• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.11a
• /
• pp.371-372
• /
• 2008

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1464-1468
• /
• 2004

This paper presents a learning controller for repetitive gait control of biped walking robot. We propose the iterative learning control algorithm which can learn periodic nonlinear load change ocuured according to the walking period through the iterative learning, not calculating the complex dynamics of walking robot. The learning control scheme consists of a feedforward learning rule and linear feedback control input for stabilization of learning system. The feasibility of learning control to biped robotic motion is shown via dynamic simulation with 12-DOF biped walking robot.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.894-899
• /
• 1997

Genernally, the life of ball screws is presented in catalogue of domestic manufacturer by the name of dynamic load capacity. But, systematic experiment method and reliable data are not secured, even now. Data presented in catalogue is obtained at already established life expression of ball-bearing. Therefore studying on the life of ball screws, characteristic qualities of ball screw must be considered. We studied systematic experiment method and by this do experiments, obtained data. This paper present above items, and expression of life prediction by experiment results.

• Journal of the Korean Society of Safety
• /
• v.17 no.4
• /
• pp.173-177
• /
• 2002

THERP (Technique for Human Error Rate Prediction) methodology has been widely used for probabilistic safety assessments. The NUREG report involving this methodology is also called the HRA handbook. The THERP assumes that all actions involved in implementing a task are considered as components. In this paper human error rates associated with maintenance are evaluated by the THERP methodology. A gas governor system is used as an example which is also a risky system like nuclear power plants. It is also demonstrated that this approach is flexible in that it can be applied to any operator actions related to test and maintenance.

• Journal of Institute of Control, Robotics and Systems
• /
• v.6 no.2
• /
• pp.155-163
• /
• 2000

This paper presents a path planning method of the sensor based intelligent vehicle using fuzzy logic controller for avoidance of moving obstacles in unknown environments. Generally it is too difficult and complicated to control intelligent vehicle properly by recognizing unknown terrain with sensors because the great amount of imprecise and ambiguous information has to be considered. In this respect a fuzzy logic can manage such the enormous information in a quite efficient manner. Furthermore it is necessary to use the relative velocity to consider the mobility of obstacles, In order to avoid moving obstacles we must deliberate not only vehicle's relative speed toward obstacles but also self-determined acceleration and steering for the satisfaction of avoidance efficiency. In this study all the primary factors mentioned before are used as the input elements of fuzzy controllers and output signals to control velocity and steering angle of the vehicle. The main purpose of this study is to develop fuzzy controllers for avoiding collision with moving obstacles when they approach the vehicle travelling with straight line and for returning to original trajectory. The ability are and effectiveness of the proposed algorithm are demonstrated by simulations and experiments.

• Journal of Chest Surgery
• /
• v.30 no.1
• /
• pp.34-39
• /
• 1997

Between May, 1994 and December, 1995, 122 adult cardiac surgical procedures requiring cardiopulmonary bypa s were performed at Kang Dong Sacred Heart Hospital, including 18 cases(14.8%) that were associated with preoperative(n:9), intraoperative(n=7), postoperative(n:2) use of an IABP (intra-aortic balloon pump). The reasons for IABP were low cardiac output and PTCA(percutaneous transluminal coronary angioplasty) failure in preoperative period, CPB(cardiopulmonary bypass) weaning difficulty in intraoperative period, and intractable arrhythmia in postoperative period. The mean age of the IABP patients was 61.8 $\pm$ 6.9 years(range, 39 to 75years). The overall hospital mortalities in patients with preoperative and intraoperative IABP insertion were 3 and 42.9% respectively. Two patients with postoperative IABP insertion are alive. The rate of IABP weaning is 66.7% for preoperative group, 85.7% for intraoperative group and 100% for postoperative group . In conclusion, if there were no irreversible myocardial damages, IABP could be used safely and emergently at any perioperative period for hemo ynamic stability, CPB weaning, and to overcome low cardiac output syndrome.

• The Korean Journal of Elementary Counseling
• /
• v.7 no.2
• /
• pp.169-180
• /
• 2008

The purpose of this study is to train peercounselors within the minimum period and use them as mentors for rejected children in order to raise the social status of those children. To do so, five mentors were assigned to five rejected children but their social status did not show significant difference. Not only that, even the social status of the mentors was decreased so the primary purpose of this study was not achieved. However, the activities in the class such as the mentor activity increased the choices that students can get. These changes were definite in the male student groups rather in female student groups. Female students had their own way of change and direction regardless of the class activities. Therefore, there is a possibility that 5th graders in the elementary school have different classroom dynamics according to their genders. The different classroom dynamic by genders and the choice and direction of rejection shown in the matrix table indicate that it is proper to use same-sex peer nomination for sociometry. Also, the results of this study raise the necessity for further studies regarding individual approaches for rejected children and the intervention methods that teachers use for those children.