• Journal of the Korean Society of Systems Engineering
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• v.8 no.2
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• pp.1-10
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• 2012

This paper aims to analyze the result of SE Process Implementation on Light Rail Transit(LRT) Project. Currently the Light Rail Transit Project of Korea applies SE to the intermediate phase, that is, E&M phase which is a manufacturing and designing procedure. More seriously, the application effect of SE is not remarkable because it applies to some specific engineering fields like RAMS and it depends on superficial consulting of foreign companies with low SE support capability and investment capital. This study points out that the "Requirement Analysis" and "System Alternative Review" has not been conducted from the initial phase (basic plan and basic design) of the LRT projects. Several projects indicate that the amount of investments for SE activities through the Korea LRT project is relatively very small in comparison with the global capital which is about 10% of total project budget. Furthermore, Korea LRT projects have very few SE professionals and weak SE organization with no government directions and guide book for the efficient implementation of SE for the LRT projects.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.383-386
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• 2002

Polycrystalline Cu(In,Ga)Se$_2$(CIGS) thin-films were grown by co-evaporation on a soda lime glass substrate. In this paper the effects of the Se evaporation temperature on the properties of CuIn0.75Ga0.25Se2 (CIGS) thin films. Structure, surface morphology and optical properties of CIGS thin films deposited at various Se evaporation temperatures have been investigated using a number of analysis techniques. X-ray diffraction (XRD) analysis shows that CIGS films exhibit a strong <112> preferred orientation. As expected, at higher Se evaporation temperatures the films displayed a lower degree of crystallinity. The <112> peak was also enhanced and other CIGS peaks appeared simultaneously. These results were supported by experimental work using scanning electron microscopy When the Se evaporation temperature was increased, the average grain size also decreased together with a reduction Cu content. The Se evaporation temperature also had a significant inf1uence on the transmission spectra. Increasing the Se evaporation temperature, the cell efficiency was improved dramatically to 11.75% with Voc = 556 mV, Jsc = 32.17 mA/cm2 and FF = 0.66. The Se evaporation temperature is an important parameter in thin film deposition regardless of the deposition technique being used to deposit thin films

• Korean journal of applied entomology
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• v.61 no.3
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• pp.449-460
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• 2022

The morphology and whole genome sequence of Spodoptera exigua nucleopolyhedrovirus K1 (SeNPV-K1) isolated in Korea were analyzed for the use as an eco-friendly control source against S. exigua. The polyhedra of SeNPV-K1 was amorphous with a size of 0.6-1.8 ㎛, and there was no external difference with the previously reported SeNPV. As a result of analyzing the nucleotide sequence of the whole genome, it was composed of 135,756 bp, which is 145 bp more than that of the previously reported SeNPV. The G+CG+C content was 44% and there were 6 homologous repeated sequences, so there was no significant difference from the previous report. As a result of ORF analysis, SeNPV-K1 had 137, two fewer than those previously reported, and 4 ORFs present only in SeNPV-K1 were confirmed. These 4 ORFs are non-essential genes and were not considered to have a significant influence on the characteristics of the SeNPV. The genome vista analysis showed that the overall sequence similarity between SeNPV-K1 and the previously reported SeNPV was very high. The whole genome of SeNPV-K1 analyzed for the first time in Korea was found to be similar to the previously reported SeNPV, but it was confirmed that it was a novel resource in Korea with different isolate.

• Korean Journal of Materials Research
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• v.16 no.11
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• pp.663-667
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• 2006

CTAB(cetyltrimethylammonium bromide)-capped CdSe nanoparticles were prepared by using a 4 : 1(v/v) distilled water-isopropyl alcohol mixture. The cadmium chloride and sodium selenosulfate were used as the cadmium and selenium source. By the analysis of XRD and XPS, the resultant particle was confirmed to be cubic CdSe phase. TEM image showed CdSe nanoparticles with empty core. The CTAB-capped sample showed an maximum absorption at 418nm, blue-shifting compared with bulk CdSe, which indicated stronger quantum confinement effect compared with uncapped sample. From FT-IR analysis, it was found that the presence of the new peaks in the $850{\sim}1250cm^{-1}$ range indicated the existence of chemical bonding between CTAB and surface of CdSe nanoparticles. Also TG analysis indicated that there were two weight-loss steps for the CTAB-capped CdSe nanoparticles. It was suggested that CTAB played a significant role in protecting CdSe nanoparticles.

• Korean Journal of Food Science and Technology
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• v.3 no.3
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• pp.144-149
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• 1971

The sensitive technique of activation analysis is well suited for this study since the elements such as As, Br, and Se in tobaccoes are expected to be high concentration. As, Br, and Hg were determined by Bethge destruction method and subsequent neutron activation analysis. $^{77m}Se$ was also by non-destruction activation analysis. The quantities of the element determined in Korean tobaccoes are given as follows in ppm: As, 0.65 ppm. Hg, 0.74 ppm. Se, 1.18 ppm. Br, 7.1 ppm. From the date given it seems that Korean tobaccoes and foreign tobaccoes contained considerably high concentration of selenium and mercury.

