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Concurrent Validity Of The Actigraph Gt3x+ And Activpal For Assessing Sedentary Behaviour In 2-3-Year-Old Children Under Free-Living Conditions, Joao Rafael Rodrigues Pereira, Eduarda Sousa-Sa, Zhiguang Zhang, Dylan P. Cliff, Rute Santos

Faculty of Social Sciences - Papers (Archive)

Objectives

ActiGraph accelerometer cut-points are commonly used to classify sedentary behaviour (SB) in young children. However, they vary from 5counts/5 s to 301counts/15 s, resulting in different estimates and inconsistent findings. The aim was to examine the concurrent validity of ActiGraph GT3X + cut-points against the activPAL for measuring SB in 2–3-year-olds during free-living conditions.

Design

Observational validation-study.

Methods

Sixty children were fitted with the activPAL and ActiGraph simultaneously for at least 2 h. Nine ActiGraph cut-points ranging from 60 to 1488 counts per minute were used to derive SB. Bland & Altman plots and equivalent tests were performed to …

Thermal Features Vis A Vis Strain Features Of Fracturing Process In Jointed Rock Layer Under Concentrated Load, Haiqing Yang, Bolong Liu, Shivakumar Karekal

Faculty of Engineering and Information Sciences - Papers: Part B

In case of earthquakes and crustal movement, the concentration of impounding load over a large region of crust can cause disturbances to the stratum. In order to quantitatively investigate crack initiation, propagation and coalescence processes of jointed stratum based on thermal variations caused by concentrated mechanical loading, a series of indention tests were performed on granite specimens. In the experiment, fracture process and resulting infrared radiation fields of specimens were respectively recorded by synchronized digital image correlation system and infrared camera. Then, thermal characteristics of mixed shear-tensile and tensile conical crack were analyzed. Experimental results indicate that the highlighted temperature …

An Adaptive Feed-Forward Phase Locked Loop For Grid Synchronization Of Renewable Energy Systems Under Wide Frequency Deviations, Aravind Chellachi Kathiresan, Jeyaraj Pandiarajan, Asokan Sivaprakash, Thanikanti Sudhakar Babu, Md Rabiul Islam

Faculty of Engineering and Information Sciences - Papers: Part B

Synchronization is a crucial problem in the grid-connected inverter’s control and operation. A phase-locked loop (PLL) is a typical grid synchronization strategy, which ought to have a high resistance to power system uncertainties since its sensitivity influences the generated reference signal. The traditional PLL catches the phase and frequency of the input signal via the feedback loop filter (LF). In general, to enhance the steady-state capability during distorted grid conditions generally, a filter tuned for nominal frequency is used. This PLL corrects large frequency deviations around the nominal frequency, which increases the PLL’s locking time. Therefore, this paper presents an …

A Laboratory Study On Fluidization Of Subgrade Under Cyclic Train Loading, Buddhima Indraratna, Mandeep Singh, Thanh Trung Nguyen, Serge Leroueil, Aruni Lakmali Abeywickrama Bamunusing Kankanamge, Richard B. Kelly, Tim Neville

Faculty of Engineering and Information Sciences - Papers: Part B

A long term issue that has hampered the efficient operation of heavy haul tracks is the migration of fluidized fines from the shallow soft subgrade to the overlying ballast, i.e., mud pumping. This paper presents a series of undrained cyclic triaxial tests, where realistic cyclic loading conditions were simulated at low confining pressure that is typical of shallow subgrade beneath a ballast track. Subgrade soil specimens with a low plasticity index collected from a field site with recent history of mud pumping were tested at frequencies from 1.0 to 5.0 Hz and a cyclic stress ratio (CSR) from 0.1 to …

Numerical Modelling Of Track Behavior Capturing Particle Breakage Under Dynamic Loading, Ngoc Trung Ngo, Buddhima Indraratna

Faculty of Engineering and Information Sciences - Papers: Part B

No abstract provided.