Advanced Materials Research Vols. 403-408

Abstract: The study of polymer/clay nanocomposites has attracted major research and commercial interests due to their superior mechanical and thermal properties to those of the neat polymers. The present work is to modelling the spherical nanoindentation of exfoliated polymer /clay nanocomposite that has nonlinear elastic behavior using numerical simulation. A two dimensional simulation is done and the effect of friction coefficient and indenter radius on load-displacement curve is investigated. It is observed that the simulation results of nanoindentation do not depend on the friction coefficient of indenter and specimen significantly.

Abstract: Several methodologies have been proposed to model the effect of length scale parameters in constitutive equations. Most of them are developed based on strain gradient theory. The main restriction is contributed to the large scale of imposed plastic deformation in comparison with implementation of length scale parameters. Also comparing to the scale of dislocation movement and hardening mechanisms, the plastic deformation in microstructures and nanostructure materials is sufficiently large that finite plasticity theory could be well justified. Therefore, the main intention of this paper is to develop strain gradient deformation with the corporation of finite plastic and dislocation theory as physically based attribution in constitutive equations. This procedure is accomplished with intrinsic length scale relation, which is dedicated to develop phenomenological of plasticity laws for microstructures in finite plasticity. Finally, the result of new theory is indicated for microstructures and its predictable results are discussed for nanostructure materials.

Abstract: We report on the catalytic growth of multiwalled carbon nanotubes by plasma enhanced chemical vapor deposition using Ni and Co catalyst deposited on SiO₂, Si₃N ₄,ITO and TiN _Xbarrier layers; layers which are typically used as diffusive barriers of the catalyst material. Results revealed higher growth rates on conductive ITO and TiN _Xas compared to non con-ductiveSiO₂, and Si₃N ₄,barriers. Micrograph images reveal the growth mechanism for nanotubes grown on SiO₂, Si₃N _{4 and ITO to be tip growth while base growth was observed for the TiN X barrier layer. Initial conclusion suggests that conductive diffusion barrier surfaces promotes growth rates however it is possible that multiwalled carbon nanotubes grown onSiO2, and Si3N 4,were encumbered as a result of the formation of silicide as shown in the results here.}

Abstract: In this work ZnO nanocrystal powders have been synthesized by using Zinc acetate dehydrate as a precursor and sol-gel method. Then the products have been annealed at temperature of 200-1050°C, for 2 hours. The powders were characterized using X-ray diffraction (XRD), UV-vis absorption and photoluminescence (PL) spectroscopy. The morphology of refrence ZnO nanoparticles have been studied using Transmission Electron Microscope (TEM). During the annealing process, increase in nanocrystal size, defects and energy gap quantitative, and decrease in specific surface area have been observed.

Abstract: In recent years, IP flow identification in botnet detection attracts attentions in network security. IP flows associated with bot masters can be used to trace the botnet source. Most botnets suffer a large of IP-based attacks. This paper attempts to explore the correlations between attack behaviors and IP flows. By data collection, sets of functions concerning inference rules and conversion of data format, this paper successfully identifies the botnet attacks by IP flows and the inference patterns. The IP flow-based intrusion detection can efficiently find alert data correlation.

Abstract: This paper presents a new receiver for antenna array to provide robustness against adaptive array imperfections. These imperfections include the array gain errors and the directional mismatch. The superior performance of the proposed receiver is primarily achieved by adding an injected pseudo-interference in the diagonally loaded Capon beamformer. Simulation results demonstrate that the proposed method has excellent performance for both binary phase shift keying (BPSK) and quadrature amplitude modulation (QAM) systems.

Abstract: Clock and Data Recovery (CDR) means that the digital data streams are sent without an accompanying clock signal. A digital CDR circuit is proposed as it does not depend on the special analog process and provide higher immunity to the noise. This design is fabricated using 0.13μm standard process and the circuit can support up to 5 GHz data rate to support the high speed standard. Compared to other CDR design with more advanced technology, our implementation can have similar performance but the manufacturing cost can be reduced.

Abstract: A new switched-capacitor multiply-by-two amplifier with an accurate gain of two is presented. The proposed architecture requires only one opamp in four phases to generate two effective outputs. It significantly suppresses the gain error due to capacitor-mismatch and also provides a better power efficiency. Monte-Carlo simulation results are presented to confirm the feasibility of this new technique, demonstrating its suitability for high-resolution pipelined A/D converter.

Abstract: The empirical results show that the dynamic conditional correlation (DCC) and the bivariate asymmetric-IGARCH (1, 1) model is appropriate in evaluating the relationship of the Switzerland’s and the Canada’s stock markets. The empirical result also indicates that the Switzerland. and the Canada’s stock markets is a positive relation. The average estimation value of correlation coefficient equals to 0.4685, which implies that the two stock markets is synchronized influence. Besides, the empirical result also shows that the Switzerland and the Canada’s stock markets have an asymmetrical effect, and the variation risks of the Switzerland and the Canada’s stock market returns also receives the influence of the good and bad news.

Abstract: This paper proposes a technique of calling ALV remotely. Firstly, sending the GPS information of the target to the ALV by wireless network, then path planning is completed by prepared map data. If the target is changing in navigation, a new path to the terminal point will be to re-plan. AdaBoost algorithm [1] is introduced for implementingroad detection; different types of classifiers are trained to detect different road surfaces. In conclusion, the ALV is able to determine driving directions on different road surfaces.