• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.4
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• pp.383-390
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• 2020

Blue light is a blue-based light existing at a wavelength between 380 and 450 nm, and it has been reported that it induces active oxygen and causes aging, and accordingly, interest in the blue light blocking effect is increasing. In this study, the effects of the polarity of oil, viscosity of the formulation, type of emulsifier, emulsified particles, and inorganic UV blocking agents on the blue light blocking effect in UV blocking products were investigated. As a result, it was confirmed that the blue light blocking rate increased as the polarity of the oil became similar to that of the organic UV blocker, and the higher the viscosity of the formulation, the higher the blue light blocking rate. The types of emulsifiers and emulsified particles had little effect on the blue light blocking effect, and the presence of inorganic UV blocking agents was found to be one of the factors that greatly influenced the blue light blocking rate. These results can effectively increase the efficiency of blocking blue light, and may be used in the development of blue light blocking products and formulation research in the future.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.272-279
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• 2022

Polyphenols are chemically unstable, and their bioactivities are reduced through oxidation. Photosensitizers (PS) induce photo-oxidation in various food systems. In this study, effects of dietary PS such as riboflavin (Rb), erythrosin B (EB), and zinc protoporphyrin on the auto-oxidation of polyphenols, gallic acid (GA) and tannic acid (TA) were evaluated under a fluorescent light. The formation of oxidation products from GA and TA increased in a PS concentration- and irradiation time-dependent manner. In addition, Rb and EB induced significant reduction in the polyphenols contents and ABTS radical scavenging activity of GA and TA under light. PS significantly enhanced the amount of reactive oxygen species generated from GA and TA. Therefore, the interaction of polyphenols with PS under light results in acceleration of polyphenol oxidation. This phenomenon should be carefully considered during food processing and storage.

• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.279-283
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• 2022

UV-vis spectroscopy is one of the powerful tools for measuring the concentrations of reactant and products during a chemical reaction. However, there is an limitation of using the technique when the reaction undergoes in high concentration and high temperature. Color analysis using camera images can provide the identical results with UV-vis analysis with regardless of the sample concentration and temperature. The catalytic reduction reaction of resazurin to resorufin was investigated using the color analysis with the color spaces such as CIE L^*a^*b^*. Moreover, the color analysis enabled the independent analysis of two different material's concentrations without the deconvolution of overlapped wavelengths unlike the case of using UV-vis spectroscopy.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.11a
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• pp.187-190
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• 2022

본 논문은 메타버스 등 인공지능 연계 증강/가상현실 부동 중계 플랫폼에서 부동산 영상 기반 매물 소개 시스템 구축에서 사생활 및 개인정보가 영상에 담기게 될 수 있는 위험이 존재하기에 부동산 영상 내의 개인정보 및 민감 정보를 인공지능 기술을 기반으로 검출하여 삭제해주고 복원해주는 인공지능 기술 연구개발을 목표로 하였다. 한국형 부동산 내 민감 object 를 정의하고, 최신 인공지능 딥러닝 기술 기반 민감 object detection 알고리즘을 연구 개발하며, 영상에서 삭제된 부분은 인공지능 기술을 기반으로 물체가 없는 실제 공간영상으로 복원해주는 영상복원 기술도 연구 개발하였다. 한국형 부동산 환경 (영상 촬영 조도, 디스플레이 스타일, 주변 가구 배치 등)에 맞는 인공지능 모델 구축을 위하여, 자체적으로 한국 영상 database 구축 및 Transfer learning for target domain adaptation 을 진행하였다. 제안된 알고리즘은 일반적인 환경에서 98%의 정확도와 challenge 환경에서 (occlusion 빛 반사, 저조도 등) 81%의 정확도를 보였다. 본 기술은 Proptech 분야에서 주목받고 있는 메타버스 기반 온라인 중계 서비스 기술을 활성화하기 위하여 기획되었으며, 특히 메타버스 부동산 중계 플랫폼의 활성화를 위하여 사생활 보호 측면에서 필요한 중요 기술을 인공지능 기술을 활용하여 연구 개발하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.145-145
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• 2020

