Y J Lee

National Fusion Research Institute, Daiden, Daejeon, South Korea

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Publications (264)565.21 Total impact

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    ABSTRACT: After a contract with Hyundai Heavy Industries Co. Ltd. (HHI) on January 2010 for the manufacture of the ITER equatorial and lower ports, manufacturing preparation activities have been performed. As part of the preparation activities, a full scale mock-up of the lower port stub extension (LPSE) #16 was fabricated by HHI in order to verify fabrication feasibility and set up the fabrication sequence for the LPSE. In this paper, major technical results from fabrication of a full scale mock-up will be presented with emphasis on the main manufacturing procedure, welding, nondestructive examination (NDE) and 3D dimensional inspection. Afterwards, progress of real product manufacturing is introduced.
    Fusion Engineering and Design 10/2014; · 0.84 Impact Factor
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    ABSTRACT: This study was conducted to compare the expression patterns of serum alpha-fetoprotein (AFP) and proteins induced by vitamin K absence or antagonist-II (PIVKA-II) in hepatocellular carcinoma (HCC) patients undergoing liver transplantation (LT) and resection at a high-volume single institution. First, 663 liver transplant recipients with HCC were selected. They were divided into hepatitis B virus (HBV) (n = 628) and hepatitis C virus (HCV) groups (n = 35). Their medical records were retrospectively reviewed. Second, another cohort of 2709 patients who underwent HCC resection included 2258 HBV, 143 HCV, and 308 non-HBV non-HCV (NBNC) patients. In the transplantation group, pretransplantation AFP level >20 ng/mL was observed in 42.5% of HBV patients and 60% of HCV patients (P = .042). PIVKA-II level >40 mAU/mL was observed in 30.6% of HBV patients and 42.9% of HCV patients (P = .127). In the resection group, a preoperative AFP level >20 ng/mL was observed in 51.7% of HBV patients and 43.3% of HCV patients (P = .052). PIVKA-II level >40 mAU/mL was observed in 59.7% of HBV patients and 56.6% of HCV patients (P = .47). Preoperative AFP level >20 ng/mL and PIVKA-II level >40 mAU/mL were observed in 35.7% and 61% of NBNC patients, respectively. Receiver-operator characteristic curve analyses revealed that the expression pattern of PIVKA-II in patients with elevated AFP level was not predictable and vice versa, regardless of background liver diseases. This study indicates that serum AFP and PIVKA-II may be expressed variably regardless of the types of background liver disease. Further large-volume multicenter studies are needed to evaluate the possibility of the etiology-dependent expression of tumor markers.
    Transplantation Proceedings 04/2014; 46(3):888-93. · 0.95 Impact Factor
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    ABSTRACT: In this paper, we develop pixels with concentric-photogates for applications in time-of-flight 3-D image sensors with single-tap architecture. The pixel uses a buried-channel device and features a reduced effective electron transit length, for the rapid transfer of a signal electron. A reduction in the interpixel irregularity of signal levels and a consequent increase in the demodulation signal amplitude are observed in the single-tap operation mode as opposed to the multitap operation mode. Specifically, we are able to achieve a demodulation contrast higher than 50% from 20 MHz modulation of an 850 nm light-emitting diode illumination. Finally, we construct a sensor composed of 198 x 108 concentric photogate pixels, each with a pitch of 28 μm, and use it to generate a 3-D image conveying gross distance information and detailed object features with a distance error of less than 1% over a range of 1 to 7 m.
    IEEE Transactions on Electron Devices 02/2014; PP(99):1-1. · 2.06 Impact Factor
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    ABSTRACT: Aluminothermic reduction of K2TiF6 in the presence of C, B, or N2 was investigated as a low exothermic combustion process for synthesizing nanoparticles of titanium ceramics such as TiC, TiB2, and TiN. Sample pellets were prepared by mixing powders of K2TiF6, Al, and non-metal (C, B) powders in stoichiometric ratios. Experiments were conducted at room temperature under either an Ar or N2 atmosphere. The combustion parameters were estimated from the temperature-time profiles, measured in the combustion wave using thermocouples. The reaction drastically proceeds within seconds, raising the temperature to 890–1170°C. The size of TiC, TiB2, and TiN nanoparticles prepared by the developed approach were, respectively, 5–30 nm, 10–60 nm, and 70–100 nm.
