Abstract: An optical fiber microwave frequency transmission method based on laser frequency offset-locking includes: generating, by a master laser and a slave laser respectively, a master laser signal and a slave laser signal; transmitting, by an optical fiber link, the master laser signal and the slave laser signal to a microwave frequency receiver, and locking a frequency difference between the master laser and the slave laser to a preset microwave frequency; receiving a return laser signal returned from the microwave frequency receiver, the return laser signal including the master laser signal, the slave laser signal and a noise of the optical fiber link; generating a reference signal, and adjusting the preset microwave frequency to compensate the noise of the optical fiber link, so that a microwave frequency subsequently received by the microwave frequency receiver approaches a frequency of the reference signal.

Abstract: A parking lot management and control method based on object activity prediction, an electronic device and a storage medium are provided. The method includes: obtaining a scene video of a parking lot; detecting and tracking objects in the scene video to generate a spatial AND-OR graph model of the parking lot, the spatial AND-OR graph model representing spatial position relationships of the objects in the scene video; performing a sub-activity extraction on the spatial AND-OR graph model to obtain a sub-activity tag set representing activity states of concerned ones of the objects; inputting the sub-activity tag set into a temporal AND-OR graph model to obtain a future activity prediction result of concerned objects in the parking lot; and transmitting control information based on the future activity prediction result of the concerned objects to a device corresponding to the parking lot.

Abstract: A multi-coil coupling-type single-pole four-throw (SP4T) switch includes: an input port and first through fourth output ports; a coupled inductor circuit including inductor coils electrically connected with the input port and the first through fourth output ports; and a transistor-based control circuit including control circuits electrically connected with the first through fourth output ports respectively. The transistor-based control circuit is configured for selecting one of the first through fourth output ports to be conducted with the input port based on level signals of the control circuits, and configuring a load of the selected output port by using the inductor coils connected with the first through fourth output ports and the control circuits connected with the others of the first through fourth output ports.

Abstract: A coupling-type single-pole double-throw (SPDT) switch adapted for a radio frequency integrated circuit includes an input port, a first output port, a second output port, a multi-coupling-coil circuit and a transistor-based control circuit. The multi-coupling-coil circuit includes coils respectively connected with the input port, the first output port and the second output port. The transistor-based control circuit includes a first control circuit, a second control circuit and a third control circuit, and configured to control an input load of the multi-coupling-coil circuit using a control level of the first control circuit and realize connections between the input port and the first output port as well as the second output port using control levels of the second control circuit and the third control circuit. Therefore, the coupling-type SPDT switch can achieve a simple switching between two working states, and have low insertion loss and high isolation degree in both working states.

Abstract: A method of road detection based on Internet of Vehicles is provided, the method is applied to vehicle terminals and includes: obtaining a target road image captured by an image collection terminal and inputting it into an improved YOLOv3 network, performing feature extraction by using backbone network of dense connection to obtain feature images with different scales; performing feature fusion of top-to-down and dense connection to the feature images by using an improved feature pyramid networks (FPN) to obtain prediction results; obtaining attribute information of the target road image according to the prediction results; the attribute information includes positions and categories of objects in the target road image; the improved YOLOv3 is formed by based on YOLOv3 network, replacing residual modules of backbone network to dense connection modules, increasing feature extraction scale, optimizing feature fusion mode of FPN, performing pruning and performing network recovery processing guided by knowledge dis

Abstract: A method of establishing an enhanced three-dimensional (3D) model of intracranial angiography is provided and includes: obtaining a bright-blood image group, a black-blood image group and an enhanced black-blood image group; preprocessing image pairs to obtain first bright-blood images and black-blood images; registering the first bright-blood image by taking the first black-blood image as reference to obtain a registered bright-blood image group; eliminating flowing void artifact to obtain an artifact-elimination enhanced black-blood image group; subtracting each image of the artifact-elimination enhanced black-blood image group from corresponding black-blood image to obtain angiography enhanced images; establishing a blood 3D model and a vascular 3D model with blood boundary expansion by using the registered bright-blood image group; establishing an angiography enhanced 3D model by using the angiography enhanced images; obtaining an enhanced 3D model of intracranial angiography based on the blood 3D model,

Abstract: A recognition method of intracranial vascular lesions based on transfer learning is provided, which includes: obtaining a bright-blood image group, a black-blood image group and an enhanced black-blood image group; registering bright-blood images to obtain a registered bright-blood image group; eliminating flowing void artifact to obtain an artifact-elimination enhanced black-blood image group; subtracting each image of the artifact-elimination enhanced black-blood image group from corresponding black-blood image to obtain angiography enhanced images; establishing a blood 3D model; establishing a vascular 3D model with blood boundary expansion; establishing an angiography enhanced 3D model by using the angiography enhanced images; obtaining an intracranial vascular enhanced 3D model based on the blood 3D model, the vascular 3D model and the angiography enhanced 3D model; and obtaining an intracranial vascular lesion recognition model based on the intracranial vascular enhanced 3D model.

