• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.5
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• pp.367-375
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• 2017

RANS computational analysis was performed on the head of the launch vehicle including the hammerhead nose pairing in the supersonic regime. The two-dimensional axisymmetric analysis was performed by using laminar, fully turbulent and transition models and compared with the experimental data. It was observed that different flow phenomena occurred depending on the Reynolds number. Under the high Reynolds number condition, the boundary layer becomes turbulent, which is not separated from the surface of the launch vehicle. With the low Reynolds number condition, laminar separation bubble was produced due to the separation and reattachment of the boundary layer on the expansion-compression edge of the hammerhead type nose fairing. The three-dimensional computations with the angle of attack showed a fully detached vortical structure due to the laminar separation bubble. It is proved that the turbulent transition should be considered to predict the separation bubble with the Reynolds number.

• Journal of Satellite, Information and Communications
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• v.7 no.1
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• pp.86-91
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• 2012

This paper described validation results of COMS Ka band antennas beam coverages which were developed by ETRI. After satellite launch, In Orbit Test(IOT) activities are stat to check spacecraft and payloads are still in healthy condition after launch. During IOT phase, ETRI measured radiation patterns of COMS Ka band antennas and compare with ground test(CATR) results. The antenna patterns similarity between IOT results and CATR results show that COMS Ka band antenna withstand launch vibration and in the good healthy condition. After IOT, ETRI performed field test for beam coverage measurements with vehicle to check if Ka band beam coverage are formed well as designed. For the beam coverage measurement, 17 points were selected over the Korean peninsula. The field measurement data were very similar with CATR data and this confirms that beam coverage are formed well over the Korean peninsula as expected.

• Computational Structural Engineering
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• v.17 no.1
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• pp.25-33
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• 2004

쉘은 곡률을 가지는 얇은 구조물로 정의된다. 자동차를 비롯하여 항공기, 우주 발사체, 인공위성, 선박 등의 운송수단과 건축물의 돔(done)과 같이 공간을 효율적으로 활용하고 동시에 경량화를 확보할 필요가 있는 경우에 쉘은 널리 사용되는 구조물이다. 쉘 이론은 1960년대까지는 전문가의 영역에 속해 있는 학문이었고 구조역학을 전공한 사람들에게도 다루기 어 려운 구조물로 인식되어 왔다. 실제 다양한 쉘의 거동은 역학과 수학의 폭넓은 지식을 요구하고 학문으로서도 그 속에서 평생을 보낼 만큼 매력적이고 어려운 부분들을 포함하고 있다고 생각된다.(중략)

• 시스템엔지니어링워크숍
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• s.6
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• pp.121-125
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• 2005

전차탄의 철갑기술과 전차의 방호기술의 경쟁적인 연구개발로 성능이 지속적으로 발전되면서 전차방호면에서는 피탄되기전에 탄을 인식하여 파괴하는 능동파괴장치로,대전차 기술면에서는 취약한 전차의 상부를 발사후 망각개념의 지능탄으로 타격하는 기술로 발전되고 있다. 본 논문에서는 군사선진국들이 개발중인 전차포 지능찬의 특성을 조사하고 새로운 체계모델을 설정하여 비교상쇄연구를 수행하였으며, 향후 무기체계로의 가용성을 분석하였다.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.3
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• pp.151-208
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• 2020

Japan's two outer space-related laws were promulgated on November 16, 2016. There are the Act on Launching of Spacecraft, etc. and Control of Spacecraft (Act No. 76 of 2016, Space Activities Act) and the Act on Securing Proper Handling of Satellite Remote Sensing Records (Act No.77 of 2016, Remote Sensing Records Act). Japan's Space Activities Act states that a person who launches a satellite from the territory of Japan, or from a ship or airplane registered in Japan, must obtain permission from the Prime Minister prior to the launch. To obtain the permission, the person must have a certificate for a rocket design and for radio equipment at a launching facility. In addition, the ability to launch a rocket safely and the purpose for the satellite launch must be evaluated. Managing a satellite from Japan also requires permission from the government. A person who launches a rocket must have insurance for any potential damage arising from accidents, and the government is to supplement the potential compensation to allow for damage that cannot be covered by private insurance. The purpose of this paper reviews regulations of launch services and management of satellites in the Japan's Space Activities Act. It also offers some implications and suggestions for regulations of launching of spacecraft and management or operation of satellites.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.8
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• pp.631-638
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• 2018

In this paper, we propose a method to improve the performance by guidance technique and applying it to the precision guided ammunition. The proposed method is a technique designed to reduce the target error of ammunition by reducing the projectile error without analyzing the motion characteristics of the shot. This technique is applied to the moving average filter technique which is widely used as signal processing technique to reduce the fluctuation of the output of the inboard mounting inertial sensor caused by the rotation and the coning motion of the ammunition. In order to compare the performance of the applied technique including the simple 3D guided control technique and the proposed improvement technique. It is confirmed that the application of this technique improves the accuracy of impact of the cannon - launched ammunition with severe environmental conditions and irregular motion characteristics unlike the missile.

