• Journal of Periodontal and Implant Science
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• 제30권3호
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• pp.699-707
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• 2000

The purpose of this study was to analyze the statistical errors of articles in the Journal of Korean Academy of Periodontology from 1973 to 1999. Of the 662 articles examined, 263 were included which analyzed the data. They were classified into 2 groups with time lapse; group 1: 1973∼1989, group 2: 1990∼1999. Authors made checklists for analyzing the data and detecting the errors and analyzed them with professional statistician. The results were as follows: 1. Of 263 atricles which applied statistical method, 40(19.3%) was in group 1, 223(49.0%) in group2. 2. In the number of statistical method applied, 170(64.6%) were analyzed with 1 statistical method, 73(27.8%) with 2 methods, 18(6.8%) with 3 methods, and 2(0.8%) with 4 methods 3. The number of statistical methods applied was 14, and they were applied in order of 119 of ANOVA, 72 of Student t-test, 63 of Paired t-test, 36 of CORRELATION, and 21 of Mann- Whitney U test. 4. In 87(33.1%) of 263 articles and in 18 error items, statistical errors were found out. In group I, 9 items (55%) of error were found out, and were in order of 5 of Student t-test instead of Paired t-test, and 4 of unnecessary statistical analysis. In group II, 16 items (29.1%) of error were found out, and were in order of 22 of Student t-test instead of Paired t-test, 7 of no multiple comparison test after ANOVA, 6 of Student t-test instead of ANOVA, 6 of unnecessary statistical analysis, and 5 of ANOVA instead of Paired t-test. In conclusion, the results noted that statistical analyses were increased, but statistical errors were decreased with time. But authors suggest that researchers should refer to standard statistical texts and seek advice from professional statisticians to avoid the statistical errors.

• 한국지구과학회지
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• 제35권4호
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• pp.225-236
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• 2014

다변량통계기법은 수리지구화학 자료의 분석 및 해석에 많이 이용되어 왔다. 본 연구에서 대응분석과 주성분분석을 동시에 사용하여 인위적인 활동에 의한 지하수의 특징을 살펴보았다. 본 연구의 목적은 NETPATH 프로그램 속의 WATEQ4F를 이용하여 지하수 화학성분의 분화를 계산하고 이를 다변량통계기법을 이용하여 지구화학적인 정보를 추출하는 것이다. 연구지역은 한반도의 남동쪽에 위치한 울산의 LPG 저장시설이다. 본 연구지역에서는 다른 저장시설에서 관찰되는 초염기성의 조성을 가지는 지하수가 관찰되었다. 이러한 인위적인 영향에 의한 높은 pH를 가지는 지하수로 인해 Al의 분화특징과 탄산염의 침전을 유발할 수 있다. 본 연구에서는 연구지역에 지하수에 영향을 주는 두 인위적인 요소(세정작용와 시멘트영향)에 의해서 수리지구화학적인 특징과 상이 어떻게 변하는 가에 초점을 두었다. 이전 연구결과와 두 통계분석을 통해 제시된 결과를 비교하여 지구화학적인 정보를 이용한 주성분분석과 대응분석인 수리지구화학 연구에서 기초연구로 활용될 수 있음을 알 수 있다.

• 한국패류학회지
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• 제28권4호
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• pp.363-375
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• 2012

The gametogenic cycle, the number of spawning seasons per year and first sexual maturiity of the pen shell, Atrina (Servatrina) pectinata, were investigated by quantitative statistical analysis using an Image Analyzer System. Compared two previous results (the spawning periods in the reproductive cycles in 1998 and 2006) by qualitative histological analysis with the present results by quantitative statistical analysis, there are some differences in the spawning periods: the spawning period (June to September) by quantitative statistical analysis was one month longer than those of two previous reports (June to July or June to August) by qualitative histological analysis. However, the number of spawning seasons studied by the qualitative and quatitative analyses occurred once per year. In quantitative statistical analysis using an image analyzer system, the patterns of monthly changes in the percent (%) of the areas occupied by follicles to the ovary area in females (or that of the areas occupied by spermatogenic stages to the testis area in males) showed a maximum in May, and then sharply droped from June to September, 2006. From these data, it is apparent that the spawning season of A. (S.) pectinata occurred once a year from June to September, indicating a unimodal gametogenic cycle during the year. Shell heights of sexually mature pen shells (size at 50% of group sexual maturity, $GM_{50}$) that were fitted to an exponential equation were 15.81 cm in females and 15.72 cm in males (considered to be one year old).

• 한국수학교육학회지시리즈C:초등수학교육
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• 제22권4호
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• pp.205-221
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• 2019

이 연구는 통계적 문제해결 과정 중에 설문지 질문 생성 단계에서 나타나는 예비초등교사들의 통계적 추론을 조사하고 이것이 이후 단계들에서의 활동에 어떻게 영향을 미치는지를 분석하는 데 목적을 두었다. 이를 위해 24개 조의 교육대학교 2학년 학생들 80명이 통계적 문제해결 과정을 직접 실행하고 통계 보고서를 작성하였으며, 그 중 22개 조의 보고서를 분석하였다. 분석 결과, 설문지 질문 생성 단계에서 예비교사들의 9가지 통계적 추론이 확인되었으며, 특히 그 중 질문 명확화 지향 추론과 변이 기반 추론은 기존 연구에서 보고되지 않았던 추론이었다. 또한, 설문지 질문 생성 단계에서의 통계적 추론이 이후 단계의 활동에 미친 영향을 알아보기 위해 자료 분석 및 결론 단계에서 예비교사들이 보고서에 기술하였던 어려움 및 이슈를 확인하였다. 그 결과, 예비교사들의 어려움이 설문지 질문 생성 과정에서의 모집단 관련 추론, 범주 수준 추론, 표준화 추론, 질문의 일관성 지향 추론, 질문 명확화 지향 추론과 관련이 있는 것으로 나타났다. 그동안 선행연구에서 질문 생성하기 단계에 크게 주목하지 않았다는 점에 비추어보면, 본 연구 결과는 질문 생성 단계에서 나타나는 다양한 통계적 추론에 좀 더 주목할 필요가 있다는 점과 질문 생성 단계에서 적절한 통계적 추론이 이루어지도록 하기 위한 교수 방안들을 논의할 필요가 있다는 점을 시사한다.

