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: 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.

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: A deployable mesh antenna based on dome-type tensegrity includes: a wire mesh reflector, a dome-type reflector support system, and a peripheral deployable truss which are coaxially arranged; the peripheral deployable truss includes: a annular main rod and end-to-end truss units disposed on the main rod; an outermost cable boundary of the dome-type reflector support system is fixedly connected to the peripheral deployable truss, and the dome-type reflector support system includes: an inner strut ring, an outer circumference of the inner strut ring is connected to radial rib units, each radial rib unit is arranged at a radial direction of the inner strut ring, and the radial rib units are connected through hoop cables; the wire mesh reflector is covered on the dome-type reflector support system to form a parabolic structure, the wire mesh reflector is petal-shaped, and the wire mesh reflector has a grid structure.

Abstract: A scene-based beam generation method for ground-to-air coverage based on convex polygon subdivision is provided and includes: obtaining a collection of base station positions by using a method of universal transverse mercator projection; constructing a three-dimensional (3D) low altitude signal coverage area; performing convex polygon subdivision on the area to be covered; and generating a beam configuration of each base station. The method realizes generation of beam configurations of base stations in the 3D low altitude signal coverage area, overcomes a problem that the existing 17 kind of scene-based beams cannot realize the coverage of 3D area, overcomes a problem of mismatch between network state information and beam configuration caused by dynamic adjustment of beam configurations. The beam configurations generated by the method does not need to obtain the number of users in real time to adjust the beam, and has a good coverage ability.

Abstract: The present application discloses a terminal structure for conduction cooling high temperature superconducting cable, comprising: a cable terminal body; a terminal thermal insulation shell, in which a vacuum thermal insulation cavity is formed, and the cable terminal body being arranged in the vacuum thermal insulation cavity; a refrigeration mechanism comprising a refrigeration output part extending into the vacuum thermal insulation cavity, and the refrigeration output part being connected to the cable terminal body through a cooling-conducting structure.

Abstract: This invention proposes a reflective surface antenna based on a triple telescopic rod drive and quasi-geodesic grid structure, including a supportive back frame, a reflective surface frame, a vertical connecting rod, a primary reflective surface, an auxiliary reflective surface, a radial support rod, a feed source, and an attitude control device. The supportive back frame and reflective surface frame have a paraboloidal truss structure. The primary reflective surface is fixed on the quasi-geodesic grid of the reflective surface; the auxiliary reflective surface is fixed at the focal point of the primary reflective surface; the feed source is fixed at the apex of the reflective surface; and the attitude control device includes a base and a telescopic rod.

Abstract: A method for joint optimization of resource allocation includes: obtaining network data volumes of two services; obtaining queue statuses at a time t; computing sub-channel slices; computing a local CPU speed scaling, a user association, a sub-carrier assignment, and a power allocation of service 1; computing a user association, a video quality decision, and a sub-carrier assignment of service 2; obtaining an initial sub-carrier assignment and an initial power allocation; obtaining the user association; obtaining the power allocation and the sub-carrier assignment of service 1; obtaining the video quality decision; obtaining the sub-carrier assignment of service 2; obtaining an optimal data transmission rate and the user association to obtain a data rate allocation; and obtaining an optimal CPU speed scaling, an optimal user association, an optimal sub-carrier assignment, an optimal power allocation, an optimal video quality decision and an optimal sub-channel allocation.

Abstract: The present application discloses a terminal structure for conduction cooling high temperature superconducting cable, comprising: a cable terminal body; a terminal thermal insulation shell, in which a vacuum thermal insulation cavity is formed, and the cable terminal body being arranged in the vacuum thermal insulation cavity; a refrigeration mechanism comprising a refrigeration output part extending into the vacuum thermal insulation cavity, and the refrigeration output part being connected to the cable terminal body through a cooling-conducting structure.

Abstract: Disclosed is a dual-link wireless ad hoc network and a security defense method in an emergency scene, aiming at comprehensively improving its security defense capability. The method comprises: sending, by a source node, the secret key and other messages which are not security defense messages through the second link; detecting, by a destination node, abnormal messages from the acquired valid messages after matching with abnormal message feature library, filtering the abnormal messages out, and quickly broadcasting the features of new abnormal messages through the first link; checking, by a new node to be added to the network, the identity and hardware state, authorizing the new node without abnormality, and broadcasting the authorization result information through the first link; adding, by other nodes receiving the security defense messages, the features of the new abnormal messages to their own abnormal message feature library, and allowing the entry of the new node.

