• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.163-167
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• 2001

A two-dimensional progressive failure analysis method is presented for the strength characterization of the composite joints under pin loading. The eight-nodes laminated she]1 element is utilized based on the updated Lagrangian formulation. The criteria by Yamada-Sun, Tsai-Wu, and the maximum stress are used for the failure estimation. The stiffness of failed layer is degraded by the complete unloading method. No factor depending on test is included in the finite element analysis except for the material strength and stiffness. Total 20 plate specimens with and without hole are tested to validate the finite element prediction. The Tsai-Wu failure criterion most conservatively estimates the strength of laminate, and the maximum stress criterion yields the highest strength because it does not consider the coupling of the failure modes. The strength by Yamada-Sun method neglecting the matrix failure effect are located between other two methods and shows best agreement with test result for laminate with hole.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.8
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• pp.1322-1331
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• 1997

A method of strength evaluation applying fracture mechanics in the adhesively bonded joints of Al/Steel dissimilar materials was investigated in this paper. Various shapes of adhesively bonded Al/Steel scarf joints focussing on fracture criterion of mixed mode crack were prepared for the static tests. Also, stress intensity factors of the interface cracks in adhesively bonded joints of Al/Steel dissimilar materials were analyzed with 2-dimensional elastic program of boundary element method(BEM), and the experiment of fracture toughness were carried out under various mixed mode conditions. From the results, the fracture criterion and method of strength evaluation by the fracture toughness in adhesively bonded joints of Al/Steel dissimilar materials were proposed.

• Journal of Mechanical Science and Technology
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• v.16 no.12
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• pp.1594-1603
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• 2002

In this paper, when the initial propagation angle of a branched crack is calculated from the maximum tangential stress criterion (MTSC) and the minimum strain energy density criterion (MSEDC), it is essential that you use stress components in which higher order terms are considered and stress components at the position in a distance 0.005㎜ from the crack tip (=r). When an interfacial crack propagates along the interface at a constant velocity, the initial propagation angles of the branched crack are similar. to the mode mixities (phase angle) and the theoretical values obtained from MTSC and MSEDC. The initial propagation angle of the branched crack depends considerably on the stress intensity factor K$_2$.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.611-615
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• 2005

Having been multimedia services in BcN network, QoS is best important factor. This paper classify existing services and newly to be offered services, analyze quality criterion and measurement method for QoS guarantee in BcN, This paper investigate end-to-end quality criterion, classify measurement method existing and newly to be offered services, search quality criterion, introduce measurement method such as call success rate, packet loss rate, one-way delay, jitter and R-value for end-to-end quality measurement.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.4
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• pp.66-70
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• 2008

The propagation of a mixed-mode crack in soda-lime silica glass is modeled by movable cellular automata (MCA). In this model, a special fracture criterion is used to describe the process of crack initiation and propagation. The results obtained using the MCA criterion are compared to those obtained from other crack initiation criteria, The crack resistance curves and bifurcation angles are determined for various loading angles. The MCA results are in close agreement with results obtained using the maximum circumferential tensile stress criterion.

• Journal of The Korean Association For Science Education
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• v.12 no.1
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• pp.93-101
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• 1992

The purposes of this study were; 1) to apply the network analysis to evaluation of students' laboratory reports, 2) to test the applicability of the systematic network analysis. For this purposes, 7th grade 88 students from 22 middle schools in Inchon city of Korea were selected and their laboratory reports were evaluated by a evaluation criterion network developed in this study. The evaluation criterion consisted of 4 categories and 10 subcategories. The results of this study suggested that the network analysis approach was suitable one for the evaluation of students' laboratory reports. This was supported by total score distribution, means/weight, Cronbach's ${\alpha}$ coefficient(0.70), and the subcategories' reliabilities. The resluts of the factor analysis indicated that the evaluation criterion network of this study had two factors.

