• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1991년도 춘계학술대회
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• pp.98-100
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• 1991

A sensitive surface acoustic wave (SAW) sensor for the detection of odorants has been constructed by depositing different phospholipids and fatty acids on the surface of the SAW device wi th the Langmuir-Blodgett technique. The characteristics of SAW device operating at 310 MHz deposited with phosphatidylcholine were analyzed. Amyl acetate, acetoin, menthone and other organic gases showed different affinities. The identification of odorants depending on the species of lipid used for coating is discussed in terms of the similarity of the normalized resonant frequency shift pattern. Using a number of different lipid-coated SAW devices, odorants could be identified by a neural-network pattern recognition with back-propagation algorithm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.11-12
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• 2011

In electromagnetic coupled resonance(ECR) WPT system, the main key for wireless power transmission is the design method of the ECR coils. The ECR coils is classified to the helical coil(3D) type and the spiral coil(2D) type as a coil structure. The pattern of the spiral coil type has been studied in favor of commercialization. In this paper, the design characteristics of the helical coil and the spiral coil is considered using a Vector Network Analyzer. It is analyzed according to the distance of coupling coefficient between the ECR coils. Also, It is analyzed for the relationships such as the maximum transmission efficiency and the resonant frequency depending on the distance between the coils.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.83-84
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• 2011

This paper presents an analysis and a novel strategy for a doubly fed induction generator (DFIG) based wind energy conversion system under unbalanced grid voltage and non-linear load conditions. A proportional-resonant (PR) current controller is applied in both grid side converter (GSC) and rotor side converter (RSC). The RSC is controlled to mitigate the stator active power and the rotor current oscillations at double supply frequency under unbalanced grid voltage while the GSC is controlled to mitigate ripples in the dc-link voltage and compensate harmonic components of the network current. Simulation results using Psim simulation program are presented for a 2 MW DFIG to confirm the effectiveness of the proposed control strategy.

• 전기학회논문지
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• 제56권1호
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• pp.88-99
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• 2007

In this paper, a novel new pulse power generator based on IGBT stacks is proposed for pulse power application. Because it can generate up to 60kV pulse output voltage without any step- up transformer or pulse forming network, it has advantages of fast rising time, easiness of pulse width variation and rectangular pulse shape. Proposed scheme consists of series connected 9 power stages to generate maximum 60kV output pulse and one series resonant power inverter to charge DC capacitor voltage. Each power stages are configured as 8 series connected power cells and each power cell generates up to 850VDC pulse. Finally pulse output voltage is applied using total 72 series connected IGBTs. To reduce component for gate power supply, a simple and robust gate drive circuit is proposed. For gating signal synchronization, full bridge invertor and pulse transformer generates on-off signals of IGBT gating with gate power simultaneously and it has very good characteristics of short circuit protection.

• Journal of information and communication convergence engineering
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• 제12권1호
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• pp.1-7
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• 2014

A novel design of a simple circular ring with open-ended monopole antenna for wireless local area network (WLAN) applications is proposed in this article. The proposed antenna consists of an open-ended circular ring and $50-{\Omega}$ microstrip feed-line. The proposed antenna is capable of generating two separate resonant modes with good impedance-matching conditions. A prototype of the proposed antenna is designed, fabricated, and measured. Acceptable agreement between the measurement and simulation results is achieved. Experimental results show that the proposed antenna has operating bandwidths of 1.99-3.04 GHz and 5.08-6.1 GHz with a return loss of less than -10 dB, covering the required bandwidths of the 2.4/5.2/5.8-GHz WLAN standards. This is a microstrip antenna for IEEE 802.11a/b wireless local area networks applications. Meanwhile, the two-dimensional (2D) radiation patterns and three-dimensional (3D) gain performance of the antenna are also observed and discussed.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권3호
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• pp.182-186
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• 2004

In this paper, 2.4GHz WLAN BPF(Band Pass Filter) which has two DGS(Defected Ground Structure) unit cells was simulated and manufactured. To do this, a unit DGS resonator with resonant frequency is designed. Then the BPF for WLAN with the center frequency of 2.4GHz md the bandwidth of 200MHz is designed using two DGS resonator, finally this circuit is fabricated. We also proposed the equivalent circuit of the BPF employing two DGS resonator. The BPF with DGS was obtained experimental results with network analyzer Agilent 8510C. The measured result shows good agreement with simulated data. Experimental results show the center frequency of 2.45GHz, the insertion loss of 1.08dB, and the 3-dB bandwidth of 470MHz(19.5%). Acceding to the measured values, it is found that the fabricated DGS BPF is available for wireless LAN.

• 동굴
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• 제80호
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• pp.21-24
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• 2007

The need for high-frequency decoupling capacitors to supply the transient current requirements to high-speed devices is ubiquitous in current microelectronics applications. Even though materials and their processes have already been developed in terms of their performances, low manufacturing cost cannot be overemphasized in current microelectronics industry. For this reason, we revisited low cost ceramic filled polymer integrated capacitor. Experiments were performed according to the design of experiment (DOE). The best recipe that has the optimized ratio of material composite was obtained using by response optimizer in Minitab. And also, high-frequency measurements were performed to get frequency dependent data using network analyzer.

• 대한전자공학회논문지
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• 제26권2호
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• pp.35-40
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• 1989

본 논문에서는 균일한 유전체로 채워져 있고 윗면에 슬릿이 있는 평행평판 도파로의 ${\pi}-$ 등가회로로 부터 구형 마이크로스트립 안테나의 복사 컨덕턴스와 서셉턴스를 동시에 구하는 새로운 방법을 제시하였다. 계산된 결과를 기존의 이론치와 비교하였다. 또한 등가전송선로를 이용하여 반사손실(return loss) 및 공진주파수를 계산하여 실험치와 비교한 결과 양호한 특성을 얻었다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.409-412
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• 2003

An inverted-F antenna for wireless local area network (WLAN) is presented. The proposed design is based on the typical dual-band planar inverted-F antennas (PIFA), which have two tunable resonant modes. The low-profile antenna is built by stamping and designed to be mounted on the metal frame of the laptop LCD panel. The obtained antenna can perform in 2.4GHz and 5GHz bands and be adopted for other wireless applications. All the measurements are performed in the actual test fixture.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.90-92
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• 2018

본 논문은 FCEV (Fuel Cell Electric Vehicles)용 고전압 직류변환 장치 (High Voltage DC/DC Converter; HDC)의 고전력밀도 달성을 위한 공진 네트워크 최적 설계 방안을 제시한다. 기 선정된 부분 공진형 회로의 스위칭 주파수에 따른 소자별 손실 분포를 고려하여 최적의 공진 네트워크 설계를 제안한다. 제안하는 설계 방안의 타당성은 이론적 분석 및 실험을 통해 검증한다.