148 research outputs found
Faccionalismo y trabajo colectivo durante la Edad del Cobre peninsular
Este trabajo presenta un modelo político para la interpretación de los grandes poblados de la Edad del Cobre en la Península Ibérica. Considera que la competencia entre facciones en sociedades segmentarias genera las condiciones para el auge de procesos de agregación, y es a su vez la base de su debilidad, situación que frecuentemente provoca la fisión de los grupos. El momento clave para la consolidación del poder de los líderes faccionales es el momento inicial de movilización de trabajo colectivo. Caso de no consolidarse, la competencia entre facciones y el desarrollo de los intereses familiares multiplica los frentes de resistencia. El modelo se aplica al registro arqueológico regional y local del Alto Guadalquivir. Finalmente se sugiere que la dinámica de agregación a gran escala únicamente puede darse en aquellos lugares en los que exista suficiente población, recursos potenciales y la tecnología suficiente para su explotación y mantenimiento. Sin embargo, para explicar la variabilidad observada durante el Calcolítico de la Península Ibérica se requiere incorporar factores políticos.This contribution presents a political model for interpreting the large Copper Age settlements of the Iberian Peninsula. It considers that factional competition within segmentary societies creates conditions that both promote aggregational processes and undermine them (frequently leading to group fission). The critical moment when factional leaders may consolidate their power is the initial mobilization of a collective workforce. If such consolidation fails to take place, factional competition and the development of household interests multiplies the fronts on which resistance to leaders can take place. This model is applied to the archaeological record of the Upper Guadalquivir. The results of this analysis suggest that the dynamics of large-scale aggregation only can develop in places were there exists a sufficiently large population, abundant potential resources, and the technology by which resources and population can be exploited and maintained. A model that will explain the variability observed in the Iberian Copper Age must also consider political factors, however
Time for action. The chronology of mining events at Casa Montero (Madrid, Spain)
We present the radiocarbon dates for twelve charcoal samples covering the complete area of the mine fi eld
of Casa Montero (Madrid, Spain), a site with more than 4000 plotted shafts. The χ2 test shows that eleven
of them are statistically identical, with a 65% probability that all mining episodes occurred between 5337
and 5218 cal BC, a time span of approximately four generations. We test this probable hypothesis against
other archaeological evidence and conclude that the comparatively large scale mining actions at Casa
Montero would have necessarily required the mobilization of several small scale Early Neolithic groups
into a succession of collective actions, probably performed in a seasonal manner. Neolithic fl int mining in
Europe was not a long term technical solution to a practical need, but an extraordinarily meaningful and
timely -historically contingent- social activity. In order to understand mining actions in these terms, we would
require a reevaluation of the statistical variability and meaning of series of radiocarbon dates already obtained
at many other fl int mines. When we do so, we might observe that, as in the case of Casa Montero, many of
these radiocarbon dates actually represent sets of short term highly active ‘generational’ mining episodes
separated in time
Computing the Component-Labeling and the Adjacency Tree of a Binary Digital Image in Near Logarithmic-Time
Connected component labeling (CCL) of binary images is
one of the fundamental operations in real time applications. The adjacency
tree (AdjT) of the connected components offers a region-based
representation where each node represents a region which is surrounded
by another region of the opposite color. In this paper, a fully parallel
algorithm for computing the CCL and AdjT of a binary digital image
is described and implemented, without the need of using any geometric
information. The time complexity order for an image of m × n pixels
under the assumption that a processing element exists for each pixel is
near O(log(m+ n)). Results for a multicore processor show a very good
scalability until the so-called memory bandwidth bottleneck is reached.
The inherent parallelism of our approach points to the direction that
even better results will be obtained in other less classical computing
architectures.Ministerio de Economía y Competitividad MTM2016-81030-PMinisterio de Economía y Competitividad TEC2012-37868-C04-0
Advances, problems and perspectives in the study of social inequality in Iberian Late Prehistory
This paper attempts a general assessment of the contributions included in this volume. We examine three main kinds of problems related to the research on social inequality in Iberian Late Prehistory. These are theoretical, empirical and interpretative. Among the first, we comment upon the very definition of social inequality, the taxonomical categories employed in social evolution, as well as the main factors causing inequality, with special attention to labour force mobilisation. Among the second, we highlight some weaknesses of the Iberian archaeological record for the investigation of the subject matter, such as the limitations of the absolute chronology or the settlement record. Finally, we discuss the propositions that have been put forward to understand the forms that social inequality took among Neolithic, Copper and Bronze Age communities, concluding that Iberian archaeologists would much benefit from a comparative perspective.Peer reviewe
Editorial: Trabajos de Prehistoria, a hombros de gigantes
The editorial opens the four-year period of the current editorial team of Trabajos de Prehistoria, assessing the leading role of the members of the previous Editorial and Advisory Boards, external reviewers and authors in the trajectory of the journal’s growing internationalization.It highlights the impetus given by Professor Antonio Gilman, outgoing editor and the first one that does not belong to a Spanish institution.We consider the implications of the generational change under way in the Spanish academy may have on the visibility of the journals and the role of an open, public and collective space for scientific communication exerted by Trabajos de Prehistoria.El editorial inicia el cuatrienio del actual equipo de la revista Trabajos de Prehistoria, valorando el protagonismo de los miembros de los anteriores Consejos de Redacción y Asesor, evaluadores externos y autores en la trayectoria de creciente internacionalización de la revista. Se destaca el impulso que el Profesor Antonio Gilman, director saliente y el primero no perteneciente a una institución española, ha dado a esa trayectoria. Se reflexiona sobre las implicaciones que el cambio generacional en curso en la academia española puede tener en la visibilidad de las revistas y se reivindica el papel de un espacio abierto, público y colectivo de comunicación científica como el ejercido por Trabajos de Prehistoria
