• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1335-1341
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• 2015

The utilization of electric vehicles has been suggested to support the frequency regulation of power system. Assuming that an intermediate aggregator exists, this study suggests a decentralized vehicle-to-grid operation scheme in which each vehicle-to-grid aggregator can behave independently of the power system operator. To implement this type of decentralized operation, this study adopts a price-based operation that has been proposed by many researches as an alternative operation scheme for the power system. In this environment, each vehicle-to-grid aggregator can determine its participation in vehicle-to-grid service in consideration of its residual energy of aggregated system and real-time market price. Consequently, the main purpose of this study is to verify whether or not the vehicle-to-grid power can effectively support the current frequency regulation function within the price-based operation scheme. Specifically, a frequency regulation method is proposed based on the real-time price signal, and a feedback controller for battery management is designed for decentralized vehicle-to-grid operation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.393-397
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• 2004

In these days, a scale of system is more and more complex and large. The centralized system has the operation management method to be limited in the large scale system. In this paper, we proposed ACOS(Autonomous decentralized Container terminal Operating System). It is applied to container terminal using by autonomous decentralized system which can solve the problem of the centralized operation system. Also, we can defined a function of the ACOS's sub-system and showed a flowchart on operation method for the ACOS.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.528-533
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• 2004

The purpose of this thesis is to construct the autonomous decentralized train traffic management structure using techniques of Autonomous Decentralized System. Currently, a method of train traffic control is making use of CTC(Centralized Traffic Control). Its operation method is divided into the remote mode and the local mode. The classified basis is according to the control authority of install signals in track side. In most cases, a large scale station is operated by the local mode. Because of dispatchers in center can not control the shunting works influence on the main route. In order to solve these problem s, we analyzed a current operation condition and system requirements. Moreover, this thesis is constructing autonomous decentralized train traffic management structure. Finally, this research proposed that interface with CTC and step-by-step construction.

• Smart Structures and Systems
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• v.22 no.5
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• pp.547-560
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• 2018

This paper investigates the operation of the $H_{\infty}$ static output-feedback controller to reduce dynamic responses under seismic excitation on the five-story and benchmark 20 story building with parametric uncertainties. Linear matrix inequality (LMI) control theory is applied in this system and then to achieve the desired LMI formulations, some transformations of the LMI variables is used. Conversely uncertainties due to material properties, environmental loads such as earthquake and wind hazards make the uncertain system. This problem and its effects are studied in this research. Also to decrease the transition of large amount of data between sensors and controller, avoiding the disruption of whole control system and economy problems, the operation of the decentralized controllers is investigated in this paper. For this purpose the comparison between the performance of the centralized, fully decentralized and partial decentralized controllers in uncoupled and coupled cases is performed. Also, the effect of the changing the number of stories in substructures is considered. Based on the numerical results, the used control algorithm is very robust against the parametric uncertainties and structural responses are decreased considerably in all the control cases but partial decentralized controller in coupled form gets the closest results to the centralized case. The results indicate the high applicability of the used control algorithm in the tall shear buildings to reduce the structural responses and its robustness against the uncertainties.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.1089-1095
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• 2014

Innumerable microgrids would be operated independently by individual operators in a future smart grid. This kind of decentralized power system requires entirely different operation scheme in the actual power system and electricity market operation. Especially, frequency regulation is very important for successive energy trade in this multi-microgrid circumstance. This paper presents an optimal energy and reserve market participation strategy and operation strategy of energy storage system (ESS) by a microgrid operator (MGO). For definite evaluation of the proposed strategy, we postulate that the MGO should participate in the Power Exchange for Frequency Control (PXFC) market, which was devised by Maria Ilic and her coworkers and is suitable to the decentralized operation circumstances. In particular, optimal reserve capacity of the frequency control market and optimal market participation ratio of ESS between frequency control market and energy market are derived theoretically and evaluated by simulations utilizing Nordic Pool Elspot price data.

