Variational Method for Studying Solitons in the KdV equation

We use a class of trial wave functions which are generalizations of gaussians to study single soliton approximate analytic solutions to the KdV equations. The variational parameters obey a Hamiltonian dynamics obtained from the Principle of Least Action. We get extremely accurate approximate single soliton solutions including their time dependence using this method.Comment: 8 page

An Investigation into Usability and First Time User Experiences within Mobile Games

With scientific research regarding usability and guidance plus First-Time User Experiences (FTUEs) in video games currently sparse, it is imperative to assist existing and future developers in the field build usable games and effective guidance systems. For the work presented in this publication, research was conducted to investigate the effects of guidance on mobile game us-ability using two independent groups; featuring two commercial games with and without the presence of a FTUE. The results show, with significance, that guidance via a FTUE increases one element of usability, ‘information quality’. However, overall usability is not increased by the presence of a FTUE. The above highlights the importance of a coherently designed interface, interaction and control systems plus the advantages of increased information quality through the delivery of guidance via a FTUE

Modular approach to analysis of chemically recuperated gas turbine cycles

Current research programmes such as the CAGT programme investigate the opportunity for advanced power generation cycles based on state-of-the-art aeroderivative gas turbine technology. Such cycles would be primarily aimed at intermediate duty applications. Compared to industrial gas turbines, aeroderivatives offer high simple cycle efficiency, and the capability to start quickly and frequently without a significant maintenance cost penalty. A key element for high system performance is the development of improved heat recovery systems, leading to advanced cycles such as the humid air turbine (HAT) cycle, the chemically recuperated gas turbine (CRGT) cycle and the Kalina combined cycle. When used in combination with advanced technologies and components, screening studies conducted by research programmes such as the CAGT programme predict that such advanced cycles could theoretically lead to net cycle efficiencies exceeding 60%. In this paper, the authors present the application of the modular approach to cycle simulation and performance predictions of CRGT cycles. The paper first presents the modular simulation code concept and the main characteristics of CRGT cycles. The paper next discusses the development of the methane–steam reformer unit model used for the simulations. The modular code is then used to compute performance characteristics of a simple CRGT cycle and a reheat CRGT cycle, both based on the General Electric LM6000 aeroderivative gas turbine

A Computer Vision Inspired Automatic Acoustic Material Tagging System for Virtual Environments

This paper presents the ongoing work on an approach to material information retrieval in virtual environments (VEs). Our approach uses convolutional neural networks to classify materials by performing semantic segmentation on images captured in the VE. Class maps obtained are then re-projected onto the environment. We use transfer learning and fine-tune a pretrained segmentation model on images captured in our VEs. The geometry and semantic information can then be used to create mappings between objects in the VE and acoustic absorption coefficients. This can then be input for physically-based audio renderers, allowing a significant reduction in manual material tagging

A comparison between expert and beginner learning for motor skill development in a virtual reality serious game

In order to be used for skill development and skill maintenance, virtual environments require accurate simulation of the physical phenomena involved in the process of the task being trained. The accuracy needs to be conveyed in a multimodal fashion with varying parameterisations still being quantified, and these are a function of task, prior knowledge, sensory efficacy and human perception. Virtual reality (VR) has been integrated from a didactic perspective in many serious games and shown to be effective in the pedological process. This paper interrogates whether didactic processes introduced into a VR serious game, by taking advantage of augmented virtuality to modify game attributes, can be effective for both beginners and experts to a task. The task in question is subjective performance in a clay pigeon shooting simulation. The investigation covers whether modified game attributes influence skill and learning in a complex motor task and also investigates whether this process is applicable to experts as well as beginners to the task. VR offers designers and developers of serious games the ability to provide information in the virtual world in a fashion that is impossible in the real world. This introduces the question of whether this is effective and transfers skill adoption into the real world and also if a-priori knowledge influences the practical nature of this information in the pedagogic process. Analysis is conducted via a between-subjects repeated measure ANOVA using a 2 \backslashtimes 22×2factorial design to address these questions. The results show that the different training provided affects the performance in this task ($$N=57$$N=57). The skill improvement is still evidenced in repeated measures when information and guidance is removed. This effect does not exist under a control condition. Additionally, we separate by an expert and non-expert group to deduce if a-priori knowledge influences the effect of the presented information, it is shown that it does not

Puffed Noncommutative Nonabelian Vortices

We present new solutions of noncommutative gauge theories in which coincident unstable vortices expand into unstable circular shells. As the theories are noncommutative, the naive definition of the locations of the vortices and shells is gauge-dependent, and so we define and calculate the profiles of these solutions using the gauge-invariant noncommutative Wilson lines introduced by Gross and Nekrasov. We find that charge 2 vortex solutions are characterized by two positions and a single nonnegative real number, which we demonstrate is the radius of the shell. We find that the radius is identically zero in all 2-dimensional solutions. If one considers solutions that depend on an additional commutative direction, then there are time-dependent solutions in which the radius oscillates, resembling a braneworld description of a cyclic universe. There are also smooth BIon-like space-dependent solutions in which the shell expands to infinity, describing a vortex ending on a domain wall.Comment: 21 pages, 3 eps figures. v2: published version, analytic solution adde

Selective BRDFs for High Fidelity Rendering

High fidelity rendering systems rely on accurate material representations to produce a realistic visual appearance. However, these accurate models can be slow to evaluate. This work presents an approach for approximating these high accuracy reflectance models with faster, less complicated functions in regions of an image which possess low visual importance. A subjective rating experiment was conducted in which thirty participants were asked to assess the similarity of scenes rendered with low quality reflectance models, a high quality data-driven model and saliency based hybrids of those images. In two out of the three scenes that were evaluated significant differences were not found between the hybrid and reference images. This implies that in less visually salient regions of an image computational gains can be achieved by approximating computationally expensive materials with simpler analytic models

Bespoke high-fidelity visualization of tiling

This paper describes the development and validation of a new service allowing products, such as tiles, to be viewed on a computer authentically in the actual lighting conditions of the area in which they are to be installed. This service leverages recent developments in physically based global illumination and High Dynamic Range (HDR) imaging, enabling real-world lighting to be accurately captured, transferred to a computer and used to relight any choice of tile in a highly realistic manner.This project is funded by TSB ICT for Manufacturing and Construction project 14345-87267. The project is also partially supported by ICT COST Action IC1005. L. P. Santos is partially funded through the FCT (Portuguese Foundation for Science and Technology) within project PEst-OE/EEI/UI0752/2011