Optimal sampling frequency in recording of resistance training exercises

The purpose of this study was to analyse the raw lifting speed collected during four different resistance training exercises to assess the optimal sampling frequency. Eight physically active participants performed sets of Squat Jumps, Countermovement Jumps, Squats and Bench Presses at a maximal lifting speed. A linear encoder was used to measure the instantaneous speed at a 200 Hz sampling rate. Subsequently, the power spectrum of the signal was computed by evaluating its Discrete Fourier Transform. The sampling frequency needed to reconstruct the signals with an error of less than 0.1% was f_99.9 = 11.615 ± 2.680 Hz for the exercise exhibiting the largest bandwidth, with the absolute highest individual value being 17.467 Hz. There was no difference between sets in any of the exercises. Using the closest integer sampling frequency value (25 Hz) yielded a reconstruction of the signal up to 99.975 ± 0.025% of its total in the worst case. In conclusion, a sampling rate of 25 Hz or above is more than adequate to record raw speed data and compute power during resistance training exercises, even under the most extreme circumstances during explosive exercises. Higher sampling frequencies provide no increase in the recording precision and may instead have adverse effects on the overall data quality.     

Teachers’ perspectives on integration of visually impaired children

ABSTRACT

The aim of this article is to show the result of research into the situation of the integration of visually impaired children in Seville (Spain). This work refers to both classroom and peripatetic teachers’ perspectives. We have worked with four peripatetic teachers and nine classroom teachers from Seville. We have used qualitative methodological procedures for data collection and analysis. The results indicate that classroom organization is the most important problem in integration, and within this problem the relationship between classroom and peripatetic teachers becomes a fundamental issue.     

Impact of question-answering tasks on search processes and reading comprehension

This study examined the effect of (a) high- and low-level questions and (b) reading the text before the questions asked on performance, delayed text recall, and deep text comprehension, as well as on specific text-inspection patterns. Participants were 37 undergraduate students who answered either high- or low-level questions using the software Read&Answer to read and answer questions on the computer screen. Additionally, half of the sample read first a text and then answered the questions (reading-first condition), whereas the other half answered the questions without having read the text in advance (no-reading-first condition). All participants had the text available to search for the answer. Results indicated that high-level questions facilitated deep comprehension but not immediate performance or delayed recall of text, independently of the reading condition, and that high- and low-level questions differentially affected text-inspection patterns.     

Global exact tracking for uncertain MIMO linear systems by output feedback sliding mode control

This paper presents a solution to the problem of global exact output tracking for uncertain MIMO (multiple-input–multiple-output) linear plants with non-uniform arbitrary relative degree using output feedback sliding mode control. The key idea to overcome the relative degree obstacle is to generalize our previous hybrid estimation scheme to a multivariable version by combining, through switching, a standard linear lead filter with a non-linear one based on robust exact differentiators, achieving uniform global exponential practical stability and exact tracking.     

Advances in the identification and measurement of Intellectual Capital and future developments in the Intellectual Capital research agenda: experience of the Intellectus Model and proposal of a synthetic index

Knowledge Management Research & Practice - Nowadays knowledge has become a key asset for firms in order to build a sustainable competitive advantage. The environment changes quickly and...     

Not Proved: Reply to Wynn

Findings on whether young infants look longer at incorrect addition and subtraction have been inconsistent or, as in our study, negative. We hypothesize that imprecise ordinal calculating with very small numbers of objects develops in late infancy and precise calculating in early childhood.     

Effects of student-facilitated learning on instructional facilitators

We investigated perceptions about learning strategy use and instructional roles among a sample of high needs adolescents (n = 230) who acted as near-peer instructional facilitators. The sample was drawn from science and mathematics classes in nonselective public secondary schools in New York City. Students participated in an inschool intervention that draws on social constructivism, theory and research on metacognition and learning strategies, role theory, and empirical findings from the peer-to-peer learning literature to promote advanced achievement among students who act as facilitators. Using a pre- and post-test single group design, we surveyed student instructional facilitators before and after program participation and related their perceptions about learning strategy use and perceptions about teaching roles to data about academic achievement. We found no survey gains in student perceptions about learning strategies or instructional roles between pre-survey (fall) and post-survey (spring). We found small but significant effects of individual perceptions about learning strategies and teaching roles on academic gains among instructional facilitators. The study also suggests that an in-school near-peer facilitated learning program can be an effective means to raise achievement in urban high schools. The study provides partial support for theories that hold that metacognition and role perceptions are involved in the academic gains of instructional facilitators, as gains in these dimensions were small compared to achievement gains.     

A small-gain theorem with applications to input/output systems, incremental stability, detectability, and interconnections

A general input-to-state stability (ISS)-type small-gain result is presented. It specializes to a small-gain theorem for ISS operators, and it also recovers the classical statement for ISS systems in state-space form. In addition, we highlight applications to incrementally stable systems, detectable systems, and to interconnections of stable systems.