Real-time diagnostics of gas/water assisted injection moulding using integrated ultrasonic sensors

YesAn ultrasound sensor system has been applied to the mould of both the water and gas assisted injection moulding processes. The mould has a cavity wall mounted pressure sensor and instrumentation to monitor the injection moulding machine. Two ultrasound sensors are used to monitor the arrival of the fluid (gas or water) bubble tip through the detection of reflected ultrasound energy from the fluid polymer boundary and the fluid bubble tip velocity through the polymer melt is estimated. The polymer contact with the cavity wall is observed through the reflected ultrasound energy from that boundary. A theoretically based estimation of the residual wall thickness is made using the ultrasound reflection from the fluid (gas or water) polymer boundary whilst the samples are still inside the mould and a good correlation with a physical measurement is observed

Physically derived sound synthesis model of a propeller

© 2017 Copyright held by the owner/author(s). A real-time sound synthesis model for propeller sounds is presented. Equations obtained from fluid dynamics and aerodynamics research are utilised to produce authentic propeller-powered aircraft sounds. The result is a physical model in which the geometries of the objects involved are used in sound synthesis calculations. The model operates in real-time making it ideal for integration within a game or virtual reality environment. Comparison with real propeller-powered aircraft sounds indicates that some aspects of real recordings are not replicated by our model. Listening tests suggest that our model performs as well as another synthesis method but is not as plausible as a real recording

Magnetic-field dependence of the critical currents in a periodic coplanar array of narrow superconducting strip

We calculate the magnetic-field dependence of the critical current due to both geometrical edge barriers and bulk pinning in a periodic coplanar array of narrow superconducting strips. We find that in zero or low applied magnetic fields the critical current can be considerably enhanced by the edge barriers, but in modest applied magnetic fields the critical current reduces to that due to bulk pinning alone.Comment: 23 pages, 7 figure

Leraning Concrete Stragegies Through Interaction

We discuss learning and the adaptive generation of concrete strategies through interactive experience. The domain is the game Tictactoe. The knowledge structures embodying strategies we represent as having tree parts: a Goal, a sequence of Actions, and a set of Constraints on those actions (GAC). We simulate such structures in a program that plays Tictactoe against different kinds of opponents. Applying these strategies leads to moves that often result in winning or losing; which in turn leads to the creation of new structures, by modifying the current GACs. These modifications are controlled by a small set of specific rules, so that the GACs are related by the ways modifications can map from one to another. Subject to certain limitations, we do a complete exploration of certain classes of strategy. This learnability analysis takes guidance from previous cognitive studies of a human subject by Lawler. The simulations were performed on a Symbolics 3600 in LISP. This work avoids abstractions in order to explore learnin

Real-Time Sound Synthesis of Aeroacoustic Sounds using Physically Derived Models

PhDThis thesis examines the use of a novel synthesis approach to reproduce aeroacoustic sound effects. This requires research into the fi eld of fluid dynamics to understand the principles which lead to a number of fundamental aeroacoustic tones. Previous research has shown that these fundamental tones can be represented by compact sound sources. Three compact sound source synthesis models are developed representing three different fundamental aeroacoustic tones, the Aeolian tone, the cavity tone and the edge tone. A number of semi-empirical equations, ones where simpli cations, generalisations or observations are considered, are found which provide mathematical relationships between the defi ning fluid dynamic parameters. Often these equations have been developed prior to computers being able to solve the complex uid dynamic equations. Frequently, these equations were developed to assist scientists and engineers reduce the aeroacoustic noise. In this instance, the equations are used to replicate the aeroacoustic sounds. The methodology of developing a compact sound source synthesis model for each of the aeroacoustic tones is presented and how this relates to the chosen noise shaping synthesis technique. Objective evaluation shows the semi-physical synthesis models perform well when compares to previously published results. Following the development of the compact sound source synthesis models, three sound e ect models are developed. These provide examples of how the synthesis models can be used to provide procedural audio sound e ects. These are swinging objects, like a sword of a club; a propeller; an Aeolian harp. Evaluation of these are carried out, with subjective evaluation indicating equal or better performance than an alternative synthesis method. The uniqueness of the implementations presented from this research is that combines the low computational requirements of a signal-based model while the parameterisation draws from equations obtained from aeroacoustic research.This work was supported by EPSRC EP/G03723X/1

A large-strain radial consolidation theory for soft clays improved by vertical drains

A system of vertical drains with combined vacuum and surcharge preloading is an effective solution for promoting radial flow, accelerating consolidation. However, when a mixture of soil and water is deposited at a low initial density, a significant amount of deformation or surface settlement occurs. Therefore, it is necessary to introduce large-strain theory, which has been widely used to manage dredged disposal sites in one-dimensional theory, into radial consolidation theory. A governing equation based on Gibson's large-strain theory and Barron's free-strain theory incorporating the radial and vertical flows, the weight of the soil, variable hydraulic conductivity and compressibility during the consolidation process is therefore presented

REAL-TIME PHYSICAL MODEL FOR SYNTHESIS OF SWORD SWING SOUNDS

Sword sounds are synthesised by physical models in real- time. A number of compact sound sources are used along the length of the sword which replicate the swoosh sound when swung through the air. Listening tests are carried out which reveal a model with reduced physics is perceived as more authentic. The model is further developed to be controlled by a Wii Controller and successfully extended to include sounds of a baseball bat and golf club

Real-time physical model of an Aeolian harp

A real-time physical sound synthesis model of an Aeolian harp is presented. The model uses semi- empirical fluid dynamics equations to inform its operation, providing suitable parameters for users to interact. A basic wind model is included as well as an interface allowing user adjustable param- eters. Sounds generated by the model were subject to objective measurements against real-world recordings, which showed that many of the physical properties of the harp were replicated in our model, but a possible link between harmonics and vibration amplitude was not. A perceptual test was performed, where participants were asked to rate sounds in terms of how plausible they were in comparison with spectral modelling synthesis and recorded Aeolian Harp samples. Evaluation showed that our model performed as well as an alternative non-physical synthesis method, but was not as authentic as actual recorded samples

A longitudinal and cross-sectional examination of the relationship between reasons for choosing a neighbourhood, physical activity and body mass index

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to examine the relationship between body mass index and neighborhood walkability, socioeconomic status (SES), reasons for choosing neighborhoods, physical activity, fruit and vegetable intake, and demographic variables.</p> <p>Methods</p> <p>Two studies, one longitudinal and one cross-sectional, were conducted. Participants included adults (n = 572) who provided complete data in 2002 and 2008 and a concurrent sample from 2008 (n = 1164). Data were collected with longitudinal and cross-sectional telephone surveys. Objective measures of neighborhood characteristics (walkability and SES) were calculated using census data and geographic information.</p> <p>Results</p> <p>In the longitudinal study, neighborhood choice for ease of walking and proximity to outdoor recreation interacted with whether participants had moved during the course of study to predict change in BMI over 6 years. Age, change in activity status, and neighborhood SES were also significant predictors of BMI change. Cross-sectionally, neighborhood SES and neighborhood choice for ease of walking were significantly related to BMI as were gender, age, activity level and fruit and vegetable intake.</p> <p>Conclusions</p> <p>Results demonstrate that placing importance on choosing neighborhoods that are considered to be easily walkable is an important contributor to body weight. Findings that objectively measured neighbourhood SES and neighborhood choice variables contributed to BMI suggest that future research consider the role of neighborhood choice in examining the relationships between the built environment and body weight.</p