• 제목/요약/키워드: T.O.F

검색결과 784건 처리시간 0.03초

1W DC-DC 컨버터를 위한 7$\times$7 mm 평면 인덕터의 제조 (Fabrication of the 7$\times$7 mm Planar Inductor for 1W DC-DC Converter)

  • 배석;류성룡;김충식;남승의;김형준;민복기;송재성
    • 한국자기학회지
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    • 제11권5호
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    • pp.222-225
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    • 2001
  • 1W급의 DC-DC converter에 탑재하기 위해 FeTaN 연자성 자성박막을 이용한 박막형 인덕터를 제조하여 특성을 평가하였다. 자심부분은 2$\mu\textrm{m}$ 두게의 F $e_{78.81}$T $a_{8.47}$ $N_{12.71}$ 연자성 박막을 사용하였으며 코일부분은 100$\mu\textrm{m}$ 두게의 Cu를 사진공정과 전기도금공정을 이용하여 제조하였다. 제조된 박막 인덕터의 디자인은 상호인덕턴스를 효율적으로 증가시킬 수 있는 double rectangular spiral형태였으며 측정된 특성은 DC-DC converter의 작동주파수인 1 MHz에서 인덕턴스 980nH, 저항 1.7 $\Omega$Q 값은 3.55였다.다.

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구륜 이동 로봇의 주행오차 감소를 위한 기구학적 보정과 속도궤적의 설계 (Kinematic Correction and a Design for Velocity Trajectory to Reduce an Odometer Error of Wheeled-Mobile Robots)

  • 김종수;문종우;박종국
    • 전자공학회논문지SC
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    • 제37권3호
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    • pp.9-18
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    • 2000
  • 본 논문에서는 구륜 이동 로봇의 기구학적 불완전성에 기인한 주행오차를 감소시키기 위한 방법을 제안한다. 별도의 표식장치 없이 엔코더만을 이용하여 구륜 반경과 차축변위를 보정한다. 또한 모터제어기의 가속해상도의 제약에 기인한 방향각 오차를 보상하기 위한 속도궤적을 제안한다. 제안된 속도궤적에 따라, 2개의 구동구륜 중 임의의 한 구륜의 속도는 주행거리에 따라 가변된다. 완전한 기구학적 보정이 이루어져도, 구륜 이동 로봇은 완전한 직선 주행을 할 수 없으며, 이러한 현상은 모터 제어기의 가속 해상도의 제약에 기인함을 보인다. 본 논문에서 제안된 방법의 유효성을 입증하기 위해 2 자유도 구륜 이동 로봇에 대해 실험을 수행하고 그 결과를 제시한다.

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암 환자 가족의 호스피스 요구도 (The Need for Hospice Care in Families of Patients with Cancer)

  • 김신정;김영순;강경아
    • 지역사회간호학회지
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    • 제15권4호
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    • pp.639-647
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    • 2004
  • Purpose: The purpose of this study was to analyze the need for hospice care programs in families of patients with cancer. Method: The study surveyed 98 families who were taking care of patients with cancer. This survey was conducted from August 2004 to October 2004 at two general hospitals in Seoul. The data were collected through a self-reporting questionnaire of 22 items. The items were classified into five areas by factor analysis to identify the construct validity. The reliability of the tool was established by Cronbach's alpha as .93 and the data collected were analyzed by descriptive statistics, t-test and ANOVA. Results: 1) The degree of need for hospice care of the subjects showed a high average of $3.26({\pm}3.7$). The need for 'emotional care of patients showed the highest mean' (M=3.47), 'management of terminal physical symptoms' (M=3.34), 'control of secondary physical problems' (M =3.26), 'acceptance of the family's difficulty' (M=3.12), 'spiritual care for preparing for death' (M=2.96), respectively. 2) With respect to the demographic characteristics of the subjects, there were statistically significant differences in hospice care needs, according to the onset of diagnosis (F=3.110, p=.030). Conclusion: Hospice care must be provided considering the needs of families of patients with cancer. In this sense, this country's needs as well as hospice nurses' higher concern and support for hospice care of patients require further education and program development to meet the current demands.

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The First Photometric Study of the Neglected Contact Binary GX Aurigae

  • Park, Jang-Ho;Lee, Jae Woo;Kim, Chun-Hwey
    • 천문학회보
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    • 제41권1호
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    • pp.41.3-42
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    • 2016
  • New CCD photometric observations of GX Aur have been made between 2004 and 2015. Our light curves are the first ever compiled and display the variable O'Connell effect. The light variations are satisfactorily modeled by including time-varying cool-spots on the component stars. Our light curve synthesis indicates that the eclipsing pair is an A-type contact binary with parameters of i = 81.1 deg, ${\Delta}T=36K$, q = 0.950 and f = 46%. Including our 25 timing measurements, a total of 83 times of minimum light spanning about 66 yr were used for a period study. It was found that the orbital period of GX Aur has varied due to two periodic oscillations superposed on an upward-opening parabolic variation. The long-term period increase rate is deduced as $+9.636{\times}10^{-10}d\;yr^{-1}$, which can be produced as a mass transfer from the secondary star to the primary at a rate of $3.136{\times}10^{-6}M_{\odot}\;yr^{-1}$, among the largest rates for contact systems. The periods and semi-amplitudes of the two periodic variations are about $P_3=8.7yr$ and $P_4=21.2yr$, and $K_3=0.011d$ and $K_4=0.017d$, respectively. The most reasonable explanation for both cycles is a pair of light-travel-time effects driven by the possible existence of an unseen third and fourth components with projected masses of $M_3=0.91M_{\odot}$ and $M_4=1.09M_{\odot}$ in eccentric orbits of $e_3=0.13$ and $e_4=0.73$. Because no third light was detected in the light curve synthesis, each circumbinary object could be a compact star or a binary itself.

