• 응용통계연구
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• 제32권1호
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• pp.29-40
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• 2019

선거여론조사 자료의 경우 무응답이 흔히 관측되며, 이와 같이 무응답이 존재하는 범주형 자료는 불완전 분할표로 표현된다. 불완전 분할표로 표현된 선거여론조사 자료에서 후보자 지지율을 추정하는 경우, 지지율은 무응답이 어떤 메카니즘을 따르는가에 따라 다르게 추정되며, 따라서 자료가 어떠한 무응답 메카니즘을 따르는지에 대한 판별이 분석에 선행되어야 한다. 그러나 최근 연구에 따르면, 관측된 자료를 이용해서는 무응답 메카니즘을 판별할 수 없음이 밝혀졌다. 이러한 문제를 해결하기 위해 다양한 무응답 메카니즘을 반영할 수 있는 민감도 분석이 제안되었다. 그러나 기존에 제안된 민감도 분석의 경우, 이원 분할표에서 각 변수의 범주 수가 두 개인 경우만을 대상으로 한다. 우리나라 선거여론조사에서 고려되는 요인이 지역, 성, 연령 등임을 감안할 때, 기존 방법론으로 민감도 분석을 시행하기에는 한계점이 존재한다. 이에 따라 본 논문에서는 기존의 민감도 분석을 다차원 불완전 분할표에 적용할 수 있도록 확장하고, 이를 우리나라 19대 대선 여론조사 자료에 적용하였다. 분석 결과, 민감도 분석의 구간이 실제 지지율을 포함하고 있을 뿐 아니라, 다양한 무응답 메카니즘의 결과를 포괄하고 있으며, 실제 지지율과 가장 가까운 예측치의 경우 후보자에 대한 지지가 무응답의 발생에 영향을 미침을 알 수 있었다.

• Communications for Statistical Applications and Methods
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• 제16권2호
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• pp.229-238
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• 2009

범주형 자료분석을 위해 고려할 수 있는 모형들은 일반적으로 최우추정에 의하여 적합이 이루어지므로 이상값에 쉽게 영향을 받을 수 있다. 본 연구에서는 분할표 자료에 포함된 이상칸(outlying cell)에 영향을 받지 않는 최대 절삭우도 추정 값(maximum trimmed likelihood estimates)을 얻기 위한 추정 방법을 제안하였다. 제안된 방법은 우도에 의존하여 분할표에 포함된 칸을 제거해나가며 절사우도의 최대값을 찾기 때문에 완전탐색(complete enumeration)에 비해 계산의 양이 매우 적다. 따라서 일반적인 다차원 분할표 자료분석을 위해 쉽게 적용될 수 있다. 실제 자료분석 예를 통해 제안된 추정방법을 설명하였으며, 모의실험을 통해 문제점과 특징을 토론하였다.

• 응용통계연구
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• 제17권1호
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• pp.89-103
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• 2004

2차원 분할표 형태의 자료에 대해 두 범주형 변수들간의 독립성을 검정함에 있어, 만일 두 변수 각각의 모분포가 이미 완전히 알려진 경우라면 이 알려진 정보를 충족할 수 있도록 분할표 자료를 보정한 후 보정된 분할표 자료에 대해 전통적인 카이제곱 검정법을 적용하는 것이 더 타당함을 논증한다 그리고 이에 근거한 제약상황 카이제곱 독립성 검정법을 유도하고 모의실험을 통해 전통적인 무보정 카이제곱 검정법과 비교한다.

• Journal of Preventive Medicine and Public Health
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• 제32권2호
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• pp.215-227
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• 1999

Objectives: To investigate compliance of hypertension patients using modified Theory of Reasoned Action(TRA). Methods: The data were collected for 7-12 April 1997, by interviewing 190 Hypertension patients in Hwachon, Kangwon-do. The analytical techniques employed include contingency table analysis and logit analysis. Results: 15.1% of patients were unaware of the fact that he/she has hypertension and 11.2% did not know that he/she should take drug. 20.8% of patients took drug continuously, 20.1% had drug intermittently, and 53.1% had never have treatment. In the contingency table analysis, several variables were found to be significantly related to patient compliance. They included variables for attitude towards the consequences of taking drugs, normative beliefs, systolic BP at the enrollment, knowledge of how to take hypertensive drugs, variables for general health behavior and experience with having health worker's home visit. The logit analysis was performed by two steps. first step uses experience with drug treatment of hypertension as the dependent variable, and second step uses continuity of treatment. Included in the predictors that are significantly related to the former analysis are subjected norms produced by combining normative beliefs and motivation to comply, knowledge of how to take hypertensive drugs, and opinion about natural recovery of diseases. The only significant determinant of continuous treatment was knowledge of how to take hypertensive drugs. Conclusions: The results of analysis suggest the usefulness of TRA as a framework for the study of compliance of hypertensive patients. The findings have some practical implication as well. One is that efforts for enhancing compliance should be directed not only patients but also to other persons influencing patient's attitude and behavior. It also suggest that correct understanding of hypertension treatment is essential to perform the appropriate patient role.

• Communications for Statistical Applications and Methods
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• 제10권2호
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• pp.291-303
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• 2003

This work is proposed an alternative identification method of outlying cell which is one of important issues in categorical data analysis. One finds that there is a strong relationship between the location of an outlying cell and the corresponding parameter estimates of the well-fitted log-linear model. Among parameters of log-linear model, an outlying cell is affected by interaction terms rather than main effect terms. Hence one could identify an outlying cell by investigating of parameter estimates in an appropriate log-linear model.

