1,375 research outputs found
Exploring quality-aware architectural transformations at run-time: the ENIA case
Adapting software systems at run-time is a key issue, especially when these systems consist of components used as intermediary for human-computer interaction. In this sense, model transformation techniques have a widespread acceptance as a mechanism for adapting and evolving the software architecture of such systems. However, existing model transformations often focus on functional requirements, and quality attributes are only manually considered after the transformations are done. This paper aims to improve the quality of adaptations and evolutions in component-based software systems by taking into account quality attributes within the model transformation process. To this end, we present a quality-aware transformation process using software architecture metrics to select among many alternative model transformations. Such metrics evaluate the quality attributes of an architecture. We validate the presented quality-aware transformation process in ENIA, a geographic information system whose user interfaces are based on coarsegrained components and need to be adapted at run-time
Solving the brachistochrone and other variational problems with soap films
We show a method to solve the problem of the brachistochrone as well as other
variational problems with the help of the soap films that are formed between
two suitable surfaces. We also show the interesting connection between some
variational problems of dynamics, statics, optics, and elasticity.Comment: 16 pages, 11 figures. This article, except for a small correction,
has been submitted to the American Journal of Physic
Modular invariant models of lepton masses at levels 4 and 5
We explore alternative descriptions of the charged lepton sector in modular
invariant models of lepton masses and mixing angles. In addition to the modulus, the
symmetry breaking sector of our models includes ordinary
flavons. Neutrino mass terms
depend only on the modulus and are tailored to minimize the number of free parameters.
The charged lepton Yukawa couplings rely upon the
flavons alone. We build modular
invariant models at levels 4 and 5, where neutrino masses are described both in terms of the
Weinberg operator or through a type I seesaw mechanism. At level 4, our models reproduce
the hierarchy among electron, muon and tau masses by letting the weights play the role
of Froggatt-Nielsen charges. At level 5, our setup allows the treatment of left and right
handed charged leptons on the same footing. We have optimized the free parameters of our
models in order to match the experimental data, obtaining a good degree of compatibility
and predictions for the absolute neutrino masses and the CP violating phases. At a more
fundamental level, the whole lepton sector could be correctly described by the simultaneous
presence of several moduli. Our examples are meant to make a first step in this direction.This project has received support in part by the MIUR-PRIN project 2015P5SBHT 003
\Search for the Fundamental Laws and Constituents" and by the European Union's Horizon
2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement Nº 674896 and 690575. The research of F. F. was supported in part by the INFN. The
research of J. C. C. was supported by the Spanish MINECO project FPA2016-78220-C3-
1-P, the Junta de Andalucía grant FQM101 and the Spanish MECD grant FPU14
Topical Application of Imiquimod as a Treatment for Chromoblastomycosis
Peer reviewedPublisher PD
A method to construct refracting profiles
We propose an original method for determining suitable refracting profiles
between two media to solve two related problems: to produce a given wave front
from a single point source after refraction at the refracting profile, and to
focus a given wave front in a fixed point. These profiles are obtained as
envelopes of specific families of Cartesian ovals. We study the singularities
of these profiles and give a method to construct them from the data of the
associated caustic.Comment: 12 pages, 5 figure
Classification of Chimney EVAR-Related Endoleaks: Insights from the PERICLES Registry
Juxtarenal aortic aneurysms (JAAs) pose significant challenges for endovascular aneurysm repair (EVAR). A short or absent infrarenal neck typically excludes standard EVAR as a viable or reasonable treatment option. In this context, the use of chimney grafts (chEVAR) is gaining in popularity and applicability. These grafts are designed to course in the aortic lumen outside the main stent-graft to maintain normal perfusion to the involved target branches. As such, they may represent a promising and less resource-intensive option for management of JAAs. However, this technical strategy is not without challenges of its own, particularly the inevitable creation of \u201cgutters\u201d that result from the interaction of the chimney graft with the main aortic stent-graft. These gutters can become a conduit for type Ia endoleak formation, hence they represent the Achilles\u2019 heel of chEVAR. Current reports point to a relatively wide-ranging incidence (0%\u201313%) of type Ia endoleaks related to chEVAR. The PERICLES Registry collected the global transatlantic experience of 13 European and US vascular centers reporting 517 patients with complex aneurysms treated with EVAR and chimney parallel grafts. Overall, 6% of
PERICLES chEVAR patients had a type Ia endoleak at completion angiography, but the rate of persistent endoleaks was only 2.9% at a mean 17.1 months of follow-up. Close review of the postoperative computed tomography angiograms of these persistent endoleak patients revealed distinct types and patterns of chEVAR-related type Ia endoleaks and form the basis of a new classification proposed
herein. It is hoped that these observations will lead to development of new treatment algorithms for effective management of chimney-related endoleaks and, in some cases, to prevent them from occurring in the first place
Spherical Foams in Flat Space
Regular tesselations of space are characterized through their Schlafli
symbols {p,q,r}, where each cell has regular p-gonal sides, q meeting at each
vertex, and r meeting on each edge. Regular tesselations with symbols {p,3,3}
all satisfy Plateau's laws for equilibrium foams. For general p, however, these
regular tesselations do not embed in Euclidean space, but require a uniform
background curvature. We study a class of regular foams on S^3 which, through
conformal, stereographic projection to R^3 define irregular cells consistent
with Plateau's laws. We analytically characterize a broad classes of bulk foam
bubbles, and extend and explain recent observations on foam structure and shape
distribution. Our approach also allows us to comment on foam stability by
identifying a weak local maximum of A^(3/2)/V at the maximally symmetric
tetrahedral bubble that participates in T2 rearrangements.Comment: 4 pages, 4 included figures, RevTe
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