• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.135-142
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• 2009

Since hold-type display systems have been developed, frame-rate up conversion (FRUC) is an essential technique to improve the temporal resolution in the display. FRUC improves the temporal resolution by interpolating one or multiple intermediate frames between two adjacent frames. In this paper, a new frame-rate up-conversion algorithm based on bilateral motion refinement with rotation is proposed. First, we perform bi-directional motion estimation between adjacent two frames to obtain a motion vector for each block. Then, we apply a modified median filtering to motion vectors for outlier-rejection and motion field smoothing. The filtered motion vectors are updated by the bilateral motion refinement with rotation. After the refined motion vector is obtained, the intermediate frame is generated by applying the overlapped block motion compensation (OBMC). Experimental results show that the proposed algorithm provides a better performance than the previous methods subjectively and objectively.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.4
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• pp.125-144
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• 2022

When a variable message signs (VMS) system displays false information related to traffic safety caused by malicious attacks, it could pose a serious risk to drivers. If the normal message patterns displayed on the VMS system are learned, it would be possible to detect and respond to the anomalous messages quickly. This paper proposes a method for detecting anomalous messages by learning the normal patterns of messages using a bi-directional generative pre-trained transformer (GPT) network. In particular, the proposed method was trained using the normal messages and their system parameters to minimize the corresponding negative log-likelihood (NLL) values. After adequate training, the proposed method could detect an anomalous message when its NLL value was larger than a pre-specified threshold value. The experiment results showed that the proposed method could detect malicious messages and cases when the system error occurs.

• Journal of Korea Multimedia Society
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• v.8 no.2
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• pp.258-268
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• 2005

The efficient provision of multicast service to moving hosts in mobile computing environments is not so easy task. Bi-directional tunneling scheme causes overhead about encapsulation and triangular routing. On the other hand, remote subscription scheme need freDuent tree reconstruction, which is inefficient for rapid moving hosts. In this paper we propose Mobility Based Mobile Multicast(MBMOM) scheme which is based on host's mobility information. Ultimately MBMOM try to find the strong points of remote subscription scheme and hi-directional tunneling scheme. If host's mobility speed is considered to be high, multicast packets are forwarded using hi-directional tunneling scheme from home agent continuously. If host's mobility speed is considered to be slow, remote subscription scheme is applied for foreign agent and it try to join multicast tree. We developed analytical models to analyze the performance of proposed scheme and simulated our scheme compared with MOM(Mobile Multicast), RBMOM(Range Based MOM), and TBMOM(Timer Based MOM) schemes. Simulation results show that our scheme has shorter transmission delay than above 3 schemes in the aspect of host's mobility speed and multicast group size.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.8
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• pp.52-59
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• 2007

In this paper, we analyzed and measured implant isolation characteristics for a 1.25 Gbps monolithic integrated hi-directional (M-BiDi) optoelectronic system-on-a-chip, which is a key component to constitute gigabit passive optical networks (PONs) for a fiber-to-the-home (FTTH). Also, we derived an equivalent circuit of the implant structure under various DC bias conditions. The 1.25 Gbps M-BiDi transmit-receive SoC consists of a laser diode with a monitor photodiode as a transmitter and a digital photodiode as a digital data receiver on the same InP wafer According to IEEE 802.3ah and ITU-T G.983.3 standards, a receiver sensitivity of the digital receiver has to satisfy under -24 dBm @ BER=10-12. Therefore, the electrical crosstalk levels have to maintain less than -86 dB from DC to 3 GHz. From analysed and measured results of the implant structure, the M-BiDi SoC with the implant area of 20 mm width and more than 200 mm distance between the laser diode and monitor photodiode, and between the monitor photodiode and digital photodiode, satisfies the electrical crosstalk level. These implant characteristics can be used for the design and fabrication of an optoelectronic SoC design, and expended to a mixed-mode SoC field.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.102-108
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• 2015

This paper proposes a new fault isolation methodology for a smart protective device which plays an agent role on the smart grid distribution system with the distributed generation. It, by itself, determines accurately whether its protection zone is fault or not, identifies the fault zone and separates the fault zone through the exchange of fault information such as the current information and the voltage information with other protective devices using bi-directional communication capabilities on the smart grid distribution system. The heuristic rules are obtained from the structure and electrical characteristics determined according to the location of the fault and DG (Distributed Generation) when faults such as single-phase ground fault, phase-to-phase short fault and three-phase short fault occur on the smart grid distribution system with DG.

• Journal of Satellite, Information and Communications
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• v.10 no.1
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• pp.44-48
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• 2015

The smart grid is a next-generation power grid to create a new value-added information technology. Power providers and consumers exchange information in real-time bi-directional, and optimize energy efficiency with using the smart grid. This paper describes the concept of demand response of the communication system used in the protocol, implementation of demand response systems with demand response scenarios for power reduction through the air conditioning control.

• Journal of information and communication convergence engineering
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• v.8 no.5
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• pp.489-492
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• 2010

This paper proposes the planar-type modified monopole antennas of loop structure. This antenna has an opened center of a conventional closed loop structure with an inside-folded terminal of the loop microstrip line. The size of the proposed antenna was minimized by folding the end of the loop. Also, the reactance value has been minimized by increasing capacitances between the coupled microstrip line. Therefore the proposed antenna has been compacted to about 20% from a conventional loop antenna and has increased its efficiency. The proposed antennas have an omni-directional pattern, the antenna gain was 3.67 [dBi] and the bandwidth was 900 MHz (2.6~3.56 GHz) with VSWR$\leq$2 from the simulated and the measured results. The frequency utilization coefficient was 29.9%. These properties could satisfy the S-DMB band.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.323-326
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• 2001

In this paper, the proposed current control algorithm is analized and discussed about how to design the auxiliary circuit with auxiliary switch which can apply ZVT operation for the main switch. The simulation results would be shown to verify the proposed current algorithm, because the main power switch is turn on with ZVT and the bi-directional Inverter is operated.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.434-436
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• 1996

This paper deals with the signal communication system for MAGLEV which is indispensible to train control with safety and high speed operation. Therefore it is necessary for signal system to ensure high speed transmission. massive transmission, low error rate, and reliability of information. And the ensured information should be transmitted between ground and on-board for safety and high speed operation. For these reasons, we have considered the guaranteed reliability by applying FSK method and HDLC protocol. Because HDLC has the advantages of high efficiency, high reliability, low bit rate, and bit transparency. HDLC is the appropriate method for data transmission in MAGLEV.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.50-55
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• 2013

The smart grid is a next-generation power grid to create a new value-added information technology. Power providers and consumers exchange information in real-time bi-directional, and optimize energy efficiency with using the smart grid. This paper describes the concept of demand response of the communication system used in the protocol communication model of the smart grid.