2,738 research outputs found
Optimizing Approach for Sifting Process to Solve a Common Type of Empirical Mode Decomposition Mode Mixing
Empirical mode decomposition (EMD), a new
data-driven of time-series decomposition, has the advantage of
supposing that a time series is non-linear or non-stationary, as
is implicitly achieved in Fourier decomposition. However, the
EMD suffers of mode mixing problem in some cases. The aim of
this paper is to present a solution for a common type of signals
causing of EMD mode mixing problem, in case a signal suffers
of an intermittency. By an artificial example, the solution shows
superior performance in terms of cope EMD mode mixing problem
comparing with the conventional EMD and Ensemble Empirical
Mode decomposition (EEMD). Furthermore, the over-sifting problem
is also completely avoided; and computation load is reduced roughly
six times compared with EEMD, an ensemble number of 50
L'accompagnement infirmier du patient atteint de sclérose en plaques: travail de Bachelor
Le prĂ©sent travail porte sur les dĂ©terminants de lâaccompagnement infirmier Ă lâĂ©gard dâune personne atteinte de sclĂ©rose en plaques (SEP). La SEP est une maladie neurodĂ©gĂ©nĂ©rative, incurable et Ă©volutive qui a des consĂ©quences sur les sphĂšres physiques, psychiques, sociales et spirituelles du patient, et par consĂ©quent, elle requiert une prise en soin globale de la part de lâinfirmiĂšre. Le traitement mĂ©dicamenteux nâest pas suffisant pour ralentir lâĂ©volution de cette affection, dâautres services de soins sont Ă©galement nĂ©cessaires pour offrir du bien-ĂȘtre au patient. Les poussĂ©es de la SEP sont imprĂ©visibles et lâĂ©volution de cette pathologie est incertaine tout comme lâavenir du patient. De plus le patient subit plusieurs pertes liĂ©es Ă sa maladie et peut donc prĂ©senter une dĂ©tresse psychologique liĂ©e Ă ces pertes. La notion « accompagnement » est, Ă lâheure actuelle, devenue une compĂ©tence qui comprend plusieurs qualitĂ©s importantes que lâinfirmiĂšre met en oeuvre au moment du diagnostic de la SEP et tout au long du chemin de vie du patient. Lâaccompagnement englobe diverses composantes telles que lâempathie, lâĂ©coute, la compassion et le respect qui permettent entre autre dâoffrir une bonne qualitĂ© dâaccompagnement au patient. Ce travail met en lumiĂšre les dix facteurs caratifs de la thĂ©orie « Human Caring » proposĂ©e par Watson (1998). Ceux-ci sont mis en lien avec plusieurs situations concrĂštes relatives Ă la SEP. Ce travail met en lumiĂšre les Ă©lĂ©ments qui contribuent Ă une bonne prise en soins et favorisent un accompagnement vis-Ă -vis du patient atteint de SEP. Tous les facteurs caratifs pris en considĂ©ration ne peuvent pas ĂȘtre considĂ©rĂ©s dans cette prise en charge, car certains dâentre eux constituent un idĂ©al, mais demeurent difficiles Ă appliquer dans la rĂ©alitĂ© de la pratique professionnelle autour de la SEP. A lâissue de cette rĂ©flexion, il est recommandĂ© aux soignants des unitĂ©s de neurologie de rĂ©flĂ©chir quant Ă la mise en place dâun outil permettant dâĂ©valuer tous les besoins des patients atteints de SEP afin de pouvoir y rĂ©pondre. La crĂ©ation dâune anamnĂšse complĂšte ou dâun questionnaire sur les attentes des personnes vivant avec cette maladie serait-il envisageable pour le futur
Photosynthesis-controlled calcification in a hypersaline microbial mat
We investigated the hypothesis that sulfate reduction rather than oxygenic photosynthesis promotes calcification in a hypersaline microbial mat by increasing the ion concentration product: ICP 5 [Ca2+] X [CO32-]. Poreâwater 3 calcium concentration profiles directly measured with microsensors show that calcium concentration in the photic zone decreased in illuminated mats and increased slightly in dark mats. High pH values in the photic zone of illuminated mats resulted in higher carbonate concentrations (2.25 mmol L-1) than in dark mats (0.75 mmol L-1), although the dissolved inorganic carbon (DIC) poreâwater concentration in the former was much lower (5.9 mmol L-1) than in the latter (9.9 mmol L-1). The pHâinduced rise in carbonate concentration in the light was the main factor influencing the ICP, while changes in Ca-1 concentration played a subsidiary role. Sulfate reduction did not result in a net pH increase in these mats, as rates in the photic zone were comparable between illuminated and dark mats (4 and 5 nmol cm-2 h-1, respectively), and pH increased in illuminated mats but not in dark mats. Calcium carbonate precipitation in the photic zone of these hypersaline mats is primarily controlled by photosynthesisinduced pH and carbonate concentration increases. However, heterotrophic bacteria, including sulfate reducers, play an important complementary role in calcification because they maintain high concentrations of DIC in the mat pore water
Inter-network regions of the Sun at millimetre wavelengths