가뭄은 과거부터 현재까지 국내뿐만 아니라 국외에서도 지속적으로 발생하고 있으며 가뭄피해를 줄이기 위하여 많은 연구가 과거에 수행되었고 현재까지도 진행되고 있다.(강동호 외 2명, 2019명) 가뭄은 일반적으로 강수량의 부족이 원인이 되어 나타나며 홍수와 달리 장기간에 걸쳐 광범위한 지역에 피해가 나타나는 특징이 있다. 그렇기에 가뭄은 감시 및 예측에 대한 어려움이 존재하며 우리나라에서도 가뭄으로 인해 수자원 공급 긴장상태를 경험하는 빈도가 점차 증가하고 있는 추세이다.(유지영 외 3명, 2016) 적조현상은 특정 조류의 폭발적인 증식으로 해수가 붉은 빛을 띄며 용존산소량을 부족하게 만들어 해양 생태계를 파괴하는 현상이다. 적조현상은 1990년대 이후 대규모 적조가 발생하여 1995년에는 적조로 인해 약 764억의 손실이 발생한 사례가 있다.(연합뉴스, 2019.09) 이후에도 적조현상은 점점 광역화, 장기화, 고밀도화 되면서 연평균 110억 이상의 피해를 지속적으로 주고 있다. 본 연구에서는 대상 지역을 대한민국 완도로 설정 하였다. 섬이라는 지역의 특성 상 가뭄이 발생하면 식수원의 공급이 어렵고 평시에도 물을 아끼기 위한 노력이 끊이지 않는 곳이다. 실제로 완도는 우리나라에서 가장 많은 피해이력이 있는 지역이다. 또 2016년 완도에서는 적조로 인해 전복이 집단 폐사하며 358억의 피해를 입은 사례가 있다.(중앙일보, 2016.09) 그렇기에 완도지역을 대상 지역으로 하여 비강우의 장기화 등의 이유로 나타나는 가뭄을 기상학적 가뭄지수 SPI를 활용하여 분석하고 ROC 분석을 통해 수온의 상승 시 나타나는 적조현상과의 관계를 분석함으로서 적조현상이 발생하는 한 척도로 가뭄의 발생 및 장기화를 생각 할 수 있는지 판단하고자 한다.

• Economic and Environmental Geology
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• v.44 no.3
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• pp.229-238
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• 2011

S-wave, which provides lithology and pore fluid information, plays a key role in estimating gas-hydrate saturation. In general, P- and S-wave velocities increase in the presence of gas-hydrate and the P-wave velocity decreases in the presence of free gas under the gas-hydrate layer. Whereas there are very small changes, even slightly increases, in the S-wave velocity in the free gas layer because S-wave is not affected by the pore fluid when propagating in the free gas layer. To verify those velocity properties of the BSR (bottom-simulating reflector) depth in the gas-hydrate prospect area in the Ulleung Basin, P- and S-wave velocity profiles were derived from multi-component ocean-bottom seismic data which were acquired by Korea Institute of Geoscience and Mineral Resources (KIGAM) in May 2009. OBS (ocean-bottom seismometer) hydrophone component data were modeled and inverted first through the traveltime inversion method to derive P-wave velocity and depth model of survey area. 2-D multichannel stacked data were incorporated as an initial model. Two horizontal geophone component data, then, were polarization filtered and rotated to make radial component section. Traveltimes of main S-wave events were picked and used for forward modeling incorporating Poisson's ratio. This modeling provides S-wave profiles and Poisson's ratio profiles at every OBS site. The results shows that P-wave velocities in most OBS sites decrease beneath the BSR, whereas S-wave velocities slightly increase. Consequently, Poisson's ratio decreased strongly beneath the BSR indicating the presence of a free gas layer under the BSR.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.2
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• pp.101-116
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• 2017

