51,046 research outputs found
Quasistatic crack evolution for a cohesive zone model with different response to loading and unloading: a Young measures approach
A new approach to irreversible quasistatic fracture growth is given, by means of Young measures. The study concerns a cohesive zone model with prescribed crack path, when the material gives different responses to loading and unloading phases. In the particular situation
of constant unloading response, the result contained in [G. Dal Maso, C. Zanini: Quasi-static crack growth for a cohesive zone model with prescribed crack path. Proc. Roy. Soc. Edinburgh Sect. A, 137A (2007), 253–279.] is recovered. In this case, the convergence of the discrete time approximations is improved
Context Semantics, Linear Logic and Computational Complexity
We show that context semantics can be fruitfully applied to the quantitative
analysis of proof normalization in linear logic. In particular, context
semantics lets us define the weight of a proof-net as a measure of its inherent
complexity: it is both an upper bound to normalization time (modulo a
polynomial overhead, independently on the reduction strategy) and a lower bound
to the number of steps to normal form (for certain reduction strategies).
Weights are then exploited in proving strong soundness theorems for various
subsystems of linear logic, namely elementary linear logic, soft linear logic
and light linear logic.Comment: 22 page
Crusade for Justice and the Question of Authenticity in African American Autobiography
This article aims at investigating the concept of authenticity and its connections with authority
and cultural dominance in Ida B. Wells\ub4s Crusade for Justice. Set in the Reconstruction period, Wells\u2019s
autobiography incorporates authenticating strategies typical of slave narratives and post-Emancipation
political memoirs, therefore it can be analyzed as a work of transition that embodies the profound shift in
authenticating issues occurring after Emancipation
How robotic surgery is changing our understanding of anatomy
The most recent revolution in our understanding and knowledge of the human body is the introduction of new technologies allowing direct magnified vision of internal organs, as in laparoscopy and robotics. The possibility of viewing an anatomical detail, until now not directly visible during open surgical operations and only partially during dissections of cadavers, has created a 'new surgical anatomy'. Consequent refinements of operative techniques, combined with better views of the surgical field, have given rise to continual and significant decreases in complication rates and improved functional and oncological outcomes. The possibility of exploring new ways of approaching organs to be treated now allows us to reinforce our anatomical knowledge and plan novel surgical approaches. The present review aims to clarify some of these issues. \ua9 2017 Arab Association of Urology
Variational problems in fracture mechanics
We present some recent existence results for the variational model of crack
growth in brittle materials proposed by Francfort and Marigo in 1998. These
results, obtained in collaboration with Francfort and Toader, cover the case of
arbitrary space dimension with a general quasiconvex bulk energy and with
prescribed boundary deformations and applied loads.Comment: 9 page
The Statistical Analyses of the White-Light Flares: Two Main Results About Flare Behaviours
We present two main results, based on the models and the statistical analyses
of 1672 U-band flares. We also discuss the behaviours of the white-light
flares. In addition, the parameters of the flares detected from two years of
observations on CR Dra are presented. By comparing with the flare parameters
obtained from other UV Ceti type stars, we examine the behaviour of optical
flare processes along the spectral types. Moreover, we aimed, using large
white-light flare data,to analyse the flare time-scales in respect to some
results obtained from the X-ray observations. Using the SPSS V17.0 and the
GraphPad Prism V5.02 software, the flares detected from CR Dra were modelled
with the OPEA function and analysed with t-Test method to compare similar flare
events in other stars. In addition, using some regression calculations in order
to derive the best histograms, the time-scales of the white-light flares were
analysed. Firstly, CR Dra flares have revealed that the white-light flares
behave in a similar way as their counterparts observed in X-rays. As seen in
X-ray observations, the electron density seems to be a dominant parameter in
white-light flare process, too. Secondly, the distributions of the flare
time-scales demonstrate that the number of observed flares gets a maximum value
in some particular ratios, which are 0.5 or its multiples, and especially
positive integers. The thermal processes might be dominant for these
white-light flares, while non-thermal processes might be dominant in the
others. To reach better results for the behaviour of the white-light flare
process along the spectral types, much more stars in a wide spectral range,
from the spectral type dK5e to dM6e, must be observed in the white-light flare
patrols.Comment: 17 pages, 7 figures, 5 tabl
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