Afrika MatematikaPub Date : 2025-06-06DOI: 10.1007/s13370-025-01334-5
Masoud Yousefi, Khosrow Rahmani, Masoud Rajabi, Ali Reyhani, Nayereh Asgari
{"title":"The ensemble learning algorithms for prediction high entropy alloys phases","authors":"Masoud Yousefi, Khosrow Rahmani, Masoud Rajabi, Ali Reyhani, Nayereh Asgari","doi":"10.1007/s13370-025-01334-5","DOIUrl":"10.1007/s13370-025-01334-5","url":null,"abstract":"<div><p>The ensemble learning algorithm is a statistical method that is unknown in HEA(s)'s prediction phase. The ensemble learning algorithm is used to check on the phase selection principles, utilizing a large experimental case study on 401 distinct HEAs, comprising 174 SS, 54 IM, and 173 SS + IM phases. Random forest(RF) has the highest accuracy compared with other ensemble \u0000learning algorithms i.e. its certainty is about 10% higher than support-vector machines(SVM) and K-nearest neighbors(KNN) for allocating HEA(s). The validity and reliability of the proposed algorithms are announced as results of the paper. Therewith, findings show two main advantages to allocating HEAs: First deduction of decision trees and improving the carefulness, and second automating missing values. In addition, to check the practical accuracy of the machine learning results, the XRD results of the TiZrNbCrV, TiZrNbFeCr, and Ti ZrNbFeV \u0000alloys are presented. All alloys are in solid solution statues without any intermetallic phases. The practical results show the ensemble learning algorithms have suitable consistency in real conditions and can be a great help to design new high entropy alloys.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 3","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145162388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Afrika MatematikaPub Date : 2025-06-04DOI: 10.1007/s13370-025-01333-6
Khalid Ul Islam Rather
{"title":"A simulation study on strategic strata boundary determination using ranked set sampling technique","authors":"Khalid Ul Islam Rather","doi":"10.1007/s13370-025-01333-6","DOIUrl":"10.1007/s13370-025-01333-6","url":null,"abstract":"<div><p>Convenient stratification criteria like nominal variables, encompassing natural conditions such as age, gender, etc., or geographical regions, don’t contribute significantly to enhancing the efficiency of estimates for the variables of interest. Therefore, it becomes imperative to devise an effective stratification framework that divides the entire population among heterogeneous strata, each homogeneous within itself, thereby achieving heightened accuracy in estimation. This study addresses the optimization of stratification methods using an auxiliary variable (X) within the context of the Neyman allocation under ranked set sampling. Specifically, the research focuses on scenarios where the regression function of the estimation variable (Y) on the X, when the variance <span>(Vleft( {y|x} right))</span>, is known. A <span>({text{cum}}sqrt[3]{{K_{2} (x)}})</span> is proposed for approximating optimal strata boundaries. Furthermore, an empirical investigation is conducted and presented to illustrate the relative efficiency of the proposed methodology.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 3","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145161676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Afrika MatematikaPub Date : 2025-06-04DOI: 10.1007/s13370-025-01329-2
A. Bekker, A. F. Otto, A. Punzo, S. D. Tomarchio, J. T. Ferreira
{"title":"Discrete mode-mixtures of unimodal positive distributions with an application to solar energy in South Africa","authors":"A. Bekker, A. F. Otto, A. Punzo, S. D. Tomarchio, J. T. Ferreira","doi":"10.1007/s13370-025-01329-2","DOIUrl":"10.1007/s13370-025-01329-2","url":null,"abstract":"<div><p>Comprehensive earth science studies consistently yield complex datasets seldom adequately represented by straightforward parametric distributions. In this paper, we introduce a discrete mode-mixture (DMM) model, motivated by the formulation of the mean mixture paradigm via the compounding method. Here, unimodal positive support mode-parameterized beta and gamma distributions represent the basic component, but with the superposition of a discrete random component on the mode. The probability density functions of the DMM models are derived in closed-form expressions, and specific characteristics are investigated. This alternative viewing of a mixture on the mode paves the way for alternative models and provides natural leverage on separation in data. With an emphasis on a solar dataset and a benchmark dataset, the performance of the proposed models is compared with that of well-known models.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 3","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-025-01329-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145161677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Afrika MatematikaPub Date : 2025-06-04DOI: 10.1007/s13370-025-01336-3
