• International Journal of Aerospace System Engineering
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• 제3권2호
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• pp.9-13
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• 2016

This study is about technical analysis in launching SLBM of North Korea. We expect that North Korea develop ICBM and SLBM by improving the technique called R-27. Also it is expected that they attempt to achievement in covertness and ambush by completing technique of cold launching. Recently, SLBM of North Korea rised 40 ~ 50 m on surface after launching in an underwater when they showed the scene of firing SLBM. We expect that they actively use not general technique but super cavitation technique. Also, they might improve the launching technique by doing SLBM launching test. This type is about that whole rocket is separated two parts and ignited with high velocity and we might think that 1st rocket is used in solid propellant to maneuver in high velocity in an underwater. After then, they might use liquid propellant for the long-range ballistic missile.

• PNF and Movement
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• 제7권4호
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• pp.1-7
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• 2009

Purpose : This paper reviews on the method of PNF stretching. Methods : This is literature study with Pubmed, medline, SPORT Discus, EBSCO, ProQuest and books. Results : PNF stretching is effective for increasing range of motion than static and ballistic stretching. CR(contract-relax) technique is effective and CRAC(contract-relax with agonist contraction) technique including agonist contraction is more effective. A minimum of one repetition, twice or three times per week is required for range of motion gains, needs to be conducted continueously. A minimum of 20% contraction intensity and more than 3 seconds contraction duration are needed to increase range of motion. Inclusion of static stretching of antagonist and agonist contraction is more effective. Conclusions : PNF stretching is more effective for increasing range of motion than other stretching methods, but, clinicians need to select proper techniques according to subjects and muscles, and conduct carefully when applying technique.

• 한국군사과학기술학회지
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• 제16권4호
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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.

• 한국군사과학기술학회지
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• 제27권3호
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• pp.355-363
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• 2024

This study proposes a method for determining the optimal target size for an artillery range considering ballistics and environmental conditions. To this end, the size of the probable error of each type of ammunition and charge determined during shooting were considered, and the effect of the firing position and target terrain characteristics on the target size was analyzed. In conclusion, the size of the target increased as the range increased, and a larger target size was required for the DPICM than for the general high explosive. Accordingly, the optimal target size must be determined by considering various factors such as topographical characteristics, shooting position location, and shooting range safety standards.

• 융합보안논문지
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• 제16권3_1호
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• pp.107-114
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• 2016

북한은 그동안 핵을 고도화하고 미사일의 발사 거리를 늘려왔다. 북한이 대화를 통해 핵을 포기할 가능성은 이미 사라진 것으로 보인다. 김정은은 중국 특사가 미사일 발사를 말리기 위해 평양을 방문했는데도 비웃듯이 로켓을 쏘아 올렸다. 상황이 이런데도 대화로 문제를 해결할 수 있을 것인가. 한반도 비핵화의 유일한 길은 실효적인 대북제재를 통해 북한이 스스로 핵을 포기하도록 하는 것이다. 이를 위해 중국은 어떤 형태로든 역할을 해야 한다. 한국 내에서는 북한의 핵 미사일 위협에 대한 자위 차원에서 고고도미사일방어체계(사드)의 도입은 물론 핵무장 여론이 높아지고 있다. 이런 흐름은 중국의 전략적 이익에 부합하지 않을 것이다. 본 논문은 북한이 앞으로 어떤 행보를 해 나갈 것인가를 예측하기 위해서는 북한의 '군사정책'이 될 것이라는 가정 하에 김정은 체제의 군사정책 특징을 분석하고 전망하여 의미 있는 시사점을 찾고자 하는데 목적이 있다.

