• Title/Summary/Keyword: J. D. Green

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Improved Computation of L-Classes for Efficient Computation of J Relations (효율적인 J 관계 계산을 위한 L 클래스 계산의 개선)

  • Han, Jae-Il;Kim, Young-Man
    • Journal of Information Technology Services
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    • v.9 no.4
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    • pp.219-229
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    • 2010
  • The Green's equivalence relations have played a fundamental role in the development of semigroup theory. They are concerned with mutual divisibility of various kinds, and all of them reduce to the universal equivalence in a group. Boolean matrices have been successfully used in various areas, and many researches have been performed on them. Studying Green's relations on a monoid of boolean matrices will reveal important characteristics about boolean matrices, which may be useful in diverse applications. Although there are known algorithms that can compute Green relations, most of them are concerned with finding one equivalence class in a specific Green's relation and only a few algorithms have been appeared quite recently to deal with the problem of finding the whole D or J equivalence relations on the monoid of all $n{\times}n$ Boolean matrices. However, their results are far from satisfaction since their computational complexity is exponential-their computation requires multiplication of three Boolean matrices for each of all possible triples of $n{\times}n$ Boolean matrices and the size of the monoid of all $n{\times}n$ Boolean matrices grows exponentially as n increases. As an effort to reduce the execution time, this paper shows an isomorphism between the R relation and L relation on the monoid of all $n{\times}n$ Boolean matrices in terms of transposition. introduces theorems based on it discusses an improved algorithm for the J relation computation whose design reflects those theorems and gives its execution results.

Photoluminescence Imaging of SiO2@ Y2O3:Eu(III) and SiO2@ Y2O3:Tb(III) Core-Shell Nanostructures

  • Cho, Insu;Kang, Jun-Gill;Sohn, Youngku
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.575-580
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    • 2014
  • We uniformly coated Eu(III)- and Tb(III)-doped yttrium oxide onto the surface of $SiO_2$ spheres and then characterized them by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction crystallography and UV-Visible absorption. 2D and 3D photoluminescence image map profiles were reported for the core-shell type structure. Red emission peaks of Eu(III) were observed between 580 to 730 nm and assigned to $^5D_0{\rightarrow}^7F_J$ (J = 0 - 4) transitions. The green emission peaks of Tb(III) between 450 and 650 nm were attributed to the $^5D_4{\rightarrow}^7F_J$ (J = 6, 5, 4, 3) transitions. For annealed samples, Eu(III) ions were embedded at a $C_2$ symmetry site in $Y_2O_3$, which was accompanied by an increase in luminescence intensity and redness, while Tb(III) was changed to Tb(IV), which resulted in no green emission.

Enhancement of the efficiency in green organic light-emitting devices utilizing multiple heterostructures acting as a hole transport layer

  • Choo, D.C.;Lee, D.U.;Yoon, Y.B.;Kim, T.W.;Kim, J.H.;Seo, J.H.;Kim, Y.K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1024-1027
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    • 2006
  • The electrical and the optical properties of organic light-emitting devices (OLEDs), with and without various kinds of multiple heterostructures were investigated. The efficiency in green OLEDs were significantly enhanced by the structure of the multiple heterostructures acting as a hole transport layer (HTL) rather than by the number of periods. These results indicate that highly efficient green OLEDs utilizing multiple heterostructures acting as a HTL can be fabricated.

