• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1340-1352
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• 2008

In this study, S-wave velocity range is gauged in every field test method at the total 5 locations in the marine deposits in Incheon area. field test method is accomplished the SPT(Standard Penetration Test), CPT(Cone Penetration Test), SPS(Suspension PS Logger), SCPT (Seismic Cone Penetration Test) and so on. The S-wave velocity of SCPT in the downhole test method is measured lower than SPS logger at the N value > 15 range. But at the N value < 15 range, SPS logger and SCPT result is measured same. In this result, although the soil strength of the downhole test method increased, the rate of S-wave velocity is tend to be slowed. This result shows that the downhole test is difficult to apply at the place that the intensity of soil is more extreme and harder soil. And it shows that the existing Imai(1982) type that is mostly used within the country is not suitable for the marine deposits. Thus, the empirical formula that can show the range of S-wave velocity in each N value for domestic soil is needed.

• 한국산학기술학회논문지
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• 제11권3호
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• pp.1023-1026
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• 2010

이 논문에서는 미세한 통로를 흐르는 고분자 블렌드의 유변학적 특성에 관하여 연구하였다. 우선 두께가 각각 0.1, 0.2 0.5 mm 인 세 종류의 슬릿 다이를 제작하였고 특수 제작한 피스톤을 부착한 모세관 점도계로 고분자 블렌드의 점도 거동을 관찰하였다. 관찰 결과 상구조가 해도 구조를 가지는 경우 고분자 블렌드의 점도는 다이의 크기에 의존하지 않음을 알 수 있었다. 그러나 상구조가 co-continuous 구조를 가지는 경우에는 점도가 다이의 크기에 의존함을 관찰하였는데, 몇몇 부가 실험 결과 이는 각 상 간의 미끄러짐이 원인임을 알 수 있었다.

• 한국환경과학회지
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• 제28권9호
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• pp.719-727
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• 2019

In this study, the effect on the stability of Aerobic Granular Sludge (AGS) with different Carbon/Nitrogen (C/N) ratios was investigated. The C/N ratios were controlled to 10.0, 7.5, 5.0, and 2.5 using the sequencing batch reactor, and the results showed that the removal efficiency of organic matter and total nitrogen decreased simultaneously with the decrease of C/N ratio. The removal efficiency of organic matter and total nitrogen at C/N ratio of 2.5 was 70.7% and 52.3% respectively. In addition, the AGS/mixed liquor suspended solids (MLSS) ratio showed a tendency to decrease from 85.7% to 73.7%, while the sludge volume index showed a tendency to increase from 82 mL/g to 102 mL/g as the C/N ratio decreased. At the same time, the apparent deviation of polysaccharide (PS) content in extracellular polymeric substances was observed, and polysaccharides/protein (PS/PN) ratio decreased from 0.62 to 0.31 as the C/N ratio decreased. Optical microscope observations showed that the reduction in C/N ratio caused the growth of filamentous bacteria and significantly affected the stability of AGS.

• Macromolecular Research
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• 제11권6호
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• pp.418-424
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• 2003

Exfoliated poly(methyl methacrylate-co-styrene) [P(MMA-co-ST)]/silicate nanocomposites were synthesized through a multistep emulsion polymerization. The methyl methacrylate monomers were polymerized first and then the styrene monomers were polymerized. The nanocomposites had core-shell structures consisting of PMMA (core) and PS (shell); these structures were confirmed by $^1$H NMR spectroscopy and TEM, respectively. P(MMA-co-ST) copolymers showed two molecular weight profiles and two glass transition temperatures (T$_{g}$) in GPC and DMA measurements. At 30 $^{\circ}C$, the nanocomposites exhibited 83 and 91 % increases in their storage moduli relative to the neat copolymer because the silicate layers were dispersed uniformly in the polymer matrix.x.

