• The Korean Journal of Applied Statistics
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• v.33 no.6
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• pp.791-804
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• 2020

Residential electricity consumption can be predicted more accurately by utilizing the realtime household electricity consumption reference that can be collected by the AMI as the ICT developed under the smart grid circumstance. This paper studied the model that predicts residential power load using the ARIMA, TBATS, NNAR model based on the data of hour unit amount of household electricity consumption, and unlike forecasting the consumption of the whole households at once, it computed the anticipated amount of the electricity consumption by aggregating the predictive value of each established model of cluster that was collected by the households which show the similiar load profile. Especially, as the typical time series data, the electricity consumption data chose the clustering analysis method that is appropriate to the time series data. Therefore, Dynamic Time Warping and Periodogram based method is used in this paper. By the result, forecasting the residential elecrtricity consumption by clustering the similiar household showed better performance than forecasting at once and in summertime, NNAR model performed best, and in wintertime, it was TBATS model. Lastly, clustering method showed most improvements in forecasting capability when the DTW method that was manifested the difference between the patterns of each cluster was used.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1029-1039
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• 2013

To avoid undesirable disconnection of healthy wind generators (WGs) or a wind power plant, a WG protection relay should discriminate among faults, so that it can operate instantaneously for WG, connected feeder or connection bus faults, it can operate after a delay for inter-tie or grid faults, and it can avoid operating for parallel WG or adjacent feeder faults. A WG protection relay based on the positive- and negative-sequence fault components is proposed in the paper. At stage 1, the proposed relay uses the magnitude of the positive-sequence component in the fault current to distinguish faults requiring non-operation response from those requiring instantaneous or delayed operation responses. At stage 2, the fault type is first determined using the relationships between the positive- and negative-sequence fault components. Then, the relay differentiates between instantaneous operation and delayed operation based on the magnitude of the positive-sequence fault component. Various fault scenarios involving changes in position and type of fault and faulted phases are used to verify the performance of the relay. This paper concludes by implementing the relay on a hardware platform based on a digital signal processor. Results indicate that the relay can successfully distinguish the need for instantaneous, delayed, or non-operation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.63-69
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• 2013

In recent years, technology for storing a preliminary power or a surplus of photovoltaic energy is required. This technique, as well as store a preliminary energy and improve the reliability of the gird safety. This system can plan a efficient power generation through the flexibility of the power supply from the perspective of not only provider but also user. Accordingly, the realization of the smart grid can be expected. This paper proposes a hybrid PCS using a photovoltaic and a lithium-polymer battery with the characteristics of high density energy. The main energy source of a hybrid PCS is a photovoltaic, grid and the auxiliary energy source is a lithium-polymer battery. The operation of a proposed system in this paper is verified with simulation and experimental results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.515-522
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• 2015

Through the correspondence works with IEC in the smart grid fields and power IT fields, we set up the interpretation work procedure and defined the work rule for correspondence by analyzing the work results. In addition, we suggest cases for discussion of terms and definitions in the IEC and analyze them and then propose a matrix classification system for standardization to solve the cases for discussion. The matrix classification system with 3-axes of classification has been applied to newly emerging terminologies followed by smart gird. We drew the usefulness in search of terms in application fields and showed the cases of applying the matrix classification. The IEC Electropedia classification standard is unclear and the classification is mixed with principle, application and product areas. We proposed a new working group in IEC TC1 for research on the matrix classification system and then TC 1 decided to organize a new WG titled in the "IEV structure and supporting tools".

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1B
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• pp.75-85
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• 2012

In this paper, we introduce the case study on the certificate system for Auto Meter Reading protocol, Device Language Message Specification which is a common language between metering devices and protocol with compatibility and conformance to the IEC 62056 standards. KEPCO has contributed to improve interoperability between different devices of multi vendors through the DLMS standard tests and led the smart metering industry in Korea. KEPCO has AMR system and successful business model for 550 thousands of households based on 24Mbps broadband powerline communications using its infrastructure. We have plan to continue on standardization activities stratagemically by participating in IEC working groups for the purpose of occupying the core technology of Smart Gird.