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Soil Management through Green Manure Crop Cultivation Prior to Tea Plantation

  • Kim, K.J.;Yoon, C.Y.;Kim, D.J.;Kim, S.K.;Heo, K.H.;Choi, J.;Lee, J.Y.;Park, J.D.
    • Korean Journal of Organic Agriculture
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    • v.19 no.spc
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    • pp.25-29
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    • 2011
  • This study was performed to analyze the improvement of soil physical property and soil biota characteristics through cultivation of green manure crops for a one-year period before creation of a tea plantation as follows. The study revealed that the contents of available phosphate tended to decrease after sod-culture by green manure cultivation and open-pollination, when compared to the level before cultivation. The ratio soil porosity increased by approximately 30% when Crotalaria juncea and Sorghum bicolar L. Moench were cultivated, while the soil bacteria and fungi also increased. In a research on microfauna using a pit fall trap, the population number of the microfauna was 174 of 27 species in the plot of open-pollinated sod-culture and no organic matter application, and 268 of 26 species in the plot of Sorghum bicolar L. Moench. Consequently, the culturing tool of Crotalaria juncea recorded the highest level of species diversity at 2.5, the evenness index at 3.7 and richness at 4.6, with the lowest level of a dominance index. The ecological quotient of microfauna was 0.76 in the plot of Sorghum bicolar L. Moench, and 0.63 in the plot of Crotalaria juncea.

New Barrier Rib Forming Method for PDP Fabrication

  • Kim, I.T.;Cho, C.R.;Koo, B.J.;Lee, S.H.;Kong, S.S.;Kim, W.B.;Mun, J.D.;Hwang, K.T.;Kim, J.D.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.351-355
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    • 2003
  • In this paper, a new barrier rib forming method of embossed barrier rib (EBR) formation process for the PDP rear panel was introduced. The process is mainly composed of green sheet fabrication, lamination of the green sheet on the rear glass panel having data electrodes, and roll embossing followed by firing. The EBR process has two advantages over the conventional barrier rib forming methods. One is the process requires less equipment investment than the conventional methods by about 20% of the current rear panel fabrication equipment investment owing to the simplified fabrication process. The other advantage is its reduced rear panel manufacturing cost by eliminating the time consuming and complicated processes and waste of materials in the conventional methods. In this study, general procedure of EBR fabrication process is described and the characteristics of prototype PDP using EBR panel are discussed.

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Self-starting vector phase conjugate laser oscillator in inverted Nd:YAG

  • Kim, D.H.;Udaiyan, D.;Green, R.P.M.;Crofts, G.J.;Damzen, M.J.
    • Journal of the Optical Society of Korea
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    • v.1 no.1
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    • pp.41-43
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    • 1997
  • We report the operation of a self-adaptive vector phase conjugate laser (VPCL) oscillator which compensates intracavity polarization distortion and wavefront aberration simultaneously. The VPCL in Nd:YAG gain media produce an output with energy of 125mJ in a 20ns single-longitudinal-mode pulse at 10Hz, which is unaffected by intracavity polarization distortion.

Effect of Mean Stress on the Fatigue Life of Engine Mount and Life Prediction (방진고무부품 피로수명에 끼치는 평균하중의 영향 및 피로수명 예측)

  • Lee, H.J.;Kim, W.D.;Choi, B.I.;Woo, C.S.;Kim, J.Y.;Koh, S.K.
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.99-104
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    • 2001
  • Effect of mean stress on the fatigue life of natural rubber for engine mount was investigated. Fatigue damage parameter based on the maximum Green-Lagrange strain was employed to account for the effect of mean stress. A procedure to predict the fatigue life of rubber components based on the maximum Green-Lagrange strain method was proposed. Nonlinear finite element analysis and fatigue test of jang-gu shape specimen were conducted to predict the fatigue life of engine mount. Predicted fatigue lives have a good agreement with tested lives within a factor of 3.

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The Analysis of Yellowish Gravity-Mura in FFS Mode

  • Park, J.B.;Park, E.J.;Park, S.H.;Park, I.C.;Kim, H.Y.;Lee, K.H.;Lee, J.Y.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.780-783
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    • 2006
  • In this paper, we confirmed the yellowish gravity-mura phenomenon in Fringe-Field Switching (FFS) mode using 2-D simulation. As the cell gap increases, while the LC efficiency of blue wavelength remains almost same, that of red and green wavelength increases continuously. As a result, yellowish phenomenon occurs.

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