조력에너지를 이용한 터빈주변 해수유동 및 토크특성 분석

박다인,이상호,최혁진 한국기계기술학회 2022 한국기계기술학회지 Vol.24 No.6

Seawater flow and turbine torque in a lab-scale tidal power generation system have been analyzed with CFD method. Its power generation is largely influenced by hydraulic flow characteristics of pressure variation and mechanical turbine torque in the system caused by vertical flow field including tangential rotation. Pressure drop through the turbine was gradually increased with flow rate by seawater level difference, and it depends on the turbine blade and system geometry. And curl was severely varied along the flow direction with more than about 8 times increase through the flow system. There was also turbine torque change with pressure inlet due to the water level. Those predicted results can be widely used as basic concept design data for efficient tidal power generation system development.

경통시스템 내 LED 렌즈의 전열특성 분석

박다인,김우순,이상호,장진성 한국기계기술학회 2022 한국기계기술학회지 Vol.24 No.6

Numerical analysis has been carried out to predict the thermal characteristics for a LED lens in mold core system. These thermal characteristics inside the lens are largely affected by geometry, material, and initial conditions of the mold core and lens system. Local temperature and heat flux variation inside the lens are compared for several initial temperatures. Maximum temperature inside the lens was decreased rapidly from the beginning of cooling process up to about 10 seconds. There was also large variation of the heat flux at the upper and lower surfaces of the lens with initial temperature distribution. And the heat flux from the thin lower surface of the lens was relatively higher than the opposite-side thick region. In addition, overall heat transfer rate from the lens through the mold core has similar transient distribution from the beginning. These results can be applied as basic heat transfer data for the LED lens design and manufacturing process in the mold core system.

벤딩기 내 기어 시스템 구조분석

박다인,이상호,김경춘 한국기계기술학회 2021 한국기계기술학회 학술대회논문집 Vol.2021 No.11

AHP 분석을 통한 영화 예매 플랫폼선택 요인 도출에 관한 연구

박다인,김대진 한국예술경영학회 2016 예술경영연구 Vol.0 No.38

In case of movies, unlike the general purchase, there are various reservation systems because it is a kind of practice to watch after purchasing a ticket. The reservation system acts as a platform because it holds the supply and demand, network, and price structure. Recently, in movie reservation platform, competition among various media platforms is intensifying in order to sell the seats of limited resource within that time. So this study aims to determine the motivational factors considered important to choose a movie reservation platform and to verify motivational factors by the reservation platform media type. For analysis, we have undergone identifying motivational factors and refining components for a movie reservation choice. We have set a hierarchy model and asked general group and expert group to choose motivational factors for reservation platform and alternatives. The AHP analysis result shows that there is a difference on priority in motivational factors for movie reservation platform between public group and expert group. It also appears that there is a difference in the degree which important to recognize in components. Reservation platform is classified as movie theater, open market media, and portal sites media. It appears that there is a noticeable difference in motivational factors leading choices by media. The difference in recognition between general and expert group exists. Therefore, a differentiated strategy for each reservation platform media should be used and a marketing strategy should be derived considering the difference since there is a difference on priority in motivational factors by groups. 영화의 경우 일반상품과 달리 티켓을 구매한 후 관람하는 것이 일종의 관행이기 때문에 다양한 예매 시스템이 존재한다. 예매 시스템은 수요와 공급, 네트워크, 가격구조를 보유하고 있어 플랫폼으로서의 역할을 수행한다. 영화 예매 플랫폼 내에 다양한 매체들은 한정된 자원인 좌석을 제한시간 안에 판매해야 이익을 극대화시킬수 있기 때문에 좌석 판매에 대한 경쟁이 심화되고 있다. 이에 본 연구는 영화 예매 플랫폼 선택에 있어 중요하게 고려하는 동기 요인을 확인하고, 예매 플랫폼 매체 유형별 선택 동기 요인을 검증하는데 목적이 있다. 분석을 위해 영화 예매 플랫폼 선택 관련 동기 요인 도출 및 항목 검증 작업을 거쳤으며, 계층 모형을 설정하여 일반인 집단과 전문가 집단을 대상으로 예매 플랫폼 선택 동기 요인 및 대안을선택하게 하였다. AHP(Analytic Hierarchy Process) 분석 결과, 일반인 집단과 전문가 집단 간 영화예매 플랫폼을 선택하는 동기 요인 간 중요도 차이가 존재했으며, 세부 항목들 역시중요하게 인식하는 정도에 차이가 있는 것으로 나타났다. 예매 플랫폼 매체는 영화관 매체, 오픈마켓 매체, 포털사이트 매체로 구분하였으며 매체별로 선택을 유도하는 중요 요인에 차이가 존재하고, 일반인 집단과 전문가 집단의 인식 차이가 존재하는 것으로 나타났다. 따라서 예매 플랫폼 매체별로 차별적인 전략을 구사하는 것이필요하다는 결론을 도출하였다. 연구 결과, 일반인 및 전문가 집단별로 중요하게 인식하는 동기 요인 간 차이가 존재하기 때문에 이를 고려한 마케팅 전략을 도출해야한다는 시사점을 얻을 수 있다.

차량 DPF 배기시스템 내 공기를 수반한 배기가스 유동장 분석

박다인,이상호 한국기계기술학회 2020 한국기계기술학회지 Vol.22 No.6

Numerical analysis has been carried out to investigate the flow field characteristics for exhaust gas in automobile engine DPF system. The DPF system performance is largely affected by exhaust gas flow while it passes through the complicated geometry of DOC/DPF system, fan shape structure, and perforated can with air for fuel combustion. Hence the characteristics of fluid velocity, pressure, and streamline are analyzed with velocity uniformity in front of DOC and swirl flow near the fan. It can be seen that the velocity uniformity increases with the gas flow rate including flow acceleration near the lower area of the fan. The air flow also influences the gas flow distribution close to the impeller and fan structure with complicated swirl flow. These results are expected to be applicable as fundamental design data for automobile engine exhaust system.

