• Title/Summary/Keyword: cross correlation function

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Added effect of uncertain geometrical parameter on the response variability of Mindlin plate

  • Noh, Hyuk Chun;Choi, Chang Koon
    • Structural Engineering and Mechanics
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    • v.20 no.4
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    • pp.477-493
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    • 2005
  • In case of Mindlin plate, not only the bending deformation but also the shear behavior is allowed. While the bending and shear stiffness are given in the same order in terms of elastic modulus, they are in different order in case of plate thickness. Accordingly, bending and shear contributions have to be dealt with independently if the stochastic finite element analysis is performed on the Mindlin plate taking into account of the uncertain plate thickness. In this study, a formulation is suggested to give the response variability of Mindlin plate taking into account of the uncertainties in elastic modulus as well as in the thickness of plate, a geometrical parameter, and their correlation. The cubic function of thickness and the correlation between elastic modulus and thickness are incorporated into the formulation by means of the modified auto- and cross-correlation functions, which are constructed based on the general formula for n-th joint moment of random variables. To demonstrate the adequacy of the proposed formulation, a plate with various boundary conditions is taken as an example and the results are compared with those obtained by means of classical Monte Carlo simulation.

Human Interface Design using Pattern Analysis of Multichannel EMG signals (다채널 EMG 신호의 패턴 해석을 이용한 휴먼 인터페이스의 설계)

  • 이용희;이경호;서재성;황기현
    • Proceedings of the IEEK Conference
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    • 2003.07c
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    • pp.2895-2898
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    • 2003
  • In this study, our primary goal is to classify the EMG(electromyographic) signals including the specific patterns related to hand motions in an arm. To do this, the EMG recognition method based on the LP coefficients and delay between multi-channels obtained by cross-correlation function is presented. The study consists of three functional parts, which are pans for obtaining the EMG signals from am muscle, analyzing LP coefficients and delay parameter obtained by cross-correlation function, and recognizing specific patterns. In the experiment, the result of the present method is compared with the results of the conventional methods. We expect that the results of this study is very effective in the mobile computer and wearable computer environment.

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Implementation of a Touch Panel System using Accelerometers (가속도센서를 이용한 터치패널시스템 구현)

  • Lee, Young-Sup;Kim, Dong-Il;Kang, Min-Su
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.12
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    • pp.1194-1202
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    • 2011
  • A touch panel system has been one of the most widely used input devices. In this study, a touch panel embedded system using accelerometers is considered in order to make commercial white-boards or plates into touch panels. Three accelerometers are located at different positions on such a white board, so that touch points on the board can be identified using the sensors. For the identification of touch points, a TDOA (Time Difference of Arrivals) technique is applied in the algorithm which was implemented in a DSP board (TI 6713 DSK), which can provide a precise touch location by using the cross-correlation function of measured signals from the three accelerometers. Experiment results show that the touch panel system with accelerometers could provide the exact touch location. Thus a novel approach using such accelerometers could be applied to a new touch panel system.

Probabilistic Target Speech Detection and Its Application to Multi-Input-Based Speech Enhancement (확률적 목표 음성 검출을 통한 다채널 입력 기반 음성개선)

  • Lee, Young-Jae;Kim, Su-Hwan;Han, Seung-Ho;Han, Min-Soo;Kim, Young-Il;Jeong, Sang-Bae
    • Phonetics and Speech Sciences
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    • v.1 no.3
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    • pp.95-102
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    • 2009
  • In this paper, an efficient target speech detection algorithm is proposed for the performance improvement of multi-input speech enhancement. Using the normalized cross correlation value between two selected channels, the proposed algorithm estimates the probabilistic distribution function of the value from the pure noise interval. Then, log-likelihoods are calculated with the function and the normalized cross correlation value to detect the target speech interval precisely. The detection results are applied to the generalized sidelobe canceller-based algorithm. Experimental results show that the proposed algorithm significantly improves the speech recognition performance and the signal-to-noise ratios.

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Correlation of motor function, balance, and cognition in patients with stroke (뇌졸중 환자의 운동기능, 균형 및 인지에 관한 상관관계분석)

  • Park, Ji won;Lee, Byounghee;Lee, Suhyun;Kim, Sangwoo
    • Journal of Korean Physical Therapy Science
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    • v.27 no.1
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    • pp.56-65
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    • 2020
  • Purpose: Individuals affected by stroke present with changes in motor function, balance, and cognition. The purpose of this study was to the correlation between motor function, balance, and cognition in patients with stroke. Design: cross-sectional study design. Methods: 67 stroke patients in the experiment were included. For evaluation of motor function which is Manual Muscle Test, Range of Motion, Modified Ashworth Scale for spasticity, grasping power, and balance was measured using the Berg Balance Scale and Functional reach test. For evaluating Cognition which is Korean-Mini Mental State Examination. Results: The results of this study's motor function, balance, and cognition showed a significant positive correlation (p<0.05). Conclusion: The results indicated that motor function, balance, and cognition were significantly correlated with each other. Therefore, it is suggested that to improve the motor function and balance of patients with stoke, it needs to evaluate the cognition and the motor function, balance, and cognitive training should be combined.

