Results 71 to 80 of about 24,580 (172)

The Power Gain Difference Method Analysis

Sensors, 2020
In this paper, we propose a new approach to passively locate the 3D position of a signal source. This novel technique, called the power gain difference (PGD), is based only on measuring the received signal strength (RSS) with multiple sensors deployed in
Jiří Veselý, Petr Hubáček, Jana Olivová   +2 more
doaj   +1 more source

CRLBs for Pilot-Aided Channel Estimation in OFDM System under Gaussian and Non-Gaussian Mixed Noise [PDF]

, 2012
The determination of Cramer-Rao lower bound (CRLB) as an optimality criterion for the problem of channel estimation in wireless communication is a very important issue. Several CRLBs on channel estimation have been derived for Gaussian noise.
Huang, J. Y., Shen, X. F., Wang, P.
core   +1 more source

Modeling the Intermediate Flow Regime in Flow‐Compensated Intravoxel Incoherent Motion MRI

Magnetic Resonance in Medicine, Volume 95, Issue 6, Page 3476-3487, June 2026.
ABSTRACT Purpose The intravoxel incoherent motion (IVIM) model is commonly used to separate the effects of motion related to diffusion and blood microcirculation (perfusion) on the MR signal. Depending on the encoding time (T), it is possible to probe the different temporal regimes of blood motion, which resemble a ballistic flow at short T and a ...
Louise Rosenqvist, Mikael Montelius, Isabella M. Björkman‐Burtscher, Elina Petersson, Maria Ljungberg, Oscar Jalnefjord   +5 more
wiley   +1 more source

Applications of the van Trees inequality : a Bayesian Cramér-Rao bound [PDF]

, 2001
We use a Bayesian version of the Cramer-Rao lower bound due to van Trees to give an elementary proof that the limiting distibution of any regular estimator cannot have a variance less than the classical information bound, under minimal regularity ...
Gill, R.D., Levit, B.Y.
core  

Toward Optimized Intravoxel Incoherent Motion (IVIM) and Compartmental T2 Mapping in Abdominal Organs

Magnetic Resonance in Medicine, Volume 95, Issue 6, Page 3161-3175, June 2026.
ABSTRACT Purpose To quantitatively assess the bias in the intravoxel incoherent motions (IVIM)–derived pseudo‐diffusion volume fraction (f) caused by the differences in relaxation times between the tissue and fluid compartments, and to develop a two‐dimensional (b‐value‐TE) fitting approach for simultaneous T2 and IVIM parameter estimation along with ...
Julia Stabinska, Thomas A. Thiel, Hans‐Jörg Wittsack, Alexandra Ljimani, Helge J. Zöllner   +4 more
wiley   +1 more source

Complementary Sensitivity of Fixed‐Time and Fixed‐Oscillation Regimes to Exchange and Structural Disorder in the Human Brain Revealed Using Oscillating‐Gradient Diffusion MRI With Ultra‐Strong Gradients

Magnetic Resonance in Medicine, Volume 95, Issue 6, Page 3429-3444, June 2026.
ABSTRACT Purpose Oscillating‐gradient spin‐echo (OGSE) diffusion MRI probes cell geometry and membrane integrity through the frequency‐dependence of kurtosis, but prior studies have reported inconsistent findings depending on how frequency is varied. We compared frequency‐dependent kurtosis in the human brain under two regimes: varying frequency with ...
Dongsuk Sung, Kwok‐Shing Chan, Julianna Gerold, Wen Zhong, Jialan Zheng, Qiyuan Tian, Hua Guo, Susie Y. Huang, Hong‐Hsi Lee   +8 more
wiley   +1 more source

Existence of unbiased estimators in discrete quantum systems

Physical Review Research
The Cramér-Rao bound serves as a crucial lower limit for the mean square error of an estimator in frequentist parameter estimation. Paradoxically, it requires highly accurate prior knowledge of the estimated parameter for constructing the optimal ...
Javier Navarro, Ricard Ravell Rodríguez, Mikel Sanz   +2 more
doaj   +1 more source

Estimators, escort probabilities, and phi-exponential families in statistical physics

, 2004
The lower bound of Cramer and Rao is generalized to pairs of families of probability distributions, one of which is escort to the other. This bound is optimal for certain families, called phi-exponential in the paper.
Naudts, Jan
core  

Absolute Quantification of Brain Deuterium Metabolic Imaging in Healthy Volunteers and Glioblastoma Patients at 7T

Magnetic Resonance in Medicine, Volume 95, Issue 6, Page 3077-3094, June 2026.
ABSTRACT Purpose We present a method for absolute quantification of deuterated metabolites in vivo at 7T. We describe acquisition protocols and an analysis pipeline compatible with 7T Terra MRIs. We apply them using a 2H/1H receive array in healthy volunteers and glioblastoma patients.
Jabrane Karkouri, Masha Novoselova, Sarah Miller, Minghao Zhang, Alexandra Constantinou, Carina Graf, Özlem Ipek, Daniel Atkinson, Brandon Tramm, Scott Schillak, Richard Mair, Kevin Brindle, Christopher T. Rodgers   +12 more
wiley   +1 more source

Modified Cramer-Rao lower bound for symbol width estimation from a phase-shift-keying signal

Tongxin xuebao, 2009
The modified Cramer-Rao lower bound（MCRB） on symbol width estimation of a phase-shift-keying signal was derived.When calculating the integration of the square of dirac delta function δ（t ）, Parseval’s theorem was used to transform the computation from ...
DENG Zhen-miao, LIU Yu
doaj   +2 more sources