• Title/Summary/Keyword: correlation function method

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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.

A study on the fastening performance and finger function of the cerebral palsied (뇌성마비자의 의복여밈 수행능력과 수지기능)

  • 김순분;함옥상;서승록
    • Journal of the Ergonomics Society of Korea
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    • v.12 no.2
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    • pp.45-62
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    • 1993
  • This study was aimed to obtain the available information for the clothing constru- ction according to the traits of the cerebral palsied. For this purpose, their abilities of eleven methods seven of fastening performance and seven finger functions were tested and their correlationships were clarified. The results are as follows : 1. The length of time needed to perform each fastening method in descending order is as follows : small button > small snap > culumn button > large button > middle button > large snap > separating zipper > velcro. As the spastic has better function than the athetoid in the performance of all fastening methods, there was a significant difference between the types of handicap and between the handi- capped and the normal, except for velcro fastening style in which there was no significant differ- ence between the types of handicap. 2. In finger functions of the cerebral palsied, according to the types of handicap there was no significant difference among grip, palm fixation and hands coordination, howefer there were significant differences among pulp pinching, lateral pinching, finger rolling and lifting control. As to the correlation between the ability of fastening performance and finger function, there was a high significant correlation between the length of time needed to perform each fastenting and finger function of hands co ordination, and that of finger rolling; and there was a significant correlation between the length of time and pulp pinching, and laternal pinching.

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Evaluation of Prospective Pulmonary Function Change for Pulmonary Resection Using Quantitative Perfusion Lung Scan (폐절제술시 정량 폐관류스캔을 이용한 폐기능 변화 예견에 대한 평가)

  • 김용진
    • Journal of Chest Surgery
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    • v.19 no.2
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    • pp.188-196
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    • 1986
  • Spirometry and regional function studies using 99m-Technetium were performed preoperatively to predict postoperative pulmonary function change in 34 patients who had various pulmonary resectional procedures at the Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital. Between two months and fourteen months postoperation all the patients were reinvestigated with spirometry and clinical examination to evaluate their functional respiratory status. The postoperative obtained values, especially forced vital capacity [FVC] and forced expiratory volume in one second [FEV1] among the other parameters were compared with the postoperative predicted values. Estimated values of FVC and FEV1 derived from preoperative spirometry and quantitative perfusion lung scan correlated well with the measured postoperative values. The linear regression line derived from correlation between postoperative estimated[X] and postoperative measured[Y] values of FVC and FEV1 in all patients are as follows; 1. Y=0.76x + 0.39 in correlation of FVC [r=0.91] 2. Y=0.88x + 0.17 in correlation of FEV1 [r=0.96],br> This method of estimation was one of the best methods of predicting postoperative pulmonary function change and valuable in determining the extent of safe resection and postoperative prognosis to a poor risk patient with chronic obstructive lung disease.

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INPUT GROUPING OF LIGICAL CIRCUIT BY USE OF M-SEQUENCE CORRELATION

  • Miyata, Chikara;Kashiwagi, Hiroshi
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.146-149
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    • 1995
  • A new method for grouping of relevant and equivalent inputs of a logical circuit was proposed by the authors by making use of pseudorandom M-sequence correlation. The authors show in this paper that it is possible to estimate the input grouping from a part of correlation functions when we admit small percentage of error, whereas it is impossible to reduce the data necessary to estimate the grouping by use of the truth table method. For example in case of 30-input logic circuit, the number of correlation functions necessary to calculate can be reducible from 1.07 * 10$^{9}$ to 465.

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Correlation between Welding Parameters and Detaching Drop Size using Regression (회귀 분석을 이용한 용접 변수와 이탈 액적 크기의 상호 관계)

  • 최상균;한창우;이상룡;이영문
    • Journal of Welding and Joining
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    • v.20 no.1
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    • pp.83-90
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    • 2002
  • Metal Transfer in gas metal arc (GMA) welding is a complex phenomenon affected by many parameters of the welding conditions and material properties. In this research, the correlation equation between the welding condition and detaching droplet size and detaching velocity in GMA welding was studied via recession analysis on the results of numerical analysis using the volume-of-fluid (VOF) method. Welding parameters and material properties were grouped into three dimensionless numbers and detaching droplet size was expressed as the function of them. Second order and exponential multi-variable correlation forms were assumed, and the coefficients of these equations were calculated for globular and spray modes as well as entire transfer modes. Applying correlation equation into available experimental data, it shows good agreement.

