1,468 research outputs found
Hull Consistency Under Monotonicity
International audienceWe prove that hull consistency for a system of equations or inequalities can be achieved in polynomial time providing that the underlying functions are monotone with respect to each variable. This result holds including when variables have multiple occurrences in the expressions of the functions, which is usually a pitfall for interval-based contractors. For a given constraint, an optimal contractor can thus be enforced quickly under monotonicity and the practical significance of this theoretical result is illustrated on a simple example
Asymmetric Synthesis of Secondary Alcohols and 1,2-Disubstituted Epoxides via Organocatalytic Sulfenylation
Enantioenriched secondary alcohols can be prepared via a short reaction sequence involving asymmetric organocatalytic sulfenylation of an aldehyde, organometallic addition, and desulfurization. This process provides access to enantioenriched alcohols with sterically similar groups attached to the alcohol carbon atom. The intermediate β-hydroxysulfides can also serve as precursors to enantioenriched 1,2-disubstituted epoxides via alkylation of the sulfur and subsequent base-mediated ring closure
Scalable Parallel Numerical Constraint Solver Using Global Load Balancing
We present a scalable parallel solver for numerical constraint satisfaction
problems (NCSPs). Our parallelization scheme consists of homogeneous worker
solvers, each of which runs on an available core and communicates with others
via the global load balancing (GLB) method. The parallel solver is implemented
with X10 that provides an implementation of GLB as a library. In experiments,
several NCSPs from the literature were solved and attained up to 516-fold
speedup using 600 cores of the TSUBAME2.5 supercomputer.Comment: To be presented at X10'15 Worksho
Surface-mediated attraction between colloids
We investigate the equilibrium properties of a colloidal solution in contact
with a soft interface. As a result of symmetry breaking, surface effects are
generally prevailing in confined colloidal systems. In this Letter, particular
emphasis is given to surface fluctuations and their consequences on the local
(re)organization of the suspension. It is shown that particles experience a
significant effective interaction in the vicinity of the interface. This
potential of mean force is always attractive, with range controlled by the
surface correlation length. We suggest that, under some circumstances,
surface-induced attraction may have a strong influence on the local particle
distribution
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