• Aerospace Engineering and Technology
• /
• v.1 no.1
• /
• pp.65-71
• /
• 2002

KOMPSAT-1 AOCS mode divided into three major mode like Sun, Maneuver, Science Mode. The Maneuver mode consist of attitude hold and Δ-V Burn submode. This paper focus on the analysis of AOCS Maneuver Mode characteristics based on on-orbit playback data. The nadir pointing performance of attitude hold submode and the process for Δ-V Burn firing with plus/ minus 90 degree pitch/ roll maneuvering was verified. And also verified that the on-orbit performance meets the AOCS subsystem specification as designed.

• Journal of Korean Home Economics Education Association
• /
• v.4 no.1
• /
• pp.31-41
• /
• 1992

The central goal of this study is to find out of the boy students in middle school the attitude towards house life and house-hold affairs of the boys； and explain what will be of their attitude after they have got Home Economics education. For the purpose of this study, 138 questionairs were distributed to the boy students who had educated Home Economics in school and the ones who had not. The results were as follows； 1. The educated group has higher score in ability of house-hold making than the other group. 2. The educated students responed affirmatively to the utility and necessity of Home Economics education. 3. The teachers who have taught Home Economics to male students have opinions that the students needed Home Economics education to increase the ability of doing house-hold work. Accordingly, Home Economics education should be taught to both sexes in order to have good quality of life, and requires more hours to study as well.

• Journal of the Korean Home Economics Association
• /
• v.36 no.5
• /
• pp.125-135
• /
• 1998

The purpose of this study is to investigate the overall levels of the middle-aged employed men's attitudes toward retirement and plans for post-retirement life, and to explore the relative effects of personal, family, and job characteristics on retirement attitude and the level of retirement plan. The data were collected from the 438 middle-aged (ranging from 41 to 50) employed men through the structured questionnaires. The data were analyzed using frequency, percentile, average, standard deviation, and multiple regression analysis. The results of the data analysis show that most of the respondents had neither positive nor negative attitude toward retirement and the level of planning for post-retirement life was slightly higher than average score on the scale. Next, the positive attitudes of middle-aged employed men toward retirement were observed from those who have higher education, larger household income, higher job security and lower job stress respondents who hold professional, administrative, or official jobs were more positive toward retirement than those who hold professional, administrative, or official jobs were more positive toward retirement than those who hold manufacturing or sales job. A well-planned post-retirement life was found among those who have better health, higher job satisfaction, job security and job orientation. Job characteristic variables such as job security and job satisfaction showed stronger impact than personal or family ones on the attitude toward retirement and the level of retirement planning. Household income and health also had significant effects.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1392-1395
• /
• 2004

In order to successfully develop attitude and orbit control subsystem(AOCS), AOCS engineer performs hardware selection, controller design and analysis, control logic and interface verification on electrical test bed, integrated system test, polarity test, and finally verification on orbit after launching. Attitude and orbit control subsystem for KOMPSAT-2 consists of standby mode, sun mode, maneuver mode, science mode, and power safe mode to stabilize and to control the spacecraft for performing the mission. The sun mode is usually divided into sun point submode, earth search submode and safe hold submode. The maneuver mode is divided into attitude hold submode and ${\triangle}$ V submode, while the science mode divided into science coarse submode and science fine submode. Moreover, it is added to back-up mode which uses wheels as an actuator for sun mode and maneuver mode. In this paper, we describe the controller design process and the performance of the design results with respect to the sun mode and the maneuver mode based on thrusters as an actuator using on flexible model.

• Journal of Institute of Control, Robotics and Systems
• /
• v.20 no.11
• /
• pp.1103-1111
• /
• 2014

The results of control law design for a tilt-rotor unmanned aerial vehicle that has a nacelle mounted wing extension (WE) are presented in this paper. It consists of a control surface mixer, stability and control augmentation system (SCAS), hold mode for altitude / speed / heading, and a guidance mode for preprogram and point navigation which includes automatic take-off and landing. The conversion corridor and the control moments derivatives between the original tilt-rotor and its variant of the nacelle mounted WE were compared to show the effectiveness of the WE. The nacelle conversion of the original tilt-rotor starts when the airspeed is greater than 30 km/h but its WE variant starts at 0 km/h in order to reduce the drag caused by the high incidence angle of the WE. The stability margins of the inner loop are presented with the optimization approach. The outer loops for the hold mode are designed with trial and error methods with linear and nonlinear simulation. The main control parameter for altitude control of the helicopter mode is thrust command and it is transferred to the pitch attitude command in airplane mode. Otherwise, the control parameter for the speed of the helicopter mode is the pitch attitude command and it is transferred to the thrust command in airplane mode. Therefore the speed and altitude hold mode are coupled to each other and are engaged at the same time when an internal pilot engages any of the altitude or speed hold modes. The nonlinear simulation results of the guidance control for the preprogrammed mode and point navigation are also presented including automatic take-off and landing in order to prove the full control law.

