Abstract: A method for encoding and decoding, an encoder and decoder for a point cloud. The method for encoding a point cloud to generate a bitstream of compressed point cloud data, in which the point cloud's geometry is represented by an octree-based structure with a plurality of nodes having parent-child relationships by recursively splitting a volumetric space containing the point cloud into sub-volumes each associated with a node of the octree-based structure, includes: determining an occupancy pattern for a parent node based on the occupancy of its child nodes; determining a planar context information for at least one of the child nodes; and entropy encoding/decoding the occupancy pattern parent node based on the determined planar context information to produce encoded/decoded data for the bitstream.

Abstract: A trusted graph data node classification method includes: (1) inputting a topological graph and node features, and calculating a discrete Ricci curvature of the discrete topological graph; (2) preprocessing the curvature and the node features; (3) mapping the curvature, reconstructing original features, and performing a semi-supervised training on graph data containing adversarial examples; and (4) performing a classification on unlabeled nodes. The new method uses a discrete curvature to extract topological information, and uses a residual network to reconstruct node feature vectors without knowing the technical details of the adversarial examples, and without using a large number of adversarial examples for adversarial training. Hence, the system effectively defends against attacks from adversarial examples on the graph data, outperforms the existing mainstream models in terms of accuracy when used in data without adversarial examples, and is thus a trusted node classification system.

Abstract: A method for defending against an adversarial sample in image classification includes: denoising, by an adversarial denoising network, an input image to acquire a reconstructed image; acquiring, by a target classification model, a predicted category probability distribution of the reconstructed image; acquiring, by the target classification model, a predicted category probability distribution of the original input image; calculating an adversarial score of the input image, and determining the input image as an adversarial sample or a benign sample according to a threshold; outputting a category prediction result of the reconstructed image if the input image is determined as the adversarial sample; and outputting a category prediction result of the original input image if the input image is determined as the benign sample. A system for defending against an adversarial sample in image classification, and a data processing terminal are further provided.

Abstract: Provided are an antenna apparatus and an electronic device. The antenna apparatus comprises a plurality of antenna units, spaced from each other; a plurality of decoupling networks, corresponding to the plurality of antenna units one to one; and a decoupling transmission line. Each of the decoupling networks comprises a first transmission line and a second transmission line; an end of the first transmission line is configured to be connected to a radio-frequency chip, the other end of the first transmission line is connected to an end of the second transmission line, a decoupling port is formed at a joint between the other end of the first transmission line and the end of the second transmission line, and the other end of the second transmission line is connected to a corresponding antenna unit; and the decoupling transmission lines is connected between adjacent decoupling ports. The electronic device comprises the antenna apparatus.

Abstract: A piezoelectric transducer is provided herein, comprising a three-dimensional structure made of a plurality of peptides, the peptides being self-assembling and the structure being piezoelectric, wherein at least a portion, or each, of said plurality of peptides comprises peptides of 2 to 10 amino acid residues, provided that the plurality of peptides is not consisted of a plurality of Phe-Phe dipeptides. Further described herein are peptides having an amino acid sequence Hyp-Phe-Phe, Boc-Dip-Dip, (L)Trp-(D)Trp or (D)Trp-(L)Trp, as well as three-dimensional structures comprising such peptides.

Abstract: A material structure for silicon-based gallium nitride microwave and millimeter-wave devices and a manufacturing method thereof are provided. The material structure includes: a silicon substrate; a dielectric layer of high thermal conductivity, disposed on an upper surface of the silicon substrate, and an uneven first patterned interface being formed between the dielectric layer and the silicon substrate; a buffer layer, disposed on an upper surface of the dielectric layer, and an uneven second patterned interface being formed between the buffer layer and the dielectric layer; a channel layer, disposed on an upper surface of the buffer layer; and a composite barrier layer, disposed on an upper surface of the channel layer. In the material structure, the uneven patterned interfaces increase contact areas of the interfaces, a thermal boundary resistance and a thermal resistance of device are reduced, and a heat dissipation performance of device is improved.

Abstract: A design method of a multi-zone grouped and light-homogenized Fresnel lens for a concentrating system includes: step 1, designing, according to a basic principle of a Fresnel lens, a planar Fresnel lens; step 2, establishing, according to an optical path characteristic of the concentrating system, an optical path equation of the concentrating system; step 3, determining a differential form of uniform distribution of luminous energy density; and step 4, based on the step 3, calculating design parameters of the multi-zone grouped and light-homogenized Fresnel lens to obtain the multi-zone grouped and light homogenized Fresnel lens.

