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Various emerging vehicular applications such as autonomous driving and safety early warning are used to improve the traffic safety and ensure passenger comfort. The completion of these applications necessitates significant computational resources to perform enormous latency-sensitive/nonlatency-sensitive and computation-intensive tasks. It is hard for vehicles to satisfy the computation requirements of these applications due to the limit computational capability of the on-board computer. To solve the problem, many works have proposed some efficient task offloading schemes in computing paradigms such as mobile fog computing (MFC) for the vehicular network. In the MFC, vehicles adopt the IEEE 802.11p protocol to transmit tasks. According to the IEEE 802.11p, tasks can be divided into high priority and low priority according to the delay requirements. However, no existing task offloading work takes into account the different priorities of tasks transmitted by different access categories (ACs) of IEEE 802.11p. In this paper, we propose an efficient task offloading strategy to maximize the long-term expected system reward in terms of reducing the executing time of tasks. Specifically, we jointly consider the impact of priorities of tasks transmitted by different ACs, mobility of vehicles, and the arrival/departure of computing tasks, and then transform the offloading problem into a semi-Markov decision process (SMDP) model. Afterwards, we adopt the relative value iterative algorithm to solve the SMDP model to find the optimal task offloading strategy. Finally, we evaluate the performance of the proposed scheme by extensive experiments. Numerical results indicate that the proposed offloading strategy performs well compared to the greedy algorithm.

A novel photocatalyst, FeTPyPY, was prepared by immobilizing water-soluble tetra(4-pyridyl)phenyl iron-porphyrin (FeTPyP) on NaY zeolite to degrade microcystin-LR (MC-LR), one of the most toxic microcystins (MCs). UV-Vis analysis, UV-Vis diffuse reflectance spectroscopy, infrared spectroscopy, cyclic voltammetry and transmission electron microscopy were employed to characterize immobilized FeTPyPY. Under visible light (λ ≥ 420 nm), MC-LR was degraded utilizing immobilized FeTPyPY by activating molecular oxygen. The results showed that 85% of MC-LR was efficiently degraded by FeTPyPY with loading amount 100:1 (mNaY:mFeTPyP) after 300 min of visible light illumination. Moreover, FeTPyPY was stable in the degradation system with pH 7.0. The degradation mechanism was evaluated using electron spin resonance, and the results demonstrated that highly reactive oxygen species (•OH radical) were generated in the system to degrade MC-LR. Therefore, immobilized FeTPyPY was available to break down the toxic groups within MC-LR by utilizing environmental •OH radical under circumneutral condition.

Platooning is a critical technology to realize autonomous driving. Each vehicle in platoons adopts the IEEE 802.11p standard to exchange information through communications to maintain the string stability of platoons. However, one vehicle in platoons inevitably suffers from a disturbance resulting from the leader vehicle acceleration/deceleration, wind gust and uncertainties in a platoon control system, i.e., aerodynamics drag and rolling resistance moment etc. Disturbances acting on one vehicle may inevitably affect the following vehicles and cause that the spacing error is propagated or even amplified downstream along the platoon, i.e., platoon string instability. In this case, the connectivity among vehicles is dynamic, resulting in the performance of 802.11p in terms of packet delay and packet delivery ratio being time-varying. The effect of the string instability would be further deteriorated once the time-varying performance of 802.11p cannot satisfy the basic communication requirement. Unlike the existing works which only analyze the steady performance of 802.11p in vehicular networks, we will focus on the impact of disturbance and construct models to analyze the time-dependent performance of 802.11p-based platooning communications. The effectiveness of the models is validated through simulation results. Moreover, the time-dependent performance of 802.11p is analyzed through numerical results and it is validated that 802.11p is able to satisfy the communication requirement under disturbance., Comment: This paper has been accepted by IEEE Transactions on Vehicular Technology. Simulation codes have been provided at: https://github.com/qiongwu86/TVT_code

The essence of human is social relation. In computer, relation can be represented by graph. It may be possible to divide a group of individuals into a few of communities according to the intensity of relation among individuals. The relation between individuals in the same community should be strong, while that between individuals in different communities should be weak. That the intensity of relation between two persons is high means that they trust each other; therefore, strong relation can be used to commit crime, for instance, corruption. Consequently, finding out strong relation can help auditor to reduce difficulty of assuring them of reliability of auditing. Seeing that those algorithms that involve iteration process have fatal defect, the authors of this paper introduce a method used to divide a group into a few of communities based on spectral clustering. This method has the advantage of high speed which means that it has favorable performance when it is used to cope with tremendous amount of data.

In order to protect the target codes generated by compiler, this paper puts forward a scheme combining compiler with hardware platform on the base of the existing protection method of executable code First, classify codes of C Language into four security levels to determine the protection strategies for different codes. Secondly, design and implement the corresponding encryption module ,decryption module and decompression module in VHDL Language after studying the structure and the principle of FPGA and the method of development software Thirdly, decompress and decode the target codes through FPGA modules when target codes is being executed. Run the target codes only when they are qualified. Finally, implement and simulate the scheme through FPGA. The simulation experiment verifies the correctness and effectiveness of encryption module, decryption module and decompression module.

The paper puts a “cloud” learning platform mode. In order to improve the quality of education and teaching and solve the problems such as single teaching systems, the gap between classroom teaching and online teaching and less interaction between the teacher and students and so on. First, force on the application of cloud computing, cloud learning and cloud platforms, we analysis and compare to characteristics of the traditional learning platform, and propose a method that based on the B-learning thinking for the cloud learning platform. Then we give an instance of practice application and it proves that the establishment of cloud study platform has improved the efficiency of the teachers’ classroom, the students’ independent learning, teacher-student interaction, and so on. It is of great significance for promoting the teaching techniques of innovation