• The Korean Journal of Air & Space Law and Policy
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• v.35 no.3
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• pp.127-150
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• 2020

A Basic Plan for the Promotion of Space Development (hereinafter referred to as "basic plan"), which prescribes mid- and long-term policy objectives and basic direction-setting on space development every five years, is one of the matters to be deliberated by the National Space Committee. Confirmed February 2018 by the Committee, the 3rd Basic Plan has a unique matter, compared to the 2nd Basic Plan. It is to construct "Korean Positioning System(KPS)". Almost every country in the world including Korea has been relying on GPS. On the occasion of the shooting down of a Korean Air flight 007 by Soviet Russia, GPS Standard Positioning Service has been open to the world. Due to technical errors of GPS or conflict of interests between countries in international relations, however, the above Service can be interrupted at any time. Such cessation might bring extensive damage to the social, economic and security domains of every country. This is why some countries has been constructing an independent global or regional satellite navigation system: EU(Galileo), Russia(Glonass), India(NaVic), Japan(QZSS), and China(Beidou). So does South Korea. Once KPS is built, it is expected to make use of the system in various areas such as transportation, aviation, disaster, construction, defense, ocean, distribution, telecommunication, etc. For this, a pan-governmental governance is needed to be established. And this governance must be based on the law. Korea is richly experienced in developing and operating individually satellite itself, but it has little experience in the simultaneous development and operation of the satellites, ground, and users systems, such as KPS. Therefore we need to review overseas cases, in order to minimize trial and error. U.S. GPS is a classic example.

• Journal of Aerospace System Engineering
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• v.11 no.3
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• pp.39-46
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• 2017

Required military demands for high reliability of weapons systems throughout stages of life cycles as high technologies combined with weapons systems, research and development continue to drive costs upwards. However, for studies on reliability of national defense weapons systems, empirical research is limited because of a lack of interest or limitations relative to data collection. This study proposes a collection process relative to field operating specifications, based on data relative to experience and management collected by visiting vessels onsite, that operate weapons systems. In addition, after drawing the operating MTBF of the launching system for the Haeseong guided missile launcher, this study compared and analyzed that with values predicted during development and identifies parts with low operating values as compared to predicted values. Results of this study relative to maintenance support troops and weapon systems development companies will contribute to maintaining operational deployment of the launching system of the Haeseong guided weapons system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.4
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• pp.38-43
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• 2002

A study on the test, design and fabrication of wind tunnel model for measurement of air load distribution on wing surfaces is presented. 447 pressure taps are installed normal to the wing surfaces, and measured by PSI-8400 system using total 8 ESPs modules installed in the model. The test was performed at 50 m/sec constant speed in the low speed wind tunnel of Agency for Defense Development. Tests were carried out to determine effects of angle of attack, angle of sideslip and flap and stores for the load distribution of wing. The test results in this paper can be applied to the design optimization of structure and validation of computational fluid dynamics.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.3
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• pp.86-92
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• 2005

Synthetic Aperture Radar is an active sensor utilizing the microwaves in order to get the requested high resolution imageries day or night regardless of the weather conditions. In this paper, the architecture of a real-time system controller for the airborne small SAR system, KOrea Miniature SAR which was developed by Agency for Defense Development is proposed considering the embedded real-time environment. The main purpose of the system controller is to control the internal and the rest of subsystem within SAR system in real-time. The main characteristics of the proposed system controller were implemented using the real-time operating system and the distributed hardware architecture for the small, low weight and real-time operation. The system controller performance and real-time operation were verified and confirmed by the demo flight with the KT-1 airplane.

• Journal of Aerospace System Engineering
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• v.16 no.5
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• pp.49-56
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• 2022

S-STEP is a small SAR satellite mission that monitors time-limited emergency targets and military anomalies in areas of interest, achieving the average revisit in less than 30 minutes by deploying a constellation of 32 satellites in low orbit at an altitude of 510 km. The mission operation mode of S-STEP is divided into normal mode, observation mode, communication mode, and orbit maintenance mode. Further,, the attitude control mode is subdivides into initial detumbling, sun pointing, target pointing, ground station pointing, and thrust direction maintenance. Based on the preliminary mission operational scenario and the satellite's characteristics, this study analyzed the attitude control performance during initial detumbling and observation modes. It verifies that each mode's attitude control accuracy requirements within the time allotted by the scenario of the S-STEP achieved.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.2
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• pp.119-125
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• 2020

A high Reynolds number transonic wind tunnel has been built in 2018 at Agency for Defense Development(ADD). The tunnel has a closed circuit with a 1.5m×1.5m test section and is injection driven from a 140bar air supply system. The Mach number range is 0.3-1.2 with a conventional contracting nozzle and 1.4 with a convergent-divergent contraction. The stagnation pressure range is 100-550kPa at the lowest Mach number. An AGARD-B standard model is tested in the transonic wind tunnel to obtain 6-DOF aerodynamic coefficients. The results are compared with those obtained from ADD trisonic wind tunnel and others. We verify that the transonic wind tunnel become available to develop an aircraft from the testing results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.12
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• pp.971-980
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• 2021

