Endüstri Mühendisliği Bölümü

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Citation Count: Satı, Benhür; Yolcu, Vahdi E, (2023). "A Bi-Objective Integrated Mathematical Model For Blood Supply Chain: Case Of Turkish Red Crescent", Journal Of Industrial And Management Optimization, Vol. 19, No. 5, pp. 3383-3418.
A Bi-Objective Integrated Mathematical Model For Blood Supply Chain: Case Of Turkish Red Crescent
(2023) Satır, Benhür; Yolcu, Vahdi; 54700
Various criteria feature in blood supply chain (BSC) designs, where cost-based and time-based are the most commonly found in the literature. In the current study, total annual cost is used together with a new time-based objective. The total time spent in the transportation of blood products is considered as time lost, and weight is given to that time according to the product amount and then normalized with respect to shelf life. In using cost and time objectives, we developed a bi-objective mixed-integer mathematical programming model for the BSC of Turkish Red Crescent (TRC, the singular authority controlling BSC throughout Turkey), including collection, production, and distribution echelons, and also considering bag-type decisions for whole-blood collection. The objective of the study was to propose a BSC design model and solution approach. With all real-life TRC instances resolved optimally, a linear programming relaxation-based heuristic was developed for large-scale problem sizes. Real-life data were obtained from the TRC and the remainder from open-to-public sources. The study's main finding is that cost and time objectives alone produce significantly different designs, whilst using them together to form efficient-frontier solutions for decision-makers adds practical value.
Citation Count: Kurt, Atil; Cetinkaya, Ferda Can; Azizoglu, Meral, "A blood distribution problem with new transportation options - an application for the Turkish Red Crescent", European Journal of Industrial Engineering, Vol. 13, No. 3, pp. 332-367, (2019).
A blood distribution problem with new transportation options - an application for the Turkish Red Crescent
(Inderscience Enterprises LTD, 2019) Kurt, Atıl; Çetinkaya, Ferda Can; Azizoğlu, Meral; 50129
This paper considers the blood distribution problem in the Central Anatolian Regional Blood Centre of the Turkish Red Crescent (TRC) and proposes several demand satisfaction options considering the irradiation centres, urgent demands, and product availability. Our aim is to maximise the total weighted blood demand satisfaction. To address the problem, we develop a mixed integer linear programming model and propose a hybrid genetic algorithm (HGA). The results of our experiments have revealed that the mathematical model cannot handle even small sized problem instances in reasonable times; however, the hybrid genetic algorithm is capable of handling complex daily operations of the Turkish Red Crescent.
Citation Count: Karasakal, O., Kandiller, L., Özdemirel, N.E. (2011). A branch and bound algorithm for sector allocation of a naval task group. Naval Research Logistics, 58(7), 655-669. http://dx.doi.org/10.1002/nav.20474
A branch and bound algorithm for sector allocation of a naval task group
(Wiley-Blackwell, 2011) Karasakal, Orhan; Kandiller, Levent; Özdemirel, Nur Evin; 5706; 2634
A naval task group (TG) is a collection of naval combatants and auxiliaries that are grouped together for the accomplishment of one or more missions. Ships forming a TG are located in predefined sectors. We define determination of ship sector locations to provide a robust air defense formation as the sector allocation problem (SAP). A robust formation is one that is very effective against a variety of attack scenarios but not necessarily the most effective against any scenario. We propose a 0-1 integer linear programming formulation for SAP. The model takes the size and the direction of threat into account as well as the defensive weapons of the naval TG. We develop tight lower and upper bounds by incorporating some valid inequalities and use a branch and bound algorithm to exactly solve SAP. We report computational results that demonstrate the effectiveness of the proposed solution approach
Citation Count: Tanergüçlü, T...et al (2012). A decision support system for locating weapon and radar positions in stationary point air defence. Information Systems Frontiers, 14(2), 423-444). http://dx.doi.org/10.1007/s10796-010-9269-6
A decision support system for locating weapon and radar positions in stationary point air defence
(Springer, 2012) Tanergüçlü, Türker; Maras, Hakan; Gencer, Cevriye; Aygüneş, Haluk; 7671; 57149
In this study, a decision support system (DSS) based on the interactive use of location models and geographical information systems (GIS) was developed to determine the optimal positions for air defence weapons and radars. In the location model, the fire units are considered as the facilities to be located and the possible approach routes of air vehicles are treated as demand points. Considering the probability that fire by the units will miss the targets, the objective of the problem is to determine the positions that provide coverage of the approach routes of the maximum number of weapons while considering the military principles regarding the tactical use and deployment of units. In comparison with the conventional method, the proposed methodology presents a more reliable, faster, and more efficient solution. On the other hand, owing to the DSS, a battery commander who is responsible for air defence becomes capable of determining the optimal weapon and radar positions, among the alternative ones he has identified, that cover the possible approach routes maximally. Additionally, he attains the capability of making such decisions in a very short time without going to the field over which he will perform the defence and hence without being subject to enemy threats. In the decision support system, the digital elevation model is analysed using Map Objects 2.0, the mathematical model is solved using LINGO 4.0 optimization software, and the user interface and data transfer are supported by Visual Basic 6.0.