Abstract: The present invention relates to a method for constructing orthogonal sequence sets in a CDMA system, including: step a: selecting natural numbers m and k, m and k satisfying m=2k+4: step b: constructing a 5-spectral value vector Boolean function; step c: constructing 24 orthogonal sequence sets by using the 5-spectral value vector Boolean function; and step d: allocating the orthogonal sequence sets to cells, and causing that sequences in each of the cells are orthogonal with one another, and sequences in each of the cells and sequences in neighboring one of the cells are orthogonal with one another. The constructing method provided by the present invention can increase the number of users in cells, reduce the signal interferences of neighboring cells, and improves the communication quality consequently.

Abstract: The present invention discloses a channel frequency spreading device for a CDMA system, including: an orthogonal sequence generating module, configured to generate orthogonal sequence sets; a storage module, connected to the orthogonal sequence generating module, and configured to store the orthogonal sequence sets; a control module, connected to the storage module, and configured to read available orthogonal sequences in the orthogonal sequence sets when receiving a user request control signal; and a channel machine, connected to the control module, and configured to receive user request data, and perform frequency spreading on the user request data according to the available orthogonal sequences and then output. The channel frequency spreading device for a CDMA system can improve the number of the sequences allocated by the cell, and solve the problem that the excessive users cannot communicate normally.

Abstract: A preparation method for a platform-shaped active region based P-I-N diode string in a reconfigurable loop antenna includes: (a) selecting an SOI substrate; (b) etching the SOI substrate to form a platform-shaped active region; (c) depositing a P-type Si material and an N-type Si material around the platform-shaped active region by an in-situ doping process to form a P region and an N region respectively; (d) depositing a polysilicon material around the platform-shaped active region; (e) forming leads on a surface of the polysilicon material and forming PADs by photolithography, to form the P-I-N diode string. Therefore, a high-performance platform-shaped active region based P-I-N diode string suitable for a solid-state plasma antenna can be provided by an in-situ doping process.

Abstract: The present invention relates to a predictive quantization coding method and a video compression system. The method includes: dividing a pixel to be processed into a plurality of pixel components; obtaining one pixel component to be processed and texture direction gradients thereof; obtaining reference pixels and a prediction residual of the pixel component to be processed; forming a prediction residual code stream; dividing the prediction residual code stream into multiple quantization units; and obtaining a quantization residual code stream. The present invention can reduce the transmission bandwidth, and reduce the theoretical limit entropy and complexity.

Abstract: The present invention relates to a quadtree-based bandwidth compression prediction method and a system thereof. The bandwidth compression prediction method for example includes: dividing a to-be-predicted macroblock; obtaining a first prediction residual and a second prediction residual; judging whether re-dividing is performed on the to-be-predicted macroblock; and outputting the prediction residual and pixel component minimum values of the final sub-macroblocks divided from the to-be-predicted macroblock. According to the quadtree-based bandwidth compression prediction method and system, during the processing of complex texture images, the prediction effect is good, the processing efficiency is high, and the theoretical limit entropy can be reduced.

Abstract: A preparation method for a GaAs/Ge/GaAs heterogeneous SPiN diode for a loop antenna includes: selecting a GeOI substrate; etching a top Ge layer of the GeOI substrate to form first and second trenches in the top Ge layer; depositing a GaAs material in, the first and second trenches; performing P-type ion implantation into the GaAs material in the first trench to form a P-type active region and performing an N-type ion implantation into the GaAs material in the second trench to form an N-type active region by ion implantation process; and forming lead holes on surfaces of the P-type active region and the N-type active region and then sputtering a metal to form the GaAs/Ge/GaAs heterogeneous SPiN diode. Therefore, a high performance GaAs/Ge/GaAs heterogeneous SPiN diode suitable for forming a solid-state plasma antenna can be prepared by deep trench isolation technology and ion implantation process.

Abstract: A manufacturing method for an AlAs—Ge—AlAs structure based plasma p-i-n diode in a multilayered holographic antenna is provided. The manufacturing method includes: selecting a GeOI substrate and disposing an isolation region in the GeOI substrate; etching the GeOI substrate to form a P-type trench and an N-type trench; depositing AlAs materials in the P-type trench and the N-type trench and performing ion implantation into the AlAs materials in the P-type trench and N-type trench to form a P-type active region and an N-type active region; and forming leads on surfaces of the P-type active region and the N-type active region to obtain the AlAs—Ge—AlAs structure based plasma p-i-n diode. Therefore, a high-performance Ge based plasma p-i-n diode suitable for forming a solid plasma antenna can be provided by using a deep trench isolation technology and an ion implantation process.

Abstract: A preparation method for a SiGe based plasma p-i-n diode string for a sleeve antenna is provided. The preparation method includes: selecting a SiGeOI substrate with a certain crystal orientation and forming isolation regions on the SiGeOI substrate; etching the substrate to form P-type trenches and N-type trenches, depths of the P-type trenches and the N-type trenches each being smaller than a thickness of a top SiGe layer of the substrate; filling the P-type trenches and the N-type trenches and forming P-type active regions and N-type active regions in the top SiGe layer of the substrate by an ion implantation process; and forming leads on the substrate so as to obtain the heterogeneous SiGe based plasma p-i-n diode. Therefore, a high-performance heterogeneous SiGe based plasma p-i-n diode suitable for forming a solid-state plasma antenna is prepared by using a deep trench isolation technology and the ion implantation process.