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Acta Oceanologica Sinica 2015年第12期34卷 44-50页

作者： LEE Dong-Kyu KWON Jae-Il SON seung hyun Pusan National University Coastal Disaster Research Center Korea Institute of Ocean Science and Technology China-Korea Joint Ocean Research Center Cooperative Institute for Research in the Atmosphere Colorado State University

During the summer in the Yellow Sea and East China Sea, the resuspension of the bottom sediment is obstructed by strong stratification and, as a result, the concentration of total suspended sediment（TSS） can be used as an excellent tracer for Changjiang Diluted Water（CDW）. To analyze the spatial and temporal variations of the CDW distribution, the monthly mean TSS from Moderate Resolution Imaging Spectroradiometer（MODIS） ocean color data are constructed and are converted to salinity using the relationship between salinity observed from AQUARIUS and TSS. The process produces the detailed horizontal distribution of salinity with very high resolution（1 km）. From monthly mean salinity map from 2002 to 2012 in July and August, the expansion patterns of CDW are analyzed. The southerly wind in July and southeasterly wind in August transport the CDW eastward and northeastward, respectively. It is found that the yearly variation of the expansion of CDW toward the southern sea area of Korea is mostly due to the variation of southerly wind and the fluctuations of fresh water discharge into the Changjiang estuary show relatively little impact on the eastward extend of CDW. When 11-year mean（from2002 to 2012） salinity map in August is compared with World Ocean Atlas 2013, it is revealed that wind in August strengthened six times from 1994 and it causes the expansion of CDW extended 150 km further eastward.

关键词： Yellow and East China Seas Changjiang diluted water total suspended sediment MODIS

Analytic Feynman Integrals of Functionals in a Banach Algebra Involving the First Variation

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Chinese Annals of Mathematics,Series B 2016年第2期37卷 281-290页

作者： hyun Soo CHUNG Vu Kim TUAN seung Jun ChanG Department of Mathematics Dankook University Department of Mathematics University of West Georgia

This paper deals with the analytic Feynman integral of functionals on a Wiener space. First the authors establish the existence of the analytic Feynman integrals of functionals in a Banach algebra S_α. The authors then obtain a formula for the first variation of integrals. Finally, various analytic Feynman integration formulas involving the first variation are established.

关键词： Analytic Feynman integral Banach algebra First variation Cameron-Storvick theorem Wiener space

Spinal pedicle subtraction osteotomy for fixed sagittal imbalance patients

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World Journal of Clinical Cases 2013年第8期1卷 242-248页

作者： seung-Jae hyun Yongjung J Kim seung-Chul Rhim Department of Neurosurgery Spine CenterSeoul National University Bundang HospitalSeoul National University College of MedicineSeongnam 463-707South Korea Department of Orthopaedic Surgery Spine ServiceColumbia University College of Physicians and SurgeonsNew YorkNY 10032United States Department of Neurosurgery Asan Medical CenterUniversity of Ulsan College of MedicineSeoul 138-736South Korea

In addressing spinal sagittal imbalance through a posterior approach, the surgeon now may choose from among a variety of osteotomy techniques. Posterior column osteotomies such as the facetectomy or Ponte or Smith-Petersen osteotomy provide the least correction, but can be used at multiple levels with minimal blood loss and a lower operative risk. Pedicle subtraction osteotomies provide nearly 3 times the per-level correction of Ponte/Smith-Petersen osteotomies; however, they carry increased technical demands, longer operative time, and greater blood loss and associated significant morbidity, including neurological injury. The literature focusing on pedicle subtraction osteotomy for fixed sagittal imbalance patients is reviewed. The longterm overall outcomes, surgical tips to reduce the complications and suggestions for their proper application are also provided.