Citation Count: Yıldırım, Gonca; Satır, Benhür, "A General Production and Financial Planning Model: Case of A Poultry Integration", Arabian Journal for Science and Engineering, (2020).
A General Production and Financial Planning Model: Case of A Poultry Integration
(Springer, 2020) Satır, Benhür; Yıldırım, Gonca; 45908; 54700
We propose a general linear programming formulation for a poultry integration to facilitate decision making in production and financial planning. The formulation is motivated by a medium-size application and by involving practitioners from the industry. It is a realistic and strategic model since we incorporate all divisions in a complex poultry integration, (including, but not limited to, feed mill, breeder coops, incubation house, broiler coops, slaughterhouse and distribution centers) as well as the interrelations among these divisions. The horizon we consider is in years, which makes the plan a strategic level plan in this fast-paced industry. Through extensive experimentation with various end-customer demand scenarios, we found out that the quantity of breeder chicks to buy at certain times during the planning horizon is the robust key decision variable in the overall system. © 2020, King Fahd University of Petroleum & Minerals.
Citation Count: Karasakal, Orhan; Karasakal, Esra; Silav, Ahmet (2021). "A multi-objective approach for dynamic missile allocation using artificial neural networks for time sensitive decisions", Soft Computing, Vol. 25, No. 15, pp. 10153-10166.
A multi-objective approach for dynamic missile allocation using artificial neural networks for time sensitive decisions
(2021) Karasakal, Orhan; Karasakal, Esra; Silav, Ahmet; 216553
In this study, we develop a new solution approach for the dynamic missile allocation problem of a naval task group (TG). The approach considers the rescheduling of the surface-to-air missiles (SAMs), where a set of them have already been scheduled to a set of attacking anti-ship missiles (ASMs). The initial schedule is mostly inexecutable due to disruptions such as neutralization of a target ASM, detecting a new ASM, and breakdown of a SAM system. To handle the dynamic disruptions while keeping efficiency high, we use a bi-objective model that considers the efficiency of SAM systems and the stability of the schedule simultaneously. The rescheduling decision is time-sensitive, and the amount of information to be processed is enormous. Thus, we propose a novel approach that supplements the decision-maker (DM) in choosing a Pareto optimal solution considering two conflicting objectives. The proposed approach uses an artificial neural network (ANN) that includes an adaptive learning algorithm to structure the DM's prior articulated preferences. ANN acts like a DM during the engagement process and chooses one of the non-dominated solutions in each rescheduling time point. We assume that the DM's utility function is consistent with a non-decreasing quasi-concave function, and the cone domination principle is incorporated into the solution procedure. An extensive computational study is provided to present the effectiveness of the proposed approach.
Citation Count: Karasakal, Esra; Karasakal, Orhan; Hazel, Şentürk. "A Multiple Criteria Ranking Method Based on Outranking Relations: An Extension for Prospect Theory", in Multiple Criteria Decision Making with Fuzzy Sets, pp. 115-133.
