1,721,004 research outputs found
A New Multiple Model Framework for Recursive Bayesian Modelling of Time Series by Neural Networks
Identification of nonlinear time series via kernels
Given a time series arising as the observations of some dynamical system, it is possible to reconstruct the qualitative behaviour of the dynamical system. Given such a reconstruction, this provides a general approach for making accurate short-term predictions. The time series reconstruction problem can be viewed as a function approximation problem which can be addressed by reproducing kernel Hilbert spaces (RKHS). Such an approach is described and related to Bayesian estimation with Gaussian priors. It is also shown that an explicit formulation of the model as an input-dependent autoregressive model is possible. This linearization is, however, unlike other approaches, exact and the autoregressive coefficients can be calculated explicitly at each time step. A particular example of RKHS approximation is applied to two benchmark problems, one synthetic and one real. The results demonstrate various aspects related to the optimization of the models and also show that the RKHS method is competitive against the best alternatives
Multi-Sensor Data Fusion in Defence and Aerospace
The UK OST Technology Foresight for defence and aerospace identified multi-sensor data fusion as a future critical enabling technology for the UK, requiring a coordinated research agenda. This review paper provides an overview of past research and applications of data fusion. The process of data fusion and sensor integration is formally introduced together with a variety of implementation architectures, that recognise data fusion as a critical element in overall systems integration. The various benefits and attributes of data fusion are discussed together with a brief review of potentially fruitful areas of future research
A novel method for identifying vortical structures
A method for identifying vortices in a 2-D velocity field is developed. A function based on the local angles of velocity with respect to a datum is calculated at each point in the 2-D field. This function is a local minimum at vortex centres. An advanced statistical technique for identifying multiple minima is used to find the minima of this function. The method is used for vortices, calculated using a RANS CFD code (CFX 4.3), forming around a very large crude carrier (VLCC) and the results are seen to be close to the centres of the vortices
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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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