Yazar "Paksoy, Turan" seçeneğine göre listele

Listeleniyor 1 - 20 / 54
  • Küçük Resim Yok
    Öğe
    Allied Closed-Loop Supply Chain Network Optimization with Interactive Fuzzy Programming Approach
    (SPRINGER INTERNATIONAL PUBLISHING AG, 2017) Calik, Ahmet; Pehlivan, Nimet Yapici; Paksoy, Turan; Karaoglan, Ismail
    The concept of closed-loop supply chain (CLSC) has started to attract growing attention due to the consumer pressures, environmental awareness, and legislations. Managers in many companies have realized that a well-designed supply chain (SC) can improve the companies' performance in the market. Thus, a lot of companies start to focus on CLSC issues including remanufacturing, refurbishing, recycling, and disposal of end-of-life products. The body of literature on CLSC management has been overwhelmingly dominated by noncooperative studies. In order to fill up this gap in the literature, we deal with an allied SC network in cooperative environment. With the implementation of allied SCs, companies not only maximize their profit but also minimize their various costs and become more flexible and efficient in the market. Following this motivation, we develop a decentralized multilevel CLSC model for allied SCs. At the first decision level, the plants in allied SCs are considered as the upper-level DMs of the Stackelberg game. At the second level, raw material suppliers, common suppliers, assembly centers, and common collection centers are considered as the lower-level DMs of the Stackelberg game. In order to tackle each decision-maker (DM)'s unique objectives, we propose a new fuzzy analytic hierarchy process (AHP)-based interactive fuzzy programming (IFP) approach. In the IFP approach, upper-level DMs determine the minimum satisfactory level for their own objectives, and by using this value, the lower DMs evaluate their own satisfactory level. A compromise solution can be derived until termination conditions are satisfied. The primary aim of this study is to design a decentralized CLSC network in cooperative environment and to propose a novel IFP approach. Finally, a numerical example is implemented and analyzed in order to demonstrate the efficiency of the proposed approach.
  • Küçük Resim
    Öğe
    Application of Fuzzy Mathematical Programming Approach to the Aggregate Production/Distribution Planning in a Supply Chain Network Problem
    (Academic Journals, 2010) Paksoy, Turan; Pehlivan, Nimet Yapıcı; Özceylan, Eren
    This paper presented an application of Fuzzy mathematical programming model to solve network design problems for supply chains via considering aggregate production planning (APP). APP goals to minimize all costs through optimal levels of production, subcontracting, inventory, backorder and work levels over a time period to meet the demand. Fuzzy logic was applied to solve the uncertain production/distribution/subcontracting costs and capacities. However, most of the existing models deal the APP problems without integrating supply chain networks. In our model, APP and supply chain design problem were considered within a single plan horizon to get better managerial results. A supply chain network which includes suppliers, manufacturers, subcontracts, retailers and customers, was developed to illustrate the performance of the proposed model. A numerical example was presented to clarify the features proposed approach. In applying the model, decision makers should find a potential to represent their human resources policies regarding the overtime and subcontract production under material requirements constraints.
  • Küçük Resim Yok
    Öğe
    Application of fuzzy optimization to a supply chain network design: A case study of an edible vegetable oils manufacturer
    (ELSEVIER SCIENCE INC, 2012) Paksoy, Turan; Pehlivan, Nimet Yapici; Ozceylan, Eren
    This study applies fuzzy sets to integrate the supply chain network of an edible vegetable oils manufacturer. The proposed fuzzy multi-objective linear programming m attempts to simultaneously minimize the total transportation costs. The first part of total transportation costs is between suppliers and silos; and rest one is between manufacturer and warehouses. The approach incorporates all operating realities and actual patterns at production/distribution network with reference to demands of warehouse capacities of tin and pet packaging lines. The model has been formulated as a multi objective linear programming model where data are modeled by triangular fuzzy numb Finally, the developed fuzzy model is applied for the case study, compiled the re ! and discussed. (C) 2011 Elsevier Inc. All rights reserved.
