627 research outputs found
Intelligent planning for allocating containers in maritime terminals
Maritime container terminals are facilities where cargo containers are transshipped between ships or between ships and land vehicles (tucks or trains). These terminals involve a large number of complex and combinatorial problems. One of them is related to the Container Stacking Problem. A container yard is a type of temporary store where containers await further transport by truck, train or vessel. The main efficiency problem for an individual stack is to ensure easy access to containers at the expected time of transfer. Stacks are 'last-in, first-out' storage structures where containers are stocked in the order they arrive. But they should be retrieved from the stack in the order (usually different) they should be shipped. This retrieval operation should be efficiently performed, since berthing time of vessels and the terminal operations should be optimized. To do this, cranes can relocate containers in the stacks to minimize the rearrangements required to meet the expected order of demand for containers. In this paper, we present a domain-dependent heuristically guided planner for obtaining the optimized reshuffling plan, given a stacking state and a container demand. The planner can also be used for finding the best allocation of containers in a yard-bay in order to minimize the number of reshuffles as well as to be used for simulation tasks and obtaining conclusions about possible yard configurations. © 2011 Elsevier Ltd. All rights reserved.This work has been partially supported by the research projects TIN2010-20976-C02-01 (Min. de Ciencia e Innovacion, Spain), P19/08 (Min. de Fomento, Spain-FEDER) and the VALi+d Program of the Conselleria d'Educacio (Generalitat Valenciana), as well as with the collaboration of the maritime container terminal MSC (Mediterranean Shipping Company S.A.).Rodríguez Molins, M.; Salido Gregorio, MA.; Barber Sanchís, F. (2012). Intelligent planning for allocating containers in maritime terminals. Expert Systems with Applications. 39(1):978-989. https://doi.org/10.1016/j.eswa.2011.07.098S97898939
Nucleonic resonance excitations with linearly polarized photon in
In this work, an improved quark model approach to the meson
photo-production with an effective Lagrangian is presented. The {\it t}-channel
{\it natural}-parity exchange is taken into account through the Pomeron
exchange, while the {\it unnatural}-parity exchange is described by the
exchange. With a very limited number of parameters, the available experimental
data in the low energy regime can be consistently accounted for. We find that
the beam polarization observables show sensitivities to some {\it s}-channel
individual resonances in the quark model symmetry limit.
Especially, the two resonances and , which belong
to the representation , have dominant contributions
over other excited states. Concerning the essential motivation of searching for
"missing resonances" in meson photo-production, this approach provides a
feasible framework, on which systematic investigations can be done.Comment: 16 pages, Revtex, 9 eps figures, to appear in PR
Systematic Regge theory analysis of omega photoproduction
Systematic analysis of available data for -meson photoproduction is
given in frame of Regge theory. At photon energies above 20 GeV the
reaction is entirely dominated by Pomeron exchange.
However, it was found that Pomeron exchange model can not reproduce the
and data at high energies
simultaneously with the same set of parameters. The comparison between
and data indicates a large room for meson exchange contribution to
-meson photoproduction at low energies. It was found that at low
energies the dominant contribution comes from and -meson exchanges.
There is smooth transition between the meson exchange model at low energies and
Regge theory at high energies.Comment: 7 pages, 8 figures, revtex
The abolition of the General Teaching Council for England and the future of teacher discipline
With the abolition of the General Teaching Council for England in the 2011 Education Act, this article considers the future of teacher discipline in England. It provides a critique of the changes to the regulation of teacher misconduct and incompetence that draws on a Foucauldian framework, especially concerning the issue of public displays of discipline and the concomitant movement to more hidden forms. In addition, the external context of accountability that accompanies the reforms to teacher discipline are considered including the perfection of the panoptic metaphor presented by the changes to Ofsted practices such as the introduction of zero-notice inspections. The article concludes that the reforms will further move teachers from being occupational professionals to being organisational professionals marking them apart from comparable professions in medicine and law
A Sucrose Solution Application to the Study of Model Biological Membranes
The small-angle X-ray and neutron scattering, time resolved X-ray small-angle
and wide-angle diffraction coupled with differential scanning calorimetry have
been applied to the investigation of unilamellar and multilamellar
dimyristoylphosphatidylcholine (DMPC) vesicles in sucrose buffers with sucrose
concentrations from 0 to 60%. Sucrose buffer decreased vesicle size and
polydispersity and increased an X-ray contrast between phospholipid membrane
and bulk solvent sufficiently. No influence of sucrose on the membrane
thickness or mutual packing of hydrocarbon chains has been detected. The region
of sucrose concentrations 30%-40% created the best experimental conditions for
X-ray small-angle experiments with phospholipid vesicles.Comment: PDF: 10 pages, 6 figures. MS Word sours
Density Matrix Renormalisation Group Approach to the Massive Schwinger Model
The massive Schwinger model is studied, using a density matrix
renormalisation group approach to the staggered lattice Hamiltonian version of
the model. Lattice sizes up to 256 sites are calculated, and the estimates in
the continuum limit are almost two orders of magnitude more accurate than
previous calculations. Coleman's picture of `half-asymptotic' particles at
background field theta = pi is confirmed. The predicted phase transition at
finite fermion mass (m/g) is accurately located, and demonstrated to belong in
the 2D Ising universality class.Comment: 38 pages, 18 figures, submitted to PR
Trust Building in Electronic Markets: Relative Importance and Interaction Effects of Trust Building Mechanisms
We examine the relative and complementary effectiveness of trust-building strategies in online environments. While prior research has examined various antecedents to trust, we investigated two trust-building mechanisms more in depth: Web site trust and vendor reputation. We tried to understand the relative effectiveness of these two important mechanisms to provide online businesses with a clear recommendation of how to establish trust in an effective and efficient manner. Drawing from the literature on trust, we proposed vendor reputation to be more effective than Web site trust. Moreover, we examined a potential complementary effect of these mechanisms so as to provide online businesses with a deeper understanding of how to derive superior trust. We hypothesize a small such effect. The study proposes a laboratory experiment to test the model
Quantum Computing and Quantum Simulation with Group-II Atoms
Recent experimental progress in controlling neutral group-II atoms for
optical clocks, and in the production of degenerate gases with group-II atoms
has given rise to novel opportunities to address challenges in quantum
computing and quantum simulation. In these systems, it is possible to encode
qubits in nuclear spin states, which are decoupled from the electronic state in
the S ground state and the long-lived P metastable state on the
clock transition. This leads to quantum computing scenarios where qubits are
stored in long lived nuclear spin states, while electronic states can be
accessed independently, for cooling of the atoms, as well as manipulation and
readout of the qubits. The high nuclear spin in some fermionic isotopes also
offers opportunities for the encoding of multiple qubits on a single atom, as
well as providing an opportunity for studying many-body physics in systems with
a high spin symmetry. Here we review recent experimental and theoretical
progress in these areas, and summarise the advantages and challenges for
quantum computing and quantum simulation with group-II atoms.Comment: 11 pages, 7 figures, review for special issue of "Quantum Information
Processing" on "Quantum Information with Neutral Particles
Developing and validating Parkinson's disease subtypes and their motor and cognitive progression
Peer reviewedPublisher PD
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