• Computers and Concrete
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• 제10권3호
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• pp.307-330
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• 2012

This work intends to contribute for the improvement of the procedure suggested by Brazilian Technical Code that takes into account the cracked concrete stiffness in the estimative of the displacement of reinforced concrete beams submitted to service loads. A damage constitutive model accounting for induced anisotropy, plastic deformations and bimodular elastic response is used in order to simulate the concrete behaviour, while an elastoplastic behaviour is admitted for the reinforcement. The constitutive models were implemented in a program for bars structures analysis with layered finite elements. Initially, the damage model is briefly presented as well as the parametric identification of the materials that have been used in the reinforced concrete beams. After that, beams with different geometries and reinforcement area are analyzed and a statistical method (ANOVA) is employed in order to identify the main variables in the problem. Soon after, the same procedure is used with another resistance of concrete, where the compression strength is changed. The numerical responses are compared with the ones obtained by Brazilian Technical Code and experimental tests in order to validate the use of the damage model. Finally, some remarks are discussed based on responses presented in this work.

• 한국의류학회지
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• 제48권3호
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• pp.467-484
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• 2024

This study aimed to enhance the design of cropped t-shirts to improve fit satisfaction among women in their 20s by tailoring the t-shirts to diverse body types. Body types were categorized using Size Korea's 8th Human Body Measurement Data, and statistical analysis was conducted based on the Statistical Package for the Social Sciences (version 26.0). This study also reviewed the literature on t-shirts and fit, the application of pattern and design improvements for different body types, verifying fit and size for each body type, and applying virtual fit effects using geometric forms. Frequency analysis and non-parametric verification were conducted using the Friedman test. The results showed that t-shirts with a horizontal rectangular shape was an effective design and that t-shirts with an inverted triangular structure also had a positive effect. In contrast, square t-shirts exhibited minimal effectiveness. These findings are expected to contribute to the consideration of customized shapes according to body type in t-shirt design. Research on customized virtual cropped t-shirts reflecting various body types can expand fit satisfaction studies, particularly amid the increasing trend of online shopping.

• Journal of the Korean Data and Information Science Society
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• 제27권2호
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• pp.373-380
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• 2016

리커트형 데이터가 순서척도임에도 불구하고 많은 연구자들이 구간척도로 간주하여 모수 방법을 적용하고 있다. 본 연구에서는 리커트형 데이터를 어떻게 분석하는 것이 적절한지 모의 실험을 통하여 알아본다. 다양한 분포를 갖는 5점 리커트형 표본을 추출하여 위치를 비교하고, 순서척도의 경우 위치비교 보다 응답분포를 살펴보는 것이 더 타당하므로 응답분포 검정을 실시한다. 위치를 비교하는 방법으로는 구간척도로 생각하고 분석하는 모수 방법인 t-검정과 순서척도로 생각하는 비모수 방법인 만- 휘트니검정 (M-W검정)을 적용하고, 응답분포를 검정하기 위해서는 카이제곱 검정과 콜모고로프 - 스미르노프검정 (K-S검정)을 실시한다. 네 가지 방법의 효율성을 비교하기 위하여 제 1종 오류 (Type I error)의 비율과 검정력 (power)을 구한다.

• 대한산업공학회지
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• 제23권4호
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• pp.755-767
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• 1997

Analyzing autocorrelated data set is still an open problem. Developing on easy and efficient method for severe positive correlated data set, which is common in simulation output, is vital for the simulation society. Bootstrap is on easy and powerful tool for constructing non-parametric inferential procedures in modern statistical data analysis. Conventional bootstrap algorithm requires iid assumption in the original data set. Proper choice of resampling units for generating replicates has much to do with the structure of the original data set, iid data or autocorrelated. In this paper, a new bootstrap resampling scheme is proposed to analyze the autocorrelated data set : the Threshold Bootstrap. A thorough literature search of bootstrap method focusing on the case of autocorrelated data set is also provided. Theoretical foundations of Threshold Bootstrap is studied and compared with other leading bootstrap sampling techniques for autocorrelated data sets. The performance of TB is reported using M/M/1 queueing model, else the comparison of other resampling techniques of ARMA data set is also reported.

• 한국수학사학회지
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• 제34권1호
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• pp.21-37
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• 2021

The purpose of the present study is to compare the differences in levels per group of high school students regarding the self-regulated learning factors for mathematics. For this purpose, a self-regulated learning measurement tool was developed and surveys were conducted. And the statistical analysis was completed using the frequency analysis, Kolmogorov-Smirnov normality test, Mann-Whitney U test and the Kruskal-Wallis H test. As a result, it is found that self-efficacy is of statistically significant differences in self-regulated learning levels regardless of the group classifications but test anxiety does not show statistically significant differences in self-regulated learning levels regardless of the group classifications.

• 동의생리병리학회지
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• 제22권1호
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• pp.189-193
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• 2008

We analyzed the research type and statistical methods in Korean Journal of Oriental Physiology and Pathology for describing the trends of Oriental medicine research. The data for the analysis of trends in Oriental medicine research was taken from a total 808 articles published in Korean Journal of Oriental Physiology and Pathology from 2004 to 2006. We surveyed the number of authors, the institutes involved in each study, and used languages in each study. Also we seperated by epidemiological study design, the studies into categories and statistical methods into 13 categories. Results showed that descriptive statistics was used in 125(14.4%) papers. Also t-test, analysis of variance, multiple comparison, chi-square test, and non-parametric test were used in 338(38.9%), 147(16.9%), 81(9.3%), 27(3.1%), 23(2.6%) papers, respectively. And 62(7.1%) papers of the involved papers didn't use statistical methods. To improve the quality of Oriental medicine related articles, we have to use proper statistical methods with consultation of statistician or other experts before accepting a manuscript are needed.

