• Reproductive and Developmental Biology
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• 제29권3호
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• pp.141-144
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• 2005

This experiment was to investigate whether the mitochondria function assessment can be used for the prediction of sperm fertility through examining the correlation between mitochondria fluoromicroscopic frequency of frozen-thawed eight Hanwoo bull semen using rhodamine123 (R123) and in vitro embryo development following fertilization. Individual sperm were stained in 5 ${\mu}g/mL$ R123-added calcium-free Sp-TALP for 30 min at 0 h, 6 h, 12 h and 24 h after thawing and examined their mid-piece under an epifluorescence microscope using 495 nm excitation filter (x1,000). Three replications were taken, and at least 300 sperm per individual were examined. When semen samples were separated into two groups (good and poor) by sperm motility and fluorescent frequencies at just after thawing, average fluorescent frequencies were remarkably reduced as time going (0 h; $53.29{\~}72.94\%$, 6 h; $21.40{\~}58.90\%$, 12 h; $8.26{\~}25.93\%$, 24 h; $1.00{\~}13.78\%$, irrespective of selected group, and there were no differences at 6 h or 12 h after thawing between selected groups but indicated significant difference at 24 h after thawing (p<0.05). In vitro fertilization rates in good and poor groups ranging $70.8{\~}77.8\%$ and $52.1{\~}84.5\%$, respectively, were not significantly different. However, in vitro development rates of the same groups ranging $25.7{\~}40.0\%$ and $12.9{\~}1.8\%$, respectively, were significant different (p<0.05). These results demonstrate that mitochondria fluoromicroscopic assessment of frozen-thawed bovine sperm may be used as a criterion to select more fertile sperm.

• 한국물환경학회지
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• 제23권2호
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• pp.236-243
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• 2007

Fluorescence measurements of dissolved organic matter (DOM) have the superior advantages over other analysis tools for the applications to water quality management due to their rapid analysis. It is known that protein-like fluorescence characteristics are well corelated with microbial activities and biodegradable organic matter. In this study, potential biochemical oxygen demand (BOD) predictor were explored using the fluorescence peak intensities and/or the integrated fluorescence intensities derived from synchronous fluorescence spectra and the first derivative spectra of river samples. A preliminary study was conducted using a mixture of a river and a treated sewage to test the feasibility of the approach. It was demonstrated that the better BOD predictor can be derived from synchronous fluorescence spectra and the derivatives when the difference between the emission and the excitation wavelengths (${\Delta}{\gamma}$) was large. The efficacy of several selected fluorescence parameters was rivers in Seoul. The fluorescence parameters exhibited relatively good correlation coefficients with the BOD values, ranging from 0.59 to 0.90. Two parameters were suggested to be the optimum BOD predictors, which were a fluorescence peak at a wavelength of 283 nm from the synchronous spectrum at the ${\Delta}{\gamma}$ value of 75 nm, and the integrated fluorescence intensity of the first derivatives of the spectra at the wavelength range between 245 nm and 280 nm. Each BOD predictor showed the correlation coefficients of 0.89 and 0.90, respectively. It is expected that the results of this study will provide important information to develop a real-time efficient sensor for river BOD in the future.

• Journal of Korean Vacuum Science & Technology
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• 제4권1호
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• pp.1-5
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• 2000

The C 1s photoelectron energy loss spectra of tris (8-hydroxy-quinoline) aluminum (Alq$_3$) and N,N'-diphenyl-N,N'-bis (3-methyl phenyl)-1,1'-bi-phenyl-4,4'-diamine (TPD) thin films have been investigated. Two major loss structures, namely the plasmon dominated loss lines and shake-up satellites, have been observed. The shake-up spectrum of the C 1s photoelectron line is directly related to the $\pi$-$\pi$$\^$*/ energy gap of the molecule which plays an important role in organic electroluminescent materials. The molecular orbitals of Alq$_3$ and TPD and their major components, quinolime and benzene, have been calculated with the AMI semi-empirical method. The amount of the plasma-dominated loss of Alq$_3$ and TPD, which has to do with the delocalization of electrons through the molecule, was about 24 eV, alike in both cases. The main peak of the C 1s shake-up spectrum of Alq$_3$ and TPD, however, was 5.2 eV and 6.8 eV respectively. It was found that the main shake-up peak reflects more the local $\pi$\longrightarrow$\pi$$\^$*/ transition of quinoline and benzene component rather than the excitation of the whole molecule of Alq$_3$ and TPD. The C 1s shake-up spectra, however, revealed some correlation with the optical energy gap of the organic eletroluminescent materials.

• 전산구조공학
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• 제5권3호
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• pp.127-137
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• 1992

해양 가이드 타워를 대상으로 하여 지진하중에 대한 심해용 구조물의 비정상 거동해법에 대하여 연구하였다. 지반운동의 비정상 특성을 정상과정 성분에 시간포락함수가 곱해진 형태로 모형화하였으며, 구조물의 비정상 거동은 시간종속 분산함수로 구하였다. 지진의 시간포락함수와 정상과정 성분의 자기상관함수를 지수함수로 수식화하여 나타냄으로써, 구조물 거동의 시간종속 분산값을 해석적인 방법으로 구할 수 있는 기법을 개발하였다. 시간에 따른 거동의 분산값을 기본자료로 하여 지진의 발생기간 동안 예상되는 최대거동을 구하였으며, 이 값을 구조물 거동을 정상과정으로 가정하여 산정한 결과와 비교 분석하였다.

