• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.1
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• pp.30-38
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• 2003

The measurement on the working gas flow in the closed cycle diesel engine is insufficient to Identify its operating condition because of lack of sensors available. For this reason, the determination of optimum operating condition and controller parameters requires heavy experimental efforts. A simulation program is developed to minimize the experimental efforts. For the development of the simulation program, mathematical models are derived based on the physical laws and linear regression. The validity of the simulation program is demonstrated using the measured data of the closed cycle diesel engine.

• Journal of Korean Society of Rural Planning
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• v.16 no.2
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• pp.21-29
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• 2010

This survey was performed with 262 dwellers who live in the city from April 1 to 30, 2009. The following analysis methods were executed; frequency analysis, reliability analysis, factor analysis, and multiple regression analysis. This study analyzed the relationship between rural tourism motivation and rural experiential tourism program preference of city dwellers. Rural tourism motivations are novelty experience, advantageousness, self-attainment, aesthetics, deviation, relationship, relaxation, and nature-scenery. And rural experiences are divided into farmhouse life experience, traditional rural culture experience, outdoor activities experience, wellbeing healthcare experience. Authors found that rural tourism motivations affect rural experiential tourism program preference. So, authors argue that rural tourism needs market segmentation strategy.

• Health Policy and Management
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• v.8 no.1
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• pp.135-154
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• 1998

In Korea, the institutional reform for the national medical insurance system is in process. Eventually, three kinds of the national medical insurance system, i.e., medical insurance program for the industrial workers, the govemment employees and the private school teachers, and the self-employeds, would be merged into an unifed system. In this study, I analyzed the annual trends of the finance in the medical insurance system in Korea, in which I found the financial instability especially in the medical insurance program for the self-employeds. The regression analysis was carried out to forecast the accumulated reserve at the end of this year for the medical insurance program for the self-employeds. I also analyzed the economic effect of the merge of the medical insurance program for the self-employeds by using the case of Japan and Korea. I found that the medical insurance for the self-employeds is expected to have financial deficit at the end of the year 1998 after the merge. In onclusion, it seems to be quite difficult to solve the financial instability in the medical insurance program for the self-employeds after it would be merged. That means that there would be a lot of problems on the way to the merge.

• Korean journal of food and cookery science
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• v.22 no.5 s.95
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• pp.702-711
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• 2006

The purpose of this study was investigate the effects of internship program particularly how the satisfaction with the internship program affects the students’ career decisions. Culinary major students at 5 different two-year colleges in Seoul and Kyunggi-do participated in this study. Out of 500 questionnaires, 415 were analysed using SPSS 13.0 and descriptive analysis, factor analysis, reliability analysis, chi-square, t-test, ANOVA, and multiple regression analysis were used. Based on conducting factor analysis results, the satisfaction measurement was classified into 4 factors: constructs, contents, benefit, environments and communication. Cronbach’s alpha was calculated for the reliability of the survey instrument. Two-thirds of the students (66.9%) answered that the internship program had helped them to decide their career. Particularly, constructs and contents of the internship program presented statistically significance to the career path. Based on the satisfaction level, students in high level wanted to be chefs while those in low level wanted to leave to other jobs. The overall satisfaction with the internship program differed according to the time of internship, internship duration, and place of internship.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.3
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• pp.357-373
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• 2013

In this paper, a back analysis program for analyzing the behavior of tunnel-ground system and evaluating the material properties and tunnel design parameters was developed. This program was designed to be able to implement the back analysis of underground structure by combination of using FLAC and optimized algorithm as direct method. In particular, Rosenbrock method which is able to do direct search without obtaining differential coefficient was adopted for the back analysis algorithm among optimization methods. This back analysis program was applied to the site to evaluate the design parameters. The back analysis was carried out using field measurement results from 5 sites. In the course of back analysis, nonlinear regression analysis was carried out to identify the optimum function of the measured ground displacement. Exponential function and fractional function were used for the regression analysis and total displacement calculated by optimum function was used as the back analysis input data. As a result, displacement recalculated through the back analysis using measured displacement of the structure showed 4.5% of error factor comparing to the measured data. Hence, the program developed in this study proved to be effectively applicable to tunnel analysis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.566-573
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• 2016

