• Journal of Gifted/Talented Education
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• v.25 no.6
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• pp.927-949
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• 2015

The purpose of this study was to find out the difference between importance and performance regarding perception of core competence of gifted education teachers through importance-performance analysis (IPA). One hundred fourteen elementary gifted education teachers including math and science participated in the study. The collected survey data was analyzed with IPA matrix. As the result, firstly, there was significant difference between importance and performance regarding perception of core competence of gifted education teachers. Secondly, core competencies of 'understanding knowledge', 'research and instruction', 'passion and motivation', and 'ethics' are high in both perceptions of importance and performance. However, both 'communication and practices' and 'professional curriculum development' are low. Thirdly, there was a difference in core competence of gifted education teachers between math and science at the competence of 'passion and motivation'. Math gifted education teachers perceived 'passion and motivation' high in both importance and performance while science gifted education teachers perceived its importance low and performance high. In addition, math gifted education teachers showed lower performance compared to its importance in the sub-categories; 'knowledge of gifted development', 'gifted child assessment', 'information gathering and its literacy', and 'creative answers to various questions'. However, science gifted education teachers showed lower performance compared to its importance in sub-categories; 'higher-order thinking skills in its subject', 'teaching methodology for self-directed learning', 'problem behavior of the gifted', and 'counseling the gifted'.

• Journal of Gifted/Talented Education
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• v.25 no.6
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• pp.857-879
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• 2015

This study investigated the relationships among middle school students' perceptions on the roles of online tutor, their deep learning, achievement, and overall evaluation of learning experiences in the context of inquiry based online gifted mathematics and science learning. For this purpose, 249 middle school students who took online course were surveyed about their perceptions on the degree to which their tutor performed the roles as an online tutor. The students were also asked about the activities which indicate deep learning approaches and overall course experiences such as the level of satisfaction, understanding and engagement in the course. The regression analyses were conducted to examine the relationships of students' perceptions on the roles of online tutor, deep learning, achievement, and overall course experiences. The results first showed that the roles of online tutor which affects students' deep learning approach such as high-order learning, integrative learning, reflective learning were the role as a subject matter and evaluation expert. Among the sub variables of deep learning approach the variable that was related to students' overall achievement was the use of high-order learning strategy. Second, the achievement in inquiry task was related to the role of tutor as a guide of learning process and method. Third, students' overall course evaluations such as the level of satisfaction, understanding and engagement were not related to any role of tutor.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.12
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• pp.1343-1350
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• 2012

This paper presents a new method for designing a dual-band WIFI antenna using the third-order harmonic mode of a monopole antenna whose first-order mode operates at the low frequency band of WIFI. As analysing the current distribution of the third-order mode of this monopole antenna, the strongest point of electric field can be found. Then by attaching a stub at this point, the resonant frequency of the stub radiator can be adjusted from the third-order mode of the monopole antenna into the high frequency band of WIFI and the input impedance at this resonant frequency can be controlled with the width of the branch, without affecting the low frequency band of WIFI (the first-order mode of the monopole antenna). The compact dual-band antenna is designed at the size of an USB(universal serial bus) dongle and the bandwidth covers 600 MHz(2.3~3 GHz) at 2 GHz and 1 GHz(4.9~5.9 GHz) at 5 GHz under -10 dB which is satisfied with WLAN frequency. Efficiency of proposed antenna achieves over 50 % at WLAN frequency.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.2
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• pp.81-89
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• 2014

The present study aims to design an optimized hull shape of a floating pendulum-type wave energy converter(WEC). The purpose of these structure is to improve the performance and stability of the WEC by reducing its motion under operating and survival wave conditions. In this study, motion reduction structures, like restoring and dampling plates were installed on a floating pendulum WEC that has been the subject of previous studies. Restoring plates were installed to increase the restoring force and shift the natural period to a shorter period. Damping plates were installed to shift the natural period to a longer period by increasing the added mass. The effects of the structures were then analyzed under different incident wave conditions. The design parameters for the motion reduction structures were size, shape, and installed position. The wave-induced motion characteristics and performance of the floating pendulum WEC were also investigated numerically. Based on the simulation results, we are able to optimize the motion reduction structure of the WEC, thus improving its efficiency and durability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.9
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• pp.817-825
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• 2013

The UHDTV system, which provides realistic service with ultra-high definite video and multi-channel audio, has been studied as a next generation broadcasting service. Since the conventional digital terrestrial transmission system is not capable to cover the increased transmission data rate of the UHDTV service, there are great necessity of researches about increase of data rate. Accordingly, the researches has been studied to increase the transmission data rate of the DVB-T2 system using dual-polarized MIMO technique and high order modulation. In order to optimize the MIMO DVB-T2 system where irregular LDPC codes are used, it is necessary to study the design of the bit mapper that matches the LDPC code and QAM symbols in MIMO channel. However, the research related to the design of the bit mapper has been limited to the SISO system. Therefore, this paper defines a new parameter that indicates the VND distribution of MIMO DVB-T2 system and performs the performance analysis according to the parameter which will be helpful for designing a MIMO bit mapper.

