• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.254-254
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• 2017

수자원장기종합계획은 수자원의 안정적인 확보와 효율적인 이용 개발 및 보전을 위하여 "하천법" 제23조에 근거하여 수립되는 물 분야의 최상위 법정계획이다. 수자원장기종합계획은 20년 단위로 수립되며, 5년마다 그 타당성 여부를 검토하여 필요한 경우에는 계획을 변경하고 있다. 국토교통부는 지난 2016년 12월 수자원장기종합계획 제3차 수정계획(2016~2020년)을 수립 고시하였다. 그런데 수자원장기종합계획과 같이 상위 개념의 법정계획의 수립을 위해서는 관련 법정계획 및 부처 간의 수평적 수직적 연계가 중요한데, 현행 법체계는 이에 미흡한 측면이 있어 보인다. 우선적으로 수평적 연계를 위해서는 수자원장기종합계획 수립과정에 이수 치수 및 방재 분야의 업무를 담당하고 있는 관련 부처의 적극적인 참여를 독려할 필요가 있다. 현재 "하천법" 제23조제4항은 수자원장기종합계획을 수립하거나 변경할 경우, 중앙행정기관의 장과 협의하도록 규정하고 있다. 그러나 현행 규정에 따른 부처별 '협의'는 국토교통부가 수자원장기종합계획을 수립한 후 관련 부처의 의견을 수렴하는 소극적 형태의 협의라고 볼 수 있다. 효율적인 수자원장기종합계획 수립을 위해서는 "하천법" 소관 부처인 국토교통부가 수자원장기종합계획 수립을 위한 기본적인 지침을 수립하여 관련 중앙부처인 환경부(환경), 국민안전처(치수), 산업통상자원부(공업용수) 및 농림축산식품부(농업용수)에 시달하고, 각 부처는 담당 분야별 계획을 수립하여 국토교통부에 송달한 후, 국토교통부는 이를 취합 검토하여 수자원장기종합계획을 수립하는 적극적 형태의 연계를 고려할 필요가 있다. 수직적 연계를 위해서는 기존의 하향식(top-down)에서 벗어나 상향식(bottom-up)의 계획수립이 필요해 보인다. 즉 국토교통부의 수자원장기종합계획 수립에 따라 하위 개념의 유역종합치수계획("하천법" 제24조) 및 댐건설장기계획("댐건설 및 주변지역지원 등에 관한 법률" 제4조) 등을 수립하는 것이 아니라, 지역별 유역별로 수자원계획을 우선적으로 마련하도록 하고 이를 기초로 전 국토를 대상으로 하는 수자원장기종합계획을 수립하는 방안이 적절해 보인다. 이를 위해서는 수자원장기종합계획 수립하기 이전에 지역별 또는 유역별로 수자원계획을 수립할 수 있도록 "하천법"에 관련 규정을 신설할 필요가 있으며, 이수뿐만 아니라 환경, 방재 분야의 하위 법정계획의 수립 시기 및 주요 내용에 대한 종합적인 검토가 요구된다.

• (The)Study of the Eastern Classic
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• no.32
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• pp.363-390
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• 2008

