Current Issue : April - June Volume : 2019 Issue Number : 2 Articles : 6 Articles
Video streaming communication networks will be a very important way to send multimedia information anytime and anywhere,\nand the construction of the network base station which transmits signals is crucial in future. However, there is a contradiction\nbetween the power consumption of LoRa nodes and the real-timeliness of mesh network. In order to solve the contradiction, this\narticle aims to combine themesh network of LoRawireless communication system with an improved artificial bee colony algorithm.\nSpecifically, an artificial bee colony algorithm, which is based on RBF radial basis neural network trained with random gradient\nmethod, is designed. Simulation results showthat the proposed algorithm solves the contradiction between power consumption and\nreal-timeliness effectively.When using this improved network system structure to send multimedia information, it shows obvious\nsuperiority in terms of the high efficiency and real-timeliness of multimedia transmission....
The noise characteristics of multichannel systems of forming signals based on hybrid frequency synthesizers with automatic\ncompensation of phase distortions of direct digital synthesizers, which are used in the composition of georadars with synthesized\naperture, are investigated. It is established that the phase noise of the output signals of the formers at the 1 kHz detuning from the\ncarrier oscillation at the output frequencies of the devices in the range from500 to 3500MHz is characterized by a level ofminus 100\n- minus 130 dB. In this case, the circuit of the signal former based on a hybrid frequency synthesizer with direct digital synthesizer\nas a reference oscillator of a phase locked loop is characterized by the worst noise characteristics but with the highest degree of\nautocompensation (about 13 dB). Conversely, the circuit of the signal former based on a hybrid frequency synthesizer with direct\ndigital synthesizer as a support generator of the phase-locked loop has the best phase noises level from the considered variants of\ndevices and least degree of autocompensation (about 6 dB)....
For intrusion detection, it is increasingly important to detect the suspicious entities and potential threats. In this paper,we introduce\nthe identification technologies of network entities to detect the potential intruders. However, traditional entities identification\ntechnologies based on the MAC address, IP address, or other explicit identifiers can be deactivated if the identifier is hidden or\ntampered.Meanwhile, the existing fingerprinting technology is also restricted by its limited performance and excessive time lapse.\nIn order to realize entities identification in high-speed network environment, PFQ kernelmodule and Storm are used for high-speed\npacket capture and online traffic analysis, respectively. On this basis, a novel device fingerprinting technology based on runtime\nenvironment analysis is proposed, which employs logistic regression to implement online identification with a sliding window\nmechanism, reaching a recognition accuracy of 77.03%over a 60-minute period. In order to realize cross-device user identification,\nWeb access records, domain names inDNS responses, andHTTP User-Agent information are extracted to constitute user behavioral\nfingerprints for online identification with Multinomial Naive Bayes model.When the minimum effective feature dimension is set\nto 9, it takes only 5 minutes to reach an accuracy of 79.51%. Performance test results show that the proposed methods can support\nover 10Gbps traffic capture and online analysis, and the system architecture is justified in practice because of its practicability and\nextensibility....
Aplaner millimetre-wave dual-band bandpass filterwithmultitransmission zeros is proposed for 5Gapplication. This filter includes\ntwo dual-mode open-loop resonators. The U-shape nonresonating node is employed to generate an extra coupling path. Finally, a\ndual-band bandpass filter with five transmission zeros is obtained.The filter is fabricated and measured. Good agreement between\nsimulation and measurement is obtained....
With the diversified wireless network access technology and large-scale equipment of multinetwork interface devices expanding,\nnetwork transmission performance for multi-homed terminals has been widely concerned by academic circles. More and more\nscholars have paid attention to Multipath Transmission Control Protocol (MPTCP) as one of the representative methods for\nstudying path transmission performance. However, their studies ignore the impact of dynamic network environments on data\ntransmission performance and seldom consider the priority of data transmission. Undoubtedly, not prioritizing packets will have a\ndramatic effect on the users experience in the heterogeneous networks. In this paper, we propose a novel priority-aware streaming\nmedia multipath data scheduler mechanism(PO-MPTCP) to achieve the following goals: (1) detecting the priority of all streaming\nmedia data; (2) achieving multiattribute-aware path evaluation and switching mechanism; (3) introducing a path-quality prioritydriven\ndata distributionmechanismto improve streaming multipath transmission performance.The simulation experiment shows\nthat PO-MPTCP proposed by this paper improves the transmission performance of streaming media and reduces the transmission\ndelay. For the result of simulation experiment, it is easy for us to find that PO-MPTCP is more efficient in data delivery than the\nstandard MPTCP mechanism....
Different color patterns of quick response (QR) codes, suchas RGB, grayscale, and binaryQR codes, are widely used in applications.\nIn this paper, we propose a novel XOR-based visual secret sharing (VSS) scheme using grayscale QR codes as cover images and\nbinary QR code as secret image. First, all the codewords of the secret QR code image are encoded into n temporary binary QR code\nimages, which are substituted for the second significant bit planes of the grayscale QR code cover images to generate n shares. Each\nshare is a grayscale QR code image, which can be decoded by a standard QR code decoder, so that it may not attract the attention\nof potential attackers when distributed in the public channel.The secret image can be recovered by XORing the codewords regions\nof QR codes which are extracted from the second significant bit planes of the grayscale shares. More importantly, the proposed\nscheme is robust to JPEG compression, addition of different noises, rotation, resizing, and cropping, which is useful in practice.\nThe effectiveness and robustness of our scheme are shown by the experimental results. The application of QR code is suitable for\nwireless multimedia data security....
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