• Journal of The Korean Association For Science Education
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• v.24 no.2
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• pp.287-297
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• 2004

In this study, students' understanding of the analogies used for chemical concepts in science textbooks, misconceptions induced by the analogy, and the factors affecting conceptual understanding were investigated. In addition to the tests of field independency and logical thinking ability, tests of students' understanding of concepts and analogies on three states of matter, pressure-volume relation, molecular motion, and changing state depending upon energy were administered. The results revealed that half of the subjects understood the analogies differently from the textbook writers' intention and that students' conceptual understanding was significantly correlated with the degree of understanding on corresponding analogies, field independency, logical thinking ability, and prior achievement of science. The results of analyzing the direct and indirect effects of each variable on conceptual understanding showed that the direct effect of prior achievement was significant and that field independency and logical thinking ability had indirect effects through understanding of analogies and prior achievement of science. The limitations and implications of using analogies in science education were discussed on the basis of the results.

• Journal of Educational Research in Mathematics
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• v.26 no.4
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• pp.755-768
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• 2016

According to TIMSS, secondary math teachers in Korea has lower confidence compare to other countries, despite the fact that teachers' confidence of teaching is an important variable. This not only influences the student's improvement but, also the quality improvement of teachers' career. Therefore, this study explores the effect of secondary math teachers' confidence according to the context variables such as teaching years, teaching preparation, collaboration with other teachers, and teaching limitation. Additionally, these context variables' $R^2$ toward the change of teaching confidence is also included. Results indicate that teaching preparation, collaboration with other teachers, and teaching limitation contribute in the confidence of teaching. $R^2$ of the change of teaching confidence shows large contribution to teaching preparation which does not accomplish with other variables.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3239-3248
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• 2010

A number of people using e-payment system has been increasing drastically during the recent period and the trend still continues. The purpose of this article was to investigate the effect of service quality and social factors on the e-payment system acceptance and the moderating effects of self-efficacy in the perspective of the interactional approach. In this research, data were collected from 2331 e-payment system users with structured questionnaires and analyzed using regression analysis method. This research found that security, responsiveness, mass media, word of mouth, security and self-efficacy of interaction effect have significant positive effects on acceptance intension. The result of this research showed that the social influence and self-efficacy interactional approach are more adequate than only service quality in accounting for the e-payment system acceptance.

• 한국해양학회지
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• v.22 no.1
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• pp.9-18
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• 1987

A number of hydrographic studies and some recent current measurements around Chejudo Island suggest an existence of a clockwise residual flow in the west and north coasts of the island all the year round. On the eastern side of the island the Tsushinma Current flows northward and northeastward. The contribution of tide-induced residual currents to the observed residual. flow around the island was examined here through numerical solution of the two-dimensional nonlinear shallow-water equations. The calculated tide-induced residual currents show a clockwise circulation around the island. Significant residuals of 2-4cms$\^$-1/are confined over sloping bottom topography around t he island and the far-field residuals are negligibly small. The inclusion of a permanent current into the model was also attempted in order to see the effects of the Tsushima Current system on the residual circulation around the is land. It was found that combined effects of tide-induced residuals and the permanent current field associatedwith the Tsushima Current explain qualitatively not only the observed clock wise residuals in the west and north coasts but also the northward flow on the eastern side of the island.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.3
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• pp.170-182
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• 2006

Last few years have seen a rapid increase in research on ubiquitous computing. Ubiquitous computing is often touted as a technology that will make computing available to the user anywhere and anytime. One important problem to be addressed in building such a ubiquitous computing environment is how to manage services and deliver them to the user in an effective manner. This paper presents our model called Personal Kiosk(PK) as a way of solving the problem. PK is a model of ubiquitous service provisioning that enables the user to use desired services anytime and anywhere. The design and implementation of the current PK in the 'Local Area' setting with related technical issues are also presented. A location-sensing technique for indoor users and a personalized service provisioning based on user location and privileges are discussed in detail.

