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Journal of Mountain Science 2014年第3期11卷 578-591页

作者： Hosung KIM Seung woo LEE Chan-young YUNE Gihong KIM Department of Civil Engineering Gangneung-Wonju National University

This paper describes a geographic information system(GIS)-based method for observing changes in topography caused by the initiation, transport, and deposition of debris flows using highresolution light detection and ranging(LiDAR) digital elevation models(DEMs) obtained before and after the debris flow events. The paper also describes a method for estimating the volume of debris flows using the differences between the LiDAR DEMs. The relative and absolute positioning accuracies of the LiDAR DEMs were evaluated using a real-time precise global navigation satellite system(GNSS) positioning method. In addition, longitudinal and cross-sectional profiles of the study area were constructed to determine the topographic changes caused by the debris flows. The volume of the debris flows was estimated based on the difference between the LiDAR DEMs. The accuracies of the relative and absolute positioning of the two LiDAR DEMs were determined to be ±10 cm and ±11 cm RMSE, respectively, which demonstrates the efficiency of the method for determining topographic changes at an scale equivalent to that of field investigations. Based on the topographic changes, the volume of the debris flows in the study area was estimated to be 3747 m3, which is comparable with the volume estimated based on the data from field investigations.

关键词： Debris flow Topographic change LiDAR DEM Volume estimation Global navigation satellitesystem (GNSS)

Verification of Beam Models for Ionic Polymer-Metal Composite Actuator

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Journal of Bionic Engineering 2009年第3期6卷 232-238页

作者： Hoon Cheol Park Quoc Viet Nguyen Jang woo Lee young Tai Yoo Artificial Muscle Research Center Konkuk University Department of Advanced Technology Fusion Konkuk University Department of Materials Chemistry and Engineering Konkuk University

Ionic Polymer-Metal Composite (IPMC) can work as an actuator by applying a few voltages.A thick IPMC actuator,where Nafion-117 membrane was synthesized with polypyrrole/alumina composite filler,was analyzed to verify the equivalent beam and equivalent bimorph beam *** blocking force and tip displacement of the IPMC actuator were measured with a DC power supply and young's modulus of the IPMC strip was measured by bending and tensile tests *** calculated maximum tip displacement and the young's modulus by the equivalent beam model were almost identical to the corresponding measured *** element analysis with thermal analogy technique was utilized in the equivalent bimorph beam model to numerically reproduce the force-displacement relationship of the IPMC *** results by the equivalent bimorph beam model agreed well with the force-displacement relationship acquired by the measured *** is confirmed that the equivalent beam and equivalent bimorph beam models are practically and effectively suitable for predicting the tip displacement,blocking force and young's modulus of IPMC actuators with different thickness and different composite of ionic polymer membrane.

关键词： jonic polymer-metal composite beam model displacement force

Malignant sweat gland tumor of breast arising in pre-existing benign tumor: A case report

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World Journal of Clinical Cases 2019年第19期7卷 3033-3038页

作者： Jin Kyung An Jeong Joo woo young Ok Hong Department of Radiology Nowon Eulji Medical CenterEulji UniversitySeoul 01830South Korea Department of Pathology Nowon Eulji Medical CenterEulji UniversitySeoul 01830South Korea

BACKGROUND Sweat glands belong to skin *** gland tumors are uncommon,especially when they occur as malignant tumors in the *** report a case of malignant sweat gland tumor of the breast,including imaging and pathological *** SUMMARY A 47-year-old woman visited our hospital with a non-tender palpable lesion in her left *** lesion had not shown changes for 10 ***,it recently increased in *** showed a well circumscribed cystic lesion with internal debris and fluid-fluid *** resonance imaging showed a well circumscribed oval mass with T1 hyper-intensity compared to muscle and T2 high signal *** was a small enhancing mural component in the inner wall of the *** tumor was *** pathologic result was a malignant transformation of benign sweat gland tumor such as *** lesion was treated with excision and radiation *** 1-year follow up,there was no local recurrence or metastasis in the *** In the case of a rapid growing cystic mass in the nipple and subareola,it is necessary to distinguish it from a malignant sweat gland tumor.

