Surface wave modelling and simulation for wave tanks and coastal areas

For testing ships and offshore structures in hydrodynamic laboratories, the sea and ocean states should be represented as realistic as possible in the wave tanks in which the scaled experiments are executed. To support efficient testing, accurate software that determines and translates the required wave maker motion into the downstream waves is very helpful. This paper describes an efficient hybrid spatial-spectral code that can deal with simulations above flat and varying bottom. The accuracy of the code will be illustrated by presenting comparisons of simulations with experimental data for various different type of non-breaking waves, from dispersive focussing waves to irregular wave fields with freak waves; the very broad-band spectra of such waves provide the main challeng

On Ideas in Motion in Baghdad and Beyond

Note on Damien Janos (ed.), Ideas in Motion in Baghdad and Beyond. Philosophical and Theological Exchanges between Christians and Muslims in the Third/Ninth and Fourth/Tenth Centuries, (Islamic History and Civilization. Studies and Texts, 124), Brill: Leiden–Boston, 201

A new automated workflow for 3D character creation based on 3D scanned data

In this paper we present a new workflow allowing the creation of 3D characters in an automated way that does not require the expertise of an animator. This workflow is based of the acquisition of real human data captured by 3D body scanners, which is them processed to generate firstly animatable body meshes, secondly skinned body meshes and finally textured 3D garments

Design of a five-axis ultra-precision micro-milling machine—UltraMill. Part 1: Holistic design approach, design considerations and specifications

High-accuracy three-dimensional miniature components and microstructures are increasingly in demand in the sector of electro-optics, automotive, biotechnology, aerospace and information-technology industries. A rational approach to mechanical micro machining is to develop ultra-precision machines with small footprints. In part 1 of this two-part paper, the-state-of-the-art of ultra-precision machines with micro-machining capability is critically reviewed. The design considerations and specifications of a five-axis ultra-precision micro-milling machine—UltraMill—are discussed. Three prioritised design issues: motion accuracy, dynamic stiffness and thermal stability, formulate the holistic design approach for UltraMill. This approach has been applied to the development of key machine components and their integration so as to achieve high accuracy and nanometer surface finish

Fitting aerodynamic forces in the Laplace domain: An application of a nonlinear nongradient technique to multilevel constrained optimization

A technique which employs both linear and nonlinear methods in a multilevel optimization structure to best approximate generalized unsteady aerodynamic forces for arbitrary motion is described. Optimum selection of free parameters is made in a rational function approximation of the aerodynamic forces in the Laplace domain such that a best fit is obtained, in a least squares sense, to tabular data for purely oscillatory motion. The multilevel structure and the corresponding formulation of the objective models are presented which separate the reduction of the fit error into linear and nonlinear problems, thus enabling the use of linear methods where practical. Certain equality and inequality constraints that may be imposed are identified; a brief description of the nongradient, nonlinear optimizer which is used is given; and results which illustrate application of the method are presented