• Title/Summary/Keyword: Robust detector

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Fast LFM Target Detection Method with Robustness for Doppler Shift in Narrow-Band Sonar Systems (협대역 소나시스템에서 도플러 천이에 강인한 고속 LFM 표적 검출기법)

  • Choi, Sang-Moon;Do, Dae-Won;Kim, Woo-Sik;Lee, Dong-Hun;Kim, Hyung-Moon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.8
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    • pp.114-125
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    • 2014
  • In a conventional sonar system, which uses LFM signal for detecting targets with varying speed, the results of multiple LFM Doppler correlators are aligned and the maximum alined result are selected as a test cell for detecting targets. As the number of the LFM Doppler correlators are increased for accurate target detection, as the required computational complexity and the memory are also increased. This fact makes it difficult to implement the accurate LFM target detector. In this paper, we propose a new fast target detection which is robust for the variation of target speed. Because the proposed method uses the summation of alined results of large numbers of LFM Doppler correlators, the proposed method increase SNR and provide robust SNR for the variation of target speed. And the proposed method can provide very fast target detection by implementing the process, the summation of alined results of large numbers of LFM Doppler correlators, as one summation filter.

3D surface Reconstruction of Moving Object Using Multi-Laser Stripes Irradiation (멀티 레이저 라인 조사를 이용한 비등속 이동물체의 3차원 형상 복원)

  • Yi, Young-Youl;Ye, Soo-Young;Nam, Ki-Gon
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.2 s.314
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    • pp.144-152
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    • 2007
  • We propose a 3D modeling method for surface inspection of non-linear moving object. The laser lines reflect the surface curvature. We can acquire 3D surface information by analyzing projected laser lines on object. ill this paper, we use multi-line laser to make use of robust of single stripe method and high speed of single frame. Binarization and channel edge extraction method were used for robust laser line extraction. A new labeling method was used for laser line labeling. We acquired sink information between each 3D reconstructed frame by feature point matching, and registered each frame to one whole image. We verified the superiority of proposed method by applying it to container damage inspection system.

Noise-Robust Porcine Respiratory Diseases Classification Using Texture Analysis and CNN (질감 분석과 CNN을 이용한 잡음에 강인한 돼지 호흡기 질병 식별)

  • Choi, Yongju;Lee, Jonguk;Park, Daihee;Chung, Yongwha
    • KIPS Transactions on Software and Data Engineering
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    • v.7 no.3
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    • pp.91-98
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    • 2018
  • Automatic detection of pig wasting diseases is an important issue in the management of group-housed pigs. In particular, porcine respiratory diseases are one of the main causes of mortality among pigs and loss of productivity in intensive pig farming. In this paper, we propose a noise-robust system for the early detection and recognition of pig wasting diseases using sound data. In this method, first we convert one-dimensional sound signals to two-dimensional gray-level images by normalization, and extract texture images by means of dominant neighborhood structure technique. Lastly, the texture features are then used as inputs of convolutional neural networks as an early anomaly detector and a respiratory disease classifier. Our experimental results show that this new method can be used to detect pig wasting diseases both economically (low-cost sound sensor) and accurately (over 96% accuracy) even under noise-environmental conditions, either as a standalone solution or to complement known methods to obtain a more accurate solution.

Fast Vehicle Detection based on Haarlike and Vehicle Tracking using SURF Method (Haarlike 기반의 고속 차량 검출과 SURF를 이용한 차량 추적 알고리즘)

  • Yu, Jae-Hyoung;Han, Young-Joon;Hahn, Hern-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.1
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    • pp.71-80
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    • 2012
  • This paper proposes vehicle detection and tracking algorithm using a CCD camera. The proposed algorithm uses Haar-like wavelet edge detector to detect features of vehicle and estimates vehicle's location using calibration information of an image. After that, extract accumulated vehicle information in continuous k images to improve reliability. Finally, obtained vehicle region becomes a template image to find same object in the next continuous image using SURF(Speeded Up Robust Features). The template image is updated in the every frame. In order to reduce SURF processing time, ROI(Region of Interesting) region is limited on expended area of detected vehicle location in the previous frame image. This algorithm repeats detection and tracking progress until no corresponding points are found. The experimental result shows efficiency of proposed algorithm using images obtained on the road.

Design and Implementation of Real-time High Performance Face Detection Engine (고성능 실시간 얼굴 검출 엔진의 설계 및 구현)

  • Han, Dong-Il;Cho, Hyun-Jong;Choi, Jong-Ho;Cho, Jae-Il
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.2
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    • pp.33-44
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    • 2010
  • This paper propose the structure of real-time face detection hardware architecture for robot vision processing applications. The proposed architecture is robust against illumination changes and operates at no less than 60 frames per second. It uses Modified Census Transform to obtain face characteristics robust against illumination changes. And the AdaBoost algorithm is adopted to learn and generate the characteristics of the face data, and finally detected the face using this data. This paper describes the face detection hardware structure composed of Memory Interface, Image Scaler, MCT Generator, Candidate Detector, Confidence Comparator, Position Resizer, Data Grouper, and Detected Result Display, and verification Result of Hardware Implementation with using Virtex5 LX330 FPGA of Xilinx. Verification result with using the images from a camera showed that maximum 32 faces per one frame can be detected at the speed of maximum 149 frame per second.

