Existence and regularity of solutions for an evolution model of perfectly plastic plates

We continue the study of a dynamic evolution model for perfectly plastic plates, recently derived from three-dimensional Prandtl-Reuss plasticity. We extend the previous existence result by introducing non-zero external forces in the model, and we discuss the regularity of the solutions thus obtained. In particular, we show that the first derivatives with respect to space of the stress tensor are locally square integrable

A generic framework for modeling airport operations at a macroscopic level,

International audienceIn this paper, a general approach for modeling airport operations is presented. Airport operations have been extensively studied in the last decades ranging from airspace, airside and landside operations. Due to the nature of the system, simulation techniques have emerged as a powerful approach for dealing with the variability of these operations. However, in most of the studies, the different elements are studied in an individual fashion. The aim of this paper, is to overcome this limitation by presenting a methodological approach where airport operations are modeled together, such as airspace and airside. The contribution of this approach is that the resolution level for the different elements is similar therefore the interface issues between them is minimized. The framework can be used by practitioners for simulating complex systems like airspace-airside operations or multi-airport systems. The framework is illustrated by presenting a case study analyzed by the authors

No more conflicts: the development of a generic airport model in a sequence-optimization framework

International audienceComponents of the airport airside such as runways, taxiways and aprons, have a significant impact in the total capacity of the airport system, where capacity is usually considered as maximum number of air traffic movements or number of passengers accommodated in a given period of time. Operations on the airside impact in the propagation of delay and consequently in the perceived level of service by passengers the terminal buildings. This paper put the focus on the airside operations at airports. A methodology for modelling operations on the ground and the successive optimization is proposed. The methodology presented in this paper is generic enough in the sense that it can be applied to any airport. The objective of this work is to come up with a generic tool that can be used by air traffic controllers in order to minimize conflicts on the ground and consequently increase the airport capacit

Tackling Uncertainty for the Development of Efficient Decision Support System in Air Traffic Management

International audienceAirport capacity has become a constraint in the air transportation networks, due to the growth of air traffic demand and the lack of resources able to accommodate this demand. This paper presents the algorithmic implementations of a decision support system for making a more efficient use of the airspace and ground capacity. The system would be able to provide support for air traffic controllers in handling large amount of flights while reducing to a minimum the potential conflicts. In this framework, airspace together with ground airport operations are considered. Conflicts are defined as separation minima violation between aircraft for what concerns airspace and runways, and as capacity overloads for taxiway network and terminals. The methodology proposed in this work consists of an iterative approach that couples optimization and simulation to find solutions that are resilient to perturbations due to the uncertainty present in different phases of the arrival and departure process. An optimization model was employed to find a (sub)optimal solution while a discrete event-based simulation model evaluated the objective function. By coupling simulation with optimization, we generate more robust solutions resilient to variability in the operations, this is supported by a case study of Paris Charles de Gaulle Airport

Open Source Interactive Map of Albania Cultural Heritage

AbstractICTs represent strategic resources for Cultural Heritage (CH) projects. Anyway, several conditions put the success of promotion projects at risk, especially if carried out at the local level. Firstly, local scale amplifies the weight of budget constraints on the priorities of public administrations, compelled to allocate funds to the physical conservation of heritage rather than to software and training. Secondly, proprietary SW, often sophisticated and complex in procedures, fails to integrate precious unformalized knowledge from local stakeholders and communities, particularly in the field of cultural tourism. Finally, a changing demand for cultural tourism, with potential visitors frequently searching for information directly on the Web before moving, requires a higher interactivity in tools and systems. The paper illustrates the work carried out at the Construction Technologies Institute for delivering procedures and SW specifically designed to simplify the publication of geo-referenced information and reduce the need for specialized skills and equipments. The described results were achieved along different research programs focusing on the Albanian CH with a learning-by-doing approach

Evolution of the seismic vulnerability of masonry buildings based on the damage data from L'Aquila 2009 event

AbstractThe purpose of this study is the analysis of vulnerability trends, with particular emphasis to the evolution of the seismic behaviour of masonry buildings over the years due to the improvements in construction practices and to the enhancement of building materials over the years, also related to the subsequent enactment of seismic prescriptions. To this aim, residential masonry buildings damaged after the 2009 L'Aquila earthquake are considered, coming from the online platform Da.D.O. (Database di Danno Osservato, Database of Observed Damage) recently released from the Italian Department of Civil Protection. General features of all the parameters available from the original database are thoroughly analysed, a selection of which is used for vulnerability analysis, namely the period of construction and the design type, the presence of structural interventions, the type of horizontal structure. Vulnerability curves are obtained through an optimization technique, minimizing the deviation between observed and predicted damage. PGA from ShakeMap is used for ground motion characterization. Damage levels defined according to the European Macroseismic Scale are considered, obtained from the observed damage for vertical structures collected during the inspections. Vulnerability curves are firstly obtained as a function of period of construction and horizontal structural types, limited to the irregular layout and bad quality vertical type only, highlighting their clear influence on seismic behaviour. Lastly, the effectiveness of retrofit intervention is evaluated comparing the vulnerability curves for strengthened masonry buildings compared to those not subjected to any retrofit interventions

Simulation-Based Virtual Cycle for Multi-Level Airport Analysis

The aeronautical industry is expanding after a period of economic turmoil. For this reason, a growing number of airports are facing capacity problems that can sometimes only be resolved by expanding infrastructure, with the inherent risks that such decisions create. In order to deal with uncertainty at different levels, it is necessary to have relevant tools during an expansion project or during the planning phases of new infrastructure. This article presents a methodology that combines simulation approaches with different description levels that complement each other when applied to the development of a new airport. The methodology is illustrated with an example that uses two models for an expansion project of an airport in The Netherlands. One model focuses on the operation of the airport from a high-level position, while the second focuses on other technical aspects of the operation that challenge the feasibility of the proposed configuration of the apron. The results show that by applying the methodology, analytical power is enhanced and the risk of making the wrong decisions is reduced. We identified the limitations that the future facility will have and the impact of the physical characteristics of the traffic that will operate in the airport. The methodology can be used for tackling different problems and studying particular performance indicators to help decision-makers take more informed decisions.Grupo de Transporte Aéreo - Grupo de Ingeniería Aplicada a la Industri