• Proceedings of the IEEK Conference
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.171-174
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• 2003

In this paper, we propose the method of stereo images composition using adaptive dense disparity estimation. For the correct composition of stereo image and 3D virtual object, we need correct marker position and depth information. The existing algorithms use position information of markers in stereo images for calculating depth of calibration object. But this depth information may be wrong in case of inaccurate marker tracking. Moreover in occlusion region, we can't know depth of 3D object, so we can't composite stereo images and 3D virtual object. In these reasons, the proposed algorithm uses adaptive dense disparity estimation for calculation of depth. The adaptive dense disparity estimation is the algorithm that use pixel-based disparity estimation and the search range is limited around calibration object.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제10권3호
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• pp.178-183
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• 2010

In this study we augmented a virtual object to an image of a flexible surface such as a paper, which is acquired from a web camera. To get more presence feeling, we consider realistic illumination on augmenting. To get the geometric relation between the camera and the flexible surface, we use markers that are printed on the surface. Using marker information in prior, three dimensional coordinates of the surface can be calculated. After the marker is removed from the input image, we attach a two dimensional texture and shadow to the flexible surface by considering realistic illumination.

• Journal of Korea Multimedia Society
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• 제16권6호
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• pp.720-734
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• 2013

In this paper, we suggest an augmented reality authoring tool system that users can easily make augmented reality contents using hand gesture and marker-based interaction methods. The previous augmented reality authoring tools are focused on augmenting a virtual object and to interact with this kind of augmented reality contents, user used the method utilizing marker or sensor. We want to solve this limited interaction method problem by applying marker based interaction method and gesture interaction method using depth sensing camera, Kinect. In this suggested system, user can easily develop simple form of marker based augmented reality contents through interface. Also, not just providing fragmentary contents, this system provides methods that user can actively interact with augmented reality contents. This research provides two interaction methods, one is marker based method using two markers and the other is utilizing marker occlusion. In addition, by recognizing and tracking user's bare hand, this system provides gesture interaction method which can zoom-in, zoom-out, move and rotate object. From heuristic evaluation about authoring tool and compared usability about marker and gesture interaction, this study confirmed a positive result.

• Journal of KIISE:Computing Practices and Letters
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• 제16권4호
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• pp.502-506
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• 2010

An augmented book is an application that augments such multimedia elements as virtual 3D objects generated by computer graphics, movie clips, or sound clips to a real book using AR technologies. It is intended to bring additional education and entertainment effects to users. For augmented books, this paper proposes an adaptive keyframe-based page tracking method to estimate the camera's 6 DOF pose in real-time after recognizing a page and performing wide-baseline keypoint matching. For a page tracking, proposed method in this paper chooses a proper keyframe and performs a tracking in two step of coarse-to-fine stage. As a result, the proposed method in this paper guarantees a robust tracking to view-point and illumination variations and real-time.

• Proceedings of the KAIS Fall Conference
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• 한국산학기술학회 2010년도 춘계학술발표논문집 1부
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• pp.225-227
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• 2010

최근 증강현실(Augmented Reality, AR) 기술의 중요성이 인식되면서 다양한 분야의 서비스에 기술 도입사례가 등장하고 있다. AR에 있어 마커 검출 기술은 가장 기본이 되는 중요한 기술이다. 하지만 마커 기반의 증강현실 시스템은 그 오차가 매우 크고 이로 인해 센서정보와 같은 다양한 보조적 정보를 요구하게 된다. 따라서 본 연구에서는 마커사용의 한계를 극복하기 위한 마커리스 트래킹(Markerless Tracking Technology)기술을 연구 하여 실시간 영상에서 목표로 하는 사물을 추적하여 증강현실 서비스로 도입하기 위한 시스템은 설계하였다. 본 시스템은 기존에 도입된 명함 분석, 자동차 번호판 인식 등 제한된 서비스의 한계를 극복하고 보다 다양한 연구 분야에 활용될 것이다.

• Proceedings of the Korea Multimedia Society Conference
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• 한국멀티미디어학회 2000년도 춘계학술발표논문집
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• pp.474-477
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• 2000

최근 3D 애니메이션 , 영화 특수효과 그리고 게임제작시 모션 캡처 시스템(Motion Capture System)을 통하여 실제 인간의 동작 및 표정을 수치적으로 측정해내어 이를 실제 애니메이션에 직접 사용함으로써 막대한 작업시간 및 인력 드리고 자본을 획기적으로 줄이고 있다. 그러나 기존의 모션 캡처 시스템은 고속 카메라를 이용함으로써 가격이 고가이고 움직임 추적에서도 여러 가지 문제점을 가지고 있다. 본 논문에서는 일반 저가의 카메라와 신경회로망 및 영상처리를 이용하여 얼굴 애니메이션용 모션 캡처 시스템에 적용할 수 있는 경제적이고 효율적인 얼굴 움직임 추적 기법을 제안한다.

