Title
A framework based on hidden Markov model with adaptive weighting for microcystin forecasting and early-warning.
Abstract
Harmful algal blooms during the eutrophication process produce toxins, such as microcystins (MCs), which endanger the ecosystems and human health. Accurate forecasting and early-warning of MCs can provide theoretical guidance for quick identification of risk in water management systems. The variation of MC concentration is affected by not only the status quo of numerous manifest biotic and abiotic factors, but also a hidden variable that represents the uncertainty of variations of these factors. Traditional approaches focus on fitting data precisely but less consider such a hidden variable, which would experience formidable barriers when encountering fluctuations in time-serial data. In this study, to address the forecasting problem with a hidden state variable and the problem of early-warning-of-risk, we build a novel integrated framework which is consist of three parts: 1) a forecasting model based on a Principal Component Analysis (PCA) and an improved Continuous Hidden Markov Model (CHMM) with adaptive exponential weighting (AEW), where the AEW-CHMM is proposed to forecast both the single-step-ahead concentration for general points and fluctuating points, and the three-step-ahead concentration existing immediately after the fluctuating point; 2) Bayesian hierarchical modeling for a ratio estimation; and 3) revised guidelines for the risk-level grading. The case study tests a real dataset of one shallow lake with the proposed approaches and other supervised machine learning methods. Computational results demonstrate that the proposed approaches are effective to offer an intelligent decision support tool for MC forecasting and early warning of risk by risk-level grading. Improved CHMM with AEW schemes is proposed as an extension of general CHMM.An AEW-CHMM is built to discern similar data patterns to forecast MCs robustly.Bayesian hierarchical model is proposed to transform MC problem into Chl-a forecast.A novel framework is proposed to integrate MC forecast and early-warning of risk.Real case is presented to show the validity of this intelligent decision support tool.
Year
DOI
Venue
2016
10.1016/j.dss.2016.02.003
Decision Support Systems
Keywords
Field
DocType
Decision support systems,Framework,Hidden Markov model,Adaptive exponential weighting,Microcystin forecasting,Early warning of risk
Warning system,Data mining,Weighting,Computer science,Decision support system,Artificial intelligence,State variable,Bayesian hierarchical modeling,Hidden variable theory,Hidden Markov model,Hierarchical database model,Machine learning
Journal
Volume
Issue
ISSN
84
C
0167-9236
Citations 
PageRank 
References 
3
0.48
14
Authors
4
Name
Order
Citations
PageRank
Peng Jiang125942.86
Xiao LIU2598.40
Jingjie Zhang330.81
Xiaoyang Yuan430.48