A Novel High-Speed Architecture for Integrating Multiple DDoS Countermeasure Mechanisms Using Reconfigurable Hardware

In this paper, we proposed a novel high-speed architecture to incorporate multiple stand-alone DDoS countering mechanisms. The architecture separates DDoS filtering mechanisms, which are algorithms, out of packet decoder, which is the basement. The architecture not only helps developers to give more concentration on optimizing algorithms but also integrate multiple algorithms to achieve more efficient DDoS defense mechanism. The architecture is implemented on reconfigurable hardware, which helps algorithms to be flexibly changed or updated. We implemented and experimented the system using NetFPGA 10G board with incorporation of Port Ingress/Egress Filtering and Hop-Count Filtering to classify IP spoofing packets. The synthesis results show that the system runs at 118.907 MHz, utilizes 38.99% Registers, and 44.75% BlockRAMs/FIFOs of the NetFPGA 10G board. The system achieves the detection rate of 100% with false negative rate at 0%, and false positive rate closed to 0.16%. The experimental results prove that the system achieves packet decoding throughput at 9.869 Gbps in half-duplex mode and 19.738 Gbps in full-duplex mode

Dynamic stiffness method for free vibrations analysis of partial fluid-filled orthotropic circular cylindrical shells

Free vibrations of partial fluid-filled orthotropic circular cylindrical shells are investigated using the Dynamic Stiffness Method (DSM) or Continuous Element Method (CEM) based on theFirst Order Shear Deformation Theory (FSDT) and non-viscous incompressible fluid equations. Numerical examples are given for analyzing natural frequencies and harmonic responses of cylindrical shells partially and completely filled with fluid under various boundary conditions. The vibration frequencies for different filling ratios of cylindrical shells are obtained and compared with existing experimental and theoretical results which indicate that the fluid filling can reduce significantly the natural frequencies of studiedcylindrical shells. Detailed parametric analysis is carried out to show the effects of some geometrical and material parameters on the natural frequencies of orthotropic cylindrical shells. The advantages of this current solution consist in fast convergence, low computational cost and high precision validating for all frequency ranges

FPGA-Based Multiple DDoS Countermeasure Mechanisms System Using Partial Dynamic Reconfiguration

In this paper, we propose a novel FPGA-based high-speed DDoS countermeasure system that can flexibly adapt to DDoS attacks while still maintaining system performance. The system includes a packet decoder module and multiple DDoS countermeasure mechanisms. We apply dynamic partial reconfiguration technique in this system so that the countermeasure mechanisms can be flexibly changed or updated on-the-fly. The proposed system architecture separates DDoS protection modules (which implement DDoS countermeasure techniques) from the packet decoder module. By using this approach, one DDoS protection module can be reconfigured without interfering with other modules. The proposed system is implemented on a NetFPGA 10G board. The synthesis results show that the system can work at up to 116.782 MHz while utilizing up to 39.9% Registers and 49.85% BlockRAM of the Xilinx Virtex xcv5tx240t FPGA device on the NetFPGA 10G board. The system achieves the detection rate of 100% with the false negative rate at 0% and false positive rate closed to 0.16%. The prototype system achieves packet decoding throughput at 9.869 Gbps in half-duplex mode and 19.738 Gbps in full-duplex mode

Bit-Interleaved Coded Modulation Systems with Iterative Decoding and Partial Reusing QAM Signal Points

A new method of reusing a subset of an M-QAM signal constellation is presented for Bit-Interleaved Coded Modulation systems with Iterative Decoding (BICM-ID). In addition to the remapping of high-energy signals to low-energy signals in order to save the average signal energy as a shaping technique known so far, a new scheme of remapping low-energy signals to high-energy signals is proposed in order to gain the equivalent distance when decoding bits, often called the Squared Euclidean Weights (SEW). Numerical analysis and simulation results show that the partial reuse of the signals in the BICM-ID system with 16-QAM can improve the system performance in terms of lowering the bit error rate in the error floor region

A Comparison of Genetic Algorithms in Optimizing Controllers for Inverted Pendulum

In our study, we compared classical genetic algorithm (GA) and non-dominated sorting GA (NSGA) II to optimize LQR and sliding mode control (SMC) for an inverted pendulum. We aimed to identify the algorithm that best improves stability and peak performance. Our results clarified each algorithm’s unique strengths. The provement is shown in Matlab simulations

Identification of rose black spot pathogen in Sa Đéc city, Đồng Tháp province of Vietnam

