最新刊期
卷 49 ， 期 5 ， 2021
- 摘要：Internet of vehicles has strict requirements in Ultra-Reliable and Low Latency Communications (URLLC). Especially in vehicle to infrastructure (V2I) scenario, URLLC is crucial to correctly transport and manage traffic conditions. 3GPP Cellular-V2X (C-V2X), as the current mainstream wireless technology supporting the URLLC, still has technical challenges. In order to further improve the communication performance, this paper designs an intelligent channel estimation framework based on C-V2I specification based on the interaction between vehicle terminal, road side unit (RSU) and edge computing Internet of Vehicles server (IoV Server) in V2I communication scenario. In IoV Server, this paper proposes a channel estimation algorithm based on deep learning, which uses one-dimensional convolutional neural network (1D CNN) to complete frequency-domain interpolation and conditional recurrent unit (CRU) to predict the time-domain state. By introducing additional velocity coding vector and multipath coding vector, the channel data in different mobile environments are accurately trained. Finally, system simulation and analysis show that the proposed algorithm can track the channel changes in different high-speed mobile environments through channel parameter coding, and realize the accurate training of channel data. Compared with the representative channel estimation algorithms in the IoV, the proposed algorithm improves the channel estimation accuracy, reduces the bit error rate and enhances the robustness.关键词：internet of vehicles;edge computing;V2I;C-V2X;channel estimation;deep learning4|5|7更新时间：2025-12-08
- 摘要：The emergence and development of intelligent transportation system (ITS) put forward higher requirements for the medium access control (MAC) protocol of vehicle communication. The widely used carrier sense multiple access (CSMA) protocol based on channel competition has the problem of uncertain time delay. MAC protocol based on time division multiple access (TDMA) can effectively solve this problem. However, TDMA protocols cannot eliminate data transmission collisions. This paper propose a communication framework combining fog computing.And a centralized TDMA MAC protocol is proposed, which could predict upcoming data transmission collisions by taking advantage of the low-latency of fog computing. Then, time slots could be well scheduled to reduce data transmission collisions. Experimental simulation results show that this method effectively reduces data transmission collisions, and improves channel resource utilization.关键词：ITS;TDMA;MAC;fog computing;collision avoidance6|5|1更新时间：2025-12-08
- 摘要：In vehicular edge computing environments, the Co-channel interferences (CCI) is a critical problem when edge nodes allocate channels for different data transmission tasks. This article formulates the problem of channel allocation in vehicular edge computing, aiming at allocating sub-channels for different data transmission tasks and maximizing the ratio of successful data transmission. We transform the global optimization problem of channel allocation into a channel allocation potential game, and prove the existence of nash equilibrium. We propose an Incentive-based probability update and strategy selection algorithm, which updates the strategy selection probability according to the incentive value of the selected strategy in each iteration, and further analyzes the Nash equilibrium converge of the algorithm. Finally, we verify the convergence of the proposed algorithm and the effectiveness of the Nash equilibrium. The experimental results show that the proposed algorithm outperforms existing representative algorithms in terms of the ratio of successful data transmission and channel utilization efficiency.关键词：vehicular edge computing;channel allocation;potential game;distributed scheduling4|4|3更新时间：2025-12-08
- 摘要：With the integration of mobile edge computing offloading into internet of vehicles, vehicular edge computing offloading can support low-latency, high-bandwidth and high-reliability application services. We first introduce the background and significance of vehicular edge computing offloading technology as well as the contributions of this survey. Then, we describe the network architecture, key challenges as well as popular application scenarios of vehicular edge computing offloading, respectively. After that, we provide the comprehensive survey of the state-of-the-art vehicular edge computing offloading from the different dimensions, including mobility analysis, offloading model, resource cooperation as well as management. Finally, we point out the future work about vehicular edge computing offloading, which can provide valuable reference and guidance for the in-depth study in vehicular edge computing offloading.关键词：internet of vehicles;mobile edge computing;vehicular edge computing;computation offloading;resource management;edge intelligence11|8|6更新时间：2025-12-08
