MCoR-Miner: Maximal Co-Occurrence Nonoverlapping Sequential Rule Mining

Abstract

The aim of sequential pattern mining (SPM) is to discover potentially useful information from a given sequence. Although various SPM methods have been investigated, most of these focus on mining all of the patterns. However, users sometimes want to mine patterns with the same specific prefix pattern, called co-occurrence pattern. Since sequential rule mining can make better use of the results of SPM, and obtain better recommendation performance, this paper addresses the issue of maximal co-occurrence nonoverlapping sequential rule (MCoR) mining and proposes the MCoR-Miner algorithm. To improve the efficiency of support calculation, MCoR-Miner employs depth-first search and backtracking strategies equipped with an indexing mechanism to avoid the use of sequential searching. To obviate useless support calculations for some sequences, MCoR-Miner adopts a filtering strategy to prune the sequences without the prefix pattern. To reduce the number of candidate patterns, MCoR-Miner applies the frequent item and binomial enumeration tree strategies. To avoid searching for the maximal rules through brute force, MCoR-Miner uses a screening strategy. To validate the performance of MCoR-Miner, eleven competitive algorithms were conducted on eight sequences. Our experimental results showed that MCoR-Miner outperformed other competitive algorithms, and yielded better recommendation performance than frequent co-occurrence pattern mining. All algorithms and datasets can be downloaded from https://github.com/wuc567/Pattern-Mining/tree/master/MCoR-Miner.

An overview of metals extraction and recovery from industrial wastewater sludge

“…[ 20 ] However, there may be some challenges during the hydrometallurgical process, such as low recovery of extracted metals, difficulties with solid–liquid separation, and the negative impact of contaminants on the purification process. [ 21,22 ] Given that hydrometallurgical operations are frequently conducted at lower temperatures than pyrometallurgical operations, the main drawback of these operations is likely the long time requirement to achieve high metal recovery. Given the emergent need for eco‐friendly methods, microwave‐assisted leaching has been studied to increase the yield of recovered metal and shorten process times.…”