Current Issue : January - March Volume : 2019 Issue Number : 1 Articles : 5 Articles
With the development of the Internet of Things (IoT) technology, a vast amount of the\nIoT data is generated by mobile applications from mobile devices. Cloudlets provide a paradigm\nthat allows the mobile applications and the generated IoT data to be offloaded from the mobile\ndevices to the cloudlets for processing and storage through the access points (APs) in theWireless\nMetropolitan Area Networks (WMANs). Since most of the IoT data is relevant to personal privacy,\nit is necessary to pay attention to data transmission security. However, it is still a challenge to realize\nthe goal of optimizing the data transmission time, energy consumption and resource utilization with\nthe privacy preservation considered for the cloudlet-enabled WMAN. In this paper, an IoT-oriented\noffloading method, named IOM, with privacy preservation is proposed to solve this problem.\nThe task-offloading strategy with privacy preservation in WMANs is analyzed and modeled as\na constrained multi-objective optimization problem. Then, the Dijkstra algorithm is employed to\nevaluate the shortest path between APs in WMANs, and the nondominated sorting differential\nevolution algorithm (NSDE) is adopted to optimize the proposed multi-objective problem. Finally,\nthe experimental results demonstrate that the proposed method is both effective and efficient....
Recently, some coarse-graining methods based on network synchronization\nhave been proposed to reduce the network size while preserving the synchronizability\nof the original network. In this paper, we investigate the effects of\nthe coarse graining process on synchronizability over complex networks under\ndifferent average path lengths and different degrees of distribution. A large\namount of experiments demonstrate a close correlation between the average\npath length, the heterogeneity of the degree distribution and the ability of\nspectral coarse-grained scheme in preserving the network synchronizability.\nWe find that synchronizability can be well preserved in spectral coarse-grained\nnetworks when the considered networks have a longer average path length or\na larger degree of variance....
Road capacity, traffic safety, and energy efficiency can be extremely improved by forming\nplatoons with a small intra-vehicle spacing. Automated controllers obtain vehicle speed, acceleration,\nand position through vehicular ad hoc networks (VANETs), which allows the performance of platoon\ncommunication to make a significant impact on the stability of the platoon. To the best of our\nknowledge, there is not much research relating to packet delay and packet dropping rate of platoon\ncommunication based on the IEEE 802.11p broadcasting. In this paper, we introduce platoon structure\nmodel, vehicle control model, and communication model for a single platoon scenario. By utilizing\nMarkov process and M/G/1/K queuing theory, we put forward an analytical model to assess\nthe property of intra-vehicle communication. The analytical model is validated by simulations\nand the influence of communication parameters on intra-vehicle communication performance are\ndiscussed. In addition, the experimental results demonstrate that the IEEE 802.11p-based intra-vehicle\ncommunication guarantee the stability of platoon....
As the ever-increasing attention to green communication, energy efficiency has become an imperative metric in the emerging\nmassive multiple-input multiple-output (MIMO) systems. In order to maximize the energy efficiency, transmit antenna selection\nhas been widely concerned by researchers. In this paper, we investigate the coded cooperation transmission for dynamic transmit\nantennas aided two-hopmassiveMIMOsystems. Explicitly, we propose a rate-less codes aided cooperation scheme for reducing the\nimplementation complexity in the broadcast phase, compared to the fixed-rate coded cooperation scheme. Furthermore,we develop\na partial cooperation scheme in the cooperative phase in order to avoid the low achievable rate caused by the full cooperation,\nespecially when the source-to-relay (S-R) channels are poor. Finally, the number of transmit antennas at the base station (BS) is\noptimized through theoretical analysis in a metric of maximizing the energy efficiency. Moreover, we also analyze the achievable\nerror performance for different modulations. Our simulation results demonstrate the effectiveness of the proposed scheme....
This paper concentrates on the detection of steganography in inactive frames of low bit\nrate audio streams in Voice over Internet Protocol (VoIP) scenarios. Both theoretical and experimental\nanalyses demonstrate that the distribution of 0 and 1 in encoding parameter bits becomes symmetric\nafter a steganographic process. Moreover, this symmetry affects the frequency of each subsequence\nof parameter bits, and accordingly changes the poker test statistical features of encoding parameter\nbits. Employing the poker test statistics of each type of encoding parameter bits as detection features,\nwe present a steganalysis method based on a support vector machine. We evaluate the proposed\nmethod with a large quantity of speech samples encoded by G.723.1 and compare it with the entropy\ntest. The experimental results show that the proposed method is effective, and largely outperforms\nthe entropy test in any cases....
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