• 한국어병학회지
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• 제16권1호
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• pp.39-49
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• 2003

Cytosolic oxidation by 4-hydroxy-2-nonenal (4HNE) and tert-butyl hydroperoxide (t-BHP) results in cell death of bovine aortic endothelial cells (BAEC). In this study, we have investigated the roles of antioxidants such as 2,3,6-tribromo-4,5-dihydroxy benzyl methyl ether (TDB) and phloroglucinol in preventing cell death. After treatment with oxidants for 6h, cells became compact and showed nuclear condensation, which were characteristics of early apoptosis. After l2h treatment, morphologic features including severe cytoplasm condensation, membrane blebbing, and apoptotic bodies were prominent and these findings were interpreted as characteristics of late-apoptosis. When the apoptotic cells were treated with antioxidants for 12h, both early and late apoptotic cells did show no significant change. After oxidant treated cells were incubated with antioxidant for 24h, the characteristics of early-apoptosis were eliminated but cells in lateapoptosis could not return to normal cells. These results suggest that TDB and phloroglucinol prevent the cells from dying through apoptosis induced by 4HNE and t-BHP in early stage.

• Journal of Pharmaceutical Investigation
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• 제37권2호
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• pp.79-84
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• 2007

This study was aimed to establish analytical method of Bi to develop a guideline of the bioequivalence test of tripotassium dicitrato bismuthate (TDB). For this purpose, a simple, specific and sensitive inductively coupled plasma-mass spectrometry (ICP/MS) method were developed and validated in human plasma. Various concentrations of bismuth standard solution (0-25ng/mL) were prepared with distilled water and human blank plasma. To 10mL of the volumetric flasks, 2mL of blank plasma was added with 8ml of distilled water. Bi standard solution was added to prepare the calibration samples and injected into ICP-MS. The plasma samples obtained from volunteers given 3 tablets of bismuth (total 900mg as TDB) were analyzed as described above. As a result, the coefficients of variation were <20% in quantitation limit (0.2 ng/mL) and <15% at the rest of concentrations. The stability test by repeated freezing-thawing cycles showed that the samples were stable only for 24hr. The stability tested for samples with a short-term period of storage at room temperature and pre-treatment prior to the analysis showed very stable over 24hr. In 8 healthy Korean subjects received Denol tablets at the dose of 900mg bismuth, AUC, $C_{max},\;T_{max}$ and half-life $(t_{1/2})$ were determined to be $198.33{\pm}173.78 ng{\cdot}hr/mL,\;64.48{\pm}27.06 ng/mL,\;0.52{\pm}0.21 hr,\;and\;5.15{\pm}2.67 hr$, respectively, from the plasma bismuth concentration-time curves. In conclusion, the method was suitable for the determination of bismuth in human plasma samples and could be applied to bioequivalence test of bismuth tablet.

• Asia pacific journal of information systems
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• 제17권1호
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• pp.59-76
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• 2007

Information and Communication Technologies (ICT) changed our everyday business drastically. Business routines have been transformed to online activities. New theories and models were developed for the brand new online environment. For online negotiations, however, the research on new mechanisms is not enough, especially for bilateral distributive negotiations. A reserve price reporting mechanism (RPR) together with its extended version (ERPR) is proposed in this paper. The key improvement of reserve price reporting mechanisms is to let the negotiators report their reserve price to a third-party system before they actually start the negotiation. A prototype of this RPR system is developed and a lab experiment is conducted to test the performance of the two mechanisms compared with traditional direct bargaining (TDB) mechanism. The results of the experiment support that the reserve price report mechanisms proposed are more efficient than the traditional one in several dimensions including social welfare.

• 식물조직배양학회지
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• 제21권3호
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• pp.131-135
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• 1994

본 실험은 식물생장조절제인 TDZ, BA, TAh, IBA, zeatin, GA$_3$가 사과대목 M.25의 기내증식에 미치는 영향을 구명하기 위해서 실시하였다. 또한 시토카닌과 오옥신의 역할을 동시에 하는 것으로 알려진 potassium humate가 뿌리형성에 미치는 효과를 알아보기 위해서 몇가지 농도로 배지에 첨가했다. 생장점 배양으로부터 건전한 산소를 얻기 위해서 BA, TDB, zeatin을 단독으로 기본배지에 첨가한 결과, zeatin 1.0 mg/L 첨가한 배지에서 100% 생존을을 나타냈고 신초생장 또한 양정하였다. 생장점 배양을 통해서 얻은 신초의 증식을 위해서 여러 종류의 생장조절제를 다양한 농도로 처리했을때 NAA 0.5 + TDZ 0.2 mg/L이 첨가된 배지에서 증식된 신소재가 평균 12.1개로 증식율이 가장 높았다. 형성된 신초로부터 발근유도는 IBA 0.6 mg/L이 첨가된 배지에서 가장 효과적이었다. 이러한 발근유도 배지에 potassium humate 250 mg/L이 첨가된 처리구에서 발근율과 부정근 돈는 IBA 0.5 mg/L 단독 처리구보다 각각 30%와 350% 이상 증가되었다.

