• 한국농림기상학회지
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• 제14권2호
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• pp.79-89
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• 2012

본 연구는 광환경 변화에 따른 병풍쌈의 엽록소 함량, 광합성 특성, 엽록소형광반응 그리고 생장 특성을 조사하기 위해 실시하였으며, 실험을 위해 병풍쌈을 무처리구(full sunlight)와 3개의 서로 다른 피음조건(88~93%, 65~75% and 45%~55% of full sunlight)에서 생육시켰다. 병풍쌈은 피음수준이 증가할수록 총 엽록소 함량, 광화학반응효율, T/R율, SLA, LAR, LWR은 증가하고 암호흡은 감소하여, 낮은 광조건에서 빛의 흡수량과 광합성에 대한 이용효율을 높이는 반응을 나타냈다. 5월의 중피음처리구에서 가장 높은 최대광합성속도와 순양자수율을 나타냈으며, 피음처리구보다 전광처리구에서 가장 낮은 최대광합성속도, 광화학반응효율, 엽록소 함량을 나타냈다. 위의 결과에 따라 병풍쌈은 음지식물로 강한 광에 대한 민감성이 매우 높고, 광을 제한하여도 강피음 상태를 지속하게 되면 광합성 능력이 크게 감소될 수 있으며, 건전한 생육을 위해서는 노천광의 65~75%를 차단시킨 광환경 조건이 적합하다고 생각된다.

• 한국수소및신에너지학회논문집
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• 제16권1호
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• pp.17-24
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• 2005

We experimented on growth in light and production of hydrogen and organic matters in dark fermentation by using C. reinhardtii. In the light, growth rate of C. reinhardtii following $CO_2$ fixation was proportional to consumption rate of nitrogen source. And the starch in cell was accumulated more when the period of culture was lengthened more. But the accumulation rate of starch in cell was decreased when the growth rate of cell become dull. In the dark fermentation, the production volume and production rate of hydrogen were the highest value in the mid exponential state among other states. The utilization efficiency of substrate was better in the early exponential state than other states. In production of organic matters, acetic acid didn't change remarkably and ethanol showed the highest value in early exponential state.

• 한국자동차공학회논문집
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• 제20권3호
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• pp.77-82
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• 2012

It is well known that the targeted fuel efficiency could only be achieved by more than 40% reduction of the vehicle weight through improved design and extensive utilization of lightweight materials. In order to obtain the goal of the weight reduction of automobiles, the researches about lighter and stronger rear sub-frame have been studied without sacrificing the safety of rear sub-frame. In this study, the weight reduction design process of rear sub-frame could be proposed based on the variation of von-Mises stress contour by substituting an AA6061 (aluminum 6061 alloy) having tensile strength of 310 MPa grade instead of SAPH440 steels. In addition, the stress ratio variations (stress over fatigue limit) of the rear sub-frame were examined and compared carefully. It could be reached that this approach method could be well established and be contributed for light-weight design guide and the optimum design conditions of the automotive rear sub-frame development.

• Journal of the Korean Wood Science and Technology
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• 제42권2호
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• pp.89-100
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• 2014

Energy consumption statistics in 2005 from the Korea Energy Management Corporation show that building energy usage was about 24.2% of total domestic energy consumption, and 64% of total building energy usage was consumed by residential buildings. Thus, about 10% of total domestic energy consumption is due to the heating of residential buildings. Building energy can be calculated by the configuration of the building envelope and the rate of infiltration (the volume of the infiltration of outdoor air and the leakage of indoor air), and by doing so, the annual energy usage for heating and cooling. Therefore, air-tightness is an important factor in building energy conservation. This investigate air infiltration and various factors that decrease it in timber frame buildings and suggest ways to improve air-tightness for several structural types. Timber frame buildings can be classified into light frame, post and beam, and log house. Post and beam includes Han-ok (a Korean traditional building). Six light frame buildings, three post and beam buildings, one Korean traditional Han-ok and a log house were selected as specimens. Blower door tests were performed following ASTM E779-03. The light frame buildings showed the highest air-tightness, followed by post and beam structures, and last, log houses.

