Search results for " Complexity"
showing 10 items of 623 documents
Relative principal congruences in congruence-modular quasivarieties
1998
The problem of definability of relative principal congruences in relatively congruence modular (RCM) quasivarieties is investigated. The RCM quasivarieties are characterized in terms of parameterized families of finite sets of pairs of terms which define relative principal congruences.
Algebraic and logical characterizations of deterministic linear time classes
1997
In this paper an algebraic characterization of the class DLIN of functions that can be computed in linear time by a deterministic RAM using only numbers of linear size is given. This class was introduced by Grandjean, who showed that it is robust and contains most computational problems that are usually considered to be solvable in deterministic linear time.
Paths Coloring Algorithms in Mesh Networks
2003
In this paper, we will consider the problem of coloring directed paths on a mesh network. A natural application of this graph problem is WDM-routing in all-optical networks. Our main result is a simple 4-approximation algorithm for coloring line-column paths on a mesh. We also present sharper results when there is a restriction on the path lengths. Moreover, we show that these results can be extended to toroidal meshes and to line-column or column-line paths.
Multi-disciplinary, Inter-disciplinary, Anti-disciplinary. Transition Knowledges in Design Education
2023
The environmental issues are recently proving to be the center and the connecting element of all the states of crisis, only apparently diversified (energy, political, migration); after the lucid forward-looking analysis of Maldonado in the 70s, the vision proposed in 2019 by the exhibition Broken Nature opens new spaces to the “design hope” activated by design, emphasizing the broad responsibility that the designer must take on contemporary challenges. The complex scenarios of the “transition” (environmental, cultural, productive) are also based on the ability of disciplinary encroachment and on the most radical forms of “anti-disciplinary” innovation, which in some cases opens to design fo…
Reduced complexity models in the identification of dynamical networks: Links with sparsification problems
2009
In many applicative scenarios it is important to derive information about the topology and the internal connections of more dynamical systems interacting together. Examples can be found in fields as diverse as Economics, Neuroscience and Biochemistry. The paper deals with the problem of deriving a descriptive model of a network, collecting the node outputs as time series with no use of a priori insight on the topology. We cast the problem as the optimization of a cost function operating a trade-off between accuracy and complexity in the final model. We address the problem of reducing the complexity by fixing a certain degree of sparsity, and trying to find the solution that “better” satisfi…
Social differentiation and land use at an Early Iron Age “princely seat”: bioarchaeological investigations at the Glauberg (Germany)
2014
Excavations at the late Hallstatt/early La Tene (6th–4th century BC) “princely seat” of the Glauberg (Hesse, Germany) revealed exceptionally furnished graves in monumental mounds, simple inhumations in associated ditches and non-normative burials of up to eight individuals in conical storage pits. The study presented here addresses bioarchaeological characteristics of these burials and their implications for social differentiation and the sphere of influence of the “princely seat”. It includes osteological, aDNA, and multi-isotope analyses of 27 human individuals and faunal remains. One of the outstandingly rich graves (tumulus 1/grave 1) contained the skeleton of a young man (the “prince”)…
Ivory in the Chalcolithic enclosure of Perdigões (South Portugal): the social role of an exotic raw material
2015
AbstractThis article discusses the social role played by ivory and ivory articles in the Perdigoes enclosures (South Portugal) during the Chalcolithic (third millennium bc), in the context of the emergence and development of social complexity on the Iberian Peninsula. Perdigoes is a Portuguese prehistoric site with some of the highest concentrations of ivory objects known in Iberia and with the greatest variety. The contexts, almost exclusively funerary, are discussed along with the results of provenance studies. Comparing the different contexts and the categories of objects made of ivory makes it possible to distinguishing a variety of active social dimensions (such as individual status, g…
‘Adaptive cycles’ and climate fluctuations: a case study from Linear Pottery Culture in western Central Europe
2014
Abstract By applying cycle-based resilience theory the dynamics of the Early Neolithic west-central European Linear Pottery Culture (LBK) are investigated. These are interpreted as resulting from a combination of internal socio-economic processes as well as external environmental parameters. Resilience theory is helpful in understanding periods of increased vulnerability and inherent trends to social complexity. Cycles and threshold levels also help to understand why societies experience periods of increasing fragility and subsequent decline. Results are based on the correlation of a typology and dendrochronology-based archaeological chronology for western LBK and various palaeoclimatic pro…
Słabości eksplanacyjne teorii inteligentnego projektu
2021
Artykuł powstrzymuje się od polemiki merytorycznej z teorią inteligentnego projektu, dalej TIP, a jedynie wskazuje na jej niedostatki metodologiczne. Dowodzi, że wbrew twierdzeniom jej zwolenników TIP nie jest falsyfikowalna. W odróżnieniu od teorii ewolucji nie może pełnić nawet roli metafizycznego programu badawczego w sensie Poppera. Co jednak ważniejsze, TIP nie pełni żadnych funkcji eksplanacyjnych. W grę wchodzą jedynie wyjaśnienia intencjonalne, TIP zaś nie jest w stanie zidentyfikować motywów domniemanego projektanta. Argument jest zilustrowany przykładami zaczerpniętymi od Stanisława Lema, które pokazują, że możliwych jest wiele alternatywnych hipotez na temat celów domniemanego pr…
Morphology-based measurement of activation time in human atrial fibrillation
2003
The measurement of the activation time is crucial to allow the correct automatic analysis and classification of intracardiac electrograms recorded in the human atria during atrial fibrillation (AF). This study proposes a method which accounts for the morphology of bipolar signals. After ventricular artifact removal and activation wave recognition, the fiducial point of the activation wave was set at its local barycentre (LB). The method was tested on a set of 30 AF bipolar recordings of increasing complexity class; its performance was compared with that of the traditional methods of maximum peak (MP) or maximum slope (MS) estimation, taking the manual measurements performed by an expert car…