• The KIPS Transactions:PartB
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• v.14B no.3 s.113
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• pp.171-182
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• 2007

We propose a simple method for tracking a nonparameterized subject contour in a single video stream with a moving camera and changing background. Then we present a method to eliminate the tracked contour object by replacing with the background scene we get from other frame. First we track the object using LOD (Level-of-Detail) canny edge maps, then we generate background of each image frame and replace the tracked object in a scene by a background image from other frame that is not occluded by the tracked object. Our tracking method is based on level-of-detail (LOD) modified Canny edge maps and graph-based routing operations on the LOD maps. We get more edge pixels along LOD hierarchy. Our accurate tracking is based on reducing effects from irrelevant edges by selecting the stronger edge pixels, thereby relying on the current frame edge pixel as much as possible. The first frame background scene is determined by camera motion, camera movement between two image frames, and other background scenes are computed from the previous background scenes. The computed background scenes are used to eliminate the tracked object from the scene. In order to remove the tracked object, we generate approximated background for the first frame. Background images for subsequent frames are based on the first frame background or previous frame images. This approach is based on computing camera motion. Our experimental results show that our method works nice for moderate camera movement with small object shape changes.

• Journal of Korea Multimedia Society
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• v.15 no.8
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• pp.1004-1016
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• 2012

This paper proposes a mobile augmented reality system to provide detail information of the products using QR code included in them. In the proposed system, we perform the estimation of the camera pose using both of marker-based and markerless-based methods. If the camera can see the QR code, we perform the estimation of the camera pose using the set of rectangles in the QR code. However, if the QR code is out of sight, we perform the estimation of the camera pose based homography between consecutive frames. Moreover, the content of the augmented reality in the proposed system is made by using meta-data. Therefore, the user can make contents of various scenario using only meta-data file without modification of our system. Especially, our system maintains the contents as newly updated state by the on-line server. Thus, it can reduce the unnecessary update of the program.

• Journal of Korea Multimedia Society
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• v.15 no.8
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• pp.963-976
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• 2012

'Gesture' except for voice is the most intuitive means of communication. Thus, many researches on how to control computer using gesture are in progress. User detection and tracking in these studies is one of the most important processes. Conventional 2D object detection and tracking methods are sensitive to changes in the environment or lights, and a mix of 2D and 3D information methods has the disadvantage of a lot of computational complexity. In addition, using conventional 3D information methods can not segment similar depth object. In this paper, we propose object detection and tracking method using Depth Projection Map that is the cumulative value of the depth and motion information. Simulation results show that our method is robust to changes in lighting or environment, and has faster operation speed, and can work well for detection and tracking of similar depth objects.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.545-552
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• 2012

In this paper, we propose Modified Multi CAMShift Algorithm based on Kalman filter and Weighted Search Windows(KWMCAMShift) that extracts skin color area and tracks several human body parts for real-time human tracking system. We propose modified CAMShift algorithm that generates background model, extracts skin area of hands and head, and tracks the body parts. Kalman filter stabilizes tracking search window of skin area due to changing skin area in consecutive frames. Each occlusion areas is avoided by using weighted window of non-search areas and main-search area. And shadows are eliminated from background model and intensity of shadow. The proposed KWMCAMShift algorithm can estimate human pose in real-time and achieves 96.82% accuracy even in the case of occlusions.

• Journal of the Korea Society of Computer and Information
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• v.25 no.5
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• pp.19-26
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• 2020

This paper proposes a framework for creating acrobatic scenes such as soccer ball lifting using various users' videos. The proposed method can generate a desired result within a few seconds using a general video of user recorded with a mobile phone. The framework of this paper is largely divided into three parts. The first is to analyze the posture by receiving the user's video. To do this, the user can calculate the pose of the user by analyzing the video using a deep learning technique, and track the movement of a selected body part. The second is to analyze the movement trajectory of the selected body part and calculate the location and time of hitting the object. Finally, the trajectory of the object is generated using the analyzed hitting information. Then, a natural object lifting scenes synchronized with the input user's video can be generated. Physical-based optimization was used to generate a realistic moving object. Using the method of this paper, we can produce various augmented reality applications.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.4
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• pp.86-93
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• 2011

