• Korean Journal of Materials Research
• /
• v.3 no.3
• /
• pp.276-281
• /
• 1993

In order to study the sintering kinetics of the ternery system, U-Ce-O, its shrinkage rate with time and temperature at the Ar atmoshpere were measured by using the dilatometer. At the sintering kinetics of U-Ce-O, sintering rate curve revealed bimodal and the first extreme point at bimodal curve was affected by the $UO_2$ the second one was due to the $CeO_2$. The sintering of $(U, Ce)O_2$ was delayed as increasing the $CeO_2$. At the same lOwt. % content, the highest sintering rate was observed at the $(U, Ce)O_2$ sample ball-milled for 4 hours.

• Korean Journal of Materials Research
• /
• v.19 no.7
• /
• pp.356-361
• /
• 2009

The optical characterization of self-assembled InAs/AlAs Quantum Dots(QD) grown by MBE(Molecular Beam Epitaxy) was investigated by using Photoluminescence(PL) spectroscopy. The influence of thin AlAs barrier on QDs were carried out by utilizing a pumping beam that has lower energy than that of the AlAs barrier. This provides the evidence for the tunneling of carriers from the GaAs layer, which results in a strong QD intensity compared to the GaAs at the 16 K PL spectrum. The presence of two QDs signals were found to be associated with the ground-states transitions from QDs with a bimodal size distribution made by the excitation power-dependent PL. From the temperature-dependent PL, the rapid red shift of the peak emission that was related to the QD2 from the increasing temperature was attributed to the coherence between the QDs of bimodal size distribution. A red shift of the PL peak of QDs emission and the reduction of the FWHM(Full Width at Half Maximum) were observed when the annealing temperatures ranged from 500 $^{\circ}C$ to 750 $^{\circ}C$, which indicates that the interdiffusion between the dots and the capping layer was caused by an improvement in the uniformity size of the QDs.

• The Bulletin of The Korean Astronomical Society
• /
• v.45 no.1
• /
• pp.29.5-30
• /
• 2020

We present an improved weak-lensing (WL) study of the high-z (z=0.87) merging galaxy cluster ACT-CL J0102-4915 ("El Gordo"), the most massive system known to date at z > 0.6. El Gordo has been known to be an exceptionally massive and rare cluster for its redshift in the current ΛCDM cosmology. Previous multi-wavelength studies have also found that the cluster might be undergoing a merging event showing two distinctive mass clumps and radio relics. The previous WL study revealed a clear bimodal mass structure and found that the entire system is indeed massive (M200a = (3.13 ± 0.56) × 1015 Msun). This mass estimate, however, was obtained by extrapolation because the previous HST observation did not extend out to the virial radius of the cluster. In this work, we determine a more accurate mass estimate of the cluster using WL analysis utilizing a new set of WFC3/IR and wide-field ACS observations. While confirming the previous bimodal mass structure, we find that the new data yield a ~20% lower mass for the entire system (M200a = (2.37 ± 0.28) × 1015 Msun). We also discuss the rarity of the cluster in the ΛCDM paradigm and suggest an updated merging scenario based on our new measurement.

• Journal of Preventive Medicine and Public Health
• /
• v.17 no.1
• /
• pp.95-106
• /
• 1984

To acquire the essential basic data to the establishment of control measure for the hazardous health effect that could be caused by harmful metals, the author measured the concentrations of trace metals in whole blood of women of $20{\sim}39$ years old living in urban and rural area using atomic absorption spectrophotometer. The summarized results were as follows; 1. The mean concentration of zinc in whole blood was $10.69{\pm}8.07{\mu}g/ml$ in rural area. The frequency distribution by zinc concentration level was nearly L-type and the cumulative frequency distribution was showed bimodal type in both area. 2. The mean iron concentration in whole blood was $323.09{\pm}87.15{\mu}g/ml$ and $322.07{\pm}104.74{\mu}g/ml$ in urban and rural area, respectively. The frequency distribution was similar to normal distribution type in both area, but the cumulative distribution was unimodal type in urban area and bimodal type in rural area. 3. The mean magnesium concentration was $41.08{\pm}19.58{\mu}g/ml$ and $40.28{\pm}16.82{\mu}g/ml$ in the area, respectively. The frequency distribution type had skewness to the right and the cumulative frequency distribution was unimodal type in both area. 4. The mean copper concentration was $1.417{\pm}0.761{\mu}g/ml$ and $1.375{\pm}0.743{\mu}g/ml$ in the area, respectively. The frequency distribution type had skewness to the right and the cumulative frequency distribution was bimodal type in both area. 5. The mean manganese concentration was $0.079{\pm}0.039{\mu}g/ml$ and $0.07{\pm}0.058{\mu}g/ml$ in the area, respectively. The frequency distribution type had skewness to the right in both area but slight irregular in rural area and the cumulative distribution was unimodal and bimodal type in urban and rural area, respectively. 6. The mean cadmium concentration in whole blood was $0.031{\pm}0.026{\mu}g/ml$ in urban and $0.028{\pm}0.023{\mu}g/ml$ in rural area. The frequency distribution type had skewness to the right and cumulative frequency distribution was bimodal type in both area.

