396 research outputs found
Nonparametric estimation of the dynamic range of music signals
The dynamic range is an important parameter which measures the spread of
sound power, and for music signals it is a measure of recording quality. There
are various descriptive measures of sound power, none of which has strong
statistical foundations. We start from a nonparametric model for sound waves
where an additive stochastic term has the role to catch transient energy. This
component is recovered by a simple rate-optimal kernel estimator that requires
a single data-driven tuning. The distribution of its variance is approximated
by a consistent random subsampling method that is able to cope with the massive
size of the typical dataset. Based on the latter, we propose a statistic, and
an estimation method that is able to represent the dynamic range concept
consistently. The behavior of the statistic is assessed based on a large
numerical experiment where we simulate dynamic compression on a selection of
real music signals. Application of the method to real data also shows how the
proposed method can predict subjective experts' opinions about the hifi quality
of a recording
[Sigma Delta] Quantization with the hexagon norm in C
It has been shown that Pulse Code Modulation (PCM) Quantizer Schemes and
§¢ Quantizer Schemes can be used to quantize one dimensional data for transmis-
sion and recovery with each scheme having its own advantages and disadvantages.
This work will discuss the viability of a two dimensional §¢ Quantization scheme for
use in transmission and recovery. Three distinct two dimensional quantizer norms,
the Box, the Diamond, and the Hexagon norm, will be compared using the Mean
Square Error to show that the Hexagon Quantizer norm out performs the others and
serves the purpose for a practical two dimensional quantizer
The study of sequential decoding techniques for spacecraft telemetry systems Final report, 12 Jan. - 12 Jun. 1968
Convolutional encoding-sequential decoding technique for coherent deep space telemetry link and near earth space mission
Best Linear Unbiased Estimation Fusion with Constraints
Estimation fusion, or data fusion for estimation, is the problem of how to best utilize useful information contained in multiple data sets for the purpose of estimating an unknown quantity — a parameter or a process. Estimation fusion with constraints gives rise to challenging theoretical problems given the observations from multiple geometrically dispersed sensors: Under dimensionality constraints, how to preprocess data at each local sensor to achieve the best estimation accuracy at the fusion center? Under communication bandwidth constraints, how to quantize local sensor data to minimize the estimation error at the fusion center? Under constraints on storage, how to optimally update state estimates at the fusion center with out-of-sequence measurements? Under constraints on storage, how to apply the out-of-sequence measurements (OOSM) update algorithm to multi-sensor multi-target tracking in clutter? The present work is devoted to the above topics by applying the best linear unbiased estimation (BLUE) fusion. We propose optimal data compression by reducing sensor data from a higher dimension to a lower dimension with minimal or no performance loss at the fusion center. For single-sensor and some particular multiple-sensor systems, we obtain the explicit optimal compression rule. For a multisensor system with a general dimensionality requirement, we propose the Gauss-Seidel iterative algorithm to search for the optimal compression rule. Another way to accomplish sensor data compression is to find an optimal sensor quantizer. Using BLUE fusion rules, we develop optimal sensor data quantization schemes according to the bit rate constraints in communication between each sensor and the fusion center. For a dynamic system, how to perform the state estimation and sensor quantization update simultaneously is also established, along with a closed form of a recursion for a linear system with additive white Gaussian noise. A globally optimal OOSM update algorithm and a constrained optimal update algorithm are derived to solve one-lag as well as multi-lag OOSM update problems. In order to extend the OOSM update algorithms to multisensor multitarget tracking in clutter, we also study the performance of OOSM update associated with the Probabilistic Data Association (PDA) algorithm
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