Scopus Kapalı Erişimli Yayınlar
Permanent URI for this collectionhttps://hdl.handle.net/11727/10761
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Item A new hybrid method to determine the hazardous risk factors(2022) Dinler, Esra; Atalay, Kumru Didem; Guler, EzgiIn risk analysis, the quantification of risk, the modeling of identified risk, and how to make decisions are all topics considered. Risk analysis activity that companies must comply with and perform at a minimum level to produce medical devices. Manufacturers should consider all risks that the device may contain to indicate that the medical device is safe. Manufacturers must also justify that this device should be manufactured because the benefit of the device is greater than the risk. This study proposes a method to measure the risk factors of the medical devices on the patient. Accordingly, a mathematical model is developed, the model is applied to a device manufactured in a company, and the results are obtained. The aggregated method developed in this study, based on the Taguchi loss function and using the hesitant fuzzy the technique for order preference by similarity to ideal solution (HF-TOPSIS) method, ensures that the risks that may occur for the patient are minimized and the risk types to be taken into account are determined. In addition, the order of importance of the risk types obtained with the proposed method in the study is compared with the TOPSIS method.Item The development of a reviewer selection method: a multi-level hesitant fuzzy VIKOR and TOPSIS approaches(2021) Kocak, Serdar; Ic, Yusuf Tansel; Atalay, Kumru Didem; Sert, Mustafa; Dengiz, Berna; 0000-0001-9274-7467; AGE-3003-2022This paper proposes a new approach for the selection of reviewers to evaluate research and development (R&D) projects using a new integrated hesitant fuzzy VIKOR and TOPSIS methodology. A reviewer selection model must have a multi-level framework in which reviewer selection strategies and related objectives guide the second level of the reviewer performance ranking process. The model must measure reviewer performance related to the activities that are necessary for the R&D project evaluation to be successful. A novel model is presented in this paper. In the proposed methodology, the aim is to select a reviewer in a hierarchical decision-making structure. The selection criteria values and their weights were obtained using the hesitant fuzzy VIKOR method. For the selection of a suitable reviewer, the conventional TOPSIS model was used. We developed a simpler procedure for effectively performing the reviewer selection process. The new approach was tested with a real case study and satisfactory results were obtained. A comparative analysis is also included in the article for illustrative purposes.Item Development of a new hesitant fuzzy ranking model for NTMP ranking problem(2021) Atalay, Kumru Didem; Ic, Yusuf Tansel; Kececi, Baris; 0000-0001-9274-7467; AGE-3003-2022Nontraditional manufacturing processes (NTMPs) bring the processing capabilities such as machining high strength and hard materials with desired accuracies and surface finish to the manufacturing companies. Therefore, there has been a significant increase in the use and number of NTMPs. Hence, choosing a particular NTMP for a specific application turns out to be a complex decision-making problem, which involves conflicting qualitative and quantitative ranking criteria. In recent NTMP ranking literature, it is noted that fuzzy approaches are better suited for handling uncertainties and incomplete information that exist within the NTMP ranking environment. This paper introduces such a fuzzy approach using the hesitant fuzzy preference selection index (PSI) method for the assessment of the criteria weights and the hesitant fuzzy correlation coefficient principle for ranking and recommending the most appropriate NTMP for a specific application. The proposed methodology and its efficiency in dealing with incomplete information under the fuzzy decision-making environment are explored with a case study. As a result of the study, the proposed model preferred the electron beam machining (EBM) as the most suitable nontraditional manufacturing process. On the other hand, triangular fuzzy TOPSIS methods offered the electrochemical machining (ECM) as the best choice among the alternatives. The differences among the ranking decisions are also analyzed in the paper. It can be concluded from the authors' various applications of the proposed hesitant fuzzy PSI method that it is extremely effective in representing fuzzy decision-making environments in NTMP ranking decisions.Item The effects of consumer confusion on hotel brand loyalty: an application of linguistic nonlinear regression model in the hospitality sector(2020) Kurtulmusoglu, Feride Bahar; Atalay, Kumru DidemThe aim of the study is to estimate the interaction and quadratic relationships between dimensions by estimating a model for the confusion dimensions that affect hotel brand loyalty, thus providing the interested parties with a perspective and direction regarding consumer confusion. This study also aimed to strengthen the use of FLS in the field of social sciences and will use this method to transform the discrete ordinal variable into a continuous variable while preserving the semantic meaning. Four hundred and six individuals participated in the study. Hypotheses demonstrating the interaction and quadratic effects between the continuous variables have been analysed using nonlinear multiple regression analysis. This study proposes a survey-based method to estimate a model for the confusion dimensions that affect hotel brand loyalty. The results demonstrated that ambiguity confusion, overload confusion, similarity confusion, quadratic effect of similarity confusion and interaction of ambiguity, overload and similarity confusion decrease the hotel brand loyalty. Also, quadratic effect of ambiguity confusion, interaction of ambiguity and overload confusion, interaction of overload and similarity confusion, interaction of ambiguity and similarity confusion increase the hotel brand loyalty. Despite its importance for marketing and consumer behaviour, the definition, measurement, dimensions and existing results of consumer confusion have begun to be discussed and examined recently in a limited scope. Studies have demonstrated that consumer confusion about tourism products is a non-functional and under-evaluated area but also is utmost prominent for tourism product. This study aimed to obtain a stronger model in which all the interactions between variables and their (quadratic) increasing effects are considered using a nonlinear regression model.Item Airfoil-slat arrangement model design for wind turbines in fuzzy environment(2020) Atalay, Kumru Didem; Dengiz, Berna; Yavuz, Tahir; Koc, Emre; Ic, Yusuf TanselIn this study, a multi-element wind turbine blade that consists of NACA 6411 and NACA 4412 leading-edge slat design is investigated computationally. Optimum design parameters of the slatted wind turbine blade leading to maximum value of C-L/C-D related to the turbine power are obtained. In the optimization process, a new fuzzy logic linear programming methodology integrating with fuzzy linear regression and 2D CFD analysis is proposed. The aerodynamic characteristics of the slatted blade are computed by using Incompressible Navier-Stokes equations and k-omega turbulence modeling. Results are compared with the results of linear programming method and direct search optimization method. The computational results reveal that the proposed methodology for performance optimization is more effective than other methods to obtain high-performance value of the C-L/C-D. The maximum value of the C-L/C-D is obtained as 25.1 leading the maximum efficiency of 0.52.