• Title/Summary/Keyword: Coordination method

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Protection Coordination Analysis for Distribution Systems Integrated with Distributed Generation (분산전원이 도입된 배전계통의 보호협조 해석방법)

  • Kim, Jae-Eon;Kim, Eui-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.5
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    • pp.2279-2284
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    • 2011
  • In most of radial distribution systems, the overcurrent protection coordination is adopted for the protection of apparatus and the improvement of electrical power system reliability. The protection coordination structure in distribution substation is composed of several circuit breakers(CB) with distribution lines originating from one substation bus under one transformer, which trip for their fault current. But sufficient analysis is necessary for the capacity of CB's in distribution systems with several distribution generations(DG). In this paper, a protection coordination method not to exceed the traditional capacity of CB's was proposed and certified through simulation by the PSCAD-EMTDC S/W.

A Study on the Protective Coordination of Generator Overexcitation and Overvoltage Relay (발전기 과여자 및 과전압 계전기 보호협조에 관한 연구)

  • Park, Ji-Kyung;Kim, Kwnag-Hyun;Kim, Chul-Hwan;Lyu, Young-Sik;Yang, Jeong-Jae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.8
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    • pp.1187-1194
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    • 2017
  • After North American wide area black out on August 14, 2003, various studies have been conducted to find out the reason of the disaster. One of main reasons was misoperation of generator protection system. Since then, protective coordination between generator protection system and excitation system controls has been hot issue among electrical engineers. Among various generator protection relays, in this paper, we focused on generator overvoltage and overexcitation relay, which protect the over-flux condition of the generator. Thus, at first, we modeled the generator overvoltage, overexcitation relay and detailed power system including excitation system, governor and etc., based on actual field data. And then, we reviewed the protective coordination of generator overvoltage and overexcitation relay using electromagnetic transient program. In addition, we discussed the protective coordination method for redundant protection relays in both automatic voltage regulator and generator side.

A Method of Fashion Recommender in Coordination with Individual Physical Features (개인의 신체적 특성에 맞춘 의류 추천 방법)

  • Kim, Jung-In
    • Journal of Korea Multimedia Society
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    • v.14 no.8
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    • pp.1061-1069
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    • 2011
  • With the development of information technology, online commercial transactions have been steadily increasing. However it is not easy to recommend the clothes in coordination with individual physical features. This paper presents a fashion coordination recommender system for women's clothes. The system includes the functionality of recommending clothes best-suited for customers in consideration of their individual physical features. It has also been designed to recommend clothes in vogue for those who are fashion-sensitive by considering the fashion trend of the times. Operated in an optional or coupling way, these functionalities of our system result in an intelligent fashion coordination system which recommends dress items to customers in various ways.

A Study of the Efficient Coordination of Logistic Distribution Centers for the China Project

  • Jin, Jun-Na;Zhang, Bao-Zhong
    • The Journal of Industrial Distribution & Business
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    • v.9 no.8
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    • pp.27-34
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    • 2018
  • Purpose - This paper discussed and illustrated the most efficient method to calculate the distribution centers for a national project in China. Through demonstration of implementing the GIS, spatial analysis, and location calculation model, this paper mainly dealt with the construction distribution problem and inconvenient supply of materials problems. Research design, data, and methodology - In this paper, the research design structure based on three steps: implementing the Geographic Information System to locate the points coordination data, calculating the distribution centers of the project, and optimizing the most efficient and effective coordination. The data of the calculation is from an actual project. The methodology of this paper is summarizing the spatial analysis capabilities and digital graphic data calculation to locate logistics distribution centers, and since the illustration of the calculation is useful for locating the coordination, the result of this paper has certain reference values for the project construction. Results - This paper illustrates the steel and cement resource of every distribution point to confirm the most efficient distribution center location coordination. Conclusions - The integrated logistical management models are used to ensure the results for the purposes of our calculation. The result of the calculation is also a useful example for future Chinese national projects.

