• Title/Summary/Keyword: T-gap

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Growth Characteristics and Physiological Adaptation of Pinus densiflora Seedling in the Canopy Gap (소나무 묘목(苗木)의 Gap내 생장(生長) 및 생리적(生理的) 적응과정(適應過程))

  • Jin, Yonghuan;Lee, Don Koo
    • Journal of Korean Society of Forest Science
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    • v.89 no.3
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    • pp.452-460
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    • 2000
  • This study was to investigate the growth characteristics, physiological adaptation of Pinus densiflora(Japanese Red Pine) seedlings at the artificial canopy gap in the Quercus acutissima plantation and to analyze its natural regeneration mechanism. Photosynthetic and transpiration rates were analyzed by different levels of photosynthetically active radiation and by seedling growth. Comparing to seedlings at the open area, those at the canopy gap showed more growth in height than in diameter with different levels of light quality and low light intensity, and the increase rate of dry weight was higher in the aboveground than in the underground, maintaining relatively high T/R rate. The C/F(the ratio of non-photosynthetic organs to photosynthetic organs in dry weight) of the aboveground at the canopy gap was higher than that at the open area by 0.1~0.2, while light saturation and light compensation points at the canopy gap were lower than that at the open area by $300{\mu}mol\;m^{-2}s^{-1}$ and 40%, respectively. The seedlings appeared to have shade tolerance to a certain extent at the young growth stage despite Pinus densiflora is typically classified shade-intolerant species. With light intensity lower than $400{\sim}450{\mu}mol\;m^{-2}s^{-1}$, photosynthetic rate and water use efficiency relatively increased by effective use of light energy.

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The New Structure in AC PDP with Long Discharge Gap for High Luminance and Luminous Efficacy (AC PDP의 휘도 및 효율 향상을 위한 Long Discharge Gap 전극구조 연구)

  • Dong, Eun-Joo;Ok, Jung-Woo;Lee, Don-Kyu;Lee, Hae-June;Lee, Ho-Joon;Park, Chung-Hoo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.5
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    • pp.827-832
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    • 2008
  • One of the most important issues in AC PDP is luminance and luminous efficacy. To improve the luminance and luminous efficacy, new sustain electrode structure which contains long discharge gap is necessary. However, it causes a rise of firing voltage. In this experiment, a new structure is proposed in order to solve this problem. To drop the firing voltage, the hump shaped electrode is inserted into the forward area of the main discharge gap. The experimental results show that proposed structures with 160um discharge gap have high firing voltage by 38V, high luminance by 30% and high luminous efficacy by 15% compared with conventional type having 60um discharge gap. In addition, the proposed structure with hump electrode shows lower firing voltage by 24V compared with the test panel with 160um discharge gap which doesn't have hump electrode though they have similar luminous efficacy.

Design of Genetic Algorithm Processor(GAP) for Evolvable Hardware (진화하드웨어를 위한 유전자 알고리즘 프로세서(GAP) 설계)

  • Sim, Kwee-Bo;Kim, Tae-Hoon
    • Journal of the Korean Institute of Intelligent Systems
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    • v.12 no.5
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    • pp.462-466
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    • 2002
  • Genetic Algorithm (GA) which imitates the process of nature evolution is applied to various fields because it is simple to theory and easy to application. Recently applying GA to hardware, it is to proceed the research of Evolvable Hardware(EHW) developing the structure of hardware and reconstructing it. And it is growing a necessity of GAP that embodies the computation of GA to the hardware. Evolving by GA don't act in the software but in the hardware(GAP) will be necessary for the design of independent EHW. This paper shows the design GAP for fast reconfiguration of EHW.

Crystal Growth of Cd4GeS6 and Cd4GeS6:Co2+Single Crystals ($Cd_{4}GeS_{6}$$Cd_{4}GeS_{6}:Co^{2+}$ 단결정의 성장)

  • Kim, D.T.;Kim, H.G.;Kim, N.O.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11b
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    • pp.1-6
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    • 2004
  • In this paper author describe the undoped and $Co^{2+}$ (0.5mole%)doped $Cd_4GeS_6$ single crystals were grown by the chemical transporting reaction(CTR) method using high purity(6N) Cd, $GeS_2$, S elements. It was found from the analysis of X-ray diffraction that the undoped and $Co^{2+}$(0.5mole%) doped $Cd_{4}GeS_{6}$ compounds have a monoclinic structure in space grop Cc. The optical energy band gap was direct band gap and temperature dependence of optical energy gap was fitted well to Varshni equation. Impurity optical absorption peaks due to the doped cobalt in the $Cd_4GeS_6:Co^{2+}$ single crystal were observed at 3593cm-1, 5048cm-1, 5901cm-1, 7322cm-1, 12834cm-1, 13250cm-1, 14250cm-1,and 14975cm-1 at 11.3K.

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Binding energy study from photocurrent signal in $CdIn_2Te_4$ crystal

  • Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.376-376
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    • 2010
  • The single crystals of p-$CdIn_2Te_4$ were grown by the Bridgman method without the seed crystal. From photocurrent measurements, it was found that three peaks, A, B, and C, correspond to the intrinsic transition from the valence band states of $\Gamma_7$(A), $\Gamma_6$(B), and $\Gamma_7$(C) to the conduction band state of $\Gamma_6$, respectively. The crystal field splitting and the spin orbit splitting were found to be 0.2360 and 0.1119 eV, respectively, from the photocurrent spectroscopy. The temperature dependence of the $CdIn_2Te_4$ band gap energy was given by the equation of $E_g(T)=E_g(0)-(9.43{\times}10^{-3})T^2/(2676+T)$. $E_g$(0) was estimated to be 1.4750, 1.7110, and 1.8229 eV at the valence band states of A, B, and C, respectively. The band gap energy of p-$CdIn_2Te_4$ at room temperature was determined to be 1.2023 eV.

