DSpace Arşivi :: by Yazar "Karaoğlan, İsmail" değerine göre listeleniyor

Yazar "Karaoğlan, İsmail" seçeneğine göre listele

Listeleniyor 1 - 16 / 16

An adaptive tabu-simulated annealing for concave cost transportation problems
(TAYLOR & FRANCIS LTD, 2008) Altıparmak, Fulya; Karaoğlan, İsmail
The transportation problem (TP) is one of the most popular network problems because of its theoretical and practical importance. If the transportation cost linearly depends on the transported amount of the product, then TP is solvable in polynomial time with linear programming methods. However, in the real world, the transportation costs are generally nonlinear, frequently concave where the unit cost for transporting products decreases as the amount of products increases. Since concave cost transportation problems (ccTPs) are NP-hard, solving large-scale problems is time consuming. In this study, we propose a hybrid algorithm based on the concepts borrowed from tabu search (TS) and simulated annealing ( SA) to solve the ccTP. This algorithm, called ATSA ( adaptive tabu-simulated annealing), is an SA approach supplemented with a tabu list and adaptive cooling strategy. The effectiveness of ATSA has been investigated in two stages using a set of TPs with different sizes. The first stage includes performance analysis of ATSA using SA, ASA ( adaptive simulated anealing) and TS, which are basic forms of ATSA. In the second stage, ATSA has been compared with the heuristic approaches given in the literature for ccTP. Statistical analysis shows that ATSA exhibits better performance than its basic forms and heuristic approaches.
A branch and cut algorithm for the location-routing problem with simultaneous pickup and delivery
(ELSEVIER, 2011) Karaoğlan, İsmail; Altıparmak, Fulya; Kara, İmdat; Dengiz, Berna
This paper addresses a location-routing problem with simultaneous pickup and delivery (LRPSPD) which is a general case of the location-routing problem. The LRPSPD is defined as finding locations of the depots and designing vehicle routes in such a way that pickup and delivery demands of each customer must be performed with same vehicle and the overall cost is minimized. We propose an effective branch-and-cut algorithm for solving the LRPSPD. The proposed algorithm implements several valid inequalities adapted from the literature for the problem and a local search based on simulated annealing algorithm to obtain upper bounds. Computational results, for a large number of instances derived from the literature, show that some instances with up to 88 customers and 8 potential depots can be solved in a reasonable computation time. (C) 2011 Elsevier B.V. All rights reserved.
Çok Kullanımlı ve Zaman Pencereli? Araç Rotalama Problemi? İçi?n Bi?r Matemati?ksel Model
(2012) Koç, Çağrı; Karaoğlan, İsmail
In this paper, the vehicle routing problem with time windows and multiple use of vehicles (VRP-TW-MUV) which is the generalized version of the classic vehicle routing problem, is considered. Unlike the classic Vehicle Routing Problem, vehicles are allowed to use more than one route in the VRP-TW-MUV. The VRP-TW-MUV is encountered usually in the distribution systems in which the product's shelf-life is short or duration of the distribution is short. Although, the VRP-TW-MUV is often encountered in practice, there are very few studies in literature. In this study, a mathematical model proposed for the VRP-TW-MUV. The proposed mathematical model is compared in terms of time to reach the best solution on the test problems of various sizes derived from the literature.
Çok temsilcili sistemler ve kargo taşıma problemleri üzerine bir uygulama
(Selçuk Üniversitesi Mühendislik-Mimarlık Fakültesi, 2010) Engin, Orhan; Karaoğlan, İsmail
Çok Temsilcili Sistemler (ÇTS), iki ya da daha fazla ajanın (temsilci) aralarında iletişim kurarak bir çevre içerisinde etkileşim göstermesi ile oluşan, yapay zekânın bir alt dalıdır. Bu çalışmada; son on yılda endüstriyel problemlerin çözümünde başarılı olarak kullanılan ÇTS ve alt sistemleri üzerinde durulmuştur. ÇTS’de kullanılan arama algoritmalarına değinilmiştir. ÇTS ile ilgili son yıllarda yapılan çalışmalar literatür özeti olarak sunulmuştur. Uygulama bölümünde de kargo taşıma problemlerinin ÇTS ile çözümüne ilişkin bir model önerilmiştir. Bu amaç için, farklı ölçeklerde rastsal olarak oluşturulan kargo taşıma problemleri, ÇTS yardımı ile modellenmiştir. Sonuç olarak, ÇTS ile çok kısa sürelerde en iyi çözümlere ulaşıldığı görülmüştür.
