• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2325-2330
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• 2003

GPS based orbit determination system for the KOMPSAT-2 has been developed. Two types of orbit determination software such as operational orbit determination and precise orbit determination are designed and implemented. GPS navigation solutions from on-board the satellite are used for the operational orbit determination and raw measurements data such as C/A code pseudo-range and L1 carrier phase for the precise orbit determination. Operational concept, architectural design, software implementation, and performance test are described.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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• pp.304-307
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• 2004

Satellite orbit determination using angles only data from single ground station is carried out. The KOMPSAT-1 satellite mono-pulse angle tracking data from 9-meter S-band antenna at KARI site in Daejeon are used for the orbit determination. Various angle tracking arcs from one-day to five-day are processed and the orbit determination results are analyzed. Antenna pointing data are predicted based on the orbit determination results to check the possibility of re-acquisition and tracking of the satellite signal. Normal satellite mission operations including orbit determination, antenna prediction, satellite re-acquisition and automatic tracking from predicted antenna angle pointing data are concluded to be possible when three-day angle tracking data from single tracking station are used for the orbit determination.

• 한국치위생학회지
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• 제21권4호
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• pp.481-489
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• 2021

Objectives: This study was conducted to understand the effect of learners' self-determination on class participation, focusing on the feedback type of educators. Methods: A survey was conducted from May 1 to May 31 2021 on dental hygiene students, and a total of 151 valid responses were analyzed. The questionnaire consisted of general characteristics, self-determination, class participation, and educator's feedback type. The analysis method used correlation analysis and hierarchical regression analysis. Results: In relation to self-determination, class participation, and feedback type of educators, self-determination was positive feedback (r=0.338, p<0.01), class participation was corrective feedback (r=0.418, p<0.01), and positive feedback was correction (r=0.742, p<0.01). As a result of the mediating effect of the educator's feedback type in the relationship between self-determination and class participation, it was found to be significant by partially mediating positive and corrective feedback. Conclusions: It was found that the right to self-determination influences class participation based on positive feedback and corrective feedback of educators. It relates to efforts to strengthen learners' self-determination and provide appropriate types of feedback from educators.

• International Journal of Aeronautical and Space Sciences
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• 제1권1호
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• pp.70-80
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• 2000

The attitude knowledge error model is formulated for specifically KOMPSAT attitude determination system using the Lefferts/Markley/Shuster method, and the attitude determination(AD) error analysis is performed so as to investgate the on-board attitude determination capability of KOrea Multi-Purpose SATellite(KOMPSAT) using the covariance analysis method. Analysis results show there is almost no initial value effect on Attitude Determination (AD) error and the sensor noise effects on AD error are drastically decreased as is predicted because of the inherent characteristic of Kalman filter structure. However, it shows that the earth radiance effect of IR-sensor(earth sensor) and the bias effects of both IR-sensor and fine sun sensor are the dominant factors degrading AD error and gyro rate bias estimate error in AD system. Analysis results show that the attitude determination errors of roll, pitch and yaw axes are 0.056, 0.092 and 0.093 degrees, respectively. These numbers are smaller than the required values for the normal mission of KOMPSAT. Also, the selected on-orbit data of KOMPSAT is presented to demonstrate the designed AD system.

• Journal of Astronomy and Space Sciences
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• 제22권3호
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• pp.243-248
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• 2005

NORAD Two Line Element (TLE) is very useful to simplify the ground station antenna pointing and mission operations. When a satellite operations facility has the capability to determine NORAD type TLE which is independent of NORAD, it is important to analyze the applicable tracking data arcs for obtaining the best possible orbit. The applicable tracking data arcs for NORAD independent TLE orbit determination of the KOMPSAT-1 using GPS navigation solutions was analyzed for the best possible orbit determination and propagation results. Data spans of the GPS navigation solutions from 1 day to 5 days were used for TLE orbit determination and the results were used as Initial orbit for SGP4 orbit propagation. The operational orbit determination results using KOMPSAT-1 Mission Analysis and Planning System(MAPS) were used as references for the comparisons. The best-matched orbit determination was obtained when 3 days of GPS navigation solutions were used. The resulting 4 days of orbit propagation results were within 2 km of the KOMPSAI-1 MAPS results.

• International Journal of Advanced Culture Technology
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• 제5권2호
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• pp.63-73
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• 2017

In this paper, we propose algorithm for determining the static and dynamic posture using the acceleration sensor of smartphone. The measured acceleration values are then analyzed according to a preprocessing to the respective axis (X, Y, Z) and posture (standing, sitting, lying) presents static posture determination criterion. The proposed static posture determination condition is used for static posture determination and dynamic posture determination. The dynamic posture is determined by using regression linear equations. In addition, transition state can be grasped by SVM change in dynamic posture determination. Experimental results are presented using data and app. Experiments were performed using data collected from 10 adults.

