• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.11
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• pp.1008-1015
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• 2015

Thermal vacuum test should be performed prior to launch to verify satellites' functionality in extremely cold/hot temperatures and vacuum conditions. A thermal vacuum chamber used to perform the thermal vacuum tests of a satellite system and its components. A cryogenic blower is a core component of the gaseous nitrogen (GN2) closed loop thermal control system for thermal vacuum chambers. A final goal of this research is development of cryogenic blower. Design requirements of a blower are 150 CFM flow rate, 0.5 bara pressure difference, hot and cold temperatures. This paper describes the performance analysis of impeller by 1D, CFD commercial software, the design of the thermal protection interface between the driving part and the fluid part. The performance of the cryogenic blower is confirmed by test at the standard air condition and is verified by on the thermal vacuum chamber at the real operating condition.

• Journal of Aerospace System Engineering
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• v.14 no.spc
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• pp.49-55
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• 2020

The average probability of a lightning strike to transport aircraft operating in airline service has been estimated to be approximately one strike in every year (or one strike per 1,000 through 20,000 flight hours). The important thing is not the probability of a lightning strike to aircraft, but the fact that aircraft is struck by lightning. Therefore, lightning protection design for aircraft should be qualified and compliance with airworthiness standards related to lightning protection must be substantiated in the process of certification. In this paper, I studied means of compliance for lightning protection through analysis of some test cases, including the KC-100 airplane that firstly obtained civil type certificate in Korea. Based on this paper, it will be also necessary to study on the effect of lightning for space launch vehicles.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.4
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• pp.523-536
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• 2013

A recent air defense missile system is required to have a capability to intercept short-range super-high speed targets such as tactical ballistic missile(TBMs) by performing engagement control efficiently. Since flight time and distance of TBM are very short, the missile defense system should be ready to engage a TBM as soon as it takes an indication of the TBM launch. As a result, it has to predict TBM trajectory accurately with cueing information received from an early warning system, and designate search direction and volume for own radar to detect/track TBM as fast as it can, and also generate necessary engagement information. In addition, it is needed to engage TBM accurately via transmitting tracked TBM position and velocity data to the corresponding intercept missiles. In this paper, we proposed a method to estimate TBM trajectory based on the Kepler's law for the missile system to detect and track TBM using the cueing information received before the TBM arrives the apogee of the ballistic trajectory, and analyzed the bias of prediction error in terms of the transmission period of cueing data between the missile system and the early warning system.

• Journal of the Korea Society of Computer and Information
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• v.11 no.4 s.42
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• pp.35-45
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• 2006

RIn this paper. we describe real-time parallel processing simulator developed for the use of performance analysis of rolling missiles. The real-time parallel processing simulator developed here consists of seeker emulator generating infrared image signal on aircraft, real-time computer, host computer, system unit, and actual equipments such as auto-pilot processor and seeker processor. Software is developed according to the design requirements of mathematic model, 6 degree-of-freedom module, aerodynamic module which are resided in real-time computer. and graphic user interface program resided in host computer. The real-time computer consists of six TI C-40 processors connected in parallel. The seeker emulator is designed by using analog circuits coupled with mechanical equipments. The system unit provides interface function to match impedance between the components and processes very small electrical signals. Also real launch unit of missiles is interfaced to simulator through system unit. In order to use the real-time parallel processing simulator developed here as a performance analysis equipment for rolling missiles, we perform verification test through experimental results in the field.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.4
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• pp.298-307
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• 2019

The evolution of the cavity and the variation of the drag for an underwater body with control fins are investigated through a numerical analysis of the steady cavitating turbulent flow. The continuity and the steady-state RANS equations are numerically solved using a mixture fluid model for calculating the multiphase turbulent flow of air, water and vapor together with the SST $k-{\omega}$ turbulence model. The method of volume of fluid is applied by the use of the Sauer's cavitation model. Numerical solutions have been obtained for the cavity flow about an underwater body shaped like the Russian high-speed torpedo, Shkval. Results are presented for the cavity shape and the drag of the body under the influence of the gravity and the free surface. The evolution of the cavity with the body speed is discussed and the calculated cavity shapes are compared with the photographs of the cavity taken from an underwater launch experiment. Also the variation of the drag for a wide range of the body speed is investigated and analyzed in details.

• The Korean Journal of Air & Space Law and Policy
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• v.31 no.1
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• pp.145-167
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• 2016

UN Security Council is entitled to power for determining the existence of the threat to the peace. Specifying the provisions adopted in accordance with the chapter 7 of the UN Charter, its resolution is deemed as document confirming its decision about the threat to the peace. In general, resolutions adopted by the Security Council acting under Chapter VII of the Charter, are considered binding, in accordance with Article 25 of the Charter. Regarding to the terms of the Resolutions to be interpreted, the word "decide" is used as to the suspension of the ballistic missile program, the word "demand" is used as to the stopping of the the launch of ballistic missile, and the word "demand" is used as to return to the missile test moratorium. These provisions may be deemed to determining specific obligations to be imposed upon the States in accordance with the 1967 Outer Space Treaty. On the other hand, the Resolutions may be limited to the decision, not leading to a sort of international legislation, the main purpose of which is to provide a legal basis for international sanctions against Northe Korea. North Korea missile test case has reminded us of continuing discussion about whether the decision of the Security Council lacks the legislative authority due to its decision process. Furthermore, having regard to the outer space and space activities, the outer space law regime would be not compatible with the Security Council decision process in that the former presupposes the agreement among all States parties, while the latter based upon the agreement between Council member States. Therefore, it is premature to consider the Security Council decision as becoming the lex specialis of the space law regime.

