• Korean Journal of Acupuncture
• /
• v.21 no.1
• /
• pp.129-147
• /
• 2004

Objectives and methods : This research aims to study about conversion system of channels. In the present study, we investigated the movement and conversion of channels on the base of three step theory(三才論), Yeak(易), Hado.Laksea(河圖洛書) and five elements motion and six kinds of factors(Six-Qi). Results and Conclusions : The organization of meridian is composed of the following three parts: hand and foot, Yin and Yang, and the viscera and bowals. It is play an important role in energy flow and its conversion. The law governing energy conversion is divided into three groups i.e. taiyin-yangming channel, shaoyin-taiyang channel and jueyin-shaoyang channel group. Those are composed of Deadea(對待) of Six-Qi, making the body homeostasis. Taken together, we suggest that the conversion system of meridian is founded on the unity between the human body and nature which provides the medical workers with a necessary method of thinking in treating diseases.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.1
• /
• pp.35-43
• /
• 1996

A computer program for automatic deriving the symbolic equations of motion for robots using the programming language MATHEMATICA has been developed. The program, developed based on the Lagrange formalism, is applicable to the closed chain robots as well as the open chain robots. The closed chains are virtually cut open, and the kinematics and dynamics of the virtual open chain robot are analyzed. The constraints are applied to the virtually cut joints. As a result, the spatial closed chain robot can be considered as a tree structured open chain robot with kinematic constraints. The topology of tree structured open chain robot is described by a FATHER array. The FATHER array of a link indicates the link that is connected in the direction of base link. The constraints are represented by Lagrange multipliers. The parallel robot, DELTA, having three-dimensional closed chains is modeled and simulated to illustrate the approach.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.3C
• /
• pp.408-418
• /
• 2004

In this paper, we propose a novel scalable video coding algorithm based on adaptively weighted multiple reference frame method. To improve the coding efficiency in the enhancement layer, the enhancement frame is predicted by the sum of adaptively weighted double motion compensated frames in the enhancement layer and the current frame in the base layer, according to the input video characteristics. By employing adaptive reference selection scheme at the decoder, the proposed method reduce the drift problem significantly. From the experimental results, the proposed algorithm shows more than 1.0 ㏈ PSNR improvement, compared with the conventional scalable H.263+ for various packet loss rate channel conditions.

• Journal of Biomedical Engineering Research
• /
• v.30 no.6
• /
• pp.495-502
• /
• 2009

This paper investigated the effects of dynamic postural control for maintaining upright standing on a support surface during continuous sinusoidal horizontal translation in anterior-posterior direction. 15 healthy young subjects participated in this experiment. The analysis of body movement was analyzed using Ariel Performance Analysis System. Motion pattern was analyzed by seven markers on subject's body. Position of markers were head, chest, hip, right knee, left knee, right ankle and left ankle. Seven different frequencies of support surface were employed ; 0.1, 0.25, 0.5, 0.75, 1, 1.5 and 2Hz at 2cm of moving path of motionbase. The experiments were performed dynamic postural reponses at the condition of eye open. The results showed that median frequency of the knee, ankle were increased in all frequency bands. Following the frequency of perturbation increased, postural control strategy was changed from ankle strategy to combined strategy. The experiment results could be applied to the dynamic postural training for the elderly and the rehabilitation training for the patients to improving the ability of postural control.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.21 no.1
• /
• pp.182-189
• /
• 2012

This study suggests a dynamic design process for deciding properly design parameters of a mass-spring type Wave Energy Converter (WEC) to achieve sufficient energy conversion from wave to power generator. The WEC mechanism, in this research, consists of a rigid sprung body, a platform, suspension springs and dampers. The rigid sprung body is supported on the platform via springs and dampers and vibrates translationally in the heave direction under wave excitation. At last the resulting heave motion of the sprung body is transmitted to rotating motion of the electric generator by rack and pinion, and transmission gears. For the purpose of vibration analysis, the WEC mechanism has been simply modelled as a mass-spring-damper system under harmonic base excitation. Its maximum displacement transmissibility and steady state response can be determined by using elementary vibration theory if the harmonic ocean wave data were provided. With the vibration analysis results, the suggested dynamic design process of WEC can determine all the design parameters of the WEC mechanism, such as sprung body mass, suspension spring constant, and damping coefficient that can give sufficient relative displacement transmissibility and the associated inertia moment to drive the electric generator and transmission gears.