• Journal of Information Technology Applications and Management
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• v.28 no.1
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• pp.83-93
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• 2021

The purpose of this study was to develop a personalized SMT (smart monitor target) game interface for game users who enjoy airsoft sports as individual purchases of SMT have increased since the advent of the untouched era. For this study, the UX (user experience) of the game interface was designed based on previous research. In particular, the personalized game service was reinforced by adding the CP (command post) of the SMT system that performs the home function of the console game, which was intended to help the user maintain immersed in the game in the personalized space of the SMT. Major design elements for the SMT game interface included layout, color, graphics, buttons, and text, and the interface design was proceeded based on them. After composing a grid with a layout in which the tab function was applied to the interface with a vertical three-segment structure and the outer margin value secured, the military camouflage pattern and texture were applied to the colored tone to perform graphics work. Targets and thumbnails were produced as illustrations using experts to ensure the consistency of the interface, and then function buttons and texts on each page were used concisely for intuitive information delivery. The design sources organized in this way were developed using the Unity engine. In the future, we hope that game user-centered personalized interfaces will continue to develop and provide differentiated services unique to SMT systems in the airsoft gun market.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.1
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• pp.163-170
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• 2023

This paper introduces the semantic modeling technology for autonomous control of manufacturing facilities and status definition algorithm. With the development of digital twin technology and various ICT technologies of the smart factory, a new production management model is being built in the manufacturing industry. Based on the advanced smart manufacturing technology, the status determination algorithm was presented as a methodology to quickly identify and respond to problems with autonomous control and facilities in the factory. But the existing status determination algorithm informs the user or administrator of error information through the grid map and is presented as a model for coping with it. However, the advancement and direction of smart manufacturing technology is diversifying into flexible production and production tailored to consumer needs. Accordingly, in this paper, a technology that can design and build a factory using a semantic-based Linked List data structure and provide only necessary information to users or managers through graph-based information is introduced to improve management efficiency. This methodology can be used as a structure suitable for flexible production and small-volume production of various types.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.198-203
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• 2019

An adhesive wireless bookbinding machine was designed with optimal motor control and automatic cover insertion for bookbinding. The noise level was improved by modifying the thrust of the machine and changing from a compressor method to an AC induction motor control method. The automatic cover insertion function was added to improve the task speed. Motor and decelerator damage can be caused by sudden braking and acceleration of the motor rotation (clockwise and counter-clockwise), so a buffer-type locational control system was developed to secure stable movement and durability. The complicated internal design was also simplified, and the volume and weight were decreased. The results show that the noise was decreased by 57% from 135 dB to 71.7 dB, and the task speed was decreased by 57% from 18 s to 9.58 s. The automatic cover insertion was designed to supply a maximum of 130 sheets per supply.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.1-11
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• 2020

As an important basic building block of the smart grid environment, smart meter provides real-time electricity consumption information to the utility. However, ensuring information security and privacy in the smart meter data aggregation process is a non-trivial task. Even though the secure data aggregation for the smart meter has been a lot of attention from both academic and industry researchers in recent years, most of these studies are not secure against internal attackers or cannot provide data integrity. Besides, their computation costs are not satisfactory because the bilinear pairing operation or the hash-to-point operation is performed at the smart meter system. Recently, blockchains or distributed ledgers are an emerging technology that has drawn considerable interest from energy supply firms, startups, technology developers, financial institutions, national governments and the academic community. In particular, blockchains are identified as having the potential to bring significant benefits and innovation for the electricity consumption network. This study suggests a distributed, privacy-preserving, and simple secure smart meter data aggregation system, backed up by Blockchain technology. Smart meter data are aggregated and verified by a hierarchical Merkle tree, in which the consensus protocol is supported by the practical Byzantine fault tolerance algorithm.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.95-99
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• 2013

GPS service is generally being used in the navigation application such as the car navigation and the smart phone. Recently, GPS service continues to increase in the timing application such as the mobile telecommunication network, the smart grid, and the financial network. As GPS signals are sensitive to GPS jamming, it should be monitored and protected. In oder to prevent and minimize the damage caused by GPS jamming, many countries are developing and operating GPS jamming monitoring system. This paper presents the implementation and the test results of the GPS jamming equipment which provides the detection, the direction finding and the location of GPS jamming.