Symbolic Dynamics in the Free-Fall Equal-Mass Three-Body Problem

The paper has been presented at the 12th International Conference on Applications of Computer Algebra, Varna, Bulgaria, June, 2006

Perturbations of Systems Describing the Motion of a Particle in Central Fields

The present paper deals with the KAM-theory conditions for systems describing the motion of a particle in central field.

Conceptual Idea of Identification of Patterns and Problem Solving in the Human’s Memory and the Possibilities to Use it in Artificial Intelligent

Given cybernetic idea is formed on the basis of neurophysiologic, neuropsychological, neurocybernetic data and verisimilar hypotheses, which fill gaps of formers, of the author as well. First of all attention is focused on general principles of a Memory organization in the brain and processes which take part in it that realize such psychical functions as perception and identification of input information about patterns and a problem solving, which is specified by the input and output conditions, as well. Realization of the second function, essentially cogitative, is discussed in the aspects of figurative and lingual thinking on the levels of intuition and understanding. The reasons of advisability and principles of bionic approach to creation of appropriate tools of artificial intelligent are proposed.

Some Fractional Extensions of the Temperature Field Problem in Oil Strata

This survey is devoted to some fractional extensions of the incomplete lumped formulation, the lumped formulation and the formulation of Lauwerier of the temperature field problem in oil strata. The method of integral transforms is used to solve the corresponding boundary value problems for the fractional heat equation. By using Caputo’s differintegration operator and the Laplace transform, new integral forms of the solutions are obtained. In each of the different cases the integrands are expressed in terms of a convolution of two special functions of Wright’s type.

On the Quotient Function Employed in the Blind Source Separation Problem

MSC 2010: 42C40, 94A12

Numerical solution of the Dirichlet initial boundary value problem for the heat equation in exterior 3-dimensional domains using integral equations

A numerical method for the Dirichlet initial boundary value problem for the heat equation in the exterior and unbounded region of a smooth closed simply connected 3-dimensional domain is proposed and investigated. This method is based on a combination of a Laguerre transformation with respect to the time variable and an integral equation approach in the spatial variables. Using the Laguerre transformation in time reduces the parabolic problem to a sequence of stationary elliptic problems which are solved by a boundary layer approach giving a sequence of boundary integral equations of the first kind to solve. Under the assumption that the boundary surface of the solution domain has a one-to-one mapping onto the unit sphere, these integral equations are transformed and rewritten over this sphere. The numerical discretisation and solution are obtained by a discrete projection method involving spherical harmonic functions. Numerical results are included.

Mi a baj a modern szervezetekkel? – Kritikai menedzsmentelméletek (What is the problem in modern organisations? – Critical Management Studies)

A nemzetközi, elsősorban európai szervezettudományban mára meghatározóvá vált a kritikai megközelítés, a hazai szakirodalomban mégis elvétve találni rá utalásokat. A szerzők írásukban tárgyalják, hogy a kritikai menedzsmentelméletek (KME) szemszögéből miként bírálható a mindenkori szervezeti gyakorlat, és miért bírálandók a főáramú menedzsmentelméletek. A tanulmány fő részében elméleti megkülönböztetéseket tesznek: egyrészt elhatárolják a kritikai megközelítést a főáramú szervezetelméletektől, másrészt több szempontból is különbséget tesznek a különféle – de egyaránt a KME alá tartozó – kritikai megközelítések között. De a kritikai szemlélethez hűen nem csak a puszta elméletismertetés volt a céljuk: e bevezetés és problémafelvető tanulmány – s a későbbiekben tervezett cikksorozat – szándékuk szerint vitaindítóként is szolgál. Abban bíznak, hogy a felvetett kérdésekről valódi, lényegi párbeszédet generálhatnak a hazai menedzsmenttudományban (kutatók, oktatók és elméletalkalmazók körében), mely kihathat a szervezeti gyakorlatra is. _____ Critical Management Studies (CMS) as a field of organization studies (OS) has become central internationally, and especially in Europe. Yet, its appearance is still very rare in the Hungarian OS literature. In this study first the authors discuss how the nowadays dominant organizational practices along with the mainstream management and organization theories are to be criticized from a Critical Management perspective. In the main section, so as to define CMS, they make important theoretical distinctions, first between CMS and mainstream organization theories (in general), and then among the different critical approaches that nevertheless all fall under the broad CMS umbrella. But, in line with a truly critical attitude, they not only go into theoretical discussions but, at least to their intention, the purpose of this introductory paper is also to addresses important problems both in the theory and the practice of organization and management. Therefore, it could serve as an opening of an important debate or dialogue in the Hungarian academic community (researchers, educators and other professionals), a theoretical discussion that could have real influence on organizational practice too.

