• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.3
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• pp.59-68
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• 2023

Currently, yellow phosphor of Y3Al5O12:Ce3+ (YAG:Ce) fluorescent material is applied to a 450~480nm blue LED light source to implement a white LED device and it has a simple structure, can obtain sufficient luminance, and is economical. However, in this method, in terms of spectrum analysis, it is difficult to mass-produce white LEDs having the same color coordinates due to color separation cause by the wide wavelength gap between blue and yellow band. There is a disadvantage that it is difficult to control optical properties such as color stability and color rendering. In addition, this method does not emit purple light in the range of 380 to 420nm, so it is white without purple color that can not implement the spectrum of the entire visible light spectrum as like sunlight. Because of this, it is difficult to implement a color rendering index(CRI) of 90 or higher, and natural light characteristics such as sunlight can not be expected. For this, need for a method of implementing sunlight with one LED by using a method of combining phosphors with one light source, rather than a method of combining red, blue, and yellow LEDs. Using this method, the characteristics of an artificial sunlight LED device with a spectrum similar to that of sunlight were demonstrated by implementing LED devices of various color temperatures with high color rendering by injecting phosphors into a 405nm deep blue LED light source. In order to find the spectrum closest to sunlight, different combinations of phosphors were repeatedly fabricated and tested. In addition, reliability and mass productivity were verified through temperature and humidity tests and ink penetration tests.

• Journal of Applied Reliability
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• v.11 no.4
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• pp.343-356
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• 2011

This paper proposes an accelerated life evaluation of drive shaft. The life test of drive shaft for independent suspension type AWD vehicle should be performed by use of the least test sample because many number of samples can't be used for the test because of its mass capacity and high price. We calculated the no failure test time by application of no failure test concept, and the already performed test data for drive shaft are applied for some kinds of reliability coefficients which are needed for calculation of life test time. And, for analysis of real driving condition of vehicle, the load spectrum is prepared using the needed road condition and vehicle data. The inverse power model is used for accelerated life test. The equivalent torque of load spectrum is achieved by use of Miner's Rule, and then the final accelerating condition is determined by decision of the accelerated test torque. This paper shows that the accelerated life test results corresponds with the target life and the proposed life test method can be very well applied to no failure life test for mass capacity machinery components.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.2
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• pp.289-298
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• 2011

TMAH-based Py-MS has been investigated to apply for a real-time classification of biological agents in the field. Acquiring reproducible data from mass spectrometry is a key to biological detection in the field. Nevertheless, it has been little studied on what factors could affect to the reproducibility of the TMAH-based Py-MS spectrum patterns. Given the TMAH-based Py-MS applied to the field system, several factors which could affect to the reproducible pattern of TMAH-based Py-MS spectra are needed to be examined, including changes in TMAH injection volume, growth temperature for microorganism, and number of cells collected in pyrolyzer, and implication of stabilizer used for lyophilization. This study showed that the reproducibility of the spectrum patterns was significantly hindered by changes in TMAH concentration and cell number, and stabilizer implication but not by growth temperature. Among those at low TMAH concentration(0.015m) was not observed the significant alterations of the spectrum pattern even when its injection volume was changed, yet was in different cell numbers and stabilizer implication.

• Textile Coloration and Finishing
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• v.10 no.3
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• pp.20-28
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• 1998

Natural indigo colorants were prepared by extraction of polygonum tintorium which was harvested just in the blooming season(in the late of July). The components were analyzed by TLC and HPLC, and its structures were analyzed by FT-IR, EI-mass and NMR. The dyeing mechanism and fermentation conditions were investigated. Its colour fastness was studied as well. The results obtained are summarized as follows ; The natural indigo powder was dissolved in DMSO and developed in eluent, $CHCl_3/CH_3CN(8.5:1.5v/v)$ by means of TLC for its quality analysis. It was segregated into indirubin as il red colour and indigo as a blue colour. In case of HPLC analysis, the retention times of indirubin and indigo were 7.442 and 6.543, respectively. FT-IR spectrum of indirubin showed a peak for NH residue between 3200 and $3300cm^{-1}.^1H-NMR$ spectrum for indigo displayed AA'BB' spin system caused by indole structure between 6.5 and 7.7ppm of H4, 5, 6 and 7, and -NH proton for indirubin showed an singlet between 10.88 and. 11.0ppm. EI-mass spectrum of indigo an d indirubin both disclosed their molecular size as 262 and it implies that these two substances are isomer.

