Developing international partnerships and exchange: initiatives from the Division of Education

In the following report we try to show how our international links and practice in the Division of Education enable students and staff to present a wider perspective on knowledge and pedagogy, in keeping with the notion of the ‘global citizen’. Crossley (2002, p.81) argues that the ‘impact of intensified globalisation is possibly the most often cited challenge facing the field of comparative and international education at this point in time.’ Henceforth, education can no longer be perceived as a localised, or even national, agenda but rather, that global forces are, ‘dramatically changing the role of the state in education, and demanding increased attention to be paid to factors operating beyond the national level’ (Crossley, 2002, p.81). We are keenly aware of Northumbria University’s wider objectives in helping our students prepare for the international and global market. Further, we are anxious to inculcate the wider notion of being a ‘global citizen’ amongst the student body, providing them with authentic international experiences and making an international element a central tenet of our wider pedagogical philosophy for emergent teachers. We have realised that, by providing a context of wider European and associated cultural awareness, and embedding such elements into our programmes, we can enable our students to be better placed as European and global citizens, as they approach the job market at the conclusion of their degree studies. Such an awareness and actual experiences can also enable students to critically reflect on their emerging pedagogies through the possession of wider and differing perspectives upon their own cultures and identities. The ‘global’ and ‘national’ modes of education might seem to be mutually exclusive and Crossley acknowledges the consequences of power and influence moving away from local communities towards a more global context. However, he reiterates that the opposite is also true, and that ‘globalisation not only pulls upwards, it pushes downwards, creating new pressures for local autonomy’ [and that] ‘national and local cultures . . . play a significant role in mediating global influences’ (Crossley, 2002, p.82)

On Combining Lensing Shear Information from Multiple Filters

We consider the possible gain in the measurement of lensing shear from imaging data in multiple filters. Galaxy shapes may differ significantly across filters, so that the same galaxy offers multiple samples of the shear. On the other extreme, if galaxy shapes are identical in different filters, one can combine them to improve the signal-to-noise and thus increase the effective number density of faint, high redshift galaxies. We use the GOODS dataset to test these scenarios by calculating the covariance matrix of galaxy ellipticities in four visual filters (B,V,i,z). We find that galaxy shapes are highly correlated, and estimate the gain in galaxy number density by combining their shapes.Comment: 8 pages, no figures, submitted to JCA

Characterization and correction of charge-induced pixel shifts in DECam

Interaction of charges in CCDs with the already accumulated charge distribution causes both a flux dependence of the point-spread function (an increase of observed size with flux, also known as the brighter/fatter effect) and pixel-to-pixel correlations of the Poissonian noise in flat fields. We describe these effects in the Dark Energy Camera (DECam) with charge dependent shifts of effective pixel borders, i.e. the Antilogus et al. (2014) model, which we fit to measurements of flat-field Poissonian noise correlations. The latter fall off approximately as a power-law r^-2.5 with pixel separation r, are isotropic except for an asymmetry in the direct neighbors along rows and columns, are stable in time, and are weakly dependent on wavelength. They show variations from chip to chip at the 20% level that correlate with the silicon resistivity. The charge shifts predicted by the model cause biased shape measurements, primarily due to their effect on bright stars, at levels exceeding weak lensing science requirements. We measure the flux dependence of star images and show that the effect can be mitigated by applying the reverse charge shifts at the pixel level during image processing. Differences in stellar size, however, remain significant due to residuals at larger distance from the centroid.Comment: typo and formatting fixes, matches version published in JINS

Michael Jarvis - solo show

The exhibition was held at Everyman Gallery, Chorlton, Manchester between 17-30 September, 2012 The exhibition consisted of 17 paintings, a series based on my study and research into cityscapes. Doorways, windows, arches, gates, streets and waterways are common motifs. The paintings demonstrate a dialogue between structure and organisation on the one hand and fragmentation and disorderliness on the other. For example, some have a grid-like structure while others are more organic and spontaneously made

Semiconductor Robot

A large line-following robot was built to transport semiconductor wafers in semiconductor factories. The criteria for a successful robot were decided upon prior to designing. The robot was designed using both mechanical and electrical engineering techniques to ensure that the final design met the outlined criteria. Each electrical subsystem was tested successfully prior to being installed on the robot. However once all the components were installed the robot was not able to move autonomously because the DC motors selected could not provide adequate torque. For future robot designs it is imperative that the motors be tested thoroughly because there is a substantial difference between specifications and actual performance

A Differentiable Perturbation-based Weak Lensing Shear Estimator

Upcoming imaging surveys will use weak gravitational lensing to study the large-scale structure of the Universe, demanding sub-percent accuracy for precise cosmic shear measurements. We present a new differentiable implementation of our perturbation-based shear estimator (FPFS), using JAX, which is publicly available as part of a new suite of analytic shear algorithms called AnaCal. This code can analytically calibrate the shear response of any nonlinear observable constructed with the FPFS shapelets and detection modes utilizing auto-differentiation (AD), generalizing the formalism to include a family of shear estimators with corrections for detection and selection biases. Using the AD capability of JAX, it calculates the full Hessian matrix of the non-linear observables, which improves the previously presented second-order noise bias correction in the shear estimation. As an illustration of the power of the new AnaCal framework, we optimize the effective galaxy number density in the space of the generalized shear estimators using an LSST-like galaxy image simulation for the ten-year LSST. For the generic shear estimator, the magnitude of the multiplicative bias $|m|$ is below $3\times 10^{-3}$ (99.7% confidence interval), and the effective galaxy number density is improved by 5%. We also discuss some planned future additions to the AnaCal software suite to extend its applicability beyond the FPFS measurements.Comment: 9 pages, 7 figures, submitted to MNRA