• 한국지리정보학회지
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• 제19권3호
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• pp.61-74
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• 2016

본 연구에서는 LANDSAT 8호, KOMPSAT 2호 위성영상과 1/25,000 수치지형도를 기반으로 작성된 음영기복도를 이용하여 2007년 1월 20일 오대산 지역에서 발생한 약 4.8의 중규모 지진과 선구조선의 관계를 분석하였다. 대부분의 선행연구는 지체구조와 관련된 선구조선 분석 연구를 하였으며, 주로 2차원의 위성영상과 음영기복도를 활용하였기에 지형의 기복 등에 대한 판독이 어려워 선구조선 추출이 제한적이었다. 본 연구에서는 이를 보완하기 위해 수치표고모델(Digital Elevation Model; DEM)을 기반으로 작성한 3차원 입체 영상과 수계망 분석을 통해 지형의 기복, 수계의 연결성 등을 판독해 선구조선을 추출하여, 2차원 영상에서 나타나는 시각적인 판독에 의한 오류를 최소화한 선구조선 판독도를 작성하였다. 또한 진앙에 대한 선구조선의 통계 요소별 밀도를 추정하기 위해 spline 내삽법을 이용하여 선구조선의 빈도, 교차점, 길이에 대한 밀도를 계산하였다. 그리고 진앙에서의 선구조선 밀도가 얼마나 밀집되어 있는지 정량적으로 표현하기 위하여 각 격자 내의 선구조선 밀도에 대해 최대 선구조선 밀도로 나누는 상대밀도 값(Value of the Relative Density; VRD)을 계산하는 알고리즘을 개발하여 밀도도(density map)를 작성하였다. 각 영상의 진앙에서의 VRD는 최소 약 0.60에서 최대 약 0.90으로 나타났지만, 각 영상별 광원의 고도각과 방위각이 차이가 있어 영상별 VRD보다 통계 요소별 VRD의 평균치를 사용하였다. 그 결과, 빈도의 평균 VRD는 약 0.85로 교차점과 길이의 평균 VRD보다 약 21% 높게 나타나, 선구조선의 빈도 요소가 진앙의 위치와의 관계가 가장 밀접함을 확인하였다. 이와 같이 3차원 영상의 선구조선 추출을 통한 밀도 분석 기술은 향후 지진 발생 가능 지역 분석에 기초자료로써의 의미가 있을 것으로 기대된다.

• Bulletin of the Korean Chemical Society
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• 제27권5호
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• pp.649-656
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• 2006

The proposed head-space supercritical fluid extraction (SFE) methodology as an alternative to an existing conventional procedure was explored for the determination of organochlorine compounds in aqueous matrix. In this study, polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were utilized as target analytes. To enhance the recovery efficiency, the factors such as the $CO _2$ density, the extraction time, and the extraction mode were investigated. Furthermore, the analytical procedures and the results obtained were compared with those provided by the conventional method (the U.S. EPA method 8080). Under the optimized conditions, i.e., a combination of static with dynamic SFE mode at 2,000 psi and 40 ${^{\circ}C}$, the head-space SFE methodology gave equivalent or better to the conventional method in recovery efficiencies with clear advantages such as simple sample treatment and fast analysis time as well as reduced solvent and reagent consumption.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권4호
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• pp.369-372
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• 2000

The purpose of this study was to investigate the distribution pattern of CGRP immunoreactive nerve fibers in the healing mucosa of extracion wound. Maxillary 1st molars of rats were extracted. All extraction sites and adjacent tissues of 3 groups of rats(1-week, 2-week and 4-week groups) were removed en bloc and processed for immunostaining and were subjected to light microscopic examination. The results obtained were as follows; In 1-week group, there was no difference in the distribution pattern of CGRP immunoreactive nerve fiber between epithelial margin adjacent to extraction socket and normal gingival epithelium. In 2-week group, some CGRP-immunoreactive nerve fibers were seen in epithelial layer. In 4-week group, many intercellular CGRP immunoreactive nerve fibers were abundant in all layers of immature epithelium characterized by scab on the mucosa and thick keratinized cell layer with irregular surface. Intraepithelial CGRP immunoreactive nerve fibers were reduced to normal level in adjacent mature epithelium. These results suggest that density of CGRP immunoreactive nerve fibers are increased transiently in epithelium during reepithelialization process and CGRP released from these nerve fibers may play an important role in the reepithelialization in the wound healing.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.39-44
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• 2022

The light extraction technology for improving the light efficiency of OLEDs is the core technology for extracting the light inside the OLEDs to the outside. This study demonstrates a simple method to generate random nanostructures (RNSs) containing high refractive index nanoparticles to improve light extraction and viewing angle characteristics. A simple dry low-temperature process makes the nanostructured scattering layer on the polymer resin widely used in the industry. The scattering layer has the shape of randomly distributed nanorods. To control optical properties, we focused on changing the shape and density of RNSs and adjusting the concentration of high refractive index nanoparticles. As a result, the film of the present invention exhibits a perpendicular transmittance of 85% at a wavelength of 550 nm. This film was used as a scattering layer to reduce substrate mode loss and improve EL efficiency in OLEDs.

• Nuclear Engineering and Technology
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• 제56권1호
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• pp.70-77
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• 2024

A low energy ion irradiation system based on the deuterium arc ion source with a high perveance of 1 µP for a single extraction aperture has been successfully developed for the investigation of ion irradiation on plasma-facing components including the first mirror of plasma optical diagnostics system. Under the optimum operating condition for mirror testing, the ion source has a beam energy of 200 eV and a current density of 3.7 mA/cm². The ion source comprises a magnetic cusp-type plasma source, an extraction system, a target system with a Faraday cup, and a power supply control system to ensure stable long time operation. Operation parameters of plasma source such as pressure, filament current, and arc power with D₂ discharge gas were optimized for beam extraction by measuring plasma parameters with a Langmuir probe. The diode electrode extraction system was designed by IGUN simulation to optimize for 1 µP perveance. It was successfully demonstrated that the ion beam current of ~4 mA can be extracted through the 10 mm aperture from the developed ion source. The target system with the Faraday cup is also developed to measure the beam current. With the assistance of the power control system, ion beams are extracted while maintaining a consistent arc power for more than 10 min of continuous operation.

