• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.682-684
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• 2001

인터넷의 급속한 확산 및 기술 발전에 따라, 기존에 오프라인으로 이루어지던 딸은 일들이 인터넷을 통해 온라인으로 처리 가능함에 따라 비용 및 시간을 크게 절감시킬 수 있었다. 그러나 이런 모든 일들은 주로 PC를 통해 이루어지며, PC이외의 가전에서 인터넷과 연동은 대중화되지 못하였다. 이는 비용 문제뿐 만 아니라, 기존 PC에서 사용하던 TCP/IP 프로토콜 스택을 가전제품에 탑재하기에는 크기가 너무 크기 때문이다. 본 논문에서는 이를 위해 가전제품에 탑재할 수 있으며, 인터넷과 연동이 가능한 기능 축약된 마이크로 TCP/IP를 설계하고 구현하였다.

• Journal of Digital Contents Society
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• v.12 no.2
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• pp.195-203
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• 2011

In-person lectures have structural issues that active communications in the classroom are limited because of the environments where the instructor usually delivers learning contents in a unilateral manner. Therefore, microcontents activities using real-time microblogging were suggested as complementary measures for the lecture in this study. Fourteen students in K University participated in the learning activity for eight weeks using a microblog during instructions. As a result, it was found that participants' positive learning activities increased by producing and collaborating ideas through real-time microblogging. Based on the results, suggestions were made as follows: strategies for the attention to the class, quality management of microcontents, and the development of blended learning design should be more studied further.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.1
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• pp.25-30
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• 2017

In this paper, dual band patch antenna was designed using a CSRR structure with negative values permeability which inserted into the ground plane. We propose an antenna that can be used in dual band f1(1.53GHz) and f2(1.63GHz) for satellite communications by using the CSRR placed on the backside of feeding line, which is a negative shape of SRR. The proposed antenna can be arrayed using microstrip line and can be made smaller than conventional patch antenna. The fabricated antenna has the input reflection coefficient of -12.5dB and -14.5dB at f1 and f2, and the gain of 2dB and -0.8dB, respectively. and it was confirmed that the performance was sufficient in the dual-band.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1998.06a
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• pp.1152-1155
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• 1998

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.343-346
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• 1991

• KSBB Journal
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• v.4 no.3
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• pp.197-202
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• 1989

The existing analog controllers for typical fermentation variables such as rpm and temperature were properly modified in order to be interiaced with microcomputers. Other necessary corrections like the impedance matching, the ground isolation, and the signal range adjustment were done for the successful interfacing between fermentor detectors and computers and for the eventual on-line feedback control of temperature and DO and the induction of the fermentation process with recombinant cells.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.4
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• pp.1-8
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• 2004

A novol clock distribution scheme is proposed for high-speed and low-power digital system to minimize clock skew and reduce dynamic power consumption. This scheme has ideal zero-skew characteristic by using folded clock lines (FCL) and phase blending circuit. For analyzing suitable line structures to FCLs, microstrip line and coplanar line are placed with folded clock lines. Simulation results show that the maximum clock-skew between two receivers located 10mm apart is less than lops at 1㎓ and the maximum clock-skew between two receivers located 20mm apart is less than 60ps at 1㎓. Also the results show that the minimum skews of clock signals regardless of process, voltage, and temperature variation are invariant.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.4
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• pp.286-297
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• 2017

This paper is a study of 6~18 GHz wideband high power amplifier which is composed of 10 single amplifier and coaxial type spatial power combiner. The property of this spatial power combiner is on a similar principle to antipodal antenna radiation mechanism. Therefore, the key structure of proposed spatial power combiner is the antipodal finline PCB board and the finline curve shape is numerically synthesized by using Klopfensein's optimum impedance taper. The measured CW output power of spatial combined high power amplifier is nearly 50 W. In conclusion we prove the good combining performance between the spatial power combiner and 10 single amplifier over 6~18 GHz frequency ranges. Also, we developed the key component PA and MFC MMIC which controls the phase and gain of the each amplifier, The main characteristic of MFC MMIC is to maximize combining efficiency of power amplifier.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.1-9
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• 2014

In this paper, a reconfigurable polarization patch antenna that uses a Y-shaped feed is proposed. The proposed antenna consists of a square patch, a Y-shaped feeding structure, a PIN diode, and a bias circuit for diode operation. The structural symmetry/asymmetry of the feeding structure is determined by the on/off operation of the PIN diode that inserted into the side of one of the lines of the Y-shaped feeding structure. For the proposed reconfigurable antenna, the two microstrip lines of the feeding structure have the same length when the PIN diode operates in the on state, and the antenna exhibits linear polarization(LP). On the other hand, when the PIN diode operates in the off state, the length of one side line of the feeding structure is relatively shorter than that of the other line. Therefore, the antenna exhibits circular polarization(CP). From the measurement results, it is found that the proposed antenna exhibits good impedance matching and axial ratio. In addition, polarization switching can be easily achieved in the same operating band.

• 전기의세계
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• v.41 no.11
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• pp.8-15
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• 1992

요즘 자기 스스로 움직이면서 간단한 동작을 명령대로 수행하는 마이크로 머신을 만드는 꿈과같은 이야기를 현실에 한발 가까이 하는 연구가 활발히 진행되고 있다. 즉, IC칩을 제작하는 미세반도체 소자 제조공정으로 수십 내지는 수백미크론 크기의 기계구조물이나 모터, 액츄에이터를 실리콘 기판 위에 제작하는 것이 가능하게 되었다. 이러한 연구분야는 1980년대 중반부터 미국, 일본, 유럽등지에서 시작되었다. 이 연구분야를 IEEE에서는 MEMS(Micro Electro Mechanical Systems)라 부르며, 매년 2월 IEEE주최로 이에 관한 International conference가 열리고 있고, 이분야에 대한 Journal도 1992년부터 발행하고 있다. MEMS를 미국에서는 NSF(National Science Foundation)에서 일본에서는 통산성에서 지원하고 있으며 현재 재료, 제작기술, 소자(센서, 액츄에이터), 시스템, 응용, 마이크로 이공학등에 관한 연구가 진행되고 있다. 이 분양의 파급효과는 의공학이나 유전자공학 뿐만이 아니라 공학에도 매우 크리라 예상된다.