• Title/Summary/Keyword: Che-Yong

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BLDC Feed back Control System Under Open Circuit Accident (개방 사고시 BLDC 피드백 제어 시스템)

  • Im, Che-Young;Lim, Jin-Woo;Lee, Dong-Su;Lee, Jin-Woo;Lee, Seung-Ho;Woo, Dae-Hyun;Kim, Ju-Young;Kim, Nam-Hyun;Jung, Sang-Yong
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.2221_2222
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    • 2009
  • 본 논문에서는 BLDC 운전 중 각 상의 결상 사고에 따른 토크 및 속도의 최적화에 대해 연구하였다. BLDC 모터의 구동을 위하여 ATmega16이 사용되었으며 제어기법으로는 PWM(Pulse Width Modulation) 기법이 사용된다. 속도 제어는 Hall Sensor의 검출 속도에 따라 Duty비를 제어하여 이루어지며 회전자 위치는 Hall Sensor 검출 방식을 통하여 이루어진다. 이러한 BLDC 모터를 이용하여 예기치 못한 결상 상황의 발생 시 토크의 감소로 인한 급제동에 대비하여 부하에 상응하는 토크를 최대한 낼 수 있도록 알고리즘을 구현하였다.

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Alkyl Hydroxy Benzoate Preservatives (Parabens) Are Estrogenic Compounds; Their Adverse Effects on Animals and Human

  • Kang, Kyung-Sun;Che, Jeong-Hwan;Park, Jin-Sung;Lee, Yong-Soon
    • Toxicological Research
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    • v.17
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    • pp.309-312
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    • 2001
  • It has recently been suggested that the release of "endocrine disrupters (EDs)" into the environment has resulted in adverse health effects on wild life populations and humans (Golden et al., 1998; Tyler et al., 1998; Kang et al., 2000). Human sperm counts have declined significantly throughout the world during the past fifty years, and which is a significant public health concern (Carlsen et al., 1992; Carlsen et al.. 1995). In addition, the EDs persisting in the environment are known to disrupt the normal endocrine systems of wildlife (Colborn, 1995; Crewet al., 1995; Folmer et at, 1996; Sumpter, 1995; Tyler, 1998). Some estrogenic chemicals bind to estrogen receptors (Bolger et al.. 1998), interfere with the binding of physiological ligands to steroid hormone-binding proteins (Danjo, 1997; Milligan et al., 1998). and show immunotoxicity (Sakae et al., 1998). (omitted) (omitted)

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Application of Denaturing Gradient Gel Electrophoresis to Estimate the Diversity of Commensal Thermophiles

  • Bae, Jin-Woo;Kim, Joong-Jae;Jeon, Che-Ok;Kim, Kwang;Song, Jae-Jun;Lee, Seung-Goo;Poo, Har-Young;Jung, Chang-Min;Park, Yong-Ha;Sung, Moon-Hee
    • Journal of Microbiology and Biotechnology
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    • v.13 no.6
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    • pp.1008-1012
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    • 2003
  • Symbiobacterium toebii has been reported as a thermophile exhibiting a commensal interaction with Geobacillus toebii. The distribution of the commensal thermophiles in various soils was investigated using a denaturing gradient gel electrophoresis (DGGE). Based on the DGGE analysis, the enrichment condition for the growth of Symbiobacterium sp. was found to also enrich populations of several other microbial spp. as well as Symbiobacterium sp. In the enrichment experiment, several different 16S rDNA sequences of commensal thermophiles were detected in all of the soil samples tested, indicating that commensal thermophiles are widely distributed in various soils.

Isolation of 4-hydroxy-5-methyl-3[2H]-furanone from Pine Needles as an Antioxidative Principle (솔잎으로부터 항산화 성분인 4-hydroxy-5-methyl-3[2H]-furanone의 분리)

  • Boo, Yong-Chool;Jeon, Che-Ok;Oh, Ji-Yeon
    • Applied Biological Chemistry
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    • v.37 no.4
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    • pp.310-314
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    • 1994
  • An antioxidant was isolated from pine needles. This compound was identified as 4-hydroxy-5-methyl-3[2H]-furanone on the basis of spectroscopic evidences and by the comparison with the synthetic one from the Maillard reaction of xylose and glycine. It scavenged 1,1-diphenyl-2-picrylhydrazyl free radicals more efficiently than 4-hydroxy-2,5-dimethyl-3[2H]-furanone and $3-hydroxy-2-methyl-{\gamma}-pyrone$ did. It exhibited inhibitory effects on the autoxidation of 3,4-dihydroxyphenylalanine and linolenic acid.

