The Kahan discretization of the Lotka-Volterra system, associated with any skew-symmetric graph Γ, leads to a family rational maps, parametrized by step size. When these maps are Poisson respect quadratic structure we say that Γ has Kahan-Poisson property. We show if is connected, it property and only cloning vertices $1,2,\dots ,n$ , an arc i → j precisely when < j, all arcs having same value....

We propose a developmental model of the summation pools within the layer 4. The model is based on the modular structure of the neocortex and captures some of the known properties of layer 4. Connections between the orientation minicolumns are developed during exposure to visual input. Excitatory local connections are dense and biased towards the iso-orientation domain. Excitatory long-range con...

Abstract We study the problem of preservation maximal canards for time discretized fast–slow systems with canard fold points. In order to ensure such preservation, certain favorable structure-preserving properties discretization scheme are required. Conventional schemes do not possess properties. perform a detailed analysis an unconventional due Kahan. The uses blow-up method deal loss normal h...

Several numerical methods for the solution of large linear ill-posed problems combine Tikhonov regularization with an iterative method based on partial Lanczos bidiagonalization of the operator. This paper discusses the determination of the regularization parameter and the dimension of the Krylov subspace for this kind of methods. A method that requires a Krylov subspace of minimal dimension is...

Dreaming is often characterized as lacking high-order cognitive (HOC) skills. In two studies, we test the alternative hypothesis that the dreaming mind is highly similar to the waking mind. Multiple experience samples were obtained from late-night REM sleep and waking, following a systematic protocol described in Kahan (2001). Results indicated that reported dreaming and waking experiences are ...