District design and route planning for customer-related field operations of natural gas distribution systems: a case study
(Selçuk Üniversitesi Mühendislik Fakültesi, 2018) Atasagun, Gözde Can; Akhüseyin, Emine; Kara, Yakup; Karaoğlan, İsmail
Approximately 24% of the world energy requirement is supplied by natural gas. A natural gas distribution system in a city consists of four main processes, i.e. construction, operating, internal installations, and customer services, which are connected to each other. In this study, customer services processes of the distribution system which are directly related to customers is considered. Mathematical formulations are presented for customer services processes such as district design, route planning and mobile team workload assignment, and applied on one of the authorized natural gas distribution company in Turkey. Performance of the proposed formulations is compared with the current system by means of the number of mobile teams and amount of workloads. The computational studies show that the number of mobile teams of the proposed system is 37% lower than the current system.
A genetic ant colony optimization approach for concave cost transportation problemsac
(IEEE, 2007) Altıparmak, Fulya; Karaoğlan, İsmail
The concave cost transportation problem (ccTP) is one of the practical distribution and logistics problems. The ccTP arises when the unit cost for transporting products decreases as the amount of products increases. Generally, these costs are modeled as nonlinear, especially concave. Since the ccTP is NP-hard, solving large-scale problems is time-consuming. In this paper, we propose a hybrid search algorithm based on genetic algorithms (GA) and ant colony optimization (ACO) to solve the ccTP. This algorithm, called h_GACO, is a GA supplemented with ACO in where ACO is implemented to exploit information stored in pheromone trails during genetic operations, i.e. crossover and mutation. The effectiveness of h_GACO is investigated comparing its results with those obtained by five different metaheuristic approaches given in the literature for the ccTP.
A hybrid discrete particle swarm optimization for vehicle routing problem with simultaneous pickup and delivery
(PERGAMON-ELSEVIER SCIENCE LTD, 2013) Göksal, Fatma Pınar; Karaoğlan, İsmail; Altıparmak, Fulya
Vehicle routing problem (VRP) is an important and well-known combinatorial optimization problem encountered in many transport logistics and distribution systems. The VRP has several variants depending on tasks performed and on some restrictions, such as time windows, multiple vehicles, backhauls, simultaneous delivery and pick-up, etc. In this paper, we consider vehicle routing problem with simultaneous pickup and delivery (VRPSPD). The VRPSPD deals with optimally integrating goods distribution and collection when there are no precedence restrictions on the order in which the operations must be performed. Since the VRPSPD is an NP-hard problem, we present a heuristic solution approach based on particle swarm optimization (PSO) in which a local search is performed by variable neighborhood descent algorithm (VND). Moreover, it implements an annealing-like strategy to preserve the swarm diversity. The effectiveness of the proposed PSO is investigated by an experiment conducted on benchmark problem instances available in the literature. The computational results indicate that the proposed algorithm competes with the heuristic approaches in the literature and improves several best known solutions. (C) 2012 Elsevier Ltd. All rights reserved.
A hybrid genetic algorithm for the location-routing problem with simultaneous pickup and delivery
(2010) Karaoğlan, İsmail; Altıparmak, Fulya
The design of distribution networks is one of the most important problems in supply chain and logistics management. The main elements in designing a distribution network are location and routing decisions. As these elements are interdependent in many distribution networks, the overall system cost can decrease if location and routing decisions are simultaneously tackled. In this paper, we consider a Location-Routing Problem with simultaneous pickup and delivery (LRPSPD) which is a general case of the location-routing problem. The LRPSPD is defined as finding locations of the depots and designing vehicle routes in such a way that pickup and delivery demands of each customer must be performed with same vehicle and the overall cost is minimized. Since the LRPSPD is an NP-hard problem, we propose a hybrid heuristic approach based on genetic algorithms (GA) and simulated annealing (SA) to solve the problem. To evaluate the performance of the proposed approach, we conduct an experimental study and compare its results with the upper bounds obtained by flow-based MIP formulation on a set of instances derived from the literature. Computational results indicate that the proposed approach is able to find optimal or very good quality solutions in a reasonable computation time.
