Recurrent Level Set Networks for Instance Segmentation

Level set (LS)-based segmentation has been widely used in medical imaging domain. It however has some difficulty when dealing with multi-instance objects in the real world. Furthermore, LS’s performance is generally quite sensitive to some initial settings and parameters such as the number of iterations. To address these issues and promote the classic LS methods to a new degree of performance in a trainable deep learning framework, we are presenting a novel approach contextual recurrent level sets (CRLS) for object instance segmentation. In the proposed networks, the curve deformation process is formed as a hidden state evolution procedure in gated recurrent units (GRUs) and updated by minimizing an energy functional composed of fitting forces and contour length

SYNTHESIS OF STARCH MODIFIED MONTMORILLONITE AS AN EFFECTIVE ADSORBENT FOR Pb (II) REMOVAL FROM WATER

The adsorbent is prepared by the montmorillonite co-modification with starch for the removal of Pb (II) ions from aqueous solution. The Fourier-transformed infrared (FTIR), X-ray diffraction (XRD) spectroscopies were used to determine the structure and characteristics of the adsorbent. The main factors affecting the removal of Pb (II) ions were investigated, including the effect of pH, contact time, adsorbent dosage and the initial concentration of Pb (II). Batch process can be used for adsorption and equilibrium studies. The experimental data were fitted using Freundlich and Langmuir adsorption models. The Langmuir isotherm best fitted the experimental data with R2 0.99 and maximum Pb (II) adsorption capacity of 21.5 mg/g indicated monolayer adsorption. Kinetic studies using pseudo-first-order and pseudo-second-order rate models showed that the process complied well with the pseudo second-order rate model

Detecting Stochastic Wave Dark Matter with Fermi-LAT γ\gamma-ray Pulsar Timing Array

Wave dark matter (DM) represents a class of the most representative DM candidates. Due to its periodic perturbation to spacetime, the wave DM can be detected with a galactic interferometer - pulsar timing array (PTA). We perform in this Letter a first analysis of applying the $\gamma$-ray PTA to detect the wave DM, with the data of Fermi Large Area Telescope (Fermi-LAT). Despite the limitation in statistics, the $\gamma$-PTA demonstrates a promising sensitivity potential for a mass $\sim 10^{-23}-10^{-22}$ eV. We show that the upper limits not far from those of the dedicated radio-PTA projects can be achieved. Particularly, we have fulfilled an analysis to cross-correlate the pulsar data, which has been essentially missing so far in real data analysis but is known to be crucial for identifying the nature of potential signals, with the Fermi-LAT data of two pulsars.Comment: 5 pages, 3 figures. Comments welcome

Nested solitons in two-field fuzzy dark matter

Dark matter as scalar particles consisting of multiple species is well motivated in string theory where axion fields are ubiquitous. A two-field fuzzy dark matter (FDM) model features two species of ultralight axion particles with different masses, $m_1 \neq m_2$, which is extended from the standard one-field model with $m_a \sim 10^{-22}\,{\rm eV}$. Here we perform numerical simulations to explore the properties of two-field FDM haloes. We find that the central soliton has a nested structure when $m_2 \gg m_1$, which is distinguishable from the generic flat-core soliton in one-field haloes. However, the formation of this nested soliton is subject to many factors, including the density fraction and mass ratio of the two fields. Finally, we study non-linear structure formation in two-field cosmological simulations with self-consistent initial conditions and find that the small-scale structure in two-field cosmology is also distinct from the one-field model in terms of DM halo counts and soliton formation time.Comment: 11 pages, 5 figures. Published versio

The Hubble Constant in the Axi-Higgs Universe

The $\Lambda$CDM model provides an excellent fit to the CMB data. However, a statistically significant tension emerges when its determination of the Hubble constant $H_0$ is compared to the local distance-redshift measurements. The axi-Higgs model, which couples an ultralight axion to the Higgs field, offers a specific variation of the $\Lambda$CDM model. It relaxes the $H_0$ tension as well as explains the $^7$Li puzzle in Big-Bang nucleosynthesis, the clustering $S_8$ tension with the weak-lensing data, and the observed isotropic cosmic birefringence in CMB. In this paper, we demonstrate how the $H_0$ and $S_8$ tensions can be relaxed simultaneously, by correlating the axion impacts on the early and late universe. In a benchmark scenario ($m=2 \times 10^{-30}$ eV) selected for experimental tests soon, the analysis combining the CMB+BAO+WL+SN data yields $H_0 = 69.9 \pm 1.5$ km/s/Mpc and $S_8 = 0.8045 \pm 0.0096$. Combining this (excluding the SN (supernovae) part) with the local distance-redshift measurements yields $H_0 = 72.42 \pm 0.76$ km/s/Mpc, while $S_8$ is slightly more suppressed.Comment: 15 pages, 11 figures, final version published on PRR Lette