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Characteristics of Atmospheric Circulation Associated with Cold Surge Occurrences in East Asia:A Case Study During 2005/06 Winter

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Advances in Atmospheric Sciences 2008年第5期25卷 791-804页

作者： Tae-Won PARK Jee-hoon jeong chang-hoi ho Seong-Joong KIM School of Earth and Environmental Sciences Seoul National University Seoul Korea Department of Earth Sciences University of Gothenburg Gothenburg Sweden Korea Polar Research Institute Incheon Korea

The characteristics of the upper-level circulation and thermodynamical properties for the period when two distinct cold surges broke out over East Asia during the 2005/06 winter are investigated. From early December 2005 to early January 2006, exceptionally cold weather lasted for approximately one month due to two successive cold surges that took place on 2 December 2005 and 2 January 2006, respectively. This study reveals that both involve the upper-tropospheric circulation, which induces the amplification and expansion of the surface Siberian high toward East Asia, but arose from different causes： the former is caused by the upper-level blocking originated from the North Pacific and the latter is caused by the upper-level wave train across the Eurasian Continent. In particular, it is suggested that the lower-tropospheric anomalous wind caused by upper-level circulation anomalies and a steep meridional temperature gradient amplified by phase-locked annual cycle combined to induce very strong cold advection in East Asia, which resulted in exceptionally cold weather that lasted for several weeks. The present results emphasize that the characteristics of the upper-tropospheric circulation can be considered as important precursors to cold surge occurrences in East Asia.

关键词： cold surge Siberian high East Asia East Asian winter monsoon upper-tropospheric circulation

Optic radiation injury in patients with aneurismal subarachnoid hemorrhage: a preliminary diffusion tensor imaging report

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Neural Regeneration Research 2018年第3期13卷 563-566页

作者： Sung ho Jang Chul hoon chang Young Jin Jung Seong ho Kim jeong Pyo Seo Department of Physical Medicine and Rehabilitation College of Medicine Yeungnam University Department of Neurosurgery College of Medicine Yeungnam University

Visual field defect is one of the various clinical manifestations in patients with subarachnoid hemorrhage（SAH）. Little is known about the pathogenic mechanism of visual field defect in SAH. In the current study,we investigated the diffusion tensor imaging （DTI） finding of the optic radiation in patients with SAH followingrupture of a cerebral artery aneurysm. We recruited 21 patients with aneurismal SAH （12 males, 9 females, mean age, 52.67 years; range, 41–68 years） who showed no definite lesion along the visual ***-one age-and sex-matched normal control subjects were also recruited. DTI data were acquired at an average of 5.9 weeks （range： 3–12 weeks） after onset and reconstruction of the optic radiation was performed using DTI-Studio software. The fractional anisotropy value, apparent diffusion coefficient value,and fiber number of the optic radiation were measured. The fractional anisotropy value of the optic radiation was significantly decreased, and the apparent diffusion coefficient value was significantly increased, in patients with aneurismal SAH than in normal control subjects. however, there was no significant difference in the fiber number of the optic radiation between patients with aneurismal SAH and normal control subjects. The decrement of fractional anisotropy value and increment of apparent diffusion coefficient value of the optic radiation in patients with aneurismal SAH suggest optic radiation injury. Therefore, we recommend a thorough evaluation for optic radiation injury in patient with aneurismal SAH.

关键词： nerve regeneration diffusion tensor imaging optic radiation subarachnoid hemorrhage visual field defect neural regeneration

Performance of a New Ion Source for KSTAR Tokamak Plasma Heating

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Plasma Science and Technology 2014年第6期16卷 620-624页

作者： Tae-Seong KIM Seung ho jeong Doo Hee chang Kwang Won LEE Sang-Ryul IN Korea Atomic Energy Research Institute

In the experimental campaign of 2010 and 2011 on KSTAR, the NBI-1 system was equipped with one prototype ion source and operated successfully, providing a neutral beam power of 0.7-1.6 MW to the tokamak plasma. The new ion source planned for the 2012 KSTAR campaign had a much more advanced performance compared with the previous one. The target performance of the new ion source was to provide a neutral deuterium beam of 2 MW to the tokamak plasma. The ion source was newly designed, fabricated, and assembled in 2011. The new ion source was then conditioned up to 64 A/100 keV over a 2-hour beam extraction and performance tested at the NB test stand （NBTS） at the Korea Atomic Energy Research Institute （KAERI） in 2012. The measured optimum perveance at which the beam divergence is a minimum was about 2.5μP, and the minimum beam divergent angle was under 1.0° at 60 keV. These results indicate that the 2.0 MW neutral beam power at 100 keV required for the heating of plasma in KSTAR can be delivered by the installation of the new ion source in the KSTAR NBI-1 system.

