Y J Lee

Seoul National University Bundang Hospital, Sŏul, Seoul, South Korea

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Publications (182)322.97 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Scedosporium spp. is the most common mold infection in pneumonia resulting from near-drowning. Three fatal scedosporiosis cases developed after solid organ transplantation, probably transmitted from the nearly-drowned donor. One heart transplant recipient and two kidney transplant recipients developed fatal scedosporiosis following deceased donor transplantation from the same donor, a nearly-drowned victim of a suicide attempt. Genotypically, indistinguishable strains of Scedosporium auratiacum were recovered from the three recipients. Two liver transplant recipients from the same donor received prophylactic voriconazole without any subsequent signs of infection. To determine the safety of donation from nearly-drowned donors, a national traceback investigation was also performed of the causes of deaths in all transplant recipients who received organs from drowned donors between 2001 and 2013. Over 13 years, 2600 deceased donor transplants were performed in Korea. Among these 2600 deceased donor transplants, 27 (1%) victims of drowning donated their organs. From these 27 donors, 84 patients received organ transplants and 18 died, including the above three. We found no microbiologic evidence of invasive mold transmission from the nearly-drowned donors to the other 15 recipients. Although disseminated infection in the donor could not be demonstrated by culture, undiagnosed disseminated donor infection and transmission of Scedosporium spp. should be considered in near-drowning events.
    American Journal of Transplantation 01/2015; · 6.19 Impact Factor
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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; · 1.15 Impact Factor
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    ABSTRACT: Objectives: Transoral laser microsurgery is considered one of the best techniques for the treatment of early stage glottic cancer. But voice outcome and quality of life (QOL) after laser cordectomy has not been fully evaluated. The aim of this study is to evaluate the voice outcome and QOL after transoral laser cordectomy in glottic cancer.
    Otolaryngology Head and Neck Surgery 09/2014; 151(1 Suppl):P194-P194. · 1.72 Impact Factor
  • Advances in Applied Ceramics 08/2014; 113(6):341-345. · 1.11 Impact Factor
  • Advances in Applied Ceramics 08/2014; 113(6):352-357. · 1.11 Impact Factor
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    ABSTRACT: SETTINGThe long-term natural course of Mycobacterium avium complex (MAC) disease with nodular bronchiectasis, the most common pulmonary non-tuberculous mycobacterial disease, is not well described. OBJECTIVE To identify risk factors for the deterioration of nodular bronchiectatic MAC lung disease over a 5-year follow-up period. DESIGNClinical and laboratory data of 67 patients with nodular bronchiectatic MAC lung disease were collected. Chest computerised tomographic images were used to count the number of lung segments involved at diagnosis and measure subcutaneous fat thickness during follow-up. RESULTSThe 34 patients who showed deterioration had significantly lower body mass index (BMI) (P = 0.004) and % predicted forced vital capacity (P = 0.032), higher numbers of lung segments involved (P P = 0.028), and thinner chest subcutaneous fat during follow-up (P 2 and more than four lung segments involved had a 240-fold increased risk of deterioration (P CONCLUSION Patients with poor nutritional status and extensive lung involvement tend to experience deterioration of nodular bronchiectatic MAC lung disease.
    The International Journal of Tuberculosis and Lung Disease 06/2014; 18(6). · 2.76 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 04/2014; 21(2):866-872. · 1.23 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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    G.H. Lee, Y.J. Lee, J.H. Cho, M.N. Kim
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    ABSTRACT: Voice activity detection is very important process that find voice activity from noisy speech signal for noise cancelling and speech enhancement. Over the past few years, many studies have been made on voice activity detection, it has poor performance for speech signal of sentence form in a low SNR environment. In this paper, it proposed new voice activity detection algorithm that has beginning VAD process using entropy and main VAD process using fuzzy membership shifted c-means clustering. We conduct an experiment in various SNR environment of white noise to evaluate performance of the proposed algorithm and confirmed good performance of the proposed algorithm.
    Journal of Korea Multimedia Society. 03/2014; 17(3).
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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. · 2.36 Impact Factor
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    ABSTRACT: High-availability Seamless Redundancy (HSR) is an emerging standard that is suitable for mission-critical communication of IEC 61850 based Substation Automation System in smart grid, where the dependability is very important. This redundancy protocol provides zero recovery time by offering duplicated frames for separate physical paths, but it generates and circulates unnecessary traffic inside the network that will degrade the performance of the network and may cause the congestion, delay, or frame loss. To improve the HSR network performance, the main drawback of generating extra traffic should be considered and eliminated. This paper demonstrates comprehensive performance analysis of IEC 61850 based substation automation networks and applies the quick removing (QR) algorithm to improve the performance of the HSR network to overcome the major drawback. The performance analysis includes the HSR modules, i.e., Doubly Attached Node for HSR (DANH), Redundancy Box (RedBox), and Quadruple Box (QuadBox), and IEC 61850 services, i.e., Generic Object Oriented Substation Events (GOOSE), Sampled Measurement Values (SMV), and report service. Performance analysis was conducted to verify the timing constraints described in IEC 61850 as a reference for designing proper HSR network topology. The numerical results show that the frame loss, restricted in mission-critical network, occurs due to large amount of traffic volume, which is the main drawback of HSR. The QR algorithm improves the traffic performance of HSR by reducing the unnecessary traffic along with the decrease of packet loss significantly.
    ICACT 2014; 02/2014
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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). · 0.98 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. · 2.20 Impact Factor
  • Fusion Engineering and Design 10/2013; 88(9-10):1960-1964. · 1.15 Impact Factor
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    G.H. Lee, Y.J. Lee, M.N. Kim
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    ABSTRACT: Voice activity detection is very important process that voice activity separated form noisy speech signal for speech enhance. Over the past few years, many studies have been made on voice activity detection, but it has poor performance in low signal to noise ratio environment or fickle noise such as car noise. In this paper, it proposed new voice activity detection algorithm using ensemble variance based on wavelet band entropy and soft thresholding method. We conduct a survey in a lot of signal to noise ratio environment of car noise to evaluate performance of the proposed algorithm and confirmed performance of the proposed algorithm.
    Journal of Korea Multimedia Society. 09/2013; 16(9).
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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; · 2.27 Impact Factor
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    ABSTRACT: Objectives: In patients with unilateral auditory dysfunctions such as tinnitus and hearing loss, differential diagnosis of cochlear, retrocochlear, or vascular problems is important. Because unilateral hearing loss and tinnitus patients are increasing recently, screening tools are required. There are many diagnostic tests for differential diagnosis about patients with unilateral auditory dysfunction, but there is no efficient screening tool which can confirm all lesions. The purpose of this work is to assess the clinical usefulness of 3D fast imaging employing steady state acquisition (3D-FIESTA) sequence in unilateral hearing loss or tinnitus.
    Otolaryngology Head and Neck Surgery 08/2013; 149(2 Suppl):P214-P215. · 1.72 Impact Factor
  • Institute of Electrical 44th Summer Conference; 07/2013
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    ABSTRACT: The new allele, HLA-DRB1*14:136, differs from DRB1*14:05:03 by two nucleotide substitutions at codon 74 with a coding change [GAG→CTG (Glu>Leu)].
    Tissue Antigens 04/2013; 81(4):239-40. · 2.35 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