  • Küçük Resim
    Öğe
    Aralık Tip-2 Bulanık AHP Yöntemi ile Üçüncü Parti Tersine Lojistik (3PTL) Firma Seçimi
    (Selçuk Üniversitesi, 2017) Çalık, Ahmet; Paksoy, Turan
    Ömrü bitmiş ve kullanılmış ürünlerin yönetimi küreselleşme, yasal düzenlemeler ve artan çevresel farkındalık nedeniyle önemli bir lojistik faaliyeti haline gelmiştir. Tersine lojistik ağındaki akışın yönetimi özel altyapı ve uzmanlık gerektirdiği için, işletmelerin ağlarındaki hangi firma ile çalışacağı önemli bir sorundur. Bu nedenle işletmeler Üçüncü Parti Tersine Lojistik (3PTL) firmalarına (sağlayıcılarına) yönelmişlerdir. 3PTL, işletmelerin tersine lojistik ağındaki ihtiyaç duydukları hizmetlerin veya lojistik faaliyetlerinin dış kaynak kullanılarak karşılanmasıdır. Bu çalışmada, en iyi 3PTL firma seçimi için yedi kriter ve üç alternatif ile aralık tip-2 bulanık Analitik Hiyerarşi Prosesi (AHP) yöntemi kullanılmıştır. Aralık tip-2 bulanık kümeler, çelişkili kriterlerin olduğu bulanık grup karar verme problemlerinin belirsizliğini yansıtmada tip-1 bulanık saylardan daha uygun, daha esnek ve daha akıllıdır. Bu nedenle, Çok Kriterli Karar Verme (ÇKKV) problemlerinin aralık tip-2 bulanık sayılar ile entegre edilmesi karar verme sürecinde avantajlar sağlayacaktır. Yapılan uygulama çalışması sonucunda, uygulanan aralık tip-2 bulanık AHP yöntemin 3PTL firma seçiminde kullanılabileceği ortaya konulmuştur.
  • Küçük Resim Yok
    Öğe
    Binary fuzzy goal programming approach to single model straight and U-shaped assembly line balancing
    (ELSEVIER SCIENCE BV, 2009) Kara, Yakup; Paksoy, Turan; Chang, Ching-Ter
    Assembly line balancing generally requires it set of acceptable solutions to the several conflicting objectives. In this study, a binary fuzzy goal programming approach is applied to assembly line balancing. Models for balancing straight and U-shaped assembly lines with fuzzy goals (the number of workstations and cycle time goals) are proposed. The binary fuzzy goal programming models are solved using the methodology introduced by Chang [Chang, C.T., 2007. Binary fuzzy goal programming. European Journal of Operational Research 180 (1), 29-37]. Ail illustrative example is presented to demonstrate the validity of the proposed models and to compare the performance of straight and U-shaped line configurations. (C) 2008 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    A Decentralized Model for Allied Closed-Loop Supply Chains: Comparative Analysis of Interactive Fuzzy Programming Approaches
    (SPRINGER HEIDELBERG, 2017) Calik, Ahmet; Paksoy, Turan; Yildizbasi, Abdullah; Pehlivan, Nimet Yapici
    The supply chain network design problem addresses various factors that maximize customers' demand and minimizes the sum of strategic, tactical, and operational costs. Companies with common activities in their supply chains have started to cooperate with each other to achieve better service levels. Based on this initiative, a multi-level mixed-integer linear programming model is developed that includes two allied supply chains with different decision makers (DM) at two different decision-making levels. The primary aim of this study is to design an allied closed-loop supply chain (CLSC) network that uses some of the same facilities. The secondary aim of this study is to examine this allied CLSC model simultaneously and analyse the impact of the DMs' objectives based on satisfaction degrees. Various interactive fuzzy programming (IFP) approaches were utilized to examine the presented multi-level CLSC model. A novel IFP approach which is based on the fuzzy analytic hierarchy process (AHP) is proposed. The effectiveness of the proposed IFP approach on the CLSC model is investigated with hypothetical data. The computational results show that the proposed approach obtains higher satisfaction degrees for upper-level DMs than the other approaches.
