Pau Fonseca

SIM-RandSHARP: a hybrid algorithm for solving the Arc Routing Problem with Stochastic Demands

This paper proposes a new hybrid algorithm for solving the Arc Routing Problem with Stochastic Demands (ARPSD). Our approach combines Monte Carlo simulation (MCS) with the RandSHARP algorithm, which is designed for solving the Capacitated Arc Routing Problem (CARP) with deterministic demands. The RandSHARP algorithm makes use of a CARP-adapted version of the Clarke and Wright Savings heuristic, which was originally designed for the Vehicle Routing Problem. The RandSHARP algorithm also integrates a biased-randomized process, which allows it to obtain competitive results for the CARP in low computational times. The RandSHARP algorithm is then combined with MCS to solve the ARPSD. Some numerical experiments contribute to illustrate the potential benefits of our approach.

A Simulation Study Regarding Different Aircraft Boarding Strategies

The airline industry is constantly subject to the search of new methods in order to increase efficiency, profitability, and customer satisfaction. Since airlines only generate revenue when their airplanes are on the air, the time they spend at the airports should be the shortest possible. Hence, the airplane turnaround time becomes a process which airlines pay special attention on. The boarding process has a very important role, since it is one of the significant elements of the turnaround time, and a slow boarding process might lead to many kinds of problems to the airline, from financial issues to customer complaints. This paper analyzes the major interferences among the passengers that cause delays in boarding times, and after comparing the different aircraft boarding strategies, it proposes the most efficient strategy.

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.

Evaluation and assessment of professional skills in the Final Year Project

In this paper, we present a methodology for Final Year Project (FYP) monitoring and assessment that considers the inclusion of the professional skills required in the particular engineering degree. This proper monitoring and clear evaluation framework provides the student with valuable support for the project implementation as well as for improving the quality of the projects, thereby reducing the academic drop-out rate. The proposed methodology has been implemented at the Barcelona School of Informatics at the Universität Politècnica de Catalunya - BarcelonaTech. The FYP is structured around three milestones: project definition, project monitoring and project completion. Skills are assigned to each milestone according to the tasks required in that phase, and a list of indicators is defined for each phase. The evaluation criteria for each indicator at each phase are specified in a rubric, and are made public both to students and teachers. Thus, the FYP includes an exhaustive evaluation method distributed throughout the whole project implementation, thereby facilitating project organization for the student as well as providing a clear and homogeneous assessment framework. The methodology for the FYP organization, assessment and evaluation was launched and piloted over two semesters. We believe the experience to be general in the sense that it has been conducted as part of an ICT engineering degree, but may easily be extended to any other engineering degree.

Castelldefels project: modeling and simulation of the computer system that gives support to the virtual campus of the Open University Of Catalonia

Summary form given only: In this paper we present a case study regarding the modeling and simulation of a real computer system called Castelldefels. This system gives support to the Virtual Campus of the Open University of Catalonia (UOC), an online university that offers e-learning services to thousands of users. After analyzing several alternatives, the OPNET software was selected as the convenient tool for developing this network-simulation research. The main target of the project was to provide the computer systems managers with a realistic simulation model of their system. This model would allow the managers: (i) to analyze the behavior of the current system in order to discover possible performance problems such as bottlenecks, weak points in the structure, among others, and (ii) to perform what-if analysis regarding future changes in the system, including the addition of new Internet-based services, variations in the number and types of users, changes in hardware or software components, etc.

Simulation model to find the best comfort, energy and cost scenarios for building refurbishment

This article proposes a methodology to assess building behaviour, whilst taking its life cycle into account. Understanding of the system can be obtained by combining well-known energy consumption calculation engines (TRNSYS) with co-simulation processes defined using Specification and Description Language (SDL). In this instance, to find the best comfort, energy and cost scenarios for energy rehabilitation, Co-simulation is conducted in two phases: the best scenes of passive systems are found, those presented as a priority; and, the active systems are made with ‘brute force analysis’. The article provides the results for a case study: a single-family home built between 1991 and 2007 and located in Mediterranean climate zone. The methodology provides a set of passive energy efficiency measures, to improve until two scales in the building energy labelling system. Using the methodology and the proposed model has enabled us to dramatically reduce the run time until 75% and therefore.