• Journal of the Korean earth science society
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• v.41 no.6
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• pp.670-683
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• 2020

The purpose of this study was to develop a test tool for convergence problem solving skill. To this end, constructs of convergence problem solving skill were defined in three domains: convergence attributes, convergence thinking, and convergence literacy domains. Thirty-seven pilot items were developed on the basis of the sub-categories for each domain that was defined through intensive literature review; problem solving & convergent thinking and creative thinking for convergence thinking domain, individual and social propensity for the convergence attributes domain, and convergence literacy as convergence literacy domain. Through an exploratory factor analysis, 30 items in the constructs of the test tool were confirmed. A confirmatory factor analysis result showed that the five construct models well captured the covariance between all the items well. Finally a statistical result shows that the reliability of the items and constructs were well established (Cronbach's α value= .963). Thus, the test tool for convergence problem solving skill developed in this study was statistically reliable.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.8
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• pp.856-867
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• 1990

In this paper, the convergence and the learning accuracy of the back-propagation (BP) method in neural network are investigated by 1) analyzing the reason for decelerating the convergence of BP method and examining the rapid deceleration of the convergence when the learning is executed on the part of sigmoid activation function with the very small first derivative and 2) proposing the modified logistic activation function by defining, the convergence factor based on the analysis. Learning on the output patterns of binary as well as analog forms are tested by the proposed method. In binary output patter, the test results show that the convergence is accelerated and the learning accuracy is improved, and the weights and thresholds are converged so that the stability of neural network can be enhanced. In analog output patter, the results show that with extensive initial transient phenomena the learning error is decreased according to the convergence factor, subsequently the learning accuracy is enhanced.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.3
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• pp.1-8
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• 1996

This paper proposes a novel transversal filter and an optimal LMS algorithm, and show how these can be realized as an adaptive equalizer. The transversal filter consists of a walsh and block pulse functions. in the LMS algorithm with equalizers, the convergence factor is an improtant design parameter because it governs stability and convergence speed. The conventional adaptation techniques use a fixed time constant convergence factor by the trial and error method. In this paper, an optimal method in the choice of the convergence factor is proposed. The proposed algorithm is obtrained that is tailored for each filter tap and is updated at each iteration. The performance of the proposed algorithm is compared iwth those of the conventional TDL and DFT equalizers by computer simulations.

• Journal of the Korean Society for Heat Treatment
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• v.36 no.4
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• pp.237-241
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• 2023

Recently, research on flexible sensors for personal health management has been gaining attention. In this study, we fabricated a crack-based flexible sensor in thin film form to measure the pulse on the wrist. We evaluated the characteristics of the sensor based on the curing conditions of the PDMS (Polydimethylsiloxane) film to optimize the sensor's gauge factor. The modulus of PDMS varies depending on the curing conditions. In this case, the modulus of PDMS has a significant influence on crack formation, leading to changes in the sensitivity of the sensor. This study examined the changes in the gauge factor associated with these variations.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.317-327
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• 2017

The purpose of this study is to analyze the effects of the convergence of the in-flight meal quality, the customer satisfaction, the brand image and brand loyalty. A total of 170 questionnaires were finally used for the 'analysis of factors, analysis of reliance, analysis of corelation and multiple regression analysis.' We found out that the in-flight meal quality came up with the food factor, service factor and cleanliness factor. The results of the study are as follows; First, only the food factor and the service factor positively affected the customer satisfaction. Second, the food factor and the service factor positively affected the brand image. Third, the customer satisfaction positively affected the brand image and the brand loyalty. Lastly, the brand image positively affected the brand loyalty. According to this study, the in-flight meal quality, customer satisfaction, brand image and brand lo oyalty in the airline service are very important factors for a successful marketing strategy.

• Convergence Security Journal
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• v.11 no.6
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• pp.31-36
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• 2011

Cloud computing is a system which efficiently utilizes resources. In this paper, we propose 2-factor authentication system combing PKI, ID_PW and location information. The proposed method improve the security of hybrid cloud systems and manage resources more safely.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.6
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• pp.1880-1890
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• 2015

The purpose of this study was to development of the 'convergence motive' scale for interdisciplinary knowledge fusion. Based on results from literature review, this study clarifies a theoretical ground for 'convergence motive'. Initial items to measure this concept were verified by content analysis and then finalized. After a pilot test done with 568 college students, gathered data were analyzed by item selection and exploratory factor analysis to verify their validity. Next, the main test implemented with 1,211 college students was analyzed with exploratory factor analysis using the method for rotation based on maximum likelihood analysis and direct oblimin for validating the final items to measure 'convergence motive'. As a result, the scale for 'convergence motive' consists of 43 items to measure the following four factors: collaboration to identifying and solving problems, challenge of a new perspective, communication for convergence, cohesion for convergence. Construct validity and criterion-related validity were performed at last to check this scale's theoretical construct. In conclusion, this study concluded that the scales for convergence motive could be generalized and applicable to other samples.

• Journal of Korean Ophthalmic Optics Society
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• v.1 no.1
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• pp.29-39
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• 1996

We studied the method which would determine the appropriate additive damping factor for the damped least sequres(DLS) optimization. We calculated eigenvalues of the product of the Jacobian matrix of error function by using the singular value decomposition(SVD) method. While suitable damping factor was appiled to the additive DLS by using SVD and Gaussian elimination method, the convergence and stability of the optimization process were examined in a triplet-type camera lens-system where the condition number is well conditioned. We compared the convergence and stability of merit function when median, maximum and minimum of eigenvalues were used as a damping factor in the optimization process. When damping factor is median of eigenvalue, the convergence and stability of merit function are more excellent than in the case of two other eigenvalues. Thus, we adopt the median of eigenvalues as an appropriate damping factor. Next, by using SVD and Gaussian elimination method, we compound the convergence and stability of optimization process for triplet-type camera lens-system design. In these two method; triplet-type camera lens-system in which condition number is well conditioned, has little improvement with the combination of DLS and SVD.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.2_1
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• pp.141-148
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• 2022

In this paper, the evaluation equations proposed by Tange et al. and Ando et al. were used to evaluate the threshold stress intensity factor ∆K^R_th(s) and fatigue limit ∆𝜎^R_wc, according to the small crack of offshore structural steel F690. Despite the differences in concept and shape of the two equations, the ∆K^R_th(s) and ∆𝜎^R_wc proved completely consistent. It is possible to use these equations to evaluate the dependence of the crack length on the ∆K^R_th(s) and ∆𝜎^R_wc of structures made of all steel grades. With these equations, the characteristics of microcracks can be quantitatively evaluated, and the safety and reliability of the structure can be secured.

• Proceedings of the Korean Magnestics Society Conference
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• 2014.05a
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• pp.117-117
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• 2014