• Journal of Power System Engineering
• /
• v.5 no.3
• /
• pp.25-30
• /
• 2001

The basis of all approaches to improve reliability of marine engines exists in analyzing the field data of troubles and failures in marine engines. In this paper, we analyzed the engine accidents of Korean fishing vessels for five years from 1995 to 1999, firstly according to engine systems, type of fishing vessels, engine makers, cylinder number, engine power and tonnage, secondly by using of principal component analysis method, one of multi-variate data analysis method. Finally, we proposed the measures to reduce engine accidents of fishing vessels for improvement of an environment in fishing industry.

• Journal of Biosystems Engineering
• /
• v.23 no.1
• /
• pp.49-56
• /
• 1998

The objectives of this study were to develop models to predict the contents of moisture and protein of single kernel of brown rice based on visible/NIR (near-infrared) spectroscopic technique. The reflectance spectra of rice were obtained in the range of the wavelength 400 to 2,500 nm with 2 nm intervals. Multiple linear regression(MLR) and partial least squares (PLS) were used to develop the models. The MLR model using the first derivative spectra(10 nm of gap) with Standard Normal Variate and Detrending (SNV and Drt.) preprocessing showed the best results to predict moisture content of the sin린e kernel brown rice. To predict the protein content of a single kernel of brown ricer the PLS model used the raw spectra with multiplicative scatter correction(MSC) preprocessing over the wavelength of 1,100~1,500 nm.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2000.10a
• /
• pp.310-313
• /
• 2000

This paper develops a model of customer satisfaction in the mobile telecommunication services. We examine the relationships among customers'overall satisfaction and underlying dimensions； perceived service quality, service value, and brand image. Variables related to customer satisfaction and dissatisfaction are derived from customer critical incidence survey. The model is estimated with multi-variate data analysis. Results indicate that the (1) technical service quality is the main driver of customer overall satisfaction, (2) some peripheral services are rapidly evolving into the core services of mobile telecommunications, and (3) the current policy of service providers does not focus on customer satisfaction but on establishing churning barrier by increasing switching costs.

• Journal of Biosystems Engineering
• /
• v.33 no.1
• /
• pp.63-68
• /
• 2008

This study was carried out to find a useful method to predict hardness of tomato using optical spectrum data. Optical spectrum of reflectance and transmittance data were collected processed by 9 kind of preprocessing methods-normalizations of mean, maximum and range, SNV (standard normal variate), MSC (multiplicative scatter correction), the first derivative and second derivative of Savitzky-Golay and Norris-Gap. With the preprocessed and non-processed original spectrum data, prediction models of hardness of tomato were developed using analytical tools of PLS (partial least squares) and MLR (multiple linear regression) and tested for their validation. The test of validation resulted that the analytical tools of PLS and MLR output similar performances while the transmittance spectra showed much better result than the reflectance spectra.

• Proceedings of the KSR Conference
• /
• 2001.10a
• /
• pp.514-519
• /
• 2001

There are a close relationship between natural disasters and train safety. So it is very important to guaranty train safety using reasonable rail-transport operation control against disasters. Therefore, based on the past record of rainfall at failure, rail-transport operation control for railway embankment under rainfall was set up. After slope check list at home and abroad had been analyzed, new slope check list was suggested and site investigations were carried out using this check list. In order to evaluate the stability of railway slopes under rainfall, explanatory variables and subordinate variables were selected for multi-variate analysis and critical rainfall was defined by statistical process. Rail-transport operation control including regional and geological properties was suggested by analyzing the critical rainfall and rail-transport operation control in other country, and this will be a good tool to control train speed under rainfall and to secure train safety.

• Communications for Statistical Applications and Methods
• /
• v.18 no.1
• /
• pp.111-118
• /
• 2011

This paper suggests a ratio-cum product estimator of a finite population mean using information on the coefficient of variation and the fcoefficient of kurtosis of auxiliary variate in stratified random sampling. Bias and MSE expressions of the suggested estimator are derived up to the first degree of approximation. The suggested estimator has been compared with the combined ratio estimator and several other estimators considered by Kadilar and Cingi (2003). In addition, an empirical study is also provided in support of theoretical findings.

• Communications for Statistical Applications and Methods
• /
• v.9 no.2
• /
• pp.305-313
• /
• 2002

Regarding to inference about a scalar measure of internal scatter of Ρ-variate normal population, this paper considers an interval estimation of the generalized variance, │$\Sigma$│. Due to complicate sampling distribution, fully parametric frequentist approach for the interval estimation is not available and thus Bayesian method is pursued to calculate the highest probability density (HPD) interval for the generalized variance. It is seen that the marginal posterior distribution of the generalized variance is intractable, and hence a weighted Monte Carlo method, a variant of Chen and Shao (1999) method, is developed to calculate the HPD interval of the generalized variance. Necessary theories involved in the method and computation are provided. Finally, a simulation study is given to illustrate and examine the proposed method.

• Journal of the Korean Statistical Society
• /
• v.26 no.2
• /
• pp.261-276
• /
• 1997

In the context of binary response regression, the problem of constructing Bayesian goodness-of-link test for testing logit link versus probit link is considered. Based upon the well known facts that cdf of logistic variate .approx. cdf of $t_{8}$/.634 and, as .nu. .to. .infty., cdf of $t_{\nu}$ approximates to that of N(0,1), Bayes factor is derived as a test criterion. A synthesis of the Gibbs sampling and a marginal likelihood estimation scheme is also proposed to compute the Bayes factor. Performance of the test is investigated via Monte Carlo study. The new test is also illustrated with an empirical data example.e.

• The International Journal of Costume Culture
• /
• v.9 no.2
• /
• pp.149-159
• /
• 2006

The purpose of the study is to compare the clothing purchasing behaviors between Korean and American college women and to gather a basic data to establish a clothing marketing strategy and effective world marketing strategy in the fashion marketing. 1,150 questionaries were distributed to 3 universities in Korea and 3 universities America from March, 15 to 30 in 2006 and a total of 800 questionnaires, 466 from Korea and 334 from American, were utilized in the final analysis. The SPSS 12.0 was used to analyze the technical statistics like average and frequency, t-test, X$^2$, factor analysis and multi-variate analysis of variance.

• Journal of the Korea Safety Management & Science
• /
• v.10 no.4
• /
• pp.127-134
• /
• 2008

The objective of this study is to evaluate the mechanical behaviors and structural integrity of the weldment of high strength steel by using an acoustic emission (AE) techniques. Monotonic simple tension and AE tests were conducted against the 3 kinds of welded specimen. In order to analysis the effectiveness of weldability, joinability and structural integrity, we used K-means clustering method as a unsupervised learning pattern recognition algorithm for obtained multi-variate AE main data sets, such as AE counts, energy, amplitude, hits, risetime, duration, counts to peak and rms signals. Through the experimental results, the effectiveness of the proposed method is discussed.