关键词： Sweat gland neoplasm Breast Ultrasonography Magnetic resonance imaging

Chicken soup for teaching and learning ESD

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World Journal of Gastroenterology 2011年第21期17卷 2618-2622页

作者： Eun young Kim Seong woo Jeon Gwang Ha Kim Division of Gastroenterology Department of Internal MedicineCatholic University of Daegu School of Medicine Division of Gastroenterology Department of Internal MedicineKyungpook National University School of Medicine Department of Internal Medicine Pusan National University School of Medicine and Medical Research InstitutePusan National University Hospital

Endoscopic submucosal dissection(ESD) is becoming a popular procedure for the diagnosis and treatment of superficial mucosal lesions,and has the advantage of en bloc resection which yields a higher complete resection and remission rate compared to endoscopic mucosal resection(EMR).However,the learning process of this advanced endoscopic procedure requires a lengthy training period and considerable experience to be proficient.A well framed training protocol which is safe,effective,easily reproducible and cost-effective is desirable to teach *** addition,the training course may need to be tailored around settings such as ethnicity,culture,workload,and disease *** Asian countries with a large volume of early gastric lesions which need endoscopic treatment,endoscopists would be able to learn ESD expanding their skills from EMR to ESD under the supervision of ***,in Western countries due to the low incidence of superficial gastric tumors,trials have utilized simulator models to improve *** Korea,the Korean Society of Gastrointestinal Endoscopy(KSGE) is playing an important role in training many gastroenterologists who have shown an interest in performing ESD by providing an annual live demonstration and a nationwide tutoring *** purpose of this article is to introduce our ESD tutoring experience,review the published papers related to this topic,and propose several suggestions for future directions in teaching and learning ESD.

关键词： Endoscopic submucosal dissection Learning Teaching

Crushing behavior of lightmass structural member

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中国有色金属学会会刊：英文版 2009年第B09期19卷 276-279页

作者： Kil-Sung LEE Yong-June YANG woo-Chae HWANG In-young YANG Department of Mechatronics Chosun University of Science and Technology Department of Advanced Part and Materials Engineering Chosun University Department of Mechanical Design Engineering Chosun University

Carbon fiber reinforced plastic (CFRP) of the advanced composite materials is widely used in lightmass structural materials of air planes, ship and automobiles because of high strength and stiffness. In this study, experimental investigation was performed for each specimen. The square section members consist of aluminum, CFRP and hybrid (aluminum/CFRP) member, and hat-shaped section members consist of CFRP and hybrid (aluminum/CFRP) members specimen. Based on the collapse characteristics of aluminum square section member, the collapse characteristics and energy absorption capability of hat-shaped section members were analyzed. The axial static collapse tests were carried out for each section member. The collapse modes and the energy absorption capability of the members were analyzed. In the lightmass design aspect, the collapse characteristics and energy absorption capability of the members were compared.

关键词：碳纤维增强复合材料碳纤维复合材料能量吸收能力行为构件破碎航空飞机 CFRP

Structural stability estimation of whirling unit

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中国有色金属学会会刊：英文版 2009年第B09期19卷 202-208页

作者： Son-Jae HWAN Han-Chang woo Lee-Sang RYONG Lee-young MOON Daegu Machinery Institute of Component & Materials Foundation Department of Automobile Yeungnam College of Science & Technology Department of Mechanical Engineering Kyung pook National University

Whirling is a cutting process in which a series of cutting edges on whirling ring remove material by turning over a rotating workpiece. In this study static and dynamic stability of whirling unit was estimated by using ADAMS and NASTRAN softwares. Each maximum force acting on the bearing attached to the spindle assembly and the cutting tool attached to the whirling ring with the rotating speed of 6 000 r/min was 235 N and 902 N respectively. The maximum stress of 0.74 MPa on the base frame is far smaller than the yield strength of 282 MPa. The calculated natural frequency of 148 Hz of the system is far from the frequency of the driving speed of 6 000 r/min. The experimentally obtained maximum cutting force of 792 N is smaller than that of calculated value. And the experimentally obtained natural frequency of 118 Hz is beyond the driving speed of 6000 r/min. From above results it can be judged that the whirling system is statically and dynamically stable.

关键词：旋转工件稳定性评价 NASTRAN软件动态稳定性结构单元固有频率行车速度

Development of a variable rate applicator for uniform fertilizer spreading

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International Journal of Agricultural and Biological Engineering 2019年第2期12卷 82-89页

作者： Cheol-woo Han Sang-yoon Lee young-ki Hong Gi-young Kweon Department of Bio-Industrial Machinery Engineering(Institute of Agriculture and Life Science) Gyeongsang National UniversityJinju 52828Korea Department of Agriculture Engineering National Academy of Agricultural ScienceRDAJeonju 54875Korea

