110,358 research outputs found
Adaptive temporal decimation algorithm with dynamic time window
Published versio
An improved 2D optical flow sensor for motion segmentation
A functional focal-plane implementation of a 2D optical flow system is presented that detects an
preserves motion discontinuities. The system is composed of two different network layers of analog
computational units arranged in a retinotopical order. The units in the first layer (the optical
flow network) estimate the local optical flow field in two visual dimensions, where the strength
of their nearest-neighbor connections determines the amount of motion integration. Whereas in an
earlier implementation \cite{Stocker_Douglas99} the connection strength was set constant in the
complete image space, it is now \emph{dynamically and locally} controlled by the second network
layer (the motion discontinuities network) that is recurrently connected to the optical flow
network. The connection strengths in the optical flow network are modulated such that visual
motion integration is ideally only facilitated within image areas that are likely to represent
common
motion sources.
Results of an experimental aVLSI chip illustrate the potential of the approach and its
functionality under real-world conditions
Signal segmentation and denoising algorithm based on energy optimisation
A nonlinear functional is considered in this short communication for time interval segmentation and noise reduction of signals. An efficient algorithm that exploits the signal geometrical properties is proposed to optimise the nonlinear functional for signal smoothing. Discontinuities separating consecutive time intervals of the original signal are initially detected by measuring the curvature and arc length of the smoothed signal. The nonlinear functional is then optimised for each time interval to achieve noise reduction of the original noisy signal. This algorithm exhibits robustness for signals characterised by very low signal to noise ratios
Enhanced Bandwidth and Diversity in Real-Time Analog Signal Processing (R-ASP) using Nonuniform C-section Phasers
We show that a continuously nonuniform coupled line C-section phaser, as the
limiting case of the step discontinuous coupled-line multisection commensurate
and non-commensurate phasers, provides enhanced bandwidth and diversity in
real-time analog signal processing (R-ASP). The phenomenology of the component
is explained in comparison with the step-discontinuous using
multiple-reflection theory and a simple synthesis procedure is provided. The
bandwidth enhancement results from the suppression of spurious group delay
harmonics or quasi-harmonics, while the diversity enhancement results from the
greater level of freedom provided by the continuous nature of the nonuniform
profile of the phaser. These statements are supported by theoretical and
experimental results
Wireless magnetic sensor network for road traffic monitoring and vehicle classification
Efficiency of transportation of people and goods is playing a vital role in economic growth. A key component for enabling effective planning of transportation networks is the deployment and operation of autonomous monitoring and traffic analysis tools. For that reason, such systems have been developed to register and classify road traffic usage. In this paper, we propose a novel system for road traffic monitoring and classification based on highly energy efficient wireless magnetic sensor networks. We develop novel algorithms for vehicle speed and length estimation and vehicle classification that use multiple magnetic sensors. We also demonstrate that, using such a low-cost system with simplified installation and maintenance compared to current solutions, it is possible to achieve highly accurate estimation and a high rate of positive vehicle classification
Reducing Audible Spectral Discontinuities
In this paper, a common problem in diphone synthesis is discussed, viz., the occurrence of audible discontinuities at diphone boundaries. Informal observations show that spectral mismatch is most likely the cause of this phenomenon.We first set out to find an objective spectral measure for discontinuity. To this end, several spectral distance measures are related to the results of a listening experiment. Then, we studied the feasibility of extending the diphone database with context-sensitive diphones to reduce the occurrence of audible discontinuities. The number of additional diphones is limited by clustering consonant contexts that have a similar effect on the surrounding vowels on the basis of the best performing distance measure. A listening experiment has shown that the addition of these context-sensitive diphones significantly reduces the amount of audible discontinuities
A new Edge Detector Based on Parametric Surface Model: Regression Surface Descriptor
In this paper we present a new methodology for edge detection in digital
images. The first originality of the proposed method is to consider image
content as a parametric surface. Then, an original parametric local model of
this surface representing image content is proposed. The few parameters
involved in the proposed model are shown to be very sensitive to
discontinuities in surface which correspond to edges in image content. This
naturally leads to the design of an efficient edge detector. Moreover, a
thorough analysis of the proposed model also allows us to explain how these
parameters can be used to obtain edge descriptors such as orientations and
curvatures.
In practice, the proposed methodology offers two main advantages. First, it
has high customization possibilities in order to be adjusted to a wide range of
different problems, from coarse to fine scale edge detection. Second, it is
very robust to blurring process and additive noise. Numerical results are
presented to emphasis these properties and to confirm efficiency of the
proposed method through a comparative study with other edge detectors.Comment: 21 pages, 13 figures and 2 table
- âŠ