• 제목/요약/키워드: correlation function method

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Muscle Function Path Analysis through Muscle Activity Analysis of Human Myofascial Meridians

  • Park, Young Hyun;Hong, Aa Reum;So, Jea Moo
    • Korean Journal of Applied Biomechanics
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    • v.27 no.4
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    • pp.279-285
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    • 2017
  • Objective: The purpose of this study was to perform a muscle function path analysis of muscle function on myofascial meridians. Method: Seven male students (mean age: $22{\pm}3.46years$; mean mass: $72.71{\pm}8.19kg$; mean height: $174{\pm}4.39cm$) without a history of musculoskeletal system symptoms or injuries were recruited for this study. The measurement muscle of the myofascial line was selected along with the muscle presented in "anatomy trains (Thomas W. Myers. 2014)", and the attachment of the surface EMG (Telemyo 2400T G2, USA) pad was determined according to "EMG analysis (Kim Tae Wan et al., 2013)". The subjects underwent maximum volumetric contraction of their fascia line end muscles three times in lying and standing postures and were subjected to the maximum number of contractions of the myofascial line muscle three times in the lying and standing postures. The sampling rate of the EMG signal was set to 1,000 Hz, and the bandwidth was 20 to 350 Hz. The activity of each muscle was quantitated using the Pearson correlation coefficient, and SPSS 22.0 was used for data analysis. Results: In myofascial meridians, a positive correlation in the myofascial connection and a negative correlation in the mechanical connection were observed. Conclusion: Muscles that show significant contract correlations with one another may be expected to be used as an effective clinical marker in muscle strengthening or relaxation therapy, and rehabilitative training. In this study, the correlation of total myofascial meridians may differ without consideration of functional posture. Future studies need to consider these points.

Image Path Searching using Auto and Cross Correlations

  • Kim, Young-Bin;Ryu, Kwang-Ryol
    • Journal of information and communication convergence engineering
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    • v.9 no.6
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    • pp.747-752
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    • 2011
  • The position detection of overlapping area in the interframe for image stitching using auto and cross correlation function (ACCF) and compounding one image with the stitching algorithm is presented in this paper. ACCF is used by autocorrelation to the featured area to extract the filter mask in the reference (previous) image and the comparing (current) image is used by crosscorrelation. The stitching is detected by the position of high correlation, and aligns and stitches the image in shifting the current image based on the moving vector. The ACCF technique results in a few computations and simplicity because the filter mask is given by the featuring block, and the position is enabled to detect a bit movement. Input image captured from CMOS is used to be compared with the performance between the ACCF and the window correlation. The results of ACCF show that there is no seam and distortion at the joint parts in the stitched image, and the detection performance of the moving vector is improved to 12% in comparison with the window correlation method.

Analysis of Bridging Stress Effect of Polycrystalline aluminas Using Double Cantilever Beam Method (Double Cantilever Beam 방법을 이용한 다결정 알루미나의 Bridging 응력효과 해석)

  • 손기선;이선학;백성기
    • Journal of the Korean Ceramic Society
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    • v.33 no.5
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    • pp.583-589
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    • 1996
  • In this study a new analytical model which can describe the relationship between the bridging stress and microstructure has beenproposed in order to investigate the microstructural effect on the R-curve behavior in polycrystalline aluminas since the R-curve can be derived via the bridging stress function. In the currently developed model function the distribution of grain size is considered as a microstructural factor in modeling of bridging stress function and thus the bridging stress function including three constants PM, n, and Cx, can be established analytically and quantitatively. The results indicate that the n value is closely related to the grain size distribution thereby providing a reliability of the current model for the bridging stress analysis. Thus this model which explains the correlation of the bridging stress distribution and microstructual parame-ters is useful for the systematic interpretation of microfracture mechanism including the R-curve behavior in polycrystalline aluminas.

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Measurement of Spatial Coherence Function of multy-mode beam by using a Sagnac Interferometer

  • Lee, Chang-Hyeok;Gang, Yun-Sik;No, Jae-U
    • Proceedings of the Optical Society of Korea Conference
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    • 2008.07a
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    • pp.187-189
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    • 2008
  • The spatial coherence function of multy-mode beam was measured by using a Sagnac interferometer and self referencing technique. For leaner polarization laser beam passing through a multy-mode fiber, its change value of spatial mode and polarization from stress of faber and input coupling angle. And each spatial mode have each polarizations, when we simulation Wigner distribution function and Spatial Correlation function of spatial multi-mode beam by using Hermit Gaussian modes leaner sum. We measured spatial coherence function of using by multy-mode fiber. One can use this measurement method to study and characterize the property of multy-mode light field coming out of GRIN multy-mode fiber.

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Stochastic Response Analysis of Transmission Tower Subjected to Young's Modulus Variation (송전철탑의 탄성계수의 변이에 따른 확률적 응답변이도)

  • 동원영;정영수
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.207-215
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    • 1993
  • With the aid of finite element method, this paper deals with the problem of structural response variability of transmission tower subjected to the spatial variability of material properties, Young's modulus herein. The spatial variability of material property are modeled as two-dimensional stochastic field which has an isotropic auto-correlation function. Response variability has been computed based on two numerical techniques, such as the Neumann expansion method in conjunction with the Monte Carlo simulation method. The results by these numerical methods are compared with those by the deterministic approach.

