The stochastic acceleration problem in two dimensions

We consider the motion of a particle in a two-dimensional spatially homogeneous mixing potential and show that its momentum converges to the Brownian motion on a circle. This complements the limit theorem of Kesten and Papanicolaou \cite{KP} proved in dimensions $d\ge 3$

Towards Intelligent Databases

This article is a presentation of the objectives and techniques of deductive databases. The deductive approach to databases aims at extending with intensional definitions other database paradigms that describe applications extensionaUy. We first show how constructive specifications can be expressed with deduction rules, and how normative conditions can be defined using integrity constraints. We outline the principles of bottom-up and top-down query answering procedures and present the techniques used for integrity checking. We then argue that it is often desirable to manage with a database system not only database applications, but also specifications of system components. We present such meta-level specifications and discuss their advantages over conventional approaches

Long time, large scale limit of the Wigner transform for a system of linear oscillators in one dimension

We consider the long time, large scale behavior of the Wigner transform W_\eps(t,x,k) of the wave function corresponding to a discrete wave equation on a 1-d integer lattice, with a weak multiplicative noise. This model has been introduced in Basile, Bernardin, and Olla to describe a system of interacting linear oscillators with a weak noise that conserves locally the kinetic energy and the momentum. The kinetic limit for the Wigner transform has been shown in Basile, Olla, and Spohn. In the present paper we prove that in the unpinned case there exists $\gamma_0>0$ such that for any $\gamma\in(0,\gamma_0]$ the weak limit of W_\eps(t/\eps^{3/2\gamma},x/\eps^{\gamma},k), as \eps\ll1, satisfies a one dimensional fractional heat equation $\partial_t W(t,x)=-\hat c(-\partial_x^2)^{3/4}W(t,x)$ with $\hat c>0$. In the pinned case an analogous result can be claimed for W_\eps(t/\eps^{2\gamma},x/\eps^{\gamma},k) but the limit satisfies then the usual heat equation

Medical applications for mobile devices (part 2)

W poprzednim odcinku niniejszego cyklu zaprezentowałemsposób, w jaki na urządzeniach mobilnych typuiPhone i iPad można instalować (za pomocą programu iTunes)aplikacje medyczne.W poprzednim odcinku niniejszego cyklu zaprezentowałemsposób, w jaki na urządzeniach mobilnych typuiPhone i iPad można instalować (za pomocą programu iTunes)aplikacje medyczne

Specyfika leczenia chirurgicznego ran powstałych podczas walk byków

Urazy zadawane torreadorom podczas walk byków cechują się własną specyfiką. W krajach, w których tego rodzaju widowiska stanowią stały element krajobrazu kulturowego, leczenie urazów zadawanych przez byki podczas korridy oraz amatorskich gonitw z bykami jest stałym elementem nauki lekarzy i chirurgów. W poniższym artykule przedstawiono podstawowe informacje na temat charakterystyki urazów zadawanych przez byki oraz specyfiki ich diagnozowania i leczenia zarówno w miejscu zdarzenia (bezpośrednio na arenie), jak i w szpitalu.Bullfight injuries are a relatively uncommon type of surgical emergency. However, in countries with a strong bullfi ghting tradition, the treatment of these injuries has in recent decades almost become a separate trauma specialization. This article presents a short history of bullfi ghting and describes the social background of bullfi ghts and local festivals, including bull running. It briefly discusses the surgical approach to injuries inflicted by bulls both at the site of injury and upon arrival in hospital