The Internet of Things has broad application in military field, commerce, environmental monitoring, and many other fields. However, the open nature of the information media and the poor deployment environment have brought great risks to the security of wireless sensor networks, seriously restricting the application of wireless sensor network. Internet of Things composed of wireless sensor network faces security threats mainly from Dos attack, replay attack, integrity attack, false routing information attack, and flooding attack. In this paper, we proposed a new intrusion detection system based onK-nearest neighbor (K-nearest neighbor, referred to as KNN below) classification algorithm in wireless sensor network. This system can separate abnormal nodes from normal nodes by observing their abnormal behaviors, and we analyse parameter selection and error rate of the intrusion detection system. The paper elaborates on the design and implementation of the detection system. This system has achieved efficient, rapid intrusion detection by improving the wireless ad hoc on-demand distance vector routing protocol (Ad hoc On-Demand Distance the Vector Routing, AODV). Finally, the test results show that: the system has high detection accuracy and speed, in accordance with the requirement of wireless sensor network intrusion detection.

Cynomorium is a herbaceous holoparasite that has been placed in Santalales, Saxifragales, Myrtales, or Sapindales. The inverted repeat (IR) region of the chloroplast genome region is slow evolving and, unlike mitochondrial genes, the chloroplast genome experiences few horizontal gene transfers between the host and parasite. Thus, in the present study, we used sequences of the IR region to test the phylogenetic placements of Cynomorium. Phylogenetic analyses of the chloroplast IR sequences generated largely congruent ordinal relationships with those from previous studies of angiosperm phylogeny based on single or multiple genes. Santalales was closely related to Caryophyllales and asterids. Saxifragales formed a clade where Peridiscus was sister to the remainder of the order, whereas Paeonia was sister to the woody clade of Saxifragales. Cynomorium is not closely related to Santalales, Saxifragales, Myrtales, or Sapindales; instead, it is included in Rosales and sister to Rosaceae. The various placements of the holoparasite on the basis of different regions of the mitochondrial genome may indicate the heterogeneous nature of the genome in the parasite. However, it is unlikely that the placement of Cynomorium in Rosales is the result of chloroplast gene transfer because Cynomorium does not parasitize on rosaceous plants and there is no chloroplast gene transfer between Cynomorium and Nitraria, a confirmed host of Cynomorium and a member of Sapindales.

No abstract

No abstract

Based on the statistical theory of X-ray dynamical diffraction for thin films, the mosaicity of three types of semiconductor epitaxic layers has been investigated by analyzing their rocking curves by the X-ray doublecrystal diffraction method. It is shown that the statistical theory can provide quantitative information on the mosaicity of the epitaxic layers such as the mean size and the mean disorientation of mosaic blocks in the layers. Some misunderstandings in interpreting experimental data are cleared up by taking into account the effect of diffuse scattering. It is emphasized that attempts to obtain structural parameters of specimens from their rocking curves by means of the Takagi-Taupin equations for coherent fields only are not strictly correct since diffuse scattering causes additional changes in the tails of the rocking curves.