• Journal of the Korean Society of Industry Convergence
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• v.26 no.4_2
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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.

• Proceedings of the KSR Conference
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• 2011.05a
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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.

• Proceedings of the KSR Conference
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• 2011.10a
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.10
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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.

• Journal of the Korean Professional Engineers Association
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• v.42 no.2
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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.

• The KSFM Journal of Fluid Machinery
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• v.15 no.5
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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.

• Journal of The Korean Digital Architecture Interior Association
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• v.7 no.2
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1011-1015
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• 2013

The demand of bike increases eco-friendly as the mean of transportation but domestic production basis becomes sluggish. In this study, the design analysis of horizontal and vertical frame is performed on the model which is proposed as the bike of new concept in conjunction with public transport system. As the result, the structural analysis is conducted on the main frame of urban bike used with cast magnesium alloy. As the vertical load of 150 kg is applied, the design technology insures that maximum stress less than 70 MPa is obtained.

• Journal of Aerospace System Engineering
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• v.15 no.4
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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.