arXiv subjects

A. del Río

Publications and source records attributed to A. del Río.

2 recordsLinked to original sources

arXiv2026

An Island-Based Parallel Biased Random-Key Genetic Algorithm for the Three-Dimensional Trailer Loading Problem

The Three-Dimensional Trailer Loading Problem (3D-TLP) involves determining the optimal placement and orientation of heterogeneous items within the confined space of a trailer while maximizing volume utilization and satisfying a wide range of complex logistical and safety constraints. The 3D-TLP is NP-hard, rendering exact optimization approaches computationally impractical for large-scale industrial applications. To address this challenge, we propose an enhanced Biased Random-Key Genetic Algorithm (BRKGA) accelerated through a novel island-based parallelization framework, PANGEA. The proposed method combines the search efficiency and robustness of BRKGA with a multi-population evolutionary scheme for genetic algorithms. This island-model strategy promotes population diversity, mitigates premature convergence, and significantly reduces computational times. The proposed solution was validated in a real trailer loading process, providing an effective solution approach for real-world large-scale logistics.

cs.NE↗

arXiv2025

Singularity resolution in the backreacted Schwarzschild geometry from 2D matter with negative central charge

Two-dimensional dilaton gravity provides a valuable framework to study the dynamics of quantum black holes. These models are often coupled to conformal scalar fields, which capture essential quantum effects such as the trace anomaly, while remaining analytically tractable. From the viewpoint of two-dimensional quantum field theory, unitary theories require a positive central charge. However, theories with a total negative central charge naturally arise from the contribution of the Faddeev-Popov ghosts to the effective action. Recent analyses of the Callan-Giddins-Harvey-Strominger (CGHS) model with a Russo-Susskin-Thorlacius (RST) counterterm have shown that a negative central charge can remove curvature singularities in the backreacted geometry. In this work, we argue that singularity resolution arises from the negative central charge itself, rather than the particular dynamics of a given model. To support this, we present analogous results in spherically reduced Einstein gravity.

gr-qc↗