• Journal of International Academy of Physical Therapy Research
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• v.11 no.3
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• pp.2155-2163
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• 2020

Background: Various treatments have been proposed for chronic low back pain (CLBP), but recent guidelines and reviews recommend regular physical exercise. However, some other studies have reported opposite results that sling exercise (SE) and other exercises (OE) did not differ in improving CLBP. Objectives: To systematically review and meta-analyze the effects of SE on CLBP in studies published in Korea. Design: A Systemic Review and Meta-analysis. Methods: Randomized controlled trials comparing SE with OE and modality therapy (MT), published up to June 2020, were identified by electronic searches. Primary outcomes were pain and disability. The weighted mean difference (WMD), stand mean difference (SMD) and 95% confidence interval (CI) were calculated using a random-effects model. Results: Based on the results of the meta-analysis, SE was effective for pain in the comparison of SE and MT [short-term: WMD=-1.64, 95% CI (-3.06, -0.22); long-term: WMD=-0.34, 95% CI (-0.42, -0.26)]. It was effective for pain in the comparison of SE and OE [short-term: WMD=-1.18, 95% CI (-2.15, -0.20); long-term: WMD=-0.66, 95% CI (-0.89, -0.43)]. It was also effective for disability in the comparison of SE and MT [short-term: SMD=-15.82, 95% CI (-23.10, -8.54)]. We found no clinically relevant differences in disability between SE and OE. Heterogeneity was high in the comparison of SE and overall variables. Conclusion: If SE is applied to physical therapy to improve the main symptoms of CLBP patients, it may contribute to their recovery. More high-quality randomized studies on the topic are warranted.

• Analytical Science and Technology
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• v.16 no.5
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• pp.399-406
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• 2003

This study was conducted to find out the analysis condition of selenium(Se) in oil refinery wastewater with a high concentration of Se using the atomic absorption spectrometry with hydride generation system (HG-AAS). From various experiments that reduced Se(VI) to Se(IV), the optimum pretreatment condition was determined to be a sample volume of 10 mL, HCl 10 mL, with a 30 min heating time in a water bath. In oil refinery wastewater, as the concentration of organics and constitution became higher, the recovery rates of Se decreased. Therefore, three acid digestion methods ($HNO_3/HClO_4$ digestion, $KMnO_4$ digestion, and microwave acid digestion) were tested on the recovery rates of Se in reference to the digestion of organics, petroleum and oxidation from organic Se(org.), Se(IV) to Se(VI). The experiment results showed that the average recovery rate of Se was the highest in microwave acid digestion, although all of the digestions were more than 90%. In consequence, the pretreatment procedure of microwave digestion followed by HCl addition was the most suitable for selenium analysis in oil refinery wastewater by using HG-AAS.

• Journal of the Korean Ceramic Society
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• v.52 no.6
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• pp.489-496
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• 2015

In this study, novel $Ag_2Se$ sensitized $TiO_2$ nanocomposites were prepared by facile sonochemical assisted synthesis method. The as-prepared products were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), and N2 adsorption BET analysis. The as-prepared $Ag_2Se/TiO_2$ nanocomposites simultaneously possessed great adsorptivity for organic dyes and efficient charge separation properties. In the decolorization of rhodamine B, a significant enhancement in the reaction rate was observed for the $Ag_2Se/TiO_2$ nanocomposite compared to the cases of using pure P25 or $TiO_2$. The sonocatalysis activity was higher due to the greater formation of reactive radicals, as well as to the increase of the active surface area of the $Ag_2Se/TiO_2$ nanocomposite.

• Journal of the Korean Ceramic Society
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• v.54 no.3
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• pp.205-210
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• 2017

In this study, we examined the photo-degradation efficiency of $CoSe_2$-Graphene-$TiO_2$ ($CoSe_2-G-TiO_2$) nanocomposites under visible light irradiation using rhodamine B (RhB) as standard dye. $CoSe_2-G-TiO_2$ nanocomposites were synthesized by ultrasonication and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopic analysis and UV-Vis absorbance spectra analysis. Our results show that the $CoSe_2-G-TiO_2$ nanocomposite exhibited significant photo degradation efficiency compared to pure $TiO_2$ and $CoSe_2-G$, approximately 85.2% of the rhodamine (Rh B) degraded after 2.5 h. It is concluded that the $CoSe_2-G-TiO_2$ nanocomposite is a promising candidate for use in dye pollutants.

• Analytical Science and Technology
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• v.18 no.1
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• pp.23-26
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• 2005

Se is well known as an anti-oxidant trace element and many customers are interested in an analysis and contents of Se in the various foodstuff samples. This study was aimed at establishig and comparing an analytical method for the determination of the Se in biological samples by neutron activation analysis using two nuclides, $^{75}Se$ and $^{77m}Se$. Keeping this objective, three NIST biological standard reference materials were chosen and the concentrations of the Se were determined under the prefixed analytical conditions such as the irradiation, decay and measurement time. The measured values by both analytical methods were evaluated with certified values. In addition, the detection limits and measurement uncertainty for the analytical results using $^{75}Se$ and $^{77m}Se$ were compared with each other.