• Title/Summary/Keyword: Multiple marker

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

  • Lee, Suwon
    • Journal of Korea Multimedia Society
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    • v.22 no.10
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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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    • v.10 no.3
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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
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.2
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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.

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

  • Moon, Ji won;Park, Dong woo;Jung, Hyun suk;Kim, Young hun;Hwang, Sung Soo
    • Journal of Korea Multimedia Society
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    • v.21 no.10
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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.

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

  • Lee, Won-Woo;Woo, Woon-Tack
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.74-79
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    • 2009
  • Fiducial markers have been used frequently in augmented reality applications. However, they represent only ID information to identify a marker, and thus they have limitations when we have multiple types of markers. In this paper, we propose a new marker design for augmented reality applications. We embed a marker’s context, such as type, size, orientation, and ID, in the barcode that has been used just for storing an ID. BY embedding the context information, it is possible to recognize multiple types of markers at once and to render corresponding contents with proper scale. Our marker design can be used in a mobile augmented reality environment where many unknown types of markers may exist.

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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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    • v.28 no.5
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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.

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

  • 김준범
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.1
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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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    • v.11 no.4
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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.

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

  • Kim, Hag-Hee
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.11
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    • pp.109-116
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    • 2010
  • This study is intended to propose a technique that can trace objects by utilizing the multimarker method in the Marker Recognition which is a bridge way connecting virtuality and reality in complex environments or in a condition hands become obstacles. In the existing marker method, the object becomes blinking when the maker is blocked since this method relies only on single marker. However, the researcher was able to confirm the appearance of augmented object when the marker was blocked for the multiple markers replaced the blocked one. In order to implement such technique, multi-marker estimation was utilized with perspective matrix. The advantage is the fast estimation process for there is no need of other calculation. The implemented technique can detect markers and locate their positions, represent 3-D object in various circumstances.

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

  • Seo, Kyung-Seok;Cho, Sang-Hyun;Park, Chang-Joon;Park, Heung-Moon
    • Proceedings of the IEEK Conference
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    • 2000.07a
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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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