3,604 research outputs found
Strategies for online inference of model-based clustering in large and growing networks
In this paper we adapt online estimation strategies to perform model-based
clustering on large networks. Our work focuses on two algorithms, the first
based on the SAEM algorithm, and the second on variational methods. These two
strategies are compared with existing approaches on simulated and real data. We
use the method to decipher the connexion structure of the political websphere
during the US political campaign in 2008. We show that our online EM-based
algorithms offer a good trade-off between precision and speed, when estimating
parameters for mixture distributions in the context of random graphs.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS359 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Has wild poliovirus been eliminated from Nigeria?
Wild poliovirus type 3 (WPV3) has not been seen anywhere since the last case
of WPV3-associated paralysis in Nigeria in November 2012. At the time of
writing, the most recent case of wild poliovirus type 1 (WPV1) in Nigeria
occurred in July 2014, and WPV1 has not been seen in Africa since a case in
Somalia in August 2014. No cases associated with circulating vaccine-derived
type 2 poliovirus (cVDPV2) have been detected in Nigeria since November 2014.
Has WPV1 been eliminated from Africa? Has WPV3 been eradicated globally? Has
Nigeria interrupted cVDPV2 transmission? These questions are difficult because
polio surveillance is based on paralysis and paralysis only occurs in a small
fraction of infections.
This report provides estimates for the probabilities of poliovirus
elimination in Nigeria given available data as of March 31, 2015. It is based
on a model of disease transmission that is built from historical polio
incidence rates and is designed to represent the uncertainties in transmission
dynamics and poliovirus detection that are fundamental to interpreting long
time periods without cases.
The model estimates that, as of March 31, 2015, the probability of WPV1
elimination in Nigeria is 84%, and that if WPV1 has not been eliminated, a new
case will be detected with 99% probability by the end of 2015. The probability
of WPV3 elimination (and thus global eradication) is >99%. However, it is
unlikely that the ongoing transmission of cVDPV2 has been interrupted; the
probability of cVDPV2 elimination rises to 83% if no new cases are detected by
April 2016.
Added July 10, 2015: On June 26, a cVDPV2 case was confirmed by the Global
Polio Laboratory Network. The date of paralysis was May 16. The case provides
new information about cVDPV2 prevalence that is useful for assessing the
accuracy of previous predictions and informing an updated forecast for the time
to cVDPV2 elimination.Comment: Added model validation section and updated cVDPV2 forecast in
response to new case data; expanded material on surveillance sensitivity;
additional minor edits; and references added. 24 pages, 4 figure
The Hierarchic treatment of marine ecological information from spatial networks of benthic platforms
Measuring biodiversity simultaneously in different locations, at different temporal scales, and over wide spatial scales is of strategic importance for the improvement of our understanding of the functioning of marine ecosystems and for the conservation of their biodiversity. Monitoring networks of cabled observatories, along with other docked autonomous systems (e.g., Remotely Operated Vehicles [ROVs], Autonomous Underwater Vehicles [AUVs], and crawlers), are being conceived and established at a spatial scale capable of tracking energy fluxes across benthic and pelagic compartments, as well as across geographic ecotones. At the same time, optoacoustic imaging is sustaining an unprecedented expansion in marine ecological monitoring, enabling the acquisition of new biological and environmental data at an appropriate spatiotemporal scale. At this stage, one of the main problems for an effective application of these technologies is the processing, storage, and treatment of the acquired complex ecological information. Here, we provide a conceptual overview on the technological developments in the multiparametric generation, storage, and automated hierarchic treatment of biological and environmental information required to capture the spatiotemporal complexity of a marine ecosystem. In doing so, we present a pipeline of ecological data acquisition and processing in different steps and prone to automation. We also give an example of population biomass, community richness and biodiversity data computation (as indicators for ecosystem functionality) with an Internet Operated Vehicle (a mobile crawler). Finally, we discuss the software requirements for that automated data processing at the level of cyber-infrastructures with sensor calibration and control, data banking, and ingestion into large data portals.Peer ReviewedPostprint (published version
Methodologies for the Automatic Location of Academic and Educational Texts on the Internet
Traditionally online databases of web resources have been compiled by a human editor, or though the submissions of authors or interested parties. Considerable resources are needed to maintain a constant level of input and relevance in the face of increasing material quantity and quality, and much of what is in databases is of an ephemeral nature. These pressures dictate that many databases stagnate after an initial period of enthusiastic data entry. The solution to this problem would seem to be the automatic harvesting of resources, however, this process necessitates the automatic classification of resources as ‘appropriate’ to a given database, a problem only solved by complex text content analysis.
This paper outlines the component methodologies necessary to construct such an automated harvesting system, including a number of novel approaches. In particular this paper looks at the specific problems of automatically identifying academic research work and Higher Education pedagogic materials. Where appropriate, experimental data is presented from searches in the field of Geography as well as the Earth and Environmental Sciences. In addition, appropriate software is reviewed where it exists, and future directions are outlined
Methodologies for the Automatic Location of Academic and Educational Texts on the Internet
Traditionally online databases of web resources have been compiled by a human editor, or though the submissions of authors or interested parties. Considerable resources are needed to maintain a constant level of input and relevance in the face of increasing material quantity and quality, and much of what is in databases is of an ephemeral nature. These pressures dictate that many databases stagnate after an initial period of enthusiastic data entry. The solution to this problem would seem to be the automatic harvesting of resources, however, this process necessitates the automatic classification of resources as ‘appropriate’ to a given database, a problem only solved by complex text content analysis.
This paper outlines the component methodologies necessary to construct such an automated harvesting system, including a number of novel approaches. In particular this paper looks at the specific problems of automatically identifying academic research work and Higher Education pedagogic materials. Where appropriate, experimental data is presented from searches in the field of Geography as well as the Earth and Environmental Sciences. In addition, appropriate software is reviewed where it exists, and future directions are outlined
Peer-to-Peer Personal Health Record
Indiana University-Purdue University Indianapolis (IUPUI)Patients and providers need to exchange medical records. Electronic Health Records and Health Information Exchanges leave a patient’s health record fragmented and controlled by the provider. This thesis proposes a Peer-to-Peer Personal Health Record network that can be extended with third-party services. This design enables patient control of health records and the tracing of exchanges. Additionally, as a demonstration of the functionality of a potential third-party, a Hypertension Predictor is developed using MEPS data and deployed as a service in the proposed framework
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