841 research outputs found
Parallel software for lattice N=4 supersymmetric Yang--Mills theory
We present new parallel software, SUSY LATTICE, for lattice studies of
four-dimensional supersymmetric Yang--Mills theory with gauge
group SU(N). The lattice action is constructed to exactly preserve a single
supersymmetry charge at non-zero lattice spacing, up to additional potential
terms included to stabilize numerical simulations. The software evolved from
the MILC code for lattice QCD, and retains a similar large-scale framework
despite the different target theory. Many routines are adapted from an existing
serial code, which SUSY LATTICE supersedes. This paper provides an overview of
the new parallel software, summarizing the lattice system, describing the
applications that are currently provided and explaining their basic workflow
for non-experts in lattice gauge theory. We discuss the parallel performance of
the code, and highlight some notable aspects of the documentation for those
interested in contributing to its future development.Comment: Code available at https://github.com/daschaich/sus
Hamiltonian Latent Operators for content and motion disentanglement in image sequences
We introduce \textit{HALO} -- a deep generative model utilising HAmiltonian
Latent Operators to reliably disentangle content and motion information in
image sequences. The \textit{content} represents summary statistics of a
sequence, and \textit{motion} is a dynamic process that determines how
information is expressed in any part of the sequence. By modelling the dynamics
as a Hamiltonian motion, important desiderata are ensured: (1) the motion is
reversible, (2) the symplectic, volume-preserving structure in phase space
means paths are continuous and are not divergent in the latent space.
Consequently, the nearness of sequence frames is realised by the nearness of
their coordinates in the phase space, which proves valuable for disentanglement
and long-term sequence generation. The sequence space is generally comprised of
different types of dynamical motions. To ensure long-term separability and
allow controlled generation, we associate every motion with a unique
Hamiltonian that acts in its respective subspace. We demonstrate the utility of
\textit{HALO} by swapping the motion of a pair of sequences, controlled
generation, and image rotations.Comment: Conference paper at NeurIPS 202
Applying Software Product Lines to Build Autonomic Pervasive Systems
In this Master Thesis, we have proposed a model-driven Software Product Line (SPL) for developing autonomic pervasive systems. The work focusses on reusing the Variability knowledge from the SPL design to the SPL products. This Variability knowledge enables SPL products to deal with adaptation scenarios (evolution and involution) in an autonomic way.Cetina Englada, C. (2008). Applying Software Product Lines to Build Autonomic Pervasive Systems. http://hdl.handle.net/10251/12447Archivo delegad
Data Augmentation for Generating Synthetic Electrogastrogram Time Series
Objective: To address an emerging need for large amount of diverse datasets
for proper training of artificial intelligence (AI) algorithms and for rigor
evaluation of signal processing techniques, we developed and evaluated a new
method for generating synthetic electrogastrogram (EGG) time series. Methods:
We used EGG data from an open database to set model parameters and statistical
tests to evaluate synthesized data. Additionally, we illustrated method
customization for generating artificial EGG alterations caused by the simulator
sickness. Results: Proposed data augmentation method generates synthetic EGG
with specified duration, sampling frequency, recording state (postprandial or
fasting state), overall noise and breathing artifact injection, and pauses in
the gastric rhythm (arrhythmia occurrence) with statistically significant
difference between postprandial and fasting states in >70% cases while not
accounting for individual differences. Features obtained from the synthetic EGG
signal resembling simulator sickness occurrence displayed expected trends.
Conclusion: The code for generation of synthetic EGG time series is freely
available and can be further customized to assess signal processing algorithms
or to increase diversity in datasets used to train AI algorithms. The proposed
approach is customized for EGG data synthesis, but can be easily utilized for
other biosignals with similar nature such as electroencephalogram.Comment: three figures and two table
BioJazz : In silico evolution of cellular networks with unbounded complexity using rule-based modeling
Systems biologists aim to decipher the structure and dynamics of signaling and regulatory networks underpinning cellular responses; synthetic biologists can use this insight to alter existing networks or engineer de novo ones. Both tasks will benefit from an understanding of which structural and dynamic features of networks can emerge from evolutionary processes, through which intermediary steps these arise, and whether they embody general design principles. As natural evolution at the level of network dynamics is difficult to study, in silico evolution of network models can provide important insights. However, current tools used for in silico evolution of network dynamics are limited to ad hoc computer simulations and models. Here we introduce BioJazz, an extendable, user-friendly tool for simulating the evolution of dynamic biochemical networks. Unlike previous tools for in silico evolution, BioJazz allows for the evolution of cellular networks with unbounded complexity by combining rule-based modeling with an encoding of networks that is akin to a genome. We show that BioJazz can be used to implement biologically realistic selective pressures and allows exploration of the space of network architectures and dynamics that implement prescribed physiological functions. BioJazz is provided as an open-source tool to facilitate its further development and use. Source code and user manuals are available at: http://oss-lab.github.io/biojazz and http://osslab.lifesci.warwick.ac.uk/BioJazz.aspx
A control systems engineering approach for adaptive behavioral interventions: illustration with a fibromyalgia intervention
abstract: The term adaptive intervention has been used in behavioral medicine to describe operationalized and individually tailored strategies for prevention and treatment of chronic, relapsing disorders. Control systems engineering offers an attractive means for designing and implementing adaptive behavioral interventions that feature intensive measurement and frequent decision-making over time. This is illustrated in this paper for the case of a low-dose naltrexone treatment intervention for fibromyalgia. System identification methods from engineering are used to estimate dynamical models from daily diary reports completed by participants. These dynamical models then form part of a model predictive control algorithm which systematically decides on treatment dosages based on measurements obtained under real-life conditions involving noise, disturbances, and uncertainty. The effectiveness and implications of this approach for behavioral interventions (in general) and pain treatment (in particular) are demonstrated using informative simulations
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