The ship movement implies current position, wave, wind, and its other factors. We need to know exactly the location and the shape of the ship and control its motion because of these effects. In order to control the small ship according to the movement of the large ship, the position and shape of the ship should be given first. In this paper we propose the method with which we know the current status of the ship without dynamic equations of the ship. There are several methods to track the system such as optical, radio frequency, radar, camera, and infrared light. We propose the movement of the ship using the GPS absolute axis. But, the genuine error by the GPS itself and the movement of the ship cause the result of the GPS of not being accurate. This paper reduces the error of the location and the shape of the ship and gives the exact values of the ship movements even if the GPS implies some error itself.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.3
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• pp.119-125
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• 2018

Various techniques for indoor positioning using a smart phone have been studied. Among them, the positioning technology using the acceleration sensor and the gyro sensor built in the smartphone is widely used in conjunction with the WiFi fingerprint technology. The location tracking technology using sensors has been used for a long time, but the performance environment of the smartphone is poor and the user is moving with the smartphone in a certain posture. Therefore, in order to improve the accuracy of location tracking in a smartphone environment, it is necessary to study and develop appropriate algorithms in a mobile environment. In this paper, we analyze the performances of frequency analysis method, maximum sum of minimum acceleration method and adaptive threshold method, which are the user's moving step count detection algorithms, and determine the most accurate method.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.12
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• pp.1103-1111
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• 2016

Korea Astronomy and Space Science Institute (KASI) has been operating SLR (Satellite Laser Ranging) system with 2kHz repetition rate for satellite precise orbit and spin determination as well as space geodesy. But the SLR system was improved to be capable of laser ranging with high repetition rate, up to 10kHz by developing new operation software and novel range gate generator, called HSLR-10. The HSLR-10 will contribute to the accurate spin rate determination of geodetic satellites and geodetic research due to its largest repetition rate in the world. In this study, the development methodology and configuration of operation software are addressed, and its validation results are also presented.

• Aerospace Engineering and Technology
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• v.8 no.2
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• pp.105-112
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• 2009

Telemetry data is very important for the Launch Mission and Flight Safety Control during the Space Launch. In Naro Space Center, several telemetry stations such as a small station in the NARO space center, two stations in Jeju and a downrange station on a ship are deployed for the stable acquisition/receiving of the telemetry signals. In this paper, the Link Margin and Reliability for the telemetry are analyzed to evaluate the probability of the signal receiving of each station. Even though the proper analysis is to using the on-board EIRP(Effective Isotropic Radiation Power) values in the direction of the ground station considering the predicted flight trajectory and the locations of the stations, the global EIRP of 95% spatial coverage has been used for the analysis, due to the limitation of the available data.

• Therapeutic Science for Rehabilitation
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• v.6 no.1
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• pp.71-83
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• 2017

Objective : This study aim is to identify whether smooth pursuit eye movement(SPEM) using portable device can alleviate chronic hemispatial neglect. Methods : We applied smooth pursuit eye movement to one chronic hemispatial neglect patient. Experimental duration was total 4weeks - 1week baseline, 2weeks SPEM intervention, 1week 2nd. baseline. The intervention was 10 SPEM sessions (30min each, 1session daily, from Monday to Friday) over a period of 2weeks. The neglect test carried out 5 times a week. The SPEM was provided on the screen when patient sat in front of the screen(8.4 inch tablet pc, distance 40cm). The SPEM video that the 24 yellow squares moving coherently from the right to the left side. Patients were instructed to perform smooth pursuit eye movement without head and neck movement. Results : As a result of the SPEM for 2weeks, the degree of neglect tended to decrease compared to baseline A. The degree of the LBT tended to increase the at the baseline A'. In contrast, the SCT showed that tendency which the degree of the neglect maintained at the baseline A'. Conclusion : We identified that SPEM using portable device is effective intervention method for chronic hemispatial neglect.