• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.79-85
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• 2019

In this paper, we propose a short-term power forecasting method by applying Long Short Term Memory (LSTM) and Gated Recurrent Unit (GRU) neural network to Internet of Things (IoT) power meter. We analyze performance based on real power consumption data of households. Mean absolute error (MAE), mean absolute percentage error (MAPE), mean percentage error (MPE), mean squared error (MSE), and root mean squared error (RMSE) are used as performance evaluation indexes. The experimental results show that the GRU-based model improves the performance by 4.52% in the MAPE and 5.59% in the MPE compared to the LSTM-based model.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.241-243
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• 2002

This paper proposes a DRMS(Distribution Remote Management System) based on the advanced digital kwh-meter. The proposed URMS is designed so as to be able to collect the voltage management data, the load management data as well as the used kwh data from advanced kwh-meter remotelly. It makes the integrated management of distribution system possible and enhances highly the economics of the existing remote meter-reading system based on the only used kwh-data. Also it can improve highly the quality of power supplied to the electric customer by minimizing the volt age management cost and by enhancing the efficiency of load management.

• Journal of Drive and Control
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• v.9 no.2
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• pp.15-20
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• 2012

Pneumatic cylinder meter-out driving apparatus is used widely because it is clean, lightweight, and can be easily serviced. In this study an estimation method of energy consumption for pneumatic cylinder meter-out driving apparatus is proposed. The proposed method is derived from state equation and energy equation of air, and, the equation of motion of a moving part of a pneumatic cylinder reflecting the characteristics of the meter-out driving. The effectiveness of the proposed method is proved by simulation study and it demonstrates that the proposed method can evaluate the energy consumption quickly and easily when the parameters of the driving apparatus are changed.

• KIEE International Transactions on Power Engineering
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• v.4A no.4
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• pp.214-220
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• 2004

Power quality monitoring is the cornerstone for power quality analysis, diagnosis and improvement. The measurement of power quality (PQ) evolves from instantaneous metering to continuous monitoring. Furthermore, recent technologies enable us to construct more flexible, reliable, rapid and economical power quality monitoring system (PQMS). Therefore, this paper presents an improved PQMS with a new distributed monitoring structure. The proposed PQMS consists of a PQ meter, PQ analyzer and GUI. The PQ meter only collects raw data and the PQ analyzer performs power quality analysis. It has several advantages compared to conventional structures in economic efficiency, modularity, speed, etc. PQ monitoring algorithms to catch steady-state trends and to detect PQ events are also adapted to the proposed structure. Using the proposed structure and monitoring algorithm, a prototype PQMS is constructed and real-time testing is performed.

• Korean Journal of Optics and Photonics
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• v.35 no.2
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• pp.61-70
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• 2024

We demonstrate a laser power meter calibration system based on 12-diode laser sources coupled to single-mode fibres in a wavelength range from 400 to 1,600 nm. In our system, three laser power controllers ensure that the output power uncertainty of all laser sources is less than 0.1% (k=2). In addition, all laser beams are adjusted to have similar beam sizes of approximately 2 mm (1/e²-width) at the measurement position to minimise unmeasured laser power on a detector. As a reference detector, we use an integrating sphere combined with silicon and indium gallium arsenide photodiodes to minimise the non-uniformity and non-linearity of responsivity. The minimum uncertainty of the calibration system is estimated to be 1.1% (k=2) for most laser wavelengths.

• Journal of Radiation Protection and Research
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• v.48 no.3
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• pp.131-143
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• 2023

Background: This study examined the detection limit of thyroid screening monitoring conducted at the time of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011 using a Monte Carlo simulation. Materials and Methods: We calculated the detection limit of a NaI(Tl) survey meter to measure ¹³¹I accumulation in the thyroid gland of children. Mathematical phantoms of 1- and 5-year-old children were developed in the simulation of the Particle and Heavy Ion Transport code System code. Contamination of the body surface with eight radionuclides found after the FDNPP accident was assumed to have been deposited on the neck and shoulder area. Results and Discussion: The detection limit was calculated as a function of ambient dose rate. In the case of 40 Bq/cm² contamination on the body surface of the neck, the present simulations showed that residual thyroid radioactivity corresponding to thyroid dose of 100 mSv can be detected within 21 days after intake at the ambient dose rate of 0.2 µSv/hr and within 11 days in the case of 2.0 µSv/hr. When a time constant of 10 seconds was used at the dose rate of 0.2 µSv/hr, the estimated survey meter output error was 5%. Evaluation of the effect of individual differences in the location of the thyroid gland confirmed that the measured value would decrease by approximately 6% for a height difference of ±1 cm and increase by approximately 65% for a depth of 1 cm. Conclusion: In the event of a nuclear disaster, simple measurements carried out using a NaI(Tl) scintillation survey meter remain effective for assessing ¹³¹I intake. However, it should be noted that the presence of short-half-life radioactive materials on the body surface affects the detection limit.

• ETRI Journal
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• v.45 no.4
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• pp.650-665
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• 2023

A novel smart metering technique capable of anomaly detection was proposed for real-time home power management system. Smart meter data generated in real-time were obtained from 900 households of single apartments. To detect outliers and missing values in smart meter data, a deep learning model, the autoencoder, consisting of a graph convolutional network and bidirectional long short-term memory network, was applied to the smart metering technique. Power management based on the smart metering technique was executed by multi-objective optimization in the presence of a battery storage system and an electric vehicle. The results of the power management employing the proposed smart metering technique indicate a reduction in electricity cost and amount of power supplied by the grid compared to the results of power management without anomaly detection.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2952-2959
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• 2013

In this paper, a smart meter applying the international communication protocols has been developed. A smart meter requires communication protocols for two-way communication and control technology, registration and deregistration of electronic devices between electric power suppliers to exchange data. Standardization for communication protocols of a smart meter has been proceeding both in the US and Europe. The smart meter developed in this paper applied ANSI C12.22 as a communication protocol which is a north american standard. A smart meter should also provide the electric consuming information and electricity charge information to the customer in real time. Thus, the customer can behave the demand response based on this information. In this paper, the measured electricity from the smart meter is reported to the customer, and IHD(In Home Display) implemented with the windows software presents the reported real time data.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.314-316
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• 2022

Instrumentation device to the amount of water used by the user is a water meter by measuring management stability is necessary. But with the onset of winter to meter water was ice inside the phase change and about 9 % and increase the volume of the meter is damaged. The existing protection bleed water meter freeze protection technology into three great bootong, supplying the heat insulation inside the external protection, water metering for water meter in the freeze protection will be divided into installing the device. Not see how far the structure for the commercialization of new technology-based products and aims to develop technologies that do not require an external power supply. Thus, freeze more vulnerable by internal pressure of the interpretation applied to a water meter in temperatures below zero internal pressure to confirm the area of preventing damage and freeze protection that can reduce the effect is superior to develop a water meter.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.2
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• pp.221-226
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• 2021

기존 3 상 전력량계(G-type) 1 대로 단상 3 호 고객 계량이 가능한 소프트웨어 기술 구현 【BIXPO 2020 발명특허대전 대상 수상】