• Title/Summary/Keyword: maximum load

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Development of Neural Network System for Short-Term Load Forecasting for a Special Day (특수일 전력수요예측을 위한 신경회로망 시스템의 개발)

  • Kim, Kwang-Ho;Youn, Hyoung-Sun;Lee, Chul-Heui
    • Journal of Industrial Technology
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    • v.18
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    • pp.379-384
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    • 1998
  • Conventional short-term load forecasting techniques have limitation in their use on holidays due to dissimilar load behaviors of holidays and insufficiency of pattern data. Thus, a new short-term load forecasting method for special days in anomalous load conditions is proposed in this paper. The proposed method uses two Artificial Neural Networks(ANN); one is for the estimation of load curve, and the other is for the estimation of minimum and maximum value of load. The forecasting procedure is as follows. First, the normalized load curve is estimated by ANN. At next step, minimum and maximum values of load in a special day are estimated by another ANN. Finally, the estimate of load in a whole special day is obtained by combining these two outputs of ANNs. The proposed method shows a good performance, and it may be effectively applied to the practical situations.

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Transient stress analysis of tracked vehicle structures under recoil impact load (주퇴충격하중을 받는 궤도차량 구조물의 천이응력해석)

  • 이영신;김용환;김영완;김동수;성낙훈
    • Journal of the korean Society of Automotive Engineers
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    • v.15 no.3
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    • pp.111-119
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    • 1993
  • In this study, the transient impact structural stress analysis of tracked vehicle structures under recoil impact load is investigated. ANSYS, ABAQUS Code are used for modelling and analytical procedures. The highest maximum Tresca stress occurs on race ring portion and its stress level is (.sigma.$_{T}$)$_{max}$ =20-40kgf/m $m^{2}$. The second highest stress occurs on upper plate of chassis and down plate of turret. The maximum stress level increases with loading direction and elevation angle. The results from liner static load analysis are very much different with impact analysis. Therefore, the practical solutions of structures under impact load can be obtained by only nonlinear transient impact analysis. The impact stress analysis of the steel vehicle structures is conducted. The maximum stress level is less than (.sigma.$_T/)$_{max}$m $m^{2}$. So, the design concept of steel structures can be adapted for new alternatives.s.s.s..s.

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Finite Element Analysis on the Bearing Loads and Stress of Safety Helmets with an Extruded Structure (정상부에 돌출구조물을 구비한 안전모의 지지하중 및 응력에 관한 유한요소해석)

  • Kim, Chung Kyun
    • Journal of the Korean Institute of Gas
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    • v.20 no.2
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    • pp.43-48
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    • 2016
  • This paper presents the finite element analysis results for bearing loads and stress distributions of safety helmets with an extruded structure. Five different analysis models with given same displacement load of 9.4mm have been analyzed for bearing loads and maximum von Mises stress. In these models, model 4 and model 5 are recommended as a maximum bearing load and low maximum stress for given displacement load of 9.4mm.

A Daily Maximum Load Forecasting System Using Chaotic Time Series (Chaos를 이용한 단기부하예측)

  • Choi, Jae-Gyun;Park, Jong-Keun;Kim, Kwang-Ho
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.578-580
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    • 1995
  • In this paper, a method for the daily maximum load forecasting which uses a chaotic time series in power system and artificial neural network. We find the characteristics of chaos in power load curve and then determine a optimal embedding dimension and delay time, For the load forecast of one day ahead daily maximum power, we use the time series load data obtained in previous year. By using of embedding dimension and delay time, we construct a strange attractor in pseudo phase plane and the artificial neural network model trained with the attractor font mentioned above. The one day ahead forecast errors are about 1.4% of absolute percentage average error.

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The Effect of Low-amplitude Cycles in Flight-simulation Loading (비행하중에서 피로균열진전에 미치는 미소하중의 영향)

  • Shim, Dong-Suk;Kim, Jung-Kyu
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1045-1050
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    • 2003
  • In this study, to investigate the effects of omitting low-amplitude cycles from a flight-simulation loading, crack growth tests are conducted on 2124-T851 aluminum alloy specimens. Three test spectra are generated by omitting small load ranges as counted by the rain-flow count method. The crack growth test results are compared with the data obtained from the flight-simulation loading. The experimental results show that omission of the load ranges below 5% of the maximum load does not significantly affect crack growth behavior, because these are below the initial stress intensity factor range. However, in the case of omitting the load ranges below 15% of the maximum load, crack growth rates decrease, and therefore crack growth curve deviates from the crack growth data under the flight-simulation loading. To optimize the load range that can be omitted, crack growth curves are simulated by the stochastic crack growth model. The prediction shows that the omission level can be extended to 8% of the maximum load and test time can be reduced by 59%.

