6,184 research outputs found
Fractional Newton-Raphson Method Accelerated with Aitken's Method
The Newton-Raphson (N-R) method is characterized by the fact that generating
a divergent sequence can lead to the creation of a fractal, on the other hand
the order of the fractional derivatives seems to be closely related to the
fractal dimension, based on the above, a method was developed that makes use of
the N-R method and the fractional derivative of Riemann-Liouville (R-L) that
has been named as the Fractional Newton-Raphson (F N-R) method.
In the following work we present a way to obtain the convergence of the F N-R
method, which seems to be at least linearly convergent for the case where the
order of the derivative is different from one, a simplified way to
construct the fractional derivative and fractional integral operators of R-L is
presented, an introduction to the Aitken's method is made and it is explained
why it has the capacity to accelerate the convergence of iterative methods to
finally present the results that were obtained when implementing the Aitken's
method in F N-R method.Comment: Newton-Raphson Method, Fractional Calculus, Fractional Derivative of
Riemann-Liouville, Method of Aitken. arXiv admin note: substantial text
overlap with arXiv:1710.0763
On the Design of Cryptographic Primitives
The main objective of this work is twofold. On the one hand, it gives a brief
overview of the area of two-party cryptographic protocols. On the other hand,
it proposes new schemes and guidelines for improving the practice of robust
protocol design. In order to achieve such a double goal, a tour through the
descriptions of the two main cryptographic primitives is carried out. Within
this survey, some of the most representative algorithms based on the Theory of
Finite Fields are provided and new general schemes and specific algorithms
based on Graph Theory are proposed
Nitrogen and carbon isotope composition of organic Fertilizers.
Synthetic (e.g. urea) and organic fertilizers (e.g. compost) differed markedly in N isotope composition and the greater the difference between organic and synthetic fertilizer the more robust will be the differentiation of crops and vegetable grown under different farming systems. The objective of this study was to compare nitrogen and carbon isotope composition of organic fertilizers and manures available for conventional and organic farming in Brazil. Seven samples of organic fertilizer, two of organo-mineral fertilizers and two of different animal manures were analyzed for nitrogen and carbon isotope composition (15N, 13C). Organic fertilizers and manure samples were enriched in 15N as expected. Using synthetic fertilizers as the primary material of organo-mineral fertilizer can imprint a low 15N value to the final product. Organic fertilizers, organo-mineral fertilizers and manures can have their organic feedstock differentiated using 13C. These are preliminary data of the isotopic composition of organic fertilizer in Brazil. Therefore, a wider survey of fertilizers and an experimental approach for organic- and organo-mineral fertilizer production is needed to elucidate the natural isotope variation of the array of available products
Dual-path state reconstruction scheme for propagating quantum microwaves and detector noise tomography
Quantum state reconstruction involves measurement devices that are usually
described by idealized models, but not known in full detail in experiments. For
weak propagating microwaves, the detection process requires linear amplifiers
which obscure the signal with random noise. Here, we introduce a theory which
nevertheless allows one to use these devices for measuring all quadrature
moments of propagating quantum microwaves based on cross-correlations from a
dual-path amplification setup. Simultaneously, the detector noise properties
are determined, allowing for tomography. We demonstrate the feasibility of our
novel concept by proof-of-principle experiments with classical mixtures of weak
coherent microwaves.Comment: 11 pages, 3 figure
Análise de crescimento de cana-de-açúcar inoculada com bactérias diazotróficas e adubada com N-fertilizantes.
Quantificação das emissões de N2O e CH4 e dejetos de suínos e cama de frangos aplicados em pastagens: influência de variáveis edafoclimáticas.
Impacto da adubação verde e da fertilização nitrogenada sobre as emissões de N2O em campim-elefante.
Impacto do sistema de integração lavoura-pecuária os estoques e carbono e nitrogênio de um latossolo do cerrado de Goiânia, GO.
Preparation and structural properties of thin films and multilayers of the Heusler compounds Cu2MnAl, Co2MnSn, Co2MnSi and Co2MnGe
We report on the preparation of thin films and multilayers of the
intermetallic Heusler compound CuMnAl, Co2MnSn, Co2MnSi and Co2MnGe by
rf-sputtering on MgO and Al2O3 substrates. Cu2MnAl can be grown epitaxially
with (100)-orientation on MgO (100) and in (110)-orientation on Al2O3 a-plane.
The Co based Heusler alloys need metallic seedlayers to induce high quality
textured growth. We also have prepared multilayers with smooth interfaces by
combining the Heusler compounds with Au and V. An analysis of the ferromagnetic
saturation magnetization of the films indicates that the Cu2MnAl-compound tends
to grow in the disordered B2-type structure whereas the Co-based Heusler alloy
thin films grow in the ordered L21 structure. All multilayers with thin layers
of the Heusler compounds exhibit a definitely reduced ferromagnetic
magnetization indicating substantial disorder and intermixing at the
interfaces.Comment: 21 pages, 8 figure
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