10,224 research outputs found
On the graphical extraction of multipole mixing ratios of nuclear transitions
We propose a novel graphical method for determining the mixing ratios
{\delta} and their associated uncertainties for mixed nuclear transitions. It
incorporates the uncertainties both on both the measured and the theoretical
conversion coefficients. The accuracy of the method has been studied by
deriving the corresponding probability density function. The domains of
applicability of the method are carefully defined
A reassessment of <i>Paralimnocythere</i> Carbonnel, 1965 (Crustacea, Ostracoda, Limnocytherinae), with a description of a new genus and two new species
The Recent and Fossil species of Paralimnocythere are reassessed and the genus is characterized using both soft part and valve morphology. Seventeen species, of which eleven have living representatives, are here retained. Relictocytherina Negadaev-Nikonov, 1968 is confirmed as a synonym of Paralimnocythere; R. orginalis (Negadaev-Nikonov, 1965), the type species is furthermore synonymous with P. relicta (Lilljeborg, 1863). Paralimnocythere psammmophila (Flössner, 1965) and P. compressa (Brady & Norman, 1889) are both reinstated as valid species, quite different from P. relicta. All Recent Balkan species are retained as valid and P. ochridense (Klie, 1934) is here re-described as an example of the Balkan endemics. Paralimnocythere messanai nov. spec. is described from interstitial habitats in an Italian river and as such constitutes the first subterranean representative of the genus. There are seven Fossil species, the oldest ones being found in Miocene deposits. Paralimnocythere Wang Wen-Sheng, 1989 is a junior homonym and the three Cytherissa-like species require a new generic name. A new genus, Kiwicythere nov. gen., is erected to comprise a new species from the Chatham Islands (K. anneari nov. spec.) and P. vulgaris McKenzie & Swanson, 1981 from New Zealand. It is here postulated that this genus does not belong to the same phyletic lineage as Paralimnocythere s.s.; it is more closely related to other southern hemisphere limnocytherids. Paralimnocythere s.s. itself has a Palaeartic distribution
Range-based covariance estimation using high-frequency data: The realized co-range
We introduce the realized co-range, utilizing intraday high-lowprice ranges to estimate asset return covariances. Using simulationswe find that for plausible levels of bid-ask bounce and infrequentand non-synchronous trading the realized co-range improves upon therealized covariance, which uses cross-products of intraday returns.One advantage of the co-range is that in an ideal world it is fivetimes more efficient than the realized covariance when sampling atthe same frequency. The second advantage is that the upward bias dueto bid-ask bounce and the downward bias due to infrequent andnon-synchronous trading partially offset each other. In a volatilitytiming strategy for S\\&P500, bond and gold futures we find that theco-range estimates are less noisy as exemplified by lowertransaction costs and also higher Sharpe ratios when using moreweight on recent data for predicting covariances.bias-correction;market microstructure noise;high-frequency date;realized co-range;realized covariance
A footnote to the Poincaré complete reducibility theorem
Poincaré's work on the reduction of abelian integrals contains implicitly an algorithm for the expression of a theta function as a sum of products of theta functions of fewer variables in the presence of reduction . The aim of this paper is to give explicit formulations and reasonably complete proofs of Poincaré's results
Optimizing wireless access networks towards power consumption : influence of the optimization algorithm
Application of opposition-based learning concepts in reducing the power consumption in wireless access networks
The reduction of power consumption in wireless access networks is a challenging and important issue. In this paper, we apply Opposition-Based Learning (OBL) concepts for reducing the power consumption of LTE base stations. More specifically, we present a new Modified Biogeography Based Optimization (BBO) algorithm enhanced with OBL techniques. We apply both the original BBO and the new Modified Opposition BBO (MOBBO) to network design cases to the city of Ghent, Belgium, with 75 possible LTE base station locations. We optimize the network towards two objectives: coverage maximization and power consumption minimization. Preliminary results indicate the advantages and applicability of our approach
Static and dynamic semantics of NoSQL languages
We present a calculus for processing semistructured data that spans
differences of application area among several novel query languages, broadly
categorized as "NoSQL". This calculus lets users define their own operators,
capturing a wider range of data processing capabilities, whilst providing a
typing precision so far typical only of primitive hard-coded operators. The
type inference algorithm is based on semantic type checking, resulting in type
information that is both precise, and flexible enough to handle structured and
semistructured data. We illustrate the use of this calculus by encoding a large
fragment of Jaql, including operations and iterators over JSON, embedded SQL
expressions, and co-grouping, and show how the encoding directly yields a
typing discipline for Jaql as it is, namely without the addition of any type
definition or type annotation in the code
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