5,972 research outputs found

    Report No. 28: Review of Methodologies Applied for the Assessment of Employment and Social Impacts

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    Joint report with ECORYS Netherlands for the DG Employment, Social Affairs and Equal Opportunities of the European Commission, Bonn 2010 (217 pages)

    An Analysis of the Spatio-Temporal Factors Affecting Aircraft Conflicts Based on Simulation Modelling

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    The demand for air travel worldwide continues to grow at a rapid rate, especially in Europe and the United States. In Europe, the demand exceeded predictions with a real annual growth of 7.1% in the period 1985-1990, against a prediction of 2.4%. By the year 2010, the demand is expected to double from the 1990 level. Within the UK international scheduled passenger traffic is predicted to increase, on average, by 5.8 per cent per year between 1999 and 2003. The demand has not been matched by availability of capacity. In Western Europe many of the largest airports suffer from runway capacity constraints. Europe also suffers from an en-route airspace capacity constraint, which is determined by the workload of the air traffic controllers, i.e. the physical and mental work that controllers must undertake to safely conduct air traffic under their jurisdiction through en-route airspace. The annual cost to Europe due to air traffic inefficiency and congestion in en-route airspace is estimated to be 5 billion US Dollars, primarily due to delays caused by non-optimal route structures and reduced productivity of controllers due to equipment inefficiencies. Therefore, to in order to decrease the total delay, an increase in en-route capacity is of paramount importance. At a global scale and in the early 1980s, the International Civil Aviation Organisation (ICAO) recognised that the traditional air traffic control (ATC) systems would not cope with the growth in demand for capacity. Consequently new technologies and procedures have been proposed to enable ATC to cope with this demand, e.g. satellite-based system concept to meet the future civil aviation requirements for communication, navigation and surveillance/ air traffic management (CNS/ATM). In Europe, the organisation EUROCONTROL (established in 1960 to co-ordinate European ATM) proposed a variety of measures to increase the capacity of en-route airspace. A key change envisaged is the increasing delegation of responsibilities for control to flight crew, by the use of airborne separation assurance between aircraft, leading eventually to ?free flight? airspace. However, there are major concerns regarding the safety of operations in ?free flight? airspace. The safety of such airspace can be investigated by analysing the factors that affect conflict occurrence, i.e. a loss of the prescribed separation between two aircraft in airspace. This paper analyses the factors affecting conflict occurrence in current airspace and future free flight airspace by using a simulation model of air traffic controller workload, the RAMS model. The paper begins with a literature review of the factors that affect conflict occurrence. This is followed by a description of the RAMS model and of its use in this analysis. The airspace simulated is the Mediterranean Free Flight region, and the major attributes of this region and of the traffic demand patterns are outlined next. In particular a day?s air traffic is simulated in the two airspace scenarios, and rules for conflict detection and resolution are carefully defined. The following section outlines the framework for analysing the output from the simulations, using negative binomial (NB) and generalised negative binomial (GNB) regression, and discusses the estimation methods required. The next section presents the results of the regression analysis, taking into account the spatio-temporal nature of the data. The following section presents an analysis of the spatial and temporal pattern of conflicts in the two airspace scenarios across a day, highlighting possible metrics to indicate this. The paper concludes with future research directions based upon this analysis.

    Network-wide assessment of ATM mechanisms using an agent-based model

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    This paper presents results from the SESAR ER3 Domino project. Three mechanisms are assessed at the ECAC-wide level: 4D trajectory adjustments (a combination of actively waiting for connecting passengers and dynamic cost indexing), flight prioritisation (enabling ATFM slot swapping at arrival regulations), and flight arrival coordination (where flights are sequenced in extended arrival managers based on an advanced cost-driven optimisation). Classical and new metrics, designed to capture network effects, are used to analyse the results of a micro-level agent-based model. A scenario with congestion at three hubs is used to assess the 4D trajectory adjustment and the flight prioritisation mechanisms. Two different scopes for the extended arrival manager are modelled to analyse the impact of the flight arrival coordination mechanism. Results show that the 4D trajectory adjustments mechanism succeeds in reducing costs and delays for connecting passengers. A trade-off between the interests of the airlines in reducing costs and those of non-connecting passengers emerges, although passengers benefit overall from the mechanism. Flight prioritisation is found to have no significant effects at the network level, as it is applied to a small number of flights. Advanced flight arrival coordination, as implemented, increases delays and costs in the system. The arrival manager optimises the arrival sequence of all flights within its scope but does not consider flight uncertainties, thus leading to sub-optimal actions.Comment: 20 pages, 6 figures, Journal of Air Transport Managemen

    Thermal comfort conditions in airport terminals: Indoor or transition spaces?

