• Title/Summary/Keyword: Lee Sam

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Structural and electrical properties of potassium tantalate niobate heterolayer thin films prepared by chemical solution deposition method

  • Byeong-Jun Park;Sam-Haeng Lee;Myung-Gyu Lee;Joo-Seok Park;Byung-Cheul Kim;Sung-Gap Lee
    • Journal of Ceramic Processing Research
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    • v.23 no.3
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    • pp.252-256
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    • 2022
  • In this study, K(Ta0.65Nb0.35)O3/K(Ta0.50Nb0.50)O3 heterolayer films were fabricated by the chemical solution deposition and spin-coating method and their structural and electrical properties were measured. All specimens represented a pseudo-cubic structure with a lattice constant of approximately 0.3999-0.4003 nm along with an observable K-deficient Ta2O5∙n(KTaO3) pyrochlore phase. Average thickness for a single coating was about 60~70 nm and average grain size was approximately 105-110 nm. Curie temperature was about 7℃ and no dependence was observed on the number of coatings and sintering atmosphere. Remanent polarization of KTN heterolayer films decreased abruptly at about 50℃. The 6-coated KTN heterolayer film sintered in O2 atmosphere showed good ΔT of 1.93℃ at about 60℃ and ΔT/ΔE of 0.15×10-6 KmV-1.

Saponins and Flavonoid Glycosides from Yellow Sweetclover

  • Kang, Sam-Sik;Lee, Young-Soon;Lee, Eun-Bang
    • Archives of Pharmacal Research
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    • v.11 no.3
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    • pp.197-202
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    • 1988
  • A new saponin, 3-O-[${\alpha}$-L-rhamnopyranosyl$(1{\rightarrow}2)$-${\beta}$-D-glucopyranosyl$(1{\rightarrow}2)$-${\beta}$-D-glucuronopyranosyl]soyasapogenol B carboxylate (6) has been isolated from the medicinal plant yellow sweetclover together with azukisaponin II(7), robinin(8), and clovin(9). 7,8, and 9 are reported for the first time from this plant. The new saponin(6) exhibited inhibitory action on leucocyte migration in inflammation.

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Electric Properties of NTC Thermistor for Current Limited (전류제한용 NTC 써미스타의 전기적 특성)

  • Yoon, J.R.;Kim, J.G.;Lee, H.Y.;Lee, S.W.
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1674-1676
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    • 1999
  • Oxide of the form $Mn_3O_4-CuO-Co_3O_4$-NiO-ZnO present properties that make them useful as power NTC thermistor for current limited. Power NTC thermistor electric properties of $Mn_3O_4-CuO-Co_3O_4$-NiO-ZnO system has been measured as a function of temperature and composition and current - voltage, time constant, activation energy, heat dissipation coefficient have also been determined.

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Assessment of Hand Function in Spastic and Athetoid Cerebral Palsied Children by Jebsen Hand Function Test (경련성과 무정위성 뇌성마비 아동의 Jebsen Hand Function Test에 의한 손기능 평가)

  • Lee, Cu-Rie;Lee, Mi-Ja
    • Journal of Korean Physical Therapy Science
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    • v.3 no.2
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    • pp.981-987
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    • 1996
  • Hand function evaluations are an important element of the assessment process in physical rehabilitation settings. The purpose of this study was to investigate hand function evaluation. Subjects consisted of 20 with spastic cerebral palsy(mean age = 9.8, SD = 1.6) and 20 with athetoid cerebral palsy(mean age = 9.6, SD = 2.3). Two groups of subjects were tested twice(pretest and posttest) by the JHFT to measure evaluations of hand function. These findings suggest that on four subtests - writing, card turning, large heavy objects and Stacking Checker-the spastic cerebral palsy perform significantly faster than athetoid cerebral palsy. But there were no significant differences between the pretest and posttest in spastic and athetoid cerebral palsy. To see the statistical differences in the experimental results was done using origin V. 3.0.

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Development of a Pegging Plan Program (I) (전주 위치 설계 지원 프로그램 개발 (I) - 유기적 3차원 설계 기법을 중심으로 -)

  • Lee, Ki-Won;Cho, Yong-Hyeon;Kwon, Sam-Young;Lee, Tae-Kwon
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1991-1996
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    • 2011
  • The detail design of overhead line can be dievided into a pegging plan and MD(Mounting Diagram) process. A program can perform a MD process was already developed and used in Honam High-Speed project. In this study, a pegging plan program which can perform mast distribution automatically is developed. The system is developed based on dot net framework 4.0 and Civil3D 2012 and used spread 4.0 component for grid UI. It can not be directly used a rail horizontal alignment and long-section profile together on drawing. Therefore using Civil3D, mathematical alignment and profile of rail can be accomplished. And this program has an advantage of user friendly operation because of close relationship between the two.

