Search results for "Hard"
showing 10 items of 2294 documents
Multiplexing AER asynchronous channels over LVDS links with flow-control and clock-correction for scalable neuromorphic systems
2017
Paper presented at the 2017 IEEE International Symposium on Circuits and Systems (ISCAS), held in Baltimore, MD, USA, on 28-31 May 2017.
On the influence of gravitational and centrifugal buoyancy on laminar flow and heat transfer in curved pipes and coils
2015
Abstract The effects of gravitational and centrifugal buoyancy on laminar flow and heat transfer in curved and helical pipes were investigated by numerical simulation. Six dimensionless numbers characterizing the problem were identified, and an analysis was conducted on the possible combinations of signs of the gravitational and centrifugal buoyancy effects. Two distinct Richardson numbers were introduced in order to quantify the importance of the two types of buoyancy, and it was shown that, in the case of heating from the wall, a maximum realizable value of the centrifugal Richardson number exists which is a linear function of the curvature δ (ratio of pipe radius a to curvature radius c)…
Route to chaos in the weakly stratified Kolmogorov flow
2019
We consider a two-dimensional fluid exposed to Kolmogorov’s forcing cos(ny) and heated from above. The stabilizing effects of temperature are taken into account using the Boussinesq approximation. The fluid with no temperature stratification has been widely studied and, although relying on strong simplifications, it is considered an important tool for the theoretical and experimental study of transition to turbulence. In this paper, we are interested in the set of transitions leading the temperature stratified fluid from the laminar solution [U∝cos(ny),0, T ∝ y] to more complex states until the onset of chaotic states. We will consider Reynolds numbers 0 < Re ≤ 30, while the Richardson numb…
A simple procedure to improve the pressure evaluation in hydrodynamic context using the SPH
2009
In literature, it is well know that the Smoothed Particle Hydrodynamics method can be affected by numerical noise on the pressure field when dealing with liquids. This can be highly dangerous when an SPH code is dynamically coupled with a structural solver. In this work a simple procedure is proposed to improve the computation of the pressure distribution in the dynamics of liquids. Such a procedure is based on the use of a density diffusion term in the equation for the mass conservation. This diffusion is a pure numerical effect, similar to the well known artificial viscosity originally proposed in SPH method to smooth out the shock discontinuities. As the artificial viscosity, the density…
Hardware implementation of content based video indexing algorithms
2005
This paper focus on hardware implementation of content based video indexing techniques by using the FPGA technology. We aim to propose hardware modules that can satisfy requirements of constrained applications, such as real time applications and complex applications that can combine a large number of techniques in the same indexing system. We represent tow examples of micro-architectures related to the dominant colors descriptor and the compact color descriptor.
Recent Advances in Security and Privacy for Future Intelligent Networks
2020
The articles in this special section focus on recent advances in security and privacy for future intelligent networks. Recent booming advancements in networking techniques have led to an evolution toward future intelligent networks (FINs). This trend takes place under a circumstance in which a great number of devices are connected for specific purposes by a variety of novel techniques. In FINs, we envision the benefits of integrating intelligence into networks. Contemporarily, these emerging techniques are still at the exploration stage, leaving many privacy and security challenges unaddressed. Existing researchers have already uncovered a great amount of attacks and threats. The situation …
Pair potential calculation of molecular associations: a vectorized version
1991
Abstract The program AMYRVF is a vectorized and largely modified version of a previous program called AMYR for calculating molecular associations by means of Fraga's pair-wise atom-atom potential. Three new minimization procedures have been implemented as well as other improvements such as the inclusion of new pair-wise dispersion energy terms with damping functions, and the calculation of topological indices. Benchmark tests have been carried out on an IBM 3090 150E VF; the timings for the new vector algorithms and for the standard scalar computations, as well as the dependence of the overall performance gain on the size of interacting systems are reported for the VS Fortran 2.4 compiler e…
An improved Flyback converter
2009
This paper presents a modified Flyback converter able to operate with higher efficiency and smaller size, overcoming most of the conventional flyback converter drawbacks, and also keeping its low cost and simplicity. In particular, the proposed converter allows the mosfet off voltage to be reduced and clamped to the input, thus recovering the transformer leakage energy. As a consequence, the duty cycle can be extended to unity, thus reducing the voltage stress across the output rectifier, and lowering both the magnetizing inductance and the transformer bias current values. In addition, due to the auxiliary mosfet, the magnetizing current can become negative, eliminating the discontinuous co…
Solid-liquid nuclear magnetic resonance relaxation and signal amplitude relationships with ranking of seasoned softwoods and hardwoods
2006
In 1H NMR (Nuclear Magnetic Resonance) relaxation measurements for a set of eight hardwood and softwood samples, each Free Induction Decay (FID) is fit by the sum of a “Solid” signal of the form A exp[−c(t/Ts)2] [1−g(t/Ts)2+h(t/Ts)4] plus a “Liquid” signal B exp(−t/T2 FID). Distributions of longitudinal (T1) relaxation times were computed separately for the Solid and Liquid components, giving also the Solid/Liquid 1H ratio α. From measurements on the samples dried, seasoned, and hydrated, the moisture content, (Liquid/Solid weight ratio) was found to be approximately 0.50/α. For each of the “Seasoned” samples (10-13% moisture content) a single T1 peak was found for the Solid and two for the…
The influence of the propagation path length on the results of the time–frequency analysis of the acoustic emission generated by partial discharges i…
2006
The paper presents the measurement results of the acoustic emission (AE) signals generated by partial discharges (PDs) at various thickness of the oil insulation layer. For the AE signals registered the time - frequency analysis was carried out based on the use of the short-time Fourier transform (STFT). Two- and three-dimensional spectrograms of the power spectrum density and the amplitude spectrum were determined. The evaluation of the influence of the propagation path length of the AE signal on the results of the time - frequency analysis was performed through the analysis of the spectrograms determined.