The interaction of U(VI) (hexavalent uranium) species with natural organic matter (NOM) in KURT (KAERI Underground Research Tunnel) groundwater is investigated using a laser spectroscopic technique. The luminescence spectra of the NOM are observed in the ultraviolet and blue wavelength regions by irradiating a laser beam at 266 nm in groundwater. The luminescence spectra of U(VI) species in groundwater containing uranium concentrations of $0.034-0.788mg{\cdot}L^{-1}$ are measured in the green-colored wavelength region. The luminescence characteristics (peak wavelengths and lifetime) of U(VI) in the groundwater agree well with those of $Ca_2UO_2(CO_3)_3(aq)$ in a standard solution prepared in a laboratory. The luminescence intensities of U(VI) in the groundwater are weaker than those of $Ca_2UO_2(CO_3)_3(aq)$ in the standard solution at the same uranium concentrations. The luminescence intensities of $Ca_2UO_2(CO_3)_3(aq)$ in the standard solution mixed with the groundwater are also weaker than those of $Ca_2UO_2(CO_3)_3(aq)$ in the standard solution at the same uranium concentrations. These results can be ascribed to calcium-U(VI)-carbonate species interacting with NOM and forming non-radiative U(VI) complexes in groundwater.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.641-647
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• 2011

Polyphenols in green tea are biologically active and may interact with commonly-consumed over-the-counter (OTC) drugs in the body. In this study, modulation of cytotoxicity of polyphenon 60 (PPE, tea polyphenol mixture) with co-treatment of several OTC drugs, including ibuprofen (Ibu), acetaminophen (AAP), and aspirin was investigated in intestinal cells. PPE showed more potent cytotoxic effects on colon cancer HCT 116 cells than on normal intestinal INT 407 cells. Ibu had the strongest cytotoxic effects on both cell types. Cytotoxicity of PPE on HCT 116 and INT 407 cells was not markedly altered by co-treated OTC drugs. Cytotoxicity of the OTC drugs was not affected by PPE. When HCT 116 cells were incubated with AAP before or after PPE treatment, cytotoxicity was slightly enhanced more than their additive effect. The present study may provide basic information of possible toxicity due to interaction of the polyphenols and the OTC drugs.

• KSBB Journal
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• v.20 no.6
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• pp.393-400
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• 2005

Hydrogen($H_2$) as a clean, and renewable energy carrier will be served an important role in the future energy economy. Several biological $H_2$ production processes are known and currently under development, ranging from direct bio-photolysis of water by green algae, indirect bio-photolysis by cyanobacteria including the separated two stage photolysis using the combination of green algae and photosynthetic microorganisms or green algae alone, dark anaerobic fermentation by fermentative bacteria, photo-fermentation by purple bacteria, and water gas shift reaction by photosynthetic or fermentative bacteria. In this paper, biological $H_2$ production processes, that are being explored in fundamental and applied research, are reviewed.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.4
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• pp.304-309
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• 2015

To evaluate the degree of contamination caused by oil spill accident in the sea, the in-situ sensors which are based on the scientific method are needed in the real site. The sensors which are based on the fluorescence detection theory can provide the useful data, such as the concentration of oil. However these kinds of sensors commonly are composed of the ultraviolet (UV) light source such as UV mercury lamp, the multiple excitation/emission filters and the optical sensor which is mainly photomultiplier tube (PMT) type. Therefore, the size of the total sensing platform is large not suitable to be handled in the oil spill field and also the total price of it is extremely expensive. To overcome these drawbacks, we designed the fluorimeter for the oil spill detection which has compact size and cost effectiveness. Before the detail design process, we conducted the experiments to measure the excitation and emission spectrum of oils using five different kinds of crude oils and three different kinds of processed oils. And the fluorescence spectrometer were used to analyze the excitation and emission spectrum of oil samples. We have compared the spectrum results and drawn the each common spectrum regions of excitation and emission. In the experiments, we can see that the average gap between maximum excitation and emission peak wavelengths is near 50 nm for the every case. In the experiment which were fixed by the excitation wavelength of 365 nm and 405 nm, we can find out that the intensity of emission was weaker than that of 280 nm and 325 nm. So, if the light sources having the wavelength of 365 nm or 405 nm are used in the design process of fluorimeter, the optical sensor needs to have the sensitivity which can cover the weak light intensity. Through the results which were derived by the experiment, we can define the important factors which can be useful to select the effective wavelengths of light source, photo detector and filters.