PMC

Simplification of service provision areas (SPAs) and service beneficiary areas (SBAs) for wind erosion prevention (WEP) service flow incorporating wind erosion simulation. The simulation of the wind erosion prevention service flow is based on the potential and actual wind erosion service flow. (a) In the bare sand land without vegetation, the potential wind erosion flow from the potential wind erosion areas (PWEs) to the potential wind erosion affected areas (PWEAs), which can recognize the maximum wind erosion amount and the maximum wind erosion affected areas. (b) In the actual land cover with vegetation, the actual wind erosion flow from the actual wind erosion areas (AWEs) to the actual wind erosion affected areas (AWEAs), which can recognize the actual wind erosion amount and actual wind erosion affected areas. (c) The wind erosion prevention service flow can establish the spatial relationship between the SPAs and SBAs. The boundary of the SPAs depends on the areas whose wind erosion prevention amount (the subtraction of potential wind erosion amount and actual wind erosion amount) is positive. The thickness of the light blue and dark blue trajectories represent its carried potential and actual wind erosion amount, respectively. The thicker the path, the more dust it carries. The flow trajectories of the WEP can be divided into two parts, dominant flow trajectories in red, and recessive flow trajectories in brown, which correspond to the dominant service beneficiary areas (DSBAs) and recessive service beneficiary areas (RSBAs), respectively. The naming rule of the dominant and recessive trajectories/areas can be assimilated to the dominant and recessive gene, with the dominant ones corresponding to the dominant gene for their obvious WEP flow effect and the recessive ones corresponding to the recessive gene for their relatively insignificant WEP flow effect. The spatial relationship between the dominant and recessive terms can be better understood from the perspective of ‘set’ in mathematics. The domain of the dominant flow trajectories/DSBAs can be assimilated to the set A and the actual wind erosion service flow trajectories/AWEAs corresponded to complementary set A. The union of the dominant flow trajectories and the recessive flow trajectories is the potential wind erosion paths. The thickness of the red and brown trajectories depend on the subtraction of the potential and actual wind erosion amount of the corresponding trajectory in light blue and dark blue at the same location, representing the wind erosion prevention service flow amount.

Measuring the amount of acetabular erosion. (a) Immediate postoperative radiograph measuring the distance from acetabular line to the level of prosthesis (A). (b) Follow-up radiograph measuring the same distance (B). (c) Immediate postoperative radiograph measuring the distance from Kohler line to prosthesis (C). (d) Follow-up radiograph measuring the same distance. Superior acetabular erosion calculated as (A and B) in mm. Medial acetabular erosion calculated as (C and D) in mm.