• 제목/요약/키워드: maximum load

검색결과 3,924건 처리시간 0.037초

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

  • 김광호;윤형선;이철희
    • 산업기술연구
    • /
    • 제18권
    • /
    • pp.379-384
    • /
    • 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.

  • PDF

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

  • 이영신;김용환;김영완;김동수;성낙훈
    • 오토저널
    • /
    • 제15권3호
    • /
    • pp.111-119
    • /
    • 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.

  • PDF

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

  • 김청균
    • 한국가스학회지
    • /
    • 제20권2호
    • /
    • pp.43-48
    • /
    • 2016
  • 본 논문에서는 돌출구조물을 장착한 안전모의 지지하중과 응력분포에 대한 유한요소 해석결과를 제시하고 있다. 9.4mm의 동일한 변위하중을 안전모에 가한 5가지의 서로 다른 해석모델에 대하여 지지하중과 von Mises 최대응력을 해석하였다. 이들 모델에서, 모델 4와 모델 5는 주어진 9.4mm의 변위하중에 대하여 최고의 지지하중과 낮은 최대응력을 보여준다는 측면에서 우수한 것으로 나타났다.

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

  • 최재균;박종근;김광호
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1995년도 하계학술대회 논문집 B
    • /
    • pp.578-580
    • /
    • 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.

  • PDF

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

  • 심동석;김정규
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2003년도 추계학술대회
    • /
    • pp.1045-1050
    • /
    • 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%.

  • PDF

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

  • 류지성;김홍태;박진형;이병로;신종계
    • 대한조선학회논문집
    • /
    • 제41권5호
    • /
    • pp.55-62
    • /
    • 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.

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

  • 이기홍;추성두;정지열;안명선
    • 한국조명전기설비학회:학술대회논문집
    • /
    • 한국조명전기설비학회 2000년도 학술대회논문집
    • /
    • pp.55-59
    • /
    • 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%.

  • PDF

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

  • 김홍태;신동석;김현정;최인욱;이미선;김용석
    • 한국물환경학회지
    • /
    • 제31권6호
    • /
    • pp.715-722
    • /
    • 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.

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

  • 류정수;김석열
    • 한국지반공학회지:지반
    • /
    • 제11권4호
    • /
    • pp.5-12
    • /
    • 1995
  • 말뚝의 재하시험이 연직지지력을 추정하기 위한 다양한 정보를 제공한다 할지라도 시험 말뚝을 극한하중까지 도달하도록 충분히 재하시킨다는 것은 상당히 어려운 일이며, 이와 같이 파괴시까지 재하하지 못한 말뚝의 연직재하시험의 결과로부터 지지력을 추정하는데 있어서 많은 도해적 방법과 수학적 방법이 시도되었다. 파괴하중을 추정하기 위하여 Southwel 연 이론을 기초로 최대곡률을 이용한 해석적 방법이 필자 등에 의하여 발표된 바 있다. 여기서 파괴하중은 Crowther가 정의한 바와 같이 특정한 기준 을 초과하였을 때의 하중으로 정의하였다. 본 논문은 최대곡률 방법에 의한 허용하중을 결정하기 위하여 Davission의 방법 및 DIN 4014의 허용하중과 비교하여 최대곡률 방법의 안전율을 2.5로 제안하였다. 그 결과 파괴시까지 재하하지 못한 연직재하시험의 결과치로부터 말뚝의 연직지지력을 추정 하는데 있어서 최대곡률 방법에 의한 허용하중의 결정은 타당성이 있는 것으로 판단되었다.

  • PDF

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

  • 최용규
    • 대한토목학회논문집
    • /
    • 제28권6C호
    • /
    • pp.379-388
    • /
    • 2008
  • 대형말뚝기초의 양방향 재하시험에서 재하용량 기준이 정확하게 규정되어 있지 않다. 그래서 양방향말뚝재하시험을 수행함에 있어 많은 혼란이 발생하고 있으며 재하용량에서 최대 2배까지의 차이가 나타나고 있다. 본 연구에서는 양방향 말뚝재하시험 기준들을 고찰하였으며, 국내에서 수행된 양방향 말뚝재하시험 사례들에 기초하여 최대등가시험하중, 재하하중 증가비, 재하용량 증가비 및 설계하중 충족비를 분석하였다. 양방향 말뚝재하시험 기준은 1방향 재하용량으로 정의되어야 하며, 1방향 재하용량은 설계하중의 2배 이상 이어야 한다는 것을 알 수 있었다.