The automated extraction of the airway tree from 3-D chest CT data can greatly reduce the workload of physicians during diagnosis (e.g. quantification of airway morphology) and treatment (computeraided bronchoscopy) of lung disease. This paper presents a method to automatically extract the airways driven by a sharpening filter, which enhances the branch edges in the input image based on the Lap...

Airways that collapse during deflation generate a crackle sound when they reopen during subsequent reinflation. Since each crackle is associated with the reopening of a collapsed airway, the likelihood of an airway to be a crackle source is identical to its vulnerability to collapse. To investigate this vulnerability of airways to collapse, crackles were recorded during the first inflation of s...

A number of methods have evolved through the years in probing the dysfunction that impacts mechanics and ventilation in asthma. What has been consistently found is the notion of heterogeneity that is not only captured in the frequency dependence of lung mechanics measurements but also rendered on imaging as patchy diffuse areas of ventilation defects. The degree of heterogeneity has been linked...

Airborne LiDAR point cloud of a forest contains three dimensional data, from which vertical stand structure (including information about under-story trees) can be derived. This paper presents a segmentation approach for multi-story stands that strips the point cloud to its canopy layers, identifies individual tree segments within each layer using a DSM-based tree identification method as a buil...

Inaccurate image segmentation often has a negative impact on object-based image retrieval. Researchers have attempted to alleviate this problem by using hierarchical image representation. However, these attempts suffer from the inefficiency in building the hierarchical image representation and the high computational complexity in matching two hierarchically represented images. This paper presen...

In this paper, we investigate the benefits of using an adaptive segmentation of the speech signal in speech enhancement. The adaptive segmentation scheme divides the signal into the longest segments within which stationarity is preserved, thus providing a good time-frequency resolution. The segmentation is performed with the help of an orthogonal library of local cosine bases using a computatio...

Airway smooth muscle (ASM) shortening is the central event leading to bronchoconstriction. The degree to which airway narrowing occurs as a consequence of shortening is a function of both the mechanical properties of the airway wall as well as the orientation of the muscle fibers. Although the latter is theoretically important, it has not been systematically measured to date. The purpose of thi...

The study highlights a novel method to segment single trees in 3D from dense airborne full waveform LIDAR data using the normalized cut segmentation. The key idea is to subdivide the tree area in a voxel space and to setup a bipartite graph which is formed by the voxels and similarity measures between the voxels. The normalized cut segmentation divides the graph hierarchically into segments whi...