• Journal of Gifted/Talented Education
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• v.25 no.6
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• pp.951-970
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• 2015

The purpose of this study is to explore related variables to influence gifted college students' career conviction and to propose a structural model. For the study, 292 college students who have experienced university affiliated gifted education program during their school days. Rational decision making test, intrinsic motivation test, career decision efficacy test, and major conviction test were utilized. SPSS program and AMOS were used for statistical analyses. The results are summarized as follows. The fit of measurement model was found to be TLI=.923, CFI=.951, RMSEA=.077, indicating most of the fit indexes were acceptable. The path to career conviction from rational decision making and intrinsic motivation was found to be insignificant, suggesting a revised model. The fit of final revised measurement model was found to be TLI =.926, CFI=.951, RMSEA=.075, indicating the model was acceptable. Interestingly, the career decision efficacy was found to be the complete mediator among the rational decision making, intrinsic motivation, and career conviction. The results of the study showed that career decision efficacy has a very important role in gifted college students'career choice and decision. Implication of the study related to the career education and counseling has been discussed in depth.

• Journal of Gifted/Talented Education
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• v.22 no.2
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• pp.265-290
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• 2012

This study try to analyze the effect that personal and social factors affects the interactions among science gifted students. For this, I analyze the interacting role of science gifted students in social co-construction and scientific model constructing class for phase change and rising-sinking time of moon and categorize according to type. I analyze aspects of interaction and association of each elements in the students after I understand character type self conception friendship a parents-children relationship relation with teachers derived from advanced research through questionnaire and depth interview. After analyzing, I find the following-close friendship form or not and usual school class participation appear important factors that have strong connection with the aspect of the interactions. Also, character type, self conception and relation of parents affect the interactions relatively lower. Through this study, We identify two things. Firstly, We must consider individual's inside factors for making animatedly the interaction among the students. Secondly, We get considering factors that devise the strategies for making the interaction animatedly.

• Geotechnical Engineering
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• v.9 no.4
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• pp.103-118
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• 1993

This paper presents the results of investigation of the rainstorm induced landslides occurred in the districts of Yongin, Ansung and Osan on July 21st 1991. More than two thousand and sirs hundred landsilides took place during or after a 3-t hours heavy rainfall and about 466 ha mountain slopes were affected by slope failures. The result of study on the effect of-iainfall on landslides shows that landslides began to occur where daily and maximum hourly rainfall exceeded 114mm and 40mm respectively, and all districts (myun) where maximum hourly rainfall exceeded 62mm were affected by landslides. The morphological study on landslides on Talbongsan area reveals that, by Walker's classi fication using D IL(failure depth ratio), 50% of the landslides were classified as flows, 20% of them as translational slides, and 30% were between flow and slide and there were few rotational slides. Over 90% of landslides tookplace at slopes of 20$^{\circ}$-40$^{\circ}$ in slope and 50m or shorter in length And more than 50% of the crown of slides locates at higher than 0.7 times of slope hight. Any differences between the kinds of tree in landslide resisting effects are shown in this case.

• Journal of the Korean Geotechnical Society
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• v.32 no.9
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• pp.51-62
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• 2016

Parametric studies for various site conditions by using 3d numerical model were carried out in order to estimate dynamic behavior of soil-pile-structure system in dry soil deposits. Proposed model was analyzed in time domain using FLAC3D which is commercial finite difference code to properly simulate nonlinear response of soil under strong earthquake. Mohr-Coulomb criterion was adopted as soil constitutive model. Soil nonlinearity was considered by adopting the hysteretic damping model, and an interface model which can simulate separation and slip between soil and pile was adopted. Simplified continuum modeling was used as boundary condition to reduce analysis time. Also, initial shear modulus and yield depth were appropriately determined for accurate simulation of system's nonlinear behavior. Parametric study was performed by varying weight of superstructure, pile length, pile head fixity, soil relative density with proposed numerical model. From the results of parametric study, it is identified that inertial force induced by superstructure is dominant on dynamic behavior of soil-pile-structure system and effect of kinematic force induced by soil movement was relatively small. Difference in dynamic behavior according to the pile length and pile head fixity was also numerically investigated.

