How to Train Your Dragon: Tamed Warping Network for Semantic Video Segmentation

Real-time semantic segmentation on high-resolution videos is challenging due to the strict requirements of speed. Recent approaches have utilized the inter-frame continuity to reduce redundant computation by warping the feature maps across adjacent frames, greatly speeding up the inference phase. However, their accuracy drops significantly owing to the imprecise motion estimation and error accumulation. In this paper, we propose to introduce a simple and effective correction stage right after the warping stage to form a framework named Tamed Warping Network (TWNet), aiming to improve the accuracy and robustness of warping-based models. The experimental results on the Cityscapes dataset show that with the correction, the accuracy (mIoU) significantly increases from 67.3% to 71.6%, and the speed edges down from 65.5 FPS to 61.8 FPS. For non-rigid categories such as "human" and "object", the improvements of IoU are even higher than 18 percentage points

Tailored biosynthesis of pseudosugars against diabetes by repurposing the promiscuous microbial enzymes

Synthetic biology plays an important role in not only revealing the complicated functions of organisms but also providing a promising route for bio-manufactures for medicine. However, we still faced the challenges for building a cost-efficient process due to shortages of suitable enzymes for the desired reactions. Molecular evolution of the promiscuous enzymes based on the knowledge of enzyme catalytic mechanisms provide a promising route for turning from proof-of-concept towards precision function. Here, we give some examples for discovering and evolving the promiscuous enzymes in artificial synthetic pathways, especially for biosynthesis of voglibose against diabetes. The precise control of catalysts enhances the ability to control the biological system, therefore provides a new path for targeting the precision function in synthetic biology

Analysis of Contact Surface Wear Performance of O-Ring Dynamic Seal Based on Archard Model

With the development of hydraulic system to high pressure gradually, the leakage risk of sealing system increases, and it is necessary to confirm the performance parameters of sealing structure through analysis and calculation. The traditional analysis of the friction and wear performance of the seal ring is limited to the amount of wear, and cannot describe the surface wear characteristics of the O-ring in detail. Based on the Archard model, this paper constructs a model to analyse and calculate the friction and wear performance of the dynamic seal structure through the material characteristics and operating parameters, analyses the friction and wear characteristics of the O-ring seal structure under different compression ratio, medium pressure, relative slip velocity and temperature, and summarizes the influence of each single variable on the wear characteristics of the dynamic seal structure. According to the analysis in this paper, the increase of medium pressure of 5 MPa will cause the wear concentration area of the contact surface to move to the back pressure side, and the overall wear will be reduced, but the increase of contact area will lead to the weakening of sealing effect. By the action of 15 MPa, when the compression ratio is between 5% and 10%, the change of cumulative wear rate and the wear rate of each node is small

Vanishing viscosity limit for compressible magnetohydrodynamics equations with transverse background magnetic field

We are concerned with the uniform regularity estimates and vanishing viscosity limit of solution to two dimensional viscous compressible magnetohydrodynamics (MHD) equations with transverse background magnetic field. When the magnetic field is assumed to be transverse to the boundary and the tangential component of magnetic field satisfies zero Neumann boundary condition, even though the velocity is imposed the no-slip boundary condition, the uniform regularity estimates of solution and its derivatives still can be achieved in suitable conormal Sobolev spaces in the half plane $\mathbb{R}^2_+$, and then the vanishing viscosity limit is justified in $L^\infty$ sense based on these uniform regularity estimates and some compactness arguments. At the same time, together with \cite{CLX21}, our results show that the transverse background magnetic field can prevent the strong boundary layer from occurring for compressible magnetohydrodynamics whether there is magnetic diffusion or not.Comment: 33 pages. arXiv admin note: text overlap with arXiv:2108.1296

A closer look at interacting dark energy with statefinder hierarchy and growth rate of structure

We investigate the interacting dark energy models by using the diagnostics of statefinder hierarchy and growth rate of structure. We wish to explore the deviations from $\Lambda$CDM and to differentiate possible degeneracies in the interacting dark energy models with the geometrical and structure growth diagnostics. We consider two interacting forms for the models, i.e., $Q_1=\beta H\rho_c$ and $Q_2=\beta H\rho_{de}$, with $\beta$ being the dimensionless coupling parameter. Our focus is the I$\Lambda$CDM model that is a one-parameter extension to $\Lambda$CDM by considering a direct coupling between the vacuum energy ($\Lambda$) and cold dark matter (CDM), with the only additional parameter $\beta$. But we begin with a more general case by considering the I$w$CDM model in which dark energy has a constant $w$ (equation-of-state parameter). For calculating the growth rate of structure, we employ the "parametrized post-Friedmann" theoretical framework for interacting dark energy to numerically obtain the $\epsilon(z)$ values for the models. We show that in both geometrical and structural diagnostics the impact of $w$ is much stronger than that of $\beta$ in the I$w$CDM model. We thus wish to have a closer look at the I$\Lambda$CDM model by combining the geometrical and structural diagnostics. We find that the evolutionary trajectories in the $S^{(1)}_3$--$\epsilon$ plane exhibit distinctive features and the departures from $\Lambda$CDM could be well evaluated, theoretically, indicating that the composite null diagnostic $\{S^{(1)}_3, \epsilon\}$ is a promising tool for investigating the interacting dark energy models.Comment: 17 pages, 4 figures; accepted for publication in JCA