• Journal of Korean Society for Geospatial Information Science
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• v.4 no.2 s.8
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• pp.91-98
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• 1996

Transportation impact assessment which can take precaution for the traffic problem to control a plan on to expand traffic facilities through these results analyzed with the business for making a big problem of traffic is a very important course on the traffic management system as well as the traffic plan and it is necessary to collect and to edit and to analyze a great deal of data fully in object zone. So it is worth while to treat the collected data on to computer. Therefore Geographic Information System will give a remarkable result to Traffic Influence Evaluation everywhere. GIS not only can join the graphic or attribute data correctly and fast, but can achieve it prominent function for intention decision means. Then total system for Landuse of surrounding district, development-plan state, traffic-facility state, traffic-development public plan state and traffic demand is animated on Traffic Influence Evolution.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.1 s.39
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• pp.61-66
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• 2007

The final object of this research is to construct general management system that can manage diverse facilities of city on the basis of ubiquitous technology. Defining data format of items in each management, type and code for the urban facilities, the researcher designed database of urban facilities through the process of establishing logic model and data modelling. By inputting designed database into RFID Tag of each urban facilities and using RFID Reader and PDA, the researcher developed system that can efficiently manage the basic attributes and information and management information of urban facilities. Applying the general management system for urban facilities constructed on the basis of ubiquitous, the researcher could check the information of target facilities and input revised data. Further, it was found that the characteristics of RFID Tag and GPS should improve the optimal hardware combination and PDA performance for the surrounding environmental influence and system performance.

• The Journal of the Korea Contents Association
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• v.6 no.1
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• pp.72-79
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• 2006

Recently, a MMORPG(Massively Multi-play Online Role Playing Game) has built distribute server by Seamless world. This paper proposes an efficient collision detection method. DLS is used to dynamically adjust spatial subdivisions in each the boundary regions of distribute server We use an index table to effectively utilize the relationships between in the nodes and can perform the collision detection efficiently by reconstructing nodes of the tree. Also, we maintain the information for the boundary region to efficiently detect the collections and adjust the boundary regions between distributed servers by using DLS. As the DLS uses pointers, the information for each server is not needed and the boundary regions between the distributed servers are efficiently searched. Using node index points, the construction table can be made to find between ray and neighborhood node, In addition, processes for Network traffic reduce because a copy of the boundary regions is not needed when a object moves with realtime.

• Journal of Broadcast Engineering
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• v.7 no.4
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• pp.300-309
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• 2002

The object of this paper is to make temporal direct mode clear by providing a solution to the following problem : if the co-located block in the list 1 reference picture for direct mode has only the 1ist 1 motion vector or both the 1ist 0 and list 1 motion vectors, then which motion vector will be used for the direct mode motion vector calculation\ulcorner This paper also shows how to derive reference picture index and direct mode motion vector for each list in order to guarantee the high coding efficiency. when the co-located macroblock is in intra mode. Furthermore, the reasonable calculation methods for the direct mode motion vectors in the various cases are presented. Finally, experimental results show that the proposed temporal direct mode provides the comparable performance against the spatial direct mode. Therefore, the simulation proves that the proposed temporal direct mode is acceptable.

• Journal of Broadcast Engineering
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• v.1 no.1
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• pp.7-13
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• 1996

MASF is a kind of temporal filter proposed for noise reduction and temporal band limitation. MASF uses motion vectors to extract temporal information in spatial domain. Therefore, inaccurate motion information causes some distortions in MASF operation. Currently, bilinear interpolation after BMA(Block Matching Algorithm) is used for the motion estimation sheme of MASF. But, this method results in unreliable estimation when the object in image sequence has larger movement than the maximum displacement assumed in BMA or the input images are severely corrupted with noise. In order to i:;olve this problem, we analyse the effect of inaccurate motion on MASF and propose a hierarchical motion estimation algorithm based on the analysis results. Experimental results show that the proposed method produces reliable output under large motion and noisy situations.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.5
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• pp.585-597
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• 2009