    Combustion Science and Technology 01/2014; 186(1). · 1.01 Impact Factor
  • S.J. Cho, Y.J. Lee, Y.H. Kim, J.Y. Koo
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    ABSTRACT: HVDC transformers are one of the main components for long distance transmission, for which many investigations have been done all over the world in order to increase their efficiency and reliability. Regarding their insulation, oil immersed pressboards are widely used, representing one of the most important elements playing a role in transformer behaviors. Under DC operation, space charges accumulating between the oil and pressboard have been reported as the influential cause possibly giving rise to unexpected service failures under the transient voltage from the grid. However, it might be possible to presume that the accumulation of space charge could be facilitated inside the multilayered pressboard causing insulation breakdown in a different way. In addition, other parameters could be potential issues to investigate: non homogeneous temperature distribution along the oil circulation path and the DC field intensity. The former could explain the conductivity variation causing the non-uniform DC field distribution, while the latter plays a role in the variation of conductivity. With these in mind, three parameters have mainly been put under experimental investigation. For this purpose, a DC voltage is applied to the oil immersed pressboard, and then the polarization and leakage current are measured and analyzed. The mobility of the space charge is calculated from the former as a function of the number of layers, while the conductivity is obtained from the latter.
    IEEE Transactions on Dielectrics and Electrical Insulation 01/2014; 21(2):866-872. · 1.36 Impact Factor
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    ABSTRACT: A study has been conducted on the electrodeposition of tantalum in a 61 mol% LiF–39 mol% NaF melt containing 1 mol% K2TaF7 at 800 °C. Tantalum was coated onto a stainless-steel base (SUS316L) by molten salt electrodeposition (MSE) at different current densities (0.5, 1.5, 2, 5, 10, 20 mA/cm2). Electrodeposition of metallic tantalum occurred primarily by electroreduction of Ta(V), i.e. TaF72 −, at a potential of <− 0.27 V (vs. Pt used as a pseudo reference electrode). At potentials less than − 0.324 V, TaF2(s) also underwent reduction to metallic tantalum. Pure metallic tantalum, without any entrapped salt, was successfully deposited on SUS316L by electrodeposition at 5 mA/cm2. This showed that the deposition efficiency and microstructure of the tantalum coating layer were strongly dependent on the current density. The densest microstructure was obtained at a current density of 5 mA/cm2. Current densities above 5 mA/cm2 caused non-uniform microstructures because of rapid deposition. A dense microstructure and an intact coating layer contributed to a significant enhancement in corrosion resistance.
    Surface and Coatings Technology 11/2013; 235:819–826. · 1.94 Impact Factor
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    ABSTRACT: Background: Pneumonia is the primary source of sepsis and is associated significantly with mortality. However, little is focused on about its clinical characteristics and outcomes. Methods : We evaluated 500 intensive care unit patients who met severe sepsis or septic shock criteria, dividing them into two distinct groups (43%, sepsis with pneumonia; 41%, sepsis with an infection other than pneumonia). Results: Moderate differences between the groups were observed. The group of sepsis with pneumonia had a higher 28-day in-hospital mortality (41% vs. 30%; P = 0.02). Multivariate analysis revealed that the presence of pneumonia associated significantly with mortality (OR 1.76, 95% CI 1.11-2.78) along with cardiopulmonary resuscitation (OR 4.20, 95% CI 1.50-11.74), serum lactate ≥3.5 mmol/L (OR 1.92, 95% CI 1.20-3.08), and SOFA score ≥12 (OR 2.41, 95% CI 1.52-3.82). Survival analysis revealed for both groups that the patients with PaO2/FiO2 (PF) ratio <170 and lactate ≥3.5 mmol/L had a worse prognosis than the patients with PF ratio ≥170 and lactate ≥3.5 mmol/L or PF ratio <170 and lactate <3.5 mmol/L. Conclusion: In patients admitted with sepsis, the pneumonia infection independently predicts 28-day inhospital mortality. Combining the levels of serum lactate and PF ratio could be a useful approach in predicting mortality of these patients.