Electrochemical CO₂-C Conversion Based on Liquid Metal Electrodes

박다인,이양우,원종빈,구형준 한국고분자학회 2023 한국고분자학회 학술대회 연구논문 초록집 Vol.48 No.1

중온형 원통다관형 수증기 개질기의 부분단열 및 반경방향 분배 구조의 영향

박다인,유상석 한국수소및신에너지학회 2017 한국수소 및 신에너지학회논문집 Vol.28 No.6

Conventional high temperature reformers are not suitable for hybrid fuel cell systems that use waste heat as a heat source. So, development of a low temperature type reformer is needed. However, the analysis was conducted in two ways to increase the thermal efficiency, because of low reforming rate due to the low heat source. First, it is a way to ger thermal gain from the outside through partial insulation. In the case of one heat source tube and several heat source tubes, we analyzed the effect of partial heat insulation in some cases. Second, we found the most efficient arrangement of the heat source tubes by changing the location of the heat source tubes. The interpretation was carred out using the COMSOL Mutiphysics program.

연료 송출용 제트펌프 3차원 전산해석 모델

박다인,윤진원,유상석 한국수소및신에너지학회 2017 한국수소 및 신에너지학회논문집 Vol.28 No.3

Jet pump in automotive fuel tank module is used to deliver fuel to fuel pump so that the pump is operated without aeration in suction side. In this study, three dimensional simulation model of jet pump is developed to understand performance variation over design parameters. Performance of jet pump is also investigated experimentally in terms of operating pressures. The experimental data is used to verify the three dimensional simulation model of jet pump. Verification results show that the three dimensional simulation model of jet pump is about 1% error with experiment. The simulations are conducted in terms of throat ratio and primary flow induction angle. As the throat ratio is increased, the flux ratio is trade-off at 3 times of throat diameter. On the other hand, as primary flow induction angle is increased, vapor pressure inside the nozzle is decreased. In summary, the results show that liquid jet pump has to be optimized over design parameters. Additionally, high velocity of induced flow is able to evolve cavitation phenomena inside the jet pump.

공연예술 투자 프로세스의 현황과 과제 : 벤처캐피탈의 뮤지컬 투자를 중심으로

박다인,박찬희,Park, Dain,Park, Chanhi 한국벤처창업학회 2014 벤처창업연구 Vol.9 No.6

최근 공연 예술 산업 시장이 증대하면서 공연 예술 콘텐츠에 대한 투자 관심이 높아지고 있다. 특히 공연예술 분야 중 뮤지컬이 가장 높은 성장세를 보이고 있는데 이에 따라 벤처캐피탈의 벤처 투자율도 증가하는 추세를 보인다. 이에 본 연구는 국내 뮤지컬 시장에 대한 벤처캐피탈 투자자 관점에 초점을 맞춰 투자 프로세스에서 발생하는 정보비대칭 문제를 살펴보고자 한다. 공연 예술의 기획과 실행에 대한 연구에 있어 투자자의 관점을 직접 분석한 연구가 부족했던 점에 착안하여, 뮤지컬 공연에 대한 투자에 있어 다양한 범위의 경험을 가진 벤처캐피탈 투자 담당자들에 대해 심층 인터뷰를 진행하였다. 인터뷰 결과, 공연 예술에 대한 '예술적인 가치와 '수익률' 이라는 극단적인 입장차이로 인해 뮤지컬 투자자의 경우 공연예술 자금 운용의 투명성에 대해 신뢰하지 못하는 결과를 보였다. 특히 주관적으로 판단되는 예술적 가치를 중시하게 될 때 투자자 및 공연예술 제작사 간의 정보비대칭이 더욱 심화된다. 이러한 문제가 공연 예술 관련 내부시장 뿐 아니라 전반적 사회적 이슈로 대두되면서 해결방안이 촉구되고 있다. 따라서 객관적인 데이터를 통합적으로 제공하거나 공연 예술 사업에 대한 SPC(특수목적회사) 운용을 활발하게 하여 거래구조를 투명하게 관리할 필요가 있다. 이에 본 연구에서는 정보비대칭문제를 줄이기 위해 통합적 데이터 시스템을 구축하고 뮤지컬 작품 투자를 위한 특수목적법인(SPC)을 설립하는 방안들을 제시하고자 한다. Source and use of investment money in the content business has been subject to closer attention, This study attempts to identify the information asymmetry problem in the performing art are, focusing on the Korean musical play. Despite the various discussions in the venture capital practice in the performing art area, there has been few studies analyzing the investors' perspective. While juggling with the 'artistic value' and 'rate of return', the investors are concerned about the 'transparency' of the performing art practice. When coupled with the subjective judgment of 'artistic value', the information asymmetry between the investor and the performing art manager becomes more delicate. In the performing art business, 'SPC(Special Purpose Company)' is considered a possible solution to organize the deal structure in this field. This study analyzes the role of SPC regarding the information asymmetry problem.

Electrochemical CO₂ Reduction Based on Liquid Metal Electrodes for Carbon Neutrality

박다인,이양우,구형준,원종빈 한국고분자학회 2022 한국고분자학회 학술대회 연구논문 초록집 Vol.47 No.2