Abstract: Provided are a method of individual tree crown segmentation from airborne LiDAR data using a novel Gaussian filter and energy function minimization. First, a dual Gaussian filter was designed with automated adaptive parameter assignment and a screening strategy for false treetops. This preserved the geometric characteristics of sub-canopy trees while eliminating false treetops. Second, anisotropic water expansion controlled by the energy function was applied to accurate crown segmentation. This utilized gradient information from the digital surface model and explored the morphological structures of tree crown boundaries as analogous to the maximal valley height difference from surrounding treetops. We demonstrate the generality of our approach using seven diverse plots in the subtropical Gaofeng Forest, China, coupled with ground verification.

Abstract: Provided are a method of individual tree crown segmentation from airborne LiDAR data using a novel Gaussian filter and energy function minimization. First, a dual Gaussian filter was designed with automated adaptive parameter assignment and a screening strategy for false treetops. This preserved the geometric characteristics of sub-canopy trees while eliminating false treetops. Second, anisotropic water expansion controlled by the energy function was applied to accurate crown segmentation. This utilized gradient information from the digital surface model and explored the morphological structures of tree crown boundaries as analogous to the maximal valley height difference from surrounding treetops. We demonstrate the generality of our approach using seven diverse plots in the subtropical Gaofeng Forest, China, coupled with ground verification.

Abstract: An apparatus and method are disclosed for inducing fluid flow. A fluid flow apparatus includes a directional membrane, a directional flow mechanism, and an oscillation module. The directional membrane allows a fluid to pass through the directional membrane in a first direction and resists fluid passing through the directional membrane in a second direction, the first direction substantially opposite the second direction. The directional flow mechanism allows a fluid to flow in a third direction and resists fluid flow in a fourth direction, the third direction substantially opposite the fourth direction. The oscillation module induces an oscillation in the directional membrane, wherein the oscillation of the directional membrane induces a flow of the fluid through the directional membrane in the first direction.

Abstract: An apparatus and method are disclosed for inducing fluid flow. A fluid flow apparatus includes a directional membrane, a directional flow mechanism, and an oscillation module. The directional membrane allows a fluid to pass through the directional membrane in a first direction and resists fluid passing through the directional membrane in a second direction, the first direction substantially opposite the second direction. The directional flow mechanism allows a fluid to flow in a third direction and resists fluid flow in a fourth direction, the third direction substantially opposite the fourth direction. The oscillation module induces an oscillation in the directional membrane, wherein the oscillation of the directional membrane induces a flow of the fluid through the directional membrane in the first direction.