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Big Data Mining and Analytics  2018, Vol. 01 Issue (03): 191-210    DOI: 10.26599/BDMA.2018.9020018
Survey on Encoding Schemes for Genomic Data Representation and Feature Learning—From Signal Processing to Machine Learning
Ning Yu, Zhihua Li, Zeng Yu*
Ning Yu is with the Department of Computing Sciences, College at Brockport, State University of New York, Brockport, NY 14422, USA. E-mail:
Zhihua Li is with the Department of Computer Science and Technology at Jiangnan University, Wuxi 214122, China. E-mail:
Zeng Yu is with the School of Information Science and Technology, Southwest Jiaotong University, Chengdu 611756, China.
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Data-driven machine learning, especially deep learning technology, is becoming an important tool for handling big data issues in bioinformatics. In machine learning, DNA sequences are often converted to numerical values for data representation and feature learning in various applications. Similar conversion occurs in Genomic Signal Processing (GSP), where genome sequences are transformed into numerical sequences for signal extraction and recognition. This kind of conversion is also called encoding scheme. The diverse encoding schemes can greatly affect the performance of GSP applications and machine learning models. This paper aims to collect, analyze, discuss, and summarize the existing encoding schemes of genome sequence particularly in GSP as well as other genome analysis applications to provide a comprehensive reference for the genomic data representation and feature learning in machine learning.

Key wordsencoding scheme      data representation      feature learning      deep learning      genomic signal processing      machine learning      genome analysis     
Received: 21 January 2018      Published: 13 January 2020
Corresponding Authors: Zeng Yu   
Cite this article:

Ning Yu, Zhihua Li, Zeng Yu. Survey on Encoding Schemes for Genomic Data Representation and Feature Learning—From Signal Processing to Machine Learning. Big Data Mining and Analytics, 2018, 01(03): 191-210.

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Fig. 1 Summary of encoding schemes.
29] (1 cal=4.18 J).">
Fig. 2 Enthalpy values of thermodynamic interactions between two molecules. The unit of measurement is kcal/mol<sup>[<xref ref-type="bibr" rid="R29">29</xref>]</sup> (1 cal=4.18 J).
Fig. 3 Difference of transition and transversion between molecules measured by Hamming distance and Euclidean distance<sup>[<xref ref-type="bibr" rid="R29">29</xref>]</sup>.
Fig. 4 Dinucleotides placed in a unit circle.
Fig. 5 Six hexagons.
Fig. 6 Constellation for real number and complex number representations.
CategoryEncoded initial position
CGR-RYA(0, 0), T(1, 0), C(0, 1), G(1, 1)
CGR-MKA(0, 0), T(1, 0), G(0, 1), C(1, 1)
CGR-WSA(0, 0), G(1, 0), C(0, 1), T(1, 1)
Table 1 Encoded initial positions of CGR-walk.
Fig. 7 3-dimensional tetrahedron in a cube.
Fig. 8 Tetrahedron encoding scheme for codons.
Fig. 9 Encoding methods based on (a) a regular tetrahedron and (b) an irregular tetrahedron.
Fig. 10 Tetrahedron-based coordinate system in Z-curve.
Fig. 11 Flow chart on the position of encoding scheme in feature learning.
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