25,189 research outputs found
Reliability-Informed Beat Tracking of Musical Signals
Abstract—A new probabilistic framework for beat tracking of musical audio is presented. The method estimates the time between consecutive beat events and exploits both beat and non-beat information by explicitly modeling non-beat states. In addition to the beat times, a measure of the expected accuracy of the estimated beats is provided. The quality of the observations used for beat tracking is measured and the reliability of the beats is automatically calculated. A k-nearest neighbor regression algorithm is proposed to predict the accuracy of the beat estimates. The performance of the beat tracking system is statistically evaluated using a database of 222 musical signals of various genres. We show that modeling non-beat states leads to a significant increase in performance. In addition, a large experiment where the parameters of the model are automatically learned has been completed. Results show that simple approximations for the parameters of the model can be used. Furthermore, the performance of the system is compared with existing algorithms. Finally, a new perspective for beat tracking evaluation is presented. We show how reliability information can be successfully used to increase the mean performance of the proposed algorithm and discuss how far automatic beat tracking is from human tapping. Index Terms—Beat-tracking, beat quality, beat-tracking reliability, k-nearest neighbor (k-NN) regression, music signal processing. I
Reliable Linear, Sesquilinear and Bijective Operations On Integer Data Streams Via Numerical Entanglement
A new technique is proposed for fault-tolerant linear, sesquilinear and
bijective (LSB) operations on integer data streams (), such as:
scaling, additions/subtractions, inner or outer vector products, permutations
and convolutions. In the proposed method, the input integer data streams
are linearly superimposed to form numerically-entangled integer data
streams that are stored in-place of the original inputs. A series of LSB
operations can then be performed directly using these entangled data streams.
The results are extracted from the entangled output streams by additions
and arithmetic shifts. Any soft errors affecting any single disentangled output
stream are guaranteed to be detectable via a specific post-computation
reliability check. In addition, when utilizing a separate processor core for
each of the streams, the proposed approach can recover all outputs after
any single fail-stop failure. Importantly, unlike algorithm-based fault
tolerance (ABFT) methods, the number of operations required for the
entanglement, extraction and validation of the results is linearly related to
the number of the inputs and does not depend on the complexity of the performed
LSB operations. We have validated our proposal in an Intel processor (Haswell
architecture with AVX2 support) via fast Fourier transforms, circular
convolutions, and matrix multiplication operations. Our analysis and
experiments reveal that the proposed approach incurs between to
reduction in processing throughput for a wide variety of LSB operations. This
overhead is 5 to 1000 times smaller than that of the equivalent ABFT method
that uses a checksum stream. Thus, our proposal can be used in fault-generating
processor hardware or safety-critical applications, where high reliability is
required without the cost of ABFT or modular redundancy.Comment: to appear in IEEE Trans. on Signal Processing, 201
MDN-VO: Estimating Visual Odometry with Confidence
Visual Odometry (VO) is used in many applications including robotics and
autonomous systems. However, traditional approaches based on feature matching
are computationally expensive and do not directly address failure cases,
instead relying on heuristic methods to detect failure. In this work, we
propose a deep learning-based VO model to efficiently estimate 6-DoF poses, as
well as a confidence model for these estimates. We utilise a CNN - RNN hybrid
model to learn feature representations from image sequences. We then employ a
Mixture Density Network (MDN) which estimates camera motion as a mixture of
Gaussians, based on the extracted spatio-temporal representations. Our model
uses pose labels as a source of supervision, but derives uncertainties in an
unsupervised manner. We evaluate the proposed model on the KITTI and nuScenes
datasets and report extensive quantitative and qualitative results to analyse
the performance of both pose and uncertainty estimation. Our experiments show
that the proposed model exceeds state-of-the-art performance in addition to
detecting failure cases using the predicted pose uncertainty
Spike Clustering and Neuron Tracking over Successive Time Windows
This paper introduces a new methodology for tracking signals from individual neurons over time in multiunit extracellular recordings. The core of our strategy relies upon an extension of a traditional mixture model approach, with parameter optimization via expectation-maximimization (EM), to incorporate clustering results from the preceding time period in a Bayesian manner. EM initialization is also achieved by utilizing these prior clustering results. After clustering, we match the current and prior clusters to track persisting neurons. Applications of this spike sorting method to recordings from macaque parietal cortex show that it provides significantly more consistent clustering and tracking results
Mixture Representations of Reliability in Coherent Systems and Preservation Results under Double Monitoring
The mixture representations of the reliability functions of the residual life and inactivity time of a coherent system with n independent and identically distributed components are obtained, given that before time t1(t1 ≥ 0), exactly r(r \u3c n) components have failed and at time t2(t2 ≥ t1), the system is either still working or has failed. Based on the stochastically ordered coefficient vectors between systems, some preservation results of the residual life and the inactivity time of the system are obtained. The results in this paper extend previous results in the literature and are useful for comparing similar systems that have different structure functions
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