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The Riparian Vegetation of Close-to-Nature River${\cdot}$Streams in Korea

  • Kim, Chul;Yang, Hyo-Sik
    • 한국자원식물학회지
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    • 제20권3호
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    • pp.234-241
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    • 2007
  • The present study was undertaken to classify and describe the riparian vegetation of the 6 river${\cdot}$stream of Korea Peninsula. As a result the vegetation was divided into nineteen communities. The vegetation units obtained in the present study were as follow: A: Salix koreensis community, B: Salix gracilistyla community, C: Robinia pseudo-acacia community, D: Amorpha fluticosa community, E: Brousonnetia papyrifera community, F: Phyllostachys bambusoides community, G: Rubus corchorifolius community, H: Phramities japonica community, I: Phramites communis community, J: Miscanthus sacchariflorus community, K: Miscanthus sinesis var. purpurascens community, L: Artemisia princeps var. orientalis community, M: Humulus japonicus community, N: Zoysia japonica community, O: Inperata cylindrica var. koenigii community, P: Agropyron tsukushiense var. transiens community, Q: Juncos effusus var. decipiens community, R: Rumex crispus community, S: Persicaria hydropiper community. The vegetation characteristics of riversides was recovered in the surveyed results according to river${\cdot}$stream basin, in other words, 10 communities in the upper river${\cdot}$stream riparian, 15 communities in the middle river${\cdot}$stream riparian, 10 communities in the down river${\cdot}$stream riparian. The Phragmites japonica community in the upper and Phragmites communis community in the down was analyzed by common community of the 6 river${\cdot}$stream riparian, respectively, but none in the middle. The standing profile of vegetation across 6 river${\cdot}$stream was seen stepwise Phragmites japonica community, Salix gracilistyla community, Miscanthus sinensis var. purpurascens community, shrub community by natural waterway in the upper, Salix gracilistyla community, Phragmites communis community, Rumex crispus community, Miscanthus sacchariflorus community, Humulus japonicus community in the middle, Phragmites communis community in the down. The differences of distributional featurs of vegetation emerged from the riparian of the 6 river${\cdot}$stream, but don't from the 6 river${\cdot}$stream.

콜레스테릴 펜타노에이트의 결정 및 분자구조 (The Crystal and Molecular Structure of Cholesteryl Pentanoate)

  • 안중태;박영자
    • 대한화학회지
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    • 제34권1호
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    • pp.1-9
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    • 1990
  • 콜레스테릴 펜타노에이트의 결정은 사방정계에 속하며 a = 21.930(3), b = 21.404(3), c = 6.419(5) $\AA$이며 단위세포안에 4개의 분자가 있다. 1.0 $\sigma$ (I)보다 큰 강도를 가진 1,520개의 회절 반점에 대한 최종 R값은 0.086이다. 직접법에 의하여 구조를 풀었으며 C-H 결합길이와 메틸기는 길이를 고정시켜 이상적인 기하학적 구조에 맞춰 cascade diagonal least-squares refinement에 의하여 정밀화하였다. 테트라시클로 고리는 정상적인 구조를 하고 있으나 에스텔과 곁사슬 부분은 열적효과에 의하여 정상적인 길이와 각도의 값에서 변화를 보이고 있으며 에스텔의 끝부분이 굽어져 치켜들고 있다. 분자는 비결합성 van der waals힘에 의하여 서로 쌓여져 있고 가장 짧은 분자간 거리는 3.529 $\AA$이다.

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한약재 보관중 발생하는 해충류 (Insect Pests Occurring in Storage Medicinal Plants)

  • 조형찬
    • 한국약용작물학회지
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    • 제15권6호
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    • pp.417-428
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    • 2007
  • 국내 유통 중인 한약재 대부분을 수입에 의존하고 있으나, 관리시설이 빈약하여 해충들에게 쉽게 노출될 수 있는 환경에 놓여 있다. 이 연구는 총 67과 134속 158종의 저장 한약재들을 대상으로 이들에서 발생하고 있는 저장물해충들을 조사하였다. 그 결과, Cassia 속의 육계, Juniperus 속의 자단향 그리고 Artemisia 속 애엽을 비롯한 44종의 한약재들에서는 곤충의 발생을 확인할 수 없었다. 한약재들에서 나타난 해충들의 발생빈도는 쌀머리대장 (A. advena) 12.3%, 권연벌레 (L. serricorne) 11.5%, 머리대장가는납작벌레 (O. surinamensis) 10.3%, 거짓쌀도둑거저리 (T. castaneum) 9.4%, 인삼벌레 (S. paniceum) 8.4% 그리고 화랑곡나방 (P. interpunctella) 7.9% 순이었다. 또한 이들 곤충들은 저장 중인 한약재들 중에서도 뿌리 또는 뿌리줄기 형태의 한약재들을 가장 선호한 것으로 보였다. 이 연구는 천연물 연구자들에게 곤충들이 발생하지 않았던 한약재들에 대한 기본 정보를 제공해줌으로써 향후 이들이 살충활성 또는 훈증활성물질을 탐색하는데 있어 이들 한약재들을 우선적으로 검토할 수 있는 유용한 자료로서 활용될 수 있을 것이다.