Abstract: Hierarchical network operation and resource control system and method for a mega satellite constellation, belonging to the field of spatial information technology, are provided. The hierarchical network operation and resource control system includes a service layer, a global organization layer, a local coordination layer and a resource layer. The service layer is used as an input to drive operation of whole system. The global organization layer is to realize “operation, measurement and control” integrated control and decision of whole network. The local coordination layer is to realize local management decision and management slice generation. The resource layer is to provide physical resource and physical device and realize resource virtualization.

Abstract: A method for enhancing network coverage based on adaptive generation of resource cell. A traditional cell in a network is taken as an initial state of the network. A correlation matrix in a current network state is generated. Whether |?i,jt??i,jt-1|/?i,jt-1>? is determined. Each access point is divided into a plurality of resource cells. A CU-DU network mapping table is generated. A middlehaul link of each of the plurality of resource cells is constructed according to the CU-DU network mapping table.

Abstract: Lightweight inter-satellite handover device and method for a mega LEO satellite network are provided. An attribute extraction sub-module extracts attributes of handover users in a user information storage unit. Based on the attributes of the handover users, a cluster sub-module clusters the handover users into user clusters. A decision set generator sub-module generates target satellite sets of the user clusters, determines each target satellite of the target satellite sets of the user clusters of each LEO satellite whether belongs to LEO satellites in a management domain of a handover decision point of managing the LEO satellite based on management domain information in a LEO satellite information storage unit, and if YES, performing inter-satellite handover by a centralized decision unit, otherwise performing inter-satellite handover by a distributed decision unit.

Abstract: A ferroelectric film phase shifter includes a substrate layer; an isolated signal layer located on the substrate layer; first, second and third top transmission line electrodes distributed on the isolated signal layer at intervals; the first and second top transmission line electrodes located at both ends of the isolated signal layer, and the third top transmission line electrode located on a middle region of the isolated signal layer; a bottom transmission line electrode located in the isolated signal layer; an intermediate transmission line structure located in a middle region of the bottom transmission line electrode and adjacent to the third top transmission line electrode; MIM hafnium oxide-based ferroelectric capacitor structures located at two ends of the bottom transmission line electrode; and metal transmission line structures located between each MIM hafnium oxide-based ferroelectric capacitor structure and each of the first top transmission line electrode and the second top transmission line electr

Abstract: This disclosure provides a package structure for a semiconductor device, comprising a three-layer film consisting of a first SiO2 film, a Si3N4 film and a second SiO2 film stacked in this order, wherein the first SiO2 film is formed by a thermal oxidation process, the Si3N4 film is formed by a low pressure chemical vapor deposition process, and the second SiO2 film is formed by a low temperature atomic layer deposition process. This disclosure also provides a method for preparing the package structure for a semiconductor device.

Abstract: A 2-bit high-power amplifying non-reciprocal reflective metasurface is provided. The metasurface comprises a plurality of metasurface units distributed in an array; each metasurface unit comprises a first metal layer, an intermediate layer, and a second metal layer which are sequentially stacked; the second metal layer comprises a receiving metal patch and a transmitting metal patch; two diodes are both positioned on a longitudinal central axis of the receiving metal patch; orientation of the slot on the transmitting metal patch is orthogonal to orientation of the slot on the receiving metal patch; the first metal layer comprises a phase shifter, which comprises first series diodes and second series diodes forming a reconfigurable 90-degree phase-shift circuit.

Abstract: A method for preparing an AlN based template having a Si substrate and a method for preparing a GaN based epitaxial structure having a Si substrate are provided. The method for preparing the AlN based template having the Si substrate, which includes: providing the Si substrate; growing an AlN nucleation layer on the Si substrate; and introducing an ion passing through the AlN nucleation layer and into the Si substrate. After the AlN nucleation layer is prepared on the Si substrate, the ions are introduced into the Si substrate and the AlN nucleation layer through the AlN nucleation layer. In this way, types of the introduced ions can be expanded. In addition, a carrier concentration at an interface between the Si substrate and the AlN nucleation layer and a carrier concentration in the AlN nucleation layer can also be reduced.

