Makale Koleksiyonu
Bu koleksiyon için kalıcı URI
Güncel Gönderiler
Öğe Quantitative type theorems in the space of locally integrable functions(Springer, 2022) Aral, Ali; Özsaraç, Fırat; Yilmaz, BasarIn this work, we introduce a new modulus of continuity for locally integrable function spaces which is influenced by the natural structure of the L-p space. After basic properties of it are given, we obtain a quantitative type theorem for the rate of convergence of convolution type integral operators and iterates of them. Their global smoothness preservation property involving the new modulus of continuity is presented. Finally, the obtained results are applied to Gauss-Weierstrass operators.Öğe Quaternionic bertrand curves in euclidean 4-space(Int Center Scientific Research & Studies, 2013) Kecilioğlu, Osman; İlarslan, KazımIn this paper, by using the similar idea of Matsuda and Yorozu [12], we prove that if bitorsion of a quatenionic curve alpha is no vanish, then there is no quaternionic curve in E-4 is a Bertrand curve. Then we define (1, 3) type Bertrand curves for quatenionic curve in Euclidean 4-space. We give some characterizations for a (1, 3) type quaternionic Bertrand curves in Euclidean 4-space by means of the curvature functions of the curve.Öğe Presic-type fixed point results via Q-distance on quasimetric space and application to (p, q)-difference equations(Vilnius Univ, Inst Mathematics & Informatics, 2023) Altun, İshak; Gençtürk, İlker; Erduran, AliIn this paper, we introduce two new properties to the Q-function, called as the 0-property and the small self-distance property, which is frequently used in studies of fixed point theory in quasimetric spaces. Then, with the help of Q-functions having these properties, we present some fixed point theorems for Presic-type mappings in quasimetric spaces. Finally, we state a theorem for the existence and uniqueness of the solution to a boundary value problem for (p, q)-difference equations to demonstrate the applicability of our theoretical results, which we support with an example.Öğe Best proximity and best periodic points for proximal nonunique contractions(Springer Basel Ag, 2021) Şahin, Hakan; Aslantaş, Mustafa; Altun, İshakTaking into account nonunique fixed point and periodic point results of Ciric (Institut Mathematique 17, 52-58, 1974) and best proximity point results in the literature, we introduce the concept of proximal nonunique contraction for nonself mappings. Then, we obtain some nonunique best proximity point theorems. Further, we describe the concept of best periodic point of nonself mappings and we present some nonunique best periodic point results. We also provide many examples to show that our new concepts are meaningful and to support our theorems. Additionally, we present a new notion for the nonself mapping H called property P-b, and then we provide some results including sufficient conditions to guarantee that H has the property P-b.Öğe Approximation by Some Baskakov-Kantorovich Exponential-Type Operators(Springer Singapore Pte Ltd, 2022) Özsaraç, Fırat; Gupta, Vijay; Aral, AliIn the present paper, we propose the modification of the Baskakov-Kantorovich operators based on mu-integral. Such operators are connected with exponential functions. We estimate moments and establish some direct results in terms of modulus of continuity.Öğe Approximation of operators related to squared Sza acute accent sz-Mirakjan basis functions(Univ Nis, Fac Sci Math, 2023) Rahman, Shagufta; Aral, Ali; Mursaleen, M.The main objective of this paper is to define a sequence of positive linear operators by means of the squared Szasz-Mirakjan basis functions. We estimate the rate of convergence in terms of the modulus of continuity and the class of Lipschitz functions. Furthermore, we have shown the comparison and convergence of these operators with the help of some illustrative graphics.Öğe Approximation Results for Hadamard-Type Exponential Sampling Kantorovich Series(Springer Basel Ag, 2023) Kurşun, Sadettin; Aral, Ali; Acar, TuncerThe present paper deals with construction of a new family of exponential sampling Kantorovich operators based on a suitable fractional-type integral operators. We study convergence properties of newly constructed operators and give a quantitative form of the rate of convergence thanks to logarithmic modulus of continuity. To obtain an asymptotic formula in the sense of Voronovskaja, we consider locally regular functions. The rest of the paper devoted to approximations of newly constructed operators in logarithmic weighted space of functions. By utilizing a suitable weighted logarithmic modulus of continuity, we obtain a rate of convergence and give a quantitative form of Voronovskaja-type theorem via remainder of Mellin-Taylor's formula. Furthermore, some examples of kernels which satisfy certain assumptions are presented and the results are examined by illustrative numerical tables and graphical representations.Öğe Approximation properties of modified Jain-Gamma operators(Vasyl Stefanyk Precarpathian Natl Univ, 2021) Erdoğan, S.; Olgun, A.In the present paper, we study some approximation properties of a modified Jain-Gamma operator. Using Korovkin type theorem, we first give approximation properties of such operator. Secondly, we compute the rate of convergence of this operator bymeans of themodulus of continuity and we present approximation properties of weighted spaces. Finally, we obtain the Voronovskaya type theorem of this operator.