Energy Reduction Factor Research Articles

Dedicated Instruction Set for Pattern-Based Data Transfers: An Experimental Validation on Systems Containing In-Memory Computing Units

In-Memory Computing (IMC) aims at solving the performance gap between CPU and memories introduced by the memory wall. However, general-purpose IMC does not consider the optimization of data transfers for patterns such as stencils and convolutions. This paper proposes a new Instruction Set Architecture (ISA) and a novel pattern encoding for IMC to transfer and organize data streams in order to perform efficiently computation. This instruction set is implemented on the Data-locality Management Unit (DMU) as a subset of the Computational SRAM (C-SRAM) Instruction Set Architecture. A programming model to interact with the DMU at languagelevel is also presented in this paper. This DMU ISA is evaluated on six applications run on three different system nodes. These system nodes are based on existing RISC-V cores and range from embedded to high-performance computing domain. Experiments show on average a speed-up of W8.81, an energy reduction factor of W6.81 and an improvement of the number of operations per cycle of W4.59, for The C-SRAM architecture integrating the proposed ISA of the DMU compared to a reference implementation on embedded systems. Results also show an improvement of the number of operations per cycle of W2.99 compared to a reference implementation on all system nodes.

Innovative nonlinear vibration control of beam structures using shear thickening fluid dampers

This paper investigates the use of shear thickening fluid (STF) dampers for reducing vibrations in beam-based structures. Designing and analyzing these systems is challenging because STF’s viscosity changes as the fluid’s vibration frequency changes. To understand the impact of key design parameters, the behavior of STF dampers in various configurations of supports is analyzed. The governing equations are derived, considering the STF dampers as nonlinear damping forces, and solved/validated using Galerkin/Hencky’s discretization methods. An energy reduction factor is introduced to compare the performance of different configurations in the frequency domain to obtain the optimal design. The results show that although the performance of STF dampers is highly dependent on the excitation frequency (with high efficiency in reducing vibrations near the resonance frequencies), the STF dampers fail to dissipate vibrations in some frequency regions. Surprising ranges of dynamic behavior, from Quasi-periodic to chaotic, are detected and analyzed. The findings also reveal that by analyzing only the shape of force–velocity curves of the STF damper, one can accurately predict the system’s performance, without the need for a full system analysis.

A study of the estimation of the photovoltaic potential at the urban level in tropical complex terrain

This work considers photovoltaic solar energy as an alternative to promote the diversification of the energy matrix and contribute to improving energy access to the citizens of Medellin Metropolitan Area, Colombia, a tropical region that is conditioned by the topography and by the different urban morphology. The objective is to direct policies and strategies for more sustainable and resilient energy use in tropical cities on complex terrain through the production of energy from alternative renewable sources. To achieve this, we assess how much of the energy demand can be generated within the city, integrated into the urban morphology at the roofs of existing buildings including the effect of topography. We use meteorological information and power measurements from three experimental solar panels. We analyze the photovoltaic energy potential in Representative Urban Areas (RUA) and provide information relevant to the whole Valley's context to guide sustainable and resilient energy planning. One particular result is about the energy reduction factor due to cloudiness, which quantifies how energy would vary under the region's cloud conditions.

Free‐rocking tests of a freestanding object with variation of center of gravity

AbstractFreestanding nonstructural objects are very common in various infrastructure systems, but their dynamic properties with variations in the center of gravity (CG) are not yet fully understood. To investigate the dynamic properties of a freestanding object as its CG is varied, a steel frame model was fabricated using movable steel plates. Two scenarios, with varying and fixed CG, were considered in the free rocking tests. The experimental rotation responses generally matched the analytical responses in the initial cycles, and the discrepancy increased as the height of the CG (hcg) increased. The magnitude of the quarter period exhibited a similar trend. When the CG was fixed, the resulting magnitude of the quarter period varied slightly with hcg, indicating that the CG is one of the primary parameters affecting the quarter period. When the CG was varied, the experimental energy reduction factor was generally larger than the analytical results computed using the methods suggested in the literature, and it was scattered around the fixed CG value. The magnitude of the damping ratio was also scattered as the quarter cycle number increased, and it slightly decreased as hcg increased. An equivalent rectangular rigid block model with an equivalent height (heq) was employed to compute the geometric and dynamic parameters of the steel frame. The accuracy of this measure was investigated in terms of the quarter period and energy reduction factor. This work is beneficial for understanding the rocking behavior of freestanding objects.

