• 한국통신학회논문지
• /
• 제30권12A호
• /
• pp.1136-1146
• /
• 2005

본 논문에서는 전력선 통신을 위해 사용되는 고압 배전선로에서 통신신호 및 잡음신호에 의해 방사되는 방사전계강도를 계산하였다. 전력선 통신 네트워크의 2포트 등가모델 및 기본적인 전송선로 이론을 이용해 입력임피던스를 계산하였다. 그리고 계산된 입력임피던스를 이용해 전력선상 전류를 계산하고 최종적으로 방사전계강도를 계산하였다. 전력선의 특성임피던스가 매우커서 입력 단에서의 반사가 심하기 때문에 입력임피던스는 일정한 주기를 가지는 정재파 형태를 가진다. 계산된 전류 및 방사전계 또한 이러한 형태임을 알 수 있었다. 실제 측정한 결과계산 치와 측정치가 매우 유사함을 알 수 있었다.

• Journal of the Optical Society of Korea
• /
• 제8권4호
• /
• pp.149-155
• /
• 2004

Newly developed modal transmission-line theory(MTLT) is used to analyze rigorously the optical power distribution in grating-assisted directional couplers(GADCs) with three guiding channels. By defining a novel coupling efficiency ${\eta}$ amenable to the rigorous analytical solutions of modal transmission-line theory, we explicitly evaluate the power coupling and distribution of TM modes. The results reveal that the incident power is sensitively partitioned through three output channels in terms of such grating parameters as the grating period, the duty cycle, and the operating wavelength.

• ETRI Journal
• /
• 제16권1호
• /
• pp.59-72
• /
• 1994

In this paper, a new N-way hybrid power combiner for improving the graceful degradation performance has been proposed. The proposed combiner has been configured with two dummy transmission lines per each section, where each dummy transmission line has a different characteristic impedance, of the standard combiner. Under this proposed configuration, a detailed theoretical analysis has been performed to show the general function of a power combiner. When any M amplifiers among N identical amplifiers are suffering the failure mode in a power combining circuit or system, the graceful degradation performance has been improved due to the separation of a transmission line and an internal resistor in every failed section from the proposed combiner by simultaneously operating two shorting devices. Simulation results for all the items which can be measured from all the items which can be measured from the proposed combiner with an eight-way configuration have been presented.

• 한국멀티미디어학회논문지
• /
• 제18권6호
• /
• pp.742-752
• /
• 2015

The communications through the power lines are called as the PLC and this is a common name for the communication modes for the information delivery. This technology transmits the data through the power lines on which the information is stored with the form of high frequency signal. The characteristic of the frequency signal is that the signal can be separated from the power line through exclusive power line modem and transmitted to the terminal devices. In this paper, 'In-home Headcount' checking algorithm using Wi-Fi and taking above mentioned advantages is proposed, and the basic Technology for such Solitary Senior Citizen's Lonely Death monitoring system has been designed and implemented. The comparative analysis has been conducted in this paper with the test-operated and test bed-completed 'Hyosimi 119 Safety-Welfare System' which is still being tested since 2008. With the 'In-home Headcount Checking Algorithm', Wi-Fi connection/disconnection status and SSIDs of relevant Wi-Fis will be checked. We expect that our proposed method will become as the basic Technology which can prevent lonely deaths of elderly people living alone. Since the PLC technology can be normally implement all the functions used on internet anticipate that the technology could be applied to many areas to construct a new form of communication network.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제53권5호
• /
• pp.345-352
• /
• 2004

Currently, high data rate PLC(Power Line Communications), up to 100 Mbps, which use frequency bandwidth between 2 MHz and 30 MHz is investigated very hard, and commercial PLC modem for low voltage powerline network (indoor) is coming soon into communication market. For the purpose of developing a fit communication system which has little distortion of signal and attenuation, it is surely necessary to know about channel environments of powerline. Especially, the impedance measurement of the powerline and impedance matching are very important. As is known, since medium-voltage powerline (22.9 ㎸) is still working, it is not so simple to measure the powerline impedance. In our study, a portable impedance measurement equipment is developed. It consists of coupling capacitor, a drain coil and impedance matching transformer. The equipment is easily connected to medium voltage line and impedance of power line is measured using a network analyzer. Also, measurement results are used for impedance matching of PLC signal. In fact, matching transformer with several different impedances are used. The matching transformer is connected between coupling capacitor and signal port. In this paper, the developed portable impedance measurement equipment and impedance measurement results are presented. Also impedance matching technique using matching transformers will be explained. We showed the result of the improved performance by the impedance matching.