GaMnAs의 Be 병행 도핑에 의한 자기 수송 특성 연구 (Magnetotransport of Be-doped GaMnAs)

  • 임완순;윤대식;우부성;고존서;김도진;임영언;김효진;김창수;김종오
    • 한국재료학회지
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    • 제15권1호
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    • pp.73-77
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    • 2005
  • Motivated by the enhanced magnetic properties of Mg-codoped GaMnN ferromagnetic semiconductors, Be-codoped GaMnAs films were grown via molecular beam epitaxy with varying Mn flux at a fixed Be flux. The structural, electrical, and magnetic properties were investigated. GaAs:(Mn,Be) films showed metallic behavior while GaAs:Mn films showed semiconducting behavior as determined by the temperature dependent resistivity measurements. The Hall-effect measurements with varying magnetic field showed clear anomalous Hall effect up to room temperature proving ferromagnetism and magnetotransport in the GaAs:(Mn,Be) films. Planar Hall resistance measurement also confirmed the properties. The dramatic enhancement of the Curie temperature in GaMnAs system was attributed to Be codoping in the GaMnAs films as well as MnAs precipitation.

소아 성장의 침구 및 수기요법에 대한 중의학 임상 연구 고찰 (Review of Clinical Researches in Chinese Medical Journal for Acupuncture, Moxibustion, and Manual Therapy of Pediatric Growth)

  • 박슬기;박소현;이선행;이진용
    • 대한한방소아과학회지
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    • 제33권1호
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    • pp.58-77
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    • 2019
  • Objectives The purpose of this study is to investigate clinical studies on the effect of acupuncture, moxibustion, and manual therapy in pediatric growth by analyzing randomized controlled trials conducted in China. Methods We searched the clinical studies from the China Academic Journal (CAJ) in China National Knowledge Infrastructure (CNKI) by specific key words and criteria. Selected 31 clinical studies were collected and analyzed. Results Total of 31 randomized controlled trials were selected and analyzed. In most of the studies, the effectiveness of acupuncture, moxibustion, and manual therapy on growth was significantly high. The most commonly used therapies were massage. The most commonly used massage methods were pinching spine (捏脊), pressing and kneading $Z\acute{u}s\bar{a}nl\check{i}$ (按?足三里), supplementing $P\acute{i}j\bar{i}ng$ (補脾經), supplementing $Sh\grave{e}nj\bar{i}ng$ (補腎經), rubbing Abdomen (摩腹), pushing $Y\check{o}ngqu\acute{a}n$ (推涌泉), supplementing $F\grave{e}ij\bar{i}ng$ (補肺經), kneading $T\grave{a}iy\acute{a}ng$ (?太陽), and kneading $Sh\acute{e}nqu\grave{e}$ (?神闕) etc. Conclusions Based on the results of the clinical studies from China, acupuncture, moxibustion, and manual therapy can be a valuable option for pediatric growth.

Evaluation of ECCD power requirement for neoclassical tearing modes suppression in the CFETR hybrid scenario

  • L.H. He;P.W. Zheng ;T. Yu
    • Nuclear Engineering and Technology
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    • 제55권8호
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    • pp.2941-2951
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    • 2023
  • The optimal minimum ECCD power is evaluated numerically for completely suppressing the 3/2 and 2/1 NTMs in the CFETR hybrid scenario. For two typical frequencies of ECCD sources launching from two upper launcher (UL) ports, fec = 210 GHz and 240 GHz with O1-mode, UL1: (Ri, Zi) = (8.47, 5.7) m and UL2: (Ri, Zi) = (8.2, 4.5) m, higher frequency of ECCD source launching from the UL2 port is better than that low frequency counterpart from the UL1 port. Using 240 GHz ECCD source launching from the UL2 port, the minimum power required to fully suppress the two NTMs with precise ECCD alignment is 12.4 MW and 16.7 MW, respectively. When good alignment cannot be achieved, the results suggest that the misalignment should not exceed 0.02α, preferably 0.015α, corresponding to 4.4 cm and 3.3 cm. Considering engineering difficulty of high-frequency gyrotron sources, the optimal minimum ECCD power with the 210 GHz source launching from the UL2 port is 17.9 MW and 20.6 MW for completely suppressing the 3/2 and 2/1 NTMs, respectively. In view of this, it is a good choice to select the 210 GHz ECCD source launching from the UL2 port in the short and medium term.