Web应用系统的渗透测试研究

介绍了当前的信息安全形势,阐述了在信息安全等级保护工作中,Web应用系统渗透测试的重要性,以及Web应用系统的主要安全弱点及对其渗透测试的实施方法,以提高渗透测试的有效性与准确性。     

南水北调中线穿黄工程盾构机刀具维护技术

南水北调中线穿黄隧洞工程地质条件复杂,隧洞穿越地层有全砂层、全土层及上砂下土的复合地层。盾构机刀盘设计采用软土型刀具、重载型刀盘传力架,并采取了多种防磨损措施,以保护刀盘具。但在盾构施工过程中,掘进参数出现异常,且在出渣物中发现金属件,表明盾构机刀盘具受到严重磨损。通过带压进仓检查,及时查清了情况,更换了部分刀具,对需要修复的刀具,在对地基进行加固后,采用常压进舱方案,进行了彻底修复。本次刀盘具检查维护的经验,对于保证穿黄工程的顺利掘进具有重要的指导意义,对于其他类似工程也有重要的参考价值。     

Attainability of the minimum data rate for stabilization of linear systems via logarithmic quantization

This paper investigates the attainability of the minimum average data rate for stabilization of linear systems via logarithmic quantization. It is shown that a finite-level logarithmic quantizer suffices to approach the well-known minimum average data rate for stabilizing an unstable linear discrete-time system under two basic network configurations. In particular, we derive explicit finite-level logarithmic quantizers and the corresponding controllers to approach the minimum average data rate.     

A comment on: “Fast and numerically stable methods for the computation of Zernike moments” by Singh et al. [Pattern Recognition, 43(2010), Pages 2497-2506]

The aim of the present comment is to point out that the q-Recursive relation introduced by Singh et al. is wrong. These errors have been corrected in the comment. The numerical experiments show that the correct recurrence relation is consistent with the original q-Recursive method.     

Model selection for zero-inflated regression with missing covariates

Count data are widely existed in the fields of medical trials, public health, surveys and environmental studies. In analyzing count data, it is important to find out whether the zero-inflation exists or not and how to select the most suitable model. However, the classic AIC criterion for model selection is invalid when the observations are missing. In this paper, we develop a new model selection criterion in line with AIC for the zero-inflated regression models with missing covariates. This method is a modified version of Monte Carlo EM algorithm which is based on the data augmentation scheme. One of the main attractions of this new method is that it is applicable for comparison of candidate models regardless of whether there are missing data or not. What is more, it is very simple to compute as it is just a by-product of Monte Carlo EM algorithm when the estimations of parameters are obtained. A simulation study and a real example are used to illustrate the proposed methodologies.     

高精度多径时延估计

提出了一种无线信道多径时延估计模型,将时廷估计问题转换为频谱估计问题,再利用具有高频谱分辨力的多重信号分类(MUSIC)算法和root MUSIC算法实现对信道多径时延的超分辨率估计,分析了基于单次测量数据进行时延估计的可行性.仿真并测试了MUSIC算法和root MUSIC算法应用于单次测量数据的性能.仿真结果表明,...     

苯-环己烷体系萃取精馏溶剂的计算机筛选

为了对苯-环己烷体系进行萃取精馏溶剂的计算机筛选,采用了基于UNIFAC分子设计方法并结合Aspen数据库进行了萃取精馏溶剂的初步筛选。利用全塔模拟筛选法对初选溶剂做了进一步的筛选,获得了效果较好的一组溶剂为：含氮杂环化合物-NMP、酰胺类-DMF、醇类-四甘醇、三甘醇等。得出结论酯类和酸类分离效果一般,酯类化合物中分...     

合成氨工艺参数优化技术开发及应用

以氨净值为响应值,影响响应值的17个过程参数为变量,经逐步回归选入触媒温度左3,触媒温度左4,循环CH_4%,H/N,NH_3%(进口)5个过程参数建立预测方程,并根据该方程对响应值的拟合结果和误差分布对样本进行分类。在此基础上,采取图形显示技术和统计分析的方法对分类样本集的过程参数进行比对分析,由此获取优类信息制订优化的工艺参数方案,经仿真验证后用于指导合成氨装置的生产试验。试验结果与试验前的对照期比较,氨净值均值由13.86提高到14.54,吨氨气耗减少15.9887m~3,吨氨电耗减少15.8kWh,节能效益十分明显