• Title/Summary/Keyword: statistical confidence

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The Effect of Self-efficacy and Commitment on Functional Satisfaction and Repurchase Intention of Mountaineering Apparels (등산객의 자기효능감과 몰입이 등산복의 기능성 만족도 및 재구매의도에 미치는 영향)

  • Hong, Byung-Sook;Kim, Chan-Ho;Lee, Eun-Jin
    • Fashion & Textile Research Journal
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    • v.12 no.5
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    • pp.599-607
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    • 2010
  • This study analyzed how the self-efficacy and commitment on functional satisfaction and repurchase intentionof mountaineering apparels. The survey was conducted over the climbers with 298 subjects. The statistical analysis methods were frequency analysis, factor analysis, reliability analysis, and regression analysis. The results showed that the self-efficacy of climbers were classified into self-regulated efficacy, self-confidence, and task difficulty preference, and the commitment of climbers were classified into behavioral commitment and cognitive commitment. The self-regulated efficacy and self-confidence influenced the behavioral commitment and the self-regulated efficacy influenced the cognitive commitment. The behavioral commitment and cognitive commitment influenced the functional satisfaction and repurchase intention of mountaineering apparels. The functional satisfaction influenced the repurchase intention of mountaineering apparels.

Reliability Estimation of Generalized Geometric Distribution

  • Abouammoh, A.M.;Alshangiti, A.M.
    • International Journal of Reliability and Applications
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    • v.9 no.1
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    • pp.31-52
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    • 2008
  • In this paper generalized version of the geometric distribution is introduced. This distribution can be considered as a two-parameter generalization of the discrete geometric distribution. The main statistical and reliability properties of this distribution are discussed. Two methods of estimation, namely maximum likelihood method and the method of moments are used to estimate the parameters of this distribution. Simulation is utilized to calculate these estimates and to study some of their properties. Also, asymptotic confidence limits are established for the maximum likelihood estimates. Finally, the appropriateness of this new distribution for a set of real data, compared with the geometric distribution, is shown by using the likelihood ratio test and the Kolmogorove-Smirnove test.

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Better Bootstrap Confidence Intervals for Process Incapability Index $C_{pp}$

  • Cho, Joong-Jae;Han, Jeong-Hye;Lee, In-Pyo
    • Journal of the Korean Data and Information Science Society
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    • v.10 no.2
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    • pp.341-357
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    • 1999
  • Greenwich and Jahr-Schaffrath(1995) considered a new process incapability index(PII) $C_{pp}$, which modified the useful index $C^{\ast}_{pm}{$ for detecting assignable causes. The new index $C_{pp}$ provides an uncontaminated separation between information concerning the process accuracy and precision while this kind of information separation is not available with the $C^{\ast}_{pm}$ index. In this paper, we will study about the index $C_{pp}$ based on the bootstrap. First, we will prove the consistency of bootstrap deriving the bootstrap asymptotic distribution for our index $C_{pp}$. Moreover, with the consistency of bootstrap, we will construct six bootstrap confidence intervals and compare their performances. Some simulation results, comparison and analysis are provided. In particular, two STUD and ABC bootstrap methods perform significantly better.

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Worst Case Sampling Method with Confidence Ellipse for Estimating the Impact of Random Variation on Static Random Access Memory (SRAM)

  • Oh, Sangheon;Jo, Jaesung;Lee, Hyunjae;Lee, Gyo Sub;Park, Jung-Dong;Shin, Changhwan
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.3
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    • pp.374-380
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    • 2015
  • As semiconductor devices are being scaled down, random variation becomes a critical issue, especially in the case of static random access memory (SRAM). Thus, there is an urgent need for statistical methodologies to analyze the impact of random variations on the SRAM. In this paper, we propose a novel sampling method based on the concept of a confidence ellipse. Results show that the proposed method estimates the SRAM margin metrics in high-sigma regimes more efficiently than the standard Monte Carlo (MC) method.

Empirical Fragility Curves for Bridge (교량의 경험적 손상도 곡선)

  • Lee, Jong-Heon;Kim, Woon-Hak;Choi, Jung-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.1
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    • pp.255-262
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    • 2002
  • This paper presents a statistical analysis of empirical fragility curves for bridge. The empirical fragility curves are developed utilizing bridge damage data obtained from the 1995 Hyogoken Nanbu(Kobe) earthquake. Two-parameter lognormal distribution functions are used to represent the fragility curves with the parameters estimated by the maximum likelihood method. This paper also presents methods of testing the goodness of fit of the fragility curves and estimating the confidence intervals of the two parameters(median and log-standard deviation) of the distribution. An analytical interpretation of randomness and uncertainty associated with the median is provided.

