• Title/Summary/Keyword: Model prediction

Search Result 11,461, Processing Time 0.04 seconds

Computation of Reference Crop Evapotranspiration for Irrigation Scheduling (관개계획을 위한 기준작물 증발산량 산정 -고삼 저수지에 대한 사례연구-)

  • 정상옥
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.40 no.1
    • /
    • pp.43-48
    • /
    • 1998
  • In order to provide basic information for the estimation of evapotranspiration for grass (Joycia Japonica), both field lysimeter experiment and model prediction were performed to estimate daily ET Various methods were used to predict daily reference crop ET and crop coefficients. Measured mean daily ET during the 1997 growing season was 4.5mm Model predicted mean daily ET during the 1997 growing season varied from 3.6 to 4.7mm depending on the prediction model Crop coefficients varied from 0.96 to 1.27 depending on the prediction model Comparison of the seven reference crop ET prediction methods used in this study shows that the Penman-Monteith method gave the smallest ET while the Hargreaves method gave the largest ET. The crop coefficient by the corrected Penman method was 1.03, which is closest to 1.0, suggesting that this method may he the best prediction method.

  • PDF

Blind MMSE Equalization of FIR/IIR Channels Using Oversampling and Multichannel Linear Prediction

  • Chen, Fangjiong;Kwong, Sam;Kok, Chi-Wah
    • ETRI Journal
    • /
    • v.31 no.2
    • /
    • pp.162-172
    • /
    • 2009
  • A linear-prediction-based blind equalization algorithm for single-input single-output (SISO) finite impulse response/infinite impulse response (FIR/IIR) channels is proposed. The new algorithm is based on second-order statistics, and it does not require channel order estimation. By oversampling the channel output, the SISO channel model is converted to a special single-input multiple-output (SIMO) model. Two forward linear predictors with consecutive prediction delays are applied to the subchannel outputs of the SIMO model. It is demonstrated that the partial parameters of the SIMO model can be estimated from the difference between the prediction errors when the length of the predictors is sufficiently large. The sufficient filter length for achieving the optimal prediction is also derived. Based on the estimated parameters, both batch and adaptive minimum-mean-square-error equalizers are developed. The performance of the proposed equalizers is evaluated by computer simulations and compared with existing algorithms.

  • PDF

Internet Roundtrip Delay Prediction Using the Maximum Entropy Principle

  • Liu, Peter Xiaoping;Meng, Max Q-H;Gu, Jason
    • Journal of Communications and Networks
    • /
    • v.5 no.1
    • /
    • pp.65-72
    • /
    • 2003
  • Internet roundtrip delay/time (RTT) prediction plays an important role in detecting packet losses in reliable transport protocols for traditional web applications and determining proper transmission rates in many rate-based TCP-friendly protocols for Internet-based real-time applications. The widely adopted autoregressive and moving average (ARMA) model with fixed-parameters is shown to be insufficient for all scenarios due to its intrinsic limitation that it filters out all high-frequency components of RTT dynamics. In this paper, we introduce a novel parameter-varying RTT model for Internet roundtrip time prediction based on the information theory and the maximum entropy principle (MEP). Since the coefficients of the proposed RTT model are updated dynamically, the model is adaptive and it tracks RTT dynamics rapidly. The results of our experiments show that the MEP algorithm works better than the ARMA method in both RTT prediction and RTO estimation.

Defect Severity-based Defect Prediction Model using CL

  • Lee, Na-Young;Kwon, Ki-Tae
    • Journal of the Korea Society of Computer and Information
    • /
    • v.23 no.9
    • /
    • pp.81-86
    • /
    • 2018
  • Software defect severity is very important in projects with limited historical data or new projects. But general software defect prediction is very difficult to collect the label information of the training set and cross-project defect prediction must have a lot of data. In this paper, an unclassified data set with defect severity is clustered according to the distribution ratio. And defect severity-based prediction model is proposed by way of labeling. Proposed model is applied CLAMI in JM1, PC4 with the least ambiguity of defect severity-based NASA dataset. And it is evaluated the value of ACC compared to original data. In this study experiment result, proposed model is improved JM1 0.15 (15%), PC4 0.12(12%) than existing defect severity-based prediction models.

A study of predicting irradiation-induced transition temperature shift for RPV steels with XGBoost modeling

  • Xu, Chaoliang;Liu, Xiangbing;Wang, Hongke;Li, Yuanfei;Jia, Wenqing;Qian, Wangjie;Quan, Qiwei;Zhang, Huajian;Xue, Fei
    • Nuclear Engineering and Technology
    • /
    • v.53 no.8
    • /
    • pp.2610-2615
    • /
    • 2021
  • The prediction of irradiation-induced transition temperature shift for RPV steels is an important method for long term operation of nuclear power plant. Based on the irradiation embrittlement data, an irradiation-induced transition temperature shift prediction model is developed with machine learning method XGBoost. Then the residual, standard deviation and predicted value vs. measured value analysis are conducted to analyze the accuracy of this model. At last, Cu content threshold and saturation values analysis, temperature dependence, Ni/Cu dependence and flux effect are given to verify the reliability. Those results show that the prediction model developed with XGBoost has high accuracy for predicting the irradiation embrittlement trend of RPV steel. The prediction results are consistent with the current understanding of RPV embrittlement mechanism.

