• 항공우주산업기술동향
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• 제6권2호
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• pp.11-21
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• 2008

본 논문은 WTO 협정의 보조금규정 및 WTO 분쟁사례를 검토, 분석하여 공정무역체제하에서 국제규범에 저촉되지 않는 방향으로 우리나라의 항공우주산업지원방안을 마련하는데 중점을 두었다. 먼저 보조금의 요건인 재정적 공여 및 혜택에 대해 분석하였으며 보조금 중에서 금지보조금, 상계조치가능보조금으로 나뉘어 있는 규정을 검토하였고, 브라질과 캐나다, 미국과 EC 간의 항공기 분쟁사례에서 어떠한 쟁점이 있었는지를 검토하였다. 우리나라의 항공우주산업은 아직 국제경쟁력을 확보하지 못한 상태이므로 정부의 적극적인 지원이 필요하나 WTO 메카니즘에 의거하여 보조금에 해당해서는 안되므로 국제규범에 저촉되지 않는 다양한 지원방안을 제안했다.

• 한국전산유체공학회지
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• 제18권4호
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• pp.41-46
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• 2013

The selection of the optimal position of the flap was performed in order to improve the aerodynamic performance during the take-off and landing processes of aircraft. For this, the existing airfoils of the main wing and flap are selected as the baseline model and the lift coefficients (cl) according to angle of attacks (AOA) were calculated with the change of the position of flap airfoil. The objective function was defined as the consideration of the maximum cl, lift to drag ratio and cl at certain AOA. Then, at 121 experimental points within $20mm{\times}20mm$ domain, two dimensional flow simulations with Spalart-Allmaras turbulence model were performed concerning the AOA from 0 to 15 degree. If the optimal position was located at the domain boundary, the domain moved to the optimal position. These processes were iterated until the position was included in the inside of the domain. From these processes, the flow separation at low AOA was removed and cl increased linearly comparing with that of the baseline model.

• 한국국방경영분석학회지
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• 제24권1호
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• pp.41-57
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• 1998

Since the aircraft has a property of moving in the three-dimensional space, it may cause personally and financially critical damage in the case of an accident. Among the causes of aircraft accident, human factor has occupied about 70% of all accidents. Specially, fatigue among human's problems has been studied earlier than any other factor. Fatigue has been the cause of 75% of accidents that are related to human factor. So many studies have been conducted. But the direction of these studies mainly attach importance to the sleep loss and circadian rhythm. Limitation for flight time of ICAO is 8 hours per day, civil airlines in domestic line also adopt the limitation. But this rule is not based on human's performance but compromise between labor and management. The long-haul flight brings about a mental block to pilot. This mental block decreases performance of pilot and loses a lot of important information. So this may cause many accidents. This paper is to offer optimal flight time according to the amount of fatigue due to increasing flight time. The optimal flight time is searched through the field experiment. The experiment has adopted two methods. One is to examine pilot's objective fatigue accumulation rate through the critical fusion frequency, and another is to investigate pilot's subjective fatigue feeling through the fatigue subjective symptoms investigation table.

• Smart Structures and Systems
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• 제5권4호
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• pp.317-328
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• 2009

Current maintenance operations and integrity checks on a wide array of structures require personnel entry into normally-inaccessible or hazardous areas to perform necessary nondestructive inspections. To gain access for these inspections, structure must be disassembled and removed or personnel must be transported to remote locations. The use of in-situ sensors, coupled with remote interrogation, can be employed to overcome a myriad of inspection impediments stemming from accessibility limitations, complex geometries, the location and depth of hidden damage, and the isolated location of the structure. Furthermore, prevention of unexpected flaw growth and structural failure could be improved if on-board health monitoring systems were used to more regularly assess structural integrity. A research program has been completed to develop and validate Comparative Vacuum Monitoring (CVM) Sensors for surface crack detection. Statistical methods using one-sided tolerance intervals were employed to derive Probability of Detection (POD) levels for a wide array of application scenarios. Multi-year field tests were also conducted to study the deployment and long-term operation of CVM sensors on aircraft. This paper presents the quantitative crack detection capabilities of the CVM sensor, its performance in actual flight environments, and the prospects for structural health monitoring applications on aircraft and other civil structures.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.377-382
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• 2006

Precision approach and landing of aircraft in a remote landing zone autonomously present several challenges. Firstly, the exact location, orientation and elevation of the landing zone are not always known; secondly, the accuracy of the navigation solution is not always sufficient for this type of precision maneuver if there is no DGPS availability within close proximity. This paper explores an alternative approach for estimating the navigation parameters of the aircraft to the landing area using only time-differenced GPS carrier phase measurement and range measurements from a vision system. Distinct ground landmarks are marked before the landing zone. The positions of these landmarks are extracted from the vision system then the ranges relative to these locations are used as measurements for the extended Kalman filter (EKF) in addition to the precise time-differenced GPS carrier phase measurements. The performance of this navigation algorithm is demonstrated using simulation.

