Search results for "control system"
showing 10 items of 971 documents
Management Control Systems and ISO Certification as Resources to Enhance Internationalization and Their Effect on Organizational Performance
2012
There has been a general consensus in recent literature that internationalization is a key success factor in the competitive business environment we now live in. Using a sample of Spanish agri-food companies, the main objective of this research is to determine the linkage of Management Control Systems (MCS), ISO certifications, internationalization and performance. The results obtained reveal, as expected, that internationalization has a direct and positive relationship with organizational performance. In addition, we find that both the use of MCS and the deployment of ISO certification positively influence companies' level of internationalization. Nevertheless, our findings clearly indicat…
Efficientamento energetico di utenze domestiche nelle isole minori italiane
2020
L’articolo tratta l’efficientamento energetico nel settore residenziale delle piccole isole non connesse alla rete di trasmissione elettrica nazionale. L’analisi ha riguardato un’utenza tipo dell’Isola di Lampedusa, individuata sulla base dei dati statistici ISTAT, di cui sono stati acquisiti i dati di consumo da bolletta e monitorati i consumi elettrici al fine di selezionare gli interventi di retrofit più adeguati. Fra questi vi sono: la sostituzione degli scalda-acqua elettrici esistenti e il ricorso a tecnologie di Building Automation Control system (BACs) per la gestione dell’impianto di illuminazione e di altri carichi elettrici flessibili. La valutazione dei risparmi conseguibili è s…
An Appearance-Like Reactor Experiment To Measure Ue3
2004
Conventional reactor neutrino experiments are dissapearance experiments, and thus have less sensitivity to small mixing angles than appearance experiments do. It has been recently shown that future reactor neutrino experiments consisiting of a near and far detector are competitive with first-generation superbeams in order to determine sin^2{2 theta_{13}} down to 10^{-2}. We show that by using the antineutrino-electron elastic scattering at the near detector around the configuration where dsigma^{bar{\nu}_e}/dT presents a dynamical zero, an appearance-like experiment can be simulated, with a sensitivity comparable to the one achieved with the inverse beta-decay reaction in the far detector. …
Performance Degradation of Discrete PID Controller for Digital Excitation Control System Due to Variation of Sampling Time
2019
Modern digital AVR are consisting PID controller in forward path ensures fast response in the event of disturbance. Digital keypad is used for setting PID gains to improve performance of the system. Digital PID controller reads the error signal at regular interval unlike analog controller that reads the error signal continuously. Regular interval at which digital processor reads error signal is called sampling time that has substantial effect on the performance of the controller and consequently affects the stability of the power system where synchronous generator using digital excitation system is connected in parallel. This paper addresses the issues of variation of sampling time on the p…
Vacuum induced berry phase: Theory and experimental proposal
2003
We investigate quantum effects in geometric phases arising when a two-level system is interacting with a quantized electromagnetic field. When the system is adiabatically driven along a closed loop in the parameter space, signatures of the field quantization are observable in the geometric phase. We propose a feasible experiment to measure these effects in cavity QED and also analyse the semi-classical limit, recovering the usual Berry phase results.
New constraints on Lorentz invariance violation from the neutron electric dipole moment
2010
We propose an original test of Lorentz invariance in the interaction between a particle spin and an electromagnetic field and report on a first measurement using ultracold neutrons. We used a high sensitivity neutron electric dipole moment (nEDM) spectrometer and searched for a direction dependence of a nEDM signal leading to a modulation of its magnitude at periods of 12 and 24 hours. We constrain such a modulation to $d_{12} < 15 \times 10^{-25} \ e\,{\rm cm}$ and $d_{24} < 10 \times 10^{-25} \ e\,{\rm cm}$ at 95~\% C.L. The result translates into a limit on the energy scale for this type of Lorentz violation effect at the level of ${\cal E}_{LV} > 10^{10}$~GeV.
Design and Study of a Wide-Band Printed Circuit Board Near-Field Probe
2021
Magnetic near-field probes (NFP) represent a suitable tool to measure the magnetic field level from a small electromagnetic interference (EMI) source. This kind of antenna is useful as a magnetic field probe for pre-compliance EMC measurements or debugging tasks since the user can scan a printed circuit board (PCB) looking for locations with strong magnetic fields. When a strong H-field point is found, the designer should check the PCB layout and components placement in that area to detect if this could result in an EMI source. This contribution focuses on analyzing the performance of an easy to build and low-cost H-field NFP designed and manufactured using a standard PCB stack-up. Thereby,…
An integrated structural health monitoring system based on electromechanical impedance and guided ultrasonic waves
2015
We propose a structural health monitoring (SHM) paradigm based on the simultaneous use of ultrasounds and electromechanical impedance (EMI) to monitor waveguides. Methods based on the propagation of guided ultrasonic waves (GUWs) are increasingly used in all those SHM applications that benefit from built-in transduction, moderately large inspection ranges, and high sensitivity to small flaws. Meantime, impedance-based SHM promises to adequately assess locally the structural integrity of simple waveguides and complex structures such as bolted connections. As both methods utilize piezoelectric transducers bonded or embedded to the structure of interest, this paper describes a unified SHM para…
Sensorless variable speed single-phase induction motor drive system based on direct rotor flux orientation
2012
The single-phase induction motor (SPIM) is one of the electrical machines more used in the World, and can be found in several fractional and sub-fractional horsepower applications in houses, offices, shoppings, farms, and industries. The introduction of more sophisticated applications has required the use of variable speed drives for SPIM, where the adoption of sensorless techniques is the more reasonable option for speed control due to the low cost of this electrical machine. A proposal for sensorless variable speed SPIM drive based on direct rotor field orientation techniques is presented in this paper. None transformation is used in order to eliminate the asymmetry of the stator windings…
Speed control design for a vehicle system using fuzzy logic and PID controller
2015
This paper consists of designing fuzzy and PID controllers for controlling the vehicle speed. The dynamic of the system is modeled to provide a transfer function for the plant. Fuzzy and PID controller are designed for linear model. The external disturbances such road grade is considered to stabilizing the system. Both controllers are modeled using MATLAB Simulink software. Finally, a comparative assessment of each simulated result is done based on the response characteristics.