2,065 research outputs found
Fault Tolerant Filtering and Fault Detection for Quantum Systems Driven By Fields in Single Photon States
The purpose of this paper is to solve a fault tolerant filtering and fault
detection problem for a class of open quantum systems driven by a
continuous-mode bosonic input field in single photon states when the systems
are subject to stochastic faults. Optimal estimates of both the system
observables and the fault process are simultaneously calculated and
characterized by a set of coupled recursive quantum stochastic differential
equations.Comment: arXiv admin note: text overlap with arXiv:1504.0678
Indoor visible light communication localization system utilizing received signal strength indication technique and trilateration method
Visible light communication (VLC) based on light-emitting diodes (LEDs) technology not only provides higher data rate for indoor wireless communications and offering room illumination but also has the potential for indoor localization. VLC-based indoor positioning using the received optical power levels from emitting LEDs is investigated. We consider both scenarios of line-of-sight (LOS) and LOS with non-LOS (LOSNLOS) positioning. The performance of the proposed system is evaluated under both noisy and noiseless channel as is the impact of different location codes on positioning error. The analytical model of the system with noise and the corresponding numerical evaluation for a range of signal-to-noise ratio (SNR) are presented. The results show that an accuracy of 12 dB
Adapting to ageing: a mixed methods study of the role of Selection, Optimisation and Compensation in the maintenance of high wellbeing
Objectives: Selection, Optimization and Compensation (SOC) may contribute to successful aging by helping older people maximize wellbeing in the context of physical decline. To explore this hypothesis, and to investigate the potential for narrative analysis to improve understanding of SOC, we analyze interviews conducted with 15 members of the 6-Day Sample, a cohort of Scots born in 1936.
Method: Interviewees were chosen based on their physical function and wellbeing scores. Interviews were analyzed to investigate ‘SOC talk’, i.e. older people’s talk about SOC behaviors in everyday life. Types and amounts of SOC talk were quantified, and talk was narratively analyzed. We hypothesized that older people who engaged in more SOC talk would have higher wellbeing.
Results: Older people who engaged in high levels of SOC talk had high wellbeing despite low physical function. Those who engaged in little SOC talk had low wellbeing despite higher physical function.
Discussion: The concept of successful aging is valuable in part because of its narrative quality: one must strive to keep one’s life story developing despite physical decline and other losses. We provide evidence, from the perspectives of older people themselves, of the ways in which SOC may play a role in that process
Inequalities in the dental health needs and access to dental services among looked after children in Scotland: a population data linkage study
Background: There is limited evidence on the health needs and service access among children and young people who are looked after by the state. The aim of this study was to compare dental treatment needs and access to dental services (as an exemplar of wider health and well-being concerns) among children and young people who are looked after with the general child population.
Methods: Population data linkage study utilising national datasets of social work referrals for ‘looked after’ placements, the Scottish census of children in local authority schools, and national health service’s dental health and service datasets.
Results: 633 204 children in publicly funded schools in Scotland during the academic year 2011/2012, of whom 10 927 (1.7%) were known to be looked after during that or a previous year (from 2007–2008). The children in the looked after children (LAC) group were more likely to have urgent dental treatment need at 5 years of age: 23%vs10% (n=209/16533), adjusted (for age, sex and area socioeconomic deprivation) OR 2.65 (95% CI 2.30 to 3.05); were less likely to attend a dentist regularly: 51%vs63% (n=5519/388934), 0.55 (0.53 to 0.58) and more likely to have teeth extracted under general anaesthesia: 9%vs5% (n=967/30253), 1.91 (1.78 to 2.04).
Conclusions: LAC are more likely to have dental treatment needs and less likely to access dental services even when accounting for sociodemographic factors. Greater efforts are required to integrate child social and healthcare for LAC and to develop preventive care pathways on entering and throughout their time in the care system
Adaptive forecasting of phytoplankton communities
The global proliferation of harmful algal blooms poses an increasing threat to water resources, recreation and ecosystems. Predicting the occurrence of these blooms is therefore needed to assist water managers in making management decisions to mitigate their impact. Evaluation of the potential for forecasting of algal blooms using the phytoplankton community model PROTECH was undertaken in pseudo-real-time. This was achieved within a data assimilation scheme using the Ensemble Kalman Filter to allow uncertainties and model nonlinearities to be propagated to forecast outputs. Tests were made on two mesotrophic lakes in the English Lake District, which differ in depth and nutrient regime. Some forecasting success was shown for chlorophyll a, but not all forecasts were able to perform better than a persistence forecast. There was a general reduction in forecast skill with increasing forecasting period but forecasts for up to four or five days showed noticeably greater promise than those for longer periods. Associated forecasts of phytoplankton community structure were broadly consistent with observations but their translation to cyanobacteria forecasts was challenging owing to the interchangeability of simulated functional species
Wide-spread inconsistency in estimation of lake mixed depth impacts interpretation of limnological processes
The mixed layer, or epilimnion, is a physical concept referring to an isothermal layer at the surface of a water body. This concept is ubiquitous within limnology, is fundamental to our understanding of chemical and ecological processes, and is an important metric for water body monitoring, assessment and management. Despite its importance as a metric, many different approaches to approximating mixed depth currently exist. Using data from field campaigns in a small meso-eutrophic lake in the UK in 2016 and 2017 we tested whether different definitions of mixed depth resulted in comparable estimates and whether variables other than temperature could be assumed to be mixed within the layer. Different methods resulted in very different estimates for the mixed depth and ecologically important variables were not necessarily homogenously spread through the epilimnion. Furthermore, calculation of simple ecologically relevant metrics based on mixed depth showed that these metrics were highly dependent on the definition of mixed depth used. The results demonstrate that an idealised concept of a well-defined fully mixed layer is not necessarily appropriate. The widespread use of multiple definitions for mixed depth impairs the comparability of different studies while associated uncertainty over the most appropriate definition limits the confirmability of studies utilising the mixed depths
My School? Critiquing the abstraction and quantification of education
This paper draws upon and critiques the Australian federal government's website My School as an archetypal example of the current tendency to abstract and quantify educational practice. Arguing in favour of a moral philosophical account of educational practice, the paper reveals how the My School website reduces complex educational practices to simple, supposedly objective, measures of student attainment, reflecting the broader 'audit' society/culture within which it is located. By revealing just how extensively the My School website reduces educational practices to numbers, the paper argues that we are in danger of losing sight of the 'internal' goods of Education which cannot be readily and simply codified, and that the teacher learning encouraged by the site marginalises more active and collective approaches. While having the potential to serve some beneficial diagnostic purposes, the My School website reinforces a view of teachers as passive consumers of information generated beyond their everyday practice
- …