• Ocean Systems Engineering
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• 제12권1호
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• pp.63-86
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• 2022

A refined projection-based purely Lagrangian meshfree method is presented towards reliable numerical analysis of fluid flow interactions with saturated/unsaturated porous media of uniform/spatially-varying porosities. The governing equations are reformulated on the basis of two-phase mixture theory with incorporation of volume fraction. These principal equations of mixture are discretized in the context of Incompressible SPH (Smoothed Particle Hydrodynamics) method. Associated with the consideration of governing equations of mixture, a new term arises in the source term of PPE (Poisson Pressure Equation), resulting in modified source term. The linear and nonlinear force terms are included in momentum equation to represent the resistance from porous media. Volume increase of fluid particles are taken into consideration on account of the presence of porous media, and hence multi-resolution ISPH framework is also incorporated. The stability and accuracy of the proposed method are thoroughly examined by reproducing several numerical examples including the interactions between fluid flow and saturated/unsaturated porous media of uniform/spatially-varying porosities. The method shows continuous pressure field, smooth variations of particle volumes and regular distributions of particles at the interface between fluid and porous media.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.249-251
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• 2014

Synthesis gas such as hydrogen and carbon monoxide was produced from $CH_4//oxygen$ mixture using two-section porous media combustor. Heat recirculation through the inner foam structure could extend the flow velocity of stable region over the laminar burning velocity. $H_2/CO$ ratio and module M from concentration of flue gas measured by Gas Chromatography was similar to those calculated by equilibrium. But it was made sure that the heat loss effect becomes more influential than heat recirculation effect as the mixture gets richer. To generate synthesis gas appropriate for methanol production, insulated pressurized porous media combustor will be designed and built in the future.

• Journal of Plant Biology
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• 제19권4호
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• pp.95-99
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• 1976

This work deals with different extraction media and reaction mixtures on photosystem II activity of Spinach chloroplasts. The photoreduction rate of ferricyanide and DPIP by intact chloroplasts which extracted with four kinds of extraction media; S-Tris-N pH 7.2, 8.0, S-Tricine-N pH 7.2, 8.0, was measured in five kinds of reaction mixtures; S-Tris-N pH 7.2, 8.0, S-Tricine-N pH 7.2, 8.0, 0.05 M-Tris pH 7.2. The extraction medium which shows the highest photoreduction rate was S-Tris-N at pH 7.2 and S-Tricine-N at pH 8.0. As to the reaciton mixture, S-Tricine-N pH 8.0 showed the highest rate. On the complex effects of extraction media and reaction mixtures, the highest photordeuction rate of Hill oxidant by intact chloroplasts was obtained by S-Tris-N pH 7.2 extraction medium and S-Tricine-N pH 8.0 reaction mixture. The second highest activity was obtained by S-Tricine-N pH 8.0 extraction medium and reaction mixture.

• 한국환경과학회지
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• 제14권9호
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• pp.843-849
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• 2005

The objective of this research was to investigate the removal efficiencies ofVOCs and odors with newly developed biofilter which was designed to sustain the biofilm constantly on the packed media. Initially, four types of media, for example, fiber, activated carbon, ceramic and the mixture of activated carbon and ceramic(AIC mixture J, were used for packed materials of biofilter. When ethylalcohol was selected as a test gas for media efficiency, fiber and AIC mixture had better removal efficiencies of ethyl alcohol than others. Removal efficiencies for acetaldehyde, ethyl alcohol, butylalcohol, ethylacetate and diethylamine in biofilter with fiber and AIC mixture as packed media were increased as the residence time increased. Butylalcohol, especially, showed the maximum removal efficiency among all used VOCs and odors. In case of ethyl acetate, the difference of removal efficiencies between low and high residence times was wide remarkably.

• 방송공학회논문지
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• 제13권5호
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• pp.681-684
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• 2008

We proposed a method to improve moving object detection capability of Gaussian Mixture Model by suggesting shape adaptive bidirectional block matching algorithm. This method achieves more accurate detection and tracking performance at various motion types such as slow, fast, and bimodal motions than that of Gaussian Mixture Model. Experimental results showed that the proposed method outperformed the conventional methods.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.73-74
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• 2015

Synthesis gas such as hydrogen and carbon monoxide was produced from $CH_4/oxygen$ mixture using insulated pressurized porous media combustor. Experimentally, two cylindrical SiC foams with the different pore density were piled up in a quartz tube and fully premixed mixture was supplied in the axial direction. After stabilizing fuel-rich flame at the interface of the two foams at several pressure conditions, mole fractions of synthesis gases were measured by gas chromatography. Heat recirculation through the inner foam structure could extend the flow velocity of stable region over the laminar burning velocity. As the pressure increased, the rich flammability limit, $H_2/CO$ ratio, and module M increased.