A High-Speed Synchronization Method Robust to the Effect of Initial SFO in DRM Systems (DRM 시스템에서 초기 샘플링 주파수 옵셋의 영향에 강인한 고속 동기화 방식)

  • Kwon, Ki-Won;Cho, Yong-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.1A
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    • pp.73-81
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    • 2012
  • In this paper, we propose a high-speed synchronization method for Digital Radio Mondiale (DRM) receivers. In order to satisfy the high-speed synchronization requirement of DRM receivers, the proposed method eliminate the initial sampling frequency synchronization process in conventional synchronization methods. In the proposed method, sampling frequency tracking is performed after integer frequency synchronization and frame synchronization. Different correlation algorithms are applied to detect the first frame of the Orthogonal Frequency Division Multiplexing (OFDM) demodulation symbol with sampling frequency offset (SFO). A frame detection algorithm that is robust to SFO is selected based on the performance analysis and simulation. Simulation results show that the proposed method reduces the time spent for initial sampling frequency synchronization even if SFO is present in the DRM signal. In addition, it is verify that inter-cell differential correlation used between reference cells is roubst to the effect of initial SFO.

A Robust PLL of PCS for Fuel Cell System under Unbalanced Grid Voltages (불평형 계통전압에 강인한 연료전지용 전력변환시스템의 PLL 방법)

  • Kim, Yun-Hyun;Kim, Wang-Rae;Lim, Chang-Jin;Kim, Kwang-Seob;Kwon, Byung-Ki;Choi, Chang-Ho
    • Proceedings of the KIPE Conference
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    • 2008.06a
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    • pp.103-105
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    • 2008
  • In grid-interconnection system, a fast, robust and precise phase angle detector is most important to grid synchronization and the active power control. The phase angle can be easily estimated by synchronous dq PLL system. On the other hand under unbalanced voltage condition, synchronous dq PLL system has problem that harmonics occur to phase angle or magnitude of grid voltage because of the effect of the negative sequence components. So, To eliminate the negative sequence components, the PLL method using APF (All Pass Filter) in a stationery reference frame to extract positive sequence components under unbalanced voltage condition is researched. In this paper, we propose a new PLL method with decoupling network using APF in a synchronous reference frame to extract the positive sequence components of the grid voltage under unbalanced grid. The cut-off frequency of APF in a synchronous reference frame can be set to twice of the fundamental frequency comparing with that of APF in a stationery reference frame which is the fundamental frequency. The proposed PLL strategy can detect the phase angle quickly and accurately under unbalanced gird voltages. Simulation and experimental results are presented to verify the proposed strategy under different kind of voltage dips.

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A Narrow Band MILES Detection System With Reduced Blind Angle of Detection Using Refractors (굴절체를 이용하여 감지 사각 문제를 개선한 협대역 마일즈 감지 시스템)

  • Ki, Hyeon-Cheol
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.49 no.7
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    • pp.10-16
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    • 2012
  • In this paper, we tried to realize a next generation MILES detection system which is robust to optical noise using a narrow band interference optical filter. Applying a narrow band interference optical filter which has the wavelength range of 895~915nm to the LASER wavelength of 900nm, we could obtain detection characteristics robust to strong optical noise which can be occurred in street battles. However, the MILES detection system has the blind range of detection in the incident angle range of $30^{\circ}{\sim}90^{\circ}$. To solve this problem we proposed a method of incident angle scatter using refractors. Applying a concave meniscus lens refractor which has diopter of 5.4 to the MILES detection system, we could eliminate the blind angle of detection.

Design of a 16-QAM Carrier Recovery Loop for Inmarsat M4 System Receiver (Inmarsat M4 시스템 수신기를 위한 16-QAM Carrier Recovery Loop 설계)

  • Jang, Kyung-Doc;Han, Jung-Su;Choi, Hyung-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.4A
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    • pp.440-449
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    • 2008
  • In this paper, we propose a 16-QAM carrier recovery loop which is suitable for the implementation of Inmarsat M4 system receiver. Because the frequency offset of ${\pm}924\;Hz$ on signal bandwidth 33.6 kHz is recommended in Inmarsat M4 system specification, carrier recovery loop having stable operation in the channel environment with large relative frequency offset is required. the carrier recovery loop which adopts only PLL can't be stable in relatively large frequency offset environment. Therefore, we propose a carrier recovery loop which has stable operation in large relative frequency offset environment for Inmarsat M4 system. The proposed carrier recovery loop employed differential filter-based noncoherent UW detector which is robust to frequency offset, CP-AFC for initial frequency offset acquisition using UW signal, and 16-QAM DD-PLL for phase tracking using data signal to overcome large relative frequency offset and achieve stable carrier recovery performance. Simulation results show that the proposed carrier recovery loop has stable operation and satisfactory performance in large relative frequency offset environment for Inmarsat M4 system.

An Improved License Plate Recognition Technique in Outdoor Image (옥외영상의 개선된 차량번호판 인식기술)

  • Kim, Byeong-jun;Kim, Dong-hoon;Lee, Joonwhoan
    • Journal of the Korean Institute of Intelligent Systems
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    • v.26 no.5
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    • pp.423-431
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    • 2016
  • In general LPR(License Plate Recognition) in outdoor image is not so simple differently from in the image captured from manmade environment, because of geometric shape distortion and large illumination changes. this paper proposes three techniques for LPR in outdoor images captured from CCTV. At first, a serially connected multi-stage Adaboost LP detector is proposed, in which different complementary features are used. In the proposed detector the performance is increased by the Haar-like Adaboost LP detector consecutively connected to the MB-LBP based one in serial manner. In addition the technique is proposed that makes image processing easy by the prior determination of LP type, after correction of geometric distortion of LP image. The technique is more efficient than the processing the whole LP image without knowledge of LP type in that we can take the appropriate color to gray conversion, accurate location for separation of text/numeric character sub-images, and proper parameter selection for image processing. In the proposed technique we use DBN(Deep Belief Network) to achieve a robust character recognition against stroke loss and geometric distortion like slant due to the incomplete image processing.