AASRI Procedia最新文献

An experiment platform of cavity flow study was built in the low-turbulence wind tunnel. With the method of installing blocks inside cavities, the boundary layer profiles which drag out the shear layer were changed. Averaged static pressure distribution along the centerline on cavity bottoms, and acoustic spectral characteristics of inspected points on cavity wall were obtained from experiments, to discuss the effect of boundary layer profile change under the condition of low-speed incompressible flow on the cavity (long depth ratio were 2 and 4 respectively) aerodynamic and acoustic characteristics. The results showed that, under the velocity of 30m/s, with the boundary layer thickness increasing, the averaged pressure increased with adverse pressure grads decreased, for cavity of L/D=2, the SPL going down in some degree and when L/D increasing to 4, the SPL increased highly in the range of medium to high frequency.

This paper addresses the problems, connected with calculation of the electric field and analysis of surface flashover of node tank SF6 circuit breaker. Namely, the gap between the grounded tank unit, a filter system and a conductive system is receiving input power. The paper also provides the recommendations for change SF6 circuit breaker design.

In this paper, a nondestructive evaluation by sensor Eddy current is used as a tool to control cracks and microcracks in materials. A simulation by a numerical approach such as the finite element method is employed to detect cracks in materials and eventually to study their propagation using a crucial parameter such as a Stress Intensity Factor (SIF). This method has emerged as one of the most efficient techniques for prospectin cracks in materials, evaluating SIFs and analyzing crack's growth in the context of linear elastic fracture mechanics (LEFM). This technique uses extrapolation of displacements from results compared with those obtained by the integral interaction. On the other hand, crack'sgrowth is analyzed as a model by combining the maximum circumferential stress criteria with the critical plane for predicting the direction of crack growth. In this research, a constant crack growth increment is determined using the classical Paris's model, or the so-called modified Paris's model. It is also shown herein that stress intensity factors needed for these models are calculated using the domain form of the J-integral interactions.

Task of automatic reconstruction of three-dimensional objects by drawing views presented. The algorithm based on a boundary representation of three-dimensional models. The algorithm consists of the following steps: automatic separation of the drawing per the views, determination of three-dimensional coordinates of vertices, definition and marking of wire model primitives, reconstruction of model faces and model elements. The fundamental concept of the algorithm is to find the structural elements of three-dimensional model with usage of pre-specified patterns. The templates are described by means of matrices. Matching algorithm uses invariants: the number of vertices, type of edges.

Are analyzed varied experimental data on DNA fluorescence inside neutrophils and other aerobic cells in flow cytometry with nanometer spatial resolution, in the large populations of cells. Fluorescence distributions, for histograms various ranks r, define classes of Good and Bad information networks DNA for good and bad health of different people, in a very dense, fractal packing of information and entropy in networks of ‘exponentially small worlds’, at variation types of positive and negative stability for information distributions. In all cells exists invariance (homeostasis) for total Shannon entropy E=lnr in hierarchy networks entropy of any scales, for any rank r. Entropy's noises form signals for self-regulation of informational homeostasis. The main reconstructions of correlations and noises, for homeostasis support, at any states of health, occur in branching distributions of central moments in the most large-scale networks of entropy, for rank r <32.

With the introduction of sophisticated algorithms, the field of signal processing has experienced enormous diversification of late. In addition to this, design of hardware efficient digital systems has grown sufficient interest amongst the researchers in recent past. In this article, an attempt has been made to realize hardware friendly powers-of-two FIR filter by using an evolutionary computation, called Self-organizing Random Immigrants Genetic Algorithm (SORIGA). In connection to this, this work makes one comparative study amongst various multiplier-less FIR filters in terms of hardware complexity when implemented on an FPGA chip. Finally, supremacy of the proposed design has firmly been established by comparing its hardware cost with many of the state-of-the-art powers-of-two FIR filters.

In the progression from CMOS technology to nanotechnology, being able to assess reliability of nano-based electronic circuits is fast becoming necessary. Due to this phenomenon, several computational-based approaches have been proposed for the reliability assessment of nanotechnology-based circuit systems. In quantifying reliability measure of the desired circuit system, faulty gates are considered as the most active part of the system. To have reliable circuit system, apart from its faulty gates, the size of error, p, in those faulty gates has to be lesser than a threshold, ɛ*. In other words, for the individual faulty gates to function reliably, the parameter interval of error in those faulty gates has to be 0 ≤ p < ɛ*, based on their respective gate error thresholds. This hypothesized that reliability of the desired circuit system does not only depend on its faulty gates, but it also depends on the error threshold of those faulty gates above which no reliable computation is possible. Therefore, there is a need to compute the exact error thresholds for individual faulty gates above which no circuit made up using those gates can calculate reliably. This paper shows the employment of Probabilistic Transfer Matrix (PTM) model in deriving the exact error threshold for individual faulty gates. The employed methodology provides simple and powerful analytic method to analyze reliability measure of nanotechnology-based circuit systems.

Human action recognition from realistic videos attracts more attention in many practical applications such as on-line video surveillance and content-based video management. Single action recognition always fails to distinguish similar action categories due to the complex background settings in realistic videos. In this paper, a novel action-scene model is explored to learn contextual relationship between actions and scenes in realistic videos. With little prior knowledge on scene categories, a generative probabilistic framework is used for action inference from background directly based on visual words. Experimental results on a realistic video dataset validate the effectiveness of the action-scene model for action recognition from background settings. Extensive experiments were conducted on different feature extracted methods, and the results show the learned model has good robustness when the features are noisy.

Finite element analysis can research the change of the structure and the interior field intensity of human and animal body organs and tissues through simulation experiment. We use finite element analysis software to analyze the spinal cord surface potential and research the transmission feature of signals generated by interneurons in spinal cord which are related with body motion control and sensory processing. A three dimensional model of electrical source in rat's spinal cord was built, the influence on potential distribution on spinal cord surface caused by position changes of electrical source in transverse direction and dorsoventral direction was analyzed and calculated. We obtained the potential distribution curves of spinal cord surface and compared the results with data from animal experiments, verifying the feasibility of scheme of locating the excitatory through potential distribution on spinal cord surface.

This study presents a new algorithm for detecting dual-tone multi-frequency (DTMF) signals. The discrete multi-frequency transform (DMFT) method with optimal phase was employed to reduce the DTMF detection computations. With the DMFT approach, the pass-band ripple is employed as a cost function, and the optimal phase can be obtained using the open-loop search method. Compared to the traditional discrete Fourier transform (DFT) approach, not only is a computational saving of 75% to 83% achieved, but spectrum efficiency is also maintained. These experimental results demonstrate the excellent performance of the DMFT method.