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11.
因特网防御DoS攻击技术评述Ⅰ--攻击分类与特征·包过滤·攻击检测与防御 总被引:1,自引:0,他引:1
概述了因特网上DoS攻击的相应分类及基本特征,评述了包过滤、攻击检测及防御技术的最新成果.前一部分介绍了入口过滤、基于路由的过滤网和有效源地址强制协议.后一方面主要讨论了适合于检测攻击包的技术,介绍了新近提出的频谱分析方法和泛滥检测系统.简要评述了已有的防御SYN泛滥攻击的技术措施,介绍了Cisco的TCP拦截技术,提出了改进策略. 相似文献
12.
形态学边缘检测的新算法及其应用 总被引:3,自引:0,他引:3
刘岚岚 《红外与毫米波学报》1998,17(5):386-390
提出了一种基于数学形态学的边缘检测的所算法,该算法具有简便和灵活可编程控制等优点,比原来主算法更国完善,在实际应用中有着很好的前景,并给出了实验结果。 相似文献
13.
14.
水下成像的现状和发展动向 总被引:5,自引:0,他引:5
本文以下水成像在军事,海洋开发工程应用为基础,论述了水下观测和成像中采用微光电视摄像机和激光器件及其系统的技术现状和发展动向。 相似文献
15.
The cutting-edge RGB saliency models are prone to fail for some complex scenes, while RGB-D saliency models are often affected by inaccurate depth maps. Fortunately, light field images can provide a sufficient spatial layout depiction of 3D scenes. Therefore, this paper focuses on salient object detection of light field images, where a Similarity Retrieval-based Inference Network (SRI-Net) is proposed. Due to various focus points, not all focal slices extracted from light field images are beneficial for salient object detection, thus, the key point of our model lies in that we attempt to select the most valuable focal slice, which can contribute more complementary information for the RGB image. Specifically, firstly, we design a focal slice retrieval module (FSRM) to choose an appropriate focal slice by measuring the foreground similarity between the focal slice and RGB image. Secondly, in order to combine the original RGB image and the selected focal slice, we design a U-shaped saliency inference module (SIM), where the two-stream encoder is used to extract multi-level features, and the decoder is employed to aggregate multi-level deep features. Extensive experiments are conducted on two widely used light field datasets, and the results firmly demonstrate the superiority and effectiveness of the proposed SRI-Net. 相似文献
16.
Zheyuan Fan 《International Journal of Communication Systems》2022,35(1):e4755
Grid technology based on parallel theory is used to study a large amount of data processing. This research mainly discusses the fault detection of grid dynamic system in a big data environment. In order to verify the communication efficiency between different security nodes of the ZSS system under different operating system conditions, this study will use four physical computers and VM Ware software to establish a simulated communication environment, using GlobusToolkit (GT)'s existing deployment mechanism to realize the overall grid dynamic deployment architecture. Using Web service technology remotely calls the monitoring module interface of resource nodes in the domain and uses standard protocols to send monitoring data. At the same time, in order for the management node to save the monitoring data in the local standardized form of XML, the administrator can use the saved historical data to process system failures, analyze, and predict system performance. In order to solve the problem of information explosion, a fault detector is used to precisely control the cost of message detection and the state distribution of the detection result and the time of message delay. Under special circumstances, it takes 60 min to execute a 30-min job, and the fault detection point consumes an average of 54.33 min. The research results show that the fault-tolerant strategy can improve the performance of resource consumption in the fault-tolerant tracking system. Adopting the method of dynamically adjustable detection interval can effectively reduce the overhead of the grid dynamic system. The detection method used in this study can meet the application requirements of the grid. 相似文献
17.
Summary The highly complex matrix of diesel particulate extracts was analyzed for nitrated polycyclic aromatic hydrocarbons (nitro-PAH)
using fused-silica capillary-column gas chromatography along with a thermionic nitrogen-phosphorus detector (TID) and high-performance
liquid chromatography followed by on-line catalytic reduction of the nitro-PAH to amino-PAH and subsequent fluorescence detection.
Positive isomer identification and quantitation of nitro-PAH are from retention times of authentic standards and their mass
spectra. The ease of nitro-PAH formation by nitration of PAH raises the question regarding the origin of these species, whether
they are produced as “native” products during the engine combustion process and/or in the exhaust, or instead, formed as the
result of chemical conversion to produce artifacts during the sampling procedure. This problem is assessed examing 1-nitropyrene-concentration
in particulates of three light-duty diesel engines for different sampling times. 1-Nitropyrene concentrations show only a
moderate increase with sampling time under average sampling conditions.
Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984 相似文献
18.
M. R. Gregg 《Chromatographia》1985,20(2):129-133
Summary Electrode surface modification by electrochemical pretreatment of glassy carbon electrodes was shown to enhance significantly the sensitivity of the electrodes for the detection of timolol and oxprenolol, but reduce slightly the sensitivity to prenalterol. This method may permit the detection of exprenolol and timolol with increased sensitivity, or may allow their detection at lower applied potentials than is presently possible. Electrode surface modification may prove to be a valuable aid to the detection of compounds that are considered to be outside the practical limits of electrochemical detection. 相似文献
19.
Summary Clenbuterol has been determined in urine by solidphase extraction on a C18 cartridge, diazotization of the eluate with nitrite, coupling of the diazonium ion with 1-(naphthyl)ethylenediamine, and
separation of the azo dye formed by HPLC with a C18 column and a micellar mobile phase containing 0.1 M sodium dodecyl sulphate, 12%n-butanol and 0.05 M citrate buffer, pH 3. Recoveries higher than 90% were obtained by mixing the samples with a 20% 0.2 M
NaOH before extraction. Limits of detection of 51 and 6.7 ng L−1 were obtained with spectrophotometric and thermal lens spectrometric detection, respectively; respective repeatabilities
were 3.1% (5 μg mL−1) and 5.6% (0.16 μg mL−1). 相似文献
20.
Roger M. Smith 《Chromatographia》1982,16(1):155-157
Summary The pungent principles of ginger and grains of paradise are examined using a reversed-phase HPLC column. An electrochemical detector is used to selectively detect the phenolic gingerols and shogaols. The retention indices of the compounds are compared using methanowater and acetonitrile-water as eluents.Presented at the 14th International Symposium on Chromatography London, September, 1982 相似文献