• Journal of the Korea Society of Computer and Information
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• v.8 no.4
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• pp.41-46
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• 2003

Recently, as the growth of the application of geographical information in various application fields, a geographic information system(GIS) has been building for using them efficiently. GIS has been managing them in use data format individually. To service geographical information based distribution efficiently, there must be a Data Conversion System that can deal with converting of GIS geographical information with incompatible formats. Therefore, in this paper, we design and implement a Spatial Data Translation System with international standard to convert geographic data efficiently.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.47-50
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• 2007

Since world coordinate system is entirely used because of the revision of land surveying law, it is needed that transformation of coordinates of geo-spatial information established by korea coordinate system to be performed. It is required, however, to have a plan for transformation of world coordinate system because the coordinate system is not unified due to the geo-spatial information system using dualistic control data of both old and new data of korea coordinate system. For this purpose, in this study, I have calculated coordinate transformation coefficient per control data of korea coordinate system and proposed a plan of transforming a dualistic coordinate system which is based on control data of korea coordinate system effectively into world coordinate system through verification of accuracy of transformation per control data.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.1 s.6
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• pp.57-66
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• 1996

For the effective use of spatial data, it is necessary to translate the diverse digital map data (here, digital map for car navigation system) into common GIS data structure(here, ARC/INFO). For this purpose, analysis on the structure of the established digital map was fulfilled, the data model for effective translation tool was designed. As a result, the possibility to translate diverse digital map structures (database) into GIS tools and to share them, with the users' point of view, was successfully verified.

• The Transactions of the Korea Information Processing Society
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• v.4 no.11
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• pp.2679-2689
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• 1997

In this paper, a multimedia authoring system using temporal/spatial synchronization manager is designed and implemented to support easy and efficient generation of multimedia title. For this goal, a flowchart-oriented logic generator which represents a title author's design intent into a practical title composition logic without extra translation process, and a logic interpreter which translate and implement the generated title logic, are designed. Furthermore, a temporal/spatial synchronization manager which manages temporal/spatial synchronization information between media data for multimedia representation, is designed. Especially, a temporal specification model and MRL, a formal language for the model, are designed to synchronize the temporal relation between media objects. The MRL represents a complex temporal relation by simple and clear form, and synchronizes efficiently multimedia representation according to the author's intent. A presentation frame editor which makes coincidence between visible size of representation media and attachment point, is implemented for spatial synchronization.

• The Journal of the Acoustical Society of Korea
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• v.21 no.5
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• pp.471-477
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• 2002

Recently, lip-reading has been studied actively as an auxiliary method of automatic speech recognition(ASR) in noisy environments. However, almost of research results were obtained based on the database constructed in indoor condition. So, we dont know how developed lip-reading algorithms are robust to dynamic variation of image. Currently we have developed a lip-reading system based on image-transform based algorithm. This system recognize 22 words and this word recognizer achieves word recognition of up to 53.54%. In this paper we present how stable the lip-reading system is in environmental variance and what the main variant factors are about dropping off in word-recognition performance. For studying lip-reading robustness we consider spatial valiance (translation, rotation, scaling) and illumination variance. Two kinds of test data are used. One Is the simulated lip image database and the other is real dynamic database captured in car environment. As a result of our experiment, we show that the spatial variance is one of degradations factors of lip reading performance. But the most important factor of degradation is not the spatial variance. The illumination variances make severe reduction of recognition rates as much as 70%. In conclusion, robust lip reading algorithms against illumination variances should be developed for using lip reading as a complementary method of ASR.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.3
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• pp.175-185
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• 2020

Three-dimensional registration is a process of matching data with or without a coordinate system to a reference coordinate system, which is used in various fields such as the absolute orientation of photogrammetry and data combining for producing precise road maps. Three-dimensional registration is divided into a method using points and a method using linear features. In the case of using points, it is difficult to find the same conjugate point when having different spatial resolutions. On the other hand, the use of linear feature has the advantage that the three-dimensional registration is possible by using not only the case where the spatial resolution is different but also the conjugate linear feature that is not the same starting point and ending point in point cloud type data. In this study, we proposed a method to determine the scale and the three-dimensional translation after determining the three-dimensional rotation angle between two data using quaternion to perform three-dimensional registration using linear features. For the verification of the proposed method, three-dimensional registration was performed using the linear features constructed an indoor and the linear features acquired through the terrestrial mobile mapping system in an outdoor environment. The experimental results showed that the mean square root error was 0.001054m and 0.000936m, respectively, when the scale was fixed and if not fixed, using indoor data. The results of the three-dimensional transformation in the 500m section using outdoor data showed that the mean square root error was 0.09412m when the six linear features were used, and the accuracy for producing precision maps was satisfied. In addition, in the experiment where the number of linear features was changed, it was found that nine linear features were sufficient for high-precision 3D transformation through almost no change in the root mean square error even when nine linear features or more linear features were used.

• Journal of Computing Science and Engineering
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• v.5 no.3
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• pp.210-222
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• 2011

In this work, we study the problem of privacy-preservation data publishing in moving objects databases. In particular, the trajectory of a mobile user in a plane is no longer a polyline in a two-dimensional space, instead it is a two-dimensional surface of fixed width $2A_{min}$, where $A_{min}$ defines the semi-diameter of the minimum spatial circular extent that must replace the real location of the mobile user on the XY-plane, in the anonymized (kNN) request. The desired anonymity is not achieved and the entire system becomes vulnerable to attackers, since a malicious attacker can observe that during the time, many of the neighbors' ids change, except for a small number of users. Thus, we reinforce the privacy model by clustering the mobile users according to their motion patterns in (u, ${\theta}$) plane, where u and ${\theta}$ define the velocity measure and the motion direction (angle) respectively. In this case, the anonymized (kNN) request looks up neighbors, who belong to the same cluster with the mobile requester in (u, ${\theta}$) space: Thus, we know that the trajectory of the k-anonymous mobile user is within this surface, but we do not know exactly where. We transform the surface's boundary poly-lines to dual points and we focus on the information distortion introduced by this space translation. We develop a set of efficient spatiotemporal access methods and we experimentally measure the impact of information distortion by comparing the performance results of the same spatiotemporal range queries executed on the original database and on the anonymized one.