• The Korean Journal of Applied Statistics
• /
• v.15 no.2
• /
• pp.337-354
• /
• 2002

This paper derives three estimation methods for the between group variance component for serially correlated random model. To compare their estimation capability, three designs having different degree of unbalancedness are considered. The so-called empirical quantile dispersion graphs(EQDGs) used to compare estimation methods as well as designs. The proposed conditional ANOVA estimation is robust for design unbalancedness, however, ML estimation is preferred to the conditional AOVA and REML estimation regardless of design unbalancedness and correlation coefficient.

• Structural Engineering and Mechanics
• /
• v.46 no.6
• /
• pp.853-868
• /
• 2013

The comparison of the effectiveness of artificial neural network (ANN) and linear regression (LR) in the prediction of strain in tie section using experimental data from eight high-strength-self-compact-concrete (HSSCC) deep beams are presented here. Prior to the aforementioned, a suitable ANN architecture was identified. The format of the network architecture was ten input parameters, two hidden layers, and one output. The feed forward back propagation neural network of eleven and ten neurons in first and second TRAINLM training function was highly accurate and generated more precise tie strain diagrams compared to classical LR. The ANN's MSE values are 90 times smaller than the LR's. The correlation coefficient value from ANN is 0.9995 which is indicative of a high level of confidence.

• The Journal of Korean Society for School & Community Health Education
• /
• v.17 no.3
• /
• pp.49-59
• /
• 2016

Objectives: This study was conducted to investigate the relationship between self-esteem and stress among adolescents. Methods: The subjects of this study were 1,025 from elementary, middle and high school students in Dangjin city. Data were measured using self-esteem scale and brief encounter psychosocial instrument. The data were analyzed frequencies, t-test, ANOVA, Pearson's correlation coefficient and multiple linear regression analysis using the SPSS 12.0 program. Results: Self-esteem was correlated with stress negatively among adolescents. In multiple linear regression analysis, self-esteem had a statistically significant negative effect on stress. Affecting factors of the self-esteem in all schools were grades, economic status and relationship with parents. Conclusion: The results of this study help to provide a basis for the development of a self-esteem management program to alleviate the stress for adolescents. The program of human relationship should be developed and provided to improve the self-esteem.

• Korean Journal of Applied Biomechanics
• /
• v.26 no.3
• /
• pp.273-284
• /
• 2016

Objective: The purpose of this study was to investigate effects of upper limb, trunk, and pelvis kinematic variables on the velocity of Apkubi Momtong Baro Jireugi in Taekwondo. Method: Twenty Taekwondo Poomsae athletes (age: $20.8{\pm}2.2years$, height: $171.5{\pm}7.0cm$, body weight: $66.2{\pm}8.0kg$) participated in this study. The variables were upper limb velocity and acceleration; trunk angle, angular velocity, and angular acceleration; pelvis angle, angular velocity, and angular acceleration; and waist angle, angular velocity, and angular acceleration. Pearson's correlation coefficient was calculated for Jireugi velocity and kinematic variables; multiple regression analysis was performed to investigate influence on Jireugi velocity. Results: Angular trunk acceleration and linear upper arm punching acceleration had significant effects on Jireugi velocity (p<.05). Conclusion: We affirmed that angular trunk acceleration and linear upper arm punching acceleration increase the Jireugi velocity.

• Journal of the Korean Data and Information Science Society
• /
• v.25 no.5
• /
• pp.1025-1038
• /
• 2014

Linear mixed model has often been utilized for genetic association analysis with family-based samples. The correlation matrix for family-based samples is constructed with kinship coefficient and assumes that parental phenotypes are independent and the amount of correlations between parent and offspring is same as that of correlations between siblings. However, for instance, there are positive correlations between parental heights, which indicates that the assumption for correlation matrix is often violated. The statistical validity and power are affected by the appropriateness of assumed variance covariance matrix, and in this thesis, we provide the linear mixed model with flexible variance covariance matrix. Our results show that the proposed method is usually more efficient than existing approaches, and its application to genome-wide association study of body mass index illustrates the practical value in real data analysis.

