scholarly journals Productive fitness in diversity-aware evolutionary algorithms

2021 ◽  
Author(s):  
Thomas Gabor ◽  
Thomy Phan ◽  
Claudia Linnhoff-Popien

AbstractIn evolutionary algorithms, the notion of diversity has been adopted from biology and is used to describe the distribution of a population of solution candidates. While it has been known that maintaining a reasonable amount of diversity often benefits the overall result of the evolutionary optimization process by adjusting the exploration/exploitation trade-off, little has been known about what diversity is optimal. We introduce the notion of productive fitness based on the effect that a specific solution candidate has some generations down the evolutionary path. We derive the notion of final productive fitness, which is the ideal target fitness for any evolutionary process. Although it is inefficient to compute, we show empirically that it allows for an a posteriori analysis of how well a given evolutionary optimization process hit the ideal exploration/exploitation trade-off, providing insight into why diversity-aware evolutionary optimization often performs better.

Author(s):  
Steven M. Corns ◽  
Kenneth M. Bryden ◽  
Daniel A. Ashlock

Graph based evolutionary algorithms (GBEAs) are a novel evolutionary optimization technique that utilize population graphing to impose a topology or geography on the evolving solution set. In many cases in nature, the ability of a particular member of a population to mate and reproduce is limited. The factors creating these limits vary widely and include geographical distance, mating rituals, and others. The effect of these factors is to limit the mating pool, reducing the rate of spread of genetic characteristics, and increased diversity within the population. GBEAs mimic these factors resulting in increased diversity within the solution population. When properly tuned to the problem and the size of the population set, GBEAs can result in improved convergence times and a more diverse number of viable solutions. This paper examines the impact of the fitness landscape, population size, and choice of graph on the evolutionary process. In general, it was found that there was an optimal population size and graph combination for each problem. This optimal graph/population was problem dependent.


Author(s):  
Praveen Kumar Dwivedi ◽  
Surya Prakash Tripathi

Background: Fuzzy systems are employed in several fields like data processing, regression, pattern recognition, classification and management as a result of their characteristic of handling uncertainty and explaining the feature of the advanced system while not involving a particular mathematical model. Fuzzy rule-based systems (FRBS) or fuzzy rule-based classifiers (mainly designed for classification purpose) are primarily the fuzzy systems that consist of a group of fuzzy logical rules and these FRBS are unit annexes of ancient rule-based systems, containing the "If-then" rules. During the design of any fuzzy systems, there are two main objectives, interpretability and accuracy, which are conflicting with each another, i.e., improvement in any of those two options causes the decrement in another. This condition is termed as Interpretability –Accuracy Trade-off. To handle this condition, Multi-Objective Evolutionary Algorithms (MOEA) are often applied within the design of fuzzy systems. This paper reviews the approaches to the problem of developing fuzzy systems victimization evolutionary process Multi-Objective Optimization (EMO) algorithms considering ‘Interpretability-Accuracy Trade-off, current research trends and improvement in the design of fuzzy classifier using MOEA in the future scope of authors. Methods: The state-of-the-art review has been conducted for various fuzzy classifier designs, and their optimization is reviewed in terms of multi-objective. Results: This article reviews the different Multi-Objective Optimization (EMO) algorithms in the context of Interpretability -Accuracy tradeoff during fuzzy classification. Conclusion: The evolutionary multi-objective algorithms are being deployed in the development of fuzzy systems. Improvement in the design using these algorithms include issues like higher spatiality, exponentially inhabited solution, I-A tradeoff, interpretability quantification, and describing the ability of the system of the fuzzy domain, etc. The focus of the authors in future is to find out the best evolutionary algorithm of multi-objective nature with efficiency and robustness, which will be applicable for developing the optimized fuzzy system with more accuracy and higher interpretability. More concentration will be on the creation of new metrics or parameters for the measurement of interpretability of fuzzy systems and new processes or methods of EMO for handling I-A tradeoff.


Author(s):  
Tian Wu ◽  
Danyan Hu ◽  
Qingfen Wang

Abstract Background Noni (Morinda citrifolia Linn.) is a tropical tree that bears climacteric fruit. Previous observations and research have shown that the second day (2 d) after harvest is the most important demarcation point when the fruit has the same appearance as the freshly picked fruit (0 d); however, they are beginning to become water spot appearance. We performed a conjoint analysis of metabolome and transcriptome data for noni fruit of 0 d and 2 d to reveal what happened to the fruit at the molecular level. Genes and metabolites were annotated to KEGG pathways and the co-annotated KEGG pathways were used as a statistical analysis. Results We found 25 pathways that were significantly altered at both metabolic and transcriptional levels, including a total of 285 differentially expressed genes (DEGs) and 11 differential metabolites through an integrative analysis of transcriptomics and metabolomics. The energy metabolism and pathways originating from phenylalanine were disturbed the most. The upregulated resistance metabolites and genes implied the increase of resistance and energy consumption in the postharvest noni fruit. Most genes involved in glycolysis were downregulated, further limiting the available energy. This lack of energy led noni fruit to water spot appearance, a prelude to softening. The metabolites and genes related to the resistance and energy interacted and restricted each other to keep noni fruit seemingly hard within two days after harvest, but actually the softening was already unstoppable. Conclusions This study provides a new insight into the relationship between the metabolites and genes of noni fruit, as well as a foundation for further clarification of the post-ripening mechanism in noni fruit.


