Yazar "Otay, Irem" seçeneğine göre listele

Listeleniyor 1 - 14 / 14
  • Küçük Resim Yok
    Öğe
    Engineering economic analysis of solar energy investments using spherical fuzzy sets
    (World Scientific Publ Co Pte Ltd, 2020) Onar, Sezi Cevik; Oztaysi, Bazar; Kahraman, Cengiz; Otay, Irem
    Solar energy is a reliable energy source that is important for the environmental sustainability. Solar energy investments become crucial for the countries like Turkey that does not have natural fossil based fuels but has a great potential of solar energy. In order to give better solar energy investment decisions, the uncertainties and ambiguities inherit in the investment decisions should be considered. Spherical fuzzy sets enable us to deal with uncertainty and ambiguity. The membership, non-membership and the hesitancies are considered in Spherical fuzzy sets, In this study a Spherical fuzzy set based net present worth analysis is proposed to deal with uncertain solar energy investments. The applicability of the proposed model is shown by an application. In this application, a solar power plant investment is evaluated by using the proposed model.
  • Küçük Resim Yok
    Öğe
    Indoor location tracking technology evaluation by using spherial fuzzy TOPSIS method
    (World Scientific Publ Co Pte Ltd, 2020) Oztaysi, Basar; Kahraman, Cengiz; Onar, Sezi Cevik; Otay, Irem
    With the emerging technologies, collecting and processing data about the behaviors of customers or employees in a specific location has become possible. The purpose of this paper is to evaluate existing data collection technologies. Technology evaluation problem is handled as a multi-criteria decision-making (MCDM) problem. In this manner, a decision model containing four criteria and four alternatives are formed. In this study, we use Spherical Fuzzy TOPSIS method to solve the technology selection problem.
  • Küçük Resim Yok
    Öğe
    Industry 4.0 project prioritization by using spherical fuzzy analytic hierarchy process
    (World Scientific Publ Co Pte Ltd, 2020) Oztaysi, Basar; Onar, Sezi Cevik; Kahraman, Cengiz; Otay, Irem
    Industry 4.0, indicated as the Fourth Industrial Revolution, also pointed out as integrated industry, smart manufacturing and industrial internet of things, has taken a great attention in terms of the potential to reflect entire industries' actions by transforming the production to a fully automated and self-coordinated digital system. This transformation process necessitates the significant amount of investments and resources to be additionally, adaptation to the current operational technologies to new initiatives could be problematic. In this study we focus on Industry 4.0 project prioritization by using Spherical Fuzzy Analytic Hierarchy Process. In the application part, we prioritize five projects according to four main project selection criteria.
  • Küçük Resim Yok
    Öğe
    An Integrated Interval-Valued Picture Fuzzy CRITIC & TOPSIS Methodology: An Application to Disaster Debris Management
    (Old City Publishing Inc, 2023) Oztaysi, Basar; Onar, Sezi Cevik; Otay, Irem; Kahraman, Cengiz
    Picture fuzzy (PF) sets show the expert's opinion about an element's membership or non-membership in the set, as well as the expert's indecision about the element's membership in the set. Interval-valued PF sets (IVPFSs) offer more flexibility than single-valued PF sets in assigning the mentioned degrees. Picture fuzzy multi-criteria decision making methods or methodologies are superior to other methods or methodologies since they can take these opinions of the experts into account in the decision mechanism. CRITIC method is a criteria weighting method based on statistical terms such as correlation coefficients and standard deviations, which has become popular recently. In this paper, the PFCRITIC method will be used to calculate the weights of the criteria and the PF-TOPSIS method is used to rank the alternatives. The proposed multi-experts IVPF CRITIC&TOPSIS methodology is applied to the post-disaster location selection of debris waste sites in Istanbul. In the comparison analysis, the integrated methodology is compared with crisp TOPSIS method based on the same data. The results show that the integrated methodology gives a consistent ranking with slight differences in closeness coefficients.
