• 제목/요약/키워드: Multiple marker

검색결과 257건 처리시간 0.02초

3차원 환경 복원을 위한 다중 키넥트의 마커리스 캘리브레이션 (Marker-less Calibration of Multiple Kinect Devices for 3D Environment Reconstruction)

  • 이수원
    • 한국멀티미디어학회논문지
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    • 제22권10호
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    • pp.1142-1148
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    • 2019
  • Reconstruction of the three-dimensional (3D) environment is a key aspect of augmented reality and augmented virtuality, which utilize and incorporate a user's surroundings. Such reconstruction can be easily realized by employing a Kinect device. However, multiple Kinect devices are required for enhancing the reconstruction density and for spatial expansion. While employing multiple Kinect devices, they must be calibrated with respect to each other in advance, and a marker is often used for this purpose. However, a marker needs to be placed at each calibration, and the result of marker detection significantly affects the calibration accuracy. Therefore, a user-friendly, efficient, accurate, and marker-less method for calibrating multiple Kinect devices is proposed in this study. The proposed method includes a joint tracking algorithm for approximate calibration, and the obtained result is further refined by applying the iterative closest point algorithm. Experimental results indicate that the proposed method is a convenient alternative to conventional marker-based methods for calibrating multiple Kinect devices. Hence, the proposed method can be incorporated in various applications of augmented reality and augmented virtuality that require 3D environment reconstruction by employing multiple Kinect devices.

A Fair Scalable Inter-Domain TCP Marker for Multiple Domain DiffServ Networks

  • Hur, Kyeong;Eom, Doo-Seop
    • Journal of Communications and Networks
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    • 제10권3호
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    • pp.338-350
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    • 2008
  • The differentiated services (DiffServ) is proposed to provide packet level service differentiations in a scalable manner. To provide an end-to-end service differentiation to users having a connection over multiple domains, as well as a flow marker, an intermediate marker is necessary at the edge routers, and it should not be operated at a flow level due to a scalability problem. Due to this operation requirement, the intermediate marker has a fairness problem among the transmission control protocol (TCP) flows since TCP flows have intrinsically unfair throughputs due to the TCP's congestion control algorithm. Moreover, it is very difficult to resolve this problem without individual flow state information such as round trip time (RTT) and sending rate of each flow. In this paper, to resolve this TCP fairness problem of an intermediate marker, we propose a fair scalable marker (FSM) as an intermediate marker which works with a source flow three color marker (sf-TCM) operating as a host source marker. The proposed fair scalable marker improves the fairness among the TCP flows with different RTTs without per-flow management. Through the simulations, we show that the FSM can improve TCP fairness as well as link utilization in multiple domain DiffServ networks.

Multi-Marker Augmented Reality System using Marker-Based Tracking with Vuforia

  • Yun, Hyun-Noh;Kim, Gi-Seong;Moon, Nammee
    • 한국컴퓨터정보학회논문지
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    • 제24권2호
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    • pp.119-126
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    • 2019
  • As interest in augmented reality has increased recently, attempts have been made to incorporate augmented reality into various fields. In implementing augmented reality, the method by which markers are used is to extract feature points of markers to recognize 3D coordinates and, in some cases, it is necessary to recognize multiple markers simultaneously. Therefore, this paper proposes optimization methods for recognising multiple markers at the same time. Unity 3D and augmented reality library Vuforia are used to implement the experimental environment. The augmented reality program produced was implemented in an application form and tested using a mobile camera. We looked for optimization methods for manufacturing markers directly and for recognizing multiple markers through changes in the experimental environment. The results of the experiment can provide a higher recognition rate in an environment where multiple marker recognition is required later.

다수 마커를 활용한 영상 기반 다중 사용자 증강현실 시스템 (An Image-based Augmented Reality System for Multiple Users using Multiple Markers)

  • 문지원;박동우;정현석;김영헌;황성수
    • 한국멀티미디어학회논문지
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    • 제21권10호
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    • pp.1162-1170
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    • 2018
  • This paper presents an augmented reality system for multiple users. The proposed system performs ar image-based pose estimation of users and pose of each user is shared with other uses via a network server. For camera-based pose estimation, we install multiple markers in a pre-determined space and select the marker with the best appearance. The marker is detected by corner point detection and for robust pose estimation. the marker's corner points are tracked by optical flow tracking algorithm. Experimental results show that the proposed system successfully provides an augmented reality application to multiple users even when users are rapidly moving and some of markers are occluded by users.

