Aiming at the problems of low efficiency, low accuracy, excessive occupancy of human resources and intelligent classification algorithm miniaturization deployment requirements in China Customs risk control methods at this stage, a customs risk control method based on an improved Butterfly Feedback neural Network Version 2 (BFNet-V2) was proposed. Firstly, the Filling in Code (FC) algorithm was used to realize the semantic replacement of the customs tabular data to the analog image. Then, the analog image data was trained by using the BFNet-V2. The regular neural network structure was composed of left and right links, different convolution kernels and blocks, and small block design, and the residual short path was added to improve the overfitting and gradient disappearance. Finally, a Historical momentum Adaptive moment estimation algorithm (H-Adam) was proposed to optimize the gradient descent process and achieve a better adaptive learning rate adjustment, and classify customs data. Xception (eXtreme inception), Mobile Network (MobileNet), Residual Network (ResNet), and Butterfly Feedback neural Network (BF-Net) were selected as the baseline network structures for comparison. The Receiver Operating Characteristic curve (ROC) and the Precision-Recall curve (PR) of the BFNet-V2 contain the curves of the baseline network structures. Taking Transfer Learning (TL) as an example, compared with the four baseline network structures, the classification accuracy of BFNet-V2 increases by 4.30%,4.34%,4.10% and 0.37% respectively. In the process of classifying real-label data, the misjudgment rate of BFNet-V2 reduces by 70.09%,57.98%,58.36% and 10.70%, respectively. The proposed method was compared with eight classification methods including shallow and deep learning methods, and the accuracies on three datasets increase by more than 1.33%. The proposed method can realize automatic classification of tabular data and improve the efficiency and accuracy of customs risk control.
Focusing on the problems of disturbed car-following behavior and instability of traffic flow caused by the uncertainty of the driver’s acquisition of road velocity limit and time delay information, a car-following model TD-VDVL (Time-Delayed Velocity Difference and Velocity limit) was proposed with the consideration of the time-delayed velocity difference and the velocity limit information in the Internet of Vehicles (IoV) environment. Firstly, the speed change caused by time delay and road velocity limit information were introduced to improve the Full Velocity Difference (FVD) model. Then, the linear spectrum wave perturbation method was used to derive the traffic flow stability judgment basis of TD-VDVL model, and the influence of each parameter in the model on the stability of the system was analyzed separately. Finally, the numerical simulation experiments and comparative analysis were carried out using Matlab. In the simulation experiments, straight roads and circular roads were selected, and slight disturbance was imposed on the fleet during driving. When conditions were the same, TD-VDVL model had the smallest velocity fluctuation rate and the fluctuation of fleet headway compared to the Optimal Velocity (OV) and FVD models. Especially when the sensitivity coefficient of the velocity limit information was 0.3, and the sensitivity coefficient of the time-delayed speed difference was 0.3, the proposed model had the average fluctuation rate of the fleet velocity reached 2.35% at time of 500 s, and the peak and valley difference of fleet headway of only 0.019 4 m. Experimental results show that TD-VDVL model has a better stable area after introducing time-delayed velocity difference and velocity limit information, and can significantly enhance the ability of car-following fleet to absorb disturbance.
Cryptographic S-boxes (or black boxes) are nonlinear components in symmetric encryption algorithms, and their algebraic properties usually determine the security performance of these encryption algorithms. Differential uniformity, nonlinearity and revised transparency order are three basic indicators to evaluate the security properties of cryptographic S-boxes. They describe the S-box’s ability against differential cryptanalysis, linear cryptanalysis and differential power attack respectively. When the input size of the cryptographic S-box is large (for example, the input length of the S-box is larger than 15 bits), the needed solving time in Central Processing Unit (CPU) is still too long, or even the solution is impracticable. How to evaluate the algebraic properties of the large-size S-box quickly is currently a research hot point in the field. Therefore, a method to evaluate the algebraic properties of cryptographic S-boxes quickly was proposed on the basis of Graphics Processing Unit (GPU). In this method, the kernel functions were split into multiple threads by slicing technique, and an optimization scheme was proposed by combining the characteristics of solving differential uniformity, nonlinearity and revised transparency order to realize parallel computing. Experimental results show that compared with CPU-based implementation environment, single GPU based environment has the implementation efficiency significantly improved. Specifically, the time spent on calculating differential uniformity, nonlinearity, and revised transparency order is saved by 90.28%, 80%, and 66.67% respectively, which verifies the effectiveness of this method.
