• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.3
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• pp.378-386
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• 2014

In this paper, safety evaluation method simulating battlefield environment was studied to verify military operability of commercial lithium secondary battery. Based on the MIL-STD-2105D and STANAG standards, safety tests of lithium secondary battery module were conducted, such as bullet impact, fragment impact, fast cook-off and slow cook-off. All results satisfied the safety evaluation criteria, founded on military standard. It suggests that the lithium secondary module has high potential to be applied in a military power source. The safety evaluation methods developed in this paper can be valuable to propose the new military standards for commercial lithium secondary batteries.

• ETRI Journal
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• v.28 no.6
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• pp.709-720
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• 2006

In this paper, we suggest a simple and efficient multiple-forwarder-based file distribution method which can work with a tree-based application layer multicast. Existing multiple-forwarder approaches require high control overhead. The proposed method exploits the assumption that receivers join a session at different times. In tree-based application layer multicast, a set of data packets is delivered from its parent after a receiver has joined but before the next receiver joins without overlapping that of other receivers. The proposed method selects forwarders from among the preceding receivers and the forwarder forwards data packets from the non-overlapping data packet set. Three variations of forwarder selection algorithms are proposed. The impact of the proposed algorithms is evaluated using numerical analysis. A performance evaluation using PlanetLab, a global area overlay testbed, shows that the proposed method enhances throughput while maintaining the data packet duplication ratio and control overhead significantly lower than the existing method, Bullet.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.9
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• pp.151-158
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• 2003

The impulse noise of bullet after shooting in small arms has an effect on the hearing ability of human. Although a silencer has been developed for noise reduction in small arms, there is only a few researches about relationships between the sound pressure level and the auditory sense of human. In this study, the quantitative sound pressure levels are revealed by experimental measurements of impulse noise with each silencer type. And the performance evaluation for noise suppression of a silencer in small arms is carried out to reduce a serious loss of the hearing ability of the small arms user. It is concluded that the evaluated results can be utilized for checking sound pressure and data accumulation for new small arms design with silencer.

• Korean Journal of Pharmacognosy
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• v.39 no.3
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• pp.194-198
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• 2008

Artemisia capillaries is a major important food and medicinal resource in Korea. In order to confirm the biological activities of Artemisia capillaries, we investigated antioxidant and anticancer activities from in vitro assays. The Artemisia capillaries methanol (MeOH) extracts was used for the evaluation of DPPH scavenging, total phenolic content, total flavonoid content, hydroxyl radical (${\bullet}OH$) scavenging, reducing power assay as antioxidant activity, as well as anticancer activities as MTT assay. As a result, the Artemisia capillaries MeOH extracts showed potent antioxidative activity and anticancer activity in vitro. These results suggest that the Artemisia capillaries MeOH extracts have a potential alleviated oxidation process, cell motility activity, and tumorigenesis.

• Journal of KSNVE
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• v.8 no.1
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• pp.203-211
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• 1998

In order to find out relationship between hit probability and gun firing of a moving tank, a turret and flexible gun system model has been developed using a recursive flexible multibody dynamics. For a firing simulation model, nodal coordinates for a finite element model of a flexible gun have been employed to include transverse loads to the gun tube due to moving bullet and ballistic pressure. Modal coordinates are also used to represent the motion induced gun vibration before a firing occurs. An efficient switching technique from modal equations to nodal equation has been introduced for an entire gun firing simulation with a rotating turret.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.141-142
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• 2017

기존의 상용화된 인체공학적 자세교정 의자나 의학적 치료 솔루션은 상대적으로 고가이며 사용자친화적인 접근성을 제공하기 어려웠다. 본 논문에서는 이 문제점을 해결하기 위해 소형 방석에 압력 센서를 접목하고 사용자에게 교정 상태를 상기시키는 시스템을 연구하고 이를 더 사용자 접근성이 좋은 방식을 고안하고자 한다. PushBullet[1] API를 사용하여 Non-Client Application 중심의 Multi-Device 기반 Push notification 기능을 연구하고 이와 기존의 바른 앉은 자세를 유지하는 자세교정 시스템을 결합한 방식을 제안한다.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1746-1751
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• 2007

The bullet train runs more than 200km/h so that it is invisible to the naked eye. For this reason, KTX solely dependent on the ATC operation system. Above all things, 'stability' and 'regular time' are essential to Train Control Operation system. But intermittently, there is a signal transmission problem between ATC operation facilities and ground equipments. which is caused by wheel sliding and friction coefficient between wheel and rail when the train starts. This paper analyzed train service data for one year for accurate survey. In addition, this thesis examines the main cause of a signal transmission problem through simulation and experiment. Further, the method to solve the conventional problem is presented.

• Journal of Mechanical Science and Technology
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• v.18 no.12
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• pp.2069-2079
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• 2004

This paper represents the description of a complex mathematical model of biomechanical interaction for human-rifle system during shooting. The model is developed by finite element method using bar elements. And three typical shooting positions, i.e. standing, kneeling and prone are used. Characteristics of interior/exterior ballistics and behaviors of human-rifle system are evaluated by this model, which takes into account the influence of environment, bullet, powder, barrel geometry parameters and anthropological parameters. The results of this study can be applied to anthropology, biomechanics, medical science, gait analysis, interior ballistics and exterior ballistics.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.4
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• pp.630-638
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• 2011

A new smooth bore test barrel was developed to be used in sensitivity assessment test for explosives and fragment impact test. The bore diameter of the barrel is 20 mm, and the powder chamber is designed to be replaceable with the 12.7 mm, 20 mm and 30 mm type chamber. The test results showed the wide range of fragment velocity from 400 to 2000 m/s, included the fragment velocity requirement of the fragment impact test(alternate procedure #1) in MIL-STD-2105B. The stability of the bullet trajectory was checked by test shots and the structural safety of the system has been confirmed through the stress analysis and the interior ballistics analysis of the barrel.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10b
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• pp.218-222
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• 2006

우수한 능력의 인공지능 개체로 구성된 게임은 그렇지 못한 게임에 비해 더 나은 흥미를 사용자에게 제공할 수 있다. 미국 Valve사의 Half-Life, Counter-Strike 및 한국 Dragonfly사의 Special-Force와 같은 실시간 FPS 전투게임에서 상대편에 대한 검색 및 목표 화하는(Targeting) 기법은 인공개체의 전투력에 중요한 하나의 요소이다. 하지만 이 같은 경우의Targeting은 정적인 대상에 대한 것이 아니라 동적인 대상에 대한 것이므로 단순한 산술 계산으로는 실용적인 효과를 내기 힘들다. 본 논문에서는 Neural Network를 이용한 학습기법을 사용하여 동적인 개체에 대한 효과적인 Targeting기법을 제안한다. 제안한 기법은 매 순간 변화하는 상황정보와 Virtual bullet이라는 가상 미사일 개념을 활용하여 학습 Data를 모델링한 후 Neural Network로 학습시켜 효과적인 Targeting이 가능하도록 구현하였다. 제안한 기법은 Java기반의 탱크전투 시뮬레이션 Framework인 Robocode에 적용하여 그 성능을 평가하였다. 제안된 기법으로 제작된 Robot(Crystal 1.0)은 ‘2006 Robocode Korea Cup에서 우승을 차지하였다.