• Title/Summary/Keyword: Gird

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NOTES FOR AUTHORS OF THE KOREAN SOCIETY OF COMPUTATIONAL FLUIDS ENGINEERING (고차 내삽기법을 사용한 중첩 격자기법)

  • Lee, K.L.;Kim, K.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2007.10a
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    • pp.209-213
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    • 2007
  • This paper presents the high order conservative interpolation methods. This method has been successfully implemented into a cell-centered finite volume methods code. Results using high order and maintaining conservation interpolation method are more accurate compared to bilinear interpolation.

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Development of Digital Excitation System for San-cheong Pumped Sorage Power Plant (산청양수 디지털 여자시스템 개발)

  • Ryu, Ho-Seon;Lim, Ick-Hun
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.956-957
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    • 2006
  • KEPRI developed digital excitation system for San-Cheong pumped storage power plant. This is the very complicated system because of operation connected with SFC(Static Frequency Converter). Many operation modes(stating, regeneration, back to back, line charging, gird connection mode etc) during the commissioning were successfully tested at san-Cheong #2.

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Development of Web Application Service to Football Data Management (축구 데이터 운용 웹 서비스 개발)

  • Cho Kyu Cheol;Lee Hae Chan
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2023.01a
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    • pp.257-260
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    • 2023
  • 본 논문에서는 Vue.js와 Spring Boot 프레임워크를 사용하여 사용자 편의성을 제공하기 위해 Gird System, Data Table, Chart 등의 기능을 활용하여 축구 데이터를 표현한 웹 응용서비스를 개발하였다. Rapid API의 Open REST API 중 하나인 API-FOOTBALL에 액세스하여 국내에서 쉽게 찾아보기 어려운 세계 축구 리그의 순위표, 일정, 팀 및 선수의 세부 정보 데이터를 활용하였다.

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Grid Based Nonpoint Source Pollution Load Modelling

  • Niaraki, Abolghasem Sadeghi;Park, Jae-Min;Kim, Kye-Hyun;Lee, Chul-Yong
    • 한국공간정보시스템학회:학술대회논문집
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    • 2007.06a
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    • pp.246-251
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    • 2007
  • The purpose of this study is to develop a grid based model for calculating the critical nonpoint source (NPS) pollution load (BOD, TN, TP) in Nak-dong area in South Korea. In the last two decades, NPS pollution has become a topic for research that resulted in the development of numerous modeling techniques. Watershed researchers need to be able to emphasis on the characterization of water quality, including NPS pollution loads estimates. Geographic Information System (GIS) has been designed for the assessment of NPS pollution in a watershed. It uses different data such as DEM, precipitation, stream network, discharge, and land use data sets and utilizes a grid representation of a watershed for the approximation of average annual pollution loads and concentrations. The difficulty in traditional NPS modeling is the problem of identifying sources and quantifying the loads. This research is intended to investigate the correlation of NPS pollution concentrations with land uses in a watershed by calculating Expected Mean Concentrations (EMC). This work was accomplished using a grid based modelling technique that encompasses three stages. The first step includes estimating runoff grid by means of the precipitation grid and runoff coefficient. The second step is deriving the gird based model for calculating NPS pollution loads. The last step is validating the gird based model with traditional pollution loads calculation by applying statistical t-test method. The results on real data, illustrate the merits of the grid based modelling approach. Therefore, this model investigates a method of estimating and simulating point loads along with the spatially distributed NPS pollution loads. The pollutant concentration from local runoff is supposed to be directly related to land use in the region and is not considered to vary from event to event or within areas of similar land uses. By consideration of this point, it is anticipated that a single mean estimated pollutant concentration is assigned to all land uses rather than taking into account unique concentrations for different soil types, crops, and so on.

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Case Study on Auto Meter Reading Protocol Certificate System for Smart Grid and Standardization (스마트 그리드를 위한 원격검침 표준 프로토콜 인증 시스템 구축과 표준화에 관한 연구)

  • Choi, In-Ji;Park, Byung-Seok;Choi, Hyo-Yeol;Myung, No-Gil;Lee, Sang-Youm
    • 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.