A Multiple Criteria Ranking Method Based on Outranking Relations: An Extension for Prospect Theory
(2022) Karasakal, Esra; Karasakal, Orhan; Hazel, Şentürk; 216553
In this study, Prospect Theory is integrated into a well-known multiple criteria ranking method, PROMETHEE. PROMETHEE considers the outranking relations among alternatives based on the preference functions. Prospect Theory evaluates the alternatives with a difference function based on gains and losses. The preference functions of PROMETHEE are modified to capture the choice behavior of the decision maker. The proposed method is a generalization of PROMETHEE that can handle the higher loss impact case as well as the usual equal loss and gain impact. The proposed method is compared with PROMETHEE, PT-PROMETHEE that is an extension of PROMETHEE with reference alternative, and the weighted sum method using an exemplary data set and Times Higher Education (THE) World University Ranking 2019 and 2020 data. The results show that rankings of alternatives change significantly when the impact of losses is larger than gains.
Citation Count: Özaktaş, Hakan; Kırkavak, Nureddin; Alpay, Ayşe Nilay (2021). "A Paradox of the Average Waiting Time for the Case of a Single Bottleneck on the Commuters' Route", Modelling and Simulation in Engineering, Vol. 2021.
A Paradox of the Average Waiting Time for the Case of a Single Bottleneck on the Commuters' Route
(2021) Özaktaş, Hakan; Kırkavak, Nureddin; Alpay, Ayşe Nilay; 58272
Average waiting time is considered as one of the basic performance indicators for a bottleneck zone on a route for commuter traffic. It turns out that the average waiting time in a queue remains paradoxically unchanged regardless of how fast the queue dissolves for a single bottleneck problem. In this study, the paradox is verified theoretically for the deterministic case with constant arrival and departure rates. Consistent results with the deterministic case have also been obtained by simulation runs for which vehicle interarrival time is a random variable. Results are tabulated for interarrival times which have uniform, triangular, normal, and exponential distributions along with a statistical verification of the average waiting time paradox.
Citation Count: Karasakal, O.; Karasakal, E., Töreyen, Ö. (2023). "A partial coverage hierarchical location allocation model for health services", European Journal Of Industrial Engineering, Vol.17, No. 4, pp. 115-147.
A partial coverage hierarchical location allocation model for health services
(2023) Karasakal, Orhan; Karasakal, Esra; Töreyen, Özgün; 216553
We consider a hierarchical maximal covering location problem (HMCLP) to locate health centres and hospitals so that the maximum demand is covered by two levels of services in a successively inclusive hierarchy. We extend the HMCLP by introducing the partial coverage and a new definition of the referral. The proposed model may enable an informed decision on the healthcare system when dynamic adaptation is required, such as a COVID-19 pandemic. We define the referral as coverage of health centres by hospitals. A hospital may also cover demand through referral. The proposed model is solved optimally for small problems. For large problems, we propose a customised genetic algorithm. Computational study shows that the GA performs well, and the partial coverage substantially affects the optimal solutions.
Citation Count: Erden, Z; Erkmen, AM; Erden, A, "A Petri Net-based inference network for design automation under nondeterminism applied to mechatronic systems", 6th UK Mechatronics Forum International Conference, pp. 17-22, (1998).
A Petri Net-based inference network for design automation under nondeterminism applied to mechatronic systems
(1998) Erden, Z.; Erkemn, A. M.; Erden, A.
This paper introduces the completed part of an ongoing research, in which a Petri Net-based design inference network is developed for the representation and analysis of the functions and their interrelationships through information flow for the conceptual design stage of mechatronic systems in order to facilitate design automation. The theoretical framework behind the network is based on transition of Hybrid Automata into Petri Nets and application of this framework is introduced by a mechatronic design example.
Citation Count: Ertem, Mustafa Alp; Buyurgan, Nebil (2013). "A Procurement Auctions-Based Framework for Coordinating Platforms in Humanitarian Logistics", in Humanitarian and Relief Logistics, pp. 111-127.
A Procurement Auctions-Based Framework for Coordinating Platforms in Humanitarian Logistics
(2013) Ertem, Mustafa Alp; Buyurgan, Nebil; 52460
This chapter focuses on an auction-based procurement framework for single coordinating platforms in humanitarian logistics. It first covers disaster relief operations, humanitarian logistics, and procurement in this context and illustrate many of the issues that make the management and coordination of procurement functions complex and challenging. Then the proposed framework along with the auction model is discussed including the unique design characteristics associated with disaster relief environment. Three-phase approach presents a complete representation of the procurement in humanitarian logistics. Results indicate that the proposed announcement options increase the fill rate. Announcement construction criteria allow coordinating platforms to use varying bundling choices.
