440 research outputs found
Bayesian Non-Exhaustive Classification A Case Study: Online Name Disambiguation using Temporal Record Streams
The name entity disambiguation task aims to partition the records of multiple
real-life persons so that each partition contains records pertaining to a
unique person. Most of the existing solutions for this task operate in a batch
mode, where all records to be disambiguated are initially available to the
algorithm. However, more realistic settings require that the name
disambiguation task be performed in an online fashion, in addition to, being
able to identify records of new ambiguous entities having no preexisting
records. In this work, we propose a Bayesian non-exhaustive classification
framework for solving online name disambiguation task. Our proposed method uses
a Dirichlet process prior with a Normal * Normal * Inverse Wishart data model
which enables identification of new ambiguous entities who have no records in
the training data. For online classification, we use one sweep Gibbs sampler
which is very efficient and effective. As a case study we consider
bibliographic data in a temporal stream format and disambiguate authors by
partitioning their papers into homogeneous groups. Our experimental results
demonstrate that the proposed method is better than existing methods for
performing online name disambiguation task.Comment: to appear in CIKM 201
Challenges in the Search for Perchlorate and Other Hydrated Minerals With 2.1-μm Absorptions on Mars
A previously unidentified artifact has been found in Compact Reconnaissance Imaging Spectrometer for Mars targeted I/F data. It exists in a small fraction (<0.05%) of pixels within 90% of images investigated and occurs in regions of high spectral/spatial variance. This artifact mimics real mineral absorptions in width and depth and occurs most often at 1.9 and 2.1 μm, thus interfering in the search for some mineral phases, including alunite, kieserite, serpentine, and perchlorate. A filtering step in the data processing pipeline, between radiance and I/F versions of the data, convolves narrow artifacts (“spikes”) with real atmospheric absorptions in these wavelength regions to create spurious absorption-like features. The majority of previous orbital detections of alunite, kieserite, and serpentine we investigated can be confirmed using radiance and raw data, but few to none of the perchlorate detections reported in published literature remain robust over the 1.0- to 2.65-μm wavelength range
Rare Phase Detections in CRISM Data at Pixel-Scale by Machine Learning Generate New Discoveries About Geology at Mars Rover Landing Sites: Jezero and NE Syrtis
The clinical course of low back pain: a meta-analysis comparing outcomes in randomised clinical trials (RCTs) and observational studies.
BACKGROUND: Evidence suggests that the course of low back pain (LBP) symptoms in randomised clinical trials (RCTs) follows a pattern of large improvement regardless of the type of treatment. A similar pattern was independently observed in observational studies. However, there is an assumption that the clinical course of symptoms is particularly influenced in RCTs by mere participation in the trials. To test this assumption, the aim of our study was to compare the course of LBP in RCTs and observational studies. METHODS: Source of studies CENTRAL database for RCTs and MEDLINE, CINAHL, EMBASE and hand search of systematic reviews for cohort studies. Studies include individuals aged 18 or over, and concern non-specific LBP. Trials had to concern primary care treatments. Data were extracted on pain intensity. Meta-regression analysis was used to compare the pooled within-group change in pain in RCTs with that in cohort studies calculated as the standardised mean change (SMC). RESULTS: 70 RCTs and 19 cohort studies were included, out of 1134 and 653 identified respectively. LBP symptoms followed a similar course in RCTs and cohort studies: a rapid improvement in the first 6 weeks followed by a smaller further improvement until 52 weeks. There was no statistically significant difference in pooled SMC between RCTs and cohort studies at any time point:- 6 weeks: RCTs: SMC 1.0 (95% CI 0.9 to 1.0) and cohorts 1.2 (0.7to 1.7); 13 weeks: RCTs 1.2 (1.1 to 1.3) and cohorts 1.0 (0.8 to 1.3); 27 weeks: RCTs 1.1 (1.0 to 1.2) and cohorts 1.2 (0.8 to 1.7); 52 weeks: RCTs 0.9 (0.8 to 1.0) and cohorts 1.1 (0.8 to 1.6). CONCLUSIONS: The clinical course of LBP symptoms followed a pattern that was similar in RCTs and cohort observational studies. In addition to a shared 'natural history', enrolment of LBP patients in clinical studies is likely to provoke responses that reflect the nonspecific effects of seeking and receiving care, independent of the study design
Evidence for Chemically Distinct Waters Forming Sulphates and Chlorides in Terra Sirenum, Mars
Gold-on-glass microwave split-ring resonators with PDMS microchannels for differential measurement in microfluidic sensing
This paper describes a microwave resonator incorporating microfluidic lab-on-chip sensor system capable of performing simultaneous differential measurement based sensing of liquid samples. The resonators are split-ring resonator shapes made of gold on glass substrates. Directly bonded on glass substrates are polydimethylsiloxane microchannels. Sensor system design incorporates a pair of identical resonators, one of which performs reference reading from the background. Tracking the difference of the responses of both resonators simultaneously, rather than a single one, is used to obtain a more linear and noise-free reading. The sensor system was produced with conventional fabrication techniques. It is compatible with low-cost, simple, easy to handle sensing applications. Results indicate that reliable differential measurement was possible owing to a well-matched pair of sensors with a response error as low as 0.1%. It was also demonstrated that differential measurement capability enables sensing with improved linearity. Measurements were performed with glucose solutions in the range of 3.2–16.1 mM, achieving a sensitivity of 0.16 MHz/mM
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