• Journal of Korea Multimedia Society
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• v.18 no.2
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• pp.149-157
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• 2015

The 3D-AVC standard aims at improving coding efficiency by applying new techniques for utilizing intra, inter and view predictions. 3D video scenes are rendered with existing texture video and additional depth map. The depth map comes at the expense of increased computational complexity of the encoding process. For real-time applications, reducing the complexity of 3D-AVC is very important. In this paper, we present a fast intra mode decision algorithm to reduce the complexity burden in the 3D video system. The proposed algorithm uses similarity between texture video and depth map. The best intra prediction mode of the depth map is similar to that of the corresponding texture video. The early decision algorithm can be made on the intra prediction of depth map coding by using the coded intra mode of texture video. Adaptive threshold for early termination is also proposed. Experimental results show that the proposed algorithm saves the encoding time on average 29.7% without any significant loss in terms of the bit rate or PSNR value.

• The Journal of Korea Robotics Society
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• v.13 no.2
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• pp.79-85
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• 2018

This study focuses on autonomous exploration based on map expansion for an underwater robot equipped with acoustic sonars. Map expansion is applicable to large-area mapping, but it may affect localization accuracy. Thus, as the key contribution of this paper, we propose a method for underwater autonomous exploration wherein the robot determines the trade-off between map expansion ratio and position accuracy, selects which of the two has higher priority, and then moves to a mission step. An occupancy grid map is synthesized by utilizing the measurements of an acoustic range sonar that determines the probability of occupancy. This information is then used to determine a path to the frontier, which becomes the new search point. During area searching and map building, the robot revisits artificial landmarks to improve its position accuracy as based on imaging sonar-based recognition and EKF-SLAM if the position accuracy is above the predetermined threshold. Additionally, real-time experiments were conducted by using an underwater robot, yShark, to validate the proposed method, and the analysis of the results is discussed herein.

• The Journal of the Korea Contents Association
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• v.8 no.4
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• pp.39-47
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• 2008

This paper describes the life GIS(Geographic Information System) system that enables users to look up the final destination on a map automatically by setting up a random radius of threshold under the present user position. Various information systems based on the existing GIS have disadvantage that a search is difficult when the destination location is not clear. And it is inefficient that the processing time is delay due to a complex configuration and large amount of informations based on the target of special business supports. Therefore, this paper improves these problems and proposes the customized life GIS which is for the general user in the Flash(Action Script) environment. The customized life GIS confirms the detail items from search results, which is destinations fitting for a condition in the suitable radius of threshold from the present user position. And the user can look up the suitable final destination on a map easily using the customized information system. The result of this paper, which is based on the sample of the large unit locations, will be expected to be able to guide more detail, extensive and various informations.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.735-739
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• 2005

This paper presents a new system to estimate the head pose of human in interactive indoor environment that has dynamic illumination change and large working space. The main idea of this system is to suggest a new morphological feature for estimating head angle from stereo disparity map. When a disparity map is obtained from stereo camera, the matching confidence value can be derived by measurements of correlation of the stereo images. Applying a threshold to the confidence value, we also obtain the specific morphology of the disparity map. Therefore, we can obtain the morphological shape of disparity map. Through the analysis of this morphological property, the head pose can be estimated. It is simple and fast algorithm in comparison with other algorithm which apply facial template, 2D, 3D models and optical flow method. Our system can automatically segment and estimate head pose in a wide range of head motion without manual initialization like other optical flow system. As the result of experiments, we obtained the reliable head orientation data under the real-time performance.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1034-1041
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• 2011

Generally, In distributed online game server system, game maps are processed separately by means of dividing into several unit blocks. But the keeping normal distribution of user in game map is very difficult because preferences of game users are not same according to individual user's private character. For this reason, if the huge number of users concentrate on particular region of same game map at once, the game server exceed their threshold so that the system can be getting down. Conversely, the efficiency of system goes down considerably because the game server must perform map processing continuously even under user_empty situation. To solve this problem, in this paper, we propose a Map management method to control relatively normal distribution of users in game maps using Map Balance Server. In suggested model, we can reduce the load of game servers by means of turn off the game map processing temporary when a server is under user_empty situation. we also can maximize server performance by means of redistribution of map processing load among servers.

