12,741 research outputs found
Lagrangian Based Methods for Coherent Structure Detection
There has been a proliferation in the development of Lagrangian analytical methods for detecting coherent structures in fluid flow transport, yielding a variety of qualitatively different approaches. We present a review of four approaches and demonstrate the utility of these methods via their application to the same sample analytic model, the canonical double-gyre flow, highlighting the pros and cons of each approach. Two of the methods, the geometric and probabilistic approaches, are well established and require velocity field data over the time interval of interest to identify particularly important material lines and surfaces, and influential regions, respectively. The other two approaches, implementing tools from cluster and braid theory, seek coherent structures based on limited trajectory data, attempting to partition the flow transport into distinct regions. All four of these approaches share the common trait that they are objective methods, meaning that their results do not depend on the frame of reference used. For each method, we also present a number of example applications ranging from blood flow and chemical reactions to ocean and atmospheric flows. (C) 2015 AIP Publishing LLC.ONR N000141210665Center for Nonlinear Dynamic
A Geometric Approach to Pairwise Bayesian Alignment of Functional Data Using Importance Sampling
We present a Bayesian model for pairwise nonlinear registration of functional
data. We use the Riemannian geometry of the space of warping functions to
define appropriate prior distributions and sample from the posterior using
importance sampling. A simple square-root transformation is used to simplify
the geometry of the space of warping functions, which allows for computation of
sample statistics, such as the mean and median, and a fast implementation of a
-means clustering algorithm. These tools allow for efficient posterior
inference, where multiple modes of the posterior distribution corresponding to
multiple plausible alignments of the given functions are found. We also show
pointwise credible intervals to assess the uncertainty of the alignment
in different clusters. We validate this model using simulations and present
multiple examples on real data from different application domains including
biometrics and medicine
Fuzzy Logic
The capability of Fuzzy Logic in the development of emerging technologies is introduced in this book. The book consists of sixteen chapters showing various applications in the field of Bioinformatics, Health, Security, Communications, Transportations, Financial Management, Energy and Environment Systems. This book is a major reference source for all those concerned with applied intelligent systems. The intended readers are researchers, engineers, medical practitioners, and graduate students interested in fuzzy logic systems
Study on the Modelling of Airport Economic Value
The primary objective of the Airport Economic Value project is to assess the value of additional passengers or additional capacity at an airport. It aims to qualify and
quantify the main relationships and trade-offs between capacity, quality of service and profitability. This study provides a better understanding of the interdependencies
of various KPIs and assesses the existence and behaviour of an airport economic optimum, in a similar way to the early 2000s, when estimating the economic en-route capacity optimum
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