• Journal of Technology Innovation
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• v.25 no.2
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• pp.89-125
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• 2017

Complex product systems (CoPs) is a engineering-intensive products with high-ended design technology, which are closely linked with national economic growth and development of social infrastructures. Accordingly, in order to understand the technological evolution of CoPs, it is necessary to identify the macro-environmental drivers surrounding the CoPs and their impact on the technological evolution of the CoPS. Therefore, we investigate the effect of policy, economic and social drivers on the technological evolution of CoPS by implementing the longitudinal case study on nuclear power plant during the periods between 1950 and 2010s. Based on the analysis of various sources of secondary data and primary data through interviews, we found that the technological evolution of nuclear power plant is progressed as "Phase 1: Application research for peaceful utilization of nuclear energy" between 1950s and 1960s, "Phase 2: The first renaissance of nuclear energy" during 1970s, "Phase 3: Enhancement of safety and the catch-up of latecomers in nuclear energy" between 1990s and 2000s, and "Phase 4: Top prioritization of safety and the development of next generation reactors for the second renaissance of nuclear energy" since 2010s. We also found that various kinds of policy, economic and social drivers, such as energy policy, investment in technology development, economic growth and energy demand, social acceptability and environmental concern, have affected the technology evolution of nuclear power plant at each phase. We emphasize the role of macroenvironmental drivers in the technological evolution of CoPS. We also suggest that countries that endeavor to develop CoPs need to utilize those drivers for enhancing competitiveness and sustaining leadership.

• Journal of Nutrition and Health
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• v.47 no.1
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• pp.1-11
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• 2014

Purpose: Several studies have proven that EGCG, the primary green tea catechin, and glucosamine-6-phosphate (PGlc) reduce triglyceride contents in 3T3-L1 adipocytes. The objective of this study is to evaluate the combination effect of EGCG and PGlc on decline of accumulated fat in differentiated 3T3-L1 adipocytes. Methods: EGCG and PGlc were administered for 6 day for differentiation of 3T3-L1 adipocytes. Cell viability was measured using the CCK assay kit. In addition, TG accumulation in culture 3T3-L1 adipocytes was investigated by Oil Red O staining. We examined the expres-sion level of several genes and proteins associated with adipogenesis and lipolysis using real-time RT-PCR and Western blot analysis. A flow cytometer Calibar was used to assess the effect of EGCG and PGluco on cell-cycle progression of differentiating 3T3-L1 cells. Results: Intracelluar lipid accumulation was significantly decreased by combination treatment with EGCG $60{\mu}M$ and PGlc $200{\mu}g/m$ compared with control and EGCG treatment alone. In addition, use of combination treatment resulted in directly decreased expression of $PPAR{\gamma}$, $C/EBP{\alpha}$, and SREBP1. In addition, it inhibited adipocyte differentiation and adipogenesis through downstream regulation of adipogenic target genes such as FAS, ACSL1, and LPL, and the inhibitory action of EGCG and PGlc was found to inhibit the mitotic clonal expansion (MCE) process as evidenced by impaired cell cycle entry into S phase and the S to G2/M phase transition of confluent cells and levels of cell cycle regulating proteins such as cyclin A and CDK2. Conclusion: Combination treatment of EGCG and PGlc inhibited adipocyte differentiation through decreased expression of genes related to adipogenesis and adipogenic and cell cycle arrest in early stage of adipocyte differentiation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.43-49
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• 2005

