arXiv subjects

G. Hamilton

Publications and source records attributed to G. Hamilton.

4 recordsLinked to original sources

arXiv2021

The Ethics of Biosurveillance

Governments must keep agricultural systems free of pests that threaten agricultural production and international trade. Biosecurity surveillance already makes use of a wide range of technologies, such as insect traps and lures, geographic information systems, and diagnostic biochemical tests. The rise of cheap and usable surveillance technologies such as remotely piloted aircraft systems (RPAS) presents value conflicts not addressed in international biosurveillance guidelines. The costs of keeping agriculture pest-free include privacy violations and reduced autonomy for farmers. We argue that physical and digital privacy in the age of ubiquitous aerial and ground surveillance is a natural right to allow people to function freely on their land. Surveillance methods must be co-created and justified through using ethically defensible processes such as discourse theory, value-centred design and responsible innovation to forge a cooperative social contract between diverse stakeholders. We propose an ethical framework for biosurveillance activities that balances the collective benefits for food security with individual privacy: (1) establish the boundaries of a biosurveillance social contract; (2) justify surveillance operations for the farmers, researchers, industry, the public and regulators; (3) give decision makers a reasonable measure of control over their personal and agricultural data; and (4) choose surveillance methodologies that give the appropriate information. The benefits of incorporating an ethical framework for responsible biosurveillance innovation include increased participation and accumulated trust over time. Long term trust and cooperation will support food security, producing higher quality data overall and mitigating against anticipated information gaps that may emerge due to disrespecting landholder rights

cs.CY↗

arXiv2020

Quality control of the CFRP mirror manufacturing process at NPF

The surface quality of replicated CFRP mirrors is ideally expected to be as good as the mandrel from which they are manufactured. In practice, a number of factors produce surface imperfections in the final mirrors at different scales. To understand where this errors come from, and develop improvements to the manufacturing process accordingly, a wide range of metrology techniques and quality control methods must be adopted. Mechanical and optical instruments are employed to characterise glass mandrels and CFRP replicas at different spatial frequency ranges. Modal analysis is used to identify large scale aberrations, complemented with a spectral analysis at medium and small scales. It is seen that astigmatism is the dominant aberration in the CFRP replicas. On the medium and small scales, we have observed that fiber print-through and surface roughness can be improved significantly by an extra resin layer over the replica's surface, but still some residual irregularities are present.

astro-ph.IM↗

arXiv2020

NPF update: Light-weight mirror development in Chile

Planet Formation research is blooming in an era where we are moving from speaking about "protoplanetary disks" to "planet forming disks" (Andrews et al., 2018). However, this transition is still motivated by indirect (but convincing) hints. Up to date, the direct detection of planets "in the making" remains elusive with the remarkable exception of PDS70b and c (Haffert et al., 2019; Keppler et al., 2018; M\"uller et al., 2018). The scarcity of detections is attributable to technical challenges, and even for the rare jewels that we can detect, characterization (resolving their hill spheres) is unachievable. The next step in this direction demands from near to mid-infrared interferometry to jump from $\sim$100 m baselines to $\sim$1 km, and from very few telescopes (two to six) to 20 or more (PFI like concepts, Monnier et al. 2018). This transition needs for more affordable near to mid-infrared telescopes to be designed. Since the driving cost for such telescopes resides on the primary mirror, in particular scaling with its diameter and weight, our approach to tackle this problem relies on the production of low-cost light mirrors.

astro-ph.IM↗

arXiv2020

Mitigating print-through effects through an optimized method for CFRP mirror production in Chile

In the manufacturing process of Carbon Fiber Reinforced Polymer (CFRP) mirrors (replicated from a mandrel) the orientation of the unidirectional carbon fiber layers (layup) has a direct influence on different aspects of the final product, like its general (large scale) shape and local deformations. In particular, optical methods used to evaluate the surface's quality, can reveal the presence of print-through, a very common issue in CFPR manufacture. In practical terms, the surface's irregularities induced, among other artifacts, by print-through, produce unwanted scattering effects, which are usually mitigated applying extra layers of different materials to the surface. Since one of the main goals of CFPR mirrors is to decrease the final weight of the whole mirror system, adding more material goes in the opposite direction of that. For this reason a different layup method is being developed with the goal of decreasing print-through and improving sphericity while maintaining mechanical qualities and without the addition of extra material in the process.

astro-ph.IM↗