• Journal of Institute of Control, Robotics and Systems
• /
• v.15 no.5
• /
• pp.543-547
• /
• 2009

This paper describes the design, simulation, development, and experiment of a six degree-of-freedom micropositioning parallel manipulator. A movable stage was supported with six links, each of which extends with a dc-servo micropositioning actuator. In case of parallel manipulator, while the solution of the inverse kinematics is easily found by the vectors of the links which are composed of the joint coordinates in base and platform, but forward kinematic is not easily solved because of the nonlinearity and complexity of the parallel manipulator's kinematic output equation with the multi-solutions. The movable range of the prototype was ${\pm}25mm$ in the x- and y-directions and ${\pm}12.5mm$ in the z-direction. The minimum incremental motion of the prototype was $1{\mu}m$ in the x- and y-directions and $0.5{\mu}m$ in the z-direction. The repeatability of the prototype was ${\pm}2{\mu}m$ in the x- and y-directions and ${\pm}1{\mu}m$ in the z-direction. The motion performance was also evaluated by not only the computer simulation of CAD model but also the experiment using a capacitive sensor system.

• Journal of Information Technology Services
• /
• v.10 no.1
• /
• pp.65-72
• /
• 2011

In this paper, we consist of three dimensional acceleration sensor as a small-sized sensor module to acquire base technologies that need to estimate exhibition audience' moving distance. and that we developed algorism and device that can calculate acceleration in gravity direction with attaching it to people's body part without regard to three dimensional direction. By making use of the sensor module, we have to process the data that let it quantitatively process possible to measure people's walk and movement by computer system. We normalized sensor output data in the process of change from sensor module to acquisition of data, rectangular coordinates and single scalar acceleration value in gravity direction. Printed out sensor data attaching sensor module to people's body part is used for motion pattern detection after normalization, Motion sensor devised mode change algorism because it print data of other pattern according to attached position of body. For algorism design, we collected data occurring during walking about subject and we also defined occurring problem domain after analyzing the data. We settle defined problem domain and that we simulated the walking number measuring instrument with highly efficient in restricted environment.

• Korean Journal of Applied Biomechanics
• /
• v.30 no.2
• /
• pp.165-172
• /
• 2020

Objective: The purpose of this study was to provide quantitative and objective data of throwing movement in baseball catcher through biomechanical analysis. Method: Eight high school baseball catchers (age: 17.3±0.7 yrs, height: 175.3±4.5 cm, weight: 82.5±9.0 kg, Career: 7.4±2.1 yrs) participated and 3-dimentional motion capture system and electromyography (EMG) were used in this study. Results: The maximum center of mass position displacement was observed in forward direction. The linear velocity magnitude of the upper extremity segments were showed as "wrist>elbow>shoulder" which is indicative of kinematic chain. For kinetic EMG data, we also observed the greater muscle activation in the left brachioradial and erector spine muscles muscle that during throwing movement. Conclusion: We expect that biomechanical data from this study will provide important training implications to baseball coaches and trainers in order to effectively train their baseball catchers.

• Journal of Ship and Ocean Technology
• /
• v.8 no.3
• /
• pp.26-39
• /
• 2004

A vessel/mooring/riser coupled dynamic analysis program in time domain is developed for the global motion simulation of a turret-moored, tanker based FPSO designed for 6000-ft water depth. The vessel global motions and mooring tension are simulated for the non-parallel wind-wave-current 100-year hurricane condition in the Gulf of Mexico. The wind and current forces and moments are estimated from the OCIMF empirical data base for the given loading condition. The numerical results are compared with the OTRC(Offshore Technology Research Center: Model Basin for Offshore Platforms in Texas A&M University) 1:60 model-testing results with truncated mooring system. The system's stiffness and line tension as well as natural periods and damping obtained from the OTRC measurement are checked through numerically simulated static-offset and free-decay tests. The global vessel motion simulations in the hurricane condition were conducted by varying lateral and longitudinal hull drag coefficients, different mooring and riser set up, and wind-exposed areas to better understand the sensitivity of the FPSO responses against empirical parameters. It is particularly stressed that the dynamic mooring tension can be greatly underestimated when truncated mooring system is used.

• Structural Engineering and Mechanics
• /
• v.47 no.5
• /
• pp.599-622
• /
• 2013

Seismic response of two dimensional liquid tanks is numerically simulated using fully nonlinear velocity potential theory. Galerkin-weighted-residual based finite element method is used for solving the governing Laplace equation with fully nonlinear free surface boundary conditions and also for velocity recovery. Based on mixed Eulerian-Lagrangian (MEL) method, fourth order explicit Runge-Kutta scheme is used for time integration of free surface boundary conditions. A cubic-spline fitted regridding technique is used at every time step to eliminate possible numerical instabilities on account of Lagrangian node induced mesh distortion. An artificial surface damping term is used which mimics the viscosity induced damping and brings in numerical stability. Four earthquake motions have been suitably selected to study the effect of frequency content on the dynamic response of tank-liquid system. The nonlinear seismic response vis-a-vis linear response of rectangular liquid tank has been studied. The impulsive and convective components of hydrodynamic forces, e.g., base shear, overturning base moment and pressure distribution on tank-wall are quantified. It is observed that the convective response of tank-liquid system is very much sensitive to the frequency content of the ground motion. Such sensitivity is more pronounced in shallow tanks.