关键词： NBI ion source KSTAR neutral beam plasma heating positive based ion

Magnetic mineral diagenesis in the post-glacial muddy sediments from the southeastern South Yellow Sea:Response to marine environmental changes

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Science China Earth Sciences 2005年第1期48卷 134-144页

作者： jeong-Hae chang Korean Institute of Geology

Core YSDP103 was retrieved in the muddy deposit under the cold eddy of the southeastern South Yellow Sea, and the uppermost 29.79 m core represents the muddy sediments formed in the shelf since about 13 ka BP. The lower part from 29.79 to 13.35 m, called Unit A2, was deposited during the period from the post-glacial transgression to the middle holocene (at about 6 14C ka BP) when the rising sea level reached its maximum, while the upper part above 13.35 m (called Unit A1) was deposited in a cold eddy associated with the formation of the Yellow Sea Warm Current just after the peak of post-glacial sea level rise. Rock-magnetic properties of the uppermost 29.79 m core were investigated in detail. The experimental results indicate that the magnetic mineralogy of the core is dominated by magnetite, maghemite and hematite and that, except for the uppermost 2.35 m, the magnetic minerals were subject to reductive diagenesis leading to significant decline of magnetic mineral content and the proportion of low-coercivity component. More importantly, ferrimagnetic iron sulphide (greigite) is found in Unit A2 but absent in Unit A1, suggesting the control of marine environmental conditions on the magnetic mineral diagenesis. Magnetic parameters show abrupt changes across the boundary between Units A1and A2, which reflects a co-effect of environmental conditions and primary magnetic components of the sediments on the diagenesis. Alternating zones of high and low magnetic parameters are observed in Unit A2, which is presumably due to periodic changes of the concentration and/or grain size of magnetic minerals carried into the study area.

关键词： environmental magnetism, magnetic minerals, diagenesis, ferrimagnetic iron sulphide, South Yellow Sea.

Filiform polyposis in the sigmoid colon: A case series

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World Journal of Gastroenterology 2010年第19期16卷 2443-2447页

作者： chang Geun Lee Yun jeong Lim Jong Sun Choi Jin ho Lee Department of Internal Medicine Dongguk University-Seoul Graduate School of Medicine Goyang 411-773 South Korea

Filiform polyposis is a rare condition of uncertain patho-genesis that is usually found in association with Crohn’s disease, ulcerative colitis, intestinal tuberculosis or histiocytosis X. We report seven interesting cases of polyposis with various pathologic components, mainly located in the left side of the colon with no associated inflammatory bowel disease, intestinal tuberculosis or histiocytosis X. Multiple finger-like polypoid lesions with the appearance of stalactites were noted on the left side of the colon, especially in the sigmoid area, at the time of colonoscopy. The polyps had a variety of sizes and shapes and were shown to have various histopathologic components among the different patients. Although filiform polyposis localized in the sigmoid colon appears not to have high oncogenic potential, periodic follow-up seems to be needed.

关键词： Filiform polyposis Sigmoid colon Inflammatory bowel disease

Characteristic evaluation of Al_2O_3/CNTs hybrid materials for micro-electrical discharge machining

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 28-32页

作者： Hyun-Seok TAK chang-Seung HA ho-Jun LEE Hyung-Woo LEE Young-Keun jeong Myung-chang KANG National Core Research Center for Hybrid Materials Solution Pusan National University Department of Electrical Engineering Pusan National University

The characteristic evaluation of aluminum oxide （A1203）/carbon nanotubes （CNTs） hybrid composites for micro-electrical discharge machining （EDM） was described. Alumina matrix composites reinforced with CNTs were fabricated by a catalytic chemical vapor deposition method. A1203 composites with different CNT concentrations were synthesized. The electrical characteristic of A1203/CNTs composites was examined. These composites were machined by the EDM process according to the various EDM parameters, and the characteristics of machining were analyzed using field emission scanning electron microscope （FESEM）. The electrical conductivity has a increasing tendency as the CNTs content is increased and has a critical point at 5% A1203 （volume fraction）. In the machining accuracy, many tangles of CNT in A1203/CNTs composites cause violent spark. Thus, it causes the poor dimensional accuracy and circularity. The results show that conductivity of the materials and homogeneous distribution of CNTs in the matrix are important factors for micro-EDM of A1203/CNTs hybrid composites.