• Journal of Korean Neurosurgical Society
• /
• v.62 no.5
• /
• pp.519-525
• /
• 2019

Objective : The circadian pattern of the onset time of aneurysmal subarachnoid hemorrhage (aSAH) has been reported by various authors. However, the effect of the degree of physical exertion on the circadian pattern has not been studied in detail. Therefore, we conducted this study to investigate the effect of physical exertion on the circadian pattern of aSAH. Methods : Of the 335 patients presenting with aSAH from January 2012 to December 2017, 234 patients with identifiable onset time and metabolic equivalent (MET) values were enrolled. The onset time of aSAH was divided into 4-hour intervals. The patient's physical exertion was then assessed on a scale between 1 and 8 METs using generally accepted MET values, and categorized into two groups-light exertion (1 to 4 METs) and moderate to heavy exertion (5 to 8 METs)-to determine the effect of the degree of physical exertion on the onset time distribution of aSAH. Multivariate analysis was used to calculate the odds ratio (OR) between the two groups to determine the effect of the degree of physical exertion on each set of time periods. Results : There was a definite bimodal onset pattern that peaked at 08:00-12:00 hours followed by 16:00-20:00 hours (p<0.001). MET values at all time intervals were found to be significantly higher than the night time (00:00-04:00 hours) values (p<0.031). The MET value distribution showed a unimodal pattern that slightly differed from the bimodal distribution of the onset time of aSAH. There were no significant differences in the ORs of each time interval according to the degree of the MET value. Conclusion : This study reaffirmed that aSAH occurs in a bimodal pattern, especially showing the highest prevalence in the morning. Although aSAH could be related to daily activity, there were no significant changes in diurnal variations affected by the degree of physical exertion.

• MALSORI
• /
• no.62
• /
• pp.149-161
• /
• 2007

In this paper we proposed a modified reliability function for improving bimodal speaker identification(BSI) performance. The convectional reliability function, used by N. Fox[1], is extended by introducing an optimization factor. We evaluated the proposed method in BSI domain. A BSI system was implemented based on GMM and it was tested using VidTIMIT database. Through speaker identification experiments we verified the usefulness of our proposed method. The experiments showed the improved performance, i.e., the reduction of error rate by 39%.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.6
• /
• pp.1266-1268
• /
• 2008

• Archives of Plastic Surgery
• /
• v.42 no.4
• /
• pp.486-489
• /
• 2015

• Bulletin of the Korean Chemical Society
• /
• v.24 no.6
• /
• pp.691-694
• /
• 2003

We report a quantum wavepacket study on the characteristic bimodal translational energy distribution of photostimulated desorbed Xe from an oxidized silicon (001) surface observed by Watanabe and Matsumoto, Faraday Discuss. 117 (2000) 203. We have simulated the theoretical translational energy distributions based on wavepacket calculations with a sudden transition and averaging model to reproduce the experiment. We discuss the desorption mechanism and suggest a very strong position dependence of the deexcitation processes for Xe/oxidized Si(001).

• The Korean Journal of Applied Statistics
• /
• v.11 no.1
• /
• pp.129-139
• /
• 1998

This article examines the use and some difficulties of Normal Test Variables(NTV) plot for clinical research. Monte Carlo Simulation results are presented based on Normal, Bimodal, Uniform, Exponential and skewed-right distributed Beta Distributions. Further, some solutions are presented and illustrated.