Ki Young Kim

Korea Research Institute of Chemical Technology, Daiden, Daejeon, South Korea

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Publications (182)168.76 Total impact

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    ABSTRACT: The pro-inflammatory cytokine interleukin-1β (IL-1β) is known to play a crucial role in the pathogenesis of osteoarthritis (OA) by stimulating several mediators that contribute to cartilage degradation. Mori folium, the leaves of Morus alba L., has long been used in traditional medicine to treat diabetes, protect the liver, and lower blood pressure; however, the role of Mori folium in OA is not yet fully understood. Therefore, in the present study, we investigated whether Mori folium water extract (MF) inhibited the catabolic effects of IL-1β in vitro, and also whether it inhibited the matrix metalloproteinases (MMPs), inducible nitric oxide (NO) synthase (iNOS) and cyclooxygenase-2 (COX-2) through the attenuation of nuclear factor-κB (NF-κB) and mitogen activated protein kinase (MAPK) pathways in SW1353 human chondrocytes. MMP proteins in culture medium were determined using a cytokine‑specific enzyme-linked immunosorbent assay (ELISA). The production of NO and prostaglandin E2 (PGE2) were evaluated using Griess reagent and ELISA. Subsequently, the mRNA and protein levels of MMPs, iNOS, COX-2, NF-κB and MAPKs were examined by RT-qPCR and/or western blot analysis. The results indicate that MF significantly reduced the IL-1β‑induced release of MMP-1 and -13 in SW1353 cells, which was associated with the inhibition of MMP-1 and -13 mRNA and protein expression in a concentration‑dependent manner at concentrations with no cytotoxicity. MF also attenuated the IL-1β-induced production of NO and PGE2, and reduced iNOS and COX-2 expression. Furthermore, we noted that MF markedly suppressed the IL-1β‑induced nuclear translocation of NF-κB, which correlated with the inhibitory effects of MF on inhibitor-κB (IκB) degradation, and the phosphorylation of p38 MAPK was selectively restored by MF upon IL-1β stimulation. These results indicate that MF inhibited the production and expression of MMP-1 and -13 and inflammatory mediators, at least in part, through suppressing the activation of either NF-κB or p38 MAPK in IL-1β-treated SW1353 chondrocytes. Therefore, the novel findings of the present study suggest that MF is a potential therapeutic choice for chondroprotection against the collagen matrix breakdown in the cartilage of diseased tissues, such as those found in patients with arthritic disorders.
    No preview · Article · Dec 2015 · International Journal of Molecular Medicine
  • Ji Won Youn · Je-Beom Jeon · Kum Hee Seo · Suk Jun Kim · Ki Young Kim
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    ABSTRACT: The optimum rotational speed (RS) of a novel centrifugation method for obtaining high-purity Si separated from Al-Si melts was evaluated numerically and experimentally. Numerical calculations showed that the separation efficiency (Si to Al ratio in the separated solid) increases and finally reaches a plateau at a high RS. The calculated relationship between RS and the separation efficiency was consistent with experimentally measured data except for the removal of primary Si crystallites, which happened at centrifugation at 800 revolutions per minute (RPM). Based on the acquired data, it was established that 700 RPM is the optimal RS for our centrifugation apparatus (developed in a previous study) to maximize the separation efficiency.
    No preview · Article · Nov 2015 · Journal of Crystal Growth
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    ABSTRACT: Preclinical Research Proinflammatory cytokine interleukin-1 beta (IL-1β) plays a crucial role in the pathogenesis of osteoarthritis (OA) by stimulating several mediators that contribute to cartilage degradation. Schisandrae Fructus (SF), the dried fruit of Schisandra chinensis (Turcz.) Baill. (Magnoliaceae), is widely used in traditional medicine for the treatment of a number of chronic inflammatory diseases. This study investigated the antiosteoarthritis properties of an ethanol extract of SF on IL-1β-stimulated SW1353 chondrocytes. SF attenuated IL-1β-induced expression and activity of matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 and also reduced the elevated levels of cyclooxygenase-2 and inducible nitric oxide synthase associated with the inhibition of prostaglandin E2 and nitric oxide production in IL-1β-stimulated SW1353 chondrocytes. In addition, SF markedly suppressed the nuclear translocation of nuclear factor-kappa B (NF-κB) by blocking inhibitor κB-alpha degradation and inhibited the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). These results indicate that the inhibitory effect of SF on IL-1β-stimulated expression of MMPs and inflammatory mediators production in SW1353 cells were associated with the suppression of the NF-κB and JNK/p38 MAPK signaling pathways. The results from this study indicate that SF may have therapeutic potential for the treatment of OA due to its anti-inflammatory and chondroprotective features. Drug Dev Res, 2015. © 2015 Wiley Periodicals, Inc.
    Full-text · Article · Oct 2015 · Drug Development Research

