2,375 research outputs found
Hybridation of Bayesian networks and evolutionary algorithms for multi-objective optimization in an integrated product design and project management context
A better integration of preliminary product design and project management processes at early steps of system design is nowadays a key industrial issue. Therefore, the aim is to make firms evolve from classical sequential approach (first product design the project design and management) to new integrated approaches. In this paper, a model for integrated product/project optimization is first proposed which allows taking into account simultaneously decisions coming from the product and project managers. However, the resulting model has an important underlying complexity, and a multi-objective optimization technique is required to provide managers with appropriate scenarios in a reasonable amount of time. The proposed approach is based on an original evolutionary algorithm called evolutionary algorithm oriented by knowledge (EAOK). This algorithm is based on the interaction between an adapted evolutionary algorithm and a model of knowledge (MoK) used for giving relevant orientations during the search process. The evolutionary operators of the EA are modified in order to take into account these orientations. The MoK is based on the Bayesian Network formalism and is built both from expert knowledge and from individuals generated by the EA. A learning process permits to update probabilities of the BN from a set of selected individuals. At each cycle of the EA, probabilities contained into the MoK are used to give some bias to the new evolutionary operators. This method ensures both a faster and effective optimization, but it also provides the decision maker with a graphic and interactive model of knowledge linked to the studied project. An experimental platform has been developed to experiment the algorithm and a large campaign of tests permits to compare different strategies as well as the benefits of this novel approach in comparison with a classical EA
La Chine, nouveau géant de la science mondiale
International audienceChina is more and more publishing and participating in the science networks.La Chine, dans le domaine de la science mondialisée, fait les réputations (classement dit de Shanghaï), publie de plus en plus, participe de façon croissante aux réseaux mondiaux, et fait des choix stratégiques de publication
The 2010 Interferometric Imaging Beauty Contest
We present the results of the fourth Optical/IR Interferometry Imaging Beauty
Contest. The contest consists of blind imaging of test data sets derived from
model sources and distributed in the OI-FITS format. The test data consists of
spectral data sets on an object "observed" in the infrared with spectral
resolution. There were 4 different algorithms competing this time: BSMEM the
Bispectrum Maximum Entropy Method by Young, Baron & Buscher; RPR the Recursive
Phase Reconstruction by Rengaswamy; SQUEEZE a Markov Chain Monte Carlo
algorithm by Baron, Monnier & Kloppenborg; and, WISARD the Weak-phase
Interferometric Sample Alternating Reconstruction Device by Vannier & Mugnier.
The contest model image, the data delivered to the contestants and the rules
are described as well as the results of the image reconstruction obtained by
each method. These results are discussed as well as the strengths and
limitations of each algorithm.Comment: To be published in SPIE 2010 "Optical and infrared interferometry II
Why Chromatic Imaging Matters
During the last two decades, the first generation of beam combiners at the
Very Large Telescope Interferometer has proved the importance of optical
interferometry for high-angular resolution astrophysical studies in the near-
and mid-infrared. With the advent of 4-beam combiners at the VLTI, the u-v
coverage per pointing increases significantly, providing an opportunity to use
reconstructed images as powerful scientific tools. Therefore, interferometric
imaging is already a key feature of the new generation of VLTI instruments, as
well as for other interferometric facilities like CHARA and JWST. It is thus
imperative to account for the current image reconstruction capabilities and
their expected evolutions in the coming years. Here, we present a general
overview of the current situation of optical interferometric image
reconstruction with a focus on new wavelength-dependent information,
highlighting its main advantages and limitations. As an Appendix we include
several cookbooks describing the usage and installation of several state-of-the
art image reconstruction packages. To illustrate the current capabilities of
the software available to the community, we recovered chromatic images, from
simulated MATISSE data, using the MCMC software SQUEEZE. With these images, we
aim at showing the importance of selecting good regularization functions and
their impact on the reconstruction.Comment: Accepted for publication in Experimental Astronomy as part of the
topical collection: Future of Optical-infrared Interferometry in Europ
Constitutive Cytokine mRNAs Mark Natural Killer (NK) and NK T Cells Poised for Rapid Effector Function
