• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.98-104
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• 2018

Macroscopic accident analyses have been conducted to incorporate transportation safety into long-term transportation planning. In macro-level accident prediction model, exposure variable(e.g. a settled population) have been used as fundamental explanatory variable under the concept that each trip will be subjected to a probable risk of accident. However, a settled population may be embedded error by exclusion of active population concept. The objective of this research study is to develop macro-level accident prediction model using floating population variable(concept of including a settled population and active population) collected from mobile phone data. The concept of accident prediction models is introduced utilizing exposure variable as explanatory variable in a generalized linear regression with assumption of a negative binomial error structure. The goodness of fit of model using floating population variable is compared with that of the each models using population and the number of household variables. Also, log transformation models are additionally developed to improve the goodness of fit. The results show that the log transformation model using floating population variable is useful for capturing the relationships between accident and exposure variable and generally perform better than the models using other existing exposure variables. The developed model using floating population variable can be used to guide transportation safety policy decision makers to allocate resources more efficiently for the regions(or zones) with higher risk and improve urban transportation safety in transportation planning step.

• Journal of Korean Society of Transportation
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• v.19 no.1
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• pp.7-16
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• 2001

The Principle objective of this paper is to introduce a systematic approach to identifying similar container ports in Asia. For this, it analyses data on port facilities, port facility availability, port service level total container throughput, and economic index, by using Multidimentional Scaling (MDS) method. Based on the analysis it identifies five groupings of similar container ports in Asia within which Port comparison can be justifiably made, evaluates a present position of five groupings on the basis of factors used to compare container ports in Asia ; and finally proposes policy implications for operation efficiency of Pusan container port in comparison with Kaohsiung Port. The major implication is that both the Kaosuing and the Pusan port have to strengthen port facility to attract more traffic, and particularly, Pusan Port has to reinforce the number of berth, total length of berth. and yard areas.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.27-36
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• 2005

Finite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates Per fault. This Paper Proposes reliability model using the generalized gamma distribution, which can capture the monotonic increasing(or monotonic decreasing) nature of the failure occurrence rate per fault. Equations to estimate the parameters of the generalized gamma finite failure NHPP model based on failure data collected in the form of interfailure times are developed. For the sake of proposing shape parameter of the generalized gamma distribution, used to the special pattern. Data set, where the underlying failure process could not be adequately described by the knowing models, which motivated the development of the gamma or Weibull model. Analysis of failure data set for the generalized gamma modell, using arithmetic and Laplace trend tests . goodness-of-fit test, bias tests is presented.

• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.722-731
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• 2014

The purpose of this study was to identify the relationship between multi-cultural family husbands' stress related to their wife and their psychological abuse based on the Stress theory of Lazarus et al. Data from 271 subjects that answered to all questions regarding the subjects' social demographic characteristics, and the husbands' stress related to their wife and their psychological abuse of their wife in statistical analyses. To analyze the data, a study model was set using multi-cultural family husbands' stress related to their wife as an independent variable and their psychological abuse of their wife as a dependent variable and the goodness-of-fit of the model for the data and the relationship between the variables were reviewed using a structural equation model. According to the results, the goodness-of-fit index of the model satisfied the statistical acceptable standard with CFI=0.909 and RMSEA=0.057. The relationship between the variables indicated that multi-cultural family husbands' stress related to their wife had significant effects on their psychological abuse of their wife. This result indicates the necessity of intervention for management of the husbands' stress in order to prevent multi-cultural family husbands' psychological abuse of their wife.

• Journal of Korean society of Dental Hygiene
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• v.12 no.3
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• pp.471-483
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• 2012

Objectives : This study looked at the relationship between occupational stress and the Oral Health Impact Profile (OHIP), to evaluate the effect of occupational stress-related factors. Methods : Data was obtained from a cross-sectional survey of 260 local officials in Gangwondo. The research comprised three questions relating to subjective oral symptoms, an occupational stress measurement tool and an oral health impact factor which was composed of questions. The data was analysed using t-test, one-way ANOVA, Pearson correlation and path analysis in Amos. Results : Occupational stress had a positive correlation to drinking frequency, Oral symptoms had a negative correlation. And drinking frequency, smoking amount and occupational stress had a positive correlation to oral symptoms. It denoted that drinking frequency, occupational stress and oral symptoms had a negative correlation to OHIP. The path model had an excellent goodness of fit (p=0.07, namely p>0.05). Five 'goodness-of-fit indices' of the model were all above 0.9: GFI=0.987, AGFI=0.952, NFI=0.902, IFI=0.939, CFI=0.934), and its RMSEA was 0.045. Occupational stress and oral symptoms had a firsthand impact on OHIP. In addition, it affected OHIP through the parameters of oral symptoms. Occupational stress exercised a firsthand influence on drinking frequency, drinking frequency exercised a firsthand influence on smoking amount. Smoking amount had a firsthand impact on oral symptoms. Conclusions: Oral health education programs for the development of an improved oral hygiene environment through reduction in drinking and smoking also need to focus on relieving stress by improving workplace culture. In addition, due to good communication is required to reduce occupational stress caused by interpersonal conflict.