  • No preview · Article · Aug 2015
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    Christian Freise · Ki Young Kim · Uwe Querfeld
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    ABSTRACT: Vascular calcifications bear the risk for cardiovascular complications and have a high prevalence among patients with chronic kidney disease. Central mediators of vascular calcifications are vascular smooth muscle cells (VSMC). They transdifferentiate into a synthetic/osteoblast-like phenotype, which is induced, for example, by elevated levels of calcium and phosphate (Ca/P) due to a disturbed mineral balance. An aqueous extract from Lindera obtusiloba (LOE) is known to exert antifibrotic and antitumor effects or to interfere with the differentiation of preadipocytes. Using murine and rat VSMC cell lines, we here investigated whether LOE also protects VSMC from Ca/P-induced calcification. Indeed, LOE effectively blocked Ca/P-induced calcification of VSMC as shown by decreased VSMC mineralization and secretion of alkaline phosphatase. In parallel, mRNA expression of the calcification markers osterix and osteocalcin was reduced. Vice versa, the Ca/P-induced loss of the VSMC differentiation markers alpha smooth muscle actin and smooth muscle protein 22-alpha was rescued by LOE. Further, LOE blocked Ca/P-induced mRNA expressions and secretions of matrix metalloproteinases-2/-9 and activation of NF- κ B, which are known contributors to vascular calcification. In conclusion, LOE interferes with the Ca/P-induced transdifferentiation/calcification of VSMC. Thus, LOE should be further analysed regarding a potential complementary treatment option for cardiovascular diseases including vascular calcifications.
    Full-text · Article · Aug 2015 · Evidence-based Complementary and Alternative Medicine
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    ABSTRACT: Methionine sulfoxide reductase A (MsrA), which stereospecifically catalyzes the reduction of methionine-S-sulfoxide, is an important reactive oxygen species (ROS) scavenger. Tissue fibrosis is a maladaptive repair process following injury, associated with oxidative stress. In this study, we investigated the role of MsrA in unilateral ureteral obstruction (UUO)-induced kidney fibrosis and its underlying mechanisms by using MsrA gene-deleted mice (MsrA(-/-)). MsrA deletion increased collagen deposition in the interstitium and the expression of collagen III and α-smooth muscle actin in the UUO kidneys, indicating that MsrA deficiency exacerbated the progression of UUO-induced kidney fibrosis. UUO reduced the kidney expression of MsrA, MsrB1, and MsrB2, thereby decreasing MsrA and MsrB activity. UUO increased hydrogen peroxide and lipid peroxidation levels and the ratio of oxidized glutathione (GSSG) to total glutathione (GSH) in the kidneys. The UUO-induced elevations in the levels of these oxidative stress markers and leukocyte markers were much higher in the MsrA(-/-) than in the MsrA(+/+) kidneys, the latter suggesting that the exacerbated kidney fibrosis in MsrA(-/-) mice was associated with enhanced inflammatory responses. Collectively, our data suggest that MsrA plays a protective role in the progression of UUO-induced kidney fibrosis via suppression of fibrotic responses caused by oxidative stress and inflammation. Copyright © 2015. Published by Elsevier Inc.
    No preview · Article · Jul 2015 · Free Radical Biology and Medicine
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    ABSTRACT: The objective of this study was to assess the possible beneficial skeletal muscle preserving effects of ethanol extract of Schisandrae Fructus (EESF) on sciatic neurectomy- (NTX-) induced hindlimb muscle atrophy in mice. Here, calf muscle atrophy was induced by unilateral right sciatic NTX. In order to investigate whether administration of EESF prevents or improves sciatic NTX-induced muscle atrophy, EESF was administered orally. Our results indicated that EESF dose-dependently diminished the decreases in markers of muscle mass and activity levels, and the increases in markers of muscle damage and fibrosis, inflammatory cell infiltration, cytokines, and apoptotic events in the gastrocnemius muscle bundles are induced by NTX. Additionally, destruction of gastrocnemius antioxidant defense systems after NTX was dose-dependently protected by treatment with EESF. EESF also upregulated muscle-specific mRNAs involved in muscle protein synthesis but downregulated those involved in protein degradation. The overall effects of 500 mg/kg EESF were similar to those of 50 mg/kg oxymetholone, but it showed more favorable antioxidant effects. The present results suggested that EESF exerts a favorable ameliorating effect on muscle atrophy induced by NTX, through anti-inflammatory and antioxidant effects related to muscle fiber protective effects and via an increase in protein synthesis and a decrease in protein degradation.
    Full-text · Article · Jun 2015 · Oxidative medicine and cellular longevity

