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Öğe A New Fuzzy Extension of the Simple WISP Method(Mdpi, 2022) Karabasevic, Darjan; Ulutas, Alptekin; Stanujkic, Dragisa; Saracevic, Muzafer; Popovic, GabrijelaThe purpose of this article is to introduce to the literature a new extension of the Simple WISP method adapted for utilizing the triangular fuzzy numbers. This extension is proposed to allow the use of the Simple WISP method for addressing decision-making problems related to uncertainties and inaccuracies, as well as for solving problems related to predictions. In addition, this article also discusses the use of linguistic variables to collect the attitudes of the respondents, as well as their transformation into appropriate triangular fuzzy numbers. The article discusses the use of two defuzzification procedures. The first normalization procedure is easy to use, while the second procedure uses the advantages that the application of asymmetric fuzzy numbers gives in terms of analysis. The usability of the proposed extension is presented through two examples.Öğe A New Hybrid MCDM Model for Insulation Material Evaluation for Healthier Environment(Mdpi, 2022) Aksakal, Berrak; Ulutas, Alptekin; Balo, Figen; Karabasevic, DarjanOne of the easiest and most common methods for effectively reducing building energy demand is the selection of adequate thermal insulation materials. Thermal insulation is a substantial contribution and an evident, logical and practical first stage toward improving energy performance, particularly in envelope-load-dominant structures located in difficult climate zones. Today's insulating materials come in a broad variety of sizes and shapes, each with its a own qualities. It is well acknowledged that material selection is one of the most difficult and time-consuming aspects of a construction project. Therefore, choosing the right insulation material is also a very important topic to increase energy efficiency. However, it is a complex problem with many criteria and alternatives. This study integrates three different multi criteria decision making methods, which are Fuzzy Best-Worst Method, CRiteria Importance Through Inter-criteria Correlation and Mixed Aggregation by COmprehensive Normalization Technique. In this study, the following eight criteria were taken into account in the evaluation: thermal conductivity, periodic thermal transmittance, specific heat, density, decrement factor, surface mass, thermal transmittance, and thermal wave shift. The first method will be used to find the subjective weights, while the second method will be used to find the objective weights. The third method will be used to rank the insulation materials. According to the results of the Fuzzy Best-Worst Method, the most important criterion was determined as thermal conductivity. According to the results of the CRiteria Importance Through Inter-criteria Correlation, the most important criterion was determined as thermal wave shift. According to the results of the Mixed Aggregation by COmprehensive Normalization Technique, the top 10 insulation materials are as follows: polyisocyanurate, polyurethane (1), polyurethane (2), wood fiber (1), kenaf, jute, cellulose (2), wood fiber (1), XPS (1) and XPS (2). According to the results of the proposed method, polyisocyanurate was determined as the best insulation material for healthier environment. This study makes two contributions to the literature: first, a new hybrid method was developed in this study. Secondly, in this study, the newly introduced Mixed Aggregation by COmprehensive Normalization Technique method was used.Öğe A New Hybrid MCDM Model for Personnel Selection Based on a Novel Grey PIPRECIA and Grey OCRA Methods(Mdpi, 2020) Ulutas, Alptekin; Popovic, Gabrijela; Stanujkic, Dragisa; Karabasevic, Darjan; Zavadskas, Edmundas Kazimieras; Turskis, ZenonasPeople represent one of the most significant resources of an organization, and therefore, personnel selection is one of the problems that organizations have increasingly been facing. The criteria that influence the final decision are usually opposing, so the application of multiple-criteria decision-making methods (MCDM) represents a suitable way for the facilitation of the given process. Additionally, the decision environment is characterized by the vagueness and uncertainty and, because of that, it is very hard to express the criteria over the exact crisp numbers. To acknowledge the unpredictability and obscurity of the available information important for the selection of the optimal candidate, a hybrid grey MCDM model for personnel selection is proposed in this paper. As an extension of the PIPRECIA method, the novel Grey Pivot Pairwise Relative Criteria Importance Assessment-the PIPRECIA-G method-is proposed and used for the determination of criteria importance. The PIPRECIA-G method preserved the good features of the PIPRECIA, but its superiority is reflected in its ability to deal with input data that are vague and grey. For the final ranking of the considered alternative candidates, the OCRA-G method is used. Basing the decision process and candidate selection on the two grey extended MCDM methods contributes to the increase of the reliability and confidence in the performed selection.