• 제목/요약/키워드: C-line

검색결과 4,692건 처리시간 0.033초

한전 배전 계통을 이용한 2단장주의 불평형 부하에 따른 중성선 전류의 영향에 관한 연구 (A Study on the Effects of Neutral Current by Unbalanced Load in Two Step Type Pole using KEPCO's Distribution System)

  • 박건우;서훈철;김철환;정창수;유연표;임용훈;이원정
    • 전기학회논문지
    • /
    • 제56권3호
    • /
    • pp.465-471
    • /
    • 2007
  • The one step type pole and two step type pole are used in KEPCO's distribution system. The neutral current increases in three-phase four-wire distribution system due to unbalanced load. Usually, power line and communication line are installed at contiguity by effect of topography in Korea. To this end, the damages such as electrostatic induction, electromagnetic induction and harmonic induction generated by induced voltage and current are occured in power line and communication line. This paper calculates the neutral current in KEPCO's distribution system using EMTP by composing various simulated conditions. Also, these results are verified by vector analysis.

Concentration Dependences of the Isotropic Raman Line Widths of Acetonitrile and Acetonitrile-d$_3$ in Carbon Tetrachloride

  • Choe, Joong-Chul;Kim, Myung-Soo
    • Bulletin of the Korean Chemical Society
    • /
    • 제7권1호
    • /
    • pp.63-66
    • /
    • 1986
  • Concentration dependences of the isotropic Raman line widths for the $ {\nu}_1$ (C-H and C-D) and the ${\nu}_2\;(C{\equiv}N)$ modes for $CH_3CN$ and $CD_3CN\;in\;CCl_4$ solutions have been investigated. For the ${\nu}_1$ modes, the dephasing seems to be a good description for the isotropic line broadening in $CCl_4$ solution even though the concentration fluctuation can reproduce the experimental results also. For the ${\nu}_2$ modes, the concentration fluctuation was the dominant mechanism for the concentration-dependent line broadening.

Cytotoxic Activities of Green and Brown Seaweeds Collected from Jeju Island against Four Tumor Cell Lines

  • Kim, Kil-Nam;Lee, Ki-Wan;Song, Choon-Bok;Jeon, You-Jin
    • Preventive Nutrition and Food Science
    • /
    • 제11권1호
    • /
    • pp.17-24
    • /
    • 2006
  • Methanolic and aqueous extracts from 37 seaweed species (10 green and 27 brown seaweeds) collected from Jeju Island coast were prepared at high ($70^{\circ}C$) and room ($20^{\circ}C$) temperatures and examined for cytotoxic activity against 4 tumor cell lines: U937 (human monoblastoid leukemia cell line), HL60 (human promyelocytic leukemia cell line), HeLa (woman cervical carcinoma cell line) and CT26 (mouse colon carcinoma line). Both MeOH extracts of Desmarestia tabacoides and Dictyota dichotoma possessed strong cytotoxic activities against all the tumor cell lines tested, but the aqueous extract exhibited no activity. On the other hand Ecklonia cava showed strong cytotoxic activities for the $20^{\circ}C$ aqueous extract against the three tumor cells except HeLa cell. Sagassum coreanum and Sagassum siliquastrum $20^{\circ}C$ aqueous extracts also exhibited strong cytotoxic activities against U937, HL60, HeLa cells. Even though green seaweeds showed less activity than brown seaweeds, $20^{\circ}C$ aqueous extracts of Codium contractum and Codium fragile exhibited strong cytotoxic activities against HL60 or CT26 cells, respectively.

FAR-INFRARED [C II] EMISSION FROM THE CENTRAL REGIONS OF SPIRAL GALAXIES

  • MOCHIZUKI KENJI
    • 천문학회지
    • /
    • 제37권4호
    • /
    • pp.193-197
    • /
    • 2004
  • Anomalies in the far-infrared [C II] 158 ${\mu}m$ line emission observed in the central one-kiloparsec regions of spiral galaxies are reviewed. Low far-infrared intensity ratios of the [C II] line to the continuum were observed in the center of the Milky Way, because the heating ratio of the gas to the dust is reduced by the soft interstellar radiation field due to late-type stars in the Galactic bulge. In contrast, such low line-to-continuum ratios were not obtained in the center of the nearby spiral M31, in spite of its bright bulge. A comparison with numerical simulations showed that a typical column density of the neutral interstellar medium between illuminating sources at $hv {\~} 1 eV $ is $N_H {\le}10^{21}\;cm^{-2}$ in the region; the medium is translucent for photons sufficiently energetic to heat the grains but not sufficiently energetic to heat the gas. This interpretation is consistent with the combination of the extremely high [C Il]/CO J = 1-0 line intensity ratios and the low recent star-forming activity in the region; the neutral interstellar medium is not sufficiently opaque to protect the species even against the moderately intense incident UV radiation. The above results were unexpected from classical views of the [C II] emission, which was generally considered to trace intense interstellar UV radiation enhanced by active star formation.