  • No preview · Article · Jun 2015
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    ABSTRACT: In the present study, we aimed to determine whether ethanol extracts of Fructus Schisandrae (FS), the dried fruit of Schizandra chinensis Baillon, mitigates the development of dexamethasone-induced muscle atrophy. Adult SPF/VAT outbred CrljOri:CD1 (ICR) mice were either treated with dexamethasone to induce muscle atrophy. Some mice were treated with various concentrations of FS or oxymetholone, a 17α-alkylated anabolic-androgenic steroid. Muscle thickness and weight, calf muscle strength, and serum creatine and creatine kinase (CK) levels were then measured. The administration of FS attenuated the decrease in calf thickness, gastrocnemius muscle thickness, muscle strength and weight, fiber diameter and serum lactate dehydrogenase levels in the gastrocnemius muscle bundles which was induced by dexamethasone in a dose-dependent manner. Treatment with FS also prevented the dexamethasone-induced increase in serum creatine and creatine kinase levels, histopathological muscle fiber microvacuolation and fibrosis, and the immunoreactivity of muscle fibers for nitrotyrosine, 4-hydroxynonenal, inducible nitric oxide synthase and myostatin. In addition, the destruction of the gastrocnemius antioxidant defense system was also inhibited by the administration of FS in a dose-dependent manner. FS downregulated the mRNA expression of atrogin-1 and muscle ring-finger protein-1 (involved in muscle protein degradation), myostatin (a potent negative regulator of muscle growth) and sirtuin 1 (a representative inhibitor of muscle regeneration), but upregulated the mRNA expression of phosphatidylinositol 3-kinase, Akt1, adenosine A1 receptor and transient receptor potential cation channel subfamily V member 4, involved in muscle growth and the activation of protein synthesis. The overall effects of treatment with 500 mg/kg FS were comparable to those observed following treatment with 50 mg/kg oxymetholone. The results from the present study support the hypothesis that FS has a favorable ameliorating effect on muscle atrophy induced by dexamethasone, by exerting anti-inflammatory and antioxidant effects on muscle fibers, which may be due to an increase in protein synthesis and a decrease in protein degradation.
    Full-text · Article · May 2015 · International Journal of Molecular Medicine
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    ABSTRACT: In the present study, the beneficial and synergistic effects of Polycalcium, a mixture of Polycan and calcium (Ca) lactate-gluconate in a 1:9 weight ratio, on a rat model of osteoarthritis (OA) were explored. Polycalcium (50, 100 and 200 mg/kg) was administered orally once per day for 28 days from 1 week after the OA-modeling surgery. Diclofenac sodium (2 mg/kg) was administered as a reference drug. Following the OA surgery, increases in the maximum extension angles, edematous changes in knee and capsule thickness, reductions in chondrocyte proliferation and cartilage glycosaminoglycan (GAG) levels, as well as changes in cartilage degeneration were observed. However, these OA-related symptoms were inhibited after 28 days of continuous oral treatment with Polycalcium. Anti-OA effects, including the induction of chondrocyte proliferation, were detected in the Polycalcium-treated rats and were more favorable compared with those in rats treated with Polycan or Ca lactate-gluconate alone (100 mg). Therefore, a mixture of Polycan and Ca lactate-gluconate was demonstrated to have beneficial synergistic effects on OA.
    Preview · Article · May 2015 · Experimental and therapeutic medicine
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    ABSTRACT: Acryl CoA: monoacylglycerol acyltransferase 2, (MGAT2) is interesting target and useful strategy for treating metabolic-related diseases such as obesity, type 2 diabetes, hypertriglyceridemia and non-alcoholic fatty liver disease. In this study, we are optimized a new and easy-to-use screening assay system to identify novel MGAT2 inhibitors. We optimized high-quality Perkinelmer's FlashPlates based MGAT2 assay have a short time-consuming, adjust for high throughput screening (HTS) and can perform extensive screening. This screening technology platform is considered to be particularly useful for biological targets for which the conventional HTS assays are difficult to implement. © 2015 Korean Chemical Society, Seoul & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
    No preview · Article · May 2015 · Bulletin of the Korean Chemical Society
  • Eun Seok Jang · Ki Young Kim · Suk Jun Kim

