1,720,976 research outputs found
The Antenna Network: A proposed scientific network based on MODIS data
No full textIn the field of remote sensing research an important achievement is the ability to receive data
directly as derived from satellite sensors, to select periods of data acquisition and therefore
to access a greater amount of inforrnation. That is the main reason why the TeleGIS laboratory
of the University of Cagliari decided to undertake this new activity with the aim to
make available to the scientific community and al1 the interested parties the data of MODIS
and AVHRR sensors (NASA 2005) covering the whole of the Mediterranean Basin (Fig. l)
and to face also new topics linked to data availability with high temporal and radiometric
resolution. The sensitivity of the sensor is such that it allows the reception even of signals
of low passes on the horizon and therefore extending the overall reception cover from the
Azores to Black Sea and from Nonvay to Mali. In this paper the development of the project
is presented together with the technical characteristics, the acquired data and the means
of access. Through the presentation of the project, an open invitation is addressed to the
scientific community in Italy, Europe and North Africa, in order to participate in a research
and training network aiming at exchanging experiences, data and contribute to a wider dissemination
of remote sensing research findings
Human impacts on Quercus suber habitats in Sardinia: past and present
No full textQuercus suber L. is a species confined to the centre and western Mediterranean basin. On the island of Sardinia its distribution is limited mainly by soils. Apart from its economic significance to local communities, cork oak habitats are recognised as having both cultural and biodiversity value at a European level. Although traditionally associated with human activities these habitats are today under increasing threat. Among the problems that affect cork oak habitats on the island are soil erosion and loss of organic matter due to ploughing and seeding for pasture. Stock numbers have increased while grazing cattle have been replaced by sheep and are proven to be particularly damaging especially to cork oak regeneration. Although the species is a passive pyrophyte, frequent fires render the trees susceptible to fungal and defoliator attacks and destroy the understory leading to soil degradation and erosion. This paper provides a review of these threats and explores their link to the changes resulting from abandonment of traditional farming methods and different management systems used in Sardinia
Changing perceptions in Mediterranean geography: the role of geospatial tools
No full textGeography and Cartography have both their foundation in the Mediterranean. Recent advances in geospatial tools such as Geographical Information Systems (GIS) and Remote Sensing (RS) have radically changed the way that we look at Mediterranean geographies. The shift from mapping to map analysis marks a turning point in geography as a discipline. This chapter is a review of the role of geospatial tools in changing perceptions and geographies in the Mediterranean. The first section deals with the nature of GIS and remote sensing and their basic principles. The second part focuses on mapping environmental perception, as con-fined to three main aspects: reconstructing the past, documenting the present and predicting the future. Reconstruction of the past includes the use of visualization techniques which simulate past landscapes or the direct identification of palaeo-features through remote sensing techniques. On documenting the present we dis-cuss the ways that GIS-based cartography creates new spatial representations. Predicting the future includes a range of applications from modelling species and vegetation distribution under environmental change to simulating future land-scapes under different land-use scenarios. The chapter provides examples in the Mediterranean where the above techniques have been applied and discusses some of the challenges that the application of geospatial analysis in the Mediterranean might face in the future
Landscape Typology in the Mediterranean context: A tool for habitat restoration
No full textDespite the wide use of Landscape Character Assessment (LCA) as a tool for landscape planning in NW Europe, there are few examples
of its application in the Mediterranean. This paper reports on the results from the development of a typology for LCA in a study area of northern Sardinia, Italy to provide a spatial framework for the analysis of current patterns of cork oak distribution and future restoration of
this habitat. Landscape units were derived from a visual interpretation of map data stored within a GIS describing the physical and cultural characteristics of the study area. The units were subsequently grouped into Landscape Types according to the similarity of shared attributes 36 using Two Way Indicator Species Analysis (TWINSPAN). The preliminary results showed that the methodology classified distinct Land- 37 scape Types but, based on field observations, there is a need for further refinement of the classification. The distribution and properties of
two main cork oak habitats types was examined within the identified Landscape Types namely woodlands and wood pastures using Patch Analyst. The results show very clearly a correspondence between the distribution of cork oak pastures and cork oak woodland and landscape types. This forms the basis of the development of strategies for the maintenance, restoration and recreation of these habitat types within the study area, ultimately for the whole island of Sardinia. Future work is required to improve the landscape characterisation , particularly with respect to cultural factors, and to determine the validity of the landscape spatial framework for the analysis of cork oak distribution as part of a programme of habitat restoration and re-creation
The use of GIS and Remote Sensing for Landscape Character Mapping: a pilot study from Sardinia.
No full textA methodology is being developed based on the use of GIS and remote sensing tools for landscape character mapping in a pilot study area in Sardinia. The methodology is based on physical and cultural attributes of the Sardinian landscape using GIS as a decision support tool. In this abstract the first steps of the methodology is presented and future work is further discussed. In particular, the applicability of this methodology is investigated as a framework for the mapping and monitoring of cork oak habitats in Sardinia. This novel approach will be used in order to explore the interplay between the physical and cultural factors in the distribution of cork oak habitats in the island
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
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