一种时变滑模平面的设计方法

在分析滑模平面设计的基础上,指出了按传统的方法设计的滑模平面的缺陷。为了克服此缺陷,根据矩阵分析理论提出了一种新的具有全局鲁棒性的时变滑模平面的设计方法,并给出了三种具体的滑模平面形式。通过理论分析和计算机仿真可以看出,基于该方法设计出滑模平面的变结构控制系统,能保证系统从任意的初始状态开始就处于设定的滑模平面上,对参数摄动和外部干扰具有很强的鲁棒性。用该方法设计出的时变滑模平面是传统的滑模平面的     

Efficient Feature Extraction Using Apache Spark for Network Behavior Anomaly Detection

Extracting and analyzing network traffic feature is fundamental in the design and implementation of network behavior anomaly detection methods. The traditional network traffic feature method focuses on the statistical features of traffic volume. However, this approach is not sufficient to reflect the communication pattern features. A different approach is required to detect anomalous behaviors that do not exhibit traffic volume changes,such as low-intensity anomalous behaviors caused by Denial of Service/Distributed Denial of Service(Do S/DDo S)attacks, Internet worms and scanning, and Bot Nets. We propose an efficient traffic feature extraction architecture based on our proposed approach, which combines the benefit of traffic volume features and network communication pattern features. This method can detect low-intensity anomalous network behaviors and conventional traffic volume anomalies. We implemented our approach on Spark Streaming and validated our feature set using labelled real-world dataset collected from the Sichuan University campus network. Our results demonstrate that the traffic feature extraction approach is efficient in detecting both traffic variations and communication structure changes.Based on our evaluation of the MIT-DRAPA dataset, the same detection approach utilizes traffic volume features with detection precision of 82.3% and communication pattern features with detection precision of 89.9%. Our proposed feature set improves precision by 94%.     

Glutenin macropolymer particles size distribution of six wheat varieties in eastern China

Size distribution of glutenin macropolymer(GMP) particles significantly affects the quality of final products in wheat. Six wheat varieties in eastern China were used for investigating the GMP content, particle size distribution and their relation. The results showed that the particle diameter of GMP changed from 0.38 μm to 269 μm. A typical bimodal curve of volume distribution of particles with peak values ranged from 4.44 μm to 5.36 μm and from 45.76 μm to 116.30 μm, respectively. Number distribution of particles showed the typical population with peak values in the range of 0.57-1.00 μm. Proportions of granules 12 μm, 12-80 μm and 80 μm were in the range of 17.1%-47.8%, 32.1%-50.3% and 10.2%-38.1% of total volume, respectively. The content of GMP was negatively correlated with the volume of GMP particles 12 μm, but positively correlated with the volume of particles 80 μm. The results suggested that the greater percentage of larger GMP particles is, the more GMP content there is in wheat grain.     

兔血清诱导Shope肿瘤细胞凋亡的实验研究

目的：前期实验结果已证明兔血清对Ｓｈｏｐｅ肿瘤细胞具有伤作用。本实验拟从细胞凋亡角度探讨兔血清杀伤该细胞的机理。方法：通过电子显微镜、激光共聚焦显微镜、琼脂糖凝胶电泳及流式细胞仪检测等方法,观察了兔血清诱导细胞凋亡的可能性。结果：经１０％兔血清处理３ｈ的中等分化程度的Ｓｈｏｐｅ肿瘤细胞（ＳＣＢ－６ａ）在电镜、激光共聚焦显微镜下均可见典型的细胞凋亡的形态学特征;１．５％琼脂糖凝胶电泳呈现明显的“阶梯状”图谱（ＤＮＡ ｌｅｄｄｅｒ）;ＰＩ染色后经流式细胞仪检测显示大量亚二倍体细胞（凋亡细胞）。结论：兔血清诱导Ｓｈｏｐｅ肿瘤细胞凋亡可能是其伤细胞的作用机理之一。     

SPIS-DSS:一种基于Chord的分布式存储系统

为了避免传统分布式存储系统的单点失效和路由瓶颈问题,将P2P资源定位模型引入其底层路由过程,以一种基于DHT(distributed Hash table)技术的结构化P2P路由模型Chord为基础,设计了一种新的分布式存储原型系统SPIS-DSS.SPIS-DSS采用Chord的一种实现JavaChord,把网络中的所有节点组织成环形拓扑,并通过幂次逼近的资源定位机制分发和回收文件,能运行在任何具有Java虚拟机的平台上,具有良好的可移植性.测试结果表明,这是一种有效的分布式存储系统,具有很好的可扩展性、健壮性和实用价值.     

Fringe is a glycosyltransferase that modifies Notch

Notch receptors function in highly conserved intercellular signalling pathways that direct cell-fate decisions, proliferation and apoptosis in metazoans. Fringe proteins can positively and negatively modulate the ability of Notch ligands to activate the Notch receptor. Here we establish the biochemical mechanism of Fringe action. Drosophila and mammalian Fringe proteins possess a fucose-specific beta1,3 N-acetylglucosaminyltransferase activity that initiates elongation of O-linked fucose residues attached to epidermal growth factor-like sequence repeats of Notch. We obtained biological evidence that Fringe-dependent elongation of O-linked fucose on Notch modulates Notch signalling by using co-culture assays in mammalian cells and by expression of an enzymatically inactive Fringe mutant in Drosophila. The post-translational modification of Notch by Fringe represents a striking example of modulation of a signalling event by differential receptor glycosylation and identifies a mechanism that is likely to be relevant to other signalling pathways.     

一种互认证密码协议的设计和分析

为在不安全的网络中建立安全的通信，提出了一种用于网络管理互认证的具有较高效率的密码协议，介绍了该密码协议的相关设计背景。总结了若干关于密码协议设计的原则，通过运用经过补充的BAN逻辑对该协议进行形式化分析，并通过计算机对该协议的握手协议过程进行仿真。仿真结果表明，在被加密协议参数相同的条件下，该协议减少了系统开销，提高了协议效率。     

面向MIS的预测支持系统的研究

通过对预测支持系统研究现状的分析,讨论了预测支持系统如何更好的适用于MIS,为其提供预测支持.并提出了更加适应MIS当今和未来发展的预测支持系统构建模式.     

防止西藏国有企业政策性寻租对策分析

由于特殊的地理环境与政治环境，西藏国有企业自生能力相对较弱，企业生产带有强制的外部经济性，因此政府给予企业政策性优惠与补贴是企业公平发展的需要。文章从西藏国有企业的领导人政策性寻租动机及诱因出发，分析了西藏现实的制度运行环境，从企业领导人的选拔、激励、绩效评价、合作剩余的归宿等多个方面研究了防止西藏国有企业领导人实施政策性寻租的对策措施。