• Title/Summary/Keyword: load balance

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Balance-Swap Optimization of Economic Load Dispatch Problem using Quadratic Fuel Cost Function (이차 발전비용함수를 사용한 경제급전문제의 균형-교환 최적화)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.243-250
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    • 2014
  • In this paper, I devise a balance-swap optimization (BSO) algorithm to solve economic load dispatch with a quadratic fuel cost function. This algorithm firstly sets initial values to $P_i{\leftarrow}P_i^{max}$, (${\Sigma}P_i^{max}$ > $P_d$) and subsequently entails two major processes: a balance process whereby a generator's power i of $_{max}\{F(P_i)-F(P_i-{\alpha})\}$, ${\alpha}=_{min}(P_i-P_i^{min})$ is balanced by $P_i{\leftarrow}P_i-{\alpha}$ until ${\Sigma}P_i=P_d$; and a swap process whereby $_{max}\{F(P_i)-F(P_i-{\beta})\}$ > $_{min}\{F(P_i+{{\beta})-F(P_j)\}$, $i{\neq}j$, ${\beta}$ = 1.0, 0.1, 0.1, 0.01, 0.001 is set at $P_i{\leftarrow}P_i-{\beta}$, $P_j{\leftarrow}P_j+{\beta}$. When applied to 15, 20, and 38-generators benchmark data, this simple algorithm has proven to consistently yield the best possible results. Moreover, this algorithm has dramatically reduced the costs for a centralized operation of 73-generators - a sum of the three benchmark cases - which could otherwise have been impossible for independent operations.

The Structure of Oriental Wooden Pagoda (동양목조탑파(東洋木造塔婆)의 구조형식(構造形式)에 관한 연구(硏究) - 법주사(法住寺) 팔상전(捌相殿)과 법륭사(法隆寺) 오중탑(五重塔)의 비교분석적 측면에서 -)

  • Kim, Kyeong-Pyo;Fujii, Keisuke;Lee, Min-Sup
    • Journal of architectural history
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    • v.1 no.1 s.1
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    • pp.88-105
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    • 1992
  • This dissertation aims to investigate the structure of Palsangjeon, a five story wooden pagoda in Pubjoo Temple which is the only wooden pagoda existing in Korea, by a comparative study of the Palsangjeon with Japanese counterparts. By doing so, the writer of the present investigation attempts to find out its structural originality. The main finding of this study are as follows. The upper part of Palsangjeon is constructed with square log frameworks called GuiTl and Sacheon-Ju around the central column. The four walls along Sacheon-Ju from the 1st level to the 3rd well resists the outside horizontal piressure. And Gui-Tl structure on the 5th level copes much better with shear force. So this frame consisting of Sacheon-Ju and log frameworks might be viewed an semi-core system, This core is supported once again by the frame of Go-Ju. That is to say. Go-Ju supports frame of Sacheon-Ju. And the frame of Pyeong-Ju on the 4th and the 5th levels also supports it. The frame of Go-Ju is supported by the frame of Pyeong-Ju on the 1st and the 2nd levels. So this structure is designed to resist the wind and also keep the balance by properly distributing vertical pressure. The plan and the elevational structure of Palsangjeon keep the balance by the perfect symmetric structure. And the frame of Sacheon-Ju forming semi-core system can resist both the lateral load and the vertical pressure for the balance of its structure. The five story pagoda in Horyuji used to stand on a central which is desigend to support the main body of the pagoda from the first level. The principles of balance is used between the Ha-Aag and short to react the rafter. Sacheon-Ju and edge column is against the lateral load. The structural jointing system is stable thanks to the log framewroks formed on every level. The five story pagoda in Horyuji poseses the structual system originated from the ancient wooden pagoda. The pagoda is found to express simple, sincere and straight forward form. On the other hand, it could be seen as a stucture resisting the earthquake and the lateral load, Palsangjeon is an excellent building which religions function is well harmonized with its structure and appearance. It not only functions extremely well as a regions place like other pagodas, but also excellently shows how multi-story wooden building should be structured.

