• 사상체질의학회지
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• 제28권1호
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• pp.51-56
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• 2016

Objectives This study was to identify the types of errors in the statistical analysis and trends of previous reported papers that used various statistical techniques.Methods We have selected 118 original articles for statistical review from the OASIS(http://oasis.kiom.re.kr) and the Pubmed(http://www.pubmed.gov) in the field of Sasang constitutional medicine. Published year was restricted from 2011 to 2015.Results 1. The ANOVA(25.72%) was the statistic of choice overall, followed by the chi-square test(21.74%), regression analysis(14.13%), t-test(11.59%), and etc. 2. By examining the errors of the statistical methods, there were 42(59.2%) thesis with errors among 71 thesis using ANOVA, 19(31.7%) thesis among 60 thesis using chi-square test, and 35(89.7%) over 39 thesis using regression analysis.Conclusions To improve the quality of Sasang Constitution, the participation of statisticians in research design will reduce the significant errors in statistical interpretation of the results.

• 응용통계연구
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• 제27권1호
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• pp.115-122
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• 2014

이 논문에서는 이진확률수열의 무작위성을 검정하는 방법을 제안한다. 연의 길이는 절사된 기하분포를 따르는데 제안하고자 하는 검정통계량은 연의 평균길이를 기초로 하고 있으며 표본크기가 커지면 점근적으로 ${\chi}^2_2$-분포를 따른다. 검정크기와 검정력을 비교하기 위해 몬테칼로모의실험을 실시했다. 로또 6/45에서의 추첨여부에 대한 수열에 적용해 보았으며 로또는 무작위성을 만족하는 것으로 나타났다.

• 성인간호학회지
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• 제14권3호
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• pp.390-400
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• 2002

Purpose: This study was to prepare the basic data for prevention of colorectal cancer and protection against its spread. Method: The subjects for the study were 204 patients with colorectal cancer from the G.S. wards of five general hospitals in Busan for the period of June 1 to September 1, 2001. The instrument used was a questionaire which was developed by Junho Shin(1995). The data was analyzed by descriptive statistics, McNemar test, ${\chi}^2$ test, paired t-test, and ANOVA. Result: 1. 57% of the studied subjects were male, 42.7% were more than 60 years old, 54.9% were of standard physique, 49.5% were the Buddhists, 50.5% were the middle or high school graduates, 83.8% were city dwellers, 48% were jobless, 69.6% had no-history of alimentary disease, 44.1% had no-family history of cancer, 82.8% were married. 2. Constipation (${\chi}^2=36.45$, p=0.0001) in clients showed a significant positive association for the prediagnosed, but diarrhea(${\chi}^2=3.947$, p=0.047) showed a significant positive association for the post-diagnosed. The preference for high seasonings(t=6.23, p=0.0001) and animal fat (t=8.35, p=0.0001) was higher significantly in the pre-diagnosed, but physical activities(${\chi}^2=30.22$, p=0.0001), an eutrophic or tonic medicine(${\chi}^2=30.22$, p=0.0001), was of and vegetables(t=-6.20, p=0.0001) was higher significantly in the post-diagnosed. 3. There were significant differences in the life style of the pre-diagnosed according to the general characteristics except religion. Conclusion: Results of the above study reveal we should be very sensitive to the change of defecation styles and consider the necessity of improving life styles as regards eating habits. When an education program is developed, the general characteristics of the subjects need to be considered.

• Communications for Statistical Applications and Methods
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• 제1권1호
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• pp.81-86
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• 1994

A Chi-square approximation to the distribution of product of independent Beta variates denoted by U is developed. The distribution is commonly used as a test criterion for the general linear hypothesis about the multivariate linear models. The approximation is obtained by fitting a logarithmic function of U to a Chi-square variate in terms of the first three moments. It is compared with the well known approximations due to Box(1949), Rao(1948), and Mudholkar and Trivedi(1980). It is found that the Chi-square approximation compares favorably with the other three approximations.

• Journal of the Korean Data and Information Science Society
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• 제24권4호
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• pp.815-824
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• 2013

국가단위의 조사와 같은 대규모 표본조사에서는 표본의 대표성을 확보하기 위해 층화, 집락, 계통, 불균등확률추출 등을 종합적으로 사용하는 복합표본설계가 일반화되어 있다. 이러한 복합표본설계에 기초한 범주형 자료분석에서는 자료의 독립성과 다항분포를 가정하는 전통적인 피어슨검정이 왜곡된 검정결과를 가져올 수 있다. 본 연구는 복합표본설계에 의한 범주형조사자료의 k-모집단 동질성검정에서 설계기반 일치통계량인 Wald 검정통계량을 유도하고, 전통적인 피어슨검정통계량을 사용할 경우 발생할 수 있는 오차요인을 항목별로 분해하여, 분산의 편의에 의한 영향, 추정량의 편의에 의한 영향, 기타 분산의 편의와 추정량의 편의가 교락되어 미치는 영향으로 각각 분해하는 식을 도출하였다. 또한, 도출된 식의 각 항목이 피어슨 카이제곱검정통계량에 미치는 상대적 크기를 경험적으로 확인하기 위해 국민건강영양조사 제4기 2차년도 자료를 이용해 경험분석 하였다. 분석결과, 변수에 따른 차이는 있지만 대체로 분산의 편의가 미치는 영향이 추정량의 편의가 미치는 영향보다 크다는 것을 명확히 확인할 수 있었다.

