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Öğe Addressing the challenges of using autonomous robots for last-mile delivery(Pergamon-Elsevier Science Ltd, 2024) Ayyildiz, Ertugrul; Erdogan, MelikeThe importance of last-mile delivery (LMD) in today's logistics networks has increased recently due to the rising popularity of e-commerce and home delivery. Various LMD modes, such as drones and autonomous vehicles, have emerged to solve the problems encountered during LMD activities and to reduce human intervention in the process. The purpose of this paper is to determine the challenges that arise when using autonomous delivery robots (ADRs) in LMD. Throughout the research, the challenges have been revealed, categorized into six titles and their significance has been calculated via the intuitionistic fuzzy (IF) pivot pairwise relative criteria importance assessment (PIPRECIA) method in conjunction with PESTEL Analysis. IF-PIPRECIA is employed for the first time in the literature with PESTEL Analysis to evaluate the challenges for the implementation of ADRs in LMD. According to the proposed methodology results, challenges related to Energy consumption, Battery life and energy management, Cybersecurity, Air pollution, and Uncertain return on investment are the most critical factors to consider when implementing ADRs in LMD.Öğe A comprehensive risk assessment framework for occupational health and safety in pharmaceutical warehouses using Pythagorean fuzzy Bayesian networks(Pergamon-Elsevier Science Ltd, 2024) Ayyildiz, Ertugrul; Erdogan, Melike; Gul, MuhammetRisk assessment plays a crucial role in managing occupational health and safety in various industries, including pharmaceutical warehouses. Bayesian Networks (BN) have been widely employed for risk assessment due to their ability to handle uncertainty and quantify risks. However, the traditional BN approach has limitations in dealing with ambiguity and continuous variables. To address this, the fuzzy BN technique, combining fuzzy logic with BN, has emerged as an effective method for risk assessment. In this study, a fuzzy BN model using Pythagorean fuzzy sets is proposed for risk assessment in a pharmaceutical warehouse. The model incorporates 24 identified risk factors, and survey data is used to determine the conditional probabilities of these factors. The novelty of the study lies in the application of Pythagorean fuzzy sets and the development of risk assessment criteria specifically for pharmaceutical warehouses. The results of a comprehensive literature review and the proposed methodology are presented. A real case analysis is conducted, followed by validation and sensitivity analysis. The results provide valuable insights into enhancing occupational health and safety practices in pharmaceutical warehouses. The study contributes to enhancing occupational health and safety practices in pharmaceutical warehouses and provides a framework for future research.Öğe Creating a road map for industry 4.0 by using an integrated fuzzy multicriteria decision-making methodology(Springer, 2020) Kaya, Ihsan; Erdogan, Melike; Karasan, Ali; Ozkan, BetulIndustry 4.0 can be defined as a creative manufacturing concept which is the integration of up-to-date technologies such as wireless systems, cyberphysical systems, Internet of things, cloud computing, big data concept to increase flexibility, and speed in production systems. The concept also aims to transform the manufacturing industry into the next generation. Selection among appropriate strategies for transition to industry 4.0 is crucial and should be considered in a multidimensional perspective since the decision process involves many strategies with respect to multicriteria based on the judgments of multiexperts. In this paper, this critical decision has been considered as a multicriteria decision-making (MCDM) problem under the uncertainty and vagueness environments. To increase the applicability of the uncertain data for the proposed methodology, intuitionistic fuzzy sets have been adopted. In other words, an integrated fuzzy MCDM methodology consists of interval-valued intuitionistic fuzzy analytic hierarchy process and interval-valued intuitionistic fuzzy technique for order performance by similarity to ideal solution has been suggested to prioritize of transition strategies for industry 4.0. According to proposed approach, Training and continuing professional development is determined as the most important strategy during the transition process, while Technology and Equipment and Tools are specified as the most crucial main and sub-criterion, respectively. For the validation process, we also applied two distance-based methods on the same decision matrices as a comparative analysis. Both analyses' results yield that the proposed methodology is applicable and effective for the decision-making process. Besides, the results of the one-at-a-time sensitivity analyses based on the changes of main criteria weights confirm the sensitivity and flexibility of the proposed methodology. Finally, a road map for transition to industry 4.0 has been determined with respect to priorities of strategies based on the constructed context.Öğe Creating proactive behavior for the risk assessment by considering expert evaluation: a case of textile manufacturing plant(Springer Heidelberg, 2021) Karasan, Ali; Erdogan, MelikeApplying risk assessment approaches to improve quality in enterprises is of great importance especially for sectors that are labor-intensive and thus frequently encountered failures. One of the methods frequently used to take precautions against failures caused by high variability in this type of sector is failure mode and effects analysis (FMEA). In this study, a hybrid FMEA approach is proposed so as to take measures against failures in the textile sector where there are high-quality differences due to its structure and failures frequently occurred. Since the different combinations of risk parameters' scores may produce the same risk degree based on the function of the FMEA's basis, misleading results for the risk analysis in the