• Title/Summary/Keyword: statistical confidence

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Statistical evaluation of drift demands of rc frames using code-compatible real ground motion record sets

  • Kayhan, Ali Haydar;Demira, Ahmet
    • Structural Engineering and Mechanics
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    • v.60 no.6
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    • pp.953-977
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    • 2016
  • Modern performance-based design methods require ways to determine the factual behavior of structures subjected to earthquakes. Drift ratio demands are important measures of structural and/or nonstructural damage of the structures in performance-based design. In this study, global drift ratio and interstory drift ratio demands, obtained by nonlinear time history analysis of three generic RC frames using code-compatible ground motion record sets, are statistically evaluated. Several ground motion record sets compatible with elastic design spectra defined for the local soil classes in Turkish Earthquake Code are used for the analyses. Variation of the drift ratio demands obtained from ground motion records in the sets and difference between the mean of drift ratio demands calculated for ground motion sets are evaluated. The results of the study indicate that i) variation of maximum drift ratio demands in the sets were high; ii) different drift ratio demands are calculated using different ground motion record sets although they are compatible with the same design spectra; iii) the effect of variability due to random causes on the total variability of drift ratio demands is much larger than the effect of variability due to differences between the mean of ground motion record sets; iv) global and interstory drift ratio demands obtained for different ground motion record sets can be accepted as simply random samples of the same population at %95 confidence level. The results are valid for all the generic frames and local soil classes considered in this study.

GARCH-X(1, 1) model allowing a non-linear function of the variance to follow an AR(1) process

  • Didit B Nugroho;Bernadus AA Wicaksono;Lennox Larwuy
    • Communications for Statistical Applications and Methods
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    • v.30 no.2
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    • pp.163-178
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    • 2023
  • GARCH-X(1, 1) model specifies that conditional variance follows an AR(1) process and includes a past exogenous variable. This study proposes a new class from that model by allowing a more general (non-linear) variance function to follow an AR(1) process. The functions applied to the variance equation include exponential, Tukey's ladder, and Yeo-Johnson transformations. In the framework of normal and student-t distributions for return errors, the empirical analysis focuses on two stock indices data in developed countries (FTSE100 and SP500) over the daily period from January 2000 to December 2020. This study uses 10-minute realized volatility as the exogenous component. The parameters of considered models are estimated using the adaptive random walk metropolis method in the Monte Carlo Markov chain algorithm and implemented in the Matlab program. The 95% highest posterior density intervals show that the three transformations are significant for the GARCHX(1, 1) model. In general, based on the Akaike information criterion, the GARCH-X(1, 1) model that has return errors with student-t distribution and variance transformed by Tukey's ladder function provides the best data fit. In forecasting value-at-risk with the 95% confidence level, the Christoffersen's independence test suggest that non-linear models is the most suitable for modeling return data, especially model with the Tukey's ladder transformation.

A Study on the Characteristics according to Sasangin - Targeting the Group of Ordinary Adolescents - (사상인(四象人)의 성격(性格) 특성(特性)에 관(關)한 연구(硏究) -정상(正常) 청소년(靑少年) 집단(集團)을 대상(對象)으로 -)

