4,393 research outputs found
On Unconstrained Quasi-Submodular Function Optimization
With the extensive application of submodularity, its generalizations are
constantly being proposed. However, most of them are tailored for special
problems. In this paper, we focus on quasi-submodularity, a universal
generalization, which satisfies weaker properties than submodularity but still
enjoys favorable performance in optimization. Similar to the diminishing return
property of submodularity, we first define a corresponding property called the
{\em single sub-crossing}, then we propose two algorithms for unconstrained
quasi-submodular function minimization and maximization, respectively. The
proposed algorithms return the reduced lattices in iterations,
and guarantee the objective function values are strictly monotonically
increased or decreased after each iteration. Moreover, any local and global
optima are definitely contained in the reduced lattices. Experimental results
verify the effectiveness and efficiency of the proposed algorithms on lattice
reduction.Comment: 11 page
Relativistic mean-field approximation with density-dependent screening meson masses in nuclear matter
The Debye screening masses of the , and neutral
mesons and the photon are calculated in the relativistic mean-field
approximation. As the density of the nucleon increases, all the screening
masses of mesons increase. It shows a different result with Brown-Rho scaling,
which implies a reduction in the mass of all the mesons in the nuclear matter
except the pion. Replacing the masses of the mesons with their corresponding
screening masses in Walecka-1 model, five saturation properties of the nuclear
matter are fixed reasonably, and then a density-dependent relativistic
mean-field model is proposed without introducing the non-linear self-coupling
terms of mesons.Comment: 14 pages, 3 figures, REVTEX4, Accepted for publication in Int. J.
Mod. Phys.
Effect of Bordered Pit Torus Position on Permeability in Chinese Yezo Spruce
The effect of different bordered pit torus positions on wood permeability was studied by air-drying and ethanol-exchange drying for green wood and by soaking in water, then followed by ethanol-exchange drying for air-dried wood of Chinese yezo spruce (Picea jezoensis var. komarovii). The results showed that different treatments caused different pit torus positions and different wood permeability. The air-drying treatment resulted in pit torus aspiration and low permeability for sapwood. The ethanol-exchange drying treatment left the pit torus in an unaspirated position and resulted in high permeability for sapwood. Soaking in water followed by ethanol-exchange drying caused deaspiration of a part of pit torus and increased permeability for both sapwood and heartwood
Structural Stability of Lexical Semantic Spaces: Nouns in Chinese and French
Many studies in the neurosciences have dealt with the semantic processing of
words or categories, but few have looked into the semantic organization of the
lexicon thought as a system. The present study was designed to try to move
towards this goal, using both electrophysiological and corpus-based data, and
to compare two languages from different families: French and Mandarin Chinese.
We conducted an EEG-based semantic-decision experiment using 240 words from
eight categories (clothing, parts of a house, tools, vehicles,
fruits/vegetables, animals, body parts, and people) as the material. A
data-analysis method (correspondence analysis) commonly used in computational
linguistics was applied to the electrophysiological signals.
The present cross-language comparison indicated stability for the following
aspects of the languages' lexical semantic organizations: (1) the
living/nonliving distinction, which showed up as a main factor for both
languages; (2) greater dispersion of the living categories as compared to the
nonliving ones; (3) prototypicality of the \emph{animals} category within the
living categories, and with respect to the living/nonliving distinction; and
(4) the existence of a person-centered reference gradient. Our
electrophysiological analysis indicated stability of the networks at play in
each of these processes. Stability was also observed in the data taken from
word usage in the languages (synonyms and associated words obtained from
textual corpora).Comment: 17 pages, 4 figure
In-Place Gestures Classification via Long-term Memory Augmented Network
In-place gesture-based virtual locomotion techniques enable users to control
their viewpoint and intuitively move in the 3D virtual environment. A key
research problem is to accurately and quickly recognize in-place gestures,
since they can trigger specific movements of virtual viewpoints and enhance
user experience. However, to achieve real-time experience, only short-term
sensor sequence data (up to about 300ms, 6 to 10 frames) can be taken as input,
which actually affects the classification performance due to limited
spatio-temporal information. In this paper, we propose a novel long-term memory
augmented network for in-place gestures classification. It takes as input both
short-term gesture sequence samples and their corresponding long-term sequence
samples that provide extra relevant spatio-temporal information in the training
phase. We store long-term sequence features with an external memory queue. In
addition, we design a memory augmented loss to help cluster features of the
same class and push apart features from different classes, thus enabling our
memory queue to memorize more relevant long-term sequence features. In the
inference phase, we input only short-term sequence samples to recall the stored
features accordingly, and fuse them together to predict the gesture class. We
create a large-scale in-place gestures dataset from 25 participants with 11
gestures. Our method achieves a promising accuracy of 95.1% with a latency of
192ms, and an accuracy of 97.3% with a latency of 312ms, and is demonstrated to
be superior to recent in-place gesture classification techniques. User study
also validates our approach. Our source code and dataset will be made available
to the community.Comment: This paper is accepted to IEEE ISMAR202
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