• Journal of computational fluids engineering
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• v.15 no.3
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• pp.1-8
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• 2010

Laminar separation bubble and transitional flow over the NACA0012 are investigated at a moderate range of Reynolds numbers. A Reynolds-Averaged Navier-Stokes code is coupled with an empirical transition model that can predict transition onset points and the length of transition region. Without solving the boundary layer equations, approximated e-N method is directly applied to the RANS code and iteratively solved together. The computational results are compared with the experimental data for the NACA0012 airfoil. Results of transition onset point and the length are compared well with experimental data and Xfoil prediction. The present RANS results show at high angles of attack better agreement with experimental data than Xfoil results using the boundary layer equations.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.2
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• pp.9-17
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• 2002

For turbulent spray combustion flows a coupled numerical procedure was developed, This method was discretized by using generalized curvilinear coordinates to handle complex geometries. The preconditioning and eigenvalue rescaling techniques were employed to provide efficient convergences over a wide range of subsonic Mach numbers. The accuracy was validated by simulating the laminar cavity flow. The film cooling effect of a liquid rocket engine (KSR-III) were investigated by a spray combustion analysis. The film cooling showed a negative effect on the combustion efficiency. In the combustion chamber wall, the film cooling effect was revealed to be promoted by the production of fuel rich zone.

• Women's Health Nursing
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• v.7 no.2
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• pp.157-168
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• 2001

The purpose of this study was to investigate of the relationship of the urinary incontinence, menopausal symptom and life satisfaction in middle aged women. The subjects of this study were 235 middle aged women, living in M city, during the period from June 21 to August 31, 2000. The instruments for this study were the urinary incontinence modified and adding by Lee Young Sook(1994), the menopausal symptom developed by Song Ae Ri and Chung Eun Soon(1998) and the life satisfaction translated and modified by Suh Kyung Hee(1988). Collected data were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients and stepwise multiple regression with SAS package. The result of this are as follows : 1. The total mean score of urinary incontinence was $1.56{\pm}0.58$ with a range of 0 to 4. The mean score on the menopausal symptom was $2.05{\pm}0.43$ with a range of 1 to 4. The mean life satisfaction score was $1.14{\pm}0.41$ with a range of 0 to 2. 2.General characteristics ralated to urinary incontinence were age and numbers of children (F=7.66, p=0.000, F=2.86, p=0.037). General characteristics ralated to menopausal symptom were age (F=7.37, p=0.000), occupation (t=5.33, p=0.021), problem of children (t=6.46, p=0.011) and marital satisfaction (F=5.65, p=0.004). General characteristics ralated to life satisfaction were type of housing (t=12.06, p=0.000), problem of children (t=6.96, p=0.008) and marital satisfaction (F=18.86, p=0.000). 3.The urinary incontinence and menopausal symptom were correlated positively (r=.235, p=.000). The urinary incontinence and life satisfaction were correlated negatively (r=-.114, p=.007). The menopausal symptom and life satisfaction were correlated negatively (r=-.277, p=.000). 4.The menopausal symptom, type of housing and marital satisfaction explained 16.6% of the variance for life satisfaction in the middle aged women.

• Journal of Biosystems Engineering
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• v.35 no.3
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• pp.182-188
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• 2010

Post-Harvest processing engineering is a field that studies prevention of the quality change of agricultural products during sorting, packaging, storage, and distribution after harvested. In distribution steps, agricultural products could be damaged by physical force, it is the main reason of low quality and they lost value of commodities. This study was performed to find the vibration characteristics of the peach, and to find the extent of the damage on the peach by fatigue stress. The vibration data was obtained on expressway and the vibration characteristics of peach was used to find the damage on the peach. To analyze the vibration characteristics of peach, the resonance frequency and vibration transmissibility were measured. The resonance frequency of the peach was 167.98 Hz and the transmissibility was 4.06 at resonance point. It was 150 ~ 250 Hz that the transmissibility was more than 1. And the transmissibility in simulated test was measured. When the trasmissibility was more than 1, the range was 15 ~ 65 Hz, and when it was less than 1, the range was 65 ~ 175 Hz. When the transmissibility was about 1, the range was 5 ~ 15 Hz. The damage and the vibration cycle numbers of peaches were compared with input frequency and acceleration. More damage and less cycle number happened in 30 Hz than in 62.5 Hz. The reason was that the transmissibility of 30 Hz was higher and the vibration displacement in lower frequency was more. The more acceleration and cycle number increased, the more the bruising volume of peaches increased. The bruising volume ratio for vibration fatigue was measured according to input acceleration and cycle number. Using measured data, regression models for bruising volume ratio(BVR) was developed as a function of the acceleration(A) and cycle number(CN) as follows. BVR = a * $A^b*$ $(CN)^c$

