• Title/Summary/Keyword: statistical confidence

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ANALYSIS OF UNCERTAINTY QUANTIFICATION METHOD BY COMPARING MONTE-CARLO METHOD AND WILKS' FORMULA

  • Lee, Seung Wook;Chung, Bub Dong;Bang, Young-Seok;Bae, Sung Won
    • Nuclear Engineering and Technology
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    • v.46 no.4
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    • pp.481-488
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    • 2014
  • An analysis of the uncertainty quantification related to LBLOCA using the Monte-Carlo calculation has been performed and compared with the tolerance level determined by the Wilks' formula. The uncertainty range and distribution of each input parameter associated with the LOCA phenomena were determined based on previous PIRT results and documentation during the BEMUSE project. Calulations were conducted on 3,500 cases within a 2-week CPU time on a 14-PC cluster system. The Monte-Carlo exercise shows that the 95% upper limit PCT value can be obtained well, with a 95% confidence level using the Wilks' formula, although we have to endure a 5% risk of PCT under-prediction. The results also show that the statistical fluctuation of the limit value using Wilks' first-order is as large as the uncertainty value itself. It is therefore desirable to increase the order of the Wilks' formula to be higher than the second-order to estimate the reliable safety margin of the design features. It is also shown that, with its ever increasing computational capability, the Monte-Carlo method is accessible for a nuclear power plant safety analysis within a realistic time frame.

A Study on Effects of Critical Thinking Dispositions on Vocational Personality in University Students (대학생들의 비판적 사고 성향이 직업적 성격에 미치는 영향)

  • Yune, So-Jung;Shin, Su-Jin;Lee, Eun-Young
    • Journal of Fisheries and Marine Sciences Education
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    • v.19 no.2
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    • pp.206-218
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    • 2007
  • The purpose of this study was to investigate effects of critical thinking dispositions on vocational personalities in university students. Subjects were 111 University students in Busan. The questionnaire used in this research were Holland's Vocational Personality Questionnaire and California Critical Thinking Disposition Inventory. The results were analyzed by correlation analysis and enter multiple regression using the SPSS statistical package (SPSS for windows 12.0; SPSS Inc., Chicago, IL, USA). The study results were as follow: First, the students had much more S and R vocational personality characteristics than the others in vocational personality characteristics and had higher inquisitiveness and self-confidence scores than the others in critical thinking dispositions. Second, there were significant relationships between vocational personality types and critical thinking dispositions. Third, some of the vocational personality types were affected by the critical thinking dispositions. Especially I, E, and C personality of vocational personalities were prospected by critical thinking dispositions. Therefore, It's necessary that we understand the relationships between vocational personality types and critical thinking dispositions. Also we have to think over how to development career programs for university students to match to the learner's vocational personality type and critical thinking dispositions.

A Structural Model on the Nursing Competencies of Nursing Simulation Learners (간호시뮬레이션 학습자의 간호역량에 관한 구조모형)

  • Park, Soo Jin;Ji, Eun Sun
    • Journal of Korean Academy of Nursing
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    • v.48 no.5
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    • pp.588-600
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    • 2018
  • Purpose: The purpose of this study was to test a model of nursing competencies of nursing simulation learners. The conceptual model was based on the theory of Jeffries's simulaton theory. Methods: Data collection was conducted in October 2017 for 310 students from two nursing universities in Kyungbuk area for 20 days. Data analysis methods were covariance structure analysis using SPSS 21.0 and AMOS 22.0 statistical programs. Results: The hypothetical model was a good fit for the data. The model fit indices were comparative fit index=.97, normed fit index=.94, Tucker-Lewis Index=.97, root mean square error of approximation=.44, and standardized root mean square residual=.04. Teacher factors were directly related to simulation design characteristics, and it was confirmed that the curriculum, classroom operation and teaching method of the instructors were important factors. Learner factors were found to have a direct effect on nursing competence, self-confidence, and clinical performance that belong to nursing capacity. In particular, the results of this study indicate that the simulation design characteristics have a partial mediating effect on learner factors and clinical performance, and a complete mediating effect on learner factors and clinical judgment ability. Conclusion: In order to improve the learner's clinical performance and clinical judgment ability, it is necessary to conduct practical training through nursing simulation besides preparing the learner and the educator.