关键词： A1203/CNTs hybrid materials micro-electrical discharge machining micro-hole electrical conductivity

Plasma Post Oxidation of Plasma Nitrocarburized SKD 61 Steel

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Journal of Materials Science & Technology 2008年第1期24卷 136-138页

作者： Insup Lee Kwang-ho jeong Department of Advanced Materials Engineering Dongeui University Busan 614-714 Korea

Plasma nitrocarburizing and plasma oxidizing treatments were performed to improve the wear and corrosion resistance of SKD 61 *** nitrocarburizing was conducted for 12 h at 540℃in the nitrogen, hydrogen and methane atmosphere to produce theε-Fe-（2-3）（N,C） *** compound layer produced by plasma nitrocarburising was predominantly composed ofε-phase,with a small proportion ofγ′-Fe-4 （N,C） phase. The thickness of the compound layer and the diffusion layer are about 10μm and about 200μm,respectively. Plasma post oxidation was performed on the nitrocarburized samples with various oxygen/hydrogen ratio at constant temperature of 500℃for 1 *** very thin magnetite （Fe-3O-4） layer of 1-2μm in thickness on top of the compound layer was *** polarization test revealed that plasma nitrocarburizing process contributed a significant improvement of corrosion resistance of SKD 61 ***,the corrosion characteristics of the nitrocarburized compound layer was deteriorated by oxidation treatment.

关键词： Plasma nitrocarburizing Post oxidation ε-Fe2-3(N,C) γ′-Fe4(N,C) Fe3O4

Preoperative defining system for pancreatic head cancer considering surgical resection

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World Journal of Gastroenterology 2016年第26期22卷 6076-6082页

作者： Seok jeong Yang ho Kyoung Hwang chang Moo Kang Woo Jung Lee Department of Surgery Ulsan University Hospital University of Ulsan College of Medicine Department of Hepatobiliary and Pancreatic Surgery Yonsei University College of Medicine Pancreaticobiliary Cancer Clinic Yonsei Cancer Center Institute of Gastroenterology Yonsei Severance Hospital

AIM: To provide appropriate treatment, it is crucial to share the clinical status of pancreas head cancer among multidisciplinary treatment ***: A retrospective analysis of the medical records of 113 patients who underwent surgery for pancreas head cancer from January 2008 to December 2012 was performed. We developed preoperative defining system of pancreatic head cancer by describing “resectability - tumor location - vascular relationship - adjacent organ involvement - preoperative CA19-9 (initial bilirubin level) - vascular anomaly”. The oncologic correlations with this reporting system were ***: Among 113 patients, there were 75 patients (66.4%) with resectable, 34 patients (30.1%) with borderline resectable, and 4 patients (3.5%) with locally advanced pancreatic cancer. Mean disease-free survival was 24.8 mo (95%CI: 19.6-30.1) with a 5-year disease-free survival rate of 13.5%. Pretreatment tumor size ≥ 2.4 cm [Exp(B) = 3.608, 95%CI: 1.512-8.609, P = 0.044] and radiologic vascular invasion [Exp(B) = 5.553, 95%CI: 2.269-14.589, P = 0.002] were independent predictive factors for neoadjuvant treatment. Borderline resectability [Exp(B) = 0.222, P = 0.008], pancreatic head cancer involving the pancreatic neck [Exp(B) = 9.461, P = 0.001] and arterial invasion [Exp(B) = 6.208, P = 0.010], and adjusted CA19-9 ≥ 50 [Exp(B) = 1.972 P = 0.019] were identified as prognostic clinical factors to predict tumor ***: The suggested preoperative defining system can help with designing treatment plans and also predict oncologic outcomes.

关键词： Preoperative defining system Pancreas head cancer Borderline resectable Adjusted CA19-9 Neoadjuvant therapy

Climatic Classification over Asia during the Middle holocene Climatic Optimum Based on PMIP Models

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Journal of Earth Science 2016年第1期27卷 123-129页

作者： Hyuntaik Oh ho-jeong Shin Center for Marine Environmental Impact Assessment National Fisheries Research and Development Institute Ocean Circulation and Climate Research Division Korea Institute of Ocean Science and Technology

When considering potential global warming projections, it is useful to understand the impact of each climate condition at 6 kyr before present. Asian paleoclimate was simulated by performing an integration of the multi-model ensemble with the paleoclimate modeling intercomparison project（PMIP） models. The reconstructed winter（summer） surface air temperature at 6 kyr before present was 0.85 oC（0.21 oC） lower（higher） than the present day over Asia, 60oE-150oE, 10oN-60oN. The seasonal variation and heating differences of land and ocean in summer at 6 kyr before present might be much larger than present day. The winter and summer precipitation of 6 kyr before present were 0.067 and 0.017 mm·day-1larger than present day, respectively. The Group B climate, which means the dry climates based on K？ppen climate classification, at 6 kyr before present decreased 17% compared to present day, but the Group D which means the continental and microthermal climates at 6 kyr before present increased over 7%. Comparison between the results from the model simulation and published paleo-proxy record agrees within the limited sparse paleo-proxy record data.

关键词： paleoclimate modeling intercomparison project (PMIP) paleoclimate global warming,Asian continent.