A two-echelon half-closed-loop logistics network system is founded for the issue of manufacturing logistics network design, including supply and return channels. Considering the integration of the uncertainty and cycl...
详细信息
A two-echelon half-closed-loop logistics network system is founded for the issue of manufacturing logistics network design, including supply and return channels. Considering the integration of the uncertainty and cycle time of the demand quantities of products and the return rates of used products, sites selection of potential logistics centers, plants and recycling plants, and transshipment problem, a stochastic, multi-time-step, capacitated mixed integer linear programming model is presented, the objective function makes total costs including fixed costs, transportation costs and storage costs in logistics centers minimize. Since such network design problems belong to a class of NP hard problems, a genetic algorithm approach-based heuristic to this model is presented. Finally a numerical example is used to prove the model and genetic algorithm validity.
This paper presents an approach to trajectory generation for Unmanned Aerial Vehicles (UAV) by using mixed integer linear programming (MILP) and a modification of the A{sup}* algorithm to optimize paths in dynamic env...
详细信息
This paper presents an approach to trajectory generation for Unmanned Aerial Vehicles (UAV) by using mixed integer linear programming (MILP) and a modification of the A{sup}* algorithm to optimize paths in dynamic environments, particularly having pop-ups with a known future probability of appearance. Each pop-up leads to one or several possible evasion maneuvers, characterized with a set of values used as decision making parameters in an integerlinearprogramming (ILP) model that optimizes the final route by choosing the most suitable alternative trajectories, according to the imposed constrains such as maximum fuel consumption and spent time. The model of the system in MILP and A{sup}* algorithms is presented, as well as the ILP formulation for decision making. Results and discussions are given to promote future real time implementations.
The paper studies the capacity planning problem in the TFT-LCD production chain. Due to two significant trends, the capacity planning decision gradually becomes an important strategic issue to which TFT-LCD industry p...
详细信息
The paper studies the capacity planning problem in the TFT-LCD production chain. Due to two significant trends, the capacity planning decision gradually becomes an important strategic issue to which TFT-LCD industry paid attention. First is the increase of product types which causes a wide range of product groups, such as mobile, monitor, notebook, TV and industrial display are produced. The second trend is the advances of new technology which cause multiple generations of technologies coexist in each manufacturing stage and production site. This paper proposes a mixed integer linear programming (MILP) to formulate the capacity planning which considers many practical characteristics and constraints in TFT-LCD production chain. A heuristic algorithm is developed to solve the MILP model.
We propose a new scheme, called protected working lightpath envelope (PWLE), for dynamic provisioning of survivable services without requiring any wavelength conversion. PWLE is a path-oriented protection strategy bas...
详细信息
We propose a new scheme, called protected working lightpath envelope (PWLE), for dynamic provisioning of survivable services without requiring any wavelength conversion. PWLE is a path-oriented protection strategy based on lightpath-protecting rho-cycles. It partitions the total network capacity into a static protection layer and a working layer available for dynamic routing. To deal with the new issues raised by lightpath-protecting p-Cycles, we propose compatible grouping so that the PWLE can be formulated as an mixed integer linear programming (MILP) model. Based on compatible grouping, we further propose compatible group routing (CGR), a distributed routing algorithm tailored for PWLE. Compared with rho-Cycle-based protected working capacity envelope (PWCE), PWLE has the advantages of high capacity efficiency, avoidance of wavelength conversion, good blocking performance and guaranteed optical transmission quality. We evaluate the performance improvement of PWLE in capacity efficiency and blocking performance through the numerical results obtained from CPLEX and simulations.
In this study the authors present a mixed integer linear programming model to solve the problem of cost minimization of sugar cane removal and its transport from the fields to the sugar mill at operational level. The ...
详细信息
In this study the authors present a mixed integer linear programming model to solve the problem of cost minimization of sugar cane removal and its transport from the fields to the sugar mill at operational level. The complexity of the problem is basically determined by the system approach which results in the generation of a great number of variables and constraints that refer to the following operational dimensions: (a) need for continuous supply to the sugar mill;(b) cutting means used in cane harvesting;(c) transportation vehicles and (d) providing routes, which are characterized by the existence of storage facilities at the beginning of the railroads. The results demonstrate the model is not only useful to minimize transportation cost, but also for scheduling daily cane road transport and harvesting quotas of cutting means. (c) 2005 Elsevier B.V. All rights reserved.