Öğe Approximation properties of two dimensional Bernstein-Stancu-Chlodowsky operators(Univ Studi Catania, Dipt Matematica, 2013) Acar, Tuncer; Aral, AliIn this paper, as a generalization of Bernstein-Stancu type operators of two variable, we introduce a new positive linear operator C-n (alpha,alpha,beta,beta,) (f; x, y) called Bernstein-Stancu-Chlodowsky on a triangular domain, with mobile boundaries, which extends to [0,infinity) x [0,infinity) as n -> infinity. We give some shape properties that are preserved and also obtain weighted approximation properties of these operators.Öğe Approximation Properties of Modified Baskakov Gamma Operators(Univ Nis, 2021) Arpagus, Seda; Olgun, AliIn this paper, we have studied an approximation properties of modified Baskakov-Gamma operator. Using Korovkin type theorem, firste we gave the approximation properties of this operator. Secondly, we computed the rate of convergence of this operator by means of the modulus of continuity and we gave an approximation properties of weighted spaces. Finally, we studied the Voronovskaya type theorem of this operator.Öğe Approximation Properties Of Modified Gauss-Weierstrass Integral Operators In Exponential Weighted Lp Spaces(Univ Nis, 2021) Yılmaz, BaşarIn this paper, we deal with modified Gauss-Weierstrass integral operators from exponentially weighted spaces L-p,L-a (R) into L-p,L-2a (R). We give the rate of convergence in terms of weighted modulus of continuity. Moreover, we prove weighted approximation of functions belonging to the space L-p,L-a (R) by these operators with the help of a Korovkin type theorem. Finally, we give pointwise approximation of such functions by these operators at generalized Lebesgue points.Öğe An intuitionistic fuzzy-based model for performance evaluation of EcoPorts(Pergamon-Elsevier Science Ltd, 2023) Yalcin, Galip Cihan; Kara, Karahan; Toygar, Arda; Simic, Vladimir; Pamucar, Dragan; Köleoğlu, NilayThe EcoPort performance level serves as a basic indicator to determine the environmental status of a port and its achievement of certification standards. The European Sea Ports Organization has defined ten essential EcoPort criteria that contribute significantly to the assessment of EcoPort performance. The primary motivation for this study is to determine the importance of the criteria from the perspective of academics and chief officers, as well as to evaluate the EcoPort performance of six port authorities that comply with three basic certification standards for environmental management systems. The research methodology and application are conducted in four phases. In the first phase, experts, criteria, and alternative ports are identified. In the second phase, the importance levels of experts are determined using neutrosophic sets, while the criteria are weighted using the intuitionistic fuzzy weighting averaging operator. In the third phase, the alternative ranking order method ac-counting for two-step normalization (AROMAN) based on the intuitionistic fuzzy sets is introduced to evaluate the EcoPort performance of the ports. In the fourth phase, the results are supported by sensitivity analysis scenarios. The research results identified air pollution as the most critical criterion, while the Valencia Port Authority secured the highest rank in terms of EcoPort performance. Ultimately, this research contributes to the literature by developing and applying the new IF-AROMAN method for EcoPort performance evaluation.Öğe An integrated neutrosophic Schweizer-Sklar-based model for evaluating economic activities in organized industrial zones(Pergamon-Elsevier Science Ltd, 2024) Kara, Karahan; Yalcin, Galip Cihan; Simic, Vladimir; Polat, Mustafa; Pamucar, DraganOrganized industrial zones (OIZs) are specialized areas where industrial activities are concentrated, and various economic activities take place collectively. Within OIZs, diverse economic activities coexist, forming shared industrial spaces. However, different regions tend to cluster different economic activities within OIZs. Given the significance of determining suitable economic activities for OIZs, developing a model for this decision problem, and testing its practical applicability is crucial. This research presents a multi-criteria decision-making approach to develop an economic activity selection model for OIZs. This model is based on type-2 neutrosophic numbers (T2NNs). Furthermore, two T2NNs aggregation operators, namely T2NN Schweizer-Sklar weighted arithmetic mean and T2NN Schweizer-Sklar weighted geometric mean aggregation operators, are developed based on the Schweizer-Sklar operations for use in determining decision-maker weights and ranking economic activities. The T2NN-based criteria importance through intercriteria correlation (CRITIC) method is employed for criterion weighting. An algorithm specific to the proposed model is devised for ranking economic activities. As a case study, this algorithm is applied to the Artvin-Arhavi OIZ, which is in the process of establishment in Turkey. Sensitivity and comparative analyses are conducted to assess the robustness of the developed aggregation operators and the model. In the case study findings, the most significant criterion is identified as investment risk, and forestry, logging, and related service activities are determined as the best economic activity. This research contributes to the field by introducing the model and novel aggregation operator for the selection of economic activities in OIZs.