50kg/mm$^{2}$급 고장력 강판의 선상가열에 따른 판상변형과 재질변화 (Distortion and transformation of high tensile strength steel plate of 50kg/mm$^{2}$grade due to line heating)

  • 정남호;최병길;박종은
    • Journal of Welding and Joining
    • /
    • 제3권1호
    • /
    • pp.11-21
    • /
    • 1985
  • The line heating is a thermoplastic working technique which is used in bending work of steel plate and in correcting the distortion of welded structure. This method is considerably effective when the water-cooling is followed. In this study, an investigation was accomplished to find the effects on the change of material properties when the line heating was applied on the high tensile steel plate of 50kg/mm^2$ grade. Some steel plates were heated to various temperatures and then cooled with water or in the air. In this study, the author measured the angular distortion continuously during line heating to find out the relation between the bending efficiency and heating or water-cooling temperature. Furthermore, its material properties were examined by the V-notch Charpy impact test, the microscope observation and the Vickers hardness test. As results, the followings were clarified. (1) The amount of angular distortion increases as the heating temperature or the water-cooling temperature rises. (2) When the steel plate is heated between 700.deg. C and 900.deg. C, and then is water-cooled over 700.deg. C, some brittle structure is observed. But if the temperature of water-cooling is below 700.deg. C, no brittle one is found. (3) When the steel plate is heated over 800.deg. C and is cooled in the air, there is no unfavrable effect.

  • PDF

A Sweep-Line Algorithm and Its Application to Spiral Pocketing

  • EL-Midany, Tawfik T.;Elkeran, Ahmed;Tawfik, Hamdy
    • International Journal of CAD/CAM
    • /
    • 제2권1호
    • /
    • pp.23-28
    • /
    • 2002
  • This paper presents an efficient line-offset algorithm for general polygonal shapes with islands. A developed sweep-line algorithm (SL) is introduced to find all self-intersection points accurately and quickly. The previous work is limited to handle polygons that having no line-segments in parallel to sweep-line directions. The proposed algorithm has been implemented in Visual C++ and applied to offset point sequence curves, which contain several islands.

계란형질들과 난황 콜레스테롤 수준에 대한 닭의 계통과 키토산의 첨가 수준간의 상호작용 효과 (Line-by-Level of Chitosan Interaction on Egg Traits and Yolk Cholesterol Level in Laying Hens)

  • 석윤오;서형철
    • 한국가금학회지
    • /
    • 제29권2호
    • /
    • pp.81-88
    • /
    • 2002
  • 백색란 계통인 Hy-line W-98과 갈색란 계통인 Hy-line Brown을 이용하여 주요 계란의 형질들과 난황 콜레스테롤 수준에 닭의 계통과 키토산의 첨가수준간의 상호작용 관계를 구명하고자 시험한 결과 난중에 대해서는 키토산의 첨가가 두 계통간에 서로 대조적인 경향을 나타내어 Hy-line Brown 계통에서만 키토산의 첨가가 난중의 증가에 기여했다. 평균 난백의 비율은 Hy-line Brown종에서는 키토산 첨가 그룹들과 대조구간에 유의한 타이를 나타내지 못했다. Hy-line W-98종에 있어서 C $H_{60}$구는 대조구에 비해서 평균난백의 비율이 유의하게(P<0.05) 낮았으나, C $H_{30}$구는 대조구와 별 차이가 없었다. 한편 평균 난황의 비율은 평균 난백의 비율에서 나타났던 경향과 반대로 Hy-line W-98종은 C $H_{60}$구가 대조구에 비해서, 그리고 Hy-line Brown은 C $H_{30}$구가 대조구에 비해서 유의하게(P<0.05)난황의 비율이 더 높게 나타났다. 평균 난각의 비율에 대해서는 두 계통 모두 키토산의 첨가로 난각의 질을 향상시키지는 못했다. 그러나 평균 난황콜레스테롤의 수준에 있어서는 두 계통 모두키토산 첨가구들이 대조구에 비해서 난황 Ig당 0.46mg~2.80mg정도가 더 낮은 것으로 나타났고, 특별히 Hy-line W-98종의 C $H_{60}$구는 대조구에 비해서 난황콜레스테롤의 수준은 유의한(P<0.05) 차이를 나타냈다. 그리고 자의 계통과 키토산 첨가수준간 상호작용 효과에 관한 유의성 분석결과 4개 시험 주령 전테 평균 난중(P<0.01), 난중에 대한 난백의 비율(P<0.05), 난황의 비율(P<0.01) 및 난각의 비율(P<0.05)은 모두 유의한 결과를 나타냈다. 한편, 전체 평균 난황콜레스테롤 수준에 대해서는 이들 두 요인간에 유의한 상호작용 효과를 나타내지 않았으나, 시험주령별 유의성 분석결과에서는 4개 시험주령 중 3개 시험주령에서 자의 계통과 키토산 첨가수준간에 유의한 상호작용 효과(P<0.01)를 나타냈다.

