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검색결과 931건 처리시간 0.025초

Phylogenetic Analysis of the Corticiaceae Based on Gene Sequences of Nuclear 18S Ribosomal DNAs

  • Lee, Seung-Shin;Jung, Hack-Sung
    • Journal of Microbiology
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    • 제35권4호
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    • pp.253-258
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    • 1997
  • The nuclear 18S ribosomal RNA genes of seven corticioid species were sequenced. These sequences were analyzed and compared with those of 24 other species of the order Aphyllophorales and phylogenetic trees were constructed using parsimonious methods. Phylogenetic analyses showed that two species among examined members of the Corticiaceae, Resinicium bicolor and Thanatephorus praticola, are located distantly from the remaining six species. The separation of R. bicolor seems to be kphylogenetically significant because it has very unique cystidia. The independent lineage of T. practicola suggests that it is also phylogenetically distinct because it has unusual features like the homobasidium producing secondary spores and the spetal ultrastructure of pore cap. Furthermore, Auriscalpium vulgare, Bondarzewia berkeleyi, and Heterobasidion annosum from different families of the Aphyllophorales proved to be closely related to the species of the Corticiaceae. They all have amyloid spores and grouped with Aleyrodiscus amorphus, which is a member of the Corticiaceae. The amyloidity of spores seems to be an improtant character throughout the order of the Aphyllophorales.

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Photochromism of A Styrene-Derived Polymer Having Pendant Phenoxyanthraquinones

  • Ju, Sang-Yong;Ahn, Kwang-Duk;Han, Dong-Keun;Suh, Dong-Hack;Kim, Jong-Man
    • Journal of Photoscience
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    • 제7권4호
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    • pp.131-133
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    • 2000
  • A Styrene-derived polymer having pendent phenoxyanthraquinones for photochromism was prepared by AIBN-initiated radical polymerization. Syntgesus of the monomers was straightforward and the polymer was obtained in 65% yield. Photoinduced rearrangement from the “trans” quinone forms to the “ana” quinone forms readily occurred both in solution and in film when the polymer was irradiated with UV light.

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Control of Pretilt Angles on Various Photo-Crosslinkable Polyimide based Polymers by Photodimerization

  • Hwang, Jeoung-Yeon;Seo, Dae-Shik;Suh, Dong-Hack
    • KIEE International Transactions on Electrophysics and Applications
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    • 제11C권4호
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    • pp.133-137
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    • 2001
  • In this research, we synthesized various photo-crosslinkable polyimide based polymers. The control of pretilt angles for a nematic liquid crystal (NLC) using the photodimerization method on the photopolymers was studied. A good thermal stability of the photopolymers was measured by thermogravimetric analysis (TGA) measurement until 450C. High pretilt angles of the NLC were otained by polarized UV exposure on the photopolymers containing biphenyl (BP), decyl (de), and cholesteryl (chal) groups, respectively. However, low pretilt angles of the NLC were measured by polarized UV exposure on the photopolymers containing fluorine and chalcone groups. The high NLC pretilt angles generated are attributable to the biphenyl and alkyl moieties, and the photodimerized chalocone group of the photopolymers. Additionally, good voltage-transmittance and response time characteristics were observed by UV exposure on the photopolymers.

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스위치드 릴럭턴스 전동기의 토오크 리플 저감 설계 (Design of Switched Reluctance Motor for Minimizing Torque Ripple)

  • 김윤현;최재학;이주;성하경;임태빈
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 하계학술대회 논문집 B
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    • pp.654-656
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    • 2002
  • The pole shape. turn-on angle. and turn-off angle are important design factors that largely influence Switched Reluctance Motor' s performance when designing a switched reluctance motor. These design factors must be considered simultaneously because an independent factor restricts the improvement of the switched reluctance motor' s performance. After performing the analysis using nonlinear same characteristic finite element method that contains a operating circuit, the influence upon the torque characteristics was analyzed by the pole shape and the angles. This paper presents the most suitable design value according to input conditions and various speeds. Especially.the most suitable angles were derived from the voltage equation. and an effective design range is showed from the angles.

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GUI환경을 갖는 퍼지기반 이동로봇제어 (Fuzzy Based Mobile Robot Control with GUI Environment)

  • 홍선학
    • 전자공학회논문지 IE
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    • 제43권4호
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    • pp.128-135
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    • 2006
  • 본 논문에서는 이동로봇 주변의 자기위치인식, 광학식 엔코더의 위치 데이터 및 초음파 센서의 환경 지도를 이용하여 퍼지 기반 센서융합 제어방식을 제시하였다. 영상 카메라를 이용하여 자기위치 인식성능을 높이고 초음파 센서에서 감지한 목표물의 형태, 거리와 특징을 퍼지 기반 제어기를 통하여 처리하여 이동로봇 주변의 환경지도를 만들어 자기위치 인식능력의 개선을 실험을 통하여 구현하였다.