• Asian Journal for Public Opinion Research
• /
• v.2 no.3
• /
• pp.196-227
• /
• 2015

The premise of the intentional model of split-ticket voting is that some voters split their tickets simply because they prefer divided government and believe in constant "checks and balances." This article examines whether this premise stands firm in an emerging democracy like Taiwan. That is, by using survey data in Taiwan, we explore whether one's attitude toward divided or unified government is "real." We hypothesize that a citizen's attitude toward "checks and balances" is subject to change, and conditional on whether her preferred party is in power. Specifically, we speculate that a citizen would tend to hold the balancing perspective or favor divided government, if her preferred party is in opposition. However, if her preferred party becomes the ruling party, she would be more likely to oppose (hold) the balancing (non-balancing) perspective or favor unified government. We then utilize panel survey data embedded in Taiwan's Election and Democratization Studies (TEDS) to verify our hypothesis.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.57-62
• /
• 2004

This paper deals with a waypoint trajectory following problem for the tilt-rotor UAV under development in Korea (TR-KUAV). In this problem, dynamic model inversion based on the linearized model and Sigma-Phi neural network with adaptive weight update are involved to realize the waypoint following algorithm for the vehicle in the helicopter flight mode (nacelle angle=0 deg). This algorithms consists of two main parts: outer-loop system as a command generator and inner-loop system as stabilizing controller. In this waypoint following problem, the position information in the inertial axis is given to the outer-loop system. From this information, Attitude Command/Attitude Hold logic in the longitudinal channel and Rate Command/Attitude Hold logic in the lateral channel are realized in the inner-loop part of the overall structure of the waypoint following algorithm. The nonlinear simulation based on the TR-KUAV is carried out to evaluate the stability and performance of the algorithm. From the numerical simulation results, the algorithm shows very good tracking performance of passing the waypoints given. Especially, it is observed that ACAH/RCAH logic in the inner-loop has the satisfactory performance due to adaptive neural network in spite of the model error coming from the linear model based inversion.

• International Journal of Aeronautical and Space Sciences
• /
• v.9 no.1
• /
• pp.76-84
• /
• 2008

This paper is mainly concerned with the vision-based attitude stabilization of a quad-rotor UAV. The methods for attitude control rely on computing the roll and pitch angles of the vehicle from a two-camera vision system. One camera is attached to the body-fixed x-axis and the other to the body-fixed y-axis. The attitude computation for the quad-rotor UAV is performed by image processing consisting of Canny edge and Hough line detection. A proportional and integral controller is employed for the attitude hold autopilot. In this paper, the quad-rotor UAV is modeled by 6-DOF nonlinear equations of motion that includes rotor aerodynamics with blade element theory. The performance of the proposed method is evaluated through 3D environmental numerical simulations.

• International Journal of Aeronautical and Space Sciences
• /
• v.13 no.4
• /
• pp.468-473
• /
• 2012

Cost is an important aspect in designing a target drone, however the poor performance of low cost IMU, GPS, and microcontrollers prevents the use of complex algorithms, such as ARS, or INS/GPS to estimate attitude angles. We propose an autopilot which uses rate gyro and GPS only for a target drone to follow a prescribed path for anti-aircraft training. The autopilot consists of an altitude hold, roll hold, and path following controller. The altitude hold controller uses vertical speed output from a GPS to improve phugoid damping. The roll hold controller feeds back yaw rate after filtering the dutch roll oscillation to estimate the roll angle. The path following controller operates as an outer loop of the altitude and roll hold controllers. A 6-DOF simulation showed that the proposed autopilot guides the target drone to follow a prescribed path well from the view point of anti-aircraft gun training.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.16 no.3
• /
• pp.7-14
• /
• 2008

In modern aircraft, an autopilot system is getting more important. There are not many autopilot systems applied to small aircraft. Also the autopilot system in large or medium aircraft is difficult to apply to small aircraft directly. It is necessary to make a new autopilot system for small aircraft. In this paper, we implement the small aircraft simulator with autopilot system using SIMULINK. The various modes of autopilot - such as altitude select/hold, attitude hold, heading hold, etc. - are implemented to the flight simulator and tested. We also implement the VOR mode for aircraft guidance.