This research aims to develop a registration method to remove the geometric inconsistency between aerial images and LIDAR data acquired from an airborne multi-sensor system. The proposed method mainly includes registration primitives extraction, correspondence establishment, and EOP(Exterior Orientation Parameters) adjustment. As the registration primitives, we extracts planar patches and intersection edges from the LIDAR data and object points and linking edges from the aerial images. The extracted primitives are then categorized into horizontal and vertical ones; and their correspondences are established. These correspondent pairs are incorporated as stochastic constraints into the bundle block adjustment, which finally precisely adjusts the exterior orientation parameters of the images. According to the experimental results from the application of the proposed method to real data, we found that the attitude parameters of EOPs were meaningfully adjusted and the geometric inconsistency of the primitives used for the adjustment is reduced from 2 m to 2 cm before and after the registration. Hence, the results of this research can contribute to data fusion for the high quality 3D spatial information.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.2
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• pp.163-171
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• 2012

High resolution satellite images have been used for building and road system analysis, landscape analysis, and ecological assessment for several years. However, in high resolution satellite images, shadows are necessarily cast by manmade objects such as buildings and over-pass bridges. This paper develops the shadow extraction procedures in urban area including various land-use classes, and the extracted shadow areas are evaluated by a manually digitized shadow map. For the shadow extraction, the Canny edge operator and the dilation filter are applied to make building edge buffer area. Also, the object-based segmentation was performed using Gram-Schmitt fusion image, and spectral and spatial parameters are calculated from the segmentation results. Finally, we proposed appropriate parameters and extraction rules for the shadow extraction. The accuracy of the shadow extraction results from the various assessment indices is 80% to 90%.

• Journal of KIISE:Software and Applications
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• v.34 no.1
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• pp.18-29
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• 2007

In this paper we present a system that classifies brain MR images by using 2 level decision tree learning. There are two kinds of information that can be obtained from images. One is the low-level features such as size, color, texture, and contour that can be acquired directly from the raw images, and the other is the high-level features such as existence of certain object, spatial relations between different parts that must be obtained through the interpretation of segmented images. Learning and classification should be performed based on the high-level features to classify images according to their semantic meaning. The proposed system applies decision tree learning to each level separately, and the high-level features are synthesized from the results of low-level classification. The experimental results with a set of brain MR images with tumor are discussed. Several experimental results that show the effectiveness of the proposed system are also presented.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.3
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• pp.115-125
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• 2011

The smartphones which have been recently are embedded with high resolution quality camera, assisted GPS, accelerometer, gyroscope and various sensors including magnetometer sensor that could be directly used for measurement. This study aims to suggest the possible application of smartphone camera providing high resolution images in terms of photogrammetry by calibrating it and assessing its accuracy. First of all, prior to the accuracy assessment of smartphone camera, camera calibration was conducted to correct lens distortion of each camera and the accuracy of image coordinates and object coordinates calculated by bundle adjustment during this procedure was analyzed. Also regarding three-dimensional positioning, result analysis depending on considering lens distortion coefficients was conducted, and finally relative accuracy of smartphone camera on metric camera was assessed. The result showed that in terms of distortion correction of smartphone camera, also higher order symmetric radial lens distortion coefficients should be considered, and three dimensional position determined by smartphone images was a little difference from that by metric camera. Therefore it is expected that smartphone images have huge possibility to be used for photogrammetry.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.3
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• pp.55-62
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• 2013

This paper aims to detect Speed Bump by using Omni-directional Camera and to suggest Real-time update scheme of Speed Bump through Vision Based Approach. In order to detect Speed Bump from sequence of camera images, noise should be removed as well as spot estimated as shape and pattern for speed bump should be detected first. Now that speed bump has a regular form of white and yellow area, we extracted speed bump on the road by applying erosion and dilation morphological operations and by using the HSV color model. By collecting huge panoramic images from the camera, we are able to detect the target object and to calculate the distance through GPS log data. Last but not least, we evaluated accuracy of obtained result and detection algorithm by implementing SLAMS (Simultaneous Localization and Mapping system).