WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collections

Permanent URI for this collectionhttps://hdl.handle.net/20.500.13091/2

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Now showing 1 - 20 of 44

Citation - WoS: 24
Citation - Scopus: 23
Artificial Bee Colony Algorithm for Solving Multi-Objective Distributed Fuzzy Permutation Flow Shop Problem
(IOS Press BV, 2022) Baysal, Mehmet Emin; Sarucan, Ahmet; Büyüközkan, Kadir; Engin, Orhan
The distributed permutation flow shop scheduling (DPFSS) is a permutation flow shop scheduling problem including the multi-factory environment. The processing times of the jobs in a real life scheduling problem cannot be precisely know because of the human factor. In this study, the process times and due dates of the jobs are considered triangular and trapezoidal fuzzy numbers for DPFSS environment. An artificial bee colony (ABC) algorithm is developed to solve the multi-objective distributed fuzzy permutation flow shop (DFPFS) problem. First, the proposed ABC algorithm is calibrated with the well-known DPFSS instances in the literature. Then, the DPFSS instances are fuzzified and solved with the algorithm. According to the results, the proposed ABC algorithm performs well to solve the DFPFS problems. © 2022 - IOS Press. All rights reserved.
Citation - WoS: 2
Citation - Scopus: 1
Bernstein-Walsh Polynomial Inequalities in Domains Bounded by Piecewise Asymptotically Conformal Curve With Nonzero Inner Angles in the Bergman Space
(SPRINGER, 2019) Abdullayev, F.G.; Abdullayev, G.A.; Şimşek, Dağıstan
We continue our investigation of the order of growth of the modulus of an arbitrary algebraic polynomial in the Bergman weight space, where the contour and weight functions have certain singularities. In particular, we deduce a Bernstein-Walsh-type pointwise estimate for algebraic polynomials in unbounded domains with piecewise asymptotically conformal curves with nonzero inner angles in the Bergman weight space.
Citation - WoS: 42
Citation - Scopus: 49
Bi-Objective Coordinated Production and Transportation Scheduling Problem With Sustainability: Formulation and Solution Approaches
(Taylor & Francis Ltd, 2023) Yağmur, Ece; Kesen, Saadettin Erhan
This paper studies a new variant of integrated production scheduling and vehicle routing problem where production of customer orders are performed under job-shop environment and order deliveries are made by a heterogeneous fleet of vehicles, each of which is allowed to take multiple trips. Two conflicting objectives are considered, namely minimisation of the total amount of CO2 emitted by the vehicles and minimisation of maximum tardiness resulting from late deliveries. To this end, we present a bi-objective mixed-integer programming formulation. Augmented epsilon-Constraint (Augmecon) method is implemented to find Pareto optimal solutions. Due to problem complexity, Augmecon cannot provide solutions even with small-sized problems. Thus, we adopt Pareto Local Search (PLS) and non-dominated sorting genetic algorithm-II (NSGA-II) for practical sized instances. For small-sized instances involving 5, 6, and 7 customers, experimental results indicate that CPU time of Augmecon are 11, 84, and 524 sec, respectively with an average number of Pareto efficient solution of 3.5. In terms of hypervolume index, Augmecon shows the best performance, followed by NSGA-II with 11.32% and PLS with 20.75% degradation for small-sized instances. For medium and large-sized instances, PLS shows worse performance than NSGA-II by 16.87% and 40.48%.
Citation - WoS: 1
Citation - Scopus: 1
Bi-Objective Optimization for Joint Production Scheduling and Distribution Problem With Sustainability
(SPRINGER INTERNATIONAL PUBLISHING AG, 2021) Yağmur, Ece; Kesen, Saadettin Erhan
This paper considers joint production and distribution planning problem with environmental factors. While the production phase of the problem consists of job shop production environment running under Just-In-Time (JIT) philosophy, the distribution phase involves a heterogeneous fleet of vehicles with regards to capacity and fuel consumption rate. Therefore, we tackle two well-known problems in Operations Research terminology which are called machine scheduling and vehicle routing problems. The joint problem is formulated as a bi-objective structure, the first of which is to minimize the maximum tardiness, the second of which aims to minimize the total amount of CO2 emitted by the vehicles. Orders are required to be consolidated to reduce the traveling time, distance, or cost. An increase in the vehicle capacity results in a higher possibility of consolidation, but in this case, the amount of CO2 emission that the vehicle emits into the air will also increase. Having shown that two objectives are conflicting in an illustrative example, we formulate the problem as amixed integer programming (MIP) formulation and use an Augmented Epsilon Constraint Method (AUGMECON) for solving the bi-objective model. On randomly generated test instances, the applicability of the MIP model through the use of AUGMECON is reported.
