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EXPERIMENTAL ESTIMATION OF A SCALING EXPONENT FOR TIP VORTEX CAVITATION VIA ITS INCEPTION TEST IN FULL-AND MODEL-SHIP

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Journal of Hydrodynamics 2012年第5期24卷 658-667页

作者： lee Jeung-Hoon JUNG Jae-Kwon lee Kyung-Jun HAN Jae-Moon PARK hyung-Gil SEO Jong-Soo Samsung Ship Model Basin(SSMB) Marine Research InstituteSamsung Heavy IndustriesScience TownDaejeon 305-380Korea

Tip vortex cavitation noise of marine propeller became primary concems to reduce hazardous environmental impacts from commercial ship or to keep the underwater surveillance of naval ships. The investigations of the tip vortex and its induced noise are normally conducted through the model test in a water cavitation tunnel. However the Reynolds number of model-test is much smaller than that of the full-scale, which subsequently results in the difference of tip vortex cavitation inception. Hence, the scaling law between model- and full-scales needs to be identified prior to the prediction and assessment of propeller noise in full scale. From previous researches, it is generally known that the incipient caivtation number of tip vortex can be represented as a power of the Reynolds number. However, the power exponent for scaling, which is the main focus of this research, has not been clearly studied yet. This paper deals with the estimation of scaling exponent based on tip vortex cavitation inception test in both full- and model-scale ships. Acoustical measurements as well as several kind of signal processing technique for an inception criterion suggest the scaling exponent as 0.30. The scaling value proposed in this study shows slight difference to the one of most recent research. Besides, extrapolation of model-ship noise measurement using the proposed one predicts the full-scale noise measurement with an acceptable discrepancy.

关键词： tip vortex cavitation underwater radiated noise scaling exponent

Gastric subepithelial lesion complicated with abscess: Case report and literature review

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World Journal of Gastroenterology 2015年第20期21卷 6398-6403页

作者： Sung Bum Kim Myung Jin Oh Si hyung lee Department of Internal Medicine Yeungnam University College of Medicine

Gastric abscess is a localized pyogenic inflammation of the gastric wall, which is a rare form of suppurative gastritis. The rarity of gastric abscess may be associated with the difficulty of early diagnosis and high mortality as a result. In general, subepithelial lesions (SELs) of the stomach are incidentally detected during the course of upper endoscopy without specific clinical symptoms and signs. However, some gastric SELs present rarely as a form of hemorrhage, obstruction, perforation, and abscess. Here we report a 45-year-old man with gastric SEL presenting as a gastric abscess, which was diagnosed as an ectopic pancreas of the stomach, along with a review of the literature. Although gastric SEL presenting as an abscess is known as a serious and life-threatening lesion, the patient made a complete recovery through surgical resection as well as medical treatment.

关键词： Suppurative gastritis Gastric abscess Subepithelial lesion Ectopic pancreas Endoscopicultrasound

Design and compensation of second-order sub-sampling digital frontend

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Journal of Central South University 2012年第2期19卷 408-416页

作者：王洪梅 KIM Jae-hyung lee Sang-hyuk KIM hyung-jung KIM Jin-up KOH Jong-seog School of Mechatronics Changwon National University Electrical and Electronic Engineering Xi'an Jiaotong-Liverpool University Smart Radio Team Electonics and Telecommunication Research Institute Korea Telecommunication Company

The problem of designing a digital frontend (DFE) was considered which can dynamically access or sense dual bands in any radio frequency (RF) regions without requiring hardware changes. In particular, second-order bandpass sampling (BPS) as a technique that enables to realize the multiband reception function was discussed. In a second-order BPS system, digital reconstruction filters were utilized to eliminate the interferences generated while down converting arbitrarily positioned RF-band signals by using the direct digitization method. However, the inaccuracy in the phase shift or the amplitude mismatch between the two sample streams may cause insufficient rejection of interference. Practical problems were studied, such as performance degradation in signal-to-interference ratio (SIR) and compensation methods to overcome them. In order to demonstrate the second- order BPS as a flexible DFE suitable for software-defined radio (SDR) or cognitive radio (CR), a DFE testbed with a reconfigurable structure was implemented. Moreover, with a view to further demonstrate the proposed compensation algorithms, experimental results show that dual bands are received simultaneously.

