Jose Luis Gonzalez-Velarde

Tecnológico de Monterrey | ITESM · Centro de Calidad y Manufactura (CCM)

This paper studies a districting problem arising in the collection of waste of electrical and electronic equipment. Given a set of collection bins, where users return end‐of‐life electronic goods, located across a region or country, the design problem involves assigning these bins to the companies responsible for the collection at a later stage. Th...

In this work, the problem of maximizing the volume of wood harvested in a single-species stand over a period of time is addressed. To this end, a solution that combines dynamic programming and a single-tree forest growth simulator is developed. In this method, the decision variable of the amount of wood to be harvested at each period is discretized...

This paper develops a general heuristic algorithm to solve the selective and periodic inventory routing problem (SPIRP) in a waste vegetable oil collection environment. In the past, the SPIRP has been formulated and solved via a valid set of inequalities and an adaptive large-neighborhood search algorithm. The proposed algorithm is based on a reduc...

Many combinatorial optimisation problems are NP-Hard. Yet in practice high quality solutions are often obtained by (meta)heuristics. These work well in some cases, but not in others, indicating a potential for algorithm selection. In this extended abstract is discussed how to apply algorithm selection to a combinatorial optimisation problem and whi...

We address a logistics districting problem faced by a parcel company whose operations consist of picking up and delivering packages over a service region. The districting process aims to find a partition of the service region into delivery and collection zones that may be served by a single vehicle that departs from a central depot. Criteria to be...

The problem of district design for the implementation of arc routing activities is addressed. The aim is to partition a road network into a given number of sectors to facilitate the organization of the operations to be implemented within the region. This problem arises in numerous applications such as postal delivery, meter readings, winter grittin...

In this paper we consider the problem of planning the production and distribution in a supply chain. The situation consists in a set of distribution centers seeking to serve to a set of retailers; these distribution centers are supplied by a set of plants trying to minimize the operation and transportation costs. The problem is formulated as a bile...

The main aim of this research is to analyze the differences between cellular manufacturing and cellular disassembly systems. While doing so, this paper makes a relevant contribution. It proposes a mathematical programming formulation for robust manufacturing and disassembly cell formation problems. A solution method based on the Tabu Search schema...

This research work deals with the multi-product multi-period inventory lot sizing with supplier selection problem. Formerly, this kind of problem was formulated and solved using an exhaustive enumeration algorithm and a heuristic algorithm. In this paper, a new algorithm based on a reduce and optimize approach and a new valid inequality is proposed...

The problem of determining optimal tolls established on a subset of arcs in a multicommodity capacitated transportation network is presented. The problem is formulated as a bilevel optimization problem where the upper level consists of an administrator who establishes tolls in some arcs of a network, while the lower level is represented by a group...

The Tactical Berth Allocation Problem (TBAP) aims to allocate incoming ships to berthing positions and assign quay crane profiles to them (i.e. number of quay cranes per time step). The goals of the TBAP are both the minimization of the housekeeping costs derived from the transshipment container flows between ships, and the maximization of the tota...

This paper introduces the family traveling salesperson problem (FTSP), a variant of the generalized traveling salesman problem. In the FTSP, a subset of nodes must be visited for each node cluster in the graph. The objective is to minimize the distance traveled. We describe an integer programming formulation for the FTSP and show that the commercia...

A disassembly cell formation problem with demand variability is addressed in this paper under a reconfigurable approach. The reconfigurable approach allows the cells to be rearranged periodically to deal with demand variability in a multi-period planning horizon. We present a first mathematical programming model for this new problem as well as a so...

A mobile device connects to the cell tower (base station) from which it receives the strongest signal. As the device moves it may connect to a series of towers. The process in which the device changes the base station it is connected to is called handover. A cell tower is connected to a radio network controller (RNC) which controls many of its oper...

The competitiveness of a container terminal is highly conditioned by the time that container vessels spend on it. The proper scheduling of the quay cranes can reduce this time and allows a container terminal to be more attractive to shipping companies. The goal of the Quay Crane Scheduling Problem (QCSP) is to minimize the handling time of the avai...

This paper addresses a supply chain design problem based on a two-echelon single-product system. In the first echelon the plants transport the product to distribution centers. In the second echelon the distribution centers transport the product to the customers. Several transportation channels are available between nodes in each echelon, with diffe...

Heuristics for combinatorial optimization are often controlled by discrete and continuous parameters that define its behavior. The number of possible configurations of the heuristic can be large, resulting in a difficult analysis. Manual tuning can be time-consuming, and usually considers a very limited number of configurations. An alternative to m...

A bi-objective commercial territory design problem motivated by a real-world application from the bottled beverage distribution industry is addressed. The problem, motivated by a real-world application from industry, considers territory compactness and balancing with respect to number of customers as optimization criteria. Previous work has focused...

This is a summary of the author's PhD thesis supervised by Jose Luis González-Velarde (Tecnológico de Monterrey, Mexico) and Belarmino Adenso-Díaz (Universidad de Oviedo, Spain) and defended on October 11, 2010 at the Tecnológico de Monterrey. The thesis is written in English and is available from the author upon request. This research focuses on R...

