在线测试平台安全性问题与具体解决方案

程序设计在线测试平台(简称OJ)是程序设计类课程训练、比赛、测试中支撑平台。由于它的开放性,存在着许多不安全的因素。本文探讨了OJ平台网页等方面存在的安全问题,以及防卫的措施。     

新能源汽车高压部件低频传导抗扰度测试系统研制

当前在新能源汽车电磁兼容领域,低压零部件的产品测试已经非常成熟.随着自动驾驶以及新能源汽车的自动化的提高,高压零部件不断增加,针对高压零部件的电磁兼容测试也不断增加.最新的国际标准ISO DTS 7637-4:2020技术草案中,已将低频传导抗扰度测试列入其中,因此,针对这种线缆耦合方式的新能源汽车高压部件低频传导抗扰...     

基于随机性测试的SNOW 2.0算法部件分析与改进

SNOW族算法是目前序列密码算法设计的一个主流方向。针对SNOW族算法现有的安全漏洞,该文以最具代表性的SNOW 2.0算法为研究对象,采用随机性测试方法对其多个域上模加、非线性S盒以及线性反馈移位寄存器(LFSR)3个核心部件进行分析,提出基于随机S盒和高性能LFSR等部件改进的多套改进方案,有效提升SNOW族算法的安全性和实现性能。     

新能源高压产品电磁兼容测试标准分析与解读

随着电动汽车的高速发展,新能源高压产品需求较大,单体所导致的电磁兼容问题越来越多,为了更好的管控和测试高压产品,本文主要对目前国际国内电磁兼容测试标准进行了分析和解读,结合高压产品测试实际测试经验,总结了高压产品测试结果的影响因素、测试方法的差异。     

GSM手机测试问题与分析

对GSM手机在进网测试中出现的功能、性能等方面的问题进行了列举和分析。     

H.248/MEGACO协议安全性分析与测试

H.248/MEGACO协议是目前媒体网关和媒体网关控制器之间的主流控制协议。面对复杂、开放的应用环境,H.248/MEGACO协议同样也面临着安全威胁。本文在对H.248协议进行分析的基础上,结合举例,对伪装攻击、报文解析健壮性及DoS攻击这3方面提出了一些有针对性的安全性测试方法。     

手机应用软件安全性测试

为了应对手机应用日益广泛所面临越来越严重的安全风险,通过对手机应用软件的使用特点及其面临安全风险进行分析,选取相应的安全测试策略,从安装与卸载、程序访问权限、数据安全性、通讯安全性以及人机接口安全性等方面进行手机应用软件的安全性测试,并详细列出了每个测试内容的测试要点和检查单,可以有效指导安全测试工作的开展.     

IDS及其安全性测试

网络入侵手段的不断变化,使得人们对IDS 的功能、性能的要求也在不断变化。那么,IDS 安全性测试的要求和方法具体有哪些?请关注本文。     

枕头效应的测试与预防

在PCB上组装BGA或CSP时,产生的枕头效应(HIP)令电子制造业很苦恼.枕头效应是由于在再流焊接过程中元件或板子翘曲所引起的,且氧化作用会使枕头效应更为严重.行业急需用于评估可能产生HIP的方法.除了介绍染色法外,还介绍了另外两种简单的方法小滴焊膏法(Tiny Dot Paste)和焊膏上焊球法(Ball Onto Paste).小滴焊膏法重点评估焊膏的抗氧化能力.焊膏上焊球法评估抗氧化性和助焊剂组合能力.这两种方法均是快速、简易和高度仿真的方法,而后者在实际工艺仿真过程中效果更好一些.     

EEG-based drowsiness estimation for safety driving using independent component analysis

Preventing accidents caused by drowsiness has become a major focus of active safety driving in recent years. It requires an optimal technique to continuously detect drivers' cognitive state related to abilities in perception, recognition, and vehicle control in (near-) real-time. The major challenges in developing such a system include: 1) the lack of significant index for detecting drowsiness and 2) complicated and pervasive noise interferences in a realistic and dynamic driving environment. In this paper, we develop a drowsiness-estimation system based on electroencephalogram (EEG) by combining independent component analysis (ICA), power-spectrum analysis, correlation evaluations, and linear regression model to estimate a driver's cognitive state when he/she drives a car in a virtual reality (VR)-based dynamic simulator. The driving error is defined as deviations between the center of the vehicle and the center of the cruising lane in the lane-keeping driving task. Experimental results demonstrate the feasibility of quantitatively estimating drowsiness level using ICA-based multistream EEG spectra. The proposed ICA-based method applied to power spectrum of ICA components can successfully (1) remove most of EEG artifacts, (2) suggest an optimal montage to place EEG electrodes, and estimate the driver's drowsiness fluctuation indexed by the driving performance measure. Finally, we present a benchmark study in which the accuracy of ICA-component-based alertness estimates compares favorably to scalp-EEG based.     