  • Küçük Resim
    Öğe
    E-Ti?careti?n Kobi?’ler Tarafından Algılanışı ve Rekabette Bi?r Araç Olarak Kullanımı: Konya Tarım Maki?neleri? Sanayi?si?’nde Bi?r Uygulama
    (Selçuk Üniversitesi, 2003) Paksoy, Turan; Ürkmez, N. Gülden; Arıcıoğlu, M. Atilla
    E-commerce is one of the new technologic developments which provides firms easier and cheaper application opportunities during the com- mercial activities. Beside the big firms that use e-commerce applications in their business process succesfully, it is wondered if the small and middle sized firms can use it as succesfully as the big ones. In this study, it is aimed to measure the degree of the diffusion and effectiveness of e-commerce usage in small and middle sized firms which act in Konya Industry and Konya Agricultural Machines and Tools Industry was chosen as the pilot sector. The datas gathered from the firms that produce agricultural machines and tools by the help of the Enquiry Method were evaluated and analyzed using the packet program of SPSS.
  • Küçük Resim Yok
    Öğe
    An empirical investigation of advanced manufacturing technology investment patterns: Evidence from a developing country
    (ELSEVIER, 2013) Bulbul, Hasan; Omurbek, Nuri; Paksoy, Turan; Bektas, Tolga
    Advanced manufacturing technology (AMT) investment patterns in developing countries is in need of further investigation, particularly in the light of the conflicting evidence from the literature. This paper provides new evidence on AMT investment patterns from the Turkish automotive industry and develops a taxonomy by exploring the relationships between AMT investment patterns, ownership structure, firm size and performance. Analysis of industry survey data suggests the existence of three groups with different AMT investment strategies. Results suggest that AMT investment patterns are not only significantly correlated with firm performance or ownership, but also reveals significant differences in manufacturing performance across investment patterns. (C) 2013 Elsevier B.V. All rights reserved.
  • Küçük Resim
    Öğe
    An Environmentally Conscious Multi-Objective Weber Problem for Green Location and Distribution Planning: A Fuzzy Weighted Additive Approach
    (2019) Engin, Batuhan Eren; Paksoy, Turan
    In this study, a multi-objective Weber (p-median) problem is treatedin order to determine the location of the warehouses to be opened and the distributionplans of products. The company carries out the distribution with three types ofvehicles differing in unit transportation cost, carbon emission and velocity. Threeconflicting objectives are aimed to be minimized, i.e.; the demand weighted totaltransportation cost, the total delivery time and the total carbon. We adopted a fuzzyweighted additive approach to deal with the multi-objective optimization function, inwhich the weights of each individual objective function are determined by AnalyticHierarchy Process.
  • Küçük Resim Yok
    Öğe
    Etkileşimli Bulanık Çok Amaçlı Doğrusal Programlama ile Bütünleşik Üretim Planlama: Hidrolik Pompa İmalatçısı Firma Örnek Olayı
    (2002) Paksoy, Turan; Atak, Mehmet
    Bu çalışmada, gerçek dünyanın bulanık olan yapısını modelleyebilen ve Analitik Hiyerarşi Yöntemi ile kullanıcı ile etkileşimli olarak çalışan, onun tercihleri doğrultusunda amaçları önceliklendiren ve çözüm aşamasında da bu etkileşimi sürdürerek en iyi çözüme ulaşmayı amaç edinen, sisteme daha gerçekçi bir yaklaşım ile hem bulanıklığı hem de çok amaçlılığı içeren bir yöntem kullanılmış ve bir endüstriyel üretim sisteminde bütünleşik üretim planı gerçekleştirilmiştir.
