1,721,024 research outputs found
Field measurements of tug waves in the Cagliari Harbor, Italy
No full textField measurements of ship-generated waves were performed in the Cagliari Harbor where tugboats are significant wave generators that can adversely affect small-sized moored vessels. A method is proposed in which the major characteristics of the ship-generated waves in areas where wind waves and swell occur can be assessed and presented. The requirements and limitations of the method are also discussed. The results of the method application to field data were compared to an extensively used empirical equation from the literature for the prediction of the maximum wave height generated by tug passages. Although this comparison was affected by the uncertainties in the formation and propagation of ship-generated waves, it confirmed the practical validity of the proposed method
Emergence of Cooperation in Competitive Environments
No full textWe study the Prisoner's Dilemma in competitive environments with the aim to investigate if, and under which conditions, a cooperative behavior emerges in an agent population. In particular, agents are embedded in two different regions of space, i.e., A continuous space and a discrete space. The former is represented by a simple square, whereas the latter by a directed network. In both spaces, agents face by playing the Prisoner's Dilemma with their neighbors. In the continuous space, neighbors are identified by a rule based on the Euclidean distance among agents. Instead, in the network, agents have as neighbors those connected with them. In the proposed model, the competitiveness corresponds to the number of opponents each agent decides to face, i.e., Competitive agents faces many agents at each time step. Therefore, in the continuous space, the competitiveness is represented by the radius of each agent within it finds its opponents. Instead, in the discrete space, the competitiveness corresponds to the agent's out-degree, i.e., The number of neighbors connected with an arrow starting from the considered agent an directed to its neighbors. We study the evolution of the system over time in both spaces, analyzing also the degree distribution (both the in-degree and the out-degree) of the resulting directed network. It is worth to highlight that, as main result, we found the competitiveness strongly improves cooperation among agents in both domains. Furthermore, as cooperation emerges when the Prisoner's Dilemma is played over a network, several agents become hubs (i.e., Agents with a high out-degree)
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
Morfologia del Saliente di Is Morus – Pula (CA) e idrodinamica attorno allo scoglio antistante
No full textSubmerged structures are becoming increasingly popular due to their capacity of providing necessary beach protection
without negative aesthetic impacts. Although large literature is available, the shoreline response to submerged
structures is not well understood at the present. Results show that these structures may induce shoreline erosion as
well as shoreline accretion. This paper aims to present the results of numerical physical modeling tests applied to
the Is Morus beach (Sardinia) where a natural submerged reef has created a widening of the beach in the form of
salient. Results are in accordance with empirical relationships provided by literature for predicting salient shape
and geometrical properties
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
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