Elsevier

Applied Mathematical Modelling

Volume 97, September 2021, Pages 588-601
Applied Mathematical Modelling

Multi-parameter grey prediction model based on the derivation method

https://doi.org/10.1016/j.apm.2021.04.016Get rights and content

Highlights

  • Based on the derivation method, a new derived grey multi-parameter prediction model (DMGM (1, n)) is proposed.

  • The mathematical analysis is used to discuss the main reason why DMGM (1, n) is superior to GMC (1, n).

  • DMGM (1, n) outperforms the other grey multivariable models by comparing the results of these models in three cases.

Abstract

In this study, in order to reduce the morbidity and improve the structural stability of the existing grey multivariable convolution forecasting model, a new derived multivariable grey model based on the derivation method, abbreviated as DMGM (1, n), is presented. Firstly, the time response formula of DMGM (1, n) is deduced by derivation method, which can avoid solving the inverse matrix so as to reduce the morbidity of the model. Secondly, the parameter identification of the model is given based on the least-squares method. Then, it is proved theoretically that DMGM (1, n) is superior to GMC (1, n) because the solution of the former overcomes the shortcoming of the latter that the original model does not take full advantage of all the information from the raw data for modeling. Finally, three real cases with different variables were performed. The fitting and prediction results indicate that DMGM (1, n) is better than GMC (1, n) and the other multivariate grey prediction models in these cases, which also demonstrates that this novel model outperforms the other grey models in this paper.

Introduction

In system research, people often get information with some uncertainty due to knowledge limitations and internal external perturbations [1]. An important part of uncertain information theory, namely the grey system, was established by Deng Julong in the 1980s [2]. Over decades of development, grey prediction model, which is a critically important part of grey system [3], has a range of applications covering energy forecasting [4], [5], [6], traffic flow prediction [7], [8], [9], [10], tourism [11], economy [12], [13], [14], and other fields [15], [16], [17], [18]. The commonly used univariate grey model GM (1, 1) [19] is a cornerstone of the grey forecasting model. However, the complicated and changeable nature of real systems cannot be reflected by this univariate model [20].

Thus, professor Deng [21] presented a multi-parameter grey forecasting model termed GM (1, N), which took into account one main feature factor (output) and N-1 action factors (input) in modeling. Although this multi-parameter model is mainly used for state analysis and decision making, it cannot be used as a prediction tool [2]. Therefore, to address this issue, a novel grey multi-parameter convolution forecasting model was proposed by Tien [22].

However, with the appearance of GMC (1, n), many researchers recently found that this model still performed with inaccuracy in some applications. Then several accurate forms of GMC (1, n) models have been presented. The process of development for GMC (1, n) is summarized in Table 1.

As Table 1 indicates, the optimisation methods for GMC (1, n) can be mainly divided into two categories, parameter optimization and the structure optimization. Parameter optimization includes background values and coefficient optimisation. Structure optimization is mainly for the stability of the system. Although these optimization methods have made numerous contributions to improve GMC (1, n) from every side, the morbidity problem of this model cannot be ignored. In grey modeling theory, solving the inverse matrix in the process of solving the time response equation is one of the causes of morbidity. The goal of this study is to establish a new grey multivariable prediction model to reduce the morbidity and improve the structural stability of GMC (1, n).

Thus, a novel multivariable grey prediction model is developed in this paper. The main contributions of this article are shown below:

  • (1)

    A new derived grey multi-parameter prediction model (DMGM (1, n)) based on the derivation method is proposed. The solution of this model is deduced by this method so as to reduce the morbidity of the model.

  • (2)

    Mathematical analysis is used to discuss the main reason why DMGM (1, n) is superior to GMC (1, n), that is, the time response equation of DMGM (1, n),i=1t1X1(0)(i), takes full advantage of all the information from the raw data for modeling.

  • (3)

    The DMGM (1, n) model outperforms the other multivariable models by comparing the fitting and forecasting effectiveness of these models in three real cases of different variables.

The remainder of this article is organized as follows. A brief introduction about the principle of GMC (1, n) in Section 2. A new grey derived multivariable model DMGM (1, n) is established In Section 3, and the solution and the parameter identification of this model are also given. In Section 4, the difference and relationship between DMGM (1, n) and GMC (1, n) are discussed. Three cases of different variables are adopted to compare the effectiveness of DMGM (1, n) with the other multivariable grey models in Section 5. The conclusions are presented in the last section.

Section snippets

The traditional GMC (1, n) model

In this section, we will give a brief introduction about the grey multivariable convolution model (GMC (1, n)) [22], which is based on the traditional GM (1, n) model by adding a control parameter u. The definition is as follows.

Definition 1

[22]. Assumed that X(0)=(X1(0),X2(0),,Xn(0)) are raw sequences, where (X2(0),X3(0),,Xn(0))are n − 1 input variables, and X1(0) is one output variable. Xi(1)(t)=i=1tXi(0)(t) and X1(1)(rp+t)=k=rp+1rp+tX1(0)(k)(t=1,2,,r+rf) are one order accumulative generation

The DMGM (1, n) model and its properties

In this section, based on GMC (1, n), we will establish the DMGM (1, n) model, which is a derived multivariable grey model. The modeling mechanism, relevant definitions and properties of the model are discussed. In consideration of the stability of the system, the time response equation of the DMGM (1, n) model is calculated by using the derivation method in the following. The modeling steps and algorithm are also indicated in the last of this section.

The difference and relationship between DMGM(1, n) and GMC(1, n)

In this section, we will theoretically prove the reason why DMGM (1, n) superior to GMC (1, n).

Case study

Three multivariable cases are presented to evaluate the effectiveness of DMGM (1, n) in this section. This new model is then compared with the other multivariable grey models. The data, analysis and additional details of the comparison results are discussed as follows.

Conclusions

This paper developed a novel multivariable grey forecasting model based on the derivation method (DMGM (1, n)). The following conclusions were obtained:

  • (1)

    The solution of the proposed DMGM (1, n) adopted the derivation method in calculating the time response formula so as to reduce the morbidity of the model. In grey modeling theory, one of the causes of morbidity is solving the inverse matrix. The parameter estimation of DMGM (1, n) is also discussed.

  • (2)

    From the stability structure of the model,

Acknowledgments

The authors give sincerest thanks to the editors and the anonymous reviewers for their helpful comments and suggestions. Thanks Prof. Xiao Xinping a lot for much advice and help during the revision of the manuscript. This research is supported by the National Natural Science Foundation of China (71871174).

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