practical risk management can be occurred. Moreover, the risk priority number (RPN) function has a limitation in the weight determining process, since it assigns the equal weight for each risk parameter in the classical FMEA. To overcome these shortcomings in the RPN calculation for the risks in the FMEA approach, a multi-criteria decision-making (MCDM) approach is applied under the framework of fuzzy logic. Through that, in this study, we aimed to prove an expert system based on the rules that specifically focusing on the risk sources of the woven fabric industry. To create such a rule-based system, inputs are generated using fuzzy AHP and modified fuzzy TOPSIS. A case study is carried out with the method proposed in a textile mill, and it is determined which risks arising from failures are higher. For the validation of the results, a comparative analysis is conducted. Moreover, for the robustness of the decisions, one-at-a-time sensitivity analysis with respect to different scenarios are applied. As a result of the analyses, it is shown that our proposed model can be used as an efficient proactive risk calculator for the managers or researchers to make useful inferences, judgments, and decisions of the production processes for eliminating the shortcomings of the traditional FMEA.Öğe A decision support mechanism in the determination of organic waste collection and recycling center location: A sample application for Turkiye(Elsevier, 2023) Ayyildiz, Ertugrul; Erdogan, MelikeThe location problem of organic waste collection and recycling plants is a significant concern for policy makers in developing countries. Factors such as rapid population growth, unplanned urbanization, and limited resources pose challenges to the efficient management of organic waste. Inadequate waste disposal practices not only endanger the environment and human health but also hinder the development of sustainable and livable cities. Therefore, it is crucial to address the specific challenges associated with locating organic waste collection and recycling facilities to ensure effective waste management and promote environmental sustainability. This study aims to identify the most appropriate location for an organic waste collection and recycling facility for compost production. This study involves identifying the most influential aspects of organic waste collection and recycling center location selection through a literature review and expert opinion. The Analytical Hierarchy Process (AHP) methodology with fuzzy interval type-2 (T2F) sets is employed to weight the criteria. The COmbinative Distance-based Assessment (CODAS) approach is extended in a T2F environment to better reflect the uncertainty and evaluate the alternative locations. The study concludes by revealing the optimal location for the food waste collection center for Trabzon city in Turkiye. To verify the validity and reliability of the proposed integrated methodology, a comparative analysis was also performed using various decision-making methods.(c) 2023 Elsevier B.V. All rights reserved.Öğe A fuzzy approach for prioritization of pharmacies to improve mask distribution process during COVID-19 pandemic-a pilot study for Istanbul(Springer London Ltd, 2023) Erdogan, MelikeWhile the whole world struggles with the COVID-19 pandemic, there are many different measures taken by countries. In this sense, the distribution of free masks to citizens between the ages of 20-65 in Turkey is one of the important measures taken against to spread of the pandemic. This distribution process is carried out through pharmacies and people can obtain their masks from any pharmacy in their area of residence. However, this situation may cause some pharmacies to be very busy, and thus social distance cannot be maintained and health and safety of the people may be threatened. In this paper, we aim to prioritize pharmacies so that only determined pharmacies in certain regions perform mask distribution process to prevent virus transmission. For this purpose, Esenler district is taken into consideration for a pilot study which is one of the risky regions in terms of virus spread in Istanbul, Turkey. Multi-criteria decision-making approach (MCDM) is used because of the necessity of handling many factors in decision-making process and the contradiction of evaluation factors in the prioritization of pharmacies. In order to best model the uncertainty in the decision process, the MCDM approach is applied in a fuzzy environment. In addition, spherical fuzzy AHP and VIKOR MCDM approaches are used as novel hybrid method in this paper. As a result of spherical fuzzy multi-criteria analysis, the pharmacies that need to provide free mask distribution in the Esenler region have been successfully identified.Öğe An integrated decision support model for effective institutional coordination framework in planning for public transportation(Springer, 2023) Bouraima, Mouhamed Bayane; Oyaro, Janet; Ayyildiz, Ertugrul; Erdogan, Melike; Maraka, Ndiema KevinThe absence of effective coordination among different institutions involved in planning for public transportation has become a prominent global concern. At present, numerous cities are grappling with the need to establish a customized framework for institutional coordination that aligns with the specific circumstances of each city. Decision-makers encounter obstacles in the form of uncertainty when evaluating strategies aimed at promoting effective institutional coordination in planning for public transportation. In this study, a two-stage model is introduced that integrated the method based on the Step-Wise Weight Assessment Ratio Analysis (SWARA) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method into a unique framework under the interval-valued spherical fuzzy (IVSF) environment to determine the weights of the criteria and ranks the strategies, respectively. A case study of Nairobi is employed to demonstrate the formulation and solution of the problem. A sensitivity analysis was carried out to evaluate the stability of the proposed model. The results of the analysis revealed that the lack of political will and corruption, inadequate participation in planning, and poor vision or plan for the city are the foremost challenges in achieving effective institutional coordination in planning for public transportation. Furthermore, the sensitivity analysis ranked the implementation of good governance principles as the top strategy to overcome these challenges. This study introduces an innovative perspective that specifically targets local governments and tackles the problem of unregulated fragmentation within public transportation agreements among diverse institutions. Furthermore, it provides a framework designed to streamline the implementation of separate public transportation initiatives.