网络数据库安全及加密技术

互联网的发展,给网络数据库数据的保密性、完整性和可用性带来了很大的威胁.本文总结了近些年数据库安全技术的发展过程,重点介绍了数据库加密技术的特点及新型的数据加密模式.     

基于ARM处理器的嵌入式WEB服务器的设计与实现

本文主要研究了基于嵌入式系统的WEB服务器的软、硬件实现,其研究核心是三星的S3C2410X微处理器.此外,还对系统的各个模块和嵌入式系统WEB服务器的工作过程进行了具体的分析.     

IPv6下基于病毒过滤防火墙的设计与实现

包过滤防火墙无法检测出网络病毒,因此对其研究很有必要.设计的防火墙屏蔽了Linux自身的TCP/IP协议栈,重新构建了适合防火墙专用的TCP/IP协议栈,完成了防火墙上TCP协议的连接保持、数据包确认、文件传输等功能.防火墙主要考虑了HTTP协议下的文件过滤,使得内网主机在通过HTTP协议下栽文件时自动过滤病毒文件,保证内网主机的安全;防火墙以Linux可加栽内核模块形式实现,可以过滤链路层以上的各层;为提高病毒检测速度,提出了将病毒检测软件运行在核心态的方法.实验结果表明:设计的防火墙在性能和功能上都达到了预期目的.     

舰载武器系统局部故障分析方法与研究

针对舰载电子与武器装备结构复杂、设备数量庞大、分布舱室多、检测点分散不集中等问题,在充分调研论证基础上,以系统局部故障分析研究为切入点,提出适用于舰船武器装备特点的局部故障的分析方法;对系统的局部故障我们采用故障树的方法进行界定,并通过核心路径跟踪技术来确定检测点;采用核心路径在线故障检测方法,有效地节省测试资源,提高测试效率。     

一种时频域联合捕捉主动声纳信号的方法

介绍了一种可应用于被动声纳的时频域联合捕捉主动声纳信号的方法及其工作流程。仿真相同噪声环境下使用该方法的发现距离与主动声纳探测距离,仿真结果表明使用该方法的发现距离远超过主动声纳探测距离,使用该方法可实现对目标的远程发现。     

一种RBAC改进模型及其在军事Web信息系统中的应用

军事Web信息系统要求用户权限必须严格控制、统一管理、维护简便.基于RBAC的访问控制模型能有效弥补DAC和MAC的不足.针对著名的RBAC96模型的缺陷,提出数据资源以业务功能表示、预设角色与用户临时权限的改进角色权限控制模型.该改进方法已经在某军事Web信息系统中得到了应用.     

Substrate-mode holographic polarization-division multi/demultiplexer for optical communications

Based on the diffractive properties of a transmission-type phase volume hologram, a new type of polarization-division multi/demultiplexer for optical communications is presented.     

Effect of the modulation transfer function of a digital image-acquisition device on phase-measuring profilometry

Systematic errors in phase-measuring profilometry that are introduced by the modulation transfer function of a digital image-acquisition device are analyzed. New phase expressions and phase-deviation formulas are given. The results for simulations and experiments demonstrate that the algorithm of phase-measuring profilometry cannot be regarded as a point-to-point operation. To obtain precise results, an optimum scheme for setting the measurement system is also proposed.     

Minimizing Energy Barrier in Intermediate Connection Layer for Monolithic Tandem WPeLEDs with Wide Color Gamut

Perovskite light-emitting diodes (PeLEDs) show promising prospects in the wide color gamut display owing to their ultra-narrow full width at half maximum (FWHM). However, up to now, all perovskite white LEDs integrated by standard red, green, and blue perovskite emitters, namely, monolithic white PeLEDs (WPeLEDs), have been rarely reported, owing to facing some issues, e.g., solvent incompatibility in solution technique, ion exchange, and energy transfer between different emission centers. Herein, centered on these issues, an optimal intermediate connection layer (ICL) of Po-T2T/LiF/Ag/HAT-CN/MoO₃ is adopted to successfully develop monolithic tandem multicolor PeLEDs and WPeLEDs for the first time. The multicolor PeLEDs can achieve the best external quantum efficiency of 1.8% and the highest luminance of 4844 cd m⁻². Besides, the red/green/blue (R/G/B) monolithic tandem WPeLED shows a standard white International Commission on Illumination coordinate of (0.33, 0.33) and achieves an extremely wide color gamut reaching  National Television Standards Committee of 130%. This study is the first to realize the standard R/G/B co-electroluminescence in a monolithic perovskite device and offers a feasible strategy for developing wide-color gamut perovskite displays.     

Point cloud completion via structured feature maps using a feedback network

Computational Visual Media - In this paper, we tackle the challenging problem of point cloud completion from the perspective of feature learning. Our key observation is that to recover the...