• Culinary science and hospitality research
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• v.16 no.2
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• pp.1-14
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• 2010

This study is focused on the image benefit cost criterion value and the pure image benefit figure of the local food service industries, V, T, and O based on the theory and factor-analyses of food service industry. To accomplish the aim of this study, theoretical and positive research methods have been applied. The steps of food service image decision projects for the activating of identification on food service have been examined through theories and positive analyses. As the results, 'the image of menu service' appears to be the most effectual factor on the pure image benefit score, which is the priority order of the project planning for the food service image marketing of Jeonju area. As for the image benefit cost criterion value, 'the image of managemental service system', 'the image of approachability', and 'the service of internal surroundings' have been proved to be the most effectual factor in V, T, O respectively. On the other hand, this study shows that V manages its image of food service most effectually with 1.7 billion won, T with 96 million won, O with 7.2 million won for the image marketing strategy.

• The Journal of Korean Academic Society of Nursing Education
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• v.26 no.1
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• pp.47-55
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• 2020

Purpose: The aim of this study was to examine the validity and reliability of the Korean version of the PTSD scale (K-PTSD) for measuring attitudes and knowledge of PTSD. Methods: A cross-sectional study design was used. The K-PTSD scale consisted of 8 items for attitudes, 8 items for general knowledge of PTSD, and 3 items for knowledge of PTSD treatment; 211 nursing students and paramedic students participated. Content validity, item analysis, and factor analysis were used to examine the construct validity. Criterion validity was tested by using educational experience with PTSD as a criterion. Cronbach's α was used to identify internal consistency reliability in the attitude scale. Results: Construct validity of the K-PTSD was verified by exploratory factor analysis, with factor loadings for attitude ranging from .59 to .84. Criterion validity in comparing knowledge of PTSD (t=2.02, p=.044) and PTSD treatment (t=3.19, p=.022) showed a significant difference according to PTSD educational experience. Cronbach's α for the attitude scale was .79 and .59. Conclusion: The findings suggest that the K-PTSD is a valid and reliable tool that can measure attitudes and knowledge of PTSD among nursing and paramedic students. However, further study is needed to retest the verification of this scale with more diverse participants.

• Journal of Korean Academy of Nursing Administration
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• v.22 no.1
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• pp.11-21
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• 2016

Purpose: The purpose of this study was to develop and test the validity and reliability of the Korean version of nurses' attitudes toward delegation and preparedness to delegate (APD). Methods: The Korean version of APD was developed through forward-backward translation methods. Internal consistency reliability, criterion validity, and construct validity using exploratory and confirmatory factor analysis were conducted using IBM SPSS Statistics 19 and AMOS 20.0. Survey data were collected from 161 nurses working in 2 general hospitals. Results: The Korean version of APD showed Cronbach's alphas of .68 and .85. Factor loadings of the 8 attitude items on the 3 subscales ranged from .60 to .86 and the 15 preparedness items on the 4 subscales ranged from .47 to .90. The model of 3 subscales for the Korean nurses' attitude toward delegation and the model of 4 subscales for the Korean nurses' preparedness to delegate were both validated by confirmatory factor analysis(NC<3, CFI>.90, RMSEA<.10). Criterion validity compared to job satisfaction showed significant correlation. Conclusion: The findings of this study demonstrate that this modified Korean version of APD is applicable for measuring Korean nurses' attitude toward delegation and preparedness to delegate.

• Journal of Korean Academy of Nursing
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• v.47 no.1
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• pp.86-97
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• 2017

Purpose: The purpose of this study was to develop and test the psychometric properties of the newly developed instrument, Meaning in Life, for elderly Korean people. Methods: Ten older adults participated in the qualitative research used to develop the initial items. Participants for the psychometric testing were 371 community-dwelling older adults. Validity and reliability analyses included content, construct, and criterion-related validities, internal consistency, and test-retest reliability. Results: The Meaning in Life Scale consisted of 12 items with three distinct factors; value of life, source of life, and will to live, which explained 86.7% of the total variance. A three-factor structure was validated by confirmatory factor analysis. Criterion-related validity was supported by comparison with the Purpose in Life Test (r=.74). Reliabilities were secured with test-retest reliability of Intra-class Correlation Coefficient (ICC) .85 and the Cronbach's alpha coefficient .90. Conclusion: The results of this study indicate that this instrument is useful to measure meaning in life in Korean elders.