Search results for "automatic"
showing 10 items of 730 documents
Feedback Linearizing Control of Induction Motor Considering Magnetic Saturation Effects
2015
This paper presents an input-output feedback linearization (FL) control technique for rotating induction motors, which takes into consideration the magnetic saturation of the iron core. Starting from a new formulation of the dynamic model taking into consideration the magnetic saturation expressed in a space-state form in the rotor-flux-oriented reference frame, the corresponding FL technique has been developed. To this aim, a particular care has been given to the choice of nonlinear functions interpolating the magnetic parameters versus the rotor magnetizing current and the corresponding magnetic characteristic. The proposed FL technique has been tested experimentally on a suitably develop…
Patvaļīga piekļūšana automatizētai datu apstrādes sistēmai. Ar to radītais kaitējums un problemātika
2016
Darbā tiek apskatīts viens no bīstamākiem un neparedzamiem noziedzīgiem nodarījumiem kas tiek dvti par kibernoziegumiem. Šo noziedzīgo nodarījumu skaits un sarežģītība pieaug ar katru gadu. Latvijā var sastapt vairākus kibernozieguma veidus. Viens no izplatītākajim ir paltvaļīga peikļūšana automatizētai datu apstrādes sistēmai, par kuru paredzēta kriminālatbildība Krimināllikuma 241.pantā. Izmeklējot šāda veida noziedzīgus nodarījumus rodas problēmas, kā parezi kvalificēt noziedzīgo nodarījumu, kam jāpievērš uzmanība, lai izmeklēšanas gala rezultātā noziedzīgs nodarījums netiktu kvalificēts pēc cita krimināllikuma panta. Pastāvot šāda veida noziedzīgo nodarījumu izmeklēšanas problēmām, Latv…
ARIANNA: pAth Recognition for Indoor Assisted NavigatioN with Augmented perception
2013
ARIANNA stands for pAth Recognition for Indoor Assisted Navigation with Augmented perception. It is a flexible and low cost navigation system for vi- sually impaired people. Arianna permits to navigate colored paths painted or sticked on the floor revealing their directions through vibrational feedback on commercial smartphones.
System identification via optimised wavelet-based neural networks
2003
Nonlinear system identification by means of wavelet-based neural networks (WBNNs) is presented. An iterative method is proposed, based on a way of combining genetic algorithms (GAs) and least-square techniques with the aim of avoiding redundancy in the representation of the function. GAs are used for optimal selection of the structure of the WBNN and the parameters of the transfer function of its neurones. Least-square techniques are used to update the weights of the net. The basic criterion of the method is the addition of a new neurone, at a generic step, to the already constructed WBNN so that no modification to the parameters of its neurones is required. Simulation experiments and compa…
Glottal Source Features for Automatic Speech-Based Depression Assessment
2017
Depression is one of the most prominent mental disorders, with an increasing rate that makes it the fourth cause of disability worldwide. The field of automated depression assessment has emerged to aid clinicians in the form of a decision support system. Such a system could assist as a pre-screening tool, or even for monitoring high risk populations. Related work most commonly involves multimodal approaches, typically combining audio and visual signals to identify depression presence and/or severity. The current study explores categorical assessment of depression using audio features alone. Specifically, since depression-related vocal characteristics impact the glottal source signal, we exa…
Automatic Processing of Changes in Facial Emotions in Dysphoria: A Magnetoencephalography Study
2018
It is not known to what extent the automatic encoding and change detection of peripherally presented facial emotion is altered in dysphoria. The negative bias in automatic face processing in particular has rarely been studied. We used magnetoencephalography (MEG) to record automatic brain responses to happy and sad faces in dysphoric (Beck’s Depression Inventory ≥ 13) and control participants. Stimuli were presented in a passive oddball condition, which allowed potential negative bias in dysphoria at different stages of face processing (M100, M170, and M300) and alterations of change detection (visual mismatch negativity, vMMN) to be investigated. The magnetic counterpart of the vMMN was el…
Opinion dynamics, stubbornness and mean-field games
2014
This paper studies opinion dynamics and stubbornness using mean-field game theory. Assuming an initial exponential density function and affine control policies we analyze under what conditions the Fokker-Planck equation returns an exponential density function over the horizon. Consensus and clusters formation are also studied.
Implicit regulation for automotive variators
2001
A well-known practice uses mechanical variators to realize the so-called continuously variable transmissions (CVTs) for automotive application. A remarkable problem for one of the most used CVTs is given by the hydraulic control of the axial thrust on the half-pulleys that is necessary for torque transmission. It involves a heavy decrease in transmission efficiency. In the present paper, the possible production of the required axial thrust by a simple spring to eliminate hydraulic losses is analysed. It is shown that the power capacity of such a regulated variator is near to the maximum possible, and the belt torque loss is always considerably lower than the sum of the belt and pump losses…
Automatic Generation of Figural Analogies With the IMak Package
2018
Automatic Item Generation (AIG) techniques are offering innovative ways to produce test items as they overcome many disadvantages involving standard item writing, such as time-consuming work and resource-intensive demands. Although this field is relatively new, it is progressing at a high speed, and several contributions have been accomplished. Nevertheless, a scarce amount of AIG software evidencing favorable psychometric properties of the generated items has been made accessible to the broad scientific community. This research had two goals: first, to present an empirical study of items produced with the aid of the Item Maker (IMak) package available online and, second, to present IMak it…
A Nonlinear Circulatory Model for Artificial Heart Studies
1983
Animals with total artificial heart replacement (TAH) have survived for up to 9 months with manually controlled driving systems. A certain physiological control is provided by the animals intact peripheral regulation resulting in pathological venous hemodynamics, expressing the needs for a technical automatic control system, replacing the natural sympathetic stimulation and Starlings Law of the heart. A nonlinear dynamic mathematical model of the human cardiovascular system (CVSM) containing the systemic and pulmonary components was outlined and verified, which is employable to analyse the hemodynamic behaviour under normal and abnormal states. By modifying this model, assuming that cardiac…