• 제목/요약/키워드: Ext

검색결과 293건 처리시간 0.024초

EXTENSIONS OF t-MODULES

  • Woo, Sung-Sik
    • 대한수학회논문집
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    • 제9권2호
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    • pp.361-367
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    • 1994
  • An elliptic module is an analogue of an elliptic curve over a function field [D]. The dual of an elliptic curve E is represented by Ext(E, $G_{m}$) and the Cartier dual of an affine group scheme G is represented by Hom(G, G$G_{m}$). In the category of elliptic modules the Carlitz module C plays the role of $G_{m}$. Taguchi [T] showed that a notion of duality of a finite t-module can be represented by Hom(G, C) in a suitable category. Our computation shows that the Ext-group as it stands is rather too "big" to represent a dual of an elliptic module.(omitted)

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꾸지뽕나무 근피의 항당뇨병 효과 (Hypoglycemic Effect of Cudrania tricuspidata Root Bark)

  • 박웅양;노재섭;이경순
    • 생약학회지
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    • 제32권3호통권126호
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    • pp.248-252
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    • 2001
  • The present study was undertaken to elucidate the hypoglycemic effect and inhibitory effect of Cudrania tricuspidata root bark on aldose reductase activity. C. tricuspidata MeOH ext. 1,000 mg/kg showed a significant blood glucose lowering effect on alloxan-induced hyperglycemic rats and increasing body weight. C. tricuspidata MeOH ext. showed a potent inhibitory effect on bovine lens aldose reductase.

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효모생육에 미치는 홍삼박의 영향 (Effect of Ginseng Residue Extract on Yeast Growth)

  • 김상달;도재호
    • Journal of Ginseng Research
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    • 제10권1호
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    • pp.1-10
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    • 1986
  • 인삼의 부산물중에서 박의 활용가능성을 조사하기 위하여 박의 구성성분, ext의 DPPH 환원력, 효모생육에 미치는 영향 및 효모균체내의 amino acid함량등에 미치는 영향등을 조사한 결과를 요약하면 다음과 같다. 박내에는 총당이 43~46%, 조단백이 14~15%, n-BuOH ext함량은 0.18% 였으며 alcohol박의 물ext는 alcohol ext에 비해 약 46%정도의 DPPH환원력이 남아있었으며 박ext를 첨가하고 효모를 배양시켰을 때 효모의 생육에 필요한 영양물질이나 생육을 촉진하는 물질이 박ext내에 존재하고 있다는 것을 알았으며 알콜박의 물추출물을 첨가하여 배양한 효모균체의 amino acid함량이 다른 ext를 첨가한 효모균체보다 많았다. 박에 cellulase를 0.1%, 20분간 처리로 박ext의 수율을 250%정도 증가시킬 수 있었다.

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In0.8Ga0.2As HEMT 소자에서 Output-conductance가 차단 주파수에 미치는 영향에 대한 연구 (Effect of Output-conductance on Current-gain Cut-off frequency in In0.8Ga0.2As High-Electron-mobility Transistors)

  • 노태범;김대현
    • 센서학회지
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    • 제29권5호
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    • pp.324-327
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    • 2020
  • The impact of output conductance (go) on the short-circuit current-gain cut-off frequency (fT) in In0.8Ga0.2As high-electron-mobility transistors (HEMTs) on an InP substrate was investigated. An attempted was made to extract the values of fT in a simplified small-signal model (SSM) of the HEMTs, derive an analytical formula for fT in terms of the extrinsic model parameters of the simplified SSM, which are related to the intrinsic model parameters of a general SSM, and verify its validity for devices with Lg from 260 to 25 nm. In long-channel devices, the effect of the intrinsic output conductance (goi) on fT was negligible. This was because, from the simplified SSM perspective, three model parameters, such as gm_ext, Cgs_ext and Cgd_ext, were weakly dependent on goi. However, in short-channel devices, goi was found to play a significant role in degrading fT as Lg was scaled down. The increase in goi in short-channel devices caused a considerable reduction in gm_ext and an overall increase in the total extrinsic gate capacitance, yielding a decrease in fT with goi. Finally, the results were used to infer how fT is influenced by goi in HEMTs, emphasizing that improving electrostatic integrity is also critical importance to benefit fully from scaling down Lg.

