Comments on enhanced yoking proof protocols for radio frequency identification tags and tag groups

A radio frequency identification (RFID) yoking proof scheme can generate proofs of simultaneous presence of two tags in the range of a specified reader so that an off-line verifier can verify the proofs later. This proof has found several interesting applications. However, many existing RFID yoking schemes are vulnerable to replay attacks. To overcome the weaknesses, Cho et al. proposed a new RFID yoking proof protocol and a new grouping protocol. Unfortunately, Cho et al.’s schemes are still vulnerable to replay attacks. In this paper, in addition to demonstrating weaknesses, we further discuss the rationale behind these weaknesses to provide a guide line for designing secure RFID yoking schemes. Based on the guide line, we propose a new RFID yoking scheme and a new RFID grouping scheme. Performance evaluation shows that our scheme outperforms its counterparts.     

闵浦二桥主塔下横梁预应力分析及施工技术

上海闵浦二桥工程是一座公轨两用一体化双层特大桥,主桥为独塔双索面连续钢板桁组合梁双层斜拉桥。该文通过理论模拟分析计算,对主塔下横梁施工过程预应力进行了分析,并介绍了其施工技术。     

Using on-board video data for safety analysis – An analysis of right hook crashes involving large buses at signalized intersections

Bus right hook (BRH) crashes at intersections are one of the most common types of crashes for bus carriers, which accounted for as high as 16% of fatal and injury crashes involving large buses at intersections in Taiwan. A BRH crash occurs when a bus and another vehicle traveling in the same direction head into an intersection, but the bus driver makes a right turn across the path of the through-moving vehicle, and both vehicles collide. This study responds to the research needs to identity factors associated with BRH crashes by utilizing in-vehicle data recorder (IVDR) data. A four step analysis procedure was developed, including (1) video data coding, (2) crash sequence analysis to identify crash contributing factors, (3) a case-control study to examine the relationship between the crash contributing factors and crash occurrence, and (4) modeling crash risk in terms of the crash contributing factors to better understand the crash generating process. This study first identified the existence of driver unattended time as the time between when the driver last checked the right back mirror to finally steering for a right turn, indicating the time period wherein the driver did not track the through vehicle on the right side using the right back mirror. It was found that BRH crashes could be attributed to the concurrence of unattended time and the speed difference between the bus and through vehicle. Several recommendations are discussed based on the results to further develop countermeasures to reduce this type of crash.     

生命在平凡中闪光——纪念杨庆文同志

“我们对着茫茫的珠江痛悼您，江水哽咽；我们对着苍翠的青山痛一阵您，群山无言。我们的好同事，您别走……”声声深情呼唤，无法留住他远去的脚步。     

基于网络时间协议(NTP)的城市轨道交通时间服务器的设计

设计了一套基于嵌入式的城市轨道交通GPS(全球定位系统)时间服务器.系统硬件采用GPS OEM板和ARM 9开发板,并在开发板上增加了Zigbee无线传输模块和扩展了的RS 485接口,可满足城市轨道交通时间信息传输多样性的要求.通过分析网络时间协议(NTP)的基本原理,设计并完成了嵌入式Linux下的服务器程序和Windows下的客户端程序；客户端程序采用Windows系统内部的高精度定时器,提高了时间分辨率,可以使局域网内计算机的授时精度达到微秒级.利用真实的网络环境对其进行测试,结果能够满足城市轨道交通行车控制和运营管理的特定要求.     

适应高爆发压力的高性能柴油机气缸盖设计

以某4DC发动机的基本参数为输入条件,对气缸盖进行了概念定义及详细设计,着重介绍了气道、油道、喷油器、配气机构和冷却水套的定义过程以及为保证气缸盖刚度和强度采取的技术措施,提出了气缸盖"W"型水套的概念。对该气缸盖设进行的设计评估结果表明,其使用性能、冷却性能、结构可靠性、铸造性能均满足设计要求,且气缸盖质量仅为30 kg,实现了气缸盖设计轻量化目标。     

浅析《现代外语》中两篇外语教学的实验报告

章通过对《现代外语》中两篇外语教学实验报告的分析，阐述丁在语言实验研究过程中，处理好各种变量的关系、总体样本与抽样之间的关系以及无关变量的控制对实验报告信度有很大的影响。     

INTERNET在箱运业务中的应用

随着INTERNET和电子商务的发展，世界上各大租箱公司也纷纷在网上开发自己的主页，并大力投资完善其功能，在信息查询、辅助交易和费用结算等方面进行了广泛的实践。同时，由于INTERNET的诸多优点．许多租箱公司还积极宣传和推动网络的运用，这对其降低经营成本、提高工作效率、提升公司形象和满足客户需求等产生了积极的作用。现将IN-TERNET在租箱业务中的应用情况介绍如下：     

杭州市交通状况及车联网市场前景的调研与分析

作为物联网在交通领域的应用,车联网可有效缓解当前的城市交通问题.为更好地把握车联网的市场前景,2012年底在杭州市开展了一次大规模随机抽样调查活动,在汽车4S店、二手车市场、高校、政府机关和企业内随机发放问卷共800份.根据对问卷结果的统计分析,绝大部分驾驶员对杭城交通状况十分不满意,造成交通问题的主因是车辆增长过快,大多数驾驶员对车联网应用及相关产品十分感兴趣,并愿意为之支付一定费用.由此可以推断车联网市场前景非常广阔.     

Lightweight mixture faults detection method for gasoline engine using on-line trend analysis

Mixture faults detection is meaningful for gasoline engines because proper mixture is the basic prerequisite for healthy running of a combustion engine. Among existing methods for faults detection, the data-driven trend analysis technique is widely used due to the simplicity and efficiency in time-domain. The CUSUM (Cumulative Sum Of Errors) algorithm is good at real-time trend extraction, but it’s easy to be costly on the fuel trim signal during the engine in normal working conditions, which will increase battery energy consumption because engine failure is rarely occurs. Hence, the conventional treatment methods of artifacts in the CUSUM algorithm are modified by means of decay function and detection time analysis. The thresholds are tuned according to the characteristics of artifacts instead of residual variability, which leads to better results of trend extraction and less computation. Then, the revised CUSUM algorithm is used for monitoring the mixture abnormal behaviors, and the mixture faults can be detected in real time through analyzing the variation features of fuel trim signal. The lightweight faults detector using the advanced CUSUM algorithm (FD-A-CUSUM) is evaluated on the experimental data collected from a Ford engine. The validation results show that while engine works under normal conditions, the computation of FD-A-CUSUM has decreased by 72.79 % in comparison with the detection method using the original CUSUM algorithm (FD-O-CUSUM), and the false alarm ratio of FD-A-CUSUM is 3.37 %. Futhermore, the detection results of FD-A-CUSUM for two leakage faults have achieved 91.18 % test accuracy.