5,054 research outputs found
Kinematic Basis of Emergent Energetics of Complex Dynamics
Stochastic kinematic description of a complex dynamics is shown to dictate an
energetic and thermodynamic structure. An energy function emerges
as the limit of the generalized, nonequilibrium free energy of a Markovian
dynamics with vanishing fluctuations. In terms of the and its
orthogonal field , a general vector field
can be decomposed into , where
.
The matrix and scalar , two additional characteristics to the
alone, represent the local geometry and density of states intrinsic to
the statistical motion in the state space at . and
are interpreted as the emergent energy and degeneracy of the motion, with an
energy balance equation ,
reflecting the geometrical . The
partition function employed in statistical mechanics and J. W. Gibbs' method of
ensemble change naturally arise; a fluctuation-dissipation theorem is
established via the two leading-order asymptotics of entropy production as
. The present theory provides a mathematical basis for P. W.
Anderson's emergent behavior in the hierarchical structure of complexity
science.Comment: 7 page
Bell-INGARCH Model
Integer-valued time series exist widely in economics, finance, biology,
computer science, medicine, insurance, and many other fields. In recent years,
many types of models have been proposed to model integer-valued time series
data, in which the integer autoregressive model and integer-valued GARCH model
are the most representative. Although there have been many results of
integer-valued time series data, the parameters of integer-valued time series
model structure are more complicated. This paper is dedicated to proposing a
new simple integer-valued GARCH model. First, the Bell integer-valued GARCH
model is given based on Bell distribution. Then, the conditional maximum
likelihood estimation method is used to obtain the estimators of parameters.
Later, numerical simulations confirm the finite sample properties of the
estimation of unknown parameters. Finally, the model is applied in the two real
examples. Compared with the existing models, the proposed model is more simple
and applicable.Comment: 16 pages,4 figure
Velocity control of longitudinal vibration ultrasonic motor using improved Elman neural network trained by CQPSO with Lévy flights
Longitudinally vibration ultrasonic motor (LV-USM), a canonical nonlinear system, utilizes the inverse piezoelectric effect of piezoelectric ceramic to generate the mechanical vibration within the scope of ultrasonic frequency. However, it is very difficult to establish a strict and accurate mathematical model. Hence seeking a dynamic identifier and controller for LV-USM avoiding the accurate mathematical model becomes a feasible approach. In this paper, a novel learning algorithm for dynamic recurrent Elman neural networks is present based on a particle swarm optimization (PSO) to identify and control an LV-USM. To overcome the PSO’s global search ability, Lévy flights, a kind of random walks, are imported to improve the ability of exploration rather than Brownian motion or Gauss disturbance based on Cooperative Quantum-behaved PSO (CQPSO). Thereafter, a controller is designed to perform speed control for LV-USM along with the nonlinear identification also using this kind of neural network. By discrete Lyapunov stability approach, the controller is proven to be stable theoretically and the latter trial shows its robustness of anti-noise performance. In the experiments, the numerical results illustrate that the designed identifier and controller can achieve both higher convergence precision and speed, relative to current state-of-the-art other methods. Moreover, this controller shows lower control error than other approaches while the displacement of the rotor disc in LV-USM appears more smooth and uniform
An oxygen pool from YBaCo4O7-based oxides for soot combustion
Acknowledgements This work is financially supported by the National Natural Science Foundation of China (no. 21477046, 21277060 and 21547007). Open Access via RSC Gold4GoldPeer reviewe
Time to tackle clonorchiasis in China
Recent publication of the global epidemiology of clonorchiasis and its relationship with cholangiocarcinoma in the journal of Infectious Diseases of Poverty has stressed the importance of Clonorchis sinensis infection. To further demonstrate its threat on public health, especially in China, comparisons between clonorchiasis and hepatitis B are made in terms of epidemiology, clinical symptoms and carcinogenicity, disability, as well as changing trends. Furthermore, major problems and prioritized researches are argued, from basic biology to intervention. Imbalance between the majority of infected population and the minority of researches in China urges for more work from Chinese scientists and international cooperation
Tetraaquatetrakis(4,4′-bipyridine dioxide-κO)terbium(III) octacyanidotungstate(V)
In the title compound, [Tb(C10H8N2O2)4(H2O)4][W(CN)8], both metal atoms are eight-coordinated. The TbIII ion displays a dodecahedral geometry, while the Wv ion exhibits a distorted square-antiprismatic geometry. The Tb atoms are located on a special position of site symmetry -4, whereas the W atoms are located on a twofold rotation axis. The cations are linked by O—H⋯O hydrogen bonds. The title compound is isotypic with the corresponding and previously described Mo compound [Qian & Yuan (2011 ▶). Acta Cryst. E67, m845]
Deformable Model-Driven Neural Rendering for High-Fidelity 3D Reconstruction of Human Heads Under Low-View Settings
Reconstructing 3D human heads in low-view settings presents technical
challenges, mainly due to the pronounced risk of overfitting with limited views
and high-frequency signals. To address this, we propose geometry decomposition
and adopt a two-stage, coarse-to-fine training strategy, allowing for
progressively capturing high-frequency geometric details. We represent 3D human
heads using the zero level-set of a combined signed distance field, comprising
a smooth template, a non-rigid deformation, and a high-frequency displacement
field. The template captures features that are independent of both identity and
expression and is co-trained with the deformation network across multiple
individuals with sparse and randomly selected views. The displacement field,
capturing individual-specific details, undergoes separate training for each
person. Our network training does not require 3D supervision or object masks.
Experimental results demonstrate the effectiveness and robustness of our
geometry decomposition and two-stage training strategy. Our method outperforms
existing neural rendering approaches in terms of reconstruction accuracy and
novel view synthesis under low-view settings. Moreover, the pre-trained
template serves a good initialization for our model when encountering unseen
individuals.Comment: Accepted by ICCV2023. Visit our project page at
https://github.com/xubaixinxbx/3dhead
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Illuminating cell signaling with genetically encoded FRET biosensors in adult mouse cardiomyocytes.
FRET-based biosensor experiments in adult cardiomyocytes are a powerful way of dissecting the spatiotemporal dynamics of the complicated signaling networks that regulate cardiac health and disease. However, although much information has been gleaned from FRET studies on cardiomyocytes from larger species, experiments on adult cardiomyocytes from mice have been difficult at best. Thus the large variety of genetic mouse models cannot be easily used for this type of study. Here we develop cell culture conditions for adult mouse cardiomyocytes that permit robust expression of adenoviral FRET biosensors and reproducible FRET experimentation. We find that addition of 6.25 µM blebbistatin or 20 µM (S)-nitro-blebbistatin to a minimal essential medium containing 10 mM HEPES and 0.2% BSA maintains morphology of cardiomyocytes from physiological, pathological, and transgenic mouse models for up to 50 h after adenoviral infection. This provides a 10-15-h time window to perform reproducible FRET readings using a variety of CFP/YFP sensors between 30 and 50 h postinfection. The culture is applicable to cardiomyocytes isolated from transgenic mouse models as well as models with cardiac diseases. Therefore, this study helps scientists to disentangle complicated signaling networks important in health and disease of cardiomyocytes
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