    Minerva anestesiologica 09/2013; · 2.82 Impact Factor
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    ABSTRACT: The effects of genomic changes in hepatitis B virus (HBV) on the occurrence of hepatocellular carcinoma (HCC) are still unclear, especially in relation to the genotype of HBV. In this study, we examined the effects of genomic changes in HBV of genotype C2 on the development of HCC. A total of 318 patients with HBV-associated HCC and 234 patients with chronic hepatitis B (CHB) were studied. All of HCC cases were diagnosed histologically and treated with surgical resection. The whole of the X, S, basal core promoter (BCP) and precore regions of the viral genome from sera or liver tissues were sequenced. All subjects had HBV of genotype C2. The prevalence of the T1653 mutation in the X region and the A1896 mutation in the precore region of HBV was significantly higher in the HCC group than in the control CHB group (22% vs 11%, P = 0.003; 50% vs 23%, P < 0.001, respectively). Moreover, the T1762/A1764 mutations in the BCP region in combination with either T1653 or A1896 were more common in the HCC compared with the CHB group (BCP+X1653: 18% vs 11%, P = 0.05; BCP+PC, 40% vs 15%, P < 0.001, respectively). In multivariate analysis, T1653 and A1896 were revealed to be independent risk factors for HCC development. G1896A in the precore region and C1653T mutation in the X region of genotype C2 HBV are important risk factors for HCC development. Also, the A1762T/G1764A double mutation may act in synergy with C1653T to increase the risk of HCC in patients chronically infected with HBV genotype C2.
    Journal of Viral Hepatitis 03/2013; 20(3):219-24. · 3.08 Impact Factor
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    ABSTRACT: In this study, intermetallic compound formation at the interface between aluminum and copper during hydrostatic extrusion was simulated by performing a solid state diffusion bonding experiment with various processing parameters, including bonding temperature and pressure and holding time, and by inserting an Ag colloid layer between the aluminum and copper. Regression equations were developed to predict thickness of diffusion layer and interface hardness.An intermetallic compound formed at the interface between the Al and Cu during diffusion bonding at 420 °C and 240 MPa for 60 min, and it was effectively controlled by inserting an Ag colloid. These experimental data will be useful for setting up processing parameters to prepare Al/Cu matrix composite materials by using hydrostatic extrusion.
    Journal of Materials Processing Technology. 03/2013; 213(3):487–494.
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    ABSTRACT: The aim of this study was to investigate the cytotoxic activities of ovotransferrin (OTF) from egg white and its enzyme hydrolysates (OTH). The OTF was hydrolyzed at 45°C for 3 h using neutrase, alcalase, acid (0.03 N HCl, pH 2.5), protamex, protex 6L, flavorzyme, α-chymotrypsin, trypsin, and collupulin MG. The enzyme to substrate ratio was 1:25 (wt/wt) in all experiments. Using the 3-(4,5-dimethylthizol-2-yl)-2,5-diphenylatetetrazolium bromide (MTT) assay, the cytotoxicity of OTF and OTH was evaluated in human cancer cell lines of various tissue origins, including the lung (A549 and SK-MES-1), stomach (AGS), breast (MCF-7), larynx (Hep-2), cervix (HeLa), and liver (HepG2). The growth of all cancer cell lines was inhibited by both OTF and OTH in a dose-dependent manner. In particular, OTF displayed relatively high cytotoxicity (≤60% inhibition effects) at 40 mg/mL. At lower concentrations (≤5 mg/mL), however, OTF- and OTH-mediated cytotoxic effects were not significant in all cancer cell lines tested. The MCF-7 cells were the least sensitive to all treatments among all cancer cell lines tested. The OTH-trypsin and OTH-neutrase showed a potent cytotoxicity (over 90% cytotoxicity) to HeLa cells at the 10 mg/mL level. The OTH-trypsin, OTH-protamex, OTH-protex 6L, and OTH-collupulin MG caused 95, 96, 86, and 87% growth inhibition, respectively, in AGS cells. These results indicated there are possibilities that OTF and OTH can be used as natural growth inhibitors of human cancer cell lines.
