182,528 research outputs found
Neuropsychological constraints to human data production on a global scale
No full textWhich are the factors underlying human information production on a global level? In order to gain an insight into this question we study a corpus of 252–633 mil. publicly available data files on the Internet corresponding to an overall storage volume of 284–675 Terabytes. Analyzing the file size distribution for several distinct data types we find indications that the neuropsychological capacity of the human brain to process and record information may constitute the dominant limiting factor for the overall growth of globally stored information, with real-world economic constraints having only a negligible influence. This supposition draws support from the observation that the files size distributions follow a power law for data without a time component, like images, and a log-normal distribution for multimedia files, for which time is a defining qualia.
Author summary: The generation of new information is limited by two key factors, by the incurring economic costs and by the capacity of the human brain to process and store data and information; the controlling agent needs to retain an overall understanding even when data is generated by semiautomatic processes. These processes are reflected in the statistical properties of the data files publicly available on the Internet. Collecting a corpus of 252–633 mil. files we find that the statistics of the file size distribution are consistent with the supposition that data production on a global level is shaped and limited by the neuropsychological information processing capacity of the brain, with economic and hardware constraints having a negligible influence
F. Gros et R. Nagaswamy. Uttaramērūr. Légendes, histoire, monuments
No full textBareau André. F. Gros et R. Nagaswamy. Uttaramērūr. Légendes, histoire, monuments. In: Revue de l'histoire des religions, tome 183, n°1, 1973. pp. 90-91
F. Gros et R. Nagaswamy. Uttaramērūr. Légendes, histoire, monuments
No full textBareau André. F. Gros et R. Nagaswamy. Uttaramērūr. Légendes, histoire, monuments. In: Revue de l'histoire des religions, tome 183, n°1, 1973. pp. 90-91
Où René Gros et Pierre Seize n’ont que faire
No full textR. Où René Gros et Pierre Seize n’ont que faire . In: Revue Internationale d'Onomastique, 4e année N°3, Septembre 1952. pp. 199-200
Why Europe will suffer more. CEPS Policy Brief No. 194, 16 July 2009
No full textEven though the financial crisis might have started in the US, CEPS Director Daniel Gros finds in a new CEPS Policy Brief that even more combustible material had accumulated in Europe, and that therefore that it likely that the cost will be higher here and the recovery slower than on the other side of the Atlantic. This conclusion is based on a careful analysis of two indicators of looming financial instability: credit expansion (or leverage) and asset price bubbles
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
P_1 covers over commutative rings
No full textIn this paper we consider the class P_1(R) modules of
projective dimension at most one over a commutative ring R and we investigate
when P_1(R) is a covering class. More precisely, we investigate
Enochs' Conjecture for this class, that is the question of whether
P_1(R) is covering necessarily implies that P_1(R) is
closed under direct limits. We answer the question affirmatively in the case of
a commutative semihereditary ring R. This gives an example of a cotorsion
pair (P_1(R), P_1(R)-orthogonal) which is not necessarily of
finite type such that P_1(R) satisfies Enochs' Conjecture.
Moreover, we describe the class P_1(R) over
(not-necessarily commutative) rings which admit a classical ring of quotients
Covering classes and 1-tilting cotorsion pairs over commutative rings
No full textWe are interested in characterising the commutative rings for which a 1-tilting cotorsion pair provides for covers, that is when the class A is a covering class. We use Hrbekšfs bijective correspondence between the 1-tilting cotorsion pairs over a commutative ring R and the faithful finitely generated Gabriel topologies on R. Moreover, we use results of Bazzoni-Positselski, in particular a generalisation of Matlis equivalence and their characterisation of covering classes for 1-tilting cotorsion pairs arising from flat injective ring epimorphisms. Explicitly, if is the Gabriel topology associated to the 1-tilting cotorsion pair, and R is the ring of quotients with respect to, we show that if A is covering, then G is a perfect localisation (in Stenstromšfs sense [B. Stenstrom, Rings of Quotients, Springer, New York, 1975]) and the localisation R has projective dimension at most one as an R-module. Moreover, we show that is covering if and only if both the localisation RG and the quotient rings R/J are perfect rings for every J ∈. Rings satisfying the latter two conditions are called G-almost perfect
The phase diagram of the square lattice bilayer Hubbard model: a variational Monte Carlo study
No full textWe investigate the phase diagram of the square lattice bilayer Hubbard model at half-filling with the variational Monte Carlo method for both the magnetic and the paramagnetic case as a function of the interlayer hopping tτ and on-site Coulomb repulsion U. With this study we resolve some discrepancies in previous calculations based on the dynamical mean-field theory, and we are able to determine the nature of the phase transitions between metal, Mott insulator and band insulator. In the magnetic case we find only two phases: an antiferromagnetic Mott insulator at small tτ for any value of U and a band insulator at large tτ . At large U values we approach the Heisenberg limit. The paramagnetic phase diagram shows at small tτ a metal to Mott insulator transition at moderate U values and a Mott to band insulator transition at larger U values. We also observe a re-entrant Mott insulator to metal transition and metal to band insulator transition for increasing tτ in the range of 5.5t < U < 7.5t. Finally, we discuss the phase diagrams obtained in relation to findings from previous studies based on different many-body approaches.© 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft
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