Deformable Convolutional Networks

Convolutional neural networks (CNNs) are inherently limited to model geometric transformations due to the fixed geometric structures in its building modules. In this work, we introduce two new modules to enhance the transformation modeling capacity of CNNs, namely, deformable convolution and deformable RoI pooling. Both are based on the idea of augmenting the spatial sampling locations in the modules with additional offsets and learning the offsets from target tasks, without additional supervision. The new modules can readily replace their plain counterparts in existing CNNs and can be easily trained end-to-end by standard back-propagation, giving rise to deformable convolutional networks. Extensive experiments validate the effectiveness of our approach on sophisticated vision tasks of object detection and semantic segmentation. The code would be released

Gr\"obner-Shirshov bases and linear bases for free multi-operated algebras over algebras with applications to differential Rota-Baxter algebras and integro-differential algebras

Quite much recent studies has been attracted to the operated algebra since it unifies various notions such as the differential algebra and the Rota-Baxter algebra. An $\Omega$-operated algebra is a an (associative) algebra equipped with a set $\Omega$ of linear operators which might satisfy certain operator identities such as the Leibniz rule. A free $\Omega$-operated algebra $B$ can be generated on an algebra $A$ similar to a free algebra generated on a set. If $A$ has a Gr\"{o}bner-Shirshov basis $G$ and if the linear operators $\Omega$ satisfy a set $\Phi$ of operator identities, it is natural to ask when the union $G\cup \Phi$ is a Gr\"{o}bner-Shirshov basis of $B$. A previous work answers this question affirmatively under a mild condition, and thereby obtains a canonical linear basis of $B$. In this paper, we answer this question in the general case of multiple linear operators. As applications we get operated Gr\"{o}bner-Shirshov bases for free differential Rota-Baxter algebras and free integro-differential algebras over algebras as well as their linear bases. One of the key technical difficulties is to introduce new monomial orders for the case of two operators, which might be of independent interest.Comment: 27 page

Effect of H2S content on relative permeability and capillary pressure characteristics of acid gas/brine/rock systems: A review

Geological storage of acid gas has been identified as a promising approach to reduce atmospheric carbon dioxide (CO2) and hydrogen sulfide (H2S) and alleviate public concern resulting from sour gas production. A good understanding of the relative permeability and capillary pressure characteristics is crucial to predict the process of acid gas injection and migration. The prediction of injection and redistribution of acid gas is important to determine storage capacity, formation pressure, plume extent and shape, and leakage potential. Herein, we reviewed existing experimental data and theoretical models used to gain a better understanding of how the H2S content affects gas density, gas viscosity, interfacial tension, wettability, relative permeability and capillary pressure characteristics of acid gas/brine/rock systems. The densities and viscosities of acid gas with different H2S mole fractions are of both temperature and pressure dependence, which vary among the gas, liquid and supercritical phases. Water/acid gas interfacial tension decreases strongly with increasing H2S content. For mica and clean quartz, water contact angle increases with increasing H2S mole fraction. In particular, wettability reversal of mica to a H2S-wet behavior occurs in the presence of dense H2S. Capillary pressure increases with decreasing contact angle. At a given saturation, the relative permeability of a fluid is higher when the fluid is nonwetting. The capillary pressure decreases with decreasing interfacial tension at a given saturation. However, existing data sets do not show a consistent link between capillary number and relative permeability. The capillary pressure decreased with increasing H2S mole fraction. However, there is no consensus on the effect of the H2S content on relative permeability curves. This may be due to the limited availability of relative permeability and capillary pressure data for acid gas/brine/rock systems; thus, more experimental measurements are required

URLLC packet management for packetized predictive control

Packetized predictive control (PPC) is an effective solution to ensure the robustness of the control system over unreliable wireless links. However, conventional wireless transmission methods in PPC suffer from either high wireless resource consumption or poor performance of real-time control due to the separately design of the two parts. To deal with the issue, we propose a communicationcontrol co-design approach to achieve good trade-off between real-time control performance and communication energy efficiency. Our results demonstrate the advantages of the communication-control co-design