• Title/Summary/Keyword: Lee Ji-Ham

Search Result 189, Processing Time 0.024 seconds

Analysis of Likelihood of Failure for the Stress Corrosion Cracking by Caustic Cracking through the Quantitative Risk Based-Inspection using API-581 BRD (API-581 절차에 의한 정량적 위험기반검사에서 부식성 균열에 의한 응력부식의 사고발생 가능성 해석)

  • Lee, Hern-Chang;Choi, Sung-Kyu;Cho, Ji-Hoon;Ham, Byung-Ho;Kim, Tae-Ok
    • Journal of the Korea Safety Management & Science
    • /
    • v.9 no.1
    • /
    • pp.65-76
    • /
    • 2007
  • The likelihood of failure for the stress corrosion cracking (SCC) of caustic cracking, which affect to a risk of facilities, was analyzed through the risk based-inspection using API-581 BRD. We found that SCC of the caustic cracking was occurred above 5 % NaOH concentration, and the technical module subfactor (TMSF) was maximized for above 50 % concentration. The heat traced and monitoring were not sensitive to the TMSF with NaOH concentration and temperature. But the steam out was more of less affect minimum value of the TMSF. Also, the inspection number, the inspection effectiveness, and the year since inspection were very sensitive to the TMSF with NaOH concentration and temperature. Therefore, the plan of next inspection will be established with compositively considering those at once.

A study on Rogowski coil for measuring Short-circuit currents (단락전류 측정용 Rogowski coil 개발)

  • Lee, Yong-Shin;Park, Ji-Hoon;Ham, Gil-Ho;Choi, Won-Suk;Chang, Yong-Moo
    • Proceedings of the KIEE Conference
    • /
    • 2000.07b
    • /
    • pp.787-789
    • /
    • 2000
  • This paper describes the theory and practical design of Rogowski coil and active integrator. The coils and integrators have the ratings as follows. 1) current ratings between 20kArms and 200kArms 2) current duration 3 seconds 3) time constant of primary circuit looms 4) inner diameter of coil is suitable for mounting at the busbar $200mm{\times}200mm$. The actual results in the short-circuit tests and compare with other sensors, such that shunt. are given also.

  • PDF

Introduction of Risk Based Inspection System Suitable for Domestic Circumstances (국내 실정에 적합한 위험기반검사 제도의 도입)

  • Lee, Hern-Chang;Cho, Ji-Hoon;Kwon, Hyuk-Myun;Ham, Byeong-Ho;Char, Soon-Chul;Kim, In-Tae;Chung, Eui-Soo;Kim, Tae-Ok
    • Proceedings of the Safety Management and Science Conference
    • /
    • 2007.04a
    • /
    • pp.143-149
    • /
    • 2007
  • 현행 우리나라의 검사제도는 사업장의 자율관리 능력을 고려하지 않고, 설비의 노후화 및 위험도와 무관하게 획일화된 방식으로 적용하여 설비의 안전성을 확보하지 못할 뿐만 아니라 정기 및 자체 검사를 병행하여 많은 불편이 있다. 따라서 사업장의 불편을 해소하고, 설비의 안전성과 신뢰도를 높일 수 있는 위험기반검사(risk based inspection, RBI)를 국내 실정에 적합하게 도입하기 위하여 사업장, 정부 및 관련 기관에서 향후 추진해야할 방향에 대하여 분석하였다. 국내에서 위험기반검사 제도가 정착될 수 있기 위해서는 먼저 법적 근거가 마련되어야 하며, 법적 제도가 마련되면 사업장에서 RBI를 적용 시 이를 검증하고, 관리할 수 있는 인증기구의 설치가 필요하다. 또한 위험기반검사를 수행하는 사업장에 대해서는 공정안전이행수준과 같은 위험기반검사 이행수준평가를 도입하고, 차등 적용하여 사업장을 관리하는 것이 바람직하다.

