This paper investigates single machine scheduling problem with unequal release times and deterioration jobs where the objective function of it is minimal makespan.A mixed integer mathematical programming optimization ...
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This paper investigates single machine scheduling problem with unequal release times and deterioration jobs where the objective function of it is minimal makespan.A mixed integer mathematical programming optimization model is developed for the problem which belongs to the NP-hard *** model is tested on examples and compared with a heuristic algorithm introduced by Lee et al..Moreover,the branch-bound algorithm proposed by Lee et *** can obtained optimal solutions the same as the results from CPLEX but the CPU time of it for 28 jobs even needs more than 2 hours,thus,the results between them are not *** to results of computational tests,it is showed that the proposed model is very effective in solving problems because it can obtain optimal solutions within a short ***,it is very useful and valuable for decision maker who requires the optimal solutions.
Some feasible mathematical model solution results in a recent paper (Fattahi et al., Int J Adv Manuf Technol, 53:363–378, 2011) are incorrect. In this note, we show by counterexamples that the results are incorrect a...
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Some feasible mathematical model solution results in a recent paper (Fattahi et al., Int J Adv Manuf Technol, 53:363–378, 2011) are incorrect. In this note, we show by counterexamples that the results are incorrect and mathematical formulation is corrected by additional constraints.
In order to slow climate change, economies need to quickly move away from finite energy sources and towards using low-carbon energy systems. However, the integration of non-dispatchable wind and solar sources comes wi...
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In order to slow climate change, economies need to quickly move away from finite energy sources and towards using low-carbon energy systems. However, the integration of non-dispatchable wind and solar sources comes with additional costs and can make the energy market unusual and unpredictable. Specifically, the presence of variable renewable energy sources makes it harder to accurately forecast energy demand. This paper is a first step in presenting a novel approach to overcoming the inherent variability of photovoltaics (PV) by combining them with a run-off-river (ROR) power plant. A mixedintegermathematical model has been developed and applied to simulate the operation of a PV-ROR hybrid energy source coupled with the national power system. Simulations demonstrate various configurations of parameters and their impact on the objective function which was to maximize the volume of energy from PV and hydropower used to cover energy demand, while ensuring that neither energy deficits nor energy surpluses exceed 5% of energy demand. Our analysis indicates that an ROR power plant with relatively small pondage is capable of subsidizing the varying energy output of the PV system. Besides conducting a simulation and optimization, this paper suggests an approach to smoothing the energy exchange with the grid based on fixed volumes of energy which should be delivered during daylight and nighttime hours. (C) 2017 Elsevier Ltd. All rights reserved.
In this paper, we study a production scheduling and vehicle routing problem with job splitting and delivery time windows in a company working in the metal packaging industry. In this problem, a set of jobs has to be p...
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In this paper, we study a production scheduling and vehicle routing problem with job splitting and delivery time windows in a company working in the metal packaging industry. In this problem, a set of jobs has to be processed on unrelated parallel machines with job splitting and sequence-dependent setup time (cost). Then the finished products are delivered in batches to several customers with heterogeneous vehicles, subject to delivery time windows. The objective of production is to minimize the total setup cost and the objective of distribution is to minimize the transportation cost. We propose mathematical models for decentralized scheduling problems, where a production schedule and a distribution plan are built consecutively. We develop a two-phase iterative heuristic to solve the integrated scheduling problem. We evaluate the benefits of coordination through numerical experiments.
In this study a new version of adjacency, which provides a more flexible layout design, is proposed. In the proposed version, departments which are nonadjacent yet close to each other are considered to be adjacent wit...
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In this study a new version of adjacency, which provides a more flexible layout design, is proposed. In the proposed version, departments which are nonadjacent yet close to each other are considered to be adjacent with a smaller adjacency rating. It is shown that the proposed adjacency is a generalized version of the traditional adjacency. A mathematicalprogramming model is developed for the proposed facility layout problem. To show the flexibility and efficacy of the proposed model, a computational study is conducted. The solution of an illustrative example as well as the solutions of several test problems, reveal flexibility and efficacy of the proposed model. (C) 2015 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.
