• 한국디자인학회:학술대회논문집
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• 한국디자인학회 1999년도 춘계 학술발표대회 논문집
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• pp.8-9
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• 1999

디자인에 있어 올바른 해결을 위한 조사가 필수적이듯이 인터페이스의 설계에 있어서도 문제를 발견하기 위한 조사는 매우 중요한 단계이다. 본 연구는 PCS Phone을 사례로 인터페이스 설계를 위한 조사와 그에 따른 결과의 분석 사례를 소개한다.(중략)

• 한국통신학회논문지
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• 제18권12호
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• pp.1945-1955
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• 1993

본 논문은 개인통신서비스(PCS)의 운영에 있어 필수적인 요소로 부상하고 있는 개인식별 기능을 갖는 두가지 키분배 방식을 제안하였다. PCS를 위한 서비스절차와 안정성 요구분석을 수행하고, 기존에 제안된 디지털 이동통신을 위한 키분배방식의 안전성을 검토하였따. 특히 기존 방식중 Park 등이 제안한 ElGamal변형방식이 이용자 인증과정에 있어서 능동적 공격자에 대해 취약함을 입증하였다. 본 제안방식 I,II 는 Rabin 과 ElGamal 암호계를 변형, 혼합한 것으로, PCS 운영에 있어서 빈번히 요구되는 인증시 계산량을 감소시켰고 이용자의 제한된 계산능력을 고려하여 이용자의 계산량을 줄였으며, PCS 안전성 요구사항을 만족시킨 것이다. 타 방식과 비교분석한 결과, 안전성 및 효율성 특히 이용자의 계산량에 있어서 제안방식이 더 개선되었음을 확인하였다.

• Journal of Information Processing Systems
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• 제9권2호
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• pp.271-286
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• 2013

Recently, a pixel-chaotic-shuffling (PCS) method has been proposed by Huang et al. for encrypting color images using multiple chaotic systems like the Henon, the Lorenz, the Chua, and the Rossler systems. All of which have great encryption performance. The authors claimed that their pixel-chaotic-shuffle (PCS) encryption method has high confidential security. However, the security analysis of the PCS method against the chosen-plaintext attack (CPA) and known-plaintext attack (KPA) performed by Solak et al. successfully breaks the PCS encryption scheme without knowing the secret key. In this paper we present an improved shuffling pattern for the plaintext image bits to make the cryptosystem proposed by Huang et al. resistant to chosen-plaintext attack and known-plaintext attack. The modifications in the existing PCS encryption method are proposed to improve its security performance against the potential attacks described above. The Number of Pixel Change Rate (NPCR), Unified Average Changed Intensity (UACI), information entropy, and correlation coefficient analysis are performed to evaluate the statistical performance of the modified PCS method. The simulation analysis reveals that the modified PCS method has better statistical features and is more resistant to attacks than Huang et al.'s PCS method.

• 디지털콘텐츠학회 논문지
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• 제14권4호
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• pp.529-536
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• 2013

태양광 풍력 하이브리드(Hybrid) 발전 시스템에서는 발전의 주 인자인 태양의 일조량과 바람의 세기 등이 환경적 요인으로 적절하지 못할 경우 충방전 성능의 한계를 가지고 있는 에너지 저장장치인 배터리를 충전하는데 어려움이 발생한다. PCS(power conditioning system)는 태양광 풍력 발전 시스템 운용에 필수적인데 기존의 대부분의 PCS는 중대형 중심이어서 소형 발전에 적합하지 않아 효율이 높고 안정적인 동작을 하는 소형 발전용 PCS 개발이 절실히 요구된다. 본 논문에서는 이러한 문제들을 해결하면서 상용(한전)전력과의 계통연계 및 독립 운영이 가능하고 배터리의 장수명화와 안정화가 가능한 1kW급 하이브리드 CC/CV(constant current/constant voltage)기능을 갖는 PCS를 설계하고 시제품으로 구현하여 그 성능을 검증한다.

• 한국결정성장학회지
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• 제12권2호
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• pp.80-86
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• 2002

$Al_{2}O_{3}/SiC$ nanocomposites were made by infiltrating partially sintered alumina bodies with polycarbosilane (PCS) solutions, which is a SiC polymer precursor, with pressureless sintering. The SiC content, densification, phases, strength, and microstructure were investigated with the processing parameters such as PCS solution concentration and heat treatment condition for PCS pyrolysis and sintering. The results were compared with those for pure alumina and nanocomposite samples made by the existing polymer precursor route (i.e. the PCS addition process). The SiC contents of up to 1.5 vol% were obtained by the PCS infiltration. PCS pyrolysis, followed by air heat treatment, was needed before sintering to avoid a cracking problem and to attain a densification as high as 98 % of theoretical. The nanocomposites exhibited significantly higher strength than pure alumina and those prepared by the PCS addition process despite larger grain size. Besides $\alpha-Al_{2}O_{3}/SiC$ and $\beta-SiC$ phases, mullite was present a little in the nanocomposites, which resulted from the reaction of $SiO_{2}$ in the pyrolysis product of PCS with the $Al_{2}O_{3}$ matrix during sintering. The nanocomposites had intagranular particles believed to be SiC, which is a typical feature of $Al_{2}O_{3}/SiC$ nanocomposites.

