Search results for "accelerometer"

Accelerometry - Simple, but challenging

2017

Directly measured and self-reported physical activity in a sample of Finnish secondary school students

2012

Background: Previous studies based on self-reports show that a majority of children and adolescents in Western countries fail to achieve the recommendation of 60 minutes moderate to vigorous physical activity (PA) on a daily basis. The specific aim of the study was to analyze the relationship between directly measured and self-reported PA in a cross-sectional sample of Finnish secondary school students. Moreover, how large proportion of adolescents accumulate at least 60 minutes of moderate to vigorous PA on a daily basis using self-reports and direct measure scores. Methods: Participants were recruited from a secondary school located in Northeast Finland. The sample comprised 96 students (…

Effect of a Service-Learning Program on the Active Lifestyle of Children with Autism Spectrum Disorder: A Pilot Study

2020

Background: active lifestyles and Physical Activity (PA) are closely related to health. Healthy habits such as being physically active should be consolidated during childhood. Children with Autism Spectrum Disorders (ASD) present fewer opportunities to be involved in PA. For this reason, we conducted a Service-Learning (SL) program to enhance the possibility of participating ASD children enjoying PA sessions. The aim of this study was to analyze and describe the evolution in terms of the frequency and intensity of PA performed by ASD children who participated in the SL program. Methods: we used a quasi-experimental design. The sample was formed by 26 children with ASD (Experimental group: n…

Wii-bändi : designing an expressive digital musical interface for therapeutic use with disabled people in a group setting

2011

This thesis presents the developmental prototype of a gesturally controlled digital musical interface. It is called Wii-bändi, as it uses Nintendo Wii controllers to translate the gestures into music, and is constructed specifically for clients with a variety of physical and mental disabilities so that they can use it in a therapeutic group context. It is argued that gestural and emotional expressivity might be based on a theory of vitality affects, and that optimal learnability could be achieved through making use of learning schemas. It then sets out how the interface was created using a methodological approach based on action research, describing the specific contexts that led to the cha…

Dog behaviour classification with movement sensors placed on the harness and the collar

2021

Dog owners’ understanding of the daily behaviour of their dogs may be enhanced by movement measurements that can detect repeatable dog behaviour, such as levels of daily activity and rest as well as their changes. The aim of this study was to evaluate the performance of supervised machine learning methods utilising accelerometer and gyroscope data provided by wearable movement sensors in classification of seven typical dog activities in a semi-controlled test situation. Forty-five middle to large sized dogs participated in the study. Two sensor devices were attached to each dog, one on the back of the dog in a harness and one on the neck collar. Altogether 54 features were extracted from th…

Reti sismiche urbane per monitoraggio sismico monitoraggio strutturale ed allerta precoce

2021

In questa tesi, viene effettuato un analisi preliminare in cui si mette in evidenza come l'italia sia un paese a rischio sismico, poichè possiede molti centri storici con strutture non progettate per eventi sismici di media entità. Si è prestato molta attenzione su quante vite umane vengono salvate dopo un terremoto catastrofico. L'analisi fa emergere come, è importante essere tempestivi nell'estrarre le persone rimaste sotto le macerie, poichè la percentuale di persone estratte vive si mantiene alta solo entro le 48 ore dall'evento. Dopo 96 ore questa percentule si attesta a 0. In eventi passati spesso i soccorsi sono arrivati con giorni di ritardo nelle zone più devastate. L'obbiettivo ch…

Smartphone data analysis for human activity recognition

2017

In recent years, the percentage of the population owning a smartphone has increased significantly. These devices provide the user with more and more functions, so that anyone is encouraged to carry one during the day, implicitly producing that can be analysed to infer knowledge of the user’s context. In this work we present a novel framework for Human Activity Recognition (HAR) using smartphone data captured by means of embedded triaxial accelerometer and gyroscope sensors. Some statistics over the captured sensor data are computed to model each activity, then real-time classification is performed by means of an efficient supervised learning technique. The system we propose also adopts a …

Implementation of a wireless instrumented sphere for fruit processing

2020

The aim of this study was to implement a wireless instrumented sphere to study the critical points in a citrus packing line by real-time measuring the impacts experienced by fruits. The noncommercial device was based on a MEMS (microelectro-mechanical system) sensor node with a sensing range from ±1 g to ±400 g (g = 9.8 m s-2), a ferroelectric RAM (FRAM) memory, a radio frequency (RF) transmitter, a microcontroller, and a 75 mAh lithium battery. The sensor node was placed inside an appropriate case with a total weight of 100 g to represent a 'Tardivo di Ciaculli' mandarin. An FR receiver allowed real-time transmission of the measured data. Total acceleration values, representing the stresse…

Bearing fault detection based on time-frequency representations of vibration signals

2015

To prevent failures of a rolling bearing in the gearbox drive system, acceleration sensors are used to detect fault-related signals of the bearing. It is a big challenge to observe and identify signals caused by bearing defects in the time domain or the frequency spectrum by a conventional Fourier analysis. The time-frequency representation of the fault-related signals implemented by the windowed Fourier transform is studied in this work. It is shown that the fault characteristic frequencies can be clearly identified in the time-frequency spectrum if a fault occurs in the bearing of the gearbox at different speeds. Otherwise, the shaft frequency and its multiples are the main harmonics in t…

Segmentation boundaries in accelerometer data of arm motion induced by music : online computation and perceptual assessment

2022

Segmentation is a cognitive process involved in the understanding of information perceived through the senses. Likewise, the automatic segmentation of data captured by sensors may be used for the identification of patterns. This study is concerned with the segmentation of dancing motion captured by accelerometry and its possible applications, such as pattern learning and recognition, or gestural control of devices. To that effect, an automatic segmentation system was formulated and tested. Two participants were asked to ‘dance with one arm’ while their motion was measured by an accelerometer. The performances were recorded on video, and manually segmented by six annotators later. The annota…