736 research outputs found
Influence of an aperture on the performance of a two-degree-of-freedom iron-cored spherical permanent-magnet actuator
AbstractâThis paper describes a computational and experimental study of a two-degree-of-freedom spherical permanent-magnet actuator equipped with an iron stator. In particular, it considers the effect of introducing an aperture in the stator core to facilitate access to the armature. The resultant magnetic field distribution in the region occupied by the stator windings, the net unbalanced radial force, and the resulting reluctance torque are determined by three-dimensional magnetostatic finite-element
analysis. The predicted reluctance torque is validated experimentally, and its implications on actuator performance are described
Attitudes toward immigrants: a cross-country perspective
This paper examines the foundations of attitudes towards immigrants by focusing on individual characteristics and country-specific effects. We use a micro-level data set from 31 countries. In particular, we utilize the module on National Identity of the 2003 International Social Survey Program (ISSP). Results indicate that gender, education, age, labor-market status, and political and religious affiliation are important indicators of the attitude toward immigrants. The largest effect appears to be that of education, with more education being positively correlated with a positive view of immigrants. Additionally, we find that country of residence matters.immigration, microeconomic behavior, comparative research.
Scalable Bayesian modeling, monitoring and analysis of dynamic network flow data
Traffic flow count data in networks arise in many applications, such as
automobile or aviation transportation, certain directed social network
contexts, and Internet studies. Using an example of Internet browser traffic
flow through site-segments of an international news website, we present
Bayesian analyses of two linked classes of models which, in tandem, allow fast,
scalable and interpretable Bayesian inference. We first develop flexible
state-space models for streaming count data, able to adaptively characterize
and quantify network dynamics efficiently in real-time. We then use these
models as emulators of more structured, time-varying gravity models that allow
formal dissection of network dynamics. This yields interpretable inferences on
traffic flow characteristics, and on dynamics in interactions among network
nodes. Bayesian monitoring theory defines a strategy for sequential model
assessment and adaptation in cases when network flow data deviates from
model-based predictions. Exploratory and sequential monitoring analyses of
evolving traffic on a network of web site-segments in e-commerce demonstrate
the utility of this coupled Bayesian emulation approach to analysis of
streaming network count data.Comment: 29 pages, 16 figure
Measuring the Economic and Cultural Values of Historic Heritage Places
This research project on the valuation of cultural heritage is developing a methodology for a quantitative valuation study of the use and non-use values of historic heritage places. The methodology developed in this project will provide a template for subsequent empirical applications to generate data of use in the formulation of heritage policies and programs. The initial stages in reaching this larger objective have involved determining how historic heritage places are to be categorised for measurement, establishing the process by which heritage attributes will be determined for valuation, and developing and trialling an effective measurement framework. The principal techniques being developed for valuation assessment in the project are derived from choice-modelling (CM) and contingent-valuation methods (CVM). A particular focus of the project is on the systematic integration of cultural and economic value assessments within a consistent theoretical framework, reflecting the need for an economic perspective on the significance criteria currently in use in heritage policy in Australia.Community/Rural/Urban Development, Environmental Economics and Policy,
The narrative braid: a model for tackling the narrative paradox in adaptive documentaries
The Narrative Paradox is a theory that describes interaction and narrative cohesion as being in tension, and asserts that the structure of a narrative is disrupted by user adaptivity, leading to possible incoherence as the system accounts for interaction. We propose an approach that may reduce this disruption. Specifically, we propose to model a narrative as a collection of threads, woven together into the discourse as a narrative braid. By separately maintaining logical coherence within a thread and thematic coherence between threads we believe it is possible to introduce inter- activity while maintaining a strong narrative structure. We discuss how this may be applied to adaptive documentaries which, with a wide base of recorded material and diverse plot threads, provide a rich medium for initial experimentation in this area
Protection and Enforcement of New Intellectual Property
The desirability of new forms of intellectual property protection for databases and domain names is beyond the scope of this Article. Instead, this Article focuses on the protection and enforcement of intellectual property rights in databases and domain names under existing law. Because of the increased value of these assets, owners should increasingly pay attention to their protection
Deposition of High Conductivity Low Silver Content Materials by Screen Printing
A comprehensive experimental investigation has been carried out into the role of film thickness variation and silver material formulation on printing capability in the screen printing process. A full factorial experiment was carried out where two formulations of silver materials were printed through a range of screens to a polyester substrate under a set of standard conditions. The materials represented a novel low silver content (45%â49%) polymer material and traditional high silver content (65%â69%) paste. The resultant prints were characterised topologically and electrically. The study shows that more cost effective use of the silver in the ink was obtained with the low silver polymer materials, but that the electrical performance was more strongly affected by the mesh being used (and hence film thickness). Thus, while optimum silver use could be obtained using materials with a lower silver content, this came with the consequence of reduced process robustness
Solution processing of TiO2 compact layers for 3rd generation photovoltaics
In this study, we introduce a new method for the deposition of TiO2 compact layers which involves the deposition of a wet film of an inorganic titanium (IV) precursor followed by fast hydrolytic conversion to crystalline TiO2 under near infrared radiative (NIR) treatment. With this, we aim to provide a scalable alternative to methods conventionally employed in laboratories for the fabrication of 3rd generation photovoltaic devices, such as high temperature pyrolysis or spin coating of organic titanium (IV) precursors. Optimization of our solution process is presented in detail. Structural features and crystalline properties of solution processed compact layers are characterized by FEG-SEM imaging and x-ray diffraction analyses and compared to compact layers produced by conventional laboratory techniques. Minimization of electron recombination is evaluated in standard liquid I-/I3- dye-sensitized solar cells (DSC). The results show that a compact, homogenous, high coverage yield crystalline TiO2 anatase layer can be produced by sequential deposition of 2â3 solution processed titanium oxide layers, each in under 30 s. In standard liquid I-/I3- DSC the solution processed compact layers strongly increased the electron lifetime, Ïn, when compared to cells prepared on a bare FTO substrate
The Effect of Sliding Speed on the Tribological Properties of Ceramic Materials
Ceramics are considered to be candidate materials for galvanising pot bearing materials due to their excellent corrosion resistance in many molten metals. Galvanising pot roll bearings must have excellent wear resistance, and, therefore, it is important to understand the wear behaviour of prospective bearing materials. This study investigates the friction- and wear-resistant properties of select ceramics, namely, pure hBN, BN M26, AlN-BN, Macor, 3YSZ, Al2O3 and Si3N4. The ceramics were tested at different sliding speeds using a pin-on-disc device equipped with SiC pins. The lowest coefficient of friction (COF) achieved was below 0.1, and it was measured for pure hBN at a 3.14 m/min sliding speed. However, a wear scar analysis showed that the BN grades suffered from severe wear. The highest wear rate was obtained for BN M26 at a 9.42 m/min sliding speed and was equal to 17.1 Ă 10â6 mm3 Nâ1 mâ1. It was shown that the wear coefficient of the tested ceramics varied exponentially with hardness. The lowest wear was observed on the 3YSZ, Al2O3 and Si3N4 ceramics, which showed no volume loss, and, for this reason, they can be potentially used as bearing materials in continuous galvanising lines
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