Aiming at the problems of slow detection and low recognition accuracy of road traffic signs in Chinese intelligent driving assistance system, an improved road traffic sign detection algorithm based on YOLOv3 (You Only Look Once version 3) was proposed. Firstly, MobileNetv2 was introduced into YOLOv3 as the basic feature extraction network to construct an object detection network module MN-YOLOv3 (MobileNetv2-YOLOv3). And two Down-up links were added to the backbone network of MN-YOLOv3 for feature fusion, thereby reducing the model parameters, and improving the running speed of the detection module as well as information fusion performance of the multi-scale feature maps. Then, according to the shape characteristics of traffic sign objects, K-Means++ algorithm was used to generate the initial cluster center of the anchor, and the DIOU (Distance Intersection Over Union) loss function was introduced to combine DIOU and Non-Maximum Suppression (NMS) for the bounding box regression. Finally, the Region Of Interest (ROI) and the context information were unified by ROI Align and merged to enhance the object feature expression. Experimental results show that the proposed algorithm has better performance, and the mean Average Precision (mAP) of the algorithm on the dataset CSUST (ChangSha University of Science and Technology) Chinese Traffic Sign Detection Benchmark (CCTSDB) can reach 96.20%. Compared with Faster R-CNN (Region Convolutional Neural Network), YOLOv3 and Cascaded R-CNN detection algorithms, the proposed algorithm has better real-time performance, higher detection accuracy, and is more robustness to various environmental changes.
For addressing real root isolation problem of transcendental function polynomials, an interval isolation algorithm for exponential function polynomials named exRoot was proposed. In the algorithm, the real root isolation problem of non-polynomial real functions was transformed into sign determination problem of polynomial, then was solved. Firstly, the Taylor substitution method was used to construct the polynomial nested interval of the objective function. Then, the problem of finding the root of the exponential function was transformed into the problem of determining the positivity and negativity of the polynomial in the intervals. Finally, a comprehensive algorithm was given and applied to determine the reachability of rational eigenvalue linear system tentatively. The proposed algorithm was implemented in Maple efficiently and easily with readable output results. Different from HSOLVER and numerical calculation method fsolve, exRoot avoids discussing the existence of roots directly, and theoretically has termination and completeness. It can reach any precision and can avoid the systematic error brought by numerical solution when being applied into the optimization problem.
A Feature Fusion Network (FFN) was proposed to judge the quality of 3D face point cloud acquired by binocular structured light scanner. Firstly, the 3D point cloud was preprocessed to cut out the face area, and the image obtained from the point cloud and the corresponding 2D plane projection was used as the input. Secondly, Dynamic Graph Convolutional Neural Network (DGCNN) and ShuffleNet were trained for point cloud learning. Then, the middle layer features of the two network modules were extracted and fused to fine-tune the whole network. Finally, three full connected layers were used to realize the five-class classification of 3D face point cloud (excellent, ordinary, stripe, burr, deformation). The proposed FFN achieved the classification accuracy of 83.7%, which was 5.8% higher than that of ShufflNet and 2.2% higher than that of DGCNN. The experimental results show that the weighted fusion of two-dimensional image features and point cloud features can achieve the complementary effect between different features.
With the development of communication technology, communication terminals gradually adopt software to be compatible with multiple communication modes and protocols. As in the traditional software radio architecture with a Central Processing Unit (CPU) of computer as an arithmetic unit, the wideband data throughput of high-speed wireless communication systems such as Multiple-Input Multiple-Output (MIMO) is not be satisfied, an acceleration method of Low Density Parity Check (LDPC) code decoder based on Graphics Processing Unit (GPU) was proposed. Firstly, according to the theoretical analysis of the acceleration performance of GPU parallelly accelerated heterogeneous computing in GNU Radio 4G/5G physical layer signal processing module, a more parallelly efficient Layered Normalized Min-Sum (LNMS) algorithm was adopted. Then, the decoding delay of the decoder was reduced by using the methods such as global synchronization strategy, reasonably allocation of GPU memory space and stream parallelism mechanism. At the same time, the LDPC code decoding process was optimized in parallel with the multi-threaded parallel technology in GPU. Finally, the GPU accelerated decoder was implemented and verified on the software radio platform, and the bit error rate performance and acceleration performance bottlenecks of the parallel decoder were analyzed. Experimental results show that compared with the traditional CPU serial code processing method, CPU+GPU heterogeneous platform has the decoding rate for LDPC codes increased to about 200 times, and the throughput of decoder can reach more than 1 Gb/s, especially in the case of large-scale data, the decoding performance is greatly improved compared with traditional decoder.