맥락 정보를 이용한 장방형 마커 인식 및 증강현실 응용 (Rectangular Marker Recognition using Embedded Context Information)

  • 이원우;우운택
    • 한국HCI학회:학술대회논문집
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    • 한국HCI학회 2009년도 학술대회
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    • pp.74-79
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    • 2009
  • 증강 현실 응용 분야에서 널리 쓰이고 있는 마커는 단순히 마커를 구분하기 위한 ID에 대한 정보만을 가지고 있기 때문에 마커의 크기를 미리 알고 있어야 하며, 한 종류의 마커만을 사용할 수 있는 제약이 있었다. 이와 같은 문제점을 해결하기 위해서 본 논문에서는 맥락정보를 포함하는 마커 디자인 및 해석 방법을 제안한다. 제안된 마커 디자인은 마커의 ID 정보 외에, 마커의 종류, 크기 및 회전 정보를 마커 내부에 2차원 바코드의 형태로 포함한다. 이와 같은 마커의 맥락 정보를 마커의 패턴에 저장함으로써 여러 종류의 마커를 사용할 수 있다. 그 외에도 마커의 크기 정보를 바탕으로 서로 다른 크기를 갖는 마커들 사이에 일관성을 유지하면서 동일한 비율로 콘텐츠를 증강하는 것이 가능하며, 가로/세로 비율이 알려져 있지 않은 직사각형의 마커들도 인식이 가능하다. 마커에 담긴 맥락 정보를 바탕으로 마커를 인식함으로써, 제안된 마커 디자인은 불특정 다수의 마커들이 존재하는 모바일 증강현실에 유용하게 쓰일 수 있다.

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Simultaneous and Sequential Integration by Cre/loxP Site-Specific Recombination in Saccharomyces cerevisiae

  • Choi, Ho-Jung;Kim, Yeon-Hee
    • Journal of Microbiology and Biotechnology
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    • 제28권5호
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    • pp.826-830
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    • 2018
  • A Cre/loxP-${\delta}$-integration system was developed to allow sequential and simultaneous integration of a multiple gene expression cassette in Saccharomyces cerevisiae. To allow repeated integrations, the reusable Candida glabrata MARKER (CgMARKER) carrying loxP sequences was used, and the integrated CgMARKER was efficiently removed by inducing Cre recombinase. The XYLP and XYLB genes encoding endoxylanase and ${\beta}$-xylosidase, respectively, were used as model genes for xylan metabolism in this system, and the copy number of these genes was increased to 15.8 and 16.9 copies/cell, respectively, by repeated integration. This integration system is a promising approach for the easy construction of yeast strains with enhanced metabolic pathways through multicopy gene expression.

기성복 디자인의 개발에서 Marking에 따른 차이가 원자재 소요량과 Maker 효율에 미치는 영향에 관한 연구 (A study on Variation of Marking Effecting the Required Property Quantity & Market Efficiency in Development of Ready-Made Clothes)

  • 김준범
    • 한국의류학회지
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    • 제23권1호
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    • pp.120-127
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    • 1999
  • The purpose of the study is to mae experimental whether the required property quantity and marker efficiency has variation of marking based on theoretical background of marking using th function of computer marking system. To investigate that variation of marking effect the required property quantity and marker efficiency as the following is tried to solve giving separation to item width of property cutting line detail which is believed to influence the required property quantity and marker efficiency. How to make experiment as follows separating in order marker of 1082 styles of women's ready-made clothes of with basic design(jacket. pants. skirt, two-piece). Then the data were subjected to analysis of variance and Duncan's multiple range test. The result of this studying as follows 1. In marker of women's jacket and pants the required property quantity shows lower when it is each item than when it is two-pice,. 2. In marker of women's pants marker efficiency shows the highest level when width is 132cm and it shows the lowest level when width is 112cm. 3. In width 152cm of skirt marker it has cutting lines shows lower the required property quantity than it doesn't have. 4. In marker of women's pants it has details shows more high marker efficiency than it doesn't have.

