• Journal of Preventive Medicine and Public Health
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• v.6 no.1
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• pp.77-79
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• 1973

The Mechanism for sorting out the covariance effect is known as the covariance analysis. The sorting out of regression and correlation effect is an obvious application of the covariance analysis. The result of Do population by age groups (15 ages interval) from 1966 Census and from 1970 Census has been applied to analyzing covariability by the analysis of covariance. The results are as follows. (1) The signicance of the regression of 1970 population on 1966 population is assured as F=116.5 (2) There is a significant difference between mean of each age group. (F=88.1) (3) There is very little evidence of significant heterogeneity of regression between age groups. (F=0.72)

• The Korean Journal of Applied Statistics
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• v.1 no.1
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• pp.39-44
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• 1987

For obtaining the m.l.e. of $\Sigma$ from p-variate Non-singular Normal parent, $N_p(\mu, \Sigma)$, Andersous' Procedure based on the invariance property of the m.l.e. seems to be generally Preferred in the view of its simplicity. This paper shows that his approach with respect to $\Sigma^{-1}$ rather than $\Sigma$ itself, he burther applicable to deriving the m.l.e. of parametersinvolved in the common factor model an dsimplex model as well.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.4
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• pp.102-108
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• 2005

Single PPM Quality Innovation Movement is originally developed quality program in Korea for supplier's quality level-up since 1995. The quality target is below the 10ppm(parts per million) in outgoing quality and delivered goods plus field claim. Recently 1,053 companies is received Single PPM Quality Certification from government. This quality program is to realized the anticipated results not only duality level's increasing, but also company's confidence, competitiveness. We were able to obtain participations of 75 questionnaire, and derived statistics by means of SPSS/PC version 10.0. In this study, we find the bottleneck factor for promotion and upgrade S-PPM, and suggest a way out of difficulties.

• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.467-475
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• 2005

This research has been conducted in order to assess the effects on quality management factor of the construction sites. 30 companies abiding by the 'construction industry law' and 32 companies abiding by the 'housing construction promotion law' have been researched in areas of quality-management environment, quality-management understanding, quality-management education on construction field, quality-system and quality-improvement. This construction quality factors are to realized the anticipated results not only quality level's increasing, but also company's confidence, competitiveness. We were able to obtain participations of 62 questionnaire, and derived statistics by means of SPSS/PC version 10.0. In this study, we find the bottleneck factor for promotion and upgrade quality management factor of the construction sites and suggest a way out of difficulties.

• Journal of the Korea Safety Management & Science
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• v.7 no.3
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• pp.29-36
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• 2005

This research has been conducted in order to assess the effects on quality management factor of the construction sites. 30 companies abiding by the 'construction industry law' and 32 companies abiding by the 'housing construction promotion law' have been researched in areas of quality-management environment, quality-management understanding, quality-management education on construction field, quality-system and quality-improvement. This construction quality factors are to realized the anticipated results not only quality level's increasing, but also company's confidence, competitiveness. We were able to obtain participations of 62 questionnaire, and derived statistics by means of SPSS/PC version 10.0. In this study, we find the bottleneck factor for promotion and upgrade quality management factor of the construction sites and suggest a way out of difficulties.

• The KIPS Transactions:PartB
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• v.13B no.3 s.106
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• pp.329-336
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• 2006

In this paper, we propose a method of significant term extraction within a document. The technique used is Principal Component Analysis(PCA) which is one of the multivariate analysis methods. PCA can sufficiently use term-term relationships within a document by term-term correlations. We use a correlation matrix instead of a covariance matrix between terms for performing PCA. We also try to find out thresholds of both the number of components to be selected and correlation coefficients between selected components and terms. The experimental results on 283 Korean newspaper articles show that the condition of the first six components with correlation coefficients of |0.4| is the best for extracting sentence based on the significant selected terms.

• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.648-657
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• 2012

This study is examined for the effects of question generating strategy and feedback(teacher feedback and student peer reviews) on science achievement, self-efficiency and perception of the class in the middle school. Three classes of middle school 1st grade in a city were sampled for the study. The students in comparative group took traditional lessons and solved questions presented on worksheets distributed by a teacher. On the other hand, the students in the experimental groups 1 and 2 generated and solved questions by themselves after traditional lessons and then participated in the activity with peer's feedback and teacher's feedback, respectively. A self-efficiency test had been conducted before the treatments and the various tests such as achievement, self-efficiency and the perception of the class were carried out after treatments. The statistical results were analysed by ANCOVA, MANCOVA and t-test. The results of this study were as follows: First, there was significant difference between the control and experimental groups in the science achievement test (p<.01). But there was no significant difference between the experimental groups (p>.05). Second, both of the experimental groups showed enhanced self-efficiency compared with comparative group (p<.01). In sub-areas of self-efficiency, there were also meaningful results in the area of self-efficiency for control experimental group 1(p<.01), and in the area of difficulty preferences for experimental group 2 (p<.01). Third, the experimental group 1, given teacher's feedback, showed more positive perception of the class than the experimental group 2 that was given peer's feedback (p<.01).

• Journal of the Korean Society for information Management
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• v.24 no.1 s.63
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• pp.55-74
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• 2007

The purposes of this study are to examine the influences of appraisal and reward on the activities of knowledge management and to search the strategies for effective appraisal and reward system to activate the knowledge management. The results of covariance structural analyses indicate that appraisal has a significant direct effect on reward and knowledge creation as well as a significant indirect effect on knowledge sharing via reward and knowledge creation. Reward has a significant direct influence on knowledge sharing. Knowledge creation also significantly affects knowledge sharing. Based on the results, the potential implications of effective appraisal and reward system to activate the knowledge management are discussed.

• Journal of Korea Port Economic Association
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• v.31 no.2
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• pp.103-114
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• 2015

The exchange rate volatility during the global financial crisis in 2007-2009 led Korean shipbuilding companies to face currency risk. The use of foreign currency derivatives to take a risk in financial exposure affects them significantly. This research analyzes how the use of foreign currency derivatives affects the Korean shipbuilding industry in relation to its foreign sales by company type and over time, especially before and after the crisis period. It is based on statistical data presented by KOSHIPA and KOSIC in 2001-2014. The results of the analysis show that there is a significant relationship between foreign currency derivatives and foreign currency exposure for all firm sizes and years, but no relationship between them overtime.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.101-104
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• 1995

We isolated sixty lactic acid bacteria(LAB) from lactic fermented products. Among 60 isolates of LAB, 30 isolates were identified as Lactobacillus casei ssp.(5 strains), Lactobacillus acidophilus(2 strains), Lactobacillus delbrueckii ssp. bulgaricus(6 strains), Lactobacillus plantarum(4 strains), Streptococcus salivarius ssp. thermophilus(11 strains), and Streptococcus faecalis(2 strains). The acid tolerance and bile resistance of 30 LAB were determined. Because the acid tolerance was affected by the initial cell concentrations, the analysis of covariance could be used to remove the effect of initial cells on acid tolerance when testing for differences in acid tolerance among six species. Viability of LAB under acidic condition, pH 3 for 2 hours at $37^{\circ}C$, was significantly different among the species. L. casei and L. acidophilus strains showed great viability, but L. bulgaricus and S. thermophilus strains were very weak in acid tolerance.