455 research outputs found
Entropy-based fuzzy clustering of interval-valued time series
This paper proposes a fuzzy C-medoids-based clustering method with entropy regularization to solve the issue of grouping complex data as interval-valued time series. The dual nature of the data, that are both time-varying and interval-valued, needs to be considered and embedded into clustering techniques. In this work, a new dissimilarity measure,
based on Dynamic Time Warping, is proposed. The performance of the new clustering procedure is evaluated through a simulation study and an application to financial time series
Les lombalgies chroniques : symptÎme ou pas symptÎme ?
Cet article Ă©tudie un aspect psychologique impliquĂ© dans certaines affections somatiques, ici les lombalgies chroniques. Plusieurs cas de patients lombalgiques reçus en entretiens psychothĂ©rapiques montrent que le statut de la douleur Ă©volue selon que le sujet lui accorde ou non une valeur de symptĂŽme, au sens psychanalytique. Le « choix » de ce statut est personnel, subjectif, inconscient, et impacte lâĂ©volution de la lombalgie. AprĂšs avoir dĂ©fini le symptĂŽme au sens mĂ©dical et au sens psychanalytique, et avoir rappelĂ© la distinction entre lâhystĂ©rie et la psychosomatique, les auteurs prĂ©sentent leur conception des rapports corps et psychĂ© selon le modĂšle de la bande de Möbius utilisĂ©e par Lacan pour dĂ©finir les rapports entre le conscient et lâinconscient. Il est cependant illusoire, en mĂ©decine gĂ©nĂ©rale, de pouvoir amener tous les patients Ă faire de leur lombalgie un symptĂŽme « psychanalytique ». Le contexte et le cadre ne sont pas les mĂȘmes car le patient qui va consulter son mĂ©decin nâen attend pas la mĂȘme chose que celui qui va consulter un psychologue, un psychanalyste ou un psychiatre. NĂ©anmoins, lâouverture des uns et des autres Ă la possibilitĂ© dâune Ă©volution du patient fondĂ©e sur un changement de sa position subjective peut ĂȘtre un avantage important, car ce qui est en jeu dans le processus de la chronicisation nâest pas seulement la disparition pure et simple de la douleur, mais la modification prĂ©alable de sa fonction pour le sujet, câest-Ă -dire le passage de la fonction premiĂšre de la douleur comme signal de danger Ă celle qui favorise lâĂ©laboration dâun sens subjectif. Et pour cela, faut-il encore que ce sujet, comme les praticiens concernĂ©s, lui reconnaissent cette seconde fonction
Forage Accumulation and Quality of Three Contrasting Ecotypes of Tall Fescue (\u3ci\u3eSchedonorus arundinaceus\u3c/i\u3e) Managed under Frequent Defoliation
In the past, tall fescue ecotypes were compared under intermediate management defoliation frequency, but now has station, Argentina (-33 ° 56 \u27S, -60 ° 33\u27 W) in autumn 2016, on a typical Argiudoll soil. The treatments were cultivars representing three ecotypes of tall fescue: (i) - Mediterranean (cv. Flecha), (ii) - Intermediate (cv. Royal Q 100) and (iii) - Continental (cv. Lujan INTA). Each plot consisted of 7 rows 6.0 m long, 0.2 m apart (8.4m2 plot size) arranged in a randomized complete block design with 4 replicates. The first cut was done at the end of September when pastures reached \u3e 90 % of soil cover. The following six cuts were done when thermal time was 550°±50°C degree days (base temperature=4°C). The forage accumulation was determined by cutting with a mowing machine the central 5 m2 of each plot, at a height of 0.05 m. A sample (0.250 g) was taken to analyze in vitro dry matter digestibility (IVDIG), crude protein (CP), neutral detergent fiber (NDF) and NDF digestibility (NDFDIG). Mixed model was applied to consider ecotype and time effects. Ecotype*time interaction was significant for all variables (p\u3c 0.0001) except for forage accumulation. The values ranged between 491 and 2,625 kg DM ha-1 for forage accumulation, while IVDIG ranged between 57.2 and 68.7%, CP between 11.5 and 19.1%, NDF between 45.5 and 62.8% and NDFDIG between 26 and 65.3%. The Mediterranean ecotype produced less forage but in many cuts with higher CP. In many cuts, IVDIG was higher in the Continental ecotype associated with less leaf diseases
Fuzzy clustering with entropy regularization for interval-valued data with an application to scientific journal citations
