1,720,962 research outputs found
Use of Hilbert Transform for Priority Determination of Partially Correlated Inputs in Source Identification via MISO Modeling
No full textA hilbert transform approach in source identification via multiple-input single-output modeling for correlated inputs
No full textSeveral approaches can be employed to tackle source/path identification problems via multiple-input single-output modeling. When the measured inputs are correlated to each other, partial coherence function approach can be,used in which conditioning of the inputs is performed before calculating the contribution of each input. To ensure that the conditioning analysis is successful, correct priorities of the correlated inputs must be provided first, which can be often resolved based on the assumption of causality between a pair of correlated inputs. The contribution of inputs is frequently assessed in the frequency domain and, furthermore, the priorities of the inputs may be frequency dependent. Here, Hilbert transform approach is employed to determine effectively such priorities in the frequency domain and is then applied to an acoustical system. The results are compared with those by other approaches. (C) 1998 Academic Press
Estimation of operational strains from vibration measurements: An application to lead wires of chips on printed circuit board
No full textDynamic strain in structures is normally measured using strain gauges. When direct strain measurement is not possible, vibration measurement can be an indirect practical alternative. That is, vibrations are measured, typically using acceleration pick-ups, on the underlying system under operational conditions and a certain relationship between strains and accelerations is imposed on the measured accelerations to estimate the strains. Therefore, this relationship or transformation matrix between the strain and vibration is very critical for the indirect estimation to be successful. The transformation matrix is often inevitably derived not under the real operational conditions, but under the idealized laboratory conditions or using computer simulations. This means that boundary conditions under which this transformation matrix is obtained are extremely important. In this study, this problem is discussed in detail and an application to the estimation of strains in lead wires connecting chips to a printed circuit board subject to loading by a cooling fan is illustrated. (C) 1998 Academic Press Limited
Indirect Identification of Transmission Forces through Rubber Bushing in Vehicle Suspension System by Using Vibration Signals on Links
No full textIdentification of Forces Transmitted onto Car Body through Rubber Bushings in Suspension System under Driving Conditions
No full textA feasibility study on indirect identification of transmission forces through rubber bushing in vehicle suspension system by using vibration signals measured on links
No full textThis paper presents a feasibility study on using the rubber bushing itself as a sensor for the identification of transmission forces in vehicle suspension systems. The method starts from the idea that the transmission forces can be related to the deformation of the rubber bushing by an appropriate model and the deformation of the rubber bushing can be obtained by estimation of the relative vibration across the bushing. Simple theories are presented to deal with modeling of a given geometry of rubber bushing by a concentric spring and damper, correlating of measurements of the vibration on the links to the stiffness and damping parameters, and selection of the vibration measurement positions. Importance of the measurement position selection in relation to the measurement noise is illustrated by simulation studies. Then, validity of the proposed indirect approach will be shown by applications to a rear suspension system of dual link type
Analysis of a Passenger Car Interior Noise under Driving Conditions by the MISO Modeling Technique
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“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
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