Advanced Materials Research Vols. 204-210

Abstract: In this paper, we introduce a robust image watermarking method based on bi-dimensional empirical mode decomposition against geometric distortion. Based on the characteristics of the image theory and human visual system, the proposed method makes use of orthogonal properties of empirical mode decomposition to achieve the bi-dimensional empirical mode decomposition transform on the image. The image is decomposed into a series of IMFs and residue which contain the different frequency parts of the image. So the watermark is adaptively weighed to the different positions of the middle frequency IMF region. The method makes use of the multi-scale analysis characteristics of image bi-dimensional empirical mode decomposition theory and the person’s sense of vision and shows excellent advantage against shearing attack. The method could show the watermark clearly when half of the image has been cut. Experimental results show this method excellent robustness for image shearing. The watermark thus generated is invisible and performs well in StirMark test and is robust to geometrical attacks. Compared with other watermarking algorithms, this algorithm is more robust, especially against geometric distortion, while having excellent frequency properties.

Abstract: Projectile impact test is carried out to investigate damage and failure behaviour under different impact velocity from 90m/s to 160m/s. Strain-time history curve on the control points are analysed in this paper. Sandwich beam dynamic response and the degree of structural degeneration under impact loading both depends on the thickness of metallic skins. The projectile impact test demonstrate difference damage characteristics between the sandwich beams with different thickness skins. The peak stress value are estimated approximately to determine the skin deformation and sandwich beam global damage degree.

Abstract: This paper describes a model of immune intrusion detection in which an independent form is introduced in. Immune intrusion detection receives the vaccine signal to control the Vaccine Module in real-time signal processing. Vaccine extraction signal is that extract from one memory detector set with antibodies to mature vaccine set and vaccination signal is that vaccinated other mature detectors which need vaccination. The objective of this model is to share antibodies (detectors), establish communication links between different detectors increase the flexibility of detectors and improve the overall detection ability of detectors. Through the simulation by MATLBE, it proves this model has greater comprehensive detection performance.

Abstract: In order to keep the stable power output of wind turbine,the bp neural network controller is designed for the pitch angle control agencies of the wind energy conversion system, and hardware implementation problem of the controller is discussed based on fpga.The simulation model is built based on the System Generator/Simulink.The results show that the wind turbine output power with the neural network’s controller is stabler than the wind turbine output power with the PID’s,and the hardware implementation of neural network will have a good application prospect in the fields of wind energy conversion system.

Abstract: The mechanical model of magneto rheological damper(MRD) is established, and the numerical simulation of seismic responses of aqueduct under earthquake excitation is performed with magneto rheological dampers. The results indicated that the magneto rheological dampers are effective in reducing the aqueduct response, the mitigation rate of semi-active control approaches with the active method The results from the present study may serve as a reference base for seismic design of large-scale aqueducts, and provide theoretical basis of aqueduct using semi-active devices.

Abstract: The analysis of codon usage may improve our understanding of the evolution and pathogenesis of DEV（Duck enteritis virus） and allow reengineering of target gene to improve their expression for gene therapy.In this study,we calculated the codon usage bias in DEV UL55 gene and performed a comparative analysis of synonymous codon usage patterns in other 26 related viruses by EMBOSS CUSP program and Codon W on line.Moreover,statistical methods were used to investigate the correlations of these related parameters. By comparing synonymous codon usage patterns in different viruses,we observed that synonymous codon usage pattern in these virus is virus specific and phylogenetically conserved, with a strong bias towards the codons with A and T at the third codon position. Phylogenetic analysis based on codon usage pattern suggested that DEV UL55 gene was clustered with the avian Alphaherpesvirus but diverged to form a single branch. The Neutrality-plot suggested GC12 and GC3s adopt the same mutation pattern,meanwhile,the ENC-plot revealed that the genetic heterogeneity in UL55 genes is constrained by the G+C content, while translational selection and gene length have no or micro effect on the variations of synonymous codon usage in these virus genes.Furthermore, we compared the codon preferences of DEV with those of E. coli, yeast and Homo sapiens.Data suggested the eukaryotes system such as human system may be more suitable for the expression of DEV UL55 gene in vitro. If the yeast and E. coli expression system are wanted for the expression of DEV UL55 gene ,codon optimization of the DEV UL55 gene may be required.

Abstract: A 561-bp complete open reading frame of the duck enteritis virus(DEV) UL55 gene (GenBank accession No EU071034) was isolated in our laboratory and amplified by common PCR using a pair of specific primers .PCR product containing this ORF was cloned into the vector of PMD18-T. Four evolutionary analysis approaches were used to construct phylogenetic trees of DEV in relation to herpesviruses based on the nucleotide sequences. Bootstrap was used as statistic method to testify the reliablity of the constructed phylogenetic tree. Phylogenetic trees indicated that DEV and other herpesviruses generated from one ancestor and DEV were grouped into the subfamily Alphaherpesvirinae. In our result, DEV showed a close relationship with the genus Mardivirus, but formed a single branch. Partial genomic organization and phylogenetic analysis in the present study provides evidence that DEV was a member of the subfamily Alphaherpesvirinae and should be assigned as an individual genus or group.

Abstract: Open-top chambers (OTCs) were used to investigate the mechanism of antioxidant enzymes to eliminate reactive oxygen species (ROS) of plants under troposphere O₃ stress. The results indicated that, compared to control, the O₃ concentration of 80±10 nL·L^-1 and 110±10 nL·L^-1 induced an increase on malondialdehyde (MDA) content and a decrease on superoxide anion (O₂) production rate and hydrogen peroxide (H₂O₂) content during the whole growth stage. Simultaneity, it showed a trend of increasing in earlier stage and decreasing in later stage of the activities of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR) and glutathione reductase (GR), while the dehydroascorbate reductase (DHAR) activity was increased in earlier period, decreased in middle periods and then increased in later period compared to control, respectively. The results show that elevated O₃ concentration accelerates ROS metabolism rates, reduces the efficiency of antioxidant enzymes that can not tolerate oxidative damage caused by elevated O₃ concentration, which represents injured affects to soybean.

Abstract: In an open P2P network environment, it’s full of various malicious actions ,dishonesty, deceit, selfish and so on. So it’s necessary to build a robust trust manage system to keep the community run healthily. There are mainly two kinds of trust system, one is based on Global Trust. the system maintains a Global Trust value for every peer. The other one is based on peer itself, it rates the object peer trust according to historical transactions between them or recommendation from the other peers. Because the second trust manage system mainly bases on Fuzzy algorithm, we call it Fuzzy Trust system. The paper will focus on Fuzzy Trust system, we will introduce the related algorithms and involve Outlier Identification algorithm to alleviate the risk from malicious action.

Abstract: The central path is the most important in the design of interior-point algorithm for linear optimization. By an equivalence reformulation for the classical Newton direction, we give a new scaled central path, from which a new search direction is obtained. We derive the complexity bound for the full-step interior point algorithm based on this searching direction and the resulting complexity bound is the best-known for linear optimization.