• Communications for Statistical Applications and Methods
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• 제12권3호
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• pp.635-642
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• 2005

In statistical diagnostics a large number of influence measures have been proposed for identifying outliers and influential observations. However it seems to be few accounts of the influence diagnostics on test statistics. We study influence analysis on the likelihood ratio test statistic whether the two sets of variables are uncorrelated with one another or not. The influence of observations is measured using the case-deletion approach, the influence function. We compared the proposed influence measures through two illustrative examples.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제4권1호
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• pp.7-18
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• 1997

Consider an $r\;\times\;c$ contingency table under the full multinomial model in which each classification is ordered. The problem is to test the null hypothesis of independence. A number of tests have been proposed for this problem. In this article we show that all of these tests can be improved on in some sense for most cases. In fact the preceding tests sometimes are inadmissible in a strict sense. Furthermore, we show by example that in some cases improved tests can yield substantially improved power functions.

• 응용통계연구
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• 제19권2호
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• pp.361-368
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• 2006

이차원 범주형 자료를 시각적으로 표현하는 이차원과 삼차원 그래프는 많이 존재한다. 그중에서 Li등(2003)은 삼차원 그래프를 이차원 평면에 투영시키는 다이아몬드 그래프를 제안하였다. 여기서 세번째 차원은 면적과 높이 그리고 길이가 관찰값에 대응하는 다이아몬드 모양으로 대체하였다. 본 논문에 서는 이차원 자료에 대하여는 두 범주형 변수의 독립성을 검정하기 위하여 다이아몬드 그래프를 이용한다. 그리고 삼차원 이상의 자료에 대해서는 자료에 가장 적합한 로그선형모형을 설정하는데 활용할 수 있다.

• Human Ecology Research
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• 제59권3호
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• pp.401-418
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• 2021

The purpose of this study was to test the effects of Practical Problem-Based Home Economics Instruction (PPBHEI) on middle school students' creativity, focusing on the content on "clothing management and recycling." This study carried out quasi-experimental research with an independent variable of PPBHEI and a dependent variable of creativity. The experiment was based on a sample of 62 (31 in each group) second grade students in the Cheongju area over four class hours. ANCOVA was performed to examine pre-test and post-test differences between the experimental group and the control group. The results showed that PPBHEI did not improve the level of creativity but improved the level of creative motivation among the sub-elements of creativity (creative thinking, creative tendency, creative motivation). In particular, PPBHEI improved the level of independence in creative tendency, intrinsic motivation, and diligence in creative motivation. From the results of this study, it can be concluded that PPBHEI is effective in improving independence, intrinsic motivation, and diligence in respect of middle school students'creativity.

• Journal of the Korean Data and Information Science Society
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• 제11권1호
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• pp.83-90
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• 2000

이원분할표의 두 범주형 변수에 대한 독립성을 검정할 때 흔히 카이제곱 검정통계량이 사용된다. 표본추출 모형이 다항이나 곱다항인 경우 이 검정통계량이 독립성 가정하에서 근사적으로 카이제곱 분포를 따르게 되는 것은 잘 알려진 사실이다. 두 주변값이 모두 주어진 경우 독립성 가정하에서 표본추출 모형은 다중 초기하분포가 되며 앞의 모형과 마찬가지로 카이제곱 통계량에 근거한 검정을 사용할 수 있다. 이 연구에서는 주변값이 주어진 경우에 카이제곱 통계량의 소표본 분포를 대표본 분포인 카이제곱 분포와 비교하고자 한다. 표본크기가 작은 몇 개의 경우에 대해 카이제곱 통계량의 소표본 분포를 직접 계산해보았다. 표본크기가 큰 몇 개의 경우는 간단한 몬테칼로 알고리듬을 통해 소표본 분포를 생성하고 카이제곱 확률도와 콜모고로브-스미노브 단일표본 검정을 이용하여 대표본 분포와의 일치성을 알아보았다.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2001년도 추계학술대회
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• pp.13-16
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• 2001

We compare methods for detecting influential observations that have a large influence on the likelihood ratio test statistics that the two sets of variables are uncorrelated with one another. For this purpose we derive results of the deletion diagnostic, the influence function, the standardized influence matrix and the local influence. An illustrative example is given.

