• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.4
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• pp.28-35
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• 2021

Infrared (IR) stealth technology to protect aircraft from heat-tracking missiles is a very important factor in the development of military aircraft. In this study, the intensities of signal generation were compared by observing the IR signals generated from the plumes of the engine and identifying them for each measurement angle. To simulate a jet engine applied to an actual aircraft, a small turbojet engine was constructed, the infrared signal characteristics for each wavelength were identified according to the measurement angle, and the total infrared radiance was derived by integrating the signal for each wavelength. Through this study, we intend to present basic data for improving the infrared stealth performance of aircraft.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.4
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• pp.116-125
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• 2023

Gimpo International Airport is a strategically utilized airport based on government policy, but there are many residents living around the airport, so it is very sensitive to changes in airport operation. In the past, similar noise results were obtained for aircraft noise at Gimpo International Airport despite changes in aircraft types and an increase in the number of aircraft operating, and recently ICAO proposed a low-noise aircraft noise standard (Ch.14). Since the new standard has a noise reduction effect of up to 15dB compared to existing aircraft noise, ICAO and Europe EASA predict that future aircraft noise will be reduced if the latest technologies such as low-noise aircraft are applied. Therefore, this study establishes the aircraft operation performance and measured noise of Gimpo International Airport in 2022 as a baseline scenario, noise changes using various scenarios of introduction of low-noise aircraft, operation of mid-to-long-distance routes, and changes in future air traffic demand were analyzed using simulation.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.3
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• pp.425-436
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• 2015

This paper presents the procedures used for estimating the stability and control derivatives of a general aviation canard aircraft from flight data. The maximum likelihood estimation method which accounts for both process and measurement noise was used for the flight data analysis of a four seat canard aircraft, the Firefly. Without relying on the parameter estimation method, several aerodynamic derivatives were obtained by analyzing the steady state flight data. A wind tunnel test, a flight test of a 1/4 scaled remotely controlled model aircraft, and the prediction of aerodynamic coefficients using the USAF Stability and Control Digital Data Compendium (DATCOM), Advanced Aircraft Analysis (AAA), and Computer Fluid Dynamics (CFD) were performed during the development phase of the Firefly and the results were compared with flight determined derivatives of a full scaled flight prototype. A correlation between the results from each method could be used for the design of the canard aircraft as well as for building the aerodynamic database.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.53-56
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• 2005

Aircraft noise is a important problem to inhabitants near airports. INM is one of programs for determining the predicted noise impact in the vicinity of airports. It has been widely using for engineers to evaluate aircraft noise. However it is difficult to predict aircraft noise in case of lack of exact INM input data. The exact informations about a fighter plane are not known well for a security problem. This study presents methods of reducing errors between measurement and simulation when the exact INM input data is not known. Especially we adjusted the thrust force of aircraft engine and reduced the error.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.1
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• pp.39-49
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• 2002

This paper presents a robust tracker design method that is specific to the trajectories of target aircraft. This method assumes that representative trajectories of the target aircraft are available. The exact trajectories known to the tracker enables the incorporation of the exact data in the tracker design instead of the measurement data. An estimator is designed to have acceptable performance in tracking a finite number of different target trajectories with a capability to trade off the mean and maximum errors between the exact trajectories and the estimated or predicted trajectories. Constant estimator gains that minimize the cost functions related to the estimation or prediction error are computed off-line from an iterative algorithm. This tracker design method is applied to the longitudinal motion tracking of target aircraft.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.3 s.120
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• pp.249-256
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• 2007

Aircraft noise is a serious problem to inhabitants near airports. INM is one of programs for determining the predicted noise impact in the vicinity of airports. It has been widely used for engineers to evaluate aircraft noise. However it is difficult to predict aircraft noise in case of lack of exact INM input data. The exact informations about a fighter plane are not known well for a security problem. This study presents methods of reducing errors between measurement and simulation when the exact INM input data is not known. Especially we adjusted the thrust force of aircraft engine and reduced the error.

• KIEAE Journal
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• v.9 no.1
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• pp.99-106
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• 2009

This study aims to survey the acoustical environment in the region around airport where there are various transportation noises such as aircraft noise, railway noise and traffic noise, and to analyze the subjective response on the noise to the people who live in house or work in office nearby airport. Measurement and subjective response evaluation were carried out at the same time and outdoor noise level was measured all day long to calculate one day results such as average Leq or one day WECPNL etc. The results showed that the military aircraft produces very high level comparing with commercial aircraft, for instance the sound level of commercial outdoor was lower than that of military aircraft indoor. Double and triple window were more effective for controlling the noise than single window, which showed the possibility of sound insulation treatment by installing windows having higher sound insulation performance. Finally the subjective response was resulted that the most annoying noise is from aircraft and counterplan they hope is 'airport moving out'. Leq 65 dB(A), the criteria value of sound insulation treatment, was corresponding to the subjective response of median annoyance '4' out of 7th scale.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.972-978
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• 1989

Proposed is improved compact self-mixing type semiconductor-laser range finder, which measures mode-hop time interval (MHI). Measurement error caused by the fluctuation of MHI is greatly reduced by averaging many contiguous MHI's. The main cause of measurement error 1.5% at ranges from 0.1m to 0.8m is attributed to the optical phase change of a returned light from a focusing lens. Accuracy improvement by stabilization of the returned light is suggested.

• 한국지형공간정보학회:학술대회논문집
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• 2005.08a
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• pp.51-59
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• 2005

With industrial development, industrial products became more refined and upscale, resulting in increased necessity for manufacturers to come up with a method to check whether products have been produced to meet the needs of the customer. For thisreason, attention was drawn to industrial photogrammetry to obtain data rapidly without contacting the target object. In this study, the experiment has been conducted with the O-2A aircraft to determine the applicability of industrial photogrammetry.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.900-904
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• 2005

Studies of community annoyance caused by civil aircraft noise exposure were carried out in fifteen areas near Gimpo and Gimhae international airports, Korea, to accumulate social survey data in Korea and to assess the relationship between aircraft noise level and degree of annoyance. Aircraft noise levels were measured automatically by airport noise monitoring system, B&K type 3597. A social survey was carried out people living within In meters of noise measurement points, as a rule. Questionnaires were only aggregated face-to-face interviews using various questions which concerned with demographic, degree of noise annoyance, interference with daily activities and health-related symptoms. The questions of noise annoyance were answered on an 11-point numerical scale. The respondents, from 18 to 70 years of age, were randomly selected and completed the questionnaire themselves. The total number of respondents for the questionnaires was 554.