    No preview · Article · Apr 2015
  • Iseul Park · Ki Young Kim

    No preview · Article · Feb 2015
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    ABSTRACT: Background The migration of vascular smooth muscle cells from the tunica media to the subendothelial region may be a key event in the development of atherosclerosis after arterial injury. In this study, we investigated the potential mechanisms underlying the anti-atherosclerotic effects of Schisandrae Semen essential oil (SSeo) in human aortic smooth muscle cells (HASMCs).Methods Metalloproteinase-2/9 (MMP-2/9) activity was evaluated by gelatin zymography and gelatinase activity assay kit. The possible mechanisms underlying SSeo-mediated reduction of by tumor necrosis factor (TNF)-¿-induced cell invasion and inhibition of secreted and cytosolic MMP-9 production in HASMCs were investigated.ResultsOur results indicate that SSeo treatment has an inhibitory effect on activation as well as expression of MMP-9 induced by TNF-¿ in HASMCs in a dose-dependent manner without significant cytotoxicity. SSeo attenuated nuclear translocation of TNF-¿-mediated nuclear factor-kappa B (NF-¿B) and blocked degradation of the NF-¿B inhibitor proteins as well as the production of reactive oxygen species. SSeo also reduced TNF-¿-induced production of pro-inflammatory mediators such as nitric oxide and prostaglandin E2 and inhibited inducible nitric oxide synthase and cyclooxygenase-2 expression in HASMCs. Furthermore, the Matrigel migration assay showed that SSeo effectively reduced TNF-¿-induced HASMC migration compared with that in the control group.Conclusions Taken together, these results suggest that SSeo treatment suppresses TNF-¿-induced HASMC migration by selectively inhibiting MMP-9 expression, which was associated with suppression of the NF-¿B signaling pathway. Taken together, these results suggest that SSeo has putative potential anti-atherosclerotic activity.
    Full-text · Article · Feb 2015 · BMC Complementary and Alternative Medicine
  • Ki Young Kim · Young-Gyu Park