• Animal cells and systems
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• 제14권3호
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• pp.225-236
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• 2010

We compared the composition of phospholipid fatty acids (PLFA) to assess the microbial community structure in the soil and rhizosphere community of non-transgenic watermelons and transgenic watermelons in Miryang farmlands in Korea during the spring and summer of 2005. The PLFA data were seasonally examined for the number of PLFA to determine whether there is any difference in the microbial community in soils from two types of watermelons, non-transgenic and transgenic. We identified 78 PLFAs from the rhizosphere samples of the two types of watermelons. We found eight different PLFAs for the type of plants and sixteen PLFAs for the interaction of plant type and season. The PLFA data were analyzed by analysis of variance separated by plant type (P<0.0085), season (P<0.0154), and the plant type${\times}$season interaction (P<0.1595). Non-parametric multidimensional scaling (NMS showed a small apparent difference but multi-response permutation procedures (MRPP) confirmed that there was no difference in microbial community structure for soils of both plant types. Conclusively, there was no significant adverse effect of transgenic watermelon on bacterial and fungal relative abundance as measured by PLFA. We could reject our hypothesis that there might be an adverse effect from transgenic watermelon with our statistical results. Therefore, we can suggest the use of this PLFA methodology to examine the adverse effects of transgenic plants on the soil microbial community.

• 한국산학기술학회논문지
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• 제18권6호
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• pp.110-118
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• 2017

본 논문은 재무관리 이론에서 현재까지 논의가 지속되고 있는 국내 유가증권시장 상장기업들의 최적자본구조 존재여부에 대한 실증론적 연구이다. 최적자본구조에 대한 주요 이론적 논리인 자금조달이론, 상충이론, 그리고 대리인 이론 등을 전제로, 모수적 그리고 비모수적 방법을 활용한 공분산모형의 분석을 통하여 표본기업들의 최적자본구조 존재 여부를 검정하였다. 구체적으로는, 상충이론과 대리인비용이론과 관련된 통제변수들이 해당모형에서 각각 활용되었으며, 이는 최적자본구조 존재를 위한 산업 간 그리고 산업 내 분석 자금조달이론 통제변수를 활용한 기존의 연구와도 대비될 수 있다. 연구결과 관련, 표본산업을 활용한 산업들 간 분석에서는 최적자본조가 존재하는 것으로 실증적으로 검정된 반면, 산업 내 분석에서는 해당 기업들 간의 통계적인 측면에서 최적자본구조가 존재하지 않는 것으로 나타났다. 이와 부합하여, 본 연구에서 도출된 결과가 잠재적인 투자가들의 측면에서 의미할 수 있는 바는, 향후 국내 기업들이 해당 산업 내의 최적부채비율에 점진적으로 접근할 경우, 기업가치 증대를 위한 재무적 기회가 상존한다는 것이다.

• 한국ITS학회 논문지
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• 제21권5호
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• pp.103-116
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• 2022

국토교통부는 원활한 자율주행자동차 서비스 확대를 위해 총 7개 지역을 자율주행자동차 시범운행지구로 지정·고시하여 매년 운영성과에 대한 평가를 받도록 하였다. 본 연구는 이를 위한 기초연구로서 자율주행자동차 서비스의 정성적 만족도를 설문조사 기반으로 평가하였다. 첫째, 세종시 자율주행 서비스 이용자와 일반인을 대상으로 자율주행 서비스 인식에 대한 설문조사를 실시하였다. 그 결과, 자율주행 서비스 이용자가 자율주행 기술에 대한 단계 인지, 이용 의향 등이 일반인에 비해 높게 나타났다. 둘째, 수요대응형 대중교통 서비스 이용자와 세종시 자율주행 서비스 이용자를 대상으로 서비스 만족도 설문조사를 실시하였다. 비모수통계분석 방법 중 윌콕슨 순위합 검정(Wilcoxon Rank Sum Test)을 통한 분석 결과, 자율주행 서비스 이용자의 경우 안전과 관련된 요인들이 전반적인 만족도에 영향을 미치는 것으로 나타났다. 반면, 수요대응형 대중교통 서비스 이용자들은 서비스 편의성과 관련된 항목들이 전반적인 만족도에 영향을 미치는 것으로 나타났다. 이러한 설문조사 결과는 향후 자율주행 서비스의 개선사항 및 정책수립에 대한 기초자료로 활용이 기대된다.

• 응용통계연구
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• 제21권6호
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• pp.969-980
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• 2008

본 연구에서는 한우의 연도, 다즙성, 향미, 전반적인 기호도에 관한 소비자 관능평가 데이터를 기반으로 소비자 맛 등급을 판별하는 방법을 비교 연구하였다. 판별방법으로는 선형판별, 이차판별, 정준판별, 비모수적 판별방법을 사용하였고, 재대입 방법에 의한 분류율을 측정하여 판별방법들의 분류능력을 비교하였다.