关键词： bandpass sampling second order band-pass sampling reconfiguration software-defined radio

Influences of etiology and endoscopic appearance on the long-term outcomes of gastric antral vascular ectasia

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World Journal of Clinical Cases 2022年第18期10卷 6050-6059页

作者： Hyo Jin Kwon Si hyung lee Joon Hyun Cho Division of Gastroenterology and Hepatology Department of Internal MedicineYeungnam University College of MedicineDaegu 42415South Korea

BACKGROUND Gastric antral vascular ectasia(GAVE)has diverse associations and presumed causes,which include liver cirrhosis,chronic kidney disease,and autoimmune *** heterogeneity of underlying disorders suggests that the pathogenesis of GAVE may be *** To compare the clinical features and long-term outcomes of GAVE according to endoscopic patterns and *** The medical records and endoscopic images of 23 consecutive patients diagnosed with GAVE by endoscopy at Yeungnam University Hospital from January 2006 to December 2020 were retrospectively *** were allocated to cirrhosis(16 patients)and non-cirrhosis groups(7 patients).GAVE subtypes,as determined by endoscopy,were categorized as punctate(a diffuse,honeycomb-like appearance,17 patients)or striped(a linear,watermelon-like appearance,6 patients).RESULTS All GAVE patients with cirrhosis(16/16,100%)had a punctate pattern by endoscopy,whereas the majority of patients(6/7,85.7%)without cirrhosis had a striped pattern(Pleeding(10/23,43%)was significantly more common in the non-cirrhosis group than in the cirrhosis group(6/7,85.7%vs 4/16,25.0%;P=0.019),and more common in the striped group than in the punctate group(5/6,83.3%vs 5/17,29.4%;P=0.052).However,mean numbers of admissions due to GAVE bleeding and argon plasma coagulation(APC)sessions to address overt bleeding were similar in the cirrhosis and non-cirrhosis groups and in the punctate and striped *** patients with GAVE bleeding were successfully treated by APC,and no patient died from GAVE-related blood loss during a median follow-up of 24 *** Punctate-type GAVE is strongly associated with liver cirrhosis,and GAVE patients without cirrhosis tend to be more prone to overt ***,the presence of cirrhosis and endoscopic patterns did not influence long-term clinical courses or outcomes in cases of overt bleeding.

关键词： Gastric antral vascular ectasia Cirrhosis Endoscopy Gastrointestinal bleeding Argon plasma coagulation

Investigation on the effectiveness of pretreatment in stormwater management technologies

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Journal of Environmental Sciences 2014年第9期26卷 1824-1830页

作者： Marla C.Maniquiz-Redillas Franz Kevin F.Geronimo lee-hyung Kim Dept.of Civil and Environmental Engineering Kongju National UniversityCheonanChungnamdoSouth Korea

The effectiveness of presettling basins as component of stormwater best management practice （BMP） technologies was investigated. Storm event monitoring and sediment collection were conducted from May 2009 to November 2012 on the presettling basins of the three BMP technologies designed to capture and treat stormwater runoff from highly impervious roads and parking lots. Data on captured runoff and sediment, total suspended solids （TSS） loadings, rainfall and runoff rate, sediment accumulation rate, as well as particle distribution and pollutant concentrations of sediment were gathered and analyzed along with the physical design characteristics of the presettling basins such as surface area and storage volume. Regression models were generated to determine significant relationships between design parameters. Results revealed that the storage volume ratio （ratio of storage volume of presettling basin to BMP） was an important parameter in designing the presettling basin of the BMP. For practicality, optimizing the design of the presetfling basin means that the storage volume ratio should be determined based on the desired captured amount of runoff and sediment from runoff to limit the frequency of maintenance caused by the accumulation of sediment. It was recommended that pretreatment of runoff should be employed when the site in which the BMP is to be sited has high TSS loading and runoff rate, and is subjected to high intensity rainfall.

关键词： Best management practicePresettling basinPretreatmentSedimentStormwater runoff

Rational strategy for power doubling of monolithic multijunction III-V photovoltaics by accommodating attachable scattering waveguides

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Light(Science & Applications) 2024年第11期13卷 2734-2744页

作者： Shin hyung lee Hyo Jin Kim Jae-Hyun Kim Gwang Yeol Park Sun-Kyung Kim Sung-Min lee School of Electrical Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea Optoelectronic Convergence Research Center Korea Photonics Technology InstituteGwangju 61007Republic of Korea Department of Applied Physics Kyung Hee UniversityYongin 17104Republic of Korea Department of Electrical Engineering Hanyang UniversitySeoul 04763Republic of Korea Division of Materials Science and Engineering Hanyang UniversitySeoul 04763Republic of Korea

While waveguide-based light concentrators offer significant advantages,their application has not been considered an interesting option for assisting multijunction or other two-terminal tandem solar *** this study,we present a simple yet effective approach to enhancing the output power of transfer-printed multijunction InGaP/GaAs solar *** utilizing a simply combinable waveguide concentrator featuring a coplanar waveguide with BaSO4 Mie scattering elements,we enable the simultaneous absorption of directly illuminated solar flux and indirectly waveguided *** deployment of cells is optimized for front-surface photon collection in monofacial *** systematic comparisons across various waveguide parameters,supported by both experimental and theoretical quantifications,we demonstrate a remarkable improvement in the maximum output power of a 26%-efficient cell,achieving an enhancement of~93%with the integration of the optimal scattering ***,a series of supplementary tests are conducted to explore the effective waveguide size,validate enhancements in arrayed cell module performance,and assess the drawbacks associated with rear *** findings provide a comprehensive understanding of our proposed approach towards advancing multi-junction photovoltaics.