关键词： Sagittal imbalance Pedicle subtraction osteotomy Clinical outcome Proximal junctional kyphosis Complication

Impact loads generated by tandem cavitation bubble on solid wall

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Journal of Hydrodynamics 2022年第3期34卷 467-482页

作者： Nyo Me Thet Naing Jaehyun Park seung-Ho hyun Rho-Taek Jung School of Naval Architecture and Ocean Engineering University of UlsanUlsanKorea School of Electrical Engineering University of UlsanUlsanKorea Foundation for Industry Cooperation University of UlsanUlsanKorea

Experiments on two cavitation bubbles,which are generated at the same instant,with three different sizes near solid wall are conducted and their impulses on the boundary are registered by polyvinylidene fluoride(PVDF)*** to being near the boundary,bubble interactions and deformed features are in contrast with those in infinite fluid *** this paper,five morphologies of bubble deformation during growth and collapse phases are observed by high-speed *** profiles are strongly influenced by inter-bubble distance(η),stand-off distance from boundary(γ),and bubble size *** of photographs coupled with sensor measurements enabled qualitative investigation of two bubble interactions on the *** sensor data acquisition,it is confirmed that lower bigger bubble with upper smaller bubble configuration produces highest impulses on the boundary compared with other vertical arrangements of the tandem cavitation bubble employed in this study.

关键词： Two bubbles spark-generated bubble impulse polyvinylidene fluoride(PVDF)

A Kinetic Study on the Control of Nitrogen in Molten Slag and Metal

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Journal of Iron and Steel Research International 2011年第S2期18卷 301-309页

作者： seung Min han Dong Joon Min Technical Research Laboratories POSCO Pohang 790-785 KOREA Department of Materials Science and Engineering YONSEI University Seoul 120-749 KOREA

Nitrogen can easily contaminate molten steel during the steelmaking process and due to the low nitrogen capacity in slag, it is difficult to remove entrapped nitrogen from liquid steel. Degassing is often done to the steel at secondary steelmaking to lower the nitrogen content, but the control can often be kinetically limited by the steel grade and also the slag composition. Thus, a fundamental understanding of nitrogen dissolution into molten slag and metal including the rate of nitrogen dissolution can help in controlling nitrogen content in the final *** kinetics of nitrogen dissolution in the molten calcium aluminate based slags and in molten steel with various element additions was investigated by measuring the 14N-15N isotope exchange reaction using a mass spectrometer at 1873 *** show that effect of elements on the rate constant of nitrogen dissolution such as Ni in Fe is relatively minimal similar to molybdenum. The surface rate constant of nitrogen dissolution in liquid Fe-10%Ni alloy was found to be 3.77×10-5 (mol/cm2·s·atm).The rate constant of nitrogen dissolution in the CaO-Al2O3-CaF2 slag was found to be wedge shaped, which decreased with increasing CaF2 to about 20 mol% followed by an increase through the rest of the CaF2 composition range. This was related to the effect of CaF2 on the structure of Al-O bonds for this slag.

关键词： rate constant slag structure molten steel isotope exchange technique adsorption coefficient nitrogen surface dissolution

Liver intravoxel incoherent motion diffusion-weighted imaging for the assessment of hepatic steatosis and fibrosis in children

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World Journal of Gastroenterology 2018年第27期24卷 3013-3020页

作者： hyun Joo Shin Haesung Yoon Myung-Joon Kim Seok Joo han Hong Koh seung Kim Mi-Jung Lee Department of Radiology Severance Hospital Severance Pediatric Liver Disease Research Group Research Institute of Radiological Science Yonsei University College of Medicine Department of Surgery Severance Hospital Severance Pediatric Liver Disease Research Group Yonsei University College of Medicine Division of Gastroenterology Hepatology and Nutrition Department of Pediatrics Severance Children's Hospital Severance Pediatric Liver Disease Research Group Yonsei University College of Medicine

