20,850 research outputs found
Design of a second life product family from the perspective of the remanufacturing agent
This thesis presents a method of solving a newly posed Second Life Product Family Design problem. This
is unique in that the architecture of the product is not speci ed to be identical to one of the recaptured
products, rather it is determined through optimization. The problem is framed using Conjoint Analysis
and the Multi Nomial Logit Model, formatted with respect to components available for inclusion in the
nal products and then solved using an implementation of Genetic Algorithms. The solution method is also
encapsulated in a software module which can be disseminated to industrial users without a background in
optimization or familiarity with Genetic Algorithms.
A case study is performed to determine the e ectiveness of the proposed solution method, and analyze
the in
uences di erent market conditions and component similarities can have on the optimal design. It is
concluded that the proposed method converges to an optimal Second Life Product Family Design
ARE CATTLE ON FEED REPORT REVISIONS RANDOM AND DOES INDUSTRY ANTICIPATE THEM?
Cattle on Feed (COF) reports are an important source of beef supply information. This study investigates whether COF report revisions are unbiased, random, and anticipated. Initial COF reports are biased, but the bias is economically small. Revisions to COF estimates are not random. Market analysts do not correctly anticipate revisions.Livestock Production/Industries,
Electromagnetic cascade in high energy electron, positron, and photon interactions with intense laser pulses
The interaction of high energy electrons, positrons, and photons with intense
laser pulses is studied in head-on collision geometry. It is shown that
electrons and/or positrons undergo a cascade-type process involving multiple
emissions of photons. These photons can consequently convert into
electron-positron pairs. As a result charged particles quickly lose their
energy developing an exponentially decaying energy distribution, which
suppresses the emission of high energy photons, thus reducing the number of
electron-positron pairs being generated. Therefore, this type of interaction
suppresses the development of the electromagnetic avalanche-type discharge,
i.e., the exponential growth of the number of electrons, positrons, and photons
does not occur in the course of interaction. The suppression will occur when 3D
effects can be neglected in the transverse particle orbits, i.e., for
sufficiently broad laser pulses with intensities that are not too extreme. The
final distributions of electrons, positrons, and photons are calculated for the
case of a high energy e-beam interacting with a counter-streaming, short
intense laser pulse. The energy loss of the e-beam, which requires a
self-consistent quantum description, plays an important role in this process,
as well as provides a clear experimental observable for the transition from the
classical to quantum regime of interaction.Comment: 13 pages, 7 figure
Crossover to Potential Energy Landscape Dominated Dynamics in a Model Glass-forming Liquid
An equilibrated model glass-forming liquid is studied by mapping successive
configurations produced by molecular dynamics simulation onto a time series of
inherent structures (local minima in the potential energy). Using this
``inherent dynamics'' approach we find direct numerical evidence for the long
held view that below a crossover temperature, , the liquid's dynamics can
be separated into (i) vibrations around inherent structures and (ii)
transitions between inherent structures (M. Goldstein, J. Chem. Phys. {\bf 51},
3728 (1969)), i.e., the dynamics become ``dominated'' by the potential energy
landscape. In agreement with previous proposals, we find that is within
the vicinity of the mode-coupling critical temperature . We further find
that at the lowest temperature simulated (close to ), transitions between
inherent structures involve cooperative, string like rearrangements of groups
of particles moving distances substantially smaller than the average
interparticle distance.Comment: Expanded from 4 to 7 page
Solution of nonlinear algebraic equations characteristic of filter circuits Summary technical report
Digital computer program developed for solving nonlinear algebraic equations characteristic of filter circuit
Optical signatures of quantum delocalization over extended domains in photosynthetic membranes
The prospect of coherent dynamics and excitonic delocalization across several
light-harvesting structures in photosynthetic membranes is of considerable
interest, but challenging to explore experimentally. Here we demonstrate
theoretically that the excitonic delocalization across extended domains
involving several light-harvesting complexes can lead to unambiguous signatures
in the optical response, specifically, linear absorption spectra. We
characterize, under experimentally established conditions of molecular assembly
and protein-induced inhomogeneities, the optical absorption in these arrays
from polarized and unpolarized excitation, and demonstrate that it can be used
as a diagnostic tool to determine the coherent coupling among iso-energetic
light-harvesting structures. The knowledge of these couplings would then
provide further insight into the dynamical properties of transfer, such as
facilitating the accurate determination of F\"orster rates.Comment: 4 figures and Supplementary information with 7 figures. To appear in
Journal of physical chemistry A, 201
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