• Proceedings of the KSRS Conference
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• v.1
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• pp.216-219
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• 2006

This paper analyzes on LHGS (LRIT/HRIT Generation Subsystem) processing timeline for COMS LHGS design. The LHGS shall transmit LRIT/HRIT (Low Rate Information Transmission/ High Rate Information Transmission) data to the users within 15 minutes after the end of the image acquisition. So, this paper performs experiment using MTSAT-1R LRIT/HRIT (11 days) and calculates minimum LHGS processing time. Only HRIT FD (Full Disk) image is considered in this paper because data size of HRIT FD image is the largest. As a result of experiment, COMS LHGS should be able to receive MI Level 1B product within 157 seconds at least.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.3
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• pp.388-396
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• 2011

Mission Equipment Package(MEP) system is a collection of avionic components that are integrated to perform the mission of the Korean Utility Helicopter(KUH). MEP system development is classified mission-critical embedded system but KUH MEP system developed including flight-critical data implementation. It is important to establish the good development and verification process for the successful system development. This paper describe the development and verification process in each phase for the KUH MEP system. MEP system design is verified through the qualification test, system failure test and compatibility test in System Integration Laboratory(SIL).

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.5
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• pp.684-696
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• 2018

The mission in missile systems can be conducted with multiple phases according to the characteristics of the systems and the targets. The safeguarded multi-phase mission includes a safeguarded phase before launch for considering the safety of operators in unexpected squib activation. However, the safeguard function should be disabled after launch to complete the mission. Therefore, the squib system needs to be selectively activated according to the phases. This paper presents a selective squib activation and check circuit design for safeguarded multi-phase missions in missile systems. The presented circuit design was implemented with various electronic components including a field-programmable gate array(FPGA). Its functions and performance were validated by both many ground tests and several flight tests.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.4
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• pp.357-367
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• 2008

Preparing for future Korean Lunar missions, preliminary Lunar mission design software is developed using a impulsive thrusting method. Developed software is capable of design and analysis every required mission phases to design Lunar mission, including the Earth departure, Lunar transfer, Lunar arrival and mission operation phases. Also, assuming that KSLV-II is selected as a launch vehicle, future Korean Lunar explorer's mass budget is estimated based on driven optimal trajectory characteristics. Tracking analysis is also performed using Deep Space Network including angle geometry analysis between Earth - Moon - Lunar explorer - Sun which are very important for communication, solar panel pointing strategy and eclipse analysis when Lunar missions are under designing phase.

• Journal of Astronomy and Space Sciences
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• v.37 no.1
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• pp.51-60
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• 2020

This study designs and analyzes satellite formation flying concepts for the Small scale magNetospheric and Ionospheric Plasma Experiments (SNIPE) mission, that will observe the near-Earth space environment using four nanosats. To meet the requirements to achieve the scientific objectives of the SNIPE mission, three formation flying concepts are analyzed: a cross-shape formation, a square-shape formation, and a cross-track formation. Of the three formation flying scenarios, the cross-track formation scenario is selected as the final scenario for the SNIPE mission. The result of this study suggests a relative orbit control scenario for formation maintenance and reconfiguration, and the initial relative orbits of the four nanosats meeting the formation requirements and thrust limitations of the SNIPE mission. The formation flying scenario is validated by calculating the accumulated total thrust required for the four nanosats. If the cross-track formation scenario presented in this study is applied to the SNIPE mission, it is expected that the mission will be successfully accomplished.

• Journal of Aerospace System Engineering
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• v.8 no.1
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• pp.36-41
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• 2014

KAFASAT is a CubeSat which has a high level mission of testing the possibility of establishing the LEO satellite constellation providing the role of communication nodes and quasi-realtime image recognition of battlefield in accordance with the aspect of future-war-environment. The high level mission is developed using the Pugh selection method, which is one of system engineering tools. In order to accomplish the high level mission objectives and deduce engineering level requirements, system engineering tools such as Analytic Hierarchy Process and Quality Function Deployment are used. The subsystem synthesis in the context of system engineering process is done using a developed integrated design environment. The paper also includes the conceptual design results of the KAFASAT, which can be used as a baseline for upcoming preliminary design.

• Journal of Astronomy and Space Sciences
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• v.32 no.3
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• pp.257-268
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• 2015

Characteristics of delta-V requirements for deploying an impactor from a mother-ship at different orbital altitudes are analyzed in order to prepare for a future lunar CubeSat impactor mission. A mother-ship is assumed to be orbiting the moon with a circular orbit at a 90 deg inclination and having 50, 100, 150, 200 km altitudes. Critical design parameters that are directly related to the success of the impactor mission are also analyzed including deploy directions, CubeSat flight time, impact velocity, and associated impact angles. Based on derived delta-V requirements, required thruster burn time and fuel mass are analyzed by adapting four different miniaturized commercial onboard thrusters currently developed for CubeSat applications. As a result, CubeSat impact trajectories as well as thruster burn characteristics deployed at different orbital altitudes are found to satisfy the mission objectives. It is concluded that thrust burn time should considered as the more critical design parameter than the required fuel mass when deducing the onboard propulsion system requirements. Results provided through this work will be helpful in further detailed system definition and design activities for future lunar missions with a CubeSat-based payload.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.10
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• pp.859-870
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• 2021

KARI (Korea Aerospace Research Institute) is developing a design framework for the concept and preliminary design of eVTOL aircrafts. A low fidelity mission analysis tool was developed for the eVTOL aircrafts of Lift-Tilt Concept, which have tilt propellers and lift propellers, using open source SUAVE package. For its development, a review for the propeller performance analysis functionality was made. To find the trim solution at each mission segment automatically, an algorithm is implemented, using a global optimization technique through parallel processings and DOE(design of experiment). Using the tool, the one seated eVTOL OPPAV(optionally piloted personal air vehicle) was modeled and evaluated, which results were compared with the preliminary design data.

• Journal of electromagnetic engineering and science
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• v.2 no.1
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• pp.22-27
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• 2002

This paper describes a SiGe HBT low noise amplifier (LNA) design for IMT-2000 mobile applications. This LNA is optimized for linearity in consideration of the out-of-band-termination capacitance. This LNA yields a noise figure of 1.2 dB, 16 dB gain, an input return loss of 11 dB, and an output return loss of 14.3 dB over the desired frequency range (2.11-2.17 GHz). When the RF input power is -2i dBm, the input third order intercept point (IIP3) of 8.415 dBm and the output third order intercept point (OIP3) of 24.415 dBm are achieved.

• Journal of the Korea Furniture Society
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• v.17 no.4
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• pp.59-83
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• 2006

This article was written in order to understand rockers of today and to provide basic data of their designs and manufacture studying pattern changes in the West. This article contains, the characteristics of the style of the Adirondack rockers, the Mission style rockers in America and the European rockers. Adirondack rockers ($1850{\sim}1940$) were made in various styles out of the mingling of rustic sensibilities with the formalism of Victorian designs. They were Old Hickory chair Co. style, Westport style, bentwood rocker style of two shape and Mottville rocker style. Mission style denoted American furniture design style of the early 20th century especially the work of Gustav Stickley and Roycroft Community. Mission style rockers had a simple, rectilinear style with exposed construction techniques, unpretentious materials (usually oak, with covering of leather, canvas or plain cloth) and little or no decoration. European rockers ($1660{\sim}1918$) have come to mean rockers from the English regional chair, Thonet, J&J Kohn, Henry Van de Velde and Hoffmann. The modernism of modern furniture was affected by the characteristics of the Adirondack rockers, the Mission style rockers and European rockers.