• Journal of Ocean Engineering and Technology
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• v.38 no.3
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• pp.115-123
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• 2024

USBL systems are essential for providing accurate positions of autonomous underwater vehicles (AUVs). On the other hand, the accuracy can be degraded by outliers because of the environmental conditions. A failure to address these outliers can significantly impact the reliability of underwater localization and navigation systems. This paper proposes a novel outlier rejection algorithm for AUV localization using Voronoi diagrams and query point calculation. The Voronoi diagram divides data space into Voronoi cells that center on ultra-short baseline (USBL) data, and the calculated query point determines if the corresponding USBL data is an inlier. This study conducted experiments acquiring GPS and USBL data simultaneously and optimized the algorithm empirically based on the acquired data. In addition, the proposed method was applied to a sensor fusion algorithm to verify its effectiveness, resulting in improved pose estimations. The proposed method can be applied to various sensor fusion algorithms as a preprocess and could be used for outlier rejection for other 2D-based location sensors.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.210-212
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• 2003

Active sensors are rapidly conquering a share on the remote sensing market and offer among others new possibilities toward automatically acquiring 3D building data. Better dissemination of information about new technological developments can possibly be achieved by short distance-learning courses. The paper describes the didactic and technical aspects of a course we have designed and conducted on airborne laser scanning and interferometric SAR. The building extraction application is a good example to illustrated the added value of short electronic-learning courses above simply publishing (digital) papers.

• Journal of Information Technology Services
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• v.12 no.4
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• pp.423-434
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• 2013

Since acquiring intelligence about political situations around the Korea Peninsular in a direct manner is nearly impossible, it is inevitable for the individuals or companies to rely on open and indirect data such as newspapers. However, since the contents in the newspapers are substantially unstructured and very large, conventional content analysis is time-consuming and hence very costly. Hence, this paper aims to propose a sentimental analysis method which computes daily 'peace index' from unstructured data in the newspapers. From the content analysis, words and phrases which represent the sentiment of a nation are carefully identified. To show the feasibility of the idea proposed in this paper, a prototype system with vocabulary repository about political situations was developed for estimating peace index automatically.

• Journal of Korean Society for Geospatial Information Science
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• v.7 no.1 s.13
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• pp.65-74
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• 1999

The construction of precise digital data and analysis system is very important to fundamental data to preserve and repair cultural properties. This study is about to acquire of digital data and to construct of analysis system for efficient maintenance of cultural properties. On the chinaware with white slip and greyish-green glaze acquiring 3D digital data and carrying the spatial analysis and monitoring were done through the softcopy photogrammetry method. So, we intend to offer the efficient method to preserve cultural properties.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.9
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• pp.1257-1263
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• 1995

This paper presents a method not only to detect moving targets from ISAR data corrupted by heavy clutter but to effectively extract the moving targets' signitures that are necessary for acquiring the velocities and images of the targets. In this method, input ISAR data are coherently processed such that echoes due to the moving targets are transformed to be in-phase and then integrated. It is shown that targets' signitures are localized in the transformed two-dimensional domain, leading to dramatic improvement of signal-to-noise (SNR) ration. The extent of the improved signal-to-noise ratio is analyzed and results implemented with simulated ISAR data are presented.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.663-665
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• 1998

The measuring data acquisition methods from local sensor are many kinds of techniques. But, if sampling time is not important and we need data of many sensors it is more resonable to be applied economical system. In this paper, the data acquisition technique is used two RS232C communication signals simultaneously. The one come from computer serial port, and another is signal changed from parallel port. In this case the circuits would be simplification and that communication cable is connected by Parallel instead of Branch connection.

• Journal of Korean Society for Geospatial Information Science
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• v.11 no.4 s.27
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• pp.45-51
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• 2003

This study intended to extract the spatial data and attribute data from the images of terrestrial photographs to compile the digital map from the images using photogrammetric analysis. In this study, the plane map of present objective area was made using the single terrestial photographs and graphical method, and the spatial or attribute data for the facilities in the area was extracted. Also, it is concluded that the efficient techniques for acquiring spatial and attribute data of the building and road facilities in proper time for the concerning area were suggested.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11S
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• pp.3739-3751
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• 2000

The remarkable progress of computer graphic and virtual reality fields has increased the need of 3D graphic data for implementing more realistic environments. However, despite this trend, lots of time and labor required to process 3D graphic information extracted still limits its application only to the specific areas. As one proper solution to this problem, 3D scanner acquiring graphic data in short time and new algorithm for a data processinig are often mentioned. In this paper, A method generatinig a virtual object quickly by not zippering range data obtained from 3D moire-scanner is introduced and its effectiveness is examined.

• Korean Journal of Remote Sensing
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• v.2 no.2
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• pp.117-131
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• 1986

The purpose of this study was to develop techniques acquiring hydrologic parameters that affect runoff conditions from Landsat imagery. Runoff conditions in a study area were analyzed by employing the U.S. Soil Conservation Service(SCS) Method. SCS runoff curve numbers(CN) were estimated by the computer analysis of Landsat imagery and digiral terrain model(DTM) data. The SCS Method requires land use/cover and soil conditions of the area as input parameters. A land use/cover map of 5 hydrological classes was produced from the Landsat multi-spectral scannerr imagery. Slope-gradient and contour and contour maps were also made using the DTM topographic data. Inundation areas depending on reservoir levels were able to be mapped on the Landsat scene by combining the contour data.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1233-1241
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• 2023

This paper investigates the efficient application of drone LiDAR technology for acquiring precise point cloud data in construction and civil engineering. A structured workflow encompassing data acquisition, processing, and accuracy verification is introduced. Practical testing on a construction site affirms that drone LiDAR surveying yields accurate and reliable data across various applications. With a focus on accuracy and verification, the results contribute to the progression of surveying methodologies in construction and civil engineering. The findings provide valuable insights into the dynamic technological landscape of these fields, establishing a foundation for more effective and precise surveying techniques. This study underscores the transformative potential of drone LiDAR technology in shaping the future of construction and civil engineering survey practices.