Determining optimum flash patterns for emergency service vehicles: An experimental investigation using high definition film

An investigation of how emergency vehicle lighting (EVL) can be improved is reported with reference to an analysis of police vehicle road traffic accidents (Study 1). In Study 2, 37 regular drivers were shown film clips of a marked police vehicle, in which flash rate (1 Hz, 4 Hz) and pattern (single, triple pulse) were varied on the blue Light Emitting Diode (LED) roofbar. Results indicate a 4 Hz flash rate conveys greater urgency than a 1 Hz rate, while a 1 Hz, single flash combination was ranked the least urgent of all combinations. Participants claimed they would leave significantly more space before pulling out in front of an approaching police car (gap acceptance) in the 4 Hz single pulse condition in comparison to other EVL combinations. The preliminary implications for which flash characteristics could prove most optimal for emergency service use are discussed with regard to effects on driver perception and expected driving behaviour.     

Spark Plasma Sintering of Nanostructured Aluminum: Influence of Tooling Material on Microstructure

The influence of tooling material, i.e., graphite and WC-Co, on the microstructure of a spark plasma sintering (SPS) consolidated, nanostructured aluminum alloy is studied in this paper. The results show that tooling selection influences microstructure evolution, independent of process parameters. The influence of tooling on microstructure is rationalized on the basis of the following factors: heating rate, electrical current density, localized heating, and imposed pressure. A theoretic framework, based on the physical properties of graphite and WC-Co, is formulated to explain the observed behavior.     

Composition effects of thermal barrier coating ceramics on their interaction with molten Ca–Mg–Al–silicate (CMAS) glass

Systematic studies have been performed to investigate the composition effects of ZrO₂-based thermal barrier coating (TBC) ceramics on their interactions with molten Ca–Mg–Al–silicate (CMAS) glass. Porous ceramic pellets (～15% porosity), instead of actual TBCs, are used in these model studies, where the penetration of molten CMAS into the pellets is investigated. This study involves a total of six compositions of ZrO₂-based ceramics: two containing low solute (Y³⁺ or Gd³⁺) concentration, three with high concentration of solute (Y³⁺, Gd³⁺ or Yb³⁺), and one containing a combined intermediate concentration of Y³⁺+Al³⁺+Ti⁴⁺ solutes. While both the type of the solute and its concentration in the ZrO₂-based TBC ceramics have been found to influence the extent of molten CMAS penetration into the pellets, the solute concentration has the most dramatic effect. In particular, molten CMAS penetration is almost completely suppressed in porous TBC ceramic pellets containing a high concentration of Y³⁺ solute (Y₂Zr₂O₇). Possible mechanisms governing these effects are presented, together with a discussion of guidelines for the chemical design of CMAS-resistant zirconate TBC ceramics. Generally, for a TBC ceramic to be highly effective against CMAS attack it must interact vigorously with the molten CMAS, which must result in the rapid crystallization of the refractory oxide phase(s) that form a sealing layer, arresting further penetration of the molten CMAS. The porous ceramic pellets approach used here could be developed into rapid-screening methodologies for the discovery of CMAS-resistant TBC ceramic compositions, and to study the effect of composition of CMAS glasses on their interactions with TBC ceramics of specific compositions.     

Future publication success in science is better predicted by traditional measures than by the <Emphasis Type="Italic">h</Emphasis> index

Although the use of bibliometric indicators for evaluations in science is becoming more and more ubiquitous, little is known about how future publication success can be predicted from past publication success. Here, we investigated how the post-2000 publication success of 85 researchers in oncology could be predicted from their previous publication record. Our main findings are: (i) Rates of past achievement were better predictors than measures of cumulative achievement. (ii) A combination of authors’ past productivity and the past citation rate of their average paper was most successful in predicting future publication success (R ² ≈ 0.60). (iii) This combination of traditional bibliographic indicators clearly outperformed predictions based on the rate of the h index (R ² between 0.37 and 0.52). We discuss implications of our findings for views on creativity and for science evaluation.     

Self‐similarity for accurate compression of point sampled surfaces

Most surfaces, be it from a fine‐art artifact or a mechanical object, are characterized by a strong self‐similarity. This property finds its source in the natural structures of objects but also in the fabrication processes: regularity of the sculpting technique, or machine tool. In this paper, we propose to exploit the self‐similarity of the underlying shapes for compressing point cloud surfaces which can contain millions of points at a very high precision. Our approach locally resamples the point cloud in order to highlight the self‐similarity of the shape, while remaining consistent with the original shape and the scanner precision. It then uses this self‐similarity to create an ad hoc dictionary on which the local neighborhoods will be sparsely represented, thus allowing for a light‐weight representation of the total surface. We demonstrate the validity of our approach on several point clouds from fine‐arts and mechanical objects, as well as a urban scene. In addition, we show that our approach also achieves a filtering of noise whose magnitude is smaller than the scanner precision.     

Exploring Homeless People's Use of Outreach Services: Applying a Social Psychological Perspective

A number of critiques have been published drawing attention to the gaps in research methods applied to issues surrounding homelessness and service utilisation in Britain. This paper discusses the use of social identity, a theory drawn from the field of applied social psychology, and synthesises it with the pathways model, thereby providing a framework to further explore service utilisation. The synthesised framework was used to predict the uptake of outreach services in a prospective study of 121 homeless people in a major UK city. In general, homeless people's use of intervention services was affected by the extent to which they identified with the support services themselves. The study demonstrates the central role of social identity in understanding service utilisation patterns, and shows the importance of applying fresh techniques to fine-tune our understanding of uptake in the long term.