• 제목/요약/키워드: $\Omega$ Type

검색결과 731건 처리시간 0.024초

An Estimation of Springing Responses for Recent Ships

  • Park, In-Kyu;Kim, Jong-Jin
    • 한국해양공학회지
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    • 제19권6호통권67호
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    • pp.58-63
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    • 2005
  • The estimation of springing responses for recent ships is carried out, and application to a ship design is described. To this aim, springing effects on hull girder were re-evaluated, including non-linear wave excitations and torsional vibrations of the hull. The Timoshenko beam model was used to calculate stress distribution on the hull girder, using the superposition method. The quadratic strip method was employed to calculate the hydrodynamic forces and moments on the hull. In order to remove the irregular frequencies, we adopted 'rigid lid' on the hull free surface level, and addedasymptotic interpolation along the high frequency range. Several applications were carried out on the following existing ships: The Bishop and Price's container ship, S-175 container ship, large container, VLCC, and ore carrier. One of them is compared with the ship measurement result, while another with that of the model test. The comparison between the analytical solution and the numerical solution for a homogeneous beam-type artificial ship shows good agreement. It is found that Most springing energy comesfrom high frequency waves for the ships having low natural frequency and North Atlantic route etc. Therefore, the high frequency tail of the wave spectrum should be increased by $\omega$$\^{-3}$ instead of $\omega$$\^{-4}$ or $\omega$$\^{-5}$ for the springing calculation.

Increase in Linolenate Contents by Expression of the fad3 Gene in Transgenic Tobacco Plants

  • Kang, Young-Hwi;Min, Bok-Kee;Park, Hee-Sung;Lim, Kyung-Jun;Huh, Tae-Lin;Lee, Se-Yong
    • BMB Reports
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    • 제29권4호
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    • pp.308-313
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    • 1996
  • An 1.4 kb of the fad3 cDNA encoding microsomal linoleic acid desaturase catalyzing the conversion of linoleic acid (18:2, ${\omega}-6$) to linolenic acid (18:2, ${\omega}-3$) was introduced into tobacco plants by the Agrobacterium-mediated plant transformation, Among the transgenic tobacco plants conferring kanamycin resistance, five transformants showing increment in unsaturated fatty acid contents were selected and further analyzed for the transgenecity, In genomic Southern blot analyses, copy numbers of the integrated fad3 DNA in chromosomal DNA of the five transgenic tobacco plants were varied among the transgenic lines. By Northern blot analyses, the abundancy of the fad3 mRNA transcript directed by Cauliflower Mosaic Virus 35S promoter was consistent with the relative copy number of the fad3 DNA integrated in the chromosome of transgenic tobacco plants. When compared with the wild type, accumulation of linolenic acid in transgenic tobacco roots was elevated 3.7- to 4.7-fold showing a corresponding decrease in the linoleic acid contents; however, slight increments for linolenic acid were noticed in transgenic leaf tissues. These results indicated that the elevated level of fad3 expression is achieved in transgenic tobacco plants.

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An Estimation of Springing Responses for Recent Ships

  • Park In-Kyu;Lee Soo-Mok;Jung Jong-Jin;Yoon Myung-Cheol
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2004년도 학술대회지
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    • pp.173-178
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    • 2004
  • The estimation of springing responses for recent ships are carried out and application to a ship design are described. To this aim, springing effects on hull girder were re-evaluated including non-linear wave excitations and torsional vibrations of the hull. The Timoshenko beam model was used to calculate stress distribution on the hull girder by the superposition method. The strip method was employed to calculate the hydrodynamic forces and moments on the hull. In order to remove the irregular frequencies, we adopted 'rigid lid' on the hull free surface level and added asymptotic interpolation along the high frequency range. Several applications to the existing ships were carried out. They are Bishop and Price's container ship, S-175 container ship, large container, VLCC and ore carrier. One of them is compared with ship measurement result while another with that of model test. Comparison between analytical solution and numerical one for homogeneous beam type artificial ship shows good agreement. It is found that most springing energy came from high frequency waves for the ships having low natural frequency and North Atlantic route etc. Therefore, the high frequency tail of the wave spectrum should be increased by $\omega^{-3}\;instead\;of\;\omega^{-4}\;or\;\omega^{-5}$ for springing calculation.

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A STUDY ON CARLESON MEASURES WITH RESPECT TO GENERAL APPROACH REGIONS

  • Suh, Choon-Serk
    • 대한수학회논문집
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    • 제17권1호
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    • pp.31-36
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    • 2002
  • In this paper we first introduce a space of homogeneous type X, and we consider a kind of generalized upper half-space X $\times$ (0, $\infty$). We are mainly concerned with some inequalities in terms of Carleson measures or in terms of certain maximal operators with respect to general approach regions in X $\times$ (0, $\infty$). The main tool of the proof is the Whitney decomposition.

A DECOMPOSITION INTO ATOMS OF TENT SPACES ASSOCIATED WITH GENERAL APPROACH REGIONS

  • Suh, Choon-Serk
    • 충청수학회지
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    • 제23권3호
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    • pp.453-461
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    • 2010
  • We first introduce a space of homogeneous type X, and develop the theory of the tent spaces on the generalized upper half-space $X{\times}(0,{\infty})$. The goal of this paper is to study that every element of the tent spaces $T_{\Omega}^{p}$($X{\times}(0,{\infty})$, $0, can be decomposed into elementary particles which are called "atoms."

