• Journal of Korean Society for Geospatial Information Science
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• v.16 no.3
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• pp.111-117
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• 2008

This study aims to develop a system which is able to monitor and analyze behavior of long span bridge in real time using multiple GPS. Through setting up many GPS at the important points of long span bridge and measuring displacement in real time, over all behavior of bridge could be analyzed. Behavior analyzing system developed in this study is able to digitize and visualize the overall and points displacement of bridge and deal with events actively. Also it is able to calculate statistical data related to analyze behavior through the constructing a database of measuring data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.731-738
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• 2006

Facing congestion, people want to know traffic information about their routes, especially real-time link travel time (LTT). In this paper, as a sequel paper of the previous non-taxi based LTT generating study by Choi et al. (1998), taxi based GPS probes have been tried to produce LTT for urban arterials. Taxis in itself are good deployment mode of GPS probes although it by nature experiences boarding and alighting time noises which should be accounted. A heuristic real-time dynamic outlier filter algorithm for taxi GPS probe has been developed focusing on urban arterials. An actual traffic survey for dynamic link travel times has been conducted using license plate method for the test arterials of Seoul city transportation network. With the algorithm, it is estimated that 70% of outliers have been filtered and the relative error has been improved by 73.7%. The filtering algorithm developed here would be expected to be in use for other spatial sites with some calibration efforts. Some limitations and future research agenda have also been discussed.

• Korean Journal of Geomatics
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• v.2 no.2
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• pp.99-105
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• 2002

The accuracy of the Digital Photologging System, designed for the construction of the road Facility Database, highly depends on the positions and attitudes of the cameras from GPS/INS integration. In this paper, the development of a loosely coupled GPS/INS is presented. The performance of the system is verified through a simulation as well as a real test data processing. Since the IMU used in this study shows large systematic errors, the possible accuracy of the positions and attitudes of this low-performance IMU when combined with precise GPS positions are assigned. Currently, the integrated system shows the positional accuracy better than 5cm in real data processing. Although the accuracy of attitude based on real test could not be assigned at this time, it is expected that better than 0.5 degrees and 1.8 degrees for horizontal and down component are achievable according to the simulation result.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.107-112
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• 2004

Corresponding to the importance of real-time position tracing in the customs free zone, the logistics monitoring system utilizing GPS and PDA correctly confirms the position of the logistics at real time. Information obtained through the use of bluetooth is transmitted into the control station that controls the flow of the logistics. This logistics monitoring system can efficiently identify the movement of the logistics all the time.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.16 no.2
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• pp.271-279
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• 1998

This paper discusses the development of compaction management system using Real Time Kinematic (RTK) GPS technology for the efficient management or compaction. The use or RTK provides the land surveyors with a graphical display of his/her corrected position on the ground at that moment in time. In this work, we intended to improve the efficiency of compaction management showing the route of rollers and the total number of compaction obtained from management software (GPSROLL v.1.0) developed in this study. The RTK GPS system installed on the roller. To improve the efficiency of field management, GPSROLL software provides also data processing module for the field soil test and the field surveying data. GPSROLL system is based on the Korean GUI for user-friendly data input and output.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.31-40
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• 2017

This paper deals with the high precision of GPS measurement reduction and its implementation on near real-time and kinematic mode for those applications requiring centimeter-level precision of the estimated coordinates, even if target stations are a few hundred kilometers away from their references. We designed the system architecture, data streaming and processing scheme. Intensive investigation was performed to determine the characteristics of the GPS medium-range functional model, IGS infrastructure and some exemplary systems. The designed system consisted of streaming and processing units; the former automatically collects GPS data through Ntrip and IGS ultra-rapid products by FTP connection, whereas the latter handles the reduction of GPS observables on static and kinematic mode to a time series of the target stations' 3D coordinates. The data streaming unit was realized by a DOS batch file, perl script and BKG's BNC program, whereas the processing unit was implemented by definition of a process control file of BPE. To assess the functionality and precision of the positional solutions, an experiment was carried out against a network comprising seven GPS stations with baselines ranging from a few hundred up to a thousand kilometers. The results confirmed that the function of the whole system properly operated as designed, with a precision better than ${\pm}1cm$ in each of the positional component with 95% confidence level.

