基于ADASYN与改进残差网络的入侵流量检测识别

针对现有入侵流量检测模型分类准确率低、小样本特征提取不足等问题,提出了一种基于自适应合成采样和Inception-Resnet模块的改进残差网络算法。该算法能够对不平衡数据集进行采样优化,有效提升模型的小样本特征提取能力。首先,通过对不平衡的数据训练集进行过采样改善数据分布,然后对非数据部分进行独热编码处理并与数据部分整合,降低预处理复杂度,最后利用改进残差网络模型进行数据训练,并进行性能评估和算法效能对比。实验结果表明,改进残差网络模型对入侵流量的检测准确率在多分类和二分类情况下分别达到89.40%和91.88%。相比于经典深度学习算法,改进残差网络模型的准确率更高,误报率更低,具备较高的可靠性和工程应用价值。

双层土壤系统中污染气体入侵建筑物流量的解析公式

加拿大阿尔伯塔省中部地区存在大量的上层是细颗粒土壤、下层是粗颗粒土壤的被石油烃(PHC)污染的双层土壤系统。针对这类土壤系统,本文构造出不同与J&E模型的解析公式,以初步估计被石油烃污染的土壤或地下水挥发出的有机气体入侵建筑物的流量。应用ECCLIPSE-2003a软件对该区某污染场进行了数值模拟,以验证该公式。结果表明:在这类双层土壤系统中,该公式是有效的。

一种有效的并行入侵检测系统流量分配策略

流量分配是影响并行入侵检测系统实时性的重要因素。首先提出了一种以局部时间内探测节点的负载平衡为目标,综合考虑探测节点的负载和处理能力的动态流量分配策略;然后通过引入负载平衡的粒度、益处估计,提出了一种动态负载平衡策略,达到了全局时间内探测节点的负载平衡;最后通过实验分析表明该策略是有效的。

基于多维指纹建模筛选机制的物联网反入侵算法研究

针对当前物联网反入侵算法存在入侵监测准确性较低,且难以适应动态入侵环境等不足,提出了一种基于多维指纹建模筛选机制的物联网反入侵算法。首先,基于数据挖掘思想,综合考虑攻击行为集合及其分布特征,采用匹配方式均衡节点缓存资源,分流攻击行为,提高网络在遭受入侵情况下的对攻击行为的命中,增强网络鲁棒性能;随后,针对入侵过程存在峰值特性,使用递归方式构建节点攻击行为模型,采取线性反序映射来获取攻击行为弹性系数并降低恶意节点入侵成功率,挖掘网络入侵行为的纳什均衡解,有效提高对恶意攻击行为的过滤效率。仿真实验表明:数据聚合-QOS联合检测算法(QoS-Aware Hybrid Data Aggregation Scheme,QA-HDA算法)、能量感知筛选监测算法(Energy-Aware Perception Algorithm,EAP算法)相比,在遭受入侵时,所提算法具有更高的临界性能及的入侵流量过滤能力。

A Study on Alien Invasive Plants from the Interactive Mechanism between Species Niche and Material/Energy Flow

[Objective]This study was to reveal the essence of mechanism about how the alien invasive plants spread.[Method]Species niche and material/energy flow were used as basic research indicators to analyze the intrinsic mechanism of alien plants invasion.[Result]Most of the invasive plants have not been explicitly defined and their effective control methods not brought forward.[Conclusion]Overrun of alien invasive plants depends on whether the niche of a species could be continuously met at spatial level.Based on this we put forward corresponding control measures,proposed an assumption to establish a cylinder-network model and discussed the definition of alien invasive plants.

Assessment of Saline Water Intrusion into Huong River in Dry Season

Most rivers in Vietnam flow directly to the sea where the interaction between fresh and salt water occurs. Because of uneven flow distribution through the year with only 20% annual flow in the dry season, while fresh water requirement for socio-economic activity in this season is much higher. With this situation, the simulation and finding out the mechanism of saline water intrusion into the estuary in general will help to suggest suitable solutions to control the situation. This paper presents results done at the Huong river estuary. Based on the data collected in current years and using MIKE11 softwave, number scenarios were simulated and found out the intruded process of saline water into the river. They will be very important parameters for which solutions to control negative effects to serve socio-economic development at the downstream of Huong river will be recommended and implemented in the later stage.

The Effects of Protruding Rock Boulders in Regulating Sediment Intrusion within the Hyporheic Zone of Mountain Streams

Excessive sedimentation in mountain stream ecosystems is a critical environmental problem due to the clogging of streambeds by sediment particles within the hyporheic zone,with detrimental effects on fish spawning habitat.In this research,the effects of an array of boulders in regulating the intrusion of incoming sand within a gravel substrate were evaluated by performing detailed experiments in a laboratory flume.A unique experimental setup and two different sampling techniques were utilized for measuring the infiltrated sand within the gravel bed under two bed shear stress conditions(moderate vs.high).For comparison purposes,experiments were performed without and with the presence of partially submerged to the flow(protruding) boulders,which is typical for the average flow conditions found in mountain streams.Results indicated that sand infiltrated primarily in the upper part of the gravel bed creating a surface seal which hindered the penetration of sand particles deeper into the bed.An exponential decrease of the amount of the infiltrated sand within the hyporheic zone was observed in all experiments regardless of the presence of boulders.However,the presence of boulders promoted sediment intrusion of sand particles especially for the moderate applied bed shear stress condition,since the total amount of the infiltrated sand was found to be on average 44% greater whenboulders were present.The findings from this study can provide additional insight regarding the role of boulders on promoting downwelling of flow and sediment within the gravel substrate with potential effects on fish habitat.

Impacts of wind stress on saltwater intrusion in the Yangtze Estuary

The observation at the Chongxi gauging station indicated the salinity of saltwater spilling over from the North Branch to the South Branch increased abnormally from November 10 to 12 in 2009 (during neap tide) and from February 11 to 12 in 2010 (during moderate tide).We found for the first time that the strong northerly wind was responsible for the above abnormal salinity increase.Previous studies indicated that the saltwater intrusion in the Yangtze Estuary is influenced mainly by the river discharge,the tide,and the wind stress,but the impacts of variations of wind speed and direction on it have not been investigated.In this study the impacts of wind stress on the saltwater intrusion were numerically simulated and the associated mechanisms were analyzed.The model results were consistent with the observed data obtained at six gauging stations during February and March in 2007 and four gauging stations in March 2008,and the abnormal salinity risings were well captured.Meanwhile,if the wind speed is reduced by half,the salinity there will be significantly decreased.Driven by the monthly mean river discharge of 11000 m 3 /s and northerly wind of 5 m/s from January to February,the model simulated the temporal and spatial variation of saltwater intrusion.The wind-driven circulation,as well as the net water and salt fluxes from the North Branch into the South Branch,was calculated and analyzed in the cases of different wind speeds and directions.The results indicated that the intensity of the saltwater intrusion in the Yangtze Estuary is significantly influenced by the wind speeds and directions.