1,721,120 research outputs found
Methodologies of evaluation of the compatibility beetween rock-habitat and funcional needs
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Progettazione di squadra versus progettazione sequenziale: intervista a Costantino Dardi; intervista a Paolo Portoghesi
No full textInterviste a Costantino Dardi e Paolo Portoghesi sui temi della progettazione e della costruzione, in particolare sulle modificazioni indotte dallo sviluppo tecnologico: Una riflessione sul "progettare" e sul "progetto" e contemporaneo di due protagonisti
PETRA: Performance Enhancing Transport Architecture for Satellite Communications
No full textThis paper presents a performance enhancing transport architecture for the satellite environment. This solution improves the network transport performance by overcoming the limits imposed by a transmission control protocol/Internet protocol (TCP/IP)-based stack suite, while maintaining the interfaces offered by it. This is an important issue since TCP/IP is widely used and most of the applications are based on it. The work starts from the state-of-the-art about the transport layer over satellite by distinguing two alternative frameworks: the black box (BB) and the complete knowledge (CK) approaches. In the former, the network is considered as a "black box" and only modifications in the terminal tools are permitted. In the latter, the complete control of any network element is allowed so as a performance optimization procedure is possible. The proposed architecture [called Performance Enhancing Transport Architecture (PETRA)] is designed in all details using the second approach. PETRA uses network elements, called relay entities, to isolate the satellite portions in case of heterogeneous networks, while a transport layer protocol stack is used to optimize the transport of information over satellite links. A special satellite transport protocol, that is part of the transport layer protocol stack, is used over such links to perform error recovery. Simulation results show that the proposed framework significantly enhances throughput performance
Phytoplankton assemblage structure and dynamics as indicator of the recent trophic and biological evolution of the western basin of Lake Como (N. Italy)
No full textWe studied the phytoplankton assemblage of the western basin of Lake Como (Northern Italy) during 1997. The phytoplankton assemblage was composed of 65 taxa, belonging to six taxonomic groups. Chlorophyta were represented by the highest number of taxa (28) followed by Bacillariophyceae (17), Cyanoprokaryota (9), Dinophyceae (6), Chrysophyceae (3) and Cryptophyta (2). The total assemblage density and biomass ranged from 902 ind ml(-)1 and 134.5 mm(3) m(-3) in February to 58 766 ind ml(-) (1) and 9360 mm(3) m(-3) in October. The density and biomass variation at three stations showed a common pattern, with higher values in the southern part of the basin where TP concentrations were always greater. The phytoplankton succession was analysed by cluster analysis (average linkage clustering) and non-metric multidimensional scaling (NMDS) ordination, both applied to a dissimilarity matrix obtained from a calculation of the Bray-Curtis index. In general, the seasonal succession followed a simple pattern, with a clear spring phase. These results are discussed considering the trophic evolution of the lake and its recent colonization by Dreissena polymorpha
Phytoplankton assemblage structure and dynamics as indicator of the recent trophic and biological evolution of the western basin of Lake Como (N. Italy)
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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
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