  • Whang, Man-Ki;Hwang, Ui-Wan;Kim, Jong-Woo
    • Journal of Oriental Neuropsychiatry
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    • v.15 no.2
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    • pp.71-88
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    • 2004
  • Objectives : The aims of this report are to examine the personal characteristics and to determine the different reactions against stress by constitutions. To achieve these goals, the statistical research was adopted. Methods : First of all, the total numbers of 398 middle school students were classified into three constitutions by QSCC II. According to each type of constitutions, both of the KPI Personality Test and Multidimensional Encountering Scale (MES) on how to deal with stress were conducted. Summary of the findings : 1. Based on the findings assessed by the QSCC II test, the constitutional distribution reveals the difference according to genders. In Chi-square test, the girl reveals significantly high (p<0.05) distribution in Soyangin. 2. In Independent T-test regarding KPI personality, the girl reveals high significance (p<0.05) in terms of 'Sociability', 'Responsibility', 'Synchronism' and 'Self-feminity' (or Feminization) while the boy reveals high significance in 'Goal-driven' (p<0.05). 3. In Independent T-test regarding the multidimensional encounter scaling, the girl reveals high significance (p<0.05) in D (expression of emotion). 4. In case of the boy, the Soeumin shows low significance (p<0.05) in 'Leadership' and 'Sociability' compared to the Taeumin or the Soyangin. On the other hand, the Soeumin reveals high significance (p<0.05) in 'Responsibility' and 'Self-control' compared to the Soyangin and additionally, shows high significance (p<0.05) in 'Self-feminity' (or Feminization) compared to the Taeumin or the Soyangin. Furthermore, the Soyangin shows high significance (p<0.05) in 'Self-confidence' compared to the Soeumin or the Taeumin. 5. In case of the girl, the Soyangin reveals high significance in 'Sociability' and 'Self-confidence' compared to the Soeumin or the Taeumin while the Soeumin has high significance in 'Synchronism' compared to the Taeumin or Soyangin. On the other hand, the Soeumin has high significance in terms of 'Responsibility', 'Self-control', and 'Self-feminity' (or Feminization) while showing low significance in 'Flexibility' compared to the Soyangin. 6. For boys, the Soeumin has low significance in 'Sociability' in comparison with both the Soyangin and the Taeumin, whereas for girls, the Soyangin reveals high significance in 'Sociability' in comparison with both the Soeumin and the Taeumin. As per the 'Self-confidence' and 'Responsibility', it has been proved that there is no notable difference between the boy and the girl, but to the contrary, as per the 'Self-confidence', both for the girl and the boy, the Soyangin has high significance (p<0.05) in comparison with the Soeumin and the Taeumin. In addition, in 'Responsibility' side, it is recognized that the Soeumin shows high significance (p<0.05) in comparison with the Soyangin both for boys and girls. Only the difference between genders, as to the 'Self-confidence', is that the Soeumin shows low distribution compared to the Taeumin in the case of boys, while the Taeumin shows low distribution compared to the Soeumin in the case of girls. In 'Self-feminity' (or Feminization), for boys the Soeumin shows high significance in comparison with both the Soeumin and the Taeumin, but to the contrary, for girls the Soeumin shows high significance (p<0.05) only against the Soyangin. 7. In case of boys, as to 'Conformability (compromise)', the Taeumin compared to the Soeumin reveals high significance (p<0.05), while for girls, the Soeumin compared to the Soyangin or the Taeumin reveals high significance (p<0.05). Consequently, it presents that the Soyangin has a tendency not to confirm (compromise) relatively in comparison with other constitutions regardless of the genders. Conclusions : In general, except that it shows some constitutional deviation by genders, the statistical findings of this report agree and comply with the personal characteristics of Sasangin presented by Je-Ma Lee.

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Willingness to Perform Cardiopulmonary Resuscitation (CPR) in Emergency Situation: Convergence factor in Undergraduate Nursing Students (간호대학생의 심폐소생술 수행의도에 영향을 미치는 융합적 요인)

  • Kim, Sun Kyung;Kim, Sun-Ae;Kim, Jong-Im;Park, Mi-Hyeon
    • Journal of the Korea Convergence Society
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    • v.9 no.8
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    • pp.311-318
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    • 2018
  • The purpose of this study was to investigate the correlation between basic self - confidence and CPR - related factors and to investigate factors affecting CPR intention in nursing college students. Data were collected between January to March, 2018. Using SPSS(ver, 24.0), independent t-test, Pearson's correlation and logistic regression were used for the statistical analysis. Among the variables related to cardiopulmonary resuscitation, there was a high correlation (r = .575~.738). In the case of AED use, there was a low correlation with self-confidence of core nursing skills, CPR confidence, proficiency, and self-efficacy (r = .163~.301). A moderate correlation (r = .415~453) was found between the variables related to core nursing skills and CPR related variabls. Logistic regression analysis showed that CPR Self-efficacy (OR=1.22, 95% CI: 1.07~1.38), and AED application Competency (OR=1.72, 95% CI: 1.09~2.75) are effect factors. Since there is a correlation with AED, which is the main tool in CPR, it is necessary to include not only the self - efficacy but also the use of AED which is closely related to CPR in the actual situation as an essential element of education.

A Study on Recognition for Foundation Before and After Foundation Education -Focused on the case of senior foundation education in M university- (창업교육 전후 창업인식에 관한 연구 -M대학교 시니어창업교육 사례를 중심으로-)

  • Jo, Yoon-Ah;Park, Min-Kyu;Moon, Yun-Geol
    • The Journal of the Korea Contents Association
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    • v.15 no.11
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    • pp.433-446
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    • 2015
  • The purpose of this study is to investigate the differences in recognition for foundation before and after foundation education for preliminary senior founder' demographic characteristics, and to verify the effects of the characteristics on the foundation interest and foundation confidence. For this, questionnaire survey was carried out for 103 preliminary senior founders who participated in the foundation education program implemented by government. The statistical significance was verified with SPSS 18.0 program. On the basis of empirical study results, the main results were withdrawn as follows. First, there was a significant difference in foundation interest between before and after foundation education. Second, there was no significant difference in foundation interest with foundation motivation at before and after foundation education. Third, there was no significant difference in foundation confidence between before and after foundation education. Fourth, there was no significant difference in foundation confidence with foundation motivation at before and after foundation education. In conclusion, this study recommends an alternative for education curriculum development and operation for improving the actual performance of the curriculums targeting the senior generation through reliable research.