Methylenetetrahydrofolate Reductase Gene Germ-Line C677T and A1298C SNPs are Associated with Colorectal Cancer Risk in the Turkish Population

  • Ozen, Filiz;Sen, Metin;Ozdemir, Ozturk
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권18호
    • /
    • pp.7731-7735
    • /
    • 2014
  • Colorectal cancer (CRC) is the third most common cause of death due to cancer in the worldwide and the incidence is also increasing in Turkey. Our present aim was to investigate any association between germ-line methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and CRC risk in Turkey. A total of 86 CRC cases and 212 control individuals of the same ethnicity were included in the current study. Peripheral blood-DNA samples were used for genotyping by StripAssay technique, based on the reverse-hybridization principle and real-time PCR methods. Results were compared in Pearson Chi-square and multiple logistic regression models. The MTHFR 677TT (homozygous) genotype was found in 20.9% and the T allele frequency 4.2-fold increased in CRC when compared with the control group.The second SNP MTHFR 1298CC (homozygous) genotype was found in 14.0% and the C allele frequency 1.4-fold elevated in the CRC group. The current data suggest strong associations between both SNPs of germ-line MTHFR 677 C>T and 1298 A>C genotypes and CRC susceptibility in the Turkish population. Now the results need to be confirmed with a larger sample size.

양방향 군집 알고리즘을 적용한 교차혼합 U자형 조립라인 균형문제 (Balancing Problem of Cross-over U-shaped Assembly Line Using Bi-directional Clustering Algorithm)

  • 이상운
    • 한국인터넷방송통신학회논문지
    • /
    • 제22권2호
    • /
    • pp.89-96
    • /
    • 2022
  • 본 논문은 NP-난제로 알려진 단일모델 교차혼합 조립라인 균형문제에 대해 휴리스틱 알고리즘을 제안하였다. 조립라인 균형문제는 주로 메타휴리스틱 방법들을 적용하고 있는 추세로 다항시간의 정확한 해를 찾는 알고리즘이 제안되지 않고 있어 실무에 적용하기가 매우 어렵다. 제안된 알고리즘은 주어진 총 조립시간 W와 순환시간 c에 대해 m* = ⌈W/c⌉의 최소 작업자수와 c* = ⌈W/m*⌉의 목표 순환시간을 구하고, i=1,2,…,m* 개의 작업대에 Ti=c* ±α≤ c가 되도록 양방향의 공정들을 배정하는 양방향 군집방법을 적용하였다. 7개의 다양한 실험 데이터에 적용한 결과 제안된 양방향 군집 알고리즘은 타 방법들과 동일한 성능을 보였다.

구형 도파관으로 차폐된 코플래너 도파관 해석 (Analysis of the Coplanar Waveguide Shielded by Rectangular Waveguide)

  • 황정섭;이상설
    • 전자공학회논문지A
    • /
    • 제30A권7호
    • /
    • pp.19-25
    • /
    • 1993
  • By using the point matching method, the coplanar waveguide shielded by the rectangular waveguide has been analyzed. The particular potential solution of C.P.W has been obtained from the boundary condition by using the point matching method. The line capacitance has been obtained from the total charge of the center conductor per length. The effective dielectric constant and the line impedance have been obtained from the line capacitance of C.P.W.

  • PDF