10,730 research outputs found
Visualizing High Dimensional Dynamical Processes
Manifold learning techniques for dynamical systems and time series have shown
their utility for a broad spectrum of applications in recent years. While these
methods are effective at learning a low-dimensional representation, they are
often insufficient for visualizing the global and local structure of the data.
In this paper, we present DIG (Dynamical Information Geometry), a visualization
method for multivariate time series data that extracts an information geometry
from a diffusion framework. Specifically, we implement a novel group of
distances in the context of diffusion operators, which may be useful to reveal
structure in the data that may not be accessible by the commonly used diffusion
distances. Finally, we present a case study applying our visualization tool to
EEG data to visualize sleep stages.Comment: 7 pages, 3 figure
Visualizing quantum mechanics in phase space
We examine the visualization of quantum mechanics in phase space by means of
the Wigner function and the Wigner function flow as a complementary approach to
illustrating quantum mechanics in configuration space by wave functions. The
Wigner function formalism resembles the mathematical language of classical
mechanics of non-interacting particles. Thus, it allows a more direct
comparison between classical and quantum dynamical features
CompEngine: a self-organizing, living library of time-series data
Modern biomedical applications often involve time-series data, from
high-throughput phenotyping of model organisms, through to individual disease
diagnosis and treatment using biomedical data streams. Data and tools for
time-series analysis are developed and applied across the sciences and in
industry, but meaningful cross-disciplinary interactions are limited by the
challenge of identifying fruitful connections. Here we introduce the web
platform, CompEngine, a self-organizing, living library of time-series data
that lowers the barrier to forming meaningful interdisciplinary connections
between time series. Using a canonical feature-based representation, CompEngine
places all time series in a common space, regardless of their origin, allowing
users to upload their data and immediately explore interdisciplinary
connections to other data with similar properties, and be alerted when similar
data is uploaded in the future. In contrast to conventional databases, which
are organized by assigned metadata, CompEngine incentivizes data sharing by
automatically connecting experimental and theoretical scientists across
disciplines based on the empirical structure of their data. CompEngine's
growing library of interdisciplinary time-series data also facilitates
comprehensively characterization of algorithm performance across diverse types
of data, and can be used to empirically motivate the development of new
time-series analysis algorithms
Driven coupled Morse oscillators --- visualizing the phase space and characterizing the transport
Recent experimental and theoretical studies indicate that intramolecular
energy redistribution (IVR) is nonstatistical on intermediate timescales even
in fairly large molecules. Therefore, it is interesting to revisit the the old
topic of IVR versus quantum control and one expects that a classical-quantum
perspective is appropriate to gain valuable insights into the issue. However,
understanding classical phase space transport in driven systems is a
prerequisite for such a correspondence based approach and is a challenging task
for systems with more then two degrees of freedom. In this work we undertake a
detailed study of the classical dynamics of a minimal model system - two
kinetically coupled coupled Morse oscillators in the presence of a
monochromatic laser field. Using the technique of wavelet transforms a
representation of the high dimensional phase space, the resonance network or
Arnold web, is constructed and analysed. The key structures in phase space
which regulate the dissociation dynamics are identified. Furthermore, we show
that the web is nonuniform with the classical dynamics exhibiting extensive
stickiness, resulting in anomalous transport. Our work also shows that pairwise
irrational barriers might be crucial even in higher dimensional systems.Comment: 10 pages, 5 figures. Contribution to William H. Miller festschrif
Belavkin-Kolokoltsov watch-dog effects in interactively controlled stochastic computer-graphic dynamic systems
Stochastic properties of the long time behavior of a continuously observed
(and interactively controlled) quantum--field top are investigated
mathematically. Applications to interactively controlled stochastic
computerographical dynamic systems are discussed.Comment: A mathematical study. 11pp, amstex [revised: 8.X.94]., (e mail:
[email protected]
