1,097 research outputs found
A Resolvent Approach to Metastability
We provide a necessary and sufficient condition for the metastability of a
Markov chain, expressed in terms of a property of the solutions of the
resolvent equation. As an application of this result, we prove the
metastability of reversible, critical zero-range processes starting from a
configuration
In and out and out again: The travails of Brazil as a security provider in Africa
The story of Brazil as a contemporary security actor in Africa can prove a peculiar one. Marked by quick gains and an equally quick recognition over a short period of time, it has also been followed by an equally quick turnaround which has led, as of 2020, to a visible disengagement on the ground. We explore the main travails in this domain, which have compromised much of the gains previously obtained throughout the continent. The chapter begins with a general balance of the progress achieved between 2003 and 2016, followed by the highlights of the recent downturn. We then analyze a specific sub-area, namely, the inroads carried out at the defence industry level, in order to showcase the promises and contradictions often associated to what the country has offered across the Atlantic. We conclude by presenting some opportunities for a new pickup of Brazilian interest in the middle and long run
Floração de espécies apícolas no Pantanal baseada em informações de herbário e literatura.
O objetivo desse estudo foi descrever e avaliar a influência do porte das plantas apícolas do Pantanal na ocorrência de floração ao longo do ano. As informações das espécies apícolas foram organizadas a partir da compilação de dados de literatura e do acervo do herbário CPAP, anotando-se o período de floração, porte de crescimento (herbáceo, arbustivo, arbóreo ou trepadeira), sendo que as palmeiras foram consideradas como de porte arbóreo, e a ocorrência ou não em área inundável (espécies aquáticas ou anfíbias e terrestres).bitstream/CPAP-2010/57290/1/BP91.pd
Micelle Forms in Lyotropic Nematics and Cholesterics
Nematic and cholesteric lyotropic liquid crystals (lyomesophases
based on micelles) with positive and negative diamagnetic
aniiSotropy wexe studied by polaxizing microscopy. The textures
of nematics oriented in a magnetic field confirm the disc- ·
like and rodlike structure of the lyomesophases. The textures
of cholesterics show a characteristic helical structure where the
pitch of the helix depends on the composition and temperature
Micelle Forms in Lyotropic Nematics and Cholesterics
Nematic and cholesteric lyotropic liquid crystals (lyomesophases
based on micelles) with positive and negative diamagnetic
aniiSotropy wexe studied by polaxizing microscopy. The textures
of nematics oriented in a magnetic field confirm the disc- ·
like and rodlike structure of the lyomesophases. The textures
of cholesterics show a characteristic helical structure where the
pitch of the helix depends on the composition and temperature
On complexity and convergence of high-order coordinate descent algorithms
Coordinate descent methods with high-order regularized models for
box-constrained minimization are introduced. High-order stationarity asymptotic
convergence and first-order stationarity worst-case evaluation complexity
bounds are established. The computer work that is necessary for obtaining
first-order -stationarity with respect to the variables of each
coordinate-descent block is whereas the computer
work for getting first-order -stationarity with respect to all the
variables simultaneously is . Numerical examples
involving multidimensional scaling problems are presented. The numerical
performance of the methods is enhanced by means of coordinate-descent
strategies for choosing initial points
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