• The Research Journal of the Costume Culture
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• v.22 no.6
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• pp.899-910
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• 2014

The purpose of this study was to analyze high school students' school uniform wearing attitude by group according to clothing attitude targeting Gyeongnam area. This study aims to provide preliminary data in the field of school uniform and marketing that clothing propensity by groups is considered. This study conducted a survey targeting 762 high school students in Gyeongnam. For statistical analysis, SPSS for Window 14.0 was used for frequency analysis, factor analysis, reliability analysis, multiple sponse analysis, cluster analysis, ANOVA analysis and Duncan's ex-post analysis method. As a result of cluster analysis on the clothing attitude, students were divided into 4 segmentation of fashion seeking group, fashion indifference group, conformity group and modesty group. As a result of verification on the difference in perception toward wearing school uniform by groups which were classified according to the propensity of clothing attitude, activity, stability, and practicality were all varied according to the propensity of clothing attitude. 4 groups were significant differences in the degree of consent to wearing school uniform, price of school uniforms, tendency to prefer famous brand when purchasing school uniform, experience of transforming school uniform, opinion about school uniform modification and reason for school uniform modification. While low graders were many in 'modesty group', upper graders were many in 'fashion seeking group', which means that more segmentalized satisfaction of clothing by group may be raised if such a fact is considered when planning clothing for high school students segmentalized by age.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.579-585
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• 2019

Increasing the detection probability of underwater targets necessitates securing the towing stability of the active towed SONAR. In this paper, to confirm the effects of tail wing fin on towing attitude and towing stability, two scale model experiments and one sea trials were conducted and the results were analyzed. The scale model tests measured the towing behavior of each of the tail fin shapes according to towing speed in a towing tank. The shape of the tail fin used in the scale model test was tested with an I-type tail fine and four Y-type tail fins, totaling five tail fins of the two kinds. The first scale model test confirmed that the Y-type tail fin was superior to the I-type tail fin in towing attitude and towing stability. The second scale model test confirmed the characteristics of the vertical tail fin height increase and the lower horizontal tail fin inclination angle application shape based on the Y-type tail fin. The shape of the application of the lower horizontal tail fin inclination angle showed the best performance. In order to verify the results of the scale model test, a full size model was constructed, sea trials were performed, and the towing attitude was measured. The results were similar to those of the scale model test.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.5
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• pp.453-458
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• 2015

We presented a quad-rotor controlling algorithm design by using sensor fusion in this paper. The controller design technique was performed by a PD controller with a Kalman filter and compensation algorithm for increasing the stability and reliability of the quad-rotor attitude. In this paper, we propose an attitude estimation algorithm for quad-rotor based sensor fusion by using the Kalman filter. For this reason, firstly, we studied the platform configuration and principle of the quad-rotor. Secondly, the bias errors of a gyro sensor, acceleration and geomagnetic sensor are compensated. The measured values of each sensor are then fused via a Kalman filter. Finally, the performance of the proposed algorithm is evaluated through experimental data of attitude estimation. As a result, the proposed sensor fusion algorithm showed superior attitude estimation performance, and also proved that robust attitude estimation is possible even in disturbance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.2
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• pp.67-74
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• 2005

This paper concerns attitude controller design for a 3-staged launch vehicle which has movable nozzle TVC systems for all stages as its control systems. The PD-type control gains are determined by shaping the corresponding closed-loop natural frequencies for the purpose of guaranteeing the required stability margin. Bending filters are also designed to stabilize the bending modes by using parametric optimization method. The designed controllers are verified using six degree of freedom flight simulations in MATLAB.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.3
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• pp.307-317
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• 2008

Relaxed static stability(RSS) concept has been applied to improve aerodynamic performance of modem version supersonic jet fighter aircraft. Therefore, flight control system are necessary to stabilize an unstable aircraft and provides adequate handling qualities. Also, flight control systems of modem version aircraft employ a safety system to support emergency situations such as a pilot unknown attitude flight conditions of an aircraft in night flight-testing. This situation is dangerous because the aircraft can lose if the pilot not take recognizance of situation. Therefore, automatic recovery system is necessary. The system called the "Pilot Activated Recovery System" or PARS, provided a pilot initiated automatic maneuver capable of an aircraft recoveries in situations of unusual attitudes. This paper addresses the concept of PARS and designed using nonlinear control law design process based on model of supersonic jet trainer. And, this control law is verified by nonlinear analysis and real-time pilot evaluation using in-house software. The result of evaluation reveals that the PARS support recovery of an aircraft unusual attitude and improve a safety of an aircraft.