Likelihood-Based Inference of Random Effects and Application in Logistic Regression (우도에 기반한 임의효과에 대한 추론과 로지스틱 회귀모형에서의 응용)

  • Kim, Gwangsu
    • The Korean Journal of Applied Statistics
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    • v.28 no.2
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    • pp.269-279
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    • 2015
  • This paper considers inferences of random effects. We show that the proposed confidence distribution (CD) performs well in logistic regression for random intercepts with small samples. Real data analyses are also done to identify the subject effects clearly.

Application of Bootstrap Method to Primary Model of Microbial Food Quality Change

  • Lee, Dong-Sun;Park, Jin-Pyo
    • Food Science and Biotechnology
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    • v.17 no.6
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    • pp.1352-1356
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    • 2008
  • Bootstrap method, a computer-intensive statistical technique to estimate the distribution of a statistic was applied to deal with uncertainty and variability of the experimental data in stochastic prediction modeling of microbial growth on a chill-stored food. Three different bootstrapping methods for the curve-fitting to the microbial count data were compared in determining the parameters of Baranyi and Roberts growth model: nonlinear regression to static version function with resampling residuals onto all the experimental microbial count data; static version regression onto mean counts at sampling times; dynamic version fitting of differential equations onto the bootstrapped mean counts. All the methods outputted almost same mean values of the parameters with difference in their distribution. Parameter search according to the dynamic form of differential equations resulted in the largest distribution of the model parameters but produced the confidence interval of the predicted microbial count close to those of nonlinear regression of static equation.

Comparison of endotracheal intubation speed and ease by using the supraglottic airway laryngopharyngeal tube: A manikin study (성문위기도기 인후두튜브(SALT)를 이용한 기관내삽관 신속성과 용이성 비교: 마네킨을 이용한 연구)

  • Yun, Seong-Woo
    • The Korean Journal of Emergency Medical Services
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    • v.19 no.2
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    • pp.29-38
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    • 2015
  • Purpose: The purpose of this study was to improve airway management ability by comparing the speed, angle of the neck, and confidence and ease of supraglottic airway laryngopharyngeal tube (SALT) and endotracheal intubation via direct laryngoscopy. Methods: The subjects of this experimental research study with a randomized crossover design were 44 emergency medicine technician - paramedics working in the fire department of 'J' - do. SPSS version 19.0 was used in the statistical analysis. Results: Speed and angle of the neck (p<.001), as well as confidence and ease (p<.001), showed significant differences between endotracheal intubation with a SALT and endotracheal intubation via direct laryngoscopy. Conclusion: If endotracheal intubation via direct laryngoscopy is difficult to use or in trauma patients, using a SALT is safe and enables fast intubation. Moreover, in order to improve the efficiency of advanced airway management, the application of SALT should be introduced in the domestic scene.

An Analysis on the Statistical Literacy of Secondary Mathematics Teachers and Adults -Focused on the Level of Understanding in a Poll Results- (중등수학교사와 일반인의 통계적 소양 분석 -여론조사 결과의 이해수준을 중심으로-)

  • So, Jaehong;Badamjav, Gundegmaa;Jeon, Youngju
    • Journal of the Korean School Mathematics Society
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    • v.23 no.3
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    • pp.397-425
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    • 2020
  • Statistical literacy is a key ability expected of citizens in information-laden societies, and is often revealed as an expected outcome of schooling and as a necessary component of adults' numeracy and literacy. Knowing how important statistical literacy is, the purpose of this research was to measure statistical literacy of adults and secondary mathematics teachers. This study explored the statistical literacy based on the level of understanding in poll results and analyzed the data obtained through semi-structured interviews with 20 secondary mathematics teachers and 20 adults. As a result, the following conclusions were obtained: First, few secondary mathematics teachers and adults correctly recognized the meaning of statistical terms and expressions included in the poll results. Second, 70% of research participants did not reach levels 3 or 4 of statistical literacy levels. Third, the statistical literacy level of secondary mathematical teachers was higher than that of adults.

The Risk of Onset of the Illnesses Based on Gender, Age, and Monthly Income;Focusing on cancer, hypertension, stroke, diabetes, arthritis, cardiac disorders (성별, 연령별, 월소득차이에 따른 질병발생의 위험성 차이연구;암, 고혈압, 중풍, 당뇨병, 관절염, 심장병을 중심으로)

