Fractional, anomalous diffusion in space-periodic potentials is investigated. The analytical solution for the effective, fractional diffusion coefficient in an arbitrary periodic potential is obtained in closed form in terms of two quadratures. This theoretical result is corroborated by numerical simulations for different shapes of the periodic potential. Normal and fractional spreading process...

We develop a heuristic model embedding Kleiber and Murray laws to describe mass growth, metastasis and vascularization in cancer. We analyze the relevant dynamics using different evolution equations (Verhulst, Gompertz and others). Their extension to reaction diffusion equation of the Fisher type is then used to describe the relevant metastatic spreading in space. Regarding this last point, we ...

We propose a new set of equations describing a cylindrical vertical cavity surface emitting laser (VCSEL) cavity under CW operation, based on the rate equations including lateral carrier diffusion. The only numerical step in the calculation consists in finding the roots of a polynomial expression. This model enables a quasi-instantaneous calculation of the laser’s light-current characteristic, ...

Social reinforcement and modular structure are two salient features observed in the spreading of behavior through social contacts. In order to investigate the interplay between these two features, we study the generalized epidemic process on modular networks with equal-sized finite communities and adjustable modularity. Using the analytical approach originally applied to clique-based random net...

small precipitation with temporal and spatial variation of rainfall is the main responsible factors on flood occurrence in arid and semi arid regions. floods in their regions usually contain high concentration of sediments which when they are deposited on the surface of lands, they change the properties of soils of the area. in this research, the effect of floodwater spreading on physic-chemica...

Fractional, anomalous diffusion in space-periodic potentials is investigated. The analytical solution for the effective fractional diffusion coefficient in an arbitrary periodic potential is obtained in closed form in terms of two quadratures. This theoretical result is corroborated by numerical simulations for different shapes of the periodic potential. Normal and fractional spreading processe...

An eecient retrieval of a relatively small number of relevant cases from a huge case base is a crucial subtask of Case-Based Reasoning (CBR). In this article, we present Case Retrieval Nets, a memory model that has recently been developed for this task. The main idea is to apply a spreading activation process to the case memory structured as a Case Retrieval Net in order to retrieve cases being...

Associative theories of learning have been used to explain human contingency learning since the 1980’s. Recent findings have led several authors to claim that there is no evidence clearly showing the engagement of associative processes of acquisition or representation in human contingency learning, and to propose non-associative accounts. Priming techniques can detect associative representation...

Learners have different knowledge, interests and also goals in any educational process. If all the learners are provided the same content the process will probably not meet expected goals. A personalized approach to a learner increases the efficiency of the learning process. It is based on information about the learner that is subject of change. Several adaptive educational systems exist. Howev...

Wave diffraction is a very important phenomenon in marine engineering and several models have been developed for its simulation. The new version of SWAN, a third generation spectral model, includes an approximation to wave diffraction. The approximation is based on the mild-slope equation for refraction and diffraction, omitting phase information. The objective this paper is to evaluate the per...