Öğe A new hybrid model based on rough step-wise weight assessment ratio analysis for third-party logistics selection(Springer, 2022) Ulutas, Alptekin; Topal, AyseIncreasing competition as a result of globalization has forced the businesses to increase efficiency by focusing on the core competencies. This led businesses to outsource logistics. As a result, most of the businesses started to use third-party logistics (3PLs). There are various and conflicting criteria involved in 3PL selection, thus the selection of 3PL is a complex task for businesses. There are several methods in the literature used for 3PL selection, most of them are multi-criteria decision-making methods. A new hybrid model including Rough step-wise weight assessment ratio analysis (SWARA), Rough preference selection Index (RPSI), and Rough improved operational competitiveness rating analysis (IOCRA) has been used to select optimal third-party logistics providers in this study. There are two contributions to this study. First one is the development of a new hybrid rough model for 3PL selection. Second one is addressing the 3PL selection decision problem with newly developed Rough PSI and Rough IOCRA methods. Using this model and conducting a comprehensive analysis, the best option as a 3PL provider may be determined as a partner for logistics. The model effectiveness has been tested in a real case with a textile business and several 3PL providers.Öğe A Novel Extension of the TOPSIS Method Adapted for the Use of Single-Valued Neutrosophic Sets and Hamming Distance for E-Commerce Development Strategies Selection(Mdpi, 2020) Karabasevic, Darjan; Stanujkic, Dragisa; Zavadskas, Edmundas Kazimieras; Stanimirovic, Predrag; Popovic, Gabrijela; Predic, Bratislav; Ulutas, AlptekinNeutrosophic sets have been recognized as an effective approach in solving complex decision-making (DM) problems, mainly when such problems are related to uncertainties, as published in numerous articles thus far. The use of the three membership functions that can be used to express accuracy, inaccuracy, and indeterminacy during the evaluation of alternatives in multiple-criteria DM can be said to be a significant advantage of these sets. By utilizing these membership functions, neutrosophic sets provide an efficient and flexible approach to the evaluation of alternatives, even if DM problems are related to uncertainty and predictions. On the other hand, the TOPSIS method is a prominent multiple-criteria decision-making method used so far to solve numerous decision-making problems, and many extensions of the TOPSIS method are proposed to enable the use of different types of fuzzy as well as neutrosophic sets. Therefore, a novel extension of the TOPSIS method adapted for the use of single-valued neutrosophic sets was considered in this paper.Öğe An analysis of the logistics performance index of EU countries with an integrated MCDM model(Sciendo, 2019) Ulutas, Alptekin; Karakoy, CagatayCountries can check the performance of their logistics' activities to determine their competitiveness in trade logistics. One way to check these performances is to analyze the country's LPI value in detail which is released by the WB every two years. When calculating the LPI, six indicators (criteria) are taken into account. The weights (importance level) of these criteria are important for countries which would like to focus more on the most important criteria and move their ranking up in the LPI list. However the WB takes into account indicators (criteria) weights equally when calculating LPI values. In order to overcome this problem some studies have used subjective weighting methods and others have used objective weighting methods. Both methods have advantages and disadvantages. The aim of this study is to integrate two weighting methods (subjective (SWARA) and objective (CRITIC)) in determining the weights of criteria in order to balance the two weighting methods. Unlike other studies in the literature this study combines two weighting methods. Additionally the PIV method, which is seldom used to address any MCDM problem, is used in this study and a new integrated MCDM model is introduced to literature. In this respect this study contributes to the literature.