Confidence Bounds following Adaptive Group Sequential Tests with Repeated Measures in Clinical Trials (반복측정자료를 가지는 적응적 집단축차검정에서의 신뢰구간 추정)

  • Joa, Sook Jung;Lee, Jae Won
    • The Korean Journal of Applied Statistics
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    • v.26 no.4
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    • pp.581-594
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    • 2013
  • A group sequential design can end a clinical trial early if a confirmed efficacy or a futility of study medication is found during clinical trials. Adaptation can adjust the design of clinical trials based on accumulated data. The key to this methodology is considered to control the overall type 1 error rate while maintaining the integrity of clinical trials. The estimation would be more complex and the sample size calculation will be more difficult if the clinical trials have repeated measurement data. Lee et al. (2002) suggested a repeated observation case by using the independent increments properties of the interim test statistics and investigated the properties of the proposed confidence interval based on the stage-wise ordering. This study extend Lee et al. (2002) to adaptive group sequential design. We suggest test statistics for the adaptation as redesigning the second stage of clinical trials and induce the stage-wise confidence interval of parameter of interests. The simulation will help to confirm the suggested method.

Structural Disambiguation using Mutual Information and the Measure of Confidence (상호 정보를 이용한 구조적 모호성 해소와 결과에 대한 확신도 측정)

  • 심광섭
    • Korean Journal of Cognitive Science
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    • v.4 no.1
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    • pp.153-176
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    • 1993
  • Structual ambiguity is one of those problem that arise in the analysis of natural language sentences.It has been considered very difficult to solve the problem.Structural ambiguity,however,should be resolved no matter how difficult it may be.Otherwise natural language processing could be virtually impossible.A statistical approach to structural disambiguation is proposed in this dissertation.The information-theoretic concept of mutual information has been empolyed in resolving structural ambiguity Mutual information can be acquired in an automatic way.from text corpora. If a structural disambiguation subsystem had the capability of self-evaluating whether the results of structural disambiguation are correct or not.it would be possible to develop a more intelligent natural language proessing system.In this paper,the concept of confidence measure is also proposed to endow the disambiguation subsystem with such intelligence.Confidence measure is a numeric value calculated after structural disambiguation. Some experiments were performed in order to show the validity of the approach.Mutual information was auto matically acquired from a corpus of 1.6milion words that were collected from scientific abstracts.The accuracy of structural disambiguation was 80%when performed over 1,639 test sentences.Notice that there was no manual tuning in advance for the experiments.The task of detecting and correcting errors in structural disambiguation will be performed very effectively if the concept of confidence measure is employed in the process.

Effect of Rehabilitation Intervention for Lifestyle Improvement of Spinal Cord Injury: Systematic Review of Randomized Controlled Trials and Meta-Analysis (척수 손상 환자의 라이프 스타일 개선을 위한 재활 중재 효과: 무작위 대조군 연구의 체계적 고찰 및 메타분석)

  • Ha, Sung Kyu;Park, Hae Yean
    • Therapeutic Science for Rehabilitation
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    • v.9 no.4
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    • pp.107-120
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    • 2020
  • Objective : The purpose of this study was to investigate the effectiveness and basis of rehabilitation intervention in patients with spinal cord injury by systematic review and meta-analysis of randomized controlled studies. Methods : Two researchers independently searched and selected a study published in an academic journal using a search term in an international thesis database. A total of 21 studies met the selection criteria, and qualitative evaluation of the study was conducted using the PEDro Scale. Meta-analysis was performed using Comprehensive Meta-Analysis 3.0 program. Results : A total of 713 subjects were included. The results of the meta-analysis showed a score of 0.406 (95.0% confidence interval: 0.221 ~ 0.591) for intervention using physical activity and 0.505 (95.0% confidence interval: 0.449 ~ 1.528) for electronic stimulation therapy, which showed medium effect; educational intervention had a 0.248 (95.0% confidence interval: 0.033 ~ 0.464), and mixed intervention 0.280 (95.0% confidence interval: 0.122 ~ 0.438). It was shown that the effect of small (small). There was a significant heterogeneity in the statistical heterogeneity test, and thus the random effects model was selected and analyzed. Conclusion : The results showed that rehabilitation interventions were effective for patients with spinal cord injury. During the rehabilitation of spinal cord injury patients, clinicians are expected to contribute to the development of programs to improve their lifestyles.