• 한국전자파학회논문지
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• 제13권9호
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• pp.873-881
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• 2002

본 논문에서는 PCS대역(1,750 MHz ~ l,870 MHz)과 IMT-2000대역(1,885 MHz ~2,200 MHz)에서 동작하는 광대역 8소자 다이폴 배열 구형반사판 안테나를 설계하고, 실제안테나를 제작하여 복사특성을 측정하였다. 안테나설계 는 모멘트법 과 HFSS(High Frequency Structure Simulator)를 이용하여 해석하고, 해석 된 결과로부터 안테나의 구조 값을 구하였다. 설계된 안테나의 타당성을 검토하기 위하여 8소자 다이폴 배열 구형반사판 안테나를 실제 제작하고 복사특성을 측정하여 계산결과와 비교하였다. 측정결과는 PCS대역과 IMT-2000대역에서 VSWR이 1.5 이하를 만족하였고, 이득은 전 대역에서 16 dBi 이다. 따라서 본 논문에서 설계한 안테나는 PCS/IMT-2000 기지국용 안테나로 사용할 수 있을 것으로 생각된다.

• 한국환경농학회지
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• 제28권4호
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• pp.409-411
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• 2009

Phytochelatins (PCs) are small-sized peptides synthesized by PC synthase (PCS) using glutathione (GSH) as a substrate, and they play an important role in the detoxification of toxic heavy metals in plants, fission yeast, and other living organisms. Recently, it has been suggested that PCS is also involved in degradation of some xenobiotics including monobromobimane. PCS cleaves the Gly residue from GSH-xenobiotics conjugates resulting in ${\gamma}$-Glu-Cys-xenobiotics, and this is to degraded further. Therefore, our research is focus on whether PCS is also involved in degradation of tolclofos-methyl, an important pesticide which has been used in ginseng cultivated areas. Heterologous expression of Arabidopsis PCS confers tolerance to tolclofos-methyl in yeast. Furthermore, PCS-deficient Cad1-3 Arabidopsis mutant showed high sensitivity to tolclofos-methyl compared with wild-type plants. These results imply that PCS is involved in degradation of tolclofos-methyl as other xenobiotics.

• 전력전자학회논문지
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• 제18권6호
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• pp.515-522
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• 2013

In this paper, a new PCS is proposed which is consisted of high boost dual converter and single phase half-bridge inverter. The proposed PCS is configured in parallel input / serial output, using two interleaved voltage doubler converter. Converter of the proposed PCS is distribute input current by configuring parallel input and reduced turn ratio of transformer by configuring serial output. Also, compositions of the inverter are composed of serial output capacitor of converter and half-bridge inverter. The dual converter and single phase half-bridge inverter is designed and characteristic of the new PCS is analysed. The system of the 1.5[kW] PCS is verified through an experimental about operation and stability.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1050-1051
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• 2015

In industry, there are several different controllers which can be implemented for power conditioning systems (PCS) such as proportional-resonant (PR), predictive deadbeat (PD), or proportional-integral (PI) controller. But there are not any comparison studies about these controllers. To investigate the differences between the three types of the controllers, this paper presents a comparative study of PR, PI, and PD controllers in a photovoltaic (PV) PCS. These controllers are designed mathematically and simulated for the comparative analysis. The PI controller is designed in the rotating reference (dq) frame. The PR and PD controllers are implemented in the natural (abc) reference frame. The PCS is composed of a DC-DC boost converter and a full bridge inverter. The filter of the PCS is an LCL filter including a passive damping resistor. The parameters of PCS are 3 kW, 25 kHz switching frequency and 220 V-60 Hz grid voltage. The comparison results between these controllers for the grid-connected PCS are clearly shown. The simulation results demonstrate the detailed characteristics of each controller for the PV PCS in order to choose the controller for individual target properly.

• 전력전자학회논문지
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• 제23권2호
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• pp.101-105
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• 2018

Shortage of electric power occurs frequently along with increased electric power demand. ESS is a precaution to solve this issue. Household ESS has a capacity of approximately 3 kW/7 kWh. Household ESS batteries are typically designed with nominal voltages between 40 and 50 V. To connect household ESS with a 220 V AC system, low battery voltages in power conditioning system (PCS) should be boosted. To boost low battery voltage and match it with AC grid voltage, the use of a transformer for a commercial frequency can be considered. To attenuate switching harmonics of the household single-phase ESS-PCS, LC filter can be installed in two positions: on the primary side or on the secondary side of a transformer. A method has been used generally in single-phase inverters for the ESS-PCS. In another method, however, the output efficiency of the ESS-PCS may be decreased. Parasitic components of the transformer can affect voltage losses, when the square wave with the switching frequency in the ESS-PCS is passed through the transformer windings. In this work, the characteristics of the transformer according to the position of an LC filter are investigated for household single-phase ESS-PCS.