18,481 research outputs found
Urban greenery and mental wellbeing in adults: Cross-sectional mediation analyses on multiple pathways across different greenery measures
Multiple mechanisms have been proposed to explain how greenery enhances their
mental wellbeing. Mediation studies, however, focus on a limited number of
mechanisms and rely on remotely sensed greenery measures, which do not
accurately capture how neighborhood greenery is perceived on the ground. To
examine: 1) how streetscape and remote sensing-based greenery affect people's
mental wellbeing in Guangzhou, China; 2) whether and, if so, to what extent the
associations are mediated by physical activity, stress, air quality and noise,
and social cohesion; and 3) whether differences in the mediation across the
streetscape greenery and NDVI exposure metrics occurred. Mental wellbeing was
quantified by the WHO-5 wellbeing index. Greenery measures were extracted at
the neighborhood level: 1) streetscape greenery from street view data via a
convolutional neural network, and 2) the NDVI remote sensing images. Single and
multiple mediation analyses with multilevel regressions were conducted.
Streetscape and NDVI greenery were weakly and positively, but not
significantly, correlated. Our regression results revealed that streetscape
greenery and NDVI were, individually and jointly, positively associated with
mental wellbeing. Significant partial mediators for the streetscape greenery
were physical activity, stress, air quality and noise, and social cohesion;
together, they explained 62% of the association. For NDVI, only physical
activity and social cohesion were significant partial mediators, accounting for
22% of the association. Mental health and wellbeing and both streetscape and
satellite-derived greenery seem to be both directly correlated and indirectly
mediated. Our findings signify that both greenery measures capture different
aspects of natural environments and may contribute to people's wellbeing by
means of different mechanisms
Theoretical and experimental methods of dynamic clothing pressure performance
A dynamic pressure measuring system has been developed in this study. This system can be used for static pressure measuring, real-time dynamic pressure measuring and pressure fatigue analysis. A 3D geometric model on fabric deformation as well as mechanical behavior has been developed, which can be used for simulating the fabric elongation during dynamic pressing, and to deduce relationship between the press depth and fabric elongation. The process parameters of measuring system have been systematically estimated and analyzed. The range of press depth fixed for dynamic pressure measurement is found to be 58-115 mm, which responds to the fabric elongation from 10% to 40%. The press velocity at 100 mm/min is considered as the optional one for dynamic pressure measurement. Five repeated test cycles can be satisfied to assess the dynamic pressure fatigue performance quickly
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