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여수국가산업단지 인근 지역 대기오염물질 농도에 영향을 미치는 요인분석
김민영,변정훈,이영훈,이건영,한지은,이예림,임지현,장봉기 순천향대학교 기초과학연구소 2022 순천향자연과학연구 논문집 Vol.28 No.1,2
Eight monitoring stations in the Yeosu National Industrial Complex will determine the concentration of air pollutants measured every hour in 2019, analyze what factors affect them, and how they correlate with the air pollutant measurements. Six air pollutants (SO2, NO2, O3, CO, PM-10 and PM-2.5) measured at eight monitoring stations around Yeosu National Industrial Complex (Seogang-dong, Wolnae-dong, Munsu-dong, Yeocheon-dong, Deokchung-dong, Hwayang-myeon, Yulchon-myeon, Samil-dong) the measurement data for each hour of the year were downloaded to analyze the concentration by weather condition, time zone, season, separation distance from Yeosu Industrial Complex, and separation distance from Gwangyang Industrial Complex. SO2, NO2, and CO concentrations were significantly higher in winter, significantly lower in summer, and O3, PM-10, and PM-2.5 concentrations were significantly higher in spring. SO2, CO, PM-10, and PM-2.5 concentrations were significantly higher between 10 a.m. and 12 p.m., NO2 concentrations were significantly higher between 7 a.m. and 9 a.m., and O3 concentrations were significantly higher between 13 p.m. and 15 p.m.(p<0.001). The concentration of air pollutants (SO2, NO2, CO, PM-10, PM-2.5) excluding O3 was found to have a negative (-) correlation with weather condition, and in the case of O3, it was found to have a positive (+) correlation with PM-10, PM-2.5, temperature and wind speed. It was confirmed that the concentration of air pollutants emitted from the Yeosu National Industrial Complex differs depending on the season, time and distance to the industrial complex. This study aims to establish measures to minimize health damage to residents living relatively close to the industrial complex and contribute to the establishment of management and response measures according to the properties of substances to reduce the concentration of air pollutants in the future.
이용근,이건일,박영준,변호영 원광대학교 생체재료·매식연구소 1995 원광생체재료·매식 Vol.4 No.2
To investigate the effect of high dose irradiation on the mechanical properties. dental acrylic resin specimens were irradiated and the Vickers hardness number(VHN) and the 3-point flexure strength(FS) were measured before and after irradiation. Five kinds of acrylic resins were studied. Two(VRS. PS2) were heat cured denture base resins. one(VSC) was chemically cured denture base resin and the other two(ORJ, VOP) were orthodontic resins. The acrylic resin specimens were made according to the manufacturer's instructions and were finally polished with Microcloth (Buehler). Among ten specimens of each material. five specimens were irraditated with 100 Gy using a linear accelerator (Mitsubishi 6 MV), and the others were not. The specimens were immersed in 37℃ D.W. for 48 hours before testing. Each specimens the VHN was measured 10 times. Their FS was measured with an universal testing machine (Instron 4302, England), with a cross-head speed of 5 mm/min. The VHNs of heat cured resins were 21.52∼25.55 kg/㎟ before irradiation and 19.93∼26.58 kg/㎟ after irradiation. Those of chemically cured resins were 11.28∼16.6kg/㎟ before irradiation and 11.3∼14.3 kg/㎟ after irradiation. The VHNs of heat cured acrylic resins were significantly higher than those of chemically cured resins were significantly higher than those of chemically cured resins before and after irradiation(p<0.05). VHN of VRS was significantly increased after irradiation, and those of VOP and PS2 were significantly decreased after irradiation (p<0.05). The FS of resins studied were 6.7∼8.0 kg/㎟ before irradiation and 6.5∼8.4 kg/㎟ after irradiation. The FS of VSC and VRS increased after irradiation and those of VOP, ORJ and PS2 decreased after irradiation, but the results were not statistically significant. Before irradiation, the FS of heat cured resins were somewhat higher than those of chemically cured resin, but not statistically significant, and after irradiation the FS of heat cured resins were significantly higher than those of orthodontic resins. In conclusion. high dose irradiation did not result in consistent changes in mechanical properties.