In recent years, the research of statistical methods to analyze complex structures of data has increased. In particular, a lot of attention has been focused on the interval-valued data. In a classical cluster analysis framework, an interesting line of research has focused on the clustering of interval-valued data based on fuzzy approaches. Following the partitioning around medoids fuzzy approach research line, a new fuzzy clustering model for interval-valued data is suggested. In particular, we propose a new model based on the use of the entropy as a regularization function in the fuzzy clustering criterion. The model uses a robust weighted dissimilarity measure to smooth noisy data and weigh the center and radius components of the interval-valued data, respectively. To show the good performances of the proposed clustering model, we provide a simulation study and an application to the clustering of scientific journals in research evaluation
Characterization of a Be(p,xn) neutron source for fission yields measurements
We report on measurements performed at The Svedberg Laboratory (TSL) to
characterize a proton-neutron converter for independent fission yield studies
at the IGISOL-JYFLTRAP facility (Jyv\"askyl\"a, Finland). A 30 MeV proton beam
impinged on a 5 mm water-cooled Beryllium target. Two independent experimental
techniques have been used to measure the neutron spectrum: a Time of Flight
(TOF) system used to estimate the high-energy contribution, and a Bonner Sphere
Spectrometer able to provide precise results from thermal energies up to 20
MeV. An overlap between the energy regions covered by the two systems will
permit a cross-check of the results from the different techniques. In this
paper, the measurement and analysis techniques will be presented together with
some preliminary results.Comment: 3 pages, 3 figures, also submitted as proceedings of the
International Conference on Nuclear Data for Science and Technology 201
Surfactant-like Effect and Dissolution of Ultrathin Fe Films on Ag(001)
The phase immiscibility and the excellent matching between Ag(001) and
Fe(001) unit cells (mismatch 0.8 %) make Fe/Ag growth attractive in the field
of low dimensionality magnetic systems. Intermixing could be drastically
limited at deposition temperatures as low as 140-150 K. The film structural
evolution induced by post-growth annealing presents many interesting aspects
involving activated atomic exchange processes and affecting magnetic
properties. Previous experiments, of He and low energy ion scattering on films
deposited at 150 K, indicated the formation of a segregated Ag layer upon
annealing at 550 K. Higher temperatures led to the embedding of Fe into the Ag
matrix. In those experiments, information on sub-surface layers was attained by
techniques mainly sensitive to the topmost layer. Here, systematic PED
measurements, providing chemical selectivity and structural information for a
depth of several layers, have been accompanied with a few XRD rod scans,
yielding a better sensitivity to the buried interface and to the film long
range order. The results of this paper allow a comparison with recent models
enlightening the dissolution paths of an ultra thin metal film into a different
metal, when both subsurface migration of the deposit and phase separation
between substrate and deposit are favoured. The occurrence of a surfactant-like
stage, in which a single layer of Ag covers the Fe film is demonstrated for
films of 4-6 ML heated at 500-550 K. Evidence of a stage characterized by the
formation of two Ag capping layers is also reported. As the annealing
temperature was increased beyond 700 K, the surface layers closely resembled
the structure of bare Ag(001) with the residual presence of subsurface Fe
aggregates.Comment: 4 pages, 3 figure
Power, norms and institutional change in the European Union: the protection of the free movement of goods
How do institutions of the European Union change? Using an institutionalist approach, this article highlights the interplay between power, cognitive limits, and the normative order that underpins institutional settings and assesses their impact upon the process of institutional change. Empirical evidence from recent attempts to reinforce the protection of the free movement of goods in the EU suggests that, under conditions of uncertainty, actors with ambiguous preferences assess attempts at institutional change on the basis of the historically defined normative order which holds a given institutional structure together. Hence, path dependent and incremental change occurs even when more ambitious and functionally superior proposals are on offer
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