• Geophysics and Geophysical Exploration
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• v.15 no.1
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• pp.23-32
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• 2012

The comparison between time-lapse seismic datasets is the most popular method in the reservoir monitoring. The method of extracting the changes only due to the change in the reservoir is the essential technique in the comparison of time-lapse seismic datasets. In the paper, the conventional cross-equalization approaches and an enhanced optimized approach have been tested and compared each other. As conventional approaches, the bandwidth equalization and phase rotation methods have been tested in frequency, time and mixed domains, respectively and their results were compared each other. In order to overcome the limit of the conventional approaches, which loses high frequency components, a new constrained optimum filtering method was proposed and experimented. The new constrained filtering method has shown the improvement in broadening the bandwidth of the components of reservoir changes by acquiring optimized match filter.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.84-84
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• 2018

인공재배 매실나무겨우살이의 의약 화장품의 소재 및 산업화 가능성을 검토하기 위해 80% 에탄올 및 증류수 초음파추출물의 Tyrosinase 저해활성을 측정하였다. 인공재배한 매실나무겨우살이(PM, 동결건조) 및 자연산 굴참나무겨우살이(QM, 열풍건조, $30^{\circ}C$, 7day)의 80% 에탄올, 증류수 초음파추출물에 대한 tyrosinase 저해활성을 측정한 결과, 물 추출물의 경우 100 ppm의 농도에서 PM과 QM 모두 5분이 경과 하였을 때 PM은 88.37%, QM은 87.69%로 최대치를 나타내었고, 농도와 시간이 증가함에 따라 tyrosinase 저해활성이 감소하는 경향을 보여주었다. PM 80% 에탄올 추출물은 5분이 경과하였을 때 2,500ppm이 92.08%로 최대값을 보여주었고 이후 시간이 지남에 따라 저해활성이 감소되는 경향을 나타내었다. 반면 5,000ppm은 5분이 경과하였을 때 66.38%로 최소값을 나타낸 반면, 20분까지 저해활성이 증가하였고 10분이 경과한 이후로 거의 일정하게 유지되어 지속적으로 감소되는 1,000ppm보다 높은 저해효과를 보여 주었다. QM 80% 에탄올 추출물은 5분이 경과하였을 때 1,000ppm이 88.14%로 가장 높았고 5,000ppm은 63.49%로 가장 낮은 저해활성을 보여주었다. 15분까지 1,000ppm이 가장 높은 저해활성을 보여주었으나 꾸준히 감소한 반면, 2,500ppm의 경우 시간이 경과함에 따라 비교적 일정한 저해활성을 보여주어 15분이 경과한 이후로 2,500ppm의 저해활성이 가장 높게 나타났다. 25분이 경과하였을 때 2,500ppm은 70.27%로 가장 높은 저해활성을 나타내었고, 5,000ppm은 30.09%로 가장 낮은 저해활성을 보여주었다. 본 연구 결과에 따르면, 물 추출물의 경우 겨우살이의 농도가 낮을수록 더 높은 tyrosinase 저해활성을 나타내었고, 80% 에탄올 추출물의 경우 2,500ppm에서 가장 높은 저해활성을 나타내어 의약 화장품의 소재 및 산업화 가능성이 높음을 확인할 수 있었다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.652-656
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• 2002

본 연구에서는 각 수요지간의 시간이 확률적으로 주어지는 경우의 TSP(Traveling Salesman Problem)를 다루고자 한다. 현실적으로, 도심의 교통 체증 등으로 인해서 각 지점간의 걸리는 시간은 시간대별로 요일별로 심한 변화를 일으키기 마련이다. 그러나, 현재까지의 연구 결과는 수요지간의 경과시간이 확정적으로 주어지는 경우가 대부분으로, 도심물류 등에서 나타나는 현실적인 문제를 해결하는데는 많은 한계가 있다 본 연구에서는 문제의 해법으로 강화학습기법의 하나인 Q학습(Q-Learning)과 Neural Network를 활용한 효율적인 알고리즘을 제시한다.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2001.05a
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• pp.75-78
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• 2001

본 논문에서는 소프트웨어의 신뢰도에 대한 정의를 하고, 테스트 시간의 경과와 신뢰도와의 관계, 결함 수정 후 경과되는 시간과 신뢰도와의 관계를 연구한다. 소프트웨어의 비용을 고찰함에 있어서 조건별로 검토하여 비용이 최소로 되는 발행시각을 결정한다. 목표신뢰도 입장에서 발행시각을 결정함에 있어서 개발 후 테스트를 시작하기 전의 신뢰도의 조건에 따른 최적발행시각을 정한다.

