• 제목/요약/키워드: Prediction.

검색결과 25,818건 처리시간 0.045초

Short-term Wind Power Prediction Based on Empirical Mode Decomposition and Improved Extreme Learning Machine

  • Tian, Zhongda;Ren, Yi;Wang, Gang
    • Journal of Electrical Engineering and Technology
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    • 제13권5호
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    • pp.1841-1851
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    • 2018
  • For the safe and stable operation of the power system, accurate wind power prediction is of great significance. A wind power prediction method based on empirical mode decomposition and improved extreme learning machine is proposed in this paper. Firstly, wind power time series is decomposed into several components with different frequency by empirical mode decomposition, which can reduce the non-stationary of time series. The components after decomposing remove the long correlation and promote the different local characteristics of original wind power time series. Secondly, an improved extreme learning machine prediction model is introduced to overcome the sample data updating disadvantages of standard extreme learning machine. Different improved extreme learning machine prediction model of each component is established. Finally, the prediction value of each component is superimposed to obtain the final result. Compared with other prediction models, the simulation results demonstrate that the proposed prediction method has better prediction accuracy for wind power.

A cavitation performance prediction method for pumps: Part2-sensitivity and accuracy

  • Long, Yun;Zhang, Yan;Chen, Jianping;Zhu, Rongsheng;Wang, Dezhong
    • Nuclear Engineering and Technology
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    • 제53권11호
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    • pp.3612-3624
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    • 2021
  • At present, in the case of pump fast optimization, there is a problem of rapid, accurate and effective prediction of cavitation performance. In "A Cavitation Performance Prediction Method for Pumps PART1-Proposal and Feasibility" [1], a new cavitation performance prediction method is proposed, and the feasibility of this method is demonstrated in combination with experiments of a mixed flow pump. However, whether this method is applicable to vane pumps with different specific speeds and whether the prediction results of this method are accurate is still worthy of further study. Combined with the experimental results, the research evaluates the sensitivity and accuracy at different flow rates. For a certain operating condition, the method has better sensitivity to different flow rates. This is suitable for multi-parameter multi-objective optimization of pump impeller. For the test mixed flow pump, the method is more accurate when the area ratios are 13.718% and 13.826%. The cavitation vortex flow is obtained through high-speed camera, and the correlation between cavitation flow structure and cavitation performance is established to provide more scientific support for cavitation performance prediction. The method is not only suitable for cavitation performance prediction of the mixed flow pump, but also can be expanded to cavitation performance prediction of blade type hydraulic machinery, which will solve the problem of rapid prediction of hydraulic machinery cavitation performance.

A STUDY ON PREDICTION INTERVALS, FACTOR ANALYSIS MODELS AND HIGH-DIMENSIONAL EMPIRICAL LINEAR PREDICTION

  • Jee, Eun-Sook
    • Journal of applied mathematics & informatics
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    • 제14권1_2호
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    • pp.377-386
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    • 2004
  • A technique that provides prediction intervals based on a model called an empirical linear model is discussed. The technique, high-dimensional empirical linear prediction (HELP), involves principal component analysis, factor analysis and model selection. HELP can be viewed as a technique that provides prediction (and confidence) intervals based on a factor analysis models do not typically have justifiable theory due to nonidentifiability, we show that the intervals are justifiable asymptotically.

Dam Sensor Outlier Detection using Mixed Prediction Model and Supervised Learning

  • Park, Chang-Mok
    • International journal of advanced smart convergence
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    • 제7권1호
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    • pp.24-32
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    • 2018
  • An outlier detection method using mixed prediction model has been described in this paper. The mixed prediction model consists of time-series model and regression model. The parameter estimation of the prediction model was performed using supervised learning and a genetic algorithm is adopted for a learning method. The experiments were performed in artificial and real data set. The prediction performance is compared with the existing prediction methods using artificial data. Outlier detection is conducted using the real sensor measurements in a dam. The validity of the proposed method was shown in the experiments.

네이만-피어슨 정리와 베이즈 규칙을 이용한 기업도산의 가능성 예측 (Application of Neyman-Pearson Theorem and Bayes' Rule to Bankruptcy Prediction)

  • 장경;권영식
    • 품질경영학회지
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    • 제22권3호
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    • pp.179-190
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    • 1994
  • Financial variables have been used in bankruptcy prediction. Despite of possible errors in prediction, most existing approaches do not consider the causal time sequence of prediction activity and bankruptcy phenomena. This paper proposes a prediction method using Neyman-Pearson Theorem and Bayes' rule. The proposed method uses posterior probability concept and determines a prediction policy with appropriate error rate.