  • Küçük Resim Yok
    Öğe
    A fuzzy linear programming model for the optimization of multi-stage supply chain networks with triangular and trapezoidal membership functions
    (PERGAMON-ELSEVIER SCIENCE LTD, 2012) Paksoy, Turan; Pehlivan, Nimet Yapici
    Supply chain management (SCM) is concerned with a complex business relations network that contains interrelationships between various entities, such as suppliers, manufacturers, distribution centers and customers. SCM integrates these entities and manages their interrelationships through the use of information technology to meet customer expectations (i.e., higher product variety and quality, lower costs and faster responses) effectively along the entire value chain. Thus, one of the vital issues in supply chain management is the design of the value chain network. In this paper, a fuzzy linear programming model for the optimization of the multi-stage supply chain model with triangular and trapezoidal membership functions is presented. The model determines the fuzzy capacities of the facilities (plants or distribution centers (DCs)) and the design of the network configuration with a minimum total cost. The total cost involves the shipping cost from suppliers; transportation costs between plants and DCs; distribution costs between DCs and customer zones; and opportunity costs from not having the material at the right time. The developed model is solved by a professional software package (LINDO), and the computational results are discussed. (C) 2011 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Fuzzy mathematical programming approaches for reverse supply chain optimization with disassembly line balancing problem
    (IOS PRESS, 2014) Ozceylan, Eren; Paksoy, Turan
    Today, the requirement of reverse supply chain (RSC) optimization takes more attention due to environmental and competitive factors. However, increasing attention and existing uncertainty in RSC also increases the difficulties for decisions of production/distribution planning. Therefore, considering strategic and tactical decisions together under fuzziness is being essential. This paper presents a fuzzy programming approach to the integration of RSC optimization (strategic level) and disassembly line balancing (DLB) (tactical level) problems. The aim of this study is to apply fuzzy modeling to optimize a RSC that involves customers, collection/disassembly centers and plants while balancing the disassembly lines in disassembly centers, simultaneously. Two types of fuzzy mathematical programming models with different aggregation operators are used. Finally, accuracy and applicability of the model is illustrated and a comparison of fuzzy approaches is done via a hypothetical example.
  • Küçük Resim Yok
    Öğe
    Fuzzy Multi Objective Optimization of Green Supply Chain Network
    (ATLANTIS PRESS, 2011) Paksoy, Turan; Pehlivan, Nimel Yapici; Ozceylan, Eren
    Because of the leading environmental disasters, global climate alteration has become one of the most important controversial issues. The greenhouse gas emissions (CO2, methane, etc.) and air pollution increase attention to develop and improve environmental strategies. Thus, environmental sanctions are forcing enterprises to re-consider and re-design supply chain processes in a green way. This paper provides a multi objective model to design a closed-loop supply chain (CLSC) network in a green frame. Our first and second objectives are minimizing the all transportation costs for forward and reverse logistics; third one is minimizing total CO2 emissions; fourth one is encouraging the customers to use recyclable materials as an environmental performance viewpoint. To provide a more realistic modeling by treating the uncertainty in decision maker's objectives, fuzzy modeling is approach is used in this study. The model is explained and tested via fulfilling a numerical example. In scenario analyses, Analytic Hierarchy Process (AHP), fuzzy AHP and fuzzy TOPSIS are applied and compared to evaluate different objectives.
  • Küçük Resim Yok
    Öğe
    Fuzzy multi-objective linear programming approach for optimising a closed-loop supply chain network
    (TAYLOR & FRANCIS LTD, 2013) Ozceylan, Eren; Paksoy, Turan
    With the urgency of remanufacturing and environmental concerns, closed-loop supply chain (CLSC) networks have drawn the attention of researchers. Although there are many CLSC network models in the literature, most of them do not consider uncertainty in general terms. However, practical situations are often not well defined and thus cannot be described precisely in real world CLSCs. In this paper a mixed integer fuzzy mathematical model is proposed for a CLSC network which includes both forward and reverse flows with multiple periods and multiple parts. A fuzzy multi-objective model (FMOM) approach is applied to take into account the fuzziness in the capacity, objectives, demand constraints and also in the reverse rates. Computational results are presented for a number of scenarios to show and validate applicability and flexibility of the model. Results show that the proposed model presents a systematic framework which enables the logistics manager (LM) to adjust the search direction during the solution procedure to obtain a desired satisfactory solution.
