• 대한수학회보
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• 제47권5호
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• pp.1025-1036
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• 2010

A new class of generalized open sets in a topological space, called e-open sets, is introduced and some properties are obtained by Ekici [6]. This class is contained in the class of $\delta$-semi-preopen (or $\delta-\beta$-open) sets and weaker than both $\delta$-semiopen sets and $\delta$-preopen sets. In order to investigate some different properties we introduce two strong form of e-open sets called e-regular sets and e-$\theta$-open sets. By means of e-$\theta$-open sets we also introduce a new class of functions called strongly $\theta$-e-continuous functions which is a generalization of $\theta$-precontinuous functions. Some characterizations concerning strongly $\theta$-e-continuous functions are obtained.

• Journal of Power Electronics
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• 제2권2호
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• pp.104-111
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• 2002

This paper presents a new hybrid control scheme using Active-Clamped Class-E(ACCE) inverter for the Induction Heating (IH) jar. The proposed hybrid control scheme has characteristics, which acts as class-E inverter at lower switch voltage and ACCE inverter at higher switch voltage than reference voltage of the main switch by feeding back voltage of the switch. The proposedv hybrid control scheme also has advantage of conventional ACCE inverter such as Zero-Voltage-Switch(ZVS) of the main switch and the reduced switch voltage due to clamping cricuit. Moreover, the proposed hybrid control method using ACCE inverter has higher output power than convenional control scheme since ACCE inverter operates like class-E inverter at low input voltage condition. The principles of the proposed control are explained in detail and the validity of the proposed control scheme is verifed through the several interesting simulated and experimental results.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.1027-1029
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• 2002

In this paper, we present the circuit topology and control scheme of single-phase dc/ac inverter based on class E dc/dc converter for automotive application. The proposed inverter consists of class E series resonant inverter and class E low dv/dt PWM synchronous rectifier with bi-directional switch.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2020년도 전력전자학술대회
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• pp.459-460
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• 2020

The design of a low distortion class E amplifier with a frequency of 6.78MHz for a wireless power transfer is presented. The amplifier with a differential out is designed to reduce the harmonics of the output current. The harmonic characteristics of various types of the class E amplifiers are compared through the simulation study.

• Journal of Periodontal and Implant Science
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• 제29권3호
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• pp.519-540
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• 1999

The purpose of this study is to compare the healing aspects of the use of ePTFE membrane alone versus combination treatment of ePTFE membrane and bone grafts on class II furcation defects. Seventeen defects were applied ePTFE membrane alone on mxillary molar buccal class II furcation defects as Group I, seventeen defects were applied ePTFE membrane and bone grafts on maxillary molar buccal class II furcation defects as Group II, twenty-three defects were applied ePTFE membrane alone on mandibular molar buccal class II furcation defects as Group III, twenty defects were applied ePTFE membrane and bone grafts on mandibular molar buccal class II furcation defects as Group IV . Measurements were made to determine clinical attachment level, probing depth, gingival depth, SBI, mobility at baseline, 3, 6, 12 months postoperatively. Additional measurements were made to determine membrane exposure level at surgery, 1, 2, 6 weeks postoperatively. And then healing patterns and postoperative complications were evaluated. The result as follows : There were statistically significant differences in probing depth reduction, clinical attachment gain, mobility reduction at values of 3, 6, 12 months postoperatively compared to values of baseline(p<0.05), whereas no significant differences in SBI and gingival recession. In group II, membrane exposure level was increased at 1, 2, 6 weeks postoperatively compared to value of baseline(p<0.05). There were statistically significant differences in changes of probing depth at 3, 6, 12 months postoperatively in combination groups of ePTFE membrane and bone graft compared to groups of ePTFE membrane alone(p<0.05). The vast majority of cases fall into typical healing and delayed healing response when membranes were removed in all groups. Pain and swelling were common postoperative complications. In conclusion, this study was showed more effective healing aspects in combination treatment of ePTFE membrane and bone graft than ePTFE membrane alone and on mandibular molar class II furcation defects than maxillary molar.

