• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.157-158
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• 2011

Golf clubs hit the ball, and golf balls fly with great speed and long distances due to the conflict. In this paper, the size of the momentum after collision of golf clubs and golf balls should seek. Also, the collision times and average force that served of golf clubs and golf balls are obtained. We know that the impulse acting body is equals the change in momentum of a body. And you can see the average force is constant force that the actual strength of a body to give the same impulse instead of force changing by the hour.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.3
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• pp.388-397
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• 2009

There are many tasks which require robotic manipulators interaction with environment. It consists of three control problems, i.e., position control, impact control and force control. The position control means the way of reaching to the environment. The moment of touching to the environment yields the impact control problem and the force control is to maintain the desired force trajectory after the impact with the environment. These three control problems occur in sequence, so each control algorithm can be developed independently. Especially for redundant manipulators, each of these three control problems has been important independent research topic. For example, joint torque minimization and impulse minimization are typical techniques for such control problems. The three control problems are considered as a single task in this paper. The position control strategy is developed to improve the performance of the task, i.e., minimization of the individual joint torques and impulse. Therefore, initial conditions of the impact control problem are optimized at the previous position control algorithm. Such a control strategy yields improved result of the impact control. Similarly, the initial conditions for the force control problem are indirectly optimized by the previous position control and impact control strategies. The force control algorithm uses the individual joint torque minimization concept. It also minimizes the force disturbances. The simulation results show the proposed control strategy works well.

• Composites Research
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• v.27 no.4
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• pp.141-145
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• 2014

This paper presents a structural health monitoring method using piezoelectric paint sensor designed for an impact sensor. The piezoelectric paint sensor can be flexibly deposited onto most structural surfaces in a thin form of the paint, and measure impact signals without any external device such as a power amplifier. In this study, a composite plate having four zones coated with piezoelectric paint was used for impact monitoring test. The sensitivity of the piezoelectric paint sensor was obtained by measuring the output voltages against the impact force. In addition to the sensitivity measurement, the impact position has been also estimated by comparing the output signals of the paint sensors when the impact occurs on the specimen.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.421-426
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• 2007

This study was analyzed dynamically by finite element method about the results of experiments which the double cantilever beam specimens with two kinds of materials were applied by impact load. And they were compared with each other as the simulation data applied onto impact velocities of 6.4 and 18.47 m/s. The crack energy release rate, force and displacement of block were calculated numerically by computer. As the numerical simulation data of specimen analyzed in this study approached the experimental data, the inspection of this specimen model suggested in this paper could be reasonable for the numerical simulation.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.1
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• pp.1-8
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• 2002

When a body enters waters, its original kinetic energy or momentum is distributed among the body and surrounding water in the form of added mass. Due to the transfer of the energy or momentum, the bode is subjected to the hydrodynamic impact forces and acceleration. This impact behavior can be an important criterion of submersible vehicle launched to the air. In this paper, based on Life-boat model, an approximate method is proposed for the evaluation of the forces and responses of cylindrical rigid bode by water entry impact. The impact forces are calculated by yon Karman's momentum theory and motion responses the body, especially acceleration, are calculated by a numerical integration of the motion equations derived by hydrodynamic force equilibrium. The proposed method is expected to be a simple but efficient tool lot the preliminary design or motion analysis of a body subjected to water entry impact.

• 건강소식
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• v.32 no.4 s.353
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• pp.28-29
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• 2008

여러분은 나이가 드신 할머니, 할아버지들이 허리가 구부러지고 팔, 다리, 허리 등이 아프다고 하시거나, 가볍게 넘어졌을 뿐인데 뼈가 부러지는 경우를 본 적이 있을 것이다. 예전에는 이런 증상을 자연적인 현상으로 생각하거나 재수가 없어서 우연히 생긴 것으로 생각하는 경우가 많았다. 그러나 사실은 뼈에 구멍이 많아지고 약해지는 골다공증이라는 질병 탓이다. 골다공증이란 골량이 현저히 감소하여 뼈가 체중이나기계적인 압력에 견디는 힘이 약해지고 실내에서 가볍게 넘어지는 것 등의 미약한 충격에도 골절이 생길수 있는 질환을 말한다.

• KOREAN POULTRY JOURNAL
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• v.3 no.12 s.26
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• pp.44-46
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• 1971

탈수건조된 계분은 산란계의 사료로서 여러번 재이용 할수 있다는 충격적인 실험연구보고가 미국 미쉬간대학의 친델박사에 의하여 발표되어 이를 소개하고자 한다. 탈수건조된 계분은 계분건조기에 의해서 제조된 것이므로 국내에서의 즉각적인 활용은 힘드리라고 예상되나 사료원료의 80$\%$이상을 수입하는 우리나라에서는 한번 음미해 볼 가치가 있어 옮겨보았다. 이글은 미국 폴트리$\cdot$다이제스트 1971년 5월호에서 전재한것임을 밝혀둔다.

• Fire Science and Engineering
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• v.5 no.3
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• pp.5-14
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• 1991

Now a days, according that the occurrence of industrial disaster is on the increase, the necessity of protective goods is increasing. Specially estimate of safety helmet for protect of head is very important. On this, in this paper, amplification ratio and natural frequencies of fire safety helmet and general safety helmet are estimated by falling impect test and frequency analysis. Also. trend of damping is estimated by using these test results. And we know that the fire safety helmet is more safe than general safety helmet for protect of head.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.2
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• pp.96-104
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• 1984

This paper is on the prediction and response of the ship hull girder due to slamming of foreward flat bottom plate. The response with respect to foreward flat bottom is divided two kinds by estimating method. One is the estimation of impact forces by slamming, Another is the response of hull girder due to impact forces, that is, displacement, velocity, acceleration, etc. must calculate the values for considered ship hull girder. In this paper, therefore, was estimated only impact forces along ship ordinate of foreward. The analysis of data for estimation followed mainly papers of Ochi. These estimated data shall contribute for ship gull construction for basic optimum design. In particular, the estimated impact forces shall be given for the response of ship gull girder on the foreward flat bottom plate with characteristics of external forces.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.618-621
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• 2008

Most hard disk drives that apply the ramp load/unload technology unload the heads at the outer edge of the disk while the disk is rotating. During the unloading process, slider-disk contacts may occur by lift-off force and rebound of the slider. The main issue of this paper is to prevent the slider-disk contact by changing the state matrix. Because the state matrix is related to the suspension and slider, to change the state matrix means the structural change of the suspension and slider. We investigate influence for variation of the state matrix components and analyze the relation between the state matrix and the suspension/slider.