• 비파괴검사학회지
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• 제31권5호
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• pp.508-515
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• 2011

보빈 치아 균열을 능동형 적외선 열화상 기술을 이용하여 가시화 하였다. 보빈 치아에 인공 크랙을 발생시킨 후, 외부에서 사인파 형태의 열을 가하면서 보빈 치아에서 방사되는 적외선을 적외선 카메라로 측정하여 이미지화 하였다. 열원의 조화주기와 동기시켜 순차적으로 측정한 보빈 치아의 이미지로부터 열원과 의 위상정보를 추출한 후 이를 다시 영상화 하여 위상 이미지를 생성하였다. 실험 결과로부터 육안이나 종래의 수동형 적외선 이미지에서는 검출하기 어려웠던 치아 크랙이 본 연구와 같은 능동적 적외선 검사방법을 통하여 보다 효과적으로 검사 할 수 있는 가능성을 확인하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.51-55
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• 2007

In this paper Statistical Energy Analysis has been considered to predict high frequency air borne interior noise. Dash panel Insulation is major part to reduce engine excitation noise. Transmission loss and absorption coefficient are considered to predict dash insulation performance. Transmission lose is derived from coupling loss factor and absorption coefficient is derived from internal damping loss factor. Material Biot properties were used to calculate each loss factors. Insulation geometry thickness distribution was hard to measure, so FeGate software was used to calculate thickness map from CAD drawing. Each predicted transmission losses between conventional insulation and light weight insulation were compared with SEA. Transmission loss measurement was performed to validate each prediction result, and it showed good correlation between prediction and measurement. Finally interior noise prediction was performed and result showed light weight insulation system can reduce 40% weight to keep similar performance with conventional insulation system, even though light weigh insulation system has lower sound transmission loss and higher absorption coefficient than conventional system.

• Earthquakes and Structures
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• 제9권1호
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• pp.145-171
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• 2015

Due to earthquakes, many structures suffered extensive damages that were attributed to the torsional effect caused by mass, stiffness or strength eccentricity. Due to this type of asymmetry torsional moments are generated that are imposed by means of additional shear forces developed at the vertical resisting structural elements of the buildings. Although the torsional effect on the response of reinforced concrete buildings was the subject of extensive research over the last decades, a quantitative index measuring the amplification of the shear forces developed at the vertical resisting elements due to lateral-torsional coupling valid for both elastic and elastoplastic response states is still missing. In this study a reliable index capable of assessing the torsional effect is proposed. The performance of the proposed index is evaluated and its correlation with structural response quantities like displacements, interstorey drift, base torque, shear forces and upper diaphragm's rotation is presented. Torsionally stiff, mass eccentric single-story and multistory structures, subjected to bidirectional excitation, are considered and nonlinear dynamic analyses are performed using natural records selected for three hazard levels. It was found that the proposed index provides reliable prediction of the magnitude of torsional effect for all test examples considered.

• Smart Structures and Systems
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• 제11권1호
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• pp.35-51
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• 2013

Over the last two decades Wavelet Transformation (WT) method has been widely utilized for the damage identification of structures. The main objective of this paper is to discuss and present some of common shortcomings and limitations of mathematical software, as well as other precautionary measures that need to be considered when using them for wavelet analysis applications. Due to popular usage of MATLABMATLAB(R) comparing to other mathematical tools among researchers for data processing of structural responses through WT analysis, this software was chosen for specific study. To the best of the authors' knowledge, these limitations and observations have not been previously identified or discussed in the literature. In this work, a square plate with a severe damage, in form of a crack, parallel to the left edge of the plate is selected for a pilot study. The steady state harmonic response is used for measuring the deflection shape across the line parallel to one edge and perpendicular to the damage. Several criteria and cases such as the smallest size damage that can be detected, correlation between the crack width and the number of sampling points, and the influence of the damage thickness on the accuracy of the result are investigated.

• 한국음향학회지
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• 제20권7호
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• pp.3-12
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• 2001

본 연구에서는 소리에 대한 주관적 평가 인자 중 하나인 러프니스 계산 모델을 구현하였다. 구현된 러프니스 모델은 기존 모델의 고찰을 통해 계산 모델을 구체화하였으며, 주파수 영역으로부터 상호 상관 인자를 구하는 방법 등을 이용하여 계산 효율 및 정확도를 향상시켰다. 또한 기존의 주관적인 러프니스 평가치와의 비교를 통해 구현된 모델의 유용성을 확인하였다. 한편 기존 모델 및 구현된 러프니스 계산 모델을 통해 얻을 수 있는 러프니스 스펙트럼이 주파수 영역에서의 슬롭 가진(slope excitation)의 영향으로 인해 실제 변조되는 주파수 대역을 탐색하기 어려운 점을 발견하고, 구현된 모델의 상관 인자 계산 부분을 실제 변조가 발생하는 임계 대역에서만 러프니스 스펙트럼 값이 존재하도록 수정하여, 러프니스 기여성분의 탐색이 보다 용이해진 방법을 제안하였다.

• Bulletin of the Korean Chemical Society
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• 제32권12호
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• pp.4210-4214
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• 2011

Quasiclassical trajectory (QCT) calculations of Ne + ${H_2}^+$ reaction have been carried out on the adiabatic potential energy surface of the ground state $1^2$ A'. The reaction probability of the title reaction for J = 0 has been calculated, and the QCT result is consistent with the previous quantum mechanical wave packet result. Quasiclassical trajectory calculations of the four polarization-dependent differential cross sections have been carried out in the center of mass (CM) frame. The P(${\theta}_r$), P(${\phi}_r$) and P(${\theta}_r$, ${\phi}_r$) distributions, the k-k'-j' correlation and the angular distribution of product rotational vectors are presented in the form of polar plots. Due to the well in $1^2$ A' PES, the reagent vibrational excitation has greater influence on the polarization of the product rotational angular momentum vectors j' than the collision energy.