Citation - WoS: 112
Citation - Scopus: 138
Comparative Analysis of Topsis, Vikor and Copras Methods for the Covid-19 Regional Safety Assessment
(ELSEVIER SCIENCE LONDON, 2021) Hezer, Seda; Gelmez, Emel; Özceylan, Eren
COVID-19, which emerged in December 2019, has affected the entire world. Therefore, COVID-19 has been a subject of research in various disciplines, especially in the field of health. One of these studies was the report made by the Deep Knowledge Group (DKG) consortium in which safe regions for COVID19 were determined. In the report, the main criteria of quarantine efficiency, government efficiency of risk management, monitoring and detection, health readiness, regional resilience, and emergency preparedness are used in the evaluation of countries and regions (alternatives). As the data and research structure used in this report are based on multi-criteria, the purpose of this study is to evaluate and analyse the safety levels of 100 regions in the world in terms of COVID-19 using Technique for Order Performance by Similarity to Ideal Solution (TOPSIS), Vise Kriterijumsa Optimizacija I Kompromisno Resenje (VIKOR) and Complex Proportional Assessment (COPRAS) methods. The data and information required in the methods were obtained from a report prepared by the DKG. The results of the methods were compared with the ranking results presented in a report of the DKG. Accordingly, it has been observed that the method that provides the closest results to the results of the report is the COPRAS method, and the method that gives the most distant results is the VIKOR method. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of King Saud Bin Abdulaziz University for Health Sciences. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).
Citation - WoS: 20
Citation - Scopus: 24
Comparative Study on the Performances of Solar Air Collectors With Trapezoidal Corrugated and Flat Absorber Plates
(SPRINGER, 2020) Darıcı, Selçuk; Kılıç, Anıl
Thermal performance of the solar air collectors which are mostly used for space heating and drying is generally low. Therefore there are different studies aimed at increasing the thermal performance of the solar air collectors. One of the technics used for this purpose is making changes in surface geometry of the absorber plate. In this research, the thermal performance of two solar air collectors constructed with trapezoidal corrugated and flat absorber plate is investigated experimentally under weather conditions of Konya/Turkey. The experiments were conducted for three different air mass flow rates of 0.022, 0.033 and 0.044 kg/s. The results obtained are compared to the ones of solar air collector with flat absorber plate. It has been observed that difference between inlet and outlet air temperatures of the solar air collectors increases as the mass flow rate decreases. For the air mass flow rate of 0.022 kg/s, the maximum temperature rise in solar air collector with trapezoidal corrugated plate is 9 degrees C compared to the flat plate solar air collector. It has been shown that thermal performance of the solar air collectors rises with the increase in mass flow rates. It is determined that the average daily thermal efficiency of the solar air collector with trapezoidal absorber plate is 63% for 0.044 kg/s.
Citation - WoS: 5
Citation - Scopus: 4
Design, Manufacture and Thermal Analysis of a Single Pass Solar Air Collector at Different Mass Flow Rates
(GAZI UNIV, FAC ENGINEERING ARCHITECTURE, 2020) Darıcı, Selçuk
Solar air collectors are generally used for drying industrial and agricultural products or for space heating. Nowadays solar energy is paid more attention due to decrease in fossil fuels and increase in energy prices. In this study, a single pass, forced convective solar air collector has been designed, manufactured and analysed experimentally under climatic conditions of Konya/Turkey. Experiments have been conducted at three different mass flow rates, on different days and under clear weather conditions. Hourly variation of solar radiation, inlet and outlet air temperatures, glass cover temperature, absorber plate temperature and thermal efficiency of the solar air collector have been examined by using the experimental data obtained. It is seen that with the increase in mass flow rate, temperature of the air at the outlet of the collector decreases while thermal efficiency of the collector increases.