부신수질 Chromaffin 세포의 $Ca^{2+}$ 통로유형이 카테콜아민 분비에 미치는 영향에 관한 정량적 연구 (Contribution of Different Types of $Ca^{2+}$ channels to Catecholamine Secretion in Rat Adrenal Chromaffin Cells)

  • Goo, Yang-Soak;Roh, Jin-A;Lee, Jung-Hwa;Chao, Eun-Jong
    • 한국의학물리학회지:의학물리
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    • 제8권1호
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    • pp.3-15
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    • 1997
  • Adrenal chromaffin cells secrete catecholamine in response to acetylcholine. The secretory response has absolute requirement for extracellular calcium, indication that $Ca^{2+}$ influx through voltage dependent $Ca^{2+}$ channel (VDCC) is the primary trigger of the secretion cascade. Although the existence of various types of $Ca^{2+}$ channels has been explored using patch clamp technique in adrenal chromaffin cells, the contribution of different types of $Ca^{2+}$ channels to catecholamine secretion remains to be established. To investigate the quantative contribution of different types of $Ca^{2+}$ channels to cate-cholamine secretion, $Ca^{2+}$ current($I_{Ca}$) and the resultant membrane capacitance increment($\Delta{C}_{m}$) were simultaneoulsy measured. Software based phasor detector technique was used to monitor $\Delta{C}_{m}$. After blockade of L type VDCC with nicardipine (1$\mu$M), $I_{ca}$ was blocked to 43.85$\pm$6.72%(mean$\pm$SEM) of control and the resultant ㅿC$_{m}$ was reduced ot 30.10$\pm$16.44% of control. In the presence of nicardipine and $\omega$-conotoxin in GVIA(l$\mu$M), an N type VDCC antagonist, $I_{ca}$ was blocked to 11.62$\pm$2.96% of control and the resultant $\Delta{C}_{m}$ was reduced to 26.13$\pm$8.25% of control. Finally, in the presence of L, N, and P type $Ca^{2\pm}$ channel antagonists(nicardipine, $\omega$-Conotoxin GVIA, and $\omega$-agatoxin IVA, respectively), $I_{ca}$ and resultant $\Delta{C}_{m}$ were almost completely blocked. From the observation of parallel effects of $Ca^{2+}$ channel antagonists on $I_{ca}$ and $\Delta{C}_{m}$, it was concluded that L, N, and also P type $Ca^{2+}$ channels served and $Ca^{2+}$ source for exocytosis and no difference was observed in their efficiency to evoke exocytosis amost L, N, and P type $Ca^{2+}$ channels.

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질소 분극면을 갖는 N형 질화물반도체의 접촉저항 감소를 위한 산소 플라즈마 효과에 관한 연구 (Study of Oxygen Plasma Effects to Reduce the Contact Resistance of n-type GaN with Nitrogen Polarity)

  • 남태양;김동호;이완호;김수진;이병규;김태근;조영창;최연식
    • 한국진공학회지
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    • 제19권1호
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    • pp.10-13
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    • 2010
  • 본 논문은 N-face n-type GaN 표면에 산소 플라즈마 처리에 의해서 오믹전극과 접촉 저항을 낮추기 위한 연구를 하였다. 120초 산소 플라즈마 처리후 Ti (50 nm) / Al (35 nm)을 증착한 결과 오믹 전극을 구현하였으며, $1.25{\times}10^{-3}\;{\Omega}cm^2$의 접촉저항을 보였다. 이는 산소 플라즈마 처리가 기존의 플라즈마 처리와 같이 질소결원이 발생하였기 때문이다. 이를 통해 쇼트키장벽 높이(SBH)이 낮아지게 되었고, 오믹 전극및 플라즈마 처리를 안 한 경우보다 더 낮은 접촉저항의 결과를 획득하였다.

3상 직렬공진형 고전압 커패시터 충전기의 해석 및 설계 (Analysis and Design of a 3-phase Series-Resonant type High Voltage Capacitor Charger)

  • 이병하;박상은;차한주
    • 전기학회논문지
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    • 제62권4호
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    • pp.510-516
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    • 2013
  • This paper suggests a 3-phase series-resonant type high voltage capacitor charger for an EML pulsed power system. The operating principle on the charger is explained by an equivalent circuit. Additionally, we analyze the charging characteristic in one discontinuous conduction mode and three continuous conduction modes. The analysis shows that the resonant current per phase is two thirds of the 3-phase charger's average charging current and one third of the single-phase charger's average charging current with the same capacity. We suggest a design method of the 3-phase capacitor charger in each operational mode and present an example of 3.5 kW capacitor charger at ${\omega}_s=0.33{\omega}_r$. The 3.5 kW 3-phase capacitor charger prototype is assembled with a TI28335 controller and a 40 kJ, 7 kV capacitor. The design rules based on the analysis are verified by experiment.

금속환경에 적용가능한 UHF대역 라벨 태그의 구현 및 성능평가 (A Folded Label Tag for Metallic Environment over UHF Band)

  • 엄태환;문병현
    • 한국산업정보학회논문지
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    • 제20권2호
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    • pp.19-24
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    • 2015
  • 본 논문에서는 일반라벨 형태의 태그를 접어서 금속환경에 사용 가능한 RFID(Radio Frequency Identification) 태그 안테나를 설계 및 제작을 하였다. 일반 라벨 태그의 경우, 금속 환경에서 인식이 열화되는 단점을 보완하여 접힌 형태의 태그 안테나를 제안한다. Ansoft사(社)의 HFSS를 사용하여 칩 임피던스는 $52-j158{\Omega}$에 따라 910MHz에서 동작하도록 설계되었다. 태그의 크기는 $65{\times}23{\times}3(mm)$이며 실제 제작 후 테스트 결과 5.5M까지 인식되었다.