• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.65-69
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• 2018

In this paper, we have developed a multi-attitude monitoring system for running farm robots for field farming. There are many agricultural robots that can select work modules for various tasks. In order to control the stable attitude of agricultural robots connected to each other, we developed a system for monitoring the roll angle and pitch angle difference by fusing the information of the attitude monitoring system mounted on the robot mainframe and the work module. The developed attitude monitoring system showed resolution below 1 degree. In this paper, roll angle difference of 20 degrees and 60 degrees is measured with a multi - attitude monitoring system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.4
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• pp.343-352
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• 2016

A multi-rotor vehicle is an unmanned vehicle consisting of multiple rotors. A multi-rotor vehicle can be categorized as tri-, quad-, hexa-, and octo-rotor depending on the number of the rotors. Multi-rotor vehicles have many advantages due to their agile flight capabilities such as the ability for vertical take-off, landing and hovering. Thus, they can be widely used for various applications including surveillance and monitoring in urban areas. Since multi-rotors are subject to uncertain environments and disturbances, it is required to implement robust attitude stabilization and flight control techniques to compensate for this uncertainty. In this research, an advanced nonlinear control algorithm, i.e. sliding mode control, was implemented. Flight experiments were carried out using an onboard flight control computer and various real-time autonomous attitude adjustments. The feasibility and robustness for flying in uncertain environments were also verified through real-time tests based on disturbances to the multi-rotor vehicle.

• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.89-95
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• 2003

In this study, the technical characteristics of geosynchronous multi-mission satellites are investigated, compared to communication satellites. Geosynchronous meteorological satellites, whose imaging data is normally shared with the international society, have large coverage for monitoring and data service. Also the higher pointing accuracy is requested to keep the spatial resolution of 1-4km, compared to those of communication satellites. Cryogenic thermal control is needed for the better performance of IR sensors and the contamination protection of optical parts should be considered. On the other hands, for the successful development of the multi-mission satellite COMS, which will be launched in 2008, the special features of attitude control, electrical power, thermal control and mechanism are investigated.

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.393-406
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• 2018

Every year in the ocean, various accidents occur frequently and illegal fishing is rampant. Moreover, their size and frequency are also increasing. In order to reduce losses of life or property caused by these, it is necessary to have a means to perform remote monitoring quickly. As an effective platform of such monitoring means, an Unmanned Aerial Vehicle (UAV) is receiving the spotlight. In these situations where marine accidents or illegal fishing occur, main targets of monitoring are ships. In this study, we propose a UAV based ship monitoring system and suggest a method of determining ship positions using UAV multi-sensory data. In the proposed method, firstly, the position and attitude of individual images are determined by using the pre-performed system calibration results and GPS/INS data obtained at the time when images were acquired. In addition, after the ship being detected automatically or semi-automatically from the individual images, the absolute coordinates of the detected ships are determined. The proposed method was applied to actual data measured at 200 m, 350 m, and 500 m altitude, the ship position can be determined with accuracy of 4.068 m, 8.916 m, and 13.734 m, respectively. According to the minimum standard of a hydrographical survey, the ship positioning results of 200 m and 350 m data satisfy grade S and the results of 500 m data do grade 1a, where the accuracy is required for positioning the coastline and topography less significant to navigation order. Therefore, it is expected that the proposed method can be effectively used for various purposes of marine monitoring or surveying.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.186-196
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• 1999

The CPS provides data with long-term stability independent of passed time and the INS provides high-rate data with short-term stability. By integrating these complementary systems, a highly accurate navigation system can be achieved. In this paper, a loosely-coupled GPS/INS integration system is designed. It is a simple structure and is easy to implement and preserves independent navigation capability of GPS and INS. The integration system consists of a NCU, an IMU, a GPS receiver, and a monitoring system. The navigation algorithm in the NCU is designed under the multi-tasking environment based on a real-time kernel system and the monitoring system is designed using the Visual C++. The integrated Kalman filter is designed as a feedback formed 15-state filter, in which the states are position errors, velocity errors, attitude errors and sensor bias errors. The van test result shows that the integrated system provides more accurate navigation solution then the inertial or the GPS-alone navigation system.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.364-367
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• 2004

This paper presents the flight software of KoDSat (KSLV-l Demonstration Satellite) which performs demonstrating the KSLV-l (Korea Space Launch Vehicle-l)'s satellite launch capability. The KoDSat Flight Software executes in a single-processor, multi-function flight computer on the spacecraft, the OBC (On Board Computer). The flight software running on the single processor is responsible for all real-time processing associated with: processor startup and hardware initialization, task scheduling, RS422 handling function, command and data handling including uplink command and down-link telemetry, attitude determination and control, battery state of charge monitoring and control, thermal control processing.

• Journal of Korea Game Society
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• v.17 no.2
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• pp.123-134
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• 2017

The purpose of this study is to investigate how teachers' acceptance of digital games is constructed in the school context and what factors influence teachers' acceptance. To do this, we conducted a survey on teachers, school counselors, and professional counselors in August 2016. A total of 250 data were analyzed. As a result, it was confirmed that the teachers' acceptance of digital game is composed of 5 factors - need for supervision, willingness to use, concern & monitoring, acceptance as alternative activities, acceptance efficacy. As a result of multi-variate multiple regression analysis, it was found that the teacher's age, the 2 factors of digital media literacy, the teacher's attitude toward student's digital game usage, and teacher's evaluation of the impact of digital games on school achievement have different effects on the 5 factors of teachers' acceptance. This study is meaningful to identify how teachers' acceptance of digital games is constructed and to explore the main factors affecting teachers' acceptance of digital games.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.588-601
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• 2013

In geophysics and geophysical exploration fields, we can use information about inclination and azimuth in various ways. These include borehole deviation logging for inversion process, real-time data acquisition system, geophysical monitoring system, and so on. This type of information is also necessarily used in the directional drilling of shale gas fields. We thus need to develop a subminiature, low-powered, multi-functional inclination and azimuth measurement system for geophysical exploration fields. In this paper, to develop real-time measurement system, we adopt the high performance low power Micro Control Unit (made with state-of-the-art Complementary Metal Oxide Semiconductor technology) and newly released Micro Electro Mechanical Systems Attitude Heading Reference System sensors. We present test results on the development of a multifunctional real-time inclination and azimuth measurement system. The developed system has an ultra-slim body so as to be installed in 42mm sonde. Also, this system allows us to acquire data in real-time and to easily expand its application by synchronizing with a depth encoder or Differential Global Positioning System.