Search results for "FREQUENCY"

Low-complexity AoA and AoD Estimation in the Transformed Spatial Domain for Millimeter Wave MIMO Channels

2021

High-accuracy angle of arrival (AoA) and angle of departure (AoD) estimation is critical for cell search, stable communications and positioning in millimeter wave (mmWave) cellular systems. Moreover, the design of low-complexity AoA/AoD estimation algorithms is also of major importance in the deployment of practical systems to enable a fast and resource-efficient computation of beamforming weights. Parametric mmWave channel estimation allows to describe the channel matrix as a combination of direction-dependent signal paths, exploiting the sparse characteristics of mmWave channels. In this context, a fast Transformed Spatial Domain Channel Estimation (TSDCE) algorithm was recently proposed …

Maximizers’ Susceptibility to the Effect of Frequency vs. Percentage Format in Risk Representation

2022

The present study explored the susceptibility of maximizers to the effect of the specific information format—frequency vs. percentage—in a risk assessment task. One-hundred and fourteen participants were randomized into two experimental conditions: a frequency format and a percentage format. In both conditions, participants had to rate the level of risk that a mental patient would harm someone after his discharge from a mental health facility, based on the information reported in the psychologist’s assessment for that patient. In the frequency condition, the information was presented in terms of frequencies, whereas in the percentage condition the same information was pres…

Precision measurement of the B-s(0)-(B)over-bar(s)(0) oscillation frequency with the decay B-s(0) -> D-s(-)pi(+)

2013

A key ingredient to searches for physics beyond the Standard Model in $B^{0}_{s}$ mixing phenomena is the measurement of the $B^{0}_{s}$-$\bar{B}^{0}_{s}$ oscillation frequency, which is equivalent to the mass difference $\Delta m_{s}$ of the $B^{0}_{s}$ mass eigenstates. Using the world's largest $B^{0}_{s}$ meson sample accumulated in a dataset, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected by the LHCb experiment at the CERN LHC in 2011, a measurement of $\Delta m_{s}$ is presented. A total of about 34,000 $B^{0}_{s}\rightarrow D^{-}_{s}\pi^{+}$ signal decays are reconstructed, with an average decay time resolution of 44 fs. The oscillation frequency is measured to…

Channel Estimation and Interference Cancellation for MIMO-OFDM Systems

2007

This paper proposes a new channel estimation method and a new interference cancellation scheme for multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems in the presence of intersymbol interference (IS1). The proposed channel estimation method uses special training sequences (TSs) to have a desirable crest-factor of the transmitted training signal, and to prevent the influence of ISI on the channel estimation performance. By using the recommended training sequences, the ill-conditioned problem of the least square (LS) filter integrated in the proposed channel estimator can be avoided. The proposed interference cancellation scheme uses the estimated cha…

Performance Analysis of STBC-OFDM Systems in Temporally or Spatially Correlated Fading Channels

2010

This paper analyzes the performance of space-time block coded orthogonal frequency division multiplexing (OFDM) systems. In our analysis, we abandon the usually made assumption of quasi-static channel conditions. Instead of this, we consider the more general and realistic case that the channel envelope changes during two consecutive transmission time slots. In addition, we take the spatial correlation between sub-channels into account. We first present a general formal expression for the bit error probability (BEP), from which we find analytical solutions for the BEP not only for temporally fading channels but also for spatially correlated channels. The knowledge of the obtained analytical …

Associations of the FTO rs9939609 and the MC4R rs17782313 polymorphisms with type 2 diabetes are modulated by diet, being higher when adherence to th…

2012

Background: Although the Fat Mass and Obesity (FTO) and Melanocortin-4 Receptor (MC4R) genes have been consistently associated with obesity risk, the association between the obesity-risk alleles with type 2 diabetes is still controversial. In some recent meta-analyses in which significant results have been reported, the associations disappeared after adjustment for body mass index (BMI). However gene-diet interactions with dietary patterns have not been investigated. Our main aim was to analyze whether these associations are modulated by the level of adherence to the Mediterranean Diet (MedDiet). Methods: Case-control study in 7,052 high cardiovascular risk subjects (3,430 type 2 diabetes c…

Novel genetic variant in FTO influences insulin levels and insulin resistance in severely obese children and adolescents.

2008

Background: The global prevalence of obesity and overweight is increasing rapidly among adults as well as among children and adolescents. Recent genome-wide association studies have provided strong support for association between variants in the FTO gene and obesity. We sequenced regions of the FTO gene to identify novel variants that are associated with obesity and related metabolic traits. Results: We screened exons 3 and 4 including exon-intron boundaries in FTO in 48 obese children and adolescents and identified three novel single nucleotide polymorphism in the fourth intronic region, (c.896 + 37A > G, c.896 + 117C > G and c.896 + 223A > G). We further genotyped c.896 + 223A > G in 962 …

84 Enhanced Characterization of the Thickness and Bone Mineral Density of the Radius and Tibia by Low-Frequency Guided-Wave Ultrasound

2009

Emergence of statistically validated financial intraday lead-lag relationships

2014

According to the leading models in modern finance, the presence of intraday lead-lag relationships between financial assets is negligible in efficient markets. With the advance of technology, however, markets have become more sophisticated. To determine whether this has resulted in an improved market efficiency, we investigate whether statistically significant lagged correlation relationships exist in financial markets. We introduce a numerical method to statistically validate links in correlation-based networks, and employ our method to study lagged correlation networks of equity returns in financial markets. Crucially, our statistical validation of lead-lag relationships accounts for mult…

Accessing finite momentum excitations of the one-dimensional Bose-Hubbard model using superlattice modulation spectroscopy

2018

We investigate the response to superlattice modulation of a bosonic quantum gas confined to arrays of tubes emulating the one-dimensional Bose-Hubbard model. We demonstrate, using both time-dependent density matrix renormalization group and linear response theory, that such a superlattice modulation gives access to the excitation spectrum of the Bose-Hubbard model at finite momenta. Deep in the Mott-insulator, the response is characterized by a narrow energy absorption peak at a frequency approximately corresponding to the onsite interaction strength between bosons. This spectroscopic technique thus allows for an accurate measurement of the effective value of the interaction strength. On th…