• Title/Summary/Keyword: Grid Scheduling

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Markov Job Scheduling Scheme based on Desktop Availability in Desktop Grid Computing Environment (데스크탑 그리드 환경에서 데스크탑 가용성 기반 마코브 작업 스케줄링 기법)

  • Byun Eun-Joung;Park Hark-Soo;Park Chan-Yeol;Choi Jang-Won;Jung Soon-Young;Hwang Chong-Sun
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.11a
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    • pp.991-993
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    • 2005
  • 데스크탑 그리드(Desktop Grid) 환경에서는 자원 제공자인 데스크탑의 자율적 연산 참여와 탈퇴를 허용하기 때문에 기존 데스크탑 그리드 시스템들은 연산 도중 잦은 중단으로 인해 연산의 완료 시간이 지연되고, 연산 수행의 신뢰성이 저하되며 연산의 완료를 보장하지 못하고 있다. 기존의 데스크탑 그리드 시스템들은 이러한 데스크탑의 동적 특성을 반영하지 못하고 있을 뿐만 아니라 데스크탑의 연산 수행 양식을 고려하지 않아 시스템의 안정성과 성능이 저하되었다. 신뢰성 높은 연산 수행을 지원하고, 데스크탑의 비예측적 연산 수행 속성을 극복하기 위해서는 데스크탑의 동적인 특성인 휘발성(volatility)을 고려한 스케줄링이 필요하다. 본 논문에서는 휴리스틱 접근을 통해 동적으로 가변하는 데스크탑의 상태를 보다 정확하게 모델링 하는 가용성 기반 마코브 작업 스케줄링 기법을 제안한다. 제안 기법은 데스크탑의 가용성을 기반으로 과거 연산 수행에 대한 패턴을 확률 모델링하여 미래 연산 수행 유형을 예측함으로써 연산 수행 도중의 불안정한 자원 제공 현상을 완화시키며 안정적인 스케줄링을 지원하여 시스템의 신뢰성과 성능을 향상시킨다.

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A Network Performance Analysis System based on Network Monitoring for Analyzing Abnormal Traffic (비정상 트래픽 분석을 위한 네트워크 모니터링 기반의 네트워크 성능 분석 시스템)

  • Kim, So-Hung;Koo, Ja-Hwan;Kim, Sung Hae;Choi, Jang-Won;An, Sung-Jin
    • Convergence Security Journal
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    • v.4 no.3
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    • pp.1-8
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    • 2004
  • Large distributed systems such as computational and data grids require that a substantial amount of monitoring data be collected for various tasks such as fault detection, performance analysis, performance tuning, performance prediction, security analysis and scheduling. to cope with this problem, they are needed network monitoring architecture which can collect various network characteristic and analyze network security state. In this paper, we suggest network performance and security analysis system based on network monitoring. The System suggest that users can see distance network state with tuning network parameters.

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PV Power Prediction Models for City Energy Management System based on Weather Forecast Information (기상정보를 활용한 도시규모-EMS용 태양광 발전량 예측모델)

  • Eum, Ji-Young;Choi, Hyeong-Jin;Cho, Soo-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.3
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    • pp.393-398
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    • 2015
  • City or Community-scale Energy Management System(CEMS) is used to reduce the total energy consumed in the city by arranging the energy resources efficiently at the planning stage and controlling them economically at the operating stage. Of the operational functions of the CEMS, generation forecasting of renewable energy resources is an essential feature for the effective supply scheduling. This is because it can develop daily operating schedules of controllable generators in the city (e.g. diesel turbine, micro-gas turbine, ESS, CHP and so on) in order to minimize the inflow of the external power supply system, considering the amount of power generated by the uncontrollable renewable energy resources. This paper is written to introduce numerical models for photo-voltaic power generation prediction based on the weather forecasting information. Unlike the conventional methods using the average radiation or average utilization rate, the proposed models are developed for CEMS applications using the realtime weather forecast information provided by the National Weather Service.

