• Title/Summary/Keyword: strong correlation

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CORRELATION FUNCTIONS OF THE ABELL, APM, AND X-RAY CLUSTERS OF GALAXIES

  • LEE SUNGHO;PARK CHANGBOM
    • Journal of The Korean Astronomical Society
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    • v.35 no.3
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    • pp.111-121
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    • 2002
  • We have measured the correlation functions of the optically selected clusters of galaxies in the Abell and the APM catalogs, and of the X-ray clusters in the X-ray-Brightest Abell-type Clusters of galaxies (XBACs) catalog and the Brightest Clusters Sample (BCS). The same analysis method and the same method of characterizing the resulting correlation functions are applied to all observational samples. We have found that the amplitude of the correlation function of the APM clusters is much higher than what has been previously claimed, in particular for richer subsamples. The correlation length of the APM clusters with the richness R $\ge$ 70 (as defined by the APM team) is found to be $r_0 = 25.4_{-3.0}^{+3.1}\;h^{-1}$ Mpc. The amplitude of correlation function is about 2.4 times higher than that of Croft et al. (1997). The correlation lengths of the Abell clusters with the richness class RC $\ge$ 0 and 1 are measured to be $r_0 = 17.4_{-1.1}^{+1.2}$ and $21.0_{-2.8}^{+2.8}\;h^{-1}$ Mpc, respectively, which is consistent with our results for the APM sample at the similar level of richness. The richness dependence of cluster correlations is found to be $r_0= 0.40d_c + 3.2$ where $d_c$ is the mean intercluster separation. This is identical in slope with the Bahcall & West (1992)'s estimate, but is inconsistent with the weak dependence of Croft et al. (1997). The X-ray bright Abell clusters in the XBACs catalog and the X-ray selected clusters in the BCS catalog show strong clustering. The correlation length of the XBACs clusters with $L_x {\ge}0.65{\times} 10^{44}\;h^{-2}erg\;s^{-1}$ is $30.3_{-6.5}^{+8.2}\;h^{-1}$ Mpc, and that of the BCS clusters with $L_x {\ge}0.70{\times} 10^{44}\;h^{-2}erg\;s^{-1}$ is $30.2_{-8.9}^{+9.8}\;h^{-1}$ Mpc. The clustering strength of the X-ray clusters is much weaker than what is expected from the optical clusters.

New Approach to Two-wheeler Detection using Correlation Coefficient based on Histogram of Oriented Gradients

  • Lee, Yeunghak;Shim, Jaechang
    • Journal of Multimedia Information System
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    • v.3 no.4
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    • pp.119-128
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    • 2016
  • This study aims to suggest a new algorithm for detecting two-wheelers on road that have various shapes according to the viewing angle for vision based intelligent vehicles. This article describes a new approach to two-wheelers detection algorithm riding on people based on modified Histogram of Oriented Gradients (HOG) using correlation coefficient (CC). The CC between two local area variables, in which one is the person riding a bike and other is its background, can represent correlation relation. First, we extract edge vectors using HOG which includes gradient information and differential magnitude as cell based. And then, the value, which is calculated by the CC between the area of each cell and one of two-wheelers, can be extracted as the weighting factor in process for normalizing the modified HOG cell. This paper applied the Adaboost algorithm to make a strong classification from weak classification. In this experiment, we can get the result that the detection rate of the proposed method is higher than that of the traditional method.

A Study of Correlation among Bone Mineral Density, Body Composition and Body Circumference on 20's Women

  • Lee, Sang-Min;Wang, Joong-San;Park, Sung-Kyu;Kim, Hong-Rae;Ko, Jin-Hee;Oh, Yu-Jung;Yoon, Hae-Ran;Kim, Ji-Sung
    • Journal of International Academy of Physical Therapy Research
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    • v.3 no.1
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    • pp.383-390
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    • 2012
  • The aim of this study was to investigate the correlation among bone mineral density(BMD), body composition and body circumference on 20's college women in Hwaseong. A total of 86 subjects were measured with BMD and body composition and body circumference. To evaluate the correlation between BMD and body composition, bone density and body weight, body mass index(BMI), lean body mass, muscle mass, fat mass and body fat mass were compared. The results of this study, weight was considered the strong correlation with BMD than the height and BMI seems to be greater significance rather than the lumbar spine and femur BMD. In addition, the relationship between body composition and BMD, lean body mass, muscle mass, body fat mass were the most relevant factors and BMD. The relationship between BMD and body circumference that have been difficult because of not enough previous studies but somewhat the study showed that association.