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Comparisons of Gait Pattern, Muscle Activity and Balance Index according to Obesity in Female College Student (여대생의 비만에 따른 보행패턴, 근활성도 및 균형지수의 비교)

  • Kim, Chan-Kyu;Lee, Byung-Hoon
    • The Journal of the Korea Contents Association
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    • v.15 no.6
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    • pp.259-266
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    • 2015
  • The purpose of this study in obesity gait and to present relevant evidence for the prevention of musculoskeletal disorders to serve as clinical data were performed. 40 female college student body healthy, normal-weight group(n=20) and obesity group(n=20) after classification the gait pattern(smartstep), the balance index (biodex balance SD), muscle activity (surface EMG) to measure quantitatively were compared. Obesity group compared to normal-weight group, the body weight due to pressure and overcoming the load, weight gain due to the unbalance in the body by increasing the ankle joint movement by walking activity of the muscles that act on the ankle movement increases the more you know could. Therefore, in order to prevent musculoskeletal disorders in obese not to and continued strengthening of the muscles and the gait training, balance training is needed.

Rolling Process and Roll Stress Analysis of CB100 using by 3D FEM (3 차원 FEM 을 이용한 CB100의 압연공정 및 롤 응력 해석)

  • Kim, J.M.;Park, C.S.;Woo, K.M.
    • Transactions of Materials Processing
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    • v.19 no.2
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    • pp.101-106
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    • 2010
  • CB100 is one of the channel type products in the steel beam. In this study, rolling process of CB100 is analyzed by 3D FEM simulation and rolling process. FEM simulation result is compared with rolling process data. Also the intermediate & finishing roll stress analysis is carried out and the suitability of the roll through roll stress resultant analysis is evaluated. In order to decrease the roll stress, new pass schedule is developed for stable load balance between intermediate and finishing rolling stand. Therefore new rolling pass schedule is verified by the analysis results of rolling process and roll stress. By the analysis results, the credibility of rolling process analysis was obtained and it was determined that the possibility of roll damage between intermediate and finishing mill was high. So the new pass schedule was developed. Through the result of rolling process and roll stress analysis, it was obtained that the reduction of roll stress and stable load balance.

Parallelization of A Load balancing Algorithm for Parallel Computations (병렬계산을 위한 부하분산 알고리즘의 병렬화)

  • In-Jae Hwang
    • Journal of the Institute of Convergence Signal Processing
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    • v.5 no.3
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    • pp.236-242
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    • 2004
  • In this paper, we propose an approach to parallelize a load balancing algorithm that was shown to be very effective in distributing workload for parallel computations. Load balancing algorithms are required in executing parallel program efficiently As a parallel computation model, we used dynamically growing tree structure that can be found in many application problems. The load balancing algorithm tries to balance the workload among processors while keeping the communication cost under certain limit. We show how the load balancing algorithm is effectively parallelized on mesh and hypercube interconnection networks, and analyzed the time complexity for each case to show that parallel algorithm actually reduced the various overhead.

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A Parallel Inverter System with an Instantaneous Power Balance Control (순시전력 균형제어를 이용한 병렬 인버터 시스템)

  • Sun, Young-Sik;Lee, Chang-Seok;Kim, Si-Kyung;Kim, Chang-Bong
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.1
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    • pp.19-28
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    • 2000
  • The parallel inverter is widely utilized because of its fault-tolerance capability, high-current output at constant voltages and system modularity. The conventional paralled inverter usually employes an active and reactive power control or a frequency and voltage droop control. However, these approaches have the disadvantages that the response time of parallel inverter control is slow against load and system parameter variation to calculate active, reactive power, frequency and voltage. This paper describes novel control scheme for equalization of output power between the parallel connected inverters. The proposed scheme has a fast power balance control response, a simplicity of implementation, and inherent peak current limiting capability since it employes a instantaneous current/voltage control with output voltage and current balance and output voltage regulation. A design procedure for the proposed parallel inverter controller is presented. Futhermore, the proposed constrol scheme is verified through the simulation in various cases such as the system parameter variation, the control parameter variation and the nonlinear load condition.

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A Study on Water Balance in Stationary Load Proton Exchange Membrane(PEM) Fuel Cell Power Generator (고정 부하를 갖는 PEM 연료전지 발전기에 있어서의 수분 평형에 관한 연구)

