• 동서간호학연구지
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• 제22권2호
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• pp.104-112
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• 2016

Purpose: This study aimed to investigate the effects of organ donation education on undergraduate students' knowledge, attitude and practice will to organ donation. Methods: The study used a quasi-experimental design. A total of 164 students from K university, Seoul, Korea were recruited; 74 in the experimental group and 90 in the control group. The experimental group received an education on organ donation developed by researchers. A structured questionnaire was used to measure the student's knowledge, attitude and practice will to organ donation before and after the education. Data were analyzed using t-test, ${\chi}^2$-test, and ANCOVA with SPSS WIN 21.0 program. Results: After the intervention, we found that the scores of knowledge, knowledge of the definition of brain death, donation attitude, total scores of attitude, emotional attitude, and behavioral attitude were significantly higher in the experimental group than the those of control group. Total knowledge scores were positively correlated with subscales of the knowledge scale and all subscales of attitude toward organ donation. Conclusion: The results indicate that organ donation education is effective to enhance knowledge and attitude to organ donation in undergraduate students.

• 제어로봇시스템학회논문지
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• 제20권4호
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• pp.468-473
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• 2014

This paper describes the in-flight alignment of SDINS (Strapdown Inertial Navigation Systems) using an EKF (Extended Kalman Filter) and a UKF (Unscented Kalam Filter), which allow large initial attitude error uncertainty. Regardless of the inertial sensors, there are nonlinear error dynamics of SDINS in cases of large initial attitude errors. A UKF that is one of the nonlinear filtering approaches for IFA (In-Flight Alignment) are used to estimate the attitude errors. Even though the EKF linearized model makes velocity errors when predicting incorrectly in case of large attitude errors, a UKF can represent correctly the velocity errors variations of attitude errors with nonlinear attitude error components. Simulation results and analyses show that a UKF works well to handle large initial attitude errors of SDINS and the alignment error attitude estimation performance are quite improved.

• 한국의류산업학회지
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• 제16권2호
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• pp.235-244
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• 2014

This study investigates the effect of visual merchandising congruity perception on brand attitude and purchase intention. In addition, this study examines the mediating role of perceived risk in the process. Four retail fashion brands with classic image were selected in the previous research to avoid the influence of different brand images. Questionnaires were distributed to 200 customers leaving the four fashion retail stores which were chosen by the previous research. A total of 167 completed questionnaires were analyzed using SPSS 18.0 and AMOS 7.0 statistical packages. The results were summarized as follows. First, visual merchandising congruity perception positively affected brand attitude. This result supports the match-up hypothesis. Second, brand attitude positively influenced purchase intention. Third, visual merchandising congruity perception did not directly affect purchase intention. Visual merchandising congruity perception indirectly influenced purchase intention by mediating brand attitude; however, it did not directly influence purchase intention. Therefore, the strategic approaches to enhance favorable brand attitude through visual merchandising congruity perception should be tried. Fourth, visual merchandising congruity perception negatively affected perceived risk. Fifth, perceived risk negatively affected brand attitude. Sixth, visual merchandising congruity perception affected brand attitude by mediating perceived risk. Therefore, it is needed to devise the visual merchandising strategy that lowers the perceived risk in order to make a positive brand attitude.

• International Journal of Aeronautical and Space Sciences
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• 제11권4호
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• pp.303-312
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• 2010

This paper introduces the upper stage attitude control system of KSLV-I, which is the first space launch vehicle in Korea. The KSLV-I upper stage attitude control system consists of two electro-hydraulic actuators and a reaction control system using cold nitrogen gas. A proportional, derivative, and integral controller is designed for the electro-hydraulic thrust vectoring system, and Schmidt trigger ON/OFF controllers are designed for the reaction control system. Each attitude controller is designed to have enough stability margins. The stability and performance of KSLV-I upper stage attitude control system is verified via hardware in the loop tests. Hardware in the loop tests are accomplished for perturbed flight conditions as well as nominal flight condition. The test results show that the attitude control loop of KSLV-I upper stage is very stable and the attitude controllers perform well for all flight conditions. Attitude controllers designed in this paper have been successfully applied to the first flight of KSLV-I on August 25, 2009. The flight test results show that all attitude controllers of the KSLV-I upper stage performed well and satisfied the accuracy specifications even during abnormal flight conditions.