  • Küçük Resim Yok
    Öğe
    Interval-Valued Pythagorean Fuzzy AHP&TOPSIS for ERP Software Selection
    (Springer International Publishing Ag, 2022) Dalyan, Tugba; Otay, Irem; Gulada, Mehmet
    The selection of an Enterprise Resource Planning (ERP) system is considerably important since it has effects on the productivity of companies. This paper aims to choose the best decision for ERP software over many conflicting criteria by using Pythagorean fuzzy (PF) Analytic Hierarchy Process (AHP) that integrated with Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method. The proposed model includes a hierarchical structure with four main criteria which are finance, technology, usability and corporate, twenty two sub-criteria and several alternatives. In this study, the evaluations are expressed using interval-valued PF sets that consist of membership and non-membership values, where the square sum of these degrees is at most 1. The weights of the criteria are computed using interval-valued PF AHP. Then, fuzzy TOPSIS method is utilized to evaluate alternatives by considering distances of alternatives to negative and positive ideal solutions (NIS, PIS), respectively. This attempt using interval-valued PF AHP-TOPSIS is deemed to be a significant contribution toward ERP selection problem.
  • Küçük Resim Yok
    Öğe
    A literature review on the extensions of intuitionistic fuzzy sets
    (World Scientific Publ Co Pte Ltd, 2020) Kahraman, Cengiz; Oztaysi, Basar; Onar, Sezi Cevik; Otay, Irem
    Intuitionistic fuzzy sets (Atanassov, 1986) are the sets whose elements have degrees of membership and non-membership satisfying the condition that their sum is at most equal to one. Thus, an expert can express his/her hesitancy through IFS whereas it is not possible with ordinary fuzzy sets. This paper presents a literature review on intuitionistic fuzzy sets based on some classifications with respect to type of intuitionistic fuzzy numbers. We use graphical and tabular illustrations for a better visualization of the review. We also propose a new extension of IFS whose name is q-Spherical fuzzy sets.
  • Küçük Resim Yok
    Öğe
    Multi-expert disaster risk management & response capabilities assessment using interval-valued intuitionistic fuzzy sets
    (Ios Press, 2020) Otay, Irem; Jaller, Miguel
    This study focuses on the evaluation of disaster risk management and response (DRMR) processes and capabilities using a multi-expert multi-criteria decision making (MCDM) framework. The proposed framework considers four sets of evaluation and performance criteria: risk knowledge and organization, risk reduction, disaster response management, and disaster response support; and 22 sub-criteria such as regulating risk management, financial management, energy, and public safety. To contend with random perception and utility, lack of information and subjectivity in the human (expert) judgment processes that could be present in expert-based models, the authors propose an interval-valued intuitionistic fuzzy sets (IVIFSs) approach. IVIFSs can handle high levels of uncertainty and define appropriate membership functions. Specifically, the proposed approach incorporates score judgement and possibility degree matrices, and estimates the local and global weights for each assessment criteria. And finally, evaluates the overall performances of the alternatives using intuitionistic fuzzy Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) approach. The authors implemented the framework to the Atlantico State of Colombia, and assessed the disaster risk management and response processes for each for the State's 23 municipalities. The authors discuss sensitivity analysis that illustrates the robustness of the results.
  • Küçük Resim Yok
    Öğe
    A novel interval valued circular intuitionistic fuzzy AHP methodology: Application in digital transformation project selection
    (Elsevier Science Inc, 2023) Otay, Irem; Onar, Sezi Cevik; Oztaysi, Basar; Kahraman, Cengiz
    Since its first introduction, ordinary fuzzy sets have been extended to new types of fuzzy sets as a tool of artificial intelligence techniques. One of the recently introduced fuzzy sets, Circular Intuitionistic Fuzzy (CIF) sets enable us to take into account instability of the membership and non-membership degrees with a circular area & its radius. In this study, we first introduce Interval Valued CIF (IVCIF) sets and their arithmetic operations to better incorporate the uncertainty and cover a broader domain. Then, we introduce a novel IVCIF Analytic Hierarchy Process (AHP) method and apply it to evaluate Digital Transformation (DT) projects with complex nature. DT projects requiring fundamental changes in processes, business models and cultures of the com-panies, contribute a significant value to the companies and increase their market shares; so that they can achieve long term success and competitive advantage. On the other hand, DT problems which are usually ill-defined and include incomplete information based on human judgments, necessitate fuzzy representation. For the success of a digital transformation and to contribute excellence in engineering applications, DT projects should be carefully analyzed. For these rea-sons, we focus on DT project evaluation problem in application. Also, sensitivity & comparative analyses are performed.
