Electrical Engineering Pusan National University

WC-Co is used widely in die and mold industries due to its unique combination of hardness, strength and wear-resistance. For machining difficult-to-cut materials, such as tungsten carbide, micro-electrical discharge machining(EDM) is one of the most effective methods for making holes because the hardness is not a dominant parameter in EDM. This paper describes the characteristics of the discharge conditions for micro-hole EDM of tungsten carbide with a WC grain size of 0.5 μm and Co content of 12%. The EDM process was conducted by varying the condenser and resistance values. A R-C discharge EDM device using arc erosion for micro-hole machining was suggested. Furthermore, the characteristics of the developed micro-EDM were analyzed in terms of the electro-optical observation using an oscilloscope and field emission scanning electron microscope.

关键词：电火花加工碳化钨钴难切削材料硬质合金放电扫描电子显微镜微孔模具行业

Deep Learning-Based Action Classification Using One-Shot Object Detection

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Computers, Materials & Continua 2023年第8期76卷 1343-1359页

作者： hyun Yoo Seo-El lee Kyungyong Chung Contents Convergence Software Research Institute Kyonggi UniversitySuwon-si16227Korea Department of Public Safety Bigdata Kyonggi UniversitySuwon-si16227Korea Division of Computer Science and Engineering Kyonggi UniversitySuwon-si16227Korea

Deep learning-based action classification technology has been applied to various fields,such as social safety,medical services,and *** an action on a practical level requires tracking multiple human bodies in an image in real-time and simultaneously classifying their *** are various related studies on the real-time classification of actions in an ***,existing deep learning-based action classification models have prolonged response speeds,so there is a limit to real-time *** addition,it has low accuracy of action of each object ifmultiple objects appear in the ***,it needs to be improved since it has a memory overhead in processing image *** learning-based action classification using one-shot object detection is proposed to overcome the limitations of multiframe-based analysis *** proposed method uses a one-shot object detection model and a multi-object tracking algorithm to detect and track multiple objects in the ***,a deep learning-based pattern classification model is used to classify the body action of the object in the image by reducing the data for each object to an action *** to the existing studies,the constructed model shows higher accuracy of 74.95%,and in terms of speed,it offered better performance than the current studies at 0.234 s per *** proposed model makes it possible to classify some actions only through action vector learning without additional image learning because of the vector learning feature of the posterior neural ***,it is expected to contribute significantly to commercializing realistic streaming data analysis technologies,such as CCTV.

关键词： Human action classification artificial intelligence deep neural network pattern analysis video analysis