P. N. Agrawal, Arun Kajla, Dharmendra Kumar
{"title":"Approximation by Gupta–Păltănea operators","authors":"P. N. Agrawal, Arun Kajla, Dharmendra Kumar","doi":"10.1007/s13370-025-01336-3","DOIUrl":"10.1007/s13370-025-01336-3","url":null,"abstract":"<div><p>We investigate the approximation degree of a general class of positive linear operators introduced by Gupta (RACSAM 113:3717–3725, 2019) by means of the modulus of continuity, Steklov mean and Voronovskaya type theorem. Some approximation results concerning the weighted approximation are also discussed. Lastly, the approximation of functions with derivatives of bounded variation is considered.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 3","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145162211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Afrika MatematikaPub Date : 2025-06-02DOI: 10.1007/s13370-025-01332-7
Nihal Taş, Nihal Özgür
{"title":"New multivalued contractions and the fixed-circle problem","authors":"Nihal Taş, Nihal Özgür","doi":"10.1007/s13370-025-01332-7","DOIUrl":"10.1007/s13370-025-01332-7","url":null,"abstract":"<div><p>A recent problem, the fixed-circle problem, deals with the geometric properties of the fixed points of a self-mapping (on metric or generalized metric spaces). In this paper, we consider this problem for the multivalued case. We obtain new fixed-circle results on metric spaces by means of the multivalued mappings. We introduce new multivalued contractions using Wardowski’s technique and obtain new fixed-circle results with some applications to integral type contractions. We provide necessary illustrative examples in order to support the validity of our obtained results.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 3","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145161007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Afrika MatematikaPub Date : 2025-05-30DOI: 10.1007/s13370-025-01328-3
Vakeel A. Khan, Mohd Kamran, Mohammad Arshad, Ayhan Esi
{"title":"A new type of (mathfrak {g})-neutrosophic metric spaces with order n","authors":"Vakeel A. Khan, Mohd Kamran, Mohammad Arshad, Ayhan Esi","doi":"10.1007/s13370-025-01328-3","DOIUrl":"10.1007/s13370-025-01328-3","url":null,"abstract":"<div><p>In this paper, we define the concept of the <span>(mathfrak {g})</span>-neutrosophic metric spaces of order n as a generalization of neutrosophic metric space. We described some properties of this novel space and construct examples based on it, then we propose the concept of statistical convergence. Also, we define the statistical convergence and statistical Cauchy sequences in <span>(mathfrak {g})</span>-neutrosophic metric spaces. Lastly, we offer an example to demonstrate our theorem.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 3","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Afrika MatematikaPub Date : 2025-05-30DOI: 10.1007/s13370-025-01335-4
Pujashree Buragohain, Nipen Saikia
{"title":"Some new congruences for t-colored overpartition function","authors":"Pujashree Buragohain, Nipen Saikia","doi":"10.1007/s13370-025-01335-4","DOIUrl":"10.1007/s13370-025-01335-4","url":null,"abstract":"<div><p>For any positive integers <i>t</i> and <i>n</i>, let <span>({overline{D}}_t(n))</span> denote the number of <i>t</i>-colored overpartitions of <i>n</i>, where each part in the partition has <i>t</i> distinct colors. In recent years, several authors established many infinite families of congruences for <span>({overline{D}}_t(n))</span> by considering different values of <i>t</i>. In this paper, we prove some infinite and particular congruences for the <i>t</i>-colored overpartition function <span>({overline{D}}_t(n))</span> for <span>(t = 2; 8m + 2; 8m + 5; 8m + 6; 16m + 2; 16m + 4,,textrm{and},,32m + 4)</span>, where <i>m</i> is any non-negative integer.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 3","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Afrika MatematikaPub Date : 2025-05-30DOI: 10.1007/s13370-025-01327-4
