• Convergence Security Journal
• /
• v.20 no.4
• /
• pp.61-70
• /
• 2020

The unmanned aerial vehicle that emerged with the 4th Industrial Revolution attracts attention not only from Korea but also from around the world, and its utilization and market size are gradually expanding. For the first time, it was used for military purposes, but it is currently used for transportation, investigation, surveillance, and agriculture. China, along with the US and Europe, is emerging as a leader in the commercial unmanned aerial vehicle market, and Korea, which has the world's seventh-largest technology in related fields, is striving to promote various technology development policies and system improvement related to unmanned aerial vehicles. Military drones will revolutionize the means of war by using a means of war called an unmanned system based on theories such as network-oriented warfare and effect-oriented warfare. Mobile equipment, including drones, is greatly affected by environmental factors such as terrain and weather, as well as technological developments and interests in the field. Now, drones are being used actively in many fields, and especially in the military field, the use of advanced drones is expected to create a new defense environment and provide a new paradigm for war.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1991.06a
• /
• pp.70-75
• /
• 1991

기어는 기계시스템에서 동력전달 및 운동전환을 담당하는 기본 요소로 공작기계, 건설기계, 농업기계 등의 산업기계와 항공기, 자동차, 선박등의 운송분야, 사무용 및 계측기기 등 산업전반에 걸쳐 사용되고 있으며, 최근에는 로보트를 위시한 자동화 장치의 구동 및 동력전달 장치로 사용되고 있다. 최근의 기어시스템은 기계류의 일반적인 경향인 고속, 고부하, 결량화 추세에 따라 고정밀, 소형화되어 가고 있으며 부하한계에 가깝도록 큰 하중에 견딜것이 요구되고 있다. 따라서 기어의 설계 및 제작시, 여유있는 설계가 허용되지 않으며 정밀성을 높이기 위한 설계로, 설계인자의 세분화가 요구되어지고 있다. 국제적으로 통용되고 있는 강도설계 규격에서 면압강도시 표면상태계수(Surface condition factor)를 정의하고 있다. 본 연구에서는 동력순환식 기어 시험장치를 이용하여 표면처리 상태가 다른 3종류(열처리를 하지 않은 기어, 침탄 및 고주파 표면 열처리한 기어)의 스퍼어 기어를 이요하여 회전수별 표면거칠기의 변화 상태를 고찰하고, 변수를 응용하여 물리적 의미를 파아갛고, 윤활해석을 통한 윤활조건과 치면상태와의 상호 관계에 대하여 고찰해 보고자 한다.

• Journal of Aerospace System Engineering
• /
• v.16 no.3
• /
• pp.35-41
• /
• 2022

UAM (Urban Air Mobility) is a new safe, secure, and more sustainable air transportation system for passengers and cargo in urban environments. Commercial operations of UAM are expected to start in 2025. Since production rates of UAM are expected to be closer to cars than conventional aircraft, the airworthiness methodology for UAM must be prepared for mass production. Composite materials are expected to be mainly used for UAM structures to reduce weight. In this paper, the composite material qualification method was derived and the materials were applied for small aircraft application. It is expected to reduce the airworthiness certification time by applying composite material qualification system and its database.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2012.03a
• /
• pp.17-17
• /
• 2012

수송용 섬유소재는 자동차, 항공기 또는 선박 등의 교통 및 운송 분야에 기여하는 사용되는 섬유소재를 말하며, 내장재, 각종 호스류, 벨트류, 타이어, 안전용품, 필터류 등을 포함하고 일반적으로 섬유, 발포체, 고무, 플라스틱, 접착제 등 유기소재가 결합된 복합체이다. 기존 섬유기술의 혁신과 더불어 IT, NT, BT, ET 등 첨단 기술과의 융합에 의한 고성능 극한 슈퍼섬유, 나노 복합섬유 등의 신소재를 개발하여 산업 전반에서 플라스틱의 금속소재 대체수요를 증가시키고 산업자재의 고성능화, 고기능화, 다양화를 이루기 위해 다양한 노력이 진행하고 있다. 현재 수송용 섬유소재 산업은 기술의 연결고리가 부족하며, 선도기업 및 원천기술이 부족하며, 자동차용 섬유부품소재 관련 기업의 역량도 부족한 실정이다. 이에 광역경제권 연계협력사업을 통해 생산기반의 대경권(대구경북)과 수요중심의 동남권(부산경남)의 네트워크를 강화하여 완성품 업체 및 수요기업과의 네트워킹을 강화하고자 한다. 따라서 본 연구에서 수송용 섬유소재개발, 수송용 친환경 oam-skin 일체형 표피재 개발, 고속성형 복합소재 및 수송용 경량부품 개발, 초경량 고내열 고강도 섬유활용 하이브리드 wire & cable 개발 등 수송용 섬유소재를 개발하고, 또한 수송용 섬유소재의 생산-수요 연계를 통한 투자활성화, 기술개발, 소재 산업 육성을 강화하여, 산학연네트워크구축, 지역 간 협력 및 국제적 협력, 생산-수요기반의 연계협력시스템을 활용한 자립형 수송용 소재 공급기지 완비하는 데 목적이 있다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.1
• /
• pp.117-124
• /
• 2010

The bird strike to small aircraft has not been an issue because of its low speed and usage as a private aircraft. So, the compliance of the bird strike regulation is limited to large fixed-wing aircraft such as the commuter category in FAR Part 23 and the civil aircraft in FAR Part 25, generally. However, the forecast of dramatic increasing of VLJ(Very Light Jet), the usage of a composite material for an aircraft structure and flight time of general aviation due to Air-taxi for the point to point transportation, would rise up the need of bird strike regulations and a safety enhancement in normal and utility categorized aircraft. In this study, the safety of bird strike to small aircraft wing leading edge made of a metal and a composite material were compared using the explicit finite element analysis.