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An Efficient Local Alignment Algorithm for DNA Sequences including N and X (N과 X를 포함하는 DNA 서열을 위한 효율적인 지역정렬 알고리즘)

  • Kim, Jin-Wook
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.3
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    • pp.275-280
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    • 2010
  • A local alignment algorithm finds a substring pair of given two strings where two substrings of the pair are similar to each other. A DNA sequence can consist of not only A, C, G, and T but also N and X where N and X are used when the original bases lose their information for various reasons. In this paper, we present an efficient local alignment algorithm for two DNA sequences including N and X using the affine gap penalty metric. Our algorithm is an extended version of the Kim-Park algorithm and can be extended in case of including other characters which have similar properties to N and X.

Temperature dependence of energy band gap for ZnO thin films

  • Hong, Myung-Seok;Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.99-100
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    • 2007
  • ZnO films on $Al_2O_3$ substrates were grown using a pulsed laser deposition method. Through photoluminescence (PL) and X-ray diffraction (XRD) measurements, the optimum growth conditions for the ZnO growth were established. The results of the XRD measurements indicate that ZnO films were strongly oriented to the c-axis of the hexagonal structure and epitaxially crystallized under constraints created by the substrate. The full width half maximum for a theta curve of the (0002) peak was $0.201^{\circ}$. Also, from the PL measurements, the grown ZnO films were observed to give free exciton behaviour, which indicates a high quality of the epilayer. The Hall mobility and carrier density of the ZnO films at 293 K were estimated to be $299\;cm^2/V\;s$ and $8.27\;{\times}\;10^{16}\;cm^{-3}$, respectively. The absorption spectra revealed that the temperature dependance of the optical band gap on the ZnO films was $E_g(T)\;=\;3.439\;eV\;-\;(5.30\;{\times}\;10^{-4}\;ev/K)T^2(367\;+\;T)$.

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Growth and temperature dependence of energy band gap for $CuAISe_2$ Single Crystal Thin Film by Hot Wall Epitaxy (Hot Wall Epitaxy(HWE)법에 의한 $CuAlSe_2$ 단결정 박막의 성장과 에너지 밴드갭의 온도 의존성)

  • Yun, Seok-Jin;Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.121-122
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    • 2007
  • Single crystal $CuAlSe_2$ layers were grown on thoroughly etched sem-insulating GaAs(l00) substrate at $410^{\circ}C$ with hot wall epitaxy (HWE) system by evaporating $CuAlSe_2$ source at $680^{\circ}C$. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of single crystal $CuAlSe_2$ thin films measured with Hall effect by van der Pauw method are $9.24{\times}l0^{16}\;cm^{-3}$ and $295\;cm^2/V{\cdot}s$ at 293K, respectively. The temperature dependence of the energy band gap of the $CuAlSe_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)\;=\;2.8382\;eV\;-\;(8.68\;{\times}\;10^{-4}\;eV/K)T^2/(T\;+\;155\;K)$.

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Temperature dependence of photocurrent spectra for $AgInS_2$ epilayers grown by hot wall epitaxy

  • Baek, Seung-Nam;Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.123-124
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    • 2007
  • A silver indium sulfide ($AgInS_2$) epilayer was grown by the hot wall epitaxy method, which has not been reported in the liteniture. The grown $AgInS_2$ epilayer has found to be a chalcopyrite structure and evaluated to be high quality crystal. From the photocurrent measurement in the temperature range from 30 K to 300 K, the two peaks of A and B were only observed, whereas the three peaks of A, B, and C were seen in the PC spectrum of 10 K. These peaks are ascribed to the band-to-band transition. The valence band splitting of $AgInS_2$ was investigated by means of the photocurrent measurement. The temperature dependence of the energy band gap of the $AgInS_2$ obtained from the photocurrent spectrum was well described by the Varshni's relation, $E_g(T)=\;E_g(0)\;eV-(7.78\;{\times}\;10^{-4}\;eV/K)T^2/(T\;+\;116\;K\;K)$. Also, Eg(0) is the energy band gap at 0 K, which is estimated to be 2.036 eV at the valence band state A and 2.186 eV at the valence band state B.

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THE COMPARING STUDY OF THE DIELECTRIC CHARACTERISTIC FROM THE LTCC MICROSTRIP RESONATOR ARCHITECTURES (LTCC MICROSTRIP RESONATOR 구조에 따른 유전특성 비교 연구)

  • Lee, Joong-Keun;Jung, Hyun-Chul;Yoo, Chan-Sei;Kim, Dong-Su;Yoo, Myung-Jae;Park, Sung-Dae;Lee, Woo-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.309-310
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    • 2005
  • Generally, the dielectric constant and loss tangent are gotten by resonators. This paper presents analysis of the comparing the dielectric constant and loss tangent from the Ring, T and series gap structures. The T structure can be analyzed easily at wideband characteristic with simple design. the Ring can ignore the radiation loss from the open-ended effect. the Series gap can get more accurate permittivity than a Ring structure. The Used materials were dupont9599 LTCC ceramic and daeju0086 Ag.

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