• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.1 s.24
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• pp.72-79
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• 2006

This study was focused on analyzing mathematical model for optimal allocation of surveillance equipment which is operated on the natural geographical condition, such as DMZ fence area. Optimal allocation algorithm was studied for the equipment to develop the whole surveillance and watch model for the two area as testing. Also 3D visualization program was developed to display and analyze the detecting effect. The results show that our suggested model will be available for enhancing security condition on the watching area.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.1 s.20
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• pp.32-38
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• 2005

In this study, Experimental analysis on submarine cable tension was performed for the safe and efficient laying and recovery of a submarine cable. The tension analysis was done through the analyzed data using the cable dynamic theory and the measured data using the experiment. The analyzed cable tension was able to decide requirements for the purpose of laying and recovery of the submarine cable. As the result of tension analysis for a Submarine cable, it was shown a proper feasibility to determine the laying and recovery conditions of the submarine cable.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.2
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• pp.91-102
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• 2002

불연속 전송선로를 해석하기 위한 유용한 방법으로서 유한요소법이나 공간도메인법등과 같은 주파수영역 해석법과 선로제작에 기초한 파라미터 측정법등이 사용된다. 시간영역의 유한차분법은 한번의 모의실험을 통해 주파수 의존적인 파라미터값을 구할수있어 불연속선로를 해석하는데 매우 효과적이다. 본 논문에서는 마이크로 스트립에 기초한 몇가지 형태의 2 포트 불연속 회로망 즉, 케스케이된 스텝 불연속 선로와 레이스트렉 지연선 및 단일 스터브 필터에 대한 정확한 모델링과 해석을 위하여 시간영역의 유한차분법의 적용방법이 논의된다. 2 포트 회로망으로 구성된 평면형 마이크로 스트립 불연속선로를 해석하기 위하여 일반적으로 분산 파라미터에 기초한 해석절차가 사용된다. 주파수 의존적인 분산 파라미터는 시간영역의 유한차분법에 의해 모니터된 입사, 반사 및 투과된 전압으로 부터 고속푸리에 변환을 통해 얻어지고, 또한 그 결과를 공간-스펙트랄 방법 및 모멘트 방법의 결과와 비교함으로써 시간영역의 유한차분법이 다양한 형태의 불연속 선로에 성공적으로 적용됨을 볼 수 있다.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.2
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• pp.217-227
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• 2002

Theoretical and experimental free vibration characteristics of cantilevered laminated composite beams with single or multiple transverse non-propagating open cracks are investigated. The presence of intrinsic cracks in beams modifies the flexibility and in turn free vibration characteristics of the structures, and the existence of the multiple cracks in an anisotropic composite beam affects the free vibration characteristics in a more complex fashion compared with the beam with a single crack. Also the experimental results are well coincide with the numerical results in the decrease of natural frequencies and the transformation of mode shapes because of intrinsic cracks in the composite or aluminum beams. It is revealed that non-destructive crack detection(NDT) or vibration based inspection(VBI) is possible by analyzing the free vibration responses of cracked composite beams.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.2
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• pp.161-168
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• 2012

In this paper, we have experimentally studied on phase characteristics of airborne radome for ELINT directional finding system, because it is difficult to find theoretical solutions for phase error of the radome. Especially, we described the millimeter wave band radome that was fabricated with cyanate-ester material and its thickness was 2mm. We presented the phase error about millimeter band radome. That phase error is about 30 degrees for parallel and perpendicular polarization in the K-Ka band. That is reasonable value for the ELINT directional finding system.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.2
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• pp.177-184
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• 2016

This paper presents a strike velocity estimation using the recursive Bayesian filter that operates both correction and prediction models to probabilistically remove noises of sensors and accurately estimate the strike velocity during the real-time experiments. Four different types of bullets such as 5.56 mm M193, 7.62 mm M80, 5.45 mm 7N10 and 7.62 mm MSC were used to validate the proposed method. Compared to the existing method, the proposed method statistically results in higher stability of the strike velocity estimation as well as its reliability for the ballistic limit velocity computation.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.2
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• pp.188-194
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• 2018

Recently a supercavitating underwater vehicle moving at high speed over 200 knots has been of interest for its practical advantage of the dramatic drag reduction. Many experimental and numerical studies have been explored, however most of the studies deal with the case of uniform flows. In this paper, we investigated physical behaviors of the artificial supercavity in a periodic gust flow. Experiments were carried out at a cavitation tunnel of the Chungnam National University(CNUCT), which is equipped to remove the gas supplied from outside of the tunnel. We devised an experimental apparatus generating vertical and horizontal gust flows, and investigated the supercavity formations at different periodic mode of the incoming flow.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.6
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• pp.1171-1177
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• 2011

A high power laser beam focused on a small area accelerates a thin material that flies and hits other target material in which a shock wave may be induced. This laser induced shock experimental method is more repeatable and cheaper but worse than other experimental method using gas gun or other apparatus. An optical system including a phase zone plate reduces the interference and also makes the focused-beam-intensity distribution uniform. We wrote a computer code that calculates light ray traces. Using the code we designed and fabricated an optical system including a phase zone plate and improved the laser-beam uniformity. We introduce preliminary experimental results of laser induced shock of the samples such as aluminum and other materials.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.6
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• pp.881-888
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• 2013

A basic study was performed to develop a mini gas generator by using a commercial automotive airbag inflater. The mini gas generator can be used for industrial and military application like a seat belt pretensioner. Some parameters were experimentally investigated to reduce the size of the inflater. Basic combustion tests were performed in the closed chamber and measured the pressure and the temperature behavior according to the design parameters. From the study, essential parameters were determined to design a mini gas generator.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.5
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• pp.581-589
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• 2019

Guided missiles assembled with the bolted joint are subjected to various shock loading conditions while flying in the air and operating on the ground or platform. Especially, It is important to analyze the effect of the shock load on the structure because it affects the structure for a short duration time while its acceleration magnitude is quite large. In this study, mechanical shock tests on the structure with the bolted joint have been carried out to measure the acceleration changes of the structure against external shock loads by electrical exciter. Variation of dynamic characteristics of a structure with fastening methods and fastening forces has been investigated through Shock Response Spectrum analysis.