Commercially available depth sensing devices are primarily designed for domains that are either macroscopic, or static. We develop a solution for fast microscale 3D reconstruction, using off-the-shelf components. By the addition of lenses, precise calibration of camera internals and positioning, and development of bespoke software, we turn an infrared depth sensor designed for human-scale motion and object detection into a device with mm-level accuracy capable of recording at up to 30Hz.
Inequalities in the social determinants of health (SDH), which drive avoidable health disparities between different individuals or groups, is a major concern for a number of international organisations, including the World Health Organization (WHO). Despite this, the pathways to changing inequalities in the SDH remain elusive. The methodologies and concepts within system science are now viewed as important domains of knowledge, ideas and skills for tackling issues of inequality, which are increasingly understood as emergent properties of complex systems. In this paper, we introduce and expand the concept of adaptive policies to reduce inequalities in the distribution of the SDH. The concept of adaptive policy for health equity was developed through reviewing the literature on learning and adaptive policies. Using a series of illustrative examples from education and poverty alleviation, which have their basis in real world policies, we demonstrate how an adaptive policy approach is more suited to the management of the emergent properties of inequalities in the SDH than traditional policy approaches. This is because they are better placed to handle future uncertainties. Our intention is that these examples are illustrative, rather than prescriptive, and serve to create a conversation regarding appropriate adaptive policies for progressing policy action on the SDH.
This paper reports on findings from a systematic review designed to investigate the state of systems science research in public health. The objectives were to: (1) explore how systems methodologies are being applied within public health and (2) identify fruitful areas of activity.
A major difference between insect vision and that of humans or standard computer vision systems is that insects are sensitive to the polarisation pattern of skylight, and also to the near-UV range of the electromagnetic spectrum. In this paper, we describe a bio-inspired imaging system that allows us to assess to what extent these features could potentially be used for autonomous robot navigation. We first establish that a low-resolution omnidirectional system incorporating a near-UV camera and a linear polariser - a simulacrum of the dorsal rim area of the insect compound eye - can resolve the clear sky natural polarisation pattern with sufficient accuracy to allow its use as a navigational tool. We then extend the bio-mimicry by incorporating an additional RGB camera, allowing us to utilise the full range of the insect's visual spectrum. This enables us to capture and investigate the visual cues insects are employing for flight control and navigation, and paves the way for incorporating a similar system in an autonomous mobile robot. Additionally, we present a robust method for estimating sun position based on the polarisation pattern and thus confirm the utility of the system as a sky compass.
We present a light-weight polarisation sensor that consists of four synchronised cameras equipped with differently oriented polarisers and fisheye lenses allowing us to image the whole sky hemisphere. Due to its low weight and compact size it is well-suited as a biomimetic sensor on-board a UAV. We describe efficient methods for reconstruction of the full-sky polarisation pattern and estimation of sun position. In contrast to state-of-the art polarisation systems for UAVs that estimate sun azimuth only, our approach can determine sun elevation as well, even in the presence of clouds and for significant pitch and roll angles of the UAV. The calibration and registration of the four fisheye cameras is achieved by extending an existing omni-directional calibration toolbox to multi-camera calibration. We present examples of full-sky reconstruction of the polarisation pattern as well as an analysis of the error in the sun position estimate. In addition, we performed a preliminary test on-board a quadcopter.