  • Küçük Resim
    Öğe
    Fuzzy Multi-Objective Optimization of a Green Supply Chain Network with Risk Management that Includes Environmental Hazards
    (TAYLOR & FRANCIS INC, 2012) Paksoy, Turan; Yapıcı Pehlivan, Nimet; Özceylan, Eren
    Among the leading environmental risks, global climate alteration has become one of the most important controversial issues. Greenhouse gas emissions (CO2, methane, etc.) and air pollution have motivated a need to develop and improve environmental management strategies. As a consequence, environmental sanctions are forcing commercial enterprises to re-consider and re-design supply chain processes in a green way. This article provides a multi-objective model to design a closed-loop supply chain (CLSC) network in a green framework. Our first and second objectives are to minimize all the transportation costs for the supply chain's forward and reverse logistics; the third objective is to minimize total CO2 emissions; the fourth objective is to encourage customers to use recyclable materials as an environmental practice. To provide more realistic modeling by treating the uncertainty in decision-makers' objectives, fuzzy modeling is used in this study. The model is explained and tested via fulfilling a numerical example. In scenario analyses, analytic hierarchy process (AHP), fuzzy AHP (F-AHP), and fuzzy TOPSIS (F-TOPSIS) approaches were applied and compared to evaluate different objectives to guide decision-makers.
  • Küçük Resim Yok
    Öğe
    Fuzzy Programming Approach to an Environmental Supply Chain Network Design Problem
    (OLD CITY PUBLISHING INC, 2015) Ozceylan, Eren; Pehlivan, Nimet Yapici; Paksoy, Turan
    Increasing the environmental concerns with legislations and responsibilities are forcing enterprises to take an attention at the impact of their supply chain operations on the environment. An optimally designed supply chain network is required to provide economic, social and environmental requirements in good flows actualizing between suppliers, manufacturers and customers. A nonlinear mixed integer programming model is proposed with the aimed of optimally determining consumed fuel, emitted CO2, driver and transportation costs in this study. However, real world supply chain operations are occurred in a highly dynamic and imprecise environment. Thus, a fuzzy mathematical programming approach is applied to cope with uncertainty in the capacities and demands. The proposed fuzzy model is validated and also compared with different fuzzy mathematical programming approaches through an example, where its applicability is demonstrated for managerial insights.
  • Küçük Resim Yok
    Öğe
    A genetic algorithm approach for multi-objective optimization of supply chain networks
    (2006) Altıparmak, Fulya; Gen, Mitsuo; Lin, Lin; Paksoy, Turan
    Supply chain network (SCN) design is to provide an optimal platform for efficient and effective supply chain management. It is an important and strategic operations management problem in supply chain management, and usually involves multiple and conflicting objectives such as cost, service level, resource utilization, etc. This paper proposes a new solution procedure based on genetic algorithms to find the set of Pareto-optimal solutions for multi-objective SCN design problem. To deal with multi-objective and enable the decision maker for evaluating a greater number of alternative solutions, two different weight approaches are implemented in the proposed solution procedure. An experimental study using actual data from a company, which is a producer of plastic products in Turkey, is carried out into two stages. While the effects of weight approaches on the performance of proposed solution procedure are investigated in the first stage, the proposed solution procedure and simulated annealing are compared according to quality of Pareto-optimal solutions in the second stage. © 2006 Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
    Öğe
    A genetic algorithm approach for optimising a closed-loop supply chain network with crisp and fuzzy objectives
    (TAYLOR & FRANCIS LTD, 2014) Demirel, Neslihan; Ozceylan, Eren; Paksoy, Turan; Gokcen, Hadi
    This paper proposes a mixed integer programming model for a closed-loop supply chain (CLSC) network with multi-periods and multi-parts under two main policies as secondary market pricing and incremental incentive policies. In the first policy, customers order and receive products from distribution centres, but at next period, they can trade among themselves with used products that are returned in a secondary market. Financial incentives are offered to the customers to influence the returns, and the correct amount of collections at different prices is determined by the second policy. In addition to the base case (crisp) formulation, a fuzzy multi-objective extension is applied to solve CLSC network problem with fuzzy objectives to represent vagueness in real-world problems. Then, developed genetic algorithm approach is applied to solve real size crisp and fuzzy CLSC problems. The effectiveness of the proposed meta-heuristic approach is investigated and illustrated by comparing its results with GAMS-CPLEX on a set of crisp/fuzzy problems with different sizes.