Change of Critical Thinking Disposition by Applying Learning Portfolio Completion

  • Kim, Jungae
    • International Journal of Advanced Culture Technology
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    • v.8 no.2
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    • pp.12-17
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    • 2020
  • This study was a similar experimental study that analyzed the effect by applying the learning portfolio completion. The study period lasted from October 1, 2019 to November 20, 2019. A total of 47 people participated in the study, and the effectiveness of the program was analyzed with the SPSS 18.0 program for critical thinking disposition. The statistical analysis method was frequency analysis and paired t-test. As a result of the analysis, the critical thinking disposition increased significantly in the application of the learning portfolio completion (Truth-seeking MD= -0.05, p <0.01), Open-mindness MD= 0.11, p <0.001), Analyticity MD= 0.76, p <0.001), Systematicity MD= -.25, p <0.001), Self-confidence MD=-0.54, p <0.001), Inquisitiveness MD=0.29, p <0.001), Maturity MD=-.0.33, p <0.001). In conclusion, the teaching method applied with the learning portfolio completion actually helped nursing students learn nursing students learn based on critical thinking. Based on these result, further research using learning portfolio is to be done and more systematic and practical application of learning portfolio completion to nursing students. This study would be used as a basic data for the study guideline development for learners.

Comprehensive Empirical Equation for Assessing Atmospheric Corrosion Progression of Steel Considering Environmental Parameters

  • Sil, Arjun;Kumar, Vanapalli Naveen
    • Corrosion Science and Technology
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    • v.19 no.4
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    • pp.174-188
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    • 2020
  • Atmospheric corrosion is a natural surface degradation process of metal due to changes in environmental parameters in the surrounding atmosphere. It is very sensitive to environmental parameters such as temperature, relative humidity, sulphur dioxide, and chloride, making it a major global economic challenge. Existing forecasting empirical corrosion models including the ISO standard are based on statistical analysis of experimental studies without considering the behavior of atmospheric parameters. The present study proposes a reliable global empirical model for estimating short and long-term atmospheric corrosion rates based on environmental parameters and corrosion mechanisms obtained from a parametric study. Repercussion of atmospheric corrosion rate due to individual and combined influences of environmental parameters specifies their importance in the estimation. New global empirical coefficients obtained for environmental parameters are statistically established (R2 =0.998) with 95% confidence limit. They are validated using experimental datasets of existing studies observed at 88 different continental locations. The current proposed model can predict atmospheric corrosion by means of corrosion formation mechanisms influenced by combined effects of environmental parameters, further abating applicability limitations of location and time.

Structural performance of unprotected concrete-filled steel hollow sections in fire: A review and meta-analysis of available test data

  • Rush, David;Bisby, Luke;Jowsey, Allan;Melandinos, Athan;Lane, Barbara
    • Steel and Composite Structures
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    • v.12 no.4
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    • pp.325-350
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    • 2012
  • Concrete filled steel hollow structural sections (CFSs) are an efficient, sustainable, and attractive option for both ambient temperature and fire resistance design of columns in multi-storey buildings and are becoming increasingly common in modern construction practice around the world. Whilst the design of these sections at ambient temperatures is reasonably well understood, and models to predict the strength and failure modes of these elements at ambient temperatures correlate well with observations from tests, this appears not to be true in the case of fire resistant design. This paper reviews available data from furnace tests on CFS columns and assesses the statistical confidence in available fire resistance design models/approaches used in North America and Europe. This is done using a meta-analysis comparing the available experimental data from large-scale standard fire tests performed around the world against fire resistance predictions from design codes. It is shown that available design approaches carry a very large uncertainty of prediction, suggesting that they fail to properly account for fundamental aspects of the underlying thermal response and/or structural mechanics during fire. Current North American fire resistance design approaches for CFS columns are shown to be considerably less conservative, on average, than those used in Europe.

