Learning Baseline Values for Shapley Values

This paper aims to formulate the problem of estimating the optimal baseline values for the Shapley value in game theory. The Shapley value measures the attribution of each input variable of a complex model, which is computed as the marginal benefit from the presence of this variable w.r.t.its absence under different contexts. To this end, people usually set the input variable to its baseline value to represent the absence of this variable (i.e.the no-signal state of this variable). Previous studies usually determine the baseline values in an empirical manner, which hurts the trustworthiness of the Shapley value. In this paper, we revisit the feature representation of a deep model from the perspective of game theory, and define the multi-variate interaction patterns of input variables to define the no-signal state of an input variable. Based on the multi-variate interaction, we learn the optimal baseline value of each input variable. Experimental results have demonstrated the effectiveness of our method

Large and tunable magnetoresistance in van der Waals ferromagnet/semiconductor junctions

Magnetic tunnel junctions (MTJs) with conventional bulk ferromagnets separated by a nonmagnetic insulating layer are key building blocks in spintronics for magnetic sensors and memory. A radically different approach of using atomically-thin van der Waals (vdW) materials in MTJs is expected to boost their figure of merit, the tunneling magnetoresistance (TMR), while relaxing the lattice-matching requirements from the epitaxial growth and supporting high-quality integration of dissimilar materials with atomically-sharp interfaces. We report TMR up to 192% at 10 K in all-vdW Fe3GeTe2/GaSe/Fe3GeTe2 MTJs. Remarkably, instead of the usual insulating spacer, this large TMR is realized with a vdW semiconductor GaSe. Integration of semiconductors into the MTJs offers energy-band-tunability, bias dependence, magnetic proximity effects, and spin-dependent optical-selection rules. We demonstrate that not only the magnitude of the TMR is tuned by the semiconductor thickness but also the TMR sign can be reversed by varying the bias voltages, enabling modulation of highly spin-polarized carriers in vdW semiconductors

Large and tunable magnetoresistance in van der Waals Ferromagnet/Semiconductor junctions

Magnetic tunnel junctions (MTJs) with conventional bulk ferromagnets separated by a nonmagnetic insulating layer are key building blocks in spintronics for magnetic sensors and memory. A radically different approach of using atomically-thin van der Waals (vdW) materials in MTJs is expected to boost their figure of merit, the tunneling magnetoresistance (TMR), while relaxing the lattice-matching requirements from the epitaxial growth and supporting high-quality integration of dissimilar materials with atomically-sharp interfaces. We report TMR up to 192% at 10 K in all-vdW Fe3GeTe2/GaSe/Fe3GeTe2 MTJs. Remarkably, instead of the usual insulating spacer, this large TMR is realized with a vdW semiconductor GaSe. Integration of two-dimensional ferromagnets in semiconductor-based vdW junctions offers gate-tunability, bias dependence, magnetic proximity effects, and spin-dependent optical-selection rules. We demonstrate that not just the magnitude, but also the TMR sign is tuned by the applied bias or the semiconductor thickness, enabling modulation of highly spin-polarized carriers in vdW semiconductors

Genome sequence of the tsetse fly (Glossina morsitans):Vector of African trypanosomiasis

Tsetse flies are the sole vectors of human African trypanosomiasis throughout sub-Saharan Africa. Both sexes of adult tsetse feed exclusively on blood and contribute to disease transmission. Notable differences between tsetse and other disease vectors include obligate microbial symbioses, viviparous reproduction, and lactation. Here, we describe the sequence and annotation of the 366-megabase Glossina morsitans morsitans genome. Analysis of the genome and the 12,308 predicted protein-encoding genes led to multiple discoveries, including chromosomal integrations of bacterial (Wolbachia) genome sequences, a family of lactation-specific proteins, reduced complement of host pathogen recognition proteins, and reduced olfaction/chemosensory associated genes. These genome data provide a foundation for research into trypanosomiasis prevention and yield important insights with broad implications for multiple aspects of tsetse biology.IS

Micromechanical Analysis of Detachment Mechanisms of Suffusion

Suffusion is a typical phenomenon of seepage-induced internal erosion, corresponding to fine particles erosion from the coarse matrix under the action of a fluid. A three-dimensional and spatially resolved fluid-solid coupling method based on lattice Boltzmann method (LBM) and discrete element method (DEM) is proposed to simulate suffusion in binary mixtures under anisotropic stress states. Based on such numerical simulations, eroded grains are identified and the mean squared displacement as well as the ratio between drag force and contact force of these eroded particles are computed to describe the detachment mechanism. The results show that the fluid force acting on eroded particles increases in the simulation which corresponding to the steep slope in squared displacements. Regardless of the initial state, the ratio between the fluid force and the contact force of the eroded particles displays a downward trend over time, reflecting the gradual dominance of the fluid force, which eventually leads to particle detachment and erosion. Based on the judgment between the direction of the fluid force and the direction of the contact force, a contact index P is then proposed to determine whether the contact is going to slide or strengthen under the action of the fluid. The distribution of indexes P for the contacts of eroded particles just prior to their detachment reflects that fluid induced sliding dominates. A particle detachment index is thus proposed and the overall detachment sensitivity of the binary samples is eventually investigated with respect to the fluid flow direction

Microscopic mechanism of particle detachment in granular materials subjected to suffusion in anisotropic stress states

International audienceSuffusion refers to a special form of internal erosion characterized by the selective erosion of the finest particles of a soil under the action of an internal fluid flow. In this work, the microscopic mechanism of particle detachment in binary mixtures subjected to suffusion under different flow directions is analyzed. We use the coupled lattice Boltzmann method (LBM) and discrete element method (DEM) to simulate the suffusion process in a granular sample subjected to an anisotropic stress state. When the macro flow direction is aligned with the principal direction of compression, it is found that the fluid flow is more intense, which increases erosion. The stress anisotropy also influences the detachment direction that is not necessarily correlated with the macroscopic flow direction. The sample's anisotropic stress state is responsible for directional variations in microstructural properties during the suffusion under different flow directions. From a micro scale point of view, a contact sliding index P and a particle detachment index Δ are defined to demonstrate that fluid-induced sliding dominates for particles about to detach

A Novel Implementation of Hardware Based Hybrid Embedded RTOS

Reliable embedded systems play an increasing role i\ud n modern life, especially in modern \ud automotive designs. Many studies have proved that i\ud t performs better in many situations. \ud Firstly, reliable embedded systems provide the syst\ud em reliability improvements. Secondly, \ud reliable embedded systems also can improve the deve\ud lopment efficiency and make the \ud development cycle shorter. \ud However, in the high real-time required occasion, t\ud he software implementation of the RTOS \ud can`t fully meet requirements. To have better real-\ud time only through the algorithm improvement \ud or just increase the processor speed. On the contra\ud ry, operating system based on a hardware \ud implementation can make it more real-time and more \ud reliable. The reason is due to that the \ud hardware circuit is independent of the processor ru\ud nning and do not take up the processing time \ud of the processor. Thereby it can save time to execu\ud te other tasks and improve real-time. In this \ud paper, ARM+FPGA will be choose as the IP hardware d\ud evelopment platform