• Spatial Information Research
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• v.16 no.1
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• pp.65-77
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• 2008

There have been many studies and technologies that define a current location of a moving vehicle with GPS(Global Positioning System). However, the navigation system with GPS has troubles to search an optimized route considering data such as realtime parking status and road conditions. Moreover, the GPS systems show malfunction in the downtown with very tall buildings, underground parking lot and the inside of buildings. On the contrary, the RFID systems are able to reflect real-time status of parking lots and roads in the downtown. This paper proposes a system of guiding path for parking lots to consider real-time constraints based on RFID. The results obtained from the implemented system show smooth guiding of a new route after immediately sensoring the change of the information of parking lots and roads: if a parking lot that a vehicle is heading to is fully occupied, the system re-searches a new route for a neighbor parking lot and immediately transfers it to customer's mobile, and if the designated route is under construction, the system guides a detour path. The proposed method will be useful for advanced integrated parking control system.

• Journal of Construction Engineering and Project Management
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• v.4 no.2
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• pp.31-40
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• 2014

The management of vehicular supply of "perishable" construction material, such as concrete mixes, faces a series of uncertainties such as weather, daily traffic patterns and accidents. Presented in this paper is a logistics control model for managing a hauling fleet with interrelated processes at both ends and queue capacities. Discrete event simulation is used to model the complex interactions of production units and the randomness of the real world. Two alternative strategies for ready mix concrete delivery, with and without an off-site waiting queue, are studied to compare supply performance. Secondly, the paper discusses the effect of an agent-based GPS tracking system providing real-time travel data that lessens the uncertainty of trucking time. The results show that the combination of GPS information with off-site queuing reduces productivity loss and process wastes of concrete placement as well as the idleness of supply trucks when crew or pump experience an unexpected stoppage.

• Journal of Satellite, Information and Communications
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• v.6 no.1
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• pp.80-85
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• 2011

In this paper, a software-based real-time GPS L1 receiver is proposed for the block correlation techniques. Recently various navigation satellite navigation receivers in the environment for the development of more efficient software-based real-time receiver need to be developed. It is composed of components such as signal supplier, signal acquisition, signal tracking, navigation data processing, and navigation solution. They are designed and implemented as component based software for enhancing reusability and modifiability for user to have more flexibility during development of receiver. This paper will describe design, implementation, and verification of the developed realtime software GNSS receiver.

• Journal of Information Technology Services
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• v.10 no.1
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• pp.105-116
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• 2011

With recent spotlight on the, uniquitous computing technology, the need for object of indentification and location infrastructure has increased. Such GPS technolgy must utilize IEEE 802.15.4 Zigbee used for existing wireless sensor network infra as a basice element for user's context-awareness in a uniquitous environement, for effectiveness.Such real-time GPS service is provided in the internal environment where the user would actually are and most high-rise buildlings apply. Underthe assumption, the real-time GPS technology is seperated by each floor, and signals do not get transmitted to other floors, the application on one floor within the high-rise buildling was conducted. This study intends to suggest a floor detection algorithm using IEE 802.15.3/Zigbee's RSSI which supports the accuracy within a couple of meters for the user's the movement between the floors in high-rise buildings in a complex environment. It proposes an floor detection algorithm using IEEE 802.15.4/Zigbee's RSSI which provides accuracy within a radius of few meters for the users movement between the floors for real-time location tracking within high-rise building in a cmoplex environment. Furthermore, for more accurate real-time location tracking, it suggests an algorithm for real-time location tracking using IEEE 802.15.4a/Zigbee's CSS technology based on triangulation. Based on the suggested algorithm, it designs a hybrid real-time location tracking service system in a high-rise buildling and test its functions.