Warehouse layout optimization is critical to inventory and logistics management in organizations. In many instances, limited warehouse space is a constraint and a barrier to expanding operations and increasing demand....
详细信息
The double row layout problem(DRLP)is to assign facilities on two rows in parallel so that the total cost of material handling among facilities is *** it is vital to save cost and enhance productivity,the DRLP plays a...
详细信息
The double row layout problem(DRLP)is to assign facilities on two rows in parallel so that the total cost of material handling among facilities is *** it is vital to save cost and enhance productivity,the DRLP plays an important role in many application ***,it is very hard to handle the DRLP because of its complex *** this paper,we consider a new simplified model for the DRLP(SM-DRLP)and provide a mixed integer programming(MIP)formulation for *** continuous decision variables of the DRLP are divided into two parts:start points of double rows and adjustable clearances between adjacent *** former one is considered in the new simplified model for the DRLP with the purpose of maintaining solution quality,while the latter one is not taken into account with the purpose of reducing computational *** evaluate its performance,our SM-DRLP is compared with the model of a general DRLP and the model of another simplified *** experimental results show the efficiency of our proposed model.
In this study,we propose a novel method for the inverse QSAR/QSPR. Given a set of chemical compounds G and their values a(G) of a chemical property, we define a feature vector f(G) of each chemical compound G. By usin...
详细信息
ISBN:
(纸本)9781450376761
In this study,we propose a novel method for the inverse QSAR/QSPR. Given a set of chemical compounds G and their values a(G) of a chemical property, we define a feature vector f(G) of each chemical compound G. By using a set of feature vectors as training data, the first phase of our method constructs a prediction function psi with an artificial neural network (ANN) so that psi(f(G)) takes a value nearly equal to a(G) for many chemical compounds G in the set. Given a target value a* of the chemical property, the second phase infers a chemical structure G* such that a(G*) = a* in the following way. We compute a vector f* such that psi(f*) = a*, where finding such a vector f* is formulated as a mixedinteger linear programming problem (MILP). Finally we generate a chemical structure G* such that f(G*) = f*. For acyclic chemical compounds and some chemical properties such as heat of formation, boiling point, and retention time, we conducted some computational experiments with our method.
The objective of this paper is to estimate the cost of retaining feeder cattle in Florida, feeding these cattle to slaughter weights, slaughtering them, and distributing the meat to retail outlets. A mixedinteger pro...
详细信息
The objective of this paper is to estimate the cost of retaining feeder cattle in Florida, feeding these cattle to slaughter weights, slaughtering them, and distributing the meat to retail outlets. A mixed integer programming model is developed. The optimal number and location of feedlots and slaughter plants are determined. The results indicate that at production levels exceeding 600 000 head, the cost of producing carcass beef in the State is comparable to the average for the United States. -Authors
In this work, we concentrate on the problem of finding a set of neurons in a trained neural network whose pruning leads to a marginal loss in accuracy. To this end, we introduce Optimizing ANN Architectures using Mixe...
详细信息
ISBN:
(数字)9783031332715
ISBN:
(纸本)9783031332708;9783031332715
In this work, we concentrate on the problem of finding a set of neurons in a trained neural network whose pruning leads to a marginal loss in accuracy. To this end, we introduce Optimizing ANN Architectures using mixed-integerprogramming (OAMIP) to identify critical neurons and prune non-critical ones. The proposed OAMIP uses a mixed-integer Program (MIP) to assign importance scores to each neuron in deep neural network architectures. The impact of simultaneous neuron pruning on the main learning tasks guides the neurons' scores. By carefully devising the objective function of the MIP, we drive the solver to minimize the number of critical neurons (i.e., with high importance score) that maintain the overall accuracy of the trained neural network. Our formulation identifies optimized sub-network architectures that generalize across different datasets, a phenomenon known as lottery ticket optimization. This optimized architecture not only performs well on a single dataset but also generalizes across multiple ones upon retraining of network weights. Additionally, we present a scalable implementation of our pruning methodology by decoupling the importance scores across layers using auxiliary networks. Finally, we validate our approach experimentally, showing its ability to generalize on different datasets and architectures.
The production process of crude palm oil (CPO) can be defined as the milling process of raw materials, called fresh fruit bunch (FFB) into end products palm oil. The process usually through a series of steps producing...
详细信息
The production process of crude palm oil (CPO) can be defined as the milling process of raw materials, called fresh fruit bunch (FFB) into end products palm oil. The process usually through a series of steps producing and consuming intermediate products. The CPO milling industry considered in this paper does not have oil palm plantation, therefore the FFB are supplied by several public oil palm plantations. Due to the limited availability of FFB, then it is necessary to choose from which plantations would be appropriate. This paper proposes a mixedinteger linear programming model the supply chain integrated problem, which include waste processing. The mathematical programming model is solved using neighborhood search approach.
Inverse QSAR/QSPR is a well-known approach for computer-aided drug design. In this study, we propose a novel method for inverse QSAR/QSPR using artificial neural network (ANNs) and mixedinteger linear programming In ...