- 摘要：In the three-dimensional vehicular ad-hoc networks (3D-VANET), high-speed moving vehicle nodes and changeable link states lead to unstable inter-vehicle communication links. Aiming at this problem, the time-space evolution graph model is constructed by introducing software define network technology to obtain network state in real-time and predict the process of time change and the link utility index is defined to quantify the wireless link performance. Then the weighted time-space evolution graph model based on link utility is established.Finally, the routing decision-making problem is transformed into a multi-attribute decision-making problem, and a link utility based reliable routing (LURR) algorithm is designed. Simulation results show that, compared with the existing four routing protocols, LURR algorithm has significantly improved packet transmission rate, end-to-end delay and routing load rate.关键词：3D-VANET;software defined network;time-space evolution graph;multi-attribute decision algorithm;routing reliability4|5|0更新时间：2025-12-08
- 摘要：Focusing on the weakness of the balance capability between global exploration and local search in the classical GWO algorithm, a novel grey wolf algorithm based on opposition learning (OLGWO), which can evolve the hyper-parameters of forecasting model, is proposed to improve the accuracy and enhance the robustness of traffic flow forecasting models. This algorithm is designed to take advantage of opposition learning strategy with the iterative process, and exploits the concept of rank correlation that can describe the Spearman correlation coefficients between the target wolf and the common wolves, and then selectively updates the each wolf of the whole population according to their values. Firstly, the performance comparison of four algorithms (OLGWO, TGWO, GWO, PSO), based on 12 benchmark functions, is conducted in terms of the two metrics, namely the optimization means and standard deviations. The results verify the outstanding performance of the proposed algorithm. Furthermore, based on the California highway traffic flow data, the four models optimized by the concerned algorithms are compared under different loss rates. The results show that the prediction accuracy of OLGWO-BP is higher than that of the others by 1.95%, 3.98% and 11.07%, respectively, and the stability is better.关键词：intelligent transportation;traffic flow prediction;grey wolf optimizer (GWO);BP neural networks;opposition learning5|4|7更新时间：2025-12-08
- 摘要：A three dimensional (3D) modified tunnel multi-bounced scattering channel model for vehicle to vehicle mobile communication is proposed under the assumption of equivalent scattering point. In this model, multi-antenna technology is adapted in both the mobile transmitter and receiver and there are line of sight (LOS) and non-LOS (NLOS) propagation paths between the transmitter and receiver. Analytical expressions of the probability density function (PDF) of the angle-of-departure (AOD) and angle-of-arrival (AOA) are presented according to the 3D MIMO channel model. Results show good agreement with the existing V2V scattering channel models and measured data in real tunnel environment,demonstrating the rationality of the underlying channel model.关键词：V2V mobile communication;tunnel spatial channel model;angle of departure;angle of arrival;probability density function3|3|0更新时间：2025-12-08
- 摘要：In order to solve the problems of considering only one transportation mode and neglecting user preference in transportation recommendation problem, and class imbalance problem in multi-class task, a context-aware multi-modal transportation recommendation method based on particle swarm optimization and LightGBM is proposed. This method comprehensively considers the user’s travel preferences in terms of time, space and travel cost, and uses mathematical statistics and representation learning methods to capture the internal relationship between user travel and various elements. At the same time, in order to alleviate the negative impact caused by the imbalance of sample class, the index optimization method based on particle swarm optimization algorithm is used to search for the optimal weight for each class, and the prediction results of the model are modified to achieve the purpose of maximizing the evaluation index. Experimental results show that compared with traditional algorithms, the model proposed in this paper has better performance in spatio-temporal feature extraction, alleviating class imbalance and recommendation accuracy.关键词：multi-modal transportation;personalized recommendation;network representation learning;particle swarm optimization;feature engineering3|7|3更新时间：2025-12-08
- 摘要：Special roads set up in highway used to realize dynamic wireless charging for In-motion electric vehicles that leads to a profound change in the field of traffic engineering. However, on the premise of the maximum charging effect of EV, how to schedule and manage such vehicles to improve traffic safety and road capacity is a key issue that cannot be avoided. Therefore, this paper first establishes the vehicle scheduling model of the system. A new reverse elitist mutation particle swarm optimization (REMPSO) algorithm is proposed.And its rapidity, stability and optimization ability are proved by comparing with the traditional particle swarm optimization and genetic algorithm. Finally, this algorithm is used to solve the system model, and the optimal moving isolation partition is obtained. Based on cooperative vehicle infrastructure system, the paper provides a feasible control strategy for the right of way scheduling of dynamic wireless charging for In-motion EV.关键词：cooperative vehicle infrastructure system;electric vehicles;dynamic wireless charging;particle swarm algorithm;scheduling4|4|2更新时间：2025-12-08
