Browsing by Author "Ic, Yusuf Tansel"

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Airfoil-slat arrangement model design for wind turbines in fuzzy environment
(2020) Atalay, Kumru Didem; Dengiz, Berna; Yavuz, Tahir; Koc, Emre; Ic, Yusuf Tansel
In 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.
Analysis of the effect of the number of criteria and alternatives on the ranking results in applications of the multi criteria decision making approaches in machining center selection problems
(2020) Ic, Yusuf Tansel; Yurdakul, Mustafa
Multi criteria machining center selection models are widely used in the literature. In the applications of multi-criteria decision making models, machining center selection criteria are directly taken from catalogues. It is known that to have a ranking model sensitive to the weights of the selection criteria, it is especially important to limit the number of selection criteria to 7 +/- 2. A similar proposal can be put forward for the number of machining centers. In this study, whether or not reducing the number of criteria and alternative machining centers make the ranking results more sensitive to the changes in the criteria weights is studied using Spearman's rank correlation test. The study results show that the ranking results become more sensitive with a reduced number of criteria and alternative machining centers.
Analysis of the manufacturing flexibility parameters with effective performance metrics: a new interactive approach based on modified TOPSIS-Taguchi method
(2022) Ic, Yusuf Tansel; Sasmaz, Turgut; Yurdakul, Mustafa; Dengiz, Berna; 0000-0001-9274-7467; AGE-3003-2022
Flexibility is one of the most important strategy parameters to achieve a long-term successful performance for a manufacturing company. Studies in the literature aim to operate a manufacturing system at optimum levels of flexibility parameters under its own manufacturing environment. This study aims to present an interactive analysis framework based on TOPSIS and Taguchi parameter design principles for investigating the effects of different levels of flexibility parameters on the performance of a flexible manufacturing cell (FMC). The main performance metric used in this study is manufacturing lead time. Other important metrics to evaluate quality control and inspection policies are also investigated in this study. To conclude, a combined model of an interactive approach based on TOPSIS and Taguchi methods are used to assess the effectiveness of the flexibility parameters for a FMC.
Analysis of the Robustness of the Operational Performance Using a Combined Model of the Design of Experiment and Goal Programming Approaches for a Flexible Manufacturing Cell
(2023) Ic, Yusuf Tansel; Yurdakul, Mustafa; Dengiz, Berna; Sasmaz, Turgut
A combined model of a 2(k) design of experiment (DOE) and goal programming (GP) approaches is presented to determine optimum levels of input variables and analyze their robustness for a multiobjective performance of a flexible manufacturing cell (FMC) in this study. Two main performance metrics, namely, manufacturing lead time (MLT) and surface roughness (SR), are considered performance outputs for the FMC. Machine sequence, robot speed, tool type, and material type are selected as the four input variables on the input side of the proposed model. The study shows that even with a limited number of experiments, one can determine optimum input levels for the multiobjective performance of the FMC and determine their robustness.
Application of Cellular Manufacturing and Simulation Approaches for Performance Improvement in an Aerospace Company's Manufacturing Activities
(2019) Ic, Yusuf Tansel; Yurdakul, Mustafa; Gulsen, Mehmet; Dalcan, Gizem; Kirdar, Didem; Kale, Meric; Altinkaya, Zeynep; Aktas, Dogukan; https://orcid.org/0000-0001-9274-7467; AGE-3003-2022
This paper presents performance improvement studies performed in manufacturing activities of an aerospace company. Cellular Manufacturing (CM) and simulation approaches are used to improve performance in the factory of the company. In the application of CM, reorganization of machines in the machining section as manufacturing cells is performed by using Rank Order Clustering (ROC) algorithm and Hollier method. The performance improvement provided by CM application is measured in terms of the total material handling distances travelled by the parts. On the other hand, a simulation model in SIMAN is developed for panel production section of the factory. Based on the performance outputs of the simulation model, various recommendations are proposed in the operation rules and numbers of resources in the panel production section. The results show that both approaches provide considerable performance improvement in the manufacturing activities of the factory.
