Yazar "Sakalli, Umit Sami" için listeleme
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Ant Colony Optimization and Genetic Algorithm for Fuzzy Stochastic Production-Distribution Planning
Sakalli, Umit Sami; Atabas, Irfan (Mdpi, 2018)In this paper, a tactical Production-Distribution Planning (PDP) has been handled in a fuzzy and stochastic environment for supply chain systems (SCS) which has four echelons (suppliers, plants, warehouses, retailers) with ... -
Brass alloy blending problem from quality and cost perspectives: A multi-objective optimization approach
Birgoren, Burak; Sakalli, Umit Sami (GAZI UNIV, FAC ENGINEERING ARCHITECTURE, 2021)Brass alloy is a composition of copper and zinc and it also includes lead, iron, tin, aluminum, nickel, antimony if necessary. One of the basic problems in brass casting is to determine which pure and scrap materials will ... -
Can the uncertainty in brass casting blending problem be managed? A probability/possibility transformation approach
Sakalli, Umit Sami; Baykoc, Omer Faruk (Pergamon-Elsevier Science Ltd, 2011)Problems about the uncertainty in raw material compositions are a critical issue for the blending problems. It is feared that uncertainty in raw material compositions would often cause percent values of the actual blend ... -
Joint optimization of quality and cost in brass casting using stochastic programming
Sakalli, Umit Sami; Birgoren, Burak (Taylor & Francis Ltd, 2019)A critical process in brass casting is the blending of pure and scrap materials to satisfy specified metal ratios. The primary focus in such blending problems has always been cost minimization. The optimal blends produced ... -
A note on "fuzzy multi-objective production/distribution planning decisions with multi-product and multi-time period in a supply chain"
Sakalli, Umit Sami (Pergamon-Elsevier Science Ltd, 2010)Liang (2008) [Liang, T. -F. (2008). A note on "fuzzy multi-objective production/distribution planning decisions with multi-product and multi-time period in a supply chain". Computers & Industrial Engineering, 55, 676-694] ... -
An optimization approach for brass casting blending problem under aletory and epistemic uncertainties
Sakalli, Umit Sami; Baykoc, Omer Faruk (Elsevier Science Bv, 2011)A critical process in brass casting is the determination of the materials and their quantities to be added into the blend. The reason of being critical is the uncertainty about metal percentages in scrap raw materials. In ... -
Optimization of Production-Distribution Problem in Supply Chain Management under Stochastic and Fuzzy Uncertainties
Sakalli, Umit Sami (Hindawi Ltd, 2017)Production-Distribution Problem (PDP) in Supply Chain Management (SCM) is an important tactical decision. One of the challenges in this decision is the size and complexity of supply chain system (SCS). On the other side, ... -
A possibilistic aggregate production planning model for brass casting industry
Sakalli, Umit Sami; Baykoc, Omer Faruk; Birgoren, Burak (Taylor & Francis Ltd, 2010)This article discusses a possibilistic aggregate production planning (APP) model for blending problem in a brass factory; the problem computing optimal amounts of raw materials for the total production of several types of ... -
A simulated annealing approach for reliability-based chance-constrained programming
Sakalli, Umit Sami (Wiley, 2014)The chance-constrained programming (CCP) is a well-known and widely used stochastic programming approach. In the CCP approach, determining the confidence levels of the constraints at the beginning of solution process is a ... -
A spreadsheet-based decision support tool for blending problems in brass casting industry
Sakalli, Umit Sami; Birgoren, Burak (Pergamon-Elsevier Science Ltd, 2009)This paper has discussed development and implementation of spreadsheet-based decision support tools for modeling and solving blending problems in a large-scale brass factory in Turkey. The user interfaces have been designed ... -
Stochastic optimization for blending problem in brass casting industry
Sakalli, Umit Sami; Baykoc, Omer Faruk; Birgoren, Burak (Springer, 2011)A critical process in brass casting is blending of the raw materials in a furnace so that the specified metal ratios are satisfied. The uncertainties in raw material compositions may cause violations of the specification ...