• The Journal of the Korea Contents Association
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• v.3 no.4
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• pp.23-28
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• 2003

This paper describes, in order to extract contour from topographic map image, an adaptive segment-length thresholding using a threshold depended on target image. First of all, after recognizing the primary symbols and detecting two edges from the projection histogram of the elevation value area, the threshold value is determined by the distance between the edges. Then, the subdivision is peformed by searching a branch point and erasing its neighboring Hack pixels. And contour components are extracted by segment-length thresholding. The experimental result shows that the final image contains non-contour component of 2.41% and contour one of 97.59%.

• Journal of KIBIM
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• v.8 no.4
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• pp.72-79
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• 2018

Rapid developments around the world have resulted in urban expansion, habitat destruction, habitat fragmentation, and pollution problems, which are the main reasons for the decline in biological diversity. The United Nations warns that many animals and plants will die out in the near future if this continues. This study was performed to propose a map of eco-corridor suitability analysis of Korean water deer(Hydropotes Inermis) to enhance biodiversity in Chuncheon city. Eight factors affecting habitat suitability were elevation, aspect, slope, forest type, distance to the road, distance to the stream, land use and green connectivity. Previous study analysis on the mobility behaviour of the Korean water deer(Hydropotes Inermis) produced a habitat suitability map by determining the threshold and assigning a value between 0 and 1 depending on the habitat suitability using the fuzzy function. A method of analysis was proposed for a number of eco-corridor through comparative analysis of the data from the produced habitat suitability map and the road-kill point. The previous studies were focused on Backdudaegan region and national parks except for urban cities. The potential habitat map of Korean water deer could be helpful as a way to prevent habitat disconnection and increase species diversity in urban areas.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.2914-2916
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• 1999

A power distribution facility map is composed of distribution facility information regions, cadastral regions and grid lines. In this map, our goal is automatic interpretation of power distribution region. For the goal, it is the first work to extract the power distribution facility region. In this paper, we propose a method to extract power distribution facility regions. The proposed method is consist of two phases, binarization phase and extending phase. The first phase generate a power distribution facility image using threshold value. The image contains many part of power distribution facility regions, but not all. The second phase extends thinned image which is generated by appling thinning operator to the power distribution facility image.

• Journal of Information Processing Systems
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• v.18 no.4
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• pp.587-598
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• 2022

To increase building change recognition accuracy, we present a deep learning-based building change detection using remote sensing images. In the proposed approach, by merging pixel-level and object-level information of multitemporal remote sensing images, we create the difference image (DI), and the frequency-domain significance technique is used to generate the DI saliency map. The fuzzy C-means clustering technique pre-classifies the coarse change detection map by defining the DI saliency map threshold. We then extract the neighborhood features of the unchanged pixels and the changed (buildings) from pixel-level and object-level feature images, which are then used as valid deep neural network (DNN) training samples. The trained DNNs are then utilized to identify changes in DI. The suggested strategy was evaluated and compared to current detection methods using two datasets. The results suggest that our proposed technique can detect more building change information and improve change detection accuracy.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.3
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• pp.19-32
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• 2002

Topographic information is indispensable in the applications that require elevational data. These applications are exemplified by watershed partition, extraction of drainage networks, viewshed analysis, derivation of geomorphologic features, quantification of landslide-terrain, and identification of topographic settings susceptible to landsliding. Therefore, we study the accuracy of data on topographic parameters derived from digital elevation models(DEMs). This research wished to analyze the effect that data source and grid size get in topography parameter using gridded DEM. An analysis of topography parameter extract and compared drainage basin, watershed slope, stream network using DEM is constructed by digital map and DTED DEM. Especially, when extract stream network from gridded DEM, received much effects according to threshold value of flowaccumulation regardless of DEM grid size. Therefore, this study applied equal threshold value of flowaccumulation for two data sources, and compare and analyzed stream network.