Relational Benefits and Visual Arts Outcomes via WeChat Business

  • Cui, Yu Hua
    • Journal of Fashion Business
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    • v.23 no.6
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    • pp.16-26
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    • 2019
  • The purpose of this study was to understand the effect of WeChat relational benefits on customer satisfaction and purchase intention. Due to the rapid development in the technological field, the use of WeChat has expanded drastically in recent years. In visual arts industry, WeChat business occupies a significant proportion of emerging industries. The recruited participants that were recruited via an online survey website were 335 (www.sojump.com). SPSS 22.0 statistical system was used to analyze the descriptive statistics, reliability, and validity. This study conceptualizes the positive relationship among relational benefits, customer satisfaction, and purchase intention of visual arts products. The findings indicated that WeChat users' relational benefits can be categorized into two distinct benefit types: confidence, and social benefits. The more relational benefits WeChat users perceived, the higher the level of satisfaction. In contrast, the positive influence of customer satisfaction on purchase intention is weaker in consumers with a higher level of perceived risk. The results of this study will help WeChat business to retain its customers, thus, gaining a long-term value for visual arts industry. Theoretical and managerial implication for WeChat business are provided.

A study on Clothing Behavior and Preference of clothing Design on the Comparison of Body types of Chinese Women (중국 여성의 체형별 의복행동 및 의상디자인 선호도 연구)

  • Kim, Hyo-Sook;Lim, Soon;Son, Hee-Heong
    • Journal of the Korean Home Economics Association
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    • v.39 no.11
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    • pp.15-26
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    • 2001
  • China adopted a free market economy and is a member of WTO. It has now emerged as one of the most promising markets in the word for the near future. The purpose of this study was to investigate of Chinese women clothing behavior and preference of clothing design by body types and to suggest basic information for high quality clothes merchandising of exporting to China. The subjects in this study were 280 Chinese women, aged from 20 to 50 living in Beijing. The survey was taken from June to July, 1999. SAS(Statistical Analysis System) is used for frequency, percentage, average, standard deviation, $\chi$$^2$-test, factor analysis. The results of this study are as follows. Ewamination on the Chinese womens clothing behavior showed that they attach importance to economy for purchasing clothes and have affirmative self-confidence. The thin body type women prefer to fashionable clothes while the fat body type has more reasonable economic behavior for clothing. It is needed to different merchandising project by body type in China..

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Toward Successful Management of Vocational Rehabilitation Services for People with Disabilities: A Data Mining Approach

  • Kim, Yong Seog
    • Industrial Engineering and Management Systems
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    • v.11 no.4
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    • pp.371-384
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    • 2012
  • This study proposes a multi-level data analysis approach to identify both superficial and latent relationships among variables in the data set obtained from a vocational rehabilitation (VR) services program of people with significant disabilities. At the first layer, data mining and statistical predictive models are used to extract the superficial relationships between dependent and independent variables. To supplement the findings and relationships from the analysis at the first layer, association rule mining algorithms at the second layer are employed to extract additional sets of interesting associative relationships among variables. Finally, nonlinear nonparametric canonical correlation analysis (NLCCA) along with clustering algorithm is employed to identify latent nonlinear relationships. Experimental outputs validate the usefulness of the proposed approach. In particular, the identified latent relationship indicates that disability types (i.e., physical and mental) and severity (i.e., severe, most severe, not severe) have a significant impact on the levels of self-esteem and self-confidence of people with disabilities. The identified superficial and latent relationships can be used to train education program designers and policy developers to maximize the outcomes of VR training programs.

An application of datamining approach to CQI using the discharge summary (퇴원요약 데이터베이스를 이용한 데이터마이닝 기법의 CQI 활동에의 황용 방안)

  • 선미옥;채영문;이해종;이선희;강성홍;호승희
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2000.11a
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    • pp.289-299
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    • 2000
  • This study provides an application of datamining approach to CQI(Continuous Quality Improvement) using the discharge summary. First, we found a process variation in hospital infection rate by SPC (Statistical Process Control) technique. Second, importance of factors influencing hospital infection was inferred through the decision tree analysis which is a classification method in data-mining approach. The most important factor was surgery followed by comorbidity and length of operation. Comorbidity was further divided into age and principal diagnosis and the length of operation was further divided into age and chief complaint. 24 rules of hospital infection were generated by the decision tree analysis. Of these, 9 rules with predictive prover greater than 50% were suggested as guidelines for hospital infection control. The optimum range of target group in hospital infection control were Identified through the information gain summary. Association rule, which is another kind of datamining method, was performed to analyze the relationship between principal diagnosis and comorbidity. The confidence score, which measures the decree of association, between urinary tract infection and causal bacillus was the highest, followed by the score between postoperative wound disruption find postoperative wound infection. This study demonstrated how datamining approach could be used to provide information to support prospective surveillance of hospital infection. The datamining technique can also be applied to various areas fur CQI using other hospital databases.

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