Study on Correlation between the Gait Analysis Indices and Lumbar X-ray Indicators (보행과 기립위 요추 방사선 지표와의 상관성 연구)

  • Park, Jong-Han;Jeong, Su-Hyeon
    • Journal of Korean Medicine Rehabilitation
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    • v.27 no.4
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    • pp.121-130
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    • 2017
  • Objectives This study was designed to investigate the correlation between the gait analysis indices and Lumbar X-ray indicators. Methods 21 cases of patients who received treatment from October 2013 to February 2017 for abnormal posture were analyzed. Three indicators were measured in the lumbar spine X-ray. These indicators include Ferguson's angle, Lumbar lordotic angle, L4-5 IVD angle. Gait analysis indices were estimated by Treadmill Gait Analysis system. The data were analyzed to find out correlation between the gait analysis indices and Lumbar X-ray indicators. Spearman correlation was used. Results Ferguson's angle and Difference of gait balance of front and rear had a negative linear relationship, but there was no statistical significance. Lumbar lordotic angle and Difference of gait balance of front and rear had a negative linear relationship, but there was no statistical significance. L4-5 IVD angle and Difference of gait balance of right and left had a negative linear relationship, but there was no statistical significance. Conclusions Difference of gait balance of front and rear had strong level of a negative linear relationship with Ferguson's angle and Lumbar lordotic angle.

An adaptive bandwidth allocation for the two-layer VBR video transmission in ATM networks (ATM망에서 2계층 VBR 비디오 전송을 위한 적응적인 대역할당)

  • 이동은;이청훈;이팔진;김영선;김영천
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.8
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    • pp.1928-1936
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    • 1996
  • In this paper, we propose an adaptive bandwidth allocation algorithm for the transmission of VBR video through ATM Networks. In order to evaluate the required bandwidth for the VBR video, the characteristics of the compressed VBR video generated by the two-layered coder are analyzed with variations in the number of GOP(N), quantizer scale(q), and the number of low-frequency DCT coefficients(.betha.). The two-layer coder which is used to separate from the number of DCT coefficients is designed to transmit the VBR video efficiently. The compressed data generated by the two-layer coder are splitted into the high priority and low priority cells. If congestion is occurred in ATM networks, the minimum image quality is maintained by the high priority cells. The required bandwidth for VBR video is estimated with a prediction algorithm using the scene anframe correlations as well as the statistical properties of the VBR video sources. Strong correlation among the adjacent slices in a frame represents by the scene correlation andstrong correlation among the frames is represented by the frame correlation. The performance of the bandwidth allocation scheme proposed is evaluated in terms of the bandwith utilization, cell loss rate, and SNR with variations in q, n, .betha.. Simulation rewsults shown that the proposed scheme is superior to the conventional methods.

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A Study on Related Factors and Coping Methods among University & College Students (대학생의 스트레스 요인 및 대처방식에 관한 연구)

  • Lee, Chang-Eun
    • The Korean Journal of Health Service Management
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    • v.7 no.4
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    • pp.13-22
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    • 2013
  • The purpose of this study was to identify the influencing types of stress and coping method among College and University students. The design for this study was descriptive using self-administered questionnaires. The data was collected from 1 July to 30 July 2012. 284 students in College and University located in Gyeongsangbuk-do. This data were analyzed by SAS 9.2 program using descriptive statistics, frequency, T-test, ANOVA, and Correlation analysis. The results were as follows. First, there was a difference between male and female in the level of stress, it was statistically significant(p<0.0001). Second, there was a remarkable difference in the level of stress between University and College students(p=0.0001). Third, in the evaluation of correlation, relation between study factor and career factor was statistically significant(0.59, p<0.001). However there was no positive correlation between the five stress-induced factors and problem-based handling way of stress. On the other hand, there was strong positive correlation between the five stress-induced factors and emotional-based coping method of stress(p<0.01).

A Study on Correlation Between Separation and Orientation of Fibres During Compression Molding of Long Fibre-Reinforced Polymeric Composites (장섬유강화 고분자복합판의 압축성형에 있어서 섬유의 분리와 배향의 상관관계에 관한 연구)

  • 이동기;유정훈;김이곤
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.1
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    • pp.62-68
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    • 1993
  • During compression molding of fibre-reinforced thermoplastics, the two main problems such as the fibre-matrix separation and the fibre orientation are produced by the flow state. As the molded product tends to be nonhomogeneous and anisotropic due to the separation and the orientation, it is necessary to clarify these in relation to the molding process variables and the fibre structure (fibre entanglement). If the entanglement of fibre structure is strong, the separation increases and the orientation is not easily aligned. Namely, these are inseparably related to each other. The correlation between the separation and the orientation have to be clarified for designing the fibre structure. In this paper, the degree of nonhomogeneity which is a measure of the separation is obtained using one-dimensional rectangular shaped part compression molding. And the orientation function is defined and measured by the image processing using soft X-rayed photograph and image scanner. Correlation between the degree of nonhomogeneity and the orientation function is discussed.

