• KEPCO Journal on Electric Power and Energy
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• v.6 no.1
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• pp.29-33
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• 2020

Despite the same system architecture and operation principle, Advanced Metering Infrastructure (AMI) and Internet of Things (IoT) are recognized as a heterogeneous system. This is due to the different object modeling and communication protocols used in smart meters and sensors. However, data interworking between AMI and IoT is expected to be inevitable in the future. In this paper, we propose Device Language Message Specification (DLMS) to Lightweight Machine to Machine (LwM2M) conversion model. The proposed interworking model can reduce the packet size by 46.5% compared to that of the encapsulation method.

• Journal of IKEEE
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• v.14 no.2
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• pp.41-50
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• 2010

TETRA is the standard of Digital Trunked Radio System suggested by the ETSI(European Telecommunications Standards Institut ). It is adopted as Electric Power IT Wireless Backbone Network in Korea. Police station and Fire Station are using TETRA network. Currently, Power Automation Protocols are DNP3.0 in Distribution Automation System, DLMS in Auto Metering Infrastructure, IEC61850 in Substation Automation. These protocols are transmissions using CDMA or WCDMA modem. If Power Automation protocol uses TETRA networks, it can be interoperable with the systems in police or fire stations. And it has outstanding ability to handle problems in a disaster situation. So, This paper propose a gateway system of Power Automation which can transmit the power automation protocol using TETRA.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.3
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• pp.41-49
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• 2011

In this paper, we propose an open protocol to be employed between a smart meter concentrator and a metering data collection server, and also evaluate its performance. Legacy concentrators performs the connection establishment and data gathering operations with DLMS/COSEM protocol standards. However, we note that there are no standardized protocols between the concentrator and the collection server, which inevitably conduces each commercial smart metering system to have its own proprietary protocol. In order to solve this problem, we propose an open protocol - Smart Meter Concentrator Control Protocol(SMCCP) by extending the existing standard protocol(DLMS/COSEM). The SMCCP can provide the proxy mode to enable efficient transmission between the concentrator and the data collection server. It also can support the relay mode to enable a direct communication between the data collection server and each far end smart meter. We also implement an emulator system and a protocol analyzer to provide its operation. In addition, we evaluate the session holding time and the link usage ratio in both relay and proxy modes with OMNET++ simulator.

• Review of KIISC
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• v.24 no.5
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• pp.82-87
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• 2014

스마트그리드는 기존의 전력시스템에 ICT 기술을 융합하여 에너지 공급자와 소비자, 서비스 제공자가 실시간으로 상호작용할 수 있는 형태의 차세대 전력망을 의미하는 것으로, 최근 대두되고 있는 에너지 위기를 타개하기 위한 중요한 솔루션 중 하나로 인식되고 있다. 그 중에서도 특히 AMI 시스템은 다양한 부가서비스 제공을 가능케 하는 스마트그리드의 핵심요소로 주목받고 있다. AMI 시스템은 그 적용범위가 광범위하고 대부분의 시스템 구성 기기가 물리적 접근이 비교적 용이한 위치에 설치되어 물리적 공격 및 사이버 공격에 대해 비교적 취약한 특성을 띤다. 이러한 보안 위협에 대응하기 위해 DLMS/COSEM 및 국내 지능형전력량계-제2부 표준에서는 지능형전력량계가 갖추어야 하는 다양한 보안기능에 대해 정의하고 있다. 하지만 각 보안기능에 대한 세부 내용을 상기 표준에서 모두 정의하고 있는 것은 아니어서 이에 대한 검토 및 논의가 필요하다. 본 고에서는 DLMS/COSEM 표준과 지능형전력량계-제2부 표준에서 정의하고 있는 보안 기능에 대해 살펴보고, 상기 표준에서 정의하고 있지 않은 보안 기능 중 지능형전력량계 유지보수를 위한 안전한 현장접근 방안에 대해 제안한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.8
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• pp.1143-1148
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• 2013

