• 제목/요약/키워드: powers

검색결과 1,725건 처리시간 0.024초

Synthesis of Carbon Nanotubes by Using Inductively Coupled Plasma Chemical Vapor Deposition at Low Temperature

  • Kim, Young-Rae;Jang, In-Goo;Cho, Hyun-Jin;Jeon, Hong-Jun;Cho, Jung-Keun;Hwang, Ho-Soo;Kong, Byung-Yun;Lee, Nae-Sung
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
    • /
    • pp.768-771
    • /
    • 2007
  • Carbon nanotubes (CNTs) were synthesized by inductively coupled plasma CVD at $450^{\circ}C$. CNTs were grown on the 1-nm-thick Fe-Ni-Co with $C_2H_2$ and $H_2$ at different pressures and plasma powers. CNTs were grown longer in height as the $H_{\alpha}/CH$ ratios became lower by decreasing plasma powers and increasing growth pressures.

  • PDF

계통 최적전압 상태 유지를 위한 다기 UPFC 운용방법 (An Operation Method of Many UPFC's for Maintaining the Optimal Voltage Profile)

  • 김태현;문승일;박종근
    • 대한전기학회논문지:전력기술부문A
    • /
    • 제49권11호
    • /
    • pp.531-535
    • /
    • 2000
  • A method to compute the reactive powers of the added buses by the decoupled UPFC model for the optimal voltage profile is presented, by which the voltage magnitudes of PQ buses can get closer to the reference value(usually one p.u.). The performance index for assessing how much the voltage magnitude is closer to the reference value is defined as the squared sum of the present voltage minus the reference voltage multiplied by the weighting number associated with the relative importance of the buses. Numerical example in a 10-unit 39-bus power system with 2 UPFC's shows that the performance index can be very much reduced by operating many UPFC's with the reactive powers for the optimal voltage profile proposed in this paper.

  • PDF

밤전분의 물리화학적 특성과 텍스쳐 특성 (Physicochemical and Textural Properties of Chestnut Starches)

  • 김세권;전유진;김용태;이병조;강옥주
    • 한국식품영양과학회지
    • /
    • 제24권4호
    • /
    • pp.594-600
    • /
    • 1995
  • To efficiently utilize not only fresh chestnut(FC) but also wormy chestnut(WC), four types of chestnut starches which were fresh chestnut starch(FCS), fresh chestnut crude starch(FCCS), wormy crude starch(WCS) and wormy chestnut crude starch(WCCS) were extracted. Amylose content of FCS(46.5%) and water binding capacity of FCCS(103.0%) were higher than those of othe three, respectively. Swelling powers of all sample starches increased rapidly from 6$0^{\circ}C$ to 8$0^{\circ}C$. Solubilities showed the same pattern as the swelling powers. In the textural properteis investigated with IUTM(instron universal testing machine), hardnesses and elasticties of chestnut starches were 50~58I.U. and 14~16I.U., respectively. The results of textural evaluations showed that it was possible to prepare chestnut mook with FCS, FCCS and WCS.

  • PDF

전력계통의 안전도를 고려한 경제급전에 관한 연구 (A Study on the Security-Constrained Economic Dispatch for Power System)

  • 김경철;최홍규;원진희
    • 조명전기설비학회논문지
    • /
    • 제16권3호
    • /
    • pp.7-14
    • /
    • 2002
  • 경제급전은 전력회사간에 생산된 전력을 사고 파는 경우에 필연적으로 고려해야 한다. 본 논문은 전력계통 안전도, 최적조류계산과 안전도를 고려한 경제급전을 설명하고, 상용화된 EDSA의 active optimal power flow 프로 그램을 이용한 사례연구를 통하여 최적의 경제급전이 되었음을 검증하였다.

A Study of Grid-Connected PV System with Power Control Structure

  • Vu, Trung-Kien;Bae, Youngsang;Oh, Seongjin
    • 전력전자학회:학술대회논문집
    • /
    • 전력전자학회 2012년도 전력전자학술대회 논문집
    • /
    • pp.329-330
    • /
    • 2012
  • The rising popularity of renewable energy sources resulted in development of the units of higher rated powers, where the large-scale plants and grid-connected type solar power systems are increased. Therefore, the importance of grid stabilization, which depends on each country or system-type, has been strengthened by different grid-codes or certifications. In this paper, the control scheme of three-phase photovoltaic system is enhanced, where both injected active and reactive powers are simultaneously controlled with the consideration of the certification of the Germany Association of Energy and Water Industries (BDEW). Experimental results are shown to verify the theoretical analysis.

