• Proceedings of the Korean Reliability Society Conference
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• 2005.06a
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• pp.385-392
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• 2005

The restriction of the use of hazardous substances in electrical and electronic equipment legislation mandates the substitution of lead and other hazardous substances in electronics products by July 2006. Due to this legislative pressure, the electronics industry is moving to adoption of lead free solders. In this paper, we investigated a flux to restrict generating electrochemical migration in lead-free solder. The lead-free solders used in this study were Sn-0.7Cu-0.01P and Sn-3.0Ag-0.5Cu. To measure the resistance of electrochemical migration, the dew-cycle test and water drop test were adopted. As the result, now flux having high durable of electrochemical migration was developed.

• Journal of Intelligence and Information Systems
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• v.13 no.4
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• pp.79-90
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• 2007

The image quality measure is an important issue in the image processing. Several methods which measure the image quality have been proposed and these are based on the mathematical point of view. However, there is difference between the mathematicalmeasure and the measure based on the human visual system and a new measure has to be proposed because the final target of the image is a human visual system In this paper, a statistical image quality measure which is considered the human visual feature was suggested. The human visual system is using the global quality of the image and the local quality of the image and the local quality is more important to human visual system. In this paper, the image divided into several segments and the image qualities were calculated respectively. After then, the statistical method using scoring was applied to the image qualities. The result of the image quality measure was similar to the result of measure based on the human visual system.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.8
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• pp.837-841
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• 2010

This paper proposes an effective similarity measure for content-based image retrieval using MPEG-7 DCD. The proposed method can measure the similarity of images with the percentage of dominant colors extracted from images. As the result of experiments, we achieved a significant improvement of 18.92% with global DCD and 47.22% with local DCD in ANMRR than the result by QHDM. This result shows that the proposed method is an effective similarity measure for content-based image retrieval. Especially, our method is useful for region-based image retrieval.

• Journal of applied mathematics & informatics
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• v.17 no.1_2_3
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• pp.315-328
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• 2005

In this paper we present a new method for designing a nozzle. In fact the problem is to find the optimal domain for the solution of a linear or nonlinear boundary value PDE, where the boundary condition is defined over an unspecified domain. By an embedding process, the problem is first transformed to a new shape-measure problem, and then this new problem is replaced by another in which we seek to minimize a linear form over a subset of linear equalities. This minimization is global, and the theory allows us to develop a computational method to find the solution by a finite-dimensional linear programming problem.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.834-839
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• 2004

In this paper, we investigate the optimal base position and joint configuration of a planar wheeled mobile manipulator in terms of manipulability measure. Taking into account the level of coordination between a manipulator and a platform, both local and global optimization problems are considered. First, based on the kinematic models of a mobile manipulator, the manipulability measures are expressed along with the analysis of the configurational dependency. Second, the geometric symmetry of a mobile manipulator in view of manipulability measure is analyzed, and for some base positions, the best and worst joint configurations are determined, Third, with reverence to the maximum, minimum, and average manipulability measures, the optimal base positions are determined, and the percent improvements due to the base relocation are discussed considering the relative scales among the platform size, the wheel radius, and the link length.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1543-1546
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• 2005

This paper presents a method to measure a large surface shape using atomic force microscopy, which has been used mostly for measuring over very tiny surfaces. Experiments are performed to measure a step height and a slope of a test sample. The proposed method is rigorously compared with the coordinate measuring machine. The repetition accuracy and the effects of the set point are also studied. The experimental results show that the proposed method is reliable and should be effective to measure both the nano-accuracy surface profile as well as the micro-accuracy global shape of a macro/micro parts using atomic force microscope.

• Korean Management Science Review
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• v.19 no.2
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• pp.59-73
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• 2002

There have been academic debates upon which measure is more desirable in measuring service quality between SERVQUAL and SERVPERF In addition, Korean fast food industry is rapidly growing due to increasing income and globalization. Our study tried to contribute to both academic and practical issues. We compared SERVQUAL and SERVPERF measures to determine which one is superior to measure service quality in Korean fast food franchise. We collected data from two branch restaurants of one American global fast food franchise system. Regression analyses resulted in that SERVPERF outperformed SERVQUAL. Furthermore, we compared the goodness of fit of the two structural equation models of SERVQUAL anO SERVPERF, respectively. The SERVPERF model showed a much better model fit than the SERVQUAL model did. Thus, we suggest that SERVPERF be used to measure service quality in Korean fast food industry.

