• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7A
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• pp.712-718
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• 2004

We report 1.6 Tb/s (160${\times}$10 Gb/s) WDM transmission over 2,000 km of single mode fiber using distributed hybrid(distributed Raman amplifier＋Erbium-doped fiber amplifier) optical amplifiers. After transmission over 2,000 km of single mode fiber, average optical signal to noise ratios of C/L-band were 20.5 dB, 21.9 dB, respectively. The minimum Q-factors of each band were 14.65 dB (BER=5.8e-8) in C-band, 13.75 dB (BER=5.0e-7) in L-band without forward error correction. We performed 1.6 Tb/s error-free transmission over 2,000 km of single mode fiber using Reed-Solomon (255, 239) forward error correction code.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.9
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• pp.720-725
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• 2001

In this study, Pb(La,Ce)Ti $O_3$ ceramics were manufactured for 20 MHz resonator application. Electromechanical coupling factor( $k_{t}$, $k_{t3}$, mechanical quality factor( $Q_{mt}$ , $Q_{mt3}$ and dydnamic range (D.R) of thickness vibration mode were measured as the variations of $\ell$/t(length/thickness) ratio of ceramic substrates. Mechanical quality factor( $Q_{mt3}$) and dynamic range of third overtone thickness vibration mode showed the highest value of 2,773 and 52.22dB at specimen S4($\ell$/t=12), respectively. The excellent temperature stability of resonant frequency suitable for resonator application was shown, regardless of thermal shock.k.ock.k.

• Journal of Integrative Natural Science
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• v.9 no.1
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• pp.1-9
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• 2016

Leucine rich repeat kinase 2 (LRRK2) is a highly promising target for Parkinson's disease (PD) that affects millions of people worldwide. A three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis was performed on a series of pyrrolopyrimidine-based selective LRRK2 kinase inhibitors. This study was performed to rationalize the structural requirements responsible for the inhibitory activity of these compounds. A reliable 3D-QSAR model was developed using comparative molecular field analysis (CoMFA) technique. The model produced statistically acceptable results with a cross-validated correlation coefficient ($q^2$) of 0.539 and a non-cross-validated correlation coefficient ($r^2$) of 0.871. Robustness of the model was further evaluated by bootstrapping and progressive scrambling analysis. This work could assist in designing more potent LRRK2 inhibitors.

• Journal of applied mathematics & informatics
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• v.39 no.1_2
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• pp.45-56
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• 2021

D.S. Kim et al. [9] considered some identities and relations for Korobov type numbers and polynomials. In this work, we investigate the degenerate Korobov type Changhee polynomials and the (p,q)-poly-Korobov polynomials. We give a generalization of the Korobov type Changhee polynomials and the (p,q) poly-Korobov polynomials. We prove some properties and identities and explicit relations for these polynomials.

• Korean Journal of Medicinal Crop Science
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• v.12 no.2
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• pp.149-153
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• 2004

This study was carried out to compare the major volatile components in essential oil from different origin of Atractylodes spp. which is being traded as a crude herbal drug in Korean herbal markets. From the two Atractylodes of major volatile components were similarly detected such as the ${\beta}-selinene,\;{\beta}-sesquiphellandrene$, germacrene B, 2,7-dimethoxy-2-methylnaphthalene and 9-methoxy-2,3-dihydrofuro{3,2-q}coumarin. Among the volatile components, the major components were 2,7-dimethoxy-2-methylnaphthalene (40.98%), 9-methoxy-2,3-dihydrofuro {3,2-q} coumarin (15.74%), and ${\beta}-sesquiphellandrene$ (1.98%) in both Atractylodes. As a results, It was found that the two Atractylodes were the same species which was being traded in the Korean herbal markets as the A. japonica. not to different species of A. japonica and A. macrocephalla, respectively.