Natural killer (NK) and NK T cells are tissue lymphocytes that secrete cytokines rapidly upon stimulation. Here, we show that these cells maintain distinct patterns of constitutive cytokine mRNAs. Unlike conventional T cells, NK T cells activate interleukin (IL)-4 and interferon (IFN)-Îł transcription during thymic development and populate the periphery with both cytokine loci previously modified by histone acetylation. Similarly, NK cells transcribe and modify the IFN-Îł gene, but not IL-4, during developmental maturation in the bone marrow. Lineage-specific patterns of cytokine transcripts predate infection and suggest evolutionary selection for invariant but distinct types of effector responses among the earliest responding lymphocytes
Modification des propriétés des poudres par enrobage à sec dans un mélangeur Cyclomix
International audienceNous présentons ici une étude de la modification de certaines propriétés de poudres aprÚs enrobage de fines particules sur des particules hÎtes dans un mélangeur de laboratoire modÚle « Cyclomix », d'une contenance de 1 litre. Ce type d'appareil présente des effets de cisaillement et d'impact, permettant de réaliser rapidement des enrobages à sec avec des volumes significatifs de poudre. De plus des possibilités d'extrapolation à des échelles supérieures (jusqu'à 500 L) existent pour préparer des quantités industrielles de poudres à surface modifiée. Plusieurs systÚmes particulaires sont utilisés, avec des particules hÎtes différentes : des poudres de gel de silice et d'amidon de maïs. Différents types de particules invitées ont été également examinées : stéarate de magnésium, silice hydrophile ou hydrophobe. Les caractéristiques morphologiques des poudres, et les densités du solide (mesurées par pycnomÚtre à hélium) ont été déterminées. Les modifications apportées aux particules hÎtes par les particules invitées sont caractérisées par des tests de cinétique d'adsorption de vapeur d'eau, de mesure d'angle de contact par goutte posée, et d'évaluation de la coulabilité par mesures de densités tassées ou non tassées. Les résultats obtenus montrent que le mélangeur Cyclomix permet de réaliser des enrobages de poudres modifiant les propriétés de façon sensible
Impact of comprehensive geriatric assessment on survival, function, and nutritional status in elderly patients with head and neck cancer: protocol for a multicentre randomised controlled trial (EGeSOR)
BACKGROUND: Survival is poorer in elderly patients with head and neck squamous cell carcinomas [HNSCCs] than in younger patients. Possible explanations include a contribution of co-morbidities to mortality, frequent refusal of standard therapy, and the use of suboptimal treatments due to concern about toxicities. The Comprehensive Geriatric Assessment [CGA] is a multidimensional assessment of general health that can help to customise treatment and follow-up plans. The CGA has been proven effective in several health settings but has not been evaluated in randomised studies of patients with cancer. Our aim here was to assess the impact of the CGA on overall survival, function, and nutritional status of elderly patients with HNSCC. METHODS/DESIGN: EGeSOR is an open-label, multicentre, randomised, controlled, parallel-group trial in patients aged 70Â years or older and receiving standard care for HNSCC. The intervention includes four components: the CGA conducted by a geriatrician before cancer treatment, participation of the same geriatrician in cancer treatment selection, a standardised geriatric therapeutic intervention designed by the same geriatrician; and geriatric follow-up for 24Â months. The primary endpoint, assessed after 6Â months, is a composite criterion including death, functional impairment [Activities of Daily Living score decrease â„2], and weight loss â„10%. Secondary endpoints include progression-free survival, unscheduled admissions, quality of life, treatment toxicities, costs, and completion of the planned cancer treatment. A centralised online system is used to perform 1:1 randomisation with a minimisation algorithm for centre, age, T and N stages, and tumour site [oral, oropharyngeal, hypopharyngeal, or laryngeal]. The estimated sample size is 704 patients, who are being recruited by 14 centres in 9 French cities. DISCUSSION: EGeSOR is the first randomised trial of the CGA in elderly cancer patients. We expect the CGA to have direct clinical benefits on the management of elderly patients with HNSCC. If this expectation is fulfilled, the trial may lead to modifications of the management model for elderly patients with cancer. TRIAL REGISTRATION: Trial registration: NCT0202506
Nuclear structure and reaction studies at SPIRAL
The SPIRAL facility at GANIL, operational since 2001, is described briefly.
The diverse physics program using the re-accelerated (1.2 to 25 MeV/u) beams
ranging from He to Kr and the instrumentation specially developed for their
exploitation are presented. Results of these studies, using both direct and
compound processes, addressing various questions related to the existence of
exotic states of nuclear matter, evolution of new "magic numbers", tunnelling
of exotic nuclei, neutron correlations, exotic pathways in astrophysical sites
and characterization of the continuum are discussed. The future prospects for
the facility and the path towards SPIRAL2, a next generation ISOL facility, are
also briefly presented.Comment: 48 pages, 27 figures. Accepted for publication in Journal of Physics
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