• 한국통신학회논문지
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• 제19권8호
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• pp.1518-1527
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• 1994

본 논문에서는 배전선을 통하여 전송된 BPSK 신호를 마이크로프로세서를 이용하여 복조하는 알고리즘을 개발하고 구현하였다. 배전선 BPSK 복조를 마이크로프로세서를 실현하기 위해서는 무엇보다 배전선을 통하여 수신된 BPSK 신호를 2진 신호로 바꿔주어야 한다. 그러므로, 본 논문에서는 먼저 전송된 BPSK 신호를 2진 신호로 바꿔주는 하드웨어를 설계하였다. 그런 다음 반송파의 주파수가 피변조 2진 신호 주파수의 우수배이면 변조점이 피변조 2진 신호의 상승에지(rising edge)와 하강에지(falling edge)에서 각각 다른 방향으로 나타난다는 사실과 배전선으로부터 수신된 BPSK 신호를 여과하고, 증폭하고, 크리핑하고, 정형하는 과정을 조절하면 변조점에서의 2진 신호 길이가 다른 점에서의 2진 신호 길이의 2배로 된다는 것에 착안하여 배전선 BPSK 신호를 복조하는 알고리즘을 개발하고, 이 알고리즘에 의한 마이크로프로세서 복조시스템을 실제로 구현하였다. 구현된 이 복조시스템은 실제의 배전선 복조에서 비트오류율(bit error rate)이 0.02% 이하이었다.

• 전기학회논문지
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• 제62권10호
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• pp.1383-1389
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• 2013

There were telecommunication noise and malfunctions of the electronic devices occurred over a wide area due to the high harmonic voltage and/or current levels of the Back-to-back converter in the DFIG wind power system even though the magnitude of all harmonics is within the international standards. The triangular carrier signals of the PWM used in the power converter system is related to the telecommunication noise because they are in the range of audible frequencies and amplified by a variety of the standing waves that were excited by harmonic voltage sources in the weak grid system such as a long distance distribution transmission lines. This paper describes the characteristics of the harmonics in the wind turbine-generator, numerical analysis and simulation of the harmonics resonance phenomena in the distribution lines as well as measuring induced voltage of the telecommunication lines in parallel with power lines in order to verify the root cause of the telecommunication noise. These noise problems can occur in a wind turbine power system with a non-linear converter at any time, as well as photovoltaic power system. So, the preliminary review of suitable filter devices and switching frequencies of the PWM have to be required by considering the stability of the controller at the design stage but as part of the measures the effect of the telecommunication cable shields was analyzed by comparing the measured data between multi-conductor with/without shields so as to attenuate the sources of the harmonics voltage induced into the telecommunication lines and to apply the most cost-effective measures in the field.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2540-2542
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• 2002

In recent years, it is a worldwide trend that many power utilities focus their attention to employ up-to-date communication technology to the automation of their power plants and distribution systems. Automation Systems in Korea was installed using twisted pair cable(TPC), power line carrier(PLC), coaxial cable(CA), wireless network(wireless data, TRS and PCS). Among the communication media only Satellite Communication guarantees the reliable communication in case of emergency such as a flood, a heavy snow and an earthquake. It can integrate two-way satellite systems to existent nationwide SCADA controlling points of electric power transmission & distribution system that enables real time remote monitoring and controlling automatically. This paper presents some of design efforts for the satellite communication network as the media of Automation Systems.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.559-562
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• 2017

도심에서 배전선로는 지중과 가공 선로의 구성, 연가, 건물과 나무로 인한 시야 방해로 추적하기가 어렵다. 이러한 3상 4선식 배전계통에서 특정 수용가가 어떤 변압기 또는 어떤 선로로부터 공급되는지를 결정하는 것이 현장의 전기 기술자에게 어려운 문제다. 배전선로 사이의 부하 평형 등을 위해 선로의 정확한 추적기술이 필요하다. 기존의 임펄스 전류를 사선에 주입하는 방식과는 다르게 활선에 고주파 신호를 주입하는 식별 방법을 제안한다. 배전선로에 고주파 전력 신호를 주입하여 분석 한 결과 고주파 신호는 배전선에서 전달 능력에 한계 능력을 갖는다. 보통 배전계통의 전력 변압기는 그러한 고주파 신호의 전달을 차폐하게 된다. 이러한 전송제한 특성을 사용하여 변압기와 배전선로를 식별하는 방법을 제안한다. 측정 배전선로의 양단에서 전기신호에 대한 동일 선로 여부를 판별하는 방식이다. 어려운 점은 원격 두 지점이 동기화되어야 하는데, 동기화 시간을 제공하는 GPS를 사용하지 않고 두 지점에 동기화를 달성한다. 새로운 형태의 선로 및 변압기 식별시스템을 설계 및 구현한다. 시스템은 전력선 통신 모듈을 바탕으로 송수신기로 구성된다. 이론적 개념을 검증하기 위해서 일반 상업용 건물에서 실험이 행하여진다.

• Journal of Power Electronics
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• 제12권4호
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• pp.567-577
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• 2012

This paper introduces a new scheme to balance the DC bus voltages of a cascaded H-bridge converter which is used as a Distribution Static Synchronous Series Compensator (D-SSSC) in electrical distribution network. The aim of D-SSSC is to control the power flow between two feeders from different substations. As a result of different cell losses and capacitors tolerance the cells DC bus voltage can deviate from their reference values. In the proposed scheme, by individually modifying the reference PWM signal for each cell, an effective balancing procedure is derived. The new balancing procedure needs only the line current sign and is independent of the main control strategy, which controls the total DC bus voltages of cascaded H-bridge. The effect of modulation index variation on the capacitor voltage is analytically derived for the proposed strategy. The proposed method takes advantages of phase shift carrier based modulation and can be applied for a cascaded H-bridge with any number of cells. Also the system is immune to loss of one cell and the presented procedure can keep balancing between the remaining cells. Simulation studies and experimental results validate the effectiveness of the proposed method in the balancing of DC bus voltages.

