• 한국군사과학기술학회지
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• 제3권2호
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• pp.131-139
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• 2000

A design of CPS attitude determination system is described in this paper. The designed system is a low cost high precision 24 channel single frequency GPS(Global Positioning System) receiver which provides a precise absolute heading and pitch (or roll) as well as a position. It uses commercial chip-set and consists of two RF parts, two signal-tracking parts, a processor, memory parts and I/Os. In order to determine precise attitude, accurate carrier phase measurements and an efficient integer ambiguity resolution method are required. To meet these requirements, a PLL (Phase Locked Loops) is designed, and an algorithm called ARCE (Ambiguity Resolution with Constraint Equation) is adopted. The hardware and software structure of the system will be described, and the performance evaluated under various conditions will be presented. The test results will promise that more reliable navigation system be possible because the system provides all navigational information such as position, velocity, time and attitude.

• 가정과삶의질연구
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• 제17권3호
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• pp.171-186
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• 1999

The purpose of this study is to understand the perception of housework self-responsibility and attitude to paid labor substitution of wife and husband examining empirically characteristics of couple's type classified by a complex of perception and attitude. The data of this study were collected from 83 dual-earner couples and 76 one-earner couples having more than one child younger than 18 and living in Seoul. The major findings are as follow: First Wives perceived housework self-responsibility much higher than husbands regardless of wives' employment status particularly in female-oriented housework such as food- clothing-related and managerial housework. Second Couples expressed considerable reluctancy about paid labor substitution and one-earner couples showede more reluctancy. Third Four couple types were categorized by a complex perception and attitude. The are 'PLS-oriented & Wife responsibility couple' 'PLS-reluctancy & Wife responsibility couple' ' PLS-dependency couple 'Dual responsibility couple' Fourth the characteristics of each type showed difference according to socioeconomic status sex role attitude housework performance.

• International Journal of Aeronautical and Space Sciences
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• 제18권3호
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• pp.555-564
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• 2017

In this paper, a new technique for attitude and heading reference system (AHRS) using low-cost MEMS sensors of the gyroscope, accelerometer, and magnetometer is addressed particularly in vibration environments. The motion of MEMS sensors interact with the scale factor and cross-coupling errors to produce random errors by the harsh environment. A new adaptive attitude estimation algorithm based on the Kalman filter is developed to overcome these undesirable side effects by analyzing windowed measurement error covariance. The key idea is that performance degradation of accelerometers, for example, due to linear vibrations can be reduced by the proposed measurement error covariance analysis. The computed error covariance is utilized to the measurement covariance of Kalman filters adaptively. Finally, the proposed approach is verified by using numerical simulations and experiments in an acceleration phase and/or vibrating environments.

• 한국학교보건학회지
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• 제30권3호
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• pp.194-201
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• 2017

Purpose: The aim of the study was to identify factors influencing confidence in performing cardiopulmonary resuscitation (CPR) of university students. Methods: Data were collected from 261 students recruited from 2 cities using a questionnaire covering confidence, knowledge and attitude in regard to CPR. Results: There was a significant positive correlation between confidence and knowledge (r=.37, p<.001), between attitude and confidence (r=.61, p<.001), and between knowledge and attitude (r=.61, p<.001). Confidence in performance increased as knowledge, attitude, grade, CPR training frequency and educational satisfaction increased. Conclusion: There is a need for CPR training programs that can improve practical training and educational satisfaction of university students.

• Journal of Astronomy and Space Sciences
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• 제30권1호
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• pp.1-10
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• 2013

An integrated orbit and attitude control algorithm for satellite formation flying was developed, and an integrated orbit and attitude software-in-the-loop (SIL) simulator was also developed to test and verify the integrated control algorithm. The integrated algorithm includes state-dependent Riccati equation (SDRE) control algorithm and PD feedback control algorithm as orbit and attitude controller respectively and configures the two algorithms with an integrating effect. The integrated SIL simulator largely comprises an orbit SIL simulator for orbit determination and control, and attitude SIL simulator for attitude determination and control. The two SIL simulators were designed considering the performance and characteristics of related hardware-in-the-loop (HIL) simulators and were combined into the integrated SIL simulator. To verify the developed integrated SIL simulator with the integrated control algorithm, an orbit simulation and integrated orbit and attitude simulation were performed for a formation reconfiguration scenario using the orbit SIL simulator and the integrated SIL simulator, respectively. Then, the two simulation results were compared and analyzed with each other. As a result, the user satellite in both simulations achieved successful formation reconfiguration, and the results of the integrated simulation were closer to those of actual satellite than the orbit simulation. The integrated orbit and attitude control algorithm verified in this study enables us to perform more realistic orbit control for satellite formation flying. In addition, the integrated orbit and attitude SIL simulator is able to provide the environment of easy test and verification not only for the existing diverse orbit or attitude control algorithms but also for integrated orbit and attitude control algorithms.

