73 research outputs found
Periodic patterns for resolution limit characterization of correlation plenoptic imaging
The measurement of the spatio-temporal correlations of light provides an
interesting tool to overcome the traditional limitations of standard imaging,
such as the strong trade-off between spatial resolution and depth of field. In
particular, using correlation plenoptic imaging, one can detect both the
spatial distribution and the direction of light in a scene, pushing both
resolution and depth of field to the fundamental limit imposed by wave-optics.
This allows one to perform refocusing of different axial planes and
three-dimensional reconstruction without any spatial scanning. In the present
work, we investigate the resolution limit in a particular correlation plenoptic
imaging scheme, by considering periodic test patterns, which provide, through
analytical results, a deeper insight in the resolution properties of this
second-order imaging technique, also in comparison with standard imaging.Comment: 16 pages, 4 figure
CHARACTERIZATION OF PTC EFFECT IN BATIO3-CERAMICS AS A SPECIAL PHASE TRANSITION – FRACTAL APPROACH
The applications of BaTiO3-ceramics are very important and constantly increasing nowadays. In that sense, we analyzed some phenomena related to inter-granular effects. We used experimental data based on Murata powders and processing technology. Our original contribution to Heywang-Jonker-Daniels inter-granular capacity model is based on thermodynamic fractal analysis applied on phase transition in ceramic structures. In this case, PTCR effect has a diffuse first-order phase transition character in a modified Landau theory-fractal approach. Its basic properties are considered. This is an original contribution as a bridge between theoretical aspects of BaTiO3-ceramics and experimental results
mHealth intervention delivered in general practice to increase physical activity and reduce sedentary behaviour of patients with prediabetes and type 2 diabetes (ENERGISED): rationale and study protocol for a pragmatic randomised controlled trial
Background
The growing number of patients with type 2 diabetes and prediabetes is a major public health concern. Physical activity is a cornerstone of diabetes management and may prevent its onset in prediabetes patients. Despite this, many patients with (pre)diabetes remain physically inactive. Primary care physicians are well-situated to deliver interventions to increase their patients' physical activity levels. However, effective and sustainable physical activity interventions for (pre)diabetes patients that can be translated into routine primary care are lacking.
Methods
We describe the rationale and protocol for a 12-month pragmatic, multicentre, randomised, controlled trial assessing the effectiveness of an mHealth intervention delivered in general practice to increase physical activity and reduce sedentary behaviour of patients with prediabetes and type 2 diabetes (ENERGISED). Twenty-one general practices will recruit 340 patients with (pre)diabetes during routine health check-ups. Patients allocated to the active control arm will receive a Fitbit activity tracker to self-monitor their daily steps and try to achieve the recommended step goal. Patients allocated to the intervention arm will additionally receive the mHealth intervention, including the delivery of several text messages per week, with some of them delivered just in time, based on data continuously collected by the Fitbit tracker. The trial consists of two phases, each lasting six months: the lead-in phase, when the mHealth intervention will be supported with human phone counselling, and the maintenance phase, when the intervention will be fully automated. The primary outcome, average ambulatory activity (steps/day) measured by a wrist-worn accelerometer, will be assessed at the end of the maintenance phase at 12 months.
Discussion
The trial has several strengths, such as the choice of active control to isolate the net effect of the intervention beyond simple self-monitoring with an activity tracker, broad eligibility criteria allowing for the inclusion of patients without a smartphone, procedures to minimise selection bias, and involvement of a relatively large number of general practices. These design choices contribute to the trial’s pragmatic character and ensure that the intervention, if effective, can be translated into routine primary care practice, allowing important public health benefits
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