Building a Graphical User Interface for Concrete Production Processes: A Combined Application of Statistical Process Control and Design of Experiment
(2019) Simsek, Baris; Pakdil, Fatma; Ic, Yusuf Tansel; Guvenc, Ali Bilge; AGQ-5008-2022
Quality improvement and control in the manufacturing industry is a necessity for responding timely to increase customer needs and sustainability expectations. In order to decrease the variance in design and production functions, graphical user interface was built in this study implementing a combined methodology based on multi-response design of experiment and statistical process control. Graphical user interface based on MATLAB (R) toolbox allows analyzing the sufficiency of measurement system, calculating the capability of concrete production process, optimizing the manufacturing process via TOPSIS-based Taguchi design methodology and comparing the improvement rate of the process capability indices based on current and optimum conditions. After the Gauge R&R analysis, the current system process capability was considered for the C30/37 class (C30) normal weight concrete through process capability indices. In optimal system, process capability ratios, which are the degrees of compliance with the specifications of C30, were determined on the basis of TOPSIS-based Taguchi optimization. Eventually, the actual capability improvement provided through the proposed methodology was considered quite significant.
A COMPARATIVE STUDY OF THE CAPABILITY OF ALTERNATIVE MIXED INTEGER PROGRAMMING FORMULATIONS
(2018) Keseci, Baris; Derya, Tusan; Dinler, Esra; Ic, Yusuf Tansel; AAC-4793-2019; F-1639-2011; AAI-1081-2020
In selecting the best mixed integer linear programming (MILP) formulation the important issue is to figure out how to evaluate the performance of each candidate formulation in terms of selected criteria. The main objective of this study is to propose a systematic approach to guide the selection of the best MILP formulation among the alternatives according to the needs of the decision maker. For this reason we consider the problem of "selecting the most appropriate MILP formulation for a certain type of decision maker" as a multi-criteria decision making problem and present an integrated AHP-TOPSIS decision making methodology to select the most appropriate formulation. As an example the proposed decision making methodology is implemented on the selection of the MILP formulations of the Capacitated Vehicle Routing Problem (CVRP). A numerical example is provided for illustrative purposes. As a result, the proposed decision model can be a tool for the decision makers (here they are the scientists, engineers and practitioners) who intend to choose the appropriate mathematical model(s) among the alternatives according to their needs on their studies. The integrated AHP-TOPSIS approach can simply be incorporated into a computer-based decision support system since it has simplicity in both computation and application.
Comparison of Fuzzy and Crisp Versions of an AHP and TOPSIS Model for Nontraditional Manufacturing Process Ranking Decision
(2019) Yurdakul, Mustafa; Ic, Yusuf Tansel; AAI-1081-2020
Nontraditional manufacturing processes (NTMPs) are especially preferred when it is necessary to machine very small and delicate parts, obtain complex shapes or process very hard and high strength materials. New NTMPs are developed continually and the total number of NTMPs being used in the machining industry is increasing so that ranking and selection of the most proper NTMP requires multi-level and systematic models. [M. Yurdakul and C. Cogun, Development of a multi-attribute selection procedure for non-traditional machining processes, Proc. Inst. Mech. Eng. J. Eng. Manuf. 217 (2003) 993-1009] developed such an NTMP ranking model. The developed NTMP ranking model in [M. Yurdakul and C. Cogan, Development of a multi-attribute selection procedure for non-traditional machining processes, Proc. Inst. Mech. Eng. J. Eng. Manuf. 217 (2003) 993-1009] had a two-level structure and used crisp Analytical Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) together to rank feasible NTMPs. This study aims to replace crisp (nonfuzzy) versions of the AHP and TOPSIS with the fuzzy ones. Application of the fuzzy NTMP ranking model is illustrated and its results are compared with the ones obtained in [M. Yurdakul and C. Cogan, Development of a multi-attribute selection procedure for non-traditional machining processes, Proc. Inst. Mech. Eng. J. Eng. Manuf. 217 (2003) 993-1009] to evaluate the significance of the differences in ranking results. The comparisons show that using fuzzy AHP and TOPSIS approaches instead of the crisp ones in the ranking model provided considerable ranking differences. The fuzzy NTMP ranking model is studied furthermore in the paper by updating the NTMP list and fine-tuning fuzzy weights of the pertinent attributes.