医用B超多普勒功能图像质量安全检测分析

随着医疗技术的不断发展，医疗超声诊断在各个领域已经广泛应用，医用B超多普勒诊断仪是利用不同类型组织间的声学差异特征或者生理结构发生的不同物理反应所产生的效应，这种效应经过不同的超声检查。本文就以综述的形式对医用B超多普勒功能图像质量的安全检测进行分析。     

电子安全与解除保险装置安全性测试方法

通过分析电子安全与解除保险装置的原理,得出了实现安全与解除保险逻辑的两片独立IC器件对保证全电子安全系统的安全性至关重要。针对使用FPGA实现的独立IC器件,引进嵌入式软件黑盒测试技术来对其进行测试。结合相关国军标给出了对安全与解除保险逻辑电路测试的要求,并以解除保险逻辑形式中的一种为例,说明了对安全与解除保险逻辑电路进行测试的测试用例的生成方法。     

电力系统高压电气试验技术及其重要性分析

电力已经成为人们生活中不可或缺的重要组成部分,因此,电力系统的保护工作应引起高度重视.电力系统中存在着大量的电力设备,其中绝大多数将对现有的电力系统产生不利的影响,甚至造成巨大的损失.因此电性试验工作量大,工作复杂,如果不注意控制有关问题,将会造成严重的财产损失和人员伤亡.以电试及其重要性为出发点,对我国电力系统电试中...     

电力系统高压电气试验技术及其重要性分析

为保证电力资源的稳定输出和电力系统安全稳定的运行,通常采取电力系统高压电气试验来检测供电线路。本文主要概述了电力系统高压电气试验技术及其重要性。     

High voltage electron lithography

Experiments with a 50 keV electron beam confirmed that backscatter exposure close to pattern edges is reduced substantially compared with the lithographic experience at 20 keV. This, together with reduced beam spreading in the resist, permits improved definition of low micrometre and submicrometre features at a uniform dose.     

Defect localization using voltage contrast IDDQ testing

I_DDQ testing detects a majority of faults occurring in logic,ICs. Nethertheless, it has not eliminated the complex task of fault isolation at the silicon level of ICs.Liquid Crystak or Emission Microscopy can deal with this challenge. Unfortunately these two techniques lack sensitivity for some defects when the abnormal current consumption (I_DDQ) remains weak.On the other hand we can use very powerful tools like the electron beam tester to deeply analyze faulty devices by internal contactless testing. In some laboratories, people have underlined the interest of merging the two techniques (I_DDQ testing and Voltage Contrast) to get fast and accurate defect localization. In this paper, we will move on to the next step of identifying practical key issues necessary for obtaining results on current VLSI.     

High voltage electron beam lithography

The advantage of high voltage electron beam lithography in submicron VLSI fabrication is outlined. Continuously-moving-stage EB systems with small deflection width are suited to high voltage electron beam machines. At 50 kV, the following experimental results were obtained:

• 1.(1) 0.75 μm lines of PMMA are formed on a 0.8 μm step.
• 2.(2) Dimension deviation from designed size due to proximity effect is below ±0.1 μm for line or space, ranging from 0.25 μm to 30 μm, adjacent to a large area.
• 3.(3) Dosages, required to obtain a resist pattern with vertical walls, are 50μC/cm² at 50 kV and 100 μC/cm² at 20 kV.
• 4.(4) Accurate position detection for a mark covered with thick overlayers can be achieved at 50 kV, but not at 20 kV.

     

High voltage GaN Schottky rectifiers

Mesa and planar GaN Schottky diode rectifiers with reverse breakdown voltages (V_RB) up to 550 and >2000 V, respectively, have been fabricated. The on-state resistance, R_ON , was 6 mΩ·cm² and 0.8 Ω cm² , respectively, producing figure-of-merit values for (V_RB )²/R_ON in the range 5-48 MW·cm^-2 . At low biases the reverse leakage current was proportional to the size of the rectifying contact perimeter, while at high biases the current was proportional to the area of this contact. These results suggest that at low reverse biases, the leakage is dominated by the surface component, while at higher biases the bulk component dominates. On-state voltages were 3.5 V for the 550 V diodes and ⩾15 for the 2 kV diodes. Reverse recovery times were <0.2 μs for devices switched from a forward current density of ~500 A·cm^-2 to a reverse bias of 100 V