• 한국환경과학회지
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• 제26권9호
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• pp.1081-1086
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• 2017

The present study was conducted for the purpose of analyzing the growth response of Dracaena braunii treated with chloride ions and to evaluate its salt tolerance. Distilled water (CON) was spiked with 1 (C1), 2 (C2), 5 (C5), 10 (C10) and 15 g/L (C15) $CaCl_2$, respectively. Acidity (pH) and electrical conductivity of hydroponic solution, and leaf width, leaf length, root length, number of leaves, fresh weight, dry weight and the water content of Dracaena braunii were measured. Acidity and electrical conductivity remarkably increased commensurate with increasing concentrations of $CaCl_2$. Growth in the C1 treatment was better than that in CON, whereas the C10 or C15 treatments caused either slow growth or withering of the plants. Fresh weight, dry weight and water content were significantly decreased in response to $CaCl_2$ concentration, compared with those in the control. These results showed that $CaCl_2$ concentration less than 1 g/L may be used as a hydroponic solution for D. braunii, as long as the water quality is not too saline. The chlorine ion has a negative effect on the growth.

• International Journal of Advanced Culture Technology
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• 제8권3호
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• pp.241-246
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• 2020

In this paper, we propose a user matching app based on hybrid app and a utilization plan to promote sports tourism in line with the growing trend of sports industry scale. The proposed app categorizes sports facilities across the country into regional, sports, private and public sports facilities to support reservations and matching. The proposed app applied a matching system in which matching scores were given according to the preference of events, places, and users by user net matching algorithm. Users can enjoy sports as a team or individual through the suggestion app even if they do not have any clubs or friends to which they belong. It can be used to improve tourism content services and establish tourism industry policies by analyzing data generated while using a user matching system.

• International Journal of Internet, Broadcasting and Communication
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• 제14권2호
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• pp.206-211
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• 2022

As the level of consumption is improved and cultural life is pursued, the consumer's consciousness structure is rapidly changing, and the demand for product selection level, variety, and quality is becoming more diverse. The restaurant economy is falling due to the prolonged COVID-19, the economic recession, income decline, and changes in population structure and lifestyle, but the Meal- kit market is growing rapidly. This study aims to identify the consumer perception of Meal-kit, which is rapidly growing as an alternative to existing meals in the fields of dining out, food, and distribution due to the development of technology and social environment using big data. As a result of the analysis, the keywords with the highest frequency of appearance were in the order of Meal-kit, Cooking, Product, Launching, and Market and were divided into 8 groups through the CONCOR analysis. We want to identify consumer trends related to the key keywords of Meal-kit, present effective data related to Meal-kit demand for Meal-kit specialized companies, and provide implications for establishing marketing strategies for differentiated competitive advantage.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권5호
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• pp.39-48
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• 2021

Analysis of the change in water content and distribution was conducted according to the supply of recirculation water to a landfill. An excavation sample analysis showed that the recirculation water injection zone had water content 8.8% point higher than that of the non-injection zone, after 8 months of operation. And due to the influence of recirculation water supply by vertical wells in injection zones, the water content increases along with depth more clearly than non-injection zone. According to an electrical specific-resistivity survey after 13 months of operation, the water content got higher towards the bottom of the landfill. The water transmission coefficient is 8.72×10^-4 cm/sec for injection zones and 3.36×10^-5 cm/sec for the intermediate cover layer; analysis shows that the intermediate cover layer may affect the penetration velocity of water supplied by the horizontal injection tube. For the scientific design and operation of re-injection facilities, it was deemed necessary to follow-up research on the residence time and behavior of re-injection water considering the ratio of recirculation water supply in horizontal and vertical tubes, and pitcher coefficient of intermediate and waste layers.

• ALGAE
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• 제32권1호
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• pp.67-74
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• 2017

The heterotrophic dinoflagellate Oxyrrhis marina is known to produce high levels of docosahexaenoic acid (DHA) when fed on diverse algal prey. However, large-scale culturing of algal prey species is not easy and requires a large amount of budget, and thus more easily cultivable and low-cost prey is required. Dried yeast was selected as a strong candidate for an alternative prey in our preliminary tests. Thus, we explored the fatty acid composition and DHA production of O. marina fed on dried yeast and compared these results to those of O. marina fed on two algal prey species: the phototrophic dinoflagellate Amphidinium carterae and chlorophyte Chlorella sp. powder. O. marina fed on dried yeast, which does not contain DHA, produced the same high level of DHA as those fed on DHA-containing A. carterae. This indicates that O. marina is likely to produce DHA by itself regardless of prey items. Furthermore, the DHA content (and portion of total fatty acid methyl esters) of O. marina satiated with dried yeast, 52.40 pg per cell(and 25.9%), was considerably greater than that of O. marina fed on A. carterae (26.91 pg per cell; 15.7%) or powder of Chlorella sp. powder (21.24 pg per cell; 16.7%). The cost of dried yeast (approximately 10 US dollars for 1 kg dried yeast) was much lower than that of obtaining the algal prey (approximately 160 US dollars for 1 kg A. carterae). Therefore, compared to conventional algal prey, dried yeast is a more easily obtainable and lower-cost prey for use in the production of DHA by O. marina.

