6,550 research outputs found
Audio-visual object localization and separation using low-rank and sparsity
The ability to localize visual objects that are associated with an audio source and at the same time seperate the audio signal is a corner stone in several audio-visual signal processing applications. Past efforts usually focused on localizing only the visual objects, without audio separation abilities. Besides, they often rely computational expensive pre-processing steps to segment images pixels into object regions before applying localization approaches. We aim to address the problem of audio-visual source localization and separation in an unsupervised manner. The proposed approach employs low-rank in order to model the background visual and audio information and sparsity in order to extract the sparsely correlated components between the audio and visual modalities. In particular, this model decomposes each dataset into a sum of two terms: the low-rank matrices capturing the background uncorrelated information, while the sparse correlated components modelling the sound source in visual modality and the associated sound in audio modality. To this end a novel optimization problem, involving the minimization of nuclear norms and matrix â„“1-norms is solved. We evaluated the proposed method in 1) visual localization and audio separation and 2) visual-assisted audio denoising. The experimental results demonstrate the effectiveness of the proposed method
Composite fermions on a torus
We achieve an explicit construction of the lowest Landau level (LLL)
projected wave functions for composite fermions in the periodic (torus)
geometry. To this end, we first demonstrate how the vortex attachment of the
composite fermion (CF) theory can be accomplished in the torus geometry to
produce the "unprojected" wave functions satisfying the correct
(quasi-)periodic boundary conditions. We then consider two methods for
projecting these wave functions into the LLL. The direct projection produces
valid wave functions but can be implemented only for very small systems. The
more powerful and more useful projection method of Jain and Kamilla fails in
the torus geometry because it does not preserve the periodic boundary
conditions and thus takes us out of the original Hilbert space. We have
succeeded in constructing a modified projection method that is consistent with
both the periodic boundary conditions and the general structure of the CF
theory. This method is valid for a large class of states of composite fermions,
called "proper states," which includes the incompressible ground states at
electron filling factors , their charged and neutral
excitations, and also the quasidegenerate ground states at arbitrary filling
factors of the form , where and are
integers and is the CF filling factor. Comparison with exact results
known for small systems for the ground and excited states at filling factors
, 2/5 and 3/7 demonstrates our LLL-projected wave functions to be
extremely accurate representations of the actual Coulomb eigenstates. Our
construction enables the study of large systems of composite fermions on the
torus, thereby opening the possibility of investigating numerous interesting
questions and phenomena.Comment: 27 pages,7 figure
Density oscillations in trapped dipolar condensates
We investigated the ground state wave function and free expansion of a
trapped dipolar condensate. We find that dipolar interaction may induce both
biconcave and dumbbell density profiles in, respectively, the pancake- and
cigar-shaped traps. On the parameter plane of the interaction strengths, the
density oscillation occurs only when the interaction parameters fall into
certain isolated areas. The relation between the positions of these areas and
the trap geometry is explored. By studying the free expansion of the condensate
with density oscillation, we show that the density oscillation is detectable
from the time-of-flight image.Comment: 7 pages, 9 figure
Penggunaan Media Ilustrasi Pop-up Sejarah Dalam Pembelajaran IPS Di SD Negeri Batursari
This study aims: (1to know the process of learning social science in SD Negeri Batursari, (2) to know the use of illustration pop-up media in relieve the teacher to foster student‟s understanding toward the social science subject. This study was conducted in SD Negeri Batursari by using qualitative research strategies. The technique in collecting data were interview, direct observation, questionnaires and research document. The data validated by using triangulation researcher, theoretical and methodological. The technique using data collection, data reduction, and data presentation and conclusion/ verification. The result showed that fourth and rade students SD Negeri Batursari very anthusiastic in participating learning social science, students were formed into small groups and students talk to each other discussing visula messages in pop-up media. Illustration pop-up media is very helpful the teacher inleraning social science, it can be seen when students most easily to understand the material by looking at the illustration in the material. The syudents helped with the media as if the were in the illustration.
