Author and reference Application field Type of study Study category Study contribution Gong and Zhang [105 ] Fuzzy system Proposed Rough sets Suggested a novel extension of the rough set theory by integrating precision rough set theory variables and intuitionistic fuzzy-rough set theory Huang et al. [106 ] Intuitionistic fuzzy Proposed Rough sets and intuitionistic fuzzy sets Proposed dominance intuitionistic fuzzy decision tables (DIFDT) based on a fuzzy-rough set approach Pawlak [3 ] Type 2 fuzzy Proposed Interval type 2 fuzzy and rough sets Integrated the interval type 2 fuzzy sets with rough set theory by using the axiomatic and constructive approaches Yang and Hinde [107 ] Fuzzy set Proposed Fuzzy set and R -fuzzy sets Suggested a new extension of fuzzy sets which was called Cheng et al. [108 ] Interval-valued fuzzy Developed Interval-valued fuzzy-rough sets Proposed two new algorithms based on converse and positive approximations which were named MRBPA and MRBCA Zhang [109 ] Intuitionistic Proposed Fuzzy-rough sets and intuitionistic fuzzy sets Proposed intuitionistic fuzzy-rough sets based on intuitionistic fuzzy coverings using intuitionistic fuzzy triangular norms and intuitionistic fuzzy implication operators Xue et al. [110 ] Fuzzy-rough C -means clustering Proposed Fuzzy-rough sets Proposed a new fuzzy-rough semisupervised outlier detection (FRSSOD) method for helping some fuzzy-rough C -means clustering and labelled samples Zhang et al. [111 ] Intuitionistic Developed Intuitionistic fuzzy-rough sets Examined the intuitionistic fuzzy-rough sets based on two universes, general binary relations, and an intuitionistic fuzzy implicator I and a pair Wei et al. [112 ] Fuzzy entropy Developed Fuzzy-rough sets Analyzed and evaluated the roughness of a rough set based on fuzzy entropy measures Wang and Hu [40 ] Proposed Fuzzy-rough sets Introduced the generalised Huang et al. [113 ] Intuitionistic fuzzy Developed Fuzzy-rough sets Developed a novel a new multigranulation rough set which was named the intuitionistic fuzzy multi-granulation rough set (IFMGRS) Wang [114 ] Type 2 fuzzy sets Developed Fuzzy-rough sets Examined type 2 fuzzy-rough sets based on extended Yang and Hu [115 ] Fuzzy Developed Fuzzy-rough sets Examined the new fuzzy covering-based rough approach by defining the notion of a fuzzy Lu et al. [116 ] Type 2 fuzzy Developed Fuzzy-rough sets Defined type 2 fuzzy-rough sets based on a wavy-slice representation of type 2 fuzzy sets Chen et al. [117 ] Fuzzy similarity relation Proposed Fuzzy-rough sets Introduced the geometrical interpretation and application of this type of membership functions D'eer et al. [118 ] Fuzzy relations Reviewed Fuzzy-rough sets Assessed the most important fuzzy-rough approaches based on the literature Wang and Hu [38 ] Fuzzy granules Proposed Fuzzy-rough sets Proposed the variable precision Ma [119 ] Fuzzy Developed Fuzzy-rough sets Presented two novel kinds of fuzzy covering rough set approaches for bridges linking covering rough sets and fuzzy-rough theory Wang [29 ] Fuzzy topology Developed Fuzzy-rough sets Investigated the topological characterizations of generalised fuzzy-rough sets regarding basic rough equalities He et al. [120 ] Fuzzy decision system Proposed Fuzzy-rough sets Proposed the inconsistent fuzzy decision system and reductions and improved discernibility matrix-based algorithms to discover reducts Yang et al. [121 ] Bipolar fuzzy sets Developed Fuzzy-rough sets Generalized the fuzzy-rough approach based on two different universes introduced by Sun and Ma Zhang [122 ] Interval type 2 Proposed Fuzzy-rough sets Suggested a new model for interval type 2 rough fuzzy sets by employing constructive and axiomatic methods Bai et al. [123 ] Fuzzy decision rules Proposed Fuzzy-rough sets Proposed an approach based on rough fuzzy sets for the extraction of spatial fuzzy decision rules from spatial data that simultaneously were two kinds of fuzziness, roughness, and uncertainties Zhao and Hu [124 ] Interval-valued fuzzy probabilistic Developed Fuzzy-rough sets Examined the fuzzy and interval-valued fuzzy probabilistic rough sets within frameworks of fuzzy and interval-valued fuzzy probabilistic approximation spaces Huang et al. [125 ] Intuitionistic fuzzy-rough sets Proposed Fuzzy-rough sets Introduced the intuitionistic fuzzy (IF) graded approximation space based on the IF graded neighborhood and discussed information entropy and rough entropy measures Khuman et al. [126 ] Type 2 fuzzy set Developed Fuzzy-rough sets Investigated the type 2 fuzzy sets and rough fuzzy sets to provide a practical means to express complex uncertainty without the associated difficulty of a type 2 fuzzy set Liu and Lin [127 ] Intuitionistic fuzzy-rough Proposed Fuzzy-rough sets Proposed a new intuitionistic fuzzy-rough approach based on the conflict distance Sun et al. [128 ] Interval-valued rough intuitionistic fuzzy Proposed Fuzzy-rough sets Proposed a new framework based on intuitionistic fuzzy-rough sets with the constructive approach Zhang et al. [129 ] Hesitant fuzzy Proposed Fuzzy-rough sets Proposed the common model based on rough set theory and dual hesitant fuzzy sets named dual hesitant fuzzy-rough sets by consideration of constructive and axiomatic models Hu [130 ] Interval-valued fuzzy Developed Fuzzy-rough sets Generalized to an integrative model based on considering interval-valued fuzzy sets and variable precision sets named generalized interval-valued fuzzy variable precision rough sets Zhao and Xiao [131 ] General type 2 fuzzy sets Proposed Fuzzy-rough sets Proposed a novel model by integrating general type 2 fuzzy sets, rough sets, and the α -plane representation method Yang et al. [132 ] Hesitant fuzzy set Proposed Fuzzy-rough sets Investigated a novel fuzzy-rough model based on constructive and axiomatic approaches to introduce the hesitant fuzzy-rough set model Zhang et al. [133 ] Interval-valued hesitant fuzzy set Proposed Fuzzy-rough sets Integrated interval-valued hesitant fuzzy sets with rough sets to introduce a novel model named the interval-valued hesitant fuzzy-rough set Wang and Hu [134 ] Fuzzy-valued operations Developed Fuzzy-rough sets Examined the fuzzy-valued operations and the lattice structures of the algebra of fuzzy values Zhao and Hu [36 ] IVF probability Developed Fuzzy-rough sets Examined the decision-theoretic rough set (DTRS) method based on fuzzy and interval-valued fuzzy (IVF) probabilistic approximation spaces Mitra et al. [135 ] Fuzzy clustering Developed Fuzzy-rough sets Developed shadowed sets by combining fuzzy and rough clustering Chen et al. [136 ] Fuzzy rule interpolation Proposed Fuzzy-rough sets Proposed a new rough fuzzy approach for handling, representation and utilisation of diverse levels of uncertainty in knowledge