Recently, according as people who have sensitive skin increase, we've been giving more importance to the safety of cosmetics. Especially, preservative is known to be one of the main stimuli which cause side-effects of cosmetics. However, there have been few reports describing cell cytotoxicity, skin penetration, oil-aqueous phase partition, anti-microbial activity of preservatives and their correlation with skin irritation. The study is aimed to develop low irritable preservative system with phenoxyethanol, one of the most commonly used preservatives in cosmetics, considering various factors mentioned above. According to our results of cell cytotoxicity against human normal fibroblasts by means of MTT assay, phenoxyethanol showed the lowest cytotoxicity when compared to other preservatives tested (cytotoxicity: pro-pylparaben > butylparaben > ethylparaben > methylparaben > triclosan > phenoxyethanol), but human patch test for assessing shin primary irritation revealed that phenoxyethanol has higher skin irritation than methylparaben and triclosan. We performed in vitro skin penetration test using horizontal Franz diffusion cells with skin membrane prepared from hairless mouse (5 ${\~}$ 8 weeks, male) to evaluate the rate of skin penetration of preservatives. From the results, we found that the higher irritable property of phenoxyethanol in human skin correlates with its predominant permeability (skin penetration: phenoxyethanol > methylparaben > ethylparaben > propylparaben > butylfaraben > triclosan). Therefore, we made an effort to reduce skin permeability of phenoxyethanol and found that not only the rate of skin penetration of phenoxyethanol but also its skin irritation is dramatically reduced in formulas containing oils with low polarity. In the experiments to investigate the effect of oil polarity on the oil-aqueous phase partition of phenoxyethanol, more than $70\%$ of phenoxyethanol was partitioned in aqueous phase in formulas containing oils with low polarity, while about $70 {\~} 90\%$ of phenoxyethanol was partitioned in oil phase in formulas containing oils with high polarity. Also, in aqueous phase phenoxyethanol showed greater anti-microbial activity. Conclusively, it appears that we can develop less toxic preservative system with reduced use dosage of phenox-yethanol and its skin penetration by changing oil composition in formulas.

• Korean Journal of Heritage: History & Science
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• v.47 no.4
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• pp.224-243
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• 2014

This study examined the materials and casting technology(cast, alloy, etc.) used in the manufacturing of bronze artifacts based on old literature such as Yongjae Chonghwa, Cheongong Geamul, and The Korea Review. In the casting experiment for restoration of Sangpyong Tongbo, a bronze and brass mother coin mold was made using the sand mold casting method described in The Korea Review. The cast was comprised of the original mold plate frame, wooden frame, and molding sand. Depending on the material of the outer frame, which contains the molding sand, the original mold plate frame can be either a wooden frame or steel frame. For the molding sand, light yellow-colored sand of the Jeonbuk Iri region was used. Next, the composition of the mother alloy used in the restoration of Sangpyong Tongbo was studied. In consideration of the evaporation of tin and lead during actual restoration, the composition of Cu 60%, Zn 30%, and Pb 10% for brass as stated in The Korea Review was modified to Cu 60%, Zn 35%, and Pb 15%. For bronze, based on the composition of Cu 80%, Sn 6%, and Pb 14% used for Haedong Tongbo, the composition was set as Cu 80%, Sn 11%, and Pb 19%. The mother coin mold was restored by first creating a wooden father coin, making a cast from the wooden frame and basic steel frame, alloying, casting, and making a mother coin. Component analysis was conducted on the mother alloy of the restored Sangpyong Tongbo, and its primary and secondary casts. The bronze mother alloy saw a 5% increase in copper and 4% reduction in lead. The brass parent alloy had a 5% increase in copper, but a 4% and 12% decrease in lead and tin respectively. Analysis of the primary and secondary mother coin molds using an energy dispersive spectrometer showed that the bronze mother coin mold had a reduced amount of lead, while the brass mother coin mold had less tin. This can be explained by the evaporation of lead and tin in the melting of the primary mother coin mold. In addition, the ${\alpha}$-phase and lead particles were found in the mother alloy of bronze and brass, as well as the microstructure of the primary and secondary coin molds. Impurities such as Al and Si were observed only in the brass mother coin mold.