Environmental impact and economic concerns have driven a variable rate technology(VRT).Spinner spreaders were mainly used for granular fertilizer application since they are simple in design,inexpensive,and can cover large ***,the spreader was not adequate for VRT because uniformity changes drastically while varying application ***,the purpose of this study was to develop a variable rate applicator with uniform spreading patterns.A commercial spreader was modified with a controller and electric actuators for controlling fertilizer discharge directions and *** was established to determine the optimum discharge direction according to the fertilizer application *** uniformity of spreading patterns in accordance with the spread amount per set unit area was evaluated by the statistical coefficient of variation(CV)lower than 15%is assumed to prevent damage to the *** results showed that CVs were 8%,9%,and 8%,respectively,for a tractor in race track mode(adjacent passes in same direction of travel)at 200 kg/hm^(2),300 kg/hm^(2),and 400 kg/hm^(2).This indicates that the fertilizer was spread uniformly,while the coefficient of variation was 12%at 200 kg/hm^(2) in back and forth mode(adjacent passes in the opposite direction of travel).Overall,the results suggest that the race track mode is suitable for operation of a tractor to ensure uniform spreading of fertilizer when applying at variable *** future goal is to establish a system for automatic variable rate application according to location in connection with soil analysis and geographic information systems.

关键词： variable rate technology fertilizer application uniform spreading spinner granular applicator fertilizer amount control

The photodynamic therapy on Streptococcus mutans biofilms using erythrosine and dental halogen curing unit

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International Journal of Oral Science 2012年第4期4卷 196-201页

作者： young-Ho Lee Ho-Won Park Ju-Hyun Lee Hyun-woo Seo Si-young Lee Department of Pediatric Dentistry Graduate SchoolCollege of DentistryGangneung-Wonju National University Department of Pediatric Dentistry College of DentistryGangneung-Wonju National University Department of Microbiology and Immunology College of DentistryGangneung-Wonju National University

The purpose of our study was to evaluate the effect of photodynamic therapy （PDT）, using erythrosine as a photosensitizing agent and a dental halogen curing unit as a light source, on Streptococcus mutans in a biofilm phase. The S. mutans biofilms were formed in a 24-well cell culture cluster. Test groups consisted of biofilms divided into four groups： group 1： no photosensitizer or light irradiation treatment （control group）; group 2： photosensitizer treatment alone; group 3： light irradiation alone; group 4： photosensitizer treatment and light irradiation. After treatments, the numbers of colony-forming unit （CFU） were counted and samples were examined by confocal laser scanning fluorescence microscopy （CLSM）. Only group 4 （combined treatment） resulted in significant increases in cell death, with rates of 75% and 55% after 8 h of incubation, and 74% and 42% at 12 h, for biofilms formed in brain-heart infusion （BHI） broth supplemented with 0% or O. 1% sucrose, respectively. Therefore, PDT of S. mutans biofilms using a combination of erythrosine and a dental halogen curing unit, both widely used in dental clinics, resulted in a significant increase in cell death. The PDT effects are decreased in biofilms that form in the presence of sucrose.

关键词： biofilms dental halogen curing unit erythrosine photodynamic therapy Streptococcus mutans

Series resistance influence on performance of waveguide-type germanium photodetectors on silicon

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Chinese Optics Letters 2017年第10期15卷 15-19页

作者： Jeong-Min Lee Minkyu Kim and woo-young Choi Department of Electrical and Electronic Engineering Yonsei University Seoul 120-749 South Korea

We investigate influences of series resistances on the performance of 1.55 μm waveguide-type germanium photodetectors（Ge-PDs） on a silicon-on-insulator substrate. The current-voltage characteristics, responsivities,saturation photo-current characteristics, electrical reflection coefficients, and photodetection frequency responses of Ge-PDs, having different series resistances, are measured, and their equivalent circuit models are established. By analyzing the resulting circuit model parameters, we determine how much Ge-PD series resistances influence Ge-PD saturation photo-currents and photodetection bandwidth. These results should be of great use for optimization of Ge-PD fabrication processes and device parameters for target applications.

关键词： Si Series resistance influence on performance of waveguide-type germanium photodetectors on silicon PD Figure

Recovery of cerium from glass polishing slurry

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Journal of Rare Earths 2011年第11期29卷 1075-1078页

作者： Jong-young Kim Ung-Soo Kim Myeong-Seop Byeon woo-Kyu Kang Kwang-Teak Hwang woo-Seok Cho Icheon Branch Korea Institute of Ceramic Engineering and TechnologyGyeongchung Rd.Sindun-MyeonIcheon-siKyeonggi-do 467-843Korea RANCO Cheongju-siChungcheongbuk-doKorea

Cerium was extracted from rare earth slurry waste used for polishing a glass ***,glass frit and flocculant were removed by froth flotation and *** recovered rare earth slurry exhibited almost the same particle size distribution as original slurry,which could be reused as slurry for glass *** the rare earth slurry,the cerium solution was obtained by an oxidative thermal treatment and subsequent chemical *** cerium solution was further purified up to 94% by selective precipitation of rare earth species.

关键词： cerium separation waste polishing slurry rare earths