• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.54 no.1
• /
• pp.56-60
• /
• 2005

In the power-line communication(PLC) systems, the power line is a wired medium. However, the power line channel has the multi-path fading characteristics like the wireless channel in the wireless communication systems because it has the signal reflection and divergence by the impedance mismatching between many branch lines and loads. So the analysis of the multi-path characteristics is very important, and it has been doing by the several measurement methods for the impulse response between the transmitter and the receiver. PN sequence method has originally been used as a wideband impulse response measurement mettled for wireless channel, but it is recently being applied to not only the wireless channel but also the wired channel like the power line channel. This method is more useful and effective for the long distance communication channel like the medium voltage power distribution line with the multi-paths[1]. In this thesis, we have measured impulse response for the medium voltage power distribution line channel by the wideband measurement method using PN sequence, analytically studied the measured data and presented the results.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1219-1222
• /
• 2005

As the optical communication is introduced to the backbone network at first and becomes a general communication method of network, the demand of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM(Wavelength Division Multiplexing) element increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this paper, the driving mechanism of ultra precision stage is studied with the aim of optimal design of stage. The travel and the resolution of stage are investigated. The hysteresis of the stage is generated because of PZT actuator. The hysteresis and the inverse hysteresis are modeled in X, Y, and Z-axis motion. The input data of desired displacement to the stage according to input voltage is obtained from the inverse hysteresis equation. In the result of experiments with the input data, the errors due to hysteresis are well compensated.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.13 no.2
• /
• pp.106-115
• /
• 2013

LED lighting control system using unidirectional DMX512 (digital multiplex with 512 pieces of information)) protocol has been the most popular. Nowadays, the user's consumption has been upgrading to the more intelligent system but the upgrading process does not affect the existing infrastructure. There were many researches use the additional communication for the feedback communication way such as WiFi, Controller Area Network (CAN), Power Line Communication (PLC), etc but all researches had inherent disadvantages that created the independent feedback with the existing DMX512 system. Our paper represents the novel method that uses the remote device management (RDM) protocol to associate the additional feedback with existent DMX512 infrastructure in the one system. The data in DMX512 frame sending to the DMX512 client is split and repacked to become the RDM packet. This RDM packet is transferred to the RDM monitor console and the response RDM packet is converted to the DMX512 frame for control DMX512 client devices. This is the closed loop control model which uses the bidirectional convertibility between RDM packet and DMX512 frame. The proposed method not only upgrades the feedback control function for the old DMX512 system without changing the existent infrastructure, but also solves compatible problems between new RDM devices and old DMX512 devices and gives the low cost solution for extending DMX512 universe.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.1
• /
• pp.217-223
• /
• 2012

Time synchronization problems is very important in everyday life and a variety of industries, In this paper, we developed PLB(Power Line Broadcasting) system which broadcast time information to each device through power line modems. In our system, the smartphone synchronized to GPS time is used as a time source and we propose, develop and evaluate a relay system to solve the difficulties of long-distance transmission of power line modem technology.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2005.05a
• /
• pp.81-86
• /
• 2005

As the optical communication is introduced to the backbone network at first and becomes a general communication method of network, the demand of kernel parts of optical communication such as PLC(Planar Light Circuit), Coupler, and WDM(Wavelength Division Multiplexing) element increases. The alignment and the attachment technology are very important in the fabrication of optical elements. In this paper, the driving mechanism of ultra precision stage is studied with the aim of optimal design of stage. The travel and the resolution of stage are investigated. The hysteresis of the stage is generated because of PZT actuator. The hysteresis and the inverse hysteresis are modeled in X, Y, and Z-axis motion. The input data of desired displacement to the stage according to input voltage is obtained from the inverse hysteresis equation. In the result of experiments with the input data, the errors due to hysteresis are well compensated.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.13 no.1
• /
• pp.221-227
• /
• 2013

Recent studies have been conducted on powerline communications as a viable alternative to the spread of the spread of the Internet and the Internet as the chief source of information act in the information age, the internet does not reach local Last Mile Solution. Powerline communication, but because it has been designed to transfer power to the high frequency signal to be sent when the close of wireless communications services impacted. The notch filters of a common way to eliminate the interference are used. In this paper, a dynamic high-performance notch filter applying WDF performance was verified through MATLAB and was implemented using a TI's TMS320C6416T DSP board.