A supply chain design problem based on a two-echelon single-product system is addressed. The product is distributed from plants to distribution centers and then to customers. There are several transportation channels available for each pair of facilities between echelons. These transportation channels introduce a cost–time tradeoff in the problem t...

In this paper, a multiobjective scatter search procedure for a bi-objective territory design problem is proposed. A territory design problem consists of partitioning a set of basic units into larger groups that are suitable with respect to some specific planning criteria. These groups must be compact, connected, and balanced with respect to the num...

A new heuristic procedure for a commercial territory design problem is introduced in this work. The proposed procedure is based on the divide-and-conquer paradigm and basically consists of a successive dichotomy process on a given large instance of the problem. During this process, a series of integer quadratic subproblems is solved. The obtained c...

A new heuristic procedure for a commercial territory design problem is introduced in this work. The proposed procedure, based on the divide-and-conquer paradigm, consists basically of a successive dichotomy process of a given large instance of the problem. During this process, a series of integer quadratic subproblems is solved. Computational resul...

This chapter explicitly shows how the European Union Directive 2002/96/EC on Waste of Electrical and Electronic Equipments (WEEE) might be transformed into efficient vehicle routing practices for the collection of end-of-life electronic appliances. The chapter presents integer programming formulations and extensions for the problem. Due to the comp...

This research aims to optimize the design of the reverse logistic network for the collection of Waste of Electric and Electronic Equipment (WEEE), in the Spanish region of Galicia. As a basis for our study a three-phase hierarchical approach is proposed. In the first phase a facility location problem is formulated and solved by means of a mixed int...

In this paper, we address a territory design problem arising from a bottled beverage distribution company. We propose a bi-objective programming model where dispersion and balancing with respect to the number of customers are used as performance criteria. Constraints such as connectivity and balancing with respect to sales volume are considered in...

This paper presents an integer programming model and describes a GRASP based algorithm to solve a vehicle routing and scheduling problem for the collection of Waste of Electric and Electronic Equipment (WEEE). The difficulty of this problem arises from the fact that it is characterized by four variants of the vehicle routing problem that have been...

Estimation of Distribution Algorithms (EDA) are a type of optimization techniques that belong to evolutionary computation. Its operation is based on the use of a probabilistic model, which tries to reach promising regions through statistical information concerning to the individuals that belong to the population. In this work, several solution appr...

In this paper the robust capacitated international sourcing problem (RoCIS) is approached. It consists of selecting a subset of suppliers with finite capacity, from an available set of potential suppliers internationally located. This problem was introduced by González-Velarde and Laguna in [1], where they propose a deterministic solution based on...

This paper deals with the following general question: which products should be in our product assortment/portfolio if part or all of the (potential) customers only order if we can deliver on-time the desired quantities for all or a predefined subset of the products that the customers desire (one-stop-shopping concept)? In this context, two strategi...

In this paper the robust capacitated international sourcing problem (RoCIS) is approached. It consists of selecting a subset of suppliers with finite capacity, from an available set of potential suppliers internationally located. This problem was introduced by González-Velarde and Laguna in [1], where they propose a deterministic solution based on...

In this work, we have conducted a study to evaluate and improve the performance of an urban transportation system. Specifically, we have designed an algorithm for obtaining new routes and assigning buses to these routes. The objective is to optimize the service level, measured as the sum of the time the passengers have to wait at the bus stops plus...

In this paper, we address a territory design problem arising from a beverage distribution company. This problem belongs to the family of territory design problems. We propose a bi-objective programming model where dispersion and balancing with respect to the number of customers are used as performance criteria. Constraints such as connectivity and...

In this paper the path dissimilarity problem is considered. The problem has previously been studied within several contexts, the most popular of which is motivated by the need to select transportation routes for hazardous materials. The aim of this paper is to formally introduce the problem as a bi-objective optimization problem, in which a single...

El propósito de este trabajo es presentar un procedimiento heurístico basado en GRASP, que permite resolver un problema de diseño de territorios comerciales con múltiples objetivos. Se propone esta técnica heurística porque en nuestro estudio previo encontramos que instancias de tamaño real resultan ser intratables mediante técnicas de solución exa...

In this paper, a scheduling problem which allows a warehouse to function as a crossdock where transit storage time for cargo is minimized according to Just in Time scheduling is studied. A model that uses the machine scheduling notation to describe the problem is written. As the problem is NP-hard, a solution approach based on a combination of two...

In this work we analyze an urban transport problem that the City Council of Burgos, a city in northern Spain, has posed to the authors. Given a fleet of buses and drivers, the problem consists in designing routes and assigning buses to the routes such that the service level is optimized. The optimality of the service level is measured in terms of t...

A known strategy to implement Mass Customization is Product Modularization. To take advantage of the benefits of modularity, the selection of a common platform is required. This selection must be done with optimization criteria based on functionality and economics. In this paper we propose metaheuristic procedures to solve the problem of selecting...

