Synthetic aperture imaging using a catheter based, circular phased array providing high resolution, dynamic focusing has been explored. Due to the high input impedance and low signal-to-noise ratio (SNR) of a classic single element synthetic aperture system, multi-element synthetic aperture processing has been proposed with SNR improvement of about 8 dB for a 33 element aperture. Reconstruction...

This paper introduces a variant of the ADALINE in which the input signals are normalized to have zero mean and unit variance, and in which the bias or “threshold weight” is learned slightly differently. These changes result in a linear learning element that learns much more efficiently and rapidly, and that is much less dependent on the choice of the step-size parameter. Using simulation experi...

This paper provides evidence for a significant relation between international financial markets’ integration and output volatility. In the framework of a threshold model, it is shown empirically that this relation depends on country’s financial risk. Financial risk indicates a country’s ability to pay its official, commercial and trade debts. In countries with low financial risk, financial open...

Mozambique A Non-Parametric Extension to the Threshold Model Bjorn Van Campenhout One of the main drawbacks of current methods to measure market integration is the assumption of constant transaction costs. In this paper, we propose a non-parametric extension to the commonly used threshold models, allowing us to estimate transaction costs in a more flexible way. We illustrate the method using we...

Dynamic task allocation is an essential aspect in modelling ant behaviour. In this paper, we propose a new (abstract) model for dynamic task allocation of agents that combines a nested layered architecture with a threshold mechanism. We apply this new model to achieve flexible ant behaviour. This serves the dual purpose of validating the abstract model, and providing a concrete model for adapti...

Viewing of annuli modulated in color in a sawtooth fashion in time results in differential threshold elevations for the detection of color changes of inscribed disks. The elevations are of nearly the same magnitude as those resulting from viewing modulated disks. However, the differential effects on thresholds for complimentary colors are reversed. The differential effects, thus, are correlated...

This study investigated a potential auditory illusion in duration perception induced by rhythmic temporal contexts. Listeners with or without musical training performed a duration discrimination task for a silent period in a rhythmic auditory sequence. The critical temporal interval was presented either within a perceptual group or between two perceptual groups. We report the just-noticeable di...

We investigate the behavior of a threshold model for the spreading of fads and similar phenomena in society. The model is giving the fad dynamics and is intended to be confined to an underlying network structure. We investigate the whole parameter space of the fad dynamics on three types of network models. The dynamics we discover is rich and highly dependent on the underlying network structure...

Vibrotactile thresholds were obtained from the anterior midline of the tongue for 10 randomly selected normal adults. Results were subsequently compared with an initial set of data obtained from three different examiners with varying degrees of exposure to threshold assessment technique. The examiner for this study was the inexperienced examiner from the initial investigation, who obtained sign...