• Title/Summary/Keyword: air transportation demand

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Analysis and Investigation of International(UIC, EN, IEC) and Domestic Standards(Test Methods) for Climatic Wind Tunnel Test of Rolling Stock (철도차량 기후환경시험을 위한 국제 규격(UIC, EN, IEC) 및 국내 규격(시험방법) 분석 및 고찰)

  • Jang, Yong-Jun;Chung, Jong-Duk;Lee, Jae-Cheon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.12
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    • pp.782-789
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    • 2020
  • The demand for the development of rolling stock technology to maintain the best performance in various climatic environments has increased to expand the overseas market of rolling stock. In this study, international and domestic standards that must be applied to build a harsh climatic environment test system were investigated and compared. The way of improvement for domestic standards is proposed. The wind velocities and temperatures are specified in the UIC, EN, and IEC standards for climatic wind tunnel, and EN 50125-1 provides the velocity test up to 180km/h, the largest wind speed. UIC and EN provide the lowest temperature of -45℃, and IEC 62498-1 provides the highest temperature 55℃. The solar radiation test was specified up to 1200W/m2 in the UIC, EN, and IEC. The IEC, EN, and KS R 9145 provide the water tightness standards, which are different from each other in water capacity, pressure, and methods. The snow test method was not well specified. KRTS-VE-Part 31 provides pressurization test methods. The airtightness standards for high-speed rolling stock are defined and regulated for internal pressure change rate in UIC 660 and 779-11. The domestic standard for the wind tunnel test was not well prepared, and the solar radiation test and snow test do not exist in Korea. Therefore, it is necessary to improve domestic standards to an international level for the climatic wind tunnel test of rolling stock.

An Economic Factor Analysis of Air Pollutants Emission Using Index Decomposition Methods (대기오염 배출량 변화의 경제적 요인 분해)

  • Park, Dae Moon;Kim, Ki Heung
    • Environmental and Resource Economics Review
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    • v.14 no.1
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    • pp.167-199
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    • 2005
  • The following policy implications can be drawn from this study: 1) The Air Pollution Emission Amount Report published by the Ministry of Environment since 1991 classifies industries into 4 sectors, i. e., heating, manufacturing, transportation and power generation. Currently, the usability of report is very low and extra efforts should be given to refine the current statistics and to improve the industrial classification. 2) Big pollution industries are as follows - s7, s17 and s20. The current air pollution control policy for these sectors compared to other sectors are found to be inefficient. This finding should be noted in the implementation of future air pollution policy. 3) s10 and s17 are found to be a big polluting industrial sector and its pollution reduction effect is also significant. 4) The effect of emission coefficient (${\Delta}f$) has the biggest impact on the reduction of emission amount change and the effect of economic growth coefficient (${\Delta}y$) has the biggest impact on the increase of emission volume. The effect of production technology factor (${\Delta}D$) and the effect of the change of the final demand structure (${\Delta}u$) are insignificant in terms of the change of emission volume. 5) Further studies on emission estimation techniques on each industry sector and the economic analysis are required to promote effective enforcement of the total volume control system of air pollutants, the differential management of pollution causing industrial sectors and the integration of environment and economy. 6) Korea's economic growth in 1990 is not pollution-driven in terms of the Barry Commoner's hypothesis, even though the overall industrial structure and the demand structure are not environmentally friendly. It indicates that environmental policies for the improvement of air quality depend mainly on the government initiatives and systematic national level consideration of industrial structures and the development of green technologies are not fully incorporated.