The Aphyllophorales of the Kyeryoungsan National Park

  • Lee, Jin-Sung;Kim, Kyung-Mo;Jung, Hack-Sung
    • Mycobiology
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    • 제30권3호
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    • pp.133-138
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    • 2002
  • Through seven field surveys to the Kyeryoungsan National Park from July to December of the year 2001, 116 specimens of the Aphyllophorales were collected and taxonomically examined. All the specimens were identified to the species by observation of morphological and microscopic characters, along with old specimens from the Kyeryoungsan National Park of SFC herbarium. They amounted to 10 families, 37 genera and 52 species, and two species among them, Antrodia xantha and Ceriporia viridans, were confirmed as new to Korea and are described here as unrecorded species.

몰핀 내성 형성 억제에 있어서 인삼 사포닌의 역할 (The Role of Ginseng Total Saponins in the Inhibition of the Development of Analgesic Tolerance to Morphine)

  • Kim, Hack-Seang;Oh, Ki-Wan;Seong, Yeon-Hee
    • Journal of Ginseng Research
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    • 제15권3호
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    • pp.179-182
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    • 1991
  • The relationship between the brain monoamines and morphine tolerance was examined in ginseng total saponins treated mice. Ginseng total saponins (100 mg/kg, i.p.) did not antagonize morphine (10 mg/kg, s.c.) analgesia in mice. Daily treatment with ginseng total saponins (100 mg/kg) did not affect the brain levels of noradrenaline, dopamine and serotonin for 5 days but inhibited the development of morphine tolerance. This inhibition of the development of morphine tolerance was not attributed to the reductions of brain noradrenaline, dopamine and serotonin in mice treated with ginseng total saponins (100 mg/kg) daily. This result suggest that a newly equilibrated state of neurologic function may involve an underlying mechanism in mice treated with ginseng total saponins.

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식물을 이용한 납(Pb) 제거 (The Removal of Pb by Plants)

  • 조문철;이상화;박영식;서근학;안갑환
    • 한국환경과학회지
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    • 제10권4호
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    • pp.269-273
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    • 2001
  • Biosorption of Pb was evaluated for plants, Persicaria chinensis, Oenanthe javanica and Salvinia natnas. The adsorption equilibrium was reached in about 1hr for Pb and the highest adsorption capacity was 150mg Pb/g biomass at S.natans. Pb adsorption process showed a pseudo second order irreversible reaction. The highest initial adsorption rate was 2000mg pb/g biomass/hr at O.javanica. In spite of pH variation, Pb adsorption capacity by was selection, Pb was selectively adsorved. The selectivity of mixture solution showed the adsorption order of Pb>Cu>Cr>Cd. The Pb adsorption capacity of P. chinensis pretreated with NaOH was increased by 30% in comparison with that of no treatment.

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통합과학교육의 실태조사 (Survey on the status of integrated science education in middle school)

  • 이학동
    • 한국과학교육학회지
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    • 제6권2호
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    • pp.43-52
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    • 1986
  • It is the purpose at thus survey to get hold at problems in teaching integrated science in middle school. For this purpose, problems and suggestions were collected by questionnaire which were made out by middle school science teachers. Through the analysis of the questionnaire, it was found that the present curriculum of science education in the college of education and the in-service training program were not suitable for training middle school science teacher. Form the results of the analysis, this survey concluded that the curriculum and program mentioned above need improvement as follows. (1) science education curriculum in the college of education should be set up with two part. One is the part that middle school science teachers are trained and the other is the part that high school science teachers are trained. (2) In-service training program should be set off into two kinds. One is the program that middle school science teachers are trained and the other program that high school science teachers are trained.

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LED BLU 밝기 분할제어를 위한 다채널 PWM 설계 (Multi Channel PWM Design for Dimming Control of LED BLU)

  • 전기만;정혜동
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 심포지엄 논문집 정보 및 제어부문
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    • pp.211-212
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    • 2008
  • 정보가전기기들의 대형화 제품개발 및 생산에 따른 전력소모가 극대화 되어있는 현실에 에너지소비를 줄이기위한 많은 연구들이 진행되고 있다. 그 중 LCD TV 분야는 전체 전력소비의 약 70% 이상이 Back-light에 의해 소비되므로 효율석인 Back-light 설계에 관한 관심이 증가하고 있다. 근래에 전통적인 CCFL 방식의 flack-light 구조에서 LED Back-light으로 점차 대체되어가고 있으며, 이러한 변화는 앞으로도 지속적으로 증가하기라 예상된다. 따라서, LED Hack-light의 효율적인 선력관기는 산업적 측면에서도 매우 주요한 부분이라 할 수 있다. 본 논문은 대형 TV의 에너지효율을 높이기위한 LED Rack-light 구성에 관한 요소들을 관계를 기술하고, 특히 Back-light 밝기제거를 통한 효율적인 전력관리를 실현위한 다채널 구동제어신호 생성에 관해 설명한다.

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