• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.1334-1337
• /
• 1997

A spacecraft attitude control ground hardware simulator development is discussed in the paper. The simulator is called KT/KARI HILSSAT(Hardware-In-the Loop Simulator Single Axis Testbed), and the main structure consists of a single axis bearing and a satellite main body model on the bearing. The single axis tabel as ans experimental hardware simulator that evaluates performance and applicability of a satellite before evolving and/or confirming a mew or and old control logic used in the KOREASAT is developed. Attitude control of spaceraft by using reaction wheel is performed.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.1233-1236
• /
• 1996

Attitude Control System for a Hydrofoil type catamaran in wave is designed using a Decentralized Adaptive Control technique which is announced already by authors. This automatic attitude control system is designed for its good seaworthiness and for robustness on the variation of center of gravity. The performance is compared with a PID controller and the results show that the Decentralized Adaptive controller has better stability on the variation of the center of gravity.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.1103-1106
• /
• 1996

Disturbance Accommodating Attitude control logic for 3-axis stabilized spacecraft is designed and compared with PIID control logic. PID controller provide the zero steady error for constant disturbances. PIID controller detect and cancel disturbances upto the ramp input. PID control logic is designed as the main control logic. We designed the disturbance observer to detect the effect of disturbance using the sinusoidal function. The detected disturbance are compensated by the additional control logic. The comparison simulation is conducted between PIID and PIID with DAC. The simulation results show that PIID with DAC shows the better attitude pointing accuracy.

• Journal of Aerospace System Engineering
• /
• v.4 no.4
• /
• pp.37-43
• /
• 2010

Need for agile satellites increases for performing various mission due to increase of satellite image applications and users. This paper performs attitude maneuver analysis by using Satellite Tool Kit(STK) made by AGI. In order to automate the STK analysis process, a MATLAB program is developed to generate STK input data and to process STK output data. Five attitude maneuver modes are analyzed and attitude angle variation and required torques are calculated.

• 제어로봇시스템학회:학술대회논문집
• /
• 1998.10a
• /
• pp.53-57
• /
• 1998

Star tracker placement configuration is proposed and the properness of the placement configuration is verified for star tracker's sun avoidance angle requirement. Precision attitude determination system is successfully designed using a gyro-star tracker inertial reference system for a candidate LEO spacecraft. Elaborate kalman filter formulation for a spacecraft is proposed for covariance analysis. The covariance analysis is performed to verify the capability of the proposed attitude determination system. The analysis results show that the attitude determination error and drift rate error are good enough to satisfy the mission of a candidate spacecraft.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.12
• /
• pp.237-245
• /
• 2018

This study was conducted to identify the effects of baby care using dolls on nursing students' contraceptive attitude, sexual attitude, and recognition of unmarried mothers. A quasi-experimental nonequivalent control group, pretest-posttest design was used. The subjects of the study were 104 nursing college students who agreed to participate. The control group (n=52) received lecture sex education while the experimental group (n=52) received lecture sex education and baby care education using a doll. The contraceptive attitude, sexual attitude, and unmarried mother's recognition were then examined. Data were collected from September to December, 2017 and analyzed using descriptive statistics, ${\chi}^2$-tests, and t-tests with the SPSS/WIN 21.0 program. The scores of contraceptive attitude differed significantly between the experimental group and the control group (t=4.66, p=<0.001). Additionally, the sexual attitude score of the experimental group was lower than that of the control group (t=-2.23, p=0.028), with pleasure playfulness showing a significant decrease (F=3.96, p=<0.001). However, recognition of unmarried mothers did not differ significantly between groups (t=-0.08, p=0.937). Overall, the results showed that baby care using a doll has positive effects on contraceptive attitude and sexual attitude. In the future, effective sex education should include methods that complement lectures.

• Journal of Korean Public Health Nursing
• /
• v.29 no.1
• /
• pp.18-28
• /
• 2015

Purpose: This study was conducted to evaluate the effect of CPR education on the knowledge, attitude and self-efficacy of elementary and middle school teachers. Methods: After obtaining informed consent from participants, data were collected from 75 teachers receiving training in emergency care using questionnaires before and after education. Data were analyzed using percentage, paired t-test, and correlation. Results: The knowledge and self-efficacy scores were the middle level and the scores for attitude were the upper middle level. The knowledge, attitude, and self-efficacy scores at posttest were significantly higher than those at pretest. Conclusion: Teachers should receive CPR education regularly, so that they can acquire the knowledge, attitude, and practical ability of CPR.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.141.5-141
• /
• 2001

An attitude GPS receiver with 3 antennas obtains 3-dimensional attitude using GPS carrier phase measurement INS obtains the 3 dimensional navigation solution for IMU consisting of accelerometers and gyro. Ground-alignment process for the low -cost INS cannot be performed well due to the large sensor noise. Using the standard GPS receiver, however, continuous in-flight alignment for the INS becomes possible, and consequently, the errors in IMU sensors and navigation solution can be compensated. Especially with attitude measurement from the attitude GPS receiver, the compensation of errors in gyroscope and attitude would be done respite of the vehicle´s dynamics and their error covariance would be reduced. This paper presents ...

• Journal of Institute of Control, Robotics and Systems
• /
• v.11 no.7
• /
• pp.621-626
• /
• 2005

With precise GPS carrier positioning result, we can get attitude information if GPS antenna has adequate attaching position on the vehicle. In this case, baseline length information can be bandied as an additional measurement or constraint. In this paper, we have proposed a method to improve the attitude accuracy. To overcome nonlinearity of baseline observation model, we analyze attitude estimation result using existing estimation method like a least square method and Kalman filter, and apply a new nonlinear estimation method an unscented Kalman filter Finally we confirm the improvement of attitude estimation result in the case of appling the unscented Kalman filter.

• Proceedings of the KIEE Conference
• /
• 2002.11c
• /
• pp.274-277
• /
• 2002

This paper deals with the attitude determination using GPS carrier phase. The main factors on attitude reliability are accuracy, error factors and the real-time ambiguity resolution speed. Firstly, these factors are reviewed. And then, the attitude reliability is improved by applying the averaging method. Finally, the attitude determination software is verified by the experiments. The accuracy of the proposed attitude determination method is 0.013$^{\circ}$ PE in live test. This result is more accurate than the existing INS equipment.