IMPROVED ITERATIVE PREDICTION FOR MULTIPLE STOP ARRIVAL TIME USING A SUPPORT VECTOR MACHINE

Transport ◽  
2012 ◽  
Vol 27 (2) ◽  
pp. 158-164 ◽  
Author(s):  
Chang-Jiang Zheng ◽  
Yi-Hua Zhang ◽  
Xue-Jun Feng
Keyword(s):  
Support Vector Machine ◽  
Prediction Model ◽  
Arrival Time ◽  
Prediction Models ◽  
Prediction Method ◽  
Support Vector ◽  
Dynamic Algorithm ◽  
Proposed Model ◽  
Speed Prediction ◽  
Two Stages

The paper presents an improved iterative prediction method for bus arrival time at multiple downstream stops. A multiple-stop prediction model includes two stages. At the first stage, an iterative prediction model is developed, which includes a single stop prediction model for arrival time at the immediate downstream stop and an average bus speed prediction model on further segments. The two prediction models are constructed with a support vector machine (SVM). At the second stage, a dynamic algorithm based on the Kalman filter is developed to enhance prediction accuracy. The proposed model is assessed with reference to data collected on transit route No 23 in Dalian city, China. The obtained results show that the improved iterative prediction model seems to be a powerful tool for predicting multiple stop arrival time.

An application of backtracking search optimization–based least squares support vector machine for prediction of short-term wind speed

2019 ◽  
Vol 44 (3) ◽  
pp. 266-281 ◽  
Author(s):  
Zhongda Tian ◽  
Yi Ren ◽  
Gang Wang
Keyword(s):  
Support Vector Machine ◽  
Wind Speed ◽  
Prediction Model ◽  
Least Squares ◽  
Support Vector ◽  
Short Term ◽  
Backtracking Search ◽  
Wind Speed Prediction ◽  
Search Optimization ◽  
Speed Prediction

Wind speed prediction is an important technology in the wind power field; however, because of their chaotic nature, predicting wind speed accurately is difficult. Aims at this challenge, a backtracking search optimization–based least squares support vector machine model is proposed for short-term wind speed prediction. In this article, the least squares support vector machine is chosen as the short-term wind speed prediction model and backtracking search optimization algorithm is used to optimize the important parameters which influence the least squares support vector machine regression model. Furthermore, the optimal parameters of the model are obtained, and the short-term wind speed prediction model of least squares support vector machine is established through parameter optimization. For time-varying systems similar to short-term wind speed time series, a model updating method based on prediction error accuracy combined with sliding window strategy is proposed. When the prediction model does not match the actual short-term wind model, least squares support vector machine trains and re-establishes. This model updating method avoids the mismatch problem between prediction model and actual wind speed data. The actual collected short-term wind speed time series is used as the research object. Multi-step prediction simulation of short-term wind speed is carried out. The simulation results show that backtracking search optimization algorithm–based least squares support vector machine model has higher prediction accuracy and reliability for the short-term wind speed. At the same time, the prediction performance indicators are also improved. The prediction result is that root mean square error is 0.1248, mean absolute error is 0.1374, mean absolute percentile error is 0.1589% and R2 is 0.9648. When the short-term wind speed varies from 0 to 4 m/s, the average value of absolute prediction error is 0.1113 m/s, and average value of absolute relative prediction error is 8.7111%. The proposed prediction model in this article has high engineering application value.

scholarly journals Maximum a posteriori Threshold Genomic Prediction Model for Ordinal Traits

2020 ◽  
Vol 10 (11) ◽  
pp. 4083-4102
Author(s):  
Abelardo Montesinos-López ◽  
Humberto Gutierrez-Pulido ◽  
Osval Antonio Montesinos-López ◽  
José Crossa
Keyword(s):  
Support Vector Machine ◽  
Prediction Model ◽  
Ridge Regression ◽  
Genomic Prediction ◽  
Prediction Models ◽  
Prediction Performance ◽  
Support Vector ◽  
Successful Implementation ◽  
A Posteriori ◽  
Ordinal Traits

