41 research outputs found

    Network Traffic Classification Based on External Attention by IP Packet Header

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    As the emerging services have increasingly strict requirements on quality of service (QoS), such as millisecond network service latency ect., network traffic classification technology is required to assist more advanced network management and monitoring capabilities. So far as we know, the delays of flow-granularity classification methods are difficult to meet the real-time requirements for too long packet-waiting time, whereas the present packet-granularity classification methods may have problems related to privacy protection due to using excessive user payloads. To solve the above problems, we proposed a network traffic classification method only by the IP packet header, which satisfies the requirements of both user's privacy protection and classification performances. We opted to remove the IP address from the header information of the network layer and utilized the remaining 12-byte IP packet header information as input for the model. Additionally, we examined the variations in header value distributions among different categories of network traffic samples. And, the external attention is also introduced to form the online classification framework, which performs well for its low time complexity and strong ability to enhance high-dimensional classification features. The experiments on three open-source datasets show that our average accuracy can reach upon 94.57%, and the classification time is shortened to meet the real-time requirements (0.35ms for a single packet).Comment: 12 pages, 5 figure

    Enzyme-Free Electrochemical Glucose Sensors Prepared by Dealloying Pd-Ni-P Metallic Glasses

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    We report the formation of enzyme-free electrochemical glucose sensors by electrochemical dealloying palladium-containing Pd-Ni-P metallic glasses. When metallic glasses with different Pd contents are used as the dealloying precursor alloys, palladium-based nanoporous metals with different ligament and pore sizes can be obtained. The chemical compositions of the nanoporous metals also vary according to the different precursor compositions. All the as-obtained nanoporous metals exhibit electrochemical catalytic activity towards the oxidation of d-glucose, indicating that the nanoporous metals prepared by dealloying the Pd-Ni-P metallic glasses are promising materials for enzyme-free electrochemical glucose sensor

    Anti-HIV-1 Activity of a New Scorpion Venom Peptide Derivative Kn2-7

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    For over 30 years, HIV/AIDS has wreaked havoc in the world. In the absence of an effective vaccine for HIV, development of new anti-HIV agents is urgently needed. We previously identified the antiviral activities of the scorpion-venom-peptide-derived mucroporin-M1 for three RNA viruses (measles viruses, SARS-CoV, and H5N1). In this investigation, a panel of scorpion venom peptides and their derivatives were designed and chosen for assessment of their anti-HIV activities. A new scorpion venom peptide derivative Kn2-7 was identified as the most potent anti-HIV-1 peptide by screening assays with an EC50 value of 2.76 µg/ml (1.65 µM) and showed low cytotoxicity to host cells with a selective index (SI) of 13.93. Kn2-7 could inhibit all members of a standard reference panel of HIV-1 subtype B pseudotyped virus (PV) with CCR5-tropic and CXCR4-tropic NL4-3 PV strain. Furthermore, it also inhibited a CXCR4-tropic replication-competent strain of HIV-1 subtype B virus. Binding assay of Kn2-7 to HIV-1 PV by Octet Red system suggested the anti-HIV-1 activity was correlated with a direct interaction between Kn2-7 and HIV-1 envelope. These results demonstrated that peptide Kn2-7 could inhibit HIV-1 by direct interaction with viral particle and may become a promising candidate compound for further development of microbicide against HIV-1

    Age-Related Study and Collision Response of Material Properties of Long Bones in Chinese Pedestrian Lower Limbs

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    In forensic examination cases, lower limb injuries are common, and pedestrians of different ages suffer different injuries when they are hit by vehicles, especially the injuries to the long bones of the lower limbs. Aging remains a challenging issue for the material properties and injury biomechanical properties of pedestrian lower limb long bones. We analyzed the regression relationship between the age of 50 Chinese pedestrians and the material properties of the lower limb long bones (femur, tibia). We compared them with previous studies to propose a regression model suitable for Chinese human long bone material properties. Through the established Human Active Lower Limb (HALL) model that conforms to the Chinese human anatomy, seven pedestrians’ (20/30/40/50/60/70/80 years old (YO)) lower limbs were parameterized to assign long bone material properties. In the finite element analysis, the Hall model was side-impacted by a family car (FCR) at speeds of 30/40/50/60/70 km/h, respectively. The results showed that an increase in age was negatively correlated with a decrease in the material properties of each long bone. Moreover, with an increase in age, the tolerance limit of long bones gradually decreases, but there will be a limit, and there is no obvious positive correlation with age. During a standing side impact, the stress change in the femur was significantly smaller than that of the tibia, and the stress of the femur and tibia decreased with age. Age is a more significant influencing factor for lower limb injuries. Older pedestrians have a higher risk of lower limb injuries. Forensic experts should pay attention to the critical factor of age when encountering lower limb traffic accident injuries in forensic identification work

    Tuning Localized Surface Plasmon Resonance of Nanoporous Gold with a Silica Shell for Surface Enhanced Raman Scattering

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    We report the tuning of localized surface plasmon resonance (LSPR) of nanoporous gold (NPG) by silica coating, which also affects the surface enhanced Raman scattering (SERS) of NPG. In this study, controllable silica shell is assembled on the NPG surface, and a fully silica thin layer causes more than 50 nm red-shift of LSPR band due to dielectric medium dependence. Additionally, ~1 nm silica coated NPG film shows excellent SERS enhancement, which is due to electromagnetic coupling between ligaments and local surface plasmon field enhancement within pores, and theoretical analysis indicates that silica coating further improves the coupling effect, which demonstrates the electromagnetic origin of the tuning of SERS effect

    A clean and efficient route for extraction of vanadium from vanadium slag by electro-oxidation combined with ultrasound cavitation

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    Extracting vanadium (V) from vanadium slag (VS) by the traditional roasting-leaching process has disadvantages of high energy consumption and high poisonous gases emission. In this work, a green and efficient route was developed to extract V from VS without roasting by electro-oxidation combined with ultrasound cavitation (EOUC) intensification in sulfuric acid solution. The leaching parameters (e.g., leaching temperature, sulfuric acid concentration, anodic current density, ultrasound power, liquid to solid ratio, leaching time and particle size) were optimized. The leaching mechanism was explored by comparing the leaching behavior and mineralogical evolution of the direct sulfuric acidic leaching (DSL), electro-oxidation-assisted sulfuric acidic leaching (EOSL), ultrasound cavitation-assisted sulfuric acidic leaching (UCSL) and EOUC methods. The results show that introducing electric field strengthens the ultrasound cavitation effect on slag particles in sulfuric acid solution. Under the optimum parameter of EOUC method, the leaching rate of V from VS is as high as 94.64 %. Using EOUC method can open the silicate-wrapped structure of the spinel, increase pore volume of VS from 0.00127 cm3 g−1 to 0.01124 cm3 g−1, decrease slag particle size from 26.8 μm to 16.4 μm and improve specific surface area from 0.508 m2 g−1 to 10.855 m2 g−1, which significantly accelerate V leaching process. The exposed spinel was oxidized by both electrochemical route and chemical route, forming a mixture of V3+ ion and VO2+ ion after leaching
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