• Current Research on Agriculture and Life Sciences
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• 제32권3호
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• pp.159-163
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• 2014

본 논문에서는 저가의 MEMS 관성 센서와 지자기 센서를 이용하여 자세 정보를 제공받는 자세측정장치(ARHS)를 구현하였다. 저가형 IMU센서와 MCU를 이용하여 운동 자세각을 계산하는 DCM 알고리즘을 설계하고, 3축짐벌에 장착하여 연산결과의 정확도를 측정하였다. DCM 알고리즘을 이용 연산된 자세각의 정확도는 roll 및 pitch에 대하여 약 1.1%로 나타났으며, yaw각의 경우는 3.7%로 나타났다. Yaw 각의 경우에는 스텝핑 모터를 구동하는 실험환경에 따른 교란의 영향으로 그 오차가 상대적으로 크게 나타난 것으로 평가되었다. 짐벌 실험장치를 이용한 센서의 검증에서 더욱 정밀한 실험을 위해서는 주변 환경 요인에 대한 제어가 요구될 것으로 보이며, 실험장치의 스테핑 모터 구동 시 발생하는 진동 및 자기장의 영향과 실험 장치의 금속성 구조물의 영향으로 생각되는 센서 데이터의 오차 및 불안정 상태를 차단할 수 있는 장치의 보완이 필요할 것으로 보인다. 그리고 지자기 센서의 경우 좁은 범위의 측정에 추가하여 넓은 범위의 측정도 보완되어야 할 것으로 생각된다.

• Journal of Electrical Engineering and Technology
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• 제7권4호
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• pp.615-625
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• 2012

GPS attitude outputs or carrier phase observables can be effectively utilized to compensate the attitude error of the strapdown inertial navigation system. However, when the integer ambiguity is not correctly resolved and/or a cycle slip occurs, an erroneous GPS output can be obtained. If the erroneous GPS output is applied to the attitude determination GPS/INS (ADGPS/INS) integrated navigation system, the performance of the system can be degraded. This paper proposes an ADGPS/INS integration system using the triple difference carrier phase observables. The proposed integration system contains a cycle slip detection algorithm, in which the inertial information is combined. Computer simulations and flight test were performed to verify effectiveness of the proposed navigation system. Results show that the proposed system gives an accurate and reliable navigation solution even when the integer ambiguity is not correctly resolved and the cycle slip occurs.

• 대한간호학회지
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• 제41권4호
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• pp.539-549
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• 2011

Purpose: The purpose of this study was to identify attitudes of adolescents toward suicide. Methods: Q-methodology which provides a method of analyzing the subjectivity of each item was used. Thirty middle and high school students classified 37 selected statements into a normal distribution using a 9 point scale. Collected data were analyzed using the Quanl PC Program. Results: Three types of attitudes toward suicide were identified. The first type (opposing suicide-moral minded) showed an attitude of opposing suicide and thinking that suicide is a sin. The second type (understanding-empathizing suicidal person) showed an attitude of understanding the situation of the adolescents who has suicidal ideation and empathizing with them. The third type (ambivalent attitude) showed an attitude of understanding the suicidal person but, at the same time, opposing suicide. Conclusion: Results of the study indicate that different approaches to suicide prevention programs should be developed based on the three types of suicide attitudes among adolescents.

• 한국수학교육학회지시리즈A:수학교육
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• 제49권1호
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• pp.1-14
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• 2010

In this paper, we study the effects of the Mathematical attitude and Disposition to the myself evaluation using the peer-evaluation feedback in in-group team teaching. For this purpose we construct a experimental class and then analyse the students' change in those aspects after applying peer-evaluation feedback made some significant changes on the students attitude in mathematics and Disposition. First, the results for this purpose on regarding the enhancement of mathematical attitude are effective. Second, the results on regarding the improvement of Disposition are effective.

• International Journal of Aeronautical and Space Sciences
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• 제3권2호
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• pp.1-12
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• 2002

This paper considers the robust and optimal three-axis attitude stabilization of rigid spacecraft with inertia uncertainties. The attitude motion of rigid spacecraft described in terms of either the Cayley-Rodrigues parameters or the Modified Rodrigues parameters is considered. A class of robust nonlinear control laws with relaxed feedback gain structures is proposed for attitude stabilization of rigid spacecraft with inertia uncertainties. Global asymptotic stability of the proposed control laws is shown by using the LaSalle Invariance Principle. The optimality properties of the proposed control laws are also investigated by using the Hamilton-Jacobi theory. A numerical example is given to illustrate the theoretical results presented in this paper.

• Journal of Astronomy and Space Sciences
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• 제15권1호
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• pp.245-250
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• 1998

위성 체의 자세결정과 자세제어는 인공위성의 임무수행능력을 결정하는 중요한 요인으로 그 정밀도를 탑재된 센서와 자세제어 구동기의 성능에 의해 결정된다. 본 연구는 비선 형 제어이론과 선형 제어이론을 적용하여 4개의 반작용 휠을 사용하는 3축 안정화 지구지향위성의 자세 제어법칙을 디자인하고 작동범위의 크기에 따른 제어 방법의 적합성을 비교하였다. 또한 휠 속도 한계를 초과하는 것을 방지하기 위해 자기 토커를 사용하여 휠모멘텀을 제거할 수 있음을 확인하였다. 이 때 반작용 휠은 전력소모를 최소화시키도록 배치된 경우로, 자기 토커는 3축 직교 자기 토커로 가정하였다. 휠 속도를 제어하는 휠 토커의 크기는 한계 치를 초과하지 않도록 디자인하였다.