# A Novel Improved Feature Extraction Technique for Ship-Radiated Noise Based on IITD and MDE

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## Abstract

**:**

## 1. Introduction

## 2. Theory of IITD-MDE

#### 2.1. IITD Algorithm

#### 2.1.1. ITD

#### 2.1.2. Comparison of Baseline-Fitting Method

#### 2.1.3. Intrinsic Scale Component (ISC)

#### 2.1.4. IITD

#### 2.2. MDE Algorithm

#### 2.2.1. DE

#### 2.2.2. MDE

#### 2.3. Comparison between ITD, IITD, and EMD

#### 2.4. Comparison between MSE, MPE, and MDE

## 3. The Proposed Feature Extraction Method

- (1)
- Perform IITD on the five types of ship-radiated noise signals of the training data and decompose signals into a series of ISCs and one monotonic trend component.
- (2)
- Calculate the correlation between ISCs and the original signal, then select the ISCs with large correlation coefficients as the feature parameter.
- (3)
- Calculate their MDE value of the chosen ISCs and set scale factor to 20.
- (4)
- Input feature vectors to SVM to establish the classifier.
- (5)
- For the test dataset, extract their features using steps (1–3), then input the features into classifier for classification and get recognition rates.

## 4. Experimental Verification and Analysis

#### 4.1. IITD Decomposition

#### 4.2. ISC Choosen

#### 4.3. Feature Extraction

#### 4.4. Ship Classification

## 5. Conclusions

## Author Contributions

## Funding

## Conflicts of Interest

## References

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**Figure 1.**The comparison of the interpolation methods: (

**a**) linear interpolation, (

**b**) cubic spline interpolation, and (

**c**) akima interpolation.

**Figure 7.**The multi-entropy value of Gaussian white noise and $1/f$ noise: (

**a**) MSE, (

**b**) MPE and (

**c**) MDE.

Ship Signal | Signal-A | Signal-B | Signal-C | Signal-D | Signal-E |

Feature Parameter | ISC2 | ISC4 | ISC2 | ISC4 | ISC3 |

Methods | Accuracy Rate | ||
---|---|---|---|

Accuracy | Mean Squared Error | Squared Correlation Coefficient | |

IITD-MDE | 86% | 0.56 | 0.7356 |

ITD-MDE | 74% | 1.44 | 0.4661 |

MDE | 50% | 2.32 | 0.2680 |

MPE | 40% | 1.84 | 0.2386 |

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**MDPI and ACS Style**

Li, Z.; Li, Y.; Zhang, K.; Guo, J.
A Novel Improved Feature Extraction Technique for Ship-Radiated Noise Based on IITD and MDE. *Entropy* **2019**, *21*, 1215.
https://doi.org/10.3390/e21121215

**AMA Style**

Li Z, Li Y, Zhang K, Guo J.
A Novel Improved Feature Extraction Technique for Ship-Radiated Noise Based on IITD and MDE. *Entropy*. 2019; 21(12):1215.
https://doi.org/10.3390/e21121215

**Chicago/Turabian Style**

Li, Zhaoxi, Yaan Li, Kai Zhang, and Jianli Guo.
2019. "A Novel Improved Feature Extraction Technique for Ship-Radiated Noise Based on IITD and MDE" *Entropy* 21, no. 12: 1215.
https://doi.org/10.3390/e21121215