• 한국해양학회지:바다
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• 제8권1호
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• pp.29-34
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• 2003

한국 서해의 곰소만에서 분리한 온대 해역 산 초유의 M. rubrum MR-MAL01 배양체가 확보되어, M. rubrum의 입자성 먹이 섭식 현상이 보고되었다. 100$\mu$mo1 photons m$^{-2}$ s$^{-1}$의 고광도(HL) 및 10 $\mu$mo1 photons m$^{-2}$ s$^{-1}$의 저광도(LL)에서 광 적응된 미동정 은편모조류 종주 CR-MAL01를 섭식한 M. rubrum의 HL및 LL적응 배양체의 흡광스펙트림을 분석하였다. LL에 적응된 은편모조류를 섭식하고 LL에 적응한 M. rubrum은 섭식 이전의 먹이 세포 흡광특성인 542nm부근의 황갈색 파장 범위에서 뚜렷한 흡광피크를 나타낸 반면, HL에 적응된 은편모조류를 섭식하고 HL에 적응한 M. rubrum은 이러한 흡광 피크를 보이지 않았다. 이는 M. rubrum세포가 자연환경에서 먹이로서 은편모조류 세포를 섭식하기 이전 이들의 광 적응 상태가 섭식 이후 M. rubrum의 광이용 효율 및 광흡수 특성 등을 결정짓는 주요 요인이 될 가능성을 시사한다. 본 연구 결과에 따라 예상되는 해양 미소생물 생태계 내에서 이들 섭식자 및 먹이생물 종의 역할에 대하여 논의하였다.

• 한국조경학회지
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• 제26권3호
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• pp.258-266
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• 1998

The purpose of this study is to investigate the actual conditions, to find problems, and to present an improvement plan of interior landscape in the subway stationis. Moreoiver, it will presume the possibilties to develop the subway and ways to utilie underground space effectively. The results are summarized as follows A light intensity was recorded 0-100 Lux as the lowest light and 500 Lux below as the highest in 61 subway stations. An average temperature of 12 $^{\circ}C$and an air humidity of 38% were recorded over a 4 month period from January to April, but includes a drastic variaton between -8.5$^{\circ}C$ and 21.5$^{\circ}C$. Soil acidity of pH 7 below and soil moisture of 1-2 wet degree were apeared in subway stations mostly. Plant forms consisted of artificial flower & flower. Plant species were recorded at a total of 54 species and appeared in the order of Araucaria heteropylla, Ophiophogon jaburan, Aspidistra elatior cv. 'Asahi' and Hedera helix. Plant height was, for the most part, below 0.5m. Plant species that was fined of conditions were Palm, Camellia japonica, Araucaria heterophylla as a high plant, dracaena fragrans, dracaena deremensis cv. Wakneckii as a middle plant, and Ophiopogon jaburan, Hedra helix, ytomium falcatum, Aspidistra elatior cv. Asahi as a low plant. It used to water materials such as small pool, small cascade, water cycles and natural materials such as natural rock, small rock, sand, bark and animal materials such as squirrels, birds, goldfish as an object for plants in the subway stations. From these actual conditions, First of all, It must make up physical environments such as light, temperature humidity, soil for plant growth, and is important to chooce suitable indoor plants and draw up systematic management in the subway environments. Also, it change plants frequently and uses variable objects for subway stationi individuatism, Moreover, indoor plants with strong environmental adaptation abities such as shade tolerance, drought tolerance and cold tolerance need to develope variable species possibly. If these improvements occur, utilization and amenity of subway stationis will increase, according to the use of interior landscape.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.14-23
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• 2018

$TiO_2-coated$ cubic ${\alpha}-Fe_2O_3$ with mostly exposed (012) and (101) facets (${\alpha}-Fe_2O_3@TiO_2$) was fabricated using a hydrothermal route for the photo-Fenton degradation of tetracycline under visible light irradiation. $TiO_2$ coating could greatly affect the photocatalytic activity of ${\alpha}-Fe_2O_3@TiO_2$. Compared with cubic ${\alpha}-Fe_2O_3$ alone for photodegradation of tetracycline, ${\alpha}-Fe_2O_3@TiO_2$ with $TiO_2$ shell of around 15 nm exhibited higher removal efficiency of tetracycline in photo-Fenton system, and its durability was slightly affected after five cycle times under same conditions. It is ascribed to the well-matched interface between cubic ${\alpha}-Fe_2O_3$ core and $TiO_2$ shell, leading to the broadened light-absorption and the efficient separation of photo-generated electon-hole pairs. The $^{\bullet}OH$ radicals were main responsible for the advanced photocatalytic performance of ${\alpha}-Fe_2O_3@TiO_2$ in visible-light driven degradation of tetracycline.

