The implementation and evaluation of an undergraduate virtual reality surveying application

Multi-media applications are increasingly being used to enhance the delivery of on-site and distance learning teaching material. However, production costs are often prohibitive, both in terms of capital investment and development time. Hence it is surprising that authors comment on the failure to adequately evaluate new educational software applications. This paper evaluates an interactive multi-media levelling resource, which comprises text-based guides, video instruction, photo-realistic panoramic scenes and multi-row object movies. Students explore 360 degree images of building sites, using traditional computer input devices, and click on hot spots to gather detailed information about the position of the optical level and staff. Readings are taken directly from the staff and students record backsights and foresights as various change points are introduced. On completion of the levelling exercise, 192 first year undergraduate students completed an evaluation based upon a series of statements drawn from technology-based training literature. The findings suggest that the exercise complements traditional learning approaches, maintains student interest, and reinforces understanding. However, significant differences in student ratings for part-time and full-time cohorts emphasise the importance of designing resources that accommodate the needs of varying student profiles. Suggestions for enhanced interactivity are offered and new areas for development allied to construction technology are identified

Virtual reality learning resources in building pathology

Building surveying students must be capable of analysing the condition of buildings and their components and, where this falls below an agreed standard, make recommendations for their repair. Hence university courses must provide opportunities for students to learn about the main causes of deterioration. Fieldwork exercises are essential but there are often problems locating appropriate buildings, programming visits to satisfy course timetables and complying with health and safety requirements. Whilst virtual surveys of existing buildings are not considered to be a substitute for real-life educational visits, this paper critically examines the development of a novel building pathology educational resource. Alternative technologies for creating digital panoramas are examined, prior to the development of an interactive case study, which enables students to conduct an on-line survey of a Grade 1 listed 16th Century hunting lodge. 360 degree panoramic scenes are linked with hot spots to create an interactive virtual tour of the building. The paper considers how virtual resources can be embedded within the curriculum, gauges tutor reaction to case study materials and identifies opportunities for the development of a suite of building pathology educational media-rich learning materials

Urban Societies in Europe since 1945: Toward a Historical Interpretation

How can we write the history of urban societies in Europe after 1945? This article offers an interpretative overview of key developments in both Eastern and Western Europe, while also discussing some key conceptual issues. Along the way, it takes stock of the relevant historiography (much of which is very recent) and introduces a selection of papers from a cycle of three international workshops held between 2011 and 2013. The papers range geographically from Britain to the Soviet Union and cover topics as diverse as post-war reconstruction and alternative communities in the 1970s. Their respective approaches are informed by an interest in the way societies have been imagined in discourses and reshaped in spatial settings. Moreover, the papers move beyond case studies, urban history's classic genre, and can therefore facilitate synthetic reflection. It is our hope that, in so doing, we can make urban history more relevant to contemporary European historians in general.</jats:p

Modification of the National Weather Service Distributed Hydrologic Model for subsurface water exchanges between grids

To account for spatial variability of precipitation, as well as basin physiographic properties, the National Weather Service (NWS) has developed a distributed version of its hydrologic component, termed the Hydrology Laboratory-Research Distributed Hydrologic Model (HL-RDHM). Because channels are the only source of water exchange between neighboring computational elements, the absence of such exchange has been identified as a weakness in the model. The primary objective of this paper is to modify the model structure to account for subsurface water exchanges without dramatically altering the conceptual framework of the water balance module. The subsurface exchanges are established by partitioning the slow response components released from the lower layer storages into two parts: the first part involves the grid's conceptual channel, while the second is added to the lower layer storages of the downstream pixel. Realizing the deficiency of the water balance module to locate the lower zone layers in sufficient depths, a complementary study is conducted to test the feasibility of further improvement in the modified model by equally shifting downward the lower zone layers of all pixels over the basin. The Baron Fork at Eldon, Oklahoma, is chosen as the test basin. Ten years of grid-based multisensor precipitation data are used to investigate the effects of the modification, plus shifting the lower zone layers on model performance. The results show that the modified-shifted HL-RDHM can markedly improve the streamflow simulations at the interior point, as well as very high peak-flow simulations at the basin's outlet. Copyright 2011 by the American Geophysical Union

The apparent optical indices of spongy nanoporous gold

Very thin spongy nanoporous gold films have a unique nanostructure and hence unusual properties. Our interest in these materials is also due to their wide range of potential application (1,2). An optical study for such nanostructured films is of fundamental interest for understanding how light interacts with such a spongy nanoporous structure. In general the gold either percolates or is very closely packed. This surface plasmons, and surface plasmon resonant effects, are expected to play a key role given the large surface area of metal and the metal backbone of the nanostructure. The ropological complexity of the nano-void network is also expected to be a major influence. The optical response has, for a metal system, quite unusual dispersion relations for the effective complex refractive index components n*, k*. Once these are better understood new optical engineering possibilities arise. We are not aware of any optical studies for spongy metal film nanostructures apart from a brief preliminary report of our own on one such film 93) whose nanstructure was different to the spongy nanoporous films presented here. We check the internal consistency and physical accpetability of the results with a Kramers-Kronig analysis of the spectrumn of n*, k* values, because of their unusual spectral character

