Wrapping Snakes for Improved Lip Segmentation

If you wish to contact a Curtin researcher associated with this document, you may obtain an email address fro

Computational fluid dynamics for nematic liquid crystals

Due to recent advances in fast iterative solvers in the field of computational fluid dynamics, more complex problems which were previously beyond the scope of standard techniques can be tackled. In this paper, we describe one such situation, namely, modelling the interaction of flow and molecular orientation in a complex fluid such as a liquid crystal. Specifically, we consider a nematic liquid crystal in a spatially inhomogeneous flow situation where the orientational order is described by a second rank alignment tensor. The evolution is determined by two coupled equations: a generalised Navier-Stokes equation for flow in which the divergence of the stress tensor also depends on the alignment tensor and its time derivative, and a convection-diffusion type equation with non-linear terms that stem from a Landau-Ginzburg-DeGennes potential for the alignment. In this paper, we use a specific model with three viscosity coefficients that allows the contribution of the orientation to the viscous stress to be cast in the form of an orientation-dependent force. This effectively decouples the flow and orientation, with each appearing only on the right-hand side of the other equation. In this way, difficulties associated with solving the fully coupled problem are circumvented and a stand-alone fast solver, such as the state-of-the-art preconditioned iterative solver implemented here, can be used for the flow equation. A time-discretised strategy for solving the flow-orientation problem is illustrated using the example of Stokes flow in a lid-driven cavity

Measuring-up in timber: A critical perspective on mid-and high-rise timber building design

Architects, engineers and researchers alike often cite practical reasons for building with wood. Since the development of curved glulam beams and columns over a century ago, the widespread use of massive structural timber elements has allowed architects and engineers to design and build in wood with unprecedented speed and scale. Moreover, rising concerns of climate change and the carbon-dioxide emissions associated with construction encourage the use of wood as a viable alternative to steel and concrete, due to CO2 sequestration in trees.In mid- and high-rise buildings, the current shift from steel and concrete towards massive structural timber elements like glulam, laminated-veneer lumber (LVL) and cross-laminated timber (CLT) is evident in a number of recently completed timber buildings in Europe, ranging from seven to nine storeys. Several speculative design proposals have also been made for ‘timber towers’ of thirty, fortytwo and even sixty-five storeys, recognising that designing with massive structural timber elements in high-rise buildings is still in its infancy. This paper offers a new perspective on building with wood at this scale, beyond carbon sequestrationand construction.This is the author's accepted manuscript. The final version has been published in Architectural Research Quarterly here: http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9295856&fileId=S1359135514000268. Copyright © Cambridge University Press 201

Engineered bamboo for shell structures

Engineered bamboo combines the benefits of a natural material with the advantages of a laminated composite, resulting in an efficient, light material well-suited to gridshell structures. Bamboo is a rapidly renewable material that can be harvested every 4-5 years. The round culm can either be used as is or it can be processed into a variety of laminated products. Engineered bamboo is currently promoted as a structural alternative to timber and glue-laminated timber, but also has potential in shell applications. In contrast to short fibre composites, engineered bamboo maintains fibre length and continuity within the raw material for exceptional mechanical properties. The composite section results in a high strength material in compression and tension, with bending properties comparable to timber products. The inherent flexibility of the material has advantages in comparison to timber, allowing for complex designs to be achieved. The present work explores the substitution of engineered bamboo in existing gridshells with a comparison to the original timber structure. As dowelled connections are key components at the boundary of gridshells, their potential for use with bamboo is also explored

UK utility data integration: overcoming schematic heterogeneity

In this paper we discuss syntactic, semantic and schematic issues which inhibit the integration of utility data in the UK. We then focus on the techniques employed within the VISTA project to overcome schematic heterogeneity. A Global Schema based architecture is employed. Although automated approaches to Global Schema definition were attempted the heterogeneities of the sector were too great. A manual approach to Global Schema definition was employed. The techniques used to define and subsequently map source utility data models to this schema are discussed in detail. In order to ensure a coherent integrated model, sub and cross domain validation issues are then highlighted. Finally the proposed framework and data flow for schematic integration is introduced