    Poultry Science 02/2013; 92(2):424-34. · 1.52 Impact Factor
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    ABSTRACT: Recently, the superconductivity projects to develop commercial superconducting devices for extra high voltage transmission lines have been undergoing in many countries. One of the critical components to be developed for high voltage superconducting devices, including superconducting transformers, cables, and fault current limiters, is a high voltage bushing, to supply high current to devices without insulating difficulties, that is designed for cryogenic environments. Unfortunately, suitable bushings for HTS equipment were not fully developed for some cryogenic insulation issues. Such high voltage bushings would need to provide electrical insulation capabilities from room temperature to cryogenic temperatures.In this paper, design factors of cryogenic bushings were discussed and test results of specimen were introduced in detail. First, the dielectric strength of three kinds of metals has been measured with uniform and non-uniform electrodes by withstand voltage of impulse and AC breakdown test in LN2. Second, puncture breakdown voltage of glass fiber reinforced plastics (GFRPs) plates has been analyzed with non-uniform electrodes. Finally, creepage discharge voltages were measured according to the configuration of non-uniform and uniform electrode on the FRP plate. From the test results, we obtained the basic design factors of extra high voltage condenser bushing, which could be used in cryogenic environment.
    Physica C Superconductivity 01/2013; 484:338–342. · 0.72 Impact Factor
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    ABSTRACT: HGMS (High Gradient Magnetic Separator) uses matrix to make high magnetic field gradient so that ferro- or para-magnetic particles can be attracted to them by high magnetic force. The magnetic force generated by the field gradient is several thousand times larger than that by background magnetic field alone. So the HGMS shows excellent performance compared with other magnetic separators. These matrixes are usually composed of stainless steel wires having high magnetization characteristics. This paper deals with superconducting HGMS which is aimed for purifying waste water by using stainless steel matrix. Background magnetic field up to 6 T is generated by a superconducting solenoid and the stainless steel matrixes are arranged inside of the solenoid. Based on magnetic field calculated by FEM (Finite Element Method), we could calculate magnetic force acting on a magnetic particle such as hematite and maghemite consisting of major impurities in the condenser water of a thermal power station.
    Physica C Superconductivity 01/2013; 484:333–337. · 0.72 Impact Factor
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    ABSTRACT: We report enhanced switching margin in perpendicular MTJ cells at 20nm node. By introducing a novel structure with superior pinned layer stability, stable magnetization switching without magnetostatic interference has been achieved. Wide switching field margins over 40s have been secured for reproducible STT switching as well as a tightly controlled Hoffset below 100Oe. Switching voltage margin of the novel structure are also wide enough to show definite STT switching.
    VLSI Technology (VLSIT), 2013 Symposium on; 01/2013
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    ABSTRACT: thin films were prepared on the Si substrate by radio frequency (RF) magnetron sputtering and then surface of the films were irradiated with intense Ar ion beam to investigate the effect of Ar ion irradiation on the properties and hydrogen gas sensitivity of the films. From atomic force microscope observation, it is supposed that intense Ar bombardments promote rough surface and increase gas sensitivity of films for hydrogen gas. The films that Ar ion beam irradiated at 6 keV show the higher sensitivity than the films were irradiated at 3 keV and 9 keV. These results suggest that the thin films irradiated with optimized Ar ion beam are promising for practical high-performance hydrogen gas sensors.
    Journal of the Korean Society for Heat Treatment. 11/2012; 25(6).
