• Journal of the Korean Chemical Society
• /
• v.28 no.1
• /
• pp.26-33
• /
• 1984

The rate constants for the following vibration-to-vibration energy exchange reactions have been calculated theoretically for the temperature range from 300 to 800K and for n = 2 to 5. HF(v=n) + DF(v=0) ${\to}$ HF(v=n-l) + DF(v=l) + ${\Delta}E$(a) DF(v=n) + HF(v=0) ${\to}$ DF(v=n-l) + HF(v=l) + ${\Delta}E$(b) In calculation the loosely-held, non-rigid dimer collision model and semiclassical method have been employed. The results show that the rate constants for the processes (a) are much greater than those for the processes (b). Also, it is found that the rate constants for the processes (a) increase with decreasing temperature and with increasing quantum number, while those for the processes (b) show the opposite tendencies. These findings are explained in terms of the sign and magnitude of the energy mismatch, ${\Delta}E$.

• Textile Coloration and Finishing
• /
• v.6 no.4
• /
• pp.9-16
• /
• 1994

알칼리 수용액 중에서의 Vinylsulfone(VS)계 반응성염료의 혼합상태의 가수분해 반응을 정량적으로 조사하였다. 혼합이량체의 생성 및 분해반응 속도상수를 각각의 염료의 가수분해반응에서 구한 속도상수를 이용하여 계산하였다. 단독이량체를 생성하는 염료들을 조합하였을 경우에는 혼합이량체가 생성되었다. C.I.Reactive Blue 19가 다른 VS계 염료들과 혼합되었을 경우에는 일반적으로 혼합이량체가 생성되었다. Blue 19와 Orange 16의 조합의 경우에는 낮은 염료농도에서만 혼합이량체가 생성되었으며, Red 22의 경우에는 단독 및 혼합이량체가 생성되지 않았다. 단독이량체가 생성되지않는 Orange 7는 다른 VS계 염료들과의 조합에서 혼합이량체를 생성함을 확인하였다. Yellow 17의 혼합이량체의 분해속도 상수값이 가장 큼을 알 수 있었다.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.12
• /
• pp.3694-3702
• /
• 1999

OSL algorithm has an advantage that repeated algorithm is easily derived, even though penalty function which has a complicated transcendental function. In order to solve this problem, we suggested MPEMG algorithm. However, though this algorithm extend convergence rate of smoothing constant, it include the problem that is not faster than OSL algorithm in the convergence rate increasing penalized log-likelihood. Accordingly, in this paper, we will suggest SMOSLG digital image restoration algorithm which is fast in the convergence rate as well as extend convergence region of smoothing constant. And also we will study the usefulness of algorithm suggested through digital image simulation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.4
• /
• pp.2818-2827
• /
• 2015

The spatial patterns and characteristics of these sequential earthquakes and ground motions induced by the earthquakes are examined by contours of peak ground velocity (PGV) and geometric mean peak ground velocity (GMPGV) using both ordinary kriging in geographical information system (GIS) and data, the records obtained from strong motion stations, acquired after recent sequential earthquakes in Canterbury, New Zealand (NZ). The performance of underground water pipeline system is examined by using data acquired after earthquakes. The spatial distribution of GMPGV is superimposed on water pipeline repairs throughout the water distribution system in areas affected principally by transient ground motion using GIS and then water pipeline repair rates, expressed as repairs/km, for different types of pipe are evaluated relative to the estimated GMPGV outside liquefaction areas. The earthquake performance of underground water pipeline systems is summarized in this study.

• Journal of the Korean Chemical Society
• /
• v.36 no.2
• /
• pp.191-196
• /
• 1992

Reaction of N,N-dimethylaniline(N,N-DMA) and iodine in $CHCl_3,\;CH_2Cl_2 : CHCl_3$(1:1), $CH_2Cl_2$(1:1), and CH2Cl2 has been studied kinetically by using conductivity method. Pseudo first-order rate constants ($k_{obs}$) and second-order rate constants ($k_{obs}$/[N,N-DMA]) are dependent on the N,N-DMA concentration. Second-order rate constants obtained were decreased with increasing N,N-DMA concentration. We analysed these results on the basis of formation of charge transfer complex as a reaction intermediate. From the construction of reaction scheme and activation parameters for the formation and transformation of charge transfer complex. The equilibrium constants decreased when the dielectric constant of solvent was increased, and the value is 1.9${\sim}$4.2$M^{-1}$. The rate of transformation are markedly affected by the solvent polarity.${\Delta}H^{\neq}$ is 6.3-12.6kJ/mol, and ${\Delta}S^{\neq}$ is large negative value of -234J/mol K.