• Restorative Dentistry and Endodontics
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• 제36권2호
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• pp.114-118
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• 2011

연구목적: 본 연구는 치근단절제술과 역충전을 시행한 환자를 대상으로 치근단미세수술의 결과에 대한 환자의 인식과 만족도를 조사하는 것을 목적으로 하였다. 연구 재료 및 방법: 연세대학교 치과보존과에서 치근단 수술 후 최소 3개월 이후 정기검진을 위해 내원한 환자를 대상으로 설문조사를 시행하였다. 응답자의 나이/성별간 응답의 차이가 있는지는 contingency table을 이용해서 분석하였다 (p=0.05). 결과: 응답자의 60% 정도가 이전에 치근단 수술에 대해서 들어본 적이 없었으며 치근단 수술을 결정한 이유는 63.3%에서 자연치를 보존하기 위해서라고 응답하였다. 이후 비슷한 상황이 생긴다면 대부분의 환자가 다시 치근단수술을 선택할 것이라고 하였으며 수술의 만족도는 전반적으로 높은 편이었다. 결론: 치근단수술은 대부분의 환자에서 만족스러운 치료로 인식되고 있다.

• 대한수의학회지
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• 제36권4호
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• pp.941-948
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• 1996

The accuracy of rectal palpation and ultrasonography for predicting the presence of a functional corpus luteum in subestrous dairy cows was investigated, using the result of a radioimmunoassay for progesterone in plasma. Luteal status (high or low progesterone concentrations) was diagnosed in 820 cows, using rectal palpation and B-mode transrectal ultrasonography, and the results of rectal palpation and ultrasonography were compared in $2{\times}2$ contingency table with plasma progesterone concentrations. A $2{\times}2$ contingency table analysis allowed the calculation of sensitivity, specificity and predictive values for rectal palpation and ultrasonography. The sensitivity, specificity, predictive value of a positive test and predictive value of a negative test were 81.9%, 67.5%, 79.0% and 71.4% for rectal palpation, and 96.3%, 88.8%, 94.5% and 92.4% for ultrasonography, respectively. The percentages of observed agreement and expected agreement between rectal palpation and ultrasonography were 71.8% and 57.1%, respectively. An evaluation of agreement between rectal palpation and ultrasonography, the value of Kappa was 0.34. It was concluded that a ultrasonography was more sensitive and specific than rectal palpation in predicting the presence of a functional corpus luteum. Therefore, ultrasonographic examination is a reliable method for assessing the functional status of ovarian structures in subestrous dairy cows.

• Communications for Statistical Applications and Methods
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• 제29권5호
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• pp.547-559
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• 2022

For a chi-squared test, which is a statistical method used to test the independence of a contingency table of two factors, the expected frequency of each cell must be greater than 5. The percentage of cells with an expected frequency below 5 must be less than 20% of all cells. However, there are many cases in which the regional expected frequency is below 5 in general small area studies. Even in large-scale surveys, it is difficult to forecast the expected frequency to be greater than 5 when there is small area estimation with subgroup analysis. Another statistical method to test independence is to use the Bayes factor, but since there is a high ratio of data dependency due to the nature of the Bayesian approach, the low expected frequency tends to decrease the precision of the test results. To overcome these limitations, we will borrow information from areas with similar characteristics and pool the data statistically to propose a pooled Bayes test of independence in target areas. Jo et al. (2021) suggested hierarchical Bayesian pooling models for small area estimation of categorical data, and we will introduce the pooled Bayes factors calculated by expanding their restricted pooling model. We applied the pooled Bayes factors using bone mineral density and body mass index data from the Third National Health and Nutrition Examination Survey conducted in the United States and compared them with chi-squared tests often used in tests of independence.

• Journal of the Korean Data and Information Science Society
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• 제20권5호
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• pp.919-924
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• 2009

Geographical location carries information such as demography, local economy, environment, and life styles, which could be the sources of cancer occurrence. Analyzing geographical location associated with cancer occurrence can be instructive to physicians, patients, and health administrators regarding resource allocation, expenditures, prophylaxis and treatments. In this paper, we explored the correspondence relationship between geographical locations and mortality rates of the cancers using correspondence analysis and illustrated the approach with the mortality rates of the top 10 cancers in the 75 counties in Arkansas from 2001 to 2005. Geographical variations with respect to the mortality rates of cancers are evaluated across Arkansas counties. Based on the contingency table, correspondence analysis model is developed and the simple indices which indicate the degree to which the regions and the cancers affect each other are calculated. Quantitative results are visualized and mapped in two-dimensional graphs.

• Communications for Statistical Applications and Methods
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• 제27권1호
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• pp.15-35
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• 2020

In research on behavioral studies, significant attention has been paid to the stage-sequential process for multiple latent class variables. We now explore the stage-sequential process of multiple latent class variables using the multivariate latent class profile analysis (MLCPA). A latent profile variable, representing the stage-sequential process in MLCPA, is formed by a set of repeatedly measured categorical response variables. This paper proposes the extended MLCPA in order to explain an association between the latent profile variable and the latent group variable as a form of a two-dimensional contingency table. We applied the extended MLCPA to the National Longitudinal Survey on Youth 1997 (NLSY97) data to investigate the association between of developmental progression of depression and substance use behaviors among adolescents who experienced Authoritarian parental styles in their youth.