Full-scale measurement and analysis of train slipstreams and wakes. Part 1: Ensemble averages

This paper describes a series of extensive and unique full-scale measurements of the slipstreams of trains of various types that were carried out as part of the EU-sponsored AeroTRAIN project, together with the analysis of the experimental data. These experiments were carried out with the fundamental aim of seeking to reduce the complexity of the current technical specifications for interoperability (TSI) testing methodology. Experimental sites in Spain and Germany were used, for a range of different train types - high-speed single-unit trains, high-speed double-unit trains, conventional passenger units and locomotive/coach combinations. The data that was obtained was supplemented by other data from previous projects. The analysis primarily involved a study of the ensemble averages of the slipstream velocities, measured both at trackside and above platforms. The differences between the flows around different train types were elucidated, and the effect of platforms on slipstream behaviour described. A brief analysis of the effects of crosswinds on slipstream behaviour was also carried out. Through a detailed analysis of slipstream velocity components, the detailed nature of the flow around the nose and in the near wake of the train was investigated, again revealing differences in flow pattern between different trains. Significant similarity in the far wake flows was revealed. These fundamental results form the basis for the detailed discussion of the proposed TSI methodology that will be presented in Part 2 of this paper. Overall the results enable the nature of the flow field around trains to be understood in far greater detail than before, and also allow the developments of a revised TSI methodology which is more efficient than current practice. © IMechE 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav

Toward a New Model of Scientific Publishing: Discussion and a Proposal

The current system of publishing in the biological sciences is notable for its redundancy, inconsistency, sluggishness, and opacity. These problems persist, and grow worse, because the peer review system remains focused on deciding whether or not to publish a paper in a particular journal rather than providing (1) a high-quality evaluation of scientific merit and (2) the information necessary to organize and prioritize the literature. Online access has eliminated the need for journals as distribution channels, so their primary current role is to provide authors with feedback prior to publication and a quick way for other researchers to prioritize the literature based on which journal publishes a paper. However, the feedback provided by reviewers is not focused on scientific merit but on whether to publish in a particular journal, which is generally of little use to authors and an opaque and noisy basis for prioritizing the literature. Further, each submission of a rejected manuscript requires the entire machinery of peer review to creak to life anew. This redundancy incurs delays, inconsistency, and increased burdens on authors, reviewers, and editors. Finally, reviewers have no real incentive to review well or quickly, as their performance is not tracked, let alone rewarded. One of the consistent suggestions for modifying the current peer review system is the introduction of some form of post-publication reception, and the development of a marketplace where the priority of a paper rises and falls based on its reception from the field (see other articles in this special topics). However, the information that accompanies a paper into the marketplace is as important as the marketplace’s mechanics. Beyond suggestions concerning the mechanisms of reception, we propose an update to the system of publishing in which publication is guaranteed, but pre-publication peer review still occurs, giving the authors the opportunity to revise their work following a mini pre-reception from the field. This step also provides a consistent set of rankings and reviews to the marketplace, allowing for early prioritization and stabilizing its early dynamics. We further propose to improve the general quality of reviewing by providing tangible rewards to those who do it well

Identities for hyperelliptic P-functions of genus one, two and three in covariant form

We give a covariant treatment of the quadratic differential identities satisfied by the P-functions on the Jacobian of smooth hyperelliptic curves of genera 1, 2 and 3

Holding a Stick at Both Ends: On Faces and Expertise

Ever since Diamond and Carey\u27s (1986) seminal work, object expertise has often been viewed through the prism of face perception (for a thorough discussion, see Tanaka and Gauthier, 1997; Sheinberg and Tarr, 2010). According to Wong and Wong (2014, W&W), however, this emphasis has simply been a response to the question of modularity of face perception, and has not been about expertise in and of itself. It is precisely this conflation of questions of expertise and modularity, the consequent focus on FFA, and the detrimental effect this had on the field of object expertise research that we discussed as part of our original review (Harel et al., 2013)

Simulations of L-band staring radar moving target integration efficiency

Aveillant Ltd has developed a staring L-band radar that deploys a static quasi-monostatic antenna in transmission and a static digital phased array on receive capable of generating multiple simultaneous beams. Because the antenna is not rotating, the radar can stare at targets and select long dwell times with no effect on the scan rate. High Doppler resolution can be achieved and used to detect small targets, such as drones, even in heavy clutter. Despite the staring array, targets moving with a variable radial velocity generate echoes with a time-varying Doppler frequency shift that limits the integration gain achievable with standard Fourier Transform based techniques. As a result, the number of pulses can be integrated remains limited to the effective coherent processing interval with a consequent suboptimal Signal to Noise Ratio (SNR). This paper presents the results of a set of simulations aimed at studying the integration gain efficiency of a staring radar of the type of the Aveillant Holographic radar for targets moving with a constant and non-constant radial velocity. The case of a target flying horizontally with respect to the radar boresight is investigated to show that compensation techniques can be potentially employed to maximise coherence on the target and the resulting integration gain

False Approximations of the Approximate Number System?

Prior research suggests that the acuity of the approximate number system (ANS) predicts future mathematical abilities. Modelling the development of the ANS might therefore allow monitoring of children's mathematical skills and instigate educational intervention if necessary. A major problem however, is that our knowledge of the development of the ANS is acquired using fundamentally different paradigms, namely detection in infants versus discrimination in children and adults. Here, we question whether such a comparison is justified, by testing the adult ANS with both a discrimination and a detection task. We show that adults perform markedly better in the discrimination compared to the detection task. Moreover, performance on discrimination but not detection, correlated with performance on mathematics. With a second similar experiment, in which the detection task was replaced by a same-different task, we show that the results of experiment 1 cannot be attributed to differences in chance level. As only task instruction differed, the discrimination and the detection task most likely reflect differences at the decisional level. Future studies intending to model the development of the ANS should therefore rely on data derived from a single paradigm for different age groups. The same-different task appears a viable candidate, due to its applicability across age groups

Intra-session and inter-day reliability of the Myon 320 electromyography system during sub-maximal contractions

Electromyography systems are widely used within the field of scientific and clinical practices. The reliability of these systems are paramount when conducting research. The reliability of Myon 320 Surface Electromyography System is yet to be determined. This study aims to determine the intra-session and inter-day reliability of the Myon 320 Surface Electromyography System. Muscle activity from fifteen participants was measured at the anterior deltoid muscle during a bilateral front raise exercise, the vastus lateralis muscle during a squat exercise and the extensor carpi radialis brevis (ECRB) muscle during an isometric handgrip task. Intra-session and inter-day reliability was calculated by intraclass correlation coefficient, standard error of measurement and coefficient of variation (CV). The normalized root mean squared (RMS) surface electromyographic signals produced good intra-session and inter-day testing intraclass correlation coefficient values (range: 0.63-0.97) together with low standard error of measurement (range: 1.49-2.32) and CV (range: 95% Confidence Interval = 0.36-12.71) measures for the dynamic-and-isometric contractions. The findings indicate that the Myon 320 Surface Electromyography System produces good to fair reliability when examining intra-session and inter-day reliability. Findings of the study provide evidence of the reliability of electromyography between trials which is essential during clinical testing.</p