Analysis of the Correlation Between Executive Function and Obstacle Gait Evaluation for the Elderly (노인의 실행기능 평가와 보행 평가사이의 상관관계 분석)

  • Lee, Seung-Min;Lee, Han-Suk
    • Journal of the Korean Society of Physical Medicine
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    • v.17 no.3
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    • pp.51-58
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    • 2022
  • PURPOSE: This study aimed to evaluate the correlation between executive function and gait evaluations for the elderly, and validate the obstacle gait evaluation as a cognitive impairment test tool. METHODS: This study was a cross-sectional design. 79 people aged 65 years or older were selected as subjects. The Korean version of the Mini-Mental State Examination (MMSE-KC) to evaluate overall cognitive function and the Trail Making Test (TMT) A, B to measure executive function were performed. The 4-meter walking speed test and the walking speed test while crossing over an obstacle were carried out to evaluate gait. The Spearman's correlation was used to measure the correlation between cognition and gait speed. RESULTS: There was no significant correlation between the 4 m gait speed and executive function( TMT-A (p = .056), TMT-B (p = .115)). However, there was a significant correlation between the 4 m gait speed and MMSE-KC (r = .277, p < .05). There was also a significant correlation between walking speed while crossing over an obstacle and all tests (MMSE-KC (r = .382, p < .01). TMT-A (r = -.327, p < .01), TMT-B (r = -.283, p < .05)). CONCLUSION: It was found that the gait speed while crossing over an obstacle was correlated with all cognitive function tests. Therefore, we suggest the use of the gait speed test while crossing over an obstacle rather than the simple gait test to diagnose cognitive decline.

A Method for Fault detecting on Power Transmission Network by use of M-sequence Correlation

  • Nishiyama, Eiji;Kuwanami, Kenshi;Owaki, Kosuke
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2570-2575
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    • 2003
  • Monitoring a power transmission line is significant for power electric companies. In this paper, we propose a new method for detecting an fault point of power transmission line by use of M-sequence correlation technique. In this method, detecting signal is used as one or plural M-sequences ( same characteristic polynomial, including normal and reverse mark, synchronized ). In receiving point, we make same sequence with the input one and take crosscorrelation function between M-sequence and the received signal. We can see transfer fanctions of plural paths between inputs and a output taps separated from different of delay times on the crosscorrelation function, and from these transfer fanctions, so we compare them when fault occurred with in usual.

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Four-Valued Cross-Correlation Function between Two Maximal Linear Recursive Sequences (최대 주기의 두 선형 순환 수열 사이의 4개의 값을 갖는 상호상관함수)

  • Choi, Un-Sook;Kim, Sung-Jin;Kim, Han-Doo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.6
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    • pp.1369-1375
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    • 2012
  • One of important problems in the theory of sequences is to determine the values and number of occurrences of each value taken on by the cross-correlation. In this paper, we find the values and the number of occurrences of each value of cross-correlation between an m-sequence u(t) of period $2^n-1$ and its decimation $u(dt)(0{\leq}t{\leq}2^n-2)$ where n=2m, 2s|m and $d=(2^{2m}+2^{2s+1}-2^{m+s+1}-1)/(2^s-1)$. Also we show that a family of decimations leads to a four-valued cross-correlation.

Analysis of cross-correlation functions of non-linear sequences (비선형수열의 상호상관함수 분석)

  • Cho, Sung-Jin;Yim, Ji-Mi
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.5
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    • pp.1138-1144
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    • 2013
  • Cross-correlation functions of maximal period sequences have been studied for decades. In this paper, we find the cross-correlation values of non-linear sequences $S_a^r(t)=Tr_1^m\{[Tr_m^n(a{\alpha}^t+{\alpha}^{dt})]^r\}$ having the maximal period $2^n-1$ for Niho type decimation $d=2^{m-2}(2^m+3)$, where n=2m. In particular, we call d Niho type decimation in case $d{\equiv}1(mod\;2^m-1)$. And we analyze the cross-correlation distributions of $S_a^r(t)$ when the phase shift ${\tau}=(2^m+1)k(0{\leq}k{\leq}2^m-2)$ and provide experiment results.

Leak Detection of Circular Piping Systems by Using Unit Impulse Response Function Analysis (단위 충격 응답함수를 이용한 원형관 시스템의 주출감지 연구)

  • 전오성;윤병옥;김창호
    • Journal of KSNVE
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    • v.4 no.3
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    • pp.337-343
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    • 1994
  • A method of the leak detection from the pipe system by using accelerometer is proposed. The signal detected from accelerometer is proved experimentally to be a dispersive wave. Based on the experiments, a method using the narrow band pass filter and the unit impulse response function is analyzed. The method uses the characteristics of the unit impulse response function, that the function is available evenin the narrow band signal because, unlike the cross correlation, it is normalized by the auto spectrum. The accelerometer is quite easier to use than the hydrophone in adapting to the pipe system.

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