The continuum intensity at wavelengths around 1 mm provides an excellent way
to probe the solar chromosphere. Future high-resolution millimetre arrays, such
as the Atacama Large Millimeter Array (ALMA), will thus produce valuable input
for the ongoing controversy on the thermal structure and the dynamics of this
layer. Synthetic brightness temperature maps are calculated on basis of
three-dimensional radiation (magneto-)hydrodynamic (MHD) simulations. While the
millimetre continuum at 0.3mm originates mainly from the upper photosphere, the
longer wavelengths considered here map the low and middle chromosphere. The
effective formation height increases generally with wavelength and also from
disk-centre towards the solar limb. The average intensity contribution
functions are usually rather broad and in some cases they are even
double-peaked as there are contributions from hot shock waves and cool
post-shock regions in the model chromosphere. Taking into account the
deviations from ionisation equilibrium for hydrogen gives a less strong
variation of the electron density and with it of the optical depth. The result
is a narrower formation height range. The average brightness temperature
increases with wavelength and towards the limb. The relative contrast depends
on wavelength in the same way as the average intensity but decreases towards
the limb. The dependence of the brightness temperature distribution on
wavelength and disk-position can be explained with the differences in formation
height and the variation of temperature fluctuations with height in the model
atmospheres.Comment: 15 pages, 10 figures, accepted for publication in A&A (15.05.07
Correlating in situ RHEED and XRD to study growth dynamics of polytypism in nanowires
Design of novel nanowire (NW) based semiconductor devices requires deep understanding and technological control of NW growth. Therefore, quantitative feedback over the structure evolution of the NW ensemble during growth is highly desirable. We analyse and compare the methodical potential of reflection high-energy electron diffraction (RHEED) and X-ray diffraction reciprocal space imaging (XRD) for in situ growth characterization during molecular-beam epitaxy (MBE). Simultaneously recorded in situ RHEED and in situ XRD intensities show strongly differing temporal behaviour and provide evidence of the highly complementary information value of both diffraction techniques. Exploiting the complementarity by a correlative data analysis presently offers the most comprehensive experimental access to the growth dynamics of statistical NW ensembles under standard MBE growth conditions. In particular, the combination of RHEED and XRD allows for translating quantitatively the time-resolved information into a height-resolved information on the crystalline structure without a priori assumptions on the growth model. Furthermore, we demonstrate, how careful analysis of in situ RHEED if supported by ex situ XRD and scanning electron microscopy (SEM), all usually available at conventional MBE laboratories, can also provide highly quantitative feedback on polytypism during growth allowing validation of current vapourâliquidâsolid (VLS) growth models
Renormalization group trajectories from resonance factorized S-matrices
We propose and investigate a large class of models possessing resonance
factorized S-matrices. The associated Casimir energy describes a rich pattern
of renormalization group trajectories related to flows in the coset models
based on the simply laced Lie Algebras. From a simplest resonance S-matrix,
satisfying the ``-property'', we predict new flows in non-unitary
minimal models.Comment: (7 pages) (no figures included
Segment-Based Genetic Programming
ABSTRACT Genetic Programming (GP) is one of the successful evolutionary computation techniques applied to solve classification problems, by searching for the best classification model applying the fitness evaluation. The fitness evaluation process greatly impacts the overall execution time of GP and is therefore the focus of this research study. This paper proposes a segment-based GP (SegGP) technique that reduces the execution time of GP by partitioning the dataset into segments, and using the segments in the fitness evaluation process. Experiments were done using four datasets and the results show that SegGP can obtain higher or similar accuracy results in shorter execution time compared to standard GP
Exact Conductance through Point Contacts in the Fractional Quantum Hall Effect
The conductance for tunneling through a point contact between two
quantum Hall edges is described by a universal scaling function, which has
recently been measured experimentally. We compute this universal function
exactly, by using the thermodynamic Bethe ansatz and a Boltzmann equation.Comment: 10 pages, 1 figur
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