Search results for "Speed"
showing 10 items of 876 documents
SOX: search for short baseline neutrino oscillations with Borexino
2015
International audience; The Borexino detector has convincingly shown its outstanding performances in the low energy regime through its accomplishments in the observation and study of the solar and geo neutrinos. It is then an ideal tool to perform a state of the art source-based experiment for testing the longstanding hypothesis of a fourth sterile neutrino with ~ eV(2) mass, as suggested by several anomalies accumulated over the past three decades in source, reactor, and accelerator-based experiments. The SOX project aims at successively deploying two intense radioactive sources, made of Cerium (antineutrino) and Chromium (neutrino), respectively, in a dedicated pit located beneath the det…
Impacts of soil moisture content on simulated mesoscale circulations during the summer over eastern Spain
2015
Abstract The Regional Atmospheric Modeling System (RAMS) version 6.0 has been used to investigate the impact and influence of initial soil moisture distributions on mesoscale circulations. To do this, two different events have been selected from the 2011 summer season: one at the beginning of the season (June) and the other one at the end of the season (August). For each of these mesoscale frameworks a total of five distinct simulations were performed varying the initial soil moisture content: a control run and four additional sensitivity tests. The control run, corresponding to a low soil moisture content, is the one used within the real-time weather forecasting system implemented in the V…
Fuzzy Non-fragile H∞ Tracking Control for Flexible Air-breathing Hypersonic Vehicles
2012
Abstract This paper proposed a fuzzy non-fragile tracking control design method for flexible air-breathing hypersonic vehicles (FAHVs). The T-S fuzzy set approach is applied to the modeling of the complex nonlinear dynamics of FAHVs, and a T-S fuzzy model is constructed, which can represent the nonlinear hypersonic vehicle system. Then, by considering the actuator controller coefficients uncertainties and disturbances, the fuzzy non-fragile H ∞ tracking problem for FAHVs is proposed. A state-feedback controller design method is proposed to guarantee the tracking performance in the presence of actuator controller coefficients uncertainties. By a Lyapunov approach, the existence conditions fo…
Reference tracking control of hypersonic vehicles using switched linear parameter-varying approach
2013
This paper is concerned with the control problem of the air-breathing hypersonic vehicle using switched linear parameter-varying (LPV) systems approach. By linearizing the nonlinear model of the hypersonic vehicle at trim points and dividing the velocity scope into several partitions, a switched LPV model for the underlying systems is derived. With aid of multiple Lyapunov-like functions technique, the controllers ensuring the tracking of given commands of the closed-loop system are designed under the mode-independent and mode-dependent switching logics, respectively. Simulation results for the hypersonic vehicle show the effectiveness of the proposed method and the advantages of the mode-d…
Strong thermal nonequilibrium in hypersonic CO and CH4 probed by CRDS
2015
A new experimental setup coupling a High Enthalpy Source (HES) reaching 2000 K to a cw-cavity ring-down spectrometer has been developed to investigate rotationally cold hot bands of polyatomic molecules in the [1.5, 1.7] μm region. The rotational and vibrational molecular degrees of freedom are strongly decoupled in the hypersonic expansion produced by the HES and probed by cavity ring-down spectroscopy. Carbon monoxide has been used as a first test molecule to validate the experimental approach. Its expansion in argon led to rotational and vibrational temperatures of 6.7 ± 0.8 K and 2006 ± 476 K, respectively. The tetradecad polyad of methane (1.67 μm) was investigated under similar condit…
Engineering the hypersonic phononic band gap of hybrid Bragg stacks.
2012
We report on the full control of phononic band diagrams for periodic stacks of alternating layers of poly(methyl methacrylate) and porous silica combining Brillouin light scattering spectroscopy and theoretical calculations. These structures exhibit large and robust on-axis band gaps determined by the longitudinal sound velocities, densities, and spacing ratio. A facile tuning of the gap width is realized at oblique incidence utilizing the vector nature of the elastic wave propagation. Off-axis propagation involves sagittal waves in the individual layers, allowing access to shear moduli at nanoscale. The full theoretical description discerns the most important features of the hypersonic one…
Frailty Tools for Assessment of Long-term Prognosis After Acute Coronary Syndrome
2020
Objective: To evaluate the 5 components of the Fried frailty phenotype (self-reported unintentional weight loss, physical activity questionnaire, gait speed, grip strength, and self-reported exhaustion) for long-term outcomes in elderly survivors of acute coronary syndrome. Methods: A total of 342 consecutive patients (from October 1, 2010, to February 1, 2012) were included. The 5 components of the Fried score and albumin concentration, as malnutrition index, were assessed before hospital discharge. Patients were followed up until April 2020 (median follow-up, 8.7 years). The end point was postdischarge all-cause mortality. Results: Mean ± SD age was 77±7 years and mean ± SD Fried score wa…
Enhancing Speed Loop PI Controllers with Adaptive Feed-forward Neural Networks: Application to Induction Motor Drives
2022
This paper proposes the idea to improve the performance of the speed loop PI controller by using feed-forward and adaptive control actions. Indeed, when the system to be controlled is required to track a rapidly changing reference frame, higher bandwidth is usually required, making the system more sensitive to noise and consequently less robust. In such cases, to achieve a better performance in reference tracking while keeping noise rejection capacity, one idea is to use a feed-forward controller, employed to enhance the required tracking, leaving the feedback action to stabilize the system and suppress higher frequency disturbance. As such, this paper analysis the classical PI based field …
Infrastructure as interface. Thinking the urban and the high -speed station: italian case-studies.
2011
This presentation will document some results of an ongoing research focusing on the role of infrastructure in contemporary design practice. The methodology is based on critical design theory and combines theoretical aspects with a case-study approach, at the junction of infrastructure, urban design and architecture. It is already well documented that 19th and 20th century infrastructure have deeply affected their programs in order to face new challenges over the last 30 decades. Railway stations are leading examples in this fields: they have gradually implemented their design, that already integrated commercial spaces and facilities, until involving in public space transformation. Instead, …
LightSpMV: Faster CSR-based sparse matrix-vector multiplication on CUDA-enabled GPUs
2015
Compressed sparse row (CSR) is a frequently used format for sparse matrix storage. However, the state-of-the-art CSR-based sparse matrix-vector multiplication (SpMV) implementations on CUDA-enabled GPUs do not exhibit very high efficiency. This has motivated the development of some alternative storage formats for GPU computing. Unfortunately, these alternatives are incompatible with most CPU-centric programs and require dynamic conversion from CSR at runtime, thus incurring significant computational and storage overheads. We present LightSpMV, a novel CUDA-compatible SpMV algorithm using the standard CSR format, which achieves high speed by benefiting from the fine-grained dynamic distribut…