Öğe An Innovative Grey Approach for Group Multi-Criteria Decision Analysis Based on the Median of Ratings by Using Python(Mdpi, 2021) Stanujkic, Dragisa; Karabasevic, Darjan; Popovic, Gabrijela; Stanimirovic, Predrag S.; Smarandache, Florentin; Saracevic, Muzafer; Ulutas, AlptekinSome decision-making problems, i.e., multi-criteria decision analysis (MCDA) problems, require taking into account the attitudes of a large number of decision-makers and/or respondents. Therefore, an approach to the transformation of crisp ratings, collected from respondents, in grey interval numbers form based on the median of collected scores, i.e., ratings, is considered in this article. In this way, the simplicity of collecting respondents' attitudes using crisp values, i.e., by applying some form of Likert scale, is combined with the advantages that can be achieved by using grey interval numbers. In this way, a grey extension of MCDA methods is obtained. The application of the proposed approach was considered in the example of evaluating the websites of tourism organizations by using several MCDA methods. Additionally, an analysis of the application of the proposed approach in the case of a large number of respondents, done in Python, is presented. The advantages of the proposed method, as well as its possible limitations, are summarized.Öğe An Integrated Simple Weighted Sum Product Method-WISP(IEEE-Inst Electrical Electronics Engineers Inc, 2023) Stanujkic, Dragisa; Popovic, Gabrijela; Karabasevic, Darjan; Meidute-Kavaliauskiene, Ieva; Ulutas, AlptekinUntil now, many different multiple criteria decision-making methods have been proposed for the facilitation of different business problems such as entrepreneurial. In this article, a new approach for selecting the most acceptable alternative is considered, which is based on the integration of weighted sum and weighted product approaches. The basic idea of the newly proposed approach is partly based on the multiobjective optimization by ratio analysis plus the full multiplicative form method, but also includes some features of the weighted aggregated sum product assessment and combined compromise solution methods. The proposed method is tested by using two illustrative examples that are related to the contractor and industrial robot selection. Additionally, to test its reliability, the obtained results are compared with the ones gained by using the multiple-criteria decision-making methods of the first and second generations. The proposed method predicts the application of a much simpler normalization procedure, involves four utility measures for defining the overall utility of alternatives, and enables a much easier ranking of them. The final conclusion is that the simple weighted sum product method is easy to use and contributes to the increasing of the reliability of decisions that are made. Therefore, the proposal uses a much simpler normalization procedure, i.e., four utility measures for determining the overall utility of alternatives, and allows a much easier ranking of alternatives.Öğe An Application of Fuzzy Integrated Model in Green Supplier Selection(HINDAWI LTD, 2019) Ulutas, Alptekin; Topal, Ayse; Bakhat, RimSustainability term has not only become increasingly important globally for individual companies, but also become important for whole supply chains. The selection of supplier is a significant decision for the sustainability of supply chains. Literature review revealed that supplier selection is made traditionally based on economic attributes which are insufficient for sustainability of supply chains as sustainability requires taking economic, environmental, and social issues into account. For this purpose, this paper proposes determining the green supplier selection attributes and then developing a methodology for assessment and ranking of green suppliers based on determined attributes. The first contribution of this study is to propose a novel method, which is FROV (fuzzy extension of range of value) to literature. The latter is to utilize fuzzy extension of preference selection index (FPSI) to identify the weights of attributes. The third is to develop a novel fuzzy multiattribute decision-making model consisting of FPSI and FROV to determine the best supplier for a Turkish textile company.Öğe Assessment of Collaboration-Based and Non-Collaboration-Based Logistics Risks with Plithogenic SWARA Method(Mdpi, 2021) Ulutas, Alptekin; Meidute-Kavaliauskiene, Ieva; Topal, Ayse; Demir, EzgiBackground: Uncertainty is the major source of hazards, and it is present in a wide range of business activities. Due to the high level of unpredictability in logistics operations, the logistics sector has traditionally operated in a high-risk environment. These risks have become considerably more complicated as the corporate environment has changed in recent years, such through globalization, environmental concerns, and changes in demand. As a result, in order for a logistics firm to thrive, it is necessary to evaluate and assess the risks associated with logistics. Methods: The Plithogenic Stepwise Weight Assessment Ratio Analysis (SWARA) has been used in this study to assess the logistics risks. The logistics risk considered in this study are transportation-related risks, purchasing-related risks, inventory-related risks, information-related risks, packaging-related risks, operational-related risks, geographical location-related risks, natural disaster-related risks, and organization-related risks. Results: The most significant logistics risks are found to be Inventory-Related Risks, while the least significant are Geographical Location-Related Risks. When compared to the standard SWARA approach, the Plithogenic SWARA method may be employed in group decision-making issues without losing information. Conclusions: The proposed technique will help logistics professionals make informed decisions and manage and analyze risks more efficiently. This study will also contribute to the literature as it is the first time that logistical risks have been addressed by utilizing the Plithogenic SWARA technique.