Josep Casanovas

A heuristic lagrangean algorithm for the capacitated plant location problem

Abstract Lagrangean techniques have been widely applied to the uncapacitated plant location problem, and in some cases they have proven to be successfull even when capacitated problems with additional constraints are taken into account. In our paper we study the application of these techniques to the capacitated plant location problem when the model considered is a pure integer one. Several lagrangean decompositions are considered and for some of them heuristic algorithms have been designed to solve the resulting lagrangean subproblems, the heuristics consisting of a two phase procedure. The first (location phase) defines a set of multipliers from the analysis of the dual LP relaxation, and makes a choice of the plants considering the resulting subproblems as a particular case of the general assignment problems. Several heuristics have been studied for this second phase, based either on a decomposition of knapsack type subproblems through a definition of a set of penalties, or of looking into the duality gap and trying to reduce it. Computational experience is reported.

Formal simulation model to optimize building sustainability

In this work, we present a simulation model that makes it possible to find optimal values for various building parameters and the associated impacts that reduce the energy demand or consumption of the building. In the study, we consider several situations with different levels of thermal insulation. To define and to integrate the different models, a formal language (Specification and Description Language, SDL) is used. The main reason for using this formal language is that it makes it possible to define simulation models from graphical diagrams in an unambiguous and standard way. This simplifies the multidisciplinary interaction between team members. Additionally, the fact that SDL is an ISO standard simplifies its implementation because several tools understand this language. This simplification of the model makes it possible to increase the model credibility and simplify the validation and verification processes. In the present project, the simulation tools used were SDLPS (to rule the main simulation process) and Energy+ (as a calculus engine for energy demand). The interactions between all these tools are detailed and specified in the model, allowing a deeper comprehension of the process that define the life of a building from the point of view of its sustainability.

Passenger flow simulation in a hub airport: An application to the Barcelona International Airport

This paper describes a conceptual model intended to be applied in a general approach to the micro-simulation of hub airports terminals. The proposed methodology is illustrated with the development of a simulation model originally intended to help in the design of the new terminal at Barcelona International Airport. This model represents in detail, among many other elements, passengers’ flows in the different areas of these complex facilities. Agent-based simulation techniques were included to represent the different actors’ behaviors, and a formal representation of the model using Specification and Description Language (SDL) was used to represent the complexity of all the system elements. To pre-process a diverse and considerable amount of raw data provided by airport designers and other sources to feed the simulation environment Flight Planner Manager was developed as a toolkit to parameterize the different model factors and to generate required specific input data. This project was conducted over 3 years leading to the development of a system not only conceived to assess in the airport initial design process but also to constitute a recurrent decision taking instrument to dynamically optimize terminal management and operations.

A novel model to predict a slab avalanche configuration using m:n-CAk cellular automata

Abstract The paper introduces a novel method to represent slab avalanche phenomena. The model is based on a cellular automaton generalization named m:n-CAk. This generalization allows the use of different layers in a single cellular automaton. Each one of these layers represents the GIS data needed to perform the calculations. The model is represented using Specification and Description Language, and is implemented in C++. The clear separation between the model representation and implementation simplifies the understanding of the behavior that rules the model. We determine experimentally two parameters that generate more accurate results in all the tested scenarios, namely the Penalization Coefficient (Kp) and the Inertial Coefficient (Ki). All the models have been validated using data from the Catalan Pyrenees.

Definition of Virtual Reality simulation models using Specification and Description Language Diagrams

A full representation of a simulation model encompasses the behavior of the elements that define the model, the definition of the probability distributions that define the delays of the events that control the model, the experimental framework needed for execution, and the graphical representation of certain model elements. This paper aims to use specification and description language to achieve a full model representation by adding two extensions to the language, which allows for a complete and unambiguous definition of a discrete simulation model that is similar to a common discrete operations research simulation tool.

Case Study on Cooperative Car Data for Estimating Traffic States in an Urban Network

The use of floating car data as a particular case of probe vehicle data has been the object of extensive research for estimating traffic conditions, travel times, and origin-to-destination trip matrices. It is based on data collected from a GPS-equipped vehicle fleet or available cell phones. Cooperative cars with vehicle-to-vehicle and vehicle-to-infrastructure communication capabilities represent a step forward, as they also allow tracking of vehicles surrounding the equipped car. This paper presents the results of a limited experiment with a small fleet of cooperative cars in the central business district of Barcelona, Spain, known as L’Eixample District. Data collected from the experiment were used to build and calibrate the emulation of cooperative functions in a microscopic simulation model that captured the behavior of vehicle sensors in Barcelona’s central business district. Such a calibrated model allows emulating fleet data on a large scale that goes far beyond what a small fleet of cooperative vehicles could capture. To determine the traffic state, several approaches were developed for estimating traffic variables—whose accuracy depends on the penetration level of the technology—on the basis of extensions of Edie’s generalized definitions of the fundamental traffic variables with the emulated data.

Simulation of reception, expedition and picking areas of a pharmaceutical products plant

Presents the development of a detailed simulation model of some main processes in a pharmaceutical products plant involved in deep structural changes due to the merge of different new company activities. Implementing an object oriented simulation methodology called LeanSim, specially designed to create models for manufacturing and logistics systems, a wide set of new software technology tools have been included to create, validate and evaluate different simulation scenarios.

Public entities driven robotic innovation in urban areas

Abstract Cities present new challenges and needs to satisfy and improve lifestyle for their citizens under the concept “Smart City”. In order to achieve this goal in a global manner, new technologies are required as the robotic one. But Public entities unknown the possibilities offered by this technology to get solutions to their needs. In this paper the development of the Innovative Public Procurement instruments is explained, specifically the process PDTI (Public end Users Driven Technological Innovation) as a driving force of robotic research and development and offering a list of robotic urban challenges proposed by European cities that have participated in such a process. In the next phases of the procedure, this fact will provide novel robotic solutions addressed to public demand that are an example to be followed by other Smart Cities.

Optimal Buildings’ Energy Consumption Calculus through a Distributed Experiment Execution

The calculus of building energy consumption is a demanding task because multiple factors must be considered during experimentation. Additionally, the definition of the model and the experiments is complex because the problem is multidisciplinary. When we face complex models and experiments that require a considerable amount of computational resources, the application of solutions is imperative to reduce the amount of time needed to define the model and the experiments and to obtain the answers. In this paper, we first address the definition and the implementation of an environmental model that describes the behavior of a building from a sustainability point of view and enables the use of several simulations and calculus engines in a cosimulation scenario. Second, we define a distributed experimental framework that enables us to obtain results in an accurate amount of time. This methodology has been applied to the energy consumption calculation, but it can also be applied to other modeling problems that usually require a considerable amount of resources by reducing the amount of time needed to perform modeling, implementation, verification, and experimentation.

FireFight: A Decision Support System for Forest Fire Containment

The FireFight project is being developed in collaboration with the GRAF wildland firefighting department (Generalitat de Catalunya, Spain). The main objective is the development of a web-accessible decision support system based on an integrated simulation and optimization framework for optimal wildfire containment. FireFight uses the tooPath (www.toopath.com) web server infrastructure to acquire the broadcasted real-time GPS position of approximately 1,650 land and aerial firefighting resources deployed across the territory. The short-term goal of the project is to help managers in making decisions about the number of extinguishing teams that should be deployed, the design of the water supply chain to bring water and other supplies to the firefighting teams, and the design of the change-of-shift transportation problem.