• Defense and Technology
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• no.2 s.228
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• pp.38-47
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• 1998

현대전 및 미래전에서 전쟁의 승패를 좌우하는 것이 첨단 무기체계라는 점을 고려하면, 국가 방위력의 개선 방향은 국방력의 양적 증가보다, 군을 과학 기술군으로 전환하는 방향으로 추진되어야 한다는 점에서 첨단 기술 확보 위주의 국방 전략 추진이 필요할 것이다.

• Defense and Technology
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• no.10 s.272
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• pp.58-63
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• 2001

과거의 전쟁양상과는 달리 미래전은 전자전이 전쟁의 승패에 중추적 역할을 담당하게 될 것이다. 전자전 지원장비인 방탐장비는 주요국가들에게 고유의 모델과 기술로 제작 운용하고 있으며, 해외구입시 기술적 종속 및 정보누출의 위험에 노출될 수 있는 소지가 있다. 이 글에서는 방탐장비의 기본원리와 탐지기법 등 이론적인 설명을 하였으며, 주요 선진국의 방향탐지 장비현황 및 발전추세를 철저히 분석하여 우리 군이 미래전에 대비하여 나아가야 할 방향과 방법을 제시하였다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.98-103
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• 2002

초음파 비가진 시인 상용분무와 초음파가진 시인 개질분무, 간접진동분무, 간접진동 및 개질의 겸용분무의 네가지 경우 모두에서 분무액적의 평균직경 및 SMD가 전 영역에 걸쳐서 노즐 글에서 분무방향으로 멀어질수록 조금씩 증가했으며, 또한 초음파 비 가진시인 상용분무 경우가 초음파 가진 세경우에 비해 크게 나타났다. 초음파 가진 세가지 경우에서는 간접진동 및 개질법 겸용의 경우에서 분무액적의 미세화가 가장 우세하게 나타났다. 이는 초음파가 분무 축방향 전영역에 걸쳐서 분무액적의 미세화에 친화적임을 입증한다. 나. 분무 방향 축에서 반경 방향으로 갈수록 분무 액적의 평균 직경과 SMD는 감소하고 있으며, 반경방향 전 영역에 걸쳐서 상용 분무시의 액적이 가장 크게, 초음파겸용 경우에서 가장 작게 나타나고 있다. 이는 초음파가 분무 내부 전 영역에 걸쳐 액적의 미세화에 친화적임을 증명한다. 다. 분무액적의 크기에 따른 분무 분포도 비교에서 네가지 경우 모두에서 축 방향 거리가 멀수록 분무액적의 크기가 다소 증가함을 보였고, 축에서 반경 방향으로는 분무액적의 크기가 다소 감소함을 보이고 있다. 상용 분무와 초음파 분무의 비교에서 초음파 겸용 가진시는 상용 분무 때 보다 분무 영역 전반에 걸쳐서 미세화가 뚜렷이 우세함을 보였다.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.124-125
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• 2003

레이저 광선이 발명이 된 이래로 레이저 빔을 360도 전 방향으로 발사시키는 광학적 장치의 필요성이 매우 컸으며, 이를 이용한 응용장치가 많이 있다. 그러나, 불행히도 이제까지 레이저 빔을 360도 전 방향으로 발사시키는 광학적인 단일 요소가 개발된 적이 없었다. 이 레이저 빔을 360도 전 방향으로 발사시키는 광학적 장치는 회전거울 혹은 회전 홀로그램을 이용한 것이 고작이었다. 하지만, 이러한 회전식장치는 장치의 복잡성, 회전 모터의 회전축의 오차 등 여러 가지 불편한 점이나, 유지보수의 어려움 등을 가지고 있었다. (중략)

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.206-209
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• 2016

High end commercial communication system, such as contemporary mobile technology (CDMA, LTE, Wi-FI, etc.) and extension of frequency band, may affect the performance of the shipborne electronic support measurement system in modern battle field. In this paper, we suggest a way to improve the performance of electronic warfare system based on direction finding algorithm simulation after discussing the limits of traditional system.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.6
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• pp.887-903
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• 2017

