39,561 research outputs found
Polynomiality for Bin Packing with a Constant Number of Item Types
We consider the bin packing problem with d different item sizes s_i and item
multiplicities a_i, where all numbers are given in binary encoding. This
problem formulation is also known as the 1-dimensional cutting stock problem.
In this work, we provide an algorithm which, for constant d, solves bin
packing in polynomial time. This was an open problem for all d >= 3.
In fact, for constant d our algorithm solves the following problem in
polynomial time: given two d-dimensional polytopes P and Q, find the smallest
number of integer points in P whose sum lies in Q.
Our approach also applies to high multiplicity scheduling problems in which
the number of copies of each job type is given in binary encoding and each type
comes with certain parameters such as release dates, processing times and
deadlines. We show that a variety of high multiplicity scheduling problems can
be solved in polynomial time if the number of job types is constant
The Commercial Music Industry in Atlanta and the State of Georgia: An Economic Impact Study
This study was prepared to ascertain the magnitude of the commercial music industry's economic impact on Atlanta and its surrounding areas. Report #8
Comments on lattice gauge theories with infrared-attractive fixed points
Theories of interacting gauge fields and fermions can possess a running gauge
coupling with an infrared attractive fixed point (IRFP). We present a minimal
description of the physics of these systems and comment on some simple
expectations for results from lattice simulations done within the basin of
attraction of the IRFP in these theories.Comment: 10 pages, 2 figures. Published version, fixed typos in version
Fault reactivation by fluid injection: Controls from stress state and injection rate
We studied the influence of stress state and fluid injection rate on the
reactivation of faults. We conducted experiments on a saw-cut Westerly granite
sample under triaxial stress conditions. Fault reactivation was triggered by
injecting fluids through a borehole directly connected to the fault. Our
results show that the peak fluid pressure at the borehole leading to
reactivation depends on injection rate. The higher the injection rate, the
higher the peak fluid pressure allowing fault reactivation. Elastic wave
velocity measurements along fault strike highlight that high injection rates
induce significant fluid pressure heterogeneities, which explains that the
onset of fault reactivation is not determined by a conventional Coulomb law and
effective stress principle, but rather by a nonlocal rupture initiation
criterion. Our results demonstrate that increasing the injection rate enhances
the transition from drained to undrained conditions, where local but intense
fluid pressures perturbations can reactivate large faults
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