Pharmaceutics ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 201 ◽  
Author(s):  
Cristina Padula ◽  
Silvia Pescina ◽  
Sara Nicoli ◽  
Patrizia Santi

Buccal mucosa has recently received much attention as a potential route for systemic delivery of drugs, including biologics and vaccines. The aim of this work was to gain insight into the mechanism of fatty acids as buccal permeation enhancers, by studying the effect of a series of medium and long chain fatty acids on the permeation of a model high molecular weight and hydrophilic molecule, fluorescein isothiocyanate labelled dextran (FD-4, m.w. 4 kDa) across porcine esophageal epithelium. A parabolic relationship between fatty acid lipophilicity and enhancement was obtained, regardless of the presence and number of double bonds. The relationship, which resembles the well-known relationship between permeability and lipophilicity of transdermal delivery, presents a maximum value in correspondence of C10 (logP approx. 4). This is probably the ideal lipophilicity for the fatty acid to interact with the lipid domains of the mucosa. When the same analysis was performed on skin data, the same trend was observed, although the maximum value was reached for C12 (logP approx. 5), in agreement with the higher lipophilicity of the skin. The results obtained in the present work represent a significant advancement in the understanding of the mechanisms of action of fatty acids as buccal penetration enhancers.


Author(s):  
Julian Berk ◽  
Sunil Gupta ◽  
Santu Rana ◽  
Svetha Venkatesh

In order to improve the performance of Bayesian optimisation, we develop a modified Gaussian process upper confidence bound (GP-UCB) acquisition function. This is done by sampling the exploration-exploitation trade-off parameter from a distribution. We prove that this allows the expected trade-off parameter to be altered to better suit the problem without compromising a bound on the function's Bayesian regret. We also provide results showing that our method achieves better performance than GP-UCB in a range of real-world and synthetic problems.


2009 ◽  
Author(s):  
Antoine Soubeyran ◽  
Raphael Soubeyran ◽  
Ngo Van Long

2017 ◽  
Vol 119 (6) ◽  
pp. 1232-1246 ◽  
Author(s):  
Aina Ravoniarison

Purpose The purpose of this paper is to examine how French senior consumers deal with duality between perceived risk and perceived value associated with functional foods (FFs) and to analyze whether the risk-value trade-off may help to derive different consumer profiles. Design/methodology/approach Data were collected from 220 senior consumers (50-70). A two-step clustering analysis was carried out on factor scores of perceived value and perceived risk. Discriminant analysis was then employed to verify the classification reliability, and analysis of variance was performed to profile the clusters on the basis of additional variables. Findings Four distinctive profiles of FF senior consumers were identified. Significant differences were found to be attributed to personality traits. Interestingly, the “Trustful enthusiasts” and the “Ambivalents” consumers do not differ in their repurchase intention, despite a significant discrepancy in risk perception. Practical implications The study is an opportunity to offer a segmentation of this attractive growing target of health-enhancing products. The typology can help the practitioners to find out a new valuable scope of messages to better communicate to elderly market. Originality/value The research seeks to contribute to the existing knowledge on seniors’ nutrition-related behavior, by proposing a segmentation still lacking in research works. Since FF perceived value appears to be multidimensional and not only utilitarian, the study provides a new insight into the experiential approach of health-enhancing eating. Also, it shows how the differences between FF consumers could be attributed to certain personal variables.


2021 ◽  
Vol 18 (5) ◽  
pp. 519-532
Author(s):  
Stephanie Pedron

This paper examines historic federal immigration policies that demonstrate how the United States has rendered entire groups of people living inside and outside of its territory as outsiders. Collective representations like the Statue of Liberty suggest that the U.S. is a nation that welcomes all immigrants, when in reality, the U.S. has historically functioned as a “gatekeeper” that excludes specific groups of people at different times. The concurrent existence of disparate beliefs within a society’s collective consciousness influences the public’s views toward citizenship and results in policy outcomes that contrast sharply from the ideal values that many collective representations signify. As restrictive immigration controls are refined, insight into how immigrant exclusion via federal policy has evolved is necessary to minimize future legislative consequences that have the potential to ostracize current and future Americans.


Sign in / Sign up

Export Citation Format

Share Document