• Journal of Korea Multimedia Society
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• v.6 no.7
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• pp.1286-1301
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• 2003

This paper introduces segmentation based environment modeling method and integration method using multiple environment map for constructing the realtime image-based panoramic navigation system. The segmentation-based environment modeling method is easy to implement on the environment map and can be used for environment modeling by extracting the depth value by the segmentation of the environment map. However, an environment model that is constructed using a single environment map has the problem of a blurring effect caused by the fixed resolution, and the stretching effect of the 3D model caused when information that does not exist on the environment map occurs due to the occlusion. In this paper, we suggest environment models integration method using multiple environment map to resolve the above problem. This method can express parallax effect and expand the environment model to express wide range of environment. The segmentation-based environment modeling method using multiple environment map can build a detail model with optimal resolution.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.831-838
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• 2011

Computer vision research area, a division of computer graphics application area that creates realistic visualization in computer, conducts vigorously researches on developing realistic 3D model or virtual environment. As the popularization and development of 3D display makes common users easy to experience a solid 3D virtual reality, the demand for virtual reality contents are increasing. This paper proposes 3D panorama system using depth point location-based depth map generation method. 3D panorama using depth map gives an effect that makes users feel staying at real place and looking around nearby circumstances. Also, 3D panorama gives free sight point for both nearby object and remote one and provides solid 3D video.

• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.439-451
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• 2005

This article provides a panoramic overview of the state-of-the-art technologies in the field of solid-state hydrogen storage methods. The emerging solid-state hydrogen storage techniques, such as nanostructured carbon materials, metal organic framework (MOFs), metal and inter-metal hydrides, clathrate hydrates, complex chemical hydride are discussed. The hydrogen storage capacity of the solid-sate hydrogen storage materials increases in proportion to the surface area of the solid materials. Also, it is believed that new functional nanostructured materials will offer far-reaching solutions to the development of on-board hydrogen storage system for the application of the transportation vehicles.

• Journal of Broadcast Engineering
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• v.17 no.6
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• pp.1014-1028
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• 2012

Recently, N-screen service and secondary device have gotten an attention from public. Also, we can experience N-screen service through various digital devices. N-screen means multimedia technology which can seamlessly consume multimedia content. Secondary device means auxiliary multimedia device which can consume content related to main content through adjunct connection to main device. Not only be electronic manufactures interested in N-screen technology and services but also digital devices applied for N-screen have been released. But it has limitation that user can only consume content to be purchased from content company server not device of user. This paper proposes the system that composes effective and various N-screen multimedia service through MPEG-4 LASeR (Lightweight Application Scene Representation) PMSI (Presentation and Modification of Structured Information) as international standard technology which can provide scene description including many instruction for dynamic update of scene.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.1
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• pp.70-77
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• 2014

This paper proposes a novel localization algorithm based on ego-motion which used Lucas-Kanade Optical Flow and warping image obtained through fish-eye lenses mounted on the robots. The omnidirectional image sensor is a desirable sensor for real-time view-based recognition of a robot because the all information around the robot can be obtained simultaneously. The preprocessing (distortion correction, image merge, etc.) of the omnidirectional image which obtained by camera using reflect in mirror or by connection of multiple camera images is essential because it is difficult to obtain information from the original image. The core of the proposed algorithm may be summarized as follows: First, we capture instantaneous $360^{\circ}$ panoramic images around a robot through fish-eye lenses which are mounted in the bottom direction. Second, we extract motion vectors using Lucas-Kanade Optical Flow in preprocessed image. Third, we estimate the robot position and angle using ego-motion method which used direction of vector and vanishing point obtained by RANSAC. We confirmed the reliability of localization algorithm using ego-motion based on fisheye warping image through comparison between results (position and angle) of the experiment obtained using the proposed algorithm and results of the experiment measured from Global Vision Localization System.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.2
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• pp.361-368
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• 1994

Radiographic planning is needed for implant placement in order to determine implant length, jaw bone volume, anatomical stucture and so on. Radiographic examination includes conventional radiography, conventional tomography and CT scan. The most accurate mesurement can be obtained from CT scan. For the cross-sectional view of mandible, CT scan reconstruction is generally needed. But the cross-sectional view of mandible can be reformed by personal computer. This study was performed to examine the clinical usefulness of reformed image using personal computer in comparison with CT scan reconstructed image. CT axial slices of 4 mandibles of 4 volunteers were used. Digital imaging system was composed of Macintosh Ⅱ ci computer, high resolution Sony XC-77 CCD camera, Quick Capture frame grabber board and 'NIH Image' program. Seven reconstructed cross-sectional images within CT machine(CT group) were obtained. And seven reformed cross-sectional images(PC group) after digitization of CT axial slices into the personal computer were obtained. PC group was compared with CT group in the objective and subjective aspects. The results were as follow: 1. Measurement of mandibular height & width in both group showed insignificant difference(P>0.05). 2. Subjective assessment of the mandibular canal in both group showed insignificant difference(P>0.05). 3. Image reformation using personal computer could provide panoramic view, which could not be obtained in CT scan reconstruction.