• Korean Journal of Remote Sensing
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• v.30 no.2
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• pp.251-258
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• 2014

We upgraded to utilize a novel method for combining the analog to digital converter and photon-counting measurements for backscatter photon signal of lidar. We have and improve the standard combining method for determination of those conversion factors between analog to digital converter data and photon-counting data measurement which is conducted dead time correction. The combining method and dead time correction method presented here has been successfully applied to experimental data obtained in Gwangju, Korea.

• The Korean Journal of Applied Statistics
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• v.31 no.2
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• pp.253-263
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• 2018

Internet addiction in adolescents is an important social issue. In this study, sparse partial least-squares regression (SPLS) was applied to internet addiction data in Korean adolescent samples. The internet addiction score and various clinical and psychopathological features were collected and analyzed from self-reported questionnaires. We considered three PLS methods and compared the performance in terms of prediction and sparsity. We found that the SPLS method with the hierarchical likelihood penalty was the best; in addition, two aggression features, AQ and BSAS, are important to discriminate and explain latent features of the SPLS model.

• Journal of The Korean Association For Science Education
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• v.25 no.5
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• pp.595-602
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• 2005

The purpose of this study was to test effects of the Triple Abduction Model (TAM) for improving the skills of scientific hypothesis generation in science learning. Twenty-six students were selected for the TAM group and 27 others were selected for a traditional group from one high school. Researchers developed and administered 10 TAM and traditional-style activities. The degree of hypothesis explanation was evaluated during the experimental treatment. Each Subjects' ability in scientific hypothesis generation was assessed by the Science Knowledge Generation Test A and B. Test A was used as a protest and B for a posttest. The results of this study revealed that the degree of hypothesis explanation of TAM was significantly higher than the degree of the traditional group, and the mean of the TAM group was equal to the mean of traditional group on the pretest. Additionally, the mean of the TAM group was significantly higher than the mean of the control group on the posttest. Therefore, instruction with TAM was more effective than the instruction using traditionals method for increasing students' hypothesis generation skills.

• Journal of the Korean Electrochemical Society
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• v.4 no.2
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• pp.70-76
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• 2001

The present work describes the capabilities of laser beam deflection (LBD) technique for the analysis of the stresses developed during hydrogen diffusion through Pd foil electrode. First, we explain briefly the elasto-diffusive (Gorsky effect) and diffusion-elastic phenomena. A model for the diffusion-elastic phenomenon is theoretically derived from the solution of the Fick's equation for given initial and boundary conditions, Vegard's second law and Hooke's law. Second, we introduce how to apply the principle of LBD technique to the study on the stresses generated during hydrogen diffusion. From the comparison of the deflection transients numerically calculated with those experimentally measured, we finally discuss the change in the tensile deflection with time in terms of hydrogen concentration profile transient and hydrogen diffusivity.

• Spatial Information Research
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• v.16 no.3
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• pp.359-372
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• 2008

This research estimated Pinus densiflora distribution and suggested an optimal grid size of DEM for ecologically better explaining spatial distribution and appearance pattern of Pinus densiflora and analyze appearance frequency of Pinus densiflora by topographical factors. And this work ultimately aimed at topographically analyzing spatial distribution of Pinus densiflora by comparing impact of topographical factors. The aspect was analyzed in detail, east, west, south, north, from DEM with 1m grid size, and simply, east, west, south or east, south from DEM with bigger grid size. As a result of distribution of Pinus densiflora by aspect, Pinus densiflora appeared in all aspect with smaller grid size, while distribution in specific aspect decreased with bigger grid size. The analysis of appearance frequency with 100m grid size represented spatial distribution characteristics of Pinus densiflora as visual interpretation showed. The results of comparing impact of aspect, slope, TWI proved that aspect have more impact on distribution of Pinus densiflora than slope and there was not enough a difference between impact of slope and TWI.