[purposes] The recommendation effect of the user-based collaborative filtering algorithm is improved by extracting the effective dense sub-sequence between the user and the project and generating the data information of the project that the user participates in with high probability, The problem of data sparsity is alleviated to some extent, and the validity of binary data method in expressing user interest is verified. [methods]There are two steps to extract the effective dense subsequences from the user rate sequence, Firstly, the effective dense subsequence is extracted based on the time range; secondly, the subsequence is extracted twice by judging the items in the subsequence with high probability that do not conform to the user's interest. Generating data for projects with high probability of user participation requires the use of project attributes of user participation projects. The validity of the binary data method is mainly verified by the comparison experiment with the scoring data and the final result of the recommendation algorithm. [results] The experimental results show that RMSE (root mean square error) is reduced by more than 0.04 on the ml-latest-small data set compared with the classical traditional collaborative filtering algorithm. When F value (the harmonic mean of accuracy and recall rate) is taken as the evaluation standard, the algorithm proposed in this paper is more accurate than other classical algorithms, and the recommendation accuracy has been significantly improved. [conclusions] The method of extracting the effective dense subsequence between the user and the project is better than the traditional collaborative filtering method in terms of recommendation effect, and using binary data in the algorithm to replace the original rate data can bring better recommendation effect.

Li Zhitao, Zhou Xiaokang. A Recommendation Algorithm Based on Efficient Dense Subsequence and Data Generation. Academic Journal of Computing & Information Science (2021), Vol. 4, Issue 1: 94-104. https://doi.org/10.25236/AJCIS.2021.040115.

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