Polymer Measure: Varadhan's Renormalization Revisited

Through chaos decomposition we improve the Varadhan estimate for the rate of convergence of the centered approximate self-intersection local time of planar Brownian motion.Comment: 5 page

Multi-mobile robot and avoidance obstacle to spatial mapping in indoor environment

The advancement of technology and techniques applied to robotics contributes to increasing the quality of life and safety of humanity. One of the most widespread applications of mobile robotics is related to monitoring indoor environments. However, due to factors such as the size of the environment impacting the monitoring response, battery autonomy, and autonomous navigation in environments with unknown obstacles, they are still significant challenges in the diffusion of mobile robotics in these areas. Strategy adopting multiple robots can overcome these challenges. This work presents an approach to use multi-robots in hazardous environments with gas leakage to perform spatial mapping of the gas concentration. Obstacles arranged in the environment are unknown to robots, then a fuzzy control approach is used to avoid the collision. As a result of this paper, spatial mapping of an indoor environment was carried out with multi-robots that reactively react to unknown obstacles considering a point gas leak with Gaussian dispersion.This work has been supported by FCT - Fundação para a Ciência e Tecnologia within the Project Scope: UIDB/05757/2020. Additionally, this work was supported in part by the National Counsel of Technological and Scientific Development of Brazil (CNPq), in part by the Coordination for the Improvement of Higher Level People (CAPES).info:eu-repo/semantics/publishedVersio

Modelos de distribuição de Zygodontomys brevicauda (Allen & Chapman, 1893) (Mammalia: Muridae) nas savanas de Roraima, norte do Brasil

The present study describes the distribution of Zygodontomys brevicauda (Rodentia, Sigmodontinae) relating the presence/absence of the species to a digital database on the vegetation of savannas of the northeastern State of Roraima , Brazil. The study area is situated in the Surumu River region, between 03o58’- 04o27’N and 60o13’-61o16’W, and is composed mainly of savanna formations. In a total effort of 9479 trap days, the trap success for Z. brevicauda was 0.57%. The probability of capture of the species was calculated for each trap station through logistic regression, using structural characteristics of each habitat. The association of capture probabilities with different habitat classes using a LANDSAT-TM satellite image allowed a spatial view of the potential distribution of the species considering the habitat mosaic of the region. The species is at least partially dependent on the savanna-forest boundary. The models show a high frequency of apparently unsuitable areas, especially of open and closed savannas, which might suggest that habitat occupancy is far from saturated. Zygodontomys brevicauda appears to be a colonizing species, and was shown to be associated particularly with the edges of the gallery forests. This habitat type may act as source habitats for open savannas.O presente estudo avalia a distribuição potencial de Zygodontomys brevicauda (Rodentia, Sigmodontinae) relacionando a presença/ausência da espécie através de uma base digital de dados sobre a vegetação das savanas do nordeste do Estado de Roraima, Brasil. A área de estudo situa-se na região do Alto e Médio Rio Surumu (3o58’-4o27’N; 60o13’-61o16’W) e é composta por várias formações, sendo mais extensas as de savana. Foram empregadas 9.479 armadilhas-dia e o sucesso de captura de Z. brevicauda foi de 0.57%. As probabilidades de captura da espécie foram calculadas para cada estação de captura através de regressões logísticas utilizando variáveis estruturais dos hábitats. As associações das probabilidades de captura com as diferentes classes de hábitats, reconhecidas via imagem de satélite LANDSAT-TM, permitiram avaliar a distribuição potencial da espécie no mosaico de hábitats da região. A espécie está parcialmente associada às áreas de contato savana-floresta. O modelo evidenciou alta freqüência de áreas potencialmente vagas, especialmente nas savanas arbóreas abertas e graminosas, sugerindo forte insaturação dos hábitats. Zygodontomys brevicauda é potencialmente uma espécie colonizadora dessas classes de hábitats, com as áreas de borda das matas de galeria atuando como hábitats-fonte para as savanas abertas

