eMMC可靠性分析与增强对策研究

eMMC是可以自我管理的闪存（NAND flash）芯片,内部集成了控制器,实现了多芯片封装,简化了应用接口设计,节省了板级空间,在移动终端领域得到了广泛应用。然而,基于flash的存储器件在掉电时容易出现比特位损坏、元数据损坏、非串行写、甚至器件不可用等可靠性问题。针对如何提高eMMC的可靠性进行了研究,提出了一些可靠性增强措施。首先,全面梳理了eMMC规范提供的可靠性特性,包括分区管理、写保护管理、可靠写、数据标签、断电通知等。继而对现有的各种可靠性措施进行了综合分析,并提出了一些提升可靠性的措施,包括,文件系统感知的磨损均衡、根据数据属性映射到合理分区、减少写入次数降低写放大效应,面向手机应用的元数据去冗、应用差异化细粒度控制可靠性、确保一致性的前提下减少日志等。     

备用复式控制系统的可靠性预计及其应用

本文全面分析了备用复式系统的可靠性问题,推导出成套的预计公式并给出一个详细的计算实例. 首先,通过考虑监控器和转换开关的动态和静态故障,细致地剖析了自动控制器本身的故障.然后,按照公用与独立两种型式的转换器,划分这些故障为独立与相依两类,并且归结到独立转换器远比公用转换器为优.同时指出转换器本身的故障必须小于各个分系统的故障,否则就不可能提高总系统的可靠性.此外,对自动停车措施的得失及温冷混合贮备的优点,也都得到了明确的结论.     

新型矿用采掘设备遥控装置的设计

针对传统遥控装置存在可靠性差、通用性不强的问题,设计了一种新型矿用采掘设备遥控装置,详细介绍了该装置的组成、硬件和软件的设计。该装置采用抗干扰设计、通信差错控制、设备状态检测等技术,提高了其可靠性和通用性。实际应用表明,该装置能够满足现阶段煤矿井下大型采掘设备的控制需求。     

一种基于微内核虚拟化的设备驱动优化模型

为解决日趋复杂的嵌入式系统的效率和可靠性问题,本文比较并分析了现有的设备驱动模型,针对嵌入式设备对虚拟化的特殊要求,参考L4微内核虚拟化技术,提出了一种新的虚拟设备驱动优化模型,不仅实现了微内核架构中多虚拟机间的驱动共享,并且在提供系统可靠性的同时,弥补了虚拟化技术带来的性能开销,提供了一个在效率、功能和可靠性三方面取得相对均衡的虚拟化环境。     

Boundary-representable partition of unity for image magnification

This paper proposes a simple yet effective algorithm to magnify 2D/3D images with preserving discontinuities of intensity. Our algorithm is based on the partition of unity （PU） approximation, which offers many advantages such as smooth representation, noise-robustness, and precise representation. Unfortunately, PU encounters difficulties when scaling images and maintaining boundaries within images owing to the nature of its approximation. To overcome this problem, we propose an approximation that preserves discontinuities. This is realized by dividing the local spherical support of PU into two parts along a locally detected discontinuity and by individually approximating intensities on each side of the discontinuity. This algorithm is suitable for magnifying a variety of images, including scanned documents, pictures, and CT-scanned images. To demonstrate the effectiveness of the proposed method, we show some experimental results for 2D/3D images.     

基于AT89C51的远距离井下综合保护照明装置的研究

本文在分析了目前我国井下低压电网微机综合保护装置存在问题的基础上,设计了基于AT89C51单片机为核心的远距离微机综合保护装置。系统采用先进的微机继电保护算法自动判断系统的短路和漏电故障,最后通过实验证实了这种微机综合保护装置在保护距离和可靠性等方面都较以往的保护系统有了一定的提高。     

地铁直流牵引供电继电保护系统的可靠性评估

随着城市轨道交通的迅速发展,对地铁可靠性、安全性的关注也越来越强,地铁继电保护系统已成为牵引供电系统安全运行的保证。过去,人们总是把可靠性分析的重点放在一次系统上,这就导致了二次系统可靠性理论研究的延缓。本文从可靠性建模的角度,找出影响继电保护可靠性的各种因素,引入可靠性评估方法,建立继电保护装置及其系统的可靠性模型。克服了过去只关注保护装置本身可靠性的局限,并着重研究了二次回路中其它设备、保护动作逻辑和保护配置方案对继电保护可靠性的影响。     

