Publications related to Screw theory

Rapid motion estimation and correction using self-encoded FID navigators in 3D radial MRI

Purpose: To develop a self-navigated motion compensation strategy for 3D radial MRI that can compensate for continuous head motion by measuring rigid body motion parameters with high temporal resolution from the central k-space acquisition point (self-enco ...

Wiley2023

Geometric Algebra for Optimal Control With Applications in Manipulation Tasks

Sylvain Calinon, Tobias Löw

Many problems in robotics are fundamentally problems of geometry, which have led to an increased research effort in geometric methods for robotics in recent years. The results were algorithms using the various frameworks of screw theory, Lie algebra, and d ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2023

Unraveling looping efficiency of stochastic Cosserat polymers

Raushan Singh, Giulio Corazza

Understanding looping probabilities, including the particular case of ring closure or cyclization, of fluctuating polymers (e.g., DNA) is important in many applications in molecular biology and chemistry. In a continuum limit the configuration of a polymer ...

AMER PHYSICAL SOC2022

Screw vs. edge dislocation strengthening in body-centered-cubic high entrophy alloys and implications for guided alloy design

William Curtin, Francesco Maresca, Carolina Baruffi

Body-centered-cubic (BCC) high entropy alloys (HEAs) can show exceptionally high strength up to high temperatures. Mechanistic theories are needed to guide alloy discovery within the immense multicomponent HEA compositional space. Here, two new theories fo ...

SPRINGER HEIDELBERG2022

To tread or not to tread: comparison between water treading and conventional flapping wing kinematics

Karen Ann J Mulleners, Alexander Gehrke, Swathi Badala Krishna

Hovering insects are limited by their physiology and need to rotate their wings at the end of each back-and-forth motion to keep the wing's leading edge ahead of its trailing edge. The wing rotation at the end of each half-stroke pushes the leading edge vo ...

IOP Publishing Ltd2022

Optical rotating torque sensor with nano newton-meter resolution based on a hanging torsion wire

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann, Billy Nussbaumer

This article presents a novel torque measuring setup working in the nano newton-meter range. The central novelty is a long (1 meter range) thin (diameter of a few tens of micrometers) metallic wire used instead of the relatively stiff torsion zone of the s ...

euspen2021

High-order based revelation of bifurcation of novel Schatz-inspired metamorphic mechanisms using screw theory

Huijuan Feng

The revelation of mechanism bifurcation is essential in the design and analysis of reconfigurable mechanisms. The first- and second-order based methods have successfully revealed the bifurcation of mechanisms. However, they fail in the novel Schatz-inspire ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Experimental studies of the equilibrium and out-of-equilibrium electronic structure of non-symmorphic topological materials

Gianmarco Gatti

Symmetry and topology are fundamental properties of nature. Mathematics provides us with a general framework to understand these concepts. On one side, symmetry describes the invariance properties of an object for specific transformations. On the other sid ...

EPFL2020

Head motion measurement and correction using FID navigators

Tobias Kober, Maryna Volodimirivna Waszak

Purpose: To develop a novel framework for rapid, intrinsic head motion measurement in MRI using FID navigators (FIDnavs) from a multichannel head coil array. ...

WILEY2019

Prospective head motion correction using FID-guided on-demand image navigators

Rolf Gruetter, Tobias Kober, Gunnar Krüger, Tom Hilbert, Bénédicte Marie Maréchal, Pavel Falkovskiy, Reto Meuli, Maryna Volodimirivna Waszak, Guillaume Bonnier

PURPOSE: We suggest a motion correction concept that employs free-induction-decay (FID) navigator signals to continuously monitor motion and to guide the acquisition of image navigators for prospective motion correction following motion detection. METHODS: ...

Wiley-Blackwell2017

Geometric Optimization of a Reciprocal Floor-Framing System with Self-Weight and Area-Loading Considerations

Corentin Jean Dominique Fivet

This paper explores the geometric optimization of a planar reciprocal frame (RF) floor framing structure, focusing on the triangular topology. The structural performance of the frames is computed and plotted against the geometric parameters for various loa ...

2017

Bloch theorem with revised boundary conditions applied to glide and screw symmetric, quasi-one-dimensional structures

Florian Paul Robert Maurin

Bloch theorem is useful for analyzing wave propagation in periodic systems. It has been widely used to determine the energy bands of various translationally-periodic crystals and with the advent of nanoscale structures like nanotubes, it has been extended ...

Elsevier2016

Effect of static and kinematic boundary conditions on the out-of-plane response of brick masonry walls

Katrin Beyer, Filippo Lucca

The Unreinforced Wall (URM) elements that are most susceptible to out-of-plane failure are wall elements of the upper storeys where the accelerations are largest. In modern URM buildings with reinforced concrete slabs, the out-of-plane mechanism involves t ...

Taylor and Francis Group2016

Muscle Moment-Arms: A Key Element in Muscle-Force Estimation

Alexandre Terrier, Philippe Müllhaupt, Alain Farron, Christoph Anselm Engelhardt, David Ingram

A clear and rigorous definition of muscle moment-arms in the context of musculoskeletal systems modelling is presented, using classical mechanics and screw theory. The definition provides an alternative to the tendon excursion method, which can lead to inc ...

Taylor & Francis2015

Variability of the pullout strength of cancellous bone screws with cement augmentation

Dominique Pioletti

Background: orthopaedic surgeons often face clinical situations where improved screw holding power in cancellous bone is needed. Injectable calcium phosphate cements are one option to enhance fixation. Methods: paired screw pullout tests were undertaken in ...

Elsevier2015

Bloch Theorem With Revised Boundary Conditions Applied To Glide Plane And Screw Axis Symmetric, Quasi-One-Dimensional Structures

Alessandro Spadoni, Florian Paul Robert Maurin

Bloch theorem provides a useful tool to analyze wave propagation in periodic systems. It has been widely used in physics to obtain the energy bands of various translationally-periodic cristals and with the advent of nanosciences like nanotubes, it has been ...

Int Center Numerical Methods Engineering2014

Adjustable fixation system for neurosurgical devices

Jean-Philippe Thiran, Rémi Charrier, David Haag

The system comprises at least a support (5) to be attached to a patient by fixing means (4), said support having an outer thread (7), a first nut (9) with an inner thread (11 ) cooperating with said outer thread (7) and an anchor having a spherical bottom ...

2012

Clebsch Optimal Control Formulation In Mechanics

Tudor Ratiu, François Gay-Balmaz

This paper introduces and studies a class of optimal control problems based on the Clebsch approach to Euler-Poincare dynamics. This approach unifies and generalizes a wide range of examples appearing in the literature: the symmetric formulation of N-dimen ...

2011

Tightening force and torque of nonlocking screws in a reverse shoulder prosthesis

Dominique Pioletti, Alexandre Terrier, Alain Farron, Francesco Merlini, Miguel Gortchacow, Stephanie Kochbeck

Background. Reversed shoulder arthroplasty is an accepted treatment for glenohumeral arthritis associated to rotator cuff deficiency. For most reversed shoulder prostheses, the baseplate of the glenoid component is uncemented and its primary stability is p ...

Elsevier2010

A Hamilton-Jacobi Formulation for Cooperative Control of Multi-Agent Systems

Denis Gillet, Sylvain Rudaz, Hajir Roozbehani

Coordination of autonomous non-point agents is studied in this work. Interactions between vehicles together with their internal dynamics have been modeled as a continuous, unconstrained differential game. In particular, collision prediction is shown to be ...

2009