1,721,508 research outputs found
Analysis of Staggered Evolutions for Nonlinear Energies in Phase Field Fracture
No full textWe consider a class of separately convex phase field energies employed in fracture mechanics, featuring non-interpenetration and a general softening behavior. We analyze the time-discrete evolutions generated by a staggered minimization scheme, where fracture irreversibility is modeled by a monotonicity constraint on the phase field variable. After recasting the staggered scheme by means of gradient flows, we characterize the time-continuous limits of the discrete solutions in terms of balanced viscosity evolutions, parametrized by their arc-length with respect to the L2-norm (for the phase field) and the H1-norm (for the displacement field). By a careful study of the energy balance we deduce that time-continuous evolutions may still exhibit an alternate behavior in discontinuity times
Laboratory testing of a combined heaving-surging wave energy converter for the nearshore zone
No full textThe EDS (Energy Double System) is a combined heave-surge oscillating-body WEC (wave energy converter) designed for the nearshore zone, composed by a heaving float and a surging paddle supported by a unique structure. This paper investigates, through laboratory modelling, the behavior of EDS at various water depths along a sloping beach. The float alone, obtained by removing the paddle from the EDS, was also tested for comparison. Tests were performed with regular waves. Results shows that, as water depth decreases, the upward motion of the float and the forward motion of the paddle are more energetic and faster than their opposite motions (downward and backward, respectively). The CWRs (capture width ratios) of the float alone and the float inside the EDS are similar and they increase as water depth increases. Thanks to the presence of the paddle, the CWR of the EDS is larger than that of the float alone at all the tested water depths; it presents a maximum off the breaking point, and then decreases as water depth increases. The interpretation of the laboratory results allowed to draft a method for detecting the optimal water depth to install the EDS in a real sea site
Storia, problemi e metodi del comparativismo linguistico. Atti del Convegno della Società Italiana di Glottologia (Bologna, 29 novembre 1 dicembre 1990)
No full text
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
Multidimensional view of e-commerce socio-economic impacts
No full textThe development of e-commerce is a complex phenomenon whose effects extend to the social
and ecological sphere. As an example, there is much interest today in the progress of an ICTbased
economy that might be beneficial to the environment. While the majority of studies has
investigated the direct cause-effect relations between specific e-commerce implementations and
some environmental indicators, there is the need for a multidimensional analysis of the various
factors involved. This may help to place the implications of online sales in the broader socioeconomic
picture, highlight the various conflicting elements, and stressing the circular effects.
This paper analyses a number of intertwined factors that are influenced and, in turn, can influence
both the development of e-commerce and its socio-economic impacts with a focus on the
environment, and in particular: a) e-strategies, i.e. the approaches adopted by online firms; b)
e-consumers, namely the modality and amount of online purchases; c) e-policies, i.e. the actions
by public authorities to regulate the business context and/or promote environmentalfriendly
activities. In addition, the study uses a model of equations previously proposed in the
literature to examine the links between the elements illustrated above and their expected impacts.
The findings show that the environmental implications of online sales are important not
only for the ecosystem, but in turn for the potential changes of consumer behaviours and for the
viable strategies of firms, thus for the development of e-commerce itself
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