Öğe An interval-valued spherical fuzzy CIMAS-WISP group decision-analytic model for blockchain platform selection in digital projects(Elsevier, 2024) Kara, Karahan; Yalçın, Galip Cihan; Simic, Vladimir; Korkuç, Çağatay; Çiçek, İlhan; Afacan, Erkan; Pamucarg, DraganDigital projects aspiring to reach target audiences are executed through decentralized and trustworthy block- chain platforms (BPs). Once the objectives and target audience of a digital project are defined, the selection of suitable BPs is undertaken. The primary objective of this research is to develop a decision support system that aids in the selection of BPs for transferring digital data and assets. Numerous quantitative parameters determine the performance of BPs, alongside qualitative parameters indicating their performance. In this study, the aim is to determine the performance of BPs based on both qualitative and quantitative parameters. Within this scope, a multi-criteria decision-making approach and interval-valued spherical fuzzy (IVSF) sets are adopted. IVSF sets are utilized to determine expert importance levels. The IVSF-criteria importance assessment (CIMAS) method is introduced for the weighting of criteria. IVSF-CIMAS enables the determination of reliability levels in calculating criterion weights. The IVSF-simple weighted sum product (WISP) method is formulated to obtain the performance ranking of BPs. Thus, in this research, the IVSF-CIMAS-WISP hybrid model is developed, and an algorithm for this novel decision-analytic model is presented. A case study is developed focusing on BP selection for a digital project to demonstrate the applicability of the proposed hybrid model. The robustness of IVSF-CIMASÖğe An Existence Result for Second-Order Boundary-Value Problems via New Fixed-Point Theorems on Quasi-Metric Space(Mdpi, 2024) Güngör, Gonca Durmaz; Altun, İshakWe introduce the new idea of (alpha - theta(sigma))-contraction in quasi-metric spaces in this paper. For these kinds of mappings, we then prove new fixed-point theorems on left K, left M, and left Smyth-complete quasi-metric spaces. We also apply our results to infer the existence of a solution to a second-order boundary-value problem.Öğe A type-2 neutrosophic entropy-based group decision analytics model for sustainable aquaculture engineering(Pergamon-Elsevier Science Ltd, 2024) Kara, Karahan; Yalçın, Galip Cihan; Simic, Vladimir; Erbay, Murat; Pamucar, DraganFish cages are crucial for the establishment of sustainable fish farms. The selection of fish cages is an essential subject to be examined for ensuring sustainability. This research introduces an advanced decision support model for the selection of fish cage types used in fish farming in reservoirs (R-FFs). The decision support model is based on multi-criteria decision-making (MCDM) approach and utilizes type-2 neutrosophic numbers (T2NNs). The importance levels of criteria are determined using the T2NN-Entropy method, and the ranking of fish cage types is achieved through the alternative ranking order method accounting for two-step normalization (AROMAN). The developed model is referred to as the T2NN-Entropy-AROMAN hybrid method and relies on expert opinions. Two advanced aggregation operators based on Yager t-norm and t-conorm operations, named T2NN Yager weighted arithmetic mean and T2NN Yager weighted geometric mean, are developed for aggregating T2NNs. The validity of these two aggregation operators is demonstrated. A real-life case study is developed to confirm the applicability of the T2NN-Entropy-AROMAN hybrid method. This case study focuses on the selection of fish cage types for the Artvin-Bor & ccedil;ka R-FF in Artvin province, Turkey. The research results indicate that floating cages are the best alternative type for sustainable fish farming. Sensitivity analysis scenarios confirm the robustness of the research model and findings. The research findings, coupled with the developed model, offer valuable insights and guidance to decision-makers, researchers, and practitioners within the sector.Öğe A single-valued neutrosophic CIMAS-CRITIC-RBNAR decision support model for the financial performance analysis: A study of technology companies(Elsevier Science Inc, 2024) Kara, Karahan; Yalçın, Galip Cihan; Çetinkaya, Aslı; Simic, Vladimir; Pamucar, DraganFinancial performance stands as a fundamental performance indicator that reflects companies' current financial conditions, providing information to investors and stakeholders about companies' financial well-being. In this research, a decision support system is developed for identifying the financial performance of companies traded on stock exchanges. This decision support system is based on a multicriteria decision -making (MCDM) approach and neutrosophic logic. The research introduces a novel method for calculating and ranking financial performance, using financial ratio indicators as selection criteria. The importance levels of financial ratio indicators are weighted through two different approaches. In the first approach, expert opinions and criteria importance assessment (CIMAS)-based on single -valued neutrosophic (SVN) sets are utilized for calculation. In the second approach, criteria importance through intercriteria correlation (CRITIC) -based on reference -based normalization processes is employed for criteria weighting. Subsequently, the results of the two criterion weightings are combined to calculate the final criterion weights. The SVN reference -based normalization alternative ranking (RBNAR) method is presented for ranking companies based on their financial performance. Thus, SVN-CIMASCRITIC-RBNAR is developed and its algorithm is presented. The novel hybrid decision support model is applied to a case study of technology companies traded on the Borsa Istanbul. The research results support the applicability of the SVN-CIMAS-CRITIC-RBNAR hybrid method. The results of the case study and sensitivity analyses affirm the applicability and robustness of the SVN-CIMAS-CRITIC-RBNAR hybrid model. The research provides detailed implications and insights for financial managers.