• Korean Journal of Applied Biomechanics
• /
• v.15 no.3
• /
• pp.143-152
• /
• 2005

The purpose of this study was to predict the failure or success of the Snatch-lifting trial as a consequence of the stand-up phase simulated in Kane's equation of motion that was effective for the dynamic analysis of multi-segment. This experiment was a case study in which one male athlete (age: 23yrs, height: 154.4cm, weight: 64.5kg) from K University was selected The system of a simulation included a multi-segment system that had one degree of freedom and one generalized coordinate for the shank segment angle. The reference frame was fixed by the Nonlinear Trans formation (NLT) method in order to set up a fixed Cartesian coordinate system in space. A weightlifter lifted a 90kg-barbell that was 75% of subject's maximum lifting capability (120kg). For this study, six cameras (Qualisys Proreflex MCU240s) and two force-plates (Kistler 9286AAs) were used for collecting data. The motion tracks of 11 land markers were attached on the major joints of the body and barbell. The sampling rates of cameras and force-plates were set up 100Hz and 1000Hz, respectively. Data were processed via the Qualisys Track manager (QTM) software. Landmark positions and force-plate amplitudes were simultaneously integrated by Qualisys system The coordinate data were filtered using a fourth-order Butterworth low pass filtering with an estimated optimum cut-off frequency of 9Hz calculated with Andrew & Yu's formula. The input data of the model were derived from experimental data processed in Matlab6.5 and the solution of a model made in Kane's method was solved in Matematica5.0. The conclusions were as follows; 1. The torque motor of the shank with 246Nm from this experiment could lift a maximum barbell weight (158.98kg) which was about 246 times as much as subject's body weight (64.5kg). 2. The torque motor with 166.5 Nm, simulated by angular displacement of the shank matched to the experimental result, could lift a maximum barbell weight (90kg) which was about 1.4 times as much as subject's body weight (64.5kg). 3. Comparing subject's maximum barbell weight (120kg) with a modeling maximum barbell weight (155.51kg) and with an experimental maximum barbell weight (90kg), the differences between these were about +35.7kg and -30kg. These results strongly suggest that if the maximum barbell weight is decided, coaches will be able to provide further knowledge and information to weightlifters for the performance improvement and then prevent injuries from training of weightlifters. It hopes to apply Kane's method to other sports skill as well as weightlifting to simulate its motion in the future study.

• Proceedings of the Optical Society of Korea Conference
• /
• 2005.02a
• /
• pp.290-291
• /
• 2005

We have presented a comprehensive effective-mass Hamiltonian for strained Wurtzite semiconductors using k${\cdot}$p method and Kane's model. This theoretical groundwork provides a foundation for investigating the electrical and optical properties of wurtzite strained quantum-well lasers.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.18 no.3
• /
• pp.167-175
• /
• 2018

Despite the rapid development of IT technology, people with visual impairments still use simple forms of walking sticks and need more advanced walking aids. Smart Cane, which is developed based on Internet service and sensor, can provide high safety and convenience compared to existing sticks for visually impaired people by conveying peripheral information and walking situation to these visually impaired people through voice and vibration. In this paper, we propose and implement SmartKane to overcome lack of miniaturization, user friendly form, and sensing sensitivity, which have been pointed out as a problem of existing SmartKane.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.160-162
• /
• 2016

A compact model of tunnel field effect transistor (TFET) has been developed. The model includes a surface potentia calculation module and a band-to-band-tunneling current module. Model comparison with TCAD shows that the mode calculates TFET surface potential and drain current accurately.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.97-98
• /
• 2007

A wide range of data is available as too causes of large power transformers. Although the percentage of transformer component failure rates vary, all data shows that the top three failure mechanisms are Load Tap Changers (LTC), Bushings and Windings. To date, the most common methods employed to determine the health of a transformer are off line tests and online temperature monitoring, winding hotspot calculations and dissolved gas analysis.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.47 no.10
• /
• pp.705-711
• /
• 2019

Dynamic behaviors of the deployable composite reflector antenna are numerically and experimentally investigated. Equations of the motion are formalized using Kane's equation by considering multibody systems with two degrees of freedom such as folding and twisting angles. To interpret structural deformations of the reflector antenna, the composite reflector is modeled using a beam model with the FSDT(First-order Shear Deformation Theory). To determine design parameters such as a torsional spring stiffness and a damping coefficient depending on deployment duration, an inverted pendulum model is simply applied. Based on the determined parameters, dynamic characteristics of the deployable reflector are investigated. In addition, its results are verified and compared through deployment tests using a gravity compensation device.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.1580-1586
• /
• 2003

This paper presents the design and the analysis of a "fish-like underwater robot". In order to develop swimming robot like a real fish, extensive hydrodynamic analysis were made followed by the study of biology of the fishes especially its maneuverability and propel styles. Swimming mode is achieved by mimicking fish-swimming of carangiform. This is the swimming mode of the fast motion using its tail and peduncle for propulsion. In order to generate configurations of vortices that gives efficient propulsion yawing and surging with a caudal fin has applied and in order to submerge and maintain the body balance pitching and heaving motion with a pair of pectoral fin is used. We have derived the equation of motion of PoTuna by two methods. In first method, we use the equation of motion of underwater vehicle with the potential flow theory for the power of propulsion. In second method, we apply the method of the equation of motion of UVM(Underwater Vehicle-Manipulator). Then, we compare these results.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.808-811
• /
• 2004

A full-color AMOLED display with an RGBW color filter pattern has been fabricated. Displays with this format require about $^1/_2$ the power of analogous RGB displays. RGBW and RGB 2.16inch diagonal displays with average power consumptions of 180 mW and 340 mW, respectively, are demonstrated for a set of standard digital still camera images at a luminance of 100 cd/$m^2$. In both cases, a white-emitting AMOLED is used as the light source. The higher efficiency of the RGBW format results because a large fraction of a typical image can be represented as white, and the white sub-pixel in an RGBW AMOLED display is highly efficient because of the absence of any color filter. RGBW and RGB AMOLED displays have the same color gamut and, aside from the power consumption difference, are indistinguishable.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.22 no.4
• /
• pp.768-778
• /
• 1998

Human beings usually absorb a shock from terrain during walking through the damping effects of joints, muscles and skin. With this analogy, a robot-leg with a shock absorber is built to absorb the impact forces at its foot during high-speed walking on irregular terrain. To control the hip position while walking, the dynamic controller suitable for high speed walking is designed and implemented based on a dynamic model by Kane's equation. The hip position tracking performances of various controllers (PID controller, computed torque controller and feedforward torque controller) are compared through the experiments of the real robot-leg.

• Journal of KSNVE
• /
• v.11 no.1
• /
• pp.118-124
• /
• 2001

The effect of a concentrated mass on the regions of dynamic instability of an axially oscillating cantilever beam is investigated in this paper. The equations of motion are derived using Kane's method and the assumed mode method. It is found that the bending stiffness is harmonically varied by axial inertia forces due to oscillating motion. Under the certain conditions between oscillating frequency and the natural frequencies, dynamic instability may occur and the magnitude of the bending vibration increase without bound. By using the multiple time scales method, the regions of dynamic instability are obtained. The regions of dynamic instability are found to be depend on the magnitude of a concentrated mass or its location.