• 한국항행학회논문지
• /
• 제27권6호
• /
• pp.804-814
• /
• 2023

인구밀도가 높은 도심지 내에서 비행하게 되는 UAM의 비행경로 하부 및 주변으로는 각종 건축물이 산재하게 된다. 그리고 UAM이 이착륙하는데 사용하는 버티포트는 도심 내의 평지 또는 건축물 상부 등에 위치하게 된다. 이처럼 UAM은 인구밀도가 높은 도심에서 운항하고, 이착륙을 위한 버티포트는 인구밀집지역에 설치됨에 따라 매우 높은 수준의 안전도가 요구된다. 특히 UAM의 안전한 착륙을 위해 최종접근진로에서 버티포트로 접근하는 UAM의 접근상태를 감시하고 접근정보를 제공할 필요가 있다. 이에 UAM 버티포트 최종접근진로 감시를 위해 좁은 부지에 설치가 가능하면서 전자파의 부담이 적다는 장점이 있는 광학장비를 활용하는 기술에 대한 연구를 진행하였다.

• 한국항행학회논문지
• /
• 제27권3호
• /
• pp.269-273
• /
• 2023

본 연구는 K-UAM 로드맵[1]을 바탕으로, 초기 UAM 조종사 교육훈련 커리큘럼 구성에 필요한 주요 교육훈련 과목을 선정하기 위해 수행하였다. 현재 UAM 기체는 VTOL 기능을 중심으로 수직 이착륙이 가능한 회전익 항공기와 유사한 특성을 갖는다. 따라서 본 연구에서는 회전익 비행교육을 대표하는 육군항공학교의 회전익 조종사 양성 교육 커리큘럼을 비교군으로 선정하여 초기 UAM 조종사 양성을 위한 교육훈련 과목을 선정하였다. 먼저 육군의 회전익 조종사 교육훈련 과목을 바탕으로 AHP 설문을 위한 계층구조를 설계하였으며 각 계층의 전문가들을 선별하여 AHP 설문을 수행하였다. AHP 분석을 통해 우선순위로 부여한 교육훈련 과목을 초기 UAM 조종사 훈련에 적용한다면 교육훈련 효과와 궁극적으로 UAM의 안전운항에 기여할 것으로 본다.

• 한국자동차공학회논문집
• /
• 제7권8호
• /
• pp.34-42
• /
• 1999

In late 1997, the portion of registered light-duty diesel vehicle was 25.3% and its emission rate was 17.1% in Korea. Especially, diesel particulate matters(DPM) and NOx are hazardous air pollutants to human health and environment in urban area. The reduction technologies of exhaust emissions from diesel engines are improvement of engine combustion, fuel quality and development of diesel exhaust after treatment , In this study , a light-duty diesel oxidation catalyst(DOC) that is one of the diesel exhaust after treatment was made for performance evaluation and the emission characteristics were tested on CVS-75 mode. And the analysis of the particle size distribution with scanning mobility particle 100, 67.6% and 66.7, 10.0% for Pt and Pt-V catalyst .And for Pt catalyst, the PM increased 7.8% because of increasing sulfate but Pt-V catalyst reduced the PM to 23.0% . Test results of particle size distribution showed that peak values of number and mass densities are respectively 100∼200nm their distribution trend independent of vehicle speed.

• 한국항공운항학회지
• /
• 제30권2호
• /
• pp.1-6
• /
• 2022

Recently, the development of UAM, which was named by NASA as an alternative to solve the traffic and environmental problems caused by the rapidly progressing urbanization. When designing UAM, the location of lift fans greatly affects the core technology of the eVTOL type, distributed electric propulsion technology and aerodynamic performance of the vehicle. In this paper, a hybrid UAM model was designed using OpenVSP, an open source aircraft configuration modeling program, and aerodynamic analysis was performed according to the lift fans position change by the vortex lattice method. As a result, it is confirmed that the flight parameters and trailing wakes are stable by fixing the lift fan with the state rotated 0° to the flow direction of the aircraft during cruise flight. Also, OpenVSP is a suitable tool to be used in aircraft configuration modeling and design.

