• Advanced Composite Materials
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• v.18 no.3
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• pp.209-219
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• 2009

Carbon nanotubes (CNTs) have shown great potential for the reinforcement of polymers or fiber-reinforced composites. In this study, mechanical properties of multi-walled carbon nanotube (MWNT)-filled plain-weave glass/epoxy composites intended for use in radar absorbing structures were evaluated with regard to filler loading, microstructure, and fiber volume fraction. The plain-weave composites containing MWNTs exhibited improved matrix-dominant and interlaminar fracture-related properties, that is, compressive and interlaminar shear strength. This is attributed to strengthening of the matrix rich region and the interface between glass yarns by the MWNTs. However, tensile properties were only slightly affected by the addition of MWNTs, as they are fiber-dominant properties.

• Journal of Aerospace System Engineering
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• v.9 no.4
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• pp.73-80
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• 2015

For Korean first lunar exploration program, KARI(Korea Aerospace Research Institute) has been researching in various fields and investigating cases of abroad lunar exploration spacecrafts. In the field of the flight software, KARI has been analysing some cases such as NASA LRO, and this paper describes the result of the case study on LRO flight software.

• Journal of Aerospace System Engineering
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• v.8 no.4
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• pp.32-38
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• 2014

Sufficient energy charging during a day is essential for a solar-powered long-endurance aircraft. Variations of flight path that is superior to a basic circle path are sought in this study for more efficient charging. Flight path associated with roll and pitch attitudes are investigated. It seems that the pitch angle can play more important role than the roll angle for the solar charging efficiency. Thus, more energy charging is observed when the entire flight path is tilted toward the direction of the sun.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1183-1187
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• 2003

Five new satellite image interpretation modules are developed. The modules are for: 1) construction of a realistic color image, 2) feature recognition by intensity filtering, 3) removal of spurious spots by next -neighbor count comparison, 4) deviation-amplification filtering, and 5) feature recognition by spectral distribution pattern. The modules were applied to a set of IKONOS images of 8 x 8 km area of the city of Daejeon, Korea, to recognize the distribution of various features such as water resources, playgrounds, forests, etc.

• Journal of Aerospace System Engineering
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• v.9 no.3
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• pp.31-38
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• 2015

Wind Turbines are becoming larger in size in order to improve economic efficiency through cost reduction, such as the construction of growth and power infrastructure of energy efficiency. It have requested the large-scale blade design and production. In the present study the new manufacture technique called a fabric-blade structure using spar, rib, and fabric membrane skin is introduced. The architectural membrane test method has been studied to be applied to the skin of the blade. The density and one-axis tensile tests of the architectural membrane materials are conducted to confirm the physical properties which are necessary to the structural designs and analyses of the wind turbine blade.

• Journal of Aerospace System Engineering
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• v.15 no.2
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• pp.1-9
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• 2021

In this paper, a thickness compensation function is introduced to consider the shear deformation and warping effect resulting from increased thickness in the composite multi-cell wing box. The thickness compensation function is used to perform the structure optimization of the multi-cell. It is determined by minimizing the error of an analytical formula using solid mechanics and the Ritz method. It is used to define a structural performance prediction expression due to the increase in thickness. The parameter is defined by the number of spars and analyzed by the critical buckling load and the limited failure index as a response. Constraints in structural optimization are composed of displacements, torsional angles, the critical buckling load, and the failure index. The objective function is the mass, and its optimization is performed using a genetic algorithm.

• Korean journal of aerospace and environmental medicine
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• v.31 no.1
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• pp.9-12
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• 2021

Aircraft accidents caused by dizziness of aviation workers are so common that they account for 5% to 10% of the total, and in most cases, have fatal consequences. Therefore, it is essential to diagnose and treat the dizziness of aviation workers properly. Common diseases caused by abnormal vestibular function include benign paroxysmal positional vertigo, Meniere's disease, and vestibular neuritis. In this paper, we first proposed an overview of these diseases' pathophysiology, diagnosis, and treatment. Also, we evaluated the importance of these diseases in aerospace medicine and presented aerospace medical dispositions for aviation medical examiners.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.884-887
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• 2023

Recently, research has been actively conducted to overcome the limitations of high-priced single sensors and reduce costs through the convergence of low-cost multi-variable sensors. This paper estimates state variables through asynchronous Kalman filters constructed using CVXPY and uses Cvxpylayers to compare and learn state variables estimated from CVXPY with true value data to estimate filter parameters of low-cost sensors fusion.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.2
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• pp.65-72
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• 2015

Performance tests of a turbopump for the developing 7-tonf liquid rocket engine were conducted. The performance of turbopump components and their power matching were measured and examined firstly under the LN2 and water environment. In the real propellant(LOX and kerosene) environment tests, design and off-design performances of turbopump were fully verified. During the off-design tests, turbopump running time was set the same as engine operating time and pump inlet pressure were set lower than nominal operating value in order to investigate pump suction capability. It have been verified that subject turbopump satisfies required performance - flow rate, head, suction performance and operational time - in the operating regime of developing liquid rocket engine.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.1
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• pp.89-97
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• 2018

The test results of a 7-tonf-class engine for the third-stage engine of KSLV-II are presented. Hot-firing tests performed with two engineering model engines are classified into ground tests and high-altitude tests according to the test conditions. The operability verification of the engines were carried out through short and long duration tests. The full duration test performed for the durability verification of the engines revealed a few of items to be improved. Synthetically, encouraging data of adding power to engine development were obtained from the test results. New engines based on these results will be manufactured and consistently verified through hot-firing tests.