28 research outputs found
Out-of-focus Blur: Image De-blurring
Image de-blurring is important in many cases of imaging a real scene or
object by a camera. This project focuses on de-blurring an image distorted by
an out-of-focus blur through a simulation study. A pseudo-inverse filter is
first explored but it fails because of severe noise amplification. Then
Tikhonov regularization methods are employed, which produce greatly improved
results compared to the pseudo-inverse filter. In Tikhonov regularization, the
choice of the regularization parameter plays a critical rule in obtaining a
high-quality image, and the regularized solutions possess a semi-convergence
property. The best result, with the relative restoration error of 8.49%, is
achieved when the prescribed discrepancy principle is used to decide an optimal
value. Furthermore, an iterative method, Conjugated Gradient, is employed for
image de-blurring, which is fast in computation and leads to an even better
result with the relative restoration error of 8.22%. The number of iteration in
CG acts as a regularization parameter, and the iterates have a semi-convergence
property as well.Comment: 11 page
Physical Activity and Health Perception in Aging: Do Body Mass and Satisfaction Matter? A Three-Path Mediated Link
<div><p>Although ageing people could benefit from healthy diet and physical activity to maintain health and quality of life, further understandings of the diet- and physical activity-related mechanisms that may cause changes in health and quality of life perception are necessary. The purpose of the study was to investigate the effect of eating attitudes, body mass and image satisfaction, and exercise dependence in the relationship between physical activity and health and quality of life perception in older individuals. Hundred and seventy-nine late middle-aged, (55–64 yrs), young-old (65–74 yrs), and old (75–84 yrs) senior athletes (n = 56), physically active (n = 58) or sedentary adults (n = 65) were submitted to anthropometric evaluations (body mass, height) and self-reported questionnaires: Body Image Dimensional Assessment, Exercise Dependence Scale, Eating Attitude Test, and Short Form Health Survey (Physical Component Summary [PCS] and Mental Component Summary [MCS] of and health and quality of life perception). Senior athletes, physically active, and sedentary participants subgroups differed (P<0.05) from each other in body mass index (BMI) and several components of body image and exercise dependence. Senior athletes showed, compared to their sedentary counterparts, further differences (P<0.05) in eating attitudes and in both PCS and MCS. Mediation analysis showed that the relationship between physical activity habit and MCS, but not PCS, was indirectly explained by a serial mediation chain composed of objective BMI and subjective body image (dis)satisfaction. Findings confirm the relevant role of physically active life habits for older individuals to perceive good physical and mental health. The novelty of the three-path mediated link between physical activity level and mental health perception suggests that the beneficial effect of a physically active lifestyle on weight control can positively impinge on the cognitive-emotional dimension of mental health by ensuring the maintenance, also at older age, of a satisfactory body image.</p></div
Anthropometric characteristics, weight category, number of medications and diseases, and educational background of participants.
<p>Anthropometric characteristics, weight category, number of medications and diseases, and educational background of participants.</p
SF-12 components in relation to activity level, age class, and gender mean±SD).
<p>SF-12 components in relation to activity level, age class, and gender mean±SD).</p
Conceptual and statistical model of the activity level and mediators effect’s on MCS.
<p>c’ = direct effect; c = total effect; a<sub>2·</sub>d<sub>32·</sub>b<sub>3 =</sub> indirect effect through BMI and BDI.</p
EAT-26 factors in relation to activity level and gender (mean±SD).
<p>EAT-26 factors in relation to activity level and gender (mean±SD).</p
EDS-21 dimensions in relation to activity level and gender (mean±SD).
<p>EDS-21 dimensions in relation to activity level and gender (mean±SD).</p
Whole body bone mineral content (BMC), trunk BMC, upper limbs BMC, lower limbs BMC in male controls (white bars), swimmers (grey bars) and basketball players (black bars) adjusted by chorological age, maturity offset, vitamin D intake and weekly training load.
<p>* indicates difference between the groups (p<0.05).</p
High-density lipoprotein-cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), triglycerides and high-sensitivity C-reactive protein (hsCRP) in male controls (white bars), swimmers (grey bars) and basketball players (black bars).
<p>* indicates difference between the groups (p<0.05).</p
Mean difference between groups on DXA assessments on trunk, upper limbs and lower limbs.
<p>Mean difference between groups on DXA assessments on trunk, upper limbs and lower limbs.</p