• Title/Summary/Keyword: Data fusion system

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Motion and Structure Estimation Using Fusion of Inertial and Vision Data for Helmet Tracker

  • Heo, Se-Jong;Shin, Ok-Shik;Park, Chan-Gook
    • International Journal of Aeronautical and Space Sciences
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    • v.11 no.1
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    • pp.31-40
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    • 2010
  • For weapon cueing and Head-Mounted Display (HMD), it is essential to continuously estimate the motion of the helmet. The problem of estimating and predicting the position and orientation of the helmet is approached by fusing measurements from inertial sensors and stereo vision system. The sensor fusion approach in this paper is based on nonlinear filtering, especially expended Kalman filter(EKF). To reduce the computation time and improve the performance in vision processing, we separate the structure estimation and motion estimation. The structure estimation tracks the features which are the part of helmet model structure in the scene and the motion estimation filter estimates the position and orientation of the helmet. This algorithm is tested with using synthetic and real data. And the results show that the result of sensor fusion is successful.

Design of Web based Plasma Properties Reference Data Collection and Evaluation System (Web기반 Plasma 물성 참조데이터 수집평가 시스템 설계)

  • Park, Jun-Hyoung;Hwang, Sung-Ha;Jang, Won-Suk;Kwon, Duek-Chul;Song, Mi-Young;Yoon, Jung-Sik
    • Proceedings of the Korea Information Processing Society Conference
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    • 2010.04a
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    • pp.1062-1065
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    • 2010
  • Plasma 물성 데이터는 Plasma내에서 일어나는 입자(전자, 원자, 이온, 분자 등)들의 충돌에 대한 데이터로써 Plasma 발생 장치 설계 및 제어의 핵심 요소이며, Plasma 공정조건 확립을 위한 필수 정보가 된다. 참조표준은 과학기술데이터나 정보에 대하여 정확도와 신뢰도에 대한 분석 및 평가가 이루어진 공인데이터를 말한다. 이러한 플라즈마 물성 정보를 체계적으로 관리하고 신뢰성 있는 데이터를 필요로 하는 산업체에 지원하기 위하여 특정 참조표준과 참조데이터로 제정, 보급하는 Plasma 물성 참조표준 수집평가 시스템이 필요하고, 이에 대한 설계가 필요하다.

Field Inspection of Phase-Array Ultrasonic for PolyEthylene Electrofusion Joints

  • Kil, Seong-Hee;Jo, Young-Do;Yoon, Kee-Bong
    • Journal of the Korean Institute of Gas
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    • v.16 no.1
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    • pp.22-25
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    • 2012
  • Welding and/or fusion in polyethylene(PE) system made on site is focused on the control of the welding or fusion process to follow proper procedure. The process control is important, but it is not sufficient for the long term reliability of a pipe system. To achieve the rate of failure close to zero, Non Destructive Testing(NDT) is necessary in addition to joining process control. For electrofusion joints several non-destructive testing methods are available. The ultrasonic phased array technique is possible to detect various defects including wire deviations and regions with lack of fusion. In this studies, testing was carried to detect the defect after electrofusion joining of polyethylene piping is utilized by the ultrasonic phased array technique. From testing data, ultrasonic phased array technique is recommended as a reliable non-destructive testing method.

Improvement of the T-history Method to Measure Heat of Fusion for Phase Change Materials

  • Hong, Hi-Ki;Park, Chang-Hyun;Choi, Ju-Hwan;Peek, Jong-Hyeon
    • International Journal of Air-Conditioning and Refrigeration
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    • v.11 no.1
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    • pp.32-39
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    • 2003
  • Though conventional calorimetry methods such as differential scanning calorimetry and differential thermal analysis are used generally in measuring heat of fusion, T-history method has advantages of a simple experimental apparatus and no requirements of sampling process, which is particularly useful for measuring thermophyical properties of in-homogeneous phase change materials in sealed tubes. However, the degree of supercooling used in selecting a range of latent heat release and neglecting sensible heat during the phase change process can cause significant errors in determining the heat of fusion. In the present study, it was shown that a 40% discrepancy exists between the original T-history and the present methods when analyzing the same experimental data. As a result, a reasonable modification to the original T-history method is proposed.

Operation diagnostic based on PCA for wastewater treatment (PCA를 이용한 하폐수처리시설 운전상태진단)

  • Jun Byong-Hee;Park Jang-Hwan;Chun Myung-Geun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.16 no.3
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    • pp.383-388
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    • 2006
  • SBR is one of the most general sewage/wastewater treatment processes and, particularly, has an advantage in high concentration wastewater treatment like sewage wastewater. A Kernel PCA based fault diagnosis system for biological reaction in full-scale wastewater treatment plant was proposed using only common bio-chemical sensors such as ORP(Oxidation-Reduction Potential) and DO(Dissolved Oxygen). During the SBR operation, the operation status could be divided into normal status and abnormal status such as controller malfunction, influent disturbance and instrumental trouble. For the classification and diagnosis of these statuses, a series of preprocessing, dimension reduction using PCA, LDA, K-PCA and feature reduction was performed. Also, the diagnosis result using differential data was superior to that of raw data, and the fusion data show better results than other data. Also, the results of combination of K-PCA and LDA were better than those of LDA or (PCA+LDA). Finally, the fault recognition rate in case of using only ORP or DO was around maximum 97.03% and the fusion method showed better result of maximum 98.02%.

