5,984 research outputs found
Adaptive DCTNet for Audio Signal Classification
In this paper, we investigate DCTNet for audio signal classification. Its
output feature is related to Cohen's class of time-frequency distributions. We
introduce the use of adaptive DCTNet (A-DCTNet) for audio signals feature
extraction. The A-DCTNet applies the idea of constant-Q transform, with its
center frequencies of filterbanks geometrically spaced. The A-DCTNet is
adaptive to different acoustic scales, and it can better capture low frequency
acoustic information that is sensitive to human audio perception than features
such as Mel-frequency spectral coefficients (MFSC). We use features extracted
by the A-DCTNet as input for classifiers. Experimental results show that the
A-DCTNet and Recurrent Neural Networks (RNN) achieve state-of-the-art
performance in bird song classification rate, and improve artist identification
accuracy in music data. They demonstrate A-DCTNet's applicability to signal
processing problems.Comment: International Conference of Acoustic and Speech Signal Processing
(ICASSP). New Orleans, United States, March, 201
Cavity-Assisted Dynamical Spin-Orbit Coupling in Cold Atoms
We consider ultracold atoms subjected to a cavity-assisted two-photon Raman
transition. The Raman coupling gives rise to effective spin-orbit interaction
which couples atom's center-of-mass motion to its pseudospin degrees of
freedom. Meanwhile, the cavity photon is dynamically affected by the atom. This
feedback between atom and photon leads to a dramatic modification of the atomic
dispersion relation, and further leads to dynamical instability of the system.
We propose to detect the change of cavity photon number as a direct way to
demonstrate dynamical instability.Comment: 5 pages, 5 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
« NOUS » ET LA CONSTRUCTION D’UN ETHOS INDIVIDUEL ET COLLECTIF DANS LE DISCOURS POLITIQUE
RÉSUMÉ. La construction de l’image d’un pays ou d’une personne s’avère importante dans les échanges internationaux. Ainsi, notre étude porte sur la construction de l’ethos à la française pour mieux connaître les stratégies concernées et pour arriver à une communication efficace avec les Français à l’avenir. Le pronom « nous », considéré comme une jonction entre « je » et « non-je », demeure un marqueur important en ce qui concerne la construction d’un ethos individuel et collectif, et nous ouvre la perspective sur sa valeur stratégique dans le discours politique aussi bien que sur sa fonction dans les relations hiérarchiques des actants. Notre travail, qui étudie le duel entre Sarkozy et Hollande en 2012 pendant les élections présidentielles, est essentiellement ancré dans l’analyse du discours, dans la théorie de l’énonciation de la subjectivité (Benveniste, 1966, 1974 ; Kerbrat-Orecchioni, 2009) en particulier. Mots-clés: discours politique, énonciation, ethos individuel et collectif, « nous », valeur stratégique.00lns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"ABSTRACT. The national or personal image building is very important in international exchange. Therefore, our study focuses on the construction of ethos in a French way in order to gain a better understanding of the relevant strategies and to achieve effective communication with Frenchmen in the future. The pronoun “we”, which is supposed to be a junction between “I” and “non-I” in enunciation, is an important symbol in the construction of individual and collective ethos, and opens up the possibility to carry out a study on its strategic value in the political discourse, as well as its function in the hierarchical relationship among the participants. Our work, which is studying the duel between Sarkozy and Hollande during the presidential election in 2012, is rooted in the theory of discourse analysis, especially in the theory of enunciation of subjectivity (Benveniste, 1966, 1974; Kerbrat-Orecchioni, 2009). Keywords: enunciation, individual and collective ethos, political discourse, strategic value, we
Learned Quality Enhancement via Multi-Frame Priors for HEVC Compliant Low-Delay Applications
Networked video applications, e.g., video conferencing, often suffer from
poor visual quality due to unexpected network fluctuation and limited
bandwidth. In this paper, we have developed a Quality Enhancement Network
(QENet) to reduce the video compression artifacts, leveraging the spatial and
temporal priors generated by respective multi-scale convolutions spatially and
warped temporal predictions in a recurrent fashion temporally. We have
integrated this QENet as a standard-alone post-processing subsystem to the High
Efficiency Video Coding (HEVC) compliant decoder. Experimental results show
that our QENet demonstrates the state-of-the-art performance against default
in-loop filters in HEVC and other deep learning based methods with noticeable
objective gains in Peak-Signal-to-Noise Ratio (PSNR) and subjective gains
visually
A Simplified Latent Semantic Indexing Approach for Multi-Linguistic Information Retrieval
Latent Semantic Indexing (LSI) approach provides a promising solution to overcome the language barrier between queries and documents, but unfortunately the high dimensions of the training matrix is computationally prohibitive for its key step of Singular Value Decomposition (SVD). Based on the semantic parallelism of the multi-linguistic training corpus we prove in this paper that, theoretically if the training term-by-document matrix can appear in either of two symmetry forms, strong or weak, the dimension of the matrix under decomposition can be reduced to the size of a monolingual matrix. The retrieval accuracy will not deteriorate in such a simplification. And we also discuss what these two forms of symmetry mean in the context of multi-linguistic information retrieval. Although in real world data the term-by-document matrices are not naturally in either symmetry form, we suggest a way to make them appear more symmetric in the strong form by means of word clustering and term weighting. A real data experiment is also given to support our method of simplification.
Properties of a coupled two species atom-heteronuclear molecule condensate
We study the coherent association of a two-species atomic condensate into a
condensate of heteronuclear diatomic molecules, using both a semiclassical
treatment and a quantum mechanical approach. The differences and connections
between the two approaches are examined. We show that, in this coupled
nonlinear atom-molecule system, the population difference between the two
atomic species plays a significant role in the ground-state stability
properties as well as in coherent population oscillation dynamics.Comment: 7 pages, 4 figure
- …