Search results for "complexity"
showing 10 items of 1094 documents
First assessment of the vermetid reefs along the coasts of Favignana Island (Southern Tyrrhenian Sea)
2015
Intertidal vermetid reefs, particularly vulnerable to environmental changes and human activities, are now experiencing high mortality in several areas of the Mediterranean Sea. Since the increase of knowledge on this habitat is important for conservation purposes, we provide a first baseline assessment of the vermetid reefs along the coasts of the Favignana Island (Marine Protected Area “Egadi Islands”). Preliminary results showed the presence of a true reef, similar to a fringing reef, displaying at least three local patterns, distinguishable for width (from 2.3 to 15.5 m), height of the outer and of the inner margin (from 5.6 to 18 cm and from 8.3 to 26 cm, respectively) and number, width…
RESULTS OF DIFFERENT ANTHROPIC USES ON THE STRUCTURE OF VERMETID REEFS
2014
The biogenic vermetid reef is a key habitat of coastal ecosystems that modifies the shoreline morphology and increases the local biodiversity. Despite its ecological relevance, rarely it is subjected to an accurate management and is often exposed to several human activities. This study aims to distinguish between the effects of different typologies of anthropic uses on the physical structure of the vermetid reef. A comparison between totally protected, partially protected and strongly anthropized reefs has been done and two variables have been analysed: the substratum complexity and the density of reef-building organism. Both the variables show higher values in totally and partially protect…
Effects of structural complexity on epifaunal assemblages associated with two intertidal Mediterranean seaweeds
2023
Brown foundation seaweeds are key elements increasing substrate heterogeneity and shaping the biodiversity in rocky coastal ecosystems. They are, however, vulnerable species that are declining due to multiple anthropogenic and climate change stressors, leading to a shift to less structural complex habitats. We investigate the role of structural attributes of two intertidal macroalgae, Ericaria amentacea and Laurencia obtusa, in shaping the abundance and diversity of their associated epifaunal assemblages. For this aim, we measured seaweeds’ biomass, thallus volume and length (used here as proxy of substrate complexity), and explored which seaweeds’ substrate attribute explained better varia…
Unmanned aerial vehicle technology to assess the state of threatened biogenic formations: The vermetid reefs of mediterranean intertidal rocky coasts
2021
Abstract Vermetid bioconstructions are biogenic formations, built by sessile gastropod molluscs belonging to the family Vermetidae worldwide distributed, occurring in the intertidal and upper subtidal in the rocky shores. In the Mediterranean basin, they occur in complex and tridimensional structures that enhance the local biodiversity, allowing to qualify the structuring species as ecosystem engineers. Due to their ecological relevance and considerable extension along the coasts, we assessed their structural complexity using unmanned aerial vehicle (UAV) technology, as tool of littoral cartography analysis of these bioconstructions, and plaster hemispheres dissolution as a descriptor index…
DOSE DEPENDENT SURVIVAL RESPONSE IN CHRONIC MYELOID LEUKEMIA UNDER CONTINUOUS AND PULSED TARGETED THERAPY
2010
A simulative study of cancer growth dynamics in patients affected by Chronic Myeloid Leukemia (CML), under the effect of a targeted dosedependent continuous or pulsed therapy, is presented. We have developed a model for the dynamics of CML in which thestochastic evolution of white blood cell populations are simulated by adopting a Monte Carlo approach. Several scenarios in the evolutionary dynamics of white blood cells, as a consequence of the efficacy of the different modelled therapies, pulsed or continuous, are described. The best results, in terms of a permanent disappearance of the leukemic phenotype, are achieved with a continuous therapy and higher dosage. However, our findings demon…
Birkhoff's aesthetics, Arnheim's entropy. Some remarks on complexity and fuzzy entropy in arts
2015
A judgement of aesthetic in arts is, by sheer consensus, a daunting task that requires evaluation of a whole host of endogenous and exogenous cultural factors. A few of them can actually provide very useful hints in tackling foundational problems in Information Science in a more natural setting than what is usually provided by a typical engineering stance. This interaction can however work the other way about, as instruments from the Information and Computer Science toolkit may help in focusing the less explored features of art and its evaluation. When all the social, historical, hermeneutical and political considerations are stripped from the living flesh of the piece, we lose most of wha…
On the Evaluation of Images Complexity: A Fuzzy Approach (revised and expanded)
2006
The inherently multidimensional problem of evaluating the complexity of an image is of a certain relevance in both computer sci- ence and cognitive psychology. Computer scientists usually analyze spa- tial dimensions, to deal with automatic vision problems, such as feature- extraction. Psychologists seem more interested in the temporal dimension of complexity, to explore attentional models. Is it possible, by merging both approaches, to define an more general index of visual complexity? We have defined a fuzzy mathematical model of visual complexity, using a specific entropy function; results obtained by applying this model to pictorial images have a strong correlation with ones from an exp…
Attentional vs computational complexity measures in observing paintings
2008
A general theoretical framework for designing cognitive architectures: Hybrid and meta-level architectures for BICA
2012
In this paper, we will discuss hybrid architectures in which different processing modules coexist and cooperate in a principled way. A fundamental and essential role is played by modules performing meta-computation, i.e., computation about computation itself. Meta-level architectures, therefore, become an essential complement of hybrid architectures for biologically inspired cognitive architectures (BICA). Engineering and modeling BICAs is a hard task due to the lack of techniques for developing and implementing their features. We propose a new concept of intelligent agent as a useful abstraction for developing BICAs and having means for representing all the involved entities together with …
Cognitive meta-learning of syntactically inferred concepts
2011
This paper outlines a proposal for a two-level cognitive architecture reproducing the process of abstract thinking in human beings. The key idea is the use of a level devoted to the extraction of compact representation for basic concepts, with additional syntactic inference carried on at a meta-level, in order to provide generalization. Higher-level concepts are inferred according to a principle of simplicity, consistent with Kolmogorov complexity, and merged back into the lower level in order to widen the underlying knowledge base.