  • PDF

$YMnO_3$/Si(100) 구조의 RF Power 의존성 (RF Power dependence in $YMnO_3$/Si(100) Structures)

  • 김진규;정순원;김용성;이남열;정상현;김광호;유병곤;이원재;유인규
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
    • /
    • pp.755-758
    • /
    • 2000
  • YMnO$_3$films have been deposited with different Rf powers of 60W, 80W, 100W, and 120W. The structural properties of YMnO$_3$films on Si(100) were analysed by XRD(X-ray diffraction). The c-axis oriented peaks of YMnO$_3$were observed deposited in YMnO$_3$/Si(100) structure of RF power at 87$0^{\circ}C$ in oxygen ambient, and the peaks were enlarged by increasing The RF powers. The dielectric constant of the film deposited at 100W and 120W of RF power were about 19, 20 respectively.

  • PDF

Comparing the empirical powers of several independence tests in generalized FGM family

  • Zargar, M.;Jabbari, H.;Amini, M.
    • Communications for Statistical Applications and Methods
    • /
    • 제23권3호
    • /
    • pp.215-230
    • /
    • 2016
  • The powers of some tests for independence hypothesis against positive (negative) quadrant dependence in generalized Farlie-Gumbel-Morgenstern distribution are compared graphically by simulation. Some of these tests are usual linear rank tests of independence. Two other possible rank tests of independence are locally most powerful rank test and a powerful nonparametric test based on the $Cram{\acute{e}}r-von$ Mises statistic. We also evaluate the empirical power of the class of distribution-free tests proposed by Kochar and Gupta (1987) based on the asymptotic distribution of a U-statistic and the test statistic proposed by $G{\ddot{u}}ven$ and Kotz (2008) in generalized Farlie-Gumbel-Morgenstern distribution. Tests of independence are also compared for sample sizes n = 20, 30, 50, empirically. Finally, we apply two examples to illustrate the results.

A new epoch of Sino-Russian relations and their regional and global influence

  • Cimek, Gracjan
    • Journal of Contemporary Eastern Asia
    • /
    • 제20권2호
    • /
    • pp.138-156
    • /
    • 2021
  • The aim of this article is to describe direction of Sino-Russian relations toward a new epoch - as the decision-making centers of both countries define them - indicating the commitment to building the future international order. It includes the synthesis of evolution of relations, descriptions of cooperation building of mutual confidence by both sides in variety of institutions; analyses of geo-economic relations emphasizing their geostrategic dimension and finally dynamics showing how two great powers want to achieve new areas of cooperation focused on building multipolar world order which is the essence of "new epoch". The argument goes towards recognizing the relationship as a "hhybrid alliance". This hybridity is a structural factor that can constrain the use of new dimensions of asymmetric interdependence as political leverage especially by United States against the two non-western powers but also facilitate to use it against West.

A GRADED MINIMAL FREE RESOLUTION OF THE 2ND ORDER SYMBOLIC POWER OF THE IDEAL OF A STAR CONFIGURATION IN ℙn

  • Shin, Yong-Su
    • 대한수학회지
    • /
    • 제56권1호
    • /
    • pp.169-181
    • /
    • 2019
  • In [9], Geramita, Harbourne, and Migliore find a graded minimal free resolution of the 2nd order symbolic power of the ideal of a linear star configuration in ${\mathbb{P}}^n$ n of any codimension r. In [8], Geramita, Galetto, Shin, and Van Tuyl extend the result on a general star configuration in ${\mathbb{P}}^n$ but for codimension 2. In this paper, we find a graded minimal free resolution of the 2nd order symbolic power of the ideal of a general star configuration in ${\mathbb{P}}^n$ of any codimension r using a matroid configuration in [10]. This generalizes both the result on a linear star configuration in ${\mathbb{P}}^n$ of codimension r in [9] and the result on a general star configuration in ${\mathbb{P}}^n$ of codimension 2 in [8].

A GRADED MINIMAL FREE RESOLUTION OF THE m-TH ORDER SYMBOLIC POWER OF A STAR CONFIGURATION IN ℙn

  • Park, Jung Pil;Shin, Yong-Su
    • 대한수학회지
    • /
    • 제58권2호
    • /
    • pp.283-308
    • /
    • 2021
  • In [30] the author finds a graded minimal free resolution of the 2-nd order symbolic power of a star configuration in ℙn of any codimension r. In this paper, we find that of any m-th order symbolic power of a star configuration in ℙn of codimension 2, which generalizes the result of Galetto, Geramita, Shin, and Van Tuyl in [15, Theorem 5.3]. Furthermore, we extend it to the m-th order symbolic power of a star configuration in ℙn of any codimension r for m = 3, 4, which also generalizes the result of Biermann et al. in [1, Corollaries 4.6 and 5.7]. We also suggest how to find a graded minimal free resolution of the m-th order symbolic power of a star configuration in ℙn of any codimension r for m ≥ 5.