Quantification of Energy-Related Parameters for Near-Fault Pulse-Like Seismic Ground Motions

An energy-based approach facilitates the explicit consideration of the damage associated with both maximum displacements and cumulative plastic deformations under earthquakes. For structural systems that can undergo pulse-like seismic ground motions close to causative faults, an energy-based approach is deemed especially appropriate with respect to well-established force- or displacement-based strategies. In such a case, in fact, most of the damage is attributable to the dominant pulse-like component, which usually occurs into the velocity time history of the seismic ground motion, thus implying high energy levels imparted to a structural system. In order to enable the implementation of an energy-based approach in the analysis and design of structures under near-fault pulse-like seismic ground motions, this study presents a comprehensive numerical investigation about the influence of seismological parameters and hysteretic behavior on the spectra of the following energy-related parameters: inelastic absolute and relative input energy; input energy reduction factor; hysteretic energy dissipation demand; hysteretic energy reduction factor; dimensionless cumulative plastic deformation ratio. Closed-form approximations are proposed for these spectra, and the numerical values of the corresponding parameters have been also calibrated (with reference to both mean and standard deviation values) as functions of earthquake magnitude, type of hysteretic behavior (i.e., non-degrading or degrading) and ductility level. The outcomes of this study are meant to support the derivation of design spectra for the energy-based seismic design of structures under near-fault pulse-like seismic ground motions.

The energy reduction factor (FER) to model sensitive clay flowslides using in situ geotechnical and rheological data

Sensitive clays, mostly found in Eastern Canada and Scandinavia, are prone to various types of landslides; among them are flowslides that may affect hectares of land. Debris from those slides has high mobility, with runout distances that may extend over hundreds of meters in relatively flat and non-channelized terrain. Most studies on the mobility use apparent rheological properties to back-calculate the runout behavior of these landslides. This works well for back-analyses of landslides but is of little help in a context of hazard mapping, where prospective analysis of future landslides is necessary. In this study, a new factor, using the destructuration index concept, is introduced to estimate the remaining energy available as kinetic energy for runout after the remolding of the sensitive clay: the energy reduction factor (FER). Using the FER allows the use of real rheological data acquired with a rheometer to analyze the post-failure behavior of a flowslide in sensitive clays. This method is applied on a sensitive clay landslide which took place in Quebec and where rheological and geotechnical data are available.

Stress-Strain Response of Cylindrical Rubber Fender under Monotonic and Cyclic Compression.

The study was devoted to the observation and modeling the mechanical behaviors of a hybrid SBR/NR (Styrene-Butadiene/Natural Rubber) hybrid vulcanized rubber fender under monotonic/cyclic compression. In experimental observations of the monotonic compression tests, it was found that lateral deformation occurred on the tested fender and was more significant with increasing the extent of the compressive strain. The relationship between the transmission stress and the compressive strain was nonlinear and the absorbed strain-energy-density was increased monotonically with the increment of the compressive strain. Among all cyclic compression tests with strain controlled, the reductions in both the stress range and the absorbed strain-energy-density up to the ten-thousandth cycle were found and then both of the cyclic properties remain approximately constant in the following compression cycles. Two new properties, the softening factor and the energy reduction factor, were introduced to quantify the effect of the strain range on the extent of the reduction in stress range and that on the absorbed strain-energy-density, respectively. It was found that both of the calculated values of the new properties increase with the increment of strain range. In mathematical modeling of the relationship between the transmission stress and the compressive strain, a new approach based on energy-polynomial-function was presented and was successfully used to simulate the monotonic curve and the stable hysteresis loop curves of the tested rubber fender in compression. Essentially, the energy-polynomial-function was obtained by performing a polynomial regression on a large amount of ( data. Moreover, the least-square approach was applied to determine the corresponding regression coefficients in . Clearly, the stress-polynomial-function in modeling the curve could be obtained from the differentiation of the energy-polynomial-function with respect to the compressive strain. In addition, to provide an adequate estimation of the mechanical properties of the cylindrical rubber fender under compression, the named cyclic stress-strain curve and cyclic energy-strain curve were developed and also modeled in this study.

Modelling the cross-shore profiles of sand beaches using artificial neural networks

Artificial neural networks (ANN) have been widely used successfully to solve coastal engineering problems. In this article, they are used to model the cross-shore profile of sandy beaches taking into account the possible effect of marine vegetation (Posidonia oceanica). Sixty ANNs were generated by modifying both the inputs and the number of neurons in the hidden layer. The best results were obtained with the following inputs: wave height perpendicular to the coast and the associated period and probability of occurrence, median sediment size, profile slope, and energy reduction factor due to P. oceanica. With these inputs and 10 neurons in the hidden layer, a mean absolute error of 0.22 m during training and 0.21 m during the test was obtained, which represents an improvement of 81.2% and 55.5% compared to models without and with P. oceanica.