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Investigation of Effects of Lightning and Icing on an e-VTOL UAM Aircraft and a Proposal for Certification Guidance (e-VTOL UAM 항공기의 낙뢰 및 결빙 영향성 분석 및 인증기술에 관한 연구)

  • Kim, Yun-Gon;Jo, Hyeonseung;Jo, Jae-Hyeon;Park, Se-Woong;Myong, Rho-Shin
    • Journal of Aerospace System Engineering
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    • v.15 no.3
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    • pp.45-56
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    • 2021
  • Demand for UAM (Urban Air Mobility) aircraft is rapidly increasing in countries around the world due to the problem of traffic congestion in urban areas. Through research and development, various e-VTOL aircraft concepts are being prepared for commercialization, for which airworthiness certification is required, since it is a manned transportation mode for people to board. Factors that pose a fatal threat to the safe operation of UAM aircraft include lightning strikes that can cause damage to structures and disturb the navigation system, as well as icing that impairs flight stability. Since the current UAM aircraft-related lightning and icing certification technology development is insufficient, there is need to develop appropriate airworthiness certification guidelines. In this study, after analyzing the laws and regulations related to aircraft by the FAA and the EASA, we tried to incorporate the lightning and icing certification guidelines for the UAM aircraft. We also analyzed the effects of lightning and icing on UAM aircraft using computational simulation, and presented the basis for establishing practical guidelines for the certification of UAM aircraft to be adopted in the future.

Analysis of Cable Protection of Duct in Lightning and HIRF Environment of UAM Aircraft and a Proposal for Certification Guidance (UAM 항공기 낙뢰 및 HIRF 환경에서 덕트의 케이블 보호 성능 분석 및 인증기술에 관한 연구)

  • Kim, Dong-Hyeon;Jo, Jae-Hyeon;Kim, Yun-Gon;Lee, Hakjin;Myong, Rho-Shin
    • Journal of Aerospace System Engineering
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    • v.16 no.3
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    • pp.23-34
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    • 2022
  • Cities around the world are increasing their demand for Urban Air Mobility (UAM) aircraft due to traffic congestion with population concentration. Aircraft with various shapes depending on fixed-wing and propulsion systems, are being prepared for commercialization. Airworthiness certification is required as it is a manned transportation vehicle that flies in the city center and transports people on board. UAM aircraft are vulnerable to lightning and HIRF environments due to the increasing use of composite materials, the use of electric motors, and use of electronic equipment. Currently, the development of certification technology, guidelines, and requirements in lightning and HIRF environments for UAM aircraft is incomplete. In this study, the certification procedures for lightning and HIRF indirect impacts of rotorcraft shown in AC 20-136B and AC 20-158A issued by the Federal Aviation Administration (FAA), were verified and applied to the computerized simulation of UAM aircraft. The impact of lightning and HIRF on ducted fan UAM aircraft was analyzed through computerized simulation, and the basis for establishing practical guidelines for certification of UAM aircraft to be operated in the future is presented.

An Evaluation of User's Facility and Suggestion for the Improvement on the Interior Design of Metropolitan Railroads Trains - Focus on the opening 14 metropolitan railroad lines in Seoul through checklist - (도시철도 차량 실내의 이용자 시설 평가와 개선방향 - 체크리스트를 통하여 수도권 노선에 운행 중인 14개 철도 차량을 대상으로 -)

  • Moon, Suh-Hyun;Kim, Gu-Seul;Shin, Kyung-Joo
    • Korean Institute of Interior Design Journal
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    • v.19 no.5
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    • pp.11-20
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    • 2010
  • User-oriented Design is necessary in planning the interior design of Metropolitan Railroads trains, since this is a typical means of transportation in this modem society and all ages people with different body scale use this facility. However, there are little studies about facility panning and zoning of Metropolitan Railroads train considering users. Therefore, in this study, after completing the checklist based on the current legal standards of facility installation of South Korea and Japan, we examined user's facility and suggest several improvement of the opening 14 metropolitan railroad lines in Seoul. Then, we evaluated this facilities according to 41 standards; general facility(24 standards), safety facility(4 standards), guide facility(11 standards), other facility(4 standards). The result of this study may be summarized as follows. 1) General facility has to be designed to obtain lots of room for storage and this facility should be fixed up tightly with secure system. 2) Safety facility should be designed to minimize a difference of floor-level between threshold of train and ground. Also, using various color and material could help passengers to distinguish different space and facility. 3) Guide facility should be designed to guide passengers to the accurate direction with proper sign design in the pathway of Metropolitan railroad train. Also, more various color, which based on the research about physiological and psychological effect, should be used to guide people. 4) Other facility should equip more visual system using common good and informative contents. Through this study, we try to understand the current interior physical condition of Metropolitan Railroads trains. However, for future studies, it is expected to supplement evaluation standards considering aesthetic design, environmental improvement of indoor air quality and the satisfaction and demand of Metropolitan Railroads trains.