    No preview · Article · Jan 2015 · Exploration Geophysics
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    ABSTRACT: Long carbon fiber reinforced polypropylene (LCFP) composites were prepared at different fiber/resin input ratios and fiber lengths by extrusion and compression molding techniques. Fiber contents and fiber lengths were controlled by the carbon fiber/resin input ratio and screw extruder speed, respectively. The effects of the fiber content and fiber length on the mechanical properties of LCFP were investigated. The fiber length of the composites with the same fiber content decreased with an increase in screw speed. Further, the mechanical properties of the composites improved with an increase in the fiber content and mean fiber length. The fracture surfaces of the composites were investigated by scanning electron microscopy (SEM).
    No preview · Article · Dec 2014 · Fibers and Polymers
  • Bok Hyun Kang · Yu Ran Gwak · Ki Young Kim
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    ABSTRACT: In this study, gas bubbling was used to deoxidise a copper melt. Prior to the deoxidation of copper, a water model was developed and evaluated to investigate the characteristics of bubbles produced by air injection with nozzles of different shapes and sizes. Bubble frequency, floating velocity and diameter were measured by a high speed video camera and were compared to theoretical results. Approximately 500 g of 99.9 % pure copper was melted in a graphite crucible by induction melting under an argon atmosphere. After samples were completely melted, CO gas was introduced from the nozzle into the copper melt to achieve deoxidisation. Oxygen concentrations in the melt were reduced to less than 6 ppm by CO gas bubbling. Electrical conductivities of the samples produced by CO bubbling were between 101.6 and 102.3 % IACS.
    No preview · Article · Oct 2014 · Transactions of the Indian Institute of Metals
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    ABSTRACT: Objective To determine the cutoff value of the pharyngeal residue for predicting reduction of aspiration, by measuring the residue of valleculae and pyriformis sinuses through videofluoroscopic swallowing studies (VFSS) after treatment with neuromuscular electrical stimulator (VitalStim) in stroke patients with dysphagia. Methods VFSS was conducted on first-time stroke patients before and after the VitalStim therapy. The results were analyzed for comparison of the pharyngeal residue in the improved group and the non-improved group. Results A total of 59 patients concluded the test, in which 42 patients improved well enough to change the dietary methods while 17 did not improve sufficiently. Remnant area to total area (R/T) ratios of the valleculae before treatment in the improved group were 0.120, 0.177, and 0.101 for solid, soft, and liquid foods, respectively, whereas the ratios for the non-improved group were 0.365, 0.396, and 0.281, respectively. The ratios of the pyriformis sinuses were 0.126, 0.159, and 0.121 for the improved group and 0.315, 0.338, and 0.244 for the non-improved group. The R/T ratios of valleculae and pyriformis sinus were significantly lower in the improved group than the non-improved group in all food types before treatment. The R/T ratio cutoff values were 0.267, 0.250, and 0.185 at valleculae and 0.228, 0.218, and 0.185 at pyriformis sinuses. Conclusion In dysphagia after stroke, less pharyngeal residue before treatment serves as a factor for predicting greater improvement after VitalStim treatment.
    Preview · Article · Oct 2014 · Annals of Rehabilitation Medicine
  • Ki Young Kim · Je Beom Jeon · Jong Sik Shin
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    ABSTRACT: This study describes the formation of a primary silicon network during separation of an Al-30% Si melt and the process conditions to make bigger primary silicon crystals. As the crucible rotates in the centrifugal separation, the unfrozen aluminum-rich phase and small silicon particles are pushed outside through the openings in the silicon network. As a result, primary silicon crystals are separated in the form of a foam after centrifugation. The recovery of the silicon ranged from 13 to 18% depending on the location in the crucible. The size of the primary silicon achieved by changing the cooling rate and quenching temperature during solidification is also measured using a quenching furnace. Primary silicon particles exhibit a coarse, plate-like morphology, although small star-like silicon particles are also found in the aluminum-rich matrix. The fraction of plate silicon decreases, while the fraction of small globular silicon increases with an increasing cooling rate. The thickness of the primary silicon plate also decreases with an increasing cooling rate in the samples quenched at various temperatures during solidification.
    No preview · Article · Oct 2014 · Crystal Research and Technology
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    ABSTRACT: The aim of the present study was to investigate the optimum composition of Polycan (β-glucan complex) and calcium lactate-gluconate (CaLG) that exhibited the most beneficial effects in ovariectomy (OVX)-induced osteoporotic rats. Polycan and CaLG single formulas (100 mg/kg each), and three doses (50, 100 and 200 mg/kg) of three mixed formulas [polycan:CaLG (PCLG)=1:99, 5:95 and 10:90] were orally administered once a day for 84 days. The effects of the test materials were compared with those of a risedronate sodium-treated group. OVX resulted in an increase in body weight, decreased bone formation, elevated serum osteocalcin levels and urine deoxypyridinoline/creatinine ratio, as well as decreased serum bone-specific alkaline phosphatase levels, femur indices, bone mineral content, bone mineral density and failure load. However, these OVX-induced osteoporotic changes markedly decreased following the administration of the test materials. Continuous oral treatment of Polycan or CaLG single formulas and the PCLG mixed formulas preserved bone mass and strength. The PCLG 10:90 mixed formula exhibited the most favorable synergistic antiosteoporotic effects in the OVX-induced osteoporotic rats as compared with equal doses of the Polycan or CaLG single formulas.
    Preview · Article · Sep 2014 · Experimental and therapeutic medicine