A Component Based Model Developed for Machine Tool Selection Decisions
(2020) Ic, Yusuf Tansel; Yurdakul, Mustafa; AAI-1081-2020
Machine tools are widely used in manufacturing sectors; such as automotive industry, metal cutting industry, aerospace industry etc. Purchase of a machine tool is a long-term capital investment decision and requires a high initial investment cost. Machine tool producers offer a wide-ranging types and models of machine tools. On the other hand, expectations and requirements of the manufacturing companies differ depending on the parts produced and their strategic objectives. High stiffness, rigidity, metal cutting performance, surface finish and low tolerance range are common expectations from machine tools. This paper aims to develop a technical evaluation model to help manufacturing companies in their machine tool purchasing decisions. In the proposed model, first components used in machine tools are analyzed and based on this analysis a technical evaluation model is developed. The application of the developed model is illustrated by making a selection among nine different machine tool alternatives.
A Decision Support System for Selection of Net-Shape Primary Manufacturing Processes
(2014) Yurdakul, Mustafa; Arslan, Emre; Ic, Yusuf Tansel; Turkbas, O. Selim; https://orcid.org/0000-0001-9274-7467; AGE-3003-2022
Developments in the capabilities of the manufacturing processes increased the number of processes that can produce a part within the requirements determined by its design and market research. The increased number of processes and unfamiliarity of manufacturing engineers to many new manufacturing processes forces the researchers to develop systematic process selection tools instead of depending on the accumulated human expertise only. In this paper, a net-shape primary manufacturing process selection decision support system (DSS), which is named PROSEL (PROcess SELection), is developed. The developed selection programme eliminates the unsuitable processes step by step by checking a part's material, annual production quantity, specified shape, thickness and presents the most economical process as the most appropriate net-shape primary process after a final cost analysis. The developed DSS is written in Visual Studio and tested with a great deal of real-life examples. It can be concluded from the tests that the programme provides the same or better primary manufacturing process selection decisions than the practical usage, and it is a very useful support tool for net-shape primary process selections.
Determination of periodic inspection time in pressurized equipment exposed to fatigue by estimating the probability of fracture
(2021) Sozen, Levent; Yurdakul, Mustafa; Ic, Yusuf Tansel; 0000-0001-9274-7467; AGE-3003-2022
It is essential to inspect the pressurized equipment such as vessels, pipes, heat exchangers, boilers, etc., which are under the influence of variable load periodically to minimize the possibility of damage occurring or early disclosure of existing damage. These inspections may be carried out at fixed time intervals or can be carried out at determined intervals depending on a risk assessment that considers settlement of the equipment, operating conditions, and the potential danger of the equipment's chemical contained. Within the scope of this study, we evaluate the thin-walled pressurized equipment under variable internal pressure load. Special attention is crucial to the hot points where the stress is relatively high for inspection of fatigue-related damage on the equipment. We know that stress concentration factors are critical in welded zones in thin-walled pressure vessels. Therefore, the fatigue crack formation in the welded joints is more likely than the equipment's base metal. As a result of the study, we present the probability of time-dependent damage under the effect of fatigue caused by variable internal pressure for butt welded joints. Also, we propose a new approach for periodic control planning. As a case study, damage probabilities of the fuel or gas pipelines operating under variable pressure are calculated based on the diversity of the mentioned parameters, and a new approach is provided to determine the most suitable periodic inspection interval.
Development and comparison of airplane fuselage panel assembly system alternatives using axiomatic design principles and simulation methodology
(2022) Celek, Osman Emre; Yurdakul, Mustafa; Ic, Yusuf Tansel; 0000-0001-9274-7467; AGE-3003-2022
This paper presents a combined usage of axiomatic design principles and simulation in developing and comparison of alternative assembly systems for airplane fuselage panels. In the application, four assembly system alternatives are obtained with axiomatic design methodology; and their performance results are obtained using simulation. The simulation results are made available for system designers to see each alternative's capabilities and make a comparison among the alternatives. The application of the proposed combined application of axiomatic design principles and simulation provides a reference guide for system designers to apply in designing other assembly systems' design.
