• Title/Summary/Keyword: Load balancing

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Modular Multilevel Converter Based STATCOM Topology Suitable for Medium-Voltage Unbalanced Systems

  • Pirouz, Hassan Mohammadi;Bina, Mohammad Tavakoli
    • Journal of Power Electronics
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    • v.10 no.5
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    • pp.572-578
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    • 2010
  • This paper discusses a transformerless shunt static compensator (STATCOM) based on a modular multilevel converter (MMC). It introduces a new time-discrete appropriate current control algorithm and a phase-shifted carrier modulation strategy for fast compensation of the reactive power and harmonics, and also for the balancing of the three-phase source side currents. Analytical formulas are derived to demonstrate the accurate mechanism of the stored energy balancing inside the MMC. Various simulated waveforms verify that the MMC based STATCOM is capable of reactive power compensation, harmonic cancellation, and simultaneous load balancing, while controlling and balancing all of the DC mean voltages even during the transient states.

Study on the Relationship between Adolescents' Self-esteem and their Sociality -Focusing on the Moderating Effect of Gender -

  • Kim, Kyung-Sook;Lee, Duk-Nam
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.1
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    • pp.147-153
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    • 2016
  • In this paper, we propose an efficient dynamic workload balancing strategy which improves the performance of high-performance computing system. The key idea of this dynamic workload balancing strategy is to minimize execution time of each job and to maximize the system throughput by effectively using system resource such as CPU, memory. Also, this strategy dynamically allocates job by considering demanded memory size of executing job and workload status of each node. If an overload node occurs due to allocated job, the proposed scheme migrates job, executing in overload nodes, to another free nodes and reduces the waiting time and execution time of job by balancing workload of each node. Through simulation, we show that the proposed dynamic workload balancing strategy based on CPU, memory improves the performance of high-performance computing system compared to previous strategies.

Bayesian Regression Modeling for Patent Keyword Analysis

  • Choi, JunHyeog;Jun, SungHae
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.1
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    • pp.125-129
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    • 2016
  • In this paper, we propose an efficient dynamic workload balancing strategy which improves the performance of high-performance computing system. The key idea of this dynamic workload balancing strategy is to minimize execution time of each job and to maximize the system throughput by effectively using system resource such as CPU, memory. Also, this strategy dynamically allocates job by considering demanded memory size of executing job and workload status of each node. If an overload node occurs due to allocated job, the proposed scheme migrates job, executing in overload nodes, to another free nodes and reduces the waiting time and execution time of job by balancing workload of each node. Through simulation, we show that the proposed dynamic workload balancing strategy based on CPU, memory improves the performance of high-performance computing system compared to previous strategies.

An Efficient Load Balancing with the Dynamic Participation of Peers in the Structured Peer-to-Peer System (구조적 피어-투-피어 시스템에서 동적 피어 참여 기반의 효율적인 로드 밸런싱)

  • Song Jin-Woo;Choi Yeon-Oh;Yang Sung-Bong
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.06d
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    • pp.235-237
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    • 2006
  • 최근 분산 해쉬 테이블(Distributed Hash Table)을 이용한 구조적 P2P(peer-to-peer) 시스템에서 로드 밸런싱에 관한 연구가 활발하게 진행되고 있다. 일반적으로 P2P 시스템에서의 피어들은 빈번하게 참여하는 동시에 탈퇴하기도 하기 때문에 로드의 불균형이 심화되는 문제점이 있다. 본 논문에서는 구조적 P2P 시스템에서 피어의 참여와 탈퇴 시 발생하는 가상서버의 이동을 효과적으로 관리하는 기법인 PALB(Peer Activity-aware Load Balancing)를 제안한다. 제안하는 PALB는 피어의 참여, 탈퇴 시에 발생하는 로드 불균형을 해결하기 위하여 적절한 수의 가상서버를 가장 적합한 피어에게 분산시킨다. 또한 이전 연구에서 제안한 OLAB(Object Lifetime-aware Load Balancing)와 함께 사용하여 로드 밸런싱 성능을 향상시킬 수 있다. PALB의 성능 평가를 위하여 동적 P2P 시스템 환경을 구성하였고, 피어와 오브젝트의 랜덤 데이터 셋을 이용하여 시뮬레이션을 수행하였다. 시뮬레이션 결과 PALB가 기존의 시스템에 비하여 더 적은 비용으로 더 나은 로드 밸런싱을 수행함을 확인하였다. 또한 OLAB와 동시에 사용하였을 경우, 매우 뛰어난 성능을 보임을 확인하였다.

