• Title/Summary/Keyword: expression of reliability

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A Note on a New Two-Parameter Lifetime Distribution with Bathtub-Shaped Failure Rate Function

  • Wang, F.K.
    • International Journal of Reliability and Applications
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    • v.3 no.1
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    • pp.51-60
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    • 2002
  • This paper presents the methodology for obtaining point and interval estimating of the parameters of a new two-parameter distribution with multiple-censored and singly censored data (Type-I censoring or Type-II censoring) as well as complete data, using the maximum likelihood method. The basis is the likelihood expression for multiple-censored data. Furthermore, this model can be extended to a three-parameter distribution that is added a scale parameter. Then, the parameter estimation can be obtained by the graphical estimation on probability plot.

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The Effects of Multiple Body Image on Clothing Behavior (다차원적 신체이미지가 의복행동에 미치는 영향)

  • 김광경;이금실;정미실
    • Journal of the Korean Society of Clothing and Textiles
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    • v.25 no.2
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    • pp.358-365
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    • 2001
  • The purpose of this study was to investigate the relation between various aspects of multiple body image and clothing behavior i.e. individuality/self expression, body improvement, social approval, sex appeal. The data were collected from 498 female university students in Seoul and Kyong Ki Province and analyzed using factor analysis, Pearsons correlations, reliability test, analysis of variance, and multiple regression analysis. The results of this study were as follows: 1) Four dimensions of multiple body image were identified : appearance, body attractiveness, degree of fitness and atheletic skill. 2) Perception on appearance and fitness aspect of multiple body image has a positive correlation with all aspects of clothing behavior i.e. individuality/self expression, body improvement, social approval and sex appeal of clothing behavior. Body attractiveness and atheletic skill of multiple body image also had a positive correlation with individuality/self expression, and sex appeal.

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ESTIMATIONS OF HEAT CAPACITIES FOR ACTINIDE DIOXIDE: UO2, NpO2, ThO2, AND PuO2

  • Eser, E.;Koc, H.;Gokbulut, M.;Gursoy, G.
    • Nuclear Engineering and Technology
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    • v.46 no.6
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    • pp.863-868
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    • 2014
  • The evaluation of thermal properties of actinide oxide fuels is a problem of high importance for the development of new generation reactors. In the present study, an expression obtained for n-dimensional Debye functions is used to derive a simple analytical expression for the specific heat capacity of nuclear fuels. To test the validity and reliability of this expression, the analytical expression is applied to $UO_2$, $NpO_2$, $ThO_2$, and $PuO_2$. It is seen that the formula was in agreement with the experimental and theoretical results reported in the literature.

A Study on the Reliability Prediction for Space Systems (우주 시스템의 신뢰성 예측에 관한 연구)

  • Yu, Seung-U;Lee, Baek-Jun;Jin, Yeong-Gwon
    • Aerospace Engineering and Technology
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    • v.5 no.2
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    • pp.227-239
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    • 2006
  • Reliability prediction provides a rational basis for design decisions such as the choice between alternative concepts, choice of part quality levels, derating factors to be applied, use of proven versus state-of-the-art techniques, and other factors. For this reasons, reliability prediction is essential functions in developing space systems. The worth of the quantitative expression lies in the information conveyed with the numerical value and the use which is made of that information and reliability prediction should be initiated early in the configuration definition stage to aid in the evaluation of the design and to provide a basis for item reliability allocation (apportionment) and establishing corrective action priorities. Reliability models and predictions are updated when there is a significant change in the item design availability of design details, environmental requirements, stress data, failure rate data, or service use profile. In this paper, the procedure, selection of reliability data and methods for space system reliability prediction is presented.

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AUV hull lines optimization with uncertainty parameters based on six sigma reliability design

  • Hou, Yuan hang;Liang, Xiao;Mu, Xu yang
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.4
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    • pp.499-507
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    • 2018
  • Autonomous Underwater Vehicle (AUV), which are becoming more and more important in ocean exploitation tasks, needs energy conservation urgently when sailing the complex mission path in long time cruise. As hull lines optimization design becomes the key factor, which closely related with resistance, in AUV preliminary design stage, uncertainty parameters need to be considered seriously. In this research, Myring axial symmetry revolution body with parameterized expression is assumed as AUV hull lines, and its travelling resistance is obtained via modified DATCOM formula. The problems of AUV hull lines design for the minimum travelling resistance with uncertain parameters are studied. Based on reliability-based optimization design technology, Design For Six Sigma (DFSS) for high quality level is conducted, and is proved more reliability for the actual environment disturbance.

A Study on the proposal of Strength Presumption Equation of Concrete Using Admixture by Nondestructive Testing (비파괴 시험에 의한 혼화재를 사용한 콘크리트의 강도 추정식 제안에 관한 연구)

  • Kim Jeong-Sup;Shin Yong-Seok;Kim Koung-Ok
    • Journal of the Korea Institute of Building Construction
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    • v.6 no.3 s.21
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    • pp.59-66
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    • 2006
  • This study aims to estimate strength approximate to actual concrete strength by presenting appropriate non-destructive strength estimation expression with admixtures such as fly ash, blast furnace slag and silica fume which are used as cement substitute and owing to theirs of cement owing to their equal conditions to blending characteristics of concrete used for domestic structures and their recyclable properties. As a result of comparing error rate of existing expressions and this estimation expression, error rate of this estimation is reduced compared to existing expressions and has higher reliability. When conventional concrete expression is applied to admixture concrete, error rate occurs and then this study suggests the following estimation expressions depending on types of admixture concrete.