• Journal of the Korean association of regional geographers
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• v.20 no.2
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• pp.230-244
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• 2014

This study is to analyze the effects of geography class using taboo games on developing student's ability to think. After playing taboo games in which students explain keyword without using presented taboo words, worksheets of participants were analyzed with interviews to demonstrate what kind of thinking skills are working. The results of the analyses are as follows. First, while divergent thinking is applied to students who explain keyword in taboo games, convergent thinking is applied to students who listen to and guess them. Second, as groups play a role as explainer or answerer in turn, they can learn divergent and convergent thinking together. Third, students seem to improve high-order thinking ability like decision-making, critical thinking, metacogniton through taboo games. Fourth, students have a tendency to use a variety of direct and/or indirect experiences (especially, from media) as well as cross curricular knowledge in order to explain keyword without using taboo words.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.1
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• pp.81-96
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• 2007

Nonlinear shoaling characteristics over surf zone are numerically investigated based on spatially averaged NavierStokes equation. We also test the validity of gradient model for turbulent stresses due to wave breaking using the data acquainted during SUPERTANK LABORATORY DATA COLLECTION PROJECT(Krauss et al., 1992). It turns out that the characteristics length scale of breaking induced current is not negligible, which firmly stands against ever popular gradient model, ${\kappa}-{\varepsilon}$ model, but favors Large Eddy Simulation with finer grid. Based on these observations, we model the residual stress of spatially averaged NavierStokes equation after Lagrangian Dynamic Smagorinsky(Meneveau et al., 1996). We numerically integrate newly proposed wave equations using SPH with Gaussian kernel function. Severely deformed water surface profile, free falling water particle, queuing splash after landing of water particle on the free surface and wave finger due to structured vortex on rear side of wave crest(Narayanaswamy and Dalrymple, 2002) are successfully duplicated in the numerical simulation of wave propagation over uniform slope beach, which so far have been regarded very difficult features to mimic in the computational fluid mechanics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6221-6226
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• 2015

In this paper, waveguide analysis was interpreted as an optical waveguide using the feedback perturbation method simple and easy to apply compared to the analysis method, while the other almost identical to the numerical calculation method. In addition, efficient coupling with an optical transmission line of optical fiber and the waveguide form the thin film of different functional elements is required in order to achieve the full optical communication system. However, problems arise, such as the light field (field) and the decrease of the access efficiency due to inconsistency in the distribution characteristics of the connection surface by the difference in size of the cross section thereof when connecting the optical fiber and the waveguide directly to the combination of a thin film. Therefore propose a new type of connector structure to increase the efficiency of the connection when connecting the optical fiber waveguide and the thin film was analyzed by applying a coupled mode theory, the binding efficiency of the modified contactor. And by diffusing Ti on the $LiNbO_3$ substrate and a wide range of applications in the manufacture of integrated optical material made of a current low-loss Ti: $LiNbO_3$ optical waveguide and making the Y-branch waveguide, and the properties were confirmed.

• Journal of KIISE:Software and Applications
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• v.27 no.1
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• pp.50-61
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• 2000

Recently the stereo vision based on conics has received much attention by many authors. Conics have many features such as their matrix expression, efficient correspondence checking, abundance of conical shapes in real world. Extensions to higher algebraic curves met with limited success. Although irreducible algebraic curves are rather rare in the real world, lines and conics are abundant whose products provide good examples of higher algebraic curves. We consider plane algebraic curves of an arbitrary degree $n{\geq}2$ with a fully calibrated stereo system. We present closed form solutions to both correspondence and reconstruction problems. Let $f_1,\;f_2,\;{\pi}$ be image curves and plane and $VC_P(g)$ the cone with generator (plane) curve g and vertex P. Then the relation $VC_{O1}(f_1)\;=\;VC_{O1}(VC_{O2}(f_2)\;∩\;{\pi})$ gives polynomial equations in the coefficient $d_1,\;d_2,\;d_3$ of the plane ${\pi}$. After some manipulations, we get an extremely simple polynomial equation in a single variable whose unique real positive root plays the key role. It is then followed by evaluating $O(n^2)$ polynomials of a single variable at the root. It is in contrast to the past works which usually involve a simultaneous system of multivariate polynomial equations. We checked our algorithm using synthetic as well as real world images.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.319-323
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• 1996

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