Öğe A Pythagorean fuzzy number-based integration of AHP and WASPAS methods for refugee camp location selection problem: a real case study for Istanbul, Turkey(Springer London Ltd, 2021) Ayyildiz, Ertugrul; Erdogan, Melike; Gumus, Alev TaskinThere is an increase in the number of people who have changed their country for compulsory reasons due to the wars experienced worldwide. This raises the problem of identifying the regions where these people, called refugees, will live in the countries. In this regard, we determine in this paper where the camps established for refugees living in Istanbul should be located. The presence of many quantitative and qualitative factors which should be handled in determining the best location has enabled this problem to have multi-criteria decision-making structure. In addition, the advantage of fuzzy logic is used to convert the evaluations taken from experts into available numbers and to include them in decision-making process. For this purpose, a novel model with the integration of Pythagorean fuzzy AHP and Pythagorean fuzzy WASPAS methods is proposed for the first time in the literature, to select the best location for the refugee camp. In addition, a comparative analysis is applied to determine the validity of the results obtained and the sensitivity analysis is applied to check the robustness of the model. As a result, the most suitable location for a refugee camp in Istanbul is identified reasonably with the proposed model.Öğe Real-time location systems selection by using a fuzzy MCDM approach: An application in humanitarian relief logistics(Elsevier, 2020) Budak, Aysenur; Kaya, Ihsan; Karasan, Ali; Erdogan, MelikeThe real-time location systems (RTLSs) with different positioning technologies allow real-time and high-precision localization of assets. Since the usage of RTLSs technologies and their population increase, RTLSs technology selection problem that addresses many factors should be considered. Therefore, it is important to determine the performance criteria and evaluation of these technologies should be investigated before RTLSs technology is applied to the system. This paper aims to select the most appropriate RTLSs technology by using a combined fuzzy based decision-making approach. Thus, the first paper for selection of RTLSs systems in a holistic approach by combining benefit and risk factors has been revealed. The developed approach is applied to humanitarian relief logistics warehouse with four alternatives which are given as Ultra-Wide Band, Wi-Fi, UHF RFID and Active RFID for the selection. The proposed approach has been integrated with interval-valued intuitionistic fuzzy (IVIF) sets that allow to deal with fuzziness inherent in decision making processes. For this aim, firstly IVIF DEMATEL is used to determine the inner and outer dependencies of the sub and main criteria; secondly, weights of the sub-criteria are obtained by using IVIF ANP. Finally, the best RTLSs technology to be used in humanitarian logistics warehouse is selected by using IVIF TOPSIS. As a result of the calculations, the best system is determined as the Wi-Fi RTLS'' system based on the given context. By the way, a sensitivity analysis has been also implemented to test and validate the developed methodology. (C) 2020 Elsevier B.V. All rights reserved.Öğe A systematic approach to evaluate risks and failures of public transport systems with a real case study for bus rapid system in Istanbul(Elsevier, 2020) Erdogan, Melike; Kaya, IhsanMaintenance planning and risk evaluation of public transport systems (PTS) is completely critical and important for the natural structure and ecological balance of the city and its' environment. It is noteworthy to take the correct actions and decisions for the process to make a significant contribution towards the development and ecological sustainability of the city. We also know that failures occurring in PTS leads to personal and social damages such as hazards for passenger life and financial loss that occurs as a result of damage to vehicles due to these failures. Therefore, it is essential to analyze failures of PTS and to improve maintenance planning for obtain a reliable transport system. For this aim, a systematic approach based on maintenance decision support system has been suggested to eliminate the risks arising from failures for Bus Rapid Transit (BRT) system in this paper. The suggested system aims to minimize the harmful effects of these risks with respect to individuals, society and environment perspectives. The proposed integrated systematic approach consists of fuzzy rule based system (FRBS), fuzzy multi criteria decision making (MCDM), stochastic MCDM, mathematical modelling, information theory and heuristic approaches. The mathematical modeling has been applied to evaluate membership functions (MFs) of FRBS and a heuristic approach named particle swarm optimization (PSO) has been also used to solve the problem. Additionally, MCDM methods are also used to prioritize the failures and to determine weights of them. The suggested systematic approach has been applied on a real case study for BRT system in Istanbul and some actions that includes more details and information about risks and failures have been suggested to obtain a more effective maintenance plan. The validity analysis also confirmed the obtained results of the suggested systematic approach.