Veri cation of Improving a Clustering Algorith for Microarray Data with Missing Values

  • Kim, Su-Young
    • The Korean Journal of Applied Statistics
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    • v.24 no.2
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    • pp.315-321
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    • 2011
  • Gene expression microarray data often include multiple missing values. Most gene expression analysis (including gene clustering analysis); however, require a complete data matric as an input. In ordinary clustering methods, just a single missing value makes one abandon the whole data of a gene even if the rest of data for that gene was intact. The quality of analysis may decrease seriously as the missing rate is increased. In the opposite aspect, the imputation of missing value may result in an artifact that reduces the reliability of the analysis. To clarify this contradiction in microarray clustering analysis, this paper compared the accuracy of clustering with and without imputation over several microarray data having different missing rates. This paper also tested the clustering efficiency of several imputation methods including our propose algorithm. The results showed it is worthwhile to check the clustering result in this alternative way without any imputed data for the imperfect microarray data.

The Development and Validity of the Children's Playfulness Rating Scale (유아용 놀이성 평정 척도 개발 및 타당화 연구)

  • Kim, Myoung-Soon;Kim, Gil-Sook;Park, Chan-Hwa
    • Korean Journal of Child Studies
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    • v.33 no.2
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    • pp.69-89
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    • 2012
  • This study was conducted in order to develop a Children's Playfulness Rating Scale(CPRS) and to analyze it in terms of item discrimination, validity, and reliability. The participants in this study consisted of 861 parents whose children were aged from three to six years old. The item discrimination, determined by comparing the highest and lowest group using ${\chi}^2$, Cramer's V, was found to be satisfactory. The reliability of factors, as measured by Cronbach's ${\alpha}$, ranged from .85 to .95. The results of factor analysis identified 4 factors and 35 items were then selected from the 45 items in the original scale. The four factors identified were as follows; (1) leading participation (2) cognitive flexibility (3) expression of joy (4) voluntary full immersion. Concurrent validity was also established by using correlations between the CPRS and CPS(Children's Playfulness Scale). In conclusion, these results demonstrated that the Children's Playfulness Rating Scale is both reliable and valid.

Developing a Scoring Rubric for Students' Mind Maps and Its Reliability (마인드 맵의 채점 기준 개발 및 신뢰도 검증)

  • Lee, Su-Jung;Su-Jung, Chan-Jong
    • Journal of the Korean earth science society
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    • v.23 no.8
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    • pp.632-639
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    • 2002
  • The purpose of the study is to develop a scoring rubric for students’ mind maps. The participants of this research were students in two fourth-grade classes selected from an elementary school in Pyungtaek-shi. After receiving basic training, students developed mind maps four times while teaming two science units. In order to score the mind maps, a scoring rubric was developed. To estimate the reliability of the rubric, selected mind maps were marked by three teachers and correlational coefficients were calculated with SPSS. As a result of the study, a scoring rubric consisted of three domains, central circle, branches, and expression were developed. The reliability of the rubric is proven to be high to very high.

The Effect of Self-Expression on Stress with Clinical Dental Practice among Students in the Department of Dental Hygiene (치위생과 학생의 자기표현이 임상실습 스트레스에 미치는 영향)

  • Chun, Ju-Yean;Lee, Hyun-Ok;Kim, Jin
    • Journal of dental hygiene science
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    • v.7 no.2
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    • pp.89-96
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    • 2007
  • The purpose of this study was to examine the relationship between the self-expression level of dental hygiene students related to communicative competence and their stress during clinical practice and what affected their stress. The subjects in this study were 125 dental hygiene students in W college, on whom a survey was conducted from September 18 through 30, 2006. After the collected data were analyzed with SPSS WIN 10.0 program, the following findings were acquired: 1. When a factor analysis was made to evaluate the self-expression of the students, there appeared three different categories of self-expression: voice/content, facial expression/attitude and sentiment. The three made a 58.1% prediction of their self-expression. As for overall reliability, they turned out highly reliable(Cronbach'a = .881). 2. The dental hygiene students got a mean of 3.58 out of possible five points in self-expression, which indicated that they expressed themselves relatively well. Concerning connections between their general characteristics and self-expression level, those who were inactive during clinical practice got a mean of 3.28, whereas the others who were active got a mean of 3.85. It implied that those who took a more active attitude to clinical practice expressed themselves better(p < .01). The person with whom they found it hard to get along made a statistically significant difference to their self-expression(p < .05). The students who didn't fare well with dental hygienists got the best score(3.70). The second best group(3.53) didn't get along with dentists, followed by assistant nurses(3.46) and patients/caregivers(3.31). As for the impact of the field of dream job, the students who hoped to work or study overseas(4.21) excelled in self-expression those who wanted to be hired in a general hospital, to go onto a school of higher grade and to work in a public dental clinic(p < .05). Among the general characteristics, satisfaction level with major, health status and motivation of choosing dental hygiene made no statistically significant differences to their self-expression. 3. Regarding relations between self-expression level and stress about clinical practice, those who didn't express themselves properly in terms of sentiment scored higher in stress level(3.65). Their stress was statistically significantly different according to self-expression level (p < .05). 4. As for the influence of self-expression and general characteristics on stress with clinical practice, sentiment was selected from among the self-expression categories as a decisive factor to affect stress. Their stress varied statistically significantly with that(p < .05). In contrast, their demographic variables made no statistically significant difference to that, which made a 79.2% prediction of it.

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