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    ABSTRACT: AIMS: Adequate evaluation and surgical management of cervical lymph node metastasis is very important in papillary thyroid carcinoma (PTC). The aim of this study was to evaluate the impact of preoperative ultrasonography (US) and computed tomography (CT) on the surgical management of cervical lymph node metastases in PTC. METHODS: Medical records and imaging findings were retrospectively analyzed for 252 patients with PTC who underwent thyroidectomy with neck dissection. RESULTS: The sensitivity of both imaging techniques was lower in the central neck (US 23%, CT 41%) than in the lateral neck (US 70%, CT 82%). The specificities of US and CT were 97% and 90% in the central neck, and 84% and 64% in the lateral neck, respectively. Our surgical plans for therapeutic neck dissection were based on imaging findings in 59% of patients who underwent lateral compartment neck dissection and in 32.1% of patients who underwent central compartment neck dissection, respectively. CONCLUSIONS: The roles of preoperative US and CT in surgical planning for central compartment neck dissection in PTC are limited because of their low sensitivity in the central neck, but US and CT may be useful in cases with non-palpable lateral neck nodes.
    European journal of surgical oncology: the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology 08/2012; · 2.56 Impact Factor
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    ABSTRACT: Recently, various high temperature superconducting (HTS) power applications have been developed and prepared for field tests and commercial applications. Comparing to conventional power applications, it could offer several advantages such as reduced size and weight, high efficiency, decreased losses, no oil, nonflammable and decrease of CO2 emissions. Besides overload operation is possible with no loss of lifetime. For HTS power applications in low temperature and high voltage environments, partial discharge (PD) measurements in cryogenic dielectric materials of HTS power applications are very important because PD was regarded as primary source for ageing and breakdown of cryogenic materials. One of the diagnostic methods for safety of the power components, the detection of PD taking place inside the apparatus has been widely investigated. The first method, phase resolved partial discharge (PRPD) Analysis was developed in the early 1970s taking the phase information of the applied AC voltage into account. We also proposed a pattern analysis method named chaotic analysis of PD(CAPD) for PDs occurred in liquid nitrogen, considering three normalized parameters obtained from the values between two consecutive PD pulses: amplitude difference (Pt), occurring time difference (Tt) and correlation between Tt and Pt. This pattern analysis method can identify the type of defects by means of PD pattern classification without employing the phase information of the applied voltage signal. For the experimental investigation, three artificial defects have been fabricated considering possible defects formed during the manufacturing process of HTS power applications: turn to turn insulation, floating particle and protrusion. And PD signals originated from these artificial defects are measured and analyzed by means of CAPD. Throughout this work, it seems that the correlation between the consecutive PD pulses, depending on the nature PDs, co- ld be clarified by CAPD.
    IEEE Transactions on Applied Superconductivity 06/2012; 22(3):77013-. · 1.20 Impact Factor
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    ABSTRACT: Au intermediate ZnO (ZAZ) thin films were prepared by radio frequency and direct current magnetron sputtering on glass substrates and then vacuum annealed. The thickness of each layer of the ZAZ films was set at 50 nm, 3 nm, and 47 nm, respectively. The structural, electrical, and optical properties of ZAZ films were investigated with respect to the variation of annealing temperature.As-deposited AZO films showed X-ray diffraction peaks corresponding to ZnO (002) and Au (111) planes and those peak intensities increased with post-deposition vacuum annealing. The optical and electrical properties of the films were strongly influenced by post-deposition annealing. Although the optical transmittance of the films deteriorated with an Au interlayer, as-deposited ZAZ films showed a low resistivity of 2.0 × 10−4 Ω cm, and the films annealed at 300 °C had a lower resistivity of 9.8 × 10−5 Ω cm. The work function of the films increased with annealing temperature, and the films annealed at 300 °C had a higher work function of 4.1 eV than the films annealed at 150 °C. The experimental results indicate that vacuum-annealed ZAZ films are attractive candidates for use as transparent electrodes in large area electronic applications such as solar cells and large area displays.
    Vacuum. 04/2012; 86(10):1494–1498.
