• Journal of Institute of Control, Robotics and Systems
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• v.15 no.10
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• pp.1021-1028
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• 2009

In this paper, a location identification for a cleaning robot using a camera shooting forward a room ceiling which kas three point landmarks is introduced. These three points are made from a laser source which is placed on an auto charger. A fisheye lens covering almost 150 degrees is utilized and the image is transformed to a camera image grabber. The widly shot image has an inevitable distortion even if wide range is coverd. This distortion is flatten using an image warping scheme. Several vision processing techniques such as an intersection extraction erosion, and curve fitting are employed. Next, three point marks are identified and their correspondence is investigated. Through this image processing and image distortion adjustment, a robot location in a wide geometrical coverage is identified.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.9
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• pp.142-150
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• 2002

This study describes a method of finding an optimal path of a soccer robot by using a concentric circle method with different radii of rotation. Comparing with conventional algorithms which try to find the shortest path length, the variable concentric circle method find the shortest moving time. The radius fur the shortest moving time for a given ball location depends on the relative location between a shooting robot and a ball. Practically it is difficult to find an analytical solution due to many unknowns. Assuming a radius of rotation within a possible range, total path moving time can be calculated by adding the times needed for straight path and circular path. Among these times the shortest time is obtained. In this paper, a graphical solution is presented such that the game ground is divided into 3 regions with a minimum, medium, and maximum radius of rotation.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.442-451
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• 2015

Smartphone users are 15 billion in all round the world, and Korean smartphone users are estimated at 40million people to 83% of the Korean population. Selfie stick is most popular item among 20, 30's age users. And they use smartphones more than 90%. In survey they express inconvenience of using selfie stick. Inconveniences are as follows. * Heavy * Handle is inconvenient. * Mistiming during taking pictures * the range of shooting is not enough. In this paper the first improvement was that rod strength is slightly stronger. The second we divide a grip into 3 parts. If 3 parts are unfolded, these can use for tripod. We use deflection Interpretation for main Finite Elements Method program.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.143-146
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• 2011

2009년 11월 14일 발생한 부산 실내사격장 화재와 관련하여 조사내용을 토대로 화재 시뮬레이션용 전선유체역학 모델인 FDS를 이용하여 재현하였으며, 시뮬레이션 결과와 화재당시 녹화된 CCTV 영상을 비교하였다. 2층 발사실에서 시작된 화재는 급격히 연소가 진행되어 약 3초 후에 휴게실로 확산되며, 약 7초 후에는 계단 및 1층 홀을 지나 사람들이 통행하는 인도에까지 연기가 분출되는 것으로 나타났다. 시뮬레이션 결과는 2층 발사실과 휴게실에 녹화된 CCTV 영상 및 1층 홀 옆의 귀금속가게에 녹화된 CCTV 영상과 거의 일치하였다.

• CDE review
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• v.21 no.2
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• pp.27-30
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• 2015

Smartphone users are 15 billion in all round the world, and Korean smartphone users are estimated at 40million people to 83% of the Korean population. Selfie stick is most popular item among 20, 30's age users. And they use smartphones more than 90%. In survey they express inconvenience of using selfie stick. Inconveniences are as follows. * Heavy * Handle is inconvenient. * Mistiming during taking pictures * the range of shooting is not enough. In this paper the first improvement was that rod strength is slightly stronger. The second we divide a grip into 3 parts. If 3 parts are unfolded, these can use for tripod. We use deflection Interpretation for main Finite Elements Method program.

• Structural Engineering and Mechanics
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• v.56 no.3
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• pp.461-472
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• 2015

In this paper, the nonlinear static response of curled cantilever beam actuators subjected to the one-sided electrostatic field is focused on. By assuming the deflection function of electrostatically actuated beam, analytical approximate solutions are established via using Galerkin method to solve the equilibrium equation. The Pull-In voltages which determine the stability of the curled beam actuators are also obtained. These approximate solutions show excellent agreements with numerical solutions obtained by the shooting method and the experimental data for a wide range of beam length. Expressions of these analytical approximate solutions are brief and could easily be used to derive the effects of various physical parameters on MEMS structures.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.2
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• pp.382-390
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• 1992

The problem of natural convection from a vertical fin is solved by coupling the thermal diffusion equation in the fin to the constitutive equations of the ambient medium involving the radiation of the medium. The analysis is accomplished by employing an integral method. The governing equations for the problem are solved by shooting method based on the Runge-Kutta Scheme at Pr= 0.7. For the range of values of the fin parameter and the radiation-conduction parameter in the analysis, the numerical results show that the radiation effects play an important role in the heat transfer and enhance the heat transfer.

• 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.

• Journal of Sensor Science and Technology
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• v.28 no.5
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• pp.318-322
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• 2019

In shooting training, an impact point identification system that uses the impact wave of the bullet to check the impact point in the target plate has been recently used. Acoustic sensors used in these systems must be able to detect shock waves of high sound pressure levels and be both waterproof and dustproof for rainy weather and dusty environments, respectively. In this study, membranes with excellent waterproof, dustproof, and sound transmitting characteristics were selected through a characteristics test; a protection cap was installed to install the selected materials. After coupling the produced protection cap to the acoustic sensor housing, the sensitivity and phase characteristics of the acoustic sensor were checked. Through the waterproof and dustproof test, the performances of its sensitivity and phase characteristics were confirmed. Finally, the normal shockwave of a 5.56 mm diameter bullet was measured using a shockwave detection signal collecting plate equipped with a prototype of the acoustic sensor at a 100 m firing range.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.12
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• pp.1084-1093
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• 2017

As the survivability of an aircraft in the battlefield becomes a critical issue, there is a growing need to improve the survivability of the aircraft. In this study, the survivability of an UCAV associated with plume IR signature was investigated. In order to analyze the survivability of the aircraft, the lock-on range and the lethal envelope, defined as the IR detection distance of the aircraft and the range of shooting down by the missile, respectively, were first introduced. Further, a method to calculate the lethal envelope for the scenario of surface-to-air missiles including the vertical plane was developed. The study confirmed that the red zone of an UCAV shows a substantial difference in the zone size as well as the characteristics in the upward and downward directions.