1,721,095 research outputs found
A Novel Method for Partitioning Feature Spaces According to their Inherent Classification Complexity
No full textThe evaluation of the intrinsic complexity of a supervised domain plays an important role in devising classification systems. Typically, the metrics used for this purpose produce an overall evaluation of the domain, without localizing the sources of complexity. In this work we propose a method for partitioning the feature space into subsets of different complexity. The most important outcome of the method is the possibility of preliminarily identifying hard and easy regions of the feature space. This possibility opens interesting theoretical and pragmatic scenarios, including the analysis of the classification error and the implementation of robust classification systems. A first group of experiments has been performed on synthetic datasets, devised to separately highlight specific and recurrent problems often found in real-world domains. In particular, the focus has been on class boundaries, noise, and density of samples. A second group of experiments, performed on selected real-world datasets, confirm the validity of the proposed method. The ultimate goal of our research is to devise a method for estimating the classification difficulty of a dataset. The proposed method makes a significant step in this direction, as it is able to partition a given dataset according to the inherent complexity of the samples contained therein
USING GUARDED EXPERTS TO PERFORM PROTEIN SECONDARY STRUCTURE PREDICTION
No full textIn this paper an ensemble-based approach for predicting protein secondary structure is proposed. Aimed at generating and selecting a population of experts whose competence is limited to proper regions of the input space, the approach enforces heuristics that promote the selection of highly cohesive regions. Expert overlapping is also promoted, to get benefits from the combination of mul- tiple experts involved in a decision. A system has been devised and implemented according to the guidelines of the proposed approach and experiments have been performed on several benchmarking datasets. Experimental results demonstrate the validity of the approach, as the system has reached an accuracy comparable with those shown by the most acknowledged cutting-edge predictors
Typification of the name Lavatera triloba subsp. pallescens (Moris) Nyman and reassessment of L. minoricensis Cambess. (L. triloba subsp. minoricensis comb. nov.)
No full textThe taxonomic identity of two poorly known taxa of the Lava -
tera triloba aggregate (Malvaceae) is clarified. The name L. triloba
subsp. pallescens (Moris) Nyman is reassessed, and a new
combination, L. triloba subsp. minoricensis, is proposed. Both
taxa were originally described as species, and later either regarded
as synonymous or alternatively subsumed as mere formae
within subsp. pallescens. The extreme rarity of the plants
led to insufficient knowledge and subsequent misinterpretation
of the basionyms, L. minoricensis Cambess. from Minorca
(Balearic Islands, Spain) and L. pallescens Moris from southwestern
Sardinia (Italy). The combination L. triloba subsp. pallescens
(Moris) Nyman was used to refer the Minorcan plants despite
their clear differences in morphology and ecology. The rediscovery
of two Sardinian populations of L. triloba subsp. pallescens in
nature, after more than 110 years without reports or collections,
has allowed for re-evaluation and typification of the misused
names
Pinna A, Pintos E, Ippoliotti S, Mascia F, Sau F, Fenu ML, Cherchi G, Nurchi A.M. (2010). Un Caso di infezione da virus H1N1 in un paziente affetto da glomerulonefrite pos-streptococcica.
No full textIdentità costituzionale europea e diritti sociali di fronte alla crisi economico-finanziaria
No full textIl presente contributo si propone di prendere in considerazione le nuove sfide che
la crisi economica ha recentemente lanciato al costituzionalismo europeo. Prese nel loro
complesso, le misure adottate dall’Unione Europea possono essere considerate insoddisfacenti
e non del tutto in accordo con il quadro costituzionale europeo dei diritti sociali. In particolare,
gli strumenti giuridici che disciplinano le performance sia fiscali che economiche
degli Stati membri e, in misura molto più ampia, il rigoroso condizionalismo nel concedere
aiuti ai paesi in difficoltà economiche – anche se a volte adottato sotto forma di Trattati internazionali
– sono difficilmente compatibili con il principio di solidarietà concesso dalla
Carta europea dei diritti dell’uomo e con la questione fondamentale della coesione economica,
sociale e territoriale nell’Unione Europea. Queste tensioni non potrebbero essere risolte
da meri interventi giurisdizionali della Corte di Giustizia europea: esse hanno bisogno, piuttosto,
di una risposta unitaria dal punto di vista politico, a cominciare da una maggiore responsabilità
democratica delle istituzioni dell’Unione Europea
L'Europa in crisi
No full textL’Europa vive da molti anni una grave crisi politica, che non è stata gestita dalle
istituzioni comuni dell’UE, ma lasciata in mano agli Stati, che non hanno saputo manifestare
una leadership in grado di gestirla, lasciando una Germania più nazionalista che in passato
da sola al governo dell’Europa. La crisi rischia di trascinare con sé i risultati raggiunti dal
processo di integrazione e di ricostituire una Europa dei nazionalismi e di scontro tra Stati.
Nonostante molti storici sostengano che la storia dell’integrazione europea si sia sviluppata
attraverso il superamento delle crisi, la mia tesi è invece che in questo caso non si tratti di
una crisi “soltanto” economica, ma molto più ampia, dell’intera Unione Europea, ad ogni
suo livello e di tutti gli Stati membri. Per risolverla occorrono soluzioni più profonde e strutturali,
più creatività politica e più coraggio, nell’azione, come nella visione
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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