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Search Results: 1 - 10 of 191600 matches for " Díaz Díaz "
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Apuntes sobre la aritmética Maya
Díaz Díaz,Ruy;
Educere , 2006,
Abstract: the mayan numeral system had a 20 base with 5 sub-base, positional and with use of cero. this essay ofers some algorithms for the basic arithmetic operations: addition, subtraction, multiplication and division, using the numbering system employed by the mayas. it can be noted that the reasoning used to solve the diferent operations are the same as in the arabic numbering system, with the diference that in the mayan numbers system there was no need to study multiplication tables.
Importancia de los estudios de mortalidad en diabéticos Importance of mortality studies performed in diabetics
Oscar Díaz Díaz
Revista Cubana de Endocrinología , 2001,
Primer consenso cubano de prediabetes First Cuban consensus of prediabetes
Oscar Díaz Díaz
Revista Cubana de Endocrinología , 2011,
Oscar Díaz Díaz
Revista Cubana de Endocrinología , 2008,
Importancia del sitio diabetes mellitus en Infomed. Importance of the web site on diabetes mellitus in Infomed.
Oscar Díaz Díaz
Revista Cubana de Endocrinología , 2008,
Rese a de "Jesús María Sanromá: An American Twentieth-Century Pianist" de Alberto Hernández
Edgardo Díaz Díaz
Centro Journal , 2009,
Why a universe as a whole must be a quantum object  [PDF]
Pedro F. González-Díaz
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.35053
Abstract: Technical and physical reasons are given in favor of the idea that single universes, accelerating or not, essentially are quantum-mechanical entities without any classical analogs, even when they are forming part of a given multi- verse.
Testing for Deterministic Components in Vector Seasonal Time Series  [PDF]
José Luis Gallego, Carlos Díaz
Open Journal of Statistics (OJS) , 2011, DOI: 10.4236/ojs.2011.13017
Abstract: Certain locally optimal tests for deterministic components in vector time series have associated sampling distributions determined by a linear combination of Beta variates. Such distributions are nonstandard and must be tabulated by Monte Carlo simulation. In this paper, we provide closed form expressions for the mean and variance of several multivariate test statistics, moments that can be used to approximate unknown distributions. In particular, we find that the two-moment Inverse Gaussian approximation provides a simple and fast method to compute accurate quantiles and p-values in small and asymptotic samples. To illustrate the scope of this approximation we review some standard tests for deterministic trends and/or seasonal patterns in VARIMA and structural time series models.
Evaluation of Residual Stresses Induced by High Speed Milling Using an Indentation Method  [PDF]
Felipe Díaz, Claudio Mammana, Armando Guidobono
Modern Mechanical Engineering (MME) , 2012, DOI: 10.4236/mme.2012.24019

In this work, a recently developed method based on the change of distance between collinear indents is used to evaluate different states of residual stress, which were generated in samples of AA 6082-T6 and AA 7075-T6 aluminium alloys milled at high speed. One of the advantages of this method, which needs a universal measuring machine, is not requiring neither the use of specific equipment nor highly skilled operators. Also, by integrating an indentation device to the mentioned machine, the absolute error of measurement can be reduced. In results obtained in samples subjected to different cutting conditions it is observed a correlation between the stress values and the depth of cut, showing the AA 6082-T6 alloy higher susceptibility to be stressed. Furthermore, the high sensitivity of the method allowed detecting very small differences in the values reached by different normal components in the zones corresponding to climb and conventional cutting. It is important to note that these differences were similar for both evaluated alloys. Finally, the directions associated with the principal components of residual stress, where maximum local plastic stretching occurs, were found to be strongly dependent on the rolling direction prior to machining.

Kinematic Decoupled Core Paradigm: Counterrotation or Just Warping  [PDF]
Rubén J. Díaz, Horacio Dottori
International Journal of Astronomy and Astrophysics (IJAA) , 2016, DOI: 10.4236/ijaa.2016.62016
Abstract: Several mechanisms have been proposed in recent years to explain kinematic decoupled cores (KDCs) in early type galaxies as well as the large differences in angular momentum between KDCs and host galaxy. Most of the proposed scenarios involve large fractions of merging events, high speed interactions with dwarf spheroidal galaxies, cusp effect of the dark matter density profiles, etc. We here argue that counterrotation as well as fast and slow rotation of disks or spheroids at the center of galaxies can also be explained by a misalignment of the central spheroid equatorial plane with regard to that defined by the observed external stellar rotation. Contrary to what happens at the outer region of disk galaxies, once instability has led to the inner warped core, the perturbed orbits can maintain a common orientation due to the rigid body like rotation at the central region of the galaxy. The spatial configuration that furnishes the smallest angular momentum difference between the KDC and the host galaxy is completely defined by observed parameters in the plane of the sky, namely, the inclination of the inner and outer disks and the angle between the two lines of nodes. As an example we modeled the paradigmatic and extreme case of the 2D radial velocity field of NGC 4382 nucleus. Tilt angles of the KDC not larger than 30 degrees also allow explaining fast and low rotators of the called “Sauron paradigm” in a unified scenario. The maximum for the three parameters, namely, velocity of the inner rotator, difference of position angle and difference with the outer rotation velocity of the whole Sauron sample, are consistently correlated in agreement with the proposed scenario. These quantities do not correlate with the galaxies magnitude, mass (since large and dwarf spheroidals show apparent counterrotation as well) or environment, also suggesting that an internal phenomenon like the central spheroid warping, that we are here proposing, may be at work.
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