• Journal of Positioning, Navigation, and Timing
• /
• 제10권4호
• /
• pp.235-242
• /
• 2021

Unmanned Aerial Vehicles (UAVs), which were used for military purposes, are gradually expanding their application fields under the influence of electrification and digitalization. Starting from the field of aerial imaging and Intelligence Surveillance and Reconnaissance (ISR) mission, nowadays the possibility of Urban Air Mobility (UAM), which transports passengers and cargo with drones, is widely under discussion. In order to occupy the rapidly growing global unmanned aerial vehicle market in advance, it is necessary to secure core technologies and develop key UAVs components based on the new technologies. In the navigation field, it is necessary to secure a precise position with guaranteed reliability and continuity, unrelated to the operating environments. The reliability and continuity should be secured in the algorithm level and in the H/W component levels also. In order to achieve this technical goal, the Ministry of Science and ICT has launched the 'Unmanned Vehicle Core Technology Research and Development Program' in 2019 to support the R&D on the unmanned vehicle technologies. In this paper, authors introduce the unmanned vehicle core technology research and development program to the related researchers. The authors summarize the backgrounds of the program and show the technological tasks and objectives on the sub-programs in the unmanned vehicle navigation program. We present the program schedules especially focused on the test and evaluation of the developed technologies and components.

• 한국항공운항학회지
• /
• 제31권1호
• /
• pp.18-25
• /
• 2023

In recent years, UAM (Urban Air Mobility) has emerged as a solution to these urbanization problems, and many related reports and diverse prospects have been reported. UAM flights are planned to take off and land at a Vertiport located in the city center and fly along a pre-established corridor. In order for UAM to operate safely in the city center, it must ensure a safe flight path that avoids the buildings in the city center and many surrounding obstacles. Therefore, in this study, we compared and examined the installation standards of the obstacle limitation surface necessary for UAM to take off and land safely at the Vertiport. First, we analyzed the helicopter obstacle limitation surfaces in Japan and overseas, and the UAM Vertiport installation standards and obstacle limitation surface application standards recently announced at the FAA and EASA. It identified differences and similarities between heliport and Vertiport, and considered improvements to domestic helicopter obstacle limitation surfaces and criteria that could meet FAA and EASA standards.

• KEPCO Journal on Electric Power and Energy
• /
• 제8권2호
• /
• pp.103-110
• /
• 2022

Ultrafine Particle number and size distributions were simultaneously measured at rural area around the power plant in Dangjin, South Korea. New Particle formation and growth events were frequently observed during January, 2021 and classified based on their strength and persistence as well as the variation in geometric mean diameter(GMD) on January 12, 21 and 17. In this study, we investigated mechanisms of new particle growth based on measurements using a high resolution time of flight aerosol mass spectrometer(HR-ToF-AMS) and a scanning mobility particle sizer(SMPS). On Event days(Jan 12 and 21), the total average growth rate was found to be 8.46 nm/h~24.76 nm/hr. These growth rate are comparable to those reported for other urban and rural sites in South Korea using different method. Comparing to the Non-Event day(Jan 17), New Particle Growth mostly occurred when solar radiation is peaked and relative humidity is low in daytime, moreover enhanced under the condition of higher precusors, NO₂ (39.9 vs 6.2ppb), VOCs(129.5 vs 84.6ppb), NH₃(11 vs 4.7ppb). The HR-ToF-AMS PM_1.0 composition shows Organic and Ammoniated nitrate were dominant species effected by emission source in domestic. On the other hand, The Fraction of Ammoniated sulfate was calculated to be approximately 16% and 31% when air quality is inflow from China. Longer term studies are needed to help resolve the relative contributions of each precusor species on new particle growth characteristics.

