Search results for " tracker"

2020

Despite the positive aspects of information technology (IT) use, it is common for users to experience negative IT incidents. Examples of negative IT incidents include getting lost in an unfamiliar country due to a dysfunctional map application and missing a monetary insurance benefit due to the failure of an activity tracker application. Such incidents can harm IT providers by giving rise to user dissatisfaction, discontinued use, switching, and negative word-of-mouth. To minimize this harm, it is important to understand how users cope after negative incidents. Specifically, information systems (IS) researchers have called for research that uncovers the complex interplay of IT users’ coping…

2020

Background Physical activity trackers (PATs) such as apps and wearable devices (eg, sports watches, heart rate monitors) are increasingly being used by young adolescents. Despite the potential of PATs to help monitor and improve moderate-to-vigorous physical activity (MVPA) behaviors, there is a lack of research that confirms an association between PAT ownership or use and physical activity behaviors at the population level. Objective The purpose of this study was to examine the ownership and use of PATs in youth and their associations with physical activity behaviors, including daily MVPA, sports club membership, and active travel, in 2 nationally representative samples of young adolescen…

Off-line path correction of robotic face milling using static tool force and robot stiffness

2015

In this paper the developed method for off-line compensation of tool deflections when milling aluminum with an industrial robot is presented. The efficiency of this approach is verified with high precision measurements of deflections using a laser tracker. The compensation method includes both the static milling process model which can predict the mean value components of the tool forces and a new combined local/global approach for estimating the combined stiffnesses of joints. With a process model such as the one presented in this paper and estimates of the robot's joint stiffness values, the tool path can be adjusted to counteract deflections of the tool during milling operations. The mod…

Using input shaping and pressure feedback to suppress oscillations in slewing motion of lightweight flexible hydraulic crane

2015

This paper presents a method to actively reduce vibrations in the flexible mechanical structure of a hydraulically actuated vehicle loader crane. Based on information on the natural frequency and damping of a simplified model of the crane an input shaping scheme is set up to control the proportional valve leading to substantially reductions in oscillations. The method is compared and combined with a pressure feedback control of the proportional valve that actively suppresses transient variations in pressure. A full scale vehicle loader crane is used in the experimental verification of the method, and the motion of the tool point of the crane is measured by a high precision laser tracker. Th…

Dynamics photovoltaic generators: Technical aspects and economical valuation

2010

The strategy adopted from many European nations and not, to entrust the electric energy production to differently energetic sources has determined an increment of the scientific research for the solar resource exploitation. These scientific community activities follows with attention from the entrepreneurial world have concentrated on the innovative techniques and methodologies of the source conversion, solar concentration and the direction's device optimization. This job focuses its attention on the simple application of solar-track device, based on consolidated technologies. The diffused application of these dispositive, could be, shortly, an important increment of electricity generation …

Performance of LoRa for Bike-Sharing Systems

2019

Today bike sharing systems are becoming popular in many cities as short-distance transit vehicles. More than 18 million bicycles are available worldwide for public use and one of the main problems that afflicts such sharing systems is the loss of bikes, which can be stolen or simply left in unknown locations. Thus, many bikes are docked or tracked using GPS and costly cellular connections. In this paper, we consider the emerging Long Range (LoRa) technology for use in bike sharing systems. LoRa exploits free ISM bands and has been conceived for low power and low data rate applications. Additionally, LoRa is characterized by large cells and heterogeneous application domains, which may lead t…

Ownership and Use of Commercial Physical Activity Trackers Among Finnish Adolescents: Cross-Sectional Study

2017

BackgroundMobile phone apps for monitoring and promoting physical activity (PA) are extremely popular among adults. Devices, such as heart rate monitors or sports watches (HRMs/SWs) that work with these apps are at sufficiently low costs to be available through the commercial markets. Studies have reported an increase in PA levels among adults with devices; however, it is unknown whether the phenomena are similar during early adolescence. At a time when adolescents start to develop their own sense of independence and build friendship, the ease of smartphone availability in developed countries needs to be investigated in important health promoting behaviors such as PA. ObjectiveThe objective…

Method for estimating combined controller, joint and link stiffnesses of an industrial robot

2014

In this paper a new combined local/global approach for estimating the combined stiffnesses of joints in anthropomorphic robots is presented. The stiffness of each joint is a combination of several effects: i) stiffness of the links, ii) stiffness of joint bearings and gears and iii) stiffness of the position control loops given by the individual axis controller gains in the controller software. Experimental results are presented for an ABB IRB6600 industrial robot using measurements from a FARO Xi laser tracker and an ATI Omega160 force/torque sensor. The results show that there is a significant variation in stiffness among the individual joints of the robot and that the stiffnesses of the …

Objectively measured physical activity and physical performance in old age

2017

Abstract Background: Physical performance is a key factor that determines how older people cope with daily tasks and maintain independency. There is strong evidence suggesting that physical activity (PA) is important in maintaining physical performance in old age. However, most studies have been done using self-reported PA. Our aim was to explore the association between objectively measured PA and physical performance in old age. Methods: We studied 695 participants (mean age 70.7 years, SD 2.7) from the Helsinki Birth Cohort Study. Physical performance was assessed with the Senior Fitness Test (SFT) and PA with a multisensory activity monitor SenseWear Pro 3 Armband. Results: Total volume …

Profiling movement behaviours in pre-school children: A self-organised map approach.

2019

Application of machine learning techniques has the potential to yield unseen insights into movement and permits visualisation of complex behaviours and tangible profiles. The aim of this study was to identify profiles of relative motor competence (MC) and movement behaviours in pre-school children using novel analytics. One-hundred and twenty-five children (4.3 ± 0.5y, 1.04 ± 0.05 m, 17.8 ± 3.2 kg, BMI: 16.2 ± 1.9 kg