• Journal of the Korean Society of Visualization
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• v.20 no.3
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• pp.74-85
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• 2022

We propose a Cubic-Interpolated Pseudo-Particle Lattice Boltzmann method (CIP-LBM) for the convection-diffusion equation (CDE) based on the Bhatnagar-Gross-Krook (BGK) scheme equation. The CIP-LBM relies on an accurate numerical lattice equilibrium particle distribution function on the advection term and the use of a splitting technique to solve the Lattice Boltzmann equation. Different schemes of lattice spaces such as D1Q3, D2Q5, and D2Q9 have been used for simulating a variety of problems described by the CDE. All simulations were carried out using the BGK model, although another LB scheme based on a collision term like two-relation time or multi-relaxation time can be easily applied. To show quantitative agreement, the results of the proposed model are compared with an analytical solution.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.219-219
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• 2021

서해안 중부 아산만 안쪽에 위치하는 평택·당진항에서 장래 개발 예정인 면적 6.9km²의 내항2공구 수역은 내항2공구 외곽호안 - 내항가호안 - 내항2공구 중앙 분리호안으로 둘러싸여 있으며, 투수성 제체인 내항가호안 사석 공극을 통하여 해수가 유통되어 조석 현상이 나타나고 있다. 2020년 8~9월의 2개월간 내항2공구 외곽호안 내·외측에서 조석 관측 결과, 2공구 수역의 최대 조차는 1.97m로서 외측 해역 최대 조차 9.79m의 20.1%이고 내·외측의 순간 수위차는 최대 5.82m에 달한다. 내항가호안은 내항2공구 개발이 거의 완료되는 시기까지 유지될 예정이므로 2공구 개발에 따른 내측 조차와 내·외측 수위차의 변화를 정확하게 예측하는 것은 내항가호안 제체 안전에 매우 중요하다. 이 연구의 목적은 장래 개발단계별 변화 예측에 앞서, 관측이 이루어진 2개월간의 실시간 내측 조석과 내·외측 수위차 시계열을 Delft3D-Flow를 이용하여 기 구축된 아산만 수치모델에서 재현하는 것이다. 내항가호안 제체 통과 유량은 내·외측 수위차에 비례하는 것으로 가정하고, 수위차 - 유량 관계식을 도출하였다. 수위차는 평택 조위관측소와 내항2공구 수역의 1분 간격 관측 조위로부터 산출하였고, 제체 통과 유량은 내측 조위(z, 평택항 DL 기준, m) - 수용적(V, 10⁶m³) 관계식으로 계산하였다. 내측 조위 - 수용적 관계식은 수심측량 성과로부터 V = 0.28z² + 3.73z + 2.96 (r²=1.00)으로 얻어졌다. 다양한 함수식의 적합성을 검토한 결과, 다음과 같은 수위차(𝚫z, m) - 제체 통과 유량(Q, m³/s) 관계식을 도출하였다. [내항가호안 내측으로 유입시] $Q_{IN}=\{\begin{array}{lll}{\exp}\{0.54\;{\ln}({\Delta}z)+6.00\}&&\text{; }{\Delta}z{\leq}1.8\\219.82{\Delta}z+158.56&&\text{; }{\Delta}z>1.8\end{array}\;\;(r^2=0.86)$ [내항가호안 외측으로 유출시] Q_OUT = -exp{0.44 ln(-𝚫z) + 5.70} (r²=0.59) 매 𝚫t 마다 제체 통과 유량을 계산하는 알고리즘을 Delft3D 소스 코드에 추가하고, 8개 분조 합성조석(M₂, S₂, K₁, O₁, N₂, K₂, P₁, Q₁)을 외력조건으로 설정하여 2개월간 조석 수치모델링을 수행하였다. 내항2공구 수역의 매 시별 조위 관측치와 모델치를 비교한 결과, 오차는 -0.37~0.37m의 범위이고, 오차 평균은 0.02m, 절대오차 평균은 0.08m로 상당히 정확하게 실시간 조위 변동을 모의하였다. 보정·검정된 이 모델을 이용하여 향후 내항2공구 개발에 따른 내측 조석과 내·외측 수위차 변화에 대한 예측모의를 진행할 예정이다.