• Nano
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• 제13권10호
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• pp.1850118.1-1850118.17
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• 2018

Nanoparticles of the semiconductor catalyst $Cd_xZn_{1-x}S$ were embedded into the metal organic framework MIL-101(Cr) to obtain $Cd_xZn_{1-x}S@MIL-101$(Cr) nanocomposites. These materials not only possess high surface areas and mesopores but also show good utilization of light energy. The ultraviolet-visible diffuse reflectance patterns of $Cd_xZn_{1-x}S@MIL-101$(Cr) nanocomposites showed that $Cd_{0.8}Zn_{0.2}S@MIL-101$(Cr) possessed good visible light response ability among the synthesized nanocomposites. The photocatalytic performance of the $Cd_xZn_{1-x}S@MIL-101$(Cr) nanocomposites were tested via degradation and mineralization of methylene blue in neutral water solution under light irradiation using a 300W xenon lamp. As a result, using $Cd_{0.8}Zn_{0.2}S@MIL-101$(Cr) as a catalyst, 99.2% of methylene blue was mineralized within 30 min. Due to the synergistic effect of adsorption by the MIL-101(Cr) component and photocatalytic degradation provided by the $Cd_{0.8}Zn_{0.2}S$ component, the $Cd_{0.8}Zn_{0.2}S@MIL-101$(Cr) catalyst displayed superior photocatalytic performance relative to $Cd_{0.8}Zn_{0.2}S$ and MIL-101(Cr). Furthermore, $Cd_{0.8}Zn_{0.2}S@MIL-101$(Cr) possessed excellent stability during photodegradation and exhibited good reusability. The remarkable photocatalytic performance of $Cd_{0.8}Zn_{0.2}S@MIL-101$(Cr) is likely due to the effective transfer of electrons and holes at the heterojunction interfaces.

• 패션비즈니스
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• 제23권1호
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• pp.37-48
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• 2019

WKSF (Warp-knitted spacer fabrics) knitted using a double Raschel machine is the three-dimensional knit that has vertically connected separate layers in loop structures. Because of its unique structure, the fabric is light, compressible and breathable. Owing to the high production speed, the use of the fabric is increasing in various areas. The purpose of this study is to establish the design process in the utilization of WKSF program and analyze the difference between WKSF and Neoprene as garment materials.. The study on the design related to WKSF has rarely been carried out because of the complexity of WKSF structure and the difficulties encountered in analyzing the structure and thread. Therefore, checking beforehand the simulation results similar to a final knit using the CAD program for WKSF can only enhance the efficiency of the design for the light knits. The conclusion drawn after designing the light knits using the CAD program and analyzing the pros and cons of WKSF through the various property evaluation techniques is as follows. The tension characteristic analysis results indicated that Neoprene specimen has the elastic transformation and resilience, thus behaving like an elastic product such as rubber. By contrast, in the event that clothing and fashion accessories are designed with WKSF, these products are kept in a boxy style fit so that the fabric can be applied flexibly to a curvy body line. In addition, WKSF is good in forming noticeably around a curvy body, because its resistance shear deformation is lower than that of Neoprene.

• 한국정보통신학회논문지
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• 제25권2호
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• pp.171-177
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• 2021

최근 머신러닝의 발전에 따라 일상생활과 산업에서 기술을 적용하는 사례들이 많아지고 있다. 금융 데이터와 머신러닝 기법을 활용한 연구 또한 활발하게 이루어지고 있다. 본 논문은 이러한 동향에 따라 상점 매출 데이터에 머신러닝 기법을 접목해 매출 예측 모델을 구축, 핀테크 산업에서의 활용 방안을 제시한다. 다양한 결측치 처리 기법을 적용하고 그래디언트 부스팅 기반의 머신러닝 기법인 XGBoost, LightGBM, CatBoost를 사용하여 각 모델의 상점 매출예측 성능을 비교한다. 연구 결과, 단일대체법 중 중앙값 대체법을 사용한 데이터셋에 XGBoost를 활용해 예측을 진행한 모델의 성능이 가장 우수했다. 연구를 통해 얻은 모델을 이용하여 상점의 매출 예측을 진행함으로서 핀테크 기업의 고객 상점들은 대출금을 상환하기 전 금융 보조를 받는 근거로, 핀테크 기업은 상환 가능성이 높은 우수 상점에 금융 상품을 제공하는 등 기업과 고객 모두에게 긍정적인 방향으로 활용할 수 있다.