• Journal of Broadcast Engineering
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• v.21 no.5
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• pp.651-661
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• 2016

최근의 디지털 사이니지는 대형 고해상도 디스플레이를 이용해 사용자에게 초고해상도 파노라마형태의 볼거리를 제공하거나 사용자와 인터렉션 등을 통해 맞춤형광고를 제공하는 등 다양한 형태로 발전하고 있다. 또 개방형 디지털 사이니지의 발전과 함께 대형 멀티 사이니지를 이용한 초고화질 영상콘텐츠를 다양한 서비스 단말장치의 연동과 웹기반의 상호운용성을 갖춘 관리시스템이 활발히 연구될 것으로 보인다. 본 논문에서는 수십대에서 백여대 이상의 고해상도 디스플레이를 연동하여 초고해상도 영상표출의 기술의 구현방안과 정형화된 영상 해상도가 아닌 초고화질 영상의 개별 콘텐츠에 대한 동기화 시키는 기술을 이용하여 멀티 콘텐츠 플레이 단말기에서 고해상도 영상을 Play Sync하는 기술을 연구한다.

• 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).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.6
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• pp.309-315
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• 2019

Objectives: The aim of this study was to evaluate the validity of the existing classification and difficulty index of impacted mandibular third molars in clinical situations and propose a more practical classification system. Materials and Methods: This study included 204 impacted mandibular third molars in 154 patients; panoramic x-ray images were obtained before tooth extraction. Factors including age, sex, and pattern of impaction were investigated. All impacted third molars were classified and scored for spatial relationship (1-5 points), depth (1-4 points), and ramus relationship (1-3 points). All variables were measured twice by the same observer at a minimum interval of one month. Finally, the difficulty index was defined based on the total points scored as slightly difficult (3-4 points), moderately difficult (5-7 points), very difficult (8-10 points), and extremely difficult (11-12 points). Results: The strength of agreement of the total points scored and difficulty index were 0.855 and 0.746, respectively. Most cases were classified as moderately difficult (73.0%). Although only 13 out of 204 cases (6.4%) were classified as extremely difficult, patients classified as extremely difficult were the oldest (P<0.05). Conclusion: For difficulty classification, the authors propose one more difficult category beyond the existing three-step difficulty index: the clinician should consider the patient's age in the difficulty index evaluation.

• Korean Journal of Cleft Lip And Palate
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• v.4 no.2
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• pp.69-78
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• 2001

Alveolar cleft exists in 75% of cleft patients, In alveolar cleft patients, alar base is widening, palatal fistular formation, maxillary growth disturbance & tooth loss of adjacent area is raised, Alveolar bone grafting, especially iliac bone grafting, is a general treatment method. As operation timing, bone grafting is classified with primary, early secondary, secondary, & late secondary, Here we report cleft width, marginal bone height, bone resorption rate, grafted shape & bone densities after secondary iliac bone grafting was done in the Dept. of oral and maxillofacial surgery of chonbuk national university hospital. We compared cleft width to bone resorption rate and grafted shape. Also, alveolar bone densities of grafted and contralateral site was compared with Emago 3 package? (Oral Diagonostic System, The Netherlands), The data obtained were analyzed using Spearman's rho coefficients and sign test with SPSS for window, The results were obtained as follows. 1. As alveolar cleft width is increase, bone resorption rate is, too. This relation showed significant difference(P<.01). 2, In proximal & distal area, alvolar cleft width and bone graft contour after bone grafting had a reverse proportional difference. It was not significant difference(P>.05). 3. After 3 month, in bone density results by using Emago 3 package? with periapical standard view, occlusal view & panoramic view, differences between grafted bone and alveolar bone of contralateral site didn't show a significant difference(P>.05). Thus, differences of bone densities in the alveolar bones didn't exist.