Engineered bamboo for structural applications

Bamboo is a rapidly renewable material that has many applications in construction. Engineered bamboo products result from processing the raw bamboo culm into a laminated composite, similar to glue-laminated timber products. These products allow the material to be used in standardised sections and have less inherent variability than the natural material. The present work investigates the mechanical properties of two types of commercially available products – bamboo scrimber and laminated bamboo sheets – and compares these to timber and engineered timber products. It is shown that engineered bamboo products have properties that are comparable to or surpass that of timber and timber-based products. Potential limitations to use in structural design are also discussed. The study contributes to a growing body of research on engineered bamboo and presents areas in which further investigation is needed.The presented work is supported by EPRSC Grant EP/K023403/1 and the Newton Trust, and forms part of a collaboration between the University of Cambridge, Massachusetts Institute of Technology (MIT) and University of British Columbia (UBC).This is the published version. It was first published at http://www.sciencedirect.com/science/article/pii/S0950061815001117

Biofilm-forming capability of highly virulent, multidrug-resistant Candida auris

The emerging multidrug-resistant yeast pathogen Candida auris has attracted considerable attention as a source of healthcare–associated infections. We report that this highly virulent yeast has the capacity to form antifungal resistant biofilms sensitive to the disinfectant chlorhexidine in vitro

Dowelled structural connections in laminated bamboo and timber

© 2016 The Authors. Structural sections of laminated bamboo can be connected using methods common in timber engineering, however the different material properties of timber and laminated bamboo suggest that the behaviour of connections in the two materials would not be the same. This study investigates the dowelled connection, in which a connector is passed through a hole in the material, and load is resisted by shear in the connector and embedment into the surrounding material. Steel dowels were used in a connection between a laminated bamboo member and a steel plate in a central slot in the bamboo, and the behaviour of this connection was compared with a similar connection in timber. The laminated bamboo was made from Moso bamboo (Phyllostachys pubescens) which had been treated by one of two preservative processes, either bleaching or caramelisation. Following testing, substantial qualitative differences between the bamboo and timber specimens were observed: the bamboo failed most often by the formation of a shear plug whereas the timber failed by a single split. The two preservative treatments resulted in different behaviour: the bleached bamboo had a degree of ductility roughly twice that of the caramelised bamboo. Digital image correlation provided full-field strain measurements, which gave further insight into the differences between the materials, particularly between bamboo and timber. Shear strain is dominant in the bamboo, compared with tensile strain perpendicular to grain in the timber. Numerical modelling showed that this difference in the strain field could be explained by the different orthotropic elastic and frictional properties of the two materials.The presented work is supported by a Leverhulme Trust Programme Grant, and EPSRC Grant EP/K023403/1

Landsat TM and ETM+ derived snowline altitudes in the Cordillera Huayhuash and Cordillera Raura, Peru, 1986–2005

The Cordilleras Huayhuash and Raura are remote glacierized ranges in the Andes Mountains of Peru. A robust assessment of modern glacier change is important for understanding how regional change affects Andean communities, and for placing paleo-glaciers in a context relative to modern glaciation and climate. Snowline altitudes (SLAs) derived from satellite imagery are used as a proxy for modern (1986–2005) local climate change in a key transition zone in the Andes. <br><br> Clear sky, dry season Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+) satellite images from 1986–2005 were used to identify snowline positions, and their altitude ranges were extracted from an Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital elevation model (DEM). Based on satellite records from 31 glaciers, average snowline altitudes (SLAs), an approximation for the equilibrium line altitude (ELA), for the Cordillera Huayhuash (13 glaciers) and Cordillera Raura (18 glaciers) from 1986–2005 were 5051 m a.s.l. from 1986–2005 and 5006 m a.s.l. from 1986–2002, respectively. During the same time period, the Cordillera Huayhuash SLA experienced no significant change while the Cordillera Raura SLA rose significantly from 4947 m a.s.l. to 5044 m a.s.l

Rapid institutional appraisal

A week-long intensive process of staff development and induction called Rapid Institutional Appraisal (RIA) was conducted in November 2000 in the Systems Discipline, Centre for Complexity and Change (CCC), at the Open University. We report the systemic roots and characteristics of the RIA as designed from traditions of soft systems methodology and rapid rural appraisal. Our experiences arising from our own use of RIA are described and the wider implications for organizational learning in a complex organization discussed. While acknowledging limitations with this RIA event, we argue that RIA offers a potential model for staff development for adaptive use in different contexts and on varying scales. The process builds on principles of "conversation" and "multiple perspectives" as the touchstone for establishing a purposeful community of practice