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Climate Prediction by a Hybrid Method with Emphasizing Future Precipitation Change of East Asia

  • Lim, Yae-Ji;Jo, Seong-Il;Lee, Jae-Yong;Oh, Hee-Seok;Kang, Hyun-Suk
    • The Korean Journal of Applied Statistics
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    • v.22 no.6
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    • pp.1143-1152
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    • 2009
  • A canonical correlation analysis(CCA)-based method is proposed for prediction of future climate change which combines information from ensembles of atmosphere-ocean general circulation models(AOGCMs) and observed climate values. This paper focuses on predictions of future climate on a regional scale which are of potential economic values. The proposed method is obtained by coupling the classical CCA with empirical orthogonal functions(EOF) for dimension reduction. Furthermore, we generate a distribution of climate responses, so that extreme events as well as a general feature such as long tails and unimodality can be revealed through the distribution. Results from real data examples demonstrate the promising empirical properties of the proposed approaches.

Optimum electrode selection for measuring the abdominal pressure using bio-impedance method (비침습적 복압 측정을 위한 생체 임피던스 전극의 최적 위치 선정)

  • An, Yang-Su;Kim, Keo-Sik;Song, Chul-Gyu
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.46-48
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    • 2007
  • In this study, we determined the optimum electrode pair for measuring the abdominal pressure using bio-impedance method. Because impedance changes differ from a weight, a height, contractile force, volume of muscle and blood other or whatever of individuals, it was quantified using values of impedance change, correlation coefficient and SNR. Our results showed the optimum electrode pair (1, 9) which could detect impedance changes due to an increase of the intensity of the abdominal pressure. The correlation coefficient and quadratic function between the RMS values of EMG and the impedance changes were 0.87 and $y=0.0014x^2$+0.0620x+0.6958, respectively. It demonstrated that the abdominal pressure could be measured non-invasively and simply using bio-impedance method. We propose that this optimum electrode configuration would be useful for future studies involving the convenient measurement of abdominal pressure by ambulatory urodynamics monitoring study.

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Structural damage detection based on changes of wavelet transform coefficients of correlation functions

  • Sadeghian, Mohsen;Esfandiari, Akbar;Fadavie Manochehr
    • Structural Monitoring and Maintenance
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    • v.9 no.2
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    • pp.157-177
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    • 2022
  • In this paper, an innovative finite element updating method is presented based on the variation wavelet transform coefficients of Auto/cross-correlations function (WTCF). The Quasi-linear sensitivity of the wavelet coefficients of the WTCF concerning the structural parameters is evaluated based on incomplete measured structural responses. The proposed algorithm is used to estimate the structural parameters of truss and plate models. By the solution of the sensitivity equation through the least-squares method, the finite element model of the structure is updated for estimation of the location and severity of structural damages simultaneously. Several damage scenarios have been considered for the studied structure. The parameter estimation results prove the high accuracy of the method considering measurement and mass modeling errors.

Study on fracture mechanics of granite specimens with different precast notch depths based on DIC method

  • Shuwen Cao;Hao Shu
    • Geomechanics and Engineering
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    • v.33 no.4
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    • pp.393-400
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    • 2023
  • Displacements near crack and stress intensity factor (SIF) are key parameters to solve rock failure issue when using fracture mechanics. In order to study the horizontal displacement and stress intensity factor of the mode I fracture, a series of three-point bending tests of granite specimens with central notch were carried out. The evolution of horizontal displacements of precast notch and crack tip opening displacements (CTOD) were analyzed based on the digital image correlation (DIC) method. Stress intensity factors for three-point bending beams with arbitrary span-to-width ratios(S/W) were calculated by using the WU-Carlsson analytical weight function for edge-crack finite width plate and the analytical solution of un-cracked stress by Filon. The present study provides a high efficient and accurate method for fracture mechanics analysis of the three-point bending granite beams.

Determining the Orientations of Broadband Stations in South Korea using Ambient Noise Cross-correlation (배경잡음 교차상관을 이용한 국내 광대역 지진계의 방위각 보정값 측정)

  • Lee, Sang-Jun;Rhie, Junkee
    • Geophysics and Geophysical Exploration
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    • v.18 no.2
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    • pp.85-90
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    • 2015
  • Orientation corrections for Korean seismic stations were calculated by using ambient noise cross-correlation. This method uses Rayleigh waves extracted from ambient noise cross-correlation instead of teleseismic waveforms from earthquakes, which have been generally used for previous studies. The theoretical background of the method is that the phase of radial-vertical cross-correlation function should be the same as that of $90^{\circ}$ phase-shifted vertical-vertical cross-correlation function. The results calculated from stacked cross-correlograms from Jan. 2007 to Sep. 2008 are comparable to the previous results obtained from teleseismic waveforms. In addition, overall the standard deviations of orientation corrections are less than $5^{\circ}$. The temporal variation in orientation corrections calculated for every 30 days shows no significant change and also standard deviations of them are mostly less than $5^{\circ}$. This means that the orientations of stations used in this study have been kept constant during the period. The sensitivity test for stacking period of the ambient noise cross-correlation method shows that continuous ambient noise record of at least about 30 days is required for estimating reliable orientation corrections.