Generating Second Order (Co)homological Information within AT-Model Context
In this paper we design a new family of relations between
(co)homology classes, working with coefficients in a field and starting
from an AT-model (Algebraic Topological Model) AT(C) of a finite cell
complex C These relations are induced by elementary relations of type
“to be in the (co)boundary of” between cells. This high-order connectivity
information is embedded into a graph-based representation model,
called Second Order AT-Region-Incidence Graph (or AT-RIG) of C. This
graph, having as nodes the different homology classes of C, is in turn,
computed from two generalized abstract cell complexes, called primal
and dual AT-segmentations of C. The respective cells of these two complexes
are connected regions (set of cells) of the original cell complex C,
which are specified by the integral operator of AT(C). In this work in
progress, we successfully use this model (a) in experiments for discriminating
topologically different 3D digital objects, having the same Euler
characteristic and (b) in designing a parallel algorithm for computing
potentially significant (co)homological information of 3D digital objects.Ministerio de Economía y Competitividad MTM2016-81030-PMinisterio de Economía y Competitividad TEC2012-37868-C04-0
Homological Region Adjacency Tree for a 3D Binary Digital Image via HSF Model
Given a 3D binary digital image I, we define and compute
an edge-weighted tree, called Homological Region Tree (or Hom-Tree,
for short). It coincides, as unweighted graph, with the classical Region
Adjacency Tree of black 6-connected components (CCs) and white 26-
connected components of I. In addition, we define the weight of an edge
(R, S) as the number of tunnels that the CCs R and S “share”. The
Hom-Tree structure is still an isotopic invariant of I. Thus, it provides
information about how the different homology groups interact between
them, while preserving the duality of black and white CCs.
An experimentation with a set of synthetic images showing different
shapes and different complexity of connected component nesting is performed
for numerically validating the method.Ministerio de Economía y Competitividad MTM2016-81030-
Toward Parallel Computation of Dense Homotopy Skeletons for nD Digital Objects
An appropriate generalization of the classical notion of
abstract cell complex, called primal-dual abstract cell complex (pACC
for short) is the combinatorial notion used here for modeling and analyzing
the topology of nD digital objects and images. Let D ⊂ I be a set of
n-xels (ROI) and I be a n-dimensional digital image.We design a theoretical
parallel algorithm for constructing a topologically meaningful asymmetric
pACC HSF(D), called Homological Spanning Forest of D (HSF
of D, for short) starting from a canonical symmetric pACC associated
to I and based on the application of elementary homotopy operations
to activate the pACC processing units. From this HSF-graph representation
of D, it is possible to derive complete homology and homotopy
information of it. The preprocessing procedure of computing HSF(I) is
thoroughly discussed. In this way, a significant advance in understanding
how the efficient HSF framework for parallel topological computation of
2D digital images developed in [2] can be generalized to higher dimension
is made.Ministerio de Economía y Competitividad TEC2016-77785-PMinisterio de Economía y Competitividad MTM2016-81030-
A parallel Homological Spanning Forest framework for 2D topological image analysis
In [14], a topologically consistent framework to support parallel topological analysis and recognition for2 D digital objects was introduced. Based on this theoretical work, we focus on the problem of findingefficient algorithmic solutions for topological interrogation of a 2 D digital object of interest D of a pre- segmented digital image I , using 4-adjacency between pixels of D . In order to maximize the degree ofparallelization of the topological processes, we use as many elementary unit processing as pixels theimage I has. The mathematical model underlying this framework is an appropriate extension of the clas- sical concept of abstract cell complex: a primal–dual abstract cell complex (pACC for short). This versatiledata structure encompasses the notion of Homological Spanning Forest fostered in [14,15]. Starting froma symmetric pACC associated with I , the modus operandi is to construct via combinatorial operationsanother asymmetric one presenting the maximal number of non-null primal elementary interactions be- tween the cells of D . The fundamental topological tools have been transformed so as to promote anefficient parallel implementation in any parallel-oriented architecture (GPUs, multi-threaded computers,SIMD kernels and so on). A software prototype modeling such a parallel framework is built.Ministerio de Educación y Ciencia TEC2012-37868-C04-02/0
Labeling Color 2D Digital Images in Theoretical Near Logarithmic Time
A design of a parallel algorithm for labeling color flat zones
(precisely, 4-connected components) of a gray-level or color 2D digital
image is given. The technique is based in the construction of a particular
Homological Spanning Forest (HSF) structure for encoding topological
information of any image.HSFis a pair of rooted trees connecting the image
elements at inter-pixel level without redundancy. In order to achieve a correct
color zone labeling, our proposal here is to correctly building a sub-
HSF structure for each image connected component, modifying an initial
HSF of the whole image. For validating the correctness of our algorithm,
an implementation in OCTAVE/MATLAB is written and its results are
checked. Several kinds of images are tested to compute the number of iterations
in which the theoretical computing time differs from the logarithm
of the width plus the height of an image. Finally, real images are to be computed
faster than random images using our approach.Ministerio de Economía y Competitividad TEC2016-77785-PMinisterio de Economía y Competitividad MTM2016-81030-
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