Yusuf Çelik, İbrahim Ülke, Mustafa Yurdakul and Yusuf Tansel Ic
This study aims to examine the springback behavior of 15-5 PH stainless steel, which is widely used in the aviation industry.
Abstract
Purpose
This study aims to examine the springback behavior of 15-5 PH stainless steel, which is widely used in the aviation industry.
Design/methodology/approach
The shaping sheet metal with a diaphragm is a widely used shaping method in aviation. In this process, the sheet metal is attached to the mold, placed in the form machine and pressure is applied. The diaphragm, which swells under the influence of gas, transmits pressure to the sheet metal surface and allows the mold to take its shape. One of the behaviors that occurs in the part after processing is springback. The mold design is shaped according to this springing amount. Some prominent parameters in the amount of springback are bending radius, bending angle, material thickness and material type. Material thickness is taken as 0.813, 1.27, 1.6 and 2 mm for experimental studies. This study compares the general full factorial design with the 2k factorial design. Then, the authors get analysis of variance (ANOVA) tables for the experiments and finite element analysis results, respectively.
Findings
At the end of the study, a mathematical expression was obtained that gives the springback rate with an accuracy of over 90%, depending on the process parameters, in 15-5 PH material. In addition, the main effects of the working parameters on the springback behavior were revealed by ANOVA method.
Originality/value
To the best of the authors’ knowledge, this is a new application that provides robust results to the springback minimization for the sheet metal bending process.
Details
Keywords
Yusuf Tansel Ic, Beril Celik, Sevcan Kavak and Busra Baki
In this study, financial performance evaluation model is developed for banks aims to measure and compare the performances of banks based on their financial ratios.
Abstract
Purpose
In this study, financial performance evaluation model is developed for banks aims to measure and compare the performances of banks based on their financial ratios.
Design/methodology/approach
Regression-AHP (Analytic Hierarchy Process)-VIKOR (Vise Kriterijumska Optimizacija I Kompromisno Resenje) integrated methodology is used. First, a literature review is done to find various bank performance measurement models with their financial metrics being compared. Then, pair-wise comparison matrices are used to find the relative weights of criteria (financial ratios) and finally VIKOR method is used to rank the banks.
Findings
It is believed that an AHP-based VIKOR framework helps to take up the explicit account of multi-criteria decision making (MCDM) methodologies in decision making and for selecting the best bank in the Turkish economy.
Research limitations/implications
In this paper, only selected financial ratios are used and analyzed for the multi-criteria decision-making (MCDM) method.
Originality/value
The systematic solution procedure of performance evaluating the banks helps the decision-makers to carry out performance evaluation studies for improving economic and managerial performance. This comparative study and analysis of bank performance using the regression-AHP-VIKOR combined model is presented for the first time. The authors have not become aware of any such studies in their literature review. This paper is an original framework of the application of the regression-AHP-VIKOR on the various financial performance metrics.
Details
Keywords
Inanç Barutcu and Yusuf Tansel Ic
The authors present a location selection model for the field hospital to build after a possible earthquake in Ankara, Turkey using the VIKOR method.
Abstract
Purpose
The authors present a location selection model for the field hospital to build after a possible earthquake in Ankara, Turkey using the VIKOR method.
Design/methodology/approach
Companies or governments that make location selection decisions to improve their performance in new investment decisions for different service industries. On the other hand, disasters, especially earthquakes, force the governments to evaluate their existing potentialities and develop action plans to improve their middle and long-term preparations. This paper proposes a VIKOR method-based location selection model for the field hospital to build after a possible earthquake. Also, the authors present a methodology using the VIKOR method that how government agencies take action for the field hospital's location selection process via VIKOR methodology.
Findings
The modeling and application results show that the field hospital's location selection decision-making process improves considerably using the VIKOR model. This paper shows that the proposed VIKOR-based model can rank alternatives suitability at various criteria targeting to minimize the possible earthquake's impact and obtains a single overall ranking score to select the best alternative.
Research limitations/implications
The study does not consider the uncertain nature of the field hospital selection problem. The application part is restricted to the Ankara case. But the proposed model can easily extend for different locations in the world.
Originality/value
This paper presents the multi-criteria decision-making (MCDM) framework study of the establishment of field hospitals and demonstrates its importance when criteria diversity is restricted.
Details
Keywords
Ergün Eraslan and Yusuf Tansel İç
The major aim of this research is to determine the socio‐economic level of geographical investment regions through fuzzy multi‐criteria decision‐making (MCDM) method. The results…
Abstract
Purpose
The major aim of this research is to determine the socio‐economic level of geographical investment regions through fuzzy multi‐criteria decision‐making (MCDM) method. The results obtained from this method are analyzed and compared with the current system and the differences are interpreted.
Design/methodology/approach
A user friendly MCDM method, the fuzzy TOPSIS, was selected and ten independent criteria out of 53 were used, that have been evaluated by reduction according to the correlations among them. Therefore, the rankings of the 26 geographical investment regions of Turkey were calculated based on their criteria.
Findings
The examinations of the rankings have shown that only four regions had similar rankings but the rankings of the remaining 22 regions differed according to the authority rankings. Furthermore, significant differences have been observed for eight regions.
Social implications
In globalization process, certain issues are of particular importance in shaping the resource allocation policies of countries, through which they adjust their resources for manufacturing and service sectors to the changing competitive conditions and govern the effect of global economics on the human resources of their countries. The allowances taken from social and economic criteria have indicated the inter‐regional differences in terms of development.
Originality/value
From a policy perspective, this study highlighted that a large number of social and economic criteria failed in identifying homogenous groups of provinces and hence failed in producing realistic policies. However, the proposed method significantly contributed to obtaining more accurate rankings by using fuzzy decision‐making under multi‐criteria.