Effects of Hydrogen in SNG on Gas Turbine Combustion Characteristics (합성천연가스의 수소함량 변화에 따른 가스터빈 연소특성 평가)

  • Park, Se-Ik;Kim, Ui-Sik;Chung, Jae-Hwa;Hong, Jin-Pyo;Kim, Sung-Chul;Cha, Dong-Jin
    • Journal of Hydrogen and New Energy
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    • v.23 no.4
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    • pp.412-419
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    • 2012
  • Increasing demand for natural gas and higher natural gas prices in the recent decades have led many people to pursue unconventional methods of natural gas production. POSCO-Gwangyang synthetic natural gas (SNG) project was launched in 2010. As the market price of natural gas goes up, the increase of its price gets more sensitive due to the high cost of transportation and liquefaction. This project can make the SNG economically viable. In parallel with this project, KEPCO (Korea Electric Power Corporation) joined in launching the SNG Quality Standard Bureau along with KOGAS (Korea Gas Corporation), POSCO and so on. KEPCO Research Institute is in charge of SNG fueled gas turbine combustion test. In this research, several combustion tests were conducted to find out the effect of hydrogen contents in SNG on gas turbine combustion. The hydrogen in synthetic natural gas did not affect on gas turbine combustion characteristics which are turbine inlet temperature including pattern factor and emission performance. However, flame stable region in ${\Phi}$-Air flow rate map was shifted to the lean condition due to autocatalytic effect of hydrogen.

A GIS-Based Method for Bicycle Route Network Determination Using AHP Analysis in Busan (GIS기반의 계층분석기법(AHP)을 활용한 부산시 자전거도로망 선정에 관한 연구)

  • Son, Eugene;Hwang, In-Sik
    • Journal of the Korean Association of Geographic Information Studies
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    • v.12 no.4
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    • pp.182-190
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    • 2009
  • To solve the problems of traffic congestion, air pollution and energy derived from increased car consumption, people are in recognition of the importance of green mode, bicycle. Bicycle use rate in Busan is lower due to the terrain and limited public transportation accessibility. Therefore, geographical conditions and use activation should be initially considered in the bicycle route planning. We calculated a weight using AHP(Analytic Hierarchy Process), make a database using GIS tool and deduced the routes applying calculated weight in this study. The result of this study, We could get reliable data as inspecting consistency of the research. Routes are deducted in the place where using demand is higher than arbitrarily chosen routes. Therefore, the route planning through AHP is expected to be utilized in area-specialty-reflected route planning or bicycle road alternatives testing.

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Study on the Application of Airworthiness Standard for the e-VTOL (e-VTOL 항공기의 감항기술기준 적용 연구)

  • Choi, Joo-Won;Hwang, Chang-Jeon;Suk, Jin-Young
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.7
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    • pp.593-599
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    • 2021
  • The demand for e-VTOL aircraft is expected to be increased rapidly in the future as a means of urban transportation due to operating cost reduction, eco-friendliness and convenience of vertical take-off and landing using pilot-aids automation system. However, there are many technical hurdles to be solved in securing safety and certification which are essential for commercialization and urban operation. So far, there is no e-VTOL aircraft that has received type certificate and standard airworthiness certificate due to the technical problems and safety requirement differences with conventional aircraft. The e-VTOL aircraft certification should also meet the equivalent level of safety required by the current airworthiness standards, but there are existing problems in securing safety and meeting current standards. In this study, the e-VTOL's certification problems and technical limitations in satisfying the current standards are presented.