A Study on Characterization and Modeling of Shallow Trench Isolation in Oxide Chemical Mechanical Polishing

  • Kim, Sang-Yong;Chung, Hun-Sang
    • Transactions on Electrical and Electronic Materials
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    • v.2 no.3
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    • pp.24-27
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    • 2001
  • The end point of oxide chemical mechanical polishing (CMP) have determined by polishing time calculated from removal rate and target thickness of oxide. This study is about control of oxide removal amounts on the shallow trench isolation (STI) patterned wafers using removal rate and thickness of blanket (non-patterned) wafers. At first, it was investigated the removal properties of PETEOS blanket wafers, and then it was compared with the removal properties and the planarization (step height) as a function of polishing time of the specific STI patterned wafers. We found that there is a relationship between the oxide removal amounts of blanket and patterned wafers. We analyzed this relationship, and the post CMP thickness of patterned wafers could be controlled by removal rate and removal target thickness of blanket wafers. As the result of correlation analysis, we confirmed that there was the strong correlation between patterned and blanket wafer (correlation factor: 0.7109). So, we could confirm the repeatability as applying for STI CMP process from the obtained linear formula. As the result of repeatability test, the differences of calculated polishing time and actual polishing time was about 3.48 seconds. If this time is converted into the thickness, then it is from 104 $\AA$ to 167 $\AA$. It is possible to be ignored because process margin is about 1800 $\AA$.

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A Study on the Correlation between Production and Perception of Korean vowel /ʌ/ and /o/ for Chinese Learners (중국인 한국어 학습자의 한국어 모음 /어/와/오/에 대한 산출과 지각 상관성 연구)

  • Kim, Eunkyung;In, Jiyoung;Seong, Cheoljae
    • Journal of Korean language education
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    • v.28 no.1
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    • pp.1-21
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    • 2017
  • The purpose of this study is to investigate the aspect of production and perception of Korean vowels /${\Lambda}$/ and /o/ and to discuss the correlation between production and perception of the two vowels. For this purpose, two separate experiments were conducted. 19 Chinese learners and 20 Korean native speakers produced Korean vowels /${\Lambda}$/ and /o/. Production experiments indicated that Koreans and Chinese female groups revealed common features in production, showing that they all pronounced /${\Lambda}$/ and /o/ in a distinguishable manner in the acoustic space. On the other hand, the Chinese male group failed to show that they could pronounce two vowels distinctively. The Chinese male group seemed to be confused in vowel height between the two vowels. A perception experiment was carried out on a continuum consisting of 11 synthesized stimuli. The perceptual judgment from referred Chinese and Korean subjects showed that Koreans and Chinese female groups had the same phonological boundaries (stimulus '04') for the two vowels on the continuum. However, the Chinese male group made perceptual criterion on stimulus '03'. These results confirmed that there was strong correlation between the aspect of production and perception.

Correlation between parameters of pulse-type motions and damage of low-rise RC frames

  • Cao, Vui Van;Ronagh, Hamid Reza
    • Earthquakes and Structures
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    • v.7 no.3
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    • pp.365-384
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    • 2014
  • The intensity of a ground motion can be measured by a number of parameters, some of which might exhibit robust correlations with the damage of structures subjected to that motion. In this study, 204 near-fault pulse-type records are selected and their seismic parameters are determined. Time history and damage analyses of a tested 3-storey reinforced concrete frame representing for low-rise reinforced concrete buildings subjected to those earthquake motions are performed after calibration and comparison with the available experimental results. The aim of this paper is to determine amongst several available seismic parameters, the ones that have strong correlations with the structural damage measured by a damage index and the maximum inter-story drift. The results show that Velocity Spectrum Intensity is the leading parameter demonstrating the best correlation, followed by Housner Intensity, Spectral Acceleration and Spectral Displacement. These seismic parameters are recommended as reliable parameters of near-fault pulse-type motions related to damage potential of low-rise reinforced concrete structures. The results also reaffirm that the conventional and widely used parameter of Peak Ground Acceleration does not exhibit a good correlation with the structural damage.