• 제목/요약/키워드: convergence of filters

검색결과 227건 처리시간 0.02초

Interference Rejection using the Data-Recycling Algorithm in DS Spread-Spectrum Communications

  • Kim, Nam-Yong
    • Journal of Electrical Engineering and information Science
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    • 제3권1호
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    • pp.126-130
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    • 1998
  • In this paper, a new interference rejection filter using the data-recycling technique is presented. The reference signal of the interference rejection filter is formed by using chip decisions, which is correlated with the narrowband interference components of the received signal. The decision feedback techniques reduce the distortion of the desired signal, which is introduced by the interference rejection filter through he use of feedback chip decisions. In order to update the filter coefficients a simple and efficient data-recycling technique that has improved performance over the conventional LMS algorithm is used. The performance of the proposed interference rejection filter is compared to filter with conventional LMS linear filter. The results show that the convergence speed of the proposed interference rejection filter using decision feedback and data-recycling technique is significantly faster than that of the conventional filters. Also, BER performance of the interference rejection filter demonstrates the superiority of the proposed filter algorithm.

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Cadence Sensing 방식의 전기자전거를 위한 정밀 토크제어 컨트롤러 설계 (Design of Precise Torque Controller for Electric Bicycle with Cadence Sensing Drive System)

  • 이주연;김대순;이종하;송제호
    • 전자공학회논문지
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    • 제54권6호
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    • pp.134-139
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    • 2017
  • 본 논문에서는 전기자전거의 정밀 토크제어를 위하여 새로운 토크제어 방식을 제안하고 구현한다. 트로틀 노이즈를 제거하기 위한 이동 평균 필터를 채택함으로써 256 단계의 세분화된 트로틀 단계로 전기자전거의 제어가 가능하다. 설계된 컨트롤러는 전기자전거에 장착 실험되어 기존의 Cadence 감지 컨트롤러 대비 개선된 선형 제어특성을 확인하였다.

An Automatic Road Sign Recognizer for an Intelligent Transport System

  • Miah, Md. Sipon;Koo, Insoo
    • Journal of information and communication convergence engineering
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    • 제10권4호
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    • pp.378-383
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    • 2012
  • This paper presents the implementation of an automatic road sign recognizer for an intelligent transport system. In this system, lists of road signs are processed with actions such as line segmentation, single sign segmentation, and storing an artificial sign in the database. The process of taking the video stream and extracting the road sign and storing in the database is called the road sign recognition. This paper presents a study on recognizing traffic sign patterns using a segmentation technique for the efficiency and the speed of the system. The image is converted from one scale to another scale such as RGB to grayscale or grayscale to binary. The images are pre-processed with several image processing techniques, such as threshold techniques, Gaussian filters, Canny edge detection, and the contour technique.

거리계전 알고리즘별 특성 비교 (Comparison of the characteristics of Distance Relaying Algorithms)

  • 강상희;이승재;노재근;양언필;정종진
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
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    • pp.34-37
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    • 2001
  • This paper presents some results after comparing the characteristics of 3 algorithms, which are discrete Fourier transform based algorithm, least square method, and modified differential approximation algorithm, used at most distance relays all over the world. In case of the DFT based distance relaying algorithm, the length of the algorithm data window and the cut-off frequency of an anti-aliasing low-pass filter adopted are fixed. On the other hand, the data window lengths are changed according to the corresponding low-pass filters in the rest two algorithms. In series of tests, the apparent impedance estimated by the modified differential approximation algorithm shows faster and more stable characteristics of convergence than the two others.

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Pose Estimation with Binarized Multi-Scale Module

  • Choi, Yong-Gyun;Lee, Sukho
    • International journal of advanced smart convergence
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    • 제7권2호
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    • pp.95-100
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    • 2018
  • In this paper, we propose a binarized multi-scale module to accelerate the speed of the pose estimating deep neural network. Recently, deep learning is also used for fine-tuned tasks such as pose estimation. One of the best performing pose estimation methods is based on the usage of two neural networks where one computes the heat maps of the body parts and the other computes the part affinity fields between the body parts. However, the convolution filtering with a large kernel filter takes much time in this model. To accelerate the speed in this model, we propose to change the large kernel filters with binarized multi-scale modules. The large receptive field is captured by the multi-scale structure which also prevents the dropdown of the accuracy in the binarized module. The computation cost and number of parameters becomes small which results in increased speed performance.