  • Küçük Resim Yok
    Öğe
    A novel pythagorean fuzzy AHP and TOPSIS method for the wind power farm location selection problem
    (Ios Press, 2020) Otay, Irem; Jaller, Miguel
    This paper proposes an Integrated Fuzzy Analytic Hierarchy Process (AHP) with the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method using Pythagorean fuzzy sets for the wind farm location selection problem. The method combines the advantages of the two methodologies to consider uncertainties and lack of information in the decision-making process (human expert capacities) and enables better representation of membership and non-membership functions, and at the same time, allows for the evaluation of large numbers of alternatives and criteria. The authors implement the method to evaluate four potential sites near cities located in the west and north-west regions of Turkey, using seven main criteria and twenty-five sub-criteria. The analyses are based on the judgements of three experts/decision-makers. Moreover, the authors compare the results (site ranking) of the methodology, with those from a Pythagorean Fuzzy AHP and an interval-valued Type-2 fuzzy AHP method. With the additional consideration of the sub-criteria, the proposed method generates slight differences in the ranking compared to the previously evaluated methods.
  • Küçük Resim Yok
    Öğe
    A novel single-valued spherical fuzzy AHP-WASPAS methodology
    (World Scientific Publ Co Pte Ltd, 2020) Otay, Irem; Kahraman, Cengiz; Oztaysi, Bapr; Onar, Sezi Cevik
    Intuitionistic fuzzy sets are the main source of several recent extensions of the ordinary fuzzy sets such as Pythagorean fuzzy sets, picture fuzzy sets, neutrosophic sets and qrung orthopair fuzzy sets. In addition to these, one of the latest extensions of these types of fuzzy sets is Spherical fuzzy sets, which have been often employed in many multiattribute decision making applications in the literature. One of the advantages of Spherical fuzzy set is that it provides a larger domain for the definition of the parameters (membership & non-membership functions and hesitancy) and it allows the parameters to be defined independently. Analytic Hierarchy Process (AHP) is one of the multi-attribute decision making methods based on pairwise comparisons of criteria and alternatives, satisfying the consistency of each pairwise comparison matrix. WASPAS (The Weighted Aggregates Sum Product Assessment) being the integration of weighted product sum and simple additive weighting methods, has been recently introduced to the literature. Under impreciseness and vagueness, linguistic evaluations are generally preferred in a decision matrix. There are many fuzzy extensions of AHP & WASPAS methods such as intuitionistic fuzzy AHP, intuitionistic fuzzy WASPAS, and Pythagorean fuzzy AHP. However, there is no paper integrating AHP and WASPAS methods using Spherical fuzzy sets. Thus, this paper aims to contribute to the literature by developing an integration of Spherical fuzzy AHP &WASPAS methods. The proposed method is applied to solve outsource manufacturer evaluation and selection problem.
  • Küçük Resim Yok
    Öğe
    q-spherical fuzzy sets and their usage in multi-attribute decision making
    (World Scientific Publ Co Pte Ltd, 2020) Kahraman, Cengiz; Oztaysi, Basar; Onar, Sezi Cevik; Otay, Irem
    Intuitionistic fuzzy sets (IFS) have been very popular in the literature after they were introduced by Atanassov (1986). Several extensions of IFS have been proposed such as Pythagorean fuzzy sets (PFS), fermatean fuzzy sets (FFS), q-rung orthopair fuzzy sets, picture fuzzy sets (PiFS), and spherical fuzzy sets (SFS). The main difference among these extensions is the number of independent membership function parameters such as membership degree, non-membership degree, and hesitancy degree. Similar to q-rung orthopair fuzzy sets, picture fuzzy sets can be extended to q-spherical fuzzy sets. This idea is handled in this paper and some operations of q-Spherical fuzzy sets are presented.