  • PDF

Studies on Biochemical Mechanism of DNA Alkylating Agents Tethered to Ligands for Retinoic acid Receptor

  • Yun, Byoung-Gu;Pyun, Sung-Jae;Ji, Sang-Mi;Ham, Won-Hoon;Lee, Young-Joo;Park, Hyun-Ju
    • Proceedings of the PSK Conference
    • /
    • 2003.10b
    • /
    • pp.176.2-176.2
    • /
    • 2003
  • Transcription factors (TF) can bind tightly to specific DNA lesions formed by some anticancer agents. The formation these TF:(drug-modified DNA) complex may disrupt expression of genes critical for cell survival, and it was proved to be one of biochemical mechanisms of anticancer activity. Based on this model, we have designed programmable DNA Alkylating agents that can also attract TF, especially nuclear receptors. As a model compound, we designed drug molecules, RA-mustard and Am580-mustard, that enable to bind both retinoic acid receptor (RAR) and DNA by using molecular modeling techniques, and synthesized them by connecting chlorambucil and ligand for RAR with a linker unit. (omitted)

  • PDF

Observations for the Ionosphere Using European Incoherent Scatter (EISCAT) in the Dayside Polar Cap/Cusp and Auroral Region

  • Geonhwa Jee;Eun-Young Ji;Eunsol Kim;Young-Sil Kwak;Changsup Lee;Hyuck-Jin Kwon;Ji-Eun Kim;Young-Bae Ham;Ji-Hee Lee;Jeong-Han Kim;Tae-Yong Yang;Hosik Kam
    • Journal of Astronomy and Space Sciences
    • /
    • v.40 no.1
    • /
    • pp.1-10
    • /
    • 2023
  • Korea Polar Research Institute (KOPRI) and Korea Astronomy and Space Institute (KASI) have been participating in the European Incoherent Scatter (EISCAT) Scientific Association as an affiliate institution in order to observe the polar ionosphere since 2015. During the period of December 16-21, 2016 and January 3-9, 2018, the observations for the polar ionospheric parameters such as the electron density profiles, ion drift, and electron/ion temperature are carried out in the polar cap/cusp region by the EISCAT Svalbard radar (ESR). The purpose of the observations is to investigate the characteristic of the winter ionosphere in the dayside polar cap/cusp region. In this paper, we briefly report the results of the ESR observations for winter daytime ionosphere and also the simultaneous observations for the ionosphere-thermosphere system together with the balloon-borne instrument High-Altitude Interferometer WIND Experiment (HIWIND) performed by the High Altitude Observatory (HAO), National Center for Atmospheric Research (NCAR). We further introduce our research activities using long-term EISCAT observations for the occurrence of ion upflow and the climatology of the polar ionospheric density profiles in comparison with the mid-latitude ionosphere. Finally, our future research plans will briefly be introduced.

Quality comparison between imported hams from black and white pigs available in the market

  • Nam, Ki-Chang;Jo, Cheorun;Lee, Hyun Jung;Park, Ji Young;Hyun, Jeong Min;Yim, Dong-Gyun
    • Korean Journal of Agricultural Science
    • /
    • v.45 no.4
    • /
    • pp.799-809
    • /
    • 2018
  • This study was performed to compare the physicochemical characteristics between imported dry-cured Hams from black and white pigs available in the domestic market. The black dry-cured hams contain higher moisture and ash contents than that of white hams, whereas the black dry-cured hams had lower fat contents than that of the black ones (p < 0.05). The hams from black ones had lower lightness ($L^*$) and yellowness ($b^*$) values than those from the white ones (p < 0.05). Moreover, the pH values and salt contents of the hams from the black ones were higher than those from the white ones (p < 0.05). Moreover, the black ones had a higher water holding capacity (WHC) than that of the white ones (p < 0.05). The thiobarbituric acid reactive substances (TBARS) values of the black ones were lower than those of the white ham samples (p < 0.05). For texture profile analysis, hardness, gumminess, chewiness, cohesiveness and shear force values were significantly lower in the black ones than in the white samples (p < 0.05). Saturated fatty acids in the white ones were higher than in the black ones, whereas unsaturated fatty acids in the black ones were higher (p < 0.05). Free amino acids such as aspartic acid and glutamic acid in the black ones were higher than in the white ones (p < 0.05). The shrinkage of muscle fiber was stronger in the white ones. Considering the meat quality parameters of ham, the black ones showed a superior meat quality. In general, this research can be used as fundamental information for the mass production of dry-cured hams in Korea.