• 대한전자공학회논문지SP
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• 제44권4호통권316호
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• pp.93-100
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• 2007

웨이브렛 변환에 근거하여 디지털영상으로부터 문자를 처리하는 새로운 접근법을 제시한다. 대상은 각필(刻筆)문자 영상이다. 각필문자에는 형성된 결상에 유사성이 존속하며 배경부분과 함께 서로 다른 준위의 다해상도 특성들로 분해된다는 점을 착안하였다. 우선 Daubechies 웨이브렛을 적용하여 영상을 부대역들로 분해한다. 저주파 부대역은 분할처리와 FCM근거 퍼지 군집분리 및 면적기반 영역처리기법을 적용하여 문자특성을 추출한다. 고주파 부대역들에는 이동창을 설정하고, 이동창의 국부 에너지를 추정하여 고주파 특성들을 활성화한다. 이들 특성들은 조합되어 역웨이브렛 과정을 통해 본래 영상 상태로 복원되고 배경부분이 배제된 문자를 추출한다. 실험 결과는 제안된 기법의 효과를 보이고 있다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.119.1-119.1
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• 2014

Toxic waste disposal: Many people think that when toxic waste is dumped into the ocean or into the air, it disappears. This belief is incorrect. Rather than disappearing, it accumulates over time and slowly destroys the environment. Ultimately, it leads to the destruction of human race. Plasma is environmentally friendly: Plasma is environmentally friendly because it is created and disappears. When plasma is formed on the earth, you need certain conditions such as accelerating electrons by an electrical discharge or a particle accelerator. When this is gone, plasma completely disappears, leaving no impact on the environment. Plasmas produce radicals: Even if plasma density is low at atmospheric pressure, many radicals (excited states of molecules) are created. These radicals are chemically very aggressive. So instead of using harmful chemicals, plasma can be utilized for less of an impact on the environment. Plasma can reach very high temperatures: Plasma is also useful because when you control the density, you can easily reach high temperatures up to $5000{\sim}6000^{\circ}C$ at atmosphere pressure. Because of this heat and the chemical aggressiveness of the plasma, there are many green applications for plasma technology. Pulsed power technology: Pulsed electric field for extraction, drying and killing bacteria. Treatment of biological tissue by pulsed electric fields: Extraction of substances from cells: Sterilisation, Medical applications, Growth stimulation, Food preparation. Each application has its specialities, especially with respect to pulse shape and electric field strength.

• Elastomers and Composites
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• 제56권4호
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• pp.223-233
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• 2021

In this study, epoxidized liquid isoprene rubber (E-LqIR) was used as a processing aid in a silica-filled natural rubber compound to improve the fuel efficiency, abrasion resistance, and oil migration problems of truck and bus radial tire tread. The wear resistance, fuel efficiency, and extraction resistance of the compound were evaluated according to the molecular weight of E-LqIR. Results of the evaluation showed that the E-LqIR compound had a lower chemical crosslink density than that of a treated distillate aromatic extract (TDAE) oil compound because of the sulfur consumption of E-LqIR. However, the filler-rubber interaction improved because of the reaction of E-LqIR with silica and crosslink with the base rubber by sulfur. As the molecular weight of E-LqIR increased, crosslink with sulfur was facilitated, and the filler-rubber interaction improved, resulting in improved abrasion resistance. The fuel efficiency performance of the E-LqIR compound was poorer than that of the TDAE oil compound because of the low chemical crosslink density and hysteresis loss at the free chain end of E-LqIR. However, the fuel efficiency performance improved as the molecular weight of E-LqIR increased.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.820-824
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• 1992

An accurate method for extracting both Si film doping concentration and front or back silicon-to-oxide fixed charge density of fully depleted SOI devices is proposed. The method utilizes the current-to-voltage and capacitance-to-voltage characteristics of both SOI NMOSFET and PMOSFET which have the same doping concentration. The Si film doping concentration and the front or back silicon-to-oxide fixed charge density are extracted by mainpulating the respective threshold voltages of the SOI NMOSFET and PMOSFET according to the back surface condition (accumulation or inversion) and the capacitance-to-voltage characteristics of the SOI PMOSFET. Device simulations show that the proposed method has less than 10% errors for wide variations of the film doping concentration and the front or the back silicon-to-oxide fixed charge density.

• Journal of Ginseng Research
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• 제22권3호
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• pp.205-210
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• 1998

Glucosidic bonds at the C20 position of the sapogenins were hydrolyzed easily in the lower pH, higher temperatures and longer times to give prosapogenins and sugars. The glucosidic bond of saponin at the C3 of ginsenoside-Rb1, which is secondary carbon, was relatively stable due to the low electron density of -0.2. But the bond of saponin at the C20 position, which is tertiary carbon with the relatively high electron density of -0.3, was liable to be hydrolyzed even in weakly acidic solution by the increase of heating time. On the other hand, red ginseng contained 13.34 mg/g of citric acid, 8.78 mg/g of malonic acid, 3.70 mg/g of oxalic acid, 2.13 mg/g of malic acid and 0.44 mg/g of succinct acid. Ginseng saponins were very stable in ginseng extract neutralized with sodium carbonate or sodium bicarbonate corresponding to the equivalent amount of the total organic acid in the red ginseng.