• 한국발생생물학회지:발생과생식
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• 제15권2호
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• pp.133-141
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• 2011

본 연구는 Amphiprion melanopus의 산란 주기 행동 및 산란 후 습성을 조사하고 이를 기반으로 부화장치를 제안하고자 하였다. 연중 수온, 염분 및 광주기가 일정한 인공적인 환경에서 사육된 4쌍의 어미들은 산란주기 및 횟수가 각각 다르게 나타났다. 반면, 수정 후 알 관리는 수컷에 의해서 주로 관리가 되었다. 부화일이 가까워질수록 수컷의 eggfanning 횟수가 증가하였고, 특히, 부화 직전에 더욱 격렬한 행동을 나타냈다. 이러한 정보를 기반으로 에어레이션형, 스프레이형, 회전 수류형 등 3종의 부화장치에 대한 clownfish류 4종의 부화율을 조사한 결과, 회전 수류형 시스템의 부화율이 87.3%로 스프레이형(74.4%)과 에어레이션형(60.5%)보다 높았다. 그리고 회전수류형에서 부화판 개수별(2, 3, 5개)에 따른 부화율은 서로 차이가 없었다. 그러므로 부화자어의 사육 크기를 고려하여 수조 크기를 결정하면 많은 개수의 부화판을 넣어 대량으로 부화시킬 수 있을 것이다.

• 대한전자공학회논문지
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• 제27권5호
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• pp.716-723
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• 1990

Transmission electron microscopy (TEM) and anger electron microscopy(AES) studies of GaAs/AlxGa1-xAs(x=0.58) quantum wells grown by low pressure metalorganic chemical vapor deposition(LP-MOCVD) are carried out. Isolated quantum well structure having the well width as small as 15 \ulcornerand multiquantum well structure, which consisted of 51 alternating layers with each thickness of 10\ulcorner were suscessfully grown. TEM analyses have shown that their interfaces were almost completely coherent without any structural disorder, alloy clustering and crystal defect. AES depth resolution have shown the compositional periodicity of superlattice structure.

• 한국표면공학회지
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• 제29권6호
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• pp.884-890
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• 1996

We have investigated a structural change of Si(100)-($2 \times 1$)-Sb surface caused by atomic hydrogen adsorption at room temperature using time-of-flight impact collision ion scattering spectroscopy (TOF-ICISS) and low energy electron diffraction (LEED). We found that when atomic hydrogen adsorbs on the Si(100)-($2 \times 1$)-Sb surface, (1) the partial desorption of Sb atoms from the Si(100) surface occurs even at room temperature, (2) the rest Sb atoms are displaced from their original positions and form an almost two-dimensional layer with dispersive distribution of Sb atoms, and (3) the structural transformation into the Si(100)-($1 \times 1$)-H periodicity is induced by the formation of the $1 \times 1$-H dihydride phase on the Si substrate.

• 충청수학회지
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• 제31권1호
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• pp.13-27
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• 2018

By using of the Banach fixed point theorem, the theory of a strongly continuous semigroup of operators and resolvent operator, we investigate the existence and uniqueness of S-asymptotically ${\omega}-periodic$ mild solutions for some differential (integrodifferential) equations with piecewise constant argument when specially ${\omega}$ is an integer.

• Computational Structural Engineering : An International Journal
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• 제3권1호
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• pp.39-47
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• 2003

Generalized CMAC (GCMAC) is a type of neural network known to be fast in learning. The network may be useful in structural engineering applications such as the identification and the control of structures. The derivatives of a trained GCMAC is relatively poor in accuracy. Therefore to improve the accuracy, a new algorithm is proposed. If GCMAC is directly differentiated, the accuracy of the derivative is not satisfactory. This is due to the quantization of input space and the shape of basis function used. Using the periodicity of the predicted output by GCMAC, the derivative can be improved to the extent of having almost no error. Numerical examples are considered to show the accuracy of the proposed algorithm.

• 한국초전도ㆍ저온공학회논문지
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• 제24권4호
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• pp.11-15
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• 2022

We conducted numerical calculations to obtain the critical current as a function of the magnetic flux through the topologically trivial and non-trivial superconducting quantum interference devices (SQUIDs), with varying the capacitive and inductive couplings of Josephson junctions (JJs). Our calculation results indicate that a nontrivial SQUID is almost indistinguishable from trivial SQUID, considering the effective capacitance coupling. When the SQUID contains 2π- and 4π-periodic supercurrents, the periodicity of the current-flux relation can be distinguished from the purely trivial or nontrivial SQUID cases, and its difference is sensitive to the relative ratio between the topologically trivial and nontrivial supercurrents. We believe that our calculation results would provide a practical guide to quantitatively measure the portion of the topologically nontrivial supercurrents in experiments.