• The Journal of the Korea Contents Association
• /
• v.9 no.11
• /
• pp.37-45
• /
• 2009

Today, Internet service is a most important Information Source. So, the Power Line Communication has been achieved to offer Internet service to Last-Mile area. But, Power Line is not suitable for communication, So, electromagnetic wave is generated from Power Line during flow of communication information. And the electromagnetic wave is interfered with Wireless Communication Service using the same frequency range. In this paper, the Notch Filter and the Spectrum Sensing technology are proposed to reduction of interference between Power Line Communication and Wireless Communication Service. The Spectrum Sensing technology is the core technology of the Cognitive Radio (CR) system. CR is the technology that temporarily allocates the frequency bandwidth by scanning surrounding wireless environments to keep licensed terminals and search the unused frequency bandwidth. The proposed emulator is implemented with Spectrum Sensing and Notch Filter system using Embedded Board.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.46 no.5
• /
• pp.44-51
• /
• 2009

In this paper, an air conditioner peak power control system using electric power line communication has been developed. The air conditioner power control system using RS-485 communication method is hard to install on the existing buildings due to difficulty in cabling, and the system using wireless communication methods has a weak point of not being able to be used in close space, while the developed system has its own advantages of overcoming the above mentioned obstacles. In addition, the system is extended to support not only single-phase electricity system but also three-phase four-wire electricity system, and therefore can be installed anywhere in the domestic environment. The system also has enhanced the ease of deployment, operational stability and economical efficiency by compact circuit design. Considering the current state requiring the energy sayings, the system would greatly contribute to the widespread use of the air conditioner power control system. The superiority in the performance and stability of the system has been proved by the design verification of each component such as remote air conditioner controller, electric power line gateway and so on, and the field test of the whole system.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.8C
• /
• pp.663-669
• /
• 2012

To solve the energy problem and finding new growth engines, interest for the smart grid is increasing and related technologies are making great efforts to secure in the world. AMI (Advanced Metering Infrastructure) Among them is the first to be constructed and getting attention as a key component of smart grid. A fusion of various technologies in technology development and demonstration is underway on Jeju Island Smart Grid Demonstration Complex in Korea, and focusing on broadband power line communication technology infrastructure is actively underway in Korea Electric Power Corporation. AMI system using power line communication technology without building a separate communication lines are available for power supply lines, but communication is impossible in occurs because admission to the power company or the ideal infrastructure for communication is not considered. In this paper, we analyze the requirements to build AMI system using Binary CDMA and powerline communications technology, and design the basic communication protocol based on Binary CDMA, implement network management and relay feature. By doing so, ways to apply Ad-hoc Binary CDMA indigenous technology to the AMI system were derived, and could build a system to make use of Wired (PLC) and wireless (Binary CDMA) simultaneously.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.11C
• /
• pp.871-876
• /
• 2010

Currently the development of powerline communication technology has become possible due to the high-speed communications. But the communication lines used for power line communication, not wires carrying power wiring is because when sending high-frequency wireless communication system unintentionally be influenced. To compensate for these shortcomings by using notch filters to reduce interference has been studied. Wavelet-based OFDM on the other hand by the method has been used to reduce interference. Wavelet-based OFDM has been used in the existing powerline OFDM scheme using FFT instead of the general structure of the CMFB filters to generate a signal. By doing so, subtly signals per frequency band, cut it, is to realize how efficient highways. It brought a deep filter characteristics, a flexible notch filter can be achieved without an external circuit has an advantage. In this paper, Using Wavelet OFDM powerline communication system is designed and presented the results of simulations.