• Journal of the Korean Geophysical Society
• /
• v.5 no.3
• /
• pp.165-174
• /
• 2002

Seismic velocity and attenuation coefficient of the rocks under the broad-band earthquake observatories of the Korea Meteorological Administration have been measured in the laboratory by using very high frequency seismic waves. Estimated P velocities of the rocks range from 3.2 km/s to 5.6 km/s, depending on the rock type, mineral, and weathering, while, the attenuation coefficients vary from 0.06 to 4.3 db/kHz-m. It seems that P velocities is inversely proportional to the attenuation coefficients of the rocks. Average travel-time delays of the broad-band stations seem to be related with the measured P velocities in the laboratory.

• Journal of the Korean Chemical Society
• /
• v.52 no.3
• /
• pp.217-222
• /
• 2008

We investigate the kinetics of diffusion-influenced catalytic reactions occurring in small reaction volume. From a simple exact model study, we find that the reaction rate coefficient decreases with the size of reaction volume. The explicit expression for the average reaction rate constant is presented, which can be regarded as a generalization of well-known Collins-Kimball rate constant into the reactions occurring in a small reaction volume. It turns out that the traditional diffusion influenced reaction dynamics is followed by a single exponential relaxation phase with a rate constant dependent on the reaction volume for the catalytic reactions occurring in small reaction volumes.

• Journal of the Korean Chemical Society
• /
• v.30 no.3
• /
• pp.307-311
• /
• 1986

The rates of hydrolysis of the complex, $trans^-[Cr(en)_2F(H_2O)]^{2+}$, have been investigated using spectrophotometric method at various temperatures and pressure. Temperature was 30${\circ}C$ to 50${\circ}C$ and pressure was varied up to 1500bar. The rate constant measured at 30${\circ}C$ is $2.632{\times}10^{-5}sec^{-1}$. The rate constants are decrease with increasing pressure at constants temperature. Activation volume and other activation parameters are calculated from these rate constants. The activation volumes are all positive and lie in the limited range 0.447 ∼ 3.152$cm^3$/mol and the activation entropies are small values. From the results, it was found that this reaction was endothermic and enthalphy controlled reaction in the experimental temperature.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.09a
• /
• pp.113-116
• /
• 2002

UV/과산화수소법을 적용하여 유기염소계 농약인 chlorothalonil을 분해하는 공정에 있어서 광화학 반응의 효율을 증대시키는 방안으로 과산화수소와 옥살산염의 최적 주입농도를 선정하여 그 제거효율을 비교하였다. 그 결과 UV조사시 과산화수소의 농도가 100ppm일 때 일차반응속도 상수(k)가 0.0869로 가장 높게 나타났으며 옥살산염에서는 1mM일 때 0.1782로 높게 나타남으로써 과산화수소와 옥살산염의 최적 농도를 산출할 수가 있었다. 최적 과산화수소와 옥살산염을 조합하여 UV조사시 반응속도 상수값(k)이 0.1893으로 UV/옥살산염보다도 분해속도가 빠르게 나타났다.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2004.05a
• /
• pp.179-182
• /
• 2004

무선통신분야에서 LMS5(Least Mean Square) 알고리즘은 식이 간단하고 계산량이 비교적 적기 때문에 널리 사용되고 있다. 그러나 시간영역에서 처리할 경우 입력신호의 고유치 변동폭이 넓게 분포되어 수렴속도가 저하하는 문제점이 있다. 이를 해결하기 위하여 신호를 FFT(Fast Fourier Trasnform)나 DCT(Discrete Cosine Transform)로 변환하여 신호간의 상관도를 제거함으로써 시간영역에서 LMS알고리즘을 적용할 때 보다 수렴속도를 크게 향강시킬 수 있다. 본 논문에서는 수렴속도 향상을 위해 시간영역의 적응 알고리즘을 직교변환인 고속웨이브렛(wavelet)변환을 이용하여 변환영역에서 수행하며, 짧은 필터계수를 가지는 DWT(Discrete Wavelet Transform)특성에 맞는 Fast running FIR 알고리즘을 이용하여 WTLMS(Wavelet Transform LMS)적응알고리즘을 통신시스템에 적용한다. 적응 알고리즘의 성능향상을 위하여 시간에 따라 적응상수의 크기를 가변시켜 수렴 초기에는 큰 적응상수로 따른 수렴이 가능하도록 하고 점차 적응상수의 크기를 줄여서 misadjustment도 줄이는 방법의 적응 알고리즘을 제안하였다. 제안한 알고리즘을 실제로 적응잡음제거기(adaptive noise canceler)에 적용하여 컴퓨터 시뮬레이션을 하였으며, 각 알고리즘들의 계산량, 수렴속도를 이용하여 각각 비교, 분서하여 그 성능이 우수함을 입증하였다.