机会传感网络移动节点连通度的影响因素

针对机会传感网络基于节点移动实现网络通信的特点,考虑到影响移动节点连通度的因素,提出了机会传感网络的移动节点连通度模型,实现了对移动节点连通度的刻画.在区域划分的机会传感网络中,分析了移动节点时间序列特征因子,得到与特征因子相关的影响移动节点连通度的因素.利用一元回归得到影响因素与时延的关系,通过回归组合分析得到移动节点的连通度模型.仿真结果表明,该模型能够反映机会传感网络移动节点的连通度.     

无线传感器网络移动未知节点的混合定位算法

针对无线传感器网络中移动节点定位问题,提出一种移动未知节点的混合定位算法。该算法在预测和过滤阶段均作了改进。在预测阶段,根据未知节点在t时刻接收到的锚节点信息个数区分四种情况进行讨论,选择最适合的方法来缩小采样区域;在过滤阶段,针对预测阶段四种不同的可能情况判断是否需要过滤。仿真结果表明,该算法在显著地缩小了采样区域的同时,提高了采样成功率和定位精度;减少了采样次数和计算量,降低了能耗,延长了网络的生存周期。     

AODV协议路由维护改进方案

在AODV路由协议的路由维护阶段,当节点检测到链路中断时,会采取一种链路修复机制,然而该机制的实施难以避免数据包的丢失和传输时延的增加,针对这个问题本文提出一种对AODV协议的改进方案。该方案通过计算节点间的链路生存期,在AODV协议的路由发现阶段引入优先节点机制,在路由维护阶段引入链路中断避免机制。仿真实验结果表明,改进的AODV路由协议减少了RREQ消息的数量,降低了丢包率,并且缩短了传输时延,特别适用于节点密度较大的车载网络。     

Adaptation of the ToxRTool to Assess the Reliability of Toxicology Studies Conducted with Genetically Modified Crops and Implications for Future Safety Testing

To determine the reliability of food safety studies carried out in rodents with genetically modified (GM) crops, a Food Safety Study Reliability Tool (FSSRTool) was adapted from the European Centre for the Validation of Alternative Methods’ (ECVAM) ToxRTool. Reliability was defined as the inherent quality of the study with regard to use of standardized testing methodology, full documentation of experimental procedures and results, and the plausibility of the findings. Codex guidelines for GM crop safety evaluations indicate toxicology studies are not needed when comparability of the GM crop to its conventional counterpart has been demonstrated. This guidance notwithstanding, animal feeding studies have routinely been conducted with GM crops, but their conclusions on safety are not always consistent. To accurately evaluate potential risks from GM crops, risk assessors need clearly interpretable results from reliable studies. The development of the FSSRTool, which provides the user with a means of assessing the reliability of a toxicology study to inform risk assessment, is discussed. Its application to the body of literature on GM crop food safety studies demonstrates that reliable studies report no toxicologically relevant differences between rodents fed GM crops or their non-GM comparators.     

Effects of dietary rumen‐protected lysine on milk yield and composition in lactating cows fed diets containing double‐low rapeseed meal

This study investigated the effects of dietary rumen‐protected lysine (RPLys) on milk yield and composition in lactating cows fed diets containing double‐low rapeseed meal. Twenty‐four cows were divided into three groups and fed one of three dietary treatments: 10% soya bean meal (SBM) diet (control), 15% double‐low rapeseed meal (DLRSM) diet and 15% DLRSM + 32 g/d RPLys (DLRSML) diet. The results showed that no differences (P > 0.05) were observed in milk yield, 4% fat correction milk (FCM), energy correction milk (ECM), protein yield, milk fat yield, milk fat, lactose yield and lactose between control and DLRSM. Supplementation with DLRSML increased (P < 0.05) milk yield, 4% FCM, ECM, and protein yield compared with the SBM. The results indicated that DLRSM and DLRSML might be used to substitute for SBM as a protein source in lactating cows, and the latter might be more beneficial to improve the performance.     

网络入侵检测系统规则链表的优化研究

网络入侵检测系统在大流量下常出现较高的丢包率,针对该问题,从规则链表入手研究。针对传统链表中RTN链表过大、平均匹配长度过长的问题,提出通过增设多媒体类型结点、方向结点以及共性规则体结点对传统规则链表进行三次分解的方法来提高检测效率。通过三次分解后,系统对链表OTN结点的平均匹配长度大幅缩短。实验结果表明,使用该方法在提高网络入侵检测系统对多媒体数据检测效率的同时,还可有效降低丢包率,同时完备性也得到提高。     

上海江湾体育场结构加固施工要点

上海江湾体育场是我国近代保护建筑之一,由于该建筑已有70年的历史,其结构在长期使用中,已出现了老化和破损,因此从保护文物建筑的角度必须进行加固。文章全面介绍该建筑物结构碳纤维的加固施工技术要点。     

轻型钢结构中屋面防水的若干问题

介绍了屋面防水设计的原则,从节点构造、屋面挠度和建筑物防水设计等方面分析了屋面渗漏产生的原因,并提出了相应的解决方案,以确保防水层达到规定的使用年限。     

基于可信平台的保护计算

随着计算机及网络技术的日趋成熟,全面解决计算机安全问题的要求就显得十分迫切。本文首先分析了已有的可信计算在解决计算机安全问题方面提供的一些手段,并指出其中存在的不足。之后提出保护计算的概念,具体阐述其机制和原理,最后论述保护计算作为一种对于可信计算的补充和完善对于解决现有计算机安全问题的所能提供的更优越的方案。     

酿酒葡萄威代尔越冬防寒试验

为了寻找在生产中既经济又方便和安全的葡萄越冬防寒方法,提高葡萄越冬抗寒性,以威代尔为试材,采用草帘+大棚膜、草帘+薄膜+覆土等8种防寒方法进行试验.结果发现,草帘+大棚膜可以替代覆土防寒,并优于其他几个处理.