• Korean Journal of Human Ecology
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• v.14 no.2
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• pp.269-276
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• 2005

The purpose of this study is to examine, according to sex and grade, the relationship and difference between mothers' parenting attitudes and self-perceived competences of their children. 197 children of the 4th through the 6th grade were selected from an elementary school in Daejeon area. We used the Perceived Competence Scale for Children (Harter, 1982) to measure their self-perceived competence and the Mother's Parenting Attitudes Scale (1990, Lee & Park) to measure parenting attitudes of their mothers. Major findings are as follows: First, there were significant differences in the children's self-perceived competence according to their perception of parental warmth and control. Children with more perception of parental warmth and consistent control considered themselves higher in cognitive and social competences and in self-worth. Boys perceived higher mother's consistent control and positive participation in parenting-attitudes than girls. Girls perceived themselves higher than boys in global self-worth. Next, Out of the three grades the 4th graders indicated more perception of attachment, authoritarian control, and positive participation in parenting attitudes. There was statistically no difference in self-perceived competences of children according to their grades. Finally, there were correlations between mothers' parenting attitudes and perceived competences of their children. Children with more perception of parental warmth, attachment, positive participation, and consistent control showed higher level of physical competence, social competence, and global self-worth.

• Safety and Health at Work
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• v.11 no.2
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• pp.178-186
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• 2020

Background: Cognitive impairment is a public health burden. Our objective was to investigate associations between work hours and cognitive function. Methods: Multi-Ethnic Study of Atherosclerosis (MESA) participants (n = 2,497; 50.7% men; age range 44-84 years) reported hours per week worked in all jobs in Exams 1 (2000-2002), 2 (2002-2004), 3 (2004-2005), and 5 (2010-2011). Cognitive function was assessed (Exam 5) using the Cognitive Abilities Screening Instrument (version 2), a measure of global cognitive functioning; the Digit Symbol Coding, a measure of processing speed; and the Digit Span test, a measure of attention and working memory. We used a prospective approach and linear regression to assess associations for every 10 hours of work. Results: Among all participants, associations of hours worked with cognitive function of any type were not statistically significant. In occupation-stratified analyses (interaction p = 0.051), longer work hours were associated with poorer global cognitive function among Sales/Office and blue-collar workers, after adjustment for age, sex, physical activity, body mass index, race/ethnicity, educational level, annual income, history of heart attack, diabetes, apolipoprotein E-epsilon 4 allele (ApoE4) status, birth-place, number of years in the United States, language spoken at MESA Exam 1, and work hours at Exam 5 (β = -0.55, 95% CI = -0.99, -0.09) and (β = -0.80, -1.51, -0.09), respectively. In occupation-stratified analyses (interaction p = 0.040), we also observed an inverse association with processing speed among blue-collar workers (adjusted β = -0.80, -1.52, -0.07). Sex, race/ethnicity, and ApoE4 did not significantly modify associations between work hours and cognitive function. Conclusion: Weak inverse associations were observed between work hours and cognitive function among Sales/Office and blue-collar workers.

• Journal of the Korean association of regional geographers
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• v.19 no.3
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• pp.551-565
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• 2013

This paper examines the aspects of development education in the Geography Syllabus in the State of NSW, Australia and geography textbooks developed by it. The aspects of development education in the Geography Syllabus and textbooks is as follows. Firstly, Development Education is implicitly described in terms of the difference of the quality of life and aid links in Geography (Mandatory) Stage 4 and Geography (Mandatory) Stage 5, but clearly in Geography Elective. Moreover, Development Geography is one of unit to learn deeply in case of Global Challenges in Stage 6. Secondly, in geography textbooks, development education is sequenced with learning of the quality of life in everyday life, understanding of diverse meaning of development and measure of development, and the role of individuals and organizations for reducing the global inequality. The implications of the findings is as follows. Firstly, geography curriculum needs to be consist of the difference of the quality of life in the middle school, and development geography in high school. Secondly, the major concepts of development education like development, measure of development and the aid etc. need to be described in the different views. Thirdly, development education needs learners to learn the interdependence and practice the global citizenship through learning of specific links of our country with others. Finally, geography textbooks should not describe the normative efforts for reducing global inequality, and treat individual practical cases as well as organizations like government and NGOs so that learners empathize with their value and attitude through individual practical cases.