• Clinical and Experimental Reproductive Medicine
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• v.12 no.1
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• pp.47-70
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• 1985

This study was presented of the 1,872 cases of infertile couples who visited and examined at the sterility clinic of Department of Obstetrics & Gynecology, Seoul National University Hospital from Sept., 1980 to Dec., 1983. Age, duration of infertility, past medical history, and other general factors were analyzed, and the factors responsible for infertility were classified and discussed. Mode of treatment, outcome of pregnancy, pregnancy rate responsible for each factor were also presented. The results were as follows: 1) The infertility was primary in 1,128, or 60.3% and secondary in 744, or 39.7%. 2) The age between 26 and 30 years of age comprised about one half of the total patients. 3) The duration of infertility between 1 and 4 years comprised about three quarters of the total patients, and the mean duration was 3.8 years. 4) The most common medical history in primary infertility was tuberculous disease, and that in secondary infertility was history of previous laparotomy. 5) About two thirds of antecedent pregnancies were abortion. 6) The major etiologic factor of infertility were male factor in 12.3%, tubal factor in 38.8%, ovulatory failure in 25.4%, uterine factor in 8.8%, cervical factor in 5.2%, peritoneal factor in 9.5%, and no demonstrable cause in 11.3%. 7) The types of male factor were azoospermia in 61.6%, oligospermia in 25.8%, low motility in 11.6%, and other abnormality in 1.0%. 8) The types of ovulatory failure were ovarian failure in 7.4%, hypothalamo-pituitary failure in 8.1 %, hypothalamo-pituitary dysfunction (including Polycystic ovarian syndrome) in 30.2%, and hyperprolactinemia in 22.4%. 9) The types of uterine factor were endometrial tuberculosis in 27.5%, uterine synechia in 33.8%, uterine anomaly in 19.7%, myoma and polyp in 9.1 %, and luteal phase defect in 9.9%. 10) The types of peritoneal factor were pelvic adhesion in 80.9% and endometriosis in 19.6%. 11) Surgeries were done in 408 patients, and they were salpingolysis, lysis of extraadnexal adhesion, salpingostomy, fimbrioplasty, ovarian wedge resection for polycystic ovarian disease, tubo-tubal anastomosis, and tubo-uterine implantation in orders. 12) 243 pregnancies were achieved during the infertility work-up, of which livebirth was 46.5%, ectopic pregnancy was 7.4%, spontaneous abortion was 7.8%, and on-going pregnancy or lost to follow-up was 36.2%. 13) Pregnancy rates in various factors were male factor in 18.7%, ovulatory factor in 31.7%, tubal factor in 24.2%, uterine factor in 34.6%, cervical factor in 19.0%, peritoneal factor in 29.0%, combined factors in 10.5%, and unexplained infertility in 37.1%. Pregnancy rate in whole patients was 25.2%.

• Analytical Science and Technology
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• v.28 no.6
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• pp.460-466
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• 2015

An isotope dilution liquid chromatography tandem mass spectrometry was developed as a primary method for the quantitative analysis of cholesterol in infant formula. Cholesterol-d₄ was used as an internal standard and spiked into the infant formula sample. In order to release cholesterol out of cholesteryl ester, which is cholesterol bound to fatty acids in infant formula, saponification was carried out. Saponification conditions were optimized with heating temperature, reaction time and the concentration of KOH. The optimum conditions were as follows; heating temperature was 70 ℃, reaction time was 180 min and the concentration of KOH was 0.8 mL of 8 M KOH for about 0.1 g infant formula sample. Extraction of cholesterol out of sample solution was carried out with hexane uisng liquid-liquid extraction. Chromatographic analysis was carried out using Phenomenex Kinetex C₁₈ column. Mobile phase was 0.1% acetic acid in methanol/water (v/v, 99/1) and flow rate was 0.3 mL/min. Cholesterol and cholesterol-d₄ were monitored at mass transfer m/z 369/259 and 373/263 respectively. Reproducibility of the method was evaluated to be 0.23% of the measurement result. The expanded uncertainty of the measurement result of cholesterol in infant formula was approximately 1.9% at a 95% confidence level. NIST standard reference material having certified values of cholesterol in infant formula, was analyzed in order to verify this method. The ID-LC/MS/MS results were well agreed with the certified values of NIST SRM within the uncertainty.