• 한국식품조리과학회지
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• 제26권3호
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• pp.314-322
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• 2010

The effects of five colored soybean (blue, red, yellow, white, and black) varieties on the quality characteristics of soybean paste (Doenjang) were investigated for proximate composition, salt content, pH, color, organic acid content, amino acid content, and mineral content after 80 days of aging. Soybean paste (Doenjang) samples were divided into TDS (traditional Doenjang prepared with soybean) and TDM (traditional Doenjang prepared with mixed soybeans, kidney bean, black soybean, kind of small bean, sword bean, green bean, red bean, at a radio of 1:1:1:1:1(w/w)). Moisture content was 49.66% for TDM and 49.52% for TDM. Protein and salt contents of the TDS sample were higher than those of TDM. The "L" values of the TDB sample increased the aging period was decreased. In contrast, the "L" and "$\alpha$" values of TDM did not show any significant differences. The main organic acids detected were malic acid > lactic acid > tartaric acid in the TDS and TDM samples. Glutamic acid contents were 2.83 g/100 g for the TDS sample and 2.15 g/100 g for the TDM. The levels of K, Mg, and Ca of the TDS sample were higher than those of TDM. No significant difference occurred between TDS and TDM regarding their quality characteristics after 80 days of aging. Further studies needed include sensory evaluation and functionality of soybean paste made from mixed soybean materials.

• Nuclear Engineering and Technology
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• 제42권5호
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• pp.552-561
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• 2010

This study investigates the solubility of neptunium (Np) in the deep natural groundwater of the Korea Atomic Energy Research Institute Underground Research Tunnel (KURT). According to a Pourbaix diagram (pH-$E_h$ diagram) that was calculated using the geochemical modeling program PHREEQC 2.0, the redox potential and the carbonate ion concentration both control the solubility of neptunium. The carbonate effect becomes pronounced when the total carbonate concentration is higher than $1.5\;{\times}\;10^{-2}$ M at $E_h$ = -200 mV and the pH value is 10. Given the assumption that the solubility-limiting stable solid phase is $Np(OH)_4(am)$ under the reducing condition relevant to KURT, the soluble neptunium concentrations were in the range of $1\;{\times}\;10^{-9}$ M to $3\;{\times}\;10^{-9}$ M under natural groundwater conditions. However, the solubility of neptunium, which was calculated with the formation constants of neptunium complexes selected in an OECD-NEA TDB review, strongly deviates from the value measured in natural groundwater. Thus, it is highly recommended that a prediction of neptunium solubility is based on the formation constants of ternary Np(IV) hydroxo-carbonato complexes, even though the presence of those complexes is deficient in terms of the characterization of neptunium species. Based on a comparison of the measurements and calculations of geochemical modeling, the formation constants for the "upper limit" of the Np(IV) hydroxo-carbonato complexes, namely $Np(OH)_y(CO_3)_z^{4-y-2z}$, were appraised as follows: log $K^{\circ}_{122}\;=\;-3.0{\pm}0.5$ for $Np(OH)_2(CO_3)_2^{2-}$, log $K^{\circ}_{131}\;=\;-5.0{\pm}0.5$ for $Np(OH)_3(CO_3)^-$, and log $K^{\circ}_{141}\;=\;-6.0{\pm}0.5$ for $Np(OH)_4(CO_3)^{2-}$.

• Nuclear Engineering and Technology
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• 제40권7호
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• pp.593-606
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• 2008

In this study, data on radionuclide migration and retardation processes in the engineered and natural barriers of High-Level Radioactive Waste (HLW) repository have been reviewed and compiled for use in the performance assessment of a HLW disposal system in Korea. The status of the database on radionuclide migration and retardation that is being developed in Korea is investigated and summarized in this study. The solubilities of major actinides such as D, Th, Am, Np, and Pu both in Korean bentonite porewater and in deep Korean groundwater are calculated by using the geochemical code PHREEQC (Ver. 2.0) based on the KAERI-TDB(Korea Atomic Energy Research Institute-Thermochemical Database), which is under development. Databases for the diffusion coefficients ($D^b_e$ values) and distribution coefficients ($K^b_d$ values) of some radionuclides in the compacted Korean Ca-bentonite are developed based upon domestic experimental results. Databases for the rock matrix diffusion coefficients ($D^r_e$ values) and distribution coefficients ($K^r_d$ values) of some radionuclides for Korean granite rock and deep groundwater are also developed based upon domestic experimental results. Finally, data related to colloids such as the characteristics of natural groundwater colloids and the pseudo-colloid formation constants ($K_{pc}$ values) are provided for the consideration of colloid effects in the performance assessment.