Gang Lyu, Yang Liu, Yuanfeng Jin, Choonkil Park
{"title":"The fixed point method and application of functional equations in fuzzy Banach space","authors":"Gang Lyu, Yang Liu, Yuanfeng Jin, Choonkil Park","doi":"10.1007/s13370-025-01327-4","DOIUrl":"10.1007/s13370-025-01327-4","url":null,"abstract":"<div><p>The aim of this manuscript is to initiate the study of the Banach contraction in fuzzy Banach spaces and apply this theorem to solve the stability of functional equation. A nontrivial example is imparted to illustrate the stability of the proposed methods.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 3","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Afrika MatematikaPub Date : 2025-05-28DOI: 10.1007/s13370-025-01320-x
Anita Tomar, U. S. Rana, Vipul Kumar
{"title":"Fixed points of (omega )-interpolative Hardy–Rogers contraction and its application in b-metric spaces","authors":"Anita Tomar, U. S. Rana, Vipul Kumar","doi":"10.1007/s13370-025-01320-x","DOIUrl":"10.1007/s13370-025-01320-x","url":null,"abstract":"<div><p>Experimental signals, besides numerous real-world problems, need a sensation of smoothness in their traces. So, non-differentiable interpolates in a dense set of points are required to model these signals. Also, fractal interpolation, based on the technique of the iterated function system, is utilized to find solutions to such problems. Motivated by the fact that numerous real-world problems may be restated via fixed point theory, the objective of this work is to bring in and utilize <span>(omega )</span>-interpolative Hardy–Rogers contraction in metric as well as b-metric spaces to establish the non-unique fixed points. We furnish illustrative examples to validate our conclusions and demonstrate the significant fact that the notion of <span>(omega )</span>-admissibility refines the notion of continuity and an <span>(omega )</span>-admissible mapping is <span>(omega )</span>-regular. We conclude the work by solving the system of linear equations.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Afrika MatematikaPub Date : 2025-05-28DOI: 10.1007/s13370-025-01330-9
Gulfam Shahzadi, Musavarah Sarwar, Aqsa Riasat
{"title":"Hybrid decision making model for COVID-19 effects: A (p, q)-rung orthopair fuzzy integrated CRITIC-DEMATEL-MABAC approach","authors":"Gulfam Shahzadi, Musavarah Sarwar, Aqsa Riasat","doi":"10.1007/s13370-025-01330-9","DOIUrl":"10.1007/s13370-025-01330-9","url":null,"abstract":"<div><p>Practical group decision-making (DM) problems commonly entail difficult scenarios when attempting to assign suitable values to the facts because of the situation’s uncertainty and unpredictability. The more general structure of (<i>p</i>, <i>q</i>)-rung orthopair fuzzy sets addresses the imprecision and ambiguity that arise in decision-making challenges. This work integrates the criteria importance through intercriteria correlation (CRITIC), the decision-making trial and evaluation laboratory (DEMATEL) approaches, and the multi-attributive border approximation area comparison (MABAC) method separately. The MABAC technique determines the distance of each decision from the boundary approximation area, making it a very reliable and useful tool for real-world problem resolution. The DEMATEL methodology is recognized as the most efficient means of determining the interactions between many criteria or components, while the CRITIC technique takes into account the correlations between attributes when determining the criteria weights. We have decided to develop the CRITIC-MABAC and DEMATEL-MABAC algorithms for (<i>p</i>, <i>q</i>)-rung orthopair fuzzy sets in light of these factors. To illustrate the application of the proposed method, a numerical example is given for determining the effect of “coronavirus disease\" (COVID-19) on daily life. The effectiveness of the proposed approach is evaluated by comparing it with existing methodologies.</p></div>","PeriodicalId":46107,"journal":{"name":"Afrika Matematika","volume":"36 2","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s13370-025-01330-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145171241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}