• 한국환경과학회지
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• 제11권12호
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• pp.1315-1320
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• 2002

Since the enzymatic degradation of microbial poly[(R)-3-hydroxybutyrate-co-3-hydroxyvalerate] (P(3HB-co-3HV)) initially occurs by a surface erosion process, a degradation behavior could be controlled by the change of surface property. In order to control the rate of enzymatic degradation, plasma gas discharge and blending techniques were used to modify the surface of microbial P(3HB-co-3HV). The surface hydrophobic property of P(3HB-co-3HV) film was introduced by CF$_3$H plasma exposure. Also, the addition of small amount of polystyrene as a non-degradable polymer with lower surface energy to P(3HB-co-3HV) has been studied. The enzymatic degradation was carried out at 37 $^{\circ}C$ in 0.1 M potassium phosphate buffer (pH 7.4) in the presence of an extracellular PHB depolymerase purified from Alcaligenes facalis T1. Both results showed the significant retardation of enzymatic erosion due to the hydrophobicity and the enzyme inactivity of the fluorinated- and PS-enriched surface layers.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.957-959
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• 2005

A noise reduction equipment in power systems was device combined in a passive element such as the form of L, R and C. A analysis of frequency characteristics for the transformer models shall be considered the additional capacitance between the windings($C_{ps}$), terminals($C_s$), and winding-ground($C_g$). A noise in transformer is modeled by take account into the different frequency. In case of the high frequency, transformer windings with stray capacitance have lower impedance. Therefore a noise is transferred from primary winding to secondary winding. Noise Cut Transformer(NCT) was the noise reduction device and was normally single phase two-winding type transformer. We analyzed frequency characteristics using the nodal network analysis with the equivalent circuit and the simulation of the MATLAB.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 추계학술대회 학술발표 논문집
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• pp.243-251
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• 2000

In general, Rough Set theory is used for classification, inference, and decision analysis of incomplete data by using approximation space concepts in information system. Information system can include quantitative attribute values which have interval characteristics, or incomplete data such as multiple or unknown(missing) data. These incomplete data cause the inconsistency in information system and decrease the classification ability in system using Rough Sets. In this paper, we present various types of incomplete data which may occur in information system and propose INcomplete information Processing System(INiPS) which converts incomplete information system into complete information system in using Rough Sets.

• 교육시설 논문지
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• 제26권6호
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• pp.51-58
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• 2019

This study embody the investigation of the winner projects of Young Architecture Program(YAP) taken place annually at front yard of MoMA PS1 since 1998. Every installation of project is experimental exhibition that have ambiguous border in the area between lightness and architecture. Thus the design have less limits as architectural space and talents can express the innovative idea strong. This paper aims to probe annual significant key words by analyzing the contemporary representative space types, materials, fabrication methods and innovative ideas, and to identify the changes of important concept of lightness and recent trend in architect design concept.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.438-440
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• 2005

광위상변조기를 이용하여 OCT용 초고속 광지연단을 설계하고 수치해석을 수행하였다. 수치해석은 electro-optic 위상 변조기에 1310nm, 10ps의 펄스폭을 갖는 레이저 광원을 적용하여 수행하였다. 수치해석결과로 500MHz의 변조 주파수일때 19ps의 시간 지연을 얻었으며, 이는 기존의 기계적 검출방식(수십kHz)의 OCT장치에 비해 1000배이상 빠른 검출이 가능할 것으로 예상된다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.192-195
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• 2002

Effect of aeration rate and agitation speed on cell growth and the production of heteropolysaccharide-7 (PS-7) by Beijerinckia indica was investigated. Aeration rate and agitation speed in a 7L bioreactor ranged from 0.5 to 1.5 vvm and from 300 to 500 rpm, respectively. Higher agitation speed with an aeration rate of 0.5 vvm in the bioreactor resulted in maintenance of higher concentration of dissolved oxygen in the medium, which enhanced the production of PS-7. In this study with a 7L bioreactor, maximal production of PS-7 was 11.0 g/L and its conversion rate from 2% (w/v) glucose was 0.55 when the aeration rate and agitation speed were 1.0 vvm and 500 rpm, respectively. Proper aeration rate and agitation speed might enhance the production of PS-7 as well as reduce the time to reach maximal production.