20,702 research outputs found
Fast Consensus under Eventually Stabilizing Message Adversaries
This paper is devoted to deterministic consensus in synchronous dynamic
networks with unidirectional links, which are under the control of an
omniscient message adversary. Motivated by unpredictable node/system
initialization times and long-lasting periods of massive transient faults, we
consider message adversaries that guarantee periods of less erratic message
loss only eventually: We present a tight bound of for the termination
time of consensus under a message adversary that eventually guarantees a single
vertex-stable root component with dynamic network diameter , as well as a
simple algorithm that matches this bound. It effectively halves the termination
time achieved by an existing consensus algorithm, which also works under
our message adversary. We also introduce a generalized, considerably stronger
variant of our message adversary, and show that our new algorithm, unlike the
existing one, still works correctly under it.Comment: 13 pages, 5 figures, updated reference
Minor salivary gland sialolithiasis: a clinical diagnostic challenge
Sialolithiasis is a non-neoplastic salivary gland disease that rarely affects the minor salivary glands. There are no guidelines in the literature which can suggest which is the best surgical approach to treat Minor Salivary Glands Sialolithiasis (MSGL). The present case was of a 48-year-old male patient complaining of painful swelling localized in the left back-commissural zone which was 0.5 mm in diameter, for which surgical enucleation approach was done and in that some small calcific masses ranging from 0.2 to 4 mm in diameter were found. They were surrounded by granulation tissue and associated with small pus oozing. Histopathological examination was carried out leading to a final diagnosis of MSGL
MeV Neutron Production from Thermal Neutron Capture in {6}^Li Simulated with Geant4
Various Li compounds are commonly used at neutron facilities as neutron
absorbers. These compounds provide one of the highest ratios of neutron
attenuation to -ray production. Unfortunately, the usage of these
compounds can also give rise to fast neutron emission with energies up to
almost 16 MeV. Historically, some details in this fast neutron production
mechanism can be absent from some modeling packages under some optimization
scenarios. In this work, we tested Geant4 to assess the performance of this
simulation toolkit for the fast neutron generation mechanism. We compare the
results of simulations performed with Geant4 to available measurements. The
outcome of our study shows that results of the Geant4 simulations are in good
agreement with the available measurements for Li fast neutron production,
and suitable for neutron instrument background evaluation at spallation neutron
sources.Comment: 6 pages, 3 figures, Proceeding of The Sixth European Conference on
Neutron Scattering, Zaragoza Spain, August 30 to September 4 201
Loss of diversity in the community of small mammals of Doñana National Park (SW Spain): another effect of the local climate change ?
Doñana National Park is an important wetland located in the southwest Spain forming part of the Mediterranean Basin, a "biodiversity hotspot" especially vulnerable to climate change. In this study, we investigate changes in diversity and abundance occurred between 1978 and 2016 in the community of small mammals of Doñana and their relationship with local climate changes. Capture-mark-recapture methods were carried out for a total of 16 years, unevenly distributed over four decades. Our findings show a consistent loss of diversity and abundance decline in the community of small mammals. Eliomys quercinus and Rattus rattus have almost disappeared from the area and Apodemus sylvaticus has sharply reduced its abundance parallel to the progressive increase of Mus spretus. Such a process is worrying for conservation as small mammals represent, after rabbits, the most important prey for carnivores and raptors in Doñana. The detected changes could be at least partially explained by the progressive increase in local temperature observed during the study period. In line with this, the species that have suffered a greater decline are those of Eurasian origin and northern distribution as is the case for E. quercinus and R. rattus while the current dominant species, M. spretus, proceeds from Africa and has a Mediterranean distribution. A non-exclusive alternative is that the extreme rarefaction of rabbits may have caused a trophic cascade effect enhancing predation by carnivores and raptors towards gradually smaller species.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
Quantum Baker Maps for Spiraling Chaotic Motion
We define a coupling of two baker maps through a pi/2 rotation both in
position and in momentum. The classical trajectories thus exhibit spiraling, or
loxodromic motion, which is only possible for conservative maps of at least two
degrees of freedom. This loxodromic baker map is still hyperbolic, that is,
fully chaotic. Quantization of this map follows on similar lines to other
generalized baker maps. It is found that the eigenvalue spectrum for quantum
loxodromic baker map is far removed from those of the canonical random matrix
ensembles. An investigation of the symmetries of the loxodromic baker map
reveals the cause of this deviation from the Bohigas-Giannoni-Schmit
conjecture
Bones in the Landfill: A Zooarchaeological Study from Faneuil Hall
Using data from recent archaeological excavations at Faneuil Hall in Boston, this thesis examines how an 18th-century urban landfill context can be used towards understanding the broader foodways of a city community. Much of today\u27s urban landscape has been artificially created over time, often through the efforts of communities to fill land and dispose of their garbage, and it is important for archaeologists to utilize these contexts in meaningful ways. The Town Dock was gradually filled in with the daily trash of the merchants, shop-keepers, and other residents of the nearby community, and the faunal assemblage gives us a glimpse into the everyday foodways of that Boston community. Domestic mammal meat was the dietary staple, and was augmented by small quantities of domestic and wild birds, saltwater fish and shellfish
elewexe – Building 172B, California Polytechnic State University – San Luis Obispo
California Polytechnic State University at San Luis Obispo recently finished constructing a new multimillion student housing project on campus. One of the six buildings, elewexe or 172B, from this housing complex was selected for a full evaluation of the fire and life safety systems using both prescriptive and performance based approaches. The building is a Type II-B four story dormitory with an R-2 occupancy classification.
For the prescriptive approach, the building was evaluated against the most current editions of the IBC and relevant NFPA code editions for building requirements, sprinkler design and fire alarm and detection. When looking at the building purely for code compliance, everything complies except for administrative controls. The building is constructed within the specifications of the IBC, the egress is adequate for the building, the sprinkler system has a proper design and a strong water supply without a fire pump, and the fire alarm and detection system meets the requirements listed in NFPA 72. One aspect of the building, that is also found in the other buildings within the housing community, is that there are unenclosed stairwells connecting four stories located within the core of the buildings. This is allowed per the 2013 version of the CBC due to an exception because the building is fully sprinklered. This exception causes a lot of emphasis to be put on the sprinklers operating in the event of a fire.
For the performance based analysis is composed of three design fires and a fire model within the report investigates one of the design fire scenarios occurring within the main core and the sprinklers not activating to see if the building design still meets the intent of the code. The results found that in such an event, the available safe egress time (ASET) was less than the required safe egress time (RSET), meaning that in the event that the sprinklers fail in a fire scenario in the core of the building, the building design fails in the intent of the code. Ways to remedy this include increasing administrative controls to limit the amount of fuel in the corridor, increasing testing and maintenance of the sprinkler system to ensure that it functions when needed, an impairment control policy, and adding compartmentation within the building to separate the core stairwell from the rest of the building
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