• Journal of the Korean Society for Aviation and Aeronautics
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• v.10 no.1
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• pp.35-44
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• 2002

Inertial Navigation System(INS) has been used in the field of air navigation for a long time but is not popular in general aviation due to high price. Recently low-price GPS is available but vulnerable to radio interference. As an alternative on these problems, GPS/INS integrated navigation system has been considered. GPS/INS is capable of implementing navigation with low-price inertial sensors but its accuracy is dependent upon how much drift of INS may be calibrated by using GPS. In order to apply GPS/INS to air navigation, it must be investigated how long drift of INS in case of no GPS aiding will be bounded within requirements for safe flight. From the above motivation, the flight test for GPS/INS navigation system was conducted in order to make sense its performance in air navigation and its result was shown.

• The KIPS Transactions:PartC
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• v.13C no.1 s.104
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• pp.95-102
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• 2006

Nowadays, GPS is used widely, especially in case which needs precise position information, such as car navigation systems and various kinds of position measuring instruments in an outdoor environment. According to their applications, there are many kinds of GPS receivers with different costs and error rates. The maximum error range of the general-purpose GPS receiver is within 30m, though the error rate depends on receiving rate of signal and weather condition. RTK(Real-Time Kinematic) and DGPS(Differential Global Positioning System) have more precise accuracy than the general-purpose GPS. However end users can't afford use them because of their high price and large size of equipments. In order for the end user to obtain precise position information, it is important that GPS receivers has portability and low price. In this study, we introduce a new system that offers precise position information using the DGPS mechanism satisfying low cost and portability.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1778-1779
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• 2011

The location of outdoor mobile robot is obtained using global coordinates from GPS. However, the error generated by GPS is about 10m ~ 100m, so the precise control is difficult. D-GPS has the error value of 1m and it is very accurate, but the price is very expensive. In this paper, a method to reduce the error in global coordinates is proposed using two low-cost GPS for the autonomous navigation control of outdoor mobile robot.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.3
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• pp.193-200
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• 2016

This paper introduces an algorithm to middle-low price drone's autonomous navigation flight system using computer vision and GPS. Existing drone operative system mainly contains using methods such as, by inputting course of the path to the installed software of the particular drone in advance of the flight or following the signal that is transmitted from the controller. However, this paper introduces new algorithm that allows autonomous navigation flight system to locate specific place, specific shape of the place and specific space in an area that the user wishes to discover. Technology developed for military industry purpose was implemented on a lower-quality hobby drones without changing its hardware, and used this paper's algorithm to maximize the performance. Camera mounted on middle-low price drone will process the image which meets user's needs will look through and search for specific area of interest when the user inputs certain image of places it wishes to find. By using this algorithm, middle-low price drone's autonomous navigation flight system expect to be apply to a variety of industries.

• Korean Journal of Geomatics
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• v.3 no.1
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• pp.7-14
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• 2003

For GIS to land and sea in Korea, GIS on land was almost completed with big cities by NGIS(National Geographic Information System) business. However, MGIS(Marine Geographic Information System) being constructed by the National Oceanographic Research Institute is still constructing geography information and definition of attribute information and real condition. We are being studied on research to get maximized the ripple effect linking GPS and Navigation techniques on GIS. GPS in accuracy is divided into navigation and precise surveying equipment. Now, GPS technology has been developed very much and low price GPS equipments are introducing. But expense on GPS equipment is high yet. Therefore, GPS equipment for navigation is used on cheap GPS equipment in a car or ship. In this paper, the author used algorithm to convert ellipsoid coordinate between WGS84 and Bessel ellipsoid and to analyze map projection between BESSEL ellipsoid and UTM plane coordinate system. And the author developed ship navigation system with cheap GPS equipment using algorithm of ellipsoid conversion and map projection. The author proposed the necessity on constructing MGIS to manage many ships.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.451-454
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• 2006

Ultrasonic Positioning System (UPS) is an absolute positioning system using ultrasonic waves and has better performance in low price than the other absolute positioning systems. UPS can be further used as pseudo-satellites in the place where GPS is not available. This study aims to evaluate the efficiency and effectiveness of using UPS as a 3D free-hand writing or drawing tool. The process includes the design and testing of VPS as an efficient 3D free-hand writing or drawing tool in the air. The paper will further explain the system architecture of the UPS and how to use GPS as 3D free-hand writing or drawing tool. The efficiency and effectiveness of the system was confirmed by a computer software simulation. The software will further display the result of drawing or writing from the user by graphics. As a result, it is possible to implement UPS as a 3D free-hand writing or drawing tool in the air.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.9
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• pp.883-890
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• 2006

Nowadays, CPS is used widely, especially in cases which need more precise position information, such as car navigation systems and even in the mobile robot for position measuring in the outdoor environment. RTK (Real-Time Kinematics) and DGPS (Differential Global Positioning System) have more precise accuracy than the general-purposed GPS. However can't easily use them because of high prices and large size of equipments. In order fur the mobile robot to obtain precise position information it is important that CPS receiver has portability and low price. In this study, we introduce a new GPS data acquisition system that offers the precise position data using the DGPS mechanism and satisfying low cost and portability. In addition to this, we propose an improved data compensation algorithm that offers more accurate position information to the outdoor mobile robot by compensating the error rate of CPS data measured from the three points with geometrical rotation and distance formula. Proposed method is verified by comparing with the precise real position data obtained by RTK. Proposed method has more than 70% performance enhancement.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.1
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• pp.39-46
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• 2004

In the GIS construction to land and sea in Korea, GIS construction on land was completed mostly for big cities by NGIS(National Geography Information System) business. However, Marine GIS being constructed by the National Oceanographic Research Institute is still constructing geography information and definition of attribute information and real condition. We have done researches to get maximized ripple effect linking GPS and Navigation techniques on GIS. GPS in accuracy is divided into navigation and precise surveying equipments. Now, GPS technology has been developed very much and with low price GPS equipments are being introduced. But costs on the GPS equipments are high yet. Therefore, the GPS equipments for navigation can be substituted by cheap GPS equipments in a car or ship. In this paper, the authors developed algorithm to convert ellipsoid coordinate between WGS84 and Bessel ellipsoid and to analyze map projection between BESSEL ellipsoid and UTM plane coordinate system. And the author developed ship navigation system with cheap GPS equipments using algorithm of ellipsoid conversion and map projection. The authors proposed the necessity on constructing Internet GIS to manage many ships.

• Journal of Advanced Navigation Technology
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• v.9 no.1
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• pp.28-33
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• 2005

In this paper, we developed the algorithm to control longitudinal and lateral motion of UAV(Unmanned Aerial Vehicle) with Infrared heat sensors and GPS(Global Positioning System) receiver. UAV was controlled to be flown horizontally and also turned coordinately maintaining the constant altitude. Accomplishing the flight test of UAV sevral times, we were able to develope low price controller to control bank angle for lateral motion, and also pitch angle and altitude for longitudinal motion simultaneously.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.507-510
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• 2011

As the amount of the wireless mobile products like a 'Smart phone' used increases, the studies about the Location Based Service (LBS) is highly increasing. Outdoor location determination can use the GPS which is built-in in the wireless mobile products. However, it is not possible to use GPS inside the huge cruise bigger than a normal building, it is regarded to consider Indoor location determination which is appropriate at the inside environment. Wi-Fi (Wireless Fidelity) does not need an extra installation process because it is already installed here and there inside the building. In this respect, Wi-Fi has low price competitiveness compared to other wireless sensor products. In this paper, I will introduce 'Bayesian Algorithm' which can recognize useful space with Wi-Fi signal.