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Forensic Body Fluid Identification by Analysis of Multiple RNA Markers Using NanoString Technology

  • Park, Jong-Lyul;Park, Seong-Min;Kim, Jeong-Hwan;Lee, Han-Chul;Lee, Seung-Hwan;Woo, Kwang-Man;Kim, Seon-Young
    • Genomics & Informatics
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    • 제11권4호
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    • pp.277-281
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    • 2013
  • RNA analysis has become a reliable method of body fluid identification for forensic use. Previously, we developed a combination of four multiplex quantitative PCR (qRT-PCR) probes to discriminate four different body fluids (blood, semen, saliva, and vaginal secretion). While those makers successfully identified most body fluid samples, there were some cases of false positive and negative identification. To improve the accuracy of the identification further, we tried to use multiple markers per body fluid and adopted the NanoString nCounter system instead of a multiplex qRT-PCR system. After measuring tens of RNA markers, we evaluated the accuracy of each marker for body fluid identification. For body fluids, such as blood and semen, each body fluid-specific marker was accurate enough for perfect identification. However, for saliva and vaginal secretion, no single marker was perfect. Thus, we designed a logistic regression model with multiple markers for saliva and vaginal secretion and achieved almost perfect identification. In conclusion, the NanoString nCounter is an efficient platform for measuring multiple RNA markers per body fluid and will be useful for forensic RNA analysis.

증강현실 구현을 위한 Multi-Marker에 관한 기법 (Techniques on Multi-Marker for the Implementation of Augmented Reality)

  • 김학희
    • 한국컴퓨터정보학회논문지
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    • 제15권11호
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    • pp.109-116
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    • 2010
  • 본 논문에서는 가상과 현실을 이어주는 하나의 방법인 마커(Marker)인식방법에서 멀티마커방법을 사용하여 복잡한 환경이나 또는 손으로 가려지는 현상에서도 추적이 가능한 기법을 제안한다. 기존의 마커인식 방법은 한 개의 마커에만 의존하기 때문에 마커가 가려짐 현상에서 객체가 깜박이는 현상을 볼 수 있는데 이 시스템에서 마커가 가려지더라도 여러 개의 마커가 가려진 마커를 대신함으로써 증강된 객체가 나타남을 확인 할 수 있다. 이러한 기술을 구현하기 위해 관점 매트릭스(perspective matrix)를 이용한 멀티 마커 추정 방법으로 다른 연산이 없기 때문에 빠르게 추정 할 수 있는 것이 특징이다. 구현된 기술은 영상으로부터 다양한 환경에서 마커를 인지하고 위치를 추정하는 기술로써 다양한 환경에서 3차원 객체를 표현 할 수 있다.

Context-free Marker-controlled Watershed Transform for Over-segmentation Reduction

  • Seo, Kyung-Seok;Cho, Sang-Hyun;Park, Chang-Joon;Park, Heung-Moon
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 ITC-CSCC -1
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    • pp.482-485
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    • 2000
  • A modified watershed transform is proposed which is context-free marker-controlled and minima imposition-free to reduce the over-segmentation and to speedup the transform. In contrast to the conventional methods in which a priori knowledge, such as flat zones, zones of homogeneous texture, and morphological distance, is required for marker extraction, context-free marker extraction is proposed by using the attention operator based on the GST (generalized symmetry transform). By using the context-free marker, the proposed watershed transform exploit marker-constrained labeling to speedup the computation and to reduce the over-segmentation by eliminating the unnecessary geodesic reconstruction such as the minima imposition and thereby eliminating the necessity of the post-processing of region merging. The simulation results show that the proposed method can extract context-free markers inside the objects from the complex background that includes multiple objects and efficiently reduces over-segmentation and computation time.

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