Search results for "arithmetic"

Personal Gains from Materials in Social Networks

2021

Importance of gains from social networks is analyzed in great extent in many countries by many researchers as social networks are reaching more and more importance. Research methods applied: analysis of scientific publications, survey of social network users on gains from materials in social networks. For evaluations by respondents in survey it was used evaluation scale 1–6 as it is used in grading system in Germany. Survey data results are analyzed by indicators of descriptive statistics – indicators of central tendency or location: arithmetic mean, median, mode and indicator of variability – standard deviation. In the research there were found differences by countries in use of social net…

Adult counting is resource demanding.

2004

Several recent studies on both the development of counting and working-memory span tasks have provided results that could be interpreted as ruling out any cognitive resource model for counting. The aim of this study was to test the hypothesis that, even in adults, counting is a demanding task that requires the allocation of cognitive resources. In a first experiment, we asked adults to count arrays of dots while maintaining 5 items in memory (either digits or letters). As we predicted, the concurrent memory load did not increase the rate of errors but induced longer counting times. In a second experiment, we asked adults to count using either the numeric chain or the alphabet while they mai…

A population-based coprological study of human fascioliasis in a hyperendemic area of the Bolivian Altiplano

1997

The community of Chijipata Alta, at an altitude of 3850 m, near the southern coast of Lake Titicaca in the Northern Altiplano of Bolivia, was surveyed for human fascioliasis. The global prevalence (66.7 %) and intensity (eggs per gram of faeces - epg: range: 24-4440; arithmetic mean: IooI; geometric mean: 390) proved to be the highest known in the world by means of coprological techniques. These results suggest the existence of highly hyperendemic subzones among the large human fascioliasis-endemic zone of the Bolivian Northern Altiplano. Despite the decrease in prevalence and intensity from children (75.0%, 24-4440 epg) to adults (41.7%, 144-864 epg), our findings show that in an hyperende…

Does the left inferior parietal lobule contribute to multiplication facts?

2005

We report a single case, who presents with a selective and severe impairment for multiplication and division facts. His ability to retrieve subtraction and addition facts was entirely normal. His brain lesion affected the left superior temporal and to lesser extent in the left middle temporal gyri and the left precentral gyrus extending inferiorly to the pars opercularis of the left frontal lobe. Interestingly, the left supramarginal and angular gyri (SMG/AG) were spared. This finding realised a double dissociation with a previously reported patient, who despite lesions in the SMG/AG did not have a multiplication impairment (van Harskamp et al., 2002). The previously suggested crucial role …

Task-induced deactivation in diverse brain systems correlates with interindividual differences in distinct autonomic indices

2018

AbstractNeuroimaging research has shown that different cognitive tasks induce relatively specific activation patterns, as well as less task-specific deactivation patterns. Here we examined whether individual differences in Autonomic Nervous System (ANS) activity during task performance correlate with the magnitude of task-induced deactivation. In an fMRI study, participants performed a continuous mental arithmetic task in a task/rest block design, while undergoing combined fMRI and heart / respiration rate acquisitions using photoplethysmograph and respiration belt. As expected, task performance increased heart-rate and reduced the RMSSD, a cardiac index related to vagal tone. Across partic…

From algorithmic computing to direct retrieval: Evidence from number and alphabetic arithmetic in children and adults

1998

A number of theories of mental arithmetic suggest that the ability to solve simple addition and subtraction problems develops from an algorithmic strategy toward a strategy based on the direct retrieval of the result from memory. In the experiment presented here, 2nd and 12th graders were asked to solve two tasks of number and alphabet arithmetic. The subjects transformed series of 1 to 4 numbers or letters (item span) by adding or subtracting an operand varying from 1 to 4 (operation span). Although both the item and operation span were associated with major and identical effects in the case of both numbers and letters at 2nd grade, such effects were clearly observable only in the case of …

On the number of covering blocks

1995

Characters that agree on prime-power-order elements

2003

Some Open Problems on Coprime Action and Character Correspondences

1994

Numerical evaluation of multiple polylogarithms

2004

Multiple polylogarithms appear in analytic calculations of higher order corrections in quantum field theory. In this article we study the numerical evaluation of multiple polylogarithms. We provide algorithms, which allow the evaluation for arbitrary complex arguments and without any restriction on the weight. We have implemented these algorithms with arbitrary precision arithmetic in C++ within the GiNaC framework.