A robust sensorless output feedback controller of the induction motor drives: New design and experimental validation

International audienceIn this paper, a sensorless output feedback controller is designed in order to drive the Induction Motor IM without the use of flux and speed sensors. Firstly, an observer that uses only the measured stator currents is synthesized to estimate the mechanical variables (speed and load torque) and the magnetic variables (fluxes) by structurally taking into account the unobservability phenomena of the Sensorless IM (SIM) and the parametric uncertainties. Secondly, a current-based field oriented sliding mode control, that uses the flux and the speed estimates given by the former observer is developed so as to steer the estimated speed and flux magnitude to the desired references. Since the observer design is independent of the control and depends on theIM parametric uncertainties, a separation principle is introduced to guarantee the practical stability of the whole closed-loop system "observer -controller" ("O-C") according to observability and unobservability time variation. A significant benchmark taking into account the unobservability phenomena of the \textit{SIM} is presented to show the performances of the whole control scheme against experimental set-up

Optical Evidence for Mixed Phase Behavior in Manganites

Synchrotron infrared measurements were conducted over the range 100 to 8000 cm-1 on a self-doped LaxMnO3-d (x~~0.8) film. From these measurements we determined the conductivity, the effective number of free carriers, and the specific phonon modes as a function of frequency. While the metal-insulator transition temperature (TMI) and the magnetic ordering temperature (TC) approximately coincide, the free carrier density onset occurs at a significantly lower temperature (~~45 K below). This suggests that local distortions exist below TMI and TC which trap the eg conduction electrons. These regions with local distortions constitute an insulating phase which persists for temperatures significantly below TMI and TC. The initial large drop in resistivity is due to the enhanced magnetic ordering while further drops correspond to reductions in the insulating phase which increase the number of free carriers.Comment: 12 pages, 5 figure

Examining the association between perceived discrimination and heart rate variability in African Americans.

Previous research attempting to delineate the role of discrimination in racial/ethnic disparities in hypertension has focused largely on blood pressure, which is chiefly governed by the sympathetic branch of the autonomic nervous system. Consequently, few studies have considered the role of the parasympathetic branch and particularly its regulation of the heart via the vagus nerve

Increasing compliance with wearing a medical device in children with autism

Health professionals often recommend the use of medical devices to assess the health, monitor the well-being, or improve the quality of life of their patients. Children with autism may present challenges in these situations as their sensory peculiarities may increase refusals to wear such devices. To address this issue, we systematically replicated prior research by examining the effects of differential reinforcement of other behavior (DRO) to increase compliance with wearing a heart rate monitor in 2 children with autism. The intervention increased compliance to 100% for both participants when an edible reinforcer was delivered every 90 s. The results indicate that DRO does not require the implementation of extinction to increase compliance with wearing a medical device. More research is needed to examine whether the reinforcement schedule can be further thinned

Towards multisensory storytelling with taste and flavor

Film makers, producers, and theaters have continuously looked at ways to embody and/or integrate multiple sensory cues in the experiences they deliver. Here, we present a reflection on past attempts, lessons learnt, and future directions for the community around multisensory TV, film, and multimedia as a historical, though renewed, space of content creation. In particular, we present an overview of what we call "tasty film", that is, film involving taste, flavor, and more broadly food and drink inputs, to influence the audience experience. We suggest that such elements should be considered beyond "add-ons" in film experiences. We advocate for experimentation with new kinds of storytelling taking inspiration from multisensory design research and work on sensory substitution. We position this article as a starting point for anyone interested in multisensory film involving taste, flavor, and foods

Effects of vigabatrin, an irreversible GABA transaminase inhibitor, on ethanol reinforcement and ethanol discriminative stimuli in mice

We tested the hypothesis that the irreversible gamma-amino butyric acid (GABA) transaminase inhibitor, γ-vinyl GABA (Vigabatrin; VGB) would reduce ethanol reinforcement and enhance the discriminative stimulus effect of ethanol, effectively reducing ethanol intake. The present studies used adult C57BL/6J (B6) mice in well-established operant, two-bottle choice consumption, locomotor activity and ethanol discrimination procedures, to examine comprehensively the effects of VGB on ethanol-supported behaviors. VGB dose-dependently reduced operant responding for ethanol as well as ethanol consumption for long periods of time. Importantly, a low dose (200 mg/kg) of VGB was selective for reducing ethanol responding without altering intake of food or water reinforcement. Higher VGB doses (>200 mg/kg) still reduced ethanol intake, but also significantly increased water consumption and, more modestly, increased food consumption. While not affecting locomotor activity on its own, VGB interacted with ethanol to reduce the stimulatory effects of ethanol on locomotion. Finally, VGB (200 mg/kg) significantly enhanced the discriminative stimulus effects of ethanol as evidenced by significant left-ward and up-ward shifts in ethanol generalization curves. Interestingly, VGB treatment was associated with slight increases in blood ethanol concentrations. The reduction in ethanol intake by VGB appears to be related to the ability of VGB to potentiate the pharmacological effects of ethanol

On perhaps becoming what you had previously despised: Psychologists as prescribers of medication

The authors contend that organized psychology's efforts to gain limited prescriptive privileges may be misguided. The modification of psychology's traditional scope of practice may produce harm in the form of lessened patient regard, devaluation of nonpharmacologic elements of practice, and markedly increased exposure to claims of malpractice. The authors also decry the disingenuous use of psychopharmacologically “underserved” populations as rationales for the pursuit of prescriptive privileges. Psychology may mount a major effort to make this change without sufficient justification, in the view of the authors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44851/1/10880_2005_Article_BF01989620.pd

Physician Decision Making for Colorectal Cancer Screening in the Elderly

Although individualized decision making is recommended to appropriately screen for colorectal cancer (CRC) in older adults, it is unclear whether physicians solicit input from older patients before making a recommendation for or against CRC screening