Research Article

[Retracted] A Literature Review Research on Monitoring Conditions of Mechanical Equipment Based on Edge Computing

Table 1

Lossless compression methods.

Compression algorithm modelCompression algorithm typeAlgorithm titleAdvantagesDisadvantages

Single-algorithm compression modelStatistical-based compression algorithmsHuffmanFast calculation speed. The greater the frequency difference, the better the compression effect.The decoding process is slow and easily influenced by file size.
Arithmetic codingGood compression effect.Complex calculation process.
RLEThe algorithm is simple and has a good compression effect when there are more repetitive characters.When there are few repetitive characters, the compression effect is poor or has the opposite effect.
Asymmetric digital systems (ANS) [22]The compression rate is close to arithmetic coding. Compression speed is close to Huffman coding.rANS requires shift decomposition and tANS requires form construction.
Finite state (FSE) [23]ANS-based algorithm with high compression performanceNeed to build a table of finite state entropy
Dictionary-based compression algorithmLZ77 [24], LZSS [25], and LZO [26]High compression efficiency and very fast decompression speed of LZOPoor compression when repeated characters are far apart
LZ78 [27]No need for a search buffer and memoryNeed to create dictionaries and manage them. Complex to compile
LZW [8]A simple method with a good compression effect and the second field of LZ78 encoding removedThe dictionary update process causes a reduction in compression ratio (CR)
Hybrid algorithm compression modelImproved compression-based algorithmMTF + single algorithm [28]Ability to improve the alignment of its data, output its index of alignment, and create a high CRGood for finite data only, not easy to handle when contains more data
BWT + single algorithm [29]BWT makes full use of its sequential arrangement and has a better compression effectThe algorithm process includes sorting, which takes up some memory and increases the time used for compression
XOR incremental encoding + single algorithm [30]Incremental encoding reduces the range of variation in the original data and reduces the number of binary bits representedWhen the adjacent data vary very much, its compression becomes worse
Hybrid compression of different single algorithmsRLE + Huffman [31]With both data effects, it can get a higher CR and faster compression speedHowever, it is limited by two compression methods on the dataset
RLE + LZW [32]Better data compression. No duplicate characters are encoded in the dictionaryIncreased risk of error codes when coding