• 한국산학기술학회논문지
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• 제13권6호
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• pp.2514-2519
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• 2012

광역경제권 선도산업은 지역 간 협력 및 연계를 통해 산업 경쟁력을 높이는 것을 정책 목표로 하고 있어 R&D의 경제적 파급효과에 대한 권역별 분석이 요구된다. 본 논문에서는 충청광역경제권 선도산업 중 'New IT' 분야의 '차세대무선통신 단말기 부품소재 글로벌 경쟁력 강화' 프로젝트에 대한 경제적 파급효과를 한국은행에서 발간한 지역산업연관표를 활용하여 분석한다.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2008년도 학술대회 2부
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• pp.173-178
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• 2008

최근 휴대폰 디스플레이의 대형화가 요구되면서 터치스크린 휴대폰의 출시가 늘어나고 있다. 본 연구에서는 터치스크린을 채용한 휴대폰 분석을 통하여 사용자가 터치 스크린 휴대폰을 사용할 때의 입력 방식에 대해 6가지로 분류하였다. 입력 방식에 따른 지문 측정 평가를 통하여 사용자 행태를 관찰하고 입력 방식에 대한 인터랙션 스타일의 시각적 피드백에 대해 연구하고자 한다.

• Journal of Electrical Engineering and Technology
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• 제5권3호
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• pp.477-483
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• 2010

This paper is studied on a novel buck-boost isolated converter for high efficiency and high power factor. The switching devices in the proposed converter are operated by soft switching technique using a new quasi-resonant circuit, and are driven with discontinuous conduction mode (DCM) according to pulse width modulation (PWM). The quasi-resonant circuit makes use of a step up-down inductor and a loss-less snubber capacitor. The proposed converter with DCM also simplifies the requirement of control circuit and reduces a number of control components. The input ac current waveform in the proposed converter becomes a quasi sinusoidal waveform in proportion to the magnitude of input ac voltage under constant switching frequency. As a result, it is obtained by the proposed converter that the switching power losses are low, the efficiency of the converter is high, and the input power factor is nearly unity. The validity of analytical results is confirmed by some simulation results on computer and experimental results.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.224-227
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• 1996

Platinum thin films were deposited on Si-wafer by DC magnetron sputtering for RTD (Resistance Thermometer Devices). We investigated the physical and electrical characteristics of these films under various conditions, the input power, working vacuum, temperature of substrate and also after annealing these films. The deposition rate was increased with increasing the input power but decreased with increasing Ar gas pressure. The resistivity were decreased wish increasing the temperature of substrate and the annealing time at 1000$^{\circ}C$. At substrate temperature 300$^{\circ}C$, input power 7(w/$\textrm{cm}^2$), working vacuum 5mtorr and annealing conditions 1000$^{\circ}C$, 240 min we obtained 10.65${\mu}$Ω$.$cm, resistivity of Pt thin film closed to the bulk value.

• E2M - 전기 전자와 첨단 소재
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• 제9권9호
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• pp.911-917
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• 1996

Platinum thin films were deposited on Si-wafer by DC rnagnetron sputtering for RTD (resistance thermometer devices). We investigated the physical and electrical characteristics of these films under various conditions, the input power, working vacuum, temperature of substrate and also after annealing these films. The deposition rate was increased with increasing the input power but decreased with increasing Ar gas pressure. The resistivity and sheet resistivity were decreased with increasing the temperature of substrate and the annealing time at 1000.deg. C. At substrate temperature of >$300^{\circ}C$, input power of 7 w/cm$^{2}$, working vacuum of 5 mtorr and annealing conditions of 1000.deg. C and 240 min, we obtained 10.65.mu..ohm..cm, resistivity of Pt thin films and 3800-3900 ppm/.deg. C, TCR(temperature coefficient of resistance). These values are close to the bulk value. These results indicate that the Pt thin films deposited by DC magnetron sputtering have potentiality for the development of Pt RTD temperature sensor.

• 전기학회논문지P
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• 제51권4호
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• pp.186-192
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• 2002

In this paper, interleaved boost power factor corrector(IBPFC) is applied as a pre-regulator in switch mode power supply. IBPFC can reduce input current ripple and effectively increase the switching frequency without increasing the switching losses, because input current is divided each 50% by two switching devices. IBPFC can be classified as three cases by duty ratio condition in continuous current mode and be carried out state space average modeling. According to the modeling, steady and transient state analysis is performed by steady elements and perturbation element. Control transfer function is derived for design of control system.

• 한국멀티미디어학회논문지
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• 제18권1호
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• pp.71-80
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• 2015

Many researches have been studied to overcome the weak points in authentication schemes of mobile devices such as pattern-authentication that is vulnerable for smudge-attack. Since random-pattern-lock authenticates users by drawing figure of predefined-shape, it can be a method for robust security. However, the authentication performance of random-pattern-lock is influenced by input noise and individual characteristics sign pattern. We introduce an optimization method of user input direction to increase the authentication accuracy of random-pattern-lock. The method uses the likelihood of each direction given an data which is angles of line drawing by user. We adjusted recognition range for each direction and achieved the authentication rate of 95.60%.

• 전력전자학회논문지
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• 제26권6호
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• pp.446-453
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• 2021

This paper proposes enhanced single-phase pulse width modulation buck, boost, and buck-boost type ac-ac converters. The proposed converters, where input and output voltages share a common ground, require no isolated voltage sensor and have no leakage current problem. The commutation problem is solved with series-connected switching cell structures without using an additional RC snubber. In addition, with the use of the polarity of input voltage, switching patterns are determined so that the inductor currents can flow through switching devices during all operational modes. Two switches are always turned on during a half-period of the input voltage; thus, the switching loss is significantly reduced. Detailed analysis and experimental results are provided to verify the performance of the proposed converter.

• ETRI Journal
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• 제45권2호
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• pp.203-212
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• 2023

In this study, we developed a co-located and space-shared multiple-input multiple-output (MIMO) antenna module with a modular design and high integration level. The proposed antenna pair includes a half-wavelength loop antenna and a dipole-type antenna printed on the front and back sides of a compact modular board. Owing to their modal orthogonality, these two independent antenna elements are highly self-isolated and free of additional decoupling components, even though they are assembled at the same location and within the same space. Thus, the proposed antenna is attractive in 5G MIMO systems. Furthermore, the proposed co-located and space-shared MIMO antenna module was employed in a 5G smartphone to verify their radiation and diversity performances. A 12 × 12 MIMO antenna system was simulated and fabricated using the proposed module. Based on the results, the proposed module can be employed in large-scale MIMO antenna systems for current and future terminal devices owing to its high integration, compactness, simple implementation, and inherent isolation.

• ETRI Journal
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• 제46권3호
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• pp.432-445
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• 2024

This paper demonstrates improved throughput and energy efficiency of wireless communications by exploiting nonorthogonal multiple access (NOMA), multiple input-multiple output (MIMO), and radio frequency energy harvesting (EH) technologies. To assess the performance of NOMA MIMO communications with EH (MMe), we consider the nonlinear characteristics of EH devices and propose explicit expressions for throughput and outage probability. Based on our results, the system performance is significantly mitigated by EH nonlinearity and is considerably improved by increasing the number of antennas. Additionally, by appropriately adjusting the system parameters, our NOMA MMe innovation can avert complete outages while optimizing system performance. Moreover, the results demonstrate the superiority of the NOMA MMe over its orthogonal multiple access MMe counterparts.