87 research outputs found
Foundational Models for Fault Diagnosis of Electrical Motors
A majority of recent advancements related to the fault diagnosis of
electrical motors are based on the assumption that training and testing data
are drawn from the same distribution. However, the data distribution can vary
across different operating conditions during real-world operating scenarios of
electrical motors. Consequently, this assumption limits the practical
implementation of existing studies for fault diagnosis, as they rely on fully
labelled training data spanning all operating conditions and assume a
consistent distribution. This is because obtaining a large number of labelled
samples for several machines across different fault cases and operating
scenarios may be unfeasible. In order to overcome the aforementioned
limitations, this work proposes a framework to develop a foundational model for
fault diagnosis of electrical motors. It involves building a neural
network-based backbone to learn high-level features using self-supervised
learning, and then fine-tuning the backbone to achieve specific objectives. The
primary advantage of such an approach is that the backbone can be fine-tuned to
achieve a wide variety of target tasks using very less amount of training data
as compared to traditional supervised learning methodologies. The empirical
evaluation demonstrates the effectiveness of the proposed approach by obtaining
more than 90\% classification accuracy by fine-tuning the backbone not only
across different types of fault scenarios or operating conditions, but also
across different machines. This illustrates the promising potential of the
proposed approach for cross-machine fault diagnosis tasks in real-world
applications.Comment: 7 pages, 1 figure, 5 tables, submitted to IEEE PESGRE 202
Active Foundational Models for Fault Diagnosis of Electrical Motors
Fault detection and diagnosis of electrical motors are of utmost importance
in ensuring the safe and reliable operation of several industrial systems.
Detection and diagnosis of faults at the incipient stage allows corrective
actions to be taken in order to reduce the severity of faults. The existing
data-driven deep learning approaches for machine fault diagnosis rely
extensively on huge amounts of labeled samples, where annotations are expensive
and time-consuming. However, a major portion of unlabeled condition monitoring
data is not exploited in the training process. To overcome this limitation, we
propose a foundational model-based Active Learning framework that utilizes less
amount of labeled samples, which are most informative and harnesses a large
amount of available unlabeled data by effectively combining Active Learning and
Contrastive Self-Supervised Learning techniques. It consists of a transformer
network-based backbone model trained using an advanced nearest-neighbor
contrastive self-supervised learning method. This approach empowers the
backbone to learn improved representations of samples derived from raw,
unlabeled vibration data. Subsequently, the backbone can undergo fine-tuning to
address a range of downstream tasks, both within the same machines and across
different machines. The effectiveness of the proposed methodology has been
assessed through the fine-tuning of the backbone for multiple target tasks
using three distinct machine-bearing fault datasets. The experimental
evaluation demonstrates a superior performance as compared to existing
state-of-the-art fault diagnosis methods with less amount of labeled data.Comment: 30 pages, 2 figures, 7 table
Towards AI enabled automated tracking of multiple boxers
Continuous tracking of boxers across multiple training sessions helps
quantify traits required for the well-known ten-point-must system. However,
continuous tracking of multiple athletes across multiple training sessions
remains a challenge, because it is difficult to precisely segment bout
boundaries in a recorded video stream. Furthermore, re-identification of the
same athlete over different period or even within the same bout remains a
challenge. Difficulties are further compounded when a single fixed view video
is captured in top-view. This work summarizes our progress in creating a system
in an economically single fixed top-view camera. Specifically, we describe
improved algorithm for bout transition detection and in-bout continuous player
identification without erroneous ID updation or ID switching. From our custom
collected data of ~11 hours (athlete count: 45, bouts: 189), our transition
detection algorithm achieves 90% accuracy and continuous ID tracking achieves
IDU=0, IDS=0
Persistence of G10P[11] neonatal rotavirus infections in southern India
BACKGROUND: Neonatal rotavirus infections are predominantly caused by distinct genotypes restricted to this age-group and are mostly asymptomatic. METHOD: Stool samples from neonates admitted for >48 h in neonatal intensive care units (NICUs) in Vellore (2014–2015) and Chennai (2015–2016) in southern India, and from neonates born at hospitals in Vellore but not admitted to NICUs (2015–2016) were tested for rotavirus by ELISA and genotyped by hemi-nested RT-PCR. RESULTS: Of 791 neonates, 150 and 336 were recruited from Vellore and Chennai NICUs, and 305 were born in five hospitals in Vellore. Positivity rates in the three settings were 49.3% (74/150), 29.5% (99/336) and 54% (164/305), respectively. G10P[11] was the commonly identified genotype in 87.8% (65/74), 94.9% (94/99) and 98.2% (161/164) of the neonates in Vellore and Chennai NICUs, and those born at Vellore hospitals, respectively. Neonates delivered by lower segment cesarian section (LSCS) at Vellore hospitals, not admitted to NICUs, had a significantly higher odds of acquiring rotavirus infection compared to those delivered vaginally [p = 0.002, OR = 2.4 (1.4–4.3)]. CONCLUSIONS: This report demonstrates the persistence of G10P[11] strain in Vellore and Chennai, indicating widespread neonatal G10P[11] strain in southern India and their persistence over two decades, leading to interesting questions about strain stability
Immune predictors of oral poliovirus vaccine immunogenicity among infants in South India.