Citation - WoS: 1
Citation - Scopus: 3
Determination of Competencies With Fuzzy Multi-Criteria Decision Making Methods for Determining the Development Program for Analyst Position in a Participation Bank
(Springer Science and Business Media Deutschland GmbH, 2022) Yel, İbrahim; Sarucan, Ahmet; Baysal, Mehmet Emin
The management and training of human resources continues to increase in importance when considering the effects such as the increase in the demand for human resources in the field of information technologies during the pandemic process. Determining the competencies of the information technology personnel and developing the deficient ones according to the competencies can be considered as the main development policy. Based on this requirement, the problem of determining the competencies of system analysts at Kuveyt Türk Participation Bank is the main subject of this study. Within the scope of the study, a survey was conducted with the participation of 11 people with at least five years of experience in the analyst position on 24 core competencies. In line with the survey results, the importance weights of the competencies were determined with fuzzy AHP. Afterwards, 10 competencies with the highest weight among 24 core competencies were determined. Evaluations were made by five experts for system analysts working in an organization in the bank for the determined 10 competencies. Rankings of system analysts were made using Neutrosophic Z-Number sets (NZN) and Fuzzy EDAS methods. These rankings became an input to the competency development program that is planned to be prepared specifically for individuals. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
Citation - WoS: 3
Citation - Scopus: 2
Distributed No-Wait Flow Shop With Fuzzy Environment
(Springer Science and Business Media Deutschland GmbH, 2022) Başar, Ramazan; Büyüközkan, K.; Engin, Orhan
In the no-wait flow shop scheduling problem, n-job should be proceeded on m-machine with the same order and do not permit the jobs to wait during the scheduling periods. Also, at the distributed no-wait flow shop scheduling problem, there are multi-factory for processing n-job with m-machine for no-wait constraint. In this study, distributed no-wit flow shop scheduling with the fuzzy due date is considered. The due date of the jobs is defined with fuzzy numbers. A parallel kangaroo algorithm is proposed to solve the distributed no-wait flow shop scheduling problem with the fuzzy due date. The proposed algorithm is tested from the literature by the benchmark problems. The results show that the proposed parallel kangaroo algorithm is efficient for distributed no-wit flow shop scheduling problems with fuzzy due date problems. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
Citation - WoS: 2
Citation - Scopus: 1
Dynamical Behavior of Rational Difference Equation /+ 1 +/-(vol 27, 49, 2021)
(SPRINGER INT PUBL AG, 2021) Oğul, Burak; Şimşek, Dağıstan; Öğünmez, Hasan; Kurbanlı, Abdullah Selçuk
[Abstract Not Available]
Dynamical Behavior of Rational Difference Equation X(n+1) = X(n-15)/+ 1 +/- X(n-3)x(n
(SPRINGER INDIA, 2024) Oğul, Burak; Şimşek, Dağıstan; Kurbanlı, Abdullah Selçuk; Öğünmez, Hasan
In this paper, we study the qualitative behavior of the rational recursive sequences x(n+1) = x(n-15)/+/- 1 +/- x(n-3)x(n-7)x(n-11)x(n-15), n is an element of N-0 where the initial conditions are arbitrary real numbers. Also, we give the numerical examples and solutions graphs of some cases of difference equations.
Citation - WoS: 3
Citation - Scopus: 3
Estimation of Turkey’s Natural Gas Consumption by Machine Learning Techniques
(2020) Erdem, Osman Emin; Kesen, Saadettin Erhan
Technological advancements coupled with growing world population require the increasing need of energy. Natural gas is one of the most important usable energy resources. Turkey is with high external dependency on energy as it has its own limited natural and underground energy resources. Thus, in order to effectively and productively use of natural gas purchased from foreign countries and to make reliable and robust energy policies for the years ahead, it is crucial to make a reasonable and plausible prediction for natural gas consumption of Turkey. In this paper, we estimate the natural gas consumption using machine learning techniques on the basis of real monthly data representing natural gas consumption of Turkey between the years 2010 and 2018. The performances of machine learning techniques involving Artificial Neural Networks, Random Forest Tree, Regression, Time Series and Multiple Seasonality Time Series are compared in predicting the natural gas consumption of Turkey. Experimental results show that among the five techniques, artificial neural networks produce the best estimation, having the lowest mean square errors, followed by regression method. Time series shows the worst performance among all the techniques.