In the painted sheet metal industry, offering a great variety of colors is an important competitive factor. However, an excessive number of colors can lead to excessive setup costs/times, inventory costs, and administrative complexity. In this paper, we address the case of a large manufacturer of painted sheet metal products located in northern Mex...

The International Sourcing Problem consists of selecting a subset from an available set of potential suppliers internationally located. The selected suppliers must meet the demand for items from a set of plants, which are also located worldwide. Since the costs are affected by macroeconomic conditions in the countries where the supplier and the pla...

The problem of determining the sequence of stops and the amount of load to carry in each segment route, named the Multi-Stop Routing Problem (MSRP) is addressed. A 0/1 mixed integer linear program and formulation refinements which facilitate the solution process are presented. Since the constraint set of the MSRP includes 0/1 mixed rows, valid ineq...

This chapter addresses the problem of designing and training artificial neural networks with discrete activation functions for the classification of patterns in two categories. When the set of patterns is not linearly separable, this problem consists of determining the amount of neurons in the hidden layer that are needed to correctly classify the...

El presente trabajo se centra en la aplicación de un procedimiento basado en Scatter Search (SS) para resolver un problema de equilibrado de líneas de montaje. Tras una introducción a los denominados Assembly Line Balancing Problems (ALBPs) se propone un modelo básico para su variante simple (SALBP). Tras ello, se presentan las heurísticas greedy (...

A fixed charge capacitated multicommodity network design problem on undirected networks is addressed. At the present time, there exists no algorithm that can solve large instances, common in several applications, in a reasonable period of time. This paper presents an efficient procedure using a scatter search framework. Computational experiments on...

A GRASP embedded Scatter Search is developed for the multicommodity capacitated network design problem. Difficulty for this problem arises from the fact that selection of the optimal network design is an NP-complete combinatorial problem. There exist no polynomial exact algorithms which can solve this problem in a reasonable period of time for real...

A common assumption when solving optimization problems is that all parameters are certain; however, in the real world, key data are often uncertain. In this paper, we introduce a formulation of the robust capacitated international sourcing problem. The main contribution of this work is that the formulation assumes a finite capacity, as opposed to t...

Una entre las metaheuristicas mas exitosas que aparecieron en los ultimos aos del siglo pasado es GRASP,un metodo multi-arranque dise~ nado para resolver problemas dificiles en optimizacion combinatoria. En su version basica cada iteracion consiste en dos fases: una fase constructiva cuyo producto es una solucion factible buena, aunque no necesaria...

We present a Tabu Search (TS) method that employs a simple version of ejection chains for coloring graphs. The procedure is tested on a set of benchmark problems. Empirical results indicate that the proposed TS implementation outperforms other metaheuristic methods, including Simulated Annealing, a previous version of Tabu Search and a recent imple...

The capacitated multicommodity network design problem presents a major challenge. At the present time, there exists no exact algorithm that can solve large instances, common in several applications, in a reasonable period of time. In these cases, heuristic methods are being used to find near optimal solutions. Some heuristic procedures need initial...

Resumen Uno de los problemas más famosos y difíciles en la teoría de optimización, es del problema del agente viajero (TSP). El interés en el estudio de técnicas para su solución es motivado por la enorme cantidad de aplicaciones prácticas de problemas de toma de decisiones donde éste aparece como subestructura. En este artículo se hace una breve r...

Computing Tools for Modeling, Optimization and Simulation reflects the need for preserving the marriage between operations research and computing in order to create more efficient and powerful software tools in the years ahead. The 17 papers included in this volume were carefully selected to cover a wide range of topics related to the interface bet...

We study two heuristic optimization techniques for wavelength assignment in WDM multihop optical networks. The selection of the route with minimum delay has been stated as a discrete optimization problem by several authors in the literature, and the stochastic ruler (SR) algorithm has been proposed as a good heuristic techniques to achieve such an...

The problem of optimally assigning highway trailers to railcar hitches in intermodal transportation is studied. An integer-linear programming formulation is constructed. The problem is formulated using set covering. The resulting formulation is very small, and possesses in practice a tight linear programming relaxation. This allows it to be solved...

The multilevel generalized assignment problem (MGAP) differs from the classical GAP in that agents can perform tasks at more than one efficiency level. Important manufacturing problems, such as lot sizing, can be formulated as MGAPs; however, the large number of variables in the related 0–1 integer program makes the use of commercial optimization p...

In recent years the Just-in-Time (JIT) production philosophy as been adopted by many companies around the world. This has motivated the study of scheduling models that embrace the essential components of JIT systems. In this paper, we present a search heurustic for the weighted earliness penalty problem with deadlines in parallel identical machines...

Resumen En este artículo se describe uno de los problemas más famosos y difíciles en la teoría de optimización. Se hace una breve reseña de métodos que se han propuesto para su solución, se presentan también algunas aplicaciones prácticas del mismo y se esboza brevemente el significado de la expresión Complejidad Computacional. Palabras clave: Inve...