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    ABSTRACT: It is challenging to differentiate between intestinal tuberculosis (ITB) and Crohn's disease in areas where TB is still prevalent. The use of diagnostic tools and verifying the drug resistance patterns of ITB can be helpful for its correct diagnosis. To determine the diagnostic sensitivity of a culture assay using colonoscopic biopsy specimens and the drug resistance patterns of Mycobacterium tuberculosis isolated from ITB. Data from 400 patients diagnosed with ITB were retrospectively analysed. Of the 400 patients, 170 (42.5%) were males; the median age at diagnosis was 40 years. The sensitivity of culture was 44.1% (145/329). Resistance to at least one anti-tuberculosis drug was identified in 13 (17.6%) and multidrug-resistant TB (MDR-TB) was diagnosed in two (2.7%) of the 74 patients for whom drug susceptibility testing was performed. Including M. tuberculosis isolated from respiratory specimens, the proportion of MDR-TB was 4.4% (5/113); previous anti-tuberculosis treatment was an independent risk factor for MDR-TB (26.7% vs. 1.0%, P < 0.01). Culture of colonoscopic biopsy specimens shows substantial diagnostic sensitivity; the frequency of MDR-TB is higher in previously treated cases than in new cases.
    The International Journal of Tuberculosis and Lung Disease 04/2012; 16(6):799-804. · 2.76 Impact Factor
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    ABSTRACT: In the present study, we examined therapeutic potential of human amnion-derived insulin-secreting cells for type 1 diabetes. Human amniotic mesenchymal stem cells (hAMs) were isolated from amnion, and cultivated to differentiate into insulin-secreting cells in vitro. After culture in vitro, the differentiated cells (hAM-ISCs) were intensively stained with dithizone, and secreted insulin and c-peptide in a high glucose-dependent manner. They expressed mRNAs of pancreatic cell-related genes, including INS, PDX1, Nkx6-1, NEUROG3, ISL1, NEUROD1, GLUT1, GLUT2, PC1/3, PC2, GCK, PPY, SST and GC, and were positive for human insulin and c-peptide. Transplantation of hAM-ISCs into the kidneys of mice with streptozotocin-induced diabetes restored body weight, and normalized the blood glucose levels, which lasted for 210 days. Only human insulin and c-peptide were detected in the blood of normalized mice after 2 months of transplantation, but little mouse insulin and c-peptide. Removal of graft-bearing kidneys from these mice resulted in causing hyperglycemia again. Human cell-specific gene, hAlu, and human pancreatic cell-specific genes of insulin, PDX1, GLUT1, GLP1R, Nkx6-1, NEUROD1, and NEUROG3 were detected in the graft-bearing kidneys. Colocalization of human insulin and human nuclei antigen was also observed. These results demonstrate that hAMs could differentiate into functional insulin-secreting cells in vitro, and human insulin secreted from hAM-ISCs following transplantation into type 1 diabetic mice could normalize hyperglycemia, overcoming immune rejection for a long period.
    Cell Transplantation 04/2012; · 4.42 Impact Factor
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    ABSTRACT: To determine the perioperative risk factors for bacterial infections after pediatric living donor liver transplantation (LDLT), we investigated the clinical profiles of 149 children who underwent pediatric LDLT between 1994 and 2008. Bacterial infections were diagnosed based on guidelines proposed by the Centers for Disease Control. We observed 36 bloodstream infections (BSIs) in 32/149 (21.5%) patients (0.24 infections per patient), which, 21 (58.3%) BSIs in 19 patients were due to gram-positive and 15 (41.7%) in 13 patients to gram-negative organisms. The most common pathogens of early BSI were coagulase-negative Staphylococcus; (n = 11; 30.6%) and Klebsiella pneumoniae (n = 8; 22.2%). The most common site of early BSI was catheter-related (n = 14; 38.9%). Multivariate analysis showed that age ≤ 1 year (P < .05; odds ratio [OR] = 3.90; 95% CI, 1.83-15.26) and bile duct complications (P < .05; OR = 6.2, 95% CI = 3.21-35.23) were significant independent risk factors for early BSIs. More cautious management of pediatric LDLTs may be necessary for younger age children particularly with postoperative biliary complications.