Development of a Computer Application for Multi-Response Taguchi Optimization
(2016) Ic, Yusuf Tansel; Duran, Hikmet; Kececi, Baris; Ilik, Emrecan; Bilgic, Berkan; 0000-0001-9274-7467; 0000-0002-2730-5993; AGE-3003-2022; F-1639-2011; AAI-1081-2020; AAC-4793-2019; AGQ-5008-2022
In this study, a computer application has been developed for the parameter optimization problem having maximum three quality characteristics and three parameters having three levels for each parameter. When the quality characteristics and the level of the parameters affecting the problem are obtained, appropriate Taguchi array in accordance with an appropriate experimental design is determined by using the developed application. After the collection of the experimental results for the quality characteristics, multi-response optimization problem is converted to single response problem by using the TOPSIS method. In the developed application any parameter design problems having single, two or three quality characteristic can be optimized.
Development of A Decision Support System for Robot Selection
(2013) Ic, Yusuf Tansel; Yurdakul, Mustafa; Dengiz, Berna; 0000-0001-9274-7467; 0000-0002-1562-5738; AGE-3003-2022; AAA-6966-2021
With the availability of more different robot types and models along with their separate specifications, selecting the most appropriate robot is becoming more difficult and complicated for companies. Furthermore, a common set of robot selection criteria is not available for the decision makers. In this study, a two-phase robot selection decision support system, namely ROBSEL, is developed to help the decision makers in their robot selection decisions. In development of ROBSEL, an independent set of criteria is obtained first and arranged in the Fuzzy Analytical Hierarchy Process (FAHP) decision hierarchy. In the first elimination phase of the decision support system, the user obtains the feasible set of robots by providing limited values for the 15 requirements. ROBSEL, then, uses FAHP decision hierarchy to rank the feasible robots in the second phase. ROBSEL is illustrated and tested and several critical issues in its practical usage are explored in the paper. The applications of ROBSEL show that ROBSEL is a useful, practical and easy to use robot selection tool and improves robot selection decisions in the companies. (C) 2012 Elsevier Ltd. All rights reserved.
Development of a Decision Support System for Selection of Reviewers to Evaluate Research and Development Projects
(2023) Kocak, Serdar; Ic, Yusuf Tansel; Sert, Mustafa; Atalay, Kumru Didem; Dengiz, Berna
The evaluation of Research and Development (R&D) projects consists of many steps depending on the government funding agencies and the support program. It is observed that the reviewer evaluation reports have a crucial impact on the support decisions of the projects. In this study, a decision support system (DSS), namely R&D Reviewer, is developed to help the decision-makers with the assignment of the appropriate reviewer to R&D project proposals. It is aimed to create an artificial intelligence-based decision support system that enables the classification of Turkish R&D projects with natural language processing (NLP) methods. Furthermore, we examine the reviewer ranking process by using fuzzy multi-criteria decision-making methods. The data in the database is processed primarily to classify the R&D projects and the word embedding model NLP, "Word2Vec". Also, we designed the Convolutional Neural Network (CNN) model to select the features by using the automatic feature learning approach. Moreover, we incorporate a new integrated hesitant fuzzy VIKOR and TOPSIS methodology into the developed DSS for the reviewer ranking process.
Development of a decision support system to determine engineering student achievement levels based on individual program output during the accreditation process
(2021) Yorulmaz, Muhammet; Ic, Yusuf Tansel; 0000-0001-9274-7467; AGE-3003-2022; C-7863-2018
Accreditation studies and the number of programs that are accredited in engineering education are increasing day by day. In the auditing process, under the criteria of program outcomes, the level of individual students' achieving program outcomes is also considered as a sub-criterion. Failure to present a systematic approach to measuring the level of achievement of the program outcomes of the students who have reached the graduation stage in the evaluations or the use of questionnaires to measure them is considered insufficient evidence. In this study, a decision support system based on a multi-criteria decision-making model has been developed to determine the achievement levels of individual program outcomes (PO) of students who have reached the graduation stage of any engineering program. The MOORA (Multi- Objective Optimization on the basis of Ratio Analysis) method was used as a multi-criteria decision-making model, and the provision levels of POs were graded. In this way, the required evidence is created automatically by calculating the PO provision levels according to the compulsory and elective courses taken by the students at the graduation stage throughout their education life. We aimed to prevent the observed deficiencies and to set an example for the programs that will work the process. We developed a decision support system that can be used by engineering programs to determine whether their program satisfies accreditation requirements.