• 한국항행학회논문지
• /
• 제27권6호
• /
• pp.690-698
• /
• 2023

현재 수많은 공항에서는 공항 협력적 의사결정지원체계 (A-CDM; airport cooperative decision making system) 도입 후 이를 기반으로 공항 이해관계자들의 정보 공유 및 결정이 가능해졌다. 이는 곧 항공기 처리시간을 최적화하고 공항 운영의 효율성을 증가시켰다. 버티포트 또한 이러한 효율성 증대를 위한 방안이 필요하다. 기존 공항의 항공기에 비해 UAM 기체는 도심 속을 비행하는 새로운 항공교통체계로써 도심 내 교통체증을 겪지 않으면서 빠르게 이동하고 싶은 사용자의 수요가 큰 비중을 차지할 것이다. 그렇기에 지연이나 뜻하지 않은 결항은 사용자의 만족도를 크게 낮추게 된다. 이러한 점을 보완하기 위해 버티포트와 UAM의 특성에 맞게 의사결정지원체계의 기준을 수립하여 V-CDM을 도입한다면 버티포트에서의 UAM에 대한 효율적인 운영이 가능해질 것이다. 본 논문에서는 버티포트의 이해관계자를 정의하고 A-CDM을 기반으로 V-CDM이 어떤 방식으로 운영되어야 하는가에 대한 방안을 제시하였다.

• Asian Journal of Atmospheric Environment
• /
• 제6권2호
• /
• pp.96-103
• /
• 2012

Ambient particulate matter (PM) and particle-bound polycyclic aromatic hydrocarbon (PAH) concentrations were measured continuously for 70 days at a Korean elementary school located near a highway. The $PM_{10}$, $PM_{2.5}$, and $PM_1$ values were measured with a light-scattering, multi-channel, aerosol spectrometer (Grimm, Model 1.107). The number concentrations of the particles were measured using a scanning mobility particle sizer and counter (SMPS+C) which counted particles from 11.1 to 1083.3 nm classified in 44 channels. Particle-bound PAHs were measured with a direct reading, photoelectric aerosol sensor. The daily $NO_2$, $SO_2$, and CO concentrations were obtained from a national air-monitoring station located near the school. The average concentrations of $PM_{10}$, $PM_{2.5}$, and $PM_1$ were 75.3, 59.3, and $52.1{\mu}g/m^3$, respectively. The average number concentration of the ultrafine particles (UFPs) was $46,307/cm^3$, and the averaged particle-bound PAHs concentration was $17.9ng/cm^3$ during the study period. The ambient UFP variation was strongly associated with traffic intensity, particularly peak concentrations during the traffic rush hours. Particles <100 nm corresponded to traffic-related pollutants, including PAHs. Additional longterm monitoring of ambient UFPs and high-resolution traffic measurements should be carried out in future studies. In addition, transient variations in the ambient particle concentration should be taken into consideration in epidemiology studies in order to examine the short-term health effects of urban UFPs.

• 미술이론과 현장
• /
• 제9호
• /
• pp.151-170
• /
• 2010

As an art group, De Stijl (1917-1931) led a total art movement encompassing painting, sculpture, design, and architecture. Among these, architecture, as a model of the total art pursued by the group, was encapsulated by the term 'plastic architecture.' The term reflects architecture's shared features with plastic art, especially its pictorial characteristics. Firstly, De Stijl architecture shares geometric form with painting. Assembled in simple, clear and rational structures, the geometric forms signified universal forms, and extended the pictorial experimentation that Mondrian exercised through Neo-Plasticism to architecture. Constructed with colour fields made of concrete wall, De Stijl architecture is geometric abstract painting embodied in space. Together with such pictorial characteristics, large plate glass windows, narrow window frames, and cantilever structure minimize the building's visual weight. De Stijl architecture, which appears suspended in the air, is an architectural version of the abstract paintings of the era that revealed unknown spaces beyond perspective. De Stijl architecture is also an 'open' architecture, where the units placed as if radiating from the center form relations with each other flexibly and organically. The observer in such a space is encouraged to experience space within time, as his/her physical and visual mobility and extension are maximized. De Stijl architecture is an example of how the time-space continuum, represented within picture frame through Cubism, Futurism, and abstract art, can be realized in space. By transforming the ideal space of painting into real space in this way, 'plastic architecture' turned out to be an architectural manifestation of the utopianism of the era, aimed at building a society in 'perfect harmony.' However, such rationalism and universalism are not free from the violence of totalization that deletes various differences. This is evident in the history that followed as the geometric form of architecture and urban planning proliferated across the globe, engulfing the diverse natural landscapes and local cultures.