Recently popularized drone technologies have revealed that low-cost small unmanned aerial vehicles(UAVs) can be a significant threat to prevailing power by operating in group or in swarms. Researchers in many countries have tried to utilize integrated swarm unmanned aerial system(SUAS) in the battlefield. Agency for Defense Development also identified four core technologies in developing SUAS: swarm control, swarm network, swarm information, and swarm collaboration, and the authors started researches on swarm control and network technologies in order to be able to operate vehicle platforms as the first stage. This paper introduces design and integration of SUAS consisting of small fixed-wing UAVs, swarm control and network algorithms, a ground control system, and a launcher, with which swarm control and network technologies have been verified by flight tests. 19 fixed-wing UAVs succeeded in swarm flight in the final flight test for the first time as a domestic research.

• Journal of Aerospace System Engineering
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• v.15 no.3
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• pp.57-64
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• 2021

In the study, to minimize the error on guided control of the KV (Kill Vehicle) and to secure the hit-to-kill performance, a position accuracy inspection for the DACS (Divert and Attitude Control System) actuation system was proposed. The accuracy performance of the DACS actuation system is one of the most important factors in the interception of ballistic missiles. In order to validate actuation control accuracy of DACS system, an inspection item was set for position accuracy, and the inspection system was designed for DACS pintle. To measure the absolute position value of the DACS pintle, an external measurement system was developed using laser displacement sensors. The inspection system was designed so that it can be compared with the actuation command in real time. The proposed position accuracy inspection system can be inspected not only in a DACS system but also in missile system level. The position accuracy inspection was performed using the designed inspection system, and analysis of the inspection result.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.66-66
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• 2010

알루미나는 높은 온도에서 열적으로 안정되고 경도가 높으며 내화학, 내마모 특성이 우수하며 또한 강도대비 비중이 낮아 무게를 줄일 수 있다는 장점을 가지고 있다. 이러한 특성으로 인하여 우주항공, 국방, 원자력등 극한의 온도를 견뎌야 하는 고도의 신뢰성이 요구되는 고온구 조물로서 응용이 되고 있다. 특히 알루미나를 휘스커 형태로 만들어 세라믹 복합체에 결합 할 경우 복합체의 기지 내에서 강화재의 역할을 함으로써 취성 파괴를 억제하고 열 전도율 저하등의 이점을 가져올 수 있다. 그리하여 본 연구에서는 알루미나 휘스커를 성장을 위하여 Al-triisoproxide계를 이용하여 화학기상증착법으로 가장 안정된 열적 특성을 가지고 온도의 변화에 따라 상 변화가 일어 나지 않는 알파 알루미나 상을 가지는 알루미나 휘스커를 성장시키기 위한 연구를 하였다. 또한 증착 온도, 압력, 입력기체비등 증착 조건을 변화시켜가면서 알파 알루미나 휘스커의 성장 거동을 살펴 보았다. 증착 조건 변화에 따라 알파 알루미나는 막이 증착되는 부분과 휘스커가 성장되는 부분이 있으며 휘스커의 밀집도와 길이방향, 직경방향 성장등 여러 가지 성장 특성을 달리하였다. 이러한 결과를 바탕으로 증착조건에 따른 알파 알루미나 휘스커 성장영역을 도식화하였다.

• Annual Conference of KIPS
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• 2010.11a
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• pp.1101-1103
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• 2010

과거 인터넷을 사용하지 않는 시스템의 경우 소프트웨어의 안전성과 강건성은 철도, 국방, 우주, 항공, 원자력 등 오류 없이 수행되어야 하는 임베디드 소프트웨어에 국한되어 있었다. 그러나 인터넷의 발전으로 인터넷을 통한 정보의 교류 및 서비스가 증대하면서 소프트웨어의 보안품질은 개인, 사회, 국가 모두에게 정보보호의 중요성을 더욱 강조하고 있다. 특히 오류 없이 수행되어야 하는 고안전성 소프트웨어의 개발 기법은 이제 응용 소프트웨어의 보안강화 활동에 활용 되고 있다. 시큐어 코딩 (Secure Coding)은 방어적 프로그램(Defensive Programming)을 포함하는 개념으로 소프트웨어의 안전성과 보안성을 향상 시킬 수 있다. 본 논문에서는 C 언어의 취약가능성 유발 명령어를 예를 들고 시큐어 코딩 기법을 적용하여 취약한 코드를 개선하였다. 이러한 개선을 통해 보안 취약성 유발 가능한 코드 부분을 손쉽게 수정하여 소프트웨어 보안품질을 개선할 수 있다.