• 한국연초학회지
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• 제4권1호
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• pp.21-27
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• 1982

Six flue-cured cultivars of Nicotiana tabacum L., 15 possible $F_1$ hybrids and 15 $F_2$ populations among them, and 15 haploid populations of $F_1$ hybrids and 6 haploid from parents, were evaluated. The variances of general combining ability were predominant for all characters studied in $F_1$ hybrid and $F_2$ population, and in haploid populations of $F_1$ hybrids except leaf width, value and reducing sugar. There were significant correlations between generations in variances and ranks of parental GCA effects estimated from general combining ability analysis of $F_1,\;F_2$ and haploid generation of $F_1$ hybrids for yield, stem height, days to flower. leaves per plant, value and total alkaloids.

• 복식문화연구
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• 제8권6호
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• pp.930-939
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• 2000

This study was done to provide the fundamental data for scientific and rational children's clothing sizing system by investigating their somatometric characteristics and classifying somatotypes. The subjects were 269 elementary schoolgirls aged from 7 to 8 years old living in Pusan and Kyungsangnam-do. Data from each girl comprises 28 anthropometic measurments and 4 photographic measurments, related to the lower half of body. To analyze somatotypes of the lower half of body, factor analysis, cluster analysis, discriminant analysis were performed for statistical analysis of the data. As to the analysis to draw somatometric factors by this age group, five factors which explain 76.85% of the whole variances were extracted. The first and second factors which explain more than 60% of the whole variances represent 'horizontal size'and 'vertical size', which characterize most aspects of the body shape of the subjects. On the basis of the cluster analysis, three different lower half of body types were categorized. Type Ⅰ has biggest horizontal size, average vertical size and most protruded belly. Type Ⅱ has average degree of horizontal size, quite big vertical size and most protruded hips. Type Ⅲ has smallest horizontal and vertical size. According to the analysis to discriminate somatotypes of the lower half of body of this age group, weight and waist circumference of discriminant function 1 and abdominal circumference of discriminant function 2 have coefficient values.

• 대한기계학회논문집
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• 제18권2호
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• pp.351-358
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• 1994

A probabilistic model and analysis methods to determine the means and variances of the velocity and acceleration in stochastically-defined planar pin jointed kinematic chains are presented. The presented model considers the effect of tolerances on link length and radial clearance and uncertainty of pin location as a net effect on the link's effective length. The determination of the mean values and variances of the output variables requires the calculation of sensitivities of secondary variables with respect to the random variables. It is shown that this computation is straightforward and can be accomplished by a conventional kinematic analysis package with minor modification. Thus, the concepts of tolerance and clearance have been captured by the model and analysis. The only input data are the nominal linkage model and statistical information. The "effective link length" model is shown to be applicable to both analytical solution and Monte Carlo simulation. The results from both methods are compared. This paper Ksolves the higher-order kinematic problems for the probabilistic design analysis of stochastically-defined mechanisms.echanisms.

• 한국자동차공학회논문집
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• 제16권3호
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• pp.166-171
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• 2008

In this paper, the optimization design module for the brake system of a vehicle is developed. As using this module, design variables, that minimize an object function and satisfy nonlinear constraint conditions, can be found easily. Before an optimization is operated, Plackett-Burman design, one of the factorial design methods, is used to choose the design variables which affect a response function significantly. Using the response surface analysis, second order recursive model function, which informs a relation between design variables and response function, is estimated. In order to verify the reliability of the model function, analysis of variances(ANOVA) table is used. The value of design variables which minimize the model function and satisfy the constraint conditions is predicted through Sequential Quadratic-Programming (SQP) method. As applying the above procedure to a real vehicle simulation model and comparing the values of object functions of a current and optimized system, the optimization results are verified.

