Lourenço, João M., Nuno Preguiça, Ricardo J. Dias, João Nuno Silva, João Garcia, and Luís Veiga NGenVM: New Generation Execution Environments. EuroSys. Nuremberg, Germany, 2009.
AbstractThis document describes a work-in-progress development of NGen-VM, a distributed infrastructure that manages execution environments with run-time and programming language support targeting applications developed in the Java programming language, deployed over clusters of many-core computers. For each running application or suite of related applications, a dedicated single-system image will be provided, regardless of the concurrent threads running on a single machine (on several cores) or scattered on different computers. Such system images rely on a single model for concurrency management (Transactional Shared Memory Model), in order fill the gap between the hardware infrastructure of clusters of many-core nodes and the application runtime that is independent from that hardware infrastructure. Interactions between threads in the same tasks will be supported by a Transactional Memory framework that provides the programming language with Atomic and Isolated code regions. Interactions between thread on different machines will also use the Transactional Memory model, but now resorting to a Distributed Shared Memory abstraction.
Ramos, Luís, Manuel L. Esquível, João T. Mexia, and João L. Silva. "
Some Asymptotic Expansions and Distribution Approximations outside a CLT Context."
Proceedings of 6th St. Petersburg Workshop on Simulation. 1. 2009. 444-448.
AbstractSome asymptotic expansions non necessarily related to the central limit theorem are discussed. After observing that the smoothing inequality of Esseen implies the proximity, in the Kolmogorov distance sense, of the distributions of the random variables of two random sequences satisfying a sort of general asymptotic relation, two instances of this observation are presented. A first example, partially motivated by the the statistical theory of high precision measurements, is given by a uniform asymptotic approximation to $(g(X+ μ_n))_{n ın \mathbbm{N}}$, where $g$ is some smooth function, $X$ is a random variable having a moment and a bounded density and $(μ_{n})_{n ın \mathbbm{N}}$ is a sequence going to infinity; the multivariate case as well as the proofs and a complete set of references will be published elsewhere. We next present a second class of examples given by a randomization of the interesting parameter in some classical asymptotic formulas, namely, a generic Laplace's type integral, by the sequence $(μ_n X)_{n ın \mathbbm{N}}$, $X$ being a Gamma distributed random variable. Finally, a simulation study of this last example is presented in order to stress the quality of asymptotic approximations proposed.
Guerra, M., F. Parente, and J. P. Santos. "
Electron impact ionization of atomic target inner-shells."
Journal of Physics: Conference Series. 194 (2009): 042047.
AbstractThere is a need for reliable theoretical methods to calculate electron-impact total ionization cross sections for the large number of neutral atoms and ions with open shell structures. These cross sections are used in a wide range of scientific and industrial applications, such as astrophysical plasmas, atmospheric science, X-ray lasers, magnetic fusion, radiation physics, semiconductor fabrication, accelerator physics and tumor therapy physics. The binary-encounter-Bethe (BEB) model [1], using an analytic formula that requires only two atomic constants, the binding energy and kinetic energy of the electrons, generates direct ionization cross sections for any neutral atom (or molecule), which are reliable in intensity (15%) and shape from the ionization threshold to a few keV in the incident energy [3], or to thousands keV if we consider its relativistic version(RBEB) [2]. In this work we present K- and L-shell ionization cross sections calculations for heavy atoms.
Martins, R., Leandro Raniero, Luis Pereira, Daniel Costa†, Hugo Aguas, Sonia Pereira, Leonardo Silva, A. Gonçalves, I. Ferreira, and E. Fortunato. "
Nanostructured silicon and its application to solar cells, position sensors and thin film transistors."
Philosophical Magazine. 89.28-30 (2009): 2699-2721.
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