• Journal of Advanced Information Technology and Convergence
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• v.8 no.2
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• pp.101-110
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• 2018

This paper introduces feedback linearization (FL) based adaptive sliding mode control (ASMC) effective against ground effects of the quadrotor UAV. The proposed control has the capability of estimation and effective rejection of those effects by adaptive mechanism, which resulting stable attitude and positioning of the quadrotor. As output variables of quadrotor, x-y-z position and yaw angle are chosen. Dynamic extension of the quadrotor dynamics is obtained for terms of roll and pitch control input to be appeared explicitly in x-y-z dynamics, and then linear feedback control including a ground effect is designed. A sliding mode control (SMC) is designed with a class of FL including higher derivative terms, sliding surfaces for which is designed as a class of integral type of resulting closed loop dynamics. The asymptotic stability of the overall system was assured, based on Lyapunov stability methods. It was evaluated through some simulation that attitude control capability is stable under excessive estimation error for unknown ground effect and initial attitude of roll, pitch, and yaw angle of $30^{\circ}$ in all. Effectiveness of the proposed method was shown for quadrotor system with ground effects.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.2
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• pp.147-156
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• 2001

In this paper, a robust attitude control scheme based on Eigenaxis rotation for the spacecraft is proposed. Eigenaxis rotation transforms the attitude of spacecraft to the shortest path and is represented by quaternion. The control law consists of PD-type control part for the nominal system and the robust control part for compensating inertia uncertainty. For the proposed controller, stability analysis is performed and the performance is shown via computer simulation.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.788-792
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• 1993

The objective of this study is to develope a satellite dynamic simulator, which can test and analyze the performance of spacecraft attitude control, antenna pointing instruments, communication equipments and spacecraft components under the space environment. The satellite simulator can be used to predict the events such as malfunction and failure of satellites in space during operation and can be used to protect against emergencies. At first, the performance test system of attitude control is investigated which can simulate motion and verify stability of spacecraft. Our system consists of an attitude control main processor and a sub-processor including some real hardwares such as attitude sensors and actuators. In this paper, we describe the procedure of designing and manufacturing the dynamic simulator hardware, which consists of the central processor board, the sub-processor board and the sun sensor, and also communication between the components.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.584-589
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• 2000

When the liquid tanks only partially filled and under translational acceleration, large quantities of liquid move uncontrollably inside the tanks and generate the liquid sloshing effect. Liquid sloshing effect could be a severe problem in launch vehicle stability and control if the liquid modes of motion couple significantly with the launch vehicle's normal modes of motion. Several methods have been employed to reduce the effect of sloshing, such as introducing baffles inside the tanks or dividing a large tank into a number of smaller ones. These techniques, although helpful in some cases, do not succeed in canceling the sloshing effects. In this paper, An attitude controller is designed for a launch vehicle with liquid sloshing effect. Both PD controller and sloshing filter are designed for the objective. PD gains and design parameters are determined by optimal algorithm. The performance of the attitude controller is evaluated via computer simulations.

• Advances in aircraft and spacecraft science
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• v.9 no.5
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• pp.433-447
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• 2022

This work deals with an explicit guidance and control architecture for autonomous lunar ascent and orbit injection, i.e., the locally-flat near-optimal guidance, accompanied by nonlinear reduced-attitude control. This is a new explicit guidance scheme, based on the local projection of the position and velocity variables, in conjunction with the real-time solution of the associated minimum-time problem. A recently-introduced quaternion-based reduced-attitude control algorithm, which enjoys quasi-global stability properties, is employed to drive the longitudinal axis of the ascent vehicle toward the desired direction. Actuation, based on thrust vectoring, is modeled as well. Extensive Monte Carlo simulations prove the effectiveness of the guidance, control, and actuation architecture proposed in this study for precise lunar orbit insertion, in the presence of nonnominal flight conditions.