Öğe Comparative Analysis of the Simple WISP and Some Prominent MCDM Methods: A Python Approach(Mdpi, 2021) Stanujkic, Dragisa; Karabasevic, Darjan; Popovic, Gabrijela; Zavadskas, Edmundas Kazimieras; Saracevic, Muzafer; Stanimirovic, Predrag S.; Ulutas, AlptekinThis article presents a comparison of the results obtained using the newly proposed Simple Weighted Sum Product method and some prominent multiple criteria decision-making methods. For comparison, several analyses were performed using the Python programming language and its NumPy library. The comparison was also made on a real decision-making problem taken from the literature. The obtained results confirm the high correlation of the results obtained using the Simple Weighted Sum Product method and selected multiple criteria decision-making methods such as TOPSIS, SAW, ARAS, WASPAS, and CoCoSo, which confirms the usability of the Simple Weighted Sum Product method for solving multiple criteria decision-making problems.Öğe COUNTRY RANKING ACCORDING TO LOGISTICS EVALUATION CRITERIA: THE EFFECT OF DIFFERENT METHODS ON THE RANKING(Mehmet Akif Ersoy Univ, 2022) Ozdagoglu, Askin; Ulutas, Alptekin; Keles, Murat KemalThe World Bank determines the logistics performance of countries every two years according to six criteria (customs, infrastructure, international shipments, logistics quality and competence, tracking and tracing and, timeliness). The purpose of this study is to evaluate the logistics performances of 160 countries included in the 2018 report published by the World Bank, using multi criteria decision making methods, and to reveal how much these evaluations are affected by the methods. The logistics performance of 160 countries is evaluated using seven different multi criteria decision making methods. Rankings made with seven different multi criteria decision making method were combined with the Borda rule method. The relationships between the rankings obtained by the application of each method are also presented with appropriate statistics.Öğe Determination of Renewable Energy Source in Turkey by COPRAS and Analysis of the Employment-Enhancing Effect of Renewable Energy Investments(MALIYE BAKANLIGI, 2017) Karaca, Coskun; Ulutas, Alptekin; Esgunoglu, MahmureThe present study estimates the increase in the number of jobs resulting from the additional investments in energy sector if Turkey's renewable energy percentage in the electricity generation is 100%. The share to be allocated to each renewable energy source within additional investment value is determined according to COPRAS-based multi-criteria decision making method. The contribution of renewable energy investment value which is determined through COPRAS to employment in the country has been estimated according to Jobs and Economic Development Impact (JEDI) Model which was developed by National Renewable Energy Laboratory (NREL). According to results of the model, it is estimated that a total of 1.132.545 additional jobs will be created with following breakdown through the installation and operation of 56.694 MW renewable energy plants instead of fossil fuel power stations: to 576.664 people directly, to 322.852 people indirectly and to 233.030 people through stimulated employment.Öğe Development of a Novel Integrated CCSD-ITARA-MARCOS Decision-Making Approach for Stackers Selection in a Logistics System(Mdpi, 2020) Ulutas, Alptekin; Karabasevic, Darjan; Popovic, Gabrijela; Stanujkic, Dragisa; Nguyen, Phong Thanh; Karakoy, CagatayThe main goal of this paper is to propose a Multiple-Criteria Decision-Making (MCDM) approach that will facilitate decision-making in the field of logistics-i.e., in the selection of the optimal equipment for performing a logistics activity. For defining the objective weights of the criteria, the correlation coefficient and the standard deviation (CCSD method) are applied. Furthermore, for determining the semi-objective weights of the considered criteria, the indifference threshold-based attribute ratio analysis method (ITARA) is used. In this way, by combining these two methods, the weights of the criteria are determined with a higher degree of reliability. For the final ranking of the alternatives, the measurement of alternatives and ranking according to the compromise solution