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    This paper reports on the investigation of the thermal comfort conditions in three airport terminals in the UK. In the course of seasonal field surveys, the indoor environmental conditions were monitored in different terminal areas and questionnaire-guided interviews were conducted with 3087 terminal users. The paper focuses on the thermal perception, preference and comfort requirements of passengers and terminal staff. The two groups presented different satisfaction levels with the indoor environment and significant differences in their thermal requirements, while both preferring a thermal environment different to the one experienced. The thermal conflict emerges throughout the terminal spaces. The neutral and preferred temperatures for passengers were lower than for employees and considerably lower than the mean indoor temperature. Passengers demonstrated higher tolerance of the thermal conditions and consistently a wider range of comfor

    Aeronautical Engineering: A continuing bibliography, supplement 120

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    This bibliography contains abstracts for 297 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1980

    Innovation in Private Infrastructure Development Effects of the Selection Environment and Modularity

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    This study investigates how the selection environment and modularity affect innovation in private infrastructure development. Our findings stem from an in-depth empirical study of the extent ten process innovations were implemented in an airport expansion programme. Our findings suggest that developer and customers can each occasionally champion or resist innovations. An innovation succeeds contingent upon the capability of the stakeholder groups to develop collectively a plan to finance and implement the innovation, which reconciles subjective individual assessments. Innovations can be particularly hard to adopt when they require financing from different budgets, or when the developer’s investment pays off only if customers behave in a specified way in the future. We also find that the degrees of novelty and modularity neither represent sufficient or necessary conditions enabling or hindering innovation. Novelty, however, makes the innovation champion’s job harder because it leads to perceptions of downside risk and regulatory changes, whereas modularity helps the champion operationalise ways that moderate resistance to innovate.Innovation; financing; implementation

    Proceedings: Sixth Annual Workshop on Meteorological and Environmental Inputs to Aviation Systems

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    The topics of interaction of the atmosphere with aviation systems, the better definition and implementation of services to operators, and the collection and interpretation of data for establishing operational criteria relating the total meteorological inputs from the atmospheric sciences to the needs of aviation communities were addressed

    Methodology for the Assessment of Spatial Economic Impacts of Transport Projects and Policies

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    In this study we develop an integrated econometric and CGE modelling framework for transport projects and transport policies at the European level by integrating network, regional economic and macro-economic impacts. The paper presents the formal structure of the integrated econometric and CGE modelling framework, explains the calibration and applies it to the policy evaluation. The effects of infrastructure investments are modelled by simulating trade cost changes in a comparative static analysis, using estimates of trade cost changes due to new infrastructure links, obtained from a transport network model. By performing a systematic and quantitative analysis of the spatial, network and socio-economic impacts of transport investments and policy and carrying out scenario simulations we improve the under-standing of the impact of transportation policies on short- and long-term spatial development in the EU.Transport Policy, Impact analysis, Spatial CGE Model

    NOSTROMO - D5.1 - ATM Performance Metamodels - Preliminary Release

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    This deliverable presents the results obtained with the meta-modelling process presented in D3.1 and D3.2 applied to the two micromodels (or simulators), Mercury and FLITAN, themselves implementing concepts from four SESAR solutions, PJ01.01, PJ07.02, PJ08-01, and PJ02.08. The objective of the meta-modelling process is explained briefly again in the introduction, in particular with respect to performance assessment. The rationale for the selection of the SESAR solutions implemented in the simulators are briefly explained too. The simulators are presented in two distinct chapters. First, a general presentation of each simulator is given, with past challenges and development, before explaining the development steps carried out to implement the concepts from the chosen solutions. Domain research questions that could be answered by these implementations are highlighted along the way. The meta-modelling process is then briefly explained again, followed by the results obtained with the two simulators, in distinct sections. The results highlight the performance of the meta-model with respect to approximating the output of the micromodels, but not the performance of the models themselves with respect to the research questions, which will be explored in WP7 instead. The deliverable closes with some considerations on the meta-modelling performance and next steps for this line of work
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