• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.1009-1024
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• 2018

With the increased use of LiDAR (Light Detection and Ranging) that can obtain over millions of point dataset, methodologies for efficient search and dimensionality reduction for the point cloud became a crucial technique. The existing octree-based "parametric algorithm" has proved its efficiency and contributed as a part of PCL (Point Cloud Library). However, the implementation of the algorithm on GPU (Graphics Processing Unit) is considered very difficult because of structural constraints of the octree implemented in PCL. In this paper, we present a method for the parametric algorithm on GPU environment and implement a projection of the queried points on four directions with an improved noise reduction.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.582-585
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• 2011

During disaster response, prioritization of limited resources is one of the most important bust challenging tasks. At the same time, it is imperative to timely provide the rescuers with the adequate equipment to facilitate lifesaving operations. However, supply of high demand equipment was insufficient during the initial phase of disaster response, challenging lifesaving operations in the case of the 9-11 terrorist attacks. In respond to the Haiti Earthquake, spatial information of the geographic area was not sufficient to support the search and rescue operations in the early phase of disaster response. However, with the help of civilians, information such as road names, infrastructure damage, and victim locations were updated into the spatial data repository. At the same time, resource outside of the disaster affected zone converges into the area to assist the response efforts, which is the effect of convergence that often made resource coordination challenging in large scale disasters. To efficiently collect information and utilize the converging resources, this paper proposes a flexible data repository for information update for equipment utilization in large scale disaster response scenarios.

• Journal of KIISE:Software and Applications
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• v.31 no.9
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• pp.1142-1149
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• 2004

Motion Estimation(ME) has been developed to reduce temporal redundancy in digital video signals and increase data compression ratio. ME is an Important part of video encoding systems, since it can significantly affect the output quality of encoded sequences. However, ME requires high computational complexity, it is difficult to apply to real time video transmission. for this reason, motion estimation algorithms with low computational complexity are viable solutions. In this paper, we present an efficient method with low computational complexity based on spatial and temporal correlations of motion vectors. The proposed method uses temporally and spatially correlated motion information, the motion vector of the block with the same coordinate in the reference frame and the motion vectors of neighboring blocks around the current block in the current frame, to decide the search pattern and the location of search starting point adaptively. Experiments show that the image quality improvement of the proposed method over MVFAST (Motion Vector Field Adaptive Search Technique) and PMVFAST (Predictive Motion Vector Field Adaptive Search Technique) is 0.01～0.3(dB) better and the speedup improvement is about 1.12～l.33 times faster which resulted from lower computational complexity.

• Science of Emotion and Sensibility
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• v.18 no.2
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• pp.3-18
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• 2015

Numerosity perception is considered as an innate ability of human being where its sensivitiy may widely vary across each individual person. The present study explored the relationship between visual working memory (VWM), visual search efficiency, and numerosity sensitivity. To accomplish this, we calculated each participant's K-value from change detection performance representing one's storage capacity in VWM, slopes of search RTs representing the search efficiency, and discrimination sensitivity for a quantity difference across two sets of dot arrays representing the numerosity sensitivity. The correlational analysis across the measurements revealed that participants with a high VWM capacity better discriminated the numerosity difference in the arrays when the spatial information in the two dot arrays was preserved. In contrast, the participants with high search efficiency discriminated better the difference in the arrays when the spatial information in the arrays was not preserved. The results indicate high VWM-capacity individuals were presumably able to use a strategy of storing the dot arrays by grouping them into a smaller pattern of dot arrays while high search-efficiency individuals were able to use a strategy of rapidly switching their focused attention across the dots in the arrays to count each individual dot. These in sum suggest that individual differences in numerosity sensitivity rely on one's working memory capacity as well as their efficient use of switching focused attention.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.2
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• pp.185-194
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• 2016

The purpose of this study is to present a method to provide environment information based on spatial information document. At present, a lot of spatial information, including environment information, is being produced, but separate software or system is required for the user to acquire the information. In particular, in the case of environment information, various types of information are being produced, such as ecology, vegetation and measurement network data. Therefore, it is necessary to present the form and the making method of spatial information document that allows using environment information as spatial information without separate software or system. To provide spatial information document-based environment information, types and forms of environment information, data format and offering methods produced by the government, in particular, the Ministry of Environment and the local governments, are analyzed. 12 fields are classified and the form of produced data is GIS DB, measurement network data, text data and so on. With decrease of paper maps, spatial information document that offers display by layer, coordinate data, attribute data, distance and area measurement, location search by coordinates, GPS location linkage and location display on the map is presented to increase utilization of geo-environment information maps. Finally, the standard document specification based on spatial information document is presented in consideration of usability and readability in order to provide a variety of environment information without separate software or system.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.4
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• pp.81-90
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• 2018