Managing QoS in a NGN using a PBM approach

Next Generation Network (NGN) management represents an enormous challenge due to the large number of managed elements, the variety of roles the managed entities play in the network and the difficulty of orchestrating management actions. Several NGN standardization bodies point toward Policy Based Management as the best approach for NGN network management. This paper describes a management solution for a NGN IP Multimedia Subsystem (IMS) QoS management scenario based on WBEM technology. The proposal is for a WBEM-based policy server, a graphical policy editor application and instrumentation logic for the NGN QoS Management. The graphical policy editor reduces the learning curve imposed by the policy specification language, allowing the specification of policies through a rich and user-friendly visual interface, hiding the CIM syntax complexity but keeping CIM’s potential

Reducing the cost of group communication with semantic view synchrony

View Synchrony (VS) is a powerful abstraction in the design and implementation of de- pendable distributed systems. By ensuring that processes deliver the same set of messages in each view, it allows them to maintain consistency across membership changes. However, experience indicates that it is hard to combine strong reliability guarantees as offered by VS with stable high performance. In this paper we propose a novel abstraction, Semantic View Synchrony (SVS), that exploits the application's semantics to cope with high throughput applications. This is achieved by allowing some messages to be dropped while still preserving consistency when new views are installed. Thus, SVS inherits the elegance of view synchronous communi- cation. The paper describes how SVS can be implemented and illustrates its usefulness in the context of distributed multi-player games

Semantically reliable multicast protocols

Reliable multicast protocols can strongly simplify the design of distributed applications. However it is hard to sustain a high multicast throughput when groups are large and heterogeneous. In an attempt to overcome this limitation, previous work has focused on weakening reliability properties. The authors introduce a novel reliability model that exploits semantic knowledge to decide in which specific conditions messages can be purged without compromising application correctness. This model is based on the concept of message obsolescence: a message becomes obsolete when its content or purpose is overwritten by a subsequent message. We show that message obsolescence can be expressed in a generic way and can be used to configure the system to achieve higher multicast throughput.Supported by the 234/J4 Franco/Portuguese Grant and by Praxis/ C/ EEI/ 12202/ 1998, TOPCO

Semantically reliable multicast: current status and future work

In multicast communication systems, a single perturbed recipient can drastically affect the performance of a complete group of processes. One way to alleviate this problem is to weakeri reliability requirements by aliowing some messages to be omitted. We propose a multicast service that exploits semantic knowledge to select which messges can be omitted without compromising the application's correctness. This service is basecf on the concept of message obsolescence: A message becomes obsolete when its content is overwritten or implicitly conveyed by a subsequent message. Besides summarizing initial research results [10] showing that message obsolescence can be expressed in a generic way imd can be used to achieve a higher stable throughput, this text advances a definition of the service and outlines our current research directions

Juvenile hormone downregulates vitellogenin production in Ectatomma tuberculatum (Hymenoptera: Formicidae) sterile workers

In the ant Ectatomma tuberculatum (Olivier 1792), workers have active ovaries and lay trophic eggs that are eaten by the queen and larvae. Vitellogenins are the main proteins found in the eggs of insects and are the source of nutrients for the embryo in the fertilized eggs and for adults in the trophic eggs. In social insects, vitellogenin titres vary between castes and affect reproductive social status, nursing, foraging, longevity, somatic maintenance, and immunity. In most insects, vitellogenin synthesis is mainly regulated by juvenile hormone. However, in non-reproductive worker ants, this relationship is poorly characterized. This study determined the effects of juvenile hormone on vitellogenin synthesis in non-reproductive E. tuberculatum workers. Juvenile hormone was topically applied onto workers, and the effect on vitellogenin synthesis in the fat body and vitellogenin titres in the haemolymph were analysed by ELISA and qPCR. Juvenile hormone downregulated protein synthesis and reduced vitellogenin titres in the haemolymph, suggesting that in workers of E. tuberculatum, juvenile hormone loses its gonadotrophic function

Sistema de apoio à decisão para o transporte não urgente de doentes em veículo partilhado

O transporte não urgente de doentes em Portugal foi alvo de reformulação legislativa de modo a reduzir os custos que acarretava. Neste artigo apresentam-se métodos heurísticos para a formação de agrupamentos de doentes a serem transportados na mesma viatura. São apresentados resultados computacionais que validam os algoritmos desenvolvidos. Os algoritmos podem ser facilmente integrados num sistema de apoio à decisão.Fundação para a Ciência e a Tecnologia (FCT)COMPETE Programa Operacional Fatores de Competitividade (POFC) Ref FCOMP-01-0124-FEDER-02060