Tree Island Response to Fire and Flooding in the Short-Hydroperiod Marl Prairie Grasslands of the Florida Everglades

Within the marl prairie grasslands of the Florida Everglades, USA, the combined effects of fire and flooding usually lead to very significant changes in tree island structure and composition. Depending on fire severity and post-fire hydroperiod, these effects vary spatially and temporally throughout the landscape, creating a patchy post-fire mosaic of tree islands with different successional states. Through the use of the Normalized Difference Vegetation Index (NDVI) and three predictor variables (marsh water table elevation at the time of fire, post-fire hydroperiod, and tree island size), along with logistic regression analysis, we examined the probability of tree island burning and recovering following the Mustang Corner Fire (May to June 2008) in Everglades National Park. Our data show that hydrologic conditions during and after fire, which are under varying degrees of management control, can lead to tree island contraction or loss. More specifically, the elevation of the marsh water table at the time of the fire appears to be the most important parameter determining the severity of fire in marl prairie tree islands. Furthermore, in the post-fire recovery phase, both tree island size and hydroperiod during the first year after the fire played important roles in determining the probability of tree island recovery, contraction, or loss.

An application of evolutionary algorithms for WAG optimisation in the Norne Field

Water-alternating-gas (WAG) is an enhanced oil recovery method combining the improved macroscopic sweep of water flooding with the improved microscopic displacement of gas injection. The optimal design of the WAG parameters is usually based on numerical reservoir simulation via trial and error, limited by the reservoir engineer’s availability. Employing optimisation techniques can guide the simulation runs and reduce the number of function evaluations. In this study, robust evolutionary algorithms are utilized to optimise hydrocarbon WAG performance in the E-segment of the Norne field. The first objective function is selected to be the net present value (NPV) and two global semi-random search strategies, a genetic algorithm (GA) and particle swarm optimisation (PSO) are tested on different case studies with different numbers of controlling variables which are sampled from the set of water and gas injection rates, bottom-hole pressures of the oil production wells, cycle ratio, cycle time, the composition of the injected hydrocarbon gas (miscible/immiscible WAG) and the total WAG period. In progressive experiments, the number of decision-making variables is increased, increasing the problem complexity while potentially improving the efficacy of the WAG process. The second objective function is selected to be the incremental recovery factor (IRF) within a fixed total WAG simulation time and it is optimised using the same optimisation algorithms. The results from the two optimisation techniques are analyzed and their performance, convergence speed and the quality of the optimal solutions found by the algorithms in multiple trials are compared for each experiment. The distinctions between the optimal WAG parameters resulting from NPV and oil recovery optimisation are also examined. This is the first known work optimising over this complete set of WAG variables. The first use of PSO to optimise a WAG project at the field scale is also illustrated. Compared to the reference cases, the best overall values of the objective functions found by GA and PSO were 13.8% and 14.2% higher, respectively, if NPV is optimised over all the above variables, and 14.2% and 16.2% higher, respectively, if IRF is optimised.

Wnt signaling in the heart fields : variations on a common theme

The work was financially supported by the European Community in the framework of the ITN CardioNet registered under number GA289600. SH acknowledges research-funding support from the British Heart Foundation. The authors would like to thank Dr Jan Ruijter for discussion and critically reading the manuscript.