Flexible diagnostic measures and new cut‐point selection methods under multiple ordered classes

2021 ◽  
Author(s):  
Yingdong Feng ◽  
Lili Tian
2019 ◽  
Vol 61 (6) ◽  
pp. 1823-1831 ◽  
Author(s):  
Morten Sorensen ◽  
Hamed Kajbaf ◽  
Victor V. Khilkevich ◽  
Ling Zhang ◽  
David Pommerenke

2015 ◽  
Vol 26 (6) ◽  
pp. 2832-2852 ◽  
Author(s):  
Tuochuan Dong ◽  
Kristopher Attwood ◽  
Alan Hutson ◽  
Song Liu ◽  
Lili Tian

Most diagnostic accuracy measures and criteria for selecting optimal cut-points are only applicable to diseases with binary or three stages. Currently, there exist two diagnostic measures for diseases with general k stages: the hypervolume under the manifold and the generalized Youden index. While hypervolume under the manifold cannot be used for cut-points selection, generalized Youden index is only defined upon correct classification rates. This paper proposes a new measure named maximum absolute determinant for diseases with k stages ([Formula: see text]). This comprehensive new measure utilizes all the available classification information and serves as a cut-points selection criterion as well. Both the geometric and probabilistic interpretations for the new measure are examined. Power and simulation studies are carried out to investigate its performance as a measure of diagnostic accuracy as well as cut-points selection criterion. A real data set from Alzheimer’s Disease Neuroimaging Initiative is analyzed using the proposed maximum absolute determinant.


2019 ◽  
Vol 9 (6) ◽  
pp. 1141 ◽  
Author(s):  
Ran Zhao ◽  
Chao Li ◽  
Xiaowei Guo ◽  
Sijiang Fan ◽  
Yi Wang ◽  
...  

Greedy algorithm is one of the important point selection methods in the radial basis function based mesh deformation. However, in large-scale mesh, the conventional greedy selection will generate expensive time consumption and result in performance penalties. To accelerate the computational procedure of the point selection, a block iteration with parallelization method is proposed in this paper. By the block iteration method, the computational complexities of three steps in the greedy selection are all reduced from O ( n 3 ) to O ( n 2 ) . In addition, the parallelization of two steps in the greedy selection separates boundary points into sub-cores, efficiently accelerating the procedure. Specifically, three typical models of three-dimensional undulating fish, ONERA M6 wing and three-dimensional Super-cavitating Hydrofoil are taken as the test cases to validate the proposed method and the results show that it improves 17.41 times performance compared to the conventional method.


2013 ◽  
Vol 4 (1) ◽  
pp. 1-4
Author(s):  
Younis Elhaddad

Genetic algorithm is a well-known heuristic search algorithm, typically used to generate valuable solutions to optimization and search problems. The most important operation in a genetic algorithm is crossover, as it has the greatest effect on its convergence rate. Therefore, in order to achieve the most optimal results in a reasonable time, one has to decide on the crossover type, as well as make a selection of a crossover point. In order to explore the effect of the crossover point selection methods on the convergence rate, we conducted experiments based on different crossover point selection criteria, whereby the results indicate the high importance of controlling the randomization of the crossover point selection range.


Sign in / Sign up

Export Citation Format

Share Document