Appraisal of Farmland Potential Productivity Using GIS (GIS를 이용한 농지 잠재생산성평가)

  • 박승기;이창수
    • Spatial Information Research
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    • v.9 no.2
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    • pp.341-352
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    • 2001
  • This study was carried out to developed that appraisement model of Potential Productivity Index(PPI). PPI model was used Farmland Productivity Index(FPI) and Labor Productivity Index(LPI) by GIS, and PPI model applied to farm land consolidation region which has been completed recently. FPI was determined by overlapping Poly Grid of the soil properties at the analyzed project region. LPI was estimated by addition productive wages ratio of total direct productive cost. Addition productive wages determined by GIS Network analysis GIS Network analysis of working distance between farm house to paddy and each paddy. PPI variation of each the analyzed paddy of Masu and Weoncheon region was 0.967~0.780 respectively, and could be showed relative largely PPI value. PPI will provide basic element for large scaling and gathering of farm land and a substitute lot of farm land consolidation, and will be maximize productivity of paddy.

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Numerical investigations of tip clearance flow characteristics of a pumpjet propulsor

  • Lu, Lin;Gao, Yuefei;Li, Qiang;Du, Lin
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.3
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    • pp.307-317
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    • 2018
  • In this study, numerical investigations of the tip clearance flow characteristics of a pumpjet propulsor based on Computational Fluid Dynamics (CFD) method have been presented. The Zwart-Gerber-Belamri (Z-G-B) cavitation model based on Reynolds Averaged Navier-Stokes (RANS) method is employed. The structured gird is applied. The formation and development of the tip clearance flows has been investigated and presented. The structure of the tip leakage vortex has been shown. The radial distributions of different velocity components with different Span along the axial direction have been carried out to present the influence of the tip clearance flow on the main flow. In addition, the influences of the tip clearance size on the pumpjet propulsor performance, including the impact on the velocity flow fields and the cavitation characteristic, have been presented.

New PLL Control for Gird Cynchronization f Distributed Power System under Faulty Grid Conditions (계통 사고시 분산전원의 계통 동기화를 위한 새로운 PLL 제어)

  • Jang, Mi-Geum;Song, Sung-Geun;Oh, Seung-Yeol;Choi, Jung-Sik;Chung, Dong-Hwa
    • Proceedings of the KIPE Conference
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    • 2011.11a
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    • pp.271-272
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    • 2011
  • 본 논문은 SOGI를 이용한 정상분 전압 검출을 기반으로 하는 SRF(synchronous reference frame)-PLL(phase locked loop) 시스템을 제안한다. 일반화된 2차 적분기의 이중으로 사용하여 QSG(Quadrature-signals generator)의 성능을 개선하여 전압 불평형, 고조파 왜곡 등으로 인한 오차 발생 시에도 빠르고 정확한 위상 검출이 가능하도록 하였으며 본 논문에서 제시한 알고리즘은 PSIM 프로그램 결과를 통하여 타당성을 입증한다.

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The Determination of Earthwork Volume using LiDAR Data (LiDAR 데이터를 이용한 토공량 산정)

  • Kang Joon-Mook;Yoon Hee-Cheon;Min Kwan-Sik;We Gwang-Jae
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.533-540
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    • 2006
  • In recent years, civil-engineering work is desired the terrain information to be more efficient in earthwork volume calculation. One method for collecting elevation data is LiDAR. Lidar data was used to produce rapidly an accurate digital elevation model of the terrain, compared with the conventional ground surveys, photogrammetty, and remote sensing. Raw Lidar data is combined with GPS positional data to georeference the data sets. Lidar data is edited and processed to generate surface models, elevation models, and contours. Here we can either create a Tin Volume Surface or a Gird Volume Surface. Triangulated Irregular Network(TIN) has complex data structure, but it can describe well terrain surface features. As we have seen, we search the efficiency for earthwork volume calculation using Lidar data. One conclusion we can draw from this study is that Lidar data is more accurate result than digital map in the calculation of earthwork volume.

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