Citation Count: Aydemir-Karadag, Ayyuce, "A profit-oriented mathematical model for hazardous waste locating-routing problem", Journal of Cleaner Production, Vol. 202, pp. 213-225, (2018).
A profit-oriented mathematical model for hazardous waste locating-routing problem
(Elsevier SCI LTD, 2018) Aydemir-Karadağ, Ayyüce; 116059
Hazardous waste management (HWM) deals with the safe, efficient and cost effective collection, transportation, treatment and disposal of wastes. This paper presents a profit-oriented mixed integer mathematical model for the hazardous waste location-routing problem, which incorporates the energy recovery from waste and the application of the polluter pays principle. The suggested model decides on the locations and numbers of recycling, incineration, sterilization, interim storage and disposal centers and on how to transfer various types of hazardous waste and waste residues among these centers from the perspective of environmental protection. The proposed model was implemented in a real life case study and tested on various hypothetical problem instances. In addition, an extended formulation was developed on a rolling horizon basis through the objective function of Net Present Value (NPV) to analyze the overall profitability of the entire HWM system for long-term planning and a sensitivity study was conducted on different interest rates. The results show that the model is applicable to real-life waste management systems and it can provide effective solutions for large-scale HWM problems. (C) 2018 Elsevier Ltd. All rights reserved.
Citation Count: Ürey Uysal, Zeynep Çiğdem, "A Sociocultural Landmark in Ankara: 96lar Residential Block", IIB International Refereed Academic Social Sciences Journal, Vol. 3, No. 5, pp. 147- 162, (2012).
A Sociocultural Landmark in Ankara: 96lar Residential Block
(2012) Ürey Uysal, Zeynep Çiğdem
Bu çalışma, Ankaranın önemli bir kentsel simgesi olan 96lar Apartmanını, gelişiminin sosyokültürel önemi bağlamında incelemeyi amaçlamaktadır. Araştırmaların da işaret ettiği gibi 96lar Apartmanı, Ankarada 1950li ve 1980li yıllar arasında etkin olan konut gelişimi ve kooperatifçilik süreçlerinin etkisinde gelişen kendine özgü mimari planlama anlayışı ve yapım süreci dolayısıyla Ankara konut mimarisi bağlamında önemli bir yere sahip olmuştur. 96lar Apartmanının sosyokültürel gelişimini ve mimari oluşumunu döneminin kültürel, sosyal ve mimari gelişmeleri ışığında analiz etmeyi amaçlayan bu çalışma, sırasıyla Ankaradaki 1950li ve 1980li yıllar arasındaki konut üretiminden, 96lar Apartmanının bu bağlam içerisindeki yerinden, planlama anlayışı ve mimari özelliklerinden ve Modern Mimariye yaptığı referanslardan bahsedecektir.
Citation Count: Uludağ Demirer, S. (2008). A study on nutrient removal from municipal wastewater by struvite formation using Taguchi's design of experiments. Environmental Engineering Science, 25(1), 1-10 http://dx.doi.org/10.1089/ees.2006.0168
A study on nutrient removal from municipal wastewater by struvite formation using Taguchi's design of experiments
(Mary Ann Liebert Inc, 2008) Uludağ Demirer, Sibel; 45685
The aim of this study is to investigate the removal of NH4+-N and PO43--P from the municipal wastewater by struvite (MgNH4PO4.6H(2)O) formation. The optimization of the NH4+-N and PO43--P removals is made by changing the total concentrations of struvite forming ions (Mg2+, NH4+, PO43-) and pH of the wastewater. The experimental design was made using Taguchi's L-9(3(4)) orthogonal array technique in the first stage of the study. The conditions yielding maximum removals of NH4+-N and PO43--P are found as molar concentration ratio of Mg:N:P of 2:2:2 and 3:3:2, respectively, using the signal-to-noise (S/N) ratio of experimental results. The removal of NH4+-N followed the stoichiometry of struvite formation, while PO43--P removal required the excess amount of Mg2+. The pH of wastewater in which the maximum NH4+-N and PO43--P removals are observed was 9.0. All of the factors tested influenced the removal of NH4+-N opposite to the removal Of PO43--P, in which the concentration of NH4+-N was found insignificant statistically. Therefore, the addition of NH4+ ion is eliminated and Taguchi's L-4(2(3)) orthogonal array was used in the second stage of experimental study. The molar concentration ratios of struvite forming ions (Mg:N:P) were found to be as 1:1:1 and 2:1:1 for maximum NH4+-N and PO43--P removals at the levels of 52.4 and 67.7%, respectively, at pH 9.0 using the S/N ratios of experimental results. The performance of proposed method in removing NH4+-N and PO43--P and foreseen problems related with effluent quality is discussed
Citation Count: Demirkiran, Z.K.; Altunok, T., "A Systems Approach for Technology Assessment and Selection", Digital Avionics Systems Conference - Proceedings, pp. 6E11-6E111, (2012).
