scholarly journals Optimising the modelling of eutrophication for Bohai Bay based on the cellular automata – support vector machine method

2014 ◽  
Vol 16 (5) ◽  
pp. 1125-1141
Author(s):  
Zheng Dongsheng ◽  
Xiang Xianquan ◽  
Tao Jianhua

With the development of marine economy, eutrophication has become one of the key issues in the marine environment. In this paper, a eutrophication model for Bohai Bay based on the cellular automata-support vector machine (CA-SVM) has been established by applying the soft computing approach with a large quantity of remote sensing data to the marine environment. In order to optimise the coupled model further, two main tasks have been done in this study. First, to choose reasonable influence factors as the input parameters of the model, nine series of training and simulation exercises were conducted based on nine different types of input parameter combinations. A reasonable input parameter combination was selected, and the eutrophication model (the basic model) was established by the comparative analysis of the simulation results. Second, according to Shelford's Law of Tolerance, an optimised model was developed. It is combined of nine special models and each model corresponds to a stage of sea surface temperature and the chlorophyll-a concentration, respectively. The comparison between the optimised model and the basic model indicated that prediction accuracy was improved by the optimised model. By this study, it can be observed this model could provide a scientific basis for the prediction and management of the aquatic environment of Bohai Bay.

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668596 ◽  
Author(s):  
Fuqiang Sun ◽  
Xiaoyang Li ◽  
Haitao Liao ◽  
Xiankun Zhang

Rapid and accurate lifetime prediction of critical components in a system is important to maintaining the system’s reliable operation. To this end, many lifetime prediction methods have been developed to handle various failure-related data collected in different situations. Among these methods, machine learning and Bayesian updating are the most popular ones. In this article, a Bayesian least-squares support vector machine method that combines least-squares support vector machine with Bayesian inference is developed for predicting the remaining useful life of a microwave component. A degradation model describing the change in the component’s power gain over time is developed, and the point and interval remaining useful life estimates are obtained considering a predefined failure threshold. In our case study, the radial basis function neural network approach is also implemented for comparison purposes. The results indicate that the Bayesian least-squares support vector machine method is more precise and stable in predicting the remaining useful life of this type of components.


2018 ◽  
Vol 184 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Gal Amit ◽  
Hanan Datz

Abstract We present here for the first time a fast and reliable automatic algorithm based on artificial neural networks for the anomaly detection of a thermoluminescence dosemeter (TLD) glow curves (GCs), and compare its performance with formerly developed support vector machine method. The GC shape of TLD depends on numerous physical parameters, which may significantly affect it. When integrated into a dosimetry laboratory, this automatic algorithm can classify ‘anomalous’ (having any kind of anomaly) GCs for manual review, and ‘regular’ (acceptable) GCs for automatic analysis. The new algorithm performance is then compared with two kinds of formerly developed support vector machine classifiers—regular and weighted ones—using three different metrics. Results show an impressive accuracy rate of 97% for TLD GCs that are correctly classified to either of the classes.


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