基于人体关节点数据的攻击性行为识别

针对人体攻击性行为识别问题，提出一种基于人体关节点数据的攻击性行为识别方法。首先，利用OpenPose获得单帧图像中的人体关节点数据，并通过最近邻帧特征加权法和分段多项式回归完成由人体自遮挡和环境因素所导致缺失值的补全；然后，对每个人体定义动态"安全距离"阈值，如果两人真实距离小于阈值，则构建行为特征矢量，其中包括帧间人体重心位移、人体关节旋转角角速度和发生交互时的最小攻击距离等；最后，提出改进的LightGBM算法w-LightGBM，并对攻击性行为进行识别。采用公共数据集UT-interaction对所提出的攻击性行为分类识别方法进行测试实验，准确率达到95.45%。实验结果表明，所提方法能够有效识别各种角度的攻击性行为。     

GreyFan:一种Wi-Fi隐蔽信道攻击框架

针对现实网络中诸如侧信道攻击、HID 攻击等传统的物理攻击，物理隔离被认为是一种较为彻底的抵御网络攻击的安全防护手段。2018 年，业界首次提出了一种物理隔离环境下的 Wi-Fi 隐蔽信道方法——Ghost Tunnel，即在Wi-Fi尚未连接的状态下，无线AP可成功将数据传给发起连接请求的计算机。提出了一种基于Ghost Tunnel方法的攻击框架—— GreyFan，利用该攻击框架攻击者可以对未连接Wi-Fi的用户实施无感知攻击，如文件隐蔽传输、任意代码执行等，并分析了相应的防御技术。     

Glass and Jamming Rheology in Soft Particles Made of PNIPAM and Polyacrylic Acid

The phase behaviour of soft colloids has attracted great attention due to the large variety of new phenomenologies emerging from their ability to pack at very high volume fractions. Here we report rheological measurements on interpenetrated polymer network microgels composed of poly(N-isopropylacrylamide) (PNIPAM) and polyacrylic acid (PAAc) at fixed PAAc content as a function of weight concentration. We found three different rheological regimes characteristic of three different states: a Newtonian shear-thinning fluid, an attractive glass characterized by a yield stress, and a jamming state. We discuss the possible molecular mechanisms driving the formation of these states.     

Phishing attacks discovery based on HTML layout similarity

Based on the similarity of the layout structure between the phishing sites and real sites,an approach to discover phishing sites was presented.First,the tag with link attribute as a feature was extracted,and then based on the feature,the page tag sequence branch to identify website was extracted,followed by the page layout similarity-HTMLTagAntiPhish,the alignment of page tag sequence tree into the alignment of page tag sequence branches was converted,this converted two-dimention tree structure into one-dimention string structure,and finally through the substitution matrix of bioinfor-matics BLOSUM62 coding,alignment score quickly to improve the phishing sites detection efficiency was computed.A series of simulation experiments show that this approach is feasible and has higher precision and recall rates.     

基于俯冲攻击的导弹先进制导律研究

为了能有效打击各种干扰目标,根据现代战场中各种干扰样式及其干扰途径,本文分析了经典制导律在对付干扰目标时的缺点;根据俯冲能规避干扰目标的方案和先进制导律的优点,分析了先进制导律在对付干扰目标的优点;最终,实现运用先进制导律有效攻击干扰目标的目的.     

基于DRFM技术的投掷式干扰机系统设计

现代雷达具有很强的抗副瓣和非相参干扰的能力,目前在我国周边有较强军事实力的国家都部署了相应的雷达防空体系。针对这些防空体系需要采取相应的干扰措施,在已有工作的基础上,提出了一种基于数字射频存储器(DRFM)技术的投掷式干扰机系统设计,分析了系统组成,关键指标以及各种干扰模式的干扰功率需求和实现方法等。     

Structural robustness of city road networks based on community

Road network robustness is the ability of a road network to operate correctly under a wide range of attacks. A structural robustness analysis can describe the survivability of a city road network that is under attack and can help improve functions such as urban planning and emergency response. In this paper, a novel approach is presented to quantitatively evaluate road network robustness based on the community structure derived from a city road network, in which communities refer to those densely connected subsets of nodes that are sparsely linked to the remaining network. First, a road network is reconstructed into a set of connected communities. Then, successive simulated attacks are conducted on the reconstructed road networks to test the performance of the networks under attack. The performance of the networks is represented by efficiency and the occurrence of fragmentation. Three attack strategies, including a random attack and two intentional attacks, are performed to evaluate the survivability of the road network under different situations. Contrary to the traditional road segment-based approach, the community-based robustness analysis on a city road network shows distinct structural diversity between communities, providing greater insight into network vulnerability under intentional attacks. Six typical city road networks on three different continents are used to demonstrate the proposed approach. The evaluation results reveal an important feature of the structure of city road networks from a community-based perspective, i.e., that the structure is robust under random failure but fragile under intentional attack. This result is highly consistent in different city road network forms.     

炮弹无线电引信干扰区域模型

对炮弹无线电引信实施干扰,使炮弹提前引爆,是降低炮弹毁伤能力的有效手段;合理地确定炮弹无线电引信干扰区域是实施干扰的首要条件。建立干扰区域模型,并对模型进行了求解,最后给出了结论。     

Effect of fine crack width and water cement ratio of SHCC on chloride ingress and rebar corrosion

SHCC (Strain Hardening Cement-based Composite) is a material known for its strain-hardening behavior under tensile and bending stress and its characteristic numerous small cracks. SHCC is expected to show superior durability because of the fineness of the cracks. In this study, chloride ingress through cracks into SHCC and progress of rebar corrosion in three mixtures of SHCC with various water-cement ratios were investigated. Through a chloride solution immersion test, it was confirmed that chloride could penetrate through even very fine cracks. The resistivity of cracked SHCC against chloride ingress is mainly governed by the accumulated crack width and the water cement ratio. Chloride pre-mixed SHCC specimens were left in a high-temperature, high-humidity chamber for 11 months to promote rebar corrosion. While the accumulated crack width and the water cement ratio were both influential to an increase in corrosion area, only the water cement ratio had bearing on corrosion loss.