259 research outputs found
Fade Depth Prediction Using Human Presence for Real Life WSN Deployment
Current problem in real life WSN deployment is determining fade depth in indoor propagation scenario for link power budget analysis using (fade margin parameter). Due to the fact that human presence impacts the performance of wireless networks, this paper proposes a statistical approach for shadow fading prediction using various real life parameters. Considered parameters within this paper include statistically mapped human presence and the number of people through time compared to the received signal strength. This paper proposes an empirical model fade depth prediction model derived from a comprehensive set of measured data in indoor propagation scenario. It is shown that the measured fade depth has high correlations with the number of people in non-line-of-sight condition, giving a solid foundation for the fade depth prediction model. In line-of-sight conditions this correlations is significantly lower. By using the proposed model in real life deployment scenarios of WSNs, the data loss and power consumption can be reduced by the means of intelligently planning and designing Wireless Sensor Network
Rehospitalization following percutaneous coronary intervention for commercially insured patients with acute coronary syndrome: a retrospective analysis
BACKGROUND: While prior research has provided important information about readmission rates following percutaneous coronary intervention, reports regarding charges and length of stay for readmission beyond 30 days post-discharge for patients in a large cohort are limited. The objective of this study was to characterize the rehospitalization of patients with acute coronary syndrome receiving percutaneous coronary intervention in a U.S. health benefit plan. METHODS: This study retrospectively analyzed administrative claims data from a large US managed care plan at index hospitalization, 30-days, and 31-days to 15-months rehospitalization. A valid Diagnosis Related Group code (version 24) associated with a PCI claim (codes 00.66, 36.0X, 929.73, 929.75, 929.78–929.82, 929.84, 929.95/6, and G0290/1) was required to be included in the study. Patients were also required to have an ACS diagnosis on the day of admission or within 30 days prior to the index PCI. ACS diagnoses were classified by the International Statistical Classification of Disease 9 (ICD-9-CM) codes 410.xx or 411.11. Patients with a history of transient ischemic attack or stroke were excluded from the study because of the focus only on ACS-PCI patients. A clopidogrel prescription claim was required within 60 days after hospitalization. RESULTS: Of the 6,687 ACS-PCI patients included in the study, 5,174 (77.4%) were male, 5,587 (83.6%) were <65 years old, 4,821 (72.1%) had hypertension, 5,176 (77.4%) had hyperlipidemia, and 1,777 (26.6%) had diabetes. At index hospitalization drug-eluting stents were the most frequently used: 5,534 (82.8%). Of the 4,384 patients who completed the 15-month follow-up, a total of 1,367 (31.2%) patients were rehospitalized for cardiovascular (CV)-related events, of which 811 (59.3%) were revascularization procedures: 13 (1.0%) for coronary artery bypass graft and 798 (58.4%) for PCI. In general, rehospitalizations associated with revascularization procedures cost more than other CV-related rehospitalizations. Patients rehospitalized for revascularization procedures had the shortest median time from post-index PCI to rehospitalization when compared to the patients who were rehospitalized for other CV-related events. CONCLUSIONS: For ACS patients who underwent PCI, revascularization procedures represented a large portion of rehospitalizations. Revascularization procedures appear to be the most frequent, most costly, and earliest cause for rehospitalization after ACS-PCI
Practical reasoning in political discourse: The UK government's response to the economic crisis in the 2008 Pre-Budget Report
This article focuses on practical reasoning in political discourse and argues for a better integration of argumentation theory with critical discourse analysis (CDA). Political discourse and its specific genres (for example, deliberation) primarily involve forms of practical reasoning, typically oriented towards finding solutions to problems and deciding on future courses of action. Practical reasoning is a form of inference from cognitive and motivational premises: from what we believe (about the situation or about means—end relations) and what we want or desire (our goals and values), leading to a normative judgement (and often a decision) concerning action. We offer an analysis of the main argument in the UK government’s 2008 Pre-Budget Report (HM Treasury, 2008) and suggest how a critical evaluation of the argument from the perspective of a normative theory of argumentation (particularly the informal logic developed by Douglas Walton) can provide the basis for an evaluation in terms of characteristic CDA concerns. We are advancing this analysis as a contribution to CDA, aimed at increasing the rigour and systematicity of its analyses of political discourse, and as a contribution to the normative concerns of critical social science
artbin: Extended sample size for randomized trials with binary outcomes