A Systems Approach for Technology Assessment and Selection
(2012) Demirkiran, Zuhal Kale; Altunok, Taner
Each system development project necessitates making decisions on the selection of technologies among available alternatives for the system and is covered in the technology assessment phase in the acquisition process. For the assessment very limited numbers of methodologies most of which are qualitative are defined in the literature. This study aims to propose a systematic model, which can be used as a guide by planners or system architects in the multi-criteria technology selection process. The model also proposes a method to define the critical technology elements for a system. A case study on Unmanned Aerial Vehicle (UAV) communication systems is presented to illustrate the applicability of the model.
Citation Count: Altunok, T., Çakmak, T. (2010). A technology readiness levels (TRLs) calculator software for systems engineering and technology management tool. Advance in Engineering Software, 41(5), 769-778. http://dx.doi.org/ 10.1016/j.advengsoft.2009.12.018
A technology readiness levels (TRLs) calculator software for systems engineering and technology management tool
(Elsevier Science Ltd, 2010) Altunok, Taner; Çakmak, Tanyel
Turkish defense industry and policy makers seek effective and successful system development programs by implementing a validation mechanism to verify the maturity of new technologies being developed in national laboratories and industry. Technology Readiness Levels (TRLs) developed by NASA as a general metric of technology advancement and it has been widely accepted as a systems engineering and technology management metric tool. In order to explore the sufficiency of this tool, first of all, academic and applicable studies of army and civil organizations have been searched out and the lessons learned have been analyzed in this study. Thereafter, questionnaires of awareness of TRLs and TRL Calculator have been applied to defense firms in Ankara, and interviews held with the technology developers, firms' speakers and defense authorities. Finally, the applicable algorithm of TRL calculator has been recommended for Turkish defense industry
Citation Count: Yüceer, Ü., Özakça, A. (2010). A truck loading problem. Computers&Industrial Engineering, 58(4), 766-773. http://dx.doi.org/10.1016/j.cie.2010.02.008
A truck loading problem
(Pergamon-Elsevier Science Ltd, 2010) Yüceer, Ümit; Özakça, Arif
A vehicle with m compartments transports q different products of various sizes from a source to n different destinations. The operational problem is how to load the compartments of the vehicle so that the replenishment time is maximized for a given route of destinations. A mixed integer linear programming model is developed for this class of problems. An investigation of the structure of the model reveals that a subproblem can be obtained in the form of a weighted distribution problem. Consequently, a simple subalgorithm finds an integer solution to this subproblem. The main algorithm bisects the interval of uncertainty until it becomes sufficiently small. There is another subalgorithm to test whether a feasible solution exists in the final interval of uncertainty by solving a Phase I problem. Our numerical experience has shown its computational efficiency and the quality of the solutions obtained. A problem of size 30 can be solved by this method in a fraction of a second. Further, an optimal solution is obtained in 82% of the randomly chosen problems
Citation Count: Sahin-Arslan, Aysenur; Ertem, Mustafa Alp, "A Warehouse Design With Containers For Humanitarian Logistics: A Real-Life Implementation From Turkey", International Journal of Industrial Engineering-Theory Applications and Practice, Vol. 26, No. 2, pp. 139-155, (2019).
