• Journal of the Korean Data and Information Science Society
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• v.18 no.2
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• pp.429-438
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• 2007

Headache is one of the most common reasons for neurological consultation. Headache as many causes and symptoms. Therefore, screening method using questionaire is helpful in diagnosis of headache. This paper is to propose a medical diagnostic method to grasp patient's diseases using the relations between symptoms and diseases. For this purpose, we develop an interview chart assigned IF(intuitionistic fuzzy) grade with the relation among symptoms and three labels of headache. The method can be used to classify patient's tone of diseases with certain degrees of belief and its concerned symptoms.

• Journal of the Korean Data and Information Science Society
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• v.22 no.3
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• pp.555-563
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• 2011

Osteoarthritis (OA) and rheumatoid arthritis (RA) are most popular types of arthritis in Korea. This study compared health-related quality of life (HRQoL) of homedwelling people with OA and RA in Korea. Data were drawn from the Korean nationwide representative survey. Subjects were 3,352 people with arthritis over 19 years of age (2,953 OA respondents and 399 RA respondents). Good HRQoL in OA respondents was dierentiated with limitation of mobility, perceived health status, age, economic status, presence of arthralgia, gender, medical coverage, and educational level. Good HRQoL in RA respondents was dierentiated with limitation of mobility, perceived health status, economic status, educational status, and presence of arthralgia. In conclusion, HRQoL and predictors of good HRQoL among people with arthritis diers for OA or RA. These results can be of use in development of health programs and clinical interventions for community-dwelling people with arthritis.

• Communications for Statistical Applications and Methods
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• v.18 no.1
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• pp.111-118
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• 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
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• v.24 no.1
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• pp.81-96
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• 2017

Cumulative logit random effects models are typically used to analyze longitudinal ordinal data. The random effects covariance matrix is used in the models to demonstrate both subject-specific and time variations. The covariance matrix may also be homogeneous; however, the structure of the covariance matrix is assumed to be homoscedastic and restricted because the matrix is high-dimensional and should be positive definite. To satisfy these restrictions two Cholesky decomposition methods were proposed in linear (mixed) models for the random effects precision matrix and the random effects covariance matrix, respectively: modified Cholesky and moving average Cholesky decompositions. In this paper, we use these two methods to model the random effects precision matrix and the random effects covariance matrix in cumulative logit random effects models for longitudinal ordinal data. The methods are illustrated by a lung cancer data set.

• The Journal of Korean Medicine
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• v.32 no.1
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• pp.84-96
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• 2011

Objectives: Sample surveys have been increasingly used by Korean medical doctors for many studies. We present how to conduct higher quality sample surveys in Korea. Methods: According to the 11 principal steps for sample surveys, the concrete issues that academic researchers tend to overlook are illustrated and a variety of methods for improving survey quality are discussed. Results: The survey statistics produced by some researchers could be subject to large errors. This would be mainly due to misunderstandings about the system of principles called survey methodology. The best strategy for avoiding these errors will be to follow the suggested guidelines. Conclusions: For the development of traditional Korean medicine, the role of survey studies is important. Conducting surveys of a better quality based on survey methodology will be beneficial to researchers.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.11a
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• pp.489-492
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• 2005

TSP(Traveling Salesman Problem)는 N개의 주어진 도시를 한번씩만 방문하여 다시 출발지로 돌아오는 여러 경로들 중 가장 짧은 거리를 구하는 문제로 유전자 알고리즘이 대표적으로 이용된다. NP-Hard문제로 분류되어 보다 우수한 결과를 얻기 위해 현재까지 다양한 연산자들이 개발되고 연구되어왔다. 본 논문에서는 이러한 연산자들을 적용하여 보다 나은 해를 얻기 위해 새로운 집단초기화 방법과 순차변환 방법을 제안하여 기존의 방법들과 비교를 통해 성능 향상을 입증 하였다.

• Journal of the Korean Statistical Society
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• v.30 no.4
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• pp.667-678
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• 2001

The asymptotic behavior and distribution for quantiles estimators using ranked samples are introduced. Applications of quantiles estimation on finding the normal ranges (2.5% and 97.5% percentiles) and the median of some medical characteristics and on finding the Hodges-Lehmann estimate are discussed. The conclusion of this study is, whenever perfect ranking is possible, the relative efficiency of quantiles estimation using ranked samples relative to SRS is high. This may translates to large savings in cost and time. Also, this conclusion holds even if the ranking is not perfect. Computer simulation results are given and real data from lows 65+ study is used to illustrate the method.

• Journal of the Korean Statistical Society
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• v.29 no.2
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• pp.219-229
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• 2000

Oh et al.(1999) 3$\times$2 crossover design for assessing bioequivalence when two new generic drug formulations and innovator are simultaneously considered. This design is not only more efficient than 3$\times$3 one, proposed by Lee et al.(1998), in practical sense, but also more ethical in medical sense. However, the general statistical methods are not directly applicable to both designs when subjects are dropped out in the experiment, even though it is always possible in bioavailability and bioequivalence studies because of some administrative and economic reasons. In this research we propose an inference to drug effects when subjects are dropped out in the planed-for 3$\times$3 and 3$\times$2 crossover experiments. An example is given for illustration.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.28 no.1
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• pp.122-129
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• 2020

Korea's HEMS are mainly operated during the week, but they are pushing for 24-hour operations. This study has made an overall comparison and review of helicopter safety management that should be accompanied to this end. For research purposes, helicopter regulations and helicopter accident statistics were analyzed, with a high accident rate associated with pilot error and night flight. It was proposed that future preparations would require reinforcement of laws and regulations, reinforcement of pilots' night training, and introduction of training and preflight risk assessments. This study will provide a direction for future helicopter safety. This study will provide for future direction of helicopter safety research.

• Journal of the Korean Data and Information Science Society
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• v.11 no.2
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• pp.269-277
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• 2000

We propose the Bayesian testing for the equality of two log-normal population means. Specifically we use the intrinsic Bayes factors suggested by Berger and Perichi (1996, 1998) based on the noninformative priors for the parameters. In order to investigate the usefulness of the proposed Bayesian testing procedures, we compare it with classical tests via both real data analysis and simulation.