| 1. |
- Rickard, Scott T., et al.
(författare)
-
SAGI : Sparsification Algorithm using Greedy Iteration
- 2005
-
Ingår i: Signal Processing with Adaptive Sparse Structured Representations. - Rennes. ; , s. 16-8
-
Konferensbidrag (refereegranskat)abstract
- We introduce a method, called SAGI (Sparsification Algo- rithm using Greedy Iteration), for making a representation of a signal more sparse in an over-complete dictionary in a greedy manner. The sparsification is achieved by iteratively increasing the magnitude of the largest signal coefficient and simultaneously reducing the other signal coefficients so as to maximize the sparsity of the representation while main- taining invariant the reconstruction of the signal from the coefficients. Any measure of sparsity can be used with the method. Two versions are presented. The first, the one-pass version, considers each coefficient once in order from largest to smallest. The second, the exhaustive version, only consid- ers the (n + 1)st largest coefficient if iteratively considering the n largest coefficients results in no increase in sparsity.
|
|
| 2. |
- Walsh, Darragh R., et al.
(författare)
-
Mechanical characterisation of the human dura mater, falx cerebri and superior sagittal sinus
- 2021
-
Ingår i: Acta Biomaterialia. - : Elsevier BV. - 1742-7061 .- 1878-7568. ; 134, s. 388-400
-
Tidskriftsartikel (refereegranskat)abstract
- The cranial meninges have been shown to play a pivotal role in traumatic brain injury mechanopathology. However, while the mechanical response of the brain and its many subregions have been studied extensively, the meninges have conventionally been overlooked. This paper presents the first comparative mechanical analysis of human dura mater, falx cerebri and superior sagittal sinus tissues. Biaxial tensile analysis identified that these tissues are mechanically heterogeneous, in contrast to the assumption that the tissues are mechanically homogeneous which is typically employed in FE model design. A thickness of 0.91 +/- 0.05 (standard error) mm for the falx cerebri was also identified. This data can aid in improving the biofidelity of the influential falx structure in FE models. Additionally, the use of a collagen hybridizing peptide on the superior sagittal sinus suggests this structure is particularly susceptible to the effects of circumf erential stretch, which may have important implications for clinical treatment of dural venous sinus pathologies. Collectively, this research progresses understanding of meningeal mechanical and structural characteristics and may aid in elucidating the behaviour of these tissues in healthy and diseased conditions.
|
|