The Influencing Factors on Adolescent's Self-Efficacy (청소년의 자기효능감 영향 요인)

  • Jeon, Eun-Young
    • Journal of East-West Nursing Research
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    • v.11 no.2
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    • pp.116-123
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    • 2005
  • Purpose: The purpose of this study was to analyze the influencing factors on adolescent's self-efficacy. Method: This was a descriptive study. The data were collected from 7th through 12th graders(N=1710) enrolled in middle schools(N=873) and high schools(N=837) in the metropolitan area of Daegu. The instruments had used for this study were the self-efficacy, the life event checklist, and Family APGAR. The data were analyzed using frequency, t-test, Pearson correlation coefficient, and multiple regression analysis. Result: Pearson correlation analysis revealed that there were negative correlations between the self-efficacy and the stress. However, in case of the subjects who recorded higher scores at self-efficacy they showed higher scores at family function. Stepwise multiple regression analysis revealed that powerful predictors of adolescent's self-efficacy were family function and relations of schoolmate. Conclusion: From these results, we can find that the family function and relations of schoolmate were actual factors theta affected the self-efficacy of adolescents. Accordingly, affirmative emotion in family, harmonic communication among family members and sharing housekeeping works is recommended as a useful method in order to enhance the family function, and then the self-efficacy of adolescence will be increased.

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A study of Family Function and Social Support toward Perceived Quality of Life in Adolescents (청소년이 지각한 가족기능, 사회적 지지 및 삶의 질에 관한 연구)

  • Kwon, Mi-Kyung;Ahn, Hye-Young;Song, Mi-Ryeong
    • Child Health Nursing Research
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    • v.12 no.2
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    • pp.180-188
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    • 2006
  • Purpose: The purpose of this study was to explore family function, social support, perceived quality of life(QOL) in adolescent period and to find out the correlations between family function, social support, perceived QOL in adolescents. Method: The questionnaire to get some information for this study consisted of adolescents'general characteristics, 20 questions regarding family function, 11 questions regarding social support, 8 questions regarding perceived QOL in adolescents. The subjects of this study consisted of 128 adolescents who were living in S area. The data were analyzed by percentage, mean, t-test, ANOVA and Pearson's correlation using the WINSPSS program. Result: The mean score for family function was 3.07(max. : 5) and there was significant difference according to middle-high school student. The mean score for social support was 2.86(max : 5) and there was no significant difference. The mean score for perceived QOL was 4.02(max score: 7) and there was significant difference according to disease condition. There was a positive correlation between family function, social support, perceived QOL in adolescents. Conclusion: Consequently, the development of program, policy assistance and policy implementation to elevate juveniles' perceived quality of life is strongly required.

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A Study on the Anisotropy of Machined Surfaces (기계 가공면의 이방성에 관한 연구)

  • Cho, Nahm-Gyoo;Choi, Han-Yong
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.11
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    • pp.234-242
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    • 1999
  • In this paper, a method for assessment of the anisotropic machined surfaces is proposed. Fractal dimension (FD) is calculated using structure function and an index of the anisotropy is obtained as a ratio of its maximum and minimum value. The upper limit of fractal region on the structure function is determined as the length of the lag where the autocorrelation function shows 20% of its maximum value. The model of the structure function is derived from that of the auto correlation function. And, it shows that the new method and the proposed index of anisotropy are useful.

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Correlation Based Image Registration for Pressure Sensitive Paint (PSP를 이용한 압력측정에서의 상관법에 의한 이미지 등록)

  • Park Sang-Hyun;Sung Hyung Jin
    • 한국가시화정보학회:학술대회논문집
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    • 2003.11a
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    • pp.63-66
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    • 2003
  • A new algorithm, CBIR (Correlation Based Image Registration) was proposed to improve the resolution of image registration for PSP (Pressure Sensitive Paint). The local displacement vectors were obtained by finding the displacement which maximizes the cross-correlation between two interrogation windows of 'wind-off' and 'wind-on' images. A recursive multigrid processing was employed to increase the non-linear spatial resolutions. The variations of image were precisely measured without identifying the control points.

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Detection of Distinctive Points in Impedance Cardiogram during Exercise by Cross-Correlation Method (상호상관 관계를 이용한 운동중의 임피던스 파형에서의 특성점 검출)

  • 오인식;송철규
    • Journal of Biomedical Engineering Research
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    • v.12 no.4
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    • pp.261-266
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    • 1991
  • As the ensemble averaged dz/dt signal during exercise gets smoothed, it is difficult to find the distinctive marks for estimation of stroke volume. The cross correlation function was made use of estimating these marks for automatic calculation by computer from the ensemble averaged dz/dt signal. LVET( Left Ventricular Ejection Time) and stroke volume were estimated based on the calculated parameters from the characteristic points. LVET, stroke volume calculated by hand, by the ensemble average and the cross correlation were compared for accuracy validation.

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