188 research outputs found
Learning to Generate Genotypes with Neural Networks
Neural networks and evolutionary computation have a rich intertwined history. They most commonly appear together when an evolutionary algorithm optimises the parameters and topology of a neural network for reinforcement learning problems, or when a neural network is applied as a surrogate fitness function to aid the evolutionary optimisation of expensive fitness functions. In this paper we take a different approach, asking the question of whether a neural network can be used to provide a mutation distribution for an evolutionary algorithm, and what advantages this approach may offer? Two modern neural network models are investigated, a Denoising Autoencoder modified to produce stochastic outputs and the Neural Autoregressive Distribution Estimator. Results show that the neural network approach to learning genotypes is able to solve many difficult discrete problems, such as MaxSat and HIFF, and regularly outperforms other evolutionary techniques
MaxSAT Evaluation 2022 : Solver and Benchmark Descriptions
Non peer reviewe
Efficiently Explaining CSPs with Unsatisfiable Subset Optimization (extended algorithms and examples)
We build on a recently proposed method for stepwise explaining solutions of
Constraint Satisfaction Problems (CSP) in a human-understandable way. An
explanation here is a sequence of simple inference steps where simplicity is
quantified using a cost function. The algorithms for explanation generation
rely on extracting Minimal Unsatisfiable Subsets (MUS) of a derived
unsatisfiable formula, exploiting a one-to-one correspondence between so-called
non-redundant explanations and MUSs. However, MUS extraction algorithms do not
provide any guarantee of subset minimality or optimality with respect to a
given cost function. Therefore, we build on these formal foundations and tackle
the main points of improvement, namely how to generate explanations efficiently
that are provably optimal (with respect to the given cost metric). For that, we
developed (1) a hitting set-based algorithm for finding the optimal constrained
unsatisfiable subsets; (2) a method for re-using relevant information over
multiple algorithm calls; and (3) methods exploiting domain-specific
information to speed up the explanation sequence generation. We experimentally
validated our algorithms on a large number of CSP problems. We found that our
algorithms outperform the MUS approach in terms of explanation quality and
computational time (on average up to 56 % faster than a standard MUS approach).Comment: arXiv admin note: text overlap with arXiv:2105.1176
Quantum Algorithm for Variant Maximum Satisfiability
In this paper, we proposed a novel quantum algorithm for the maximum satisfiability problem. Satisfiability (SAT) is to find the set of assignment values of input variables for the given Boolean function that evaluates this function as TRUE or prove that such satisfying values do not exist. For a POS SAT problem, we proposed a novel quantum algorithm for the maximum satisfiability (MAX-SAT), which returns the maximum number of OR terms that are satisfied for the SAT-unsatisfiable function, providing us with information on how far the given Boolean function is from the SAT satisfaction. We used Grover’s algorithm with a new block called quantum counter in the oracle circuit. The proposed circuit can be adapted for various forms of satisfiability expressions and several satisfiability-like problems. Using the quantum counter and mirrors for SAT terms reduces the need for ancilla qubits and realizes a large Toffoli gate that is then not needed. Our circuit reduces the number of ancilla qubits for the terms T of the Boolean function from T of ancilla qubits to ≈⌈log2T⌉+1. We analyzed and compared the quantum cost of the traditional oracle design with our design which gives a low quantum cost
Momentum-inspired Low-Rank Coordinate Descent for Diagonally Constrained SDPs
We present a novel, practical, and provable approach for solving diagonally
constrained semi-definite programming (SDP) problems at scale using accelerated
non-convex programming. Our algorithm non-trivially combines acceleration
motions from convex optimization with coordinate power iteration and matrix
factorization techniques. The algorithm is extremely simple to implement, and
adds only a single extra hyperparameter -- momentum. We prove that our method
admits local linear convergence in the neighborhood of the optimum and always
converges to a first-order critical point. Experimentally, we showcase the
merits of our method on three major application domains: MaxCut, MaxSAT, and
MIMO signal detection. In all cases, our methodology provides significant
speedups over non-convex and convex SDP solvers -- 5X faster than
state-of-the-art non-convex solvers, and 9 to 10^3 X faster than convex SDP
solvers -- with comparable or improved solution quality.Comment: 10 pages, 8 figures, preprint under revie
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