We study the behaviour of the Ben-Yishai hypercolumn model (Ben-Yishai et al., Proc. Natl. Acad. Sci. USA 92 (1995) 3844) under presentation of oriented stimuli, having extended this model by including plastic a!erent (LGN to cortex) connections. We "nd that Hebbian plasticity creates a self-organising map and show that constraining or modifying the standard Hebb rule in a particular way will l...

It is common knowledge that the modern world generates and stores information at an increasing rate. A typical example is the emerging field of e-science, where the adoption of high-performance computing has led to the generation of vast volumes of scientific data. The usefulness of the stored information, of course, depends crucially on the ability to query it effectively, and hence on the use...

The goal of example-based texture synthesis methods is to generate arbitrarily large textures from limited exemplars in order to fit the exact dimensions and resolution required for a specific modeling task. The challenge is to faithfully capture all of the visual characteristics of the exemplar texture, without introducing obvious repetitions or unnatural looking visual elements. While existin...

Control laws obtained by combining a least squares parameter estimator and a minimum variance strategy based on the estimated parameters have asymptotically optimal performance .

We study a number of open issues in spectral clustering: (i) Selecting the appropriate scale of analysis, (ii) Handling multi-scale data, (iii) Clustering with irregular background clutter, and, (iv) Finding automatically the number of groups. We first propose that a ‘local’ scale should be used to compute the affinity between each pair of points. This local scaling leads to better clustering e...

Modern operating systems are highly parameterized, allowing system administrators to tune them in order to achieve optimal performance for the local workload. However, this is a diicult and time consuming process. We propose a mechanism to automate this process, by running simulations of system performance for various parameter values instead of the system's idle loop. The simulations are drive...

The paper presents considerations regarding to design and simulation of two adaptive controllers (self-tuning controller with feedback and respectively reference compensation) with application to a power system. The self-tuning control strategy is applied for the excitation control of a synchronous generator. There are analyzed the performances of the both considered self-tuning control structu...

A back-propagation neural network is applied to a nonlinear self-tuning tracking problem. Traditional self-tuning adaptive control techniques can only deal with linear systems or some special nonlinear systems. The emerging back-propagation neural networks have the capability to learn arbitrary nonlinearity and show great potential for adaptive control applications. A scheme for combining back-...