SyncShare:一种用于手机终端的视频实时分享同步机制

描述用于手机终端的视频实时同步播放机制SyncShare,用户利用该机制能通过无线局域网将视频实时地分发给其他用户以便同步观看.同步视频块是同步分享播放的基础,同时网络编码策略也被应用在该系统中.通过将SyncShare机制部署在真实的手机终端上,测试了系统的同步播放性能,例如CPU使用率、电池能量消耗以及延时特性等.同时,不同编码策略下的CPU使用率和电池消耗对比也在实验中得到体现.实验结果表明,使用网络编码能有效减少最多45％的平均同步延时.     

HP-VCS: A high-quality and printer-friendly visual cryptography scheme

Visual Cryptography Scheme (VCS) is a secret-sharing scheme which aims to encrypt a secret message into multiple shares and transmit them to participants over an untrusted communication channel. Although human vision can easily reveal the secret message by stacking a sufficient number of shares, this scheme reduces the visual quality of recovered images. This paper presents a novel high-quality and printer-friendly VCS. When providing high-quality recovery, this scheme keeps the size of the shares the same as the secret image. Experimental results show that, compared with previous work, the proposed scheme significantly improves the performance of recovered images.     

基于VCS的固存坏块仿真系统设计与应用

NAND Flash固态存储器(固存)广泛应用于航天工程,受限于微电子特性及制造工艺,固存在出厂及使用过程中均会产生坏块,通常由固存控制FPGA(现场可编程门阵列)来管理并标记坏块_]。为保证固存控制FPGA对坏块管理的正确性、健壮性,必须对其进行严格验证。提出了基于VCS的固存坏块仿真验证系统,为固存控制FPGA提供了所需的外围接口,特别是提供了固存坏块反馈机制,令固存坏块产生时机受控;实时向FPGA反馈固存读写过程及产生的坏块信息;将坏块表建立、维护和固存响应过程记录到数据文件;实现了坏块分布的可配置性和仿真系统的闭环性、可记录性。仿真系统可有效发现坏块管理的设计缺陷,进而优化设计,提高航天固存产品可靠性。     

A real-time personalized route recommendation system for self-drive tourists based on vehicle to vehicle communication

Recently, traffic jams and long queuing problems in tourist hot spots is growing with the increasing number of self-drive tourists. Some recommendation systems have been developed in attempt to relieve these problems. However, all these systems lack information pertaining to real-time traffic as well as the ability of personalization. In this research, we have developed a novel route recommendation system to provide self-drive tourists with real-time personalized route recommendations. This will help to reduce the traffic jams and queuing time in tourist hot spots. It will also help to personalize visiting routes based on the user’s specific preferences. Ultimately, based on the evaluation results given by experienced self-drive tourists, we have shown that the proposed system not only saves total visiting time, but also meets their specific visiting preferences.     

基于Matlab的异步电动机间接矢量控制系统研究

交流电机高性能调速系统中,间接矢量控制系统控制方法比较简单,不需要进行磁通检测,而像通常的转差控制方法一样,只要测出电动机转子频率,加上根据需要的转矩推算出应有的转差频率,以此控制定子电流的瞬时频率,就能使电动机的电流和转矩迅速由原先的工作状态变到新的所需工作状态。本文利用Matlab/Simulink对间接矢量控制系统进行研究,结果表明系统稳定,并具有较好的静动态性能。     

点焊机恒流变结构控制器的研究与设计

针对传统电焊机控制中很难达到控制精确且响应迅速这一问题,提出了一种基于变结构控制思想的控制规则,此规则由传统PID控制与模糊逻辑控制复合构建而成,此控制规则已应用于电焊机控制箱的设计,并在实践中取得了良好的效果。     

基于W25Q80BL的FPGA配置控制器的设计与验证

随着FPGA的规模不断增大,其配置信息的容量也越来越大,所以如何方便快捷的读取配置信息也成为了越来越重要的问题。利用W25Q80BL型号的SPI FLASH支持四线同时读取数据的功能来实现主动模式下快速加载配置信息到FPGA。在接收到四组来自FLASH的数据后,FPGA把数据并行写入到四条chain里,较大的缩短了配置时间。仿真结果证实了设计的有效性与可行性。     

The influence of mechanochemical treatment of sintered submicrocrystalline corundum substrates on the structure of bioglass composites

The influence of mechanochemical treatment of submicrocrystalline sintered corundum on the structure of bioglass composites containing α-Al₂O₃ and CaO-SiO₂-P₂O₅ glasses was examined in the context of the possibility to form hydroxyapatite after being immersed in the simulated body fluid solution. Measurements of specific surface area and size and X-ray analysis of submicrocrystalline sintered corundum were conducted. Bioglass composites were obtained by placing submicrocrystalline sintered corundum grains in the CaO-SiO₂-P₂O₅ sol system, gelling and sintering at 800°C. The specimens were examined under a scanning electron microscope before and after immersion in the simulated body fluid solution for 24 and 120 h. Using the VCS algorithm, calculations of thermodynamic stability of compounds occurring in these bioglass composites were carried out, verifying the X-ray analysis. Original Russian Text ? B. Staniewicz-Brudnik, S. Szarska, K. Gamrat, 2008, published in Sverkhtverdye Materialy, 2008, Vol. 30, No. 6, pp. 40–48.     

薄壁梁轴向压溃力的影响参数

薄壁梁被广泛应用于吸能元件,其轴向压溃变形是一种理想的吸能模式。基于VCS(Visual CrashStudio)模型,采用正交试验法研究了影响薄壁梁轴向压溃力的设计参数。在此基础上,分析了既能使薄壁梁保持一定吸能水平,又能降低力的波动范围促使变形更稳定的途径,采用有限元模型对分析结果进行了验证。研究表明,改变截面几何形状使截面的折角数目增多,同时降低板厚可以达到上述目的。     

Nested Visual Cryptography Scheme

A new nested visual cryptography scheme is proposed for n cooperated user groups. It can encode the secret image consists of black and white pixels into share images which should be distributed to each user in each group. To decode the secret, users in at least k out of n groups should be present, and at least p out of q users should provide their shares for each attendant group （where p and q can be distinct for each group）. For the proposed scheme, the known scheme can be regarded as a simple instance which has only one user in each group. Compared to S-extended visual cryptography scheme, there is no need to enumerate all the user sets which can decode the secret.