51 research outputs found
Towards a Robust WiFi-based Fall Detection with Adversarial Data Augmentation
Recent WiFi-based fall detection systems have drawn much attention due to
their advantages over other sensory systems. Various implementations have
achieved impressive progress in performance, thanks to machine learning and
deep learning techniques. However, many of such high accuracy systems have low
reliability as they fail to achieve robustness in unseen environments. To
address that, this paper investigates a method of generalization through
adversarial data augmentation. Our results show a slight improvement in deep
learning-systems in unseen domains, though the performance is not significant.Comment: Will appear in Proceedings of the 54th Annual Conference on
Information Sciences and Systems (CISS2020
Stability investigations of isotropic and anisotropic exponential inflation in the Starobinsky-Bel-Robinson gravity
In this paper, we would like to examine whether a novel
Starobinsky-Bel-Robinson gravity model admits stable exponential inflationary
solutions with or without spatial anisotropies. As a result, we are able to
derive an exact de Sitter inflationary to this Starobinsky-Bel-Robinson model.
Furthermore, we observe that an exact Bianchi type I inflationary solution does
not exist in the Starobinsky-Bel-Robinson model. However, we find that a
modified Starobinsky-Bel-Robinson model, in which the sign of coefficient of
term is flipped from positive to negative, can admit the corresponding
Bianchi type I inflationary solution. Unfortunately, stability analysis using
the dynamical system approach indicates that both of these inflationary
solutions turn out to be unstable. Interestingly, we show that a stable de
Sitter inflationary solution can be obtained in the modified
Starobinsky-Bel-Robinson gravity.Comment: 26 pages, 2 figures. V2 with the abstract revised to improve its
clarity, some relevant references added, and some typos fixed. All main
calculations and conclusions remain unchanged. Comments are welcom
Conditional Support Alignment for Domain Adaptation with Label Shift
Unsupervised domain adaptation (UDA) refers to a domain adaptation framework
in which a learning model is trained based on the labeled samples on the source
domain and unlabelled ones in the target domain. The dominant existing methods
in the field that rely on the classical covariate shift assumption to learn
domain-invariant feature representation have yielded suboptimal performance
under the label distribution shift between source and target domains. In this
paper, we propose a novel conditional adversarial support alignment (CASA)
whose aim is to minimize the conditional symmetric support divergence between
the source's and target domain's feature representation distributions, aiming
at a more helpful representation for the classification task. We also introduce
a novel theoretical target risk bound, which justifies the merits of aligning
the supports of conditional feature distributions compared to the existing
marginal support alignment approach in the UDA settings. We then provide a
complete training process for learning in which the objective optimization
functions are precisely based on the proposed target risk bound. Our empirical
results demonstrate that CASA outperforms other state-of-the-art methods on
different UDA benchmark tasks under label shift conditions
Anisotropic power-law inflation for models of non-canonical scalar fields non-minimally coupled to a two-form field
In this paper, we investigate the validity of the so-called cosmic no-hair
conjecture in the framework of anisotropic inflation models of non-canonical
scalar fields non-minimally coupled to a two-form field. In particular, we
focus on two typical {\it k}-inflation and Dirac-Born-Infeld inflation models,
in which we find a set of exact anisotropic power-law inflationary solutions.
Interestingly, these solutions are shown to be stable and attractive during an
inflationary phase using the dynamical system analysis. The obtained results
indicate that the non-minimal coupling between the scalar and two-form fields
acts as a non-trivial source of generating stable spatial anisotropies during
the inflationary phase and therefore violates the prediction of the cosmic
no-hair conjecture, even when the scalar field is of non-canonical forms.Comment: 16 pages, 6 figures. Comments are welcom
The impact of intraspecific competition on tree growth in planted Korean pine forest
The aim of this study was to explore the correlation of competition indices (CIs) on individual tree growth for Korean pine (Pinus koraiensis) plantation using partial correlation analysis and generalized linear models. The data were collected from 15 permanent plots in Mengjiagang forestry farm, Northeast China. The results showed that the distance dependent CIs have a higher predictive capacity for individual growth of pine trees. The control index of competitive trees number (CI1) combined with the selection fixed competitor trees (M2) was found to be the most well correlated competition measure with five - years diameter increment. Thus, the competition index (CI1- M2) was recommended for developing individual tree growth models. The subject tree diameter at breast height, crown width, height to crown base, tree volume and basal area all showed a significantly linear correlation with tree competition intensity (P 0,05). Diameter at breast height, crown width, tree volume and basal area all decreased with increasing competition intensity, whereas the height to crown base increased. There was no significant relationship between competition intensity and tree height (P 0,05). The optimal model of predicting individual growth with logarithm of diameter at breast height and CIs as the independent variables due to the best fitting performance. This results also showed considerable improvement in predicting individual tree periodic growth when including competition indices that the mean absolute error is reduced in the range of 22â25%.