이영환 ( Lee Yeong Hwan ),김용범 ( Kim Yong Beom ),정도영 ( Jeong Do Yeong ),이유경 ( Lee Yu Gyeong ),김건영 ( Kim Geon Yeong ),이준승 ( Lee Jun Seung ),이중건 ( Lee Jung Geon ),최덕례 ( Choe Deog Lye ),박미자 ( Park Mi Ja ),이영 대한신장학회 2001 Kidney Research and Clinical Practice Vol.20 No.6
The incidence of Tuberculosis among the patients with end-stage renal disease(ESRD) has increased up to 16 times of that in the general population. The impairment of the cellular immunity in the ESRD patients may have a role in the pathogenesis. Extrapulmonary tuberculous manifestations such as lymph node, peritoneum, and pleura involvement are more frequent in the ESRD patients than in the general population. However, there has been no case of upper gastrointestinal(UGI) bleeding as a result of a gastric tuberculosis in the ESRD patient on hemodialysis. Here we report an unusual case of a hemodialysis patient with UGI bleeding secondary to a tuberculous gastric ulcer. A 31-year-old female on hemodialysis was admitted with melena. Endoscopy revealed a benign gastric ulcer with a visible bleeding vessel at the base, located in the anterior wall of the antrum. An exploratory laparotomy showed multiple, round, small and yellow nodules on the visceral peritoneum as well as a 1-cm sized gastric ulcer. After gastric resection, a histological examination including peritoneal nodules demonstrated chronic granulomatous inflamation with caseous necrosis and giant cells. The patient has been on antituberculosis medication and followed up in the outpatient department without any event for 8 months.
Lee, Jung Geon,Ahn, Curie,Yoon, Sung-Chul,Park, Jong Hoon,No, Jin Ju,Moon, Chang Suk,Song, Eun Kyeung,Hwang, Yeong Hwan,Hwang, Dae Yeon,Kim, Yon Su,Han, Jin Suk,Kim, Suhnggwon,Lee, Jung Sang,Kim, Seun 한국유전학회 2002 Genes & Genomics Vol.24 No.3
Two genetic loci, PKD1 and PKD2, have been identified as being responsible for ADPKD, but the presence of an intrafamilial clinical diversity suggests that there are disease-modifying loci. We studied the associations between polymorphism in the ecNOS gene, which are known to be associated with chronic tubulointerstitial and vascular changes, and ADPKD progression in Korean patients. A total of 112 individuals who had ADPKD and 41 normal control subjects were genotyped by PCR-RFLP, the Glu298Asp variant of ecNOS gene was discriminated with MboI. The distribution of the alleles for the ecNOS Glu298Asp polymorphism in ADPKD was: G 88 %, T 12 %, which was similar to the result of Korean population (95:5, p = 0.128) but different from Western controls (65:35, p = 0.000). No differences were found between the CRF and the non-CRF groups (p = 1.000) or the early hypertension and the normotension groups (p = 1.000). In conclusion, our results suggest that the polymorphism at Glu298Asp of ecNOS has no association with the renal progression in Korean ADPKD patients.
Lee, Geon Seok,Ji, Gyeong Hwan,Kwon, Gu-Young,Bang, Su Sik,Lee, Yeong Ho,Sohn, Song-Ho,Park, Kijun,Shin, Yong-June Institute of Electrical and Electronics Engineers 2018 IEEE transactions on applied superconductivity Vol.28 No.4
<P>In this paper, we propose a new time-frequency based analysis method that monitors the state of the high temperature superconducting (HTS) cable system in a real-time manner and detects the current imbalance of HTS cable system. The new time-frequency-based method utilizes the cross Wigner–Ville distribution to analyze the time-frequency localized phase difference of the reflected signal, which varies depending on the insulation characteristics of the HTS cable system. Also, a real-world AC 22.9 kV 50 MVA HTS cable system and a current source are used to validate the performance of the new monitoring method in order to detect current imbalance phenomenon.</P>
Geon Seok Lee,Gu-Young Kwon,Su Sik Bang,Yeong Ho Lee,Seung Jin Chang,Song-Ho Sohn,Kijun Park,Yong-June Shin Institute of Electrical and Electronics Engineers 2016 IEEE transactions on applied superconductivity Vol.26 No.4
<P>For the electrical insulation of a high-temperature superconducting (HTS) cable, wrapped polypropylene laminated paper (PPLP) tape is typically used. Unfortunately, it is possible that unexpected faults at insulation layers will be present in the cables as a result of either a problematic manufacturing process or an incomplete installation procedure. In order to protect against operational failures of grid-connected HTS cable systems, this paper proposes a nondestructive diagnostic technique, i.e., time-frequency domain reflectometry (TFDR), and focuses on the characteristic of HTS cable that caused the local insulation defects. To verify the performance of the proposed method, detection and localization of local insulation failure via TFDR are compared with traditional time-domain reflectometry. The experiments are conducted at room temperature and under liquid nitrogen in order to check the efficacy of the proposed method in varieties of HTS cable's conditions. In addition, to improve the accuracy of detection and localization, a methodology to analyze incident signals, which are composed of upchirp and downchirp signals, is presented.</P>
