• Journal of the Korean School Mathematics Society
• /
• v.11 no.4
• /
• pp.569-593
• /
• 2008

Since 2005 KICE-TLC has focused on the development of supporting programs for teaching consultation and pedagogical content knowledge(PCK). The purpose of this year's research was to explore types of pedagogical content knowledge(PCK, hereafter) for effective teaching mathematics topics drawn from the amended national mathematics curriculum announced in February, 2007. Based on this year's PCK research, we will develop mathematics teaching consulting program from 2009 research by field testing of developed mathematics PCK. The major source of data for this study was transcripts of audiotapes of the group discussions that took place during the regular weekly meetings where we compared and analyzed three teachers' classes. We also conducted open-ended interviews with the three teachers and collected reflective notes written by participants. This research provided teachers with an opportunity to think about what is important in the teaching of a topic and why, and to consider possibilities for future development. This research highlights the importance of teacher meetings where teachers share their expertises and insights through reflection and dialogue. By introducing the concept of PCK, examining, analyzing and modelling it in pre-service and in-service teacher education practice, we can contribute to extend teachers' professional learning. Finally, just like quality student learning, quality teaching and teacher education practices require critical reflection and careful scaffolding.

• Tunnel and Underground Space
• /
• v.13 no.5
• /
• pp.331-343
• /
• 2003

Though the Grouting has been in use for a long time, it is still regarded as an technique rather than engineering. The study of ground improvement by grouting is rare especially in jointed rock mass. In this study, biaxial compression tests were performed in the jointed rock mass models with .ough surfBce joints assembled with blocks before and after grouting. The load-deformation curves of the jointed rock masses showed a non-linear relationship before grouting but showed a relatively linear deformaion behavior after grouting. Improvement ratio (deformation modulus after grouting/deformation modulus before grouting) decreased with increasing joint spacing and lateral stress. Improvement ratio decreased exponentially with increasing deformation modulus of the rock mass model before grouting. Three-dimensional FDM analysis was performed to a highway tunnel case using experimental data of grouted rock. The convergence of the tunnel predicted after grouting by the numerical modelling coincided with those attained from the field measurement.

• Geophysics and Geophysical Exploration
• /
• v.13 no.1
• /
• pp.24-30
• /
• 2010

This study utilises repeated numerical tests to understand the effects of variable near-surface conditions on time-lapse seismic surveys. The numerical tests were aimed at reproducing the significant scattering observed in field experiments conducted at the Naylor site in the Otway Basin for the purpose of $CO_2$ sequestration. In particular, the variation of elastic properties of both the top soil and the deeper rugose clay/limestone interface as a function of varying water saturation were investigated. Such tests simulate the measurements conducted in dry and wet seasons and to evaluate the contribution of these seasonal variations to seismic measurements in terms of non-repeatability. Full elastic pre-stack modelling experiments were carried out to quantify these effects and evaluate their individual contributions. The results show that the relatively simple scattering effects of the corrugated near-surface clay/limestone interface can have a profound effect on time-lapse surveys. The experiments also show that the changes in top soil saturation could potentially affect seismic signature even more than the corrugated deeper surface. Overall agreement between numerically predicted and in situ measured normalised root-mean-square (NRMS) differences between repeated (time-lapse) 2D seismic surveys warrant further investigation. Future field studies will include in situ measurements of the elastic properties of the weathered zone through the use of 'micro Vertical Seismic Profiling (VSP)' arrays and very dense refraction surveys. The results of this work may impact on other areas not associated with $CO_2$ sequestration, such as imaging oil production over areas where producing fields suffer from a karstic topography, such as in the Middle East and Australia.