고속 저장 장치를 위한 입출력 스택 최적화 (Optimizing I/O Stack for Fast Storage Devices)

  • 한혁
    • 한국콘텐츠학회논문지
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    • 제16권5호
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    • pp.251-258
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    • 2016
  • 최근 클라우드 컴퓨팅, 사회 관계망 서비스 등의 분야에서 고속 저장 장치에 대한 수요가 크게 증가하고 있다. 성능이 우수한 고속 저장 장치가 개발되고 있지만 현재 리눅스 운영체제의 입출력 스택은 하드 디스크 드라이브를 고려해서 설계되었기 때문에 고속 저장 장치를 충분히 활용하고 있지 못하다. 이 논문에서는 고속 저장 장치의 입출력 대역폭과 입출력 지연시간을 최대로 활용할 수 있는 최적화된 입출력 스택을 제안한다. 이를 위해 기존 리눅스의 블록 입출력 계층을 새로운 인터페이스를 가지는 입출력 계층으로 대체하고 최적화한다. 제안된 입출력 계층은 기존의 하드 디스크 드라이브를 고려한 블록 계층을 우회하고 디바이스 드라이버를 최적화하여 고속 저장 장치의 성능을 최대한 이용할 수 있게 해준다. 또한, 리눅스의 ext2/ext4 파일 시스템을 제안된 입출력 계층 위에서 동작할 수 있도록 최적화하였고, 벤치마크 실험 결과를 통해서 제안하는 입출력 스택은 기존 리눅스 입출력 스택과 비교하여 1.7배 정도의 성능 향상이 있음을 확인할 수 있었다.

목감천 복원설계를 위한 비정상성을 고려한 설계홍수량의 산정 (Estimation of Design Discharge Considering Nonstationarity for River Restoration in the Mokgamcheon)

  • 이길성;오진호;박기두;성장현
    • 대한토목학회논문집
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    • 제33권4호
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    • pp.1361-1375
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    • 2013
  • Lee et al. (2011)이 제시한 목감천 유역의 하천복원 설계절차에 근거하여 수리구조물의 설계와 관련 있는 설계홍수량을 산정에 있어 비정상성을 고려하여 산정하였다. 본 연구의 목적은 목감천 유역에서 비정상성을 고려한 새로운 설계홍수량을 제안하기 위함이다. 설계홍수량 산정방법인 설계-호우단위도법과 직접 홍수빈도해석법을 적용하였으며, 각각의 방법에 사용되는 빈도분석은 NCAR (National Center for Atmospheric Research)에서 개발된 extRemes 모형을 통하여 비정상성을 고려하였다. 직접 홍수빈도해석의 방법은 유량으로부터 직접 빈도해석을 수행한다는 점에서 신뢰성이 기대되지만, 설계-호우단위도법보다 다소 과소 추정되었다. 따라서 가장 크게 산정된 설계호우-단위도법의 100년 빈도 설계홍수량을 목감천 유역의 설계홍수량으로 결정하였다.

Theoretical considerations on the giant magnetoimpedance effect in amorphous ribbons

  • Phan, Manh-Huong;Nguyen Cuong;Yu, Seong-Cho
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2003년도 하계학술연구발표회 및 한.일 공동심포지엄
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    • pp.60-61
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    • 2003
  • Theoretical considerations on a giant magneto-impedance (GMI) effect in amorphous ribbons (i.e., thin films) have been made in terms of the expressions of effective permeability and impedance derived in the frame of classical electrodynamics and ferromagnetism. The dependence of GMI effect on the external do magnetic field (H$\_$ext/) and the frequency of alternating current are simulated and discussed in the knowledge of energy conversion consisting of the current energy loss, the ferromagnetic energy consumption, and the magnetic energy storage in the film. The obtained results are summarized as follow: (a) As frequency f< 20 ㎒, the real part of effective permeability (${\mu}$′) changes slightly. The peak of the ${\mu}$′curve always locates at H$\_$ext/=H$\_$ani/ - the anisotropy field. However, the peak value of ${\mu}$′ tends to increase with increasing frequency in the frequency range of 11-20 ㎒. (b) In the frequency range, f= 21-23 ㎒, a negative peak additionally appears. Meanwhile, both the positive and negative peak values rapidly increase with increasing frequency and their peak positions shift towards a high H$\_$ext/. (c) The positive peak value of ${\mu}$′ starts to decrease at f= 29 ㎒ and its negative peak does so at about 35 ㎒. Then, both peaks keep such a tendency and their peak positions move to high H$\_$ext/, as increasing frequency. (d) The dependence of the imaginary part of effective permeability (${\mu}$") on the external dc magnetic field and the frequency of the alternating field indicates that there is only one peak involved in ${\mu}$" for the whole frequency range. (e) The impedance vs. magnetic field curves at various frequencies show that there is a critical value of frequency around f= 18-19 ㎒ where the transition between two frequency regimes occurs; the one (low frequency) in which ${\mu}$′ predominantly contributes to the GMI effect and the other (high frequency) in which ${\mu}$" determines the GMI effect.

