Search results for " ori"
showing 10 items of 1374 documents
Dynamical Compensation of the Load Torque in a High-Performance Electrical Drive with an Induction Motor
2018
This paper describes a new method for dynamical estimation of load disturbance in induction motors by using Nonlinear Unknown Input Observers (NUIO). This estimation is then used to compensate dynamically the load torque in a Field Oriented Control (FOC) induction motor drive to increase its load-rejection capability. The method has been verified both in simulation and experimentally on a experimental rig.
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…
Sensorless variable speed single-phase induction motor drive system
2012
It is usual find single-phase induction motor (SPIM) in several house, office, shopping, farm, and industry applications, which are become each time more sophisticated and requiring variable speed drives. Considering the low cost of this machine, the adoption of sensorless speed control is the more reasonable option for SPIM drives. This paper presents a proposal for sensorless variable speed SPIM drive based on direct rotor field orientation techniques. An observer based on two independent linear close-loop control systems provides the estimation of the rotor flux and speed from the measurements of the stator currents and voltages. These estimatives are used by close-loop systems for speed…
Dielectrophoretic trapping of DNA origami.
2008
In this thesis three-dimensional tube-shaped DNA-origamis were dielectrophoretically trapped within lithographically fabricated nanoelectrodes. The origamis had been premade while the electrodes were fabricated specifically for these experiments with two different gapsizes, 150 nm and 400 nm. The aim of the work was to capture individual nanotubes in the gap between the electrodes by utilizing the dielectrophoretic forces present in the structure when a solution containing the origamis was put onto the electrodes and a voltage was applied. It was observed during the experiments that the success of the dielectrophoretic trapping depended strongly on the trapping conditions. This caused the t…
Dielectrophoretic trapping of multilayer DNA origami nanostructures and DNA origami-induced local destruction of silicon dioxide
2015
DNA origami is a widely used method for fabrication of custom-shaped nanostructures. However, to utilize such structures, one needs to controllably position them on nanoscale. Here we demonstrate how different types of 3D scaffolded multilayer origamis can be accurately anchored to lithographically fabricated nanoelectrodes on a silicon dioxide substrate by DEP. Straight brick-like origami structures, constructed both in square (SQL) and honeycomb lattices, as well as curved "C"-shaped and angular "L"-shaped origamis were trapped with nanoscale precision and single-structure accuracy. We show that the positioning and immobilization of all these structures can be realized with or without thi…
Kokemus elämänhallinnasta eläkkeelle siirryttäessä ja kolmannessa iässä
2008
Suomalaisen yhteiskunnan vanheneminen ja suurten ikäluokkien siirtyminen eläkkeelle ja kolmanteen ikään nostaa esille kysymyksiä, miten vastattaisiin tulevaisuuden palvelujen tarpeisiin ja miten palvelujärjestelmää olisi kehitettävä. Tutkimuksen tarkoitus on selvittää 60- ja 65-vuotiaiden ikääntyvien elämänhallintaa ja nykyistä sekä tulevaa tuen tarvetta. Elämänhallinnan viitekehyksenä on Antonovskyn koherenssiteoria, jossa elämänhallinta rakentuu merkityksellisyydestä, hallinnantunteesta ja ymmärrettävyydestä. Aineisto koostuu 35 Helsingin Vanhan kaupungin alueella asuvan henkilön haastattelusta. Haastateltavista enemmistö oli jo eläkkeellä, mutta osa oli vielä työelämässä. Haastattelu rak…
Graphical models for estimating network determinants of multi-destination trips in Sicily
2017
Abstract This paper proposes a two-step approach for analysing the main determinants of multi-destination trip behaviour. It is based on a combination of graphical models and of a multinomial logistic regression model; the aim is to analyse direct and indirect effects of a wide set of tourist- and trip-related characteristics on multi-destination trip behaviour. Empirical data have been derived from a frontier survey of approximately 4000 incoming tourists in Sicily (Italy) at the end of their trip. Results suggest that multi-destination trips depend directly on the length of stay, the number of previous visits and motivation for the trip, and only indirectly on the interview month, travel …
Resultado económico y de empleo en las organizaciones sociales de origen familiar
2018
La Unión Europea ha apostado por el modelo de empresa social como una herramienta para corregir los desequilibrios socioeconómicos en los países miembros. En el contexto de la economía española, las organizaciones familiares destacan debido a su fuerte presencia y apoyo. El objetivo de este trabajo es estudiar la relación entre el rendimiento económico y el nivel de empleo, como indicador de impacto social, en las organizaciones aragonesas de origen familiar, así como las diferencias en esta interacción cuando la forma lucrativa o no lucrativa de la estructura formada por la unidad familiar se introduce como variable moderadora. Para ello, se obtuvo una muestra de 2.931 empresas y 117 funda…
Educación para la innovación agraria. Un modelo para la acción educativa
2019
[ES] Este estudio se centra en la figura del productor agrario valenciano y su comportamiento frente a la innovación. Adoptar una postura proclive a la innovación depende de múltiples factores que influyen en la gestión de la empresa agraria. Este estudio utiliza los datos procedentes de una encuesta a productores agrarios valencianos, diseñada ad hoc para la investigación, que profundiza en los factores socioeconómicos que pueden decantar al productor agrario hacia una postura favorable a la innovación. Posteriormente, el estudio se centra en obtener un perfil tipo que caracteriza al productor según sus características y las de su explotación, según su actitud innovadora y la orientación h…