基于SoPC的大容量存储控制器的设计与实现

电子技术的飞速发展要求嵌入式存储设备具有更低的功耗、更小的体积以及更大的存储容量,同时,以FPGA作为物理载体进行芯片设计的可编程片上系统(SoPC)技术将处理器、内存控制器、I/O接口控制器等系统设计需要的功能模块集成到一个芯片上实现,具有集成度高、功耗小、可靠性高等优点。在对SoPC系统以及大容量存储控制器进行研究的基础上,较为详细地介绍了一个基于SoPC系统的大容量存储控制器的设计与实现,阐述了流水线技术以ECC纠错技术的具体实现方案,并对方案的可行性进行了分析,设计功能得到了仿真验证。     

Heading south with a north-up map: A choice processing analysis of map alignment effects

This study employed an information accumulation model of choice reaction times to investigate alignment effects in mental representations of maps. University students studied a map from a single orientation (with north at the top). In a subsequent two-choice reaction time task, the students’ spatial knowledge of the map was assessed employing spatial left/right judgments, which were made from imagined perspectives that were either north-aligned or south-aligned. Data showed a standard alignment effect, favoring north- over south-aligned trials. To examine the locus of this effect, data were fit using the Linear Ballistic Accumulator (LBA) model of speeded decisions (Brown & Heathcote, 2008). Of interest were three model parameters: drift rate, the speed at which evidence accumulates toward a response; response threshold, the amount of evidence demanded from the decision maker before selecting a response; and non-decision time, the time consumed by pre- and postdecisional processes. The best-fitting model suggested that non-decision time accounted for the alignment effect. The difference in non-decision time between north and south-aligned judgments suggests a mental alignment stage on south-aligned trials, accounting for the longer reaction times for judgements misaligned with the presented north orientation of the map.     

嵌入式虚拟机管理器内存虚拟化方法研究

嵌入式虚拟机管理器需对3类硬件资源进行虚拟化才能支持客户OS的正常运行,而且支持虚拟内存的客户OS需对MMU页表进行虚拟化;以NXP公司的PowerPC架构处理器为例介绍了MMU概况、管理方法,并提出MMU虚拟化的需求;研究了XEN、ViMo、KVM/ARM、NOVA、MobiVMM 5个典型虚拟机管理器软件中所采用的主流内存虚拟化方案,并给出了基于软件影子页表、基于硬件支持特性、软硬件结合等3种对MMU页表进行虚拟化的解决方案.     

Spatial memory exclusivity: Examining performance of multiple object-location memories

Research on location memory suggests that integration of separate sources of information does not occur when recalling the position of a common target object. In a relatively simple task, previous research shows no observable benefit from holding two spatial memories compared to one. It has been suggested that exclusively utilizing only one of two memories may account for this finding. The current research tests the robustness of this idea as well as an alternative in the form of an averaging approach to combining spatial information. The results suggest that exclusivity may not be the best account for performance of multiple object-location memories. Rather, memories may well combine in a manner similar to averaging, where information is available for each memory but combined in a nonbeneficial way.     

基于磁记忆技术对含缺陷焊缝的疲劳试验

对含有不同隐形损伤的40Cr焊板进行射线检测、疲劳试验和正交磁记忆信号测量，探索试件在疲劳应力作用下磁记忆信号的变化特征。试验结果表明：单一测量方式下的磁特征值不能表征焊板在疲劳循环载荷下的变化特征，所得结论存在偶然性；研究发现，可用磁场矢量梯度积分特征和磁场矢量合成梯度特征来评价焊板的疲劳损伤过程，并建立了以磁场矢量梯度特征为损伤参量的疲劳损伤模型，从而可以对含有隐形损伤焊接构件的疲劳寿命进行定量评估，为金属磁记忆技术在焊接缺陷定量评价上的进一步研究提供参考依据。     

Spatial working memory is enhanced for movement experts in traditional and embodied tasks

Movement experts tend to outperform non-experts on some tasks of spatial ability, suggesting that movement experts possess enhanced spatial-cognitive abilities, which may be developed over years of practice. In the current study, movement experts (dancers and athletes) and non-experts completed one verbal working memory task and two spatial working memory tasks—a traditional Corsi block-tapping task and a new full-bodied version of the Corsi task, nicknamed the “Twister Task.” Movement experts outperformed non-experts on both the Corsi and Twister tasks but not on the verbal task, suggesting that movement experience may relate to spatial working memory specifically. Additionally, the Twister task significantly correlated with the traditional Corsi task, providing validation for a new measure of spatial working memory.     

运载火箭控制系统半实物仿真实时网络技术应用研究

针对新一代运载火箭组合化、系统化、通用化的特点,必须在现有的运载火箭控制系统半实物仿真试验的基础上,建立新型的运载火箭控制系统分布式半实物仿真系统,实现仿真设备的组合化、功能的多样化。本文从系统总体角度出发,对运载火箭半实物仿真试验实时网络设备进行深入分析和科学选型,同时对其接口软件进行设计,以提供实时网络各节点之间高效、方便的通信接口。最终设计出比较完备的运载火箭半实物仿真试验实时网络集成方案,确保各种仿真设备能够连成一个有机整体,形成仿真试验能力。     

一种LSTM模型预测BC值的空间碎片无控再入预报方法

提出一种利用长短周期记忆(LSTM)神经网络模型动态预测无控再入过程中弹道系数(BC)值实现空间碎片高精度再入时刻预报。通过利用空间碎片两行根数(TLE)、简化通用摄动模型(SGP4)与公开的物体陨落时间作为实测数据样本,利用迭代修正BC值方法构建预测模型的训练集,由此构造用于预测BC值的LSTM模型预测BC,再采用高精度轨道外推动力学模型配合预测BC值预报再入时刻,结果表明基于LSTM模型预测BC的空间碎片再入时刻预报方法是可行的,在95%的置信度内,90天以上的再入时刻预报精度小于10%,30天预报精度小于8%。     

分布式实时仿真中网络系统扩展的研究与实现

基于实时网络建立的半实物仿真系统能满足强实时性及高精度的要求,随着仿真应用技术的发展,需要参与半实物仿真的实物越来越多,由于共享内存光纤网络产品的飞速发展,如何用最新的实时网产品来扩展原有的实时网络系统是一个必须解决的关键问题。本文阐述了如何扩展的研究结果和实现方法。     

一种基于双中断的反射内存网通信方法研究

在飞机D级模拟器研制中,针对模拟器仿真设备和真实设备之间数据传输问题,分析了传统以太网广播和组播的机制,提出了一种基于双中断的反射内存网通信方法实施方案。该方案通过在反射内存网上模拟以太网的广播与组播,实现了环形网络中各节点间的高速通信。该方案的实现,不仅解决了环网各节点通信过程中读写串行化的问题,还解决了模拟器研制过程中设备之间的实时通信、错帧、丢帧以及数据同步问题。目前,该通信方法已应用至飞机D级模拟器中。