• 제목/요약/키워드: J$_{}$ c/

검색결과 18,696건 처리시간 0.048초

CONTINUOUSLY TUNABLE VISIBLE LIGHT EMISSION FROM QUANTUM-CONFINED EXCITONS IN ION BEAM SYNTHESIZED SI NANOCRYSTALS IN $SiO_2$

  • Kwon, Young-Soo;Rho, T.H.;Lee, Chaee-Kang;Cha, G.B.;Hong, Soon-C.;Nam, J.;Kim, J.H.;Kang, H.J.;Moon, D.W.;Ha, Y.H.;Paik, Sun-M.;Song, H.;Lee, Eung-S.;Yoo, Sung-M.;Choi, Jin-M.;Whang, Chung-N.;Kim, J.S.;Ihm, K.W.;Hwang, C.C.;Kim, H.S.;Kim, Y.K.;Park, C.Y.
    • 한국재료학회:학술대회논문집
    • /
    • 한국재료학회 1998년도 IUMRS-ICEM ABSTRACT BOOK
    • /
    • pp.85.4-85
    • /
    • 1998
  • PDF

크리이프-피로 상호작용하의 균열성장속도 예측에 관한 연구 (A Study on Prediction of Crack growth Rate Under Creep-Fatigue Interaction)

  • 주원식;조석수
    • 한국해양공학회지
    • /
    • 제9권2호
    • /
    • pp.98-111
    • /
    • 1995
  • High temperature low cycle fatigue shows that cycle-dependent crack growth owing to cyclic plastic deformation occurred simultaneosly with time-dependent crack growth owing to intergranular deformation. Consequently, to estimate crack growth rate uniquely, many to investigators have proposed various kinds of parameters and theories but these could not produce satisfactory results. Therefore the goal of this study is focused on prediction of crack growth rate using predominant damage rule, linear cumulative damage rule and transitional parameter ${\Delta}J_c/{\Delta}J_f$. On the basis of these sinusoidal loading waveform at 600$^{\circ}C$ and 700$^{\circ}C$.

  • PDF

MPEG-21과 OpenIPMP (MPEG-21 and OpenIPMP)

  • 김기섭;김태훈;유준식;김형중;한형석;김종흠;송정석;문익주
    • 한국정보통신설비학회:학술대회논문집
    • /
    • 한국정보통신설비학회 2003년도 하계학술대회
    • /
    • pp.215-217
    • /
    • 2003
  • 본 논문에서는 음악이나 동영상과 같은 디지털 미디어 컨텐츠의 유통과 보안을 위하여 개인 사용자의 접속 권한을 부여하고 제한을 가할 수 있는 OpenIPMP에 대하여 살펴본다. 그리고 본 논문은 디지털 미디어 컨텐츠의 저작권보호와 복제 방제를 위해 워터마킹 기술을 OpenIPMP에 연동시켰다. 아울러 디지털 미디어 권한에 대하여 표현하고 처리하고자 하는 목적으로 MPEG-21 REL을 역시 OpenIPMP에 연동시켰다.

  • PDF

[r, s, t; f]-COLORING OF GRAPHS

  • Yu, Yong;Liu, Guizhen
    • 대한수학회지
    • /
    • 제48권1호
    • /
    • pp.105-115
    • /
    • 2011
  • Let f be a function which assigns a positive integer f(v) to each vertex v $\in$ V (G), let r, s and t be non-negative integers. An f-coloring of G is an edge-coloring of G such that each vertex v $\in$ V (G) has at most f(v) incident edges colored with the same color. The minimum number of colors needed to f-color G is called the f-chromatic index of G and denoted by ${\chi}'_f$(G). An [r, s, t; f]-coloring of a graph G is a mapping c from V(G) $\bigcup$ E(G) to the color set C = {0, 1, $\ldots$; k - 1} such that |c($v_i$) - c($v_j$ )| $\geq$ r for every two adjacent vertices $v_i$ and $v_j$, |c($e_i$ - c($e_j$)| $\geq$ s and ${\alpha}(v_i)$ $\leq$ f($v_i$) for all $v_i$ $\in$ V (G), ${\alpha}$ $\in$ C where ${\alpha}(v_i)$ denotes the number of ${\alpha}$-edges incident with the vertex $v_i$ and $e_i$, $e_j$ are edges which are incident with $v_i$ but colored with different colors, |c($e_i$)-c($v_j$)| $\geq$ t for all pairs of incident vertices and edges. The minimum k such that G has an [r, s, t; f]-coloring with k colors is defined as the [r, s, t; f]-chromatic number and denoted by ${\chi}_{r,s,t;f}$ (G). In this paper, we present some general bounds for [r, s, t; f]-coloring firstly. After that, we obtain some important properties under the restriction min{r, s, t} = 0 or min{r, s, t} = 1. Finally, we present some problems for further research.