Congestion Detection for QoS-enabled Wireless Networks and its Potential Applications

  • Ramneek, Ramneek;Hosein, Patrick;Choi, Wonjun;Seok, Woojin
    • Journal of Communications and Networks
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    • v.18 no.3
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    • pp.513-522
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    • 2016
  • We propose a mechanism for monitoring load in quality of service (QoS)-enabled wireless networks and show how it can be used for network management as well as for dynamic pricing. Mobile network traffic, especially video, has grown exponentially over the last few years and it is anticipated that this trend will continue into the future. Driving factors include the availability of new affordable, smart devices, such as smart-phones and tablets, together with the expectation of high quality user experience for video as one would obtain at home. Although new technologies such as long term evolution (LTE) are expected to help satisfy this demand, the fact is that several other mechanisms will be needed to manage overload and congestion in the network. Therefore, the efficient management of the expected huge data traffic demands is critical if operators are to maintain acceptable service quality while making a profit. In the current work, we address this issue by first investigating how the network load can be accurately monitored and then we show how this load metric can then be used to provide creative pricing plans. In addition, we describe its applications to features like traffic offloading and user satisfaction tracking.

Dynamic Reserve Estimating Method with Consideration of Uncertainties in Supply and Demand (수요와 공급의 불확실성을 고려한 시간대별 순동예비력 산정 방안)

  • Kwon, Kyung-Bin;Park, Hyeon-Gon;Lyu, Jae-Kun;Kim, Yu-Chang;Park, Jong-Keun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.11
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    • pp.1495-1504
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    • 2013
  • Renewable energy integration and increased system complexities make system operator maintain supply and demand balance harder than before. To keep the grid frequency in a stable range, an appropriate spinning reserve margin should be procured with consideration of ever-changing system situation, such as demand, wind power output and generator failure. This paper propose a novel concept of dynamic reserve, which arrange different spinning reserve margin depending on time. To investigate the effectiveness of the proposed dynamic reserve, we developed a new short-term reliability criterion that estimates the probability of a spinning reserve shortage events, thus indicating grid frequency stability. Uncertainties of demand forecast error, wind generation forecast error and generator failure have been modeled in probabilistic terms, and the proposed spinning reserve has been applied to generation scheduling. This approach has been tested on the modified IEEE 118-bus system with a wind farm. The results show that the required spinning reserve margin changes depending on the system situation of demand, wind generation and generator failure. Moreover the proposed approach could be utilized even in case of system configuration change, such as wind generation extension.

DER Energy Management System for Optimal Management of Grid-Connected Microgrids (전력망 연계형 마이크로그리드 최적운영을 위한 분산에너지자원 에너지관리시스템)

  • Choi, Jongwoo;Shin, Youngmee;Lee, Il-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.42 no.4
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    • pp.932-938
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    • 2017
  • This paper presents the structure of an energy management system for distributed energy resources of a grid-connected microgrid. The energy management system of a grid-connected microgrid collects information of the microgrid such as the status of distributed energy resources and the time varying pricing plan through various protocols. The energy management system performs forecasting and optimization based on the collected information. It derives the operation schedule of distributed energy resources to reduce the microgrid electricity bill. In order to achieve optimal operation, the energy management system should include an optimal scheduling algorithm and a protocol that transfers the derived schedule to distributed energy resources. The energy management system operates as a rolling horizon controller in order to reduce the effect of a prediction error. Derived control schedules are transmitted to the distributed energy resources in real time through the international standard communication protocol.