一种新型硬件设备错误检测方法

设备驱动的可靠性对于操作系统的可靠性具有重要意义.在编写驱动时总是假设硬件设备一直正常工作,但实际上硬件设备经常会出错.因此这个假设有可能会导致驱动甚至整个操作系统失效.硬件设备会产生中断相关的错误,典型的中断相关错误有持续中断和不产生中断.这类错误会导致操作系统内核不能正常工作.因此,在驱动中检测中断相关的错误对于提高操作系统稳定性具有重要意义.本文介绍了基于定时器的检测持续中断和不产生中断的方法.该方法相比以前的方法具有开销小、精确度高的优点.     

基于USB设备的用户态驱动框架

传统的linux系统为了获得更好的性能,将设备驱动运行在内核空间,不可避免的降低了系统的可靠性和稳定性.基于常用的USB设备提出了一种全新的驱动架构,它将驱动以进程的形式运行在用户空间,并且支持热插拔,驱动管理等特性,实验结果表明这种架构性能良好,能够满足实际应用需求.     

微机线路保护装置的研制

随着智能化微机保护产品在电力系统中广泛应用,微机保护产品在继承常规保护技术的基础上,其智能化特点日益突出。因此为了更好地满足电力系统对可靠性和安全性的要求,从微机线路保护装置的保护功能、辅助功能、用户接口等方面进行了具体的阐述,最终实现了适用于110kV及以下电压等级输电线路的微机线路保护装置的设计。     

Reducing burn-in time through high-voltage stress test and Weibull statistical analysis

To guarantee an industry standard of reliability in ICs, manufacturers incorporate special testing techniques into the circuit manufacturing process. For most electronic devices, the specific reliability required is quite high, often producing a lifespan of several years. Testing such devices for reliability under normal operating conditions would require a very long period of time to gather the data necessary for modeling the device's failure characteristics. Under this scenario, a device might become obsolete by the time the manufacturer could guarantee its reliability. High-voltage stress testing (HVST) is common in IC manufacturing, but publications comparing it with other test and burn-in methods are scarce. This article shows that the use of HVST can dramatically reduce the amount of required burn-in.     

基于MediaPipe的非触摸式在线签名认证系统

针对手写签名认证的可靠性和设备依赖性问题,设计并实现了一种基于MediaPipe的非触摸式在线签名认证系统.该系统以MediaPipe为基础框架,通过视频获得在线手写签名,并提取签名轨迹点的时序特征作为匹配模板,进而采用加权联合概率策略构建签名认证模型.该模型在边缘端设备的平均认证等误率(EER)为3.04%.采用基于PyQt设计的应用作为可视化UI界面,实现在视频场景中的非触摸式在线签名交互认证.该系统使用实时视频感知交互方式实现在线签名认证,无需其他的外部设备,具有更低的设备依赖性和更高的认证可靠性.     

TMS320LF2812在电力系统测频测相装置中的应用

提出了一种基于数字信号处理器（DSP）的测频测相方法，用于同步发电机微机励磁系统中机组频率及机端电压电流相位差的测量，与传统的单片机、PLC或FPGA测频测相装置相比，其硬件电路大为简化，测频测相装置的可靠性极大提高，而且测频测相精度较高，提高了发电机励磁控制的可靠性和控制精度。     

基于DSP和FPGA直接数字频率合成系统的设计

在研究微硬盘读写通道时,模拟伺服信号的信号发生器必不可少。本文研究了一种基于DSP和FPGA直接数字频率合成技术组成的程控信号发生器,其频率分辨率可达0．001Hz,波形输出的频率、幅值和相位精度高,稳定性好,且失真度低。该方法与传统实现方式相比,电路实现简单、易修改,便于程控并可模拟各种伺服信号。     