Keywords: Pop-Up Media, Social Science Learnin
Measurement back-action on the quantum spin-mixing dynamics of a spin-1 Bose-Einstein condensate
We consider a small F=1 spinor condensate inside an optical cavity driven by
an optical probe field, and subject the output of the probe to a homodyne
detection, with the goal of investigating the effect of measurement back-action
on the spin dynamics of the condensate. Using the stochastic master equation
approach, we show that the effect of back-action is sensitive to not only the
measurement strength but also the quantum fluctuation of the spinor condensate.
The same method is also used to estimate the atom numbers below which the
effect of back-action becomes so prominent that extracting spin dynamics from
this cavity-based detection scheme is no longer practical
Potential use of electrical somatosensory modality for BCI
INTRODUCTION: P300 is commonly used in noninvasive brain computer interface (BCI). Most P300 based BCIs were focus on visual and auditory stimulation [1]. Several previous reports present the potential use of vibrotactile stimulus for P300 BCI [2,3]. As an alternative, electrical somatosensory stimuli can be used for BCI ...published_or_final_versio
Nutrients removal performance and sludge properties using anaerobic fermentation slurry from food waste as an external carbon source for wastewater treatment
© 2018 Elsevier Ltd Enhancement of nitrogen and phosphate removal using thermophilic fermentation slurry from food waste (FSFW) as external carbon source was investigated. Based on the batch tests, the soluble and particulate fractions of the FSFW acted as easily and slowly biodegradable carbon sources, respectively, and the fermented slurry showed the combined nutrients removal properties of soluble and solid organics. During the long-term operation of a sequencing batch reactor (SBR) with FSFW for wastewater treatment, the sludge particle size increased obviously, the bacterial metabolic capacity improved significantly, and some functional microorganisms were enriched selectively, which significantly promoted the nitrogen removal efficiency (approximately 90%) by enhancing the anoxic denitrification and simultaneous nitrification and denitrification (SND) processes. Moreover, high phosphate removal efficiency (above 98%) was achieved through the aerobic and anoxic phosphate accumulation processes. Thus, using the FSFW as supplementary carbon source is a suitable solution for both food waste disposal and wastewater treatment
Interactions of energetic electrons with ULF waves triggered by interplanetary shock: Van Allen Probes observations in the magnetotail
Abstract We present in situ observations of a shock-induced substorm-like event on 13 April 2013 observed by the newly launched Van Allen twin probes. Substorm-like electron injections with energy of 30-500 keV were observed in the region from L∼5.2 to 5.5 immediately after the shock arrival (followed by energetic electron drift echoes). Meanwhile, the electron flux was clearly and strongly varying on the ULF wave time scale. It is found that both toroidal and poloidal mode ULF waves with a period of 150 s emerged following the magnetotail magnetic field reconfiguration after the interplanetary (IP) shock passage. The poloidal mode is more intense than the toroidal mode. The 90 phase shift between the poloidal mode Br and Ea suggests the standing poloidal waves in the Northern Hemisphere. Furthermore, the energetic electron flux modulations indicate that the azimuthal wave number is ∼14. Direct evidence of drift resonance between the injected electrons and the excited poloidal ULF wave has been obtained. The resonant energy is estimated to be between 150 keV and 230 keV. Two possible scenaria on ULF wave triggering are discussed: vortex-like flow structure-driven field line resonance and ULF wave growth through drift resonance. It is found that the IP shock may trigger intense ULF wave and energetic electron behavior at L∼3 to 6 on the nightside, while the time profile of the wave is different from dayside cases
Does stability of relativistic dissipative fluid dynamics imply causality?
We investigate the causality and stability of relativistic dissipative fluid
dynamics in the absence of conserved charges. We perform a linear stability
analysis in the rest frame of the fluid and find that the equations of
relativistic dissipative fluid dynamics are always stable. We then perform a
linear stability analysis in a Lorentz-boosted frame. Provided that the ratio
of the relaxation time for the shear stress tensor, , to the sound
attenuation length, , fulfills a certain
asymptotic causality condition, the equations of motion give rise to stable
solutions. Although the group velocity associated with perturbations may exceed
the velocity of light in a certain finite range of wavenumbers, we demonstrate
that this does not violate causality, as long as the asymptotic causality
condition is fulfilled. Finally, we compute the characteristic velocities and
show that they remain below the velocity of light if the ratio
fulfills the asymptotic causality condition.Comment: 30 pages, 10 figures
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