50 research outputs found

    Support to Design for Air Traffic Management: An Approach with Agent-Based Modelling and Evolutionary Search

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    This paper presents a methodology to manage the support to design in ATM operations. We propose a workflow for the design of ATM solutions in a performance-based setting. The methodology includes the evaluation of the impact on human behaviour and exploits a combination of different paradigms, such as Agent-Based Modelling and Simulation, and Agent-Based Evolutionary Search. We prove the soundness of the methodology by carrying out a real case study, which is the transition from Direct Routing to Free Routing in the Italian airspace. The validation results exhibit limited errors for the assessment of the performance metrics under evaluation. Furthermore, the optimization of sector collapsing/decollapsing configuration is discussed to demonstrate the effectiveness of the implemented engines

    Simulation-Based Evolutionary Optimization of Air Traffic Management

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    In the context of aerospace engineering, the optimization of processes may often require to solve multi-objective optimization problems, including mixed variables, multi-modal and non-differentiable quantities, possibly involving highly-expensive objective function evaluations. In Air Traffic Management (ATM), the optimization of procedures and protocols becomes even more complicated, due to the involve-ment of human controllers, which act as final decision points in the control chain. In this article, we propose the use of computational intelligence techniques, such as Agent-Based Modelling and Simulation (ABMS)and Evolutionary Computing (EC), to design a simulation-based distributed architecture to optimize control plans and procedures in the context of ATM. We rely on Agent-Based fast-time simulations to carry out offline what-if analysis of multiple scenarios, also taking into account human-related decisions, during the strategic or pre-tactical phases. The scenarios are constructed using real-world traffic data traces, while multiple optimization variables governed by an EC algorithm allow to explore the search space to identify the best solutions. Our optimization approach relies on ad-hoc multi-objective performance metrics which allow to assess the goodness of the control of aircraft and air traffic regulations. We present experimental results which prove the viability of our approach, comparing them with real-world data traces, and proving their meaningfulness from an Air Traffic Control perspective

    Conservation status of Italian coastal dune habitats in the light of the 4th Monitoring Report (92/43/EEC Habitats Directive)

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    Coastal dunes are among habitats with the worst conservation status on a global, European and national scale. Monitoring and reporting are of strategic importance to determine the effectiveness of the implementation of Habitats Directive and to preserve the unique biodiversity heritage of the Italian dunes. In this study we show main results of the 4th National Report with specific reference to the macro-habitat “Coastal Sand Dunes and Inland Dunes”, highlighting its updated current conservation status at the national and Biogeographical level. A comprehensive Working Group of territorial experts collected, updated, validated and integrated the data available for 11 Annex I Habitats, distributed in the Alpine, Continental and Mediterranean Biogeographical Regions. The conservation status was evaluated through the following criteria: geographic range, surface area, structure, functions, pressures, threats, conservation measures and prospects. Results highlighted the dramatically bad conservation status of Italian dune Habitats: the overall assessment reported 88% of habitats in bad conservation status and the remaining 12% is in inadequate conditions. Results showed a generalised threat and a worrying conservation status both on herbaceous and wooded communities, in particular in some relevant habitats, such as the shifting dunes. Main pressures and threats were linked to residential, commercial and industrial activities, as well as alien species. Although some of the changes in distribution and trends are probably deriving from more accurate and updated data, the alarming conservation status of Italian sand dunes requires a better knowledge of pressures and threats for further management actions and monitoring plans, inside and outside protected areas

    Towards the Integration of Higher Airspace Operations in the European ATM Network

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    While very limited HAO are supported today by existing ATM processes, owing to innovation the number of operations is expected to grow substantially in the coming years. This will involve different geographical distributions and types of vehicles, ranging from slow moving HAPS to very high-speed vehicles. New entrants will provide new challenges in terms of flight-performance envelopes, operating at level bands not used today and where their operational behavior and performance may generate additional uncertainty in ATM. Therefore, the major challenge is to research new solutions needed for a safe, fair and effective integration of the new entrants in the new operational environment by providing validated flight trajectories, procedural packages for both nominal and contingency scenarios and real time monitoring capability. This paper presents principles, assumptions and concept elements for the integration of HAO in Europe, which have been developed during the SESAR project European Concept for Higher Airspace operations (ECHO)

    Long-Term Drug Survival and Effectiveness of Secukinumab in Patients with Moderate to Severe Chronic Plaque Psoriasis: 42-Month Results from the SUPREME 2.0 Study