设备驱动程序可靠性和正确性保障方法与技术研究进展

随着计算机技术的不断发展,计算机系统在安全攸关领域得到了广泛应用,其中的软件系统正逐渐成为重要的使能部件.在计算机系统中,设备驱动程序扮演了软件与硬件设备之间桥梁的角色.由于与计算机平台、操作系统、设备3个方面同时关联所导致的复杂性,设备驱动程序的开发难度大、成本高,程序中所存在的错误和缺陷常常导致系统失效,在安全攸关领域造成不可挽回的损失.以设备驱动程序可靠性和正确性保障为目标,分别从故障的隔离与恢复、正确性分析和验证、设计建模与复杂性控制这3个方面对当前相关方法和技术进行分析,为开展进一步深入的研究工作打下基础.     

Enhancing yield at the end of the technology roadmap

Scaled manufacturing technologies require advanced techniques for improving device reliability and production yield. We present a transistor-level redundancy technique for manufacturing devices with low vulnerability and improving yield in future circuits The technique relies on appropriate design style selection and controlled redundancy to achieve area and power trade-offs.     

基于COTS器件的高费效比商业卫星计算机研究

对国内外基于COTS(Commercial Off-The-Shelf)器件的商业卫星计算机进行了研究。针对商业卫星公司对卫星可靠性、运算性能、成本控制、研发周期等要求和实际空间运行环境,分析了目前国内外商用卫星的设计模式和特点,提出一种基于汽车级COTS器件的商业卫星单板计算机系统。在可靠性设计上采用了EDAC、双核Lock-Step等技术,选用单粒子免疫的器件的MRAM和反熔丝FPGA,在保证计算机系统安全性、可靠性、成本控制和运算性能的同时,避免了多核或多处理器冗余加固方案导致的额外软件开发成本,缩短产品研发周期。研究对基于COTS器件的商业卫星计算机的可靠性设计有一定参考价值。     

Performance of multilayered fluoropolymer surface coating for DEP surface microfluidic devices

One of the key structural features of a surface microfluidic (SMF) device is the surface coating, since it directly affects both the performance and reliability of the SMF device. This work examines and compares the performance of liquid dielectrophoresis (LDEP) SMF devices, fabricated with conventional spin-coated Teflon^? surface to those coated with a recently developed fluoropolymer composite coating, which have been shown to be superior for low-voltage electrowetting actuation. We have focused on SMF devices that leverage LDEP and utilize high AC voltages to actuate aqueous samples on hydrophobic surfaces and produce droplet arrays of controlled size and structure to facilitate rapid and large-scale combinatorial bio-assays. Our findings demonstrate the superior performance, robustness and reliability of the composite coating over the conventional spin-coated Teflon^? coating, for repeated high-voltage, high-frequency LDEP actuations for homogenous, emulsion and variable volume aqueous sample dispensing.     

配电网停电定位法的研究

随着配电系统设备的日益增多,设备种类的日趋繁杂,要在最短时间内找出停电故障设备,及早恢复供电是很困难的.本文根据配电网的拓扑结构特点,利用馈线的电气连通性,对配电网的停电定位进行了深入分析,提出利用启示性搜索规则迅速准确地找出故障设备.从而使维修人员能及时准确到达现场维修,以缩短停电时间,提高供电可靠性.     

Reliability and performance enhancements for SSD RAID

NAND based solid state storage devices are almost ubiquitously used in safety-critical embedded devices, and recent advances have demonstrated RAID architectures specific to solid state storage devices resulting in increased data reliability, with architectural enhancements to solve the age convergence problem. However, these techniques require devices to be taken off-line while components are replaced—consequently these devices are of limited use in hard real time systems. There are further real time issues in that the conventional architectures ignore other characteristics of solid state devices such as garbage collection and meta data management. In this paper we investigate techniques that support the replacement of aged devices in the array in such a way that we provide continuous system reliability. We also improve the performance overhead of the reconstruction process using a novel data migration policy. The techniques are implemented and tested in a trace-driven simulator, and results demonstrate that average I/O response time is improved by up to 39% with improvement by up to 45% in its standard deviation, overheads in terms of device replacement time are negligible, and read performance is improved by an average of 8%.