A Hierarchical Genetic Algorithm for System Identification and Curve Fitting with a Supercomputer Implementation

This paper describes a hierarchical genetic algorithm (GA) framework for identifying closed form functions for multi-variate data sets. The hierarchy begins with an upper GA that searches for appropriate functional forms given a user defined set of primitives and the candidate independent variables. Each functional form is encoded as a tree structure, where variables, coefficients and functional primitives are linked. The functional forms are sent to the second part of the hierarchy, the lower GA, that optimizes the coefficients of the function according to the data set and the chosen error metric. To avoid undue complication of the functional form identified by the upper GA, a penalty function is used in the calculation of fitness. Because of the computational effort required for this sequential optimization of each candidate function, the system has been implemented on a Cray supercomputer. The GA code was vectorized for parallel processing of 128 array elements, which gr..

Counseling about sudden unexpected death in epilepsy (SUDEP): A global survey of neurologists’ opinions

Objective: To investigate the opinions and attitudes of neurologists on the counseling about sudden unexpected death in epilepsy (SUDEP) worldwide. Methods: Practicing neurologists from around the world were invited to participate in an online survey. On February 18th, 2021, we emailed an invitation including a questionnaire (using Google-forms) to the lead neurologists from 50 countries. The survey anonymously collected the demographic data of the participants and answers to the questions about their opinions and attitudes toward counseling about SUDEP. Results: In total, 1123 neurologists from 27 countries participated; 41.5% of the respondents reported they discuss the risk of SUDEP with patients and their care-givers only rarely. Specific subgroups of patients who should especially be told about this condition were considered to be those with poor antiseizure medication (ASM) adherence, frequent tonic-clonic seizures, or with drug-resistant epilepsy. The propensity to tell all patients with epilepsy (PWE) about SUDEP was higher among those with epilepsy fellowship. Having an epilepsy fellowship and working in an academic setting were factors associated with a comfortable discussion about SUDEP. There were significant differences between the world regions. Conclusion: Neurologists often do not discuss SUDEP with patients and their care-givers. While the results of this study may not be representative of practitioners in each country, it seems that there is a severe dissociation between the clinical significance of SUDEP and the amount of attention that is devoted to this matter in daily practice by many neurologists around the world