• 한국기계가공학회지
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• 제9권4호
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• pp.26-31
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• 2010

Finding sufficient supplies of clean energy for future is one of the society's most important challenges according to technologies. Alternative renewable energy source such as solar energy can be substituted for exceeding human energy need. The main factor affect to solar performance is a collective intensity. To enhance intensity, suitable equipment is a solar tracker. The solar tracker consists of sun point detector module, mechanical mechanism module with actuator and control system module. This paper presents sun point detector for solar tracker of daylight system. To evaluate the detecting accuracy, an experimental device is implemented. In experimental results, the accuracy of development system has under 0.11%/0.5deg.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.36-40
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• 2003

The considered satellite is supposed to operate in the earth-point mode and sun-point mode in accordance with the mission requirements. The magnetic field correction is based on the orbit geometry using a set of measured magnetic field data from the three-axis-magnetometer and its algorithm excludes the earth’s magnetic field model. Moreover, the usefulness of the proposed method is investigated throughout the simulation of KOMPSAT-1.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.496-499
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• 1991

Photovoltaic system has very low energy conversion efficiency and the output characteristics of solar cell is varied by the Insolation quantity and the temperature. In order to improve the efficiency of photovoltaic system, the energy which has got from solar cell must be use maximum. In this paper, it was stimultaneous executed both MPPT control and instrumentation in order that the operating point of solar cell is located maximum power point, using the PWM inverter and micro-computer, which is for the purpose of acquiring maximum power from the solar cell. As a result, maximum power point tracking had carried out and the efficiency of photovoltaic system improved, even if insolation quantity and the temperature are varied.

• 한국의상디자인학회지
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• 제25권3호
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• pp.157-164
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• 2023

The purpose of this study is to compare and analyze bust point information presented in literature and the 8th Korean Anthropometric Survey (Size Korea 2021) as a basis for pattern making for Korean adult women. Therefore, the the bust point position was analyzed through the length from the side neckline to the bust point and the horizontal length from the bust point to the chest. The results are as follows. First, Size Korea's population shows an increase in bust circumference and Side Neck Point to Bust Point with age, with the largest Bust-Point Breadth in the 30s, followed by the 20s, 40s, 60s, and 50s. Second, the Bust-Point Breadth in the female Basic Bodice pattern of Kang Soon-hee, and Oh Sun-hee, which were created from the bust circumference measurements of Size Korea's population, was wider than the measurements, and the difference was verified as a highly significant. Third, in the female Basic Bodice pattern of Kang Soon-hee, and Oh Sun-hee created with the bust circumference dimensions of Size Korea's population, the length of Neck Point to Bust Point was shorter than the measured value, and the difference was highly significant. Fourth, the Bust-Point Breadth and Neck Point to Bust Point in the female Basic Bodice pattern of Kang Soon-hee, and Oh Sun-hee, which were created with the bust circumference of the population of Size Korea by age, were analyzed in different age groups and showed significant differences from the measurements of Size Korea.

• Kyungpook Mathematical Journal
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• 제55권1호
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• pp.103-107
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• 2015

In this paper, we investigate the stability of Pompeiu's points in the sense of Hyers-Ulam.

• 대한임베디드공학회논문지
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• 제8권4호
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• pp.205-212
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• 2013

In recent, the demand of Unmanned Aerial Vehicles (UAVs) that can autonomous navigation and remote control has been increased in military, civil and commercial field. Particularly, existing researches focused on autonomous navigation method based on vanish point and remote control method based on event processing in indoor environments. However, the existing methods have some problems. For instance, a detected vanish point in intersection point has too much detection errors. In addition, the delay is increased in existing remote control system for processing images in real time. Thus, we propose improved vanish point algorithm by removing detection errors in intersection point. We also develop a remote control system with android platform by separating flying control and image process. Finally, we compare the proposed methods with existing methods to show the improvement of our approaches.

• Journal of Astronomy and Space Sciences
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• 제38권2호
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• pp.145-155
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• 2021

In this work, preliminary launch opportunities from NARO Space Center to the Sun-Earth Lagrange point are analyzed. Among five different Sun-Earth Lagrange points, L1 and L2 points are selected as suitable candidates for, respectively, solar and astrophysics missions. With high fidelity dynamics models, the L1 and L2 point targeting problem is formulated regarding the location of NARO Space Center and relevant Target Interface Point (TIP) for each different launch date is derived including launch injection energy per unit mass (C3), Right ascension of the injection orbit Apoapsis Vector (RAV) and Declination of the injection orbit Apoapsis Vector (DAV). Potential launch periods to achieve L1 and L2 transfer trajectory are also investigated regarding coasting characteristics from NARO Space Center. The magnitude of the Lagrange Orbit Insertion (LOI) burn, as well as the Orbit Maintenance (OM) maneuver to maintain more than one year of mission orbit around the Lagrange points, is also derived as an example. Even the current work has been made under many assumptions as there are no specific mission goals currently defined yet, so results from the current work could be a good starting point to extend diversities of future Korean deep-space missions.

• Journal of applied mathematics & informatics
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• 제27권1_2호
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• pp.343-350
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• 2009

We prove the existence of common fixed point for multivalued maps satisfying general contractive type conditions.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2108-2111
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• 2005

The mission life of a satellite determines the amount of fuel required on-board, while the total mass requirement limits the fuel to be loaded. Hence, for the design of thruster control loop, not only the satellite pointing accuracy but the saving of fuel is to be considered. In this paper, a two-step fuzzy controller is proposed for the thruster control loop to save fuel consumption. This approach combines requirements for pointing control accuracy with minimum fuel consumption into a fuzzy controller design. To demonstrate this approach, we have designed a fuzzy controller for the Sun point Mode of KOMPSAT-2. The performance of this fuzzy controller design is compared with that of PD controller used for KOMPSAT-2.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2017년도 추계학술발표대회
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• pp.1244-1245
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• 2017

Using a small computer called Raspberry Pie, the webcam is interlocked with the webcam to detect the desired color using hsv and find the representative line using the hough transform in the detected color. Another new line is extracted and the coordinates where the lines meet are called the vanishing point and we want to make a system that autonomously travels through the vanishing point.