• Journal of The Korean Association For Science Education
• /
• v.36 no.1
• /
• pp.75-86
• /
• 2016

The purpose of the present study is to develop and validate an instrument to assess STEM career motivation. We developed 32 items for 7 constructs (i.e. education experience, career value, academic self-efficacy, career self-efficacy, career interest, parents' support, and career motivation) on STEM career motivation based on Social Cognitive Career Theory (SCCT; Lent et al.,1994). 767 first year high school students participated in this study. The items were validated by Messick's framework (1995). In this study, we examined the validity of items in four aspects (i.e. content, substantive, structural and generalizability of validity). Methodologically, we used Rasch analysis, Exploratory factor analysis, confirmative factor analysis based on structural equation modelling. We confirmed that our instrument with 32 items as valid and reliable for measuring the STEM career motivation. In addition, we tested the STEM career motivation model based on SCCT. Our model explained the data well, suggesting that external factors (education experience and parents' support) and cognitive factors (perception of value, self-efficacy and interest) were significantly related to STEM career motivation.

• Journal of Digital Convergence
• /
• v.10 no.8
• /
• pp.327-333
• /
• 2012

The objective of this study is to explore the structural relationships between positive parenting style, self-efficacy, stress, depression, and school adjustment of adolescents. The data in this study used from the 2010 Korea Youth Health Status Survey(N=7,187). To explore these relationships between each variable showed in this study model, structural equation modelling(SEM) was carried out by using IBM SPSS AMOS Ver. 19.0. The main findings of this study are as follows; Firstly, The positive parenting style made a positive effect on self-efficacy, and reduced the stress and depression, eventually affected school adjustment positively. Secondly, the more self-efficacy, and the less stress and depression. And the more self-efficacy, and the more school adjustment. Thirdly, as considering the indirect effect of positive parenting style on school adjustment through the mediating variable as self-efficacy, positive parenting style is more important variable than any other factors. These results implies that positive and intimate parent-children relationships or parenting attitudes on adolescents are necessary highly.

• The Journal of the Korea Contents Association
• /
• v.20 no.4
• /
• pp.348-357
• /
• 2020

Discussions on entrepreneurship are increasing, but the methodology that can be applied to actual small to mid-sized businesses and venture firms is insufficient, and research on measuring achievement and application is lacking. In this regard, this paper analyzed actual proof on the relationship among entrepreneurial orientation, R&D capabilities, market share, and the creation of BSC future values that can be empirically applied to small to mid-sized businesses and venture firms. A factor analysis and hypothesis verification have been conducted with the SEM model utilizing SmartPLS 3.0 on the recent 7th year (2017) data from the Human Capital Corporate Panel (HCCP) of the Korea Research Institute for Vocational Education and Training. The actual proof analysis revealed that entrepreneurial orientation creates a positive influence on R&D capabilities and the creation of BSC, and also on market share, with R&D capabilities as a parameter. On the other hand, the relationship between entrepreneurial orientation and market share proved to be not statistically meaningful. Future value creation of BSC also could not mediate the relation between entrepreneurial orientation and market share. Therefore, this research has proven that a company must cultivate its personnel's R&D capabilities with their entrepreneurial orientation. Furthermore, it is a significant fact that BSC, the conventional measuring tool for performance management, could not mediate the relationship between entrepreneurial orientation and market share. Future companies aiming at innovation should consider developing a new index that could measure the corporate-level entrepreneurship and conduct performance management.

• Korean Journal of Health Education and Promotion
• /
• v.22 no.2
• /
• pp.195-213
• /
• 2005

Objectives: This study aims to determine fostering stress and mental health state that mothers of handicapped children perceive as primary care givers and to analyze their demand for information assistance in order to release their stress so that it can provide materials that contribute to establishment of assistance system for families with handicapped children. Methods: The research subjects were 340 mothers whose children went to a nursery for special children, 3 general nurseries and 6 special schools in Daegu, and the data were collected using structures questionnaires. The survey analyzed mothers' fostering stress, their demand for fostering information assistance, children's daily activity abilities. Component concepts of each scale was validated by adopting confirmatory factor analysis, and factors affecting demand for fostering information assistance were analyzed by adopting covariance structural analysis. Results: Younger mothers tend to have higher demand for information, and mothers with younger children or children with double handicaps also have higher demand. Mothers under 30 have the lowest demand for public health and medical care assistance and for home and community life assistance, while mothers with children with physical handicaps have the highest. The validity of component concepts was verified by categorizing as cognitive structure models fostering stress, information demand, children's daily activity abilities, and their appropriateness was evaluated through confirmatory factor analysis using structural equation modelling. And then, GFI (more than 0.9), CFI (more than 0.9), TLI (more than 0.9) and RMSAE (less than 0.08) were used to evaluate the appropriateness. It was found that all the component concepts are valid, as every item is within appropriate range. The result of analyzing information demand demonstrated that children's handicap levels significantly affect their mothers' mental health, while fostering stress significantly affect mothers' metal health, information demand. As well, it was confirmed that mothers' mental health has a significant effect on information demand. Conclusions: Therefore, to reduce special children's mothers' uncertainty, helplessness and fostering burden, it is necessary to provide them with information on children's challenges, development and fostering and to offer them quality public health, medical care and welfare assistance along with family and local community life assistance.