• 전기전자학회논문지
• /
• 제23권3호
• /
• pp.777-784
• /
• 2019

인적이 드문 한적한 곳이나 산악 지역에서 화재가 발생 하였을 때 화재 상황을 정확하게 파악하고 적절한 초동 대처를 한다면 피해를 최소화할 수 있으므로 사전 화재인지시스템과 자동알림시스템이 요구된다. 본 연구에서는 객체인식을 위한 딥러닝 알고리즘 중 Faster-RCNN 및 SSD(single shot multibox detecter)을 사용한 화재 인식시스템을 전력선 통신과 연동하여 자동알림시스템을 시연하였으며 향 후 고압송전망을 이용한 산불화재 감시에 응용 가능함을 제시하였다. 학습된 모델을 장착한 라즈베리파이에 파이카메라를 설치하여 화재 영상인식을 수행하였으며, 검출된 화재영상은 유도형 전력선 통신망을 통하여 모니터링 PC로 전송하였다. 학습 모델별 라즈베리파이에서의 초당 프레임 율은 Faster-RCNN의 경우 0.05 fps, SSD의 경우 1.4 fps로 SSD의 처리속도가 Faster-RCNN 보다 28배 정도 빨랐다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.1678-1679
• /
• 2007

This paper is the electric power system remote control of semiconductor plasma manufacturing equipment using PLC(power line communication). PLC is useful for economical data link but various problems and limitations are caused in using power lines for communications channel Develop of Semiconductor plasma manufactur ing equipment and remote automation technologies of tool develops day after day and standards. Also, Remote electric power control and device module control by GUIRCS(Graphic User Interface Remote Control System) of tool are monitoring in real time.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2003년도 춘계종합학술대회
• /
• pp.115-118
• /
• 2003

본 고에서는 전력선 통신이 해상 통신 서비스에 주는 간섭에 대해서 기술하였다. 전력선 통신 뿐 만 아니라 통신선을 이용하는 ADSL이나 VDSL은 고속의 데이터 전송을 위해 광대역을 사용하는데 이때 발생되는 전파 방사가 해상 통신 둥 기존 무선 서비스에 간섭을 주게 된다. 본 고에서는 30MHz이하의 대역에서 사용되고 있는 해상 통신 서비스가 전력선 통신에 의해서 간섭을 받게 될 수 있는 가능성을 분석하고 이러한 간섭을 피하기 위한 보호 대책에 대해서 기술하였다.

• 정보학연구
• /
• 제6권4호
• /
• pp.81-91
• /
• 2003

본 논문은 가정내 설치되어 있는 전력선을 이용한 스마트 홈 구축에 적합한 9.6Kbps 전력선 통신 시스템 구현에 관한 것이다. 제안한 전력선 통신 시스템은 가변 감쇄 특성과 가전기기에 의해 발생되는 각종 잡음들, 그리고 각종 가전기기 접속에 의한 임피던스 특성 변화등에 강한 신호 방식으로 100KHz~200KHz 대역 확산 주파수와 선형형태의 Chirp 신호를 사용하였다. 전력선통신 환경과 유사한 의사 부하 망을 제작하여 구현한 시스템에 대한 성능 실험을 하였다. 실험결과 의사 부하망 환경에서의 통신은 매우 만족하게 이루어졌으며, 구현된 Chirped-SS 방식의 9.6Kbps전력선 통신 시스템이 스마트 홈 구축에 있어서 상용화 할만한 성능을 가짐을 확인할 수 있었다.

• 조명전기설비학회논문지
• /
• 제24권10호
• /
• pp.157-162
• /
• 2010

Power line communication, using 25[kV] high voltage of railway catenary, is to provide information which is real-time safety information for train operations and train workers in driving. Lots of noise were occupied in the contact wire by electrical and communication equipments. A signal attenuation was caused characteristics of the contact wire and messenger wire. For relaying communications to transmit information using the contact wire, catenary the noise and signal attenuation were investigated. And the final goal of the study was realized to transmit video information by power line communication on electric railway.