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: A low turn-on voltage GaN diode having an anode metal with a consistent crystal orientation and a preparation method thereof. The low turn-on voltage GaN diode having an anode metal with a consistent crystal orientation provided by the present disclosure includes a substrate layer, a GaN buffer layer, a GaN channel layer and an AlGaN barrier layer, which are arranged in sequence from bottom to top; a cathode arranged on the AlGaN barrier layer; a groove arranged in the GaN channel layer and the AlGaN barrier layer, and an anode provided on a bottom and a side wall of the groove and part of the AlGaN barrier layer; a dielectric layer provided on an uncovered portion of the AlGaN barrier layer; wherein, a contact portion of the anode with the groove and the AlGaN barrier layer is W or Mo metal with a crystal orientation of <100>.

Abstract: A bidirectional blocking monolithic heterogeneous integrated Cascode-structure field effect transistor, which mainly solves a problem that the existing monolithic heterogeneous integrated Cascode-structure field effect transistor has no reverse blocking characteristic. The field effect transistor includes a substrate, a GaN buffer layer, an AlGaN barrier layer and a SiN isolation layer, wherein an isolation groove is etched in the middle of the SiN isolation layer, a Si active layer is printed on the SiN isolation layer on one side of the isolation groove so as to prepare a Si metal oxide semiconductor field effect transistor, and a GaN high-electron-mobility transistor is prepared on the other side of the isolation groove, and a drain electrode of the GaN high-electron-mobility transistor is in Schottky contact with the AlGaN barrier layer to form a bidirectional blocking monolithic heterogeneous integrated Cascode-structure field effect transistor.

Abstract: The present disclosure discloses a method for sharing models among autonomous vehicles based on a blockchain, the method comprising the steps of: 1) creating a mobile edge computing network; 2) generating a key pair for each node in the mobile edge computing network; 3) creating a local model set of a mobile node set in the mobile node computing network; 4) enabling each mobile node to communicate with a corresponding nearest mobile edge computing node; 5) creating supernode sequences by the mobile edge computing node; 6) creating a blockchain based on the supernode sequences; and 7) updating the local model set.

Abstract: A system and method of index modulation based joint mode frequency hopping with vortex electromagnetic waves for anti-jamming are provided. The system is additionally provided with a transmit signal carrier selector that provides diversified options, a receive signal carrier selector that is strictly synchronized with the transmit signal carrier selector, and a group of fast Fourier transformation modules to output a binary demodulation signal with jamming eliminated. The method includes: binary information division; index modulation and information modulation; information loading and hopping; information transmission, de-hopping, and jamming filtering; and calculation of the jamming probability and an average bit error rate.

Abstract: A distributed support vector machine privacy-preserving method includes: dividing a secret through secret sharing among all participating entities, iteratively exchanging a part of the information divided by the participating entities, and solving sub-problems locally; performing an iteration until a convergence is reached to find a global optimal solution; and in consideration of the generality of the privacy-preserving method, adopting a privacy-preserving method based on a vertical data distribution and a privacy-preserving method based on a horizontal data distribution, respectively; wherein the participating entities do not trust each other, and interact through a multi-party computation for local training. The method is applied to an honest-but-curious scenario, and uses the idea of data division to perform local computation through the interaction of part of the data among users to finally reconstruct the secret to preserve data privacy.

Abstract: A method for joint optimization of resource allocation includes: obtaining network data volumes of two services; obtaining queue statuses at a time t; computing sub-channel slices; computing a local CPU speed scaling, a user association, a sub-carrier assignment, and a power allocation of service 1; computing a user association, a video quality decision, and a sub-carrier assignment of service 2; obtaining an initial sub-carrier assignment and an initial power allocation; obtaining the user association; obtaining the power allocation and the sub-carrier assignment of service 1; obtaining the video quality decision; obtaining the sub-carrier assignment of service 2; obtaining an optimal data transmission rate and the user association to obtain a data rate allocation; and obtaining an optimal CPU speed scaling, an optimal user association, an optimal sub-carrier assignment, an optimal power allocation, an optimal video quality decision and an optimal sub-channel allocation.

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.