• 수산해양기술연구
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• 제32권2호
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• pp.157-163
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• 1996

To ceramic film, $SiO_2$ and $Al_2O_3$, coated on pure Fe and stainless steel(SUS41O) by RF magnetron sputtering, the adherence between mm and substarte was studied. The adherence index (${\chi}$) was determined by the measure of micro hardness test. Also, the corrosion resistance on oxide coatings was studied using electrochemical measurement. The main results obtained are as the following: 1) In the micro-hardness test, with $1{\mu}m$ thickness mm, it has only one the value of ${\chi}$. Above $2{\mu}$thickness fIlm, however, get another value of ${\chi}$as the cracks in fIlm. 2) The oxide fIlm adhere well on the mild materials such as pure steel than high intensity materials like stainless. 3) Alumina($Al_2O_3$) coated materials have better corrosion resistance than silica($SiO_2$)coated materials

• Corrosion Science and Technology
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• 제9권5호
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• pp.209-215
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• 2010

To elucidate the effect of aging time on resistance to localized corrosion of hyper duplex stainless steel, a double-loop electrochemical potentiokinetic reactivation test a potentiodynamic anodic polarization test, a scanning electron microscope-energy dispersive spectroscope analysis, and a thermodynamic calculation were conducted. With an increase in aging time, sigma phases are precipitated much more than chi phases due to the meta-stable chi phase acting as a transition phase. As aging time at $850^{\circ}C$ increases, the corrosion resistance decreases owing to an increase in Cr, Mo and W depleted areas adjacent to the intermetallic phases such as sigma phases and chi phases.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.223-226
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• 2009

Recently, Mining negative association rules has received some attention and proved to be useful. Negative association rules are useful in market-basket analysis to identify products that conflict with each other or products that complement each other. Several algorithms have been proposed. However, there are some questions with those algorithms, for example, misleading rules will occur when the positive and negative rules are mined simultaneously. The chi-squared test that based on the mature theory and Correlation Coefficient can avoid the problem. In this paper, We proposed the algorithm PNCCR based on chi-squared test and correlation is proposed. The experiment results show that the misleading rules are pruned. It suggests that the algorithm is correct and efficient.

• 산업기술연구
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• 제36권
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• pp.71-76
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• 2016

In this study, we determined the precise coordinates of TBMs (Tidal Bench Marks), which used as the national reference points in coastal area of Korea, using a GPS data analysis SW for the academic and scientific applications, GAMIT/GLOBK. For accurate 3-D positioning of TBM locations, we performed the GPS point surveying according to the national surveying policy and also acquired the GPS data for 48 TBMs located in the western and southern coastal part of Korea. Considering the results of baseline analysis to each observation session obtained from GAMIT module, the baseline analysis was realized to be done precisely because the values of Normalized RMS (NRMS) were mostly less than ${\pm}0.20mm$. Before the network adjustment using GLOBK module, we evaluated the suitability of observations for each session by applying the chi-squared test (${\chi}^2$ test) to the degree of freedom in observed session. An overall distributions of ${\chi}^2$ test were less than 1.0 for all sessions, and the statistical of ${\chi}^2$ test showed the average, 0.267 with minimum and maximum value, 0.063 and 0.653, respectively. Finally, we analyzed the network adjustment for 48 TBMs to reduce the residuals of baseline analysis on each point by connecting with 42 permanent GPS stations in Korea. In the network adjustment procedure, we set up the weighted values of each permanent station to be allocated between 0.9 and 1.14, and also removed the observed points having residual exceeds 4-times of standard deviation ($4{\sigma}$).

• 한국컴퓨터정보학회논문지
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• 제10권6호
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• pp.65-74
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• 2005

본 논문에서는 비디오의 자동분류를 지원하기 위한 기반기술로서. 변형된 $x^{2}$-테스트와 자동 임계치 결정 알고리즘을 이용한 장면전환 검출 방법을 제안하였다. 변형된 $x^{2}$-테스트는 기존의 컬러 히스토그램과 각 채널 공간(RGB)에 NTSC표준에 따른 명암도 등급을 따로 계산하여 채널의 차이 값을 보다 세분화 할 수 있으며, 두 프레임사이의 상대적인 컬러 값 차이를 강조하는 기존의 $x^{2}$-테스트를 결합하여 보다 강건한 장면전환을 검출할 수 있다. 자동 임계치 결정 알고리즘은 연속된 프레임들로부터 변형된 $x^{2}$-테스트를 이용하여 추출된 차이 값을 이용한다. 먼저, 주어진 전체 차이 값들로부터 평균과 표준편차를 구하며, 이 평균값을 만족하는 차이 값들로부터 다시 평균과 표준편차를 계산하며, 이러한 연속적인 평균값 및 표준편차의 계산으로부터 표준편차가 가장 큰 시점에서의 평균값을 기준으로 임계치를 결정하는 방법이다. 제안된 방법은 다양한 비디오 데이터에서 실험되었으며, 실험결과 제안된 방법은 자동 임계치 결정에 효율적이며, 신뢰할만한 장면들을 검출하였다.