• The Journal of Asian Finance, Economics and Business
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• 제7권12호
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• pp.11-19
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• 2020

This study examines the factors that affect firm's liquidity in manufacturing companies listed in Vietnam. Factors studied include the board size, the board independence, the firm size, the firm age, and its return. We use different metrics to measure firm's solvency status, including the cash ratio, the quick ratio, and the cash conversion cycle. Accordingly, three econometric models are built to test hypotheses proposed by researchers in order to explain the relationship between the five factors above and liquidity's measures. The study used the data set of manufacturing companies listed on the Ho Chi Minh City Stock Exchange in the period from 2015 to 2019. The final sample group comprises 139 firms with 633 observations. The results show that in manufacturing firms, while the cash ratio and the quick ratio are positively associated to the board size, the board independence, and the firm's profitability, the net operating cycle is negatively correlated to the board size, the firm size, the board independence, and the profitability. Therefore, larger firms with larger board size and more independent members can help to improve capital management efficiency.There is no evidence for the relationship between the firm age and solvency measurements, between cash conversion cycle and firm's profitability.

• 한국전자통신학회논문지
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• 제10권4호
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• pp.527-532
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• 2015

국내 섬지역의 전력 수급은 계통 연계가 어려워 일반적으로 디젤 발전기에 의존하고 있어 관리 비용이 매우 높다. 이러한 문제를 해결하기 위해 최근 계통 독립형 마이크로그리드 기술에 대한 연구 및 실증이 활발히 진행 중이다. 본 논문은 에너지 자립섬을 위한 계통 독립형 마이크로그리드 통합 모니터링 시스템을 제안한다. 먼저 태양광, 풍력, 디젤 발전설비, 송 배전망의 상태 및 부하, 그리고 에너지 저장 시스템의 모니터링을 위한 소프트웨어 시스템 아키텍처를 설계한 후 관리자가 쉽게 파악할 수 있는 모니터링 소프트웨어를 구현한다. 구현된 모니터링 소프트웨어는 발전설비의 상태 및 오류를 실시간으로 시각화함으로써 관리자의 신속한 의사 결정이 가능하다.

• 한국과학교육학회지
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• 제19권3호
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• pp.471-478
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• 1999

In this study, the relationships among learners' cognitive variables, motivational variables, and conceptual understandings in learning with analogy were investigated. The instruments regarding analogical reasoning ability, field dependence-independence, mental capacity, and logical thinking ability were administered. Some subtests (self-efficacy, expectancy, self-concept of ability, and value) of the Patterns of Adaptive Learning Survey were administered. After students learned with a worksheet that included analogy, a conception test regarding 'stoichiometry that included limiting reagent' was also administered. It was found that learners' conceptual understandings were significantly correlated with the logical thinking ability and the field dependence-independence among the cognitive variables, and the self-efficacy and the self-concept of ability among the motivational variables. The multiple regression analysis of the cognitive variables on conceptual understandings revealed that the logical thinking ability was the most significant predictor. The field dependence-independence also had predictive power. In the analysis of the motivational variables, the self concept of ability was the only significant predictor.

• The Journal of Asian Finance, Economics and Business
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• 제7권9호
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• pp.159-168
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• 2020

This is a quantitative research, underpinned by the philosophy of natural science and deduction approach that examines the impact of the various aspects of corporate governance mechanism on the choice of capital structure of Vietnamese listed firms. We focus on the effect of factors such as the board size, the board independence, and especially different ownership structures, which include the managerial ownership, the state ownership, the concentrated ownership, and the foreign ownership. They are the main scopes of corporate governance and are supposed to be relevant to determine the corporate financing choice. To explain the causal relationship between factors, we construct the regression model and then test it by using different statistical method approaches, including the pooled OLS, the fixed effects model, and the random effects model. Data are collected from 336 firms with shares listed in the Ho Chi Minh City Stock Exchange in Vietnam, totaling 1583 observations. Overall, the results reveal that the board size, state ownership, and concentrated ownership have positive impact on the firm's capital structure, whereas foreign ownership appears to have negative influence on the capital structure. The research does not find evidence of a the correlation between board independence, managerial ownership and corporate capital struture.