Yazar "Kahraman, Cengiz" seçeneğine göre listele

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    A novel CRITIC based weighted FMEA method: Application to COVID-19 blood testing process
    (Journal of Multiple-Valued Logic & Soft Computing, 2021) Haktanır, Elif; Kahraman, Cengiz
    Prioritizing the risk factors in production and service processes has a great importance since limited resources must be well managed. Classical Failure Mode and Effects Analysis (FMEA) is the most used method for this purpose in the literature. However, it handles a small number of parameters and assigns them equal weights. To overcome this inadequacy, we introduce a more comprehensive FMEA method which allows to assign different weights to the risk parameters. The new FMEA model includes nine risk parameters each having a different weight obtained from CRiteria Importance Through Intercriteria Correlation (CRITIC) method. The paper also introduces a fuzzy version of the proposed CRITIC Based Weighted Failure Mode and Effects Analysis (CBW-FMEA) method, which employs triangular and trapezoidal fuzzy numbers. All the proposed models are applied to COVID-19 blood testing process and the results are presented comparatively.
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    A novel interval-valued pythagorean fuzzy QFD method and its application to solar photovoltaic technology development
    (Pergamon-Elsevier Science Ltd, 2019) Haktanır, Elif; Kahraman, Cengiz
    Quality function deployment (QFD) is a focused methodology for carefully listening to the voice of the customer and then effectively responding to those needs or customer requirements, (CRs) and expectations through design requirements (DRs). In classical QFD, exact numbers are used to determine the priorities of the CRs and the position of the company among the competitors. However, vagueness and impreciseness are inevitable uncertainties in those kinds of human evaluations, which are generally realized by linguistic terms. In this paper, the uncertainty in design processes is captured by a relatively new extension of ordinary fuzzy sets, Pythagorean fuzzy sets (PFS), aiming at presenting a larger domain to experts for assigning a membership degree and a non-membership degree together with their hesitancy. We perform all the evaluation processes in the house of quality (HOQ) based on interval-valued PFS (IVPFS) and present some novel definitions for measuring and prioritizing CRs, DRs, and determining the position of the company among the competitors. We give an application of the proposed IVPF-HOQ model for solar photovoltaic technology development.
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    A novel picture fuzzy CRITIC & REGIME methodology: Wearable health technology application
    (2022) Haktanır, Elif; Kahraman, Cengiz
    Picture fuzzy sets (PFSs) are one of the most promising extensions of ordinary fuzzy sets with three parameters, namely positive membership, neutral membership, and negative membership, for defining the membership status of an element to a set. CRiteria Importance Through Intercriteria Correlation (CRITIC) & REGIME methods are recently developed multi criteria decision making (MCDM) methods for calculating the criteria weights and ranking alternatives, respectively. CRITIC method determines the criteria weights by using the values in the decision matrix. REGIME method is a compensatory MCDM method employing superiority and guide indices, superiority identifier and impacts, and REGIME matrices. In this paper, an integrated CRITIC & REGIME methodology is developed for the first time by using single-valued PFSs in order to use the advantage of PFSs in handling ambiguity and impreciseness. The main contribution of our study is to demonstrate theoretically and practically how to transform superiority and guide indices, superiority identifier and impacts, and REGIME matrices to the PF environment. A new interval valued Relative Magnitude Index scale and an original Percentile Rank under Vagueness function have been developed. The developed methodology is applied to the selection problem of wearable health technology (WHT). Comparative and sensitivity analyses are presented. These analyses show that CRITIC & REGIME methodology produces very effective and valid results, and unlike the other methods, it shows slight ranking differences due to the statistical-based calculations it contains.
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    Classification of non-pharmaceutical anti-COVID ınterventions based on novel FTOPSIS-sort models
    (Springer Science and Business Media Deutschland GmbH, 2022) Radaev, Alexander; Haktanır, Elif; Yatsalo, Boris; Kahraman, Cengiz
    Assigning alternatives to predefined ordered categories under multicriteria conditions is the essence of multi-criteria sorting problematic. The family of fuzzy multi-criteria sorting models with the common name FTOPSIS-Sort are introduced based on the fuzzy extension of Multi-Criteria Decision Analysis (MCDA) ordinary method TOPSIS with the use of different approaches to assess functions of fuzzy numbers and different fuzzy ranking methods. The features of adjusting Fuzzy TOPSIS (FTOPSIS) models to sorting problematic are presented. The developed FTOPSIS-Sort models are implemented for multi-criteria sorting of non-pharmaceutical interventions against COVID-19.
