• Title/Summary/Keyword: real-time localization

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Variable localization of Toll-like receptors in human fallopian tube epithelial cells

  • Amjadi, Fatemehsadat;Zandieh, Zahra;Salehi, Ensieh;Jafari, Reza;Ghasemi, Nasrin;Aflatoonian, Abbas;Fazeli, Alireza;Aflatoonian, Reza
    • Clinical and Experimental Reproductive Medicine
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    • v.45 no.1
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    • pp.1-9
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    • 2018
  • Objective: To determine the localization, expression, and function of Toll-like receptors (TLRs) in fallopian tube epithelial cells. Methods: The localization of TLRs in fallopian tube epithelial cells was investigated by immunostaining. Surprisingly, the intensity of staining was not equal in the secretory and ciliated cells. After primary cell culture of fallopian tube epithelial cells, ring cloning was used to isolate colonies of ciliated epithelial cells, distinct from non-ciliated epithelial cells. The expression of TLRs 1-10 was examined by quantitative real-time polymerase chain reaction, and protein localization was confirmed by immunostaining. The function of the TLRs was determined by interleukin (IL)-6 and IL-8 production in response to TLR2, TLR3, TLR5, TLR7, and TLR9 ligands. Results: Fallopian tube epithelial cells expressed TLRs 1-10 in a cell-type-specific manner. Exposing fallopian tube epithelial cells to TLR2, TLR3, TLR5, TLR7, and TLR9 agonists induced the secretion of proinflammatory cytokines such as IL-6 and IL-8. Conclusion: Our findings suggest that TLR expression in the fallopian tubes is cell-type-specific. According to our results, ciliated cells may play more effective role than non-ciliated cells in the innate immune defense of the fallopian tubes, and in interactions with gametes and embryos.

A Moving Camera Localization using Perspective Transform and Klt Tracking in Sequence Images (순차영상에서 투영변환과 KLT추적을 이용한 이동 카메라의 위치 및 방향 산출)

  • Jang, Hyo-Jong;Cha, Jeong-Hee;Kim, Gye-Young
    • The KIPS Transactions:PartB
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    • v.14B no.3 s.113
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    • pp.163-170
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    • 2007
  • In autonomous navigation of a mobile vehicle or a mobile robot, localization calculated from recognizing its environment is most important factor. Generally, we can determine position and pose of a camera equipped mobile vehicle or mobile robot using INS and GPS but, in this case, we must use enough known ground landmark for accurate localization. hi contrast with homography method to calculate position and pose of a camera by only using the relation of two dimensional feature point between two frames, in this paper, we propose a method to calculate the position and the pose of a camera using relation between the location to predict through perspective transform of 3D feature points obtained by overlaying 3D model with previous frame using GPS and INS input and the location of corresponding feature point calculated using KLT tracking method in current frame. For the purpose of the performance evaluation, we use wireless-controlled vehicle mounted CCD camera, GPS and INS, and performed the test to calculate the location and the rotation angle of the camera with the video sequence stream obtained at 15Hz frame rate.

A Study on the Robust Sound Localization System Using Subband Filter Bank (서브밴드 필터 뱅크를 이용한 강인한 음원 추적시스템에 대한 연구)

  • 박규식;박재현;온승엽;오상헌
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.1
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    • pp.36-42
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    • 2001
  • This paper propose new sound localization algorithm that detects the sound source bearing in a closed office environment using two microphone array. The proposed Subband CPSP (Cross Power Spectrum Phase) algorithm is a development of previously Down CPSP method using subband approach. It first split the received microphone signals into subbands and then calculates subband CPSP which result in possible source bearings. This type of algorithm, Subband CPSP, can provide more robust and reliable sound localization system because it limits the effects of environmental noise within each subband. To verify the performance of the proposed Subband CPSP algorithm, a real time simulation was conducted and it was compared with previous CPSP method. From the simulation results, the proposed Subband CPSP is superior to previous CPSP algorithm more than 5% average accuracy for sound source detection.