Noise Reduction for Photon Counting Imaging Using Discrete Wavelet Transform

  • Lee, Jaehoon;Kurosaki, Masayuki;Cho, Myungjin;Lee, Min-Chul
    • Journal of information and communication convergence engineering
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    • 제19권4호
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    • pp.276-283
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    • 2021
  • In this paper, we propose an effective noise reduction method for photon counting imaging using a discrete wavelet transform. Conventional 2D photon counting imaging was used to visualize the object under dark conditions using statistical methods, such as the Poisson random process. The photons in the scene were estimated using a statistical method. However, photons which disturb the visualization and decrease the image quality may occur in the background where there is no object. Although median filters are used to reduce the noise, the noise in the scene remains. To remove the noise effectively, our proposed method uses the discrete wavelet transform, which removes the noise in the scene using a specific thresholding method that utilizes photon counting imaging characteristics. We conducted an optical experiment to demonstrate the denoising performance of the proposed method.

A Study on an Automatic Multi-Focus System for Cell Observation

  • Park, Jaeyoung;Lee, Sangjoon
    • Journal of Information Processing Systems
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    • 제15권1호
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    • pp.47-54
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    • 2019
  • This study is concerned with the mechanism and structure of an optical microscope and an automatic multi-focus algorithm for automatically selecting sharp images from multiple foci of a cell. To obtain precise cell images quickly, a z-axis actuator with a resolution of $0.1{\mu}m$ was designed to control an optical microscope Moreover, a lighting control system was constructed to select the color and brightness of light that best suit the object being viewed. Cell images are captured by the instrument and the sharpness of each image is determined using Gaussian and Laplacian filters. Next, cubic spline interpolation and peak detection algorithms are applied to automatically find the most vivid points among multiple images of a single object. A cancer cell imaging experiment using propidium iodide staining confirmed that a sharp multipoint image can be obtained using this microscope. The proposed system is expected to save time and effort required to extract suitable cell images and increase the convenience of cell analysis.

An Enhancement of Image Segmentation Using Modified Watershed Algorithm

  • Kwon, Dong-Jin
    • International journal of advanced smart convergence
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    • 제11권4호
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    • pp.81-87
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    • 2022
  • In this paper, we propose a watershed algorithm that applies a high-frequency enhancement filter to emphasize the boundary and a local adaptive threshold to search for minimum points. The previous method causes the problem of over-segmentation, and over- segmentation appears around the boundary of the object, creating an inaccurate boundary of the region. The proposed method applies a high-frequency enhancement filter that emphasizes the high-frequency region while preserving the low-frequency region, and performs a minimum point search to consider local characteristics. When merging regions, a fixed threshold is applied. As a result of the experiment, the proposed method reduced the number of segmented regions by about 58% while preserving the boundaries of the regions compared to when high frequency emphasis filters were not used.

Measurement of Leukocyte Motions in a Microvessel Using Spatiotemporal Image Analysis

  • Kim, Jin-Woo
    • Journal of information and communication convergence engineering
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    • 제6권3호
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    • pp.315-319
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    • 2008
  • This paper describes a method for recognizing and measuring the motion of each individual leukocyte in microvessel from a sequence of images. A spatiotemporal image is generated whose spatial axes are parallel and vertical to vessel region contours. In order to enhance and extract only leukocyte traces with a turned velocity range even under noisy background, we use a combination of a filtering process using Gabor filters with sharp orientation selectivity and a subsequent 3D spatiotemporal grouping process. The proposed method is shown to be effective by experiments using image sequences of two kinds of microcirculation, rat mesentery microvessels and human retinal capillaries.

Transmission Performance of Half-Symbol-Rate-Carrier Offset QPSK Modulation in Band-limited Channels

  • Yeo, Hyeop-Goo
    • Journal of information and communication convergence engineering
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    • 제7권2호
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    • pp.152-156
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    • 2009
  • This paper examines the BER performance of the recently proposed half-symbol-rate-carrier (HSRC) offset quadrature phase-shift-keying (OQPSK) receiver for high-speed data communication. A modified demodulation technique using a bit-time period signal integration, the bit-error-rate (BER) performance of the HSRC-OQPSK signal improves more than 4dB compared to that of a demodulation technique using a symbol-time period integration. This paper also examines the BER performance of modified demodulation with various band-limited channels modeled using low-pass filters, and the three different data-rate systems are simulated and compared with the performance of the system using the conventional demodulation technique.