991 research outputs found
Generalized Hybrid Evolutionary Algorithm Framework with a Mutation Operator Requiring no Adaptation
This paper presents a generalized hybrid evolutionary optimization structure that not only combines both nondeterministic and deterministic algorithms on their individual merits and distinct advantages, but also offers behaviors of the three originating classes of evolutionary algorithms (EAs). In addition, a robust mutation operator is developed in place of the necessity of mutation adaptation, based on the mutation properties of binary-coded individuals in a genetic algorithm. The behaviour of this mutation operator is examined in full and its performance is compared with adaptive mutations. The results show that the new mutation operator outperforms adaptive mutation operators while reducing complications of extra adaptive parameters in an EA representation
Use of the q-Gaussian mutation in evolutionary algorithms
Copyright @ Springer-Verlag 2010.This paper proposes the use of the q-Gaussian mutation with self-adaptation of the shape of the mutation distribution in evolutionary algorithms. The shape of the q-Gaussian mutation distribution is controlled by a real parameter q. In the proposed method, the real parameter q of the q-Gaussian mutation is encoded in the chromosome of individuals and hence is allowed to evolve during the evolutionary process. In order to test the new mutation operator, evolution strategy and evolutionary programming algorithms with self-adapted q-Gaussian mutation generated from anisotropic and isotropic distributions are presented. The theoretical analysis of the q-Gaussian mutation is also provided. In the experimental study, the q-Gaussian mutation is compared to Gaussian and Cauchy mutations in the optimization of a set of test functions. Experimental results show the efficiency of the proposed method of self-adapting the mutation distribution in evolutionary algorithms.This work was supported in part by FAPESP and CNPq in Brazil and in part by the Engineering and Physical Sciences Research Council (EPSRC) of the UK under Grant EP/E060722/1 and Grant EP/E060722/2
A Weighted U Statistic for Genetic Association Analyses of Sequencing Data
With advancements in next generation sequencing technology, a massive amount
of sequencing data are generated, offering a great opportunity to
comprehensively investigate the role of rare variants in the genetic etiology
of complex diseases. Nevertheless, this poses a great challenge for the
statistical analysis of high-dimensional sequencing data. The association
analyses based on traditional statistical methods suffer substantial power loss
because of the low frequency of genetic variants and the extremely high
dimensionality of the data. We developed a weighted U statistic, referred to as
WU-seq, for the high-dimensional association analysis of sequencing data. Based
on a non-parametric U statistic, WU-SEQ makes no assumption of the underlying
disease model and phenotype distribution, and can be applied to a variety of
phenotypes. Through simulation studies and an empirical study, we showed that
WU-SEQ outperformed a commonly used SKAT method when the underlying assumptions
were violated (e.g., the phenotype followed a heavy-tailed distribution). Even
when the assumptions were satisfied, WU-SEQ still attained comparable
performance to SKAT. Finally, we applied WU-seq to sequencing data from the
Dallas Heart Study (DHS), and detected an association between ANGPTL 4 and very
low density lipoprotein cholesterol
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