• Journal of Environmental Impact Assessment
• /
• v.23 no.6
• /
• pp.432-444
• /
• 2014

When the water quality modelling is done with a manual calibration, it is possible that the researcher's opinion may affect the objectivity of the research. Hence, the role of the automatic calibration is highly important. This research applies a technique to automatically calibrate the water quality parameters by implementing an optimization method. This involves estimating the optimum water quality parameters targeting influential parameters towards the lake's BOD, DO, Phosphorus, Nitrogen and Phytoplankton. To accurately calculate the water temperature and hydraulic characteristics of a deep, stratifying lake, EFDC, a 3-dimensional hydraulic model which can be linked to the WASP7 was applied. With EFDC, the segment of the lake is formed and utilized as an input data of the WASP7. For the calibration of the water quality parameters of the WASP7, an influence coefficient algorithm and a genetic algorithm was applied. Of the five water quality variables for calibration, the normalized residuals of the observed and calculated values of DO, TN, CBOD were relatively small and the three water quality variables were calibrated properly. Yet the accuracy of the calibration of TP and Chl-a was relatively low.

• Economic and Environmental Geology
• /
• v.48 no.3
• /
• pp.205-212
• /
• 2015

We have verified applicability of UAV(Unmanned Aerial Vehicle) photogrammetry to a mining engineering. The test mine is a smectite mine located at Gyeongju city in Gyeongnam province, Koera. 448 photos over area of $600m{\times}380m$ were taken with overlapped manner using Cannon Mark VI equipped to multicopter DJI S1000, which were processed with AgiSoft Photoscan software to generate orthophoto and DEM model of the study area. photogrammetry data with 10 cm resolution were generated using 6 ground control positions, which were exported to the 3D geological modeling software to make a topographic surface object. Monitoring of amount of ore production and landsliding could be done with less than 1 hours photographing as well as low cost. A direct link between UAV photogrammetry and 3D geological modeling technology might increase productivity of a mine due to appling the topographical surface change immediately according to the mining operation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.32 no.5
• /
• pp.469-479
• /
• 2014

N-RTK(Network based RTK) methods are able to improve the accuracy of GNSS positioning results through modelling of the distance-dependent error sources(i.e. primarily the ionospheric and tropospheric delays and orbit errors). In this study, the comparison of the TTFF(Time-To-Fix-First ambiguity), accuracy and discrepancies in horizontal/vertical components of N-RTK methods(VRS and FKP) with the static GNSS at 20 Unified Control Stations covering Incheon metropolitan city area during solar storms(Solar cycle 24 period) were performed. The results showed that the best method, compared with the statics GNSS survey, is the VRS, followed by the FKP, but vertical components of both VRS and FKP were approximately two times bigger than horizontal components. The reason for this is considered as the ionospheric scintillation because of irregularities in electron density, and the tropospheric scintillation because of fluctuations on the refractive index take the place. When the TTFF at each station for each technique used, VRS gave shorter initialization time than FKP. The possible reasons for this result might be the inherent differences in principles, errors in characteristics of different correction networks, interpolating errors of FKP parameters according to the non-linear variation of the dispersive and non-dispersive errors at rover when considering both domestic mobile communication infra and the standardized high-compact data format for N-RTK. Also, those test results revealed degradation of positing accuracy, long initialization time, and sudden re-initialization, but more failures to resolve ambiguity during space weather events caused by Sunspot activity and solar flares.