1,720,957 research outputs found
Wildlife strike risk assessment : development of new methodologies in two International Italian airports
No full textAircraft collisions with wildlife, hereafter wildlife strikes, are a growing threat to civil aviation safety. Of these wildlife strikes, bird-aircraft collisions (hereafter birdstrikes) are of major concern because of the strike frequency and associated damage. Importantly, these wildlife-strike statistics reflect an increasing risk to aviation safety due to the considerable increase of air traffic and growth of the civil aviation industry, demographic explosion of synanthropic bird species and their habituation to live in human-modified habitats and to exploit food sources deriving from human activities. Furthermore, airports are highly attractive for wildlife, whose presence pose substantial hazards to aviation, leading to a high occurrence of wildlife strikes. As a consequence, the adoption of strategies aimed to limit the wildlife-aircrafts collisions at airports and keep under control the risk is strongly needed. The current PhD research project fits into this perspective, with the aim to develop new tools for wildlife strike risk assessment, which may be used by airport managers to improve the aviation safety worldwide. The study has been conducted in two international Italian airports: The Venice Marco Polo airport and the Treviso Antonio Canova airport, highly attended by wildlife since located in very important naturalistic areas, respectively on the inland border of the Venice lagoon and along the River Sile Regional Natural Park. The main objective of the research is to develop a new holistic bio-geographic risk index or Attraction Risk Index (ARI) for birdstrike risk assessment. The innovation of the ARI risk index is to combine the environmental features and attractive sites for wildlife around airports, with the wildlife attending the studied airport as well as the recorded air traffic and birdstrikes. Additionally, the present study is intended to provide information on the relative attractiveness of sources to wildlife in order to highlight the most appealing ones, thus the most hazardous from an aviation perspective. Results from the study will help in dealing with airport management problems and safety improvement.Le collisioni tra la fauna selvatica e gli aerei, fenomeno conosciuto come wildlife strike, costituiscono una minaccia crescente per la sicurezza aerea. Tra tutti, gli impatti che destano maggior preoccupazione sono i birdstrikes, ovvero le collisioni tra i velivoli e l’avifauna. Ciò a causa della frequenza con cui si verificano tali incidenti e dei danni ad essi associati. Negli ultimi anni il trend di wildlife strike è aumentato drasticamente, di pari passo col crescente traffico aereo e l'esplosione demografica di specie definite ‘sinantrope’ in quanto abituate a frequentare habitat antropizzati e a sfruttare fonti alimentari derivanti dalle attività umane. Gli aeroporti risultano altamente attrattivi per la fauna selvatica, la cui presenza pone dunque un rischio concreto per l'aviazione, portando altresì ad un’elevata incidenza di wildlife strikes all’interno del sedime aeroportuale. Di conseguenza, risulta fondamentale l’adozione di strategie atte a limitare il numero di impatti e a tenere sotto controllo il rischio.
Questo progetto di dottorato si inserisce in questa prospettiva, con l'obiettivo di sviluppare nuovi strumenti per l’analisi del rischio di wildlife strike, che potranno essere utilizzati dai gestori aeroportuali al fine di implementare la sicurezza aerea su scala globale.
Lo studio è stato condotto in due aeroporti Internazionali Italiani: l'aeroporto Marco Polo di Venezia e l'aeroporto Antonio Canova di Treviso, entrambi altamente frequentati da fauna selvatica essendo situati in aree particolarmente importanti dal punto di vista naturalistico, rispettivamente al confine con la laguna di Venezia e lungo il Parco Naturale Regionale del fiume Sile.
L'obiettivo principale della ricerca è quello di sviluppare un nuovo indice di rischio, denominato Attraction Risk Index (ARI). Tale indice risulta innovativo nel campo dell’analisi del rischio di wildlife strike in quanto utilizza un approccio olistico, integrando fra loro le caratteristiche ambientali e le fonti attrattive per la fauna selvatica presenti nell’area circostante l’aeroporto, le specie in esso rilevate, il traffico aereo e gli impatti registrati. Inoltre, il presente studio fornisce informazioni circa l’ attrattività relativa delle fonti con l’obiettivo di definire i prime drivers per la fauna selvatica e dunque gli elementi più pericolosi per il traffico aereo. I risultati ottenuti sono volti ad una corretta gestione aeroportuale e ad implementare la sicurezza aerea
The abundance of yellow-legged gulls Larus michahellis breeding in the historic centre of Venice, Italy and the initial effects of the new waste collection policy on the population
No full textThe yellow-legged gull Larus michahellis has undergone widespread colonization of the urban environment in the recent past. The first urban breeding gulls were recorded in the historical centre of Venice, Italy, in 2000, and by 2005 there were already 24 roof-nesting pairs, with this number increasing significantly over the last decade. In 2016, a new door-to-door garbage collection system was introduced in Venice to prevent the accumulation of rubbish in the streets and limit the trophic resources available for the species. This study provides an up-to-date estimate of the Venice yellow-legged gull urban population using distance sampling method. We also studied the effect of the new waste collection system on the species by comparing the population estimate before (2017) and after (2018) the full implementation of this change and by analysing the trend of individuals collected in the old town by the wildlife recovery service during 2010–2018. Results estimated ca. 430 breeding pairs in June 2018 showing a 36% decrease with respect to 2017. We also found a decrease in the number of 1-year-old birds and pulli collected by the wildlife recovery service starting from 2016, when the policy implementation began. Our data did not show a significant decrease in the overall number of individuals, suggesting that the new policy has a stronger effect on the breeding success of the species than on adult survival. This study emphasizes the importance of preventing rubbish accumulation in the streets as factor for reducing the abundance of urban yellow-legged gulls
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
A land-use perspective for birdstrike risk assessment: The attraction risk index
Full text linkCollisions between aircraft and birds, birdstrikes, pose a serious threat to aviation safety.
The occurrence of these events is influenced by land-uses in the surroundings of airports.
Airports located in the same region might have different trends for birdstrike risk, due to differences
in the surrounding habitats. Here we developed a quantitative tool that assesses
the risk of birdstrike based on the habitats within a 13-km buffer from the airport. For this purpose,
we developed Generalized Linear Models (GLMs) with binomial distribution to estimate
the contribution of habitats to wildlife use of the study area, depending on season.
These GLMs predictions were combined to the flight altitude of birds within the 13-km buffer,
the airport traffic pattern and the severity indices associated with impacts. Our approach
was developed at Venice Marco Polo International airport (VCE), located in northeast Italy
and then tested at Treviso Antonio Canova International airport (TSF), which is 20 km
inland. Results from the two airports revealed that both the surrounding habitats and the
season had a significant influence to the pattern of risk. With regard to VCE, agricultural
fields, wetlands and urban areas contributed most to the presence of birds in the study
area. Furthermore, the key role of distance of land-uses from the airport on the probability of
presence of birds was highlighted. The reliability of developed risk index was demonstrated
since at VCE it was significantly correlated with bird strike rate. This study emphasizes the
importance of the territory near airports and the wildlife use of its habitats, as factors in need
of consideration for birdstrike risk assessment procedures. Information on the contribution
of habitats in attracting birds, depending on season, can be used by airport managers and
local authorities to plan specific interventions in the study area in order to lower the risk
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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