Identification of the causes of poor oral vaccine immunogenicity in low-income countries might lead to more effective vaccines. We measured mucosal and systemic immune parameters at the time of vaccination with oral poliovirus vaccine (OPV) in 292 Indian infants aged 6-11 months, including plasma cytokines, leukocyte counts, fecal biomarkers of environmental enteropathy and peripheral blood T-cell phenotype, focused on gut-homing regulatory CD4+ populations. We did not find a distinct immune phenotype associated with OPV immunogenicity, although viral pathogens were more prevalent in stool at the time of immunization among infants who failed to seroconvert (63.9% vs. 45.6%, p = 0.002). Using a machine-learning approach, we could predict seroconversion a priori using immune parameters and infection status with a median 58% accuracy (cross-validation IQR: 50-69%) compared with 50% expected by chance. Better identification of immune predictors of OPV immunogenicity is likely to require sampling of mucosal tissue and improved oral poliovirus infection models
Impact of maternal antibodies and microbiota development on the immunogenicity of oral rotavirus vaccine in African, Indian, and European infants: a prospective cohort study
Identifying risk factors for impaired oral rotavirus vaccine (ORV) efficacy in low-income countries may lead to improvements in vaccine design and delivery. We measured maternal rotavirus antibodies, environmental enteric dysfunction (EED), and bacterial gut microbiota development among infants receiving two doses of Rotarix in India (n = 307), Malawi (n = 119), and the UK (n = 60), using standardised methods across cohorts. ORV shedding and seroconversion rates were significantly lower in Malawi and India than the UK. Maternal rotavirus-specific antibodies in serum and breastmilk were negatively correlated with ORV response in India and Malawi, and this was mediated partly by a reduction in ORV replication. In the UK, ORV replication was not inhibited despite comparable maternal antibody levels. In both India and Malawi, pre-vaccination microbiota diversity was negatively correlated with ORV immunogenicity, suggesting that high early-life microbial exposure may contribute to impaired vaccine efficacy
The effect of probiotics and zinc supplementation on the immune response to oral rotavirus vaccine: A randomized, factorial design, placebo-controlled study among Indian infants.
BACKGROUND: Strategies are needed to improve oral rotavirus vaccine (RV), which provides suboptimal protection in developing countries. Probiotics and zinc supplementation could improve RV immunogenicity by altering the intestinal microbiota and immune function. METHODS: Infants 5weeks old living in urban Vellore, India were enrolled in a randomized, double-blind, placebo-controlled trial with a 4-arm factorial design to assess the effects of daily zinc (5mg), probiotic (1010Lactobacillus rhamnosus GG) or placebo on the immunogenicity of two doses of RV (Rotarix®, GlaxoSmithKline Biologicals) given at 6 and 10weeks of age. Infants were eligible for participation if healthy, available for the study duration and without prior receipt of RV or oral poliovirus vaccine other than the birth dose. The primary outcome was seroconversion to rotavirus at 14weeks of age based on detection of VP6-specific IgA at ?20U/ml in previously seronegative infants or a fourfold rise in concentration. RESULTS: The study took place during July 2012 to February 2013. 620 infants were randomized equally between study arms and 551 (88.9%) completed per protocol. Seroconversion was recorded in 54/137 (39.4%), 42/136 (30.9%), 40/143 (28.0%), and 37/135 (27.4%) infants receiving (1) probiotic and zinc, (2) probiotic and placebo, (3) placebo and zinc, (4) two placebos. Seroconversion showed a modest improvement among infants receiving probiotic (difference between groups 1, 2 and 3, 4 was 7.5% (97.5% Confidence Interval (CI): -1.4%, 16.2%), p=0.066) but not zinc (difference between groups 1, 3 and 2, 4 was 4.4% (97.5% CI: -4.4%, 13.2%), p=0.272). 16 serious adverse events were recorded, none related to study interventions. CONCLUSIONS: Zinc or probiotic supplementation did not significantly improve the low immunogenicity of rotavirus vaccine given to infants in a poor urban community in India. A modest effect of combined supplementation deserves further investigation. TRIAL REGISTRATION: The trial was registered in India (CTRI/2012/05/002677)
An approach to identify the cognitive load on the operator using pupillometry information
by C.Sharma, Babji Srinivasan and Rajagopalan Srinivasa
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