Publication Stats

1k Citations
322.97 Total Impact Points

Institutions

  • 2014
    • Seoul National University Bundang Hospital
      Sŏul, Seoul, South Korea
  • 2009–2014
    • National Fusion Research Institute
      Daiden, Daejeon, South Korea
    • Korea Institute of Energy Research
      Sŏul, Seoul, South Korea
  • 2005–2014
    • Chungnam National University
      • • Graduate School of Green Energy Technology
      • • College of Agriculture and Life Sciences
      Daiden, Daejeon, South Korea
  • 2011–2013
    • Hanyang University
      • Department of Electronic and Electrical Engineering
      Sŏul, Seoul, South Korea
    • Korea Electrotechnology Research Institute-KERI
      Tsau-liang-hai, Busan, South Korea
  • 2000–2013
    • Ulsan University Hospital
      Urusan, Ulsan, South Korea
  • 2012
    • Korean Institute of Ceramic Engineering and Technology
      Sŏul, Seoul, South Korea
  • 2006–2012
    • Asan Medical Center
      • • Department of Gastroenterology
      • • Division of Liver Transplantation and Hepato-Biliary Surgery
      • • Division of Hepato-Biliary and Pancreas Surgery
      Seoul, Seoul, South Korea
  • 1996–2012
    • University of Ulsan
      • • Department of Materials Engineering
      • • Asan Medical Center
      • • Department of Surgery
      Urusan, Ulsan, South Korea
  • 2001–2011
    • Ajou University
      Sŏul, Seoul, South Korea
  • 2010
    • Yonsei University
      • Department of Pharmacology
      Seoul, Seoul, South Korea
  • 2007–2010
    • National Veterinary Research Quarantine Service
      Sŏul, Seoul, South Korea
  • 2008
    • Seoul Metropolitan Children's Hospital
      Sŏul, Seoul, South Korea
    • Seoul National University Hospital
      • Department of Pathology
      Sŏul, Seoul, South Korea
  • 2000–2008
    • Korea University
      Sŏul, Seoul, South Korea
  • 2004–2007
    • Gwangju Institute of Science and Technology
      • School of Materials Science and Engineering
      Gwangju, Gwangju, South Korea
    • Korea Basic Science Institute KBSI
      Sŏul, Seoul, South Korea
  • 2005–2006
    • Catholic University of Korea
      • • Department of Radiology
      • • College of Medicine
      Sŏul, Seoul, South Korea
  • 2002–2003
    • Korea Research Institute of Standards and Science
      Daiden, Daejeon, South Korea
  • 2001–2003
    • Cheju Halla University
      Tse-tsiu, Jeju, South Korea
  • 1997–2003
    • Seoul National University
      • • Department of Nuclear Medicine
      • • College of Pharmacy
      Sŏul, Seoul, South Korea
  • 1999–2001
    • Yonsei University Hospital
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea