{"title":"Fuzzy indices of some graphs with applications","authors":"Bilal Ahmad Rather, Hilal Ahmad Ganie, Parvez Ali","doi":"10.1007/s00236-026-00548-9","DOIUrl":null,"url":null,"abstract":"<div><p>We evaluate the closed forms of the fuzzy topological indices for fuzzy graph structures: the friendship graph and the windmill graph. General expressions are derived for the first and second fuzzy Zagreb indices, the fuzzy Randic index, the fuzzy harmonic index, the fuzzy <i>F</i>-index, the fuzzy Misbalance Prodeg index, the fuzzy Sombor index, and the fuzzy Nirmala index. The formulas are established for arbitrary vertex and edge membership values satisfying the Rosenfeld condition, and therefore apply to a broad class of admissible fuzzy graph structures. Suitable choices of membership values yield explicit closed forms for the fuzzy friendship graph <span>\\(F_n\\)</span> and the fuzzy windmill graph <span>\\(W_{k,n}\\)</span>. The analysis also identifies inconsistencies in previously reported formulas, particularly those arising from incorrect fuzzy degrees, unspecified parameters, and edge memberships that do not agree with the stated graph structures [14]. The practical relevance of the proposed indices is demonstrated through an emergency medical referral network modeled by <span>\\(F_3\\)</span> and a renewable-energy microgrid represented by <span>\\(W_{4,2}\\)</span>, where comparisons between normal and stressed operating conditions reveal changes in connectivity, balance, and system reliability.</p></div>","PeriodicalId":7189,"journal":{"name":"Acta Informatica","volume":"63 4","pages":""},"PeriodicalIF":1.2000,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Informatica","FirstCategoryId":"94","ListUrlMain":"https://link.springer.com/article/10.1007/s00236-026-00548-9","RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"COMPUTER SCIENCE, INFORMATION SYSTEMS","Score":null,"Total":0}
引用次数: 0
Abstract
We evaluate the closed forms of the fuzzy topological indices for fuzzy graph structures: the friendship graph and the windmill graph. General expressions are derived for the first and second fuzzy Zagreb indices, the fuzzy Randic index, the fuzzy harmonic index, the fuzzy F-index, the fuzzy Misbalance Prodeg index, the fuzzy Sombor index, and the fuzzy Nirmala index. The formulas are established for arbitrary vertex and edge membership values satisfying the Rosenfeld condition, and therefore apply to a broad class of admissible fuzzy graph structures. Suitable choices of membership values yield explicit closed forms for the fuzzy friendship graph \(F_n\) and the fuzzy windmill graph \(W_{k,n}\). The analysis also identifies inconsistencies in previously reported formulas, particularly those arising from incorrect fuzzy degrees, unspecified parameters, and edge memberships that do not agree with the stated graph structures [14]. The practical relevance of the proposed indices is demonstrated through an emergency medical referral network modeled by \(F_3\) and a renewable-energy microgrid represented by \(W_{4,2}\), where comparisons between normal and stressed operating conditions reveal changes in connectivity, balance, and system reliability.
期刊介绍:
Acta Informatica provides international dissemination of articles on formal methods for the design and analysis of programs, computing systems and information structures, as well as related fields of Theoretical Computer Science such as Automata Theory, Logic in Computer Science, and Algorithmics.
Topics of interest include:
• semantics of programming languages
• models and modeling languages for concurrent, distributed, reactive and mobile systems
• models and modeling languages for timed, hybrid and probabilistic systems
• specification, program analysis and verification
• model checking and theorem proving
• modal, temporal, first- and higher-order logics, and their variants
• constraint logic, SAT/SMT-solving techniques
• theoretical aspects of databases, semi-structured data and finite model theory
• theoretical aspects of artificial intelligence, knowledge representation, description logic
• automata theory, formal languages, term and graph rewriting
• game-based models, synthesis
• type theory, typed calculi
• algebraic, coalgebraic and categorical methods
• formal aspects of performance, dependability and reliability analysis
• foundations of information and network security
• parallel, distributed and randomized algorithms
• design and analysis of algorithms
• foundations of network and communication protocols.