• Korean Journal of Psychosomatic Medicine
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• v.23 no.2
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• pp.129-135
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• 2015

Objectives : In children and adolescents, the prevalence of overweight has increased in the last 20 years. little research is available on the prevalence of obesity in children with autism spectrum disorders(ASD). The purpose of our study was to determine the prevalence of overweight among a clinical population of children diagnosed with autism spectrum disorders(ASD). Methods : Retrospective chart review of children ages 3-18 years seen between 2012 and 2015 at a Konyang University hospital psychiatric clinic. Diagnostic, medical, and demographic information was extracted from the charts. Body mass index(BMI) was calculated from measures of height and weight recorded in the child's chart. The Center for Disease Control's BMI growth reference was used to determine an age and gender-specific BMI z-score for the children. Results : In our study, children with ASD compared to non ASD group had significantly higher BMI percentiles (p=0.032). The prevalence of overweight($BMI{\geq}85th$ to 95th percentiles) and obesity($BMI{\geq}95th$ percentiles) was 35% and 19% respectively in children with ASD and without ASD. Conclusions : Despite noted limitations, our data suggest that overweight and obesity in children with ASD are more prevalent than without ASD. Longitudinal and further study is needed to examine the factors associated with obesity in this population.

• YAKHAK HOEJI
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• v.42 no.6
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• pp.552-557
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• 1998

Acyl CoA synthetase inhibitor, was purified from the culture broth of a Bacillus sp. B-6, which had been isolated from soil, by chloroform extract, silica gel column chro matography and preparative TLC. The purified acyl CoA synthetase inhibitor showed higher Antifungal activity against C. al-bicans (MIC: 8${\mu}$g/ml). Though the analysis of UV spectrum, melting point, IR spectrum, Mass-spectrum, $^1H$-NMR and $^{13}C$-NMR spectrum, the inhibitor could be identified as phenazine-l-carboxylic acid.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.43.1-43.1
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• 2017

We investigate properties of black hole (BH) binaries formed in globular clusters, by using direct N-body simulations. Comparing with previous studies which usually considered single BH masses, our models consist of two-component BH masses, or continuous BH mass function with single mass ordinary cluster stars. During the early stage of dynamical evolution, initially distributed BHs are move to the cluster center by dynamical friction, then BH-BH binaries start to be formed, and eventually be ejected from the cluster due to three body interaction. Finally we find the formation efficiency of high mass BHs are alwats larger than that of lower mass BHs, implying that a BH mass spectrum expected from GW observation should be biased to high mass. In addition, mass ratios of BHs in binaries prefer similar masses (ratio~1), while the most extreme case is less than 3. Expected merger rate from our models is about 7 BH-BH mergers per $Mpc^3$ per yr.

• Journal of the Korean Chemical Society
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• v.51 no.4
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• pp.356-360
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• 2007

5,7-Diaryl-3,4,6-trihydronaphthalen-2-ones have been synthesized from 3,5-diaryl-cyclohex-2-en-1- ones and methyl vinyl ketone in the presence of sodium ethoxide. The products were characterized by IR, UV-Visible, 1H-NMR, 13C-NMR and mass spectral techniques. To confirm 1H and 13C signals, HSQC spectrum was recorded and analyzed.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.645-650
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• 2017

This technical note demonstrates the feasibility of using laser ablation inductively coupled plasma mass spectrometry for the characterization of U-7Mo/Ale5Si dispersion fuel. Our measurements show 5.0% Relative Standard Deviation (RSD) for the reproducibility of measured $^{98}Mo/^{238}U$ ratios in fuel particles from spot analysis, and 3.4% RSD for $^{98}Mo/^{238}U$ ratios in a NIST-SRM 612 glass standard. Line scanning allows for the distinction of U-7Mo fuel particles from the Al-5Si matrix. Each mass spectrum peak indicates the presence of U-7Mo fuel particles, and the time width of each peak corresponds to the size of that fuel particle. The size of the fuel particles is estimated from the time width of the mass spectrum peak for $^{98}Mo$ by considering the scan rate used during the line scan. This preliminary application clearly demonstrates that laser ablation inductively coupled plasma mass spectrometry can directly identify isotope ratios and sizes of the fuel particles in U-Mo/Al dispersion fuel. Once optimized further, this instrument will be a powerful tool for investigating irradiated dispersion fuels in terms of fission product distributions in fuel matrices, and the changes in fuel particle size or shape after irradiation.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.650-654
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• 1999

Undaria pinnatifida oxidized by nitric acid had a high capacity of Cu/sup 2+/ uptake (3.5 mmol Cu/sup 2+/g dry mass) at pH 4 and showed high affinity to Cu/sup 2+/ and Pb/sup 2+/, in a mixed-metal system, compared to Ca/sup 2+/ and Mg/sup 2+/. The IR spectrum showed increase of carboxylic acid on the surface of Undaria pinnatifida, mostly due to the effect of the oxidation reaction.