A CLASS OF EVOLUTIONARY VARIATIONAL INEQUALITIES WITH VOLTERRA-TYPE TERM

We consider a class of abstract evolutionary variational inequalities arising in the study of frictionless contact problems for linear viscoelastic materials with long-term memory. We prove an existence and uniqueness result, by using arguments of time-dependent elliptic variational inequalities and Banach's fixed point theorem. We then consider numerical approximation of the problem by introducing spatially semi-discrete, time semi-discrete and fully discrete schemes. For both schemes, we show the existence of a unique solution and derive error estimates. Finally, we apply the abstract results to the analysis and numerical approximation of the Signorini frictionless contact problem between two viscoelastic bodies with long-term memory.

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A CLASS OF EVOLUTIONARY VARIATIONAL INEQUALITIES WITH APPLICATIONS IN VISCOELASTICITY

Mathematical Models and Methods in Applied Sciences ◽

10.1142/s0218202505000820 ◽

2005 ◽

Vol 15 (10) ◽

pp. 1595-1617 ◽

Cited By ~ 26

Author(s):

M. BARBOTEU ◽

J. R. FERNÁNDEZ ◽

T.-V. HOARAU-MANTEL

Keyword(s):

Variational Inequalities ◽

Error Estimates ◽

Contact Problems ◽

Approximate Solutions ◽

Uniqueness Result ◽

Viscoelastic Materials ◽

Evolutionary Equations ◽

Fully Discrete ◽

Evolutionary Variational Inequalities ◽

Weak Solvability

We consider a class of abstract evolutionary variational inequalities arising in the study of contact problems for viscoelastic materials. We prove an existence and uniqueness result, using arguments of nonlinear evolutionary equations and Banach's fixed point theorem. We then consider the numerical approximation of the problem. By introducing a fully discrete scheme we show the existence of a unique solution and derive error estimates on the approximate solutions, which represent the main results of the work. We apply the abstract results in the study of two contact problems involving viscoelastic materials. The first one is a Signorini frictionless problem for Kelvin–Voigt materials and the second one is a frictional contact problem for linear Maxwell materials. We provide the variational and numerical analysis of the first problem including error estimates and numerical simulations and we prove the unique weak solvability of the second problem.

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A Signorini frictionless contact problem for viscoelastic materials with long-term memory

Numerical Mathematics and Advanced Applications ◽

10.1007/978-88-470-2089-4_30 ◽

2003 ◽

pp. 327-336 ◽

Cited By ~ 2

Author(s):

Á. D. Rodríguez Arós ◽

M. Sofonea ◽

J. M. Viaño

Keyword(s):

Contact Problem ◽

Long Term Memory ◽

Viscoelastic Materials ◽

Term Memory ◽

Frictionless Contact

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Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

Behavioral and Brain Sciences ◽

10.1017/s0140525x15000928 ◽

2016 ◽

Vol 39 ◽

Author(s):

Mary C. Potter

Keyword(s):

Working Memory ◽

Rapid Serial Visual Presentation ◽

Language Comprehension ◽

Short Term Memory ◽

Visual Presentation ◽

Long Term Memory ◽

Short Term ◽

Term Memory ◽

Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

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Comparison of Auditory, Language, Memory, and Attention Abilities in Children With and Without Listening Difficulties

American Journal of Audiology ◽

10.1044/2020_aja-20-00018 ◽

2020 ◽

Vol 29 (4) ◽

pp. 710-727

Author(s):

Beula M. Magimairaj ◽

Naveen K. Nagaraj ◽

Alexander V. Sergeev ◽

Natalie J. Benafield

Keyword(s):

Auditory Processing ◽

Short Term Memory ◽

Group Differences ◽

Long Term Memory ◽

Short Term ◽

Significant Group ◽

Term Memory ◽

Memory And Attention ◽

Speed And Accuracy

Objectives School-age children with and without parent-reported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results In addition to significantly poorer speech-perception-in-noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. Supplemental Material https://doi.org/10.23641/asha.12808607

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Retrieval from Memory or Procedural Strategies for Addition Problems

Swiss Journal of Psychology ◽

10.1024/1421-0185/a000036 ◽

2011 ◽

Vol 70 (1) ◽

pp. 35-39 ◽

Cited By ~ 3

Author(s):

Muriel Fanget ◽

Catherine Thevenot ◽

Caroline Castel ◽

Michel Fayol

Keyword(s):

Reaction Times ◽

Long Term Memory ◽

Verbal Reports ◽

Term Memory ◽

Simple Addition ◽

Memory Traces ◽

Addition Problem ◽

Retrieval From Memory ◽

Calculation Procedures

In this study, we used a paradigm recently developed ( Thevenot, Fanget, & Fayol, 2007 ) to determine whether 10-year-old children solve simple addition problems by retrieval of the answer from long-term memory or by calculation procedures. Our paradigm is unique in that it does not rely on reaction times or verbal reports, which are known to potentially bias the results, especially in children. Rather, it takes advantage of the fact that calculation procedures degrade the memory traces of the operands, so that it is more difficult to recognize them when they have been involved in the solution of an addition problem by calculation rather than by retrieval. The present study sharpens the current conclusions in the literature and shows that, when the sum of addition problems is up to 10, children mainly use retrieval, but when it is greater than 10, they mainly use calculation procedures.

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The Acute Effect of Alcohol on Various Memory Processes

Journal of Psychophysiology ◽

10.1027/0269-8803/a000038 ◽

2010 ◽

Vol 24 (4) ◽

pp. 249-252 ◽

Cited By ~ 7

Author(s):

Márk Molnár ◽

Roland Boha ◽

Balázs Czigler ◽

Zsófia Anna Gaál

Keyword(s):

Low Dose ◽

Short Term Memory ◽

Acute Effect ◽

Long Term Memory ◽

Term Memory ◽

Memory Processes ◽

Different Types ◽

The Brain ◽

Legal Consequences

This review surveys relevant and recent data of the pertinent literature regarding the acute effect of alcohol on various kinds of memory processes with special emphasis on working memory. The characteristics of different types of long-term memory (LTM) and short-term memory (STM) processes are summarized with an attempt to relate these to various structures in the brain. LTM is typically impaired by chronic alcohol intake but according to some data a single dose of ethanol may have long lasting effects if administered at a critically important age. The most commonly seen deleterious acute effect of alcohol to STM appears following large doses of ethanol in conditions of “binge drinking” causing the “blackout” phenomenon. However, with the application of various techniques and well-structured behavioral paradigms it is possible to detect, albeit occasionally, subtle changes of cognitive processes even as a result of a low dose of alcohol. These data may be important for the consideration of legal consequences of low-dose ethanol intake in conditions such as driving, etc.

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