Energy Saving In Wireless Sensor Network Using Burst Algorithm

A wireless sensor network is composed of a large number of low-cost devices distributed over a geographic area. Sensor nodes have limited processing capabilities therefore simplified protocol architecture should be designed so as to make communications simple and efficient. Moreover, the power supply unit is based on an energy-limited battery the networks should be aimed at minimizing the energy consumption. A forwarding scheme for WSN aimed at combining low computational complexity and high performance in terms of energy efficiency and reliability. The approach relies on a packet-splitting algorithm based on the BURST algorithm. The performance of burst is to be obtained by Shortest Path with Load Balancing (SP).The energy efficiency is low in this splitting process compare to those shortest paths. To estimation of the mean energy reduction factor achievable with the forwarding scheme should be derived and the reassembling is done in destination side, the values to be coded in code block. Simulated using MATLAB simulator. The proposed algorithm outperforms in terms of energy saving and increases the network lifetime. Index: BURST, WSN, SP, ENERGY EFFICIENCY, PACKETS.

Density-functional theory with adaptive pair density: The Gutzwiller approximation as a density functional

We propose a density functional to find the ground state energy and density of interacting particles, where both the density and the pair density can adjust in the presence of an inhomogeneous potential. As a proof of principle we formulate an a priori exact functional for the inhomogeneous Hubbard model. The functional has the same form as the Gutzwiller approximation but with an unknown kinetic energy reduction factor. An approximation to the functional based on the exact solution of the uniform problem leads to a substantial improvement over the local density approximation.

Nonlinear Aircraft Loads in Severe Atmospheric Turbulence

The problem of predicting loads due to turbulence for aircraft with nonlinear flight-control systems is reviewed, and related recent research in this area is described. Two alternative approaches to the problem, stochastic simulation and worst-case analysis, are compared and problem areas associated with each are identified. It is concluded that the latter method, which involves a search over a specified family of gust patterns to find the pattern thatcauses maximum load,is appropriate for investigating a limited number of criticalcases, butthat apreliminary simplified method of estimation is called for by computational considerations as a means of identifying such critical cases. A new genetic algorithm is described and proposed as the most reliable method of performing the search. It is illustrated how this search algorithm can be simplified computationally by introducing a weighting factor that penalizesthemorecomplexgustpatterns,astepthatissupportedbymeasurementsoftheamplitudesofgustpatterns in severe turbulence. Nomenclature � A = measure of response found by power spectral density analysis a = empirical constant in Eq. (2) b = empirical constant in Eq. (2) e = energy-reduction factor n = number of component ramp gusts in the discrete gust pattern pi = absolute value of the wavelet coefficient SI = information entropy U = energy of the single-wavelet pattern U� = design gust velocity

Experimental study of torsional impact fatigue of shafts

This paper presents a methodology to study the fatigue strength of shafts under repeated impacts. The equipment for repeated impacts was designed for torsion tests of shafts for the same loading conditions as in service. The stress concentration effect, due to a fillet radius between square and circular cross-sections of the axle, was emphasized. Five groups of shafts with radius between 0.5 and 3.2 mm from a number of 100 shafts with different notch radius were selected. Based on a model proposed by the authors for defining the energy reduction factor β due to a notch the variation of the notch sensitivity factor η versus fillet radius was analyzed for two different numbers of cycles. It was observed that for a high number of cycles ( N=2×10 6 impacts) the behaviour is similar to that of traditional fatigue tests. Oppositely, at lower number of cycles the particular aspect of the notch sensitivity is highlighted in the limited durability domain.

Performance evaluation of W-CDMA in actual impulsive noise scenarios using adaptive antennas

It is well known that impulsive noise may significantly degrade wireless digital communication performance. The authors quantify the BER degradation of W-CDMA signals in the presence of measured impulsive noise interference, and evaluate the performance improvement obtained using adaptive antennas in cellular base stations. The scope of this contribution is two-fold. First, the BER under actual impulsive noise conditions in a single-user situation is estimated by means of Monte Carlo simulations. Then, performance evaluation is made in the presence of MAI in actual impulsive interference scenarios. Shot noise has been modelled as a train of pulses, whose parameters have been obtained from actual data of measurement campaigns in the UMTS band carried out in a typical urban environment. The antenna array has been modelled according to the specifications of a smart antenna prototype under development. Results show that adaptive antennas with beamforming based on the MMSE criteria provide a significant interference energy reduction factor at the array output with respect to a conventional sectored antenna when impulsive noise is present, which straightforwardly implies link quality improvement and system capacity enhancement.