Inhibition of Hepatocellular Carcinoma Cell Growth by the Extract of Symphytum offcinale L. and the Possible Mechanisms for this Inhibition

  • Ham, Seung-Shi;Park, Kyong-Gun;Lee, Yong-Moon;Lee, Young-Ik;Yoon, Ji-Won;Kim, Seong-Jin;Lee, euk-Sik
    • Preventive Nutrition and Food Science
    • /
    • v.2 no.3
    • /
    • pp.236-240
    • /
    • 1997
  • A crude extract of Smphytum officinale L. (comfrey) was for its ability to inhibit he growth of hepatocellular carcinoma cells and expression of the insulin-like growth factor I (IGF-II) gene. The DNA synthesis of hepatocellular carcinoma cell lines, Hep G2, Hep 3B, and PLC/PRF/5 was inhibited by a crude extract of Smphytum officinale in both a time- and a dose-dependent manners. This plant extract also inhibited expression of the IGF-II gene. Since IGF-II exerts a mitogenic effect on Hep G2 cells, these results suggest that the growth inhibition by Symphytum officinale extract is, in part, mediated through the inhibition of IGF-II gene expression.

  • PDF

The Study of Training Scenario for the KA-32T Helicopter Simulator (KA-32T 헬리콥터 시뮬레이터를 위한 훈련 시나리오 연구)

  • Jeong, Ji-Hoon;Kang, Seung-On;Lee, Ki-Hak;Park, Yong-Jin;Ko, Kang-Myung;Ham, Dae-Young;Lee, Dong-Ho;Jun, Hyang-Sig;Choi, Hyung-Sik
    • Journal of the Korean Society for Aviation and Aeronautics
    • /
    • v.16 no.2
    • /
    • pp.28-35
    • /
    • 2008
  • The purpose of this study is to develop a training scenario for KA-32T helicopter simulator. First, the concept of training scenario are classified into training elements and training information. Secondly, the training elements are defined according to the property of each element: flight phase, situation, and environment. The main mission of KA-32T on the operation of KFS(Korea Forest Service) is the forest fire extinguishment mission, and it is divided into the two disciplines: water supply and water discharge. Finally the mission scenario for two disciplines are defined and developed as the combination of the normal procedures of training scenario and the mission procedures.

  • PDF

Exposures of Ultrafine Particles for Passengers of Elephant Vehicle in the Seoul Grand Park (서울대공원 코끼리 열차 특성에 따른 탑승자의 초극미세입자(Ultrafine Particles) 노출)

  • Joo, Song-Yi;Hwang, Ji-Hee;Ham, Seung-Hon;Lee, Ki-Young
    • Journal of Environmental Health Sciences
    • /
    • v.38 no.5
    • /
    • pp.393-397
    • /
    • 2012
  • Objectives: The objectives of this study were to measure passengers' exposure to ultrafine particles (UFP) and to determine effects of fuel, operating condition and position of seat. Method: UFP exposures in front and back seats of the Elephant vehicle in Seoul Grand Park were simultaneously measured by a condensation particle counter (P-Trak model 8525, TSI). The measurements were conducted 7 times with diesel-powered vehicle and 3 times with electricity vehicle in one day. The vehicle stopped at 3 locations along with 2.2 km of driving route. Results: UFP concentration in diesel-powered vehicle was significantly higher than electricity vehicle. At front seat of diesel-powered vehicle, average UFP exposure during stopping was significantly higher than during moving. When diesel-powered vehicle moved, UFP exposure in back seat was significantly higher than in front seat. Conclusions: Passengers in the diesel-powered Elephant vehicle could be exposed to high level of UFP. The UFP exposure was associated with operation condition and position of seat.

Analysis of Parameters Affecting the Consequence of the Flash Fire Accident by the Release of Heavy Gas (무거운 가스의 누출에 의한 플래쉬화재사고에서 사고결과에 미치는 매개변수의 영향 분석)

  • Kim, Tae-Ok;Lee, Hern-Chang;Ham, Byeong-Ho;Cho, Ji-Hoon;Shin, Dong-Il;Jang, Seo-Il
    • Journal of the Korea Safety Management & Science
    • /
    • v.8 no.6
    • /
    • pp.29-39
    • /
    • 2006
  • The effect of parameters on the consequence of the flash fire accident by the release of heavy gas(in this study, xylene vapor) was analyzed. Simulation results showed that the distance with the lower flammable limit($X_{LFL}$) was increased with the increase of the release hole diameter. For the case of the elevated release, $X_{LFL}$ was increased with the increase of the wind speed and the release height, but $X_{LFL}$ was not affected by the wind speed for the release on the ground level. Therefore, the accident in the elevated release was more dangerous than the release on the ground level. In this condition, the release height had more effect on $X_{LFL}$ at the night time than the daytime and in the urban area than the rural area.