• Title/Summary/Keyword: Coefficient of Variance

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The Asymptotic Variance of the Studentized Residual Autocorrelations for a Generalized Random Coefficient Autoregressive Processes

  • Park, Sang-Woo;Cho, Sin-Sup;Hwang, Sun Y.
    • Journal of the Korean Statistical Society
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    • v.26 no.4
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    • pp.531-541
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    • 1997
  • The asymptotic distribution of residual autocorrelation functions from a generalized p-order random coefficient autoregressive process (GRCA(p)) is derived. To this end, we first describe the GRCA(p) models and then consider the normalised residuals after fitting the model. This result can be applied to the residual analysis for the diagonostic purpose.

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Hospital Services Utilization in Type-I Medicaid Elderly Beneficiaries (의료급여 1종 노인 수급권자의 입원이용)

  • Lim, Seung-Joo
    • Journal of East-West Nursing Research
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    • v.15 no.2
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    • pp.63-70
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    • 2009
  • Purpose: The purpose of this study was to evaluate hospital service utilization by the types of hospitals in Type I Medicaid claims frequently cited by elderly beneficiaries. Methods: Three frequently claimed inpatient diseases were selected: cerebral infarction, hypertension and diabetes mellitus. Relevant data were collected for the year 2008 from the computer database of the National Health Insurance Corporation. The data was analyzed using SPSS by descriptive statistics, ANOVA and coefficient of variation. Results: The coefficient of variance of hospitalization per episode was higher than daily hospital expenditure among hospitals for all three diseases. The coefficient of variance of hospitalization per episode was highest for cerebral infarction. The coefficient of variation of hospital expenditure per hospital day was highest for hypertension. Conclusions: Evaluating of the volume and pattern of hospital service utilization and the appropriateness for hospital admission for Type-I Medicaid elderly beneficiaries is important for Medicaid-based case management.

A study on the analyzing of uncertainty for actual evapotranspiration: flux tower, satellite-based and reanalysis based dataset (실제증발산 자료의 불확실성 파악에 관한 연구: flux tower, 인공위성 및 재분석자료)

  • Baik, Jongjin;Jeong, Jaehwan;Park, Jongmin;Choi, Minha
    • Journal of Korea Water Resources Association
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    • v.52 no.1
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    • pp.11-19
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    • 2019
  • In this study, the actual evapotranspiration products of Global Land Data Assimilation System (GLDAS), Global Land Evaporation Amsterdam Model (GLEAM) and MOD16, which are satellite- and reanalysis-based dataset, were validated at the flux tower sites (i.e., CFK and SMK) managed by Korea Institute of Hydrological Survey, and the uncertainty and correlation analysis were conducted using Triple Collocation (TC) method. The result of validation with the flux tower showed better agreement in the order of GLEAM> GLDAS>MOD16. At the result of three combinations (S1: flux tower vs. GLDAS vs. MOD16, S2: flux tower vs. GLDAS vs. GLEAM, S3: flux tower vs. GLEAM vs. MOD16), the order of best to worst is GLEAM, GLDAS, MOD16, and flux tower for CFK (GLDAS> GLEAM>MOD16>flux tower for SMK). Since the error variance and correlation coefficients of the flux tower show relatively worse performance in TC analysis than the other products, By applying TC method to three products (GLDAS vs. GLEAM vs. MOD16), the uncertainty of each dataset were evaluated at the Korean Peninsula, As a results, the GLDAS and GLEAM performed reasonable performance (low error variance and high correlation coefficient), whereas results of MOD16 showed high error variance and low correlation coefficient at the cropland.

A Study on the Soft Ground Distubance Characteristics by Large Block Sample (대형자연시료를 이용한 지반교란 특성에 관한 연구)

  • Yu, Seong-Jin
    • Journal of the Korea Construction Safety Engineering Association
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    • s.43
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    • pp.98-106
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    • 2007
  • In this paper, a ground disturbance effects, strength and consolidation characteristics of soft clay through using the large block samples($\theta$:300mm, H:400mm) and the piston samples, f hose which had been gathered in west coast and south coast. Especially, we have assessed the coefficient of horizontal consolidation when penetrating the mandrel considering the variance of ratio between diameter and height in drainage sample through the experiment of the oedometer test and Rowecell and also investigated the disturbance area in smear zone by interior model test, the strength originated by disturbance, the variance in characteristics of the consolidation. As the result, the large block sample has been investigated that ihe uniaxial compression test(qu) was shown bigger than the piston sample by about 11-19%. Under the size of anistropy in consolidation, the coefficient ratio of consolidation(ch/cv,) perfomed by standard consolidation test(SC) was shown bigger than that of (Cro/Cv) by the Rowecell test. And the coefficient ratio of consolidation(Cro/Cv) perfomed by piston sample was evaluated bigger than that Of (Cro/Cv) by the large block sample by about 0.9-1.9. The coefficient ratio of consolidation along with the variance in ratio of between diameter and height when penetrating the mandrel was shown big difference according to the characteristics of soil of the specimen. In addition, ds/dw of smear zone at the marine clay in west-south was ranged from 1.6 to 4.2. The width of variance in rat io[(qud)/(quud)] of strength n the area between disturbance and undisturbance was shown big as about 72-91% but the principle was judged with the similiar range when the decrease of the strength in smear zone become the zone under 25% in unditurbance area.