CuâFe Incorporated Graphene-Oxide Nanocomposite as Highly Efficient Catalyst in the Degradation of Dichlorodiphenyltrichloroethane (DDT) from Aqueous Solution
Fe/graphene oxide and CuâFe/graphene oxide nanocomposite were synthesized by the atomic implantation method to study the photocatalytic degradation of dichlorodiphenyltrichloroethane (DDT). The synthesized nanocomposites were characterized by the XRD, N2 isotherms, SEM with EDX, TEM and XPS analysis. Characterization results have reported that oxides of Cu and Fe were uniformly distributed on graphene oxide and exited in the form of Cu+ and Fe2+ ions in CuâFe/graphene oxide nanocomposite. The high photocatalytic DDT removal efficiency 99.7% was obtained for CuâFe/graphene oxide under the optimal condition of 0.2 g/L catalyst, 15 mg/L H2O2 and pHâ5. It was attributed to the reduction of Fe3+ to Fe2+ by Cu+ ions and âOH radicals formation. However, it was dropped to 90.4% in the recycling study by leaching of iron and without a change in phase structure and morphology
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A Schrödinger Equation for Evolutionary Dynamics
We establish an analogy between the FokkerâPlanck equation describing evolutionary landscape dynamics and the Schrödinger equation which characterizes quantum mechanical particles, showing that a population with multiple genetic traits evolves analogously to a wavefunction under a multi-dimensional energy potential in imaginary time. Furthermore, we discover within this analogy that the stationary population distribution on the landscape corresponds exactly to the ground-state wavefunction. This mathematical equivalence grants entry to a wide range of analytical tools developed by the quantum mechanics community, such as the RayleighâRitz variational method and the RayleighâSchrödinger perturbation theory, allowing us not only the conduct of reasonable quantitative assessments but also exploration of fundamental biological inquiries. We demonstrate the effectiveness of these tools by estimating the population success on landscapes where precise answers are elusive, and unveiling the ecological consequences of stress-induced mutagenesisâa prevalent evolutionary mechanism in pathogenic and neoplastic systems. We show that, even in an unchanging environment, a sharp mutational burst resulting from stress can always be advantageous, while a gradual increase only enhances population size when the number of relevant evolving traits is limited. Our interdisciplinary approach offers novel insights, opening up new avenues for deeper understanding and predictive capability regarding the complex dynamics of evolving populations
A Schr\"odinger Equation for Evolutionary Dynamics
We establish an analogy between the Fokker-Planck equation describing
evolutionary landscape dynamics and the Schr\"{o}dinger equation which
characterizes quantum mechanical particles, showing how a population with
multiple genetic traits evolves analogously to a wavefunction under a
multi-dimensional energy potential in imaginary time. Furthermore, we discover
within this analogy that the stationary population distribution on the
landscape corresponds exactly to the ground-state wavefunction. This
mathematical equivalence grants entry to a wide range of analytical tools
developed by the quantum mechanics community, such as the Rayleigh-Ritz
variational method and the Rayleigh-Schr\"{o}dinger perturbation theory,
allowing us to not only make reasonable quantitative assessments but also
explore fundamental biological inquiries. We demonstrate the effectiveness of
these tools by estimating the population success on landscapes where precise
answers are elusive, and unveiling the ecological consequences of
stress-induced mutagenesis -- a prevalent evolutionary mechanism in pathogenic
and neoplastic systems. We show that, even in a unchanging environment, a sharp
mutational burst resulting from stress can always be advantageous, while a
gradual increase only enhances population size when the number of relevant
evolving traits is limited. Our interdisciplinary approach offers novel
insights, opening up new avenues for deeper understanding and predictive
capability regarding the complex dynamics of evolving populations
Surface-based protein domains retrieval methods from a SHREC2021 challenge
publication dans une revue suite Ă la communication hal-03467479 (SHREC 2021: surface-based protein domains retrieval)International audienceProteins are essential to nearly all cellular mechanism and the effectors of the cells activities. As such, they often interact through their surface with other proteins or other cellular ligands such as ions or organic molecules. The evolution generates plenty of different proteins, with unique abilities, but also proteins with related functions hence similar 3D surface properties (shape, physico-chemical properties, âŠ). The protein surfaces are therefore of primary importance for their activity. In the present work, we assess the ability of different methods to detect such similarities based on the geometry of the protein surfaces (described as 3D meshes), using either their shape only, or their shape and the electrostatic potential (a biologically relevant property of proteins surface). Five different groups participated in this contest using the shape-only dataset, and one group extended its pre-existing method to handle the electrostatic potential. Our comparative study reveals both the ability of the methods to detect related proteins and their difficulties to distinguish between highly related proteins. Our study allows also to analyze the putative influence of electrostatic information in addition to the one of protein shapes alone. Finally, the discussion permits to expose the results with respect to ones obtained in the previous contests for the extended method. The source codes of each presented method have been made available online
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