We obtain a criterion for pulsating front speed-up by general periodic incompressible flows in two dimensions and in the presence of KPP nonlinearities. We achieve this by showing that the ratio of the minimal front speed and the effective diffusivity of the flow is bounded away from zero and infinity by constants independent of the flow. We also study speed-up of reaction-diffusion fronts by v...

We introduce a strategy for the verification of relational specifications based on the analysis of monotonicity of variables within formulas. By comparing with the Alloy Analyzer, we show that for a relevant class of problems this technique outperforms analysis of the same problems using SAT-solvers, while consuming a fraction of the memory SAT-solvers require.

Bob chooses a function from a set of functions and gives Alice the black box that computes it. Alice is to find a characteristic of the function through function evaluations. In the quantum case, the number of function evaluations can be smaller than the minimum classically possible. The fundamental reason for this violation of a classical limit is not known. We trace it back to a disambiguatio...

Leave-one-out Cross Validation (LOO-CV) gives an almost unbiased estimate of the expected generalization error. But the LOO-CV classical procedure with Support Vector Machines (SVM) is very expensive and cannot be applied when training set has more that few hundred examples. We propose a new LOO-CV method which uses modified initialization of Sequential Minimal Optimization (SMO) algorithm for ...

Simulations of biological evolution, in which computers are used to evolve systems toward a goal, often require many generations to achieve even simple goals. It is therefore of interest to look for generic ways, compatible with natural conditions, in which evolution in simulations can be speeded. Here, we study the impact of temporally varying goals on the speed of evolution, defined as the nu...

Grounding is the task of reducing a first order formula to ground formula that is equivalent on a given universe, and is important in many kinds of problem solving and reasoning systems. One method for grounding is based on an extension of the relational algebra, exploiting the fact that grounding over a given domain is similar to query answering. In this paper, we introduce two methods for spe...

ŠŤASTNÝ, J., PROCHÁZKA, D., KOUBEK, T., LANDA, J.: Augmented reality usage for prototyping speed up. Acta univ. agric. et silvic. Mendel. Brun., 2011, LIX, No. 2, pp. 353–360 The integral part of production process in many companies is prototyping. Although, these companies commonly have high quality visualization tools (large screen projections, virtual reality), prototyping was never abandone...

A classic result known as the speed-up theorem in machineindependent complexity theory shows that there exist some computable functions that do not have best programs for them [2, 3]. In this paper we lift this result into type-2 computation under the notion of our type2 complexity theory depicted in [15, 13, 14]. While the speed-up phenomenon is essentially inherited from type-1 computation, w...