855,878 research outputs found
Cross-Recurrence Quantification Analysis of Categorical and Continuous Time Series: an R package
This paper describes the R package crqa to perform cross-recurrence
quantification analysis of two time series of either a categorical or
continuous nature. Streams of behavioral information, from eye movements to
linguistic elements, unfold over time. When two people interact, such as in
conversation, they often adapt to each other, leading these behavioral levels
to exhibit recurrent states. In dialogue, for example, interlocutors adapt to
each other by exchanging interactive cues: smiles, nods, gestures, choice of
words, and so on. In order for us to capture closely the goings-on of dynamic
interaction, and uncover the extent of coupling between two individuals, we
need to quantify how much recurrence is taking place at these levels. Methods
available in crqa would allow researchers in cognitive science to pose such
questions as how much are two people recurrent at some level of analysis, what
is the characteristic lag time for one person to maximally match another, or
whether one person is leading another. First, we set the theoretical ground to
understand the difference between 'correlation' and 'co-visitation' when
comparing two time series, using an aggregative or cross-recurrence approach.
Then, we describe more formally the principles of cross-recurrence, and show
with the current package how to carry out analyses applying them. We end the
paper by comparing computational efficiency, and results' consistency, of crqa
R package, with the benchmark MATLAB toolbox crptoolbox. We show perfect
comparability between the two libraries on both levels
A computational approach for cam size optimization of disc cam-follower mechanisms with translating roller followers
The main objective of this work is to present a computational approach for design optimization of disc cam mechanisms with eccentric translating roller followers. For this purpose, the objective function defined here takes into account the three major parameters that influence the final cam size, namely the base circle radius of the cam, the radius of the roller and the offset of the follower. Furthermore, geometric constraints related to the maximum pressure angle and minimum radius of curvature are included to ensure good working conditions of the system. Finally, an application example is presented and used to discuss the main assumptions and procedure adopted throughout this work.Fundação para a Ciência e a Tecnologia (FCT
Feature Selection Library (MATLAB Toolbox)
Feature Selection Library (FSLib) is a widely applicable MATLAB library for
Feature Selection (FS). FS is an essential component of machine learning and
data mining which has been studied for many years under many different
conditions and in diverse scenarios. These algorithms aim at ranking and
selecting a subset of relevant features according to their degrees of
relevance, preference, or importance as defined in a specific application.
Because feature selection can reduce the amount of features used for training
classification models, it alleviates the effect of the curse of dimensionality,
speeds up the learning process, improves model's performance, and enhances data
understanding. This short report provides an overview of the feature selection
algorithms included in the FSLib MATLAB toolbox among filter, embedded, and
wrappers methods.Comment: Feature Selection Library (FSLib) 201
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