蜜罐识别技术研究

蜜罐技术是一种欺骗入侵者以达到采集黑客攻击方法和保护真实主机目标的诱骗技术,它的核心价值在于被探测、被攻击或者被威胁,以此达到对这些攻击活动的检测与分析,从而了解攻击者的目的、攻击手段甚至于心理习惯,最终实现从观察攻击者的行为中学习到深层次的信息保护的方法。在蜜罐技术的应用过程中,最为关键的一点就是蜜罐系统对攻击者所具有的迷惑性。从蜜罐系统特有的系统特征、硬件特征以及网络特征出发,分析各种蜜罐系统或者虚拟机系统中可能存在的一些可识别的特性,提出一些识别方案并针对部分方法进行了编程识别,希望能够引起安全行业的重视,能够推动蜜罐技术的发展。     

超空泡图像的自适应多尺度小波边缘检测

针对水下高速射弹试验获取的超空泡图像中夹杂较多噪声,而传统边缘检测算法在自动边缘检测中抑制噪声效果差的问题。文中采用自适应多尺度小波边缘检测,对超空泡图像进行边缘检测。算法中首先对图像进行多尺度下的小波变换和相邻尺度间的梯度增强,再采用K均值聚类进行边缘的自动检测,得到不同尺度下的边缘,根据小波基的不同选择对应的多尺度融合方法进行多尺度融合,得到最终的边缘图像。实验表明,文中算法相比传统边缘检测算法,有效地抑制了图像中噪声,得到了更完整的边缘信息。     

基于SRS优先级划分及时移传输机制的SL空口同步方案

在LTE-V2X（long term evolution-vehicle to everything）系统中,存在部分车载用户无法获取基站的同步参考信号（synchronization reference signal,SRS）,从而无法与网络进行通信的问题。为解决这一问题,提出一种副链接（sidelink,SL）空口同步方案。车载用户根据SRS优先级划分机制选择最优的SRS,同时可获取该SRS的优先级以及确定自身发送SRS的优先级;并设计SRS时移传输机制使得不同优先级SRS在不同时帧上传输来区分优先级,与此同时还可有效抑制同频干扰。仿真结果显示,该方案在同步源优先级为 4 个等级时,同步定时误差均满足车载用户的同步需求。本文所提方案不仅扩大了空口同步范围,还可以有效抑制车载用户之间的同频干扰,可作为LTE-V2X系统实现有效可行的空口同步方案之一。     

一种改进的电力线通信系统脉冲噪声抑制方法

为了抑制脉冲噪声对电力线正交频分复用（OFDM）通信系统的影响,最常用的方法之一是在接收端OFDM解调器之前前置一个置零非线性单元,即传统置零法。然而,由于引入了非线性失真,其性能并不理想。针对传统置零法引起的非线性失真问题,提出了一种基于迭代消除非线性失真的改进置零法。首先,对接收到的时域OFDM信号进行脉冲噪声检测和置零处理;然后,在频域利用已检测的符号来重构时域置零处理引入的非线性失真,并通过迭代提高重构的准确性;最后,从频域接收信号中减去重构的非线性失真。仿真结果表明,所提改进算法与传统置零法相比,有非常大的性能提升,增强了电力线OFDM通信系统对脉冲噪声的抵抗能力。     

Markov game modeling of mimic defense and defense strategy determination

Network mimic defense technology enhances the robustness of active defense through the redundancy,dynamic and diversity as well as the decision feedback mechanism.However,little work has been done for its security assessment and existing classic game models are not suitable for its dynamic characteristics and lack of universality.A Markov game model was proposed to analyze the transfer relationship between offensive and defensive status and the measurement method of safety and reliability of mimic defense,and calculated the offensive and defensive game equilibrium through non-linear programming algorithm to determine the best defensive strategy considering performance.Experiments give a comparison with the multi-target hiding technique and shows that the mimic defense has a higher defensive effect.Combining with the specific network case,the specific attack and defense path for the exploit of the system vulnerability is given and the effectiveness of the defense strategy algorithm is verified.     

RPMA low-power wide-area network planning method based on data mining

A network planning method based on data mining was proposed for RPMA low-power wide-area network with large density of base stations and uneven traffic distribution.First,a signal quality prediction model was established by using the boosting regression trees algorithm,which was used to extract the coverage distribution spacial pattern of the network.Then ,the weighted k-centroids clustering algorithm was utilized to obtain the optimal base station deployment for the current spacial pattern.Finally,according to the total objective function,the best base station topology was determined.Experiment results with the real data sets show that compared with the traditional network planning method,the proposed method can improve the coverage of low-power wide-area networks.     

构建一种新型综合性课程的探索

本文针对现有课程设置过程中,课时和知识内容之间的矛盾,借鉴现有综合课程设计的研究成果,提出以实践内容为主体构建综合性课程的方式解决课时安排的矛盾.具体构建方式是以实践类综合设计为平台,在课程中加入新的理论知识,即要求学生在实践中自学理论知识.本文提出的构建方式具有很强的实用性,对于现有教学中存在的一些问题具有很好的指导...     

基于SystemVerilog的I^2C总线模块验证

针对I2C总线模块,介绍了一种基于Systemverilog验证环境的验证IP设计。这种基于面向对象设计的验证架构可以很容易地被重用。文中分析了基于Systemverilog验证环境的结构,并在介绍I2C总线协议的基础上,重点论述了验证环境中事务产生器及驱动器的设计     

Research on algorithm for raster map multi-level sharing based on region incrementing color visual cryptography

In view of the characteristics of raster map,important data of the map were divided into different map layers by using the idea of map segmentation.A regional incremental color visual cryptographic scheme for raster map sharing was designed,and a model based on this scheme was proposed.At the same time,the specific application process was given.In order to solve the problem of large pixel expansibility and poor visual effect of image recovery in traditional regional incremental visual cryptography scheme,random numbers and the access structure optimization were used.Construction of the method was simple and the additional overhead of generating and saving the encryption matrix was avoided.The experimental results show that the scheme can achieve multilevel raster map sharing with the map’s perfect recovery,meanwhile the extension of the scheme pixel is greatly reduced.     

硅基金字塔结构光控太赫兹调制器

提出一种硅基金字塔结构光控太赫兹波调制器。通过化学刻蚀方法在高阻硅基底形成微米级的金字塔结构,研究该结构与高阻硅片对激光的反射率及对太赫兹的调制情况。实验表明,金字塔结构可有效降低激光反射率,提升激光利用率,并且通过增加太赫兹波调制面积,达到显著增强太赫兹波的调制效果,其调制深度达到90%以上。该硅基金字塔结构光控调制器可在极低的激光功率下工作,具有宽带、大幅度调制的特点,在太赫兹成像领域具有重要应用价值。