ABSTRACT Product line selection and pricing are two crucial decisions for the profitability of a ... more ABSTRACT Product line selection and pricing are two crucial decisions for the profitability of a manufacturing firm. Remanufacturing, on the other hand, may be a profitable strategy that captures the remaining value in used products. In this paper we develop a mixed-integer nonlinear programming model form the perspective of an original equipment manufacturer (OEM). The objective of the OEM is to select products to manufacture and remanufacture among a set of given alternatives and simultaneously determine their prices so as to maximize its profit. It is assumed that the probability a customer selects a product is proportional to its utility and inversely proportional to its price. The utility of a product is an increasing function of its perceived quality. In our base model, products are discriminated by their unit production costs and utilities. We also analyze a case where remanufacturing is limited by the available quantity of collected remanufacturable products. We show that the resulting problem is decomposed into the pricing and product line selection subproblems. Pricing problem is solved by a variant of the simplex search procedure which can also handle constraints, while complete enumeration and a genetic algorithm are used for the solution of the product line selection problem. A number of experiments are carried out to identify conditions under which it is economically viable for the firm to sell remanufactured products. We also determine the optimal utility and unit production cost values of a remanufactured product, which maximizes the total profit of the OEM.
... Planning in a Refinery MURAT DRAMAN, i. KUBAN ALTINEL, NUAZ BAJGORIC, ALI TAMER ONAL, AND BUR... more ... Planning in a Refinery MURAT DRAMAN, i. KUBAN ALTINEL, NUAZ BAJGORIC, ALI TAMER ONAL, AND BURAK BIRGOREN Department of ... its components, and finally, internally generates and solves the mathematical programming model without any interaction with the user. ...
In this paper we introduce a new self-organizing neural network, the Kohonen Network Incorporatin... more In this paper we introduce a new self-organizing neural network, the Kohonen Network Incorporating Explicit Statistics (KNIES) that is based on Kohonen's Self-Organizing Map (SOM). The primary difference between the SOM and the KNIES is the fact that every iteration in the training phase includes two distinct modules-the attracting module and the dispersing module. As a result of the newly introduced dispersing module the neurons maintain the overall statistical properties of the data points. Thus, although in SOM the neurons individually find their places both statistically and topologically, in KNIES they collectively maintain their mean to be the mean of the data points, which they represent. Although the scheme as it is currently implemented maintains the mean as its invariant, the scheme can easily be generalized to maintain higher order central moments as invariants. The new scheme has been used to solve the Euclidean Travelling Salesman Problem (TSP). Experimental results for problems taken from TSPLIB [Reinelt, G. (1991). TSPLIB-A travelling salesman problem library. ORSA Journal on Computing, 3, pp. 376-384] indicate that it is a very accurate NN strategy for the TSP-probably the most accurate neural solutions available in the literature.
An application development framework for a software project based on fusion as an object‐oriented... more An application development framework for a software project based on fusion as an object‐oriented application development method is presented. An object‐oriented approach has been adopted for the design and implementation of the prototype interactive visual modelling system for building a visual presentation of a refinery process and creation of linear programming model for optimizing production decision variables. The main reason for this selection is the consideration of object‐oriented programming (OOP) as an obvious vehicle for the development of complex visual interactive modelling systems. The main dimensions of the framework are as follows: OO approach, fusion method, computer‐aided software engineering (CASE) tool, application development tool, GUI development tool, and C++ as an implementation language.
ABSTRACT This work considers the capacitated multi-facility Weber problem, which is concerned wit... more ABSTRACT This work considers the capacitated multi-facility Weber problem, which is concerned with locating m facilities and allocating their limited capacities to n customers in order to satisfy their demand at minimum total transportation cost. This is a nonconvex optimization problem and difficult to solve. Therefore, we propose new approximate solution methods. Some of them are based on the relaxation of the capacity constraints and apply the subgradient algorithm. The resulting Lagrangean subproblem is a variant of the well-known Multi-facility Weber Problem and can be solved using column generation and branch-and-price on a variant of the set covering formulation. Others are based on the approximating mixed integer linear programming formulations obtained by exploiting norm properties and the alternate solution of the discrete location and transportation problems. The results of a detailed computational analysis are also reported. Supplementary materials are available for this article. Go to the publisher’s online edition of IIE Transaction, datasets, additional tables, detailed proofs, etc.