Öğe A spherical fuzzy-based DIBR II-AROMAN model for sustainability performance benchmarking of wind energy power plants(Pergamon-Elsevier Science Ltd, 2024) Kara, Karahan; Yalçın, Galip Cihan; Simic, Vladimir; Yıldırım, Ali Tuğrul; Pamucar, Dragan; Siarry, PatrickWind energy power plants (WEPPs) are renewable energy generation facilities that are increasingly used today. The performance evaluations of these energy plants are generally based on technical performance. Although there are studies in the literature focusing on determining the technical performance of WEPPs, there is a lack of research on evaluating their sustainable performance. The primary motivation of this study is to develop a decision model for identifying the sustainable performance of WEPPs. The model incorporates fuzzy logic and multi-criteria decision-making (MCDM) approaches, incorporating expert opinions and both qualitative and quantitative criteria. To determine the influence levels of experts, spherical fuzzy (SF) sets are utilized. The weighting of criteria is achieved using the SF-defining interrelationships between ranked criteria II (DIBR II) method, which is a novel extension of the DIBR II method based on SF sets. Additionally, an SF-alternative ranking order method accounting for two-step normalization (AROMAN) method is developed for ranking the sustainable performance of WEPPs, building upon the AROMAN method, and adapting it to SF sets. This hybrid model is named the SF-DIBR II-AROMAN hybrid model. The step-by-step procedures of this model are presented in the research, and an algorithm for these procedures is developed. To demonstrate its practicality, a case study is conducted, focusing on WEPPs with a capacity ranging from 25 to 150 megawatts in & Ccedil;anakkale, Turkey. According to the research results, among the fifteen WEPPs in the & Ccedil;anakkale region, Saros WEPP is identified as having the best one. The robustness of the obtained results is ensured through sensitivity analyses. Based on the results of two sensitivity analysis scenarios, Saros WEPP is found to have the highest sustainable performance. The SF-DIBR II-AROMAN hybrid model results are compared with different alternative ranking method results, highlighting its superior aspects. Overall, SF-DIBR II-AROMAN is consistent and robust. The research also provides insights and managerial implications, as well as explains the benefits of the proposed model for evaluating WEPPs' sustainable performance.Öğe A single-valued neutrosophic-based methodology for selecting warehouse management software in sustainable logistics systems(Pergamon-Elsevier Science Ltd, 2024) Kara, Karahan; Yalçın, Galip Cihan; Simic, Vladimir; Önden, İsmail; Edinsel, Sercan; Bacanin, NebojsaWarehouse operations cover activities that must be carried out systematically. Warehouse management systems (WMS) are needed for successful warehouse management. With digitalization, alternative software programs for WMS have increased. In this study, the selection of the WMS software program for the general warehouse type is discussed. The main motivation of the research is to develop a suitable alternative selection methodology based on criteria for warehouse managers. The research is carried out in several stages. In the first stage, the software selection criteria are determined based on the literature review. In the second stage, the criteria are weighted with the criteria importance through the intercriteria correlation (CRITIC) method based on single-valued neutrosophic sets (SVNSs). In the third stage, alternatives for WMS software are ranked with the technique for order preference by similarity to an ideal solution (TOPSIS) based on SVNSs. Three decision-makers, four al-ternatives, and eight criteria are used in the study. The empirical research is conducted on a warehouse providing general storage services in Turkey. In addition, the sensitivity analyses are performed and the results are compared. According to the research findings, the most valuable criterion in WMS software selection is deter-mined as ease of use. As a result of the research, suggestions are developed for WMS software manufacturers, warehouse managers, and researchers. The novelty of this research is that WMS selection is applied for the first time using multi-criteria decision-making methods.Öğe A Robin boundary value problem for the Cauchy-Riemann operator in a ring domain(Walter De Gruyter Gmbh, 2022) Gençtürk, İlker; Linares, Yankis R.In this paper, we study a Robin condition for the inhomogeneous Cauchy-Riemann equation w(z) = f in a ring domain R, by reformulating it as a Dirichlet boundary condition.
