Search results for "production [muon]"
showing 10 items of 91 documents
A Novel Solution for the Elimination of Mode Switching in Pump-Controlled Single-Rod Cylinders
2020
This paper concerns the stability issue of pump-controlled single-rod cylinders, known as mode switching. First, a review of the topic is provided. Thereafter, the most recently proposed solution for the elimination of mode switching is investigated and shown to result in unstable behavior under certain operating conditions. A theoretical analysis is provided demonstrating the underlying mechanisms of this behavior. Based on the analysis, a novel control strategy is proposed and investigated numerically. Proper operation and stability are demonstrated for a wide range of operating conditions, including situations under which the most recently proposed solution results in unstable behavior a…
A model of COVID-19 pandemic evolution in African countries
2021
We studied the COVID-19 pandemic evolution in selected African countries. For each country considered, we modeled simultaneously the data of the active, recovered and death cases. In this study, we used a year of data since the first cases were reported. We estimated the time-dependent basic reproduction numbers, $R_0$, and the fractions of infected but unaffected populations, to offer insights into containment and vaccine strategies in African countries. We found that $R_0\leq 4$ at the start of the pandemic but has since fallen to $R_0 \sim 1$. The unaffected fractions of the populations studied vary between $1-10$\% of the recovered cases.
Acoustical analysis of Spanish vowels produced by laryngectomized subjects.
2001
The purpose of this study was to describe the acoustic characteristics of Spanish vowels in subjects who had undergone a total laryngectomy and to compare the results with those obtained in a control group of subjects who spoke normally. Our results are discussed in relation to those obtained in previous studies with English-speaking laryngectomized patients. The comparison between English and Spanish, which differ widely in the size of their vowel inventories, will help us to determine specific or universal vowel production characteristics in these patients. Our second objective was to relate the acoustic properties of these vowels to the perceptual data obtained in our previous work (J. L…
Influence of articulation rate on two memory tasks in young and older adults.
2008
This study investigated the relation between phonological loop functioning and age. Phonological loop is a time-based subsystem of the Working Memory Model of Baddeley and Wilson, which uses rehearsal of information as an active process to avoid phonological decay. Performance differences were examined between young and older adults in two speech-based memory tasks, such as the immediate serial recall of words and the Digit Ordering Task. Analysis showed that performance on both tasks was lower for the older group. Articulation rate was also measured to test the hypothesis that the impairment of some cognitive functions in adults can be associated to their slowness or the greater time need…
Two Distinct Auditory-Motor Circuits for Monitoring Speech Production as Revealed by Content-Specific Suppression of Auditory Cortex
2015
Speech production, both overt and covert, down-regulates the activation of auditory cortex. This is thought to be due to forward prediction of the sensory consequences of speech, contributing to a feedback control mechanism for speech production. Critically, however, these regulatory effects should be specific to speech content to enable accurate speech monitoring. To determine the extent to which such forward prediction is content-specific, we recorded the brain's neuromagnetic responses to heard multisyllabic pseudowords during covert rehearsal in working memory, contrasted with a control task. The cortical auditory processing of target syllables was significantly suppressed during rehear…
Left-hemispheric dominance for articulation: a prospective study on acute ischaemic dysarthria at different localizations.
2006
Dysarthria is a frequent symptom in cerebral ischaemia. However, speech characteristics of these patients have not previously been investigated in relation to lesion site in a prospective study. We investigated the auditory perceptual features in 62 consecutive patients with dysarthria due to a single, non-space-occupying cerebral infarction confirmed by MRI. Standardized speech samples of all patients were stored within 72 h after stroke onset using a digital tape recorder. Speech samples were assessed independently by two experienced speech therapists, who were unaware of the clinical and neuroradiological findings, using an interval scale ranging from 0 to 6. Separately assessed were fea…
Alterations in speech and voice in patients with mucopolysaccharidoses.
2013
The mucopolysaccharidoses are a group of lysosomal disorders characterized by abnormal accumulation of glycosaminoglycans within cell lysosomes leading to a variety of signs and symptoms including alterations in speech and voice production. These changes were analysed in 44 patients with mucopolysaccharidosis (MPS) types I, II, and VI using standardized protocols. Compared to healthy individuals the diadochokinetic rate for the fast repetition of syllables was slower and more irregular, the voice-onset time for the voiceless consonant /p/ was shorter, and most patients had a hoarse voice. The fundamental frequency (F0) of sustained spoken vowels was in the normal range for most women and ch…
Computerized acoustic voice analysis and subjective scaled evaluation of the voice can avoid the need for laryngoscopy after thyroid surgery.
2008
Because of frequent postoperative alterations in voice, many surgeons include laryngoscopy as a routine examination before/after thyroid surgery. The aim of this work was to determine whether more comfortable and easier subjective or objective postoperative voice assessments could complement or replace laryngoscopy.Sixty-four consecutive patients scheduled to undergo thyroid surgery underwent preoperative objective computerized acoustic voice analysis (CAVA), subjective scaled evaluation of the voice (SSEV) with the GIRBAS scale, and fiberoptic laryngoscopy. All patients had 7- and 30-day postoperative follow-up assessments using the same tests.CAVA measurements of jitter and noise-to-harmo…
Facility layout problem: Bibliometric and benchmarking analysis
2019
Facility layout problem is related to the location of departments in a facility area, with the aim of determining the most effective configuration. Researches based on different approaches have been published in the last six decades and, to prove the effectiveness of the results obtained, several instances have been developed. This paper presents a general overview on the extant literature on facility layout problems in order to identify the main research trends and propose future research questions. Firstly, in order to give the reader an overview of the literature, a bibliometric analysis is presented. Then, a clusterization of the papers referred to the main instances reported in literat…
Enhanced Electrochemical Properties of Na0.67MnO2 Cathode for Na-Ion Batteries Prepared with Novel Tetrabutylammonium Alginate Binder
2022
This research was funded by the State Education Development Agency, the Republic of Latvia, grant number 1.1.1.2/VIAA/1/16/166, "Advanced Materials for Sodium-Ion Batteries". Institute of Solid-State Physics, University of Latvia as the Centre of Excellence has received funding from the European Union's Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2.