AIM To evaluate the correlation between intravoxel incoherent motion(IVIM) diffusion-weighted imaging(DWI) parameters and the degree of hepatic steatosis and fibrosis in *** This retrospective study was approved by the institutional review board. The children(≤ 18 years) who underwent liver IVIM DWI with 8 b-values under the suspicion of hepatic steatosis or fibrosis from February 2013 to November 2016 were included. Subjects were divided into normal, fatty liver(FAT), and fibrotic liver(FIB) groups. The slow diffusion coefficient(D), fast diffusion coefficient(D*), perfusion fraction(f), and apparent diffusion coefficient(ADC) were measured. MR proton density fat fraction(PDFF), MR elastography(MRE), and IVIM values were *** A total of 123 children(median age of 12 years old, range: 6-18 years) were included, with 8 in the normal group, 93 in the FAT group, and 22 in the FIB group. The D* values were lower in the FIB group compared with those of the normal(P = 0.015) and FAT(P = 0.003) groups. The f values were lower in the FIB group compared with the FAT group(P = 0.001). In multivariate analyses, PDFF value was positively correlated with f value(β = 3.194, P < 0.001), and MRE value was negatively correlated with D* value(β =-7.031, P = 0.032). The D and ADC values were not influenced by PDFF or MRE *** In liver IVIM DWI with multiple b-values in children, there was a positive correlation between hepatic fat and blood volume, and a negative correlation between hepatic stiffness and endovascular blood flow velocity, while diffusion-related parameters were not affected.

关键词： Intravoxel incoherent motion Diffusionweighted imaging Fibrosis Fatty liver Pediatrics

Predicting gastroesophageal varices through spleen magnetic resonance elastography in pediatric liver fibrosis

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World Journal of Gastroenterology 2019年第3期25卷 367-377页

作者： Haesung Yoon hyun Joo Shin Myung-Joon Kim Seok Joo han Hong Koh seung Kim Mi-Jung Lee Department of Radiology Severance Hospital Severance Pediatric Liver Disease Research Group Research Institute of Radiological Science Yonsei University College of Medicine Department of Surgery Severance Hospital Severance Pediatric Liver Disease Research Group Yonsei University College of Medicine Division of Gastroenterology Hepatology and Nutrition Department of Pediatrics Severance Children's Hospital Severance Pediatric Liver Disease Research Group Yonsei University College of Medicine

BACKGROUND A recent retrospective study confirmed that hepatic stiffness and splenic stiffness measured with magnetic resonance elastography(MRE) are strongly associated with the presence of esophageal varices. In addition, strong correlations have been reported between splenic stiffness values measured with MRE and hepatic venous pressure gradients in animal models. However, most studies have been conducted on adult populations, and previous pediatric MRE studies have only demonstrated the feasibility of MRE in pediatric populations, while the actual clinical application of spleen MRE has been *** To assess the utility of splenic stiffness measurements by MRE to predict gastroesophageal varices in *** We retrospectively reviewed abdominal MRE images taken on a 3 T system in pediatric patients. Patients who had undergone Kasai operations for biliary atresia were selected for the Kasai group, and patients with normal livers and spleens were selected for the control group. Two-dimensional spin-echo echoplanar MRE acquisition centered on the liver, with a pneumatic driver at 60 Hz and a low amplitude, was performed to obtain hepatic and splenic stiffness values. Laboratory results for aspartate aminotransferase to platelet ratio index(APRI) were evaluated within six months of MRE, and the normalized spleen size ratio was determined with the upper normal size limit. All Kasai group patients underwent gastroesophageal endoscopy during routine follow-up. The MannWhitney U test, Kendall's tau b correlation and diagnostic performance analysis using the area under the curve(AUC) were performed for statistical *** The median spleen MRE value was 5.5 kPa in the control group(n = 9, age 9-18 years, range 4.7-6.4 kPa) and 8.6 kPa in the Kasai group(n = 22, age 4-18 years,range 5.0-17.8 kPa). In the Kasai group, the APRI, spleen size ratio and spleen MRE values were higher in patients with portal hypertension(n = 11) than in patients without(n =

关键词： Biliary atresia Magnetic resonance elastography Kasai operation Splenic stiffness Portal hypertension

Successful treatment of multiple hepatocellular adenomas with percutaneous radiofrequency ablation

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World Journal of Gastroenterology 2013年第42期19卷 7480-7486页