The effects of dental-hygiene students' goal achievement orientation on their self-efficacy and major adaptation and satisfaction (치위생과 학생들의 성취목표지향성과 자기효능감이 전공적응 및 만족에 미치는 영향)

  • Jung, Gi-Ok
    • Journal of Korean society of Dental Hygiene
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    • v.12 no.1
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    • pp.167-178
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    • 2012
  • Objectives : The purpose of this research is to examine the effects of the goal achievement orientation of the students in dental-hygiene practice classes on their self-efficacy and on their adaptation to and satisfaction with their major. Methods : A survey was conducted among the dental-hygiene students in schools located in the Daegu region on October 24-31, 2011. A total of 212 accomplished questionnaires were gathered as sources of final analytical data. Statistical analysis was conducted on the collected data, using the SPSS 19.0 program. Results : 1. The students who had good personal relationships(p=.000) and who chose their major and school based on their aptitude(p=.029) were found to have a higher degree of satisfaction than those who did not have good personal relationships and who did not choose their major and school based on their aptitude. 2. Self-confidence(p=.004), self-control efficacy(p=.000), mastery approach(p=.000), and performance approach(p=.003) were found to have positive correlations with major adaptation while task difficulty preference(p=.000) was found to have a negative correlation with the same. 3. Self-confidence(p=.004), self-control efficacy(p=.000), mastery approach(p=.000), and performance approach(p=.045) were also found to have a positive correlation with major satisfaction while task difficulty preference(p=.000) was found to have a negative correlation with the same. 4. Mastery approach(p=.000) in goal achievement orientation was found to have a positive effect on self-efficacy while mastery avoidance(p=.001) was found to have a negative effect on the same. Mastery avoidance showed the greatest effect on self-confidence(p=.000) while mastery approach showed the greatest effect on self-control efficacy(p=.000) and task difficulty preference(p=.000). 5. In goal achievement orientation, mastery approach(p=.000) was found to have a positive effect on major adaptation while mastery avoidance was found to have a negative effect on the same. Meanwhile, with regard to self-efficacy, self-control efficacy(p=.037) and task difficulty preference(p=.008) were found to have positive effects on major adaptation. 6. In the case of major satisfaction, mastery approach(p=.000) in goal achievement orientation was found to have a positive effect on it, and in self-efficacy, self-control efficacy(p=.038) and task difficulty preference(p=.002) were found to have positive effects on it. Conclusions : Accordingly, to raise the level of the dental-hygiene students' adaptation to and satisfaction with their major, the students should be given appropriate tasks so that they can raise their mastery goal, and they should be encouraged to raise their approach goal rather than their avoidance goal. In addition, the students should be provided assistance in setting self-expectations and in developing confidence in their capabilities.

A Study on Pulping Process Condition through Design of Experiments (실험계획법을 이용한 고지 해리 공정조건에 관한 연구)

  • Kim, Sung-Kwon;Lee, Joon-Koo;Sung, Dae-Hyung
    • Applied Chemistry for Engineering
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    • v.9 no.4
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    • pp.529-535
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    • 1998
  • This study was made to investigate the effect of variation in pulping process conditions such as wastepaper blending treatments, temperature, and chemical blending treatments on the deinked pulp. Design of experiments was used to select the major factors which significantly influenced on the deinked pulp. As one of the statistical analysis technique, analysis of variance and multiple comparison technique was used to find the best process condition and the predicted values and confidence intervals for brightness and strength were obtained. In the condition of $Na_2SiO_3$ 2.0%, $H_2O_2$ 0.5% and wastepaper blending treatments (KONP : AONP : OMG = 40 : 30 : 30 wt %) the highest brightness of 50.5% was predicted with 90% confidence interval (49.0, 52.0). On a concentration of $H_2O_2$ 0.5%, the highest tensile index of $35.7N{\cdot}m/g$ was predicted with 90% confidence interval (34.6, 36.6) at the pulping temperature of $50^{\circ}C$. On a concentration of surfactant 0.1%, the highest burst index of $0.129kPa{\cdot}m^2/g$ was predicted with 90% confidence interval (0.125, 0.133) at the pulping temperature of $50^{\circ}C$.

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