Distributed splitting of constraint satisfaction problems

Constraint propagation aims to reduce a constraint satisfaction problem into an equivalent but simpler one. However, constraint propagation must be interleaved with a splitting mechanism in order to compose a complete solver. In~cite{monfroy:sac2000 a framework for constraint propagation based on a control-driven coordination model was presented. In this paper we extend this framework in order to integrate a distributed splitting mechanism. This technique has three main advantages: 1),in a single distributed and generic framework, propagation and splitting can be interleaved in order to realize complete distributed solvers, 2), by changing only one agent, we can perform different kinds of search, and 3), splitting of variables can be dynamically triggered before the fixed point of a propagation is reached

Desenvolvimento e implementação de um protótipo para acesso e consulta de imagens médicas em equipamentos móveis no padrão DICOM

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência da Computação

The Visigothic Kingdom

How did the breakdown of Roman rule in the Iberian Peninsula eventually result in the formation of a Visigothic kingdom with authority centralised in Toledo? This collection of essays challenges the view that local powers were straightforwardly subjugated to the expanding central power of the monarchy. Rather than interpret countervailing events as mere ‘delays’ in this inevitable process, the contributors to this book interrogate where these events came from, which causes can be uncovered and how much influence individual actors had in this process. What emerges is a story of contested interests seeking cooperation through institutions and social practices that were flexible enough to stabilise a system that was hierarchical yet mutually beneficial for multiple social groups. By examining the Visigothic settlement, the interplay between central and local power, the use of ethnic identity, projections of authority, and the role of the Church, this book articulates a model for understanding the formation of a large and important early medieval kingdom

The Role of Commutativity in Constraint Propagation Algorithms

Constraint propagation algorithms form an important part of most of the constraint programming systems. We provide here a simple, yet very general framework that allows us to explain several constraint propagation algorithms in a systematic way. In this framework we proceed in two steps. First, we introduce a generic iteration algorithm on partial orderings and prove its correctness in an abstract setting. Then we instantiate this algorithm with specific partial orderings and functions to obtain specific constraint propagation algorithms. In particular, using the notions commutativity and semi-commutativity, we show that the {\tt AC-3}, {\tt PC-2}, {\tt DAC} and {\tt DPC} algorithms for achieving (directional) arc consistency and (directional) path consistency are instances of a single generic algorithm. The work reported here extends and simplifies that of Apt \citeyear{Apt99b}.Comment: 35 pages. To appear in ACM TOPLA

The Visigothic Kingdom

How did the breakdown of Roman rule in the Iberian Peninsula eventually result in the formation of a Visigothic kingdom with authority centralised in Toledo? This collection of essays challenges the view that local powers were straightforwardly subjugated to the expanding central power of the monarchy. Rather than interpret countervailing events as mere ‘delays’ in this inevitable process, the contributors to this book interrogate where these events came from, which causes can be uncovered and how much influence individual actors had in this process. What emerges is a story of contested interests seeking cooperation through institutions and social practices that were flexible enough to stabilise a system that was hierarchical yet mutually beneficial for multiple social groups. By examining the Visigothic settlement, the interplay between central and local power, the use of ethnic identity, projections of authority, and the role of the Church, this book articulates a model for understanding the formation of a large and important early medieval kingdom

Urban Interactions

"This volume is dedicated to eliciting the interactions between localities across late antique and early medieval Europe and the wider Mediterranean. Significant research has been done in recent years to explore how late “Roman” and post-“Roman” cities, towns and other localities communicated vis-à-vis larger structural phenomena, such as provinces, empires, kingdoms, institutions and so on. This research has contributed considerably to our understanding of the place of the city in its context, but tends to portray the city as a necessarily subordinate conduit within larger structures, rather than an entity in itself, or as a hermeneutical object of enquiry. Consequently, not enough research has been committed to examining how local people and communities thought about, engaged with, and struggled against nearby or distant urban neighbors. Urban Interactions addresses this lacuna in urban history by presenting articles that apply a diverse spectrum of approaches, from archaeological investigation to critical analyses of historiographical and historical biases and developmental consideration of antagonisms between ecclesiastical centers. Through these avenues of investigation, this volume elucidates the relationship between the urban centers and their immediate hinterlands and neighboring cities with which they might vie or collaborate. This entanglement and competition, whether subterraneous or explicit across overarching political, religious or other macro categories, is evaluated through a broad geographical range of late “Roman” provinces and post-“Roman” states to maintain an expansive perspective of developmental trends within and about the city.

Helmintofauna gastrointestinal em aves de rapina no Estado do Pará.