作者： Sun Young Ahn Soo Young Park Young Oh Kweon Won Young Tak han Ik Bae seung hyun Cho Department of Internal Medicine Kyungpook National University HospitalDaegu 700-721South Korea Department of Pathology Kyungpook National University HospitalDaegu 700-721South Korea Department of Radiology Kyungpook National University HospitalDaegu 700-721South Korea

Hepatocellular adenoma (HCA) is one of the important complications of glycogen storage disease type?Ia (GSD-Ia) because it can be transformed into hepatocellular carcinoma. Although surgical resection is a standard treatment of choice for solitary HCA, multiple HCAs in GSD-Ia patients present as therapeutic challenges for curative treatment. Therefore, treatment strategy according to malignant potential is important in management of HCAs in GSD-Ia. The authors present a case of histologically proven multiple HCAs without β-catenin mutations occurred in a GSD-Ia patient treated successfully with percutaneous radiofrequency ablation as a minimally invasive therapy.

关键词： Glycogen storage disease Hepatocellular adenoma Radiofrequency ablation β-catenin activation Glycogen storage disease

Intraoperative neurophysiological monitoring in spinal surgery

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World Journal of Clinical Cases 2015年第9期3卷 765-773页

作者： Jong-Hwa Park seung-Jae hyun Department of Neurosurgery Spine CenterSeoul National University Bundang Hospital Seoul National University College of Medicine

Recently, many surgeons have been using intraoperative neurophysiological monitoring(IOM) in spinal surgery to reduce the incidence of postoperative neurological complications, including level of the spinal cord, cauda equina and nerve root. Several established technologies are available and combined motor and somatosensory evoked potentials are considered mandatory for practical and successful IOM. Spinal cord evoked potentials are elicited compound potentials recorded over the spinal cord. Electrical stimulation is provoked on the dorsal spinal cord from an epidural electrode. Somatosensory evoked potentials assess the functional integrity of sensory pathways from the peripheral nerve through the dorsal column and to the sensory cortex. For identification of the physiological midline, the dorsal column mapping technique can be used. It is helpful for reducing the postoperative morbidity associated with dorsal column dysfunction when distortion of the normal spinal cord anatomy caused by an intramedullary cord lesion results in confusion in localizing the midline for the myelotomy. Motor evoked potentials(MEPs) consist of spinal, neurogenic and muscle MEPs. MEPs allow selective and specific assessment of the functional integrity of descending motor pathways, from the motor cortex to peripheral muscles. Spinal surgeons should understand the concept of the monitoring techniques and interpret monitoring records adequately to use IOM for the decision making during the surgery for safe surgery and a favorable surgical outcome.

关键词： Motor-evoked potentials Somatosensoryevoked potentials Intraoperative neurophysiological monitoring Direct wave Spinal surgery

Prediction models for recurrence in patients with small bowel bleeding

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World Journal of Clinical Cases 2023年第17期11卷 3949-3957页

作者： Ji hyun Kim seung-Joo Nam Division of Gastroenterology and Hepatology Department of Internal MedicineKangwon National University School of MedicineChuncheon 24341South Korea

Obscure gastrointestinal bleeding(OGIB)has traditionally been defined as gastrointestinal bleeding whose source remains unidentified after bidirectional *** can present as overt bleeding or occult bleeding,and small bowel lesions are the most common *** small bowel can be evaluated using capsule endoscopy,device-assisted enteroscopy,computed tomography enterography,or magnetic resonance *** the cause of smallbowel bleeding is identified and targeted therapeutic intervention is completed,the patient can be managed with routine ***,diagnostic tests may produce negative results,and some patients with small bowel bleeding,regardless of diagnostic findings,may experience *** those at risk of rebleeding can help clinicians form individualized surveillance *** studies have identified different factors associated with rebleeding,and a limited number of studies have attempted to create prediction models for *** article describes prediction models developed so far for identifying patients with OGIB who are at greater risk of *** models may aid clinicians in forming tailored patient management and surveillance.

关键词： Obscure gastrointestinal bleeding Prediction model Rebleeding Small bowel bleeding Video capsule endoscopy