In this article, the author studied the relationship between the Sovereign and the follower in Juyeok which contained some eliments, such as Eum-Yang, Soseong 8 gyae, Daeseong 64 gyae. In Juyeok, the 'Sovereign 5 hyo' (1) shows distinctiveness in basic characteristics whether they are Eum or Yang(high level classification), (2) shows characteristics of Soseong-gyae to which they belong(middle level classification), (3) shows different characteristics according to Daeseong-gyae's circumstances(low level classification). Five Yanghyo are regarded as male sovereign having masculinity, whereas five Eumhyo are female sovereign with femininity. Gungyae is the most 'sturdy type leader' who possesses dignity and has good judgement. Taegyae, the blessing type leader, holds affection and calmness within sturdiness. Rigyae is gorgeous and passionate 'enthusiastic type leader'. Jingyae, the pioneering leader, bravely starts ascending in Eum-dominant atmosphere. Songyae has the virtue of hesitancy and concession, known as the leader of humbleness. Gamgyae always stay low and calm, regarded as a leader of sense. Gangyae shoots up from the earth, meaning a leader of strong will. Gongyae, embracing type leader, is straight and square, though it tries to embrace everything. Daeseong-gyae(64gyae) is formed by Soseong-gyae piling another Soseong-gyae. The characteristics of Soseong 8gyae are embodied in two-level form, the top(inner gyae) and the bottom(outer gyae). Simultaneously, the whole characteristics of 대성괘 are embodied. The Sovereign should show his/her leadership based on the 'characteristics of Daeseong-gyae'. These characteristics are the contingency from 'contingency leadership'. In other words, they are preconditions which leaders ought to admit.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.3
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• pp.137-149
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• 2021

Cable-stayed bridges are infrastructure facilities of a highly public nature; therefore, it is essential to ensure operational safety and prompt response in the event of a collapse or damage caused by natural and social disasters. Among social disasters, impact accidents can occur in bridges when a vehicle collides with a pier or when crashes occur due to aircraft defects. In the case of offshore bridges, ship collisions will occur at the bottom of the pylon. In this research, a procedure to evaluate the structural behavior of a cable-stayed bridge for aircraft impact is suggested based on a numerical analysis approach, and the feasibility of the procedure is demonstrated by performing an example assessment. The suggested procedure includes 1) setting up suitable aircraft impact hazard scenarios, 2) structural modeling considering the complex behavior mechanisms of cable-stayed bridges, and 3) structural behavior evaluation of cable-stayed bridges using numerical impact simulation. It was observed that the scenario set in this study did not significantly affect the target bridge. However, if impact analysis is performed through various scenarios in the future, the load position and critical load level to cause serious damage to the bridge could be identified. The scenario-based assessment process employed in this study is expected to facilitate the evaluation of bridge structures under aircraft impact in both existing bridges and future designs.

• Design & Manufacturing
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• v.15 no.2
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• pp.11-16
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• 2021

Recently, three-dimensional (3D) cell culture systems, which are superior to conventional two-dimensional (2D) vascular systems that mimic the in vivo environment, are being actively studied to reproduce drug responses and cell differentiation in organisms. Conventional two-dimensional cell culture methods (scaffold-based and non-scaffold-based) have a limited cell growth rate because the culture cannot supply the culture medium as consistently as microvessels. To solve this problem, we would like to propose a 3D culture system with an environment similar to living cells by continuously supplying the culture medium to the bottom of the 3D cell support. The 3D culture system is a structure in which microvascular structures are combined under a scaffold (agar, collagen, etc.) where cells can settle and grow. First, we have manufactured molds for the formation of four types of microvessel-mimicking chips: width / height ①100 ㎛ / 100 ㎛, ②100 ㎛ / 50 ㎛, ③ 150 ㎛ / 100 ㎛, and ④ 200 ㎛ / 100 ㎛. By injection molding, four types of microfluidic chips were made with GPPS (general purpose polystyrene), and a 100㎛-thick PDMS (polydimethylsiloxane) film was attached to the top of each microfluidic chip. As a result of observing the flow of the culture medium in the microchannel, it was confirmed that when the aspect ratio (height/width) of the microchannel is 1.5 or more, the fluid flows from the inlet to the outlet without a backflow phenomenon. In addition, the culture efficiency experiments of colorectal cancer cells (SW490) were performed in a 3D culture system in which PDMS films with different pore diameters (1/25/45 ㎛) were combined on a microfluidic chip. As a result, it was found that the cell growth rate increased up to 1.3 times and the cell death rate decreased by 71% as a result of the 3D culture system having a hole membrane with a diameter of 10 ㎛ or more compared to the conventional commercial. Based on the results of this study, it is possible to expand and build various 3D cell culture systems that can maximize cell culture efficiency by cell type by adjusting the shape of the microchannel, the size of the film hole, and the flow rate of the inlet.