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    Purpose: SUPREME, a phase IIIb study conducted in Italy, demonstrated safety and high efficacy of secukinumab for up to 72 weeks in patients with moderate-to-severe plaque-type psoriasis. SUPREME 2.0 study aimed to provide real-world data on the long-term drug survival and effectiveness of secukinumab beyond 72 weeks. Patients and Methods: SUPREME 2.0 is a retrospective observational chart review study conducted in patients previously enrolled in SUPREME study. After the end of the SUPREME study, eligible patients continued treatment as per clinical practice, and their effectiveness and drug survival data were retrieved from medical charts. Results: Of the 415 patients enrolled in the SUPREME study, 297 were included in SUPREME 2.0; of which, 210 (70.7%) continued secukinumab treatment throughout the 42-month observation period. Patients in the biologic-naïve cohort had higher drug survival than those in the biologic-experienced cohort (74.9% vs 61.7%), while HLA-Cw6–positive and HLA-Cw6–negative patients showed similar drug survival (69.3% and 71.9%). After 42 months, Psoriasis Area and Severity Index (PASI) 90 was achieved by 79.6% of patients overall; with a similar proportion of biologic-naïve and biologic-experienced patients achieving PASI90 (79.8% and 79.1%). The mean absolute PASI score reduced from 21.94 to 1.38 in the overall population, 21.90 to 1.24 in biologic-naïve and 22.03 to 1.77 in biologic-experienced patients after 42 months. The decrease in the absolute PASI score was comparable between HLACw6–positive and HLA–Cw6-negative patients. The baseline Dermatology Life Quality Index scores also decreased in the overall patients (10.5 to 2.32) and across all study sub-groups after 42 months. Safety was consistent with the known profile of secukinumab, with no new findings. Conclusion: In this real-world cohort study, secukinumab showed consistently high long-term drug survival and effectiveness with a favourable safety profile

    Shedding light on typical species : implications for habitat monitoring

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    Habitat monitoring in Europe is regulated by Article 17 of the Habitats Directive, which suggests the use of typical species to assess habitat conservation status. Yet, the Directive uses the term “typical” species but does not provide a definition, either for its use in reporting or for its use in impact assessments. To address the issue, an online workshop was organized by the Italian Society for Vegetation Science (SISV) to shed light on the diversity of perspectives regarding the different concepts of typical species, and to discuss the possible implications for habitat monitoring. To this aim, we inquired 73 people with a very different degree of expertise in the field of vegetation science by means of a tailored survey composed of six questions. We analysed the data using Pearson's Chi-squared test to verify that the answers diverged from a random distribution and checked the effect of the degree of experience of the surveyees on the results. We found that most of the surveyees agreed on the use of the phytosociological method for habitat monitoring and of the diagnostic and characteristic species to evaluate the structural and functional conservation status of habitats. With this contribution, we shed light on the meaning of “typical” species in the context of habitat monitoring

    An overview of the Italian forest biodiversity and its conservation level, based on the first outcomes of the 4th Habitat Report ex-Art. 17

