• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.11b
• /
• pp.446-452
• /
• 2002

This paper Presents a 3-D design and a Vibration control of a new walking R.G.O.(Robotic Gait Orthosis) and would like to develop a simulation by this walking system. The vibration control and evaluation of the new knee joint mechanism on the biped walking R.G.O.(Robotic Gait Orthosis) was a very unique system and was to obtain by the 3-axis accelerometer with a low frequency vibration for the paraplegia It will be expect that the spinal cord injury patients are able to recover effectively by a biped walking R.G.O.. The new knee joint system of both legs were adopted with a good kinematic characteristics. It was designed attached a DC-srevo motor and controller, with a human wear type. It was able to accomodate itself to a environments of S.C.I. Patients. It will be expect that the spinal cord injury patients are able to recover effectively by a new walking R.G.O. system.

• Journal of Korean Physical Therapy Science
• /
• v.26 no.3
• /
• pp.15-22
• /
• 2019

Background: The purpose of this study is to explore the effect of the functions of GMFM and ICF-CY on the activities and participation of ICF-CY sub-items. Design: Cross-sectional study. Method: This study compared and analyzed 95 children with cerebral palsy [type of CP: spasticity 86 (90.5%), hypotonia 4 (4.2%), mixed 5 (5.3%); type of palsy: quadriplegia 13 (13.7%), diplegia 71 (74.7%), hemiplegia 11 (11.6%)] using sub-items of functions, activities and participation from GMFM and ICF-CY. Result: The results show that the activities and participation of ICF-CY (9 sub-items) have significant effect on the functions of GMFM and ICF-CY (8 sub-items) (p<0.05). Conclusion: It is intended to provide data to establish practical therapeutic goals and interventions for functions, activities and participation, which are sub-categories of ICF-CY in cerebral palsy.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.15 no.2
• /
• pp.175-181
• /
• 2007

The objective of this study was to develop formability evaluation techniques in order to apply aluminum sandwich panel for automotive body parts. For this purpose, newly adopting formability evaluation (using limit dome height and plane strain test) was carried out in order to secure the fundamental data for the measurement of sheet metal forming and the establishment of optimum forming conditions of the aluminum sandwich panel. The results showed that there were good agreements between the old formability evaluation method and the new method which was more simplified than that of old one. From the results of these formability evaluation, the formability of sandwich panel was higher than that of aluminum alloy sheet alone which was the skin component for the sandwich panel. Also, it was found that sandwich panel could reduce the weight and could have the same flexural rigidity simultaneously when it was compared to the automotive steel sheet.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.5
• /
• pp.819-832
• /
• 2017

We propose a new switching control scheme for a ball and beam system by utilizing two linearization methods. First, the Jacobian linearization is applied and state observer is developed afterward. Then, motivated [6], the approximate input-output linearization is carried out, and after that, the Jacobian linearization is applied along with the design of state observer. Since the second approach requires two linearizations, it is called a two-step linearization method. The state observer is needed for the estimation of the velocities of ball and motor movement. Since the Jacobian linearization based controller tends to provide faster response at the initial time, and after that, the two-step linearization based controller tends to provide better response in terms of output overshoot and convergence to the origin, it is natural to give a switching control scheme to provide the best overall control response. The validity of our control scheme is shown in both simulation and experimental results.

• Journal of Biomedical Engineering Research
• /
• v.28 no.4
• /
• pp.461-470
• /
• 2007

Human can learn how to shape their brain electrical activity in a desired direction through continuous feedback of the electroencephalogram (EEG), and this technique is known as Neurofeedback (or EEG biofeedback), which has been used since the late 1960s in clinical applications. In this study, a portable wireless EEG (named wEEG) has been designed and implemented, which consists of a mobile station (a wireless two-channel EEG acquisition device) and a base station (a bridge between mobile station and computer). Moreover, a SensoriMotor Rhythm (SMR) training system was also implemented with the wEEG for enhancing attention with virtual environment. Experiment results based on 16 volunteers' (8 females and 8 males, average age is $27{\pm}4$) were reported in this paper. The results show that the SMR ratio of 87.5% subjects increased about 0.7% in training status than that in the stable status. With the proposed system, many training protocol scan be designed easily and can be done at home in our daily life conveniently. Additionally, the proposed system will be useful for disabled and aged people.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2005.11a
• /
• pp.433-436
• /
• 2005