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Study on the Localization Concordance of Video and Audio (시선에 따른 영상 음향 정위 일치에 관한 연구)

  • Lee, Kyou-Won;Choi, Hae-Geun;Park, So-Youn;Park, Goo-Man;Kim, Seong-Kweon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.6
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    • pp.1293-1300
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    • 2018
  • The $360^{\circ}$ video has a lot of image information and usefulness; however, the position of the audio source judged by hearing is different from the position on the screen. Therefore, human feels tired, the immersion decrease and user cant watch the video for Moreer time. In this paper, the concordance rate of the video and the audio localization is defined. The rate is expressed in a percentage. It means how much the system makes the sound localization real according to the position of the source on the screen. With this rate, the audio localization performance of immersive audio producing and playing system can be evaluated. It will be helpful for developers to make the higher performance system and expected to contribute to make makinguality system with reality.

Localization Algorithms for Mobile Robots with Presence of Data Missing in a Wireless Communication Environment (무선통신 환경에서 데이터 손실 시 모바일 로봇의 측위 알고리즘)

  • Sin Kim;Sung Shin;Sung Hyun You
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.4
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    • pp.601-608
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    • 2023
  • Mobile robots are widely used in industries because mobile robots perform tasks in various environments. In order to carry out tasks, determining the precise location of the robot in real-time is important due to the need for path generation and obstacle detection. In particular, when mobile robots autonomously navigate in indoor environments and carry out assigned tasks within pre-determined areas, highly precise positioning performance is required. However, mobile robots frequently experience data missing in wireless communication environments. The robots need to rely on predictive techniques to autonomously determine the mobile robot positions and continue performing mobile robot tasks. In this paper, we propose an extended Kalman filter-based algorithm to enhance the accuracy of mobile robot localization and address the issue of data missing. Trilateration algorithm relies on measurements taken at that moment, resulting in inaccurate localization performance. In contrast, the proposed algorithm uses residual values of predicted measurements in data missing environments, making precise mobile robot position estimation. We conducted simulations in terms of data missing to verify the superior performance of the proposed algorithm.

The Method of Reducing the Delay Latency to Improve the Efficiency of Power Consumption in Wireless Sensor Networks

  • Ho, Jang;Son, Jeong-Bong
    • 한국정보컨버전스학회:학술대회논문집
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    • 2008.06a
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    • pp.199-204
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    • 2008
  • Sensor nodes have various energy and computational constraints because of their inexpensive nature and ad-hoc method of deployment. Considerable research has been focused at overcoming these deficiencies through faster media accessing, more energy efficient routing, localization algorithms and system design. Our research attempts to provide a method of improvement MAC performance in these issues. We show that traditional carrier-sense multiple access(CSMA) protocols like IEEE 802.11 do not handle the first constraint adequately, and do not take advantage of the second property, leading to degraded latency and throughput as the network scales in size, We present more efficient method of a medium access for real-time wireless sensor networks. Proposed MAC protocol is a randomized CSMA protocol, but unlike previous legacy protocols, does not use a time-varying contention window from which a node randomly picks a transmission slot. To reduce the latency for the delivery of event reports, it carefully decides a fixed-size contention window, non-uniform probability distribution of transmitting in each slot within the window. We show that it can offer up to several times latency reduction compared to legacy of IEEE 802.11 as the size of the sensor network scales up to 256 nodes using widely used simulator ns-2. We, finally show that proposed MAC scheme comes close to meeting bounds on the best latency achievable by a decentralized CSMA-based MAC protocol for real-time wireless sensor networks which is sensitive to latency.

