315 research outputs found
Approximate solutions in space mission design
In this paper, we address multi-objective space mission design problems. From a practical point of view, it is often the case that,during the preliminary phase of the design of a space mission, the solutions that are actually considered are not 'optimal' (in the Pareto sense)but belong to the basin of attraction of optimal ones (i.e. they are nearly
optimal). This choice is motivated either by additional requirements that the decision maker has to take into account or, more often, by robustness considerations. For this, we suggest a novel MOEA which is a modification of the well-known NSGA-II algorithm equipped with a recently
proposed archiving strategy which aims at storing the set of approximate solutions of a given MOP. Using this algorithm we will examine some space trajectory design problems and demonstrate the benefit of the novel approach
A review of research into business coaching supervision
A systematic search of the coaching literature for original peer-reviewed studies into business coaching supervision yielded seven research reports. Evaluation of these studies showed them to be low in the reporting of methodological rigour. However, as an emerging area of research with great importance for the development of the profession of business coaching these studies provide valuable insights into the functions of supervision and its benefits. Gaps in knowledge and directions for future research are identified. There is a need for future research to be more rigorous in its reporting of methods and analytic procedures, small scale qualitative research that can provide insight into the issues and challenges of coaching supervision in specific contexts, and large scale quantitative research which can provide broader and generalizable understandings into the uses and benefits of supervision
Color Transparency Effects in Electron Deuteron Interactions at Intermediate Q^2
High momentum transfer electrodisintegration of polarized and unpolarized
deuterium targets, is studied. We show that the importance of final
state interactions-FSI, occuring when a knocked out nucleon interacts with the
other nucleon, depends strongly on the momentum of the spectator nucleon. In
particular, these FSI occur when the essential contributions to the scattering
amplitude arise from internucleon distances . But the absorption
of the high momentum may produce a point like configuration, which
evolves with time. In this case, the final state interactions probe the point
like configuration at the early stage of its evolution. The result is that
significant color transparency effects, which can either enhance or suppress
computed cross sections, are predicted to occur for .Comment: 37 pages LaTex, 12 uuencoded PostScript Figures as separate file, to
be published in Z.Phys.
Coupled Maps on Trees
We study coupled maps on a Cayley tree, with local (nearest-neighbor)
interactions, and with a variety of boundary conditions. The homogeneous state
(where every lattice site has the same value) and the node-synchronized state
(where sites of a given generation have the same value) are both shown to occur
for particular values of the parameters and coupling constants. We study the
stability of these states and their domains of attraction. As the number of
sites that become synchronized is much higher compared to that on a regular
lattice, control is easier to effect. A general procedure is given to deduce
the eigenvalue spectrum for these states. Perturbations of the synchronized
state lead to different spatio-temporal structures. We find that a mean-field
like treatment is valid on this (effectively infinite dimensional) lattice.Comment: latex file (25 pages), 4 figures included. To be published in Phys.
Rev.