The combustion behavior of initiators and can-type ignitor, acting on vacuum pressure, was invested. It was found that if the ignited propellants of a can-type igniter were exposed at certain level of low pressure, it would be burnt improperly or even be extinguished. When we design the can-type igniters for some rocket motor, it is most important that the pressure built-up by the gases which were already burnt inside of the igniter case keep as high as possible. For this purpose, it is recommended that the ignitor case have some strength to produce as much gases as possible before breaking out and the free volume be kept as small as possible.

• Smart Structures and Systems
• /
• v.1 no.1
• /
• pp.13-27
• /
• 2005

Simultaneous precision positioning and vibration suppression of a reciprocating flexible manipulator is investigated in this paper. The flexible manipulator is driven by a multifunctional active strut with fuzzy logic controllers. The multifunctional active strut is a combination of a motor assembly and a piezoelectric stack actuator to simultaneously provide precision positioning and wide frequency bandwidth vibration suppression capabilities. First, the multifunctional active strut and the flexible manipulator are introduced, and their dynamic models are derived. A control strategy is then proposed, which includes a position controller and a vibration controller to achieve simultaneous precision positioning and vibration suppression of the flexible manipulator. Next, fuzzy logic control approach is presented to design a fuzzy logic position controller and a fuzzy logic vibration controller. Finally, experiments are conducted for the fuzzy logic controllers and the experimental results are compared with those from a PID control scheme consisting of a PID position controller and a PID vibration control. The comparison indicates that the fuzzy logic controller can easily handle the non-linearity in the strut and provide higher position accuracy and better vibration reduction with less control power consumption.

• Structural Engineering and Mechanics
• /
• v.30 no.1
• /
• pp.1-20
• /
• 2008

The dynamic characteristics of the passive, semi-active, and active tuned-liquidcolumn dampers (or TLCDs) are studied in this paper. The design of the latter two are based on the first one. A water-head difference (or simply named as water head in this paper) of a passive TLCD is pre-set to form the so-called semi-active one in this paper. The pre-set of water head is released at a proper time instant during an earthquake excitation in order to enhance the vibration reduction of a structure. Two propellers are installed along a shaft inside and at the center of a passive TLCD to form an active one. These two propellers are driven by a servo-motor controlled by a computer to provide the control force. The seismic responses of a five-story shear building with a passive, semiactive, and active TLCDs are computed for demonstration and discussion. The responses of this building with a tuned mass damper (or TMD) are also included for comparison. The small-scale shaking-table experiments of a pendulum-like system with a passive or active TLCD to harmonic and seismic excitations are conducted for verification.

• Journal of Yeungnam Medical Science
• /
• v.6 no.2
• /
• pp.217-222
• /
• 1989

In this study, high frequency oscillatory ventilator was designed and constructed. Using designed by phase-lock loop system, in order to accurately and easily treat both the outlet volume and rpm. A system has been designed and is being evaluated using CD4046A PLL IC. We use this PLL IC for the purpose of motor controls. The device consists of PLL system, pumping mechanism, piston, cylinder, and special crank shaft are required. This system characteristics were as follows : 1) Frequency : 20-1800rpm. 2) Outlet air volume : 1-50cc.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.4
• /
• pp.905-910
• /
• 2008

In this paper, a circular motion table which is able to simulate movement of object is designed and the experiment of control system using circular motion table is presented. Circular motion table is consisted of three axes changed on length and of ball splines which keep vertical centre axis of circular plate. Variable length of three axes make circular plate incline as vertical centre axis is kept on vertical center axis of circular motion table. It is designed that control system drives three servo motor, that is, make change length of axis simultaneously or independently. And this paper presents example of flight simulation using circular motion table. it will contribute toward nurture expert manpower of aerospace/robotics to popularize circular motion table and make an experiment using it.