• The Journal of Korea Robotics Society
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• 제12권4호
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• pp.411-418
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• 2017

During the intramedullary nailing procedure, surgeons feel difficulty in manipulation of the X-ray device to align it to axes of nailing holes and suffer from the large radiation exposure from the X-ray device. These problems are caused by the fact the surgeon cannot see the hole's location directly and should use the X-ray device to find the hole's location and direction. In this paper, we proposed the robotic guidance of the distal screwing using an optical tracking system. To track the location of the hole for the distal screwing, the reference marker is attached to the proximal end of an intramedullary nail. To guide the drill's direction robustly, the 6-degree-of-freedom robotic arm is used. The robotic arm is controlled so as to align the drill guiding tool attached the robotic arm with the obtained the hole's location. For the safety, the robot's linear and angular velocities are restricted to the predefined values. The experimental results using the artificial bones showed that the position error and the orientation error were 0.91 mm and $1.64^{\circ}$, respectively. The proposed method is simple and easy to implement, thus it is expected to be adopted easily while reducing the radiation exposure significantly.

• Journal of the Korea Society of Computer and Information
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• 제16권6호
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• pp.89-97
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• 2011

When examining current process of object tracking and search, objects were tracked by extracting them from image that was inputted through fixed single camera and objects were recognized through Zoom function to know detailed information on objects tracked. This study proposed system that expresses information on area that can seek and recognize object tracked as augmented reality by recognizing and seeking object by using multi camera. The result of experiment on proposed system showed that the number of pixels that was included in calculation was remarkably reduced and recognition rate of object was enhanced and time that took to identify information was shortened. Compared with existing methods, this system has advantage of better accuracy that can detect the motion of object and advantage of shortening time that took to detect motion.

• Journal of Plant Biotechnology
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• 제50권
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• pp.190-199
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• 2023

Date palm (Phoenix dactylifera L.: Arecaceae) is a dioecious species where only female trees bear fruits. In their natural state, date palms produce dates once a year. However, in Thailand, some trees were observed to produce dates during the off-season, despite no variations in morphology. The availability of such off-season fruits can significantly increase their market value. Interestingly, most female off-season date palms investigated in this study were obtained through micropropagation. Hence, there is an urgent need for genetic markers to distinguish female offseason flowering plantlets within tissue culture systems. In this study, we aimed to develop random amplification of polymorphic DNA-sequence characterized amplified region (RAPD-SCAR) markers for the identification of female off-season flowering date palms cultivated in Thailand. A total of 160 random decamer primers were employed to screen for specific RAPD markers in off-season flowering male and female populations. Out of these, only one primer, OPN-02, generated distinct genomic DNA patterns in female off-season flowering (FOFdp) individuals compared to female seasonal flowering genotypes. Based on the RAPD-specific sequence, specific SCAR primers denoted as FOFdpF and FOFdpR were developed. These SCAR primers amplified a single 517-bp DNA fragment, predominantly found in off-season flowering populations, with an accuracy rate of 60%. These findings underscore the potential of SCAR marker technology for tracking offseason flowering in date palms. Notably, a BLAST analysis revealed a substantial similarity between the SCAR marker sequence and the transcript variant mRNA from Phoenix dactylifera encoding the SET DOMAIN GROUP 40 protein. In Arabidopsis, this protein is involved in the epigenetic regulation of flowering time. The genetic potential of the off-season flowering traits warrants further elucidation.

• Journal of Internet Computing and Services
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• 제12권3호
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• pp.119-129
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• 2011

Vision-based Human computer interaction is an emerging field of science and industry to provide natural way to communicate with human and computer. Especially, recent increasing demands for mobile augmented reality require the development of efficient interactive technologies between the augmented virtual object and users. This paper presents a novel approach to construct marker-less mobile augmented reality object and control the object. Replacing a traditional market, the human hand interface is used for marker-less mobile augmented reality system. In order to implement the marker-less mobile augmented system in the limited resources of mobile device compared with the desktop environments, we proposed a method to extract an optimal hand region which plays a role of the marker and augment object in a realtime fashion by using the camera attached on mobile device. The optimal hand region detection can be composed of detecting hand region with YCbCr skin color model and extracting the optimal rectangle region with Rotating Calipers Algorithm. The extracted optimal rectangle region takes a role of traditional marker. The proposed method resolved the problem of missing the track of fingertips when the hand is rotated or occluded in the hand marker system. From the experiment, we can prove that the proposed framework can effectively construct and control the augmented virtual object in the mobile environments.