- 摘要：Connected and automated vehicles (CAVs) will become the mainstream of urban traffic. However, the existing scheduling schemes, such as traffic lights, are difficult to guide CAVs to pass through intersections efficiently. In order to improve vehicle traffic efficiency, a scheduling scheme based on sequential selection is designed for intersections without traffic lights. A feasible time for a vehicle to arrive at the intersection is planned according to its physical abilities and status of other CAVs. Extensive simulation experiments are conducted on the SUMO platform to verify the effectiveness of the proposed scheme. From the experimental results, it is revealed that the proposed scheme improves the traffic efficiency at intersections, comparing with other methods. Especially, when the traffic load is heavy, the performance gain of the proposed scheme is more obvious.关键词：connected and automated vehicles(CAV);sequential selection;scheduling;traffic efficiency3|4|1更新时间：2025-12-08
- 摘要：With the increasing demands for higher positioning precision of global satellite navigation systems, pseudorange biases have been receiving more and more attentions in recent years. Unfortunately, few researches have been done on the pseudorange biases of Beidou navigation satellite system (BDS). The origin of BDS pseudorange biases are illustrated thoroughly in the beginning, and then based on which the dependency of biases on receiver configurations are studied. Our research used high-fidelity BDS satellite signal observations collected by a 40 m high-gain dish antenna in Haoping Observatory, and used software receiver technology to achieve the pseudorange biases results of BDS B1I and B3I signals from different front-end bandwidths, different correlator spacings and different satellite elevations. Finally, based on the characteristics of BDS pseudorange biases, the suggested settings of BDS receiver configurations such as front-end bandwidth and correlator spacing are clearly proposed for the first time. Research results show that the pseudorange biases of BDS signals will be less than approximately 20 cm under the condition proposed in this paper. This study will contribute to a better understanding of and special attention to pseudorange biases, and will be a significant promotion to a clear definition of the appropriate receiver parameter settings in the ICDs for BDS and other individual satellite system.关键词：Beidou navigation satellite system;pseudorange biases;mitigation method;receiver configuration;interface control documents3|4|2更新时间：2025-12-08
- 摘要：In the ultra-dense heterogeneous wireless network, the traditional vertical handoff algorithm can not describe the fuzziness and randomness of the network state at the same time, so the network performance can not be effectively improved. A vertical handoff algorithm based on the interval type II fuzzy neural network is proposed to solve above problem. A two-stage decision system is reconstructed: in the network’s prescreening stage, the historical access rate is defined to set the threshold combine with the number of current candidate network sets. According to the received signal strength and the remaining available bandwidth, all the networks within the user’s receiving range are preliminarily screened; The delay, packet loss rate and bit error rate of the remaining candidate networks are taken as the inputs of the it2fnn in the vertical handoff decision stage. The fuzzy logic reasoning is completed by using the structure of the feedforward neural network, and the output decision value is calculated after the training, and the optimal network is selected. The simulation results show that the algorithm can ensure low time consumption, and effectively reduce the error probability of handoff decision and the number of handoff failures and handoff times. Meanwhile, it can improve the total throughput of networks.关键词：interval type II fuzzy neural network;ultra-dense;vertical handoff;fuzziness;randomness2|4|4更新时间：2025-12-08
- 摘要：In order to relieve the drift phenomenon in dynamic non-rigid online reconstruction, an on-line fusion strategy for dense deformation field based on a single RGB-D sensor is proposed, realizing the dynamic reconstruction for non-rigid geometries. By local smoothing and input constraint strategy, the optimal deformation problem is transformed into nonlinear regular variational optimization problem. We use the data parallel flash optimization strategy to achieve on-line tracking of non-rigid scene in camera tracking rate. Experiments show that the proposed method achieves robust tracking of non-rigid scenes, which reduces drift in the process of online reconstruction, this algorithm is suitable for fast moving scene as well as the object lack of geometric features.关键词：RGB-D sensor;dynamic reconstruction;robust tracking2|4|0更新时间：2025-12-08
- 摘要：It is very important to recognize parathyroid nodules correctly in ultrasound images for the treatment of hyperparathyroidism. Due to individual differences of patients and complexity of ultrasound images, parathyroid nodules can’t be recognized accurately by only using morphological features and texture features. In this paper, a prior knowledge feature description method is proposed on account of the characteristic of envelope and the relative location between the nodule and the thyroid. SVDD is applied to recognize parathyroid nodules based on the fusion features of prior knowledge features, morphological features and texture features. The experimental results show that the prior knowledge features can describe the characteristics of parathyroid nodules well, and the accuracy by using the fusion features which combined prior knowledge features is higher than that of only using morphological features and texture features for the recognition of parathyroid nodules.关键词：parathyroid nodules;prior knowledge features;SVDD;ultrasound images3|5|2更新时间：2025-12-08