The 'Hyper-connected society' in which all objects such as people, device, place are connected via networks and share information being realized. As the information and communication environment changes, spatial information also faces a significant challenge. Korean government is striving to meet the social demand for spatial information that will bring 'Hyper-connectivity' such as autonomous vehicles, drones. Until now, however, it has only partially responded to urgent demand and has not prepared a fundamental countermeasure. In order to effectively and actively respond to the demand for spatial information that is needed in the Hyper-connected society, a strategy that can lead to mid- to long-term fundamental changes is needed. The purpose of this study is to analyze the future demand and application characteristics of spatial information confronted with a big paradigm shift called 'Hyper-connected society', and to search spatial information strategy that can cope with the demand of spatial information in future society.

• Proceedings of the Korea Contents Association Conference
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• 2003.11a
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• pp.423-430
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• 2003

Generally, elements of DRM(Digital Road Map) consist of road, background and landmark data. The landmark, expressed as text and symbol, on map and additional search data are processed by GISSD(Geo-spatial Information System Service Data). This paper aims to develop the DBMS(Database Management System) for operating landmark and search data, and to discuss the characteristics and application of the DBMS. To accomplish the two objectives, the following four tasks were performed in this study. First, the working scopes of field survey and specification to construct the GISSD were defined. Second, the suggested process of manufacture and design of database were described. Third, the software for required construction and management of the system were developed. Lastly, the properties of developed system and data were analyzed. Especially, the efforts for the GISSD in this study are expected to provide a direct use and practical application to the creation of landmark in DRM and search data.

• Journal of Korea Multimedia Society
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• v.4 no.5
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• pp.390-395
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• 2001

In this paper, we propose a fast warping prediction using bit-pattern for motion estimation. Because of the spatial dependency between motion vectors of neighboring node points carrying motion information, the optimization of motion search requires an iterative search. The computational load stemming from the iterative search is one of the major obstacles for practical usage of warping prediction. The motion estimation in the proposed algorithm measures whether the motion content of the area is or not, using bit-pattern. Warping prediction using the motion content of the area make the procedure of motion estimation efficient by eliminating an unnecessary searching. Experimental results show that the proposed algorithm can reduce more 75% iterative search while maintaining performances as close as the conventional warping prediction.

• Journal of Korean Society for Geospatial Information Science
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• v.4 no.2 s.8
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• pp.173-180
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• 1996

In a grid based data transformation, the different gridding methods provide different interpretations of scattered data because each method calculate grid node values using a different weighted mathematical algorithms. Therefore, it is necessary to review the interpolated characteristics of some gridding methods according to search distance, search area and search options before determing the best method with a data set. For this, in this paper, six different gridding methods with the same search conditions are applied to a scattered data obtained from sterro-plotter. The interpolated characteristics of the scattered geographic data considered through comparison of coincidence between the data point and the grid node being interpolated. And also, shows the real application of gridding methods through calculating volumes and creating cross sections.

• Journal of the Ergonomics Society of Korea
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• v.28 no.4
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• pp.91-99
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• 2009

A visual stress may provoke migraine, cephalalgia, intervene a long term reading and learning capability and reduce the productivity of a laborer who uses computer for a good while. In this study, a web based screening tool for visual stress was developed, it applied to 72 visually normal young persons in parallel with traditional questionnaire about symptoms of visual stress. To estimate visual stress, It is proposed to measure difference of visual search time of Han Gul characters as targets between visual stressful pattern and non-visual stressful pattern as global background of characters. As a result of test, 5 subjects were screened whose mean visual search time in the stressful pattern with 6 CPD spatial frequency increase significantly more than in none stressful pattern(t-test, one-tailed, p=$1.0407\times10^{-11}$). 2 of them were diagnosed as mild visual stress syndrome in the clinic. None had visual distortion and 50% of subjects had visual discomfort in results of the questionnaire. Correlation between visual search time increase rate and normalized number of visual discomfort may be slight(C. coefficient=0.1355). This study may contribute as a basic research for screening person with migraine, visual reading disabilities and VDT syndrome. It is required to apply the test to visual reading disabilities, migraine with visual distortion and/or visual discomfort as well as normal person for higher reliability of the screening tool.