• 디지털융복합연구
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• 제20권5호
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• pp.275-280
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• 2022

본 논문은 비대면 미술감상 교육을 위해 사용자의 상황 정보 및 취향에 맞는 태그가 융합된 융·복합 예술 플레이리스트 콘텐츠를 사용자에게 추천하는 기술을 제안하고자 한다. 제안한 기술의 구현을 위해 예술 작품의 특성을 분석하고, 분석된 작품들의 태그를 기반으로 관련된 음악과 미술작품을 매칭한다. 또한 매칭된 작품을 활용해 융·복합 예술 관람 플레이리스트 콘텐츠를 자동으로 생성하는 기술을 제안하고자 한다.

• 한국기계가공학회지
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• 제20권7호
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• pp.80-88
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• 2021

The behavior of the injection system was determined through FFT and PSD analysis of the pressure data of the common rail, and when the diesel fuel is mixed with water, the pressure data of the common rail, depending on the water content and engine rotation speed, represent a different frequency component distribution. Recently, a theory has been suggested that mixing diesel fuel with water controls engine overheating, fuel efficiency, NOx, CO, etc., but if water content exceeds 10%, it can have a fatal adverse effect on the engine's injection system. In the future, it is necessary to promote fault diagnosis and prediction studies of diesel engines using FFT and PSD results from common rail pressure data.

• Elastomers and Composites
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• 제57권1호
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• pp.13-19
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• 2022

Polycarbonate diol-based waterborne polyurethane (WPU) was prepared by prepolymer mixing process. The prepolymer mixture contained the polycarbonate diol, isophorone diisocyanate (IPDI), dimethylol propionic acid, triethylamine, and ethylenediamine (EDA). The NCO/OH ratio in the prepolymer was adjusted by controlling the molar ratio of IPDI, and its effects on the properties of WPU were studied. The structure of WPU was characterized by fourier transform infrared spectroscopy. The average particle size increased and viscosity decreased with increasing NCO/OH ratio and EDA content in WPU. The reduced phase separation between soft and hard segments increased glass transition temperature. The reduction in the thermal decomposition temperature could be attributed to the low bond energy of urethane and urea groups, which constituted the hard segment. Additionally, the polyurethane chain mobility was restricted, elongation decreased, and tensile strength increased. The hydrogen bond between the hard segments formed a dense structure that hindered water absorption.

• 한국게임학회 논문지
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• 제6권2호
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• pp.33-44
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• 2006

본 논문은 디지털 기술의 발전에 따른 문화콘텐츠 유통의 발전, 특히 게임산업의 유통체계를 살펴보고 있다. 컨버젼스 기술의 발전에 따라, 문화콘텐츠 유통에 있어서 핵심적인 가치의 중심은 플랫폼에서 콘텐츠로 옮겨가고 있는데, 이와 관련하여 특히 게임산업의 유통구조에서는 3가지 유형(오프라인, 온라인, 모바일 게임)이 나타난다고 알려지고 있다. 본 논문에서는 심층인터뷰 등을 통한 사례조사를 통해 앞으로 통합적인 모델로 발전할 것으로 검증하고 있다. 결론적으로 본 논문은 이러한 변화에 맞추어 앞으로 문화콘텐츠산업의 장기적인 발전을 위해 유통구조의 개선, 기업과 퍼블리셔 등 관계자들의 갈등해소, 국제화 등을 위한 다각적 정책지원이 더욱 필요함을 제안하고 있다.

• 한국환경과학회지
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• 제31권7호
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• pp.569-577
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• 2022

This study aimed to evaluate the growth of Cichorium intybus, Brassica juncea, and Lactuca sativa at varying seed ratios, and to suggest an efficient management plan for sustainable indoor agriculture systems. It was treated with mixed sowing as follows: 30 chicory seeds (chicory alone: CC), 22 chicory seeds + 8 lettuce seeds (C₃L₁), 20 chicory seeds + 10 lettuce seeds (C₂L₁), 15 chicory seeds + 15 lettuce seeds (C₁L₁) as intraspecies, and 30 mustard seeds (mustard alone: MC), 22 mustard seeds + 8 lettuce seeds (M₃L₁), 20 mustard seeds + 10 lettuce seeds (M₂L₁), 15 mustard seeds + 15 lettuce seeds (M₁L₁) as interspecies. The study identified the competitive response in seed germination between Cichorium intybus and Lactuca sativa, and in the C₃L₁ experimental group, Lactuca sativa had the highest leaf length, root length, chlorophyll content, and fresh weight. Therefore, the higher the ratio of Cichorium intybus, the higher the growth and productivity of Lactuca sativa; however, higher the ratio of Lactuca sativa, the lower the growth of Cichorium intybus. Furthermore, the nitrogen and potassium content in the substrate was the highest in the C₃L₁ experimental grorp which had the highest seeding rate of the Cichorium intybus. Comparing the groups Brassica juncea and Lactuca sativa, the higher the seeding ratio of Lactuca sativa, the higher the growth and productivity of Brassica juncea. Therefore, a companion seeding of Brassica juncea and Lactuca sativa is beneficial; this could be effective in having a high seeding ratio of Lactuca sativa.