Lots of shallow tunnels are constructed in the mountainous areas where the stress distribution in the ground around tunnel is not simple, also the impact of stress conditions on the longitudinal load transfer characteristics is unclear. The tunnel construction methods and the ground conditions would also affect the longitudinal load transfer characteristics which would be dependant on the displacement patterns of tunnel face. Therefore, in this study, the slope of the ground surface was varied in $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$, and the longitudinal load transfer depended on the deformation conditions of tunnelface (that were maximum deformation on the top, constant deformation, and maximum deformation on the bottom), and the stress distribution at tunnelface. As results, when the tunnelface deformed, the earth presure on the tunnelface decreased and the load at tunnel crown increased. The load transferred on the crown was influenced by the earth presure on tunnel face. Smaller load would be transfered to the wide areas when the slope of ground surface decreased. When the slope of ground surface became larger, the longitudinal load transfer would be smaller and would be concentrated on tunnelface, In addition, the shape of the transferred load distribution in the longitudinal direction was dependant on the deformation shape of tunnelface. The deformation shape of tunnelface and stress conditions in longitudinal sections would affect the shape and the magnitude of the load transfer in the longitudinal directions.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.487-497
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• 2016

If a tunnel is excavated, the released stress is redistributed in the ground around the tunnel face, which lead the stress state of the surrounding ground of the tunnel and the load acting on the tunnel support to change. If the tunnel face deforms, the ground ahead of it is relaxed, and the earth pressure acting on it decreases. And if the displacement increases so much that, the ground ahead of the tunnel face reaches in failure state. At this time, load would be transferred longitudinally in the tunnel, depending on the cover and the face deformations. The longitudinal load transfers in the tunnels induced by the tunnelling has been often studied; however, the relation between the deformation of the tunnel face and the longitudinal load transfer was rarely studied. Therefore in this study assesses the characteristics of the longitudinal load transfer as the face was failed by displacement by conducting a model test in a shallow tunnel. In other words, the longitudinal load transfer of the tunnel with the progress of the face deform was measured by conducting a model test, beginning at the state of earth pressure at rest. As results of this study, most of the longitudinal load transfers occurred drastically at the beginning of the displacement of the tunnel face, and as the displacement of the face approached the ultimate displacement, it converged to the ultimate displacement at a gentler slope. In other words, when the ground ahead of the tunnel face was still in an elastic state, the longitudinally transferred load increased sharply at the beginning stage but it tended to increase gradually if it approached to the ultimate limit. Thus, it was noted that the earth pressure in the face and the longitudinal load transfer of the tunnel had the same decreasing tendency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.756-763
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• 2015

NAVWAR (NAVigation WARfare) such as an integral part of EW (Electronic Warfare) for making navigation systems malfunctioning expands rapidly in the future military warfare. First of all, Navigation systems of ground radio and satellite were investigated. And the definition of NAVWAR and vulnerability related to GNSS were analyzed. As a result, we propose the development direction for future navigation system such as constructing eLoran system, developing an integrated receiver, establishing alert steps of watch system, and so on.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.3
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• pp.300-304
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• 2015

This paper presents an omnidirectionally beam-steerable orthogonal loop resonator for wireless power transfer. The resonator is composed of two orthogonal loops. These connections of two loops and the current direction on the loops are determined by the control of switch. The magnetic field direction is determined by the vector sum of each loop current. The beam is steerable to eight directions by four switch modes. Using the suitable switch mode, the simulation and measurement efficiencies in the whole azimuthal direction are 56.3~60.0 %(deviation 3.7 %) and 41.2~48.7 %(deviation 7.5 %), respectively. The results show a little variation of transmission efficiency in the azimuthal direction.

• Journal of Internet Computing and Services
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• v.12 no.6
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• pp.139-147
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• 2011

We proposed the secure and efficient passive RFID protocol which is based on one-way hash based low-cost authentication protocol (OHLCAP). The paper introduces OHLCAP and the vulnerabilities of OHLCAP and suggests security solutions by analyzing them. Afterwards, The paper presents the proposed protocol and demonstrates computational performance and security of the protocol. This protocol not only has the resistances against eavesdropping attack, impersonation attack, desynchronization attack, and replay attack but also provides untraceability and forward secrecy.