A Warehouse Design With Containers For Humanitarian Logistics: A Real-Life Implementation From Turkey
(Univ Cincinnati Industrial Engineering, 2019) Şahin-Arslan, Ayşenur; Ertem, Mustafa Alp; 52460
The purpose of this study is to investigate how and at what cost freight containers could be used as an inventory holding mechanism for humanitarian logistics. The layout and cost comparison of two alternatives are performed-stocking in a warehouse and material storage in containers. An optimum layout for storage in containers is proposed. It was found that container stockpiling uses the available area and space better than the warehouse option to stock the same number of material pallets. Leasing and purchasing costs of these alternatives are compared using present worth analysis. The results revealed that the container leasing option is not cost effective when land cost is included. Warehouse leasing results in the least setup cost, however, it incurs more operating costs, including lighting, ventilation, and maintenance as well as handling of the pallets. A real-life implementation of the proposed container stockpiling idea is presented for Turkey.
Citation Count: Kabarcık, Ahmet; Kandiller, Levent; Aygüneş, Haluk, "Ağların hareketli yol-kesici tarafından en kısa güzergâh kullanılarak kesilmesi", Savunma Bilimleri Dergisi, Vol. 11, No. 1, pp. 223-237, (2012).
Ağların hareketli yol-kesici tarafından en kısa güzergâh kullanılarak kesilmesi
(2012) Kabarcık, Ahmet; Kandiller, Levent; Aygüneş, Haluk; 17500; 5706; 57149
Bu makalede yolların hareketli yol-kesici tarafından devre dışı bırakıldığı bir ağ kesme problemi ele alınmıştır. İçiçe geçmiş iki ağdan biri ağ-kullanıcı tarafından, diğeri ise yol-kesici tarafından kullanılmaktadır. Yol-kesici ağı üzerindeki düğümler ağ-kullanıcı ağındaki yolların ya da düğümlerin üzerinde konuşlanmıştır. Yol-kesici ağı üzerindeki düğümler imha edilmeye aday noktalardır. Bu çalışmada ağ-kullanıcının başlangıç ve hedef düğümleri arasındaki tüm güzergâhlarını imha etmek için yol-kesicinin kullanacağı en kısa güzergâh bulunmaya çalışılmaktadır. Problemin çözümü için dal-sınır yöntemi kullanılarak bir algoritma geliştirilmiştir.
Citation Count: Uludag-Demirer, S.; Demirer, G.N.; Chen, S., "Ammonia removal from anaerobically digested dairy manure by struvite precipitation", Process Biochemistry, Vol.40, No.12, pp.3667-3674, (2005).
Ammonia removal from anaerobically digested dairy manure by struvite precipitation
(Elsevier Science LTD, 2005) Uludağ Demirer, Sibel; Demirer, G. N.; Chen, S.
Ammonia is one of the most important contaminants impairing the quality of water resources. When this is considered along with the fact that the global demand for nitrogenous fertilizers is in constant rise, the need for recovery as well as removal of nitrogen is well justified. Crystallization of N and P in the form of struvite (MgNH4PO4 center dot 6H(2)O), which is a slow releasing and valuable fertilizer, is one possible technique for this purpose. This study investigated the removal of NR4+ through struvite precipitation from the effluents of one- (R1) and two-phase (R2) anaerobic reactors digesting dairy manure. To force the formation of struvite in the anaerobic reactor effluents, Ma(2+) ion was added by using both Mg(OH)(2) and MgCl2 center dot 6H(2)O. To prevent the effect of different total phosphorus (TP) concentration in the effluents of RI and R2, as well as to not limit the formation of struvite, an excess amount Of PO43- (0.14 M) was added in the form of NaHPO4. Different stoichiometric Mg2+:NH4+:PO43- ratios were tested to determine the required Mg2+ concentrations for maximum NH4+ removal by keeping NH4+:PO43- ratio constant for the effluents of reactors RI and R2. The results revealed that very high NH4+ removal efficiencies (above 95%) were possible by adding Mg 21 ions higher than 0.06 M concentration in the effluents from reactors RI and R2. It was also observed that the initial pH adjustment to 8.50 using NaOH did not result in any significant increase in the removal of NH4+ and the removal of NH4+ in the reactors treated with MgCl2 center dot 6H(2)O was higher than those treated with Mg(OH)(2) for the same Mg2+ concentration.

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