• Journal of the Korea Concrete Institute
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• v.26 no.6
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• pp.687-694
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• 2014

This study established a displacement ductility ratio model for ductile design for the boundary element of shear walls. To determine the curvature distribution along the member length and displacement at the free end of the member, the distributions of strains and internal forces along the shear wall section depth were idealized based on the Bernoulli's principle, strain compatibility condition, and equilibrium condition of forces. The confinement effect at the boundary element, provided by transverse reinforcement, was calculated using the stress-strain relationship of confined concrete proposed by Razvi and Saatcioglu. The curvatures corresponding to the initial yielding moment and 80% of the ultimate state after the peak strength were then conversed into displacement values based on the concept of equivalent hinge length. The derived displacement ductility ratio model was simplified by the regression approach using the comprehensive analytical data obtained from the parametric study. The proposed model is in good agreement with test results, indicating that the mean and standard deviation of the ratios between predictions and experiments are 1.05 and 0.19, respectively. Overall, the proposed model is expected to be available for determining the transverse reinforcement ratio at the boundary element for a targeted displacement ductility ratio.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.11 s.114
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• pp.1120-1131
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• 2006

This paper describes the numerical analysis techniques using the Combined Integration/Matrix Method to calculate ground potential rise which can be occurred in the various grounding systems. Combined Integration/Matrix Method is used to reduce the error and computation time with the analytical integration equation and the proper segmentaion of earth embedded conductor. To do it, optimal segmentaion method for the buried conductors is presented through error analysis which is capable of applying the practical scaled various grounding systems. The optimum length of segmented element is much co-related with the buried depth of grounding electrode and the maximum length of buried electrode. As a result, less 3 precent errors was obtained by proposed model. The proposed model is applied to verify an effect of multi-grounding problems which was aroused much controversy with separated or common grounding between the high power grounding system and low power grounding system such as signal and telecommunication grounding.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.1
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• pp.45-50
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• 2009

By Laser Through-Silicon-Via process, debris and particles occur when you are forming. Therefore the research of TSV cleaning become important to remove those particles and debris. Both chemical cleaning method that uses a surfactant and physical cleaning method that uses a brush were studied with the via of $30{\mu}m$ diameter and $100{\mu}m$ depth on the 8 inch CMOS Image Sensor wafer. On the DI water and a surfactant in mixture ratio of 2:1, debris show $73{\mu}m^2$ per $0.054mm^2$. Cleaning is superior by lower mixture ratio of DI water and surfactant. In addition, It is less than 5% of debris distribution in the laser condition changed by Laser's frequency and its speed and cleaning had no effect. In the physical cleaning, there are no crack and damage when the system condition is set by $1000{\sim}3000rpm$ strip, $50{\sim}3000rpm$ rinsing, and $200{\sim}300rpm$ brushing Therefore, debris and particles can be removed by enforced chemical method and physical method.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.4
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• pp.98-111
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• 2015

Urban environmental problems such as flooding, depletion of ground water, pollution of urban streams and the heat island effect caused by urban development and climate change can be mitigated by the improvement of the urban water cycle. For the effective planning of water cycle management it is necessary to establish aerial Hydrotope Maps, with which we can estimate the status and change of the water allowance for any site. The structure of the German water balance model BAGLUVA, which is based on soil and vegetation, was analyzed and the input data and boundary condition of the model was compared with Korean data and research results. The BAGLUVA Model consists of 5 Input categories (climate, land use, topography, soil hydrology and irrigation). The structure and interconnection of these categories are analyzed and new concepts and implementation methods of topographic factor, maximum evapotranspiration ratio, effective rooting depth and Bagrov n parameter was compared and analyzed. The relation of real evapotranspiration ($ET_a$)-maximum evapotranspiration ($ET_{max}$) - precipitation (P) was via Bagrov n factor represented. The aerial and land use oriented Hydrotope Map can help us to investigate the water balance of small catchment areas and to set goals for volume of rainwater management and LID facilities effectively in the city. Further, this map is a useful tool for implementing water resource management within landscape and urban planning.