The age-adjusted incidence rate (AAR) of colorectal cancer in Korea peaked in 2011 and then began to decline. However, the AAR of colorectal cancer in Jeju increased continually from 1999 to 2013. Compared with the 16 major cities in Korea, the inhabitants of Jeju-do have a low cancer screening program participation rate, high alcohol consumption rate and high BMI. The present study aimed to provide a statistical basis for the lowering of the incidence of colorectal cancer in Jeju-do. The Jeju regional cancer institute data from 1999 to 2013 was used to analyze the between Jeju-do and Korea using the Joinpoint Regression program (Statistical Methodology and Applications Branch, Surveillance Research Program, National Cancer Institute) Version 4.2.0 - April 2015. The AAR of colorectal cancer in Jeju-do has being increasing because of the increase in the rates of male colon cancer (average annual percent change 8.422%, p-value<0.000), female colon cancer (AAPC 6.136%, p-value<0.000), male rectal cancer (AAPC 4.221%, p-value 0.003) and colon cancer in people aged over 50 years (AAPC 7.986% p-value<0.000). The results of this study suggest that the treatment of precancerous lesions of the male rectum and lowering of the incidence of colon cancer in people aged over 50 years are necessary to reduce the colorectal cancer incidence rate in Jeju-do.

• The Korean Journal of Applied Statistics
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• v.31 no.1
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• pp.123-137
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• 2018

A nonlinear mixed effects model is mainly used to analyze repeated measurement data in various fields. A nonlinear mixed effects model consists of two stages: the first-stage individual-level model considers intra-individual variation and the second-stage population model considers inter-individual variation. The individual-level model, which is the first stage of the nonlinear mixed effects model, estimates the parameters of the nonlinear regression model. It is the same as the general nonlinear regression model, and usually estimates parameters using the least squares estimation method. However, the least squares estimation method may have a problem that the estimated value of the parameters and standard errors become extremely large if the assumed nonlinear function is not explicitly revealed by the data. In this paper, a new estimation method is proposed to solve this problem by introducing the ridge regression method recently proposed in the nonlinear regression model into the first-stage individual-level model of the nonlinear mixed effects model. The performance of the proposed estimator is compared with the performance with the standard estimator through a simulation study. The proposed methodology is also illustrated using quantitative high throughput screening data obtained from the US National Toxicology Program.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.248-251
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• 2005

In this paper, health monitoring technique has been studied for performance deterioration caused by the defects of the gas turbine. The parameters for performance diagnostics have been extracted by using GSP program for modeling the target engine. The virtual sensor model for the health monitoring has been built of those data. The position and magnitude of the defects of the engine components have been determined by using Multiple Linear Regression technique and the method using the weight in order to diagnose the single and multiple defects.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1525-1525
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• 2001

Non-destructive determination of soluble solids(Brix) in harvested fruits using near infrared(hereafter, NIR) spectroscopy has been reported by many researchers. We have just reported on non-destructive estimation of Brix in harvested melons using a NIR Systems Model 6500 spectrophotometer(Ito et al., 2000). There is a melon cultivar that is difficult to judge the harvest time from the external appearance. If we can determine Brix in growing fruits non-destructively in the field, immature fruits will not be harvested. A portable m spectrophotometer for field use has been just developed by Kubota Corporation. The spectral data of growing melons were measured by the portable spectrophotometer. A commercial program was used for multiple linear regression analysis. Brix in growing melons could be estimated by a multiple regression equation calibrated with harvested melons. Absorbances of 906 and 874 nm were included as the independent variables in the multiple regression equation, and these wavelengths are key wavelengths for non-destructive Brix determination.

• Proceedings of the KSRS Conference
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• v.2
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• pp.547-550
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• 2006

This study is to suggest a methodology to produce landslide hazard map by combining LRA (Logistic Regression Analysis) and AHP (Analytic Hierarchy Program) Approach. Topographic factors (slope, aspect, elevation), soil drain, soil depth and land use were adopted to classify landslide hazard areas. The method was applied to a 520 $km^2$ region located in the middle of South Korea which have occurred 39 landslides during 1999 and 2003. The suggested method showed 58.9 % matching rate for the real landslide sites comparing with the classified areas of high-risk landslide while LRA and AHP showed 46.1 % and 48.7 % matching rates respectively.