• Journal of Electrical Engineering and Technology
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• v.7 no.2
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• pp.141-150
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• 2012

The present study examines an efficient congestion management system compatible with the evolving environment. The key is to build an information model shared and exchanged for marketbased solutions to alleviate congestion. Traditional methods for congestion management can be classified into two categories, i.e., the centralized scheme and the decentralized scheme, depending on the extent to which the independent system operator (ISO) is involved in market participants' (MPs) activities. Although the centralized scheme is more appropriate for providing reliable system operation and relieving congestion in near real-time, the decentralized scheme is preferred for supporting efficient market operation. The minimum set of information between the ISO and MPs for decentralized scheme is identified: i) congestion-based zone, ii) Power Transfer Distribution Factors, and iii) transmission congestion cost. The mathematical modeling of the proposed information is expressed, considering its process of making effective use of information. Numerical analysis is conducted to demonstrate both cost minimization from the MP perspective and the reliability enhancement from the ISO perspective based on the proposed information exchange scheme.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.35-35
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• 2000

In this paper, we introduce a conservative control approach using a full feedback map and suggest a switching control between the conservative and default control. For the conservative control, we use the coordinator which performs the conjunction operation of the full feedback map information of local supervisors. Since the switching control with the coordinator extends the ability of local supervisors in the decentralized supervisory control, we can solve the problem in case the coobservability condition can not be satisfied.

• Management & Information Systems Review
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• v.2
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• pp.133-167
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• 1998

This article discusses the findings of an empirical study conducted on 62 large organizations. The major purpose of the study was to analyze the relationship of Information System Resources distribution between the system plan control and system development and system operation. In this study information system resource is broadly Identified by computer hardware, software, data, procedure, operator. Because of the real centralization/decentralization issue facing organizations is much broader then the choice between alternative computer hardware configurations. And there are three separate resources of the information system that can be decentralized system plan and control, system development, system operations. The decision regarding how to organize each of these three separate resources is based on a different set of criteria. Furthermore, each decision can be made relatively independently of the others. In this article the results of a study are indicated below. In the degree of decentralization of information system resources between system plan control and system development and system operations were found the positive relationship. Therefore, the more information system resources are decentralized in the one dimension, the more information system resources are decentralized in the other dimensions, and the more information system resources are centralized in the one dimension, the more information system resources are centralized in the other dimensions.

• Journal of the Korean Society for Railway
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• v.9 no.3 s.34
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• pp.282-290
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• 2006

In the current train operation system, large scaled stations like Cheongnyangni and Yongsan are not remote controlled from the central operator but manually by local operator. It is because there are so many entering and exit of trains between depot and mainline which are operating through the large scaled stations and it is very effective to traffic flow on the mainline. Therefore, Kyong Bong Technology Co., Ltd. (KBTech) and Korea Railway Research Institute (KRRI) are continuing the research and development to import 'Autonomous Decentralized System (ADS)'as part of a new train operation control system which is a national policy project of MOCT (Ministry Of Construction & Transportation). The concept of the 'Autonomous Decentralized System (ADS)' has born in 1970's in Japan by the influences of molecular biology. The special features of ADS are being a system that able to do the online expansion, online maintenance and fault tolerance. This thesis introduces the concept of technology of ADS and also describes the system designing & development to apply with large scaled stations.

• Journal of Korean Society on Water Environment
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• v.39 no.1
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• pp.76-86
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• 2023

We are on the verge of paradigm shift for the design and operation of our urban water systems from treatment- and efficiency-based to recirculation- and sustainability-based. One of the most frequently suggested alternatives to embody this paradigm shift is to decentralize the currently highly centralized urban water infrastructure. However, claims for water infrastructure decentralization are often criticized due to poor economic feasibility, unstable performance, and unprofessional operation and maintenance. The current study critically reviews the literature to discuss the technical advancement needs to overcome such challenges. Firstly, decentralized water infrastructure was briefly defined and the rationale for the proposal of its introduction to the next-generation urban water systems was laid down. The main discussion focused on the following water technologies, which require special attention when working with decentralized water infrastructure: i) material collection, storage, and transport; ii) easily scalable water treatment; iii) sensor, information, and communications; and iv) system optimization. The principles, current development status, and challenges were discussed for each of the water technologies. The discussion on the water technologies has enabled the identification of future research needs for their application to the next-generation urban water systems which will be designed following decentralized water infrastructure. This paper will significantly improve the current understanding on water infrastructure decentralization and provides insight on future direction of water technology development.