• The Korean Journal of Applied Statistics
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• v.21 no.1
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• pp.35-51
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• 2008

Comparative studies in Phase III clinical trials quite often involve two or more equally important endpoints, and one cannot select primary endpoint from them. O'Brien(1984) proposed for continuous endpoints the OLS and GLS statistics as milti-variate test statistics. Pocock et al. (1987) mentioned the possibility of analyzing a mixture of data types, such as quantitative, binary and survival data types, with the OLS and GLS statistics, but the authors did not explore problems in combining several endpoints of different types. Furthermore, they did not perform a simulation study to assess the efficiencies of the OLS and GLS statistics for endpoints of a mixture of data types. In this paper, we propose the combining methods of correlated P-values for the analysis of multiple endpoints, and compare the efficiencies of this method with those of OLS and GLS statistics for a mixture of data types with a simulation study. Among the several methods of combining P-values that are more advantageous than combining of OLS and GLS statistics, method B maintains nominal significance levels and is more efficient, while method F and G have type I error rates that are larger than the specified significance levels, which might occasionally lead to a wrong conclusion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.3
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• pp.367-373
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• 2014

In this study, we investigated the anticancer activity of methyl gallate (MG), which is the major biologically active component of Galla Rhois, in RC-58T/h/SA#4 human prostate cancer cells. MG inhibited cell proliferation in a dose-dependent manner. Cell death induced by MG increased the population of cells in sub-G1 phase, formation of apoptotic bodies, nuclear condensation, and DNA fragmentation. Apoptosis induced by MG was associated with activation of initiator caspases-8 and -9 as well as effector caspase-3. Endocrine disruptors such as dioxin and bisphenol A increased growth of RC-58T/h/SA#4 cells in charcoal-treated FBS (cFBS) medium. Cell proliferation was highest upon treatment with 1 nM and $0.1{\mu}M$ dioxin and bisphenol A, respectively. MG also dose-dependently inhibited cell proliferation in RC-58T/h/SA#4 cells treated with endocrine disruptors. These results indicate that MG exerts anticancer effects on RC-58T/h/SA#4 primary human prostate cancer cells.

• Radiation Oncology Journal
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• v.24 no.3
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• pp.179-184
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• 2006

[ $\underline{Purpose}$ ]: To explore the effect of recombinant human EGF on the proliferation and survival of human fibroblast cell lines following irradiation. $\underline{Materials\;and\;Methods}$: Fibroblast was originated human skin and primary cultured. The trypan blue stain assay and MTT assay were used to study the proliferative effects of EGF on human fibroblast cell lines in vitro. An incubation of fibroblasts with rhEGF for 24 hours immediately after irradiation was counted everyday. Cell cycle distributions were analyzed by FACS analysis. $\underline{Results}$: Number of fibroblast was significantly more increased rhEGF (1.0 nM, 10 nM, 100 nM, 1,000 nM) treated cell than control after 8 Gy irradiation. Most effective dose of rhEGF was at 160 nM. These survival differences were maintained at 1 week later. Proportion of S phase was significantly increased on rhEGF treated cells. $\underline{Conclusion}$: rhEGF cause increased fibroblast proliferation following irradiation. We expect that rhEGF was effective for radiation induced wound healing.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.1-12
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• 2006

The purpose of this study were to evaluate the efficacy of the newly developed Digital Imaging Fiber-Optic Trans-illumination (DIFOTI) system in detecting carious lesions in vivo as gold standard with confocal laser scanning microscopy and compared the efficacy of traditional radiography and DIFOTI system in vito as gold standard with confocal laser scanning microscopy, too. For the in vivo study, the subject pool consisted of 23 grammar school age patients just prior to entering the mixed dentition phase Each patient was given a DIFOTI examination of the anterior and posterior teeth. During $6{\sim}8$ months, the naturally expire primary teeth were collected and the efficacy of DIFOTI system was compared with confocal laser scanning microscopy. For in vitro study, 40 primary teeth were collected and decalcified by Carbopol decalcification solution for 1, 2, 4 and 8 days. Every experiment period, all teeth were DIFOTI examined and sectioned to take an image of confocal laser scanning microscopy Sensitivity and specificity were calculated from the result of DIFOTI examine and confocal laser scanning microscopy analysis. The results are as follows : 1. From the in vivo study, the sensitivity of DIFOTI examine was 0. 61 and specificity was 0.63. 2. From the in vivo study, the sensitivity of DIFOTI examine was 0.71 and specificity was 0.75.