27,275 research outputs found

    Speech Recognition by Composition of Weighted Finite Automata

    Full text link
    We present a general framework based on weighted finite automata and weighted finite-state transducers for describing and implementing speech recognizers. The framework allows us to represent uniformly the information sources and data structures used in recognition, including context-dependent units, pronunciation dictionaries, language models and lattices. Furthermore, general but efficient algorithms can used for combining information sources in actual recognizers and for optimizing their application. In particular, a single composition algorithm is used both to combine in advance information sources such as language models and dictionaries, and to combine acoustic observations and information sources dynamically during recognition.Comment: 24 pages, uses psfig.st

    INPE LANDSAT system

    Get PDF
    There are no author identified significant results in this report

    Gauges and functional measures in quantum gravity II: higher-derivative gravity

    Get PDF
    We compute the one-loop divergences in a higher-derivative theory of gravity including Ricci tensor squared and Ricci scalar squared terms, in addition to the Hilbert and cosmological terms, on an (generally off-shell) Einstein background. We work with a two-parameter family of parametrizations of the graviton field, and a two-parameter family of gauges. We find that there are some choices of gauge or parametrization that reduce the dependence on the remaining parameters. The results are invariant under a recently discovered \u201cduality\u201d that involves the replacement of the densitized metric by a densitized inverse metric as the fundamental quantum variable

    Chemical abundances and kinematics of barium stars

    Get PDF
    In this paper we present an homogeneous analysis of photospheric abundances based on high-resolution spectroscopy of a sample of 182 barium stars and candidates. We determined atmospheric parameters, spectroscopic distances, stellar masses, ages, luminosities and scale height, radial velocities, abundances of the Na, Al, alphaalpha-elements, iron-peak elements, and s-process elements Y, Zr, La, Ce, and Nd. We employed the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code {\sc moog}. We found that the metallicities, the temperatures and the surface gravities for barium stars can not be represented by a single gaussian distribution. The abundances of alphaalpha-elements and iron peak elements are similar to those of field giants with the same metallicity. Sodium presents some degree of enrichment in more evolved stars that could be attributed to the NeNa cycle. As expected, the barium stars show overabundance of the elements created by the s-process. By measuring the mean heavy-element abundance pattern as given by the ratio [s/Fe], we found that the barium stars present several degrees of enrichment. We also obtained the [hs/ls] ratio by measuring the photospheric abundances of the Ba-peak and the Zr-peak elements. Our results indicated that the [s/Fe] and the [hs/ls] ratios are strongly anti-correlated with the metallicity. Our kinematical analysis showed that 90% of the barium stars belong to the thin disk population. Based on their luminosities, none of the barium stars are luminous enough to be an AGB star, nor to become self-enriched in the s-process elements. Finally, we determined that the barium stars also follow an age-metallicity relation.Comment: 30 pages, 26 figures, 18 tables, accepted for publication in MNRA

    Gravitational Collapse of a Massless Scalar Field and a Perfect Fluid with Self-Similarity of the First Kind in (2+1) Dimensions

    Full text link
    Self-similar solutions of a collapsing perfect fluid and a massless scalar field with kinematic self-similarity of the first kind in 2+1 dimensions are obtained. Their local and global properties of the solutions are studied. It is found that some of them represent gravitational collapse, in which black holes are always formed, and some may be interpreted as representing cosmological models.Comment: 13 page

    How can Multi-Professional Education Support Better Stewardship?

    Get PDF
    Antimicrobial stewardship is widely accepted as an efficient strategy to combat the growing threat of antimicrobial resistance. Education is one of the cornerstones of successful antimicrobial stewardship programs. There is also general agreement that antimicrobial stewardship is a team effort that must involve the whole continuum of healthcare workers. Providing adequate education for all different professionals although challenging is deemed crucial to achieve good results. This paper reviews the different strategies available to educate the multiple healthcare workers, discusses how education can improve antimicrobial stewardship programs and outlines some of the challenges faced and research gaps that need to be addressed in order to improve education in this field

    Comunicação e divulgação científica na agricultura.

    Get PDF
    Em instituições públicas de pesquisa, desenvolvimento e inovação (PD&I) como a Empresa Brasileira de Pesquisa Agropecuária (Embrapa), a comunicação e a divulgação científica para a agricultura enfrentam inúmeros desafios que vão desde o acesso e a a forma como são exercitados estes processos até os relacionados à melhoria das condições políticas, sociais e econômicas deste importante segmento. Partindo da discussão sobre as tendências que norteiam a comunicação para a disseminação das informações e conhecimentos produzidos pela Embrapa, este artigo tem o objetivo de apresentar um esboço de modelo comunicacional de divulgação científica fundamentado na lógica da midiatização, cujo pilar é a edificação de uma relação comunicativa dialógica e participativa. Entende-se que o esboço de modelo proposto propulsiona a divulgação e a transferência dos conhecimentos gerados na empresa e a assimilação destes por parte do público a qual se destina

    Alfvenic Heating of Protostellar Accretion Disks

    Full text link
    We investigate the effects of heating generated by damping of Alfven waves on protostellar accretion disks. Two mechanisms of damping are investigated, nonlinear and turbulent, which were previously studied in stellar winds (Jatenco-Pereira & Opher 1989a, b). For the nominal values studied, f=delta v/v_{A}=0.002 and F=varpi/Omega_{i}=0.1, where delta v, v_{A} and varpi are the amplitude, velocity and average frequency of the Alfven wave, respectively, and Omega_{i} is the ion cyclotron frequency, we find that viscous heating is more important than Alfven heating for small radii. When the radius is greater than 0.5 AU, Alfvenic heating is more important than viscous heating. Thus, even for the relatively small value of f=0.002, Alfvenic heating can be an important source of energy for ionizing protostellar disks, enabling angular momentum transport to occur by the Balbus-Hawley instability.Comment: 21 pages, 9 figures. Accepted for publication in Ap
    corecore