• Computers and Concrete
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• 제26권4호
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• pp.351-365
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• 2020

This work presents numerical and experimental analyses of the behavior of reinforced-concrete deep beams with unconventional geometries. The main goal here is to experimentally and numerically study these geometries to find possible new behaviors due to the material nonlinearity of reinforced concrete with complex geometries. Usually, unconventional geometries result from innovative designs; in general, studies of reinforced concrete structures are performed only on conventional members such as beams, columns, and labs. To achieve the goal, four reinforced-concrete deep beams with geometries not addressed in the literature were tested. The models were numerically analyzed with the Adaptive Micro Truss Model (AMTM), which is the proposed method, to address new geometries. This work also studied the main parameters of the constitutive model of concrete based on a statistical analysis of the finite element (FE) results. To estimate the ultimate loads, FE simulations were performed using the Monte Carlo method. Based on the obtained ultimate loads, a probabilistic distribution was created, and the final ultimate loads were computed.

• 산업공학
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• 제20권3호
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• pp.339-352
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• 2007

Beyond SERVQUAL-based service quality research, we develop a measurement model of public service quality that would provide researchers and practitioners in the public sector with a foundation for systematic investigation and implementation. Firstly, we explore the attributes of public service quality that lead to customer satisfaction by using the critical incident technique (CIT). We identified four dimensions of public service qualities. We also found that the critical attributes of service quality differ according to the types of customers. Secondly, to achieve a high degree of empirical confidence, we conduct statistical tests and analyses on the classification scheme and on the attributes of service quality that we derived from the CIT analysis. Through these analyses, we could remove the redundancy among attributes and group the attributes into new constructs, which are mutually exclusive and exhaustive; we built a more sophisticated measurement model of service quality.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.672-675
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• 1995

Because of a sudden growth of the research of fatigue failure, recent machines or structures have been designed by damage tolerance design in many fields. Consequently, it is the most primary factor to clarity the specific character of fatique failure in the design of machines or structures considering reliability. A statistical analysis is required to analyze the outcome of an experiment or a life estimate by reason of that fatigue failure contains lots of random elements. Reliability analysis which has tukenn the place of the existing analyses in the consideration of the uncertainty of a material, is a very efficient way. Even reliability analysis, however, is not a perfect way to analyses the uncertainties of all the materials. This thesis would refer to a newly conceived data analysis that the coefficient of a system could cause the ambiguity of the relationship of an input and output.

• 한국경영과학회지
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• 제12권1호
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• pp.111-111
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• 1987

With the increasing interest of reducing process variation, statistical process control has served the pivotal tool in most industrial quality programs. In this study, system analyses have been performed associated with a cost incorporated version of a process control, a quadratic loss-based X over bar control chart model. Specifically, two issues, the capital/research investments for improvement of a system and the precision of a parameter estimation, have been addressed and discussed. Through the analysis of experimental results, we show that process variability is seen to be one of the most important sources of loss and quality improvement efforts should be directed to reduce this variability. We further derive the results that, even if the optimal designs may be sensitive, the model appears to be robust with regard to misspecification of parameters. The approach and discussion taken in this study provide a meaningful guide for proper process control. We conclude this study with providing general comments.

• 경영과학
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• 제12권1호
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• pp.111-124
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• 1995

With the increasing interest of reducing process variation, statistical process control has served the pivotal tool in most industrial quality programs. In this study, system analyses have been performed associated with a cost incorporated version of a process control, a quadratic loss-based X over bar control chart model. Specifically, two issues, the capital/research investments for improvement of a system and the precision of a parameter estimation, have been addressed and discussed. Through the analysis of experimental results, we show that process variability is seen to be one of the most important sources of loss and quality improvement efforts should be directed to reduce this variability. We further derive the results that, even if the optimal designs may be sensitive, the model appears to be robust with regard to misspecification of parameters. The approach and discussion taken in this study provide a meaningful guide for proper process control. We conclude this study with providing general comments.

• 한국보건간호학회지
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• 제27권1호
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• pp.76-88
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• 2013

Purpose: The purpose of this study was to identify the degree of sleep quality and its associated factors in adults. Methods: The data was collected from 986 adults aged 19 to 64 by convenience sampling. Subjects completed a questionnaire composed of Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory, and other questions that self-rated health and sociodemographic variables. Statistical methods used included descriptive statistics, simple logistic regression, and multiple logistic regression analyses. Results: The global PSQI score was 5.7. About 45% of the subjects were poor sleepers (global PSQI score >5). Multiple logistic regression analyses showed that factors significantly associated with sleep quality were depression and poor self-rated health in young and middle-aged adults. Depression was the most significant associated factor. The presence of a spouse was also associated with sleep quality in young adults. Conclusion: These findings suggest that people with poor sleep quality should have their health carefully screened for depression. In addition, we recommend the development of a nursing program for improving sleep quality.