• International Journal of Aeronautical and Space Sciences
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• 제14권2호
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• pp.140-145
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• 2013

The development of high performance fabrics have advanced body armor technology and improved ballistic performance while maintaining flexibility. Utilization of the shear thickening phenomenon exhibited by Shear Thickening Fluids (STF) has allowed further enhancement without hindering flexibility of the fabric through a process of impregnation. The effect of STF impregnation on the ballistic performance of fabrics has been studied for impact velocities below 700 m/s. Studies of STF-impregnated fabrics for high velocity impacts, which would provide a transition to significantly higher velocity ranges, are lacking. This study aims to investigate the effect of STF impregnation on the high velocity impact characteristics of Kevlar fabric by effectively dispersing silica nanoparticles in a suspension, impregnating Kevlar fabrics, and performing high velocity impact experiments with projectile velocities in the range of 1 km/s to compare the post impact characteristics between neat Kevlar and impregnated Kevlar fabrics. 100 nm diameter silica nanoparticles were dispersed using a homogenizer and sonicator in a solution of polyethylene glycol (PEG) and diluted with methanol for effective impregnation to Kevlar fabric, and the methanol was evaporated in a heat oven. High velocity impact of STF-impregnated Kevlar fabric revealed differences in the post impact rear formation compared to neat Kevlar.

• 한국CDE학회논문집
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• 제19권4호
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• pp.316-323
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• 2014

This paper proposes the 3D modeling and simulation technique for predicting the integrated performance of combat vehicle. To consider the practical driving and firing condition of a combat vehicle, the full vehicle model, which can define the six degrees-of-freedom of vehicle motion and various firing angles, is developed. The critical design parameters such as the stiffness and damping coefficient of suspension system are applied to construct the analysis model of vehicle. A simple ballistic model, which incorporates the empirical interior ballistic model and the point mass trajectory model, is built to estimate the firing range and the firing recoil force. To predict the integrated performance and analyze the effect of system parameters, MATLAB/SIM-ULINK model of a combat vehicle for performing the real time simulation is also developed. Several simulation tests incorporating the road bump and the firing recoil force are presented to confirm the effectiveness of the proposed vehicle model.

• 한국군사과학기술학회지
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• 제13권6호
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• pp.1051-1057
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• 2010

Database for the damage reference by armor piercing bullet test was established for both tube and plate specimens having a range of thickness. As the inclined angles of hit are increasing, it has been found that penetration damage diameter tends to increases accordingly in both specimen of the tube and plate, and such penetration damage diameter on the rear side becomes bigger than those on the front side. The tube specimen showed that the damage becomes bigger when central areas rather than the peripheral were hit. Through the plate test, it also has been found that the penetration ballistic limit for Al alloy is about 25.4mm and that of stainless steel about 12.7mm. From the fatigue analysis results using the database for damage reference, it has been identified whether the safety requirements of military aircraft could be met.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제4권11호
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• pp.361-368
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• 2015

대공화기사격통제장치에서 유효사거리는 정지한 표적에 대해 충분한 파괴력을 가질 수 있도록 탄속이 음속 이상을 유지하는 거리로 정의되고 있다. 접근하는 표적은 탄과 표적 간 상대속도가 증가하므로 실질적인 교전 사거리는 위의 유효사거리보다 더욱 연장된다. 그러나 기존에 제시된 TOF 계산식은 유효사거리 내에서만 정확하고 유효사거리를 벗어나면 정확하지 못하다. 본 논문은 교전사거리를 보장할 수 있도록 유효사거리 내에서와 유효사거리 밖에서도 충분한 정확도를 가진 실시간 처리가 가능한 탄자비행시간 계산 기법을 제시한다. 시뮬레이션을 통해 30미리 대공 탄에 대한 본 논문의 유용성을 보인다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.177-180
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• 2010

고압관, 가압관, 발사관으로 구성된 Ballistic Range의 일종인 2단식 경가스 총을 사용하여 초음속 액체 제트의 분무 특성을 연구하였다. 135 bar의 압축공기는 고압관과 가압관 사이에 OHP필름으로 구성된 격막을 파열시킨 후 가압관의 발사체를 약 250 m/s의 속도로 가속하였다. 가속된 발사체는 액체 저장부에 충돌하여 액체를 초고압으로 가압한 후 초음속으로 분사시키며, 특히 초음속 액체 제트는 미립화된 다중 제트의 형태를 나타내고 액체 제트 전방 영역에서 충격파를 수반한다. 다양한 분사 노즐의 기하학적 형상에 대한 분무시험결과 초음속 액체 제트의 속도와 충격파 각도가 각각 다르게 생성되었으며, L/d가 9.9, 11.9, 23.8의 조건에 대하여 L/d가 23.8의 경우에 액체 제트의 분사속도가 마하수 1.53으로 가장 낮게 측정되었다.