• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.1
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• pp.27-35
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• 2009

The moving picture blur noise of LCD is measured and the characteristics of it are evaluated. From the results, blur noise is generated only when the sight line moves while pursuing the moving image and blur noise is not generated when the sight line is fixed. In addition, decrease of gray level by the image blur has a linearity and velocity dependence. The blur noise simulator based on this experimental results is developed. From the results of blur noise simulation, the faster the moving speed of image is, the more blur noise has increased and these agree with the results of measurement. In the result of simulating blur noise characteristics by the duty ratio control of backlight, noise is reduced by lowering of the duty ratio. but the blur noise increases if there is in the both of adjacent two frames. Moreover, the case of doubling the frame rate to 120[Hz], decreasing the moving speed of the image by making an new image between the adjacent two frames brings the reduction of blur noise.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.145.2-145.2
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• 2011

메탄 하이드레이트는 낮은 온도와 높은 압력 조건에서 물분자들의 격자구조에 메탄가스분자가 포획되어 수소결합으로 형성되는 외관상 얼음과 비슷한 결정성 화합물이다. $1m^3$의 메탄 하이드레이트는 표준상태에서 $172m^3$의 메탄가스와 $0.8m^3$의 물로 분해되며, $-10^{\circ}C{\sim}-20^{\circ}C$의 온도에서는 하이드레이트 입자표면에서 생성되는 얼음막으로 인하여 상압에서도 안정하게 존재하는 자기보존 효과를 가지고 있다. 따라서 이와 같은 특징을 천연가스 수송 및 저장의 방법으로 이용할 경우 $-162^{\circ}C$의 초저온을 만들고 유지시키기 위하여 고가의 설비를 필요로 하는 기존의 LNG 수송방법을 대체할 수 있다. 특히 연간 천연가스 소비량을 0.4 ~ 1.0 million ton으로 가정했을 때, 하이드레이트 수송방법은 LNG 수송에 비해 18 ~ 25% 정도의 비용을 절약할 수 있는 경제적인 방법으로 알려져 있다. 그러나 하이드레이트를 인공적으로 제조할 경우 물분자와 가스분자의 반응율이 낮기 때문에 하이드레이트가 생성되기까지 많은 시간이 소요되며, 하이드레이트에 포획되는 가스분자의 양도 적다. 따라서 본 연구에서는 이와 같은 문제점을 해결하기 위하여 다공성 물질인 천연 제올라이트와 제올라이트 13X를 이용하여 제올라이트 혼합유체를 제조하였으며, 메탄가스와 반응시켜 하이드레이트를 생성시키는 실험을 수행하였다. 그 결과, 하이드레이트 생성 시 천연 제올라이트와 제올라이트 13X 모두 0.01 wt%의 혼합비율에서 가장 좋은 효과를 나타내었으며, 하이드레이트에 포획된 가스의 양은 같은 과냉도 조건에서 천연제올라이트와 제올라이트 13X 혼합유체를 이용하여 하이드레이트를 생성 시켰을 때, 증류수보다 각각 4배, 5배 높음을 보였다. 또한 낮은 과냉도에서 하이드레이트 생성 시 제올라이트, 제올라이트13X 혼합유체에서 하이드레이트 생성시간이 증류수에서 하이드레이트를 생성시킬 때보다 빨라짐을 확인하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.8-17
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• 2010

This paper proposes a novel LCD CCFL-backlight electronic ballast using the phase-shift full-bridge inverter. The proposed electronic ballast reduces the ignition voltage and eliminates current spikes using the new digital dimming control applied with soft-starting. Thus the electronic ballast improves ignition behavior of the CCFL and hence increases the CCFL's life span. For this, this paper analyzes the full-bridge inverter topology of the proposed electronic ballast and explains the new digital dimming control algorithm applied to the ballast, briefly. And this paper shows a design example of the prototype circuit and explains an implementation method of the digital dimming control which is implemented on a single-chip microcontroller with software. This was implemented as actual prototype electronic ballast, and its experimental results showed that the proposed electronic ballast operates correctly. The ignition voltage of the prototype in the digital dimming operation was reduced about 30[%] compared with the conventional electronic ballast and there were not any current spikes.

• Journal of the Mineralogical Society of Korea
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• v.17 no.1
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• pp.85-97
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• 2004

Weathering of hornfels pebble in the marine terrace deposits, Yangnam-Myon, Gyeongju was investigated by X-ray diffraction, scanning electron microscopy, and chemical analysis. In the early stage of weathering, only plagioclase was leached leaving pores. With progress of weathering, biotite and chlorite were tranformed to hydrobiotite and chlorite-vermiculite, respectively. Quartz, K-feldspar, and muscovite were not altered. Thickness of weathering rinds and their mineralogical characteristics were different between terraces of different elevations. In the lower second terrace, the weathering of pebble was dominated by the decomposition of plagioclase, while in the upper third terrace, weathering was characterized by the transformation of biotite and chlorite with precipitation of halloysite from the weathering of plagioclase. Thickness of weathering rind and weathering products were varied even within the same terrace deposit probably due to local variation of drainage conditions.