A hybrid particle swarm optimization for vehicle routing problem with simultaneous pickup and delivery
(2010) Göksal, Fatma Pınar; Altıparmak, Fulya; Karaoğlan, İsmail
Vehicle routing problem (VRP) is an important and well-known combinatorial optimization problem encountered in many transport logistics and distribution systems. The VRP has several variants depending on tasks performed and on some restrictions, such as time windows, multiple vehicles, backhauls, simultaneous delivery and pick-up, etc. In this paper, we consider vehicle routing problem with simultaneous pickup and delivery (VRPSPD). The VRPSPD deals with optimally integrating goods distribution and collection when there are no precedence restrictions on the order in which the operations must be performed. Since the VRPSPD is an NP-hard problem, we present a solution approach based on particle swarm optimization (PSO) in which a local search is performed by variable neighborhood descent algorithm (VND). The effectiveness of the proposed PSO (h-PSO) is investigated by an experiment conducted on benchmark problem instances available in the literature. The computational results indicate that the proposed algorithm competes with the heuristic approaches in the literature.
The location-routing problem with simultaneous pickup and delivery: Formulations and a heuristic approach
(PERGAMON-ELSEVIER SCIENCE LTD, 2012) Karaoğlan, İsmail; Altıparmak, Fulya; Kara, İmdat; Dengiz, Berna
In this paper, we consider a variant of the Location-Routing Problem (LRP), namely the LRP with simultaneous pickup and delivery (LRPSPD). The LRPSPD seeks to minimize total cost by simultaneously locating the depots and designing the vehicle routes that satisfy pickup and delivery demand of each customer at the same time. We propose two polynomial-size mixed integer linear programming formulations for the problem and a family of valid inequalities to strengthen the formulations. While the first formulation is a node-based formulation, the second one is a flow-based formulation. Furthermore, we propose a two-phase heuristic approach based on simulated annealing, tp_SA, to solve the large-size LRPSPD and two initialization heuristics to generate an initial solution for the tp_SA. We then empirically evaluate the strengths of the proposed formulations with respect to their ability to find optimal solutions or strong lower bounds, and investigate the performance of the proposed heuristic approach. Computational results show that the flow-based formulation performs better than the node-based formulation in terms of the solution quality and the computation time on small-size problems. However, the node-based formulation can yield competitive lower bounds in a reasonable amount of time on medium-size problems. Meantime, the proposed heuristic approach is computationally efficient in finding good quality solutions for the LRPSPD. (C) 2011 Elsevier Ltd. All rights reserved.
A memetic algorithm for the capacitated location-routing problem with mixed backhauls
(PERGAMON-ELSEVIER SCIENCE LTD, 2015) Karaoğlan, İsmail; Altıparmak, Fulya
The design of distribution networks is one of the most important problems in supply chain and logistics management. The main elements in designing a distribution network are location and routing decisions. As these elements are interdependent in many distribution networks, the overall system cost can decrease if location and routing decisions are simultaneously tackled. In this paper, we consider a Capacitated Location-Routing Problem with Mixed Backhauls (CLRPMB) which is a general case of the capacitated location-routing problem. CLRPMB is defined as finding locations of the depots and designing vehicle routes in such a way that pickup and delivery demands of each customer must be performed with the same vehicle and the overall cost is minimized. Since CLRPMB is an NP-hard problem, we propose a memetic algorithm to solve the problem. To evaluate the performance of the proposed approach, we conduct an experimental study and compare its results with the lower bounds obtained by the branch-and-cut algorithm on a set of instances derived from the literature. Computational results indicate that the proposed approach is able to find optimal or very good quality solutions in a reasonable computation time. (C) 2014 Elsevier Ltd. All rights reserved.
A steady-state genetic algorithm for multi-product supply chain network design
(PERGAMON-ELSEVIER SCIENCE LTD, 2009) Altıparmak, Fulya; Gen, Mitsuo; Lin, Lin; Karaoğlan, İsmail
Supply chain network (SCN) design is to provide an optimal platform for efficient and effective supply chain management (SCM). The problem is often an important and strategic operations management problem in SCM. The design task involves the choice of facilities (plants and distribution centers (DCs)) to be opened and the distribution network design to satisfy the customer demand with minimum cost. This paper presents it solution procedure based on steady-state genetic algorithms (ssGA) with it new encoding structure for the design of a single-source, multi-product, multi-stage SCN. The effectiveness of the ssGA has been investigated by comparing its results with those obtained by CPLEX, Lagrangean heuristic, hyrid GA and simulated annealing on a set of SCN design problems with different sizes. (C) 2007 Elsevier Ltd. All rights reserved.