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    In 2019 the 4th Report ex-Art. 17 on the conservation status (CS) of Annex I Habitats of the 92/43/EEC Directive was expected by every EU/28 country, with reference to the period 2013-18. In Italy, the process was in charge to the Italian Institute for Environmental Protection and Research (ISPRA), on behalf of the Ministry for Environment, Land and Sea Protection (MATTM), with the scientific support of the Italian Botanical Society (SBI). A large group of thematic and territorial experts elaborated the available data concerning the 124 types of terrestrial and inland water Habitats present in Italy, 39 of which are represented by Forest Habitats (Group 9),. The main aim of the work was the evaluation of the overall CS of each Habitat by Biogeographic Region (Mediterranean, Continental and Alpine), for a total amount of 294 assessments. A high proportion of these (92, corresponding to 31% of the total) referred to Forest Habitats, including 20 marginal types for which the CS was not requested. The analysis was carried out at different scales: a) administrative territory, through the data contained in the ISPRA database, whose compilation was in charge to the Regions and Autonomous Provinces; b) Natura 2000 site, with the latest updates available (Standard Data Forms updated to 2018); c) national scale, implementing the distribution maps for each Habitat based on the European grid ETRS89-LAEA5210 (10x10 km2 mesh); d) Biogeographic Region, scale of the final assessment. Cartographic outcomes, associated databases and additional data used for the assessments will be available online on the ISPRA Portal as soon as the validation process by the European Commission will be completed. A dedicated archive named "HAB_IT" has been created in the national database "VegItaly" (1), managed by the Italian Society of Vegetation Science, where the phytosociological relevés representative of the various Annex I Habitats in Italy will be archived and freely accessible. An overview of the results regarding the Forest habitats is here provided, including a comparison with the outcomes of the former reporting cycle, the 3rd Report ex-Art. 17 (2). In several cases (e.g. 9120, 91L0), the distribution maps have been remarkably improved due to better knowledge and more fitful interpretation. The conservation status resulted as Favourable (FV) for 6,7%, Inadequate (U1) for 58,7% and Bad (U1) for 32,0% of the 72 assessed forest Habitat types. In no case there was an improvement of the conservation status, while in 6 cases a worsening of the conditions resulted from the data analysis, pointing out the Habitats types with a higher need of action. Similarly to other projects carried out as a team by the network of Annex I Habitat experts of the Italian Botanical Society and the Italian Society for Vegetation Science (e.g. 3, 4), this is another step in the direction of supporting the implementation of the 92/43/EEC "Habitat" Directive in Italy and Europe. On this ground, the high biodiversity of the Italian forest Habitats could be emphasized, however results pointed out that some rare or endemic types (e.g. Alnus cordata or Betula aetnensis-dominated forests) are still scarcely acknowledged by the most prominent EU conservation tools such as the Annex I to the "Habitat" Directive. 1) F. Landucci et al. (2012) Plant Biosyst., 146(4), 756-763 2) P. Genovesi et al. (2014) ISPRA, Serie Rapporti, 194/2014 3) E. Biondi et al. (2009) Società Botanica Italiana, MATTM, D.P.N., http://vnr.unipg.it/habitat/ 4) D. Gigante et al. (2016) Plant Sociology, 53(2), 77-8

    The co-occurrence of different grassland communities increases the stability of pollination networks

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    High heterogeneity of grassland communities supports a high diversity of species and represents a key point for the retention of pollinators in agricultural landscapes. In the present study, we explored whether the co-occurrence of different grassland communities has any effect on the stability of the network of pollination interactions. We monitored pollination interactions in two co-occurring grassland communities, differing in disturbance history and water and nutrient supply. The monitoring was carried out during the summer season (7 surveys). For each survey we compared the role in the pollination networks (i.e., keystone vs. peripheral species) of habitat-specialist and habitat-generalist plant and pollinator species. We found that plant and pollinator species of the two different grassland communities were highly interconnected, revealing that pollination interactions occur at a level of organization above that of the single community. The co-occurrence of the two grassland communities increased the type, number and frequency of contacts, thereby contributing to networks stability. The role of habitat-specialist and habitat-generalist plant and pollinator species in pollination networks was asymmetric, with habitat-specialist plants and habitat-generalist pollinators being keystone species, while habitat-generalist plants and habitat-specialist pollinators being peripheral in the pollination networks. Our results showed that the stability of the network does stem from the co-occurrence of different species pools having different but complementary roles in the pollination networks. From a conservation perspective, the maintenance of different grassland communities is important not only because they allow the conservation of habitat-specialist species, but specifically because plant species specialized in either grassland community are also keystone for the maintenance of the stability of the pollination networks.High heterogeneity of grassland communities supports a high diversity of species and represents a key point for the retention of pollinators in agricultural landscapes. In the present study, we explored whether the co-occurrence of different grassland communities has any effect on the stability of the network of pollination interactions. We monitored pollination interactions in two co-occurring grassland communities, differing in disturbance history and water and nutrient supply. The monitoring was carried out during the summer season (7 surveys). For each survey we compared the role in the pollination networks (i.e., keystone vs. peripheral species) of habitat-specialist and habitat-generalist plant and pollinator species. We found that plant and pollinator species of the two different grassland communities were highly interconnected, revealing that pollination interactions occur at a level of organization above that of the single community. The co-occurrence of the two grassland communities increased the type, number and frequency of contacts, thereby contributing to networks stability. The role of habitat-specialist and habitat-generalist plant and pollinator species in pollination networks was asymmetric, with habitat-specialist plants and habitat-generalist pollinators being keystone species, while habitat-generalist plants and habitat-specialist pollinators being peripheral in the pollination networks. Our results showed that the stability of the network does stem from the co-occurrence of different species pools having different but complementary roles in the pollination networks. From a conservation perspective, the maintenance of different grassland communities is important not only because they allow the conservation of habitat-specialist species, but specifically because plant species specialized in either grassland community are also keystone for the maintenance of the stability of the pollination networks
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