The train platforming problem consists in the allocation of passenger trains to platforms in a railway station. One of the important problems a dispatcher has to solve, especially in a large railway station, is to dec...
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ISBN:
(纸本)9783319114637;9783319114620
The train platforming problem consists in the allocation of passenger trains to platforms in a railway station. One of the important problems a dispatcher has to solve, especially in a large railway station, is to decide, at which platform track an approaching train should arrive. There is a tool helping him in his job called the track occupancy plan. The plan specifies for each arriving or departing train the platform track along with the time slot during which the track will be occupied by the train. This paper deals with a method for computer-aided design of the track occupancy plan. The problem is formulated as a bi-criterion mixedintegerprogramming problem. The first objective is to minimise the deviations of the arrival and departure times proposed by the model from the times specified by the timetable. The second criterion maximises the desirability of the platform tracks to be assigned to the trains. The model is solved using a lexicographic approach and the local branching algorithm. The model was verified by using the real data of Prague main station. Results of the experiments are included.
To evaluate the status of biodiversity and to determine how current conservation efforts can be improved, biodiversity monitoring is crucial. An important aspect of data quality lies in its spatial resolution. It is u...
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To evaluate the status of biodiversity and to determine how current conservation efforts can be improved, biodiversity monitoring is crucial. An important aspect of data quality lies in its spatial resolution. It is unclear how finer scale land cover and land value information might further benefit biodiversity conservation. This paper aimed to assess the impacts of scale by modelling the conservation of endangered European wetland species and their corresponding habitats. Fine-scale datasets were derived by integrating existing geographical, biophysical and economic data. A habitat allocation model, based on principles from systematic conservation planning and economic theory, was developed to estimate area requirements and opportunity costs of habitat protection in Europe. Coarse-scale and fine-scale simulations were compared by inputting both resolutions into the model. Habitat locations were restricted either only by historical species occurrence data at UTM 50 resolution or additionally by explicit wetland data at 1-km(2) resolution. Coarse country-average land rents were contrasted with spatially detailed land rent estimates at a 5' resolution. Costs of habitat protection and area requirements for reserves may be severely underestimated when conservation planning relies only on coarse-scale data, which may result in notable shortcomings in conservation target achievement. Improvements in conservation benefits far outweigh the additional costs of acquiring fine-scale data.
Multiprotocol Label Switching has become the important technique in NGN'development,contributing for doing an efficient Traffic Engineering in order to provide the QoS and to optimize resource *** this purpose,it ...
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Multiprotocol Label Switching has become the important technique in NGN'development,contributing for doing an efficient Traffic Engineering in order to provide the QoS and to optimize resource *** this purpose,it is possible to apply mixed integer mathematical programming techniques to model routing problem minimizing implantation,operation and maintenance network *** present an optimization model applied to the MPLS network planning,which assign paths based on capacity and network architecture constraints,considering LSP *** model is consolidated in two case studies,applying them to plan a MPLS *** main characteristics of the MPLS concerning to the network planning approach are presented.
In this paper, the numerical analysis of a multistage formulation of the distribution expansion problem developed is presented. The approximate objective function is employed without sacrificing optimality. A complete...
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In this paper, the numerical analysis of a multistage formulation of the distribution expansion problem developed is presented. The approximate objective function is employed without sacrificing optimality. A complete nonlinear mathematicalprogramming optimization is employed to identify the global optimum. The algorithm is applied here to two practical test cases. Details of the input data and configuration of test systems as well as the solutions are listed and discussed. Computational considerations are addressed.
In this paper, the objectives and detailed analysis of the multistage distribution expansion are presented. The problem is modeled as a directed graph minimum edge cost network flow problem. This new formulation detai...
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In this paper, the objectives and detailed analysis of the multistage distribution expansion are presented. The problem is modeled as a directed graph minimum edge cost network flow problem. This new formulation details a multistage framework within a single mathematical program while addressing several deficiencies of previous approaches. The accuracy of a single step approximation of the objective function, without using the conventional linearization techniques, is discussed. Each of the constraints is introduced in terms of industry standard practices. Detailed numerical results for practical study cases are provided in a separate paper.
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