• The Korean Journal of Air & Space Law and Policy
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• v.26 no.1
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• pp.177-213
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• 2011

The purpose of this paper is to research on the liability and cases for space damage with reference to the space activity under the international space treaty and national space law of major countries. The United Nations has adopted two treaties relating to the liability for space damage as follows: the Outer Space Treaty of 1967 and the Liability Convention of 1972. Korea has enacted the Outer Space Damage Compensation Act of 2008 relating to the liability for space damages. The Outer Space Treaty of 1967 regulates the international responsibility for national activities in outer space, and the national tort liability for damage by space launching object. The Liability Convention of 1972 regulates the absolute liability by a launching state, the faulty liability by a launching state, the joint and several liability by a launching state, the person claiming for compensation, the claim method for compensation, the claim period of compensation, the claim for compensation and local remedy, the compensation amount for damage by a launching state, and the establishment of the Claims Commission. The Outer Space Damage Compensation Act of 2008 in Korea regulates the definition of space damage, the relation of the Outer Space Damage Compensation Act and the international treaty, the non-faulty liability for damage by a launching person, the concentration of liability and recourse by a launching person, the exclusion of application of the Product Liability Act, the limit amount of the liability for damage by a launching person, the cover of the liability insurance by a launching person, the measures and assistance by the government in case of occurring the space damage, and the exercise period of the claim right of compensation for damage. There are several cases with reference to the liability for damage caused by space accidents as follows: the Collision between Iridium 33 and Cosmos 2251, the Disintegration of Cosmos 954 over Canadian Territory, the Failure of Satellite Launching by Martin Marietta, and the Malfunctioning of Westar VI Satellite. In the disputes and lawsuits due to such space accidents, the problems relating to the liability for space damage have been settled by the application of absolute(strict) liability principle or faulty liability principle. The Liability Convention of 1972 should be improved as follows: the clear definition in respect of the claimer of compensation for damage, the measure in respect of the enforcement of decision by the Claims Commission. The Outer Space Damage Compensation Act of 2008 in Korea should be improved as follows: the inclusion of indirect damage into the definition of space damage, the change of the currency unit of the limit amount of liability for damage, the establishment of joint and several liability and recourse right for damage by space joint launching person, and the establishment of the Space Damage Compensation Review Commission. Korea has built the space center at Oinarodo, Goheung Province in June 2009. Korea has launched the first small launch vehicle KSLV-1 at the Naro Space Center in August 2009 and June 2010. In Korea, it will be the possibility to be occurred the problems relating to the international responsibility and the liability for space damage in the course of space activity. Accordingly the Korean government and launching organization should make the legal and systematic policy to cope with such problems.

• Atmosphere
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• v.22 no.4
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• pp.489-497
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• 2012

Recently released a top secret document explicitly shows that the early development plan for an earth observation satellite in the USA has a hidden and more important purpose for a concept of 'free space' than the scientific purpose. At that time, the hidden and secret concept imbedded within the early space development plan prevail other national policies of the USA government for purpose of the national security. Under these circumstances, it is quite reasonable to accept a possibility that the meteorological satellites which play a key role in the every area of meteorology and climatology was also born for the hidden purposes. Even it is so, it is quite amazing that the first meteorological satellite is launched in the USA despite of the facts that the major users of the meteorological satellites were not very enthusiastic with the meteorological satellite and the program was not started as a formal meteorological satellite project. This was only possible because of the external socio-political impact caused by the successful launch of the Russian Sputnik satellite and a few key policy developers who favored the meteorological satellite program. It is also interesting to note that the beginning of the first Korean meteorological satellite program was initiated by a similar socio-political influence occurred by the launch of a North Korean satellite.

• Bulletin of the Korean Space Science Society
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• 1993.04a
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• pp.7.1-7
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• 1993

위성의 정밀 거리 결정을 위해 1993년 9월 5일부터 IS일간 중국의 상해 천문대 Sheshan관측소와 장춘 인공위성 관측소에서 LAGEOS 11 (Laser Geodynamics Satellite II)에 대한 SLR (Satellite Laser Ranging) 관측을 수행하였다. SLR 관측에서는 지상의 관측소에서 발사한 LASER 펄스 (pulse)가 반사경들(retroflectors)로 둘러싸인 인공위성에 반사되어 돌아오는 RTT (Round Trip Time)를 측정하여 위성까지의 거리를 결정하는데, 관측된 시간과 거리 자료는 많은 잡음(noise)를 포함하고 있기 때문에 정확한 자료를 얻기 위해서는 많은 보정이 필요하다. 관측된 시간, 거리 자료를 지상 목표물 조준(ground target ranging )에 의한 system보정, 원자시계와 GPS에서 수신된 시간과의 시간 비교, 측정된 온도, 기압, 상대 습도에 따른 대기 영향의 보정 등을 통해 오차를 줄이고 다시 LASERF beam의 대기 굴절에 따른 거리 변화 보정, 위성의 질량 중심 거리(offset) 보정, 조석력에 의한 변화값 보정, 전자기적 지연(electromagnetic delay)에 의한 상대론적 보정등을 통해서 정밀한 거리 자료를 얻었다.

• Bulletin of the Korean Space Science Society
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• 2003.10a
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• pp.51-51
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• 2003

인공위성의 개발 단계는 Prototype Model(PM), Engineering Model(EM), Qualification Model(QM) 그리고 Flight Model(FM)로 구분된다. 이때, Prototype 개발을 제외한 EM, QM, FM 개발단계는 반드시 종합조립시험(AIT)을 통하여 System Integration Test를 수행한다. 이 중에서 위성발사 전 최종 종합조립시험단계인 FM AIT는 위성의 최종시험단계이므로 Scenario Test를 포함한 지상에서 수행하여야 할 모든 시험을 수행한다. 이때, EM, QM 단계와는 다르게 FM AIT는 전기적 및 기계적 시험을 수행하나, 본 논문에서는 전기적 시험 과정과, Control Center 구성도 등을 포함하고 있는 Hardware 부분과, 관련 시험을 수행하게 될 Simulator를 포함한 Software 부분으로 나누어 소개하며, 기타 FM AIT 수행에 필요한 Electrical Ground Support System (EGSE) 전체 구성을 소개한다.