• Journal of Advanced Navigation Technology
• /
• v.21 no.1
• /
• pp.1-12
• /
• 2017

As the current ground transportation system becomes saturated, there is a need to develop a roadable personal air vehicle (PAV). Therefore, researches for PAV development and operation system development are being actively carried out in various countries around the world. PAV, the next generation transportation system, is a new concept of personal transportation that combines ground transportation, air traffic, and IT industry. Also, the development of PAV can solve the saturation of traffic congestion and shorten the travel time dramatically. In this study, we analyzed the certification criteria of FAR Part 23, which is going to be revised, and analyzed the patents and folding mechanism of Terrafugia Transition and Aeromobil 3.0, which are the most advanced of roadable PAV. Also, we used $OpenVSP^{(R)}$ for the reverse configuration design of the existing Terafugia transition and Aeromobile 3.0. Aerodynamic analyses were performed for the reverse configuration design using the $XFR5^{(R)}$ program.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.46 no.1
• /
• pp.18-31
• /
• 2018

Rotorcrafts have more severe crashworthiness conditions than fixed wing aircraft owing to VTOL and hovering. Recently, with the increasing demand for highly efficient transportation system, application of composite materials to aircraft structures is increasing. However, due to the characteristics of composite materials that are susceptible to impact and crash, demand to prove the crashworthiness of composite structures is also increasing. The purpose of present study is to derive the structural concept of composite subfloor for rotorcrafts and verify it. In order to design a crashworthy composite subfloor, the conceptual design of the testbed helicopter for the demonstration and the derivation of energy absorbing requirement were carried out, and the composite energy absorber was designed and verified. Finally, the testbed for the demonstration of a crashworthy composite structure was fabricated, and performed free drop test. It was confirmed that the test results meet the criteria for ensuring occupant survivability.

• Journal of Advanced Navigation Technology
• /
• v.21 no.5
• /
• pp.435-442
• /
• 2017

The runway visual range affected by fog and so on is one of the important indicators to determine whether aircraft can take off and land at the airport or not. In the case of airports where transportation airplanes are operated, major weather forecasts including the runway visual range for local area have been released and provided to aviation workers for recognizing that. This paper proposes a runway visual range estimation model with a deep neural network applied recently to various fields such as image processing, speech recognition, natural language processing, etc. It is developed and implemented for estimating a runway visual range of local airport with a deep neural network. It utilizes the past actual weather observation data of the applied airfield for constituting the learning of the neural network. It can show comparatively the accurate estimation result when it compares the results with the existing observation data. The proposed model can be used to generate weather information on the airfield for which no other forecasting function is available.

• The Journal of the Korea Contents Association
• /
• v.19 no.11
• /
• pp.12-21
• /
• 2019

In the era of the Fourth Industrial Revolution, drones have become a flexible device that can be integrated with new technologies. The drones were originally developed as military unmanned aircraft and are now being used in various fields. In the environment and weather observation area, the atmospheric boundary layer is near the surface where the atmosphere is the most active in the meteorological phenomenon and has a close influence on human activities. In order to carry out the study of these atmospheric boundary layers, it is necessary to observe precisely the lower atmosphere and secure the observation technology. The drones in the meteorological field can be used for meteorological observations at a relatively low maintenance cost compared to existing equipment. When used in conjunction with various sensors, the drones can be widely used in atmospheric boundary layer and local meteorological studies. In this study, the possibility of meteorological observations using drones was confirmed by conducting vertical meteorological (temperature and humidity) observation experiments equipped with a combined meteorological sensor and a radio sonde on drones owned by NIMS.

• Journal of Advanced Navigation Technology
• /
• v.25 no.1
• /
• pp.52-59
• /
• 2021

According to the International Air Transport Association (IATA), 61% of the accidents occurred during the approach and landing phase of the flight, with 16% of the accidents caused by unstable access of the commercial aircraft. It was identified that the pilot's unstable approach and poor manipulation of correction led to accidents by continuing the excessive approach without go-around manuever. The causes of unstable access may vary, including airport approach procedures, pilot error, misplanning, workload, ATC (Air Traffic Contol) congestion, etc. In this study, we use the flight data analysis system to select domestic case airports and aircraft type where unstable approach events occur repeatedly. Through flight data analysis, including main events, airport approach procedures, pilot operations, as well as various environmental factors such as weather and geographical conditions at the airport. It aims to identify and eliminate the tendency of unstable approach events and the causes and risks of them to derive implications for mitigating unstable approach events and for developing navigation safety measures.