Polynomial evaluation over finite fields: new algorithms and complexity bounds

An efficient evaluation method is described for polynomials in finite fields. Its complexity is shown to be lower than that of standard techniques when the degree of the polynomial is large enough. Applications to the syndrome computation in the decoding of Reed-Solomon codes are highlighted.Comment: accepted for publication in Applicable Algebra in Engineering, Communication and Computing. The final publication will be available at springerlink.com. DOI: 10.1007/s00200-011-0160-

Association Between Speed of Multimorbidity Accumulation in Old Age and Life Experiences: A Cohort Study

Abstract Rapidly accumulating multiple chronic conditions (multimorbidity) during aging are associated with many adverse outcomes. We explored the association between 4 experiences throughout life—childhood socioeconomic circumstances, early-adulthood education, midlife occupational stress, and late-life social network—and the speed of chronic disease accumulation. We followed 2,589 individuals aged ≥60 years from the Swedish National Study on Aging and Care in Kungsholmen for 9 years (2001–2013). Information on life experiences was collected from detailed life-history interviews. Speed of disease accumulation was operationalized as the change in the count of chronic conditions obtained from clinical examinations, medical histories, laboratory data, drug use, and register linkages over 9 years. Linear mixed models were used to analyze the data. Speed of disease accumulation was lower in individuals with more than elementary education (for secondary, β × time = −0.065, 95% CI: −0.126, −0.004; for university, β × time = −0.118, 95% CI: −0.185, −0.050); for active occupations compared with high-strain jobs (β × time = −0.078, 95% CI: −0.138, −0.017); and for richer social networks (for moderate tertile, β × time = −0.102, 95% CI: −0.149, −0.055; for highest tertile, β × time = −0.135, 95% CI: −0.182, −0.088). The association between childhood circumstances and speed of disease accumulation was attenuated by later-life experiences. Diverse experiences throughout life might decelerate chronic disease accumulation during aging

Performance and Reliability Analysis of Cross-Layer Optimizations of NAND Flash Controllers

NAND flash memories are becoming the predominant technology in the implementation of mass storage systems for both embedded and high-performance applications. However, when considering data and code storage in non-volatile memories (NVMs), such as NAND flash memories, reliability and performance be- come a serious concern for systems' designer. Designing NAND flash based systems based on worst-case scenarios leads to waste of resources in terms of performance, power consumption, and storage capacity. This is clearly in contrast with the request for run-time reconfigurability, adaptivity, and resource optimiza- tion in nowadays computing systems. There is a clear trend toward supporting differentiated access modes in flash memory controllers, each one setting a differentiated trade-off point in the performance-reliability optimization space. This is supported by the possibility of tuning the NAND flash memory performance, reli- ability and power consumption acting on several tuning knobs such as the flash programming algorithm and the flash error correcting code. However, to successfully exploit these degrees of freedom, it is mandatory to clearly understand the effect the combined tuning of these parameters have on the full NVM sub-system. This paper performs a comprehensive quantitative analysis of the benefits provided by the run-time reconfigurability of an MLC NAND flash controller through the combined effect of an adaptable memory programming circuitry coupled with run-time adaptation of the ECC correction capability. The full non- volatile memory (NVM) sub-system is taken into account, starting from the characterization of the low level circuitry to the effect of the adaptation on a wide set of realistic benchmarks in order to provide the readers a clear figure of the benefit this combined adaptation would provide at the system leve

Price discovery of credit spreads in tranquil and crisis periods

In this paper we investigate the price discovery process in single-name credit spreads obtained from bond, credit default swap (CDS), equity and equity option prices. We analyse short term price discovery by modelling daily changes in credit spreads in the four markets with a vector autoregressive model (VAR). We also look at price discovery in the long run with a vector error correction model (VECM). We find that in the short term the option market clearly leads the other markets in the sub-prime crisis (2007-2009). During the less severe sovereign debt crisis (2009-2012) and the pre-crisis period, options are still important but CDSs become more prominent. In the long run, deviations from the equilibrium relationship with the option market still lead to adjustments in the credit spreads observed or implied from other markets. However, options no longer dominate price discovery in any of the periods considered. Our findings have implications for traders, credit risk managers and financial regulators

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde