19,819 research outputs found
On the Performance Limits of Pilot-Based Estimation of Bandlimited Frequency-Selective Communication Channels
In this paper the problem of assessing bounds on the accuracy of pilot-based
estimation of a bandlimited frequency selective communication channel is
tackled. Mean square error is taken as a figure of merit in channel estimation
and a tapped-delay line model is adopted to represent a continuous time channel
via a finite number of unknown parameters. This allows to derive some
properties of optimal waveforms for channel sounding and closed form Cramer-Rao
bounds
Large Deviations in the Free-Energy of Mean-Field Spin-Glasses
We compute analytically the probability distribution of large deviations in
the spin-glass free energy for the Sherrington-Kirkpatrick mean field model,
i.e. we compute the exponentially small probability of finding a system with
intensive free energy smaller than the most likely one. This result is obtained
by computing the average value of the partition function to the power as a
function of . At zero temperature this absolute prediction displays a
remarkable quantitative agreement with the numerical data.Comment: version to be submitted to PRL plus full power series in the
appendix, added references and minor correction
Safe discontinuation of nilotinib in a patient with chronic myeloid leukemia: a case report
Case presentation. We report the case of a 64-year-old Caucasian man diagnosed with chronic-phase chronic myeloid leukemia in April 2005. After 4 years of treatment with imatinib, he became intolerant to the drug and was switched to nilotinib. Two years later, he decided to stop nilotinib. Undetectable molecular response persisted for 30 months after discontinuation of the drug.
Introduction. Although there is a considerable amount of data in the literature on safe discontinuation of first-generation tyrosine kinase inhibitor therapy in patients with chronic myeloid leukemia, little is known about discontinuation of second-generation tyrosine kinase inhibitor therapy. Most previous studies have been focused on dasatinib, and the few cases of nilotinib withdrawal that have been reported had a median follow-up of 12 months. To the best of our knowledge, the present report is the first to describe nilotinib withdrawal with 30 months of follow-up.
Conclusion: Our present case suggests that nilotinib withdrawal is safe for patients with chronic myeloid leukemia who achieve a stable undetectable molecular response. Our patient was homozygous for killer immunoglobulin-like receptor haplotype A, previously reported to be a promising immunogenetic marker for undetectable molecular response. We recommend additional studies to investigate patient immunogenetic profiles and their potential role in complete response to therap
Neighborhood Effects: Accomplishments and Looking Beyond Them
The paper addresses the empirical significance of the social context in economic decisions. Decisions of individuals who share spatial and social milieus are likely to be interdependent, and econometric identification of social effects poses intricate data and methodological problems, including dealing with self-selection in spatial and socail groups. It uses a simple empirical framework to introduce social interactions effects at different levels of aggregation, and examines estimation problems into linear models, the impact of self-selection and of non linearities. It also examines neighborhood effects in job matching and proposes a research agenda that offers new techniques and data sources.Neighborhood effects, social interactions, social networks, social effects, self-selection, neighborhood choice, social multiplier, spatial effects
Statistical Characterization and Mitigation of NLOS Errors in UWB Localization Systems
In this paper some new experimental results about the statistical
characterization of the non-line-of-sight (NLOS) bias affecting time-of-arrival
(TOA) estimation in ultrawideband (UWB) wireless localization systems are
illustrated. Then, these results are exploited to assess the performance of
various maximum-likelihood (ML) based algorithms for joint TOA localization and
NLOS bias mitigation. Our numerical results evidence that the accuracy of all
the considered algorithms is appreciably influenced by the LOS/NLOS conditions
of the propagation environment
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