method (MARCOS) is utilized. For demonstrating the applicability of the proposed approach, an illustrative case study pointing to the selection of the best manual stacker for a small warehouse is performed. The final results are compared with the ones obtained using the other proved MCDM methods that confirmed the reliability and stability of the proposed approach. The proposed integrated approach shows itself as a suitable technique for applying in the process of logistics equipment selection, because it defines the most influential criteria and the optimal choice with regard to all of them in a relatively easy and comprehensive way. Additionally, conceiving the determination of the criteria with the combination of objective and semi-objective methods enables defining the objective weights concerning the attitudes of the involved decision-makers, which finally leads to more reliable results.Öğe Evaluation of GIS-based multi-criteria decision-making methods for sanitary landfill site selection: the case of Sivas city, Turkey(Springer, 2020) Karakus, Can Bulent; Demiroglu, Demet; Coban, Aysen; Ulutas, AlptekinLandfill is the most common method used to eliminate municipal solid waste in developing countries. As in all developing residential units, Sivas city is also encountering a major solid waste problem menacing both public health and environment. This study analyzes the 7 criteria (geological structure, land ability class, transportation, groundwater, surface water, residential areas, and existing land use) utilized for solid waste landfill area preference reasons by employing some Geographical Information System (GIS) based, multi-criteria decision-making methods such as Analytical Hierarchy Process (AHP) and Simple Additive Weighting (SAW). Evaluation of alternative areas defined by AHP and SAW methods is conducted with the help of Combinative Distance-Based Assessment (CODAS). The study area was classified as most suitable, suitable, averagely suitable, too little suitable and not suitable in terms of their sanitary landfill properties. According to AHP and SAW analyses results, it was determined that a large part of the study area (respectively, 46.82% and 27.81%) is within the category of averagely suitable. After the application based on GIS oriented multi-criteria decision-making analysis, 4 alternative places as solid waste disposal areas were recommended by taking environmental and physical factors into consideration. AHP-CODAS and SAW-CODAS methods were mutually utilized to rank these 4 areas according to their suitability. As a result, Area1 in integrated weights (AHP and SAW)-CODAS was selected as the most appropriate place for sanitary permanent landfill.Öğe Location selection for logistics center with fuzzy SWARA and CoCoSo methods(Ios Press, 2020) Ulutas, Alptekin; Karakus, Can Bulent; Topal, AyseLogistics centers are home to many and varied facilities, such as storage, transportation of goods, handling, reassembling, clearing, disassembling, quality control, social services and providing accommodation, so on. Providing logistical activities from one location can provide some macro advantages, as well as regional development in developing countries. For the micro level, logistics center selection has an effective role in increasing the operational efficiency and decreasing the costs of the firms. While the wrong location selection for logistics center affects the operations and costs of the companies negatively, the optimal location selection increases the performance, competitiveness, profitability of the firms and reduces the costs of the firms. Since many different qualitative and quantitative criteria are considered in the selection of the logistics center, this selection problem is an MCDM problem. A new integrated MCDM model is proposed to solve this problem for Sivas province in Turkey. This study presents two contributions to the literature. Firstly, the number of studies related to CoCoSo method is limited in the literature, therefore, the CoCoSo method is proposed in this study. Secondly, a new integrated GIS-based MCDM model comprising fuzzy SWARA and CoCoSo is introduced to literature to address the location selection problem for a logistics center. In this study, the results of CoCoSo method and the resulfts of other MCDM methods (COPRAS, VIKOR, ARAS, MOORA, and MABAC) are compared to test the accuracy of results obtained by CoCoSo. Besides, the criteria weights are changed and the possible changes in the results are tracked.Öğe New Grey Integrated Model to Solve a Machine Selection Problem for a Textile Company(Inst Chemical Fibres, 2020) Ulutas, AlptekinThe textile sector has become an indispensable part of the Turkish economy. The sewing machine is a long-lasting and easy-to-use tool widely used in the garment industry, which is a branch of the textile industry. The sewing machine is an indispensable production tool for the textile industry and sewing machine selection is a significant decision for the production performance of textile companies. Selecting an appropriate sewing machine increases production performance, while selecting an improper one reduces production performance. The sewing machine selection problem is a typical machine selection issue. Many criteria, such as cost, productivity, safety etc. are considered in the machine selection. Therefore, MCDM methods are applicable to solve the machine selection problem. This study develops an integrated grey MCDM model including Grey AHP and ROV-G to select the most appropriate sewing machine for an apparel textile company.Öğe Pallet truck selection with MEREC and WISP-S methods(Univ Novi Sad, Fac Economics Subotica, 2022) Ulutas, Alptekin; Stanujkic, Dragisa; Karabasevic, Darjan; Popovic, Gabrijela; Novakovic, SrdanBackground: The article presents an MCDM model based on the MEREC and WISP-S methods for pallet truck selection. Purpose: The main purpose of the study was to apply a new MCDM model for pallet truck selection in the textile workshop. Study design/methodology/approach: This article presents a simplified adoption of the Simple Weighted Sum Product (WISP) method, the Simplified WISP (WISP-S) method. The proposed method has fewer computation steps than the regular WISP method. In addition, this study proposes a new hybrid MCDM model in the literature by combining the MEREC method and the WISP-S method. Finding/conclusions: The obtained results can be achieved in a shorter time compared to regular WISP. The application of the new method is considered in this study. In order to check whether the WISP-S method achieves accurate results, the results of the WISP-S method and the results of the ROV and WASPAS methods were compared. As a result of the comparison of the results of the methods, it was observed that the WISP-S method achieved accurate results. Limitations/future research: As a direction for future research, other MCDM models can be applied for solving the same problem. When it comes to the limitations of the proposed model, it can be mentioned that the MCDM model is based on the use of crisp numbers.Öğe PERFORMANCE ANALYSIS FOR THE MOST CONVENIENT WIND TURBINE SELECTION IN WIND ENERGY FACILITY(Editura Ase, 2022) Zavadskas, Edmundas Kazimieras; Ulutas, Alptekin; Balo, Figen; Stanujkic, Dragisa; Karabasevic, DarjanAs governments seek renewable and more sustainable energy resources, wind energy has emerged as one of the most rapidly developing renewable power resources. The relevance of wind energy turbines has grown as more nations turn to renewable energy. A significant criterion that conduces to wind energy's efficient production is the proper wind turbine's utilize. Due to the fact that a lot of wind turbine manufacturers have built a global presence, it is critical for project administrators to do informed selections about which wind energy turbines to establish in every specific design. Therefore the problem of wind energy turbine choice is critical for nations experiencing global warming and climate change. This study proposes a new hybrid MCDM model including CCSD and MULTIMOOSRAL methods. In this study, 11 100kW wind turbines (T) are evaluated based on 14 criteria. According to the results of the proposed model, T7 coded wind turbine alternative was determined as the best one. The results of the proposed method were compared with other MCDM methods and it was confirmed that the proposed method reached accurate results. In addition, it was determined that the changes in the criteria weights changed the ranking of the alternatives.Öğe The Selection of Appropriate Renewable Energy Source For Turkey By Using Entropy and Waspas Methods(EGE UNIV, FAC ECONOMICS & ADMIN SCIENCES, 2018) Karaca, Coskun; Ulutas, AlptekinThe production and consumption of energy, which are indispensable inputs for production, cause negative externalities on the environment and human health as well as harm the development of the country. Therefore, countries have two basic motivations when selecting energy source. The first is to have a strong economy by taking into account the increase in production and competitive power provided by the energy source, and the second is to avoid the selection of energy source that will reduce the prosperity of the people. The technical, economic, environmental and social criteria of renewable energy sources are ranked with respect to their importance degree by means of Entropy method in this study where the energy source selection which can be suitable for our country is made. In this study where the energy source selection which can be suitable for our country is made and in second stage the WASPAS method is used to suggest which renewable energy source is the most suitable to meet the energy demand in Turkey. The results obtained in WASPAS method indicated the ranking of renewable energy sources, which are the suitable for investment in Turkey, as Hydro, Geothermal, Wind, Biomass, Solar.