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Load Leveling of Block Erection Network Using Diminution of Maximum Load Based on Constraint Satisfaction Technique (제약만족기법 기반의 최대부하감소를 통한 탑재 네크워크의 부하평준화)

  • Ryu, Ji-Sung;Kim, Hong-Tae;Park, Jin-H.;Lee, Byung-No;Shin, Jong-Gyu
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.5
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    • pp.55-62
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    • 2004
  • The logistics of entire shipbuilding process are integrated during the block erection process and the schedules for the erection process are made prior to. the schedules of any other processes. Therefore, efficient scheduling of the block erection process are one of most important issues in shipbuilding. There are only a few studies published regarding block erection scheduling methods because of its complexity and variability. This paper proposes an algorithm for diminution of maximum load based on constraint satisfaction technique. it is developed primarily for the efficiency in load leveling and applicability to the actual block erection process. The proposed algorithm is applied to actual block erection process and the results shows improvements in load leveling. It can also be used for the scheduling of fabrication, sub-assembly, and assembly to improve load leveling.

A Survey on the Load Profiles of the Power Transformers and Motors in Apartment Housing (아파트에서의 동력부하 운전실태 조사)

  • 이기홍;추성두;정지열;안명선
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2000.11a
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    • pp.55-59
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    • 2000
  • This paper gives various load profiles of power transformers and motors in apartment housing. The load profile of power transformer shows that it is peaked in winter by heating system, and the maximum value of load profiles in power transformer is ranged 25%∼35%, which shows it is operated on over-capacity. The maximum value of demand factor in water supply system is about 60% and this of wastewater treatment system is about 50%.

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A Study on the Activation of Non-government Participation in Total Maximum Daily Load System using Private Discharge Facilities Reduction Potential Analysis (개별배출시설 삭감잠재량 분석을 통한 수질오염총량제의 민간참여 활성화 방안 연구)

  • Kim, Hongtae;Shin, Dongseok;Kim, Hyeonjeong;Choi, Inuk;Lee, Miseon;Kim, Yongseok
    • Journal of Korean Society on Water Environment
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    • v.31 no.6
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    • pp.715-722
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    • 2015
  • Four major river basin in Korea has been managed with Total Maximum Daily Load(TMDL) System. Water quality indicators as targeted pollutants for TMDL were BOD and TP. In order to satisfy water quality criteria, government allocation using public treatment facilities and its action plan has been used. However, the role to improve water quality were recently faced to its limitation. It is time to require the role of non-government allocation in private discharge facilities to control good water quality. This study investigated three different scenarios in reduction demands of non-government allocations about industry and private sewages. The three different scenarios were discharge under 1) legal water quality standard, 2) water quality level in 2011 and 3) current water quality level with maximum value in group. The results showed that reduction potential in water discharge for TP indicator was 1,118kg/day, under second scenario with 20% of deduction. This results arrived at 42% of whole reduction potential costs and 0.012mg/L improvement in water quality. In conclusion, to intrigue voluntary participation in non-government allocation, various benefits such as tax reduction, tax exemption, and water quality trading should be provided.

A Study on the Vertical Bearing Capacity of Pile using the Maximum Curvature Method (최대곡률 방법을 이용한 말뚝의 연직지지력 연구)

  • 류정수;김석열
    • Geotechnical Engineering
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    • v.11 no.4
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    • pp.5-12
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    • 1995
  • Although the pile Load test provides various informations to predict the bearing capacity of a pile, it has a considerable difficulty of requiring a large amount of weight to enable the test pile to be loaded sufficiently until the yielding or ultimate load is obtained. Many graphical and mathematical methods have been attempted to estimate the bearing capacity from the result of a vertical load test without loading to failure. In the previous work an analytical method to estimate the failure load using the maxi mum curvature which was based on the Southwell's theory was presented by the author. The failure load, as proposed by Crowther, should be defined as the load at which the predefined that criteria are exceeded. The allowable loads by Davisson's method and DIN 4014 were compared with the loads of piles using the maximum curvature, and this paper proposed the allowable load in which the safety factor of the maximum curvature was 2.5. As a result of study, it was reasonable to conclude that the allowable load determined by the maximum curvature method could estimate the vertical bearing capacity from the pile load test without loading to failure.

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A Study on the Loading Capacity Standard of Bi-directional Pile Load Test (BD PLT) (양방향말뚝재하시험의 재하용량 기준에 관한 연구)

  • Choi, Yongkyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6C
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    • pp.379-388
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    • 2008
  • In the bi-directional pile load test (BD PLT) for pile load tests of Mega pile foundations, loading capacity standard is not specified exactly. Therefore there are so many confusions in performing the BD PLT and variations up to maximum 2 times in loading capacity are come out. In this study, standards of bi-directional pile load test (BD PLT) were considered. Based on cases of the bi-directional pile load test performed in domestic areas, maximum equivalent test load, test load increasing ratio, loading capacity increasing ratio and sufficiency ratio of design load were analyzed. It could be known that the loading capacity standard of bi-directional pile load test must be defined as 1-directional loading capacity and also must be established as more than 2 times of design load.