Black spot is one of the most destructive diseases of roses, causing premature defoliation, thus progressively weakening the plant and even leading to death. This study aimed at identifying the pathogen causing black spot on Rosa chinensis Jacq. cv. nhung (Hồng Nhung) and R. chinensis Jacq. var. minima (Hồng Tỉ Muội) in Sa Đéc city, Đồng Tháp province, Vietnam, using a combination of conidia morphology and pathogenicity tests including detached leaf and intact plant techniques. A total of 32 infected leaf samples with the black spot typical symptoms were collected from six rose cultivation areas. The morphological characterization of the conidia obtained from these samples was elliptical, hyaline, two-celled and had vacuole-like structures, similar to those produced by Diplocarpon. In pathogenicity test, the symptoms were observed on cv. nhung but not var. minima in the detached leaf technique while symptoms were observed on both cultivars in intact plants technique. These included black spots with perforated edges, aggregating into bigger patches. The infected leaves could yellow and defoliate at 21 days after inoculation. Compared to the previous pathogenic studies and description of diseases on roses, the fungal pathogen was identified as fungus Diplocarpon rosae

Green human resource management and employee pro-environmental behaviors: The role of individual green value

This quantitative study is aimed at exploring the effect of Green Human Resource Management (GHRM) practices on employee Pro-Environmental Behaviors (PEB). Our conceptual model was developed based on the Ability, Motivation, and Opportunity (AMO) framework and the Attitude-Behavior-Context theory (ABC). Our model was tested using data from 696 full-time medical staff working in Vietnamese hospitals. In order to fully understand how GHRM practices, Green knowledge sharing, individual green value, and employee pro-environmental behaviors are related, structural equation modeling is combined with necessary condition analysis. The results indicate that (a) green training and involvement (GRS), green recruitment (GTI), and green performance management and compensation (GPC) positively impact GKS, and (b) GKS is positively related to PEB. The findings also demonstrate that the individual green value plays a moderating role in the connection between GRS, GTI, GPC, and GKS. A discussion is included on how practices within GHRM can stimulate employees to exhibit GKS and PEB, as well as the implications for GHRM theory and practice

Disinfection performance of an ultraviolet lamp: a CFD investigation

Ultraviolet (UV)-based devices have shown their effectiveness on various germicidal purposes. To serve their design optimisation, the disinfection effectiveness of a vertically cylindrical UV lamp, whose wattage ranges from P = 30 − 100 W, is numerically investigated in this work. The UV radiation is solved by the Finite Volume Method together with the Discrete Ordinates model. Various results for the UV intensity and its bactericidal effects against several popular virus types, i.e., Corona-SARS, Herpes (type 2), and HIV, are reported and analysed in detail. Results show that the UV irradiance is greatly dependent on the lamp power. Additionally, it is indicated that the higher the lamp wattage employed, the larger the bactericidal rate is observed, resulting in the greater effectiveness of the UV disinfection process. Nevertheless, the wattage of P ≤ 100W is determined to be insufficient for an effective disinfection performance in a whole room; higher values of power must hence be considered in case intensive sterilization is required. Furthermore, the germicidal effect gets reduced with the viruses less sensitive to UV rays, e.g, the bactericidal rate against the HIV virus is only ∼8.98% at the surrounding walls

FLAVONOIDS AND TRITERPENOIDS FROM CALLISTEMON CITRINUS AND THEIR INHIBITORY EFFECT ON NO PRODUCTION IN LPS-STIMULATED RAW264.7 MACROPHAGES

Phytochemical investigation of the leaves and stems of Callistemon citrinus (Curtis) Skeels led to the isolation of 12 flavonoid and triterpenoid compounds,  including one new flavonoid, callistine A (1) and six known flavonoids 6,7- dimethyl-5,7-dihydroxy-4’-methoxy flavone (2), astragalin (3), quercetin (4), catechin (5), eucalyptin (6), and 8-demethyleucalyptin (7), along with 5 triterpenoids, 3-β-acetylmorolic acid (8), 3β-hydroxy-urs-11-en-13(28)-olide (9), betulinic acid (10), diospyrolide (11) and ursolic acid (12). Their chemical structures were determined from the spectroscopic evidences counting 1D- and 2D-NMR and HR-MS data. All the isolated compounds were examined for their anti-inflammatory activity against LPS-activated NO production in macrophage RAW264.7 cells. Among them, quercetin (4) and 3β-hydroxy-urs-11-en-13(28)-olide (9) showed potential inhibition activity in nitric oxide (NO)  production in RAW264.7 cells exposed to LPS