• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.7
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• pp.595-600
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• 2014

The characteristics of kinetic energy transfer during a collision between a rigid target particle on a surface and a fragile bullet particle moving at a high velocity were analyzed using molecular dynamics simulation. Bullet particles made of $CO_2$ were considered and their size, temperature, and velocity were varied over a wide range. The fraction of kinetic energy transferred from the bullet particle to the target particle was almost independent of the former's size or velocity; however, it was sensitively dependent on its temperature, which can be attributed to the change in the bullet rigidity with temperature. This fraction was nearly twice as high for $CO_2$ bullets as for Ar bullets. This result explains the reason for the more superior cleaning performance of $CO_2$ bullets than Ar bullets with regard to contaminants in the 10 nm size range.

• Conservation Science in Museum
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• v.28
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• pp.65-88
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• 2022

The characteristics and behavior of bullets are important because they are directly related to the firearm performance. However, research related to bullets have been small. In this paper, scientific analysis was conducted to find out the materials and manufacturing process of metal bullets during the Joseon Dynasty, owned by Korea Army Museum, and the types of firearms available were classified and organized according to the bullet diameter. As a result, bullets were classified into iron bullets, lead bullets, and lead-coated iron bullets. Most of the iron bullets and lead bullets were made from casting. Some iron bullets were made from forging. And the lead-coated iron bullet was made by pouring molten lead after putting the iron bullet into the mold. Finally, the bullets could be used for Hand Cannon, Matchlock Musket, Frankish Cannon, Hyeon-ja Cannon, Dae-Wiwon Cannon, Small Cannon, and Hong-Yi Cannon.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.4
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• pp.114-122
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• 2000

Bullet impact tests for solid rocket motor were performed and its results wert described. Two motors were made of composite and steel for case material, respectively and their reactions to the bullet impact were compared. Throughout the tests it had been tried to setup the procedure of bullet impact test and criteria of the judgment for the reactions.

• KIISE Transactions on Computing Practices
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• v.21 no.7
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• pp.443-451
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• 2015

This paper proposes a signal modelling method that can effectively detect the shock wave(SW) sound and muzzle blast(MB) sound from the gunshot of a small arm rifle. In order to localize a counter sniper in battlefield, an accurate detection of both shock wave sound and muzzle blast sound are the necessary keys in estimating the direction and the distance of the counter sniper. To verify the performance of the proposed algorithm, a real gunshot sound in a domestic military shooting range was recorded and analyzed. From the experimental results, the proposed signal modelling method was found to be superior to the comparative system more than 20% in a shock wave detection and 5% in a muzzle blast detection, respectively.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.1
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• pp.30-38
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• 2002

Bullet impact tests for two solid rocket motors were performed and its results were compared and analyzed. One was loaded with the existing propellant with decreased weight content of burning rate catalyst and added high density additives to improve mechanical properties and the other was loaded with the existing propellant with decreased weight content of burning rate catalyst to improve its insensitivity as well as to maintain the ballistic performance. The composite cases were used for both motors.

• The Journal of the Acoustical Society of Korea
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• v.34 no.1
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• pp.60-65
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• 2015

In this paper, we used the sound of gunshots recorded by multiple microphones to increase the accuracy of the calculation of the distance between sniper and the microphone array. This method is crucial for achieving military objectives. Gunshots are comprised of the explosion of driving gas from the muzzle and the supersonic shock wave from the flying bullet. The original distance calculation method compares the time difference of arrival and angle of incidence to estimate the sniper's location. The disadvantage of this method is that when the angles of incidence coincide the margin of error increases, to solve this problem we suggest a new method using the characteristic changes of the shock wave with the increase of perpendicular distance between the microphone and the trajectory of the bullet. This theory is verified by experiments.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.227-230
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• 2010

본 논문은 부산 실내사격장 화재와 관련하여 급격한 연소 확대 경로 및 발화원인에 대하여 분석하였다. 연소 확대 경로 분석을 위하여 실내사격장에 광범위하게 사용되는 스펀지형 흡음재의 연소실험을 수행하였다. 흡음재 연소 실험은 일반형과 낭연 처리된 흡음재를 대상으로 실시하였으며, 화약잔사 흡착 시, 연소 특성을 평가하였다. 발화원인에 대한 분석을 위하여 총기 사용 과정에서 발생되는 유탄된 탄환의 비산거리 및 크기를 실측하고, 유탄된 탄환에 대한 운동에너지 계산을 통하여 화약잔사와 충격하는 경우, 충분한 발화 가능성이 있음을 확인하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.200-200
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• 2005

• 월간 기계설비
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• no.9 s.194
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• pp.87-88
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• 2006

최근 삶의 질이 향상됨에 따라 쾌적한 환경 추구와 WellBeing 문제가 사회 이슈로 부각되면서 생산라인 및 위생배관에 대한 관심이 높아지고 있다. 그 중에서도 특히 우리가 먹고 마시는 공기와 물은 물론 냉난방과 각종 액체, 가스 통신선 등이 전달되는 통로인 Pipeline 속의 청결은 인체의 건강에 직접적인 영향을 미치므로 더욱 세심한 주의가 요구되고 있다. 조은 시스템은 최근 생산라인 및 건축물 배관 등의 파이프라인을 신개념으로 클리닝하는 시스템을 한국에 도입시켜 파이프클리닝에 새로운 바람이 불 것으로 예상 된다.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.794-798
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• 1990

To improve gun hit probability and to correct miss distance between target and bullet. It assumes that a radar tracks both the targets and bullets fired by a gun system. This papers describes an adaptive algorithm developed for processing the large number of radar measurements. The gun-order computation is enhanced by feedback from the ballistic estimator.