Identification of Alternative Splicing and Fusion Transcripts in Non-Small Cell Lung Cancer by RNA Sequencing

  • Hong, Yoonki;Kim, Woo Jin;Bang, Chi Young;Lee, Jae Cheol;Oh, Yeon-Mok
    • Tuberculosis and Respiratory Diseases
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    • v.79 no.2
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    • pp.85-90
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    • 2016
  • Background: Lung cancer is the most common cause of cancer related death. Alterations in gene sequence, structure, and expression have an important role in the pathogenesis of lung cancer. Fusion genes and alternative splicing of cancer-related genes have the potential to be oncogenic. In the current study, we performed RNA-sequencing (RNA-seq) to investigate potential fusion genes and alternative splicing in non-small cell lung cancer. Methods: RNA was isolated from lung tissues obtained from 86 subjects with lung cancer. The RNA samples from lung cancer and normal tissues were processed with RNA-seq using the HiSeq 2000 system. Fusion genes were evaluated using Defuse and ChimeraScan. Candidate fusion transcripts were validated by Sanger sequencing. Alternative splicing was analyzed using multivariate analysis of transcript sequencing and validated using quantitative real time polymerase chain reaction. Results: RNA-seq data identified oncogenic fusion genes EML4-ALK and SLC34A2-ROS1 in three of 86 normal-cancer paired samples. Nine distinct fusion transcripts were selected using DeFuse and ChimeraScan; of which, four fusion transcripts were validated by Sanger sequencing. In 33 squamous cell carcinoma, 29 tumor specific skipped exon events and six mutually exclusive exon events were identified. ITGB4 and PYCR1 were top genes that showed significant tumor specific splice variants. Conclusion: In conclusion, RNA-seq data identified novel potential fusion transcripts and splice variants. Further evaluation of their functional significance in the pathogenesis of lung cancer is required.

Cooperative Spectrum Sensing using Kalman Filter based Adaptive Fuzzy System for Cognitive Radio Networks

  • Thuc, Kieu-Xuan;Koo, In-Soo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.1
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    • pp.287-304
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    • 2012
  • Spectrum sensing is an important functionality for cognitive users to look for spectrum holes before taking transmission in dynamic spectrum access model. Unlike previous works that assume perfect knowledge of the SNR of the signal received from the primary user, in this paper we consider a realistic case where the SNR of the primary user's signal is unknown to both fusion center and cognitive radio terminals. A Kalman filter based adaptive Takagi and Sugeno's fuzzy system is designed to make the global spectrum sensing decision based on the observed energies from cognitive users. With the capacity of adapting system parameters, the fusion center can make a global sensing decision reliably without any requirement of channel state information, prior knowledge and prior probabilities of the primary user's signal. Numerical results prove that the sensing performance of the proposed scheme outperforms the performance of the equal gain combination based scheme, and matches the performance of the optimal soft combination scheme.

Machine Learning-Based Filter Parameter Estimation for Inertial/Altitude Sensor Fusion (관성/고도 센서 융합을 위한 기계학습 기반 필터 파라미터 추정)

  • Hyeon-su Hwang;Hyo-jung Kim;Hak-tae Lee;Jong-han Kim
    • Journal of Advanced Navigation Technology
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    • v.27 no.6
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    • pp.884-887
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    • 2023
  • Recently, research has been actively conducted to overcome the limitations of high-priced single sensors and reduce costs through the convergence of low-cost multi-variable sensors. This paper estimates state variables through asynchronous Kalman filters constructed using CVXPY and uses Cvxpylayers to compare and learn state variables estimated from CVXPY with true value data to estimate filter parameters of low-cost sensors fusion.

Effective Heterogeneous Data Fusion procedure via Kalman filtering

  • Ravizza, Gabriele;Ferrari, Rosalba;Rizzi, Egidio;Chatzi, Eleni N.
    • Smart Structures and Systems
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    • v.22 no.5
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    • pp.631-641
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    • 2018
  • This paper outlines a computational procedure for the effective merging of diverse sensor measurements, displacement and acceleration signals in particular, in order to successfully monitor and simulate the current health condition of civil structures under dynamic loadings. In particular, it investigates a Kalman Filter implementation for the Heterogeneous Data Fusion of displacement and acceleration response signals of a structural system toward dynamic identification purposes. The procedure is perspectively aimed at enhancing extensive remote displacement measurements (commonly affected by high noise), by possibly integrating them with a few standard acceleration measurements (considered instead as noise-free or corrupted by slight noise only). Within the data fusion analysis, a Kalman Filter algorithm is implemented and its effectiveness in improving noise-corrupted displacement measurements is investigated. The performance of the filter is assessed based on the RMS error between the original (noise-free, numerically-determined) displacement signal and the Kalman Filter displacement estimate, and on the structural modal parameters (natural frequencies) that can be extracted from displacement signals, refined through the combined use of displacement and acceleration recordings, through inverse analysis algorithms for output-only modal dynamics identification, based on displacements.

Space and Time Sensor Fusion Using an Active Camera For Mobile Robot Navigation

  • Jin, Tae-Seok;Lee, Bong-Ki;Park, Soo-Min;Lee, Kwon-Soon;Lee, Jang-Myung
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2002.11a
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    • pp.127-132
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    • 2002
  • This paper proposes a sensor-fusion technique where the data sets for the previous moments are properly transformed and fused into the current data sets to enable accurate measurement, such as, distance to an obstacle and location of the service robot itself. In the conventional fusion schemes, the measurement is dependent on the current data sets. As the results, more of sensors are required to measure a certain physical parameter or to improve the accuracy of the measurement. However, in this approach, instead of adding more sensors to the system the temporal sequence of the data sets are stored and utilized for the measurement improvement. Theoretical basis is illustrated by examples and the effectiveness is proved through the simulations. finally, the new space and time sensor fusion (STSF) scheme is applied to the control of a mobile robot in an unstructured environment as well as structured environment.

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