An unrealistic and very restrictive assumption of component testing models in the literature is t... more An unrealistic and very restrictive assumption of component testing models in the literature is the stochastic independence of the components. The independence assumption is hardly true for a complex system where all components operate under the same environmental conditions which may change randomly in time. We consider such a model where stochastic dependence is due to the common environment that
In this paper, we consider the balanced unidirectional cyclic layout problem (BUCLP) arising in t... more In this paper, we consider the balanced unidirectional cyclic layout problem (BUCLP) arising in the determination of workstation locations around a closed loop conveyor system, in the allocation of cutting tools on the sites around a turret, in the positioning of stations around a unidirectional single loop AGV path. BUCLP is known to be NP-Complete. One important property of this
Unlike its cousin, the Euclidean Traveling Salesman Problem (TSP), to the best of our knowledge, ... more Unlike its cousin, the Euclidean Traveling Salesman Problem (TSP), to the best of our knowledge, there has been no documented all-neural solution to the Euclidean Hamiltonian Path Problem (HPP). The reason for this is the fact that the heuristics which map the cities onto the neurons “lose their credibility” because the underlying cyclic property of the order of the neurons
... top of page AUTHORS. Search for M. Hakan Akyüz Search for Temel Öncan Search for İ. ... [4]. ... more ... top of page AUTHORS. Search for M. Hakan Akyüz Search for Temel Öncan Search for İ. ... [4]. Al-Loughani L. Algorithmic approaches for solving the Euclidean distance location-allocation problems. PhD thesis, Virginia Polytechnic Institute and State University, USA; 1997. ...
In this work, the mixed integer linear programming (MILP) model developed in Orçun et. al 1996 fo... more In this work, the mixed integer linear programming (MILP) model developed in Orçun et. al 1996 for optimal planning and scheduling of batch process plants under uncertain operating conditions is further improved to deal also with discrete probability functions. Furthermore, the logic behind integrating the processing uncertainties within the MILP model is implemented on the variations in the production volumes
In this work, a mathematical programming model for optimal scheduling of the operations of a batc... more In this work, a mathematical programming model for optimal scheduling of the operations of a batch processing chemical plant is developed. The model is capable to handle all possible deterministic variations in the set-up and operation times of batch operations, and the model is sufficiently general to include the uncertainties introduced by the probabilistic behavior of set-up and operation times
... Wireless sensor networks are based on the collaborative effort of a very large number of low-... more ... Wireless sensor networks are based on the collaborative effort of a very large number of low-power, low-cost, multi ... point coverage models based on set covering formulations do not seem to have a direct concern with efficient energy usage, Yang et al.'s work provides a ...
ABSTRACT Product line selection and pricing are two crucial decisions for the profitability of a ... more ABSTRACT Product line selection and pricing are two crucial decisions for the profitability of a manufacturing firm. Remanufacturing, on the other hand, may be a profitable strategy that captures the remaining value in used products. In this paper we develop a mixed-integer nonlinear programming model form the perspective of an original equipment manufacturer (OEM). The objective of the OEM is to select products to manufacture and remanufacture among a set of given alternatives and simultaneously determine their prices so as to maximize its profit. It is assumed that the probability a customer selects a product is proportional to its utility and inversely proportional to its price. The utility of a product is an increasing function of its perceived quality. In our base model, products are discriminated by their unit production costs and utilities. We also analyze a case where remanufacturing is limited by the available quantity of collected remanufacturable products. We show that the resulting problem is decomposed into the pricing and product line selection subproblems. Pricing problem is solved by a variant of the simplex search procedure which can also handle constraints, while complete enumeration and a genetic algorithm are used for the solution of the product line selection problem. A number of experiments are carried out to identify conditions under which it is economically viable for the firm to sell remanufactured products. We also determine the optimal utility and unit production cost values of a remanufactured product, which maximizes the total profit of the OEM.
... Planning in a Refinery MURAT DRAMAN, i. KUBAN ALTINEL, NUAZ BAJGORIC, ALI TAMER ONAL, AND BUR... more ... Planning in a Refinery MURAT DRAMAN, i. KUBAN ALTINEL, NUAZ BAJGORIC, ALI TAMER ONAL, AND BURAK BIRGOREN Department of ... its components, and finally, internally generates and solves the mathematical programming model without any interaction with the user. ...
In this paper we introduce a new self-organizing neural network, the Kohonen Network Incorporatin... more In this paper we introduce a new self-organizing neural network, the Kohonen Network Incorporating Explicit Statistics (KNIES) that is based on Kohonen's Self-Organizing Map (SOM). The primary difference between the SOM and the KNIES is the fact that every iteration in the training phase includes two distinct modules-the attracting module and the dispersing module. As a result of the newly introduced dispersing module the neurons maintain the overall statistical properties of the data points. Thus, although in SOM the neurons individually find their places both statistically and topologically, in KNIES they collectively maintain their mean to be the mean of the data points, which they represent. Although the scheme as it is currently implemented maintains the mean as its invariant, the scheme can easily be generalized to maintain higher order central moments as invariants. The new scheme has been used to solve the Euclidean Travelling Salesman Problem (TSP). Experimental results for problems taken from TSPLIB [Reinelt, G. (1991). TSPLIB-A travelling salesman problem library. ORSA Journal on Computing, 3, pp. 376-384] indicate that it is a very accurate NN strategy for the TSP-probably the most accurate neural solutions available in the literature.