详细信息
ISBN:
(纸本)9789897583988
Inverse QSAR/QSPR is a well-known approach for computer-aided drug design. In this study, we propose a novel method for inverse QSAR/QSPR using artificial neural network (ANNs) and mixedinteger linear programming In this method, we introduce a feature function f that converts each chemical compound G into a vector f (G) of several descriptors of G. Next, given a set of chemical compounds along with their chemical properties, we construct a prediction function iv with an ANN so that psi( f (G)) takes a value nearly equal to a given chemical property for many chemical compounds G in the set. Then, given a target value y* of the chemical property, we conversely infer a chemical structure G K having the desired property y* in the following way. We formulate the problem of finding a vector x* such that (i) psi(x*) = y and (ii) there exists a chemical compound G* such that f(G*) = x* (if one exists over all vectors x* in (i)) as a mixedinteger linear programming problem (MILP). In an existing method for the inverse QSAR/QSPR, the second condition (ii) was not guaranteed. For acyclic chemical compounds and some chemical properties such as heat of formation, boiling point, and retention time, we conducted computational experiments.
This work presents a new methodology for planning and tracking a time-optimal trajectory for class 8 vehicles on roads in which traffic lights exist. This approach takes the non-convex nature of the problem and simpli...
详细信息
This work presents a new methodology for planning and tracking a time-optimal trajectory for class 8 vehicles on roads in which traffic lights exist. This approach takes the non-convex nature of the problem and simplifies it by introducing a set of integer decision variables. Due to the planned trajectory taking place over distances greater than a kilometer, an inner loop controller is developed to refine the high-level trajectory and guarantee that the ego vehicle does not cross into intersections during a red light phase. In order to account for model differences between the inner loop and outer loop systems an event triggered replan methodology is introduced. This event triggered replan allows for the high-level plan to adjust the trajectory to the current states of the ego vehicle without creating an unnecessary computational burden. This full system is then evaluated on three test scenarios in which the ego vehicle must navigate through two intersections with varying red light phases. The tests successfully demonstrate the feasibility of this method for generating safe, time-optimal trajectories for class 8 vehicles. Copyright (c) 2024 The Authors.
Massive connectivity is a critical challenge of Internet of Things (IoT) networks. In this paper, we consider the grant-free uplink transmission of an IoT network with a multi-antenna base station (BS) and a large num...
详细信息
ISBN:
(纸本)9781665443852
Massive connectivity is a critical challenge of Internet of Things (IoT) networks. In this paper, we consider the grant-free uplink transmission of an IoT network with a multi-antenna base station (BS) and a large number of single-antenna IoT devices. Due to the sporadic nature of IoT devices, we formulate the joint activity detection and channel estimation (JADCE) problem as a group-sparse matrix estimation problem. Although many algorithms have been proposed to solve the JADCE problem, most of them are developed based on compressive sensing technique, yielding suboptimal solutions. In this paper, we first develop an efficient weighted l(1)-norm minimization algorithm to better approximate the group sparsity than the existing mixed l(1)/l(2)-norm minimization. Although an enhanced estimation performance in terms of the mean squared error (MSE) can be achieved, the weighted l(1)-norm minimization algorithm is still a convex relaxation of the original group-sparse matrix estimation problem, yielding a suboptimal solution. To this end, we further reformulate the JADCE problem as a mixed integer programming (MIP) problem, which can be solved by using the branch-and-bound method. As a result, we are able to obtain an optimal solution of the JADCE problem, which can be adopted as an upper bound to evaluate the effectiveness of the existing algorithms. Moreover, we also derive the minimum pilot sequence length required to fully recover the estimated matrix in the noiseless scenario. Simulation results show the performance gains of the proposed optimal algorithm over the proposed weighted l(1)-norm algorithm and the conventional mixed l(1)/l(2)-norm algorithm. Results also show that the proposed algorithms require a short pilot sequence than the conventional algorithm to achieve the same estimation performance.
Regression analysis fits predictive models to data on a response variable and corresponding values for a set of explanatory variables. Often data on the explanatory variables come at a cost from commercial databases, ...
详细信息
Regression analysis fits predictive models to data on a response variable and corresponding values for a set of explanatory variables. Often data on the explanatory variables come at a cost from commercial databases, so the available budget may limit which ones are used in the final model. In this dissertation, two budget-constrained regression models are proposed for continuous and categorical variables respectively using mixedinteger Nonlinear programming (MINLP) to choose the explanatory variables to be included in solutions. First, we propose a budget-constrained linear regression model for continuous response variables. Properties such as solvability and global optimality of the proposed MINLP are established, and a data transformation is shown to signicantly reduce needed big-Ms. Illustrative computational results on realistic retail store data sets indicate that the proposed MINLP outperforms the statistical software outputs in optimizing the objective function under a limit on the number of explanatory variables selected. Also our proposed MINLP is shown to be capable of selecting the optimal combination of explanatory variables under a budget limit covering cost of acquiring data sets. A budget-constrained and or count-constrained logistic regression MINLP model is also proposed for categorical response variables limited to two possible discrete values. Alternative transformations to reduce needed big-Ms are included to speed up the solving process. Computational results on realistic data sets indicate that the proposed optimization model is able to select the best choice for an exact number of explanatory variables in a modest amount of time, and these results frequently outperform standard heuristic methods in terms of minimizing the negative log-likelihood function. Results also show that the method can compute the best choice of explanatory variables affordable within a given budget. Further study adjusting the objective function to minimize the Bayesi
暂无评论