• Communications for Statistical Applications and Methods
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• 제27권3호
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• pp.285-299
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• 2020

In many cases, we are interested in identifying independence between variables. For continuous random variables, correlation coefficients are often used to describe the relationship between variables; however, correlation does not imply independence. For finite discrete random variables, we can use the Pearson chi-square test to find independency. For the mixed type of continuous and discrete random variables, we do not have a general type of independent test. In this study, we develop a independence test of a continuous random variable and a discrete random variable without assuming a specific distribution using kernel density estimation. We provide some statistical criteria to test independence under some special settings and apply the proposed independence test to Pima Indian diabetes data. Through simulations, we calculate false positive rates and true positive rates to compare the proposed test and Kolmogorov-Smirnov test.

• Communications for Statistical Applications and Methods
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• 제8권1호
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• pp.51-63
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• 2001

We are interested in the conditional independence in sparse $2\tims2\tims$K tables with very rare cell counts. The most popular test is Cochran-Mantel-Haenszel statistic when sample sizes are moderately large enough to guarantee the chi-square approximation. We will consider jackknifing the CMH test and also suggest an approximate normal distribution for the standardized jackknifed CMH statistic. The main focus of this paper is to improve the chi-squared approximation to the CMH test by using the asymptotic normality of the jackknifed CMH test when sample sizes are very sparse but K and N$\infty$. The performance of the proposed jackknifed test, in the sense of significance level control and power, will be compared with that of the CMH test through a Monte Carlo study.

• 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.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2000년도 추계학술발표회 논문집
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• pp.33-38
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• 2000

Krishnamoorphy and Raghavarao(1993) invented exact binomial and asymptotically normal test procedures for truthful answering in the repeated randomized response models under the assumption that two repeated response measures are independent. Under the same assumption, Lakshmi and Raghavarao(1992) suggested asymptotic chi-square test for respondents' truthful answering in the same models. In this article we detect the factors and the conditions with which two response variables might be independent, and find the condition for independence in the repeated randomized response models with considering untruthful answer. But, the condition of independence make the randomized model no meaning. Under the assumption of conditional independence between two response variables, we can apply the same logical statements on deriving the tests for truthful answering in the repeated randomized response models as in Krishnamoorphy and Raghavarao(1993).

• Communications for Statistical Applications and Methods
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• 제19권3호
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• pp.495-500
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• 2012

We consider a Bayesian test of independence in a two-way contingency table that has some zero cells. To do this, we take a three-stage hierarchical Bayesian model under each hypothesis. For prior, we use Dirichlet density to model the marginal cell and each cell probabilities. Our method does not require complicated computation such as a Metropolis-Hastings algorithm to draw samples from each posterior density of parameters. We draw samples using a Gibbs sampler with a grid method. For complicated posterior formulas, we apply the Monte-Carlo integration and the sampling important resampling algorithm. We compare the values of the Bayes factor with the results of a chi-square test and the likelihood ratio test.

• 사상체질의학회지
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• 제21권1호
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• pp.79-84
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• 2009

1. Objectives This study was proposed to use the test-retest method to verify the independence and agreement between the questions (Short Form Sasang Classification Questionnaire for American ; SF_SSCQ-A). 2. Methods The questionnaire was administered to 50 American and they were asked to complete the questionnaire again two weeks after the first administration. The final subjects are 42 except of 5 dropouts and 3 insufficient respondents. A reliability analysis for each individual question was conducted using the test-retest method to verify the independence and agreement between the questions. To verify independence, a Chi-square test with crosstabs analysis and p-values was used. The agreement verification was conducted by using the Cohen kappa coefficient. In addition, the constitutional variable was defined as the constitutional attribute of each question, and Pearson's correlation coefficient was confirmed after testing the scale. 3. Results and Conclusions The test-retest method showed that Pearson's correlation coefficients for the results of the two tests ranged from 0.66 to 0.87. The Chi-square test results indicated that there are 7 independent item. Among the other 114 questions, the agreement test revealed that 88 questions (70.5%) showed above common agreement.

• 응용통계연구
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• 제28권6호
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• pp.1245-1255
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• 2015

본 논문에서는 한국 유가증권시장의 시가총액 상위 8개사 주가 수익률 절대값(absolute return)을 이용하여, 분포의 적합도 검정(goodness of fit test) 및 기업들 간의 독립성 검정(independence test)을 실시하였다. 검정 결과 개별 주가 수익률은 압축된 지수분포(compressed exponential distribution)를 이루는 것으로 나타났다. 이 때 파라미터는 1 < ${\beta}$ < 2 인 경우가 ${\beta}=1$(지수분포), ${\beta}=2$(정규분포)보다 우세한 것으로 확인되었다. 한편 독립성 검정에서는 대부분의 기업들이 관련성을 지니고 있는 것으로 나타났다.

• Journal of the Korean Statistical Society
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• 제25권3호
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• pp.381-391
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• 1996

In the analysis of contingency table with ordered categories, the relationship between odds for adjacent categories has received con-siderable interest. We consider likelihood ratio tests of independence against an order restriction on odds in 2 $\times$ k contingency tables.

• 응용통계연구
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• 제16권2호
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• pp.455-467
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• 2003

소표본 분할표 자료에서 적합도 검정통계량들의 카이제곱 근사 적용 가능에 대하여 많은 연구가 진행되었다. 소표본에서 세 가지 검정 통계량(피어슨 카이제곱 Χ$^2$, 일반화 가능도비 G$^2$, 그리고 역발산 Ι(2/3) 검정통계량)에 관하여 비교한 Rudas(1986)의 연구를 확장하여, 최근에 제안된 차이측도(BWHD(1/9), BWCS(1/3), NED(4/3) 검정통계량)를 포함시켜 비교 분석하였다. 독립모형의 이차원 분할표, 조건부 독립모형과 한 변수 독립 모형을 따르는 삼차원 분할표에 대한 모의실험을 통하여 생성된 90과 95 백분위수와 이에 대응하는 95% 신뢰구간을 살펴보고 실제 백분위수와 비교하였다. 그 결과 Χ$^2$, Ι(2/3), 그리고 BWHD(1/9) 검정통계량이 유사한 결과를 나타내었고 이 통계량들이 기존에 제안된 검정통계량들보다 적은 표본크기에서도 카이제곱 근사방법에 적용 가능함을 발견하였다.

• 국제학술발표논문집
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• The 10th International Conference on Construction Engineering and Project Management
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• pp.231-237
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• 2024

The global shift towards sustainable energy practices underscores the importance of residential photovoltaic (PV) adoption, a trend that has been gaining more attention in Hong Kong. Despite this, existing research in this area lacks quantitative analysis, with a particular deficiency in statistically robust surveys across diverse residential sectors in Hong Kong and in comparative studies between PV installers and non-PV installers. Addressing these gaps, this study employed a comprehensive questionnaire survey to collect data from a representative sample of both PV installers and non-PV installers regarding their housing types and homeownerships, followed by chi-square tests of independence to explore the demographic distinctions influencing residential PV adoption. The findings highlight significant variance in adoption rates between homeowners and tenants, with a noticeable inclination for PV installation among owners of independent houses. In contrast, co-tenants in residential flats demonstrated a lower propensity for PV adoption. These insights provide a crucial understanding of the factors that affect PV system uptake and could inform the formulation of targeted policies to boost renewable energy integration in urban residential settings.