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Derivation of the Critical Minimum Values of the Multiple Correlation Coefficient for Augmenting Hydrologic Samples (수문자료 확충을 위한 다중상관계수의 한계최소치 유도)

  • 허준행
    • Water for future
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    • v.27 no.1
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    • pp.133-140
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    • 1994
  • The augmenting hydrologic data using a correlation procedue has been used to improve the estimates of the mean and variance at the site of interest with short record when one or more nearby sites with longer records are available. The variance of the unbiased maximum likelihood estimator of ${{\sigma}_v}^2$ derived by Moran based on the multivariate normal distribution is modified into the form of Matalas and jacobs for the bivariate normal distribution to get the critical minimum values of the multiple correlation coefficient which give the improvement for estimation the variance at the site of interest. Those values are tabulated for various lengths of records and the number of sites.

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Interrelationship of phase-error variance and correlation coefficient in microwave imaging (마이크로웨이브 이미징에서 위상오차 분산과 코릴레이션 계수와의 상호관계)

  • 강봉순;장훈기
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.10
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    • pp.1-6
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    • 1997
  • This paper presents the theoretical derivaion relating and image correlationcoeffcient capable of assessing image quality, with phase-error variance in antenna aperture domain. We show that when the phase-error variance of a range bin selected as an adaptive beamformer is known, the quality of the reconstructed image is predictable and moreover, the resultant correlation coeffcient is obviously greater than the derive dlower boudn. To support the derivation, real data are used for image formation where the dominant scatterer algorithm (DSA) is applied for phase compensations.

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Analysis of Global Gravitational Models based on measured gravity data (육상 중력자료 기반의 전 지구 중력장 모델 분석)

  • Choi, Kwang-Sun;Lee, Young-Cheol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.9
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    • pp.1833-1839
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    • 2011
  • In this study, Global Gravitational Model EGM2008, EGM96 and 16,786 gravity points measured on land were compared and analyzed. On the assumption that land gravity data is most accurate, the correlation coefficient, differences, MSE and difference variance along the height were computed between land gravity data and EGM2008, EG96. The correlation coefficient, land gravity data and EGM2008, was computed most largely with 0.824 and the correlation coefficient with EGM96 was computed with 0.538. The standard deviation of differences between land gravity and EGM2008, EGM96 were 13.196 magl, 18.685 mgal respectively. Also the difference variance scope of EGM2008 was smaller than EGM96. There was no large variance of free-air anomaly differences between land gravity data and EGM2008 along the height however free-air anomaly differences with EGM96 varied along the height changes. Consequently EGM2008 nicely expresses Korea gravity field more than EGM96.

Confidence intervals on variance components in multiple regression model with one-fold nested error strucutre (중첩오차를 갖는 중회귀모형에서 분산의 신뢰구간)

  • 박동준
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1996.04a
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    • pp.495-498
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    • 1996
  • Regression model with nested error structure interval estimations about variability on different stages are proposed. This article derives an approximate confidence interval on the variance in the first stage and an exact confidence interval on the variance in the second stage in two stage regression model. The approximate confidence interval is based on Ting et al. (1990) method. Computer simulation is provided to show that the approximate confidence interval maintains the stated confidence coefficient.

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Comparison of Performance and Stability Parameters for Soybean Yield (콩 수량안전성 분석방법간 비교)

  • Suk-Ha, Lee;Yong-Hwan, Ryu;Yeul-Gue, Seung;Seok-Dong, Kim;Eun-Hi, Hong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.5
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    • pp.604-608
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    • 1997
  • Ten selected soybean genotypes, consisting of nine from a pedigree breeding programme and one recommended variety, were evaluated in nine different locations and over two years for stability of yield performance. Variance component analysis revealed that soybean regional yield trials should be performed at more locations rather than in more years. Five stability parameters, which were coefficient of variability, regression coefficient, deviation parameter, variance component for genotype$\times$environment interaction, and ecovalence, were employed in the evaluation. Significant genotype$\times$environment interaction was present with respect to soybean yield. The highest average yield over nine locations and two years was shown in Suwon 145, which was considered to be stable in all stability statistics. In rank correlation among stability parameters, there were highly significant correlations among stability parameters derived from three Eberhart and Russell's, Plaisted's, and Wricke's methods. Due to the different ranking of genotypes by different stability parameters, a comprehensive method should be employed to identify the promising genotype as well as to characterize the relationship between genotype and environment.

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Similarity Measurement Between Titles and Abstracts Using Bijection Mapping and Phi-Correlation Coefficient

  • John N. Mlyahilu;Jong-Nam Kim
    • Journal of the Institute of Convergence Signal Processing
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    • v.23 no.3
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    • pp.143-149
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    • 2022
  • This excerpt delineates a quantitative measure of relationship between a research title and its respective abstract extracted from different journal articles documented through a Korean Citation Index (KCI) database published through various journals. In this paper, we propose a machine learning-based similarity metric that does not assume normality on dataset, realizes the imbalanced dataset problem, and zero-variance problem that affects most of the rule-based algorithms. The advantage of using this algorithm is that, it eliminates the limitations experienced by Pearson correlation coefficient (r) and additionally, it solves imbalanced dataset problem. A total of 107 journal articles collected from the database were used to develop a corpus with authors, year of publication, title, and an abstract per each. Based on the experimental results, the proposed algorithm achieved high correlation coefficient values compared to others which are cosine similarity, euclidean, and pearson correlation coefficients by scoring a maximum correlation of 1, whereas others had obtained non-a-number value to some experiments. With these results, we found that an effective title must have high correlation coefficient with the respective abstract.