We describe the command artbin, which offers various new facilities for the calculation of sample size for binary outcome variables that are not otherwise available in Stata. While artbin has been available since 2004, it has not been previously described in the Stata Journal. artbin has been recently updated to include new options for different statistical tests, methods and study designs, improved syntax, and better handling of noninferiority trials. In this article, we describe the updated version of artbin and detail the various formulas used within artbin in different settings
Wrinkling of foils
Aluminum and copper metal webs less than 150 microns (6-mils) are considered foils. Demand for aluminum and copper foils are growing, driven by growing markets for flexible electronics, flat panel displays, lithium batteries, and solar products. In many of these products, thinner foils have cost or weight advantages, but as with nearly any web, thinner means an increased sensitivity to wrinkling in web handling processes.Nearly all of published web handling research and development work have been based on polymer films and paper webs. Since the web wrinkling theories are based on first principles, they should apply to the foil webs. However, applying models confirmed with paper or foil on narrow widths (less than 0.3m or 12-in wide) to the uncharted territories of foils with 20x elastic modulus and 4x width increases will likely lead to interesting discoveries.This paper will present a comparison of empirical wrinkling results from trials of handling thin and wide aluminum and copper foils (less 25 micron thick by greater than 0.6m wide (less than 0.001-in thick by 24-in. wide). The experimental results will be compared to wrinkling theory, with conclusion about how wrinkling in foils differs from film and paper webs
A Study of the Day - Night Effect for the Super - Kamiokande Detector: I. Time Averaged Solar Neutrino Survival Probability
This is the first of two articles aimed at providing comprehensive
predictions for the day-night (D-N) effect for the Super-Kamiokande detector in
the case of the MSW \nu_e \to \numt transition solution of the solar neutrino
problem. The one-year averaged probability of survival of the solar \nue
crossing the Earth mantle, the core, the inner 2/3 of the core, and the (core +
mantle) is calculated with high precision (better than 1%) using the elliptical
orbit approximation (EOA) to describe the Earth motion around the Sun. Results
for the survival probability in the indicated cases are obtained for a large
set of values of the MSW transition parameters and
from the ``conservative'' regions of the MSW solution,
derived by taking into account possible relatively large uncertainties in the
values of the B and Be neutrino fluxes. Our results show that the
one-year averaged D-N asymmetry in the survival probability for
neutrinos crossing the Earth core can be, in the case of , larger than the asymmetry in the probability for (only mantle
crossing + core crossing) neutrinos by a factor of up to six. The enhancement
is larger in the case of neutrinos crossing the inner 2/3 of the core. This
indicates that the Super-Kamiokande experiment might be able to test the
region of the MSW solution of the solar neutrino
problem by performing selective D-N asymmetry measurements.Comment: LaTeX2e - 18 Text Pages + 21 figures = 39 Pages. - Figures in PS +
text file sk1b14.tex requires two auxiliary files (included
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Treating sample covariances for use in strongly coupled atmosphere-ocean data assimilation
Strongly coupled data assimilation requires cross-domain forecast error covariances; information from ensembles can be used, but limited sampling means that ensemble derived error covariances are routinely rank deficient and/or ill-conditioned and marred by noise. Thus they require modification before they can be incorporated into a standard assimilation framework. Here, we compare methods for improving the rank and conditioning of multivariate sample error covariance matrices for coupled atmosphere-ocean data assimilation. The first method, reconditioning, alters the matrix eigenvalues directly; this preserves the correlation structures but does not remove sampling noise. We show it is better to recondition the correlation matrix rather than the covariance matrix as this prevents small but dynamically important modes from being lost. The second method, model state-space localisation via the Schur product, effectively removes sample noise but can dampen small cross-correlation signals. A combination that exploits the merits of each is found to offer an effective alternative
cAMP-Dependent Co-stabilization of Axonal Arbors from Adjacent Developing Neurons
Axonal arbors in many neuronal networks are exuberant early during development and become refined by
activity-dependent competitive mechanisms. Theoretical work proposed non-competitive interactions
between co-active axons to co-stabilize their connections, but the demonstration of such interactions is
lacking. Here, we provide experimental evidence that reducing cyclic AMP (cAMP) signaling in a subset of
retinal ganglion cells favors the elimination of thalamic projections from neighboring neurons, pointing to a
cAMP-dependent interaction that promotes axon stabilization
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