Cosmological Dynamics of Phantom Field
We study the general features of the dynamics of the phantom field in the
cosmological context. In the case of inverse coshyperbolic potential, we
demonstrate that the phantom field can successfully drive the observed current
accelerated expansion of the universe with the equation of state parameter
. The de-Sitter universe turns out to be the late time attractor
of the model. The main features of the dynamics are independent of the initial
conditions and the parameters of the model. The model fits the supernova data
very well, allowing for at 95 % confidence level.Comment: Typos corrected. Some clarifications and references added. To appear
in Physical Review
Metagenomic Nanopore sequencing of influenza virus direct from clinical respiratory samples
Influenza is a major global public health threat as a result of its highly pathogenic variants, large zoonotic reservoir, and pandemic potential. Metagenomic viral sequencing offers the potential for a diagnostic test for influenza virus which also provides insights on transmission, evolution, and drug resistance and simultaneously detects other viruses. We therefore set out to apply the Oxford Nanopore Technologies sequencing method to metagenomic sequencing of respiratory samples. We generated influenza virus reads down to a limit of detection of 102 to 103 genome copies/ml in pooled samples, observing a strong relationship between the viral titer and the proportion of influenza virus reads (P = 4.7 × 10−5). Applying our methods to clinical throat swabs, we generated influenza virus reads for 27/27 samples with mid-to-high viral titers (cycle threshold [CT] values, 99% complete sequences for all eight gene segments. We also detected a human coronavirus coinfection in one clinical sample. While further optimization is required to improve sensitivity, this approach shows promise for the Nanopore platform to be used in the diagnosis and genetic analysis of influenza virus and other respiratory viruses
Teleparallel Lagrange Geometry and a Unified Field Theory
In this paper, we construct a field theory unifying gravity and
electromagnetism in the context of Extended Absolute Parallelism (EAP-)
geometry. This geometry combines, within its structure, the geometric richness
of the tangent bundle and the mathematical simplicity of Absolute Parallelism
(AP-) geometry. The constructed field theory is a generalization of the
Generalized Field Theory (GFT) formulated by Mikhail and Wanas. The theory
obtained is purely geometric. The horizontal (resp. vertical) field equations
are derived by applying the Euler-Lagrange equations to an appropriate
horizontal (resp. vertical) scalar Lagrangian. The symmetric part of the
resulting horizontal (resp. vertical) field equations gives rise to a
generalized form of Einstein's field equations in which the horizontal (resp.
vertical) energy-momentum tensor is purely geometric. The skew-symmetric part
of the resulting horizontal (resp. vertical) field equations gives rise to a
generalized form of Maxwell equations in which the electromagnetic field is
purely geometric. Some interesting special cases, which reveal the role of the
nonlinear connection in the obtained field equations, are examined. Finally,
the condition under which our constructed field equations reduce to the GFT is
explicitly established.Comment: Latex file, 33 page
Non linear equation of state and effective phantom divide in brane models
Here, DGP model of brane-gravity is analyzed and compared with the standard
general relativity and Randall-Sundrum cases using non-linear equation of
state. Phantom fluid is known to violate the weak energy condition. In this
paper, it is found that this characteristic of phantom energy is affected
drastically by the negative brane-tension of the RS-II model. It is
found that in DGP model strong energy condition(SEC) is always violated and the
universe accelerates only where as in RS-II model even SEC is not violated for
and the universe decelerates
Towards a Model of Corporate and Social Stakeholder Engagement: Analyzing the Relations Between a French Mutual Bank and Its Members
International audienceThe aim of this article is to develop a new classification of stakeholders based on the concept of corporate and social engagement. Engagement is analyzed as an organizational learning process between the managers of an organization and its stakeholders. It is a necessary condition to improve the organization's impact on its economic, social, and natural environment. Applied to the membership of a French mutual bank in order to identify the members' varying levels of engagement, this new mapping technique may help managers to adapt their practices to the degree of engagement of each identified group of members, and to modify their financial products and communications to foster engagement among as many of these groups as possible
Patterning of light-emitting conjugated polymer nanofibres.
Organic materials have revolutionized optoelectronics by their processability, flexibility and low cost, with application to light-emitting devices for full-colour screens, solar cells and lasers. Some low-dimensional organic semiconductor structures exhibit properties resembling those of inorganics, such as polarized emission and enhanced electroluminescence. One-dimensional metallic, III-V and II-VI nanostructures have also been the subject of intense investigation as building blocks for nanoelectronics and photonics. Given that one-dimensional polymer nanostructures, such as polymer nanofibres, are compatible with sub-micrometre patterning capability and electromagnetic confinement within subwavelength volumes, they can offer the benefits of organic light sources to nanoscale optics. Here we report on the optical properties of fully conjugated, electrospun polymer nanofibres. We assess their waveguiding performance and emission tuneability in the whole visible range. We demonstrate the enhancement of the fibre forward emission through imprinting periodic nanostructures using room-temperature nanoimprint lithography, and investigate the angular dispersion of differently polarized emitted light
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