Tootfinder

Faster exponential algorithms for cut problems via geometric data structures
L\'aszl\'o Kozma, Junqi Tan
https://arxiv.org/abs/2506.22281 https://

Faster exponential algorithms for cut problems via geometric data structures
For many hard computational problems, simple algorithms that run in time $2^n \cdot n^{O(1)}$ arise, say, from enumerating all subsets of a size-$n$ set. Finding (exponentially) faster algorithms is a natural goal that has driven much of the field of exact exponential algorithms (e.g., see Fomin and Kratsch, 2010). In this paper we obtain algorithms with running time $O(1.9999977^n)$ on input graphs with $n$ vertices, for the following well-studied problems: - $d$-Cut: find a proper cut in wh…

Validation of the MySurgeryRisk Algorithm for Predicting Complications and Death after Major Surgery: A Retrospective Multicenter Study Using OneFlorida Data Trust
Yuanfang Ren, Esra Adiyeke, Ziyuan Guan, Zhenhong Hu, Mackenzie J Meni, Benjamin Shickel, Parisa Rashidi, Tezcan Ozrazgat-Baslanti, Azra Bihorac
https://arxiv.org/abs…

Validation of the MySurgeryRisk Algorithm for Predicting Complications and Death after Major Surgery: A Retrospective Multicenter Study Using OneFlorida Data Trust
Despite advances in surgical techniques and care, postoperative complications are prevalent and effects up to 15% of the patients who underwent a major surgery. The objective of this study is to develop and validate models for predicting postoperative complications and death after major surgery on a large and multicenter dataset, following the previously validated MySurgeryRisk algorithm. This retrospective, longitudinal and multicenter cohort analysis included 508,097 encounters from 366,875 a…

Methodology for intelligent injection point location based on geometric algorithms and discrete topologies for virtual digital twin environments
J. Mercado Colmenero, A. Torres Alba, C. Martin Donate
https://arxiv.org/abs/2507.20922

Methodology for intelligent injection point location based on geometric algorithms and discrete topologies for virtual digital twin environments
This article presents an innovative methodology for locating injection points in injection-molded parts using intelligent models with geometric algorithms for discrete topologies. The first algorithm calculates the center of mass of the discrete model based on the center of mass of each triangular facet in the system, ensuring uniform molten plastic distribution during mold cavity filling. Two sub-algorithms intelligently evaluate the geometry and optimal injection point location. The first sub…

Energy-Resolved EBSD using a Monolithic Direct Electron Detector
Nicol\`o M. Della Ventura, Kalani Moore, McLean P. Echlin, Matthew R. Begley, Tresa M. Pollock, Marc De Graef, Daniel S. Gianola
https://arxiv.org/abs/2507.20105

Energy-Resolved EBSD using a Monolithic Direct Electron Detector
Accurate quantification of the energy distribution of backscattered electrons (BSEs) contributing to electron backscatter diffraction (EBSD) patterns remains as an active challenge. This study introduces an energy-resolved EBSD methodology based on a monolithic active pixel sensor direct electron detector and an electron-counting algorithm to enable the energy quantification of individual BSEs, providing direct measurements of electron energy spectra within diffraction patterns. Following detec…

Electromagnetic Formation Flying Using Alternating Magnetic Field Forces and Control Barrier Functions for State and Input Constraints
Sumit S. Kamat, T. Michael Seigler, Jesse B. Hoagg
https://arxiv.org/abs/2508.18501

Electromagnetic Formation Flying Using Alternating Magnetic Field Forces and Control Barrier Functions for State and Input Constraints
This article presents a feedback control algorithm for electromagnetic formation flying with constraints on the satellites' states and control inputs. The algorithm combines several key techniques. First, we use alternating magnetic field forces to decouple the electromagnetic forces between each pair of satellites in the formation. Each satellite's electromagnetic actuation system is driven by a sum of amplitude-modulated sinusoids, where amplitudes are controlled in order to prescribe the tim…

Galois theory by calculator
Thomas W. Mattman, Robertson-Figaniak, Zoe Steele
https://arxiv.org/abs/2508.18595 https://arxiv.org/pdf/2508.18595

Galois theory by calculator
We present an algorithm to determine the Galois group of an irreducible monic polynomial $f(x) \in \mathbb{Z}[x]$ of degree at most five. Following work of Conrad, Dummit, and Stauduhar this comes down to answering two questions: Is a given integer a square? and Does a given polynomial have an integral root? Since these are both easily addressed with a calculator, our algorithm amounts to Galois theory by calculator. For example, we have an implementation at Desmos.com. In an appendix we presen…

Efficient Probabilistic Parity Shaping for Irregular Repeat-Accumulate LDPC Codes
Diego Lentner, Thomas Wiegart, Richard D. Wesel
https://arxiv.org/abs/2508.19696 https://

Efficient Probabilistic Parity Shaping for Irregular Repeat-Accumulate LDPC Codes
Algorithms are presented that efficiently shape the parity bits of systematic irregular repeat-accumulate (IRA) low-density parity-check (LDPC) codes by following the sequential encoding order of the accumulator. Simulations over additive white Gaussian noise (AWGN) channels with on-off keying show a gain of up to 0.9 dB over uniform signaling.

The hidden subgroup problem for infinite groups
Greg Kuperberg (UC Davis)
https://arxiv.org/abs/2507.18499 https://arxiv.org/pdf/2507.18499

The hidden subgroup problem for infinite groups
Following the example of Shor's algorithm for period-finding in the integers, we explore the hidden subgroup problem (HSP) for discrete infinite groups. On the hardness side, we show that HSP is NP-hard for the additive group of rational numbers, and for normal subgroups of non-abelian free groups. We also indirectly reduce a version of the short vector problem to HSP in $\mathbb{Z}^k$ with pseudo-polynomial query cost. On the algorithm side, we generalize the Shor-Kitaev algorithm for HSP in $…

Algorithmic Collusion is Algorithm Orchestration
Cesare Carissimo, Fryderyk Falniowski, Siavash Rahimi, Heinrich Nax
https://arxiv.org/abs/2508.14766 https://

Algorithmic Collusion is Algorithm Orchestration
This paper proposes a fresh `meta-game' perspective on the problem of algorithmic collusion in pricing games a la Bertrand. Economists have interpreted the fact that algorithms can learn to price collusively as tacit collusion. We argue instead that the co-parametrization of algorithms -- that we show is necessary to obtain algorithmic collusion -- requires algorithm designer(s) to engage in explicit collusion by algorithm orchestration. To highlight this, we model a meta-game of algorithm para…

A Robust Method for Pitch Tracking in the Frequency Following Response using Harmonic Amplitude Summation Filterbank
Sajad Sadeghkhani, Maryam Karimi Boroujeni, Hilmi R. Dajani, Saeid R. Seydnejad, Christian Gigu\`ere
https://arxiv.org/abs/2506.19253

A Robust Method for Pitch Tracking in the Frequency Following Response using Harmonic Amplitude Summation Filterbank
The Frequency Following Response (FFR) reflects the brain's neural encoding of auditory stimuli including speech. Because the fundamental frequency (F0), a physical correlate of pitch, is one of the essential features of speech, there has been particular interest in characterizing the FFR at F0, especially when F0 varies over time. The standard method for extracting F0 in FFRs has been the Autocorrelation Function (ACF). This paper investigates harmonic-structure-based F0 estimation algorithms,…