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TOA Estimation Technique for IR-UWB Based on Homogeneity Test

  • Djeddou, Mustapha;Zeher, Hichem;Nekachtali, Younes;Drouiche, Karim
    • ETRI Journal
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    • v.35 no.5
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    • pp.757-766
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    • 2013
  • This paper deals with the estimation of the time of arrival (TOA) of ultra-wideband signals under IEEE 802.15.4a channel models. The proposed approach is based on a randomness test and consists of determining whether an autoregressive (AR) process modeling an energy frame is random or not by using a distance to measure the randomness. The proposed method uses a threshold that is derived analytically according to a preset false alarm probability. To highlight the effectiveness of the developed approach, simulation setups as well as real data experiments are conducted to assess the performance of the new TOA estimation algorithm. Thereby, the proposed method is compared with the cell averaging constant false alarm rate technique, the threshold comparison algorithm, and the technique based on maximum energy selection with search back. The obtained results are promising, considering both simulations and collected real-life data.

Position Recognition and Indoor Autonomous Flight of a Small Quadcopter Using Distributed Image Matching (분산영상 매칭을 이용한 소형 쿼드콥터의 실내 비행 위치인식과 자율비행)

  • Jin, Taeseok
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.2_2
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    • pp.255-261
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    • 2020
  • We consider the problem of autonomously flying a quadcopter in indoor environments. Navigation in indoor settings poses two major issues. First, real time recognition of the marker captured by the camera. Second, The combination of the distributed images is used to determine the position and orientation of the quadcopter in an indoor environment. We autonomously fly a miniature RC quadcopter in small known environments using an on-board camera as the only sensor. We use an algorithm that combines data-driven image classification with image-combine techniques on the images captured by the camera to achieve real 3D localization and navigation.

Sound Localization Technique for Intelligent Service Robot 'WEVER' (지능형 로봇 '웨버'를 위한 음원 추적 기술)

  • Lee, Ji-Yeoun;Hahn, Min-Soo;Ji, Su-young;Cho, Young-Jo
    • Proceedings of the KSPS conference
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    • 2005.11a
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    • pp.117-120
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    • 2005
  • This paper suggests an algorithm that can estimate the direction of the sound source in realtime. Our intelligent service robot, WEVER, is used to implement the proposed method at the home environment. The algorithm uses the time difference and sound intensity information among the recorded sound source by four microphones. Also, to deal with noise of robot itself, the kalman filter is implemented. The proposed method takes shorter execution time than that of an existing algorithm to fit the real-time service robot. The result shows relatively small error within the range of ${\pm}$ 7 degree.

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Evaluation of Real-time Target Positioning Accuracy in Spinal Radiosurgery (척추방사선수술시 실시간 추적검사에 의한 병소목표점 위치변이 평가)

  • Lee, Dong Joon
    • Progress in Medical Physics
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    • v.24 no.4
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    • pp.290-294
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    • 2013
  • Stereotactic Radiosurgery require high accuracy and precision of patient positioning and target localization. We evaluate the real time positioning accuracy of isocenter using optic guided patient positioning system, ExacTrac (BrainLab, Germany), during spinal radiosurgery procedure. The system is based on real time detect multiple body markers attached on the selected patient skin landmarks. And a custom designed patient positioning verification tool (PPVT) was used to check the patient alignment and correct the patient repositioning before radiosurgery. In this study, We investigate the selected 8 metastatic spinal tumor cases. All type of tumors commonly closed to thoracic spinal code. To evaluate the isocenter positioning, real time patient alignment and positioning monitoring was carried out for comparing the current 3-dimensional position of markers with those of an initial reference positions. For a selected patient case, we have check the isocenter positioning per every 20 millisecond for 45 seconds during spinal radiosurgery. In this study, real time average isocenter positioning translation were $0.07{\pm}0.17$ mm, $0.11{\pm}0.18$ mm, $0.13{\pm}0.26$ mm, and $0.20{\pm}0.37$ mm in the x (lateral), y (longitudinal), z (vertical) directions and mean spatial error, respectively. And body rotations were $0.14{\pm}0.07^{\circ}$, $0.11{\pm}0.07^{\circ}$, $0.03{\pm}0.04^{\circ}$ in longitudinal, lateral, table directions and mean body rotation $0.20{\pm}0.11^{\circ}$, respectively. In this study, the maximum mean deviation of real time isocenter positioning translation during spinal radiosurgery was acceptable accuracy clinically.