Abstract: Provided is an analysis method for transmission and reflection coefficients of a wire mesh of a mesh antenna. The method mainly derives coordinate points of a minimum repeating unit of the wire mesh according to model parameters of the wire mesh; secondly, determines a minimum repeating unit curve of the wire mesh by periodic cubic spline curve interpolation, and determines an organization structure of the wire mesh by vector superposition; thirdly, discretizes an organization structure curve of the organization structure of the wire mesh, to extract a coordinate point of an electromagnetic analysis periodic unit of the wire mesh, and establishes a solid model of the electromagnetic analysis periodic unit of the wire mesh to realize the analysis of the transmission coefficient and the reflection coefficient of the wire mesh; and finally, determines the transmission coefficient and the reflection coefficient of the deformed wire mesh by static analysis.

Abstract: Provided is a binarization method for CT sectional image of fiber package containing artifacts, which includes: performing brightness adjustment on the source image obtained after converting of the HSV image model by using a composite tangent function; creating a planar morphological structural element having a morphology similar to that of a target object to obtain a background image without the target object; obtaining a second intermediate image by a subtraction operation of the first intermediate image and the background image; improving an image contrast of the second intermediate image again to obtain a third intermediate image; and binarizing the third intermediate image by using a local adaptive threshold binarization algorithm and removing a background noise to obtain a final binarized image. The binarization method can improve the uneven brightness of the image under complex illumination, alleviate the artifacts, and strip similar objects from the background with similar gray scales.

Abstract: A SiC ohmic contact preparation method is provided and includes: selecting a SiC substrate; preparing a graphene/SiC structure by forming a graphene on a Si-face of the SiC substrate; depositing an Au film on the graphene of the graphene/SiC structure; forming a first transfer electrode pattern on the Au film by a first photolithography; etching the Au film uncovered by the first transfer electrode pattern through a wet etching; etching the graphene uncovered by the Au film through a plasma etching after the wet etching; forming a second transfer electrode pattern on the SiC substrate by a second photolithography; depositing an Au material on the Au film exposed by the second transfer electrode pattern and forming an Au electrode and then annealing. The graphene reduces potential barrier associated with the SiC interface, specific contact resistance of ohmic contact reaches the order of 10?7˜10?8 ?·cm2, and the method has high repeatability.

Abstract: A method, base station and user equipment are provided for wireless communication. The method can include steps: transmitting data on a first frequency band; transmitting, on a second frequency band, a detection signal for detecting a channel condition of the second frequency band; generating channel condition information about the second frequency band based on the received detection signal; feeding back the channel condition information via the first frequency band; and selecting a current data transmission frequency band based at least in part on the feedback channel condition information about the second frequency band and/or traffic requirement information; wherein the current data transmission frequency band is any one of the first frequency band, the second frequency band or a cooperative transmission of the first frequency band with the second frequency band.

Abstract: A multi-geomagnetic sensor speed measurement system comprises a geomagnetic vehicle detection module, a data transmission module, a data reception module and a backend data processing module. When measuring, the geomagnetic vehicle detection module collects the geomagnetic data when the vehicle passes and processes it to obtain temporal data; the backend processing module receives the data for data cleaning; the backend processing module selects the reference sensors and opens individual time windows; the backend processing module processes the temporal data based on the number of temporal data in the time window; in the case of duplicate-detection, a measurement threshold ? is set and the temporal data is merged based on the threshold ?; in the case of mis-detection, the data is interpolated to make up for the mis-detection; based on the alignment result, a minimum variance method is used to estimate the speed of the vehicle.

Abstract: The present disclosures discloses a method of target feature extraction based on millimeter-wave radar echo, which mainly solves the problems that techniques in the prior art cannot fully utilize raw radar echo information to obtain more separable features and cannot accurately distinguish targets with similar physical shapes and motion states. The method is implemented as follows: acquiring measured data of targets, generating an original RD map, and removing ground clutter of the map; sequentially performing target detection, clustering and centroid condensation on the RD map after the ground clutter removal; acquiring a continuous multi-frame RD maps and carrying out the target tracking; according to the tracking trajectory, selecting candidate areas and extracting features based on a single piece of RD map and features based on two successive RD maps, respectively.