Due to the ever-increasing data collected in genomic breeding programs, there is a need for genomic prediction models that can deal better with big data. For this reason, here we propose a Maximum a posteriori Threshold Genomic Prediction (MAPT) model for ordinal traits that is more efficient than the conventional Bayesian Threshold Genomic Prediction model for ordinal traits. The MAPT performs the predictions of the Threshold Genomic Prediction model by using the maximum a posteriori estimation of the parameters, that is, the values of the parameters that maximize the joint posterior density. We compared the prediction performance of the proposed MAPT to the conventional Bayesian Threshold Genomic Prediction model, the multinomial Ridge regression and support vector machine on 8 real data sets. We found that the proposed MAPT was competitive with regard to the multinomial and support vector machine models in terms of prediction performance, and slightly better than the conventional Bayesian Threshold Genomic Prediction model. With regard to the implementation time, we found that in general the MAPT and the support vector machine were the best, while the slowest was the multinomial Ridge regression model. However, it is important to point out that the successful implementation of the proposed MAPT model depends on the informative priors used to avoid underestimation of variance components.

scholarly journals An Optimized Method of Wind Speed Prediction with Support Vector Machine and Genetic Algorithm

2021 ◽  
Vol 15 ◽  
pp. 212-217
Author(s):  
Guan-fa Li ◽  
Wen-sheng Zhu
Keyword(s):  
Genetic Algorithm ◽  
Time Series ◽  
Support Vector Machine ◽  
Wind Speed ◽  
Power System ◽  
Prediction Models ◽  
Optimization Method ◽  
Support Vector ◽  
Wind Speed Prediction ◽  
Speed Prediction

Due to the randomness of wind speed and direction, the output power of wind turbine also has randomness. After large-scale wind power integration, it will bring a lot of adverse effects on the power quality of the power system, and also bring difficulties to the formulation of power system dispatching plan. In order to improve the prediction accuracy, an optimized method of wind speed prediction with support vector machine and genetic algorithm is put forward. Compared with other optimization methods, the simulation results show that the optimized genetic algorithm not only has good convergence speed, but also can find more suitable parameters for data samples. When the data is updated according to time series, the optimization range of vaccine and parameters is adaptively adjusted and updated. Therefore, as a new optimization method, the optimization method has certain theoretical significance and practical application value, and can be applied to other time series prediction models.

scholarly journals A Novel Prediction Method of Dynamic Wall Pressure for Silos Based on Support Vector Machine

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Hanhua Yu ◽  
Zhijun Xu ◽  
Tingting Liu ◽  
Fang Yuan
Keyword(s):  
Support Vector Machine ◽  
Prediction Model ◽  
Mechanical Characteristics ◽  
Lateral Pressure ◽  
Prediction Method ◽  
Wall Pressure ◽  
Model Fit ◽  
Support Vector ◽  
Simulation Methods ◽  
Grid Search Method

The physical properties and mechanical characteristics of storage materials are significantly different from those of ordinary solids and liquids. The distribution of dynamic wall pressure during silo discharge is quite complicated. Considering the nonlinear relationship between the factors which affect the dynamic lateral pressure of silos, a prediction method of dynamic wall pressure for silos based on support vector machine (SVM) is proposed here, and furthermore, the modified grid search method (GSM) is incorporated in obtaining the optimal support vector machine parameters to improve the accuracy of the prediction. Comparing the results of the proposed prediction model with the results of experiment methods and simulation methods, it can be found that the SVM prediction model shows high accuracy and high generalization ability, and the prediction results of the model fit well with the results of experiment and simulation methods. The proposed method can provide reference for the prediction of the dynamic wall pressure of silos.

scholarly journals A Prediction Model for Cognitive Impairment Risk in Colorectal Cancer after Chemotherapy Treatment