• 천문학회지
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• 제55권4호
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• pp.111-121
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• 2022

Based on the light an exoplanet blocks from its host star as it passes in front of it during a transit, the mid-transit time can be determined. Periodic variations in mid-transit times can indicate another planet's gravitational influence. We investigate 83 transits of TrES-1 b as observed from 6-inch telescopes in the MicroObservatory robotic telescope network. The EXOTIC data reduction pipeline is used to process these transits, fit transit models to light curves, and calculate transit midpoints. This paper details the methodology for analyzing transit timing variations (TTVs) and using transit measurements to maintain ephemerides. The application of Lomb-Scargle period analysis for studying the plausibility of TTVs is explained. The analysis of the resultant TTVs from 46 transits from MicroObservatory and 47 transits from archival data in the Exoplanet Transit Database indicated the possible existence of other planets affecting the orbit of TrES-1 and improved the precision of the ephemeris by one order of magnitude. We now estimate the ephemeris to be (2 455 489.66026 BJD_TDB ± 0.00044 d) + (3.0300689 ± 0.0000007) d × epoch. This analysis also demonstrates the role of small telescopes in making precise midtransit time measurements, which can be used to help maintain ephemerides and perform TTV analysis. The maintenance of ephemerides allows for an increased ability to optimize telescope time on large ground-based telescopes and space telescope missions.

• 방사성폐기물학회지
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• 제5권3호
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• pp.189-197
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• 2007

레이저유도파열검출 기술을 이용하여 우라늄(VI) 가수분해물의 용해도를 측정하였다. 측정 용액의 우라늄 농도 범위는 $2{\times}10^{-4}{\sim}4{\times}10^{-6}\;M$, pH 범위는 $3.8{\times}7.0$, 그리고 이온 강도는 0.1 M $NaClO_4$이며, 온도는 $25.0{\pm}0.1^{\circ}C$로 유지하였다. 문헌에 제시된 가수분해 상수와 specific ion interaction theory(SIT)를 이용하여 이온 강도 I=0 일 때의 용해도 곱 (solubility product) 상수 ${\log}K^{\circ}_{sp}=-22.85{\pm}0.23$를 구하였다. 동일한 시료에 대해 흡수 및 형광 스펙트럼을 측정하여 가수분해 화학종의 존재를 확인하였다. $2{\times}10^{-4}\;M$ 우라늄 농도에서 용액 중에 존재하는 주요 가수분해 화학종은 $(UO_2)_2(OH)_2^{2+}$와 $(UO_2)_3(OH)_5^+$임을 보였다.

• 한국전자거래학회지
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• 제22권4호
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• pp.159-173
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• 2017

기술력 기반의 중소벤처기업에 대한 기술금융 지원을 위해 정부는 2014년 7월부터 기술보증기금 및 일정 자격을 갖춘 민간 기술신용평가사에게 일종의 기술력 등급평가인 기술신용평가를 실시하여 은행의 여신에 활용토록 하였다. 본 논문에서는 최근까지의 기술신용평가 현황 및 한국신용정보원에서 축적하고 있는 기술평가 관련 가용 지표들에 대한 선행 연구를 개략적으로 살펴본 후 기술평가등급점수에 유의적인 영향을 미치는 지표(indicator)를 통상적인 다중회귀기법으로 탐색할 것이다. 본 논문의 관심 대상인 지표 별 등급 영향도와 모형의 적합도는 대표적인 기계학습 분류기(classifier)인 일반화가속모형(Generalized Boosting Model; GBM)을 적용하여 분석하였는 바, 주요 지표를 독립변수(feature)로 투입하여 지표의 상대적 중요성 및 분류 정확도를 산출하였다. 분석결과 회귀모형과 기계학습 모형 간 지표별 상대적인 중요도는 크게 차이나지 않는 것으로 분석되었으나, GBM 모형의 경우 회귀모형에 비해서 이노비즈인증, 연구소 및 연구개발전담부서 보유, 특허등록건수, 벤처확인 지표 등 기술개발역량이 상대적으로 기술등급에 더 큰 영향을 미치는 것으로 분석되었다.