Citation - WoS: 8
Citation - Scopus: 7
Examination Timetabling Problem With Scarce Resources: a Case Study
(INDERSCIENCE ENTERPRISES LTD, 2018) Keskin, Muhammed Emre; Döyen, Alper; Akyer, Hasan; Güler, Mehmet Güray
Examination timetabling problem (ETP) is one of the hardest administrative tasks that has to be undertaken at each semester in all faculties. Although the major structure of the problem remains intact, requirements may change from faculty to faculty causing major changes in the solution procedures. The number of academic staff and the level of infrastructures of newly established universities cannot keep up with the increasing number of departments and students. This scarcity brings several additional constraints to the ETP. In this study, we propose a two stage solution procedure for the ETP of such universities. We apply our solution method to a real problem. We show that better feasible solutions can be found in shorter computation times compared to commercial softwares. Moreover we show that the total examination period length can be reduced from seven days to six days with the proposed method.
Citation - WoS: 9
Forward Supply Chain Network Design Problem: Heuristic Approaches
(2018) Koç, Çağrı; Özceylan, Eren; Kesen, Saadettin Erhan; Çil, Zeynel Abidin; Mete, Süleyman
Determining positions and counting of actors, amount of product flow between and decreasing transportation costs are handled as a network design problem in supply chain management. Supply chain network design (SCND) problem belongs to the class of NP-hard problems. It has therefore appealed to a number of researchers’ close attention. However, existing literature lacks of common benchmark instances for forward SCND problems so as to make a fair comparison between developed and applied heuristic approaches. To this end, 450 new benchmark instances ranging from small to large size for forward SCND problems with two, three and four-echelon are generated and a mathematical model for each of the problems is formulated. Due to the complexity issues, we develop two heuristic solution approaches, genetic algorithm (GA) and hybrid heuristic algorithm (HHA), and we apply them to the large pool of benchmark instances. Comparative experiments show that both the GA and HHA can yield feasible solutions in much less computational time and, in particular, outperforms CPLEX regarding the solution quality as the number of echelon grows.
Citation - WoS: 13
Citation - Scopus: 15
A Fuzzy Logic Based Methodology for Multi-Objective Hybrid Flow Shop Scheduling With Multi-Processor Tasks Problems and Solving With an Efficient Genetic Algorithm
(IOS Press BV, 2022) Engin, Orhan; Yılmaz, Mustafa Kerim
In the conventional scheduling problem, the parameters such as the processing time for each job and due dates are usually assumed to be known exactly, but in many real-world applications, these parameters may very dynamically due to human factors or operating faults. During the last decade, several works on scheduling problems have used a fuzzy approach including either uncertain or imprecise data. A fuzzy logic based tool for multi-objective Hybrid Flow-shop Scheduling with Multi-processor Tasks (HFSMT) problem is presented in this paper. In this study, HFSMT problems with a fuzzy processing time and a fuzzy due date are formulated, taking O?uz and Ercan's benchmark problems in the literature into account. Fuzzy HFSMT problems are formulated by three-objectives: the first is to maximize the minimum agreement index and the second is to maximize the average agreement index, and the third is to minimize the maximum fuzzy completion time. An efficient genetic algorithm(GA) is proposed to solve the formulated fuzzy HFSMT problems. The feasibility and effectiveness of the proposed method are demonstrated by comparing it with the simulated annealing (SA) algorithm in the literature. © 2022 - IOS Press. All rights reserved.
Citation - WoS: 14
Citation - Scopus: 16
A Hybrid Genetic Local and Global Search Algorithm for Solving No-Wait Flow Shop Problem With Bi Criteria
(Springer Nature, 2021) Keskin, K.; Engin, Orhan
This paper addresses the m-machine no-wait Flow Shop Scheduling with Setup Times (NW-FSSWST). Two performance measures: total flow time and makespan are considered. The objective is to find a sequence that minimizing total flow time (? Cj) and makespan (Cj) simultaneously. A Hybrid Genetic Local and Global Search Algorithm (HGLGSA) is proposed to solve the NW-FSSWST for two performance criteria. The hybrid genetic algorithm is constructed by insert-search and self-repair algorithm with self-repair function. The proposed HGLGSA is tested on 192 benchmark problems of NW-FSSWST in the literature. A full factorial experimental design is made for determined the best parameter sets that improve the performance of the proposed algorithm. The computational results are compared with the benchmark solutions from the literature. The experimental results demonstrate the effectiveness and efficiency of the proposed HGLGSA for solving NW-FSSWST. © 2021, The Author(s).