• 한국조명전기설비학회지:조명전기설비
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• 제8권4호
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• pp.38-45
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• 1994

본 논문에서는 신호감쇄 및 연집잡음(burst noise)이 존재하는 전력선 반송 채널에서 디지틀 데이터를 복조하기 위한 BPSK(Binary Phase Shift Keying) 복조기의 설계에 대하여 논한다. 이러한 BPSK 복조기의 실현에 있어서 반송파 동기호로는 소형화 및 안정화가 요구되며, 입력주파수의 변동에 대해서 낮은 위상 오차가 필요하게 된다. 이와 같은 요구조건을 만족하기 위해서 본 논문에서는 반송주파수가 10.4[kHz]이고, 전송속도가 110[bps]인 재변조방식의 BPSK 복조기를 설계 제작하였다. 설계 제작한 반송파 동기회로는 기존의 아날로그 소자로 구성되었던 승산기(multiplier) 및 지연회로를 PLL(Phase Locked Loop) IC로 대치하여 소형화 및 안정성을 확보하였으며, PLL회로 설계시에 주위온도 등을 고려하여 주파수 인입범위를 $\pm$4[kHz], 정상위상오차를 $\pm$60로 설정하였다. 기능시험 결과로부터, BPSK 복조기의 동작기능은 정상상태에서 설계조건에 만족함을 알 수 있었다.

• Biomolecules & Therapeutics
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• 제27권3호
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• pp.290-301
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• 2019

Paeonol has neuroprotective function, which could be useful for improving central nervous system disorder. The purpose of this study was to characterize the functional mechanism involved in brain transport of paeonol through blood-brain barrier (BBB). Brain transport of paeonol was characterized by internal carotid artery perfusion (ICAP), carotid artery single injection technique (brain uptake index, BUI) and intravenous (IV) injection technique in vivo. The transport mechanism of paeonol was examined using conditionally immortalized rat brain capillary endothelial cell line (TR-BBB) as an in vitro model of BBB. Brain volume of distribution (VD) of [$^3H$]paeonol in rat brain was about 6-fold higher than that of [$^{14}C$]sucrose, the vascular space marker of BBB. The uptake of [$^3H$]paeonol was concentration-dependent. Brain volume of distribution of paeonol and BUI as in vivo and inhibition of analog as in vitro studies presented significant reduction effect in the presence of unlabeled lipophilic compounds such as paeonol, imperatorin, diphenhydramine, pyrilamine, tramadol and ALC during the uptake of [$^3H$]paeonol. In addition, the uptake significantly decreased and increased at the acidic and alkaline pH in both extracellular and intracellular study, respectively. In the presence of metabolic inhibitor, the uptake reduced significantly but not affected by sodium free or membrane potential disruption. Similarly, paeonol uptake was not affected on OCTN2 or rPMAT siRNA transfection BBB cells. Interestingly. Paeonol is actively transported from the blood to brain across the BBB by a carrier mediated transporter system.

• Journal of Microbiology and Biotechnology
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• 제16권9호
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• pp.1369-1376
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• 2006

Self-organized nanogels were prepared from pullulan/biotin conjugates (PU/Bio) for the development of an effective anticancer drug delivery system. The degree of biotin substitution was 11, 19, and 24 biotin groups per 100 anhydroglucose units of pullulan. The physicochemical properties of the nanogels (PU/Bio1, 2 and 3) in aqueous media were characterized by dynamic light scattering, transmission electron microscopy, and fluorescence spectroscopy. The mean diameter of all the samples was less than 300 nm with a unimodal size distribution. The critical aggregation concentrations (CACs) of the nanoparticles in distilled water were $2.8{\times}10^{-2},\;1.6{\times}10^{-2}$, and $0.7{\times}10^{-2}mg/ml$ for the PU/Bio1, 2, and 3, respectively. The aggregation behavior of the nanogels indicated that biotin can perform as a hydrophobic moiety. To observe the specific interaction with a hepatic carcinoma cell line (HepG2), the conjugates were labeled with rhodamine B isothiocyanate (RITC) and their intensities measured using a fluorescence microplate reader. The HepG2 cells treated with the fluorescence-labeled PU/Bio nanoparticles were strongly luminated compared with the control (pullulan). Confocal laser microscopy also confirmed internalization of the PU/Bio nanogels into the cancer cells. Such results demonstrated that the biotin in the conjugate acted as both a hydrophobic moiety for self-assembly and a tumor-targeting moiety for specific interaction with tumor cells. Consequently, PU/Bio nanogels would appear to be a useful drug carrier for the treatment of liver cancer.

• 한국신뢰성학회지:신뢰성응용연구
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• 제9권2호
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• pp.131-148
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• 2009

An organic light emitting diode (OLED), also light emitting polymer (LEP) and organic electro luminescence (OEL), is any light emitting diode (LED) whose emissive electroluminescent layer is composed of a film of organic compounds. The layer usually contains a polymer substance that allows suitable organic compounds to be deposited. They are deposited in rows and columns onto a flat carrier by a simple "printing" process. The resulting matrix of pixels can emit light of different colors. Such systems can be used in television screens, computer displays, small, portable system screens such as cell phones and PDAs, advertising, information and indication. OLEDs can also be used in light sources for general space illumination, and large-area light-emitting elements. In this paper, we develop the general guide line of the accelerated life test for assuring B10 life of AMOLED(Active Matrix Organic Light Emitting Diode) and PMOLED(Passive Matrix Organic Light Emitting Diode) which are widely used for display monitor less than 115 mm.