• Restorative Dentistry and Endodontics
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• v.26 no.1
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• pp.16-22
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• 2001

The purpose of this study was to evaluate the marginal microleakage of condensable composite resin restorations according to flowable resin lining of internal cavity wall. The eighty extracted human molar teeth without caries and/or restorations are used The experimental teeth were randomly assigned into four groups of ten teeth each. Eighty caries-free extracted human molars were used in this study. The conventional class II cavities (box-shaped on mesial and distal surface, faciolingual width : 3mm, gingival wall depth : 1.5mm) were prepared 1mm below cementoenamel junction with a # 701 carbide bur. The teeth were divided into four groups, and then each group were subdivided into A & B group according to flowable resin & compomer lining ; Group 1-A : Tetric Ceram filling, Group 1-B : Tetric Flow lining and Tetric Ceram filling, Group 2-A Ariston pHc filling, Group 2-B : Tetric Flow lining and Ariston pHc filing, Group 3-A SureFil filling, Group 3-B : Dyract Flow lining and SureFil filling, Group 4-A : Pyramid filling, Group 4-B : Aeliteflo lining and Pyramid filling. To simulate as closely as possible the clinical situation during retoration placement, a "restoration template" was fabricated, and the condensable resin was filled using a three-sited light-curing incremental technique. All the materials used were applied according to the manufacturers' instructions. The specimens were stored in the 100% humidity for 7 days prior to thermocycling (100 thermal cycles of 5~55$^{\circ}C$ water with a 30-second dwell time) The specimens were immersed in 2% metyleneblue dye for 24 hours, and then embedded in transparent acrylic resin and sectioned mesiodistally with diamond wheel saw. The degree of marginal leakage was scored under stereomicroscope ($\times$20) and the data were analyzed by Kruskal-Wallis test and Wilcoxon signed ranks test. The results were as follows : 1. In the gingival margins of all the group, microleakage of subgroup B was less than subgroup A. 2. In the group 1, 2, 4, there was significant differences between subgroup A and B (p<0.05), but in the group 3, there was not significant different between group 3-A (SureFil) and group 3-B (Dyract flow/SureFil) (p>0.05). 3. In the subgroup A and B, there was significant different between all group except group 4 of subgroup A. From the results above, it was suggested that the cavity lining of flowable resin and flowable compomer in condensable resin restoration decrease microleakage at gingival margin, and does improve their ability to seal the gingival margin of class II preparation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.4
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• pp.44-51
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• 2004

This study was to investigate and identify the trends and the direction of the researches related to the rooftop greening by analyzing the content of the studies published in Korea during the past two decades. Internet search was to collect data for this study, and the articles reviewed are limited to research journals, theses, and doctoral dissertations. The collected articles were then examined for content analysis and classified into several categories according to year, topic, and types of journals. The results showed that the total number of articles published in Korea for the period 1984-2004 was 97. While there was only one article in 1984, the number of articles has increased to 16 in 2000, 20 in 2003, and 16 in 2004 now. According to the analysis of the 97 data, there were 25 master's theses and 3 doctoral dissertations and 69 articles published in journals. Articles about rooftop greening were published most frequently in the Korea Institute of Landscape Architecture(11 articles), followed by Journal of Architectural Institute of Korea(8 articles) and Journal of Korea Society for Environment Restoration(7 articles).The studies regarding the rooftop greening has increased in number since the Ministry of Construction and Transportation made it possible to 10-15 cm shallow depth of soil in rooftop greening in 2000, which was above 100 cm before 2000. The articles examined are classified into four areas of research according to topic. The number of articles in each area is as follows : 57 articles in the field of the technology, 17 in the study of the plan and system, 10 in the case study, and 12 in the plant study, Particularly, the studies concerning technology are subdivided into the five areas and the number of each area is as follows : 25 studies for the plant base, 15 for design plan, 13 for the efficacy of the rooftop greening, 3 for the managing program, and 1 for the relation with buildings. Over the years, the studies for the rooftop greening have increased in number since these studies have made a positive effect on the improvement of the urban ecosystem and on the environment of the city lacking greens. However, the majority of research are for plant and planting base and those researches are not enough to make some effects on the improvement of the environment, it seems necessary to provide some system applicable to the field or to design practical study in order to contribute to the urban environment in Korea.