• Macromolecular Research
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• 제15권6호
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• pp.553-559
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• 2007

Nanocomposite films were prepared by sol-gel synthesis from vanadium triisopropoxide with $poly((oxyethylene)_9$ methacrylate)-graft-poly(dimethyl siloxane), POEM-g-PDMS, producing in situ growth of vanadium oxide within the continuous ion-conducting POEM domains of micro phase-separated graft copolymer. The formation of vanadium oxide was confirmed by wide angle x-ray scattering (WAXS) and Fourier transform infrared (FT-IR) spectroscopy. Small angle x-ray scattering (SAXS) revealed the spatially-selective incorporation of vanadium oxide in the POEM domains. Upon the incorporation of vanadium oxide, the domain periodicity of the graft copolymer monotonously increased from 17.2 to 21.0 nm at a vanadium content 14 v%, above which it remained almost invariant. The selective interaction of vanadium oxide with POEM was further verified by differential scanning calorimetry (DSC) and FT-IR spectroscopy. The nanocomposite films exhibited excellent mechanical properties $(l0^{-5}-10^{-7}dyne/cm^2)$, mostly due to the confinement of vanadium oxide in the POEM chains as well as the interfaces created by the microphase separation of the graft copolymer.

• 천문학회지
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• 제44권3호
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• pp.97-108
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• 2011

The photometric light curves of the W-type W UMa eclipsing contact binary system BB Pegasi have been found to be extremely asymmetric over all the observed 63 years in all wavelengths UBVR. The light curves have been characterized by occultation primary minima. Hence, the morphology of these light curves has been studied in view of these different asymmetric degrees. The system shows a distinct O'Connell effect, as well as depth variation. A 22.96 years of stellar dark spots cycle has been determined for the system. Almost the same cycle (22.78 yr) has been found for the depth variation of MinI and MinII. We also present an analysis of mid-eclipse time measurements of BB Peg. The analysis indicates a period decrement of $5.62{\times}10^{-8}$ day/yr, which can be interpreted in terms of mass transfer at a rate of $-4.38{\times}10^{-8}M_{\odot}$/yr, from the more to the less massive component. The O - C diagram shows a damping sine wave covering two different cycles of 17.0 yr and 12.87 yr with amplitudes equal to 0.0071 and 0.0013 day, respectively. These unequal durations show a non-periodicity which may be explained as a result of magnetic activity cycling variations due to star spots. The obtained characteristics are consistent with similar chromospherically active stars, when applying the Applegate's (1992) mechanism.

• 한국항공우주학회지
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• 제31권2호
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• pp.10-16
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• 2003

초음속 유동장에서 비정상 직열배치공동 유동 연구를 Navier-Stokes 방정식과 k-$\varepsilon$난류모델을 이용하여 수치 모사하였다. 공동주위의 비정상유동은 자유 전단층과 공동 내부 유동의 상호 작용에 의한 주기성으로 특정지어진다. 수치적 방법은 van Leer의 유량한계계수를 이용한 유량벡터분리법에 기반을 둔 TVD방법을 사용하였다. 먼저, 단일 공동에 대한 압력비 그래프를 통한 주진동 주파수를 비교하였다. 직열배치공동유동에서는 전후방 공동을 몇가지 세장비로 조합하여, 전방 공동의 영향에 의한 후방 공동 유동장의 주진동 주파수 특성등을 분석하였다. 전방공동의 세장비가 작은 경우에는 강한 전방공동의 전단층이 후방공동의 전단츨과 합하여 하나의 전단층 특성을 줌으로 전후방 공동의 주진동특성이 비슷하게 나타나고, 전방공동의 세장비가 큰경우에는 전방공동의 전단층이 확산되면서 내부에 후방공동의 전단층이 발생함으로 주진동수의 특성이 다르게 나타나는 것을 볼 수 있었다.

• 한국응용곤충학회지
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• 제45권2호
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• pp.169-172
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• 2006

고구마 큰검정풍뎅이 성페로몬 주성분인 L-isoleucine methyl ester (LIME)와 부성분인 (R)-(-)-linalool의 함량비가 2.5:1일 때 가장 큰 유인효과를 나타냈으며, 유인효과가 미치는 거리는 14 m와 21 m의 중간이었다. 한국에 발생하는 큰검정풍뎅이의 성페로몬에 대한 반응은 일본에 발생하는 큰검정풍뎅이와 마찬가지로 48시간 주기를 보이는 것으로 나타났다.