Publication Stats

1k Citations
168.76 Total Impact Points


  • 2015
    • Korea Research Institute of Chemical Technology
      • Division of Drug Discovery Research
      Daiden, Daejeon, South Korea
  • 2011-2015
    • Wonkwang University
      • Division of Beauty Design
      Riri, Jeollabuk-do, South Korea
    • Sejong University
      Sŏul, Seoul, South Korea
  • 1999-2015
    • Yeungnam University
      • • Department of Biochemistry and Molecular Biology
      • • College of Medicine
      경산시, Gyeongsangbuk-do, South Korea
  • 2014
    • Yonsei University Hospital
      Sŏul, Seoul, South Korea
  • 2012-2014
    • Samsung Advanced Institute of Technology
      Usan-ri, Gyeonggi-do, South Korea
    • Korea University of Technology and Education
      • Department of Energy, Materials and Chemical Engineering
      Changnyeong, South Gyeongsang, South Korea
  • 2004-2014
    • Korea Institute of Industrial Technology
      안산시, Gyeonggi-do, South Korea
    • Keimyung University
      Sŏul, Seoul, South Korea
  • 2013
    • Daegu Haany University
      Daikyū, Daegu, South Korea
  • 2009-2012
    • National Cheng Kung University
      • Department of Physics
      臺南市, Taiwan, Taiwan
    • Hyundai Motor Company
      Sŏul, Seoul, South Korea
    • National Institute of Crop Science
      Sŏngnam, Gyeonggi Province, South Korea
    • Korea Institute of Energy Research
      Sŏul, Seoul, South Korea
    • Hanyang University
      • Department of Industrial Engineering
      Sŏul, Seoul, South Korea
  • 2000-2012
    • Kyungpook National University
      • • Department of Microbiology
      • • School of Computer Science and Engineering
      • • Department of Electronic Engineering
      • • Department of Electrical Engineering
      Daikyū, Daegu, South Korea
  • 2008-2011
    • Korea Institute of Science and Technology
      Sŏul, Seoul, South Korea
    • Union Corporation, South Korea
      Sŏul, Seoul, South Korea
  • 2009-2010
    • Kyung Hee University
      • College of Pharmacy
      Sŏul, Seoul, South Korea
  • 1994-2010
    • Korea Advanced Institute of Science and Technology
      • • Department of Electrical Engineering
      • • Department of Chemical and Biomolecular Engineering
      Sŏul, Seoul, South Korea
  • 2007-2009
    • Northwestern University
      • Department of Electrical Engineering and Computer Science
      Evanston, Illinois, United States
  • 2001-2009
    • Chung-Ang University
      • School of Mechanical Engineering
      Seoul, Seoul, South Korea
  • 2003-2008
    • Information and Communications University
      Daiden, Daejeon, South Korea
    • Sungkyunkwan University
      • Department of Chemical Engineering
      Sŏul, Seoul, South Korea
  • 1996-2008
    • Kangwon National University
      • Department of Geophysics
      Shunsen, Gangwon-do, South Korea
  • 2003-2007
    • Dongseo University
      • Department of International Logistics
      Tsau-liang-hai, Busan, South Korea
  • 2002-2007
    • Konyang University Hospital
      Gaigeturi, Jeju-do, South Korea
    • Hongik University
      • Department Electronic and Electrical Engineering
      Sŏul, Seoul, South Korea
    • Catholic University of Korea
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea
  • 2006
    • Electronics and Telecommunications Research Institute
      Sŏul, Seoul, South Korea
  • 2002-2005
    • Konyang University
      • College of Medicine
      Ronsan, Chungcheongnam-do, South Korea
  • 1997-2005
    • Pusan National University
      • • Department of Atmospheric Sciences
      • • Department of Industrial Engineering
      Tsau-liang-hai, Busan, South Korea
  • 1997-2001
    • Chonnam National University Hospital
      Sŏul, Seoul, South Korea