• 한국산업융합학회 논문집
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• 제26권4_2호
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• pp.639-648
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• 2023

In modern society, UAM (Urban Air Mobility) transportation system is being developed as an alternative to urban traffic congestion and environmental problems, and electric vertical take-off and landing (eVTOL) is a combination of vertical take-off and landing function and electric power. It is attracting attention as an innovative next-generation transportation method as an eco-friendly alternative that reduces noise and air pollution by providing efficient mobility within the city. Since eVTOL development requires designing and implementing airframes suitable for various mission purposes, the power system needs to be developed as a platform concept before airframe development. In this study, we empirically proposed a test bench concept equipped with a stable power supply and an efficient control system, essential in developing a power platform with a combined function in the form of a fuselage and module type specialized for various mission purposes. The proposed drivetrain platform test bench consists of a system verifying the stable take-off and landing software and a power platform adjusting the motor's thrust. It will serve as a verification system that can be developed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.263-268
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• 2011

There are many exclusive freight cars in railway freight transportation system. Gondola is one kind of freight cars. Gondolas have a role to carry bulk-type cargo such as coals and ores. A few problems are occurring due to exclusive freight cars. Operation company has redundant freight cars because exclusive freight cars can carry limited items. And purchasing cost of freight cars is higher and higher because of irregular bid. Operation efficiency of gondola is very low because return time of gondola is much longer than that of container car. In this study, we analysed the introduction effect of hopper-type container for through transit. First, we identified the characteristics of spatial distribution on freight stations. And we provided the effect of hopper-type container in terms of operation efficiency, cost reduction, new demand excavation and image enhancement of eco-friendly railroad.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2961-2964
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• 2011

Greenhouse gas and energy reduction goal management system is announced to reduce national CO2 emission in 2011. The target business sector of the system has to follow the procedure of the system and get the assessment. The percentage of the national CO2 reduction goad is 30 % compared to the amounts of BAU. In railway business sector, 6 bodies are included in this system so that railway industry cannot stay and sustain its better position any more than other transportation industry. Most of the industry except Railway industry is struggling to develop its product more environmentally friendly and get the 3rd party certification like Eco-labelling and Carbon footprint. To get environmental certification, LCA method has to be applied because life cycle approach is needed to respond current environmental requirement. The purpose of this project is to facilitate railway vehicle manufacturer obtaining the environmental certification termed Korea EPD. By doing so, the environmental performance evaluation tool would be developed and modelled within the LCA framework and therefore applied especially for rail vehicle.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.244-247
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• 2006

Railway is superior to the other land transportation systems in aspects of energy efficiency and environmental problems. Energy efficiency and environmental problems are not considered during a preliminary feasibility study. Investment for railway is low because of low B/C in the economical efficiency analysis during the preliminary feasibility study. The body of this paper studies the data which can reflect environmental problems an assessment of environmental impact. Investment for railway would be higher when main environmental elements are considered before the choice of the railway lines.

• 전기학회논문지
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• 제61권10호
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• pp.1524-1528
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• 2012

According to the Article 4(Confirmity Assessment)of the Electrotechnical Regulation, Confirmity Assessment for the Electrotechnical Regulation decides confirmity of Electrotechnical Regulation; whether to satisfy performances and requirements(determined from Electrotechnical Regulation). It evaluates technical requirements, new technology and standards. However, it does not evaluate technical content stated from Electrotechnical Regulation & Conformity Criteria. From Confirmity Assessment, the technology will be decided whether to fulfill performances and technical requirements. Which is predetermined by contents related to Electrotechnical Regulation. Test standards and test conditions will be overlooked to determine its performances and technical requirements for safety. This paper will show that, studies have been done to determine the guideline for Confirmity Assessment, which is evaluated from performances and technical requirements associated with Confirmity Assessment of electrical installation for new technology of wireless power transfer.

• 기술사
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• 제42권2호
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• pp.41-48
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• 2009

The Government declared 'Low-Carbon Green Growth' as the new national vision for future development to improve economic growth and quality of life through higher energy efficiency, less energy consumption, wider use of renewable energy, etc. Korea can no longer delay participating in international efforts against global warming by reducing carbon dioxide and other greenhouse gas emissions. Thus low-carbon green growth is not a matter of choice, and it becomes indispensible to sustaining the nation's economic development. The Government is determined to take the initiative in speeding up economic recovery by carrying out the large scale investment projects such as the Korean version of a 'Green New Deal. The 49 trillion-won projects include river improvement, eco-friendly transportation networks, advanced information infrastructure, water resources & dam construction, green cars & clean energy development, etc. which will create nearly one million new jobs over the next four years.

• 한국유체기계학회 논문집
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• 제15권5호
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• pp.54-59
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• 2012

In order to have the high efficiency of aircraft wing and to improve the energy efficiency in field of eco-friendly transportation, the performance characteristics of the aircraft wing were studied with the change of lift to drag ratio through the CFD analysis. The design process was focused on generating the high lift force and low drag force as the lift to drag ratio was increased. In this paper, various dimple patterns were numerically designed to investigate the flow characteristics. Hexagon-and circle-shaped dimples, dimple distance and position were changed as the artificial conditions. The numerical analyses were conducted by using the commercial code, ANSYS CFX. Numerical results dependent on the turbulence intensity and lift to drag ratio distribution were graphically depicted for various dimple patterns.

• 한국디지털건축인테리어학회논문집
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• 제7권2호
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• pp.25-32
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• 2007

Cities should be developed and managed deliberately since reckless development and selfish expansion deteriorate the quality of life in the cities by creating various problems in transportation, residence and environment. In particular, the semi-agricultural zones have been designated in order to address such problems as the overpopulation caused by the influx of people into the cities and promote balanced regional development and eco-friendly cultivation of the land across the nation. But the problems of metropolitan areas, such as the overpopulation and lack of infrastructure, are spreading even to the semi-agricultural zones, which should be the last areas to be developed into cities. We should blame the indolence of our policies on land first, rather than the selfish cities that slip from the grip of the law. This study concludes that the self-agricultural zones should be developed and managed with plans by the public sector rather than the autonomous development by the private sector.

• 한국산학기술학회논문지
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• 제14권3호
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• pp.1011-1015
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• 2013

최근 친환경 이동수단으로 자전거 수요가 증가하고 있으나, 국내 생산기반은 전무한 실정이다. 본 연구에서는 경량 마그네슘 소재로 대중교통기관과 연계가능한 신개념 자전거로 제안된 모델에 대해 수평프레임과 수직프레임 설계 해석을 수행하였다. 연구결과, 주조용 마그네슘 합금을 사용하는 도심형 자전거의 주요 프레임에 대한 구조해석을 실시하여 150kg 수직하중시 최대응력이 70 MPa이하를 나타내는 설계기술을 확보하였다.

• 항공우주시스템공학회지
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• 제15권4호
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• pp.21-29
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• 2021

As global environmental regulations have been strengthened, the eco-friendly market has grown rapidly. In the field of aircraft, research on electric vertical take-off and landing aircraft that can enter city centers and perform personal air transportation using electric propulsion is ongoing. For aircraft using electric propulsion methods to operate reliably, electric power thrust systems are a key factor. Electric aircraft require a high power density for propulsion systems with strict limits on volume and weight. The efficient control of inverter systems is essential for achieving high power density. Therefore, in this paper, the characteristics of inverters and motors were analyzed through simulations based on the space vector pulse width modulation (PWM) and discontinuous PWM methods for controlling inverter systems.