Two echelon location routing problem with simultaneous pickup and delivery: Mixed integer programming formulations and comparative analysis
(Springer Verlag, 2016) Yıldız, Ece Arzu Demircan; Karaoğlan, İsmail; Altıparmak, Fulya
This paper addresses the two-echelon location routing problem with simultaneous pickup and delivery (2E-LRPSPD). The 2E-LRPSPD deals with optimally locating primary and secondary facilities, and integrating goods distribution from depots and collection from customers and secondary depots. To the best of our knowledge there is no previous study on this problem. We propose two mixed integer programming formulations for the 2E-LRPSPD. While the first formulation is a two-index node-based formulation, the second one is a two-index flow-based formulation. Moreover, a family of valid inequalities are adapted from the literature to strengthen the formulations. In order to evaluate the performances of the formulations and valid inequalities, we conduct an experimental study on the instances derived from the literature. The computational results show that the flow-based formulation produces better lower bounds than the node-based formulation on small and medium-size problems. © Springer International Publishing Switzerland 2016.
Two-echelon vehicle routing problem with simultaneous pickup and delivery: Mathematical model and heuristic approach
(PERGAMON-ELSEVIER SCIENCE LTD, 2018) Belgin, Önder; Karaoğlan, İsmail; Altıparmak, Fulya
The vehicle routing problem is one of the most important areas of logistics management. This study considers two-echelon vehicle routing problem with simultaneous pickup and delivery (2E-VRPSPD) which is a variant of vehicle routing problem. In the 2E-VRPSPD, the pickup and delivery activities are performed simultaneously by the same vehicles through depot to satellites in the first echelon and from satellites to customers in the second echelon. To solve the problem, firstly, a node-based mathematical model is proposed and three valid inequalities from the literature are adapted to strengthen the model. Because of the NP-hardness of the 2E-VRPSPD, secondly, a hybrid heuristic algorithm based on variable neighborhood descent (VND) and local search (LS), called VND_LS, is developed to solve medium- and large-size instances of the 2E-VRPSPD. We conduct an experimental study to investigate the effectiveness of the valid inequalities on the mathematical model and also to evaluate the effectiveness and efficiency of the VND_LS. Computational results show that valid inequalities have significant effect to strengthen the mathematical formulation. Furthermore, the VND_LS finds good solutions for the problem efficiently. Finally, we apply the VND_LS to compare single- and two-echelon distribution systems for a supermarket chain located in Turkey. The results indicate that the VND_LS can easily be applied for real-world problems.
Two-echelon vehicle routing problem with simultaneous pickup and delivery: Mathematical model and valid inequalities
(Universite de Lorraine, 2015) Belgin, Önder; Karaoğlan, İsmail; Altıparmak, Fulya
As one of the most important areas of logistics management, vehicle routing is well-known combinatorial optimization problem. In this study a variant of vehicle routing problem called twoechelon vehicle routing problem with simultaneous pickup and delivery (2E-VRPSPD) is considered. The 2E-VRPSPD performs the pickup and delivery activities simultaneously by the same vehicles through depot to satellites in the first echelon and from satellites to customers in the second echelon. In this study, we propose a node-based mathematical model for the problem and three valid inequalities adapted from the literature to strengthen the model. Computational results are provided to demonstrate the effectiveness of the proposed mathematical model.
Zaman bağımlı araç rotalama problemi için bir matematiksel model
(2014) Koç, Çağrı; Karaoğlan, İsmail
Bu çalışmada klasik Araç Rotalama Probleminin (ARP) genelleştirilmiş bir çeşidi olan Zaman Bağımlı Araç Rotalama Problemi (ZBARP) ele alınmıştır. ZBARP, ARPden farklı olarak, araç hızının düğümler arasında değişken olduğu durumlarda araç filosunun rotalanması olarak tanımlanmaktadır. ZBARP için literatürdeki modellerden farklı bir şekilde ilk olarak, ilk giren ilk çıkar (FIFO) özelliğini sağlayan, zamana bağlı hız fonksiyonunu göz önüne alan ve doğrusal yapıya sahip yeni bir karma tam sayılı matematiksel model geliştirilmiştir. Literatürden türetilen test problemleri üzerindeki deneysel çalışmalar sunulmuş ve modelin performansı en iyi çözüme ulaşma zamanı ve en iyi çözümden yüzde sapma değeri açısından değerlendirilmiştir. Çeşitli parametrelerin değişmesinin modelin performansı üzerindeki etkisinin anlaşılması için 3 farklı senaryo analizi oluşturulmuştur.

Yazar "Karaoğlan, İsmail" seçeneğine göre listele

Sayfa Başına Sonuç

Sıralama seçenekleri