• Computers and Concrete
• /
• v.20 no.3
• /
• pp.275-282
• /
• 2017

Grouting is an operation often carried out to consolidate and seal the rock mass in dam sites and tunnels. One of the important parameters in this operation is grouting pressure. In this paper, analytical models used to estimate pressure are investigated. To validate these models, grouting data obtained from Seymareh and Aghbolagh dams were used. Calculations showed that P-3 model from Groundy and P-25 model obtained from the results of grouting in Iran yield the most accurate predictions of the pressure and measurement errors compared to the real values in P-25 model in this dams are 12 and 14.33 Percent and in p-3 model are 12.25 and 16.66 respectively. Also, SPSS software was applied to define the optimum relation for pressure estimation. The results showed a high correlation between the pressure with the depth of the section, the amount of water take, rock quality degree and grout volume, so that the square of the multiple correlation coefficient among the parameters in this dams were 0.932 and 0.864, respectively. This indicates that regression results can be used to predict the amount of pressure. Eventually, the relationship between the parameters was obtained with the correlation coefficient equal to 0.916 based on the data from both dams generally and shows that there is a desirable correlation between the parameters. The outputs of the program led to the multiple linear regression equation of P=0.403 Depth+0.013 RQD+0.011 LU-0.109 V+0.31 that can be used in estimating the pressure.

• Tunnel and Underground Space
• /
• v.25 no.1
• /
• pp.24-36
• /
• 2015

The Geochang granite widely used in construction works is one of the most popular dimension stones in Korea. In order to evaluate the physical properties of rock, a lot of laboratory tests for the Geochang granite were conducted to find unit weight, absorption ratio, P wave velocity, S wave velocity, uniaxial compressive strength, Young's modulus, Poisson's ratio, tensile strength, cohesion, friction angle and point load strength index. The uniaxial compressive strength of the Geochang granite was 19.5 times tensile strength and also 8.6 times cohesion, besides P wave velocity was 1.5 times S wave velocity. Correlation analyses were also conducted to find the correlation among 11 different physical properties, where the uniaxial compressive strength showed Pearson correlation coefficient of more than 0.8 with Poisson's ratio, point load strength index and Young's modulus, respectively. Regression analyses were finally conducted by means of both linear and multiple analysis and the brief results including coefficient of determination of more than 0.7 were presented.

• Current Research on Agriculture and Life Sciences
• /
• v.24
• /
• pp.49-53
• /
• 2006

The objective of this study was to present regression equations between reservoir water quality and land use types of the watersheds. In order to derive regression equations, a multiple linear regression analysis was used using observed data from 88 reservoirs in the Kyungpook Provcince. The measured values of BOD, COD, T-N, and T-P were correlated with the areas of land use types. 23 regression equations were obtained for all the water quality items and watershed sizes. The results showed that 2 regression equations have the multiple correlation coefficient(MCC) above 0.90, 10 regression equations have the MCC values from 0.70 to 0.90, 9 equations have the MCC from 0.40 to 0.70, and 2 equations have the MCC from 0.20 to 0.40. The results of this study can be used to estimate reservoir water quality simply and quickly in the planning phase.

• Phonetics and Speech Sciences
• /
• v.1 no.4
• /
• pp.97-103
• /
• 2009

This paper describes a new algorithm for encoding spectral envelope in the time domain alias cancellation (TDAC) part of G.729.1. The spectral envelope and modified discrete cosine transform (MDCT) coefficients of the weighted code-excited linear predictive (CELP) coding error in lower-band and the higher-band input signal are encoded in the TDAC part. In order to reduce allocation bits for spectral envelope coding, a new algorithm using sub-band correlation between adjacent frames is proposed. In addition, to improve the quality of decoded signals, two bit allocation strategies using reduced bits from the proposed algorithm are proposed. The performance of the proposed algorithm is evaluated in terms of objective quality and bit reduction rates. Experimental results show that the proposed algorithm increases the quality of sounds significantly.

• Journal of the Korean Society of School Health
• /
• v.29 no.2
• /
• pp.98-106
• /
• 2016

Purpose: The purpose of this study was to examine the relationship between sleep quality and mental health among adolescents and identify the factors relating to mental health. Methods: The subjects consisted of 285 middle school students. The data were collected from May $2^{nd}$ to $27^{th}$, 2016. The data were analyzed using t-test, ANOVA, Pearson's correlation coefficient and multiple linear regression with SPSS ver. 21. Results: The mean score for quality of sleep in adolescents was $4.20{\pm}2.64$, and the mean score for mental health was $13.67{\pm}12.93$. Poor sleepers showed higher scores for mental health than good sleepers. Mental health was found to have a positive correlation with both stress and quality of sleep. Stress and sleep quality were found to be significant factors influencing mental health and explained 59% of the variance in mental health. Conclusion: These findings indicate that effective intervention programs enhancing sleep quality should be provided for adolescents in order to prevent poor mental health.