The key of cross-modal image-text retrieval is how to capture the semantic correlation between images and text effectively. Most of the existing methods learn the global semantic correlation between image region features and text features or local semantic correlation between inter-modality objects, and ignore the correlation between the intra-modality object relationships and inter-modality object relationships. To solve this problem, a method of Cross-Modal Tensor Fusion Network based on Semantic Relation Graph (CMTFN-SRG) for image-text retrieval was proposed. Firstly, the relationships of image regions and text words were generated by Graph Convolutional Network (GCN) and Bidirectional Gated Recurrent Unit (Bi-GRU) respectively. Then, the fine-grained semantic correlation between the data of two modals was learned by using the tensor fusion network to match the learned semantic relation graph of image regions and the graph of text words. At the same time, Gated Recurrent Unit (GRU) was used to learn global features of the image, and the global features of the image and the text were matched to capture the inter-modality global semantic correlation. The proposed method was compared with the Multi-Modality Cross Attention (MMCA) method on the benchmark datasets Flickr30K and MS-COCO. Experimental results show that the proposed method improves the Recall@1 of text-to-image retrieval task by 2.6%, 9.0% and 4.1% respectively on the test datasets Flickr30K, MS-COCO1K and MS-COCO5K.And mean Recall (mR) improves by 0.4, 1.3 and 0.1 percentage points respectively. It can be seen that the proposed method can effectively improve the precision of image-text retrieval.
In view of the disadvantages of the standard Artificial Bee Colony (ABC) algorithm such as weak development ability and slow convergence, a new ABC algorithm based on multi-population combination strategy was proposed. Firstly, the different-dimensional coordination and multi-dimensional matching update mechanisms were introduced into the search equation. Then, two combination strategies were designed for the hire bee and the follow bee respectively. The combination strategy was composed of two sub-strategies focusing on breadth exploration and depth development respectively. In the follow bee stage, the population was divided into free subset and non-free subset, and different sub-strategies were adopted by the individuals belonging to different subsets to balance the exploration and development ability of algorithm. The 15 benchmark functions were used to compare the proposed improved ABC algorithm with the standard ABC algorithm and other three improved ABC algorithms. The results show that the proposed algorithm has better optimization performance in both low-dimensional and high-dimensional problems.
In Positron Emission Tomography (PET) computed imaging, traditional iterative algorithms have the problem of details loss and fuzzy object edges. A high quality Median Prior (MP) reconstruction algorithm based on correlation coefficient and Forward-And-Backward (FAB) diffusion was proposed to solve the problem in this paper. Firstly, a characteristic factor called correlation coefficient was introduced to represent the image local gray information. Then through combining the correlation coefficient and forward-and-backward diffusion model, a new model was made up. Secondly, considering that the forward-and-backward diffusion model has the advantages of dealing with background and edge separately, the proposed model was applied to Maximum A Posterior (MAP) reconstruction algorithm of the median prior distribution, thus a median prior reconstruction algorithm based on forward-and-backward diffusion was obtained. The simulation results show that, the new algorithm can remove the image noise while preserving object edges well. The Signal-to-Noise Ratio (SNR) and Root Mean Squared Error (RMSE) also show visually the improvement of the reconstructed image quality.
In visual detection of subminiature accessory, the extracted target contour will be affected by the existence of foreign matter in the field like dust and hair crumbs. In order to avoid the impact for measurement brought by foreign matter, a method of culling foreign matter fake information based on prior knowledge was put forward. Firstly, the corners of component image with foreign matter were detected. Secondly, the corner-distribution features of standard component were obtained by statistics. Finally, the judgment condition of foreign matter fake imformation was derived from the corner-distribution features of standard component to cull the foreign matter fake information. Through successful application in an actual engineering project, the processing experiments on three typical images with foreign matter prove that the proposed algorithm ensures the accuracy of the measurement, while effectively culling the foreign matter fake information in the images.