This paper deals a watt-hour meter monitor system with applying a Power Line Communication (PLC) modem and a Data Concentrator Unit (DCU). PLC modem uses the power line, so there is no need to install dedicated wiring. This system makes it possible to monitor the amount of electricity of previous current month metering data, so it can easily apply a PC-management for the electric charges and maintenance with gathering the metering data.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.534-537
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• 1999

This paper describes a design of pipelined adaptive decision-feedback equalizer (PADFE) for high bit-rate wireless digital communication systems. To enhance the throughput rate of ADFE, two pipeline stages are inserted into the critical path of ADFE by using delayed least-mean-square (DLMS) algorithm. Redundant binary (RB) arithmetic is applied to all the data processing of ADFE including filter laps and coefficient update blocks. When compared with conventional methods based on two's complement arithmetic, the proposed approach reduces arithmetic complexity, as well as results in a very simple complex-valued filter structure, thus suitable for VLSI implementation. The design parameters (filter tap, coefficient and internal bit-width, etc.) and equalization performance (bit error rate, convergence speed, etc.) are analyzed by algorithm-level simulation using COSSAP. The PADFE was designed using VHDL and Synopsys, and mapped into two ALTERA FLEX10k100 FPGAs.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.605-606
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• 2012

In this paper, we consider the problem of scheduling sensor activity to prolong the network lifetime while guaranteeing both discrete target coverage and connectivity among all the active sensors and the sink, called connected target coverage (CTC) problem. We proposed a distributed scheme called Distributed Lifetime-Maximizing Scheme (DLMS) to solve the CTC problem. Our proposed scheme significantly reduces the cost of the construction of the connected cover graphs in comparison with the some conventional schemes. In addition, the energy consumption is more balanced so that the network lifetime will be increased. Our simulation results show that DLMS scheme performs much better than the conventional schemes in terms of the network lifetime.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.10
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• pp.1435-1441
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• 2013

This paper deals a watt-hour meter monitor system applying a Power Line Communication (PLC) MODEM and a Data Concentrator Unit (DCU) which can apply to Internet map based Graphical User Interface (GUI). The PLC MODEM is profitable by saving the cost of installing dedicated wiring, and Internet map GUI also is able to contribute an easy access to monitoring system for non export users. This system makes it possible to monitor the amount of electricity of previous/ current month metering data via Internet mapping service. The implement system can easily apply a PC-management for the electric charges and maintenance with gathering the metering data.

• The Journal of Korean Institute of Information Technology
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• v.15 no.12
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• pp.157-164
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• 2017

Mobile ECG signal measurement is a technique to measure small signals of several mV, and many studies have been conducted to remove noise including wandering scheme. Removal of the equipotential line noise caused by shaking or movement of the electrode cable is one of the core research contents for the electrocardiogram measurement. In this study, we proposed a modified step-size of combined NLMS(normalized least squares) and DLMS(delayed least squares) adaptive filter to eliminate baseline noise from ECG signals. The proposed method mainly adjusts initial filter step-size to reduce distortion of original ECG signals characteristic after eliminating baseline noise. The modified filter step-size is scaled by filter order size and distortion minimization factor. This method is suitable for portable ECG device with a small processor and less power consumption. This technique also decreases computation time which is essential for real-time filtering. The proposed filter also increase the signal to noise ratio (SNR) compared to conventional NLMS filter.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.1 no.2
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• pp.199-207
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• 1997

The Maximum Likelihood Sequence Estimation scheme is modified to improve the error performance of the correlative coding in the Tamed FM. To remove intersymbol interference, the Decision Feedback Equalization scheme with the delayed LMS algorithm and the Viterbi algorithm(10-symbol delay) in the delayed adaptive equalization are proposed for the performance of decision-directed adaptive equalization under the High Frequency channels, and the condition of convergence is analyzed.