The aim of this study is to forecast the number of free-riders in P2P networks which can help network managers to know the status of the networks in advance and take appropriate measures to cope with free-riding behav...
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In order to ensure the reliability and security of working environments under the open network environment dynamically,a fine-grain real-time and dynamic trust monitoring model is proposed which is based on behavior a...
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Quantum random numbers are a fundamental resource to security and cryptography. Based on the intrinsically random processes, quantum random number generators(QRNGs) provides an opportunity to certify genuine random ...
Quantum random numbers are a fundamental resource to security and cryptography. Based on the intrinsically random processes, quantum random number generators(QRNGs) provides an opportunity to certify genuine random numbers. All implementations of QRNGs that invoke device-independent(DI), the violation of Bell inequality are necessary to guarantee that the outcomes of the measurements cannot be determined in advance. For the single Clauser-Horne-Shimony-Holt(CHSH) inequality, it is not optimal with respect to randomness certification. Since local projective measurement are performed, one random bit can be certified from the maximally entangled two-qubit states. Recently, Andersson et al. [Phys. Rev. A 97, 012314(2018)] had proven that the device-independent certification can obtain two random bits through the maximum quantum violation of Gisin’s elegant Bell inequality. Here, we report a proof-of-principle realization of optimal randomness certification with practical photonic apparatus. In our experiment, we implement two kinds of qubit measurement, mutually unbiased bases(MUBs) and symmetric informationally complete positive operator-valued measures(SIC-POVM) of four-outcomes, respectively. Through randomness extractor, including Toeplitz-hashing extractor and an improved linear feedback shift register(LFSR), we finally extracted random bit string which have good uniformity and pass all randomness tests of the NIST.
In viewing of the problem that network coding can improve network throughput as well as increase network complexity, this paper proposed a special cognitive wireless mesh network topology while constructed a novel cod...
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In viewing of the problem that network coding can improve network throughput as well as increase network complexity, this paper proposed a special cognitive wireless mesh network topology while constructed a novel coding algorithm. In the multicast model based on wireless channel, the algorithm improved information transmission rate to some extent with random linear processing of data at intermediate nodes, therefore transported several combinations of data messages. Compared with traditional random message distribution algorithms, the proposed algorithm can reduce transmission number of source packets effectively and improve network throughput measured with network coding gain. The effectiveness of the algorithm has been verified by the theoretical deduction and experimental results.
Traditional video synopsis methods model the processing into an optimization formula where relations among objects such as collision cost are utilized while entire re-calculation is introduced under each possible temp...
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ISBN:
(纸本)9781509028610
Traditional video synopsis methods model the processing into an optimization formula where relations among objects such as collision cost are utilized while entire re-calculation is introduced under each possible temporal shift. Unlike the pairwise cost optimization, we propose a low-complexity and efficient online synopsis method where each tube is processed independently. Without tubes' comparison, the rearrangement is accomplished by a simple projection strategy and an updating projection matrix which records the newest information of the moving space. Furthermore, buffer and a predefined fitness condition also help to increase spatial and temporal utilization. Experiment results demonstrate that the proposed method is superior to other synopsis methods in the processing speed and temporal consistency.
Traditional mobile communication systems mainly work on the licensed frequency band near or below 3 GHz; however, this band is becoming increasingly crowded. On the other hand, there are abundant unlicensed spectrum r...
Traditional mobile communication systems mainly work on the licensed frequency band near or below 3 GHz; however, this band is becoming increasingly crowded. On the other hand, there are abundant unlicensed spectrum resources in higher frequency bands, e.g., 6 GHz, 15 GHz, and 28 GHz, and if those bands are applied, the current spectrum shortage problem could be effectively alleviated. However, the wireless channel characteristics and models are important but still unknown, and thus in this study, extensive measurements and modeling have been conducted to study the characteristics of the high-frequency 15-GHz band. Specifically, a PN(Pseudo Noise) sequence based time-domain measurement system was built and applied to measure the propagation characteristics of the LOS (Line-of-Sight) and NLOS (Non-Line-of-Sight) scenarios in an indoor corridor at 15 GHz. Then, in-depth analysis and modeling on the large-scale characteristics of wireless channels, the relationship between distance and path loss, the path loss exponent, and the shadow fading standard variance are provided. Moreover, the relationship between received power and different elevation angles was studied. In the measurement, two 25-dBi horn antennas with a 10 half-power beam width are used to change elevation angles in the transmitting terminal and azimuth angles in the receiving terminal for all measurement points. The findings and results in this work will serve as a reference and basis for future theoretical studies of the 15-GHz band.
"Device-independent"not only represents a relaxation of the security assumptions about the internal working of the quantum devices,but also can enhance the security of the quantum *** the paper,we put forwar...
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"Device-independent"not only represents a relaxation of the security assumptions about the internal working of the quantum devices,but also can enhance the security of the quantum *** the paper,we put forward the first device-independent quantum secure direct communication(DIQSDC)protocol and analyze its security and communication efficiency against collective *** practical noisy quantum channel condition,the photon transmission loss and photon state decoherence would reduce DI-QSDC’s communication quality and threaten its absolute *** solving the photon transmission loss and decoherence problems,we adopt noiseless linear amplification(NLA)protocol and entanglement purification protocol(EPP)to modify the DI-QSDC *** the help of the NLA and EPP,we can guarantee DI-QSDC’s absolute security and effectively improve its communication quality.
Although wavefront parallel processing(WPP) proposed in the HEVC standard and various inter frame WPP algorithms can achieved comparatively high parallelism, their scalability for its parallelism is still very limited...
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Although wavefront parallel processing(WPP) proposed in the HEVC standard and various inter frame WPP algorithms can achieved comparatively high parallelism, their scalability for its parallelism is still very limited due to various dependencies introduced in spatial and temporal prediction in HEVC. In this paper, through pixel correlation analysis, establishment of CTU node model, multi-core resource allocation strategy, we proposed an intra/inter-frame joint WPP coding algorithm for multi-core platform which can significantly improve the parallelism, while achieved good results in bit rate, PSNR, and acceleration ratio. Experiments on standard HD test sequence show that the proposed algorithm can lead to up to 2x, 1.3x speed up compared with the original WPP and IWF parallelism.
Refers to the both dynamic and multivariate network environment, we proposed a cognitive networks(CNs) available resource health assessment model, did health assessment of CNs resource availability through comprehensi...
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Refers to the both dynamic and multivariate network environment, we proposed a cognitive networks(CNs) available resource health assessment model, did health assessment of CNs resource availability through comprehensive fuzzy assessment model based on intelligent agent according to user Quality of Service(QoS) combined with network real-time state. Finally, by taking video on demand (VOD) as an example, we assessed the health degree of VOD service. The experimental results represented that the proposed approach can real-timely assess overall network performance as well as CNs available resource health effectively, therefore further guarantee the CNs overall performance and service end to end QoS.
The performance of wavelet transform based image compressed sensing coding algorithms severely rely on the level of wavelet transform. To this end, this paper investigated the combination of mutil-level wavelet full s...
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The performance of wavelet transform based image compressed sensing coding algorithms severely rely on the level of wavelet transform. To this end, this paper investigated the combination of mutil-level wavelet full sub-band in compressed sensing framework. Firstly, we constructed a full sub-band coefficient sparse vector of mutil-level discrete wavelet transform. Secondly, we designed a weight matrix to improve measurement matrix. Finally, sparsity vector was processed by compressed sensing to get the measured value. Compared with the exiting algorithms, the experimental results of the proposed algorithm show that the PSNRs of reconstructed images is improve up to 1~2 dB under the same objective quality.
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