- 摘要：In order to improve the accuracy of GPR (ground penetrating radar) B-SCAN hyperbola detection, the deep learning method is applied to the processing of GPR data. In order to solve the problem of insufficient samples in the data set, the GPR B-SCAN image data is augmented by using cycle generative adversarial networks algorithm (CycleGAN). The Faster R-CNN operator is used to locate the hyperbolic image area, making full use of the symmetry of the hyperbolic structure and its directional difference characteristics, designing the corresponding convolution kernel template, and realize effective segmentation of hyperbolic targets in B-SCAN images through convolution operation. The least square method is used to perform quadratic curve fitting on the hyperbolic target to obtain an accurate hyperbolic image. Compared with B-SCAN image detection algorithms such as transfer learning-based methods, HOG (histogram of oriented gradients) algorithm and Hough transform algorithm, the results obtained by the method in this paper are optimal on the comprehensive measurement index F.关键词：deep learning;ground penetrating radar;cycle generative adversarial networks;convolution operation4|6|7更新时间：2025-12-08
- 摘要：An adaptive flow balancing algorithm is proposed for the Packet_In transmission bottleneck caused by the limited control link performance between the control plane and the data plane in software-defined networking (SDN). The control plane of the SDN network has the characteristics of having a global topology and real-time status of switches, therefore we solve the bottleneck problem of the uplink control link by using thresholds to control the starting and ending conditions of flow balancing and redirecting flow in overloaded switch to neighbor switch. Compared with the existing methods, the upload control link load is reduced by 33% and packet loss rate of Packet-In massage is reduced by 50%, and the deployment overhead is little.关键词：software defined network;control link;global topology;flow optimization;adaptive4|4|1更新时间：2025-12-08
- 摘要：Aimed at the problems, such as low key exchange efficiency and large meaningless consumption of secret key materials, when the existing routing schemes for trust relaying QKD (quantum key distribution) network used in the wide-area environment, a hierarchical routing scheme which is suitable for wide-area QKD network was designed. This routing scheme divided the QKD network into multiple routing areas, built a hierarchical network by topological aggregation and designed a cross-domain routing algorithm based on the principle of the lowest layer matching. Then the hop number in the routing path is decreased, and the efficiency of key exchange and the utilization rate of secret key materials ware increased. At last, the simulation results shows that our hierarchical routing scheme can increase about 77.6% utilization rate of secret key materials and reduce service delay by half compared with the existing routing schemes which just relaying secret key hop by hop in a single layer.关键词：QKD (quantum key distribution) network;quantum key distribution;routing scheme;hierarchical network2|4|0更新时间：2025-12-08
- 摘要：To classify three types of brain CT (computerized tomography) images in Alzheimer's disease, lesion (e.g.,brain tumor) and healthy aging, an improved ResNet-10 convolutional neural network is proposed in this papers. A residual hybrid attention module is embedded in the residual identity mapping to capture the location and content information of brain tissue in brain CT images, solving the original model to extract weak distinguish features problems. In addition, to simplify the improved model and alleviate the overfitting, several techniques such as global average pooling and Dropout are used in the model. Moreover, to have strong generalization ability in the case of limited sample quantity, tag smoothing cross-entropy loss function is adopted to train the model. Experimental results show that the improved ResNet-10 achieves 97.47% accuracy in classifying brain CT images.关键词：residual hybrid attention module;label smoothing;brain CT;convolutional neural network4|5|9更新时间：2025-12-08
- 摘要：In light of the characteristics of spatio-temporal data stream, we propose a moving object spatial index construction method called HSTRCL, which is based on time window data sorting and bulk loading. It segments the continuous spatio-temporal data stream with fixed-length time windows; after finishing caching the data of a time window, by combining parallel processing and optimized bulk loading technology, we isolate as much as possible the time-consuming work of data partitioning and sorting operations from the traditional build process, and parallize them with the reception of data streams and other build operations. Furthermore, we avoid unnecessary locking synchronization overhead. And all these techniques improve the efficiency of index construction. In addition, to meet the performance and diverse query requirements, we also adopt the primary-auxiliary index construction technology based on Hash and STR. To further improve the performance in the object query scenario, we invent another moving object spatial index construction method OAHSTRCL via time window object aggregation and bulk loading, where objects are divided more finely, and the object query time required is about 65% of HSTRCL, though it will affect the performance of spatial query to some extent. Theoretical analysis and experiments have demonstrated the effectiveness of our proposed methods.关键词：spatio-temporal data stream;moving object;spatial index;R-tree;object aggregation2|4|1更新时间：2025-12-08