• 대한전자공학회논문지TC
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• 제48권2호
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• pp.85-89
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• 2011

본 논문에서는 메타구조를 이용하여 하나의 RF LDMOS로 새로운 Class-E 전력증폭기를 구현하였다. CRLH 구조는 Class-E 전력증폭기 특성을 갖는 메타물질 전송 선로를 만들 수 있다. CRLH 전송 선로는 전력증폭기의 정합 회로를 구현을 위하여 주파수 오프셋과 CRLH 전송 선로의 비선형 위상 기울기에 의해 얻을 수 있다. 또한, 제안된 전력증폭기의 효율을 향상 시키기 위하여 출력 정합 회로에 CRLH 구조를 이용하여 구현하였다. 동작 주파수는 13.56MHz로 정하였다. Class-E 전력 증폭기의 측정된 출력 전력은 39.83dBm, 이득은 11.83 dB이다. 이 지점에서 얻은 전력효율(PAE)은 73%이다.

• 전자공학회논문지
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• 제51권9호
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• pp.41-45
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• 2014

본 논문에서는 입력전력에 따라 드레인 바이어스를 조절하여 낮은 입력 전력에서도 고효율 동작이 가능한 무선전력전송용 고효율 class-E 전력증폭기를 설계하였다. 고효율 동작이 가능한 class-E 전력증폭기에 적응형 바이어스 조절회로를 추가하여 낮은 입력 전력에서 드레인 바이어스를 조절함으로써 전체적인 효율의 향상을 얻을 수 있다. 제안된 적응형 class-E 전력증폭기는 효율의 향상을 위해 직렬 공진회로와 입, 출력 정합회로를 이용하여 구현하였으며, 입력전력에 따라 드레인 바이어스를 조절하기 위해 방향성 결합기, 전력 검출기, 연산 증폭기를 이용하여 적응형 바이어스 조절회로를 구성하였다. 따라서 전력증폭기의 최대출력과 전력효율은 13.56 MHz에서 41.83 dBm, 85.67 %이고, 0 dBm ~ 6 dBm의 낮은 입력 전력에서 고정형 바이어스보다 평균 8 %의 효율의 증가를 확인하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.499-502
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• 2004

A two-stage Class E power amplifier operated at 2.44GHz is designed in 0.25-$\mu$m CMOS process for Class-l Bluetooth application. The power amplifier employs c1ass-E topology to exploit its soft-switching property for high efficiency. A preamplifter with common-mode configuration is used to drive the output-stage of Class-E type. The amplifier delivers 20-dBm output power with 70$\%$ PAE (power -added-efficiency) at 2-V supply voltage.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.87-90
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• 2005

High-efficiency switched-mode circuits such as the class-E amplifier are well-known in the MHz frequency range. The class-E amplifier is a type of switching mode amplifier offering very high efficiency approaching 100%. In this paper of the class-E amplifier by using pHEMT device, the design has been done theoretically and experimentally, with simulation by using the harmonic balance method using circuit simulator. The amplifier using microstrip circuit and the pHEMT demonstrate 66% power-added- efficiency (PAE) at 2.4GHz with 17.6dBm of output power.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 추계학술대회 논문집
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• pp.79-81
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• 2007

본 논문에서는 소나용 고출력 전력증폭기의 효율을 향상시키기 위하여 Class E 설계 기법을 분석하고 소나 시스템의 송신기에 적용하였다. Class E 기법에 기반하여 전력소자를 스위칭 모드로 동작시켜서 Zero Voltage Switching(ZVS)이 발생하도록 회로를 설계함으로써 전력 소자의 전력 손실을 최소화하고 전력 증폭기의 효율을 최대화하여 주었다. 설계된 Class E 기법의 전력 증폭기의 동작 및 타당성을 시뮬레이션을 통하여 검증하였다.