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Shu-Ping Zhou ◽  
Su-Ding Fei ◽  
Hui-Hui Han ◽  
Jing-Jing Li ◽  
Shuang Yang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Support Vector Machine ◽  
Logistic Regression ◽  
Cognitive Impairment ◽  
Prediction Model ◽  
Clinical Utility ◽  
Prediction Models ◽  
Predictive Ability ◽  
Support Vector ◽  
Colorectal Cancer Patients

Background. A prediction model can be developed to predict the risk of cancer-related cognitive impairment in colorectal cancer patients after chemotherapy. Methods. A regression analysis was performed on 386 colorectal cancer patients who had undergone chemotherapy. Three prediction models (random forest, logistic regression, and support vector machine models) were constructed using collected clinical and pathological data of the patients. Calibration and ROC curves and C -indexes were used to evaluate the selected models. A decision curve analysis (DCA) was used to determine the clinical utility of the line graph. Results. Three prediction models including a random forest, a logistic regression, and a support vector machine were constructed. The logistic regression model had the strongest predictive power with an area under the curve (AUC) of 0.799. Age, BMI, colostomy, complications, CRA, depression, diabetes, QLQ-C30 score, exercise, hypercholesterolemia, diet, marital status, education level, and pathological stage were included in the nomogram. The C -index (0.826) and calibration curve showed that the nomogram had good predictive ability and the DCA curves indicated that the model had strong clinical utility. Conclusions. A prediction model with good predictive ability and practical clinical value can be developed for predicting the risk of cognitive impairment in colorectal cancer after chemotherapy.

Short-Term Wind Speed Prediction on Base of Improved Least Squares Support Vector Machine

2014 ◽  
Vol 599-601 ◽  
pp. 1972-1975
Author(s):  
Zheng Zhao ◽  
Long Xin Zhang ◽  
Hai Tao Liu ◽  
Zi Rui Liu
Keyword(s):  
Support Vector Machine ◽  
Wind Speed ◽  
Prediction Model ◽  
Least Squares ◽  
Wind Farm ◽  
Support Vector ◽  
Short Term ◽  
Wind Speed Prediction ◽  
Neural Network Prediction ◽  
Speed Prediction

Accurate wind speed prediction is of significance to improve the ability to coordinate operation of a wind farm with a power system and ensure the safety of power grid operation. According to the randomness and volatility of wind speed, it is put forward that a WD_GA_LS_SVM short-term wind speed combination prediction model on basis of Wavelet decomposition (WD), Genetic alogorithms (GA) optimization and Least squares support vector machine (LS_SVM). Short-term wind speed prediction is carried out and compared with the neural network prediction model with use of the measured data of a wind farm. The results of error analysis indicate the combination prediction model selected is of higher prediction accuracy.

Traffic Prediction over Wireless Networks

2010 ◽  
pp. 87-112 ◽  
Author(s):  
Huifang Feng ◽  
Maode Ma
Keyword(s):  
Support Vector Machine ◽  
Wireless Networks ◽  
Bandwidth Allocation ◽  
Prediction Models ◽  
Prediction Method ◽  
Traffic Prediction ◽  
Support Vector ◽  
Time Series Models ◽  
Artificial Neural ◽  
Dynamic Bandwidth

The predictability of network traffic is an important and widely studied topic because it can lead to the solutions to get more efficient dynamic bandwidth allocation, admission control, congestion control and better performance of wireless networks. In this chapter, firstly, the authors briefly describe a number of traffic models that include time series models, artificial neural networks models, wavelet-based models, and support vector machine-based models. Secondly, they give the prediction method and metrics of measuring the accuracy of a prediction. Finally, they examine the feasibility of applying support vector machine into the prediction of actual traffic in WLANs and evaluate the performance of different prediction models such as ARIMA, FARIMA, and artificial neural network, wavelet-based and support vector machine-based models for the prediction of the real WLANs traffic.

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