Bulk and surface plasmons in highly nanoporous gold films

The far field plasmonic behaviour of nanoporous gold films with void densities ranging from 60% to 90% has been investigated and modelled. These layers have good dc conductivity and quite different nanostructure to traditional porous layers in which the metal percolates. Our gold films with void density f above 70% have high thermal emittance for a conductor at their thicknesses and their flat spectral response at visible and near infrared wavelengths is not metal like. We derive effective optical constants which become plasmonic at wavelengths between 1.8 and 4 νm for f from 72 to 87%. This onset is much longer than that in bulk gold. For void densities below 70% the onset of plasmonic behaviour is much closer to the dense material. A simple test is implemented to test for surface plasmon polaritons (SPPs) under illumination. The more porous films show no evidence of SPP, while the less porous films display weak evidence. Thus by tailoring void content in these nanostructures we can tailor the onset of effective plasmonic response across a wide range from 0.8 to 4 νm and emittance from around 0.9 down to low values. An effective uniform metal response is thus found in the presence of surface nanostructure without the interface absorption found in dense gold layers with structured surfaces. © 2007 IOP Publishing Ltd

Nanoscale coatings of AuAl<inf>x</inf> and PtAl<inf>x</inf> and their mesoporous elemental derivatives

A method to produce nanoscale films of AuAlx and PtAlx, and their mesoporous elemental derivatives is described, and the morphology and optical properties of these coatings explored. The color of the AuAlx film is bright purple, in agreement with ab initio calculations and experimental observations for the compound AuAl2, but becomes black after de-alloying with NaOH. The film of PtAlx is silver-grey and changes to grey after being converted to mesoporous Pt by de-alloying. Both mesoporous coatings exhibit a very rough surface, with pores of between 2 and 20 nm in diameter, and display a significantly more absorptive optical characteristic compared to their ordinary elemental counterparts. © 2005 Elsevier B.V. All rights reserved

A proposed testbed for detector tomography

Measurement is the only part of a general quantum system that has yet to be characterized experimentally in a complete manner. Detector tomography provides a procedure for doing just this; an arbitrary measurement device can be fully characterized, and thus calibrated, in a systematic way without access to its components or its design. The result is a reconstructed POVM containing the measurement operators associated with each measurement outcome. We consider two detectors, a single-photon detector and a photon-number counter, and propose an easily realized experimental apparatus to perform detector tomography on them. We also present a method of visualizing the resulting measurement operators.Comment: 9 pages, 4 figure

Optical properties of refractory TiN, AlN and (Ti,Al)N coatings

© 2015 SPIE. Titanium nitride is a golden-colored semiconductor with metallic optical properties. It is already widely used in room temperature spectrally-selective coatings. In contrast, aluminum nitride is a relatively wide-band gap, non-metallic material. Both nitrides have exceptional thermal stability, to over 1000 °C, but are susceptible to oxidation. We will show here that composite coatings consisting of these materials and their complex oxides have considerable potential for spectrally-selective applications, including at elevated temperatures. In particular, we examine the metastable materials produced by magnetron sputtering. The effective dielectric functions of these materials can be tuned over a wide range by manipulation of their microstructure. This provides a strategy to assemble materials with tunable dielectric functions using a 'bottom-up' approach. The results are compared to those achievable by conventional, 'top-down', planar optical stacks comprised of alternating layers of TiNx and AlN

How to Establish and Follow up a Large Prospective Cohort Study in the 21st Century - Lessons from UK COSMOS.

Large-scale prospective cohort studies are invaluable in epidemiology, but they are increasingly difficult and costly to establish and follow-up. More efficient methods for recruitment, data collection and follow-up are essential if such studies are to remain feasible with limited public and research funds. Here, we discuss how these challenges were addressed in the UK COSMOS cohort study where fixed budget and limited time frame necessitated new approaches to consent and recruitment between 2009-2012. Web-based e-consent and data collection should be considered in large scale observational studies, as they offer a streamlined experience which benefits both participants and researchers and save costs. Commercial providers of register and marketing data, smartphones, apps, email, social media, and the internet offer innovative possibilities for identifying, recruiting and following up cohorts. Using examples from UK COSMOS, this article sets out the dos and don'ts for today's cohort studies and provides a guide on how best to take advantage of new technologies and innovative methods to simplify logistics and minimise costs. Thus a more streamlined experience to the benefit of both research participants and researchers becomes achievable