Development of a decision support system to select materials for pressure vessels
(2018) Ic, Yusuf Tansel; Balci, Arif; Yurdakul, Mustafa; AAI-1081-2020
Improvements in technologies applied in material field and continual increase in the number of material types force to develop and use new approaches in material selection. In this paper, a multi-criteria decision support system, called MATSEL, is developed to make material selection decisions for pressure vessel components more thorough and inclusive. MATSEL consists of two separate stages. In the first elimination stage of the MATSEL, it obtains a feasible set of materials for a specified pressure vessel component. MATSEL, then, uses three different multi criteria approaches namely ELECTRE, TOPSIS and VIKOR in the second stage to rank the feasible materials. An overall total score is obtained by summing the rankings of every feasible material and MATSEL proposes the material with the lowest total score as the most suitable one for the specified component. In this study, the statistical similarities between the rankings are also calculated to analyze the differences between rankings if there are any. Instead of inputting the materials every time MATSEL is used, a material data base is formed with the usage of ASME (American Society of Mechanical Engineers) and Ashby material selection diagrams for selection of alternative materials for the specified application.
Development of A Financial Performance Benchmarking Model for Corporate Firms
(2015) Ic, Yusuf Tansel; Tekin, Muhtesem; Pamukoglu, Fazil Ziya; Yildirim, S. Erdinc; 0000-0001-9274-7467; AGE-3003-2022; AGQ-5008-2022; AAI-1081-2020
In this study, we developed a financial performance evaluation model to rank the corporate firms of 24 sectors in the Turkish economy. The developed model is based on the financial ratiosand Technique for Order Preference by Similiarity to Ideal Solution (TOPSIS) approach. This model of ferscorporate firm's rating scores with respect to its competitors belonging to the same industry. The developed model is coded in Visual Basic and tested with real case studies. Financial performance evaluation rankings obtained from TOPSIS, Vise Kriterijumska Optimizacija I Kompromisno Resenje (VIKOR), Grey Relational Grade (GRA), and Multi-Objective Optimization on thebasis of Ratio Analysis (MOORA) methods were compared by using Spearman's rank correlation test. Based on the test results, it was found that the TOPSIS method is the most appropriate method for the evaluation of financial performance. An application is also provided in the paper for illustrative purposes.
Development of a Goal Programming Model Based on Response Surface and Analytic Hierarchy Process Approaches for Laser Cutting Process Optimization of St-52 Steel Plates
(2022) Yurdakul, Mustafa; Tukel, Taha; Ic, Yusuf Tansel
This paper presents an integrated model for optimization of laser cutting process of St-52 steel plates with multiple performance characteristics using Goal Programming (GP), Analytic Hierarchy Process (AHP), and Response Surface Methodology (RSM) approaches. In this study, optimum levels of the laser cutting process input parameters namely, material thickness, cutting speed, laser power, and assist gas pressure are obtained. For optimization purposes, four different surface roughness types of a cut surface, surface hardness, cutting time, and heat-affected zone (HAZ) of the cut surface are considered as performance outputs (responses) in this study. Optimization of multiple performance objectives (responses) requires obtaining regression functions with RSM first, and then weighting the regression functions using the AHP and finally combining the multiple functions into a single overall goal within a GP model and solving the model to optimize the laser cutting process. The study clearly shows that the presented optimization model is flexible enough to optimize the laser cutting process for various scenarios and conflicting priorities.
Development of A Graphical User Interface for Determining The Optimal Mixture Parameters of Normal Weight Concretes: A Response Surface Methodology Based Quadratic Programming Approach
(2014) Simsek, Baris; Ic, Yusuf Tansel; Simsek, Emir H.; Guvenc, Ali Bilge; https://orcid.org/0000-0001-9274-7467; AGE-3003-2022
The optimization of a normal weight concrete mixture proportions for determination of the desired concrete quality is an important issue for concrete manufacturers and users. In this study, the constrained quadratic programming methodology is based on meta-models developed by using response surface methodology for determining optimal normal weight concrete mixture proportions. We developed a graphical user interface to take the burden of numerous experiments and complex mathematical calculations away from laboratory experts and manufacturers. However, we developed a graphical user interface based on MATLAB (R) toolbox which allows performing optimization of normal weight concrete mixture proportions interactively. The GUI was tested through real case studies and satisfactorily results were obtained. The results showed that developed graphical user interface was functional, effective and flexible in solving the optimization problems of normal weight concrete mixture proportions. (C) 2014 Elsevier B.V. All rights reserved.