Search results for "arithmetic"

Adaptive algorithms robust to impulsive noise with low computational cost using order statistic

2009

Abstract In this paper a family of adaptive algorithms robust to impulsive noise and with low computational cost are presented. Unlike other approaches, no cost functions or filtering of the gradient are considered in order to update the filter coefficients. Its initial basis is the basic LMS algorithm and its sign-error variant. The proposed algorithms can be considered as some sign-error variants of the LMS algorithm. The algorithms are successfully tested in terms of accuracy and convergence in a standard system identification simulation in which an impulsive noise is present. Simulations show that they improve the performance of LMS variants that are robust to impulsive noise.

Predicting arithmetical achievement from neuro-psychological performance: a longitudinal study

1998

In this article, we show that the performances of 5- to 6-year-old children in arithmetic tests can be predicted from their performances in neuro-psychological tests administered a number of months in advance, independently of their level of development.

Algorithmic Solution of Arithmetic Problems and Operands-Answer Associations in Long-Term Memory

2001

Many developmental models of arithmetic problem solving assume that any algorithmic solution of a given problem results in an association of the two operands and the answer in memory (Logan & Klapp, 1991; Siegler, 1996). In this experiment, adults had to perform either an operation or a comparison on the same pairs of two-digit numbers and then a recognition task. It is shown that unlike comparisons, the algorithmic solution of operations impairs the recognition of operands in adults. Thus, the postulate of a necessary and automatic storage of operands-answer associations in memory when young children solve additions by algorithmic strategies needs to be qualified.

2018

Early number skills underlie success in basic arithmetic. However, very little is known about the skill profiles among children in preprimary education and how the potential profiles are related to arithmetic development. This longitudinal study of 440 Finnish children in preprimary education (mean age 75 months) modeled latent performance-level profile groups for the early number skill components that are proposed to be key predictors of arithmetic (symbolic number comparison, mapping, and verbal counting skills). Based on three assessment time points (September, January, and May), four profile groups were found: the poorest-performing (6%), low-performing (16%), near-average-performing (3…

Counting and RAN: Predictors of arithmetic calculation and reading fluency.

2013

This study examined whether counting and rapid automatized naming (RAN) could operate as significant predictors of both later arithmetic calculation and reading fluency. The authors also took an important step to clarify the cognitive mechanisms underlying these predictive relationships by controlling for the effect of phonological awareness and verbal short-term memory. Due to rather strong covariance between verbal short-term memory and phonological awareness, short-term memory could be controlled only partially. Participants, 200 children from a longitudinal study, were followed from age 5 to 10 years. Structural equation modeling showed counting to be a strong predictor, not only of lat…

SORTING CONJUGATES AND SUFFIXES OF WORDS IN A MULTISET

2014

In this paper we are interested in the study of the combinatorial aspects related to the extension of the Burrows-Wheeler transform to a multiset of words. Such study involves the notion of suffixes and conjugates of words and is based on two different order relations, denoted by <lex and ≺ω, that, even if strictly connected, are quite different from the computational point of view. In particular, we introduce a method that only uses the <lex sorting among suffixes of a multiset of words in order to sort their conjugates according to ≺ω-order. In this study an important role is played by Lyndon words. This strategy could be used in applications specially in the field of Bioinformatic…

Linguistic and spatial skills predict early arithmetic development via counting sequence knowledge

2013

Utilizing a longitudinal sample of Finnish children (ages 6-10), two studies examined how early linguistic (spoken vs. written) and spatial skills predict later development of arithmetic, and whether counting sequence knowledge mediates these associations. In Study 1 (N = 1,880), letter knowledge and spatial visualization, measured in kindergarten, predicted the level of arithmetic in first grade, and later growth through third grade. Study 2 (n = 378) further showed that these associations were mediated by counting sequence knowledge measured in first grade. These studies add to the literature by demonstrating the importance of written language for arithmetic development. The findings are …

Dissociations and interactions between time, numerosity and space processing

2009

AbstractThis study investigated time, numerosity and space processing in a patient (CB) with a right hemisphere lesion. We tested whether these magnitude dimensions share a common magnitude system or whether they are processed by dimension-specific magnitude systems. Five experimental tasks were used: Tasks 1–3 assessed time and numerosity independently and time and numerosity jointly. Tasks 4 and 5 investigated space processing independently and space and numbers jointly. Patient CB was impaired at estimating time and at discriminating between temporal intervals, his errors being underestimations. In contrast, his ability to process numbers and space was normal. A unidirectional interactio…

Bringing the Cognitive Estimation Task into the 21st Century: Normative Data on Two New Parallel Forms

2014

The Cognitive Estimation Test (CET) is widely used by clinicians and researchers to assess the ability to produce reasonable cognitive estimates. Although several studies have published normative data for versions of the CET, many of the items are now outdated and parallel forms of the test do not exist to allow cognitive estimation abilities to be assessed on more than one occasion. In the present study, we devised two new 9-item parallel forms of the CET. These versions were administered to 184 healthy male and female participants aged 18–79 years with 9–22 years of education. Increasing age and years of education were found to be associated with successful CET performance as well as gend…

Cognitive Correlates of the Covariance in Reading and Arithmetic Fluency: Importance of Serial Retrieval Fluency

2019

This study examines the core predictors of the covariance in reading and arithmetic fluency and the domain-general cognitive skills that explain the core predictors and covariance. Seven-year-old Finnish children (N = 200) were assessed on rapid automatized naming (RAN), phonological awareness, letter knowledge, verbal counting, number writing, number comparison, memory skills, and processing and articulation speed in the spring of Grade 1 and on reading and arithmetic fluency in the fall of Grade 2. RAN and verbal counting were strongly associated, and a constructed latent factor, serial retrieval fluency (SRF), was the strongest unique predictor of the shared variance. Other unique predic…