A PROFIRABILITY MODEL BASED ON PRIMARY FACTOR ANALYSIS IN THE EARLY PHASE OF HOUSING REDEVELOPMENT PROJECTS

  • Kyeong-Hwan Ahn;U-Yeong Gim;Jong-Sik Lee;Won Kwon;Jae-Youl Chun
    • International conference on construction engineering and project management
    • /
    • 2013.01a
    • /
    • pp.497-501
    • /
    • 2013
  • An important decision-making element for the success of housing redevelopment projects is a prediction of the profitability of redevelopment. Risk factors influencing profitability were deduced through a review of the literature about profitability and a risk analysis developed by a survey of maintenance projects. In addition, a profitability prediction depending on the analysis of risk factors is necessary to judge the business feasibility of a project in the planning stages. A profitability prediction model of management and disposal method, which is calculated by proportional rate and which helps estimate contributions to profitability, is proposed to prevent difficulties in business development. The proposed model has the potential to prevent interruptions, reduce the length of projects, generate cost savings, and enable rational decision-making during the project period by allowing a judgment of profitability at the planning stage.

  • PDF

Traffic Flow Prediction with Spatio-Temporal Information Fusion using Graph Neural Networks

  • Huijuan Ding;Giseop Noh
    • International journal of advanced smart convergence
    • /
    • v.12 no.4
    • /
    • pp.88-97
    • /
    • 2023
  • Traffic flow prediction is of great significance in urban planning and traffic management. As the complexity of urban traffic increases, existing prediction methods still face challenges, especially for the fusion of spatiotemporal information and the capture of long-term dependencies. This study aims to use the fusion model of graph neural network to solve the spatio-temporal information fusion problem in traffic flow prediction. We propose a new deep learning model Spatio-Temporal Information Fusion using Graph Neural Networks (STFGNN). We use GCN module, TCN module and LSTM module alternately to carry out spatiotemporal information fusion. GCN and multi-core TCN capture the temporal and spatial dependencies of traffic flow respectively, and LSTM connects multiple fusion modules to carry out spatiotemporal information fusion. In the experimental evaluation of real traffic flow data, STFGNN showed better performance than other models.

Development and Validation of a Prediction Model: Application to Digestive Cancer Research (예측모형의 구축과 검증: 소화기암연구 사례를 중심으로)

  • Yonghan Kwon;Kyunghwa Han
    • Journal of Digestive Cancer Research
    • /
    • v.11 no.3
    • /
    • pp.157-164
    • /
    • 2023
  • Prediction is a significant topic in clinical research. The development and validation of a prediction model has been increasingly published in clinical research. In this review, we investigated analytical methods and validation schemes for a clinical prediction model used in digestive cancer research. Deep learning and logistic regression, with split-sample validation as an internal or external validation, were the most commonly used methods. Furthermore, we briefly introduced and summarized the advantages and disadvantages of each method. Finally, we discussed several points to consider when conducting prediction model studies.

Developing the Prediction Model for Color Design by the Image Types in the Office Interior (오피스 실내 색채계획을 위한 이미지별 예측모델 작성)

  • 진은미;이진숙
    • Korean Institute of Interior Design Journal
    • /
    • no.32
    • /
    • pp.97-104
    • /
    • 2002
  • The purpose of this study is to suggest the prediction model for the color design by the image types in the office interior. This prediction model of the color design is for the more comfortable environment by using suitable, various colors fitted with business functions. In this research, we carried out the evaluation experiment with the variables such as the color on ceiling, wall, floor and the harmonies of color schemes. We set the prediction index through the multi-regression analysis. And the prediction model was made by these results. The design methods by the prediction model are as follows. 1) The $\ulcorner$variable$\lrcorner$ image was deeply influenced by the value and chroma and it was marked high in low value and high chroma and the harmonies of contrast and different color. 2) The $\ulcorner$comfortable$\lrcorner$ image was related to the value and chroma and it was marked high in high value and low chroma and harmonies of homogeneity and similar. 3) The $\ulcorner$warm$\lrcorner$ image was greatly influenced by the hue and the harmony of color schemes, and it was marked high in the warm colors and harmonies of homogeneity.

Semi-supervised Software Defect Prediction Model Based on Tri-training

  • Meng, Fanqi;Cheng, Wenying;Wang, Jingdong
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.15 no.11
    • /
    • pp.4028-4042
    • /
    • 2021
  • Aiming at the problem of software defect prediction difficulty caused by insufficient software defect marker samples and unbalanced classification, a semi-supervised software defect prediction model based on a tri-training algorithm was proposed by combining feature normalization, over-sampling technology, and a Tri-training algorithm. First, the feature normalization method is used to smooth the feature data to eliminate the influence of too large or too small feature values on the model's classification performance. Secondly, the oversampling method is used to expand and sample the data, which solves the unbalanced classification of labelled samples. Finally, the Tri-training algorithm performs machine learning on the training samples and establishes a defect prediction model. The novelty of this model is that it can effectively combine feature normalization, oversampling techniques, and the Tri-training algorithm to solve both the under-labelled sample and class imbalance problems. Simulation experiments using the NASA software defect prediction dataset show that the proposed method outperforms four existing supervised and semi-supervised learning in terms of Precision, Recall, and F-Measure values.