• ETRI Journal
• /
• v.28 no.3
• /
• pp.393-396
• /
• 2006

This letter proposes a new impedance matching scheme of a traveling wave electro-absorption modulator (TWEAM) module for a 60 GHz band radio-over-fiber (ROF) link. A microstrip band pass filter (BPF) was used to achieve impedance matching at the 60 GHz band, and termination resistance was carefully designed to obtain an input impedance close to $50\;{\Omega}$. Also, a bias circuit for the device was designed in the module. The measured return loss and frequency response show that the modulator module observes the characteristics of a filter without the need of a further tuning process.

• Journal of Gifted/Talented Education
• /
• v.26 no.1
• /
• pp.53-76
• /
• 2016

This research studies the perception to gifted education teachers between the middle school gifted education for STEAM and Convergence Gifted Education for revitalizing Convergence Gifted Education. The conclusions according to the analysis, it shows that the awareness of gifted education teachers for Convergence Gifted Education is lower than the level of the awareness for STEAM, and it appears that the Gifted education teachers especially has the experience adapting Convergence Gifted Education who awareness for Convergence Gifted Education is the highest. On the other hand, not only teachers has the experience adapting Convergence Gifted Education and the very poorly recognition for the task of Comprehensive Plan for Gifted Education promotion including the development of an creative and convergence content, a they has the very low experience for the development. And it analyzes that although there is no meaningful differences, teachers who are in science gifted teachers and the mature experienced man realizes very optimistically the necessity need of Convergence Gifted Education. Therefore, it analyzes that recognition to the necessity need of Convergence Gifted Education is reinforced through the training for the gifted teachers in the mathematics gifted education and in less teaching experience. But it points out that answers over the majority cognized to resemble the Convergence Gifted Education and STEAM, though the object is only different. Furthermore, it suggests that the differentiated Convergence Gifted Education curriculum providing the suitableness for the characteristic and level is needed for the desirable fixedness.

• Current Optics and Photonics
• /
• v.3 no.1
• /
• pp.66-71
• /
• 2019

Application of liquid crystal (LC) materials to a flexible device is challenging because the bending of LC displays easily causes change in thickness of the LC layer and orientation of LCs, resulting in deterioration in a displayed image quality. In this work, we demonstrate a prototype device combining a flexible polymer substrate and an optically isotropic LC-polymer composite in which the device consists of interdigitated in-plane switching electrodes deposited on a flexible colorless polyimide substrate and the composite consisting of nano-sized LC droplets in a polymer matrix. The device can keep good electro-optic characteristics even when it is in a bending state because the LC orientation is not disturbed in both voltage-off and -on states. The proposed device shows a high potential to be applicable for future flexible LC devices.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2019.05a
• /
• pp.372-374
• /
• 2019

Recent college education in the face of the Fourth Industrial Revolution highlights problem-solving skills or creativity over the passing of professional knowledge. In addition, the need for convergence education is growing further as high-tech information and communication technologies are converging to create innovative changes. In this study, after IT convergence education was conducted and after general convergence education was conducted, the difference in creative problem solving capabilities was compared and analyzed. The study found that students who received IT convergence education had higher creative problem solving capabilities than general convergence education, and showed a statistically significant difference. In order to foster creative problem-solving skills, universities will need to promote IT convergence education in various courses.

• Journal of the Optical Society of Korea
• /
• v.15 no.3
• /
• pp.293-299
• /
• 2011

In this study, we demonstrated Fourier-domain/swept-source optical coherence tomography (FD/SS-OCT) at a center wavelength of 800 nm for in vivo human retinal imaging. A wavelength-swept source was constructed with a semiconductor optical amplifier, a fiber Fabry-Perot tunable filter, isolators, and a fiber coupler in a ring cavity. Our swept source produced a laser output with a tuning range of 42 nm (779 to 821 nm) and an average power of 3.9 mW. The wavelength-swept speed in this configuration with bidirectionality is 2,000 axial scans per second. In addition, we suggested a modified zero-crossing method to achieve equal sample spacing in the wavenumber (k) domain and to increase the image depth range. FD/SS-OCT has a sensitivity of ~89.7 dB and an axial resolution of 10.4 ${\mu}m$ in air. When a retinal image with 2,000 A-lines/frame is obtained, an acquisition speed of 2.0 fps is achieved.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1998.06a
• /
• pp.95-100
• /
• 1998

A notion of 'fuzzy' convergence of filters on a set is introduced. We show that the collection of fuzzy L-limit spaces forms a cartesian closed topological category and obtain an interesting relationship between the notions of 'fuzzy' convergence structure and convergence approach spaces.

• Communications of the Korean Mathematical Society
• /
• v.11 no.4
• /
• pp.1087-1094
• /
• 1996

In this paper, we introduce the notion of the n-th pretopological modification. Also, we find some properties which hold between convergence quotient maps and n-th pretopological modifications.

• Journal of the Chungcheong Mathematical Society
• /
• v.5 no.1
• /
• pp.167-172
• /
• 1992

In this paper, we introduce $T_0$, $T_1$ and Hausdorff axioms in fibrewise convergence spaces as a generalization of fibrewise topological spaces and of convergence spaces. Furthermore we investigate some results about the fibrewise Hausdorff convergence space.

• The Journal of Natural Sciences
• /
• v.11 no.1
• /
• pp.7-10
• /
• 1999

In this paper, we obtain the relations among the categories such as Seq, Conv and Top by using various functors between them.

• Convergence Security Journal
• /
• v.16 no.3_1
• /
• pp.87-98
• /
• 2016

As the informative society becomes intensified, the rise of the convergence security offers an alternative strategic correspondence to the technology leaks that are becoming more advanced, complex, and intelligent. In order to the convergence security to provide its efficacy, training convergence security specialists is essential. However, research on the subject has yet to be considered sufficient. Thus this research focuses on defense industry security specialists to define the duty and analze critical task as well as drawn and therefore the required academic level of the critical task was examined. These research work contributes to the competence development of convergence security specialists and further enhancement on convergence security training process of academic institutions and job training institutions.