Citation - WoS: 7
Citation - Scopus: 10
An Integrated Disaster Preparedness Model for Retrofitting and Relief Item Transportation
(SPRINGER, 2019) Döyen, Alper; Aras, Necati
In this study, a two-stage stochastic integer programming model is developed with a centralized planning perspective to simultaneously address mitigation and response decisions in humanitarian logistics, where the mitigation decisions involve both building and transportation infrastructure retrofitting. The objective is to minimize the total cost of retrofitting, relief item transportation and relief item shortage under a limited mitigation budget. Due to the excessive number of binary decision variables, solving the model becomes computationally difficult. Therefore, we propose Lagrangean relaxation to decouple the overall model and solve it by Lagrangean heuristics. Computational results indicate the efficiency of the solution approaches in providing high quality feasible solutions to problem instances of realistic size and complexity.
Integrated Production and Outbound Distribution Activities With Multiple Vehicles
(WORLD SCIENTIFIC PUBL CO PTE LTD, 2020) Yağmur, Ece; Kesen, Saadettin Erhan
This paper deals with a variant of the integrated production and outbound distribution scheduling (IPODS) problem by considering multiple heterogenous capacitated vehicles. The problem reflects a real world applications since both production and distribution stages. In production phase orders are produced according to permutation flow shop system. In distribution phase multiple heterogenous capacitated vehicles serve customers and each vehicle can be used more than once. Objective is to determine the integrated schedule which has the minimum summation of total tour time and tardiness. So IPODS problem covers two NP-hard problem which are called as machine scheduling and vehicle routing. Therefore we can say that the integrated problem is also NP-hard. We propose a new mathematical model for integrated problem and evaluate the performance of the model on randomly generated test instances. Comparative results show that CPLEX is able to find optimal solutions for only small sized instances and the performance of the model is not satisfying for operational level scheduling decisions.
Integrated Production and Outbound Distribution Scheduling Problem With Due Dates
(WORLD SCIENTIFIC PUBL CO PTE LTD, 2020) Yağmur, Ece; Kesen, Saadettin Erhan
Integrated production and outbound distribution scheduling (IPODS) problem consists of two combinatorial optimization problem which are known as machine scheduling and vehicle routing in the literature. There are many situations that will require production and distribution decisions have to be made together in the case that there is very limited time between production and distribution activities such as perishable products or products which have limited lifespan. In addition, make to order businesses based on just in time philosophy is another application area because of the zero-inventory level between the production and distribution phase. In this study, we developed a new Memetic Algorithm (MA) to obtain optimal or near-optimal solutions in a reasonable time. The performance of the algorithm is compared with the solutions of the mathematical model of the same problem studied by [1]. Computational results show that proposed MA is capable of finding optimal or near optimal solutions which are found by CPLEX in less than a minute.
Interval Type-2 Fuzzy Rule-Based Bwm Approach for Sustainable Supplier Selection
(2022) Öztürk, Müslüm; Torğul, Belkız; Paksoy, Turan
Fuzzy logic is a theory based on human-specific approximate reasoning. Therefore, fuzzy logic applications can bring simple and more effective solutions to situations that classical methods cannot overcome. The type-1 fuzzy set is a set, which has a continuous (crisp) membership degree to which a membership degree between 0 and 1 is assigned, and is characterised by membership functions. Type-2 fuzzy sets, which have the power to express uncertainty better, are expressed by membership functions, where the membership degrees of each element belonging to that set also specify a fuzzy set.Therefore, type-2 fuzzy sets allow us to include the membership functions uncertainty in fuzzy set theory. Using expert knowledge and using sensitivity of human to reflect the level of the decision maker influence is expressed as a fuzzy rule based system. Recently, it has been seen that fuzzy rules are frequently used together with multi-criteria decision making (MCDM) methods. Again, combining fuzzy rules with type-2 fuzzy numbers is also found. In this study, the Best Worst Method (BWM), one of the MCDM methods, has been integrated with fuzzy rules based interval type-2. The developed hybrid method was defined as Interval Type-2 Fuzzy Rule-Based BWM (IT2 FRB BWM). The proposed hybrid method has an important place when there are alternatives with similar ranking positions. Thus, even if there is a small difference in each alternative, it will show the difference better (more sensitively). This makes the proposed hybrid method forceful and unique.The proposed approach has been applied to a sustainable supplier selection problem comparatively with the BWM. The results show that the IT2 FRB BWM approach is more successful in ordering alternatives than the classical BWM method.

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Browsing WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collections by Department "Fakülteler, Mühendislik ve Doğa Bilimleri Fakültesi, Endüstri Mühendisliği Bölümü"