• 대한간호학회지
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• 제38권2호
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• pp.287-297
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• 2008

Purpose: The purpose of this study was to identify factors related to nurses' organizational citizenship behavior using multilevel analysis which included both nurse characteristics at individual levels and nursing unit characteristics at group levels. Methods: The sample was composed of 1,996 nurses who were selected from 182 nursing units in 28 hospitals in six metropolitan cities and seven provinces using cluster sampling. Data were collected using self-reported questionnaires from February to March 2006. Results: The results of the study indicated that individual level variables related to organizational citizenship behavior were religion, job position, clinical career, self efficacy, positive affectivity, and supervisor support. The group level variables related to organizational citizenship behavior were collective efficacy, number of nurses in a nursing unit, and the average salary level of a nursing unit. 30.9% of individual level variances of organizational citizenship behavior were explained by the nurses' individual level variables. The explanatory power of group level variables, which is related to group level variances of organizational citizenship behavior, was 75.5%. Conclusion: This research showed that it was necessary to develop appropriate strategies related to not only individual factors, but also higher-level organizational factors such as collective efficacy, to improve individual performances in the hospital.

• Structural Engineering and Mechanics
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• 제47권3호
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• pp.307-329
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• 2013

The bending problem of Euler-Bernoulli discontinuous beams is dealt with, in which the discontinuities are due to the loads and eventually to essential constrains applied along the beam axis. In particular, the loads are modelled as random delta-correlated processes acting along the beam axis, while the ulterior eventual discontinuities are produced by the presence of external rollers applied along the beam axis. This kind of structural model can be considered in the static study of bridge beams. In the present work the exact expression of the response quantities are given in terms of means and variances, thanks to the use of the stochastic analysis rules and to the use of the generalized functions. The knowledge of the means and the variances of the internal forces implies the possibility of applying the reliability ${\beta}$-method for verifying the beam.

• Journal of the Korean Data and Information Science Society
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• 제16권3호
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• pp.609-620
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• 2005

In the secondary data analysis for categorical data, situations often arise in which the estimated cell variances are available, but not the full matrix of variances. In this case researchers are often inclined to use Pearson-type test statistics for homogeneity. However, for a complex sample observed cell proportions are not distributed as multinomial and Pearson-type test statistic generally is not distributed asymptotically as chi-square distribution. This paper evaluates powers for Wald test and Pearson-type test and the first order corrected test of Pearson-type test for homogeneity. The resulting power curves indicate that as the misspecification effect increases, the amount of inflation of significance level and the loss of power Pearson-type test are getting more severe.

• 품질경영학회지
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• 제27권1호
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• pp.101-110
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• 1999

Products are often evaluated on rating scales to measure and quantify their attributes of interest. In case that one wishes to compare multiple rating datasets simultaneously, there must be a standardized scale with which one can discriminate relative differences among corresponding scale means. In this regard, the concept of Thurstonian modeling applied to various discrimination tests including the triangular method has been recently being reconsidered. In this paper we extend previous researches on the triangular method and evaluate the effect of unequal variances and correlated variables upon the probability of correct response using Monte-Carlo simulation. We observed that the probability of correct response depends on dimensionality, variances, and correlation structure of stimulus sets. But it does not depend on the relative orientation in a multidimensional space.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.373-382
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• 2008

A method to investigate the design variable tolerance effects on the variances of the response, the characteristics, and the performance of a mechanical system is presented in this paper. The Monte-Carlo method has been conventionally employed to achieve such goals. However, the Monte-Carlo method has some serious drawbacks related to the computation time and the consistent solution convergence. To resolve the drawbacks of the method, a method employing sensitivity information is proposed. Sensitivity equations for a mechanical system are obtained analytically by differentiating the multi-body formulation with respect to a design variable. By using the chain rule along with the sensitivity information, the variances of the response, the characteristics, and the performance of a dynamic system can be calculated.

• 성인간호학회지
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• 제16권2호
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• pp.288-296
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• 2004

Purpose: Illness intrusiveness (illness induced lifestyle disruption) by symptoms was investigated in 439 patients with rheumatoid arthritis. Method: The cross-sectional and retrospective survey design was used. Fatigue, disability, pain, and depression were considered as symptoms of rheumatoid arthritis. Result: Patients were reported to perceive more illness intrusiveness than other chronic disease patients such as end stage renal disease, bipolar disorder, and peritoneal dialysis patients. They were especially intrusive into work, health, and active recreation domains. Stepwise regression analysis identified four variables counting for 26% of illness intrusiveness variances: fatigue, disability, marital status, and depression. All of the symptoms except pain were found to significantly predict illness intrusiveness. Fatigue explained 16% of illness intrusiveness variances. Conclusion: Fatigue and depression usually overlooked by health professionals must be carefully assessed and managed to reduce perceived illness for rheumatoid arthritis patients.