5,410 research outputs found
Large-Scale Sensor Network Localization via Rigid Subnetwork Registration
In this paper, we describe an algorithm for sensor network localization (SNL)
that proceeds by dividing the whole network into smaller subnetworks, then
localizes them in parallel using some fast and accurate algorithm, and finally
registers the localized subnetworks in a global coordinate system. We
demonstrate that this divide-and-conquer algorithm can be used to leverage
existing high-precision SNL algorithms to large-scale networks, which could
otherwise only be applied to small-to-medium sized networks. The main
contribution of this paper concerns the final registration phase. In
particular, we consider a least-squares formulation of the registration problem
(both with and without anchor constraints) and demonstrate how this otherwise
non-convex problem can be relaxed into a tractable convex program. We provide
some preliminary simulation results for large-scale SNL demonstrating that the
proposed registration algorithm (together with an accurate localization scheme)
offers a good tradeoff between run time and accuracy.Comment: 5 pages, 8 figures, 1 table. To appear in Proc. IEEE International
Conference on Acoustics, Speech, and Signal Processing, April 19-24, 201
Minimum target prices for production of direct acting antivirals and associated diagnostics to combat Hepatitis C Virus
Combinations of direct-acting antivirals (DAAs) can cure hepatitis C virus (HCV) in the majority of treatment-naïve patients. Mass treatment programs to cure HCV in developing countries are only feasible if the costs of treatment and laboratory diagnostics are very low. This analysis aimed to estimate minimum costs of DAA treatment and associated diagnostic monitoring. Clinical trials of HCV DAAs were reviewed to identify combinations with consistently high rates of sustained virological response across hepatitis C genotypes. For each DAA, molecular structures, doses, treatment duration, and components of retrosynthesis were used to estimate costs of large-scale, generic production. Manufacturing costs per gram of DAA were based upon treating at least 5 million patients per year and a 40% margin for formulation. Costs of diagnostic support were estimated based on published minimum prices of genotyping, HCV antigen tests plus full blood count/clinical chemistry tests. Predicted minimum costs for 12-week courses of combination DAAs with the most consistent efficacy results were: US152 for sofosbuvir+ribavirin; US115 for MK-8742+MK-5172. Diagnostic testing costs were estimated at US34 for two HCV antigen tests and US171-360 per person without genotyping or US$261-450 per person with genotyping. These cost estimates assume that existing large-scale treatment programs can be established. (Hepatology 2015;61:1174–1182
High-Field Shubnikov-de Haas Oscillations in the Topological Insulator BiTeSe
We report measurements of the surface Shubnikov de Haas oscillations (SdH) on
crystals of the topological insulator BiTeSe. In crystals with large
bulk resistivity (4 cm at 4 K), we observe 15 surface SdH
oscillations (to the = 1 Landau Level) in magnetic fields up to 45
Tesla. Extrapolating to the limit , we confirm the -shift
expected from a Dirac spectrum. The results are consistent with a very small
surface Lande -factor.Comment: Text expanded, slight changes in text, final version; Total 6 pages,
6 figure
The opportunities and challenges of using cricket as a sport-for-development tool in Samoa
This study investigates benefits and challenges associated with the use of sport – in this case cricket – as a community development tool in Samoa. This Pacific Island nation, like others in the region, has been the focus of various development programs in the post-colonial era, with developed economy neighbours like Australia and New Zealand providing aid funding. Some of that has involved sport as a development tool, underpinned either by funding from the national government, foreign aid agencies, or a combination of both. The present paper, by focusing on a cricket for development (CFD) program in Samoa, aims to explore outcomes and limitations associated with the use of sport as a community engagement tool. The paper pursues that goal by examining the activities of relevant sport and government organisations, and – most crucially – it interviews key stakeholders involved in the CFD process in Samoa. In short, the prime purpose of this paper is to identify and interpret – from the perspective of locals – whether the CFD program has brought benefits to Samoan communities, and the challenges and limitations they see thus far. This is important because, to date, there has been an absence of qualitative inquiry into the efficacy of sport for development (SFD) programs in Samoa, and very limited research in a Pacific Islands context
Investigation of particles size effects in Dissipative Particle Dynamics (DPD) modelling of colloidal suspensions
In the Dissipative Particle Dynamics (DPD) simulation of suspension, the fluid (solvent) and colloidal particles
are replaced by a set of DPD particles and therefore their relative sizes (as measured by their exclusion zones) can affect the maximal packing fraction of the colloidal particles. In this study, we investigate roles of the conservative, dissipative and random forces in this relative size ratio (colloidal/solvent). We propose a mechanism of adjusting the DPD parameters to properly model the solvent phase (the solvent here is supposed to have the same isothermal compressibility to that of water)
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Prevalence and determinants of anxiety and depression in end stage renal disease (ESRD). A comparison between ESRD patients with and without coexisting diabetes mellitus
Objective: To compare anxiety and/or depressive symptoms between patients with end-stage renal disease with and without comorbid diabetes and identify factors associated with symptoms of distress in this population.
Methods: Data from two studies (conducted between 2010 and 2014) were pooled. A total of 526 patients on hemodialysis (68.8% with diabetes) completed the Hospital Anxiety and Depression Scale (HADS). Elevated symptoms were defined as HADS-Anxiety or HADS-Depression ≥ 8. Univariate and multivariate logistic regressions were used to estimate associations between diabetic status, and other socio-demographic and clinical factors with baseline clinical anxiety and depression.
Results: A total of 233 (45.4%) reported elevated anxiety symptoms and 256 (49.9%) reported elevated depressive symptoms sufficient for caseness. Rates were not different between patients with and without diabetes. Risk for clinical depression was higher in patients who were single/unpartnered (OR = 1.828), Chinese vs. Malay (OR = 2.05), or had lower albumin levels (OR = 0.932). None of the parameters were associated with anxiety caseness.
Conclusion: Sociocultural factors rather than comorbid burden may help identify patients at risk for depression. The high rates of anxiety and depression underlie the importance for monitoring and intervention in dialysis care
Reporting and Comparing School Performances
This report provides advice on the collection and reporting of information about the performances of Australian schools. The focus is on the collection of nationally comparable data. Two purposes are envisaged: use by education authorities and governments to monitor school performances and, in particular, to identify schools that are performing unusually well or unusually poorly given their circumstances; and use by parents/caregivers and the public to make informed judgements about, and meaningful comparisons of, schools and their offerings. Our advice is based on a review of recent Australian and international research and experience in reporting on the performances of schools. This is an area of educational practice in which there have been many recent developments, much debate and a growing body of relevant research
Enhanced soliton interactions by inhomogeneous nonlocality and nonlinearity
We address the interactions between optical solitons in the system with
longitudinally varying nonlocality degree and nonlinearity strength. We
consider a physical model describing light propagation in nematic liquid
crystals featuring a strongly nonlocal nonlinear response. We reveal that the
variation of the nonlocality and nonlinearity along the propagation direction
can substantially enhance or weaken the interaction between out-of-phase
solitons. This phenomenon manifests itself as a slowdown or acceleration of the
soliton collision dynamics in one-dimensional geometries or of the soliton
spiraling rate in bulk media. Therefore, one finds that by engineering the
nonlocality and nonlinearity variation rate one can control the output soliton
location.Comment: 22 pages, 5 figures, to appear in Physical Review
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