• Journal of Aerospace System Engineering
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• v.12 no.3
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• pp.86-96
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• 2018

The High Agility and Remote Control Camera System Can-Satellite ($HA+RC^2S$ CanSat) proposed in this study is a satellite designed by the authors of this work and submitted as an entry in the 2017 CanSat competition in Goheung gun, Jeonnam, Korea. The primary mission of this work is to develop a high agility camera system (HACS) that can obtain high quality images in the air. This objective is achieved by using a tuned mass damper (TMD) to attenuate the residual vibration that occurs immediately after rotating the camera. The secondary objective is to obtain a self-image of CanSat in the air using a remote control self-camera system (RCSS) that is wirelessly controlled using a joystick from a ground station. This paper describes the development process of the $HA+RC^2S$ CanSat, including mission definition, system design, manufacturing, function and performance tests carried out on the ground, and final launch test.

• The Korean Journal of Air & Space Law and Policy
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• v.22 no.1
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• pp.75-103
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• 2007

The purpose of this paper is to suggest to tackle the problem of poor cooperation in space activities, by re-examining the nature of the competitive political environment, and by building up a normative overarching framework, One of the most acute problems that hampers regional cooperation is the U.S. influence as represented in the MTCR, a supplier's cartel, as was evidenced in the ill-fate of the 2001 launch contract between China and Korea the next year. Notably China, the third space power in the world, has not been allowed to join the MTCR despite her application in June 2004. A possible reconciliation between China and the MTCR over her application for a partnership would set a cornerstone in building up a cooperative environment in the Northeast Asia. Just as the Helsinki process was an overarching norm building framework, comprising human rights, security and environmental issues, it would be desirable that a future peace framework in Northeast Asia dealing with the pending issues of Korean peninsula should also comprise of such broad issues as one relating to cooperation in space activities in the region. South Korea could tap expertise from her neighbor China. When South Korea become an independent space power either with her own technology or otherwise, she would be in a better position to play a role as a balancer in coordinating between the two neighboring space giants. It is remarkable that the Japanese led APRSAT has contributed much in establishing Sentinel Asia as a part of the Disaster Management Scheme, in that each participant, whether it be a state agency, or a private entity like a university or a research institute, can tap the common data to contribute to the common good of safety.

• The Korean Journal of Air & Space Law and Policy
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• no.spc
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• pp.59-86
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• 2007

The purpose of this paper is to suggest to tackle the problem of poor cooperation in space activities, by re-examining the nature of the competitive political environment, and by building up a normative overarching framework, One of the most acute problems that hampers regional cooperation is the U.S. influence as represented in the MTCR, a supplier's cartel, as was evidenced in the ill-fate of the 2001 launch contract between China and Korea the next year. Notably China, the third space power in the world, has not been allowed to join the MTCR despite her application in June 2004. A possible reconciliation between China and the MTCR over her application for a partnership would set a cornerstone in building up a cooperative environment in the Northeast Asia. Just as the Helsinki process was an overarching norm building framework, comprising human rights, security and environmental issues, it would be desirable that a future peace framework in Northeast Asia dealing with the pending issues of Korean peninsula should also comprise of such broad issues as one relating to cooperation in space activities in the region. South Korea could tap expertise from her neighbor China. When South Korea become an independent space power either with her own technology or otherwise, she would be in a better position to play a role as a balancer in coordinating between the two neighboring space giants. It is remarkable that the Japanese led APRSAT has contributed much in establishing Sentinel Asia as a part of the Disaster Management Scheme, in that each participant, whether it be a state agency, or a private entity like a university or a research institute, can tap the common data to contribute to the common good of safety.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.1
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• pp.121-146
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• 2018

In traditional international law, a state was internationally responsible only for its activities. With the diversification of the subjects of international law and with the expansion of state's activities, however, bearing international responsibility by the state for its nationals or private enterprises has been recognised in international case law and states practices. Also, this was codified in 2001 by International Law Commission, finishing Draft articles on Responsibility of States for Internationally Wrongful Acts. Yet, international responsibility of state for private entities carrying out space activities including launching of satellites and space launch vehicles has been dealt with as an exception from state responsibility in general international law. As we have seen the successful launching of 'Falcon Heavy' by SpaceX which is an american private entity, the private activities in outer space are expanding to even as far as deep space such as Mars. In other words, the scope of the private activities is too enormous to deal with the activities, irrespective of general theories on state responsibility in international law. Therefore, it will be significant to see the constituent elements of state responsibility for private activities in outer space from the point of general international law, without prejudice to provisions related to international space law.