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A Load Balancing and Security Scheme of Mobile Agents based on the mobile Trust Model (신뢰모델을 기반으로 한 이동 에이전트의 로드밸런싱과 에이전트 보호 기법)

  • Jung, Chang-Ryul;Lee, Sung-Keun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.10
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    • pp.2337-2344
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    • 2013
  • Mobile Agent is an autonomous mobility technology is being applied in various fields. In particular, mobile agents execution in the Internet environment through the safe execution of the security must be guaranteed. Also, agent to run the agent, the agent's workload should be distributed. In this paper, a trust model based on the security mechanism of the agent execution is proposed. Proposed mechanism to ensure safe execution of the agent was not considered in existing relative researches for rational agent workload distribution and load balancing to improve throughput was. The proposed trust-based security mechanisms for agents to go through security analysis proved safe execution of the agent.

Performance Load Balancing and Sensitivity Analysis of Ramjet/Scramjet for Dual-Combustion/Dual-Mode Ramjet Engine Part I. Performance Load Balancing (이중램제트(이중연소/이중모드)엔진을 위한 램제트/스크램제트의 작동영역분배 및 성능민감도분석 Part I. 작동영역분배)

  • Kim, Sun-Kyoung;Jeon, Chang-Soo;Sung, Hong-Gye;Byen, Jong-Ryul;Yoon, Hyun-Gull
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.6
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    • pp.586-595
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    • 2010
  • An analytical study based on physical understandings and aero-thermodynamic theories was conducted to observe the performance characteristics and to derive the essential design parameters of dual ramjet(dual-combustion/dual-mode) propulsion for wide Mach number. The performances and operating limitations of the engines with two types combustors, such as constant pressure- and constant area- combustor, over various flight Mach numbers was investigated. Finally, the transition Mach number from ramjet to scramjet was carried out to optimize performance load balancing of ramjet and scramjet.

Performance Improvement of Centralized Dynamic Load-Balancing Method by Using Network Based Parallel Genetic Algorithm (네트워크기반 병렬 유전자 알고리즘을 이용한 중앙집중형 동적부하균등기법의 성능향상)

  • Song, Bong-Gi;Sung, Kil-Young;Woo, Chong-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.1
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    • pp.165-171
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    • 2005
  • In this paper, the centralized dynamic load-balancing was processed effectively by using the network based parallel genetic algorithm. Unlike the existing method using genetic algorithm, the performance of central scheduler was improved by distributing the process for the searching of the optimal task assignment to clients. A roulette wheel selection and an elite preservation strategy were used as selection operation to improve the convergence speed of optimal solution. A chromosome was encoded by using sliding window method. And a cyclic crossover was used as crossover operation. By the result of simulation for the performance estimation of central scheduler according to the change of flexibility of load-balancing method, it was verified that the performance is improved in the proposed method.

A Multi-path Routing Mechanism with Local Optimization for Load Balancing in the Tactical Backbone Network (전술 백본망에서 부하 분산을 위한 다중 경로 지역 최적화 기법)

  • Kim, Yongsin;Kim, Younghan
    • Journal of KIISE
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    • v.41 no.12
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    • pp.1145-1151
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    • 2014
  • In this paper, we propose MPLO(Multi-Path routing with Local Optimization) for load balancing in the tactical backbone network. The MPLO manages global metric and local metric separately. The global metric is propagated to other routers via a routing protocol and is used for configuring loop-free multi-path. The local metric reflecting link utilization is used to find an alternate path when congestion occurs. We verified MPLO could effectively distribute user traffic among available routers by simulation.

A Proposition and Analysis of Useful Load Balancing Algorithm For Overloaded Daemon In WDCS (WDCS 에서 과부하 데몬을 위한 효율적인 부하분산 알고리즘 제안과 분석)

  • 문형섭;이홍도
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2000.10a
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    • pp.292-295
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    • 2000
  • This paper presents effective Load Balancing Algorithm by exampling EvtProc Daemon controlling the Event handling among the W/S Daemon which manages and controls Digital Cross Connect Systems. In this paper, when a lot of event occur, charging process waits regular times instead of executing consecutive exec process. so, We can reduce overheads of fork and exec process. another method of reducing the overheads is it that waiting process handles consecutives events of Op Code. And We also presents effective and stable management scheme of event handling , for the generation of event handling Child process by charging the Load Balancing to the main child process

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A Method for Client-Server Allocation for Maximum Load Balancing and Automatic Frame Rate Adjustment in a Game Streaming Environment (게임 스트리밍 환경에서 최대 부하 균등 및 자동 프레임 레이트 조절을 위한 클라이언트-서버 배정 방법)

  • Kim, Sangchul
    • Journal of Korea Game Society
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    • v.20 no.4
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    • pp.77-88
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    • 2020
  • Recently, interest in game streaming is high in cloud-based gaming. In game streaming, remote game servers perform graphics rendering and stream the resulting scene images to clients' device on the Internet. We model the client-server allocation (CSA) problem for balancing the GPU load between servers in a game streaming environment as an optimization problem, and propose a simulated annealing-based method. The features of our method are that the method takes into account the constraints on network delay and has the ability to automatically adjust the frame rate of game sessions if necessary.