Belavkin-Kolkoltsov watch-dog effects in interactively controlled stochastic computer-graphic dynamic systems. A mathematical study
Stochastic properties of the long-time behaviour of a continuously observed
(and interactively controlled) quantum-field top are investigated
mathematically. Applications to interactively controlled stochastic
computer-graphic dynamic systems are discussed.Comment: an essentially completed version of chao-dyn/940601
PDFSense: Mapping the sensitivity of hadronic experiments to nucleon structure
Recent high precision experimental data from a variety of hadronic processes
opens new opportunities for determination of the collinear parton distribution
functions (PDFs) of the proton. In fact, the wealth of information from
experiments such as the Large Hadron Collider (LHC) and others, makes it
difficult to quickly assess the impact on the PDFs, short of performing
computationally expensive global fits. As an alternative, we explore new
methods for quantifying the potential impact of experimental data on the
extraction of proton PDFs. Our approach relies crucially on the correlation
between theory-data residuals and the PDFs themselves, as well as on a newly
defined quantity --- the sensitivity --- which represents an extension of the
correlation and reflects both PDF-driven and experimental uncertainties. This
approach is realized in a new, publicly available analysis package PDFSense,
which operates with these statistical measures to identify particularly
sensitive experiments, weigh their relative or potential impact on PDFs, and
visualize their detailed distributions in a space of the parton momentum
fraction x and factorization scale \mu. This tool offers a new means of
understanding the influence of individual measurements in existing fits, as
well as a predictive device for directing future fits toward the highest impact
data and assumptions.Comment: 6 pages, 3 figures. arXiv admin note: substantial text overlap with
arXiv:1803.0277
Time-resolved x-ray microscopy for materials science
X-ray microscopy has been an indispensable tool to image nanoscale properties
for materials research. One of its recent advances is to extend microscopic
studies to the time domain for visualizing the dynamics of nanoscale phenomena.
Large-scale x-ray facilities have been the powerhouse of time-resolved x-ray
microscopy. Their upgrades including a significant reduction of the x-ray
emittance at storage rings and fully coherent ultrashort x-ray pulses at free
electron lasers, will lead to new developments in instrumentation and open new
scientific opportunities for x-ray imaging of nanoscale dynamics with the
simultaneous attainment of unprecedentedly high spatial and temporal
resolutions. This review presents recent progress in and the outlook for
time-resolved x-ray microscopy in the context of ultrafast nanoscale imaging
and its applications to condensed matter physics and materials science
Open Quantum Systems and Quantum Algorithms
The model of open quantum systems is adopted to describe the non-local
dynamical behaviour of qubits processed by entangling gates. The analysis gets
to the conclusion that a distinction between evaluation steps and task-oriented
computing steps is justified only within classical computation. In fact, the
use of entangling gates permits to reduce two steps (evaluation and
calculation) to a single computational one, and this determines an effective
computational speed-up. The application of the open quantum systems model
suggests that the reduction to one-computational step is strongly related to
the existence of Universal Dynamical Maps describing the evolution of component
systems of two-qubits gates. As the description in terms of Universal Dynamical
Map is possible only in the presence of a separable initial state, it turns out
that the internal reduced dynamics with respect to entangling gates is neither
unitary nor Markovian. The fact imposes a holistic vision on the structure of
the algorithm, where the entangling gates shall remain indivisible unities, or
black boxes, in order to preserve computational speed as well as reversibility.
This fact suggests to adopt a perspective on computation which is completely
non-classical: the whole algorithm turns out not to be the sequence of its
temporal parts
Belavkin-Kolokoltsov Watch-Dog Effects in Interactively Controlled Stochastic Computer-Graphic Dynamical Systems. A Summary of Mathematical Researches
This paper contains a summary of mathematical researches of stochastic
properties of the long time behavior of a continuously observed (and
interactively controlled) quantum--field top. Applications to interactively
controlled stochastic computer-graphic dynamical systems are also discussed.Comment: 15 pages amstex [printing errors corrected]. This is the enlarged
version of chao-dyn/9406013 supplied by Comments from hep-th/9401047 and
hep-th/940106
- …