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두경부 편평상피세포암에서 종양억제유전자들의 변이 (Alteration of Multiple Tumor Suppressor Genes in Head and Neck Squamous Cell Carcinoma)

  • 송시연;박강식;배창훈
    • 대한두경부종양학회지
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    • 제20권2호
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    • pp.147-155
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    • 2004
  • Objectives: Head and neck squamous cell carcinoma (HNSCC) is the most common head and neck malignant tumor. The molecular genetic changes involving both oncogenes and tumor suppressor genes are known to be involved in head and neck squamous cell carcinogenesis, but the roles of the known tumor suppressor genes in carcinogenesis are not fully elucidated. The objectives of this study are to demonstrate the genetic alterations including the loss of heterozygosity (LOH) , amplification, and microsatellite instability of known tumor suppressor genes in HNSCC and to evaluate the relationship between genetic alterations of tumor suppressor genes and clinicopathologic features. Materials and Methods: Genetic alterations of 10 micro satellite markers of the 6 known tumor suppressor genes (APC, EXT1, DPC4, p16, FHIT, and PTEN) were analysed by DNA-PCR in paraffin-embedded histologically confirmed HNSCC specimens. Results: The genetic alterations of tumor suppressor genes were found frequently. Among the genetic alterations, LOH was most frequently found one. LOH was found frequently in APC (45.4%), EXT1 (36.4%), DPC4 (54.5%), and p16 (50%), but not found in FHIT. Also, the author found that abnormalities of APC gene was related to cervical lymph node metastasis and recurrence and that abnormalities of EXT1 gene were coexisted with those of APC gene or DPC4 gene. But these coexistences had no correlation with clinical features. Conclusion: These results suggested that APC, EXT1, p16, and DPC4 genes might play important roles and multiple tumor suppressor genes may participate dependently or independently in the carcinogenesis of HNSCC. These results also suggested that APC gene might relate to prognosis.

인삼의 중추신경계에 대한 작용 -인삼이 흰쥐의 정서반응에 미치는 영향- (Effects of Panax Ginseng on the Central Nervous System -Effect of Panax Ginseng on the Emotional Response in Rats-)

  • 김응찬;조항영;김주명
    • 생약학회지
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    • 제2권1호
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    • pp.23-28
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    • 1971
  • This study was planned to see whether the Panax Ginseng root has any influence upon the emotionality in rats exposed to a novel open-field and induced by a grid shock. Sixty four male albino rats whose body weight ranged from 130 to 180 gm were used. They were divided into four groups, i.e., placebo control group, 5mg/kg Ginseng ext. group, 10mg/kg Ginseng ext. group, and 20mg/kg Ginseng ext. group. Sixteen rats were subjected in each group. Open-field activity was measured in a $2.20m\;{\times}\;2.20m$ open-field that was divided into 15cm squares. Four novel objects and food pellets were put with an equal distance in the open-field. Locomotion was recorded by entering the number of squares traversed for 4 min. and behaviors which were shown at the 10-sec. period were checked by a modified Jarrad and Bunnel's observation procedure. Sensitivity to the grid shock was measured in a compartment of shuttle box. 10, 20, 30, 40, 50, 60 and 70 volt ac. 2 sec., electric shock were delivered in each subject by the grid to animal's feet. Flinch, vocalization and jumping responses were rated in each shock level. The results obtained were as follows: 1.) 5mg/kg and 10mg/kg Ginseng ext. groups were tended to increase the ambulation and exploration compared with placebo control. 2.) All Ginseng extract groups were defecated significantly less often than placebo control in the open-field and shock situation. 3.) Thresholds to the electric shock were tended to elevate in all Ginseng groups. 4.) These results suggest that Ginseng extract has a stimulant action in open-field and a tranqulizing action in feared situation.

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녹각이 Galactosamine에 의해 유도된 간장해에 미치는 영향 (Effect of Old Antler Extracts on the Galactosamine-induced Hepatotoxicity in Rats)

  • 박은미;조수열;김명주
    • 한국식품영양과학회지
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    • 제22권5호
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    • pp.511-516
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    • 1993
  • 간장해에 미치는 녹각추출물(water-ext., neutral ext. 및 ether-ext.)의 효과를 구명할 목적으로 녹각을 추출 분리하여 급여하고 매주 일정시각에 galactosa-mine (400mg/kg of body weight)으로 간장해를 유도한 후 녹각추출물이 간기능 상태의 지표인 효소활성에 미치는 영향을 생화학적 측면에서 비교.고찰하였다 체중증가량, 식이섭취량 및 식이효율은 Control군에 비해 galactosamine 투여군에서 감소를 보였고, 각각의 녹각추출물 급여로 증가하는 경향을 보였다. 체중100g당 장기무게는 간장의 경우 Balactosamine 투여로 현저한 증가를 보였으나 각각의 녹각추출물 급여가 이들의 수치를 감소시켰고, 신장, 비장 및 심장에는 별다른 차이가 없었다. 혈청 aminotransferase 활성은 galactosamine투여로 인해 증가하였으며, 각각의 녹각추출물중 water-ext.가 galactosamine투여에 의한 효소 활성도의 변화를 현저히 완화시켰다. 혈청 LDH와 ALP의 활성은 galactosamine투여로 증가하였고, 녹각추출물을 병행 투여한 군에서 Water-CaIN군의 활성이 Control군 수준에 가장 가깝게 감소하였다.

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