Spatial target path following and coordinated control of multiple UUVs

  • Qi, Xue;Xiang, Peng;Cai, Zhi-jun
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.832-842
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    • 2020
  • The coordination control of multiple Underactuated Underwater Vehicles (UUVs) moving in three dimensional space is investigated in this paper. The coordinated path following control task is decomposed into two sub tasks, that is, path following control and coordination control. In the spatial curve path following control task, path following error dynamics is build in the Serret-Frenet coordinate frame. The virtual reference object can be chosen freely on the desired spatial path. Considering the speed of the UUV, the line-of-sight navigation is introduced to help the path following errors quickly converge to zero. In the coordination control sub task, the communication topology of multiple UUVs is described by the graph theory. The speed of each UUV is adjusted to achieve the coordination. The path following system and the coordination control system are viewed as the feedback connection system. Input-to-state stable of the coordinated path following system can be proved by small gain theorem. The simulation experiments can further demonstrate the good performance of the control method.

A study on the Restaurant Total Coordination and Traditionality Expression Method of Japanese Restaurant in New york (뉴욕 소재 일식당의 레스토랑 토탈 코디네이션과 전통성 표현 방법에 관한 연구)

  • Lee, Ji-Hyun;Oh, Hye-Kyung
    • Korean Institute of Interior Design Journal
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    • v.19 no.5
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    • pp.140-147
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    • 2010
  • The objectives of this study are, first to define the concept of restaurant total coordination and establish its components as a design strategy for planning and managing all elements comprising a restaurant, and second, to survey the total coordination of Japanese restaurants in foreign countries and examine how traditionality, which is an element for globalizing Japanese restaurants, is expressed. This study was conducted through literature review for defining the concept of restaurant total coordination and extracting its components and a field survey for analyzing the current state of restaurant total coordination and traditionality expression methods. The results of this study are as follows. First, Japanese restaurants categorized into Type A with relatively high traditionality expression(3.3 or higher) were 25% of the surveyed restaurants. These restaurants showed the traditional characteristics of Japanese style as they are without contemporary adaptation for all components of restaurant. Second, 41.7% of the restaurants were categorized into Type B with traditionality expression between 1.7 and 3.3. They were mostly popular casual restaurants at which people can enjoy Japanese food comfortably. In visual and spatial design elements, traditional and contemporary styles appeared in the equal percentage, and decoration, table setting and food design were styled according to Japanese traditions. Third, 4 cases(33.3%) were categorized into Type C with traditionality expression below 1.7. Because they were fine dining restaurants that sold high priced dishes, formality and consistency were also high. Through all design elements including visual, spatial, table setting and food design elements, elegant and simple contemporary images were dominant. The results of this study will be used as basic materials to establish the concept of total coordination that views the visual, spatial, table setting and food design elements comprising a restaurant, which were approached separately in previous studies on restaurants, together from the viewpoint of integrative deigns, and to make design strategies for globalizing Korean restaurants based on Japanese restaurant cases.

A Coordination Agent Model based on Extracting Similar Information (유사 정보 추출에 기반한 조성 에이전트 모델)

  • 양소진;이현수;오경환
    • Korean Journal of Cognitive Science
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    • v.12 no.1_2
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    • pp.55-63
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    • 2001
  • Speaking generally, agent-based technology is a kind of technology to handle the flood of information resulted from the popularization of the internet. Agent system is a multi-distributed system which consists of both homogeneous and heterogeneous agents. Generally there is a coordination agent in between which is in charge of control and m message flow among the application agents. The purpose of this thesis is to propose a coordination method among agents, some of which provide informations and some of which request them. In multi-agent system, the Information Providing Agent(IPA) registers its capabilities to Coordination Agent(CA) and the Information Requesting Agent(lRA) requests CA what it needs. To coordinate them with satisfactory results the coordination agent ought to have an ability to return a relatively proper data to the requester which is supposed to be similar even though it is not so exact as was intended. For this, this thesis proposes a scheme for an coordination agent to find an IPA which provides an information which correlates most closely with that of IRA.