• Journal of Korean Society of Forest Science
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• v.98 no.6
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• pp.719-725
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• 2009

This study was conducted to establish the optimal condition for acclimatization from somatic embryos of Eleutherococcus seoulensis. Torpedo-shaped embryos of Eleutherococcus seoulensis were cultured on 1/3 MS and WPM media supplemented with $GA_3$ (3.0, 5.0 mg/L) for 4 weeks. Plentlets were transferred to 1/2 SH solid medium with 1.0 mg/L $GA_3$ and 0.2% activated charcoal for shoot and root elongation and them elongated plantlets further developed on 1/2 SH medium for 4 weeks. Developed plantlets further elongated into well-shaped leaf and root system on 1/3 SH medium under ventilation condition for 4 weeks. Plantlets grew normally on 1/3 SH basal medium, were acclimated on various soil. Survival frequency of plantlets was influenced by soil type(peatmoss+perlite, perlite, soil on Nam mountain). The highest survival rate to soil was more than 70% when plantlets were 1/3 SH medium under ventilation condition in Nam mountain soil. These results indicate that the systematic procedure of plant production in Eleutherococcus seoulensis could be practically applicable for mass propagation.

• Journal of the Mineralogical Society of Korea
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• v.31 no.2
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• pp.103-111
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• 2018

Mineralogical properties of two Asian dust (Hwangsa) samples collected during dust events in April 6 and 15, 2018 were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD analyses showed that Asian dusts were dominated by phyllosilicates (62 wt%) comprising illite-smectite series clay minerals (ISCMs) (55%), chlorite (3%) and kaolinite (4%). Nonphyllosilicate minerals were quartz (18%), plagioclase (9%), K-feldspar (3%), calcite (3%), and gypsum (2-4%). Mineral compositions determined by SEM chemical analyses were consistent with XRD data. ISCMs occur as submicron grains forming aggregate particles or coating coarse mineral grains such as quartz, plagioclase, K-feldspar, chlorite, and calcite. The ISCMs are often associated with calcite nanofibers and gypsum blades. Mineralogical properties of 2018 dusts were similar to those of previous dusts although clay contents were higher than that of coarse 2012 dust.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.4
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• pp.301-307
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• 2016

This paper proposes a lyric search method to consider the characteristics of the user query. According to the fact that queries for the lyric search are derived from highlight parts of the music, this paper uses the hierarchical agglomerative clustering to find the highlight and proposes a Gaussian weighting to consider the neighbor of the highlight as well as highlight. By setting the mean of a Gaussian weighting at the highlight, this weighting function has higher weights near the highlight and the lower weights far from the highlight. Then, this paper constructs a index of lyrics with the gaussian weighting. According to the experimental results on a data set obtained from 5 real users, the proposed method is proved to be effective.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.7 no.1
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• pp.20-25
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• 2014

There are several severe problems for LED device, the next generation's economy green lighting: as the temperature increases, the lamp efficiency decreases; if the temperature is over $80^{\circ}C$, the lifetime of lighting decreases; Red Shift phenomenon that wavelength of spectrum line moves toward long wavelength occurs; and optical power decreases as $T_j$ increases. Thus, Heat sink design that can minimize the heat of LED device is currently in progress. While the thermal resistance of COB Type LED was reduced by direct coupling of LED chip to the board, residential 13.5W requires Heat sink in order resolve heat issue. This study designed Heat Sink suitable for residential 13.5W COB LED down-light and selected the optimum Fin thickness through flow simulation that packaged the designed Heat Sink and 13.5W COB. And finally it analyzed and evaluated the thermal modes using contacting thermometer.

• Journal of the Mineralogical Society of Korea
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• v.6 no.1
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• pp.38-47
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• 1993

Clinoptilolite and mordenite are important constituents of the Nuldaeri Trachytic Tuff and Guryongpo Dacitic Tuff of the Tertiary Janggi Group which were deposited in a lacustrine environment. The diagenetic cystallization sequences of zeolites in different tuffaceous sediments and their chemical behaviors have been studied to know the process of their formation. The paragenetic sequence established from textural observations and chemical data : Ca-smectite ${\leftrightarrow}$(Ca, K)-clinoptilolite${\leftrightarrow}$(K, Na)-mordenite, indicates that the chemical activities of alkalic ions and Si/Al activity ratio in pore fluids changed systematically with diagenetic alteration. The chemical trend of zeolite formation is characterized by decreasing Ca and Mg, non-variable Na and increasing K in the Nuldaeri Trachytic Tuff and by decreasing Ca and Mg, non-variable Na and increasing-decreasing K in the Guryongpo Dacitic Tuff. The paragenesis from glass via smectite to alkali zeolites indicates a sequence of incongruent dissolution reactions and subsequent crystallization. Inhomogeneity in chemical composition of each zeolite may be attributed to such processes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.2
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• pp.401-407
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• 2014

There are increasing interests in COB (Chip On Board) that densely arranged many LED chips on one board in order to solve the heat issue. There are many problems being on the rise: the lifespan decreases as the temperature of LED devices increases; Red Shift phenomenon, in which wave length of spectral line moves from original wave length to long wave length, occurs; and optical power decreases as $T_j$ increases. In order to resolve such problems, this study selected the optimum thickness and length of Fin, planned the second Heat sink that is optimum for COB LED with 15W, and analyzed thermal mode by Solid Works Flow Simulation through 15W COB packaging with the planned Heat sink. 15W COB down-light Heat sink that is produced based on this analysis was utilized to analyze thermal mode through contact thermometer and electrical properties through Kelthley 2430.