• Journal of the Korean Chemical Society
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• v.56 no.6
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• pp.669-672
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• 2012

Classical molecular dynamics (MD) simulations using a scaled OSS2 potential originally derived from ab initio calculations are used to study the radial distribution functions of water. The original OSS2 water potential is shown to represent a glassy or an ice at ambient temperature, but the diffusion coefficient increases on increasing the temperature of the system or decreasing the density. This suggests scaling the OSS2 potential. The O-O, O-H, and H-H radial distribution functions and the corresponding coordination numbers for the scaled OSS2 potential, obtained by MD simulation, are in good agreement with the experiment results and calculations for the SPC/E water potential over a range of temperatures.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1668-1672
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• 2013

We developed a standoff Raman detection system for explosive molecules (EMs). Our system was composed of reflective telescope with 310 mm diameter lens, 532 nm pulse laser, and Intensified Charge-Coupled Device (ICCD) camera. In order to remove huge background noise coming from ambient light, laser pulses with nanosecond time width were fired to target sample and ICCD was gated to open only during the time when the scattered Raman signal from the sample arrived at ICCD camera. We performed standoff experiments with military EMs by putting the detector at 10, 20 and 30 m away from the source. The standoff results were compared with the confocal Raman results. Based on our standoff experiments, we were able to observe the peaks in the range of 1200 and $1600cm^{-1}$, where vibrational modes of nitro groups were appeared. The wave numbers and shapes of these peaks may serve as good references in detecting and identifying various EMs.

• 한국전산유체공학회:학술대회논문집
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• 2009.11a
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• pp.60-64
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• 2009

Laminar separation bubble and transitional flow over an airfoil are investigated at a moderate range of Reynolds numbers. In this research, a Reynolds-Averaged Navier-Stokes code is coupled with an empirical transition model that can predict transition onset points and the length of transition region. Without solving the boundary layer equations, approximated e-N method is directly applied to the RANS code and iteratively solved together. The computational results are compared with the experimental data for NACA0012 airfoil. Results of transition onset point and length are compared well with experimental and XFOIL prediction. In high angle of attack the present RANS results show better agreement than XFOIL results using the boundary layer equations.

• Journal of applied mathematics & informatics
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• v.20 no.1_2
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• pp.445-454
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• 2006

We describe a solution to the Ornstein-Uhlenbeck equation $\frac{dI}{dt}-\frac{1}{\tau}$I(t)=cV(t) where V(t) is a constant multiple of a Gaussian white noise. Our solution is based on a discrete set of Gaussian white noise obtained by taking sample points from a sum of single frequency harmonics that have random amplitudes, random frequencies, and random phases. Hence, it is different from the solution by the standard random walk using random numbers generated by the Box-Mueller algorithm. We prove that the power of the signal has the additive property, from which we derive that the Lyapunov characteristic exponent for our solution is positive. This compares with the solution by other methods where the noise is kept to be in an error range so that its Lyapunov exponent is negative.

• Korean Journal of Microbiology
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• v.35 no.3
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• pp.192-196
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• 1999

CHEF-PFGE(Contour-Clarnped Homogeneous Electric field- Pulsed Field Gel Electrophoresis) was used to identify electrophoretic karyotype for eight strains belonging to the Fzisoriuni section Liseolo. Chromosome numbers were nine to thirteen bands, ranging in size Cram 0.75 to 6.45 Mb. The total genome size was eslimated to range from 38.19 Mb to 43.12 Mb and numerous chromosome-length polymorphisms (CLPs) were observed. For the chromosome localizalion of the gene, 1GS sequence(2.6 Kb) of rDNA from F: moniliforme, chs-2 gene(2.8 Kb) and 4 - 3 gene(3.8 Kb) from Neuuospora cmssa were wed as probes.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.226-231
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• 2000

New types of the micro heat flux sensor are designed and fabricated using SU-8 and Cu electroplating. And then calibrated under convection environment. The thermal path was made by SU-8 structure and electroplated Cu layers. The bottom surface of the micro heat flux sensor receives the heat flux from the wall, Then the heat flows along the Cu layers and drains out to the environment with producing the temperature difference at the upper layer of Cu. By measuring this temperature difference, the heat flux from the wall can be obtained. The temperature difference is measured by thermopile which is composed of Ni-Cr pairs or Al-chromel pairs. The calibration is accomplished under convection environment because it is most frequent situation. The range of the sensitivity is 0.11~2.02$\mu$V/(㎽/$\textrm{cm}^2$) for the various heat flux and Reynolds numbers.