• Journal of the Korean earth science society
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• v.41 no.6
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• pp.575-587
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• 2020

Meteorological phenomena are observed by the Korea Meteorological Administration in a variety of ways (e.g., surface, upper-air, marine, ocean, and aviation). However, there are limits to the meteorological observation of the planetary boundary layer (PBL) that greatly affects human life. In particular, observations using a sonde or aircraft require significant observational costs in economic terms. Therefore, the goal of this study was to measure and analyze the meteorological factors of the vertical distribution of the see-land breeze among local meteorological phenomena using meteorological drones. To investigate the spatial distribution of the see-land breeze, a same integrated meteorological sensor was mounted on each drone at three different points (seaside, bottom of mountain, and mountainside), including the Boseong tall tower (BTT) at the Boseong Standard Weather Observatory (BSWO) in the Boseong region. Vertical profile observations for air temperature, relative humidity, wind direction, wind speed, and air pressure were conducted up to 400 m every 30 minutes from 1100 LST to 1800 LST on August 4, 2018. The spatial characteristics of meteorological phenomena for temperature, relative humidity, and atmospheric pressure were not shown at the four points. Strong winds (~8 m s-1) were observed from the midpoint (~100 m) at strong solar radiation hour, and in the afternoon the wind direction changed from the upper layer at the inland area to the west wind. It is expected that the analysis results of the lower atmospheric layer observed using the meteorological drone may help to improve the weather forecast more accurately.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.2
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• pp.133-142
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• 2022

The purpose of this study is to develop an impact crusher with a radial rotating plate installed at the bottom, which is a shock absorber that can produce high-quality recycled coarse aggregate for concrete and to verify the effect of improving the quality performance of recycled coarse aggregate and its applicability through concrete tests. As a result, it showed improved quality in all items such as absolute dry density, absorption rate, abrasion resistance, Particle shape judgment rate, amount lost in the 0.08 mm sieve passing test, alkali aggregate reaction, clay mass, stability, and impurity content, and it was found to meet the criteria of recycled aggregate quality standards. In addition, the air volume and slump of concrete to which recycled coarse aggregate is applied meet all domestic standards. According to the test results of the compressive strength characteristics by age of concrete according to the mixing ratio of the recycled coarse aggregate, it was confirmed that the mixing ratio of the recycled coarse aggregate was applicable up to 60 %.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.11-21
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• 2022

All-solid-state batteries are one of the promising candidates for next-generation batteries and are drawing attention as a key component that will lead the future electric vehicle industry. This study analyzes 10,280 comments on Reddit, which is a global social media, in order to identify policy issues and public interest related to all-solid-state batteries from 2016 to 2021. Text mining such as frequency analysis, association rule analysis, and topic modeling, and sentiment analysis are applied to the collected global data to grasp global trends, compare them with the South Korean government's all-solid-state battery development strategy, and suggest policy directions for its national research and development. As a result, the overall sentiment toward all-solid-state battery issues was positive with 50.5% positive and 39.5% negative comments. In addition, as a result of analyzing detailed emotions, it was found that the public had trust and expectation for all-solid-state batteries. However, feelings of concern about unresolved problems coexisted. This study has an academic and practical contribution in that it presented a text mining analysis method for deriving key issues related to all-solid-state batteries, and a more comprehensive trend analysis by employing both a top-down approach based on government policy analysis and a bottom-up approach that analyzes public perception.