• 한국환경과학회지
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• 제23권2호
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• pp.303-312
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• 2014

As for chemical characteristics of cultivated media waste, the total content of nitrogen, phosphoric acid, and potassium was 6.93%; organic matter content was 67.78%; pH and EC were 7.20 and 1.46 ds/m, respectively. Organic acids identified during stabilization included citric acid, oxalic acid, fumaric acid, and acetic acid, which was highest. During the stabilization of cultivated media waste, temperature decreased and pH increased on the 15th day, and the germination index was 88 after the period, indicating that at least 15 days of stabilization is needed when cultivated media waste is used for growth material of crop. As for germination characteristics, when the mixture rate of cultivated media waste was 20% and under, germination of cucumber and oriental melon was favorable without difference compared to the control plots. For lettuce and Chinese cabbage, no statistically significant difference was found when the rate was 10% and under compared to the control plots. As for seedling quality after 20 days of sowing, cucumber, oriental melon, and Chinese cabbage showed favorable growth only when the mixture rate of cultivated media waste was 10% and under; lettuce showed lower growth characteristics regardless of mixture rate when compared to the control plots. Cultivated media waste may be significantly useful for cucumber and oriental melon, but not for Chinese cabbage and lettuce.

• Journal of information and communication convergence engineering
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• 제11권2호
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• pp.95-102
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• 2013

This paper presents a stochastic driver behavior modeling framework which takes into account both individual and general driving characteristics as one aggregate model. Patterns of individual driving styles are modeled using a Dirichlet process mixture model, as a non-parametric Bayesian approach which automatically selects the optimal number of model components to fit sparse observations of each particular driver's behavior. In addition, general or background driving patterns are also captured with a Gaussian mixture model using a reasonably large amount of development data from several drivers. By combining both probability distributions, the aggregate driver-dependent model can better emphasize driving characteristics of each particular driver, while also backing off to exploit general driving behavior in cases of unseen/unmatched parameter spaces from individual training observations. The proposed driver behavior model was employed to anticipate pedal operation behavior during car-following maneuvers involving several drivers on the road. The experimental results showed advantages of the combined model over the model adaptation approach.

• 한국약용작물학회지
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• 제23권4호
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• pp.271-276
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• 2015

This study was conducted to investigate the effect of shading degree and rooting media on the growth of Caragana sinica and Sedum middendorffianum after cutting. In C. sinica, the highest rooting rate was obtained in cuttings planted in horticultural soil (Sunshine Mix #1) and peat moss mixture (peat moss : perlite = 1 : 1, v/v) under one layer of 35% shading and in cuttings planted in kanumatsuchi soil mixture (kanumatsuchi soil : decomposition of granite = 1 : 1, v/v) under non-shading. Whereas, regardless of shading degree, most cuttings of S. middendorffianum rooted in both horticultural soil and peat moss mixture. Cuttings of C. sinica showed the highest root length, 10.4cm in kanumatsuchi soil mixture under one layer of 35% shading but the highest fresh and dry weight of roots in kanumatsuchi soil mixture under non-shading. In S. middendorffianum, the highest root length, fresh and dry weight of root were obtained in cuttings planted in horticultural soil under non-shading. With these results, we recommended that cuttings of C. sinica should be propagated in kanumatsuchi soil mixture under non-shading and cuttings of S. middendorffianum in horticultural soil under non-shading.

• 한국유기농업학회지
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• 제7권2호
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• pp.179-188
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• 1999

분립과 상토재(vermiculite, perlite, peat moss)의 혼합비율이 Orchardgrass 유식물체의 생육에 미치는 영향을 조사하였다. 분립과의 혼합비율은 각각 100:0(control), 75:25, 50:50, 25:75, 0:100이였고 얻어진 결과는 다음과 같다. 1. 초장(PL)과 상토재와의 다른 혼합구에서 보다도 PM과의 혼합구에서 월등히 좋았다. 2. 경수(NT)는 다른 혼합구와 달리 분립 : PM(50:50)에서 유의하게 증가했다. 3. 근장(RL)은 다른 처리구와 유의하게 차이가 있었으며, PE와의 혼합비율에서 뿌리의 길이생장이 높았다. 4. 엽중(LW)은 50:50의 모든 혼합구에서 유의한 차이가 없었고, 특히 분리 : PM(75:25)와 분립 : PM(25:75)의 혼합구에서 유의한 차이가 인정되지 않았다. 5. 지상부 경중(SW)은 50:50의 모든 혼합구와 분립 : PM(75:25), 분립 : VL(75:25)에서 유의한 차이가 없었다. 6. Orchardgrass 유식물체의 지상부 경중과 지하부의 건물중이 생물학적 수량 증가 경향을 나타내었다. 7. 분립과 PM의 혼합비율이 50% 이상에서 orchardgrass 유식물체의 생물학적 수량을 증가시켰다.