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How deep neural networks learn — a dynamical-systems perspective
No full textAfter giving an introduction to deep learning, I will discuss how deep networks learn. This can be analysed and understood, in part, using concepts from dynamical-systems and random-matrix theory [1]. For deep neural networks, the maximal finite-time Lyapunov exponent forms geometrical structures in input space, akin to coherent structures in dynamical systems such as turbulent flow. Ridges of large positive exponents divide input space into different regions that the network associates with different classes in a classification task. The ridges visualise the geometry that deep networks construct in input space, and help to quantify how the learning depends on the network depth and width [2].
[1] Bernhard Mehlig, Machine Learning with neural networks, Cambridge University Press (2021).
[2] Storm, Linander, Bec, Gustavsson & Mehlig, Finite-time Lyapunov exponents of deep neural networks, Phys. Rev. Lett. 132 (2024) 057301
Fast Solution Techniques for Polytopic hp-Discontinuous Galerkin Methods for Radiation Transport Problems
Get PDF''Appendicitis during Pregnancy: A Narrative Review Comparing Laparoscopic and Open Approaches''
No full text'''Background:''' Acute appendicitis is the most common non-obstetric surgical emergency during pregnancy. The choice between laparoscopic appendectomy (LA) and open appendectomy (OA) remains controversial due to maternal and fetal safety concerns. '''Objective:''' To analyze current evidence comparing laparoscopic and open appendectomy in pregnant women. '''Methods:''' A narrative review was conducted using PubMed, Elsevier, and ClinicalKey. Systematic reviews, meta-analyses, and observational studies published between 2000 and 2023 were included. '''Results:''' LA was associated with shorter hospital stay, fewer wound infections, and faster recovery compared to OA. Earlier meta-analyses suggested a slightly higher risk of fetal loss with LA (OR ~1.7), but more recent studies and sensitivity analyses demonstrated no significant differences. LA is increasingly considered safe throughout all trimesters when performed with appropriate surgical technique and intraoperative monitoring. '''Conclusions:''' Laparoscopic appendectomy provides maternal benefits and comparable fetal safety to open surgery. The choice of surgical approach should be guided by surgeon expertise and institutional resources
Obedience Without Command: The Silent Authority of Predictive Systems
Get PDFThis article investigates the paradox of obedience without command in predictive societies. Authority, once tied to explicit orders and visible command structures, is now embedded in syntactic operations that organize compliance without issuing instructions. Obedience Without Command explores how predictive systems generate silent authority, where rules are followed not because they are commanded, but because their form leaves no alternative. Through case studies of financial reporting, automated governance, and predictive scoring, the paper develops a framework to understand authority that operates without decisionmakers, and obedience that emerges without command. Acknowledgment / Editorial Note This article is published with editorial permission from LeFortune Academic Imprint, under whose license the text will also appear as part of the upcoming book Syntactic Authority and the Execution of Form. The present version is an autonomous preprint, structurally complete and formally self-contained. No substantive modifications are expected between this edition and the print edition. LeFortune holds non-exclusive editorial rights for collective publication within the Grammars of Power series. Open access deposit on SSRN is authorized under that framework, if citation integrity and canonical links to related works (SSRN: 10.2139/ssrn.4841065, 10.2139/ssrn.4862741, 10.2139/ssrn.4877266) are maintained. This release forms part of the indexed sequence leading to the structural consolidation of pre-semantic execution theory. Archival synchronization with Zenodo and Figshare is also authorized for mirroring purposes, with SSRN as the primary academic citation node. For licensing, referential use, or translation inquiries, contact the editorial coordination office at: [[email protected]
Alcohol Intoxication as Just Cause for Employment Termination: A Comparative Medical–Legal Perspective in Argentina, Peru, Costa Rica, and Mexico
No full textDrunkenness as grounds for termination of the employment relationship without employer liability has been widely debated in Latin America. Although contemplated in the labor laws of Argentina, Peru, Costa Rica, and Mexico, recent case law questions its strict application. From a medical perspective, alcoholism is recognized as a chronic, progressive disease, creating tension between workers' right to health and employers' authority to terminate contracts[1–3]. This article provides a medical-legal comparative analysis of legal and health criteria regarding workplace drunkenness. The study highlights the principle of proportionality, recognition of alcoholism as a disease, and the need to align labor regulations with occupational health[4–6]. We conclude that mere drunkenness should not suffice to justify dismissal, except when workplace safety, productivity, or third-party integrity is compromised, emphasizing preventive and rehabilitative measures[7,8]
Stability in Composite Bearing Structures within Room-and-Pillar Goafs under Repeated Mining
Get PDFDuring repeated mining of shallow and closely spaced coal seams, the failure of coal pillars within the upper goaf can induce dynamic hazards—such as shield jamming, support collapse, and roof fall—at the lower fully mechanized working face. To assess the stability of composite bearing structures, this study adopts a comprehensive approach that integrates orthogonal experimental design with single-factor experiments, supported by numerical simulation methods. Firstly, a composite bearing structure model is developed based on the engineering conditions of the Xingelao Coal Mine, followed by a comprehensive mechanical analysis. Secondly, experimental variables such as cement content, fly ash content, river sand content, and solid/slurry concentration are considered to systematically analyze their impact on backfill strength through proportion adjustment experiments. Furthermore, the controlled variable method is applied to adjust the backfill ratio, ultimately determining the optimal backfill mix ratio S8-2/3, which demonstrates a 7-day uniaxial compressive strength of 2.70 MPa with a backfill ratio of 2/3. This ratio satisfies both the mine’s strength requirements and cost-effectiveness criteria. Based on this, a failure model for the “backfill-pillar” composite bearing structure is established by integrating stress-strain curves with observed failure modes during load-bearing processes. Finally, numerical simulation software was utilized to perform a stability analysis on both the composite load-bearing structure formed by post-backfilling in the roomand-pillar goaf and the overlying strata of the mined-out area. Numerical simulation results indicate that, under repeated mining conditions, the use of S8-2/3 backfilling material in room-and-pillar goafs significantly enhances the load-bearing capacity of residual coal pillars. It also effectively controls overburden movement and supports the safe and efficient extraction of coal resources.OPEN ACCESS Received: 23/04/2025 Accepted: 16/06/2025 Published: 22/09/202
Exploring the Socio-Economic impacts of various extension services on Public Infrastructures: A Qualitative Assessment
No full textThis study assesses the socio-economic impact of the extension projects conducted by the Civil Engineering Department as part of the "Integrated Engineering Services for Sustainable Agro-Industrial and Infrastructure Development" program from 2016 to 2020. Using a qualitative, multiple-case design, the research focused on facility assessments at two public schools, the construction of a vermicompost facility, and a rainwater harvesting system at a public gymnasium. Key findings demonstrate that the department's technical assistance led to measurable improvements in school infrastructure and safety, resulting in tangible cost savings for the beneficiaries. The findings were used to guide school development plans and secure project funding from the Department of Education. While the rainwater harvesting facility proved beneficial for daily operations, a critical gap in capacity and power resilience was identified for use during large-scale calamities. This study validates the strategic value of targeted university extension services and provides a model for future program enhancement and policy-making