• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.10 s.103
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• pp.1195-1201
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• 2005

In this paper, the effect of a moving mass on dynamic behavior of the cracked cantilever beam on elastic foundations is presented. Based on the Euler-Bernoulli beam theory, the equation of motion can be constructed by using the Lagrange's equation. The crack section is represented by a local flexibility matrix connecting two undamaged beam segments. That is, the crack is modelled as a rotational spring. This flexibility matrix defines the relationship between the displacements and forces across the crack section and is derived by applying fundamental fracture mechanics theory The crack is assumed to be in the first mode of fracture. As the depth of crack is increased, the tip displacement of the cantilever beam is Increased. When the depth of crack is constant, the frequency of a cracked beam is proportional to the spring stiffness.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.4 no.4
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• pp.187-200
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• 1992

A general scheme is developed to determine the Langrangian motions of water particles by the Eulerian velocity at their mean positions by using Taylor's theorem. Utilizing the Stokes finite-amplitude wave theory, the orbital motions and the mass transport velocity including the effects of higher-order wave components are determined. The fifth-order approximation of orbital motion gives very good predictions of actual water particle motion in Stokes fifth-order wave theory except near the free-surface. The fifth-order theory predicts the mass transport velocity less than that given by the existing second-order theory over the whole water depth.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.337-338
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• 2010

Projectile is said that objects thrown on the ground of the atmosphere. This objects exercises the parabolic motion because of the fact under the influence of gravity in the direction perpendicular and it does not include the horizontal force neglecting air resistance. In this paper, the experiment target is where subsidence occurred by that some of the road is lost to a certain depth using projectile motion. It says how far away and falling from the edge of the road when you have gone over the edge of depressed road that a car was driving at a constant speed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.39 no.2
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• pp.99-111
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• 2003

The fundamental studies on the productivity improvement of the purse seine fishery are presented in this paper. The experiment on net shooting and hauling was carried out in the near sea of Jeju Island (33$^{\circ}$37.8' N, 126$^{\circ}$31.1' E) by using the Cheju national university training ship (A-Ra, 990tons) which was constructed for the one boat system operation of purse seine. The corkline and leadline of the purse seine used for the experiment were 829.1m and 995.7m in length, respectively. Micro data recorder system, net sonde, and tensiometer were used to measure the depth of leadline and the tension of purse seine. Based on the measurement data, the motion and tension of purse seine at the time of shooting, hauling, and pursing were characterized. The experimental results are summarized as follows ; 1. The shooting and hauling of net were found to be possible in the one boat system experimental operation. 2. At the time of purse seine shooting, the relationship between the depth (Dp) of leadline and elapsed time (Et) was found to be Dp=7.58Et-6.48. 3. At the time of pursing, the relationship between the depth (Dp) of leadline and elapsed time (Et) was found to be Dp=-0.8Et$^2$＋7.42Et＋92.04. 4. At the time of pursing, the tension (metric tons) of purse seine attained its maximum value (14.7tons) when the elapsed time is 8 minutes. The relationship with the elapsed time was found to be T=-0.13Et$^2$＋3.23Et-5.72.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.513-515
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• 2019

Techniques to recognize depth values using Kinect infrared projectors continue to evolve. Techniques to track human movements are being developed from the Marcris method to the Bimarris method. Capture of facial movement using Kinect has disadvantages that are not sophisticated. In addition, a method to control the gestures and movements on the face in real time requires much research. Therefore, this paper proposes a technique to create natural 3D image contents by studying technology to apply and control branding technology to extracted face recognition data using Kinect infrared method.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.47-54
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• 2013

In this paper, we present an inertial sensor-based motion capturing system to measure and analyze whole body movements. This system implements a wireless AHRS(attitude heading reference system) we developed using a combination of rate gyroscope, accelerometer and magnetometer sensor signals. Several AHRS modules mounted on segments of the patient's body provide the quaternions representing the patient segments's orientation in space. We performed 3D motion capture using the quaternion data calculated. And a method is also proposed for calculating three-dimensional inter-segment joint angle which is an important bio-mechanical measure for a variety of applications related to rehabilitation. To evaluate the performance of our AHRS module, the Vicon motion capture system, which offers millimeter resolution of 3D spatial displacements and orientations, is used as a reference. The evaluation resulted in a RMSE of 2.56 degree. The results suggest that our system will provide an in-depth insight into the effectiveness, appropriate level of care, and feedback of the rehabilitation process by performing real-time limbs or gait analysis during the post-stroke recovery process.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.1
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• pp.24-29
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• 2006

In this paper, the effect of open crack on the dynamic behavior of simply supported Timoshenko beam with a moving mass was studied. The influences of the depth and the position of the crack on the beam were studied on the dynamic behavior of the simply supported beam system by numerical methods. The equation of motion is derived by using Lagrange's equation. The crack section is represented by a local flexibility matrix connecting two undamaged beam segments. The crack is modeled as a rotational spring. This flexibility matrix defines the relationship between the displacements and forces on the crack section and is derived by applying fundamental fracture mechanics theory. As the depth of the crack increases, the mid-span deflection of the Timoshenko beam with a moving mass is increased.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.239-243
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• 2005

Fully three-dimensional Large Eddy Simulation calculations of the flow past 2D cavity are conducted to study the purging of neutrally buoyant or dense miscible contaminants introduced instantaneously inside the cavity. The length to depth ratio(L/D) is 2 and Reynolds number based on the depth is 3,360. Fully developed turbulent inflow are fed at the inlet from precursor simulation of channel flow. Mean flow pattern and unsteady features are investigated based on the experimental data of Pereira and Sousa. From the study of mass exchange processes, it is found that the mechanism of removal of the contaminant is very different between the non-buoyant and buoyant cases. In the buoyant case, internal wave motion which interacts with a strong cavity vortex is dominant in the ejection mechanism of the contaminants.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.221-224
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• 1996

Since impact phenomenon is highly nonlinear, the analysis and control of the contact motion has been a challenging subject. Various researches have been carried out mostly for the contact of a rigid robotic manipulator with a stiff and elastic environment. This paper is motivated by a new contact task: the in-circuit test of a printed circuit board. In this process, high speed contact occurs between a rigid probing manipulator and a plastically deformable work environment. A new dynamic model of the impact controlled probing task has been proposed, considering contact with the plastically deformable object. Approaching velocity conditions to avoid an excess of the allowable penetration depth and control the generated impact force properly are derived from the proposed model. The results of the simulation studies are made for various probing conditions and show the validity of the proposed model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.799-804
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• 2004

In this paper a dynamic behavior of simply supported cracked simply supported beam with the moving masses is presented. Based on the Timoshenko beam theory, the equation of motion can be constructed by using the Lagrange's equation. The crack section is represented by a local flexibility matrix connecting two undamaged beam segments i.e. the crack is modelled as a rotational spring. This flexibility matrix defines the relationship between the displacements and forces across the crack section and is derived by applying fundamental fracture mechanics the of. And the crack is assumed to be in th first mode of fracture. As the depth of the crack and velocity of fluid are increased the mid-span deflection of the pipe conveying fluid with the moving mass is increased. As depth of the crack is increased, the effect that the velocity of the fluid on the mid-span deflection appeals more greatly.