RELATION BETWEEN MICROSTRUCTURE AND SOFT MAGNETIC PROPERTIES OF Fe-TM-C-N (TM:Hf, Zr AND Nb) NANOCRYSTALLINE FILMS

  • Ryu, H.J.;Choi, J.O.;Han, S.H.;Kim, H.J.;Lee, J.J.;Kang, I.K.
    • 한국자기학회지
    • /
    • 제5권5호
    • /
    • pp.519-523
    • /
    • 1995
  • The Fe-TM-C-N nanocrystalline films (TM : Hf, Zr and Nb) are investigated to examine the relation between microstructure and soft magnetic properties. In these films, as the atomic radius of TM element increases, $P_{N2}$ which was added to get good soft magnetic properties was decreased and the maximum value of the permeability shifted to the high Fe range in the composition diagram. The best soft magnetic properties achieved in these films are : Hc of 0.15 Oe, $\mu_{eff}$ of 7800 (1MHz) and $4{\pi}M_{s}$ of 17.5 kG in Fe-Hf-C-N film ; Hc of 0.06 Oe, $\mu_{eff}$ of 2750 (1MHz) and $4{\pi}M_{s}$ of 16.8 kG in Fe-Zr-C-N film and Hc of 0.31 Oe; $\mu_{eff}$ of 2100 (1MHz) and $4{\pi}M_{s}$ of 15.5 kG in Fe-Nb-C-N film. It was considered that the stronger the bonding force between TM and C(N), the finer TM(C,N) phase is precipitated and therefore, the finer $\alpha$-Fe grains are formed. The effective permeability of the Fe-Zr-C-N films and Fe-Nb-C-N films remains nearly constant up to 10 MHz.

  • PDF

Pt/C 및 Pt-Ru/C 촉매를 사용한 직접 메탄올 연료전지 연료극의 메탄올 산화 반응 특성 (Oxidation Characteristics of Methanol on Pt/C and Pt-Ru/C Catalyst for the Anode of Direct Methanol Fuel Cell)

  • 정두환;이창형;신동열
    • 에너지공학
    • /
    • 제7권1호
    • /
    • pp.35-43
    • /
    • 1998
  • 본 연구에서는 Pt/C와 Pt-Ru/C 촉매를 이용하여 직접메탄올 연료전지용 연료극 전극을 제조하고 전극 및 메탄올 산화 특성에 대하여 고찰하였다. 전극은 SEM, TEM 및 열중량 분석을 통하여 특성을 조사하였다. 메탄올의 산화 특성은 1M CH3OH+1M H2SO4 용액에서 정전위/정전류계를 이용하여 반전지 시험 및 순환 전압-전류법으로 조사하였다. 연구결과를 통하여 메탄올 산화전극은 촉매층 내에 PTFE가 20w% 포함되었을 경우가 백금촉매의 이용률이 높고 우수한 성능을 보여 주었다. Pt-Ru/C 이원촉매는 Pt/C 촉매에 비하여 메탄올 산화특성이 우수하고 성능이 우수한 촉매임을 알 수 있었다. Pt/Ru/C와 Pt/C 촉매를 이용하여 제조한 전극의 메탄올 산화반응에 대한 활성화 에너지는 11.60 kJ/mol과 26.85 kJ/mol이었다.

  • PDF

ON THE UNIQUENESS OF CERTAIN TYPE OF SHIFT POLYNOMIALS SHARING A SMALL FUNCTION

  • Saha, Biswajit
    • Korean Journal of Mathematics
    • /
    • 제28권4호
    • /
    • pp.889-906
    • /
    • 2020
  • In this article, we consider the uniqueness problem of the shift polynomials $f^n(z)(f^m(z)-1){\prod\limits_{j=1}^{s}}f(z+c_j)^{{\mu}_j}$ and $f^n(z)(f(z)-1)^m{\prod\limits_{j=1}^{s}}f(z+c_j)^{{\mu}_j}$, where f(z) is a transcendental entire function of finite order, cj (j = 1, 2, …, s) are distinct finite complex numbers and n(≥ 1), m(≥ 1), s and µj (j = 1, 2, …, s) are integers. With the concept of weakly weighted sharing and relaxed weighted sharing we obtain some results which extend and generalize some results due to P. Sahoo [Commun. Math. Stat. 3 (2015), 227-238].