Given an implicit polynomial equation or a rational parametrization, we develop algorithms to determine whether the set of real and complex points defined by the equation, i.e., the surface defined by the equation, in the sense of Algebraic Geometry, is a cylindrical surface, a conical surface, or a surface of revolution. The algorithms are directly applicable to, and formulated in terms of, the implicit equation or the rational parametrization. When the surface is cylindrical, we show how to compute the direction of its rulings; when the surface is conical, we show how to compute its vertex; and when the surface is a surface of revolution, we show how to compute its axis of rotation directly from the defining equations.

Download full-text PDF

Source
http://dx.doi.org/10.1109/TVCG.2016.2625786DOI Listing

Publication Analysis

Top Keywords

equation rational
12
rational parametrization
12
surface surface
12
surface revolution
12
surface
10
implicit equation
8
cylindrical surface
8
defined equation
8
surface conical
8
equation
5

Similar Publications

Surveillance of Clostridioides difficile on hospital admission and outpatient antibiotic use in Germany-a 9 year ecological analysis.

J Antimicrob Chemother

January 2025

Institute for Hygiene and Environmental Medicine, Charité-Universitätsmedizin Berlin, Joint institution of Freie Universität Berlin and Humboldt-Universität Berlin, Institut für Hygiene und Umweltmedizin, Campus Benjamin Franklin, Hindenburgdamm 27, 12203 Berlin, Germany.

Background: Antibiotic consumption is considered an important risk factor for Clostridioides difficile infection (CDI). This ecological analysis investigates the influence of outpatient antibiotic prescriptions in statutory health insurance (SHI) on the admission prevalence of CDI in German hospitals participating in voluntary CDI surveillance through the hospital infection surveillance system (Krankenhaus-Infektions-Surveillance-System; KISS).

Methods: The annual CDI admission prevalence of a hospital at the federal state level was associated with the outpatient antibiotic consumption of the corresponding federal state.

View Article and Find Full Text PDF

Advancing microbiome-gut-brain axis science requires systematic, rational and translational approaches to bridge the critical knowledge gaps currently preventing full exploitation of the gut microbiome as a tractable therapeutic target for gastrointestinal, mental and brain health. Current research is still marked by many open questions that undermine widespread application to humans. For example, the lack of mechanistic understanding of probiotic effects means it remains unclear why even apparently closely related strains exhibit different effects in vivo.

View Article and Find Full Text PDF

Selecting Initial Conditions for Trajectory-Based Nonadiabatic Simulations.

Acc Chem Res

January 2025

Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom.

ConspectusPhotochemical reactions have always been the source of a great deal of mystery. While classified as a type of chemical reaction, no doubts are allowed that the general tenets of ground-state chemistry do not directly apply to photochemical reactions. For a typical chemical reaction, understanding the critical points of the ground-state potential (free) energy surface and embedding them in a thermodynamics framework is often enough to infer reaction yields or characteristic time scales.

View Article and Find Full Text PDF

The (3+1)-dimensional mKdV-ZK model is an important framework for studying the dynamic behavior of waves in mathematical physics. The goal of this study is to look into more generic travelling wave solutions (TWSs) for the generalized ion-acoustic scenario in three dimensions. These solutions exhibit a combination of rational, trigonometric, hyperbolic, and exponential solutions that are concurrently generated by the new auxiliary equation and the unified techniques.

View Article and Find Full Text PDF

Ball-milling of addition polymers such as polyolefins, polystyrene and polyacrylates can be used for depolymerization to obtain the respective monomers. However, absolute yields are typically low, especially from polyolefins which are notoriously difficult to depolymerize. To increase the viability of ball milling as a recycling technique, the effect of milling parameters on small hydrocarbon and monomer yields has to be understood.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!