  • Lee, Jun-Oh;Kim, Se-Jin;Lee, Sun-Dong
    • Journal of Society of Preventive Korean Medicine
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    • v.12 no.1
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    • pp.19-48
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    • 2008
  • In order to verify the risk of onset of the illnesses based on gender, age, and monthly income 1,739 subjects from Hongcheon county, Gangwon province were selected. Questionnaire on demographic sociology, health condition, existence of illnesses(cancer, hypertension, stroke, diabetes, arthritis, cardiac disorders), and usage of public health services was surveyed from October 1, 2006 to October 20, 2006. Following conclusions were reached on the basis of the questionnaire : - For demographic sociological peculiarities, gender, age, occupation, and education level were evenly distributed. Most were under normal marriage(67.38%), health insurance(86.39%), 494(36.0%) individuals with less than monthly income of 1 million won, 494(36.0%) individuals with monthly income between 1 and 2 million won, 219(16.0%) with monthly income between 2 and 3 million won, and 164(12.0%) individuals with more than 3 million won, thus showing relatively low income. - For health status, 1,199(70.28%) individuals are non-smokers, 209(45.63%) individuals smoke $10{\sim}20$ cigarettes a day, 754(44.02%) individuals exercise less than twice a week are the major sector of the population. 1,518(88.10%) individuals have regular checkup more than once and 1,131(65.49%) stated their health condition less than average. - For comparison of existence of illnesses between genders, there was no statistical significance on cancer, stroke, and diabetes. But statistical significance was shown on hypertension(P value 0.025), arthritis(P value 0.000), and cardiac disorders(P value 0.016). Statistical significance was seen in the age comparison, and OR(confidence interval) drastically increased with increase in age. - There was no difference between the primary health clinic(P value 0.000), most visited clinic(P value 0.000), selection criteria(P value 0.000), and satisfaction on efficacy(P value 0.000). There was a tendency preferring hospital than public health center with increase in income. - For correlation between the existence of illnesses among different income levels, except for cancer(P value 0.172), statistical significance was seen in hypertension(P value 0.000), stroke(P value 0.003), diabetes (P value 0.001), arthritis(P value 0.000), and cardiac disorders(P value 0.000). The number of individuals suffering from illnesses and ratio all decreased for all illnesses with increase in income. - After adjusting confounding factors(gender, age, income, marriage, occupation, education) and male (1) as the standard, OR (confidence interval) of cancer, hypertension, stroke, diabetes, arthritis, cardiac disorders were 0.47(0.11${\sim}$2.05), 1.27(0.89${\sim}$1.81), 0.58(0.21${\sim}$1.59), 0.71(0.41${\sim}$1.23), 1.79(1.34${\sim}$2.39, P<0.01), and 1.46(0.72${\sim}$2.96), respectively. Risk of arthritis is significantly high in female and 20's (1) as the standard, OR(confidence interval) of cancer, hypertension, stroke, diabetes, arthritis, cardiac disorders were 1.01(0.96${\sim}$1.07), 1.06(1.04${\sim}$1.07, P<0.01), 1.05(1.01${\sim}$1.10, P<0.01), 1.06(1.03${\sim}$1.08, P<0.01), 1.05(1.03${\sim}$1.06, P<0.01), and 1.06(1.04${\sim}$1.09, P<0.01), respectively. Risk of onset for illnesses significantly increased with yearly aging except for cancer. - For comparison between monthly income after adjusting confounding factors(gender, age, income, marriage, occupation, education), with less than 1 million won (1) as the standard, OR(confidence interval) of cancer for 1 to 2 million won, 2 to 3 million won, and more than 3 million won were 0.23(0.03${\sim}$2.16), 2.53(0.41${\sim}$15.43), and 1.73(0.15${\sim}$19.50), respectively. OR(confidence interval) of hypertension were 1.12(0.76 ${\sim}$1.66), 0.68(0.34${\sim}$1.34), and 2.04(1.08${\sim}$3.86, P<0.01), respectively. OR(confidence interval) of stroke were 0.96(0.30${\sim}$3.08) for 1 to 2 million won, and 0.80(0.08${\sim}$8.46) for 2 to 3 million won. OR(confidence interval) of diabetes were 0.73(0.38${\sim}$1.38), 0.65(0.24${\sim}$1.71), and 0.69(0.24${\sim}$2.01), respectively. The values were 0.76(0.55${\sim}$1.03), 1.14(0.75${\sim}$1.73), and 0.90(0.56${\sim}$1.46), respectively for arthritis. OR(confidence interval) of cardiac disorders were 1.15(0.53${\sim}$2.48), 0.63(0.13${\sim}$3.12), and 1.20(0.28${\sim}$5.14), respectively. Risks of cancer, hypertension, stroke, diabetes, arthritis, and cardiac disorders were dependent of monthly income, and stroke and diabetes decreased with increase in income. Summarizing above data, arthritis was significantly higher in women and increase in age by each year brought significant increase in the chance of onset in hypertension, stroke, diabetes, arthritis, and cardiac disorders except for cancer. Stroke and diabetes decreased with increase in income. Above findings can be applied and reflected in public health policies at the national level, and it can also be applied at the personal level for individual health maintenance and prevention.

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