- 摘要：In view of the problems existing in the automated warehouse, such as many in and out tasks, unbalanced utilization of stacker, great difference in product quality and the impact of task execution process on quality, an emotional bacteria foraging algorithm based on weight strategy and non-uniform elimination diffusion probability distribution is proposed. In order to minimize the running time, equalize the utilization rate of stacker, stabilize the shelf and influence the quality of products, an integrated optimization model is built. In view of the shortcomings of the bacterial foraging algorithm, such as uncertain chemotaxis step length and constant elimination diffusion probability, the Gaussian distribution search mechanism is introduced to update the individual position in the chemotaxis process to avoid the algorithm falling into local optimization, and the emotion is introduced in the mutation process, the weight strategy is introduced to update the individual speed, and the individual emotion perception factor is given to realize the adaptive step size to avoid the premature convergence of the algorithm; around the constancy of probability in the elimination diffusion process, the non-uniform probability distribution is proposed to replace the traditional constant distribution to ensure the population diversity. Simulation and algorithm comparison results show that the proposed algorithm has better performance.关键词：automated warehouse;bacterial foraging algorithm;emotional mutation;Gaussian distribution search mechanism;weight strategy;non-uniform probability distribution2|4|1更新时间：2025-12-08
- 摘要：A MOS-like low operating voltage gate-controlled silicon-based light-emitting device is designed and fabricated using 0.18μm standard CMOS technology. The light emitting device adapts a n+-p+-p+-n+-p+-p+-n+ interdigital structure, in which a poly-Si gate between two adjacent p+ regions working as a third-terminal control electrode was designed. The poly-Si gate is used to produce field-induced junctions at the edge of source/drain region, so as to decrease the breakdown voltage of p+/n-well junction and increase optical power of the device. The measured results indicate that the device can emit yellow visible light with wavelength from 420nm to 780nm. Under forward gate voltage of 3V, the breakdown voltage of p+/n-well junction can be reduced to below 3V, and the optical power can be increased to more than twice. Because of its low operating voltage and full compatibility with CMOS technology, the device can be integrated with other CMOS circuits by using a single power supply, which has certain applications in the field of silicon-based optoelectronic integration.关键词：microelectronics;Si-LED;standard CMOS process;optoelectronic integration2|4|0更新时间：2025-12-08
- 摘要：The main problems in the current development process of the Internet of Things are outlined, and the feasibility of the combination of software defined network and the Internet of Things is studied. After summarizing and analyzing the relevant software-defined Internet of Things architecture, the SDIoT general architecture is proposed and the basic architecture of Software-Defined Vehicular Networks is discussed. Through the analysis of the existing research results, the challenges and key technologies are elaborated from three aspects: heterogeneous interconnection, resource management, security and reliability. Finally, taking Vehicular Ad-hoc Network as an example, the advantages and prospects of SDIoT applications are clarified, and the possible research directions in the future is prospected.关键词：Internet of Things;software defined network;heterogeneous interconnection;resource management2|4|6更新时间：2025-12-08
- 摘要：Aiming at the problem of insufficient timing synchronization capability and low accuracy of Ethernet in the military, industrial and other fields at present, a highly reliable clock synchronization interface circuit with a high-precision clock synchronization protocol is designed. The current mainstream with the highest precision is the IEEE1588 precision clock synchronization protocol; In-depth study and analysis of the best master clock algorithm and master-slave clock synchronization principle of the IEEE1588 protocol, proposed an ethernet clock synchronization method based on DP83640, provides a solution for stamping time stamps at the physical layer to achieve high-precision clock synchronization in ethernet, explain the master-slave clock software time synchronization process, test and verify the synchronization accuracy of master-slave clocks, which can achieve sub-microsecond clock synchronization accuracy.关键词：clock synchronization;IEEE1588 protocol;DP83640;Ethernet2|4|4更新时间：2025-12-08
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