Parasitos do trato digestório são frequentemente detectados nestas aves, porém o conhecimento da helmintofauna em aves de rapina no Brasil ainda é incipiente. Portanto, o objetivo deste trabalho é investigar a helmintofauna gastrointestinal de aves de rapina que ocorrem no Estado do Pará, Brasil. Foram utilizadas 33 carcaças e helmintos regurgitados por um indivíduo, totalizando 34 indivíduos de 14 espécies: Megascops choliba (n=10), Rupornis magnirostris (n=8), Tyto furcata (n=5), Megascops usta (n=1), Athene cunicularia (n=1), Ibycter americanus (n=1), Asio clamator (n=1), Geranoaetus albicaudatus (n=1), Caracara plancus (n=1), Gampsonyx swainsonii (n=1), Buteogallus schistaceus (n=1), Micrastur ruficollis (n=1), Falco rufigularis (n=1) e Elanoides forficatus (n=1). Foi verificado 73,5% (n=20) de parasitismo nos exemplares analisados. A helmintofauna gastrointestinal apresentou grande riqueza de espécies, totalizando 12 táxons: os nematódeos Porrocaecum angusticolle em C. plancus, Subulura forcipata e Dispharynx sp. em M. choliba, Microtetrameres sp. em R. magnirostris e Procyrnea sp. em B. schistaceus; os trematódeos Platynosomum illiciens em M. choliba, T. furcata e G. swainsonii, Athesmia sp. em G. albicaudatus e Strigea sp. em R. magnirostris; e os acantocéfalos Centrorhynchus kuntzi em R. magnirostris, Centrorhynchus millerae em E. furficatus, Centrorhynchus guira e Centrorhynchus sp. em M. choliba. Nenhum cestódeo foi encontrado. As carcaças de M. usta, A. clamator, A. cunicularia, I. americanus, M. ruficollis e F. rufigularis não apresentaram helmintos gastrointestinais. C. guira e P. angusticolle representam novas ocorrências no território brasileiro e no Estado do Pará, estendendo seu alcance geográfico. São considerados novos hospedeiros: M. choliba para C. guira e S. forcipata; E. forficatus para C. millerae; B. schistaceus para Procyrnea sp.; C. plancus para P. angusticolle; G. albicaudatus para Athesmia sp.; e M. choliba e G. swainsonii para P. illiciens. Estes resultados reforçam a necessidade de ampliar as pesquisas no campo da parasitologia de aves de rapina no Brasil e, particularmente, no Estado do Pará.Parasites of digestive tract are frequently detected in these birds, but the knowledge of helminthofauna in birds of prey in Brazil is still incipient. Therefore the objective of this work is to investigate the gastrointestinal helminthofauna of birds of prey that occur in the State of Pará, Brazil. 33 carcasses and helminths regurgitated by one individual were used, totaling 34 individuals of 14 species: Megascops choliba (n = 10), Rupornis magnirostris (n = 8), Tyto furcata (n = 5), Megascops usta (n = 1), Athene cunicularia (n = 1), Ibycter americanus (n =1), Asio clamator (n = 1), Geranoaetus albicaudatus (n = 1), Caracara plancus (n = 1), Gampsonyx swainsonii (n = 1), Buteogallus schistaceus (n = 1), Micrastur ruficollis (n = 1), Falco rufigularis (n = 1) and Elanoides forficatus (n = 1). There was 73.5% (n = 20) of parasitism in the analyzed specimens. The gastrointestinal helminthofauna presented a great richness of species, totaling 12 taxa: the nematodes Porrocaecum angusticolle in C. plancus, Subulura forcipata and Dispharynx sp. in M. choliba, Microtetrameres sp. in R. magnirostris and Procyrnea sp. in B. schistaceus; the trematodes Platynosomum illiciens in M. choliba, T. furcata and G. swainsonii, Athesmia sp. in G. albicaudatus and Strigea sp. in R. magnirostris; and the acanthocephalans Centrorhynchus kuntzi in R. magnirostris, Centrorhynchus millerae in E. furficatus, Centrorhynchus guira and Centrorhynchus sp. in M. choliba. No cestodes were found. The carcasses of M. usta, A. clamator, A. cunicularia, I. americanus, M. ruficollis and F. rufigularis did not show gastrointestinal helminths. C. guira and P. angusticolle represent new occurrences in the Brazilian territory and in the State of Pará, extending their geographic reach. New hosts are considered: M. choliba for C. guira and S. forcipata; E. forficatus for C. millerae; B. schistaceus for Procyrnea sp.; C. plancus for P. angusticolle; G. albicaudatus for Athesmia sp .; and M. choliba and G. swainsonii for P. illiciens. These results reinforce the need to expand research in the field of birds of prey parasitology in Brazil and, particularly, in the State of Pará

Università e territorio. Studi e progetti per l’ambito urbano lecchese nel decennale del corso di laurea ingegneria edile-architettura

ll volume, realizzato a integrazione e supporto dell’omonima mostra ideata e realizzata da Marco Muscogiuri e Piero Poggioli (Lecco, Scuderie di Villa Manzoni, Febbraio-Marzo 2009), raccoglie i testi redatti dai docenti del Politecnico di Milano e documenta il lavoro di studio, di analisi e di progetto, sviluppato sul territorio lecchese nell’ambito della didattica e della ricerca universitaria