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H.264 기반 스케일러블 비디오 부호화에서 부호화 효율을 고려한 잔여신호 예측에 관한 연구 (Adaptive Residual Prediction for coding efficiency on H.264 Based Scalable Video Coding)

  • 박성호;오형석;김원하
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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    • pp.189-191
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    • 2005
  • In the scalable extension of H.264/AVC, the codec is based on a layered approach to enable spatial scalability. In each layer, the basic concepts of motion compensated prediction and intra prediction are employed as in standard H.264/AVC. Additionally inter-layer prediction algorithm between successive spatial layers is applied to remove redundancy. In the inter-layer prediction, as the prediction we can use the signal that is the upsampled signal of the lower resolution layer. In this case, coding efficiency can be variable as the kinds of interpolation filter. In this paper, we investigate the approach to select the interpolation filter for residual signal in order to optimal prediction.

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A network traffic prediction model of smart substation based on IGSA-WNN

  • Xia, Xin;Liu, Xiaofeng;Lou, Jichao
    • ETRI Journal
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    • 제42권3호
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    • pp.366-375
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    • 2020
  • The network traffic prediction of a smart substation is key in strengthening its system security protection. To improve the performance of its traffic prediction, in this paper, we propose an improved gravitational search algorithm (IGSA), then introduce the IGSA into a wavelet neural network (WNN), iteratively optimize the initial connection weighting, scalability factor, and shift factor, and establish a smart substation network traffic prediction model based on the IGSA-WNN. A comparative analysis of the experimental results shows that the performance of the IGSA-WNN-based prediction model further improves the convergence velocity and prediction accuracy, and that the proposed model solves the deficiency issues of the original WNN, such as slow convergence velocity and ease of falling into a locally optimal solution; thus, it is a better smart substation network traffic prediction model.

NON-CAUSAL INTERPOLATIVE PREDICTION FOR B PICTURE ENCODING

  • Harabe, Tomoya;Kubota, Akira;Hatori, Yoshinoir
    • 한국방송∙미디어공학회:학술대회논문집
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    • 한국방송공학회 2009년도 IWAIT
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    • pp.723-726
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    • 2009
  • This paper describes a non-causal interpolative prediction method for B-picture encoding. Interpolative prediction uses correlations between neighboring pixels, including non-causal pixels, for high prediction performance, in contrast to the conventional prediction, using only the causal pixels. For the interpolative prediction, the optimal quantizing scheme has been investigated for preventing conding error power from expanding in the decoding process. In this paper, we extend the optimal quantization sceme to inter-frame prediction in video coding. Unlike H.264 scheme, our method uses non-causal frames adjacent to the prediction frame.

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수요예측시스템 상의 다양한 예측방법의 예측력 비교 (The Comparison of Prediction Capability from Various Prediction methods on Demand.)

  • 김도관
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2017년도 춘계학술대회
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    • pp.137-139
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    • 2017
  • 생산 분야에서는 최적의 수요예측을 통해 최적의 생산량을 적용하는 형태로 변모해가고 있다. 본 연구에서는 현재 수요예측 시스템에서 활용되는 다양한 예측방법들의 예측력을 비교하고자 한다. 이를 통해 최적의 예측력을 제공하는 방법론을 탄력적으로 선택하게 하는 방안을 제공하고자 한다.

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Quantum Computing Impact on SCM and Hotel Performance

  • Adhikari, Binaya;Chang, Byeong-Yun
    • International Journal of Internet, Broadcasting and Communication
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    • 제13권2호
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    • pp.1-6
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    • 2021
  • For competitive hotel business, the hotel must have a sound prediction capability to balance the demand and supply of hospitality products. To have a sound prediction capability in the hotel, it should be prepared to be equipped with a new technology such as quantum computing. The quantum computing is a brand new cutting-edge technology. It will change hotel business and even the whole world too. Therefore, we study the impact of quantum computing on supply chain management (SCM) and hotel performance. Toward the goal we have developed the research model including six constructs: quantum (computing) prediction, communication, supplier relationship, service quality, non-financial performance, and financial performance. The result of the study shows a significant influence of quantum (computing) prediction on hotel performance through the mediating role of SCM in the hotel. Quantum prediction is highly significant in enhancing the SCM in the hotel. However, the direct effect between the quantum prediction and hotel performance is not significant. The finding indicates that hotels which would install the quantum computing technology and utilize the quantum prediction could hugely benefit from the performance improvement.