    Transplantation Proceedings 04/2012; 44(3):794-6. · 0.95 Impact Factor

Publication Stats

3k Citations
565.21 Total Impact Points

Institutions

  • 2009–2014
    • National Fusion Research Institute
      Daiden, Daejeon, South Korea
  • 2001–2014
    • Chungnam National University
      • • Graduate School of Green Energy Technology
      • • College of Agriculture and Life Sciences
      • • Department of Neurology
      Daiden, Daejeon, South Korea
    • Catholic University of Korea
      • Department of Internal Medicine
      Seoul, Seoul, South Korea
  • 2013
    • Johns Hopkins University
      Baltimore, Maryland, United States
  • 2011–2013
    • Hanyang University
      Sŏul, Seoul, South Korea
    • Ajou University
      Sŏul, Seoul, South Korea
  • 1996–2013
    • Ulsan University Hospital
      Urusan, Ulsan, South Korea
  • 2012
    • Korean Institute of Ceramic Engineering and Technology
      Sŏul, Seoul, South Korea
  • 2003–2012
    • Asan Medical Center
      • • Department of Gastroenterology
      • • Division of Liver Transplantation and Hepato-Biliary Surgery
      • • Division of Hepato-Biliary and Pancreas Surgery
      • • Department of Orthopedic Surgery
      Seoul, Seoul, South Korea
    • Pohang University of Science and Technology
      • Department of Electronic and Electrical Engineering
      Andong, North Gyeongsang, South Korea
  • 1996–2012
    • University of Ulsan
      • • Department of Materials Engineering
      • • Asan Medical Center
      • • Department of Surgery
      Ulsan, Ulsan, South Korea
  • 2010
    • Yonsei University
      • Department of Pharmacology
      Seoul, Seoul, South Korea
  • 2001–2010
    • National Veterinary Research Quarantine Service
      Sŏul, Seoul, South Korea
  • 2008
    • Seoul Metropolitan Children's Hospital
      Sŏul, Seoul, South Korea
  • 2007
    • University of California, Berkeley
      Berkeley, California, United States
  • 2005
    • Research Institute of Industrial Science and Technology
      Sŏul, Seoul, South Korea
  • 2000–2005
    • Sungkyunkwan University
      • School of Advanced Materials Science and Engineering (AMSE)
      Seoul, Seoul, South Korea
    • Korea University
      Sŏul, Seoul, South Korea
  • 2004
    • Korea Basic Science Institute KBSI
      Sŏul, Seoul, South Korea
    • Electronics and Telecommunications Research Institute
      Sŏul, Seoul, South Korea
  • 2003–2004
    • University of Helsinki
      • Laboratory of Physical Chemistry
      Helsinki, Province of Southern Finland, Finland
  • 1998–2003
    • Cheju Halla University
      Tse-tsiu, Jeju, South Korea
  • 2000–2002
    • National Cancer Center Korea
      Kōyō, Gyeonggi Province, South Korea
  • 2000–2001
    • University of Pittsburgh
      Pittsburgh, Pennsylvania, United States
  • 1999–2001
    • Yonsei University Hospital
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea
  • 1998–2001
    • Korea Research Institute of Bioscience and Biotechnology KRIBB
      • Protein Engineering Laboratory
      Ansan, Gyeonggi, South Korea
  • 1997–2001
    • Seoul National University
      • College of Pharmacy
      Seoul, Seoul, South Korea
  • 1996–2001
    • Korea Advanced Institute of Science and Technology
      • Department of Biological Sciences
      Sŏul, Seoul, South Korea
  • 1990–1999
    • William Beaumont Army Medical Center
      El Paso, Texas, United States
  • 1993
    • Henry Ford Hospital
      • Department of Radiation Oncology
      Detroit, MI, United States
  • 1987–1988
    • University of California, San Francisco
      • Department of Radiation Oncology
      San Francisco, CA, United States