• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.439-441
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• 2015

The ballistic missile is very threatening weapon system because it is difficult to detect and intercept due to fast speed. Recently, many countries worry about North Korea's ballistic missile launching tests especially the success of launching Kwangmyongsong-3 satellite by Eunha-3 long range rocket at 2012. This event means announcement of North Korea have capability to develop ICBM(Intercontinental Ballistic Missile) to all over the world. In this paper, it is surveyed and described that history, types and threat of ballistic missiles.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.349-352
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• 2010

This is conceptual study of vitiated air heater(VAH), the necessary ground test facility, for characteristics studies of scramjet combustion and development of scramjet engines. The VAH is one of various types which provided hot air to an intake or a combustion chamber of scramjet and it must use suitable fuel to get hot combustion gas and more similar mixture gas(vitiated air) to real air. In the study, foreign VAHs being capable of providing very high temperature were researched, and injectors for VAH using LNG(CH4) or hydrogen were designed conceptually to develop scramjet vehicle.

• Aerospace Engineering and Technology
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• v.1 no.2
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• pp.83-90
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• 2002

This paper describes the development of scientific payload system onboard the KSR-III. The ozone detector(UVR), Langmuir electron probe(LEP), airglow photometer(AGP), and magnetometer(MAG) constitute this system. The purpose of the ozone detector is to measure the ozone density profile and the LEP measures the electron density and temperature in the ionosphere over the Korean Peninsula. The AGP detects airglow in the mesosphere over the Korean Peninsular. The MAG provides rocket attitude and the magnetic fluctuation information during the flight. With the developed payloads, the ground calibration tests and the environmental tests have been performed.

• Aerospace Engineering and Technology
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• v.9 no.1
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• pp.17-27
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• 2010

KSLV-I KM plume including alumina particle has been studied using the continuum solver. Alumina particles are assumed to have 7 different diameters, and the specific ratio of the plume gas is assumed to be 1.2, with which the internal nozzle flow characteristics are similar to those of the chemically equilibrium analysis results. The results showed that the expansion angle of the particles is smaller than that of the gas phase, and that the big sized alumina particles are gathered in the plume core and the expansion angles of the big sized particles are smaller than those of the light particles. When the emissivity of the particles are assumed to be 0.1, the radiative heat flux is equivalent to those measured during the flight test of KSLV-I.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.11
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• pp.894-901
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• 2017

In the existence of motion, azimuth phase error due to accuracy limitation of GPS/IMU and system delay is unavoidable and it is essential to apply autofocus to estimate and compensate the azimuth phase error. In this paper, autofocus algorithm using MWLS(Modified WLS) is proposed. It shows the robust performance compared with original WLS using new target selection/sorting metric and iterative azimuth phase estimation technique. SAR raw data obtained in a captive flight test is used to validate the performance of the proposed algorithm.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.2
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• pp.131-138
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• 2009

Analytical modal verification is considered as the process to provide an acceptable description of the subject structure's behaviour. In general, results of original analytical model are different with actual structure results to uncertainty like non-linearity of material, boundary and modified shape, etc. In this paper, the dynamic model of glider's wing is correlated with static deformation and vibration test results by goal-attainment method, multi-objects optimization technique. The structural responses are predicted by using finite element method and optimization is carried out by using the SQP(sequential quadratic programming) method which is widely used in the constrained nonlinear optimization problem. The MAC(Modal Assurance Criterion) is used to modify the mode shapes and quantify the similarity.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.5
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• pp.429-436
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• 2017

Since the telemetry performance using the time-delayed data dissipates the wireless channel resources, we propose the spectral efficient retransmission scheme in this paper. In the proposed scheme, the telemetry data is retransmitted based on triggered memory to improve the spectral efficiency. The proposed scheme minimizes the error caused by multipath fading, antenna pattern as well as the error caused by the flight events. In the flight simulation data, we show the proposed scheme improves the telemetry performance based on spectral efficient retransmission.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.47-52
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• 2004

In the design of scramjet intake for hypersonic flight, a variety of aerothermodynamics phenomena are encountered. These phenomena include blunt leading - edge effects, boundary layer development issues, transition, inviscid / viscous coupling, shock - shock interactions, shock / boundary - layer interactions, and flow profile effects. For intakes that are designed to operate within a narrow Mach number / altitude envelope, an understanding of a few of these phenomena might be required. In this work several predominant flowfield phenomena (viscous phenomena, boundary - layer separation, and combustor entrance profile) are discussed to investigate the performance of the intake at the altitude and angle of attack extremes of the HyShot flight experiment.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.67-75
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• 2019

The laminar burning velocity of endothermic fuel surrogates is measured in this study, in order to investigate combustion characteristics of aviation fuel after being used as coolant in an active cooling system of a hypersonic flight vehicle. A Bunsen burner was manufactured such that the laminar burning velocity can be taken for two types of surrogate fuels, SF-1 and 2. The results showed that the burning velocity of surrogate fuels was faster at high equivalence ratio conditions than that of the reference fuel (RF), and specifically, the velocity of SF-1 had the maximum value at the highest equivalence ratio compared with those of SF-2 and RF.

• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.48-55
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• 2019

This paper presents a study on Fault History Management Equipment (FHME) of Unmanned Aerial Systems (UAS). UAS comprise of various types of electronic equipment for high reliability design for flight safety. Consequently, it is mandatory for each on-board equipment to have its own Built-In-Test (BIT) function, because rapid fault-detections for UAS are necessary. FHME is developed for the purposes of display, storage and management of such BIT results on ground. This paper describes the outline, development requirements, design and verification process of FHME.