Search results for "switching"
showing 10 items of 288 documents
To switch or not to switch: Brain potential indices of attentional control after task-relevant and task-irrelevant changes of stimulus features
2009
Attention is controlled by the interplay of sensory input and top-down processes. We compared attentional control processes during task switching and reorientation after distraction. The primary task was to discriminate laterally and centrally presented tones; these stimuli were composed of a frequent standard or an infrequent deviant pitch. In the distraction condition, pitch was irrelevant and could be ignored. In the switch condition, pitch changes were relevant: whenever a deviant tone was presented, participants had to discriminate its pitch and not its direction. The task in standard trials remained unchanged. In both conditions, deviants elicited mismatch negativity (MMN), P3a, P3b, …
Peri‐implant marginal bone loss reduction with platform‐switching components: 5‐Year post‐loading results of an equivalence randomized clinical trial
2019
Abstract Aim To compare the clinical performance and marginal bone levels of implants restored with platform‐switching (PS) or platform‐matching (PM) abutments. Materials and Methods Adult patients missing two or more adjacent teeth in the posterior mandible received 2–4 CAMLOG SCREW‐LINE implants and were randomly allocated to the PM or PS group, receiving the corresponding prosthetic components from surgery onwards. Implants were conventionally loaded with single cemented crowns. Patients were followed annually for 5 years. Outcome measures were marginal bone level changes, implant survival, performance of the prosthetic components and clinical parameters plaque index, sulcus bleeding ind…
Maddalena Opioid Switching Score in patients with cancer pain
2021
Evaluation of opioid switching (OS) for cancer pain has not been properly assessed. The aim of this study was to assess an integrated score (Maddalena Opioid Switching Score) as a simple and repeatable tool to evaluate the outcomes of OS, facilitating the interpretation and comparison of studies, and information exchange among researchers. The integrated score took into account pain intensity, intensity of opioid-related symptoms, and cognitive function by using an author's formula. Physical and psychological symptoms were evaluated by the Edmonton Symptom Assessment Scale and Patient Global Impression (PGI) by the minimal clinically important difference. One hundred six patients were analy…
On-Line Derivatization into Precolumns for the Determination of Drugs by Liquid Chromatography and Column Switching: Determination of Amphetamines i…
1996
A chromatographic system for the on-line derivatization of drugs using column switching is described. The system uses a 20 mm × 2.1 mm i.d. precolumn packed with a unmodified ODS stationary phase. This column is used for sample cleanup and enrichment of the analytes. Next, the trapped analytes are derivatized by injection of the derivatization reagent into the precolumn. Finally, the derivatives are transferred to the analytical column for their separation under reversed-phase conditions. The influence of several parameters such as the reaction time, the amount of derivatization reagent, or the system design has been studied using some amphetamines as model compounds and three derivatizatio…
Column-switching techniques for high-performance liquid chromatography of drugs in biological samples.
1993
In recent years, an increasing number of publications have demonstrated the potential of column-switching techniques for the chromatographic separation, determination and preparative isolation of analytes from biological matrices. Column-switching systems greatly facilitate drug analysis, by on-line sample clean-up and trace enrichment, or by improving the analytical separative process. In this paper, the main applications of column-switching techniques to drug analysis in biological samples, are reviewed.
Asynchronous L1 control of delayed switched positive systems with mode-dependent average dwell time
2014
Abstract This paper investigates the stability and asynchronous L 1 control problems for a class of switched positive linear systems (SPLSs) with time-varying delays by using the mode-dependent average dwell time (MDADT) approach. By allowing the co-positive type Lyapunov–Krasovskii functional to increase during the running time of active subsystems, a new stability criterion for the underlying system with MDADT is first derived. Then, the obtained results are extended to study the issue of asynchronous L 1 control, where “asynchronous” means that the switching of the controllers has a lag with respect to that of system modes. Sufficient conditions are provided to guarantee that the resulti…
Stabilization of positive switched systems with time-varying delays under asynchronous switching
2014
Published version of an article in the journal: International Journal of Control, Automation and Systems. Also available from the publisher at: http://dx.doi.org/10.1007/s12555-013-0486-x This paper investigates the state feedback stabilization problem for a class of positive switched systems with time-varying delays under asynchronous switching in the frameworks of continuous-time and discrete-time dynamics. The so-called asynchronous switching means that the switches between the candidate controllers and system modes are asynchronous. By constructing an appropriate co-positive type Lyapunov-Krasovskii functional and further allowing the functional to increase during the running time of ac…
Semantic Verbal Fluency in Children with and without Autism Spectrum Disorder: Relationship with Chronological Age and IQ
2016
We administered a semantic verbal fluency (SVF) task to two groups of children (age range from 5 to 8): 47 diagnosed with Autism Spectrum Disorder (ASD Group) and 53 with typical development (Comparison Group), matched on gender, chronological age, and non-verbal IQ. Four specific indexes were calculated from the SVF task, reflecting the different underlying cognitive strategies used: clustering (component of generativity and lexical-semantic access), and switching (executive component, cognitive flexibility). First, we compared the performance of the two groups on the different SVF task indicators, with the ASD group scoring lower than the Comparison Group, although the difference was grea…
Er:Cr:YSGG laser with electrooptic PLZT ceramics Q-switching Fabry-Perot interferometer output mirror
2001
Summary form only given. Q-switching of Er:Cr:YSGG laser with transparent PLZT ceramics electro-optic modulators was reported previously. The extremely large quadratic EO effect in PLZT allows to build small size moderate control voltages. The high induced birefringence in PLZT results from an essential contribution to polarization (and consequently to the birefringence) of processes with longer relaxation times up to seconds, corresponding to the Er:Cr:YSGG laser operating rate. PLZT ceramics have also a high value of the refractive index (n /spl ap/ 2.2-2.3 for /spl lambda/ = 3 /spl mu/m, slightly depending on PLZT composition and temperature) and thus considerable Fresnel reflections R/s…
PLZT Electro-optic Q-switch for Er:Cr:YSGG laser
1999
Q-switching of the Er:Cr:YSGG laser at 2.79 micrometers is realized using electrooptic modulators of PLZT X/65/35 ceramics. The high (but slow as compared with single crystals) electrooptical effect in PLZT allowed to construct Q-switches with an aperture larger than 4 X 4 mm 2 , small lengths of 3 - 6 mm, with a control voltage of 1000 - 1500 V. Q-switching is realized using modulators in two modes--as a (lambda) /2 switch placed into the laser cavity at the Brewster angle avoiding reflection losses and as a (lambda) /4 switch with higher single pass losses due to Fresnel reflections. A higher laser output was obtained using (lambda) /2 switching. The obtained pulses had a halfwidth of 150…