• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.214-218
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• 2002

In recent years, precision positioning stage is demanded for some industrial fields such as semi-conductor lithography, ultra precision machining, and fabricating of nano structure. In this research, precision multi-axis positioning stage, which consists of pzt actuator, flexure, and capacitance gauge, is designed and developed. The performance of 3-axis positioning, characteristics of motion and resolution are verified.

• Journal of the Korea Society of Computer and Information
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• v.21 no.6
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• pp.55-62
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• 2016

In this paper, we present indoor positioning technologies using the wireless signal categorizing them into triangulation based, fingerprinting based, and cell ID based technologies. We describe several representative techniques for each of them emphasizing their strengths and weaknesses. We define important performance issues for indoor positioning technologies and analyze recent technologies according to the performance issues. We believe that this paper provide wise view and necessary information for recent indoor positioning technologies using wireless signals.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.1
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• pp.45-52
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• 2024

As part of the Global Positioning System (GPS) modernization program in the United States, Civil Navigation (CNAV) and CNAV-2 messages were developed to introduce flexibility and modern features to the Legacy Navigation (LNAV) message. This paper explores the additional parameters introduced in CNAV/CNAV-2 compared to LNAV, focusing on their roles from the user's perspective. This paper compares the structural and parameter differences among LNAV, CNAV, and CNAV-2. Additionally, we analyze the types and roles of parameters newly incorporated into CNAV/CNAV-2 that were absent in LNAV.

• Journal of the Korean GEO-environmental Society
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• v.22 no.12
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• pp.51-57
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• 2021

Underground lifelines such as water supply/sewer pipe, power cable and gas pipe are indispensable facilities to the life of urban society. These lifelines have been constructed long time ago and buried positioning information is not precisely recorded. Moreover, they have been concentrated on the narrow area and are complicatedly entangled in 3-dimension. In the fourth industrial revolution, a 3-dimensional visualization for underground lifelines is strongly required, and a database (D/B) with precise positioning information should be preceded. In this study, image processing technology for precise positioning of underground buried lifelines is introduced, which is able to build the database more accurately, efficiently and practically.

• Journal of Astronomy and Space Sciences
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• v.25 no.3
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• pp.291-298
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• 2008

With the growth of civil and commercial applications, the Global Navigation Satellite System(GNSS) that provides the positioning, navigation, and timing information affects to our life. In order to meet all the requirements of civilian user, new positioning technology with the accuracy of 10cm level has been applied and the positioning accuracy is getting improved. In this study, dual coverage(DAEJ, SUWN) GPS measurements were applied to improve the positioning accuracy for GPS L1 single frequency users. We processed some GPS data obtained from the distributed test sites in the wide area over Korea Peninsula. As a result, the combined solution output using dual coverage showed more improved positioning accuracy than that of single coverage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.851-853
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• 2013

Recently, location-based service as the developed continuously, interest in positioning technology is increasing. As the most famous indoor positioning technology, WPS is a positioning technology using WiFi, which can complement the limits of the indoor positioning to have a GPS. In this paper, to provide a system for monitoring the position of the inside of the user based on the position information that using the RSSI signal of the wireless AP based WPS technology, they grip the location information of the mobile nodes in the indoor. If using the method proposed, it is expected to be applied to various services it is possible to apply the WPS, this is because it is possible to estimate in real time the location distribution of mobile nodes in the indoor.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.422-428
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• 2002

In this study, actuator, sensor, guide, power transmission element and control method are considered for ultra-precision positioning apparatus. Through previous process, single plane X-Y stage with ultra-precision positioning is manufactured. Global stage for the purpose of materialization with robust system, is combined by using AC servo motor and ball screw and rolling guide. And ultra-precision positioning system is developed by micro stage with elastic hinge type and piezo element. global servo and micro servo for the purpose of materialization positioning accuracy with nm(nanometer) are controlled simultaneously by using incremental encoder and laser interferometer as displacement measurement sensor. Through previous process, ultra-precision positioning system (100mm stroke and ${\pm}$ 10nm positioning accuracy) with single plane X-Y stage are materialized.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.161-166
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• 2002

Recently, researches on precision machining of nato-order, especially in the field of optical components and semi-conductors have been under development very actively. A accuracy of machining and positioning in a critical issue in ultra-precision machining. This paper proposes a new positioning system which can give excellent dynamic characteristics and reduce errors in horizontal, vertical, pitching, and yawing motions. In this paper, we suggest a connecting mechanism (the couplings) to reduce motion errors such as chatter and runout while preserving the positioning accuracy. We verified the good performance in the new connecting systems with various coupling types, which we classified into the fixed type, the spring type, the aeroctatic-nozzle type, and the aeroctatic-porous type according to the way of reducing the chatter and error.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1995.10a
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• pp.18-23
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• 1995

The study was carried out to develope a precision positioning apparatus, consisting of DC servo motor and piezoelectric actuator. This system is composed of fine and coarse apparatus, measurement system and control system, Piezoelectric actuator is designed for fine positioning. Coarse positioning using lead screw is drived by DC servo motor. Control system output a signal from laser interferometer and microsense to amplifier of DC servo motor and piezoelectric actuator after digital signal processing(DSP). Resolution of this apparatus measure with laser interferometor and microsense

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.2
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• pp.103-112
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• 2017

Due to the large size and high complexity of modern buildings, the interest and the studies about indoor spatial information are increasing. Previous studies related to indoor spatial information were mostly about relevant technologies, and the application of indoor spatial information has been less studied. In the present study, the public administrative work areas where indoor spatial information may be applied were identified by using a modified delphi technique. And the indoor LOD (Level of Detail) and indoor positioning accuracy for indoor spatial information applications considering user requirements was established as standards for efficiently establishing and providing services. The required LOD and positioning accuracy for services was established by reestablishing indoor LOD and positioning accuracy and classifying services with reference to those. The indoor LOD was reestablished from LOD 0 to 4 by focusing on service utilization and general recognition, and the positioning accuracy was reestablished in three levels by considering the accuracy of the present positioning technology and service utilization status.