  • Bakhtiar, Agung;Oh, Hoo-Kyu;Yoon, Jung-In;Kim, Young-Bok;Choi, Kwang-Hwan
    • Journal of the Korean Solar Energy Society
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    • v.31 no.4
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    • pp.128-135
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    • 2011
  • 일반적으로 PEM 연료전지에서는 수분 균형이 시스템의 효율에 결정적으로 영향을 미치기 때문에, 이에 대한 균형(balance)을 잡는 것이 매우 중요하다. 특히, 촉매 층에서 물이 넘치는 익수현상(flooding)이나 건조현상(drying)이 발생하게 되면 연료전지의 효율이 급격하게 저하하므로, 항상 수분의 균형이 잡히도록 시스템을 제어하는 것이 일반적이다. 이 때,수분의 익수현상이나 건조현상은 PEM 연료전지의 용량과 주위의 환경, 즉 온도와 습도에 많은 영향을 받게 된다. 금번 논문에서는 가정용 규모인 3kW급에서 10kW급까지의 PEM 연료전지를 설치하였을 때, 주위의 환경(온도와 습도)이 수분 이동에 어떠한 영향을 미치는 지를 시간에 따라서 시뮬레이션(simulation)한 결과를 보여주고 있다. 결과에서 유입공기의 온도가 $50^{\circ}C$ 이하일 경우, 고정부하가 5kW급 이하이면 대부분이 건조현상이 발생하였으나, 고정부하가 6kW급 이상이 되면 익수현상이 운전시간이 20분 이내에서 발생하였다. 또한 고정부하를 최고 10kW급까지 올린 경우, 유입공기의 온도가 $50^{\circ}C$까지는 익수현상이 발생하였으나 $60^{\circ}C$ 이상인 경우에는 거의 건조현상이 발생함을 알 수 있었다.

Determination of Interception Flow by Pollution Load Budget Analysis in Combined Sewer Watershed (II) - Establishment of Intercepting Capacity and Reduction Goal of Overflow Pollution Load - (오염부하 물질수지 분석을 통한 합류식 하수관거 적정 차집용량 결정(II) - 차집용량과 월류오염부하 삭감목표 설정 -)

  • Lee, Doojin;Shin, EungBai
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.5
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    • pp.557-564
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    • 2005
  • The objective of this study is to evaluate a criteria of intercepting capacity and a reduction goal of overflow pollution load in combined sewer system. In the current criteria of intercepting capacity in the domestic sewage facility standard, it is known that three times of peak sewage (Q) in dry period or runoff flow by 2mm/hr is not appropriate since the intercepted flow is estimated by runoff and show different result even in the same watershed. Though a reduction goal of overflow pollution load can be determined from 1) same level of storm-water runoff pollution load in separated storm sewer, 2) less than 5% sewage load in dry weather period, by the domestic sewage facility standard, the simulated results from storm-water model show large differences between two criteria. While it is predicted that sewage pollution load standard three time larger than separated storm sewer standard in high population density and urbanized area, it is shown that separate storm sewer standard larger than sewage pollution load standard in middle population density and developing area. Accordingly, it is proposed that more reasonable intercepting flow and reduction goal of overflows pollution load should be established to minimize discharging pollution load in combined sewer systems. For the purpose, a resonable standard has to be amended by pollution load balance considering the characteristics of a watershed for generation, collection, treatment, and discharging flow.

A Novel Globally Adaptive Load-Balanced Routing Algorithm for Torus Interconnection Networks

  • Wang, Hong;Xu, Du;Li, Lemin
    • ETRI Journal
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    • v.29 no.3
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    • pp.405-407
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    • 2007
  • A globally adaptive load-balanced routing algorithm for torus interconnection networks is proposed. Unlike previously published algorithms, this algorithm employs a new scheme based on collision detection to handle deadlock, and has higher routing adaptability than previous algorithms. Simulation results show that our algorithm outperforms previous algorithms by 16% on benign traffic patterns, and by 10% to 21% on adversarial traffic patterns.

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A Study On The Power Factor Correction Of The Boost Converter Without The Input Current Measurement (입력 전류의 측정이 필요없는 Boost 컨버터의 역률 보정에 관한 연구)

  • Cho, Sang-Jun;Lee, Kwang-Won
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.376-378
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    • 1996
  • This paper presents a new PFC control method which replaces a fast line current measurement with a filtered load current measurement. Using the power balance relation between the input and the output of the boost converter. the input current can be described as the function of load current. Thus the PWM signal which effects the switching control of the boost converter is generated using the PFC input voltage, the PFC output voltage and the load current as input variables. By using a filter between the bridge rectifier and a dc-to-dc converter, the input voltage of the dc-to-dc converter is forced to always maintain above zero volt. Then the input current traces a sinewave in phase. The proposed scheme accomplishes a very high power factor and a low harmonic distortion of the line current. The validity of this scheme is demonstrated through simulation.

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