An application development framework for a software project based on fusion as an object‐oriented... more An application development framework for a software project based on fusion as an object‐oriented application development method is presented. An object‐oriented approach has been adopted for the design and implementation of the prototype interactive visual modelling system for building a visual presentation of a refinery process and creation of linear programming model for optimizing production decision variables. The main reason for this selection is the consideration of object‐oriented programming (OOP) as an obvious vehicle for the development of complex visual interactive modelling systems. The main dimensions of the framework are as follows: OO approach, fusion method, computer‐aided software engineering (CASE) tool, application development tool, GUI development tool, and C++ as an implementation language.
ABSTRACT This work considers the capacitated multi-facility Weber problem, which is concerned wit... more ABSTRACT This work considers the capacitated multi-facility Weber problem, which is concerned with locating m facilities and allocating their limited capacities to n customers in order to satisfy their demand at minimum total transportation cost. This is a nonconvex optimization problem and difficult to solve. Therefore, we propose new approximate solution methods. Some of them are based on the relaxation of the capacity constraints and apply the subgradient algorithm. The resulting Lagrangean subproblem is a variant of the well-known Multi-facility Weber Problem and can be solved using column generation and branch-and-price on a variant of the set covering formulation. Others are based on the approximating mixed integer linear programming formulations obtained by exploiting norm properties and the alternate solution of the discrete location and transportation problems. The results of a detailed computational analysis are also reported. Supplementary materials are available for this article. Go to the publisher’s online edition of IIE Transaction, datasets, additional tables, detailed proofs, etc.
An unrealistic and very restrictive assumption of component testing models in the literature is t... more An unrealistic and very restrictive assumption of component testing models in the literature is the stochastic independence of the components. The independence assumption is hardly true for a complex system where all components operate under the same environmental conditions which may change randomly in time. We consider such a model where stochastic dependence is due to the common environment that
In this paper, we consider the balanced unidirectional cyclic layout problem (BUCLP) arising in t... more In this paper, we consider the balanced unidirectional cyclic layout problem (BUCLP) arising in the determination of workstation locations around a closed loop conveyor system, in the allocation of cutting tools on the sites around a turret, in the positioning of stations around a unidirectional single loop AGV path. BUCLP is known to be NP-Complete. One important property of this
Unlike its cousin, the Euclidean Traveling Salesman Problem (TSP), to the best of our knowledge, ... more Unlike its cousin, the Euclidean Traveling Salesman Problem (TSP), to the best of our knowledge, there has been no documented all-neural solution to the Euclidean Hamiltonian Path Problem (HPP). The reason for this is the fact that the heuristics which map the cities onto the neurons “lose their credibility” because the underlying cyclic property of the order of the neurons
... top of page AUTHORS. Search for M. Hakan Akyüz Search for Temel Öncan Search for İ. ... [4]. ... more ... top of page AUTHORS. Search for M. Hakan Akyüz Search for Temel Öncan Search for İ. ... [4]. Al-Loughani L. Algorithmic approaches for solving the Euclidean distance location-allocation problems. PhD thesis, Virginia Polytechnic Institute and State University, USA; 1997. ...
In this work, the mixed integer linear programming (MILP) model developed in Orçun et. al 1996 fo... more In this work, the mixed integer linear programming (MILP) model developed in Orçun et. al 1996 for optimal planning and scheduling of batch process plants under uncertain operating conditions is further improved to deal also with discrete probability functions. Furthermore, the logic behind integrating the processing uncertainties within the MILP model is implemented on the variations in the production volumes
In this work, a mathematical programming model for optimal scheduling of the operations of a batc... more In this work, a mathematical programming model for optimal scheduling of the operations of a batch processing chemical plant is developed. The model is capable to handle all possible deterministic variations in the set-up and operation times of batch operations, and the model is sufficiently general to include the uncertainties introduced by the probabilistic behavior of set-up and operation times
... Wireless sensor networks are based on the collaborative effort of a very large number of low-... more ... Wireless sensor networks are based on the collaborative effort of a very large number of low-power, low-cost, multi ... point coverage models based on set covering formulations do not seem to have a direct concern with efficient energy usage, Yang et al.'s work provides a ...
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