• 한국항공운항학회지
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• 제20권3호
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• pp.44-50
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• 2012

The noise reduction is important one of considerations in the process of a civil aircraft development program. External noise sources are classified into an air-born source and a structure-born source. Among these noise sources, the most affected noise source into a cabin is the air-born noise source from an engine or propeller. The external noise is transmitted into the cabin through the fuselage structure of airplane which are composed of an fuselage structure, an interior trim panel and an acoustic insulation layer between an fuselage structure and an interior trim panel. Therefore, appropriate fuselage structure and acoustic insulation layer is very important to reduce the internal noise level. In this paper, the vibro-acoustic coupled analysis of the cabin noise of the 80~90 seats regional turboprop aircraft is carried out to validate the acoustic analysis method using Direct BEM and FEM. The sound pressure level onto the fuselage skin is acquired by fan-source noise analysis using BEM, and which sound pressure is used as acoustic noise source in vibro-acoustic noise analysis for cabin noise analysis using FEM.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1907-1915
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• 2008

Recently the assurance of railroad safety is very important issue in KOREA because there are lots of changes in the railroad industries. The Railway Safety Act was established in order to cope with these changes effectively and prevent the railroad transportation accidents. According to this law, Korea Transportation Safety Authority (KOTSA) has been entrusted with 'Integrated Railroad Safety Audit (IRSA)'. Even though newly introduced IRSA is conducted smoothly, it is necessary to study the methodology and criteria of the state's safety audit system in other fields to improve the efficiency. In ICAO (International Civil Aviation Organization) Safety Management Manual, a state's safety programme embraces those regulations and directives for the conduct of safe operations from the perspective of aircraft operators and those providing air traffic services(ATS), aerodromes and aircraft maintenance. The safety programme may include provisions for such diverse activities as incident reporting, safety investigations, safety audits and safety promotion. To implement such safety activities in an integrated manner requires a coherent SMS(Safety Management System). In this paper, to improve the efficiency of IRSA, we investigated the ICAO's the State's Aviation Safety Audit Systems and ICAO Safety Management Manual. And through the result of investigation, we proposed the improvement concept of IRSA.

• 한국항공운항학회지
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• 제29권4호
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• pp.166-172
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• 2021

Obstacle Limitation Surfaces (OLS) are set to protect a certain amount of airspace to limit objects, such as building, other structures, penetrating OLS for safety and regularity of aircraft operations in the vicinity of aerodromes. However, many civil petitions have been raising for effective utilization of lands and permission of building construction which penetrating OLS. While Republic of Korea are limiting installation of penetrating objects based on the National law of airport facilities, such objects are possibly permitted, only if, the possible risks coming from objects are acceptable or negligible in terms of safety and regularity in aircraft operations through the evaluation process, called as an aeronautical study. However, many countries are currently applying their own criteria, processes resulting in failing secure reliable results in aeronautical study. This research aims to establish the framework on criteria, process, and methodologies how the aeronautical study works including work flows between many stakeholder and responsibilities to be specified in national regulation system.

• 항공우주산업기술동향
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• 제8권2호
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• pp.124-135
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• 2010

2009년 4월 27일 일본과 미국은 항공기 및 부품의 감항성인증을 상호수락하기 위한 항공안전협정(BASA) 및 감항성이행절차(IPA)를 체결하였다. 항공안전협정이 해당 민간항공당국이 수행해야 하는 법적 책임을 경감시키지는 않는다. 다만, 역량있는 상대국가의 감항당국이 해당 민간항공당국을 대신하여 자국의 항공기 인증제도에 필적할 만한 방법으로 수행한 인증기능을 인정하는 방법을 통하여, 해당 민간항공당국은 적합성판정을 함에 있어서 대체방법으로 활용하는 것이다. 이를 통해 항공안전협정은 안전을 저해하지 않으면서 여러 국가의 인증에 소요되는 비용과 시간을 경감시키면서 교역을 촉진하는 데 기여하고 있는 것이다. 본 논문에서는 가장 최근에 미국과 BASA를 체결한 일본의 항공기 인증제도 및 항공안전협정 체결 현황에 대하여 제시한다.

• 한국항행학회논문지
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• 제17권1호
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• pp.1-8
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• 2013

항공교통관리에 있어서 ADS-B(Automatic Dependent Surveillance-Broadcast)와 multilateration은 국제민간항공기구에서 지정한 차세대 시스템 중 핵심기술이다. 그러나 오늘날, 모든 항공기가 ADS-B를 장착하고 있지는 않다. ADS-B 미장착 항공기의 위치 획득을 위해 TIS-B(Traffic Information Service-Broadcast)가 사용되는데, TIS-B는 레이더로부터 획득한 항공기 위치를 제공한다. 본 논문에서는 TIS-B를 대체할 수 있는 2차 감시레이더 신호를 활용한 onboard multilateration 시스템을 제안한다. TIS-B는 레이더 자료를 이용해 항공기 위치를 제공하므로 그 오차가 굉장히 큰 반면, onboard multilateration 시스템은 TDOA(Time Difference of Arrival) 기법을 이용하므로 항공기 위치 오차가 매우 작다. 성능비교 결과, 본 논문에서 제안된 onboard multilateration 시스템이 TIS-B에 비해 공항 인근에서는 37.39%, 공항 200마일 부근에서는 51.61% 성능이 우수한 것으로 나타났다.