• Title/Summary/Keyword: Choi Je-woo

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Cytotoxic Effect of the Extract from Acetobacter aceti OLS-001 (초산균체 추출물의 In Vitro계 암세포 증식 억제 효과)

  • Lee, Byung-Woo;Yoo, Yik-Je;Yoo, Moo-Yung;Hwang, Woo-Ik;Choi, Chun-Un
    • Korean Journal of Food Science and Technology
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    • v.27 no.4
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    • pp.445-448
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    • 1995
  • This study was performed to observe cytotoxic effect of Acetobacter aceti OLS-001 extract against cancer cell lines, including mouse leukemic lymphocyte(P388, L1210) and human rectal(HRT-18) cell. The anticancer substance were prepared by ethanol precipitation of the glass bead extraction combined with hot water of Acetobacter aceti OLS-001. The growth rates of the cancer cells in medium containing Acetobacter aceti extract were inhibited gradually to a significant degree in proportion to the increase of the extract concentration. Morphology of HRT-18 cells in medium containing Acetobacter aceti extract were seen to be shrinked and fragmented.

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A study of PM-10 and Heavy Metal characteristics in the air at the each site of a subway station. (지하철역사내 측정위치별 PM-10 및 중금속 농도특성에 관한 연구)

  • Chang Jung-Wook;Cho Jang-Je;Choi Woo-Gun;Park Duk-Sin;Jung Woo-Sung;Kim Tae-Oh
    • Proceedings of the KSR Conference
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    • 2003.10c
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    • pp.389-394
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    • 2003
  • Subway has been used one of major public transportations because of overpopulation and heavy traffic problems in the metropolitan areas. So, the air pollution has been serious. In this study, continuous date of PM-10 (particles with aerodynamic diameter < $10{\mu}m$) and heavy metal concentration measurements for winter, spring and summer. These measurements have been carried out in the outdoor, concourse, platform, tunnel. The study results showed that the average seasonally concentration of PM-10 particles were $141.57{\mu}g/m^3$ in winter. $129.34{\mu}g/m^3$ in spring and $122.73{\mu}g/m^3$. The average concentration of PM-l0 particles at indoor higher than outdoor. The concentration of Fe, Cu, showed the largest peak concentrations during the respective season.

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Suitability Selection on Habitable Environments of Corbicula Japonica in the Songji Lagoon by GIS (GIS를 이용한 송지호 재첩서식의 적지선정)

  • Choi, You-Gil;Woo, Young-Bae;Uh, Je-Sun;Choi, Chul-Jae;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.9
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    • pp.965-972
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    • 2015
  • In this paper, we describe a method for the suitability selection on habitable environments of Corbicula Japonica in the Songji Lagoon. Acquired data by in-situ measurements analysed in applying GIS. In order to identify the characteristics of environment in Songji Lagoon, water temperature, salinity, Dissolved Oxygen, and PO4-P were used. This study is expected to use the basic data for Corbicula Japonica breeding in similar lagoon environments.

Synthesis and Characterization of Transformer Oil containing Nanoparticles (나노분말이 첨가된 변압기 절연유 제조 및 정적열전특성 평가)

  • Song, Hyun-Woo;Choi, Cheol;Choi, Kyung-Shik;Oh, Je-Myung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.49-52
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    • 2004
  • New hydrophobic alumina nanoparticles were synthesized from alumina powders which were hydrophilic nano-agglomerates with diameters from ${\mu}m$ to mm by surface modification. The synthesized hydrophobic alumina nanoparticles which were retreated with Oleic acid were analyzed by Fourier transform infrared spectrophotometer and transmission electron microscopy. Then transformer oil containing surface-modified alumina naonparticles were synthesized. The synthesized hydrophobic alumina nanoparticles were well-dispersed in transformer oil. The coefficient of viscosity and dielectric strength of the Nano-transformer oil were investigated with viscometer and high voltage experiment device. In this study, the thermal conductivity of Nano-transformer oil was investigated to reduce the oil temperature of transformer by transient hot-wire method.

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A Study on Human Body Impact Characteristics of the Human-rifle System on Shooting (인체-화기시스템의 인체충격특성에 관한 연구)

  • Lee Young-Shin;Lee Jang-Won;Choi Young-Jin;Chae Je-Wook;Choi Eui-Jung;Kim In-Woo
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.7 s.184
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    • pp.159-167
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    • 2006
  • The impact time history of human body with K2 rifle on stand shooting posture is analyzed and compared with experimental results. Analysis model is Korean 50% tile of twenties and height, weight is 174 cm, 62 kgf respectively. The muscle and bone human model of Korean man's twenties 50% tile is applied. ADAMS program is used for kinematic analysis and human model is developed by Life Mod program. The effect of the ground support condition, grip position and human weight factor are studied. Maximum impact force of shoulder is 784 N. The horizontal displacement of K2 rifle muzzle is 2.9 cm.

An automatic motorized feeder pipe inspection robot (자율 주행형 급수 배관 검사)

  • Choi, Chang-Hwan;Jeon, Pung-Woo;Choi, Yong-Je;Jeong, Seung-Ho;Kim, Seung-Ho
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.816-821
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    • 2004
  • The outlet feeder pipe thinning in a PHWR (Pressured Heavy Water Reactor) is caused by high pressure steam flow inside the pipe, which is a well known degradation mechanism called FAC (Flow Assisted Corrosion). In order to monitor the degradation, the thickness of the outlet bends closed to the exit of the pressure tube should be measured and analyzed at every official overhaul. This paper develops an automatic feeder pipe inspection system that can minimize the irradiation dose by automating the measurement process. The robot can move by itself on the feeder pipe by using an inch worm mechanism, which is constructed by two gripper bodies that can fix their body on the pipe and one extendable and retractable body connected the two gripper bodies to move forward and backward.

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Analysis of a Security Vulnerability of URL Attack on Apache Web Server (아파치 웹서버의 URL 공격에 대한 보안취약성 분석)

  • Choi, Jong-Cheon;Choi, Jin-Woo;Cho, Seong-Je
    • Proceedings of the Korea Information Processing Society Conference
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    • 2004.05a
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    • pp.1027-1030
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    • 2004
  • 본 논문에서는 기계어 프로그램만 주어진 환경에서 디버깅 및 역공학 도구를 사용하여 소프트웨어 보안취약성을 분석하는 방법에 대한 연구를 수행하였다. 즉, MS사의 윈도우즈 2000 서버 운영체제 상에서 아파치(Apache) 웹서버를 대상으로, URL 공격에 대한 한 취약성을 재연하고, 취약점이 있는 코드 부분을 추출하였다. 이는 기계어 프로그램을 실행하면서 보안 취약성 분석 절차를 이해하고 보안 결함을 발견해 내는 기반 자료로 활용될 수 있을 것이다.

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