Location Generalization Method of Moving Object using R-Tree and Grid (R-Tree와 Grid를 이용한 이동 객체의 위치 일반화 기법)

  • Ko, Hyun;Kim, Kwang-Jong;Lee, Yon-Sik
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.2 s.46
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    • pp.231-242
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    • 2007
  • The existing pattern mining methods[1,2,3,4,5,6,11,12,13] do not use location generalization method on the set of location history data of moving object, but even so they simply do extract only frequent patterns which have no spatio-temporal constraint in moving patterns on specific space. Therefore, it is difficult for those methods to apply to frequent pattern mining which has spatio-temporal constraint such as optimal moving or scheduling paths among the specific points. And also, those methods are required more large memory space due to using pattern tree on memory for reducing repeated scan database. Therefore, more effective pattern mining technique is required for solving these problems. In this paper, in order to develop more effective pattern mining technique, we propose new location generalization method that converts data of detailed level into meaningful spatial information for reducing the processing time for pattern mining of a massive history data set of moving object and space saving. The proposed method can lead the efficient spatial moving pattern mining of moving object using by creating moving sequences through generalizing the location attributes of moving object into 2D spatial area based on R-Tree and Area Grid Hash Table(AGHT) in preprocessing stage of pattern mining.

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Real-Time Scheduling Strategy for Resource Allocation in Grid Computing (그리드 컴퓨팅에서 자원 할당을 위한 실시간 스케줄링 정책)

  • 최준영;이원주;전창호
    • Proceedings of the Korean Information Science Society Conference
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    • 2004.04a
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    • pp.85-87
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    • 2004
  • 그리드 컴퓨팅에서는 자원의 상세 정보를 실시간으로 사용하기 어렵기 때문에 자원 관리와 할당이 기존 시스템에 비해 비효율적이다. 따라서, 본 논문에서는 작업의 총 실행시간을 예측하여 그리드 자원을 할당하는 새로운 스케줄링 정책을 제안한다. 이 스케줄링 정책의 특징은 원격 스케줄러와 로컬스케줄러를 사용하여 2단계 스케줄링을 수행한다. 원격 스케줄러에서는 자원 데이터베이스에 저장된 네트워크 환경과 로컬시스템의 정보를 사용하여 작업의 총 실행시간을 예측한다. 그리고 총 실행시간이 최소인 로컬시스템에 작업을 할당한다. 로컬스케줄러에서는 할당된 작업의 대기시간과 처리시간을 계산한 후, 작업을 데드라인 내에 처 리 할 수 있다면 로컬 시스템에서 처리한다. 하지만 데드라인을 초과하면 다른 로컬시스템으로 이주시켜 처리함으로써 작업실패율(failure rate)과 자원비용(resource cost)을 최소화한다.

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On-line Optimal EMS Implementation for Distributed Power System

  • Choi, Wooin;Baek, Jong-Bok;Cho, Bo-Hyung
    • Proceedings of the KIPE Conference
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    • 2012.11a
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    • pp.33-34
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    • 2012
  • As the distributed power system with PV and ESS is highlighted to be one of the most prominent structure to replace the traditional electric power system, power flow scheduling is expected to bring better system efficiency. Optimal energy management system (EMS) where the power from PV and the grid is managed in time-domain using ESS needs an optimization process. In this paper, main optimization method is implemented using dynamic programming (DP). To overcome the drawback of DP in which ideal future information is required, prediction stage precedes every EMS execution. A simple auto-regressive moving-average (ARMA) forecasting followed by a PI-controller updates the prediction data. Assessment of the on-line optimal EMS scheme has been evaluated on several cases.

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Newton-Krylov Method for Compressible Euler Equations on Unstructured Grids

  • Kim Sungho;Kwon Jang Hyuk
    • 한국전산유체공학회:학술대회논문집
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    • 1998.11a
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    • pp.153-159
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    • 1998
  • The Newton-Krylov method on the unstructured grid flow solver using the cell-centered spatial discretization oi compressible Euler equations is presented. This flow solver uses the reconstructed primitive variables to get the higher order solutions. To get the quadratic convergence of Newton method with this solver, the careful linearization of face flux is performed with the reconstructed flow variables. The GMRES method is used to solve large sparse matrix and to improve the performance ILU preconditioner is adopted and vectorized with level scheduling algorithm. To get the quadratic convergence with the higher order schemes and to reduce the memory storage. the matrix-free implementation and Barth's matrix-vector method are implemented and compared with the traditional matrix-vector method. The convergence and computing times are compared with each other.

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