• Korean small business review
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• v.43 no.1
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• pp.1-33
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• 2021

This study explores differential value implications of R&D expenditure across firms, especially in terms of growth potential of small businesses. Analyzing Korean listed firms for the period from 1982 to 2014, we document the followings. First, large firms, defined as the top quintile group based on market capitalization, have spent higher R&D expenditure compared to small (bottom quintile group) and medium (middle quintile groups) firms and the difference between groups has enlarged over time. Relatedly, the persistence of R&D spending, measured by the association between current R&D expenditure and cumulative future R&D expenditure over the next five years, is lowest in small firms. Second, R&D of large (small) firms are more (less) likely to generate operating profits over the next five years. Additional analyses suggest that the relation between R&D and gross margin is strongest in large firms, suggesting that R&D underlies their competitiveness in the product market. Third, small firms have borne the highest uncertainty related to R&D investment proxied by the association between current R&D and volatility of future earnings. As a result, the likelihood of R&D leading to future patents is also lowest in small firms. Fourth, the probability of moving up to the next size group within the next five years is significantly lower in small firms than others. Finally, we find that the divergence in R&D expenditure between large and small firms is positively associated with product market concentration. Overall, our findings confirm the small business growth trap in relation to R&D investment.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.1
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• pp.95-104
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• 2022

Micro hydropower is a readily available renewable energy source that can be harvested utilizing hydrokinetic turbines from shallow water canals, irrigation and industrial channel flows, and run-off river stream flows. These sources generally have low head (<1 m) and low velocity which makes it difficult to harvest energy using conventional turbines. A horizontal-axis screw turbine was designed and numerically tested to extract power from such low-head water sources. The 3-bladed screw-type turbine is placed horizontally perpendicular to the incoming flow, partially submerged in a narrow water channel at no-head condition. The turbine hydraulic performances were studied using Computational Fluid Dynamics models. Turbine design parameters such as the shroud diameter, the hub-to-shroud ratios, and the submerged depths were obtained through a steady-state parametric study. The resulting turbine configuration was then tested by solving the unsteady multiphase free-surface equations mimicking an actual open channel flow scenario. The turbine performance in the shallow channel were studied for various Tip Speed Ratios (TSR). The highest power coefficient was obtained at a TSR of 0.3. The turbine was then scaled-up to test its performance on a real site condition at a head of 0.3 m. The highest power coefficient obtained was 0.18. Several losses were observed in the 3-bladed turbine design and to minimize losses, the number of blades were increased to five. The power coefficient improved by 236% for a 5-bladed screw turbine. The fluid losses were minimized by increasing the blade surface area submerged in water. The turbine performance was increased by 74.4% after dipping the turbine to a bottom wall clearance of 30 cm from 60 cm. The final output of the novel horizontal-axis screw turbine showed a 2.83 kW power output at a power coefficient of 0.63. The turbine is expected to produce 18,744 kWh/year of electricity. The design feasibility test of the turbine showed promising results to harvest energy from small hydropower sources.

• Journal of the Korean Regional Science Association
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• v.39 no.2
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• pp.3-18
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• 2023

The aim of this study is to analyze problems with regional development projects by examining their actual conditions and to propose measures to promote such projects based on the size of local cities. To achieve this goal, problems associated with regional development projects were analyzed, and measures for their promotion were derived by dividing these projects into planning, strategy, policy, and institutional sectors according to the size of local cities. The problems identified with regional development projects include diversification leading to similar and overlapping projects, lack of participation by local experts, top-down government structure for designating and supporting regional development projects, and insufficient budget. In order to address these issues, local experts have suggested differential measures based on the size of local cities. Specifically, in the planning sector, it was proposed that economic, cultural, social, and welfare functions be expanded and reorganized primarily around small and medium-sized cities, and that long-term strategies be established for regional large cities through various partnerships and step-by-step procedures. In the policy sector, it was suggested that the implementation of bottom-up development under the leadership of local governments should be focused on small and medium-sized cities, and that the transition from a specific industry-oriented policy to a corporate growth policy needs to be established around large cities. Finally, in the institutional sector, it was recommended that a performance evaluation system for the use of financial resources and a system for expanding financial resources should be established primarily in small and medium-sized cities.