• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.639-643
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• 2008

Since seasonal changes, blooming of a flower, etc., which take place in accordance with passage of time, transpire over an extended duration of time, one performs the Time-Lapse so that one can watch them quickly by compressing time. Because such a Time-Lapse records a wide range of conditions including the place, angle of view, and time found in a natural state in accordance with a precise interval of time and in the samestate, it is also referred to as Interval recording. The Time-Lapse technique is used widely in various fields such as education, science, documentary, and the media. In terms of acquiring a Time-Lapse image, by making it possible for one to treat an image by deleting and adjusting unnecessary backgrounds excluding the main subject for photography such as the flower unlike existing methods and by making it possible for one to apply extensively the real-life recorded image as a library or image data in 2D or 3D, the present study seeks to propose a technique for the background treatment of Time-Lapse image that allows for everyone to bestow creativity to image production easily and conveniently.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.435-442
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• 2015

In this paper, we propose a tracking and recognition of pedestrian/vehicle for intelligent multi-visual surveillance system. The intelligent multi-visual surveillance system consists of several fixed cameras and one calibrated PTZ camera, which automatically tracks and recognizes the detected moving objects. The fixed wide-angle cameras are used to monitor large open areas, but the moving objects on the images are too small to view in detail. But, the PTZ camera is capable of increasing the monitoring area and enhancing the image quality by tracking and zooming in on a target. The proposed system is able to determine whether the detected moving objects are pedestrian/vehicle or not using the SVM. In order to reduce the tracking error, an improved camera calibration algorithm between the fixed cameras and the PTZ camera is proposed. Various experimental results show the effectiveness of the proposed system.

• Archives of Plastic Surgery
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• v.36 no.5
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• pp.654-659
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• 2009

Purpose: A botulinum toxin type A (BoNT - A) injection has been used as a noninvasive management for lower face contouring since 2000. The aim of this study was to compare reduction rate of lower face width for a longtime according to repeated Botox$^{(R)}$ injections on masseter muscles for lower face contouring procedure. Methods: Forty - five patients were analyzed for single session of Botox$^{(R)}$ injection and 13 patients were evaluated for repeated Botox$^{(R)}$ injections for over two years. Single injection group was tracked regular intervals at 1, 3, 6, 10, 12 months after injection, and repeated injection group was measured at every injection time. Twenty - five to thirty units of Botox$^{(R)}$ was injected into each masseteric muscle at five to six points at the prominent portions of the mandibular angle. Standardized frontal view of digital photographs were analyzed by Adobe Photoshop$^{(R)}$ (version CS3) to measure an reduction rate of lower face width. Results: Reduction rate was 3.7%, 6.9%, 6.2%, 4%, 4% at 1, 3, 6, 10, 12 months post injection each other in single injection group. However, more than 8% reduction rate was found in repeated injection group persistently for more than two years. Conclusion: This study shows that effective duration of Botox$^{(R)}$ injection for lower face contouring is expected to continue over one year clinically. Moreover, repeated injections maintained lower reduction rate consistently for a long time. Therefore, repeated injections on masseter muscles at regular intervals are most effective procedure for lower face contouring.

• International Journal of Highway Engineering
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• v.11 no.4
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• pp.49-58
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• 2009

Current sunshine regulations of our country, focused on common houses and general construction, are failing to reflect adequately the characteristics of roads and elevated structures. Besides, researches are chiefly being conducted on a pitch between common houses and its diverse effects, neglecting clearance between a road or elevated structure and a residential area, environmental elements brought on by structures, such as sunshine difficulty, and their resultant factors Therefore, this study, focused on the sunshine environment of elevated structures adjacent to a residential district, as part of all roads and elevated structures, looked over currently used clearance adequacy level and analyzed the characteristics of structures in relation to an angle of direction. Then, clearance ratio by heights was calculated through a pitch by characteristics of a structure. With a view to minimize the sunshine difficulty that might occur in the future construction, it aims to propose the basic data needed for calculating the minimum clearance, while emphasizing the necessity for institutional alignment on structures.

• Journal of the Korea Society for Simulation
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• v.24 no.3
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• pp.9-16
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• 2015

This research focuses on analysis of the flight trajectory characteristics of SLBM (Submarine Launched Ballistic Missile) of North Korea. Recently, North Korea tested launching of SLBM which is threatening international security. Also it is known that North Korea had possessed the technologies about SLBM since they disassembled submarines out of commission of the former Soviet Union. If the development of the SLBM of North Korea is completed, it should be affected as asymmetric threat to South Korea. Therefore, for active respondence to these threat, it is essential to analyze the SLBM systematically. In this point of view, this work made a SLBM flight model and simulated. In addition, we controled flight trajectories according to adjusting loft angle and described their characteristics. The sea-based ballistic missile defense system is required for an effective response to the flight trajectory of the SLBM from mid-course to terminal phase.

