1,721,058 research outputs found
Il Dizionario del Calindri e il Catasto Boncompagni: due fonti a confronto per la storia del paesaggio castanicolo nella montagna bolognese del secolo XVIII
No full textAttraverso l’esempio dei castagneti che nel XVIII secolo costituivano la dote più essenziale della montagna, si mettono a confronto due fonti coeve, il Dizionario corografico di Serafino Calindri e il Catasto Boncompagni, che descrivono per la prima volta in maniera esaustiva (o quasi) il territorio della collina e della montagna bolognese, ossia li terreni posti al di sopra della Via Emilia (ad est della città di Bologna), e strada maestra di Bazzano (ad ovest di Bologna). Malgrado le differenze di finalità e prospettive, queste due fonti si integrano bene per ricostruire il paesaggio storico e le caratteristiche dei castagneti in particolare
Utilizzo del Dizionario corografico di Serafino Calindri per ricostruire i sistemi agro-forestali del XVIII secolo
No full textIn this paper we present an approach aimed at systematically collecting and explicitly analyzing the agroforestry data reported in the historical-geographical (chorographic) descriptions. Our study area is the Bolognese hilly and mountain territory and Serafino Calindri’s chorographic dictionary (1781 and 1783) is our data source. We obtained a matrix of 240 units for 18 agroforestry products with the related productivity. The proposed methodological approach allowed to reconstruct the Eighteenth-century Provisioning Ecosystem Services in terms of nutrition (e.g., wheat, grapes, fruit, nuts, acorns, hay and meadows), raw materials (e.g., hemp, silk) and / or energy supply (e.g., wood). We also obtained a landscape framework consisting of two main land cover categories, which were the hillside agricultural areas (organized mainly as mixed crops producing wheat, grapes, fruit, hemp and silk) and the mountain forest and semi-natural areas characterized by the production of wood, acorns, nuts from chestnut, hay and meadows. The proposed approach confirms that historical-geographic descriptions are valuable records of the past landscape and can be useful for better understanding how the present’s landscape legacy
Using Monte Carlo simulations to estimate relative fire ignition danger in a low-to-medium fire-prone region
No full textA comprehensive assessment of tire ignition danger is nowadays a basic step towards the prioritization of fire management measures. In this study we propose performing a fire selectivity analysis using Monte Carlo simulations to statistically estimate the relative fire ignition danger in a low-to-intermediate fire-prone region such as Canton Ticino, Switzerland. We define fire ignition danger as the likelihood that at a given place a fire will be ignited. For each 25 m x 25 m pixel of the study area, landscape characteristics that may be related to the probability of fire ignition such as vegetation type, elevation, aspect, slope, urban-forest interface were first split into 9-12 categories. The selectivity of each category with respect to fire ignition was then statistically tested by means of Monte Carlo simulations. Finally, we proposed two different approaches for calculating the ignition danger index: cumulating the scores of the Monte Carlo simulations to a final index or producing synthetic scores by performing a principal component analysis of the Monte Carlo results. The validation of the resulting fire danger indices highlights the suitability of both proposed approaches. The PCA-option allows a slightly better discrimination between ignition and non-ignition points and may be of more general application. (C) 2010 Elsevier B.V. All rights reserved
Bootstrapping Wildfire Selectivity for the Forest Types of Canton Ticino (Switzerland)
No full textDisturbances spreading through the landscape, like wildfires, are essential processes in modeling landscape structure and dynamics. Like other disturbances, fire may spread from a local epicenter with a propagation rate enhanced or retarded by the spatial arrangement of fuel across the landscape. Therefore, fire ignition and spread are a direct consequence of the presence and arrangement of fire-prone habitats. Generalizing the concept of "habitat selection" to every spatially distributed ecological process, the resource selection functions used in zoology to summarize habitat use by wildlife can be also used to characterize the wildfire's pattern across the landscape. The aim of this paper is thus to quantify the relationship between forest cover and burnt area in Canton Ticino (Switzerland) during 1980-2007 using a bootstrap test of significance: that is, to identify forest types that burn more (or less) than expected from a random null model based on the regional availability of the resource (forest type). The results show that fires behave selectively for most forest types; whereas chestnut stands and broad-leaved forests display over-proportional burnt areas, coniferous forests typically burn less than expected by a random null model
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
Mapping fire ignition risk in a complex anthropogenic landscape
No full textThe progressing spread of urban development into the surrounding fuel-loaded wildland creates a particular landscape structure where the co-occurrence of human activities and flammable fuel greatly increases the fire ignition risk. In this framework, land use and land cover (LULC) maps derived from remotely sensed images represent a useful tool for assessing fire risk. The aim of this letter is thus to use a LULC map derived from QuickBird satellite imagery for assessing ignition risk at the rural-forest interface in Sardinia (Italy). Our results show that fire risk is strongly positively correlated with anthropogenic land use and negatively correlated with semi-natural and natural vegetation cover, such as shrubland or forest
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
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
- …
