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Node Preservation and its Effect on Crossover in Cartesian Genetic Programming

Kocherovsky, Mark, Bakurov, Illya, Banzhaf, Wolfgang

arXiv.org Artificial Intelligence

While crossover is a critical and often indispensable component in other forms of Genetic Programming, such as Linear- and Tree-based, it has consistently been claimed that it deteriorates search performance in CGP. As a result, a mutation-alone $(1+λ)$ evolutionary strategy has become the canonical approach for CGP. Although several operators have been developed that demonstrate an increased performance over the canonical method, a general solution to the problem is still lacking. In this paper, we compare basic crossover methods, namely one-point and uniform, to variants in which nodes are ``preserved,'' including the subgraph crossover developed by Roman Kalkreuth, the difference being that when ``node preservation'' is active, crossover is not allowed to break apart instructions. We also compare a node mutation operator to the traditional point mutation; the former simply replaces an entire node with a new one. We find that node preservation in both mutation and crossover improves search using symbolic regression benchmark problems, moving the field towards a general solution to CGP crossover.


Unifying and Optimizing Data Values for Selection via Sequential-Decision-Making

Chi, Hongliang, Wu, Qiong, Zhou, Zhengyi, Light, Jonathan, Dodwell, Emily, Ma, Yao

arXiv.org Artificial Intelligence

Data selection has emerged as a crucial downstream application of data valuation. While existing data valuation methods have shown promise in selection tasks, the theoretical foundations and full potential of using data values for selection remain largely unexplored. In this work, we first demonstrate that data values applied for selection can be naturally reformulated as a sequential-decision-making problem, where the optimal data value can be derived through dynamic programming. We show this framework unifies and reinterprets existing methods like Data Shapley through the lens of approximate dynamic programming, specifically as myopic reward function approximations to this sequential problem. Furthermore, we analyze how sequential data selection optimality is affected when the ground-truth utility function exhibits monotonic submodularity with curvature. To address the computational challenges in obtaining optimal data values, we propose an efficient approximation scheme using learned bipartite graphs as surrogate utility models, ensuring greedy selection is still optimal when the surrogate utility is correctly specified and learned. Extensive experiments demonstrate the effectiveness of our approach across diverse datasets.


Evolutionary Algorithms Simulating Molecular Evolution: A New Field Proposal

Browning, James S. L. Jr., Tauritz, Daniel R., Beckmann, John

arXiv.org Artificial Intelligence

The genetic blueprint for the essential functions of life is encoded in DNA, which is translated into proteins -- the engines driving most of our metabolic processes. Recent advancements in genome sequencing have unveiled a vast diversity of protein families, but compared to the massive search space of all possible amino acid sequences, the set of known functional families is minimal. One could say nature has a limited protein "vocabulary." The major question for computational biologists, therefore, is whether this vocabulary can be expanded to include useful proteins that went extinct long ago, or maybe never evolved in the first place. We outline a computational approach to solving this problem. By merging evolutionary algorithms, machine learning (ML), and bioinformatics, we can facilitate the development of completely novel proteins which have never existed before. We envision this work forming a new sub-field of computational evolution we dub evolutionary algorithms simulating molecular evolution (EASME).


Game-theoretic Counterfactual Explanation for Graph Neural Networks

Chhablani, Chirag, Jain, Sarthak, Channesh, Akshay, Kash, Ian A., Medya, Sourav

arXiv.org Artificial Intelligence

Graph Neural Networks (GNNs) have been a powerful tool for node classification tasks in complex networks. However, their decision-making processes remain a black-box to users, making it challenging to understand the reasoning behind their predictions. Counterfactual explanations (CFE) have shown promise in enhancing the interpretability of machine learning models. Prior approaches to compute CFE for GNNS often are learning-based approaches that require training additional graphs. In this paper, we propose a semivalue-based, non-learning approach to generate CFE for node classification tasks, eliminating the need for any additional training. Our results reveals that computing Banzhaf values requires lower sample complexity in identifying the counterfactual explanations compared to other popular methods such as computing Shapley values. Our empirical evidence indicates computing Banzhaf values can achieve up to a fourfold speed up compared to Shapley values. We also design a thresholding method for computing Banzhaf values and show theoretical and empirical results on its robustness in noisy environments, making it superior to Shapley values. Furthermore, the thresholded Banzhaf values are shown to enhance efficiency without compromising the quality (i.e., fidelity) in the explanations in three popular graph datasets.


Researchers promote sex robots that can turn down sex with their owners The College Fix

#artificialintelligence

'Divorced from reality,' says critical law professor Are "virtuous sex robots" the way of the future? University researchers suggest that robots created for human pleasure should be designed so that they can grant or withhold consent, as well as teach sex education. Anco Peeters, a doctoral student at Australia's University of Wollongong, and Pim Haselager, associate professor at The Netherlands' Radboud University, published "Designing Virtuous Sex Robots" in the International Journal of Social Robotics last month. The paper examined four areas: "virtue ethics and social robotics," "Contra instrumentalist accounts," "Consent practice through sex robots" and "Implications of virtuous sex robots." The authors do not focus on child sex robots or sex robots that play into rape fantasies, but "the potential positive aspects of intimate human–robot interactions through the cultivation of virtues."