• Journal of the KSME
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• v.16 no.2
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• pp.84-91
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• 1976

An experimental investigation of the natural circulating boiling flow characteristic in three cases of annulus with different outer diameter, and the effect of annular gap size on the burnout behavior is presented. The experimental work was conducted for each case of test section at system pressure of $1kg/cm^2$ and inlet subcooling $0-20^{\circ}C$ in the full range of throttling ratio. As the result, the following facts were found. 1) With the increase of ${\Delta}T_{sub}$, $D_{2}$ and A/A_{o}$, $q_{BO}$ increases on the whole, and with the decrease of ${\Delta}T_{sub}$ and $D_{2}$, hydrodynamic instability is accelerated to happen prematually. 2)With the increase of ${\Delta}T_{sub}$, $D_{2}$ and A/A_{o}$ burnout characteristic shows the high velocitylow quality burnout, and with the decrease, low-velocity-high quality burnout. 3)With the decrease of A/A_{o}$, hyddrodynamic instability is singnificantly restrained and the difference of $q_{BO}$ in each $D_2$ under same condition is gradually reduced, finally converging into $1.9{\times}10^{5}kcal/m^{2}-hr$.

• The Korean Journal of Mycology
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• v.35 no.1
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• pp.33-36
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• 2007

An attempt was made to investigate the status of harmful microorganisms occurring on different kinds of oak bed-logs during shiitake cultivation. As a result, totally 14 species of harmful microorganisms, including Trametes versicolor, were confirmed. Twelve kinds of harmful microorganisms were observed on Quercus acutissima, 9 kinds on Q. mongolica and 10 kinds on Q. aliena. Diatrype stigma, Hypoxylon truncatum, Hypoxylon sp. and Trichoderma sp. occupied 75.1% of the total harmful fungi occurred on Q. acutissima. H. truncatum and Trichoderma sp. occupied 71.2% of the total harmful fungi occurred on Q. mongolica. On Q. aliena, the occurrence of H. truncatum, Trichoderma sp. and Hypoxylon howeianum was 80.3%. D. stigma and Hypoxylon sp. were observed exclusively on Q. acutissima bed-logs, and the outbreak ratios were 51.6% and 13.1%, respectively. H. truncatum was observed on 46.6% of Q. aliena bed-logs and Trichoderma sp. was observed on 30.3% of Q. mongolica bed-logs.

• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.887-896
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• 2004

The present study was carried out to investigate the blood markers of Mongolian horses. The blood redcell types and blood protein types(biochemical polymorphisrns) were tested from 19 Mongolian horses by serological and electrophoretic procedure, and their phenotypes and gene frequencies were estimated. The blood group and biochemical polymorphism phenotypes observed with high frequency were $A^{af}$(42.1%), $C^a$(89.5%), $K^-$(84.2%), $U^a$(63.2%), $P^a$(42.1%) $P^-$42.1%), $Q^c$(31.6%) $Q^-$(31.6%), $AL^{AB}$((52.6%), AI$B^K$(89.5%), $ES^1$(63.2%), $GC^F$(78.9%), $HB^BI$1(68.4%), PG$D^F$(84.2%), $TF^{FIR}$(21.1%), $TF^{F2R}$(21.1%)(21.1%), and genotypes $D^{cgm/dghm}$(15.8%), $D^{dghm/dghm}$(15.8%), $D^{ad/dghm}$(10.5%), $D^{ade/dghm}$(10.5%), in Mongolian horses, respectively. Alleles observed with high frequency were $A^a$(0.4211), $C^a$(0.8947), $K^-$(0.8421), $U^a$(0.6316), $P^a$(0.4474), $Q^c$(0.4474), $D^{dghm}$(0.4211), $AL^B$(0.6579), $AIB^K$(0.9211), $ES^I$(0.7895), $GC^F$(0.8947), $HB^{BI}$(0.7895), $PGD^F$(0.8421) and $TF^R$(0.3421) in Mongolian horses. These results present basic information for estimating the genetic relationships between the Korean native horse, and developing a system for parentage verification and individuals identification in Mongolian horse.