• 제어로봇시스템학회논문지
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• 제9권10호
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• pp.852-860
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• 2003

We introduce the error models for an attitude determination system(ADS) with gyroscopes and stellar sensor. The ADS error models are derived according to the definition of the reference frame and of the attitude error. The equivalent error models applicable to the attitude determination system with large attitude errors are presented. The simulation results show that the proposed error models improve performance of the attitude determination system.

• 한국측량학회지
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• 제20권2호
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• pp.199-206
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• 2002

대부분의 노선선정에 있어서 GSIS의 적용은 노선선정시 고려되는 토지이용, 토공량, 지가등 몇 가지의 기본자료를 선택하여 데이터베이스를 구축하고 구축한 데이터를 분석하여 노선선정 방안을 제시하고 있다. 그러나 이러한 방안은 노선선정시 고려되는 다중인자들에 대한 복합적인 고려가 미미한 단계라고 할 수 있다. 이러한 문제를 해결하기 위하여 GSIS를 이용하여 최적노선 선정시 다중의사 결정 지원 및 노선선정 절차의 표준화를 시도하여야 한다. 따라서, 본 연구에서는 도로의 최적 노선선정시 AHP기법을 이용하여 다중인자의 정량화를 시도함으로서 노선선정에 이용되는 자료가 효율적으로 제공되어 최적의 노선선정이 되도록 하였다. AHP기법을 적용한 결과 종래의 노선선정시 다중인자들의 경중률을 임의로 적용하던 것보다 합리적으로 최적노선을 선정할 수 있었다.

• Journal of Positioning, Navigation, and Timing
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• 제13권2호
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• pp.199-206
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• 2024

The GEO-KOMPSAT-2A (GK2A) satellite, which was launched in December 2018, carries weather observation payloads and uses the image navigation and registration system to calibrate the observation images. The calibration system requires accurate orbit prediction data and depends on the accuracy of the orbit determination accuracy. In order to find a possible way to improve the current orbit determination accuracy of the GK2A flight dynamic subsystem module, orbit determination software was developed to independently evaluate the orbit determination accuracy. A comprehensive satellite dynamic model is applied for a batch-type least squares filter. When determining the orbit, thrust firing during station-keeping maneuvers and wheel-off loading maneuvers is taken into account. One month of GK2A ranging data were processed to estimate the satellite position on a daily basis. The orbit determination error was evaluated by comparing estimates during overlapping estimation intervals.

• 한국프랜차이즈경영연구
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• 제11권4호
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• pp.31-44
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• 2020

Purpose: The purpose of this study is to examine the effects of CEO's self-determination on entrepreneurship, business performance (operational and financial performance). Also, this research provide some strategic insights for improving business performance. In the proposed model, self-determination consists of autonomy, competence, and relatedness, and entrepreneurship consists of innovation, initiative and risk sensitivity, and proactiveness. More specifically, this study proposes a framework that entrepreneurship and operational performance will play mediating roles between self-determination and financial performance. Research design, data, methodology: In this study, an online survey was conducted on SME CEOs for analysis, and a total of 122 samples were used. In the analysis process for hypothesis verification and evaluation, frequency analysis was first performed to identify the demographic characteristics of the respondents, and confirmatory factor analysis was conducted to assess the reliability and validity of the measurement model. In addition, a structural model analysis was conducted to examine the structural relationships between CEO's self-determination, entrepreneurship, and business performance (operational and financial performance) using SmartPLS 3.0. Results: The findings and summary are as follows. First, the autonomy of self-determination has a positive effect on entrepreneurship. Second, the competence of self-determination affects entrepreneurship and operational performance. Third, it affects the innovation, initiative and risk sensitivity of the CEO's entrepreneurship, and ultimately, its operational performance. The results show that the business performance of Start-up also increases when self-determination can be a factor in increasing entrepreneurship in three sub-dimensionalities. Conclusions: The conclusion of this study is that in order for SMEs to develop into a sustainable company by securing competitiveness after start-up, external motivation such as external help and support from the state (local government) is important, but competence and relationship, which are components of self-determination. The intrinsic motivation of the CEO may be more important. To this end, CEO's should prioritize learning for competency development, and the government should pay attention to providing various educational programs through establishment of education policies and education systems to enhance the competency of start-up CEO's.