  • Küçük Resim Yok
    Öğe
    Score and accuracy functions for different types of spherical fuzzy sets
    (World Scientific Publ Co Pte Ltd, 2020) Otay, Irem; Kahraman, Cengiz; Oztaysi, Basar; Onar, Sezi Cevik
    Spherical fuzzy sets are the latest extension of the ordinary fuzzy sets, which are based on three independent parameters, namely membership degree, non-membership degree and hesitancy degree. The squared sum of these parameters must be equal or less than 1. Several papers have been published on the arithmetic operations, aggregation operators, defuzzification operations and many others in the literature. However, there are still gaps in these operations for different types of spherical fuzzy numbers such as triangular, trapezoidal, and left-right (LR) fuzzy numbers. In this paper, we focus on score and accuracy functions for several types of spherical fuzzy numbers by illustrating numerical examples.
  • Küçük Resim Yok
    Öğe
    Selection of learning analytics projects by using spherical fuzzy TOPSIS
    (World Scientific Publ Co Pte Ltd, 2020) Onart, Sezi Cevik; Kahraman, Cengiz; Oztaysi, Basar; Otay, Irem
    Learning analytics is the measurement of student progress by the collecting, analysis and reporting data in the learning environment. Learning analytics methods try to find out the dependent pattern in dataset gathered. Learning Analytics improve student outcomes in several ways, first, using learning analytics leads to measure student success correctly. With this information students can find accurate teaching techniques and support themselves. Also, it gives proper and faster feedback about learning technique to the stakeholders (principals, teachers, parents). The scope and the aim of learning analytic projects may differ for different organizations. Selecting the right learning analytic project is crucial for the overall success of the learning process. Despite their benefits, while selecting the learning analytic projects not only financial benefits but also various factors including Privacy, Access, Transparency, Security, Accuracy, Restrictions, and Ownership should be taken into account. Yet, evaluating these factors is not easy since they involve uncertainties. Therefore, the selection of learning analytic projects is a complex process that includes various uncertainties. In this study, we utilize an Spherical fuzzy TOPSIS approach for selecting Learning Analytics Projects This method enabled us defining the uncertainties with independent parameters.
  • Küçük Resim Yok
    Öğe
    Tech-center location selection by interval-valued spherical fuzzy AHP based MULTIMOORA methodology
    (Springer, 2023) Otay, Irem
    Intense market competition, changes in demand structure and acceleration in the technological developments have led companies to offer innovative and technology driven solutions in order to have competitive advantage and to survive in the market. In this aspect, tech-centers offering technological & innovative engineering solutions, and providing customized services to the needs of the companies, have taken attentions of academicians and practitioners. In this study, a tech-center location evaluation problem having a strategic and complex structure on the success and performance of the engineering companies, is analyzed. By considering inherent uncertainties and lack of information in the multi-criteria & multi-expert based tech-center location selection problem, the fuzzy set theory as a tool of artificial intelligence is employed. In the study, one of the recently proposed fuzzy sets namely Spherical fuzzy sets are used to handle uncertainty in a better way by incorporating a larger domain. According to the best knowledge of the authors, it is the first study concentrating on tech-centers and employing an integrated interval-valued Spherical fuzzy Analytic Hierarchy Process (AHP) & MULTIMOORA methodology to solve location selection problem of a tech-center. In the study, a novel defuzzification function is also presented. In the application section, a case of a company planning to launch a tech-center is analyzed. Moreover, sensitivity analysis is applied to test the applicability and robustness of the method. The results of the proposed multi-expert Spherical fuzzy methodology are also compared with the results of AHP & MULTIMOORA methodology utilizing interval-valued intuitionistic fuzzy sets.