| 1. |
- Luo, Hongmin, et al.
(författare)
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Preventing Distributed Denial-of-Service Flooding Attacks with Dynamic Path Identifiers
- 2017
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Ingår i: IEEE Transactions on Information Forensics and Security. - : Institute of Electrical and Electronics Engineers (IEEE). - 1556-6013 .- 1556-6021. ; 12:8, s. 1801-1805
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, there are increasing interests in using path identifiers (PIDs) as inter-domain routing objects. However, the PIDs used in existing approaches are static, which makes it easy for attackers to launch distributed denial-ofservice (DDoS) flooding attacks. To address this issue, in this paper, we present the design, implementation, and evaluation of D-PID, a framework that uses PIDs negotiated between neighboring domains as inter-domain routing objects. In DPID, the PID of an inter-domain path connecting two domains is kept secret and changes dynamically. We describe in detail how neighboring domains negotiate PIDs, how to maintain ongoing communications when PIDs change. We build a 42-node prototype comprised by six domains to verify D-PID’s feasibility and conduct extensive simulations to evaluate its effectiveness and cost. The results from both simulations and experiments show that D-PID can effectively prevent DDoS attacks.
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| 2. |
- Luo, Jiawei, et al.
(författare)
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Online Sparse DOA Estimation Based on Sub–Aperture Recursive LASSO for TDM–MIMO Radar
- 2022
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Ingår i: Remote Sensing. - : MDPI AG. - 2072-4292. ; 14:9
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Tidskriftsartikel (refereegranskat)abstract
- The least absolute shrinkage and selection operator (LASSO) algorithm is a promising method for sparse source location in time–division multiplexing (TDM) multiple–input, multiple– output (MIMO) radar systems, with notable performance gains in regard to resolution enhancement and side lobe suppression. However, the current batch LASSO algorithm suffers from high– computational complexity when dealing with massive TDM–MIMO observations, due to high– dimensional matrix operations and the large number of iterations. In this paper, an online LASSO method is proposed for efficient direction–of–arrival (DOA) estimation of the TDM–MIMO radar based on the receiving features of the sub–aperture data blocks. This method recursively refines the location parameters for each receive (RX) block observation that becomes available sequentially in time. Compared with the conventional batch LASSO method, the proposed online DOA method makes full use of the TDM–MIMO reception time to improve the real–time performance. Additionally, it allows for much less iterations, avoiding high–dimensional matrix operations, allowing the computational complexity to be reduced from O( K3) to O( K2). Simulated and real–data results demonstrate the superiority and effectiveness of the proposed method.
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| 3. |
- Tang, Jinfeng, 1984, et al.
(författare)
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Comprehensive evaluation of the effectiveness on metals recovery and decontamination from MSWI fly ash by an integrating hydrometallurgical process in Guangzhou
- 2020
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 728
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Tidskriftsartikel (refereegranskat)abstract
- Municipal solid waste incineration (MSWI) fly ash generally contains substantial toxic elements which can be easily released into the environment, giving rise to serious environmental contaminations. In order to dispose of these harmful fly ashes safely and feasibly, an advanced and reliable strategy is needed. This work presented an integrated method designed for recycling of valuable copper (Cu) and zinc (Zn) through hydrochloric acid leaching and sequential extraction (using LIX 860N-I and Cyanex 572 for Cu and Zn as extractants, respectively) and clean-up of cadmium (Cd) and lead (Pb) in consequential waste effluent by adsorption with a versatile material – bundle-like hydroxyapatite (B-HAP). The method was applied in the pilot scale tests with recovery yields of 95% and 61% for Cu and Zn, respectively. Additionally, satisfied removal efficiencies of Cd and Pb (over 95% for both) were realized, reaching the acceptable emission level for Cd and Pb in China. A scenario based on the latest MSW data in 2018 in Guangzhou was assessed through the integrated pilot experiment. The evaluation demonstrates a reduction of a $ 20.8 million cost; over 48.2 k GJ of energy consumption and 5800 tons of CO2 emission can be reduced in 2018, comparing to that landfilled in hazardous waste sites, which reveals great benefits. The valuable metal recovery in combination with decontamination of toxic elements/substances as a complete and combined process gives a promising fly ash treatment strategy in future.
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| 4. |
- Zhang, Yongchao, et al.
(författare)
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High-Throughput Hyperparameter-Free Sparse Source Location for Massive TDM-MIMO Radar : Algorithm and FPGA Implementation
- 2023
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Ingår i: IEEE Transactions on Geoscience and Remote Sensing. - 0196-2892. ; 61
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Tidskriftsartikel (refereegranskat)abstract
- The sparse iterative covariance-based estimation (SPICE) algorithm is promising for hyperparameter-free sparse source location for time-division-multiplexing multiple-input-multiple-output (TDM-MIMO) radar systems, with well-documented merits in resolution enhancement and sidelobe suppression. Regrettably, the method typically requires a large number of iterations to converge, each requiring high-dimensional matrix operations, rendering the existing batch SPICE method impractical and expensive to implement in hardware when dealing with massive TDM-MIMO observations. In order to enable real-time processing, this article presents a subaperture-recursive (SAR) SPICE method, allowing for recursively refining the location parameters for each received (RX) block observation that becomes available sequentially in time. The proposed method not only offers the same benefits as the batch SPICE method but also allows for computationally efficient online processing, without the need for high-dimensional matrix operations, notably reducing the required hardware resources as well as processing time. We further present a high-throughput architecture for the resulting method on an XCZU15EG-FFVB1156 field-programmable gate array (FPGA). In combination with simulation results, we demonstrate the effectiveness through experimental data measured by a cascaded MIMO radar system with 12 transmit (TX) and 16 receive (RX) antennas, demonstrating that the computational time of resolving closely spaced sources on 256 predefined grid points can be processed in merely 12 ms.
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| 5. |
- Zhang, Yongchao, et al.
(författare)
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Online Sparse Reconstruction for Scanning Radar Using Beam-Updating q-SPICE
- 2022
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Ingår i: IEEE Geoscience and Remote Sensing Letters. - 1545-598X. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- The generalized sparse iterative covariance-based estimation ( $q$ -SPICE) algorithm was recently introduced for scanning radar applications, resulting in substantial improvements in the angular resolution and quality of the processed images. Regrettably, the computational complexity and storage cost are high and quickly increase with growing data size, limiting the applicability of the estimator. In this letter, we strive to alleviate this problem, deriving a beam-updating $q$ -SPICE algorithm, allowing for efficiently updating of the sparse reconstruction result for each online radar measurement along the scanned beam. The resulting method is a regularized extension of the current online $q$ -SPICE implementation, which not only offers constant computational and storage cost, independent of the data size, but also provides enhanced robustness over the current online $q$ -SPICE. Our experimental assessment, conducted using both simulated and real data, demonstrates the advantage of the beam-updating $q$ -SPICE method in the task of sparse reconstruction for scanning radar.
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