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    Defects control charts using interval-valued penthagorean fuzzy sets
    (Springer, 2021) Haktanır, Elif; Kahraman, Cengiz
    Defects control charts are one of the attributes control charts which are constructed based on the number of defects on a product or in an inspection unit. Since the term ‘defect’ can be vague due to the subjective decisions of the quality control operator, it cannot be precisely defined. In such cases, fuzzy set theory can be used to add more information and flexibility to attribute based-process control. After the introduction of the ordinary fuzzy sets to the literature, it has been extended to many new types of fuzzy sets. One of the recent extensions, q-rung orthopair fuzzy sets, which is a generalization of intuitionistic fuzzy sets and Pythagorean fuzzy sets, provides a broader space to express ambiguous information, For the q-rung orthopair fuzzy sets the sum of the qth power of the membership degree and the qth power of the non-membership degree is equal to or less than one. In this study, the fifth power of the q-rung orthopair fuzzy sets is used to represent the impreciseness in the construction of the defects control charts and names as penthagorean fuzzy sets. An application in a TV production system is presented as an illustrative example. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG.
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    Fuzzy multi-criteria sorting models FMAVT-Sort and FTOPSIS-Sort: features and application within the case studies
    (Springer Science and Business Media Deutschland, 2023) Radaev, Alexander; Haktanır, Elif; Yatsalo, Boris; Kahraman, Cengiz
    The need to sort alternatives according to ordered categories, especially in problems consisting of a large number of alternatives, makes it effective to use of multi-criteria sorting methods. A family of fuzzy multi-criteria sorting models FMAVT-Sort and FTOPSIS-Sort based on a fuzzy extension of MAVT and TOPSIS methods respectively and the their features are presented. In the developed models, different approaches can be used both for calculating functions of fuzzy numbers and for ranking of fuzzy numbers. Case studies showing the application of the developed models to sort problems related to the Internet of Things and anti-COVID measures are presented.
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    Interval-valued neutrosophic failure mode and effect analysis
    (Ios Press, 2020) Haktanır, Elif; Kahraman, Cengiz
    Failure mode and effects analysis (FMEA) is a structured approach for discovering possible failures that may occur in the design of a product or process. Since classical FMEA is not sufficient to represent the vagueness and impreciseness in human decisions and evaluations, many extensions of ordinary fuzzy sets such as hesitant fuzzy sets, intuitionistic fuzzy sets, Pythagorean fuzzy sets, spherical fuzzy sets, and picture fuzzy sets. Classical FMEA has been handled to capture the uncertainty through these extensions. Neutrosophic sets is a different extension from the others handling the uncertainty parameters independently. A novel interval-valued neutrosophic FMEA method is developed in this study. The proposed method is presented in several steps with its application to an automotive company in order to prioritize the potential causes of failures during the design process by considering multi-experts' evaluations.
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    Interval-Valued Pythagorean Fuzzy Entropy Weight Method and Its Application to Supplier Selection
    (Springer Science and Business Media Deutschland GmbH, 2022) Haktanır, Elif; Kahraman, Cengiz
    Entropy Weight Method (EWM) aims at weighting the criteria by measuring value dispersion. The greater dispersion and greater degree of differentiation mean more information in this method. Humans generally prefer linguistic assessments in multi criteria decision-making, which involves some degree of uncertainty. This uncertainty is handled by interval-valued Pythagorean fuzzy (IVPF) sets in this chapter. Multi decision makers’ evaluations are aggregated by IVPF weighted geometric (IVPFWG) operator. The proposed method is applied to a supplier selection problem and compared with IVPF-CRITIC method. The obtained results are presented, and future research suggestions are given. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
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    Z-fuzzy hypothesis testing in statistical decision making
    (Ios Press, 2019) Haktanır, Elif; Kahraman, Cengiz
    Hypothesis tests are a statistical decision-making tool for testing if a hypothesized parameter value is supported by the sample data or not. Vagueness and impreciseness in the sample data require fuzzy techniques to be employed in the analysis. These techniques can be based on intuitionistic fuzzy sets, hesitant fuzzy sets, type-2 fuzzy sets, neutrosophic sets, or spherical fuzzy sets. In this paper, Z-fuzzy numbers are used to capture the vagueness in the sample data and develop Z-fuzzy hypothesis testing. A Z-fuzzy number is represented by a restriction function that is usually a triangular or trapezoidal fuzzy number and a reliability function representing the confidence level to the restriction function. Illustrative examples for left and right sided hypothesis testing and sensitivity analyses are presented.