  • Küçük Resim
    Öğe
    Güneş Enerji̇si̇ ve Su Isıtma Si̇stemleri̇ İmal Eden Bi̇r İşletmede Bulanık İşlem Süreleri̇ İle Malzeme İhti̇yaç Planlama
    (Selçuk Üniversitesi, 2004 Ağustos) Paksoy, Turan; Altıparmak, Fulya
    Malzeme İhtiyaç Planlama (MİP) sistemi, stok maliyetlerini azaltırken verimliliği ve müşteri memnuniyetini artırmayı hedefleyen bir üretim yönetim sistemidir. Son yıllarda, Türkiye’de özellikle imalat sanayiinde bir çok firma bu sistemi kullanmaya başlamış veya kullanmayı planlamaktadır. Her yeni sistemde olduğu gibi MİP sistemi, gerçek üretim sistemlerinin doğasında barındırdıkları karmaşıklığın ve belirsizliğin etkisiyle, başlangıç aşamasında pek çok güçlük içerir. Bu çalışmada, güneş enerjisi ve su ısıtma sistemleri imal eden bir işletmede, işlem sürelerindeki belirsizliğin Bulanık Küme Teorisi ile tanımlandığı durumda MİP sisteminin uygulanması incelenmektedir.
  • Küçük Resim
    Öğe
    İki Amaçlı Farklı Makine Seçenekli Kapalı Döngü Tedarik Zinciri Optimizasyonu: Bulanık Çözüm Tekniği Uygulaması
    (Selçuk Üniversitesi Mühendislik Fakültesi, 2019) Engi̇n, Batuhan Eren; Paksoy, Turan
    Tedarik zinciri yönetimi, küreselleşme çağının başlangıcından beri akademisyenlerin ve uygulayıcıların artan ilgisini çekmeye devam etmiştir. Son yıllarda, tedarik zinciri yönetiminin odak noktası, enerji tüketimi, karbon emisyonları gibi ekonomik, sosyal ve çevresel yönlerin ortaklaşa ele alındığı sürdürülebilir akış yönetimi olmaya başlamıştır. Bu çalışmada, çok dönemli kapalı döngü tedarik zinciri ağ tasarım probleminin optimizasyonu için iki amaçlı karmaşık tamsayılı doğrusal programlama modelinin formüle edilmesi ve çözülmesi gerçekleştirilmiştir. Model, farklı makine tiplerinde faaliyet gösteren tesislerin toplam operasyon maliyeti ve toplam karbon emisyonları olmak üzere iki ayrı amacın minimizasyonunu hedeflerken, üretim ve dağıtım stratejilerini belirlemekte ve yeni veya eski tip makinelerin kullanımına da karar vermektedir. Daha eski ve güncel olmayan makinelerin ilk satın alma maliyeti, yeni ve güncellenmiş makinelere göre daha düşük olmasına rağmen, eski makineler, saat başına daha yüksek maliyetle çalışırken yeni makinelere göre saat başına daha fazla karbon salmaktadır. Ayrıca, bir saat içinde üretilen ürünlerin sayısı, yani üretkenlik, yeni makinelerde daha üstündür. Bu iki amaçlı kapalı döngü tedarik zinciri modelinin çözümü için bulanık ağırlıklandırma yaklaşımı kullanılmıştır. Sonuçlar, üretimde yeni nesil teknolojilere yatırım yapılmasının hem ekonomik hem de çevresel amaçlara ulaşmak için önemli olduğunu göstermektedir.