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Synthesis, Crystal Structure and Characterization of Cu(II) and Cd(II) Coordination Compounds Based on Ligand 2-(3-(Pyridin-2-yl)-1H-pyrazol-1-yl)acetic Acid

  • Zhang, Ya-Jun;Wang, Cui-Juan;Mao, Kai-Li;Liu, Xiao-Lei;Huang, Shuai;Tong, Yan;Zhou, Xian-Li
    • Bulletin of the Korean Chemical Society
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    • v.35 no.7
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    • pp.2086-2092
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    • 2014
  • Two novel coordination compounds $[Cu_2(pypya)_3(H_2O)_2]{\cdot}Cl{\cdot}(H_2O)_5$ (1) and $\{[Cd(pypya)(ta)_{1/2}]{\cdot}H_2O\}_n$ (2) (Hpypya=2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl)acetic acid, $H_2ta$=terephthalic acid) were synthesized and characterized by single X-ray diffraction. Structure determination reveals that complex 1 and complex 2 crystallize in the triclinic system, with the P-1 space group. The asymmetric unit of 1 contains two Cu(II) ions, and their coordination modes are different. These units of complex 1 are linked together via hydrogen bonds and ${\pi}-{\pi}$ interactions, and the 3D structure of complex 1 was formed. Complex 2, a mononuclear Cd(II) coordination compound, has a 2D structure which was constructed via coordination bonds. TGA and fluorescence spectra analysis of complex 1 and complex 2 have also been studied. In addition, the geometry parameters of complex 1 have been optimized with the B3LYP method of density functional theory (DFT) to explain its coordination behavior. The electronic properties of the complex 1 and ligand Hpypya have been investigated based on the nature bond orbital (NBO) analysis at the B3LYP level of theory. The result verifies that the synergistic effect have occurred in the compound.

Evaluation of the Open Method of Coordination in Social Inclusion: Theoretical Expectations and Reality (유럽연합의 개방형 정책조정 (Open Method of Coordination)에 대한 이론적 기대와 현실: 빈곤정책의 사례)

  • Kim, Seung Hyun
    • Journal of International Area Studies (JIAS)
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    • v.14 no.3
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    • pp.57-80
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    • 2010
  • This study aims at the evaluation of procedural changes and policy outcome caused by the Open Method of Coordination(OMC) on Social Inclusion in the European Union. The policy instruments of the OMC introduced by the Lisbon Council can be divided into two groups: the outcome-oriented New Public Management(NPM) and the process-oriented Directly Deliberative Polyarchy(DDP). By considering the adoption process of the NPM instruments, it can be said that OMC could not be effective due to the vagueness of its objectives, the institutional barriers in decentralized decision-making, and the rejection of benchmarking by the Member States. The intended learning by deliberation and peer review as indicated by the normative DDP, is hard to achieve because they are not so reflexive due to relatively restricted and closed participation. We also cannot find any significant reduction of poverty after the long implementation of the OMC. Considering the higher recognition of poverty problem and expanding NGOs concerned with it, however, we may see some significant impact in the future.

A study on Optimal Operation of Protection Coordination Devices Evaluation System in Distribution System with Distributed Sources (분산전원이 연계된 배전계통에 보호협조기기 평가시스템의 최적운용에 관한 연구)

  • Ji, Sungho;Song, Bangwoon;Kim, Byungki;Rho, Daeseok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.6
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    • pp.2971-2978
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    • 2013
  • Recently, with the world-wide issues about global warming and CO2 reduction, a number of distributed generations(DGs) such as photovoltaic(PV) and wind power(WP), are interconnected with the distribution systems. However, DGs can change the direction of the power flow from one-direction to bi-direction, and also change the direction and amount of fault current of existing distribution systems. Therefore, it may cause the critical problems on the power quality and protection coordination. This paper proposes an operation algorithm for bi-directional protection coordination using and apply it for the evaluation system for protection coordination. From the simulation results It is found that the proposed method is more effective and convenient than existing method.