• The Korean Journal of Nuclear Medicine
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• v.34 no.2
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• pp.144-153
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• 2000

Purpose: The purpose of this study was to evaluate the relationship between radiation-induced activation of DNA repair genes and radiation induced apoptosis in A431 cell line. Materials and Methods: Five and 25 Gys of gamma radiation were given to A431 cells by a Cs-137 cell irradiator. Apoptosis was evaluated by flow cytometry using annexin V-fluorescein isothiocyanate and propidium iodide staining. The expression of DNA repair genes was evaluated by both Northern and Western blot analyses. Results: The number of apoptotic cells increased with the increased radiation dose. It increased most significantly at 12 hours after irradiation. Expression of p53, p21, and hRAD50 reached the highest level at 12 hours after 5 Gy irradiation. In response to 25 Gy irradiation, hRAD50 and p21 were expressed maximally at 12 hours, but p53 and GADD45 genes showed the highest expression level after 12 hours. Conclusion: Induction of apoptosis and DNA repair by ionizing radiation were closely correlated. The peak time of inducing apoptosis and DNA repair was 12 hours in this study model. hRAD50, a recently discovered DNA repair gene, was also associated with radiation-induced apoptosis.

• 한국생태학회:학술대회논문집
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• 1999.05a
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• pp.98.1-98.1
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• 1999

• Journal of the Microelectronics and Packaging Society
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• v.1 no.2
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• pp.125-134
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• 1994

저항범위가 다른 두종류의 Ru계 후막저항계(1Kohm/sq. 100kohm/sq.)를 선택하여 도전상의 상전이 기구를 반응조건을 변화시켜 연구하였다. 저저항체의 경우 도전상으로는 RuO2였으며 700-100$0^{\circ}C$에서 1시간 반응한 경우 반응온도에 따른 구성상의 변화는 없었다 반응온도 90$0^{\circ}C$에서 반응시간이 경과함에 따라 도전상은 RuO2가 Glass의 구성성분인 Pb와 반응하여 Rb2(Ru1.69 Pb0.31)O6.5로 변하고 시간이 36시간 경과한 후에는 도전상이 Pb4Al2Si2O10인 결정으로 둘러 쌓이는 반응인 peritectic reaction이 일어났다. 고전항체의 경 우 도전상으로는 Pb2(Ru1.69 Pb0.31)O6.5로 변하고 시간이 36시간 경과한 후에는 더전상이 Pb4Al2Si2O10인 결정으로 둘러쌓이는 반응인 peritectic reaction 이 일어났다. 고저항체의 경 우 도전상으로는 Pb2(Ru1.69 Pb0.31)O6.5인 pyrochrole 상이였다. 100$0^{\circ}C$에서 1시간 반응시킬 경 우 도전상이 RuO2로 변하였다. 반응온도를 90$0^{\circ}C$로 하고 반응시간을 변화시키면 도전상인 Pb2(Ru1.69 Pb0.31)O6.5가 (Ru1.69Pb0.31)O4x로 변하면서 공존하였다.

• Korean journal of food and cookery science
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• v.16 no.4
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• pp.358-362
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• 2000

To investigate the effect of sourdough on the quality characteristics of barley bread, sourdough starlet with Lactobacillus plantarum, Lactobacillus sanfrancisco and Enterococcus mundtii was used for baking after 48 hours incubation at 37$\^{C}$. The specific volume of the bread containing sourdough starter was greater than that the control. Retarding of the firmness was observed in the bread with Lactobacillus sanfrancisco compared with the control and other breads. Above results suggest that sourdough starter fermented by Lactobacillus can be used as natural bread improver.

• Korean Journal of Environmental Agriculture
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• v.7 no.2
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• pp.124-129
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• 1988

Prolonged aquatic toxicity tests (7-days) of six pesticides to the freshwater fish Oryzias latipes were performed to confirm the adequacy of the exposure times, 48-hr or 96-hr, which has been required by the protocols for the aquatic acute toxicity test. The toxicity curves were plotted for each chemical, and the significance of the difference between lethal threshold concentrations and 48-hr or 96-hr LC50's was analysed statistically. The lethal threshold concentrations of butachlor, fenobucarb, and chlorothalonil were clearly defined on the 5th day, 2nd day, and 2nd day at 0.53mg/1, 10.3mg/l, and 0.085mg/1, respectively. But the toxicity curves of alachlor, diazinon, and iprobenfos continued with no threshold for 7 days. Four out of six test pesticides failed to show the threshold concentration during the 96-hr exposure time. Therefore, the results of the acute toxicity test using 48-hr or 96-hr exposure time would not describe the ideal toxicity of pesticides. It is recommended that the prolonged exposure should be continued long enough to define the threshold adequately.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.3
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• pp.491-498
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• 2005

Occlusal fissures and pits are ideal places for the development of caries. Pit and fissure sealants are now considered as a very effective means to prevent dental caries. The purpose of this investigation was to examine the effect on the sealant penetration of the elapse of time from the application of sealant until exposure to visible light, and to examine the effect of the filler content and tooth position on the sealant penetration. 192 extracted human premolars were used to this experiment. Following enamel conditioning, a light-polymerized sealant was applied and 4 different periods of time(3, 5, 10, 20 seconds) were allowed until exposure to the light source. The results obtained were as follows; 1. According to time, in both unfilled sealant and filled sealant penetration increases deeply through mindfulness. 2. Sealant that apply to mandiblar premolar penetrated deeply through than to maxillay teeth. 3. Penetration difference according to filler content, unfilled sealant penetrated deeply through than filled sealant. The result from this study indicated that unfilled sealant penetrated most deeply in mandible when at least 20s time elapsed.