• International Journal of Aeronautical and Space Sciences
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• 제11권2호
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• pp.80-86
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• 2010

We propose a spacecraft attitude estimation algorithm using a federated unscented Kalman filter. For nonlinear spacecraft systems, the unscented Kalman filter provides better performance than the extended Kalman filter. Also, the decentralized scheme in the federated configuration makes a robust system because a sensor fault can be easily detected and isolated by the fault detection and isolation algorithm through a sensitivity factor. Using the proposed algorithm, the spacecraft can continuously perform a given mission despite navigation sensor faults. Numerical simulation is performed to verify the performance of the proposed attitude estimation algorithm.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2005년도 한국우주과학회보 제14권1호
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• pp.133-137
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• 2005

우주시스템 연구실에서 개발 중인 HAUSAT-2의 피치모멘텀 바이어스 시스템을 설계하고 성능을 검증하였다. HAUSAT-2의 자세제어시스템은 초기자세획득모드와 정상모드로 분리되어 궤도에서 운용된다. 본 논문은 피치모멘텀 바이어스 시스템을 사용하여 위성이 운용될 경우 각 모드에 따라 자세제어가 가능한 범위를 해석하였고 ,모멘팀 휠 구동에 의하여 발생되는 모멘팀 덤핑 현상에 대하여 연구하였다.

• 제어로봇시스템학회논문지
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• 제10권10호
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• pp.956-960
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• 2004

The Vehicle Dynamic Simulator(VDS) is a key equipment of the performance verification of attitude control subsystem and it simulates the real dynamic environment that spacecraft undergoes during mission operation. All the software models and hardware interfaces necessary for the closed-loop simulation of the spacecraft dynamics are implemented. Using VDS, KOMPAT-2 attitude control logic functions and performance was verified. In this paper, the hardware and software configurations of KOMPSAT-2 VDS was described briefly and the information flow and exchanges between software models and actual hardwares during close loop simulation was described in the systematic point of view.

• Journal of Biosystems Engineering
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• 제32권4호
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• pp.230-236
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• 2007

In this study, a tail rotor system for an agricultural RF controlled helicopter was developed and tested. This study concluded the mechanical development of the 'Agro-heli' by completing the tail rotor system and its radio console. The RF control system was closely related with the tail system for the control of flying attitude. The thrust of the tail system balance off the reaction torque, created by the main rotor. Lifting tests with and without the tail system were compared for estimating the consumption of power. The tail system would use $4{\sim}5%$ of the total power which was in an acceptable range. Flying performance and attitude was visually inspected. It showed reliable and safe control during the distance flying trials and could be adapted for utilization in aerial applications. Aerial application using an RF controlled agricultural helicopter may make precise and timely spraying possible.

• 한국산학기술학회논문지
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• 제14권11호
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• pp.5714-5722
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• 2013

본 연구는 임상실습 전 간호대학생의 손씻기 관련 특성과 손씻기 지식과 태도 및 수행도를 파악하여 올바른 손씻기 교육프로그램 개발에 관한 기초자료를 제공하고자 시행되었다. 3개 대학의 간호대학생 418명을 대상으로 2011년 9월부터 10월까지 설문지를 이용하여 자료수집을 하였다. 연구결과, 대상자의 1일 평균 손씻기 수는 7.2회, 시간은 평균 19.1초였다. 대상자의 손씻기 지식, 태도, 수행도 점수는 각각 11.34점(1~15), 3.42점(1~5), 3.6점(1~5)이었다. 손씻기에 적당한 소요시간, 손을 씻은 후의 주의사항 등에 대해서는 절반 이상의 대상자가 잘 모르고 있는 것으로 나타났으며, 손씻기 전 시계를 제거하는 것, 코를 만지거나 기침한 후, 돈을 만진 후에 손을 씻는 것 등은 수행이 잘 이루어지지 않는 것으로 조사되었다. 이상의 결과를 바탕으로 간호대학생들의 손씻기 수행도 증가를 위한 교육프로그램을 개발하여 반복교육을 실시함으로써 올바른 습관형성이 이루어지도록 해야 할 것이다.