• The Korean Journal of Applied Statistics
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• v.33 no.1
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• pp.107-114
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• 2020

Extreme value distributions have often been used for the analysis (e.g., prediction of return level) of data which are observed from natural disaster. By the extreme value theory, the block maxima asymptotically follow the generalized extreme value distribution as sample size increases; however, this may not hold in a small sample case. For solving this problem, this paper proposes the use of a log-logistic (LLG) distribution whose validity is evaluated through goodness-of-fit test and model selection. The proposed method is illustrated with data from annual maximum earthquake magnitudes of China. Here, we present the predicted return level and confidence interval according to each return period using LLG distribution.

• Journal of Korea Water Resources Association
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• v.53 no.10
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• pp.917-928
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• 2020

The purpose of this study is to find the appropriate probability distribution representing the size distribution of suspended cohesive sediment. Based on goodness-of-fit test for a significance level of 5% using the Kolmogorov-Smirnov test, it is found that the floc size distributions measured in laboratory experiment and field study show different results. In the case of sample data collected from field experiments, the Gamma distribution is the best fitting form. In the case of laboratory experiment results, the sample data shows the positively-skewed distribution and the GEV distribution is the best fitted. The lognormal distribution, which is generally assumed to be a floc size distribution, is not suitable for both field and laboratory results. By using 3-parameter lognormal distribution, it is shown that similar size distribution with floc size distribution can be simulated.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.3
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• pp.799-808
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• 2016

To find the pattern of personal data leak incidents and confirm which distribution is suitable for, this paper searched the personal data leak incidents reported by the media from 2011 to 2014. Based on result, this research estimated the statistical distribution using the 'K-S Statistics' and tested the 'Goodness-of-Fit'. As a result, the fact that in 95% significance level, the Poisson & Exponential distribution have high 'Goodness-of-Fit' has been proven quantitatively and, this could find it for major personal data leak incidents to occur 12 times in a year on average. This study can be useful for organizations to predict a loss of personal data leak incidents and information security investments and furthermore, this study can be a data for requirements of the cyber-insurance.

• The Korean Journal of Applied Statistics
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• v.26 no.1
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• pp.37-47
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• 2013

A Q-Q plot is an effective and convenient graphical method to assess a distributional assumption of data. The primary step in the construction of a Q-Q plot is to obtain a closed-form expression to represent the relation between observed quantiles and theoretical quantiles to be plotted in order that the points fall near the line y = a + bx. In this paper, we introduce a Q-Q plot to assess goodness-of-fit for inverse Gaussian distribution. The procedure is based on the distributional result that a transformed random variable $Y={\mid}\sqrt{\lambda}(X-{\mu})/{\mu}\sqrt{X}{\mid}$ follows a half-normal distribution with mean 0 and variance 1 when a random variable X has an inverse Gaussian distribution with location parameter ${\mu}$ and scale parameter ${\lambda}$. Simulations are performed to provide a guideline to interpret the pattern of points on the proposed inverse Gaussian Q-Q plot. An illustrative example is provided to show the usefulness of the inverse Gaussian Q-Q plot.

• The Korean Journal of Applied Statistics
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• v.30 no.4
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• pp.579-590
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• 2017

The multivariate empirical distribution function could be defined when its distribution function can be estimated. It is known that bivariate empirical distribution functions could be visualized by using Step plot and Quantile plot. In this paper, the multivariate empirical distribution plot is proposed to represent the multivariate empirical distribution function on the unit square. Based on many kinds of empirical distribution plots corresponding to various multivariate normal distributions and other specific distributions, it is found that the empirical distribution plot also depends sensitively on its distribution function and correlation coefficients. Hence, we could suggest five goodness-of-fit test statistics. These critical values are obtained by Monte Carlo simulation. We explore that these critical values are not much different from those in text books. Therefore, we may conclude that the proposed test statistics in this work would be used with known critical values with ease.