Search results for "Tracking"
showing 10 items of 709 documents
Modeling the machined surface quality of an aluminum alloy using the active experiment type
2019
Abstract The surface roughness obtained by the cutting processes has always been a subject of great interest when it is intended to improve the quality of the final product requested by the customer. The objective of this scientific paper involves a comparative study on the tracking of the surface roughness measured both longitudinally and transversely in the direction of the cutting feed movement, following the end-milling process of an aluminum alloy used in the aerospace industry worldwide. Practical experiments have conducted in a prestigious company in the aerospace industry of Romania. Regarding the cutting regime, in terms of milling, a cutting speed was adopted to maintain its const…
Pillararene-based fluorescent sensors for the tracking of organic compounds
2019
Abstract Fluorescent chemosensors based on pillararene complexes represent a new, promising branch in sensor technology. Because of CH⋅⋅⋅π interactions, aliphatic chains are well suited for the columnar cavities of pillararenes and bulky or sheet-like (sub)structures can be arranged on the portals. Thus, pillararenes form versatile receptors and an alteration of the fluorescence behavior upon complexation ensures the function of these chemosensors as the reporter. Although this field of research exists only since a few years, remarkable chemosensors were developed for substances as diverse as medical drugs, biochemicals, herbicides and explosives.
SiPMs coated with TPB: coating protocol and characterization for NEXT
2012
[EN] Silicon photomultipliers (SiPM) are the photon detectors chosen for the tracking readout in NEXT, a neutrinoless \bb decay experiment which uses a high pressure gaseous xenon time projection chamber (TPC). The reconstruction of event track and topology in this gaseous detector is a key handle for background rejection. Among the commercially available sensors that can be used for tracking, SiPMs offer important advantages, mainly high gain, ruggedness, cost-effectiveness and radio-purity. Their main drawback, however, is their non sensitivity in the emission spectrum of the xenon scintillation (peak at 175 nm). This is overcome by coating these sensors with the organic wavelength shifte…
Laser Vibrometer Interferometry for Speckle Patterns Tracking Systems
2017
In this paper we propose a modulated laser system combining a speckle pattern tracking method for surface tilting changes sensing with an interferometer for surface z-axis changes sensing at the same scan time.
Demonstration of remote optical measurement configuration that correlates to glucose concentration in blood
2010
An optical approach allowing the extraction and the separation of remote vibration sources has recently been proposed. The approach has also been applied for medical related applications as blood pressure and heart beats monitoring. In this paper we demonstrate its capability to monitor glucose concentration in blood stream. The technique is based on the tracking of temporal changes of reflected secondary speckle produced in human skin (wrist) when being illuminated by a laser beam. A temporal change in skin’s vibration profile generated due to blood pulsation is analyzed for estimating the glucose concentration. Experimental tests that were carried out in order to verify the proposed appro…
Robust control for autonomous spacecraft evacuation with model uncertainty and upper bound of performance with constraints
2014
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2014/589381 This paper studies the problem of guaranteed cost control for spacecraft evacuation. The relative dynamic model is established based on Clohessy-Wiltshire (C-W) equations. The paper has taken parameter uncertainty, output tracking, disturbance attenuation, and fuel cost into consideration. The paper introduces a new Lyapunov approach, so the controller design problem can be transferred into a convex optimization problem subject to linear matrix inequality (LMI) constraints. By using the controller, the spacecraft evacuation can be …
Approximation-Based Adaptive Fuzzy Tracking Control for a Class of Nonstrict-Feedback Stochastic Nonlinear Time-Delay Systems
2015
This paper focuses on the problem of approximation-based adaptive fuzzy tracking control for a class of stochastic nonlinear time-delay systems with a nonstrict-feedback structure. A variable separation approach is introduced to overcome the design difficulty from the nonstrict-feedback structure. Mamdani-type fuzzy logic systems are utilized to model the unknown nonlinear functions in the process of controller design, and an adaptive fuzzy tracking controller is systematically designed by using a backstepping technique. It is shown that the proposed controller guarantees that all signals in the closed-loop system are fourth-moment semiglobally uniformly ultimately bounded, and the tracking…
Maximum Power Point Tracker for Standalone PV System Using Neural Networks
2019
In this work, designing and implementation of a maximum power point tracker (MPPT) based on an artificial neural network is proposed. The output voltage of the selected photovoltaic array is controlled by a DC to DC boost converter in a way that the PV array generates the available possible maximum power correspond to the available solar irradiance and temperature. The neural network (NN) is capable of forecasting the required terminal voltage of the PV array in order to generate the possible maximum power. The pulse width modulation (PWM) signal, which drives the boost converter, is generated through a raspberry pi according to the forecasted terminal voltage. The terminal voltage of the P…
Real time estimation of photovoltaic modules characteristics and its application to maximum power point operation
2007
In this paper, an approximate curve fitting method for photovoltaic modules is presented. The operation is based on solving a simple solar cell electrical model by a microcontroller in real time. Only four voltage and current coordinates are needed to obtain the solar module parameters and set its operation at maximum power in any conditions of illumination and temperature. Despite its simplicity, this method is suitable for low cost real time applications, as control loop reference generator in photovoltaic maximum power point circuits. The theory that supports the estimator together with simulations and experimental results are presented.
Attentional biases toward emotional images in the different episodes of bipolar disorder: an eye-tracking study.
2014
Attentional biases toward emotional information may represent vulnerability and maintenance factors in bipolar disorder (BD). The present experimental study examined the processing of emotional information in BD patients using the eye-tracking technology. Bipolar patients in their different states (euthymia, mania, depression) simultaneously viewed four pictures with different emotional valence (happy, neutral, sad, threatening) for 20 s while their eye movements were monitored. A group of healthy individuals served as the control. The data revealed the following: (i) a decrease in attention to happy images in BD patients in their depressive episodes compared to healthy individuals, and (ii…