• Advances in nano research
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• v.1 no.1
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• pp.13-27
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• 2013

Carbon nanotube characterized by additional inductive effect as compared with the traditional conductors like copper wires of the same size. Consequently, carbon nanotubes have high characteristic impedance and slow wave propagation in comparison with traditional conductors. Due to these characteristics, carbon nanotubes can be used as antenna. In view of this, we describe and review the present research progress on carbon nanotube antennas. We present different analysis models and results which are developed to investigate the characteristics of CNT antennas. Then we conclude by summarizing the characteristics of CNT antennas and specifying the operating frequency limit.

• 한국초전도학회:학술대회논문집
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• v.16
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• pp.77-77
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• 2006

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1809-1811
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• 1999

In recent years, attempts have been made to greatly improve the display quality of active-matrix liquid crystal display devices, and many techniques have been proposed to solve such problems as gate delay, feed-through voltage and image sticking. Gate delay is one of the biggest limiting factors for large-screen-size, high-resolution thin-film transistor liquid crystal display (TFT/LCD) design. Many driving method proposed for TFT/LCD progress. Thus we developed gate driving signal generator. Since Pixel-Design Array Simulation Tool (PDAST) can simulate the gate, data and pixel voltages of a certain pixel on TFT array at any time and at any location on an array, the effect of the driving signals of gate lines on the pixel operations can be effectively analyzed.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1666-1667
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• 2011

본 논문에서는 CSRR을 이용하여 0.5~1.5GHz 대역의 광대역 필터를 최적 설계 연구 하였다. Metamaterial의 일종인 CSRR은 LC 공진기 역할을 하며 전송선로와 결합하여 필터 특성을 나타낸다. 또한 높은 Q-factor의 특성을 갖기 때문에 협대역 대역통과 필터 특성을 갖는다. 이에 본 논문에서는 CSRR을 이용하여 광대역 대역통과 특성을 갑기 위해서 전송선로의 형태를 변형하고 진화알고리즘중 하나인 진화 전략기법을 이용하여 단일 셀의 최적 설계를 수행하였다. 이후 단위 셀을 다단으로 연결하여 최종 광대역 필터를 설계하였다. 본 논문에서 설계된 광대역 필터는 0.5~1.5GHz의 대역폭을 갖으며 00~00dB의 삽입손실을 갖는다. 그리고 저지대역에서 00~00dB의 저지 특성을 갖는다.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.132-134
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• 2006

This paper presents the design and implementation of 1 kW prototype DC-DC power converter with bridge voltage-doubler suitable for small scale PEM fuel cell system and its associated control scheme. The operation principle of this converter is described using some operating waveforms and the switching mode equivalent circuits based on simulation results and a detailed circuit operation analysis and soft-switching conditions.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.449-451
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• 2000

Crosstalk is the primary cause of image distortion in active matrix liquid crystal displays (AMLCD). Crosstalk produces voltage errors that limit gray scale fidelity and consequently, degrades display resolution, contrast ratio, color fidelity, and image quality. In this study, crosstalk phenomena of some methods to compensate level shift voltages has been simulated. This will be contributed to find the way to design the excellent image quality of the TFT-LCDs.

• Proceedings of the KIEE Conference
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• 2008.05a
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• pp.151-152
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• 2008

In this paper, a dual band LNA (Low Noise Amplifier) with a matching circuit using varactor diode is designed for 912MHz and 2450MHz RFID system. The operating frequency is controlled by the bias voltage applied to the varactor diode. The measured results demonstrate that gain is 13.6dB and 6.8dB at 912MHz and 2450MHz. The measured NF (Noise Figure) is 1.4dB and 3.1dB at 912MHz and 2450MHz, respectively.

• Proceedings of the KIEE Conference
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• 2008.05a
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• pp.157-158
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• 2008

In this paper, a dual band microstrip patch Antenna is designed for RFID Application. The antenna shows a good performance at the frequencys, 433MHz and 2.45GHz for the radiation characteristics and input impedance matching as well. The reflection factor is lower than 15dB and a good directivity higher than 3dB is achieved for both frequency.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.166-168
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• 2007

A dimmable ballast system for the electrodeless fluorescent lamp is proposed. The proposed scheme is composed of the electronic ballast and the wireless communication part. They both are realized with one EPLD (Erasable Programmable Logic Device). The dimming levels of each lamps can be controlled by a management system through wireless communication technology. 10 ballasts are used for the group lighting system and the experiment results show the system works well.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2144-2145
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• 2006

무선 센서네트워크는 환경 모니터링과 같은 다양한 어플리케이션을 갖고 있는 향상된 기술이다. 이를 구성하는 각각의 노드들은 특정지역에 분산되어 네트워크를 구성해서 해당 지역의 이벤트나 정보를 주기적으로 사용자에게 전달한다. 이때 토폴로지 제어는 네트워크의 수명과 통신에 중요한 영향을 미치는 요인이다. 본 논문에서는 무선 센서 네트워크에서 클러스터 기반의 분산형 토폴로지 제어기법을 제안한다. 이 기법은 먼저 네트워크를 클러스터 기반의 계층적인 구조로 구성한 후, 각각의 클러스터 내에서 최소 신장트리 (Minimum Spanning Tree)를 이용하여 토폴로지 제어를 수행한다. 이를 통해 무선센서 네트워크는 에너지 효율적이며 분산된 토폴로지 제어를 수행할 수 있고, 결과적으로 네트워크의 수명을 연장할 수 있다.