Color revelation characteristics of color mortar using iron oxide and carbon black (산화철과 카본블랙을 사용한 컬러 모르터르의 색상발현 특성)

  • Seok, Hwa-Song;Hong, Chang-Woo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.30 no.4
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    • pp.156-161
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    • 2020
  • Recently, as there has been growing demand for aesthetic quality in structural materials, the development of excellent color cement concrete having good coloration properties has become a requirement. This study is designed to analyze the basic physical properties of mortar and the properties of keeping the coloration under an ultraviolet ray accelerated weathering test environment according to changes in the mixing ratio between carbon black and iron oxide used as colorants. The test results show that the use of carbon black and iron oxide reduces the initial flow by 6.3~17.2 % and the air content by 3.5~31.5 % but increases the unit volume weight by 3.4~5.5 %, compared to ordinary Portland cement (OPC). In addition, the study shows that the addition of iron oxide increases the self drying shrinkage. So, caution needs to be taken on the workability of the concrete. The brightness value L represented by black showed the most excellent black colour when carbon black 3 % and iron oxide 5 % are added. According to UV accelerated weatherproof test, the brightness value L was found to increase in all experiment specimens by 4.28~11.97 %, and the color change by UV was found to be higher for the case where carbon black colorant was not used. Therefore, in terms of color revelation characteristics, the case using carbon black 3 % and iron oxide 5 % was found to show the best black color.

A Study on Development of Prototype Test Train Design in G7 Project for High Speed Railway Technology (G7 고속전철기술개발사업에서의 시제차량 통합 디자인 개발)

  • 정경렬;이병종;윤세균
    • Archives of design research
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    • v.16 no.4
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    • pp.185-196
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    • 2003
  • The demand for an environment-friendly transportation system, equipped with low energy consumption, and low-or zero-pollution has been on the increase since the beginning of the World Trade Organization era. Simultaneously, the consistent growth of high-speed tram technology, combined with market share, has sparked a fierce competition among technologically-advanced countries like France, Germany, and Japan in an effort to keep the lead in high-speed train technology via extensive Research and development(R&D) expenses. These countries are leaders in the race to implement the next-generation transportation system, build intercontinental rail way networks and export the high-speed train as a major industry commodity. The need to develop our own(Korean) 'high-speed train' technology and its core system technology layouts including original technology serves a few objectives: They boost the national competitive edge; they develop an environmental friendly rail road system that can cope with globalization and minimize the social and economic losses created by the growing traffic-congested delivery costs, environment pollution, and public discomforts. In turn, the 'G7 Project-Development of High Speed Railway Technology' held between 1996 and 2002 for a six-year period was focused on designing a domestic train capable of traveling at a speed of 350km/h combined and led to the actual implementation of engineering and producing the '2000 high-speed train:' This paper summarizes and introduces one of the G7 Projects-specifically, the design segment achievement within the development of train system engineering technology. It is true that the design aspect of the Korean domestic railway system program as a whole was lacking when compared with the advanced railroad countries whose early phase of train design emphasized the design aspect. However, having allowed the active participation of expert designers in the early phase of train design in the current project has led to a new era of domestic train development and the implementation of a way to meet demand flexibly with newly designed trains. The idea of a high-speed train in Korea and its design concept is well-conceived: a faster, more pleasant, and silent based Korean high-speed train that facilitates a new travel culture. A Korean-type of high-speed train is acknowledged by passengers who travel in such trains. The Korean high-speed prototype train has been born, combining aerodynamic air-cushioned design, which is the embodiment of Korean original design of forehead of power car minimized aerodynamic resistance using a curved car body profile, and the improvement of the interior design with ergonomics and the accommodation of the vestibule area through the study of passenger behavior and social culture that is based on the general passenger car.

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