• Journal of Conservation Science
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• v.37 no.4
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• pp.312-321
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• 2021

Underwater archaeology relies heavily on photography and video image recording during surveillances and excavations like ordinary archaeological studies on land. All underwater images suffer poor image quality and distortions due to poor visibility, low contrast and blur, caused by differences in refractive indices of water and air, properties of selected lenses and shapes of viewports. In the Yellow Sea (between mainland China and the Korean peninsula), the visibility underwater is far less than 1 m, typically in the range of 30 cm to 50 cm, on even a clear day, due to very high turbidity. For photographing 1 m x 1 m grids underwater, a very wide view angle (180°) fisheye lens with an 8 mm focal length is intentionally used despite unwanted severe barrel-shaped image distortion, even with a dome port camera housing. It is very difficult to map wide underwater archaeological excavation sites by combining severely distorted images. Development of practical compensation methods for distorted underwater images acquired through the fisheye lens is strongly desired. In this study, the source of image distortion in underwater photography is investigated. We have identified the source of image distortion as the mismatching, in optical axis and focal points, between dome port housing and fisheye lens. A practical image distortion compensation method, using customized image processing software, was explored and verified using archived underwater excavation images for effectiveness in underwater archaeological applications. To minimize unusable area due to severe distortion after distortion compensation, practical underwater photography guidelines are suggested.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.822-823
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• 2014

The usual method of generating an image for a multiview display system requires acquiring a color image and depth information of a reference camera. Then, intermediate images, generated using DIBR method, will be captured at a number of different viewpoints and composed to construct an multiview image. When such intermediate views are generated, several holes would be shown because some hidden parts are shown when the screenshot is taken at different angle. Previous research tried to solve this problem by creating a new hole-filling algorithm or enhancing the depth information. This paper describes a new method of enhancing the intermediate view images by applying the Ball Pivoting algorithm, which constructs meshes from a point cloud. When the new method is applied to the Microsoft's "Ballet" and "Break Dancer" data sets, PSNR comparison shows that about 0.18~1.19 increasement. This paper will explaing the new algorithm and the experiment method and results.

• Journal of Broadcast Engineering
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• v.25 no.6
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• pp.882-897
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• 2020

Recently, the use of immersive media contents representing Panorama and 360° video is increasing. Since the viewing angle is limited to generate the content through a general camera, image stitching is mainly used to combine images taken with multiple cameras into one image having a wide field of view. However, if the parallax between the cameras is large, parallax distortion may occur in the stitched image, which disturbs the user's content immersion, thus an image stitching overcoming parallax distortion is required. The existing Seam Optimization based image stitching method to overcome parallax distortion uses energy function or object segment information to reflect the location information of objects, but the initial seam generation location, background information, performance of the object detector, and placement of objects may limit application. Therefore, in this paper, we propose an image stitching method that can overcome the limitations of the existing method by adding a weight value set differently according to the type of object to the energy value using object detection based on deep learning.

• The Journal of the Korea Contents Association
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• v.21 no.1
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• pp.119-128
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• 2021

The most typical method to generate traffic information is installing vehicle detectors and collecting various traffic variables. The information collection accuracy of a vehicle detector affects the reliability of the generated traffic information. The most universal vehicle detector is an image detector. This study installed a magnetic detector in the same position as an image detector and evaluated the accuracy of traffic volume and speed data depending on a variety of environment. Based on the evaluation, more errors occurred as the image detector was placed farther from the camera, whereas more errors were found to occur during the night rather than the day. Although rainfall did not affect the collection of traffic volume, it negatively affected speed data collection. Therefore, an analysis of the camera's view angle and its optimization depending on the camera installation position and height are required to enhance the currently operated image detector performance. It is judged that a separate performance evaluation criterion should be prepared in a bad weather environment.

• Imaging Science in Dentistry
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• v.51 no.1
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• pp.63-71
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• 2021

Purpose: The aim of this study was to assess the artefacts of 12 fixed orthodontic appliances in magnetic resonance images obtained using 1.5-T and 3-T scanners, and to evaluate different imaging sequences designed to suppress metal artefacts. Materials and Methods: In vitro, study casts of 1 adult with normal occlusion were used. Twelve orthodontic appliances were attached to the study casts and scanned. Turbo spin echo (TSE), TSE with high readout bandwidth, and TSE with view angle tilting and slice encoding for metal artefact correction were used to suppress metal artefacts. Artefacts were measured. In vivo, 6 appliances were scanned: 1) conventional stainless-steel brackets; 2) nickelfree brackets; 3) titanium brackets; 4) a Herbst appliance; 5) a fixed retainer; and 6) a rapid maxillary expander. The maxilla, mandible, nasopharynx, tongue, temporomandibular joints, and cranial base/eye globes were assessed. Scores of 0, 1, 2, and 3 indicated no artefacts and minor, moderate, and major artefacts, respectively. Results: In vitro, titanium brackets and the fixed retainer created minor artefacts. In vivo, titanium brackets caused minor artefacts. Conventional stainless-steel and nickel free brackets, the fixed retainer, and the rapid maxillary expander caused major artefacts in the maxilla and mandible. Conventional stainless-steel and nickel-free brackets caused major artefacts in the eye globe (3-T). TSE with high readout bandwidth reduced image artefacts in both scanners. Conclusion: Titanium brackets, the Herbst appliance, and the fixed retainer caused minor artefacts in images of neurocranial structures(1.5-T and 3-T) when using TSE with high readout bandwidth.