关键词： waveguide scattering power

Challenges for clinicians treating autoimmune pancreatitis:Current perspectives

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World Journal of Clinical Cases 2023年第1期11卷 30-46页

作者： Seong-Hun Kim Yun Chae lee hyung Ku Chon Division of Gastroenterology Department of Internal MedicineJeonbuk National University Medical SchoolJeonju 54907South Korea Department of Internal Medicine Institution of Wonkwang Medical ScienceWonkwang University School of Medicine and HospitalIksan 54538South Korea

Autoimmune pancreatitis(AIP)is a rare disease clinically characterized by obstructive jaundice,unintentional weight loss,acute pancreatitis,focal pancreatic mass,and *** is classified into two subtypes-type 1 and type 2-according to pathological findings,clinical features,and serology test results,but some cases may be defined as type not otherwise in the absence of pathological findings and inflammatory bowel *** address the differences in diagnostic criteria by country,standard diagnostic criteria for AIP were proposed in 2011 by an international consensus of expert *** diagnosis of AIP from pancreatic ductal adenocarcinoma is important but remains challenging for ***,all subtypes of AIP show dramatic response to steroid *** review discusses the current perspectives on the diagnosis and management of AIP in clinical practice.

关键词： Autoimmune pancreatitis Pancreatic cancer International consensus diagnostic criteria Steroid

Fabrication and Characterization of Electrodeposited Ni-SiC-h/BN Composite Coatings

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Journal of Materials Science & Technology 2014年第8期30卷 796-802页

作者： Gobinda Gyawali hyung-Suk Kim Khagendra Tripathi Tae-Ho Kim Soo Wohn lee Research Center for Eco-Multifunctional Nano Materials Sun Moon UniversityAsanRepublic of Korea Department of Environmental Engineering Sun Moon UniversityChungnam 336-708Republic of Korea

Ni—SiC—h/BN composite materials were prepared by electrodeposition technique with the dispersion of SiC（10 g/L） and h/BN nanosheets（10 g/L） in a nickel sulfamate electrolytic *** ratio of sodium dodecyl sulfate（SDS） and cetyltrymethyl ammonium bromide（CTAB） surfactants were used to evaluate the effect of surfactants on the properties of the electrodeposited composite *** coating samples were characterized by scanning electron microscopy,X-ray diffraction,Vickers microhardness test,scratch and tribology *** results revealed that the co-deposition of nanoparticles was significantly influenced by surfactants during electrodeposition *** or polyhedral nickel crystallites were observed at higher ratio of SDS/CTAB while smaller oval grains with refined surface morphologies were obtained at lower ratio of SDS/CTAB *** addition,wt%of particles co-deposition was increased,and Vickers microhardness,wear and coefficient of friction of the electrodeposited composite coatings were improved at increased CTAB and decreased SDS contents in the electrolyte during electrodeposition process.

关键词： Ni-SiC-h/BN Composite coating Surfactant Microstructure Scratch Wear

Power interconnected system clustering with advanced fuzzy C-mean algorithm

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Journal of Central South University 2011年第1期18卷 190-195页

作者：王洪梅 KIM Jae-hyung JUNG Dong-Yean lee Sang-Min lee Sang-Hyuk School of Mechatronics Changwon National University Daeho Tech Co.Ltd. Changwon 641-465Korea Department of Electronics Engineering Inha University

An advanced fuzzy C-mean （FCM） algorithm was proposed for the efficient regional clustering of multi-nodes interconnected systems. Due to various locational prices and regional coherencies for each node and point, modified similarity measure was considered to gather nodes having similar characteristics. The similarity measure was needed to contain locafi0nal prices as well as regional coherency. In order to consider the two properties simultaneously, distance measure of fuzzy C-mean algorithm had to be modified. Regional clustering algorithm for interconnected power systems was designed based on the modified fuzzy C-mean algorithm. The proposed algorithm produces proper classification for the interconnected power system and the results are demonstrated in the example of IEEE 39-bus interconnected electricity system.

关键词： fuzzy C-mean similarity measure distance measure interconnected system clustering