The growing trend of employing multiproduct manufacturing facilities along with the randomness inherent in the biopharmaceutical manufacturing environment is creating significant scheduling and planning challenges for...
详细信息
The growing trend of employing multiproduct manufacturing facilities along with the randomness inherent in the biopharmaceutical manufacturing environment is creating significant scheduling and planning challenges for the biopharmaceutical industry. This work focuses on capturing the effect of uncertainty in fermentation titers when optimizing the planning of biopharmaceutical manufacturing campaigns. A mixed integer linear programming ( MILP) model based on previous work is derived via chance constrained programming ( CCP). The methodology is applied to two illustrative examples, and the results are compared with those from the deterministic model and a multiscenario model accompanied by an iterative construction algorithm. The computational results indicate that the proposed methodology offers significant improvements in solution quality over the compared approaches and presents an opportunity for biopharmaceutical manufacturers to make better medium term planning decisions, particularly under uncertain manufacturing conditions.
Optimal guidance for a dynamical system from a given point to a set of targets is discussed. Detecting for the best target is done in such a way that the capture time is minimized and desirability of targets is maximi...
详细信息
Optimal guidance for a dynamical system from a given point to a set of targets is discussed. Detecting for the best target is done in such a way that the capture time is minimized and desirability of targets is maximized. By extending measure theoretical approach for the classical optimal control problem to this case, the nearly optimal control is constructed from the solution of a mixed integer linear programming problem. To find the lower bound of the optimal time a search algorithm is proposed. Numerical examples are also given. Copyright (C) 2005 John Wiley & Sons, Ltd.
A systematic framework is developed to solve the parametric mixed integer linear programming (pMILP) problems where uncertain parameters are present on the right-hand side (RHS) of the constraints. For the case of mul...
详细信息
A systematic framework is developed to solve the parametric mixed integer linear programming (pMILP) problems where uncertain parameters are present on the right-hand side (RHS) of the constraints. For the case of multiple uncertain parameters, a new algorithm of multiparametric linearprogramming (mpLP) is proposed, which solves a number of nonlinear problems (NLP) iteratively. At each iteration, a point at which the objective value cannot be represented by the current optimal functions is found, and the new optimal function is included in the next iteration. Given the range of uncertain parameters in a MILP problem, the output of this proposed framework is a set of optimal integer solutions and their corresponding critical regions and optimal functions. A number of examples are presented to illustrate the applicabilities of the proposed approach and comparison with existing techniques. (D 2006 American Institute of Chemical Engineers.
Mathematical programming is used as a nonparametric approach to supervised classification. However, mathematical programming formulations that minimize the number of misclassifications on the design dataset suffer fro...
详细信息
Mathematical programming is used as a nonparametric approach to supervised classification. However, mathematical programming formulations that minimize the number of misclassifications on the design dataset suffer from computational difficulties. We present mathematical programming based heuristics for finding classifiers with a small number of misclassifications on the design dataset with multiple classes. The basic idea is to improve an LP-generated classifier with respect to the number of misclassifications on the design dataset. The heuristics are evaluated computationally on both simulated and real world datasets. (c) 2004 Elsevier B.V. All rights reserved.
This study considers a scheduling algorithm and mathematical models for a real polyvinyl chloride (PVC) plant. According to general rules of the PVC plant, the basic PVC scheduling model is formulated as mixedinteger...
详细信息
This study considers a scheduling algorithm and mathematical models for a real polyvinyl chloride (PVC) plant. According to general rules of the PVC plant, the basic PVC scheduling model is formulated as mixed integer linear programming (MILP). This model includes production, inventory management, packing, and shipment processes. The basic PVC scheduling model is customized for two PVC production processes with different characteristics, resulting in two detailed PVC scheduling models. An optimization algorithm has been developed to solve these scheduling models. This algorithm is a hybrid algorithm combining the genetic algorithm for integerprogramming (IP) and the interior point method for linearprogramming (LP). A heuristic technique has also been developed to reduce the number of solving LPs. Finally, the optimized results of the models were analyzed.
暂无评论