An effective automatic detection system for multi-protocol attack

Since there exists multi-protocol attack when several security protocols are co-executed in a computer network, an automatic detection system for multi-protocol attack (ADMA) is proposed. The system is composed of two parts named protocol search subsystem and attack verification subsystem. According to the consistency condition of the type of encrypted messages between the target protocol and the secondary protocol, the protocol search subsystem can automatically search for the candidate secondary protocols, which may be used to attack the target protocol. By improving the SAT-based model checking, attack verification subsystem can automatically verify whether multi-protocol attack exists between the target protocol and the candidate secondary protocols or not. The experiment results show that ADMA system can implement automatic detection for multi-protocol attack, and some new multi-protocol attacks are found in the detection.     

基于机器视觉的种子质量检测新型算法

在分析已有区域标记算法的基础上,提出了一种新的二值图像连通区域准确标记算法。顺序扫描和标记二值图像的各个像素点,准确判断标记过程中出现的标记冲突,并建立标记冲突的模型,在算法中增加回溯扫描算法,消除标记冲突引起的标记误差。实验证明:该算法可以准确地标记出各种形状的连通区域,与已有算法相比,扫描重复率低,运行准确,速度快,具有很好的应用前景。     

基于SBL-PRM算法的柑橘采摘机器人实时路径规划

针对动态非结构化环境下的柑橘采摘机器人实时路径规划问题,采用单次查询、双向采样与延迟碰撞检测相结合的SBL-PRM（Single-query,Bi-directional,Lazy collision checking,Probabilistic Roadmap Method）算法,对无遮挡和遮挡两种场景下的柑橘采摘情况进行仿真试验,分析最大采样点数S、邻域阈值ρ、局部路径检测阈值ε、路径平滑次数N等参数对规划时间和成功率的影响。结果表明,在S=3000,ρ=0.6,ε=0.03,N=10时,无遮挡和遮挡两种场景下路径规划的平均时间分别为1 ms、60 ms左右,规划成功率均为100%。仿真试验证明了SBL-PRM算法在柑橘采摘机器人实时路径规划中的有效性。     

Comparison of moisture distribution along radial direction in a log cross section of heartwood and mixed sapwood and heartwood during radio-frequency/vacuum drying

The purpose of this study was to compare the distribution of moisture contents (MCs) along the radial direction during radio-frequency/vacuum (RF/V) drying of log cross sections of heartwood (HLC) where sapwood was removed from a green log cross section and log cross section of mixed sapwood and heartwood (MLC) prepared with debarked logs of Japanese larch (Larix leptolepis) and locust (Robinia pseudoacacia). For Japanese larch, an even distribution of MC was observed over the entire cross section in HLC not only at the initial stage of drying but also up to the completion of drying. Furthermore, the moisture gradient between the outermost slice and the adjacent inner slice was more gradual compared with that in MLC. For locust, the moisture gradient between the outermost slice and the adjacent inner slice became severe as drying progressed. It decreased after reaching the maximum during the middle stage of drying but continued until the late stage of drying. Furthermore, despite the fact that the average initial MC of mixed slice within MLC was higher compared with that in heartwood slice, this trend reversed immediately after drying started. It was suggested that the possibility of formation of border checking would be high during drying the MLC, since it would be so complicate that the sapwood and heartwood reach fiber saturation point together because of differences in their green MCs and permeability between them.     

囊虫病循环抗原检测用于疗效考核

分别对 15头囊虫病猪和 15例囊虫病患者治疗前后血清循环抗原 (CA)的变化情况作了观察。用吡喹酮治疗囊虫病猪 15头 ,经剖检证实治愈 13头 ,其中 10头在治疗后 15 d血清中 CA的衰减幅度大于 2 ,治疗 30 d后 13头猪血清 CA的衰减幅度大于 2 (其中 3头猪 CA转阴 ) ,治疗 6 0 d后 CA转阴猪达 10头 ;未治愈的 2头病猪 ,CA一直变化不大。用丙硫咪唑治疗囊虫病患者 15例 ,其中 9例经 1个疗程治愈 ,治疗后 30 d CA的衰减幅度大于 2 ,治疗 6 0 d后 CA全部转阴 ;3例经 2个疗程治愈 ,6 0 d后 CA的衰减幅度大于 2 ,1例转阴 ;2例经 3个疗程治愈 ,治疗 90 d后 CA的衰减幅度大于 2 ;1例严重感染的患者经 6个疗程治疗未治愈 ,其血清中 CA的衰减幅度小于 2。以上结果表明 ,血清 CA的光密度 (D值 )变化能准确反应囊虫在患者体内的生存状态 ,治疗前后 CA的衰减幅度大于 2或 CA消失可作为囊虫病治愈的考核依据。     

应用微卫星PCR对中国3个品系实验用小型猪的遗传检测

以 12个 STR(shord tandem repeat)座位的 PCR对中国 3个品系实验用小型猪进行了遗传检测。结果 ,3个座位品系间扩增结果相同 ;9个座位呈现品系间多态性 ,其中 2个座位在 3个品系间均具有差异。贵州小型香猪与西双版纳近交系小耳猪间有 6个座位有差异 ,其遗传距离为 0 .186 4;贵州小型香猪与广西巴马小型猪间有 3个座位有差异 ,其遗传距离为 0 .12 73;广西巴马小型猪与西双版纳近交系小耳猪间有 5个座位有差异 ,其遗传距离为 0 .1333。由此表明 ,3个品系小型猪间的遗传背景具有一定差异 ,同时表明这 9个座位可选择为小型猪遗传检测的多态性座位。     

固定式半自动牧草压捆机设计及喂入装置运动仿真

针对中国牧业机械实际生产和应用的现状和需求,设计了一种新型固定式半自动牧草压捆机。基于Pro／Engineer建立了压捆机的喂入装置和压缩机构的仿真模型,并进行了结构件的运动干涉检查以及机构运动仿真,以此缩短设计周期,降低研制成本。     

带有斜墙的混合结构房屋的抗震计算

本文根据变形协调原理,推导出刚性楼(屋)盖混合结构房屋斜墙的侧移刚度和承担的地震剪力的计算公式,给出其抗震验算方法,并通过算例展示了抗震计算过程。     

基于描述逻辑的领域本体知识逻辑检测

对本体库进行逻辑检测是本体构建的一个重要环节。基于描述逻辑的领域本体知识逻辑检测主要归结为判断概念关于TBox的可满足性以及判断ABox关于TBox的一致性。本文采用基于Tableaux算法的Pellet推理机对茶虫害本体库进行逻辑检测,验证了本体逻辑定义的有效性、完备性,为茶虫害本体的评价和二次开发以及后期应用奠定基础。     

大肠杆菌生物膜毒力基因的检测

通过确定大肠杆菌形成生物膜毒力基因的分布情况,为大肠杆菌生物膜的形成机理提供理论依据。本实验利用PCR聚合酶链式反应,对25株大肠杆菌阳性菌株菌进行了相关毒力因子fimH,Kp sMTII,chuA,fliC,yja和PapC的检测筛选。其结果显示：KpsMTII在所检测25株菌中出现的频率最高,占40%;其次是fliC,占32.5%,fimH占20%,合计占52.5%;chuA占7.5%,yja和PapC均未检出。结果表明：细菌粘附结构fimH基因和fliC基因是影响大肠杆菌形成生物膜的主要粘附结构毒力基因,其次是大肠杆菌毒力因子KpsMTII基因,最后是外膜蛋白血红素chuA基因。