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A Study on Specification of Hardware and Insulator for 400km/h Class High-speed Railway (400km/h급 고속철도용 금구 및 애자사양에 대한 고찰)

  • Cho, Ho-Ryung;Lee, Ki-Won;Kwon, Sam-Young;Cho, Young-Hyeon;Lee, Sang-Sik
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1444-1452
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    • 2011
  • At present, Kyungbu high-speed railway is operated with 300km/h, Honam high-speed railway is being constructed with 350km/h, and the development for the overhead contact line system is to be conducted for the next-generation high-speed railway with the speed of 400km/h. It is necessary to set up the specification and criteria for the key parts such as dropper, termination clamp and tension insulator for the 400km/h railway line. In this paper, the specification and the criteria for dropper, termination clamp and tension insulator has been reviewed and proposed in order to secure long-term reliability and stability under the maximum speed of 400km/h. Also, the specification, criteria and international standards for 300km/h class and 350km/h class railway line system and the international standards related with the insulators have been reviewed, compared and analysed.

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Noise Reduce in the Rotary Compressor for air-conditioner using Structural Modification (구조 변경을 통한 공조용 압축기의 소음저감)

  • Kim, Jin-Soo;Lee, Seung-Mock;Ha, Jong-Hun;Lee, Jang-Woo;Ha, Sam-Chul
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2010.10a
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    • pp.556-563
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    • 2010
  • The main noise source of the rotary compressor for air conditioner was analyzed by using the measurement of sound intensity, modal analysis and operational deflection shape(ODS) analysis. In this study, the key noise source of rotary compressor was an accumulator, and noise was sharply increased due to the accumulator's resonance which has a big contribution to the noise. To reduce the excessive noise generated from accumulator, structural modification through ODS analysis were applied. Its validation was conducted by the measurement of noise and vibration on the accumulator's surface. The total noise was significantly reduced by 4.2dB(A).

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Development of grid-tied 6.6kW bidirectional V2G OBC for EV/PHEV (EV/PHEV를 위한 V2G 계통연계 양방향 OBC 개발)

  • Lee, Byung Kwon;Kim, Sam Gyun;Kim, Seok Joon;Kim, Jong Pil;Lee, Jun Young
    • Proceedings of the KIPE Conference
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    • 2016.07a
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    • pp.387-388
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    • 2016
  • 본 논문은 V2G를 위한 Bidirectional OBC를 제안한다. 상용화 시 적시 적용 가능한 높은 역/전송 효율의 Bidirectional OBC 전력회로를 제안하고 베터리 전력을 입력원으로 분산형 전력공급 장치에서 요구하는 품질을 만족하는 전력 생산을 위해 계통연계 회로 및 제어 기술을 제안한다. Bidirectional OBC의 PFC Type은 양방향 구현을 위해 기존 MOSFET과 Diode로 구현된 구조와 달리 모두 IGBT를 이용하여 Single Phase Inverter를 구현 하였으며, IGBT 이용 시 예측되는 Reverse Recovery Loss 개선을 위하여 Hybrid Switch 구조를 제안 하였다. Bidirectional OBC의 DC/DC Type은 전송 및 역송에 따라 Buck동작과 Boost 동작이 가능하도록 설계 하였고 Secondary LC Resonant Topology 가변구조법을 사용 하였다.

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A Study on Muscle Fatigue Changes using AR Model-based Median Frequency in EMG (AR모델을 이용한 중앙주파수의 근피로 변화에 관한 연구)

  • Cho, EunSeuk;Cha, Sam;Lee, Sangsik;Lee, Kiyoung
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.2 no.1
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    • pp.17-22
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    • 2009
  • In this paper, we extract well-known parameters such as zero crossing rate(ZCR), low band energy(Band) and median frequency(MDF) from surface electromyogram (EMG), and compare to evaluate themselves as measures for fatigue. In experiments, 3 males and 3 females volunteered to participate in surface EMG recordings placed on the biceps brachii and each recording experiment continued until exhaustion.

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Fine Needle Aspiration Cytology of Acinic Cell Carcinoma of the Parotid Gland - A Case Report - (이하선의 선방세포암종의 세침흡인 세포학적 소견 - 1예 보고 -)

  • Jeon, Seok-Hoon;Paik, Seung-Sam;Lee, Won-Mi;Park, Moon-Hyang;Lee, Jung-Dal
    • The Korean Journal of Cytopathology
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    • v.7 no.2
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    • pp.225-229
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    • 1996
  • We experienced a case of well-differentiated acinic cell carcinoma of the parotid gland in a 65 year-old woman, which was correctly diagnosed preoperatively by fine needle aspiration(FNA) cytology. FNA cytology smears showed clusters or sheets of monomorphic acinic cells having reticulated or finely vacuolated basophilic or acidophilic cytoplasm. The cellular population was homogeneous or slightly polymorphic, having centrally located, round nuclei with finely reticular chromatin and inconspicuous nucleoli. Herein we report this case with its histologic features and review of literatures.

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