Analysis of Wave Propagation of HTS Cables for Compensation of Thermal Loss on Connectors
Yeong Ho Lee,Su Sik Bang,Gu-Young Kwon,Geon Seok Lee,Gyeong Hwan Ji,Song-Ho Sohn,Kijun Park,Yong-June Shin Institute of Electrical and Electronics Engineers 2017 IEEE transactions on applied superconductivity Vol.27 No.4
<P>High temperature superconducting (HTS) cable operates under relatively low temperature and its unique operating condition brings new challenges in the area of maintenance and diagnostics of the cable. As an example, a temperature difference occurs on connection systems between instruments on room temperature and HTS cables which eventually leads to thermal energy loss. The thermal energy loss affects frequency characteristics of the cable which are critical aspects for simulation and maintenance of the HTS cable systems. In this paper, an attempt to reduce thermal loss is introduced with an improved connector applying a Peltier module. The performance of the designed connector is verified with analysis of electromagnetic wave propagation properties of HTS tapes and a cable. The investigation of S -parameters and the proposed connection method is expected to be further applied to various HTS systems in future.</P>
Lee, Geon Seok,Kwon, Gu-Young,Bang, Su Sik,Lee, Yeong Ho,Sohn, Song-Ho,Park, Kijun,Shin, Yong-June Institute of Electrical and Electronics Engineers 2017 IEEE transactions on applied superconductivity Vol.27 No.4
<P>A high-temperature superconducting (HTS) cable system with the 22.9 kV, 50 MVA, and 410 m length is installed and operated at 154 kV Icheon substation of Korea Electric Power Corporation (KEPCO). Unfortunately, it is a difficult task to diagnose and monitor electrical and thermal characteristics of the HTS cable system in a real-time manner. In order to protect operational failures of grid-connected HTS cable systems, this paper proposes time-frequency domain reflectometry (TFDR) and analysis techniques, i.e., time-frequency cross correlation and instantaneous frequency estimation. To verify the performance of the proposed method, the temperature is changed via the cryogenic refrigeration system and the status of the grid-connected HTS cable is monitored via TFDR in a real-time manner.</P>
( Yeong Geon Lee ),( Jae Woong Hwang ),( Sang Bum Park ),( Il Seob Shin ),( Soo Kyung Kang ),( Kwang Won Seo ),( Yong Soon Lee ),( Kyung Sun Kang ) 한국조직공학·재생의학회 2008 조직공학과 재생의학 Vol.5 No.4
Therapy using stem cells for the liver fibrosis is a prospective alternative to overcome the insufficiency of transplantable liver donor. Here, we demonstrated xenogeneic human cell therapy for the treatment of rat liver fibrosis without the use of an immunosuppressant. Liver fibrosis was induced by dimethylnitrosamine for 5 weeks in six-week-old male Sprague-Dawley rats. Human umbilical cord blood- and adipose tissue-derived multipotent stem cells were injected intravenously by the tail vein after one week. Blood samples were collected and liver samples were stained with Masson`s trichrome in order to evaluate the amount of fibrosis. After the cell injection, the level of total protein, albumin, alanine transaminase and aspartic acid transaminase was recovered to the similar level of the normal rats. The liver weight per body weight increased after the cell injection. Collagen fiber, near the portal triad and marginal region, was reduced, significantly. Taken together, it is suggested that xenotransplantation of multipotent stem cells might be a candidate for the treatment of liver fibrosis without the use of an immunosuppresant.
이건식(Geon-Sik Lee),모동영(Dong-Yeong Mo),이상철(Sang-Cheol Lee),최창영(Chang-Young Choi),조춘호(Chun-Ho Cho),김태웅(Tae-Woong Kim),박귀근(Gwi-Geun Park) 전력전자학회 2010 전력전자학술대회 논문집 Vol.2010 No.7
매트릭스컨버터의 제어기법은 입력측의 전류형과 출력측의 전압형의 조합에 의해 구성된 미래지향형 AC/AC 전력변환시스템이다. 이를 제어하기위해서 기존 SVPWM을 적용하면 섹터정보 및 인가시간의 계산과정이 복잡해지고 계산량이 많아지는 단점이 있다. 본 논문에서는 상기의 문제점을 해결하기 위해 전압형 인버터에 사용하고 있는 기존 간략형 SVPWM과 함께 입력측 전류형에도 이를 변형하여 적합한 간략형 SVPWM를 동시에 적용하여 전체의 PWM에 관련된 계산과정을 단순화시키고 계산량을 저감시킬 수 있는 제어기법을 제안한다.