88,815 research outputs found
Tele-operated climbing and mobile service robots for remote inspection and maintenance in nuclear industry
No full textDigital IIR filter design using particle swarm optimisation
No full textAdaptive infinite-impulse-response (IIR) filtering provides a powerful approach for solving a variety of practical signal processing problems. Because the error surface of IIR filters is typically multimodal, global optimisation techniques are generally required in order to avoid local minima. This contribution applies the particle swarm optimisation (PSO) to digital IIR filter design in a realistic time domain setting where the desired filter output is corrupted by noise. PSO as global optimisation techniques offers advantages of simplicity in implementation, ability to quickly converge to a reasonably good solution and robustness against local minima. Our simulation study involving system identification application confirms that the proposed approach is accurate and has a fast convergence rate and the results obtained demonstrate that the PSO offers a viable tool to design digital IIR filters. We also apply the quantum-behaved particle swarm optimisation (QPSO) algorithm to the same digital IIR filter design and our results do not show any performance advantage of the QPSO algorithm over the PSO, although the former does have fewer algorithmic parameters that require tuning
Non-parametric linear time-invariant system identification by discrete wavelet transforms
No full textWe describe the use of the discrete wavelet transform (DWT) for non-parametric linear time-invariant system identification. Identification is achieved by using a test excitation to the system under test (SUT) that also acts as the analyzing function for the DWT of the SUT's output, so as to recover the impulse response. The method uses as excitation any signal that gives an orthogonal inner product in the DWT at some step size (that cannot be 1). We favor wavelet scaling coefficients as excitations, with a step size of 2. However, the system impulse or frequency response can then only be estimated at half the available number of points of the sampled output sequence, introducing a multirate problem that means we have to 'oversample' the SUT output. The method has several advantages over existing techniques, e.g., it uses a simple, easy to generate excitation, and avoids the singularity problems and the (unbounded) accumulation of round-off errors that can occur with standard techniques. In extensive simulations, identification of a variety of finite and infinite impulse response systems is shown to be considerably better than with conventional system identification methods.Department of Computin
Detección molecular del gen mecA y las subunidades Luk-S y Luk-F que codifican Panton Valentine Leukocidin (PVL), en Staphylococcus aureus resistente a Oxacilina (ORSA) en pacientes del Hospital Solidaridad de la Ciudad de Managua, Enero – Octubre 2017
No full textEn el presente estudio descriptivo de corte transversal, se analizaron 24 aislamientos de Staphylococcus aureus que presentaron resistencia a Oxacilina (ORSA), provenientes de pacientes atendidos en el Hospital solidaridad de la ciudad de Managua, de Enero a Octubre del año 2017. La identificación de las cepas ORSA se realizó a través del sistema automatizado VITEX 2 Compact; así mismo mediante la técnica de PCR punto final se detectó la presencia del gen mecA que confiere resistencia a toda la familia de βetalactámicos, y las subunidades Luk-S y Luk-F, que codifican la producción de Panton Valentine Leukocidin (PVL), responsables de necrosis tisular y destrucción de leucocitos en los pacientes infectados. La resistencia a Oxacilina codificada por el gen mecA, se demostró en 23 aislamientos con una frecuencia del 96%; la subunidad Luk-S se encontró en 15 cepas para una frecuencia de 63% y la subunidad Luk-F en 22 para un 92%. Las principales muestras clínicas de donde se aislaron cepas ORSA portadores de estos genes fueron: secreciones, heridas, orina, sangre y abscesos; así mismo, las salas con mayor número de aislamiento fueron: consulta externa, medicina de varones y UCI. El perfil de resistencia a los antimicrobianos se realizó mediante Concentración Mínima Inhibitoria (CIM) a través del sistema Vitek 2 Compact. Se demostró que las cepas presentaron mayor resistencia a las fluoroquinolonas: Ciprofloxacina 15 (63%), Levofloxacino 9 (38%) y Moxifloxacina 4 (17%) resistentes; para macrólidos y lincosamidas: Eritromicina: 16 (67%), Clindamicina: 9 (38%) resistentes. Los aminoglucósidos (Gentamicina) y Trimetoprim Sulfametoxazol: 2 (8%) resistentes; Tetraciclina: 8 (33%) y Rifampicina: 1 (4%) resistente. El 100% de las cepas presentaron sensibilidad a Estreptograminas, Nitrofurantoina, Tigeciclina, Linezolid y Vancomicina
Design of planar inverted-F antennas (PIFA) for multiband wireless applications
No full textA small three bands printed inverted-F antenna with independently controlling the resonant frequency is presented. The proposed antenna consists of two arms
supported by shorting walls fed by 50 Ω microstrip transmission line and a ground plane. The antenna occupied a compact size of 26 x 25 x 3.75 mm. The main radiated patch
injected with slot and another arm to generate and control the three resonant frequencies to cover 2.4, 3.7 and 5.2GHz
Wireless Local Area Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX). The simulated and measured results show that the antenna achieves a gain of 2, 3 and 5 dBi respectively and radiation efficiency of 50%, 60% and 85% for the three bands respectively. The simulated and measured result for the return loss is in good agreements
Fuzzy-logic tuned constant modulus algorithm and soft decision-directed scheme for blind equalisation
No full textVariations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
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