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A study on surface settlement characteristics according to the cohesive soil depth through laboratory model tests (실내모형시험을 통한 점성토 지반의 토피고에 따른 지표침하 특성연구)

  • Kim, Young-Joon;Im, Che-Geun;Kang, Se-Gu;Lee, Yong-Joo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.16 no.6
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    • pp.507-520
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    • 2014
  • In this study, the surface displacement was investigated according to the various depth of cover when the tunnel excavation equipment was used in a clay soil. For this the laboratory scaled model test was carried out using the soil sample similar to the in-situ conditions. We carried out four tests according to tunnel depth(1.5D, 2.0D, 2.5D, 3.0D). The distribution of impact due to tunnelling was quantitatively analyzed in the three-dimension by measuring the surface displacement. In addition, the pattern of surface displacements was figured out.

A Study on Comparison of Key Words from between Dongyisusebowon and Myungsunrok (《동의수세보원(東醫壽世保元)》과 《명선록(明善錄)》에 나타난 주요(主要) 어구(語句)에 관(關)한 비교(比較) 연구(硏究))

  • Yu, Jun-Sang;Kim, Dal-Rae
    • Journal of Sasang Constitutional Medicine
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    • v.9 no.1
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    • pp.273-297
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    • 1997
  • The objective of this article is to carry on the comparative study of the two books, Dongyisusebowon and Myungsunrok. Je-Ma Lee showed, in fact, the intellectual achievement in his book, Dongyisusebowon. And Lee showed more close relationships with Suk-Ji Han's idea. The common ideas from this comparative study of both scholars are as follows. 1. Lee understands the real character of human being according to Chu-Ztu(朱子)'s doctrine, with the supplement of Han's. 2. Lee explains the Sung-Jung(性情) in Cosmology and the theory of Human Nature, but he concentrates upon the Sung-Jung in the theory of Human Nature, especially in constitutional medicine. 3. Lee states the Tai-Geuk(太極) in the meaning of heart from the medical viewpoint, he agrees with the Han's idea. 4. I try to comprehend Myungsunrok in the Wang-Yang-Ming(王陽明)'s concept. 5. Han explains that Sung-Jung-I-Ki(性情理氣) is one concept with two aspects, Che-Yong(體用). In addition, Lee has formed his 'Chun-In-Sung-Myung(天人性命)' thought in harmonization with Han's idea and Chu-Tzu's idea.

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Investigating creep behavior of Ni-Cr-W alloy pressurized tube at 950 ℃ by using in-situ creep testing system

  • Zhong, Yang;Lan, Kuan-Che;Lee, Hoon;Zhou, Bomou;Wang, Yong;Tsang, D.K.L.;Stubbins, James F.
    • Nuclear Engineering and Technology
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    • v.52 no.7
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    • pp.1481-1485
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    • 2020
  • The creep behavior of Ni-Cr-W alloy at 950 ℃ has been investigated by a novel creep testing system which is capable of in-situ measurement of strain. Tubular specimens were pressurized with argon gas for effective stresses up to 32 MPa. Experimental results show that the thermal fatigue reduces the creep life of the tubular specimens and with the introduction of thermal cycling fatigue the primary stage disappears and the creep rate higher than the pure thermal creep (without thermal fatigue). Also the creep behavior of Ni-Cr-W alloy doesn't consist in the secondary stage. A new creep equation has been derived and implemented into finite element method. The results from the finite element analyses are in good agreement with the creep experiment.

Study on the Micro Channel Assisted Release Process (미세 유체통로를 이용한 대면적 평판 구조의 부양에 관한 연구)

  • Kim, Che-Heung;Lee, June-Young;Kim, Yong-Kweon
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1924-1926
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    • 2001
  • A novel wet release process ($\mu$ CARP - Micro Channel Assisted Release Process) for releasing an extreme large-area plate structure without etching hole is proposed and experimented. Etching holes in conventional process reduce a effective area and degrade an optical characteristics by a diffraction. In addition, as the area of a released structure increases, the stietion becomes more serious. The proposed process resolves these problems by the introduction of a micro fluidic channel beneath the structure which will be released. In this paper, a 5 mm${\times}$5mm-single crystal silicon plate structure was released by the proposed $\mu$CARP without etch holes on the structure. The variation in etching time with respect to the of the introduced micro channel is also examined. This process is expected to be beneficial for the actuator of a nano-scale data storage and the scanning mirror.

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The Optimum Offset Range on the Top of T-Bar Stiffener and Bracket (최적 T-Bar Offset(Vertical Stiffener Misalignment) 허용오차 정립)

  • Lee, Kyung-Seok;Yu, Chang-Hwa;Shon, Sang-Yong;Che, Jung-Sin
    • Special Issue of the Society of Naval Architects of Korea
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    • 2008.09a
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    • pp.1-9
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    • 2008
  • This report contains the results of structural analysis for the verification of the optimum offset range on the top of T-Bar with stiffener and BKT using at DSME Offset range as $6.0{\sim}10.0mm$ based on the 3-D FE analysis and experimental results of angie type stiffener as described in Annex 1 has been used as yard standard over ten (10) years under all Classification approval. Recently, Owner and Class have requested the confirmation for the misalignment based on the Yard's Standard so that a couple of locations for LNGC and LPGC has been investigated the structural strength by FE method using the offset ranges from 0.0 to 18.0 mm.

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