138 research outputs found
Fulfilling Multiple Intent Queries Using Compound Responses
Information-seeking queries to a virtual assistant can often cover multiple facets of a given topic. For example, a query of the form “what is the latest on covid-19” can reasonably be answered with the latest epidemiological statistics, medical information of disease symptoms, news relating to disease spread, etc. No single interpretation of such a query is likely to meet all of the user\u27s original information-seeking intent. This disclosure describes techniques for answering queries that can include multiple reasonable answers derived from different corpora. The techniques incorporate information from the different corpora and presents it in a manner that obviates the need for a user to understand finer distinctions between the corpora. Effectively, the techniques provide a compound response that is stitched together from available facts, related news stories, and other sources of information to cover the user’s information needs
Use of graphene as protection film in biological environments
Corrosion of metal in biomedical devices could cause serious health problems to patients. Currently ceramics coating materials used in metal implants can reduce corrosion to some extent with limitations. Here we proposed graphene as a biocompatible protective film for metal potentially for biomedical application. We confirmed graphene effectively inhibits Cu surface from corrosion in different biological aqueous environments. Results from cell viability tests suggested that graphene greatly eliminates the toxicity of Cu by inhibiting corrosion and reducing the concentration of Cu(2+) ions produced. We demonstrated that additional thiol derivatives assembled on graphene coated Cu surface can prominently enhance durability of sole graphene protection limited by the defects in graphene film. We also demonstrated that graphene coating reduced the immune response to metal in a clinical setting for the first time through the lymphocyte transformation test. Finally, an animal experiment showed the effective protection of graphene to Cu under in vivo condition. Our results open up the potential for using graphene coating to protect metal surface in biomedical application
High-Performance Atomically-Thin Room-Temperature NO2 Sensor.
The development of room-temperature sensing devices for detecting small concentrations of molecular species is imperative for a wide range of low-power sensor applications. We demonstrate a room-temperature, highly sensitive, selective, stable, and reversible chemical sensor based on a monolayer of the transition-metal dichalcogenide Re0.5Nb0.5S2. The sensing device exhibits a thickness-dependent carrier type, and upon exposure to NO2 molecules, its electrical resistance considerably increases or decreases depending on the layer number. The sensor is selective to NO2 with only minimal response to other gases such as NH3, CH2O, and CO2. In the presence of humidity, not only are the sensing properties not deteriorated but also the monolayer sensor shows complete reversibility with fast recovery at room temperature. We present a theoretical analysis of the sensing platform and identify the atomically sensitive transduction mechanism
Use of graphene as protection film in biological environments
Corrosion of metal in biomedical devices could cause serious health problems to patients. Currently ceramics coating materials used in metal implants can reduce corrosion to some extent with limitations. Here we proposed graphene as a biocompatible protective film for metal potentially for biomedical application. We confirmed graphene effectively inhibits Cu surface from corrosion in different biological aqueous environments. Results from cell viability tests suggested that graphene greatly eliminates the toxicity of Cu by inhibiting corrosion and reducing the concentration of Cu2+ ions produced. We demonstrated that additional thiol derivatives assembled on graphene coated Cu surface can prominently enhance durability of sole graphene protection limited by the defects in graphene film. We also demonstrated that graphene coating reduced the immune response to metal in a clinical setting for the first time through the lymphocyte transformation test. Finally, an animal experiment showed the effective protection of graphene to Cu under in vivo condition. Our results open up the potential for using graphene coating to protect metal surface in biomedical application
Explaining Convolutional Neural Networks through Attribution-Based Input Sampling and Block-Wise Feature Aggregation
As an emerging field in Machine Learning, Explainable AI (XAI) has been
offering remarkable performance in interpreting the decisions made by
Convolutional Neural Networks (CNNs). To achieve visual explanations for CNNs,
methods based on class activation mapping and randomized input sampling have
gained great popularity. However, the attribution methods based on these
techniques provide lower resolution and blurry explanation maps that limit
their explanation power. To circumvent this issue, visualization based on
various layers is sought. In this work, we collect visualization maps from
multiple layers of the model based on an attribution-based input sampling
technique and aggregate them to reach a fine-grained and complete explanation.
We also propose a layer selection strategy that applies to the whole family of
CNN-based models, based on which our extraction framework is applied to
visualize the last layers of each convolutional block of the model. Moreover,
we perform an empirical analysis of the efficacy of derived lower-level
information to enhance the represented attributions. Comprehensive experiments
conducted on shallow and deep models trained on natural and industrial
datasets, using both ground-truth and model-truth based evaluation metrics
validate our proposed algorithm by meeting or outperforming the
state-of-the-art methods in terms of explanation ability and visual quality,
demonstrating that our method shows stability regardless of the size of objects
or instances to be explained.Comment: 9 pages, 9 figures, Accepted at the Thirty-Fifth AAAI Conference on
Artificial Intelligence (AAAI-21
GenHPF: General Healthcare Predictive Framework with Multi-task Multi-source Learning
Despite the remarkable progress in the development of predictive models for
healthcare, applying these algorithms on a large scale has been challenging.
Algorithms trained on a particular task, based on specific data formats
available in a set of medical records, tend to not generalize well to other
tasks or databases in which the data fields may differ. To address this
challenge, we propose General Healthcare Predictive Framework (GenHPF), which
is applicable to any EHR with minimal preprocessing for multiple prediction
tasks. GenHPF resolves heterogeneity in medical codes and schemas by converting
EHRs into a hierarchical textual representation while incorporating as many
features as possible. To evaluate the efficacy of GenHPF, we conduct multi-task
learning experiments with single-source and multi-source settings, on three
publicly available EHR datasets with different schemas for 12 clinically
meaningful prediction tasks. Our framework significantly outperforms baseline
models that utilize domain knowledge in multi-source learning, improving
average AUROC by 1.2%P in pooled learning and 2.6%P in transfer learning while
also showing comparable results when trained on a single EHR dataset.
Furthermore, we demonstrate that self-supervised pretraining using multi-source
datasets is effective when combined with GenHPF, resulting in a 0.6%P AUROC
improvement compared to models without pretraining. By eliminating the need for
preprocessing and feature engineering, we believe that this work offers a solid
framework for multi-task and multi-source learning that can be leveraged to
speed up the scaling and usage of predictive algorithms in healthcare.Comment: Accepted by IEEE Journal of Biomedical and Health Informatic
Homogeneous bilayer graphene film based flexible transparent conductor
Graphene is considered a promising candidate to replace conventional
transparent conductors due to its low opacity, high carrier mobility and
flexible structure. Multi-layer graphene or stacked single layer graphenes have
been investigated in the past but both have their drawbacks. The uniformity of
multi-layer graphene is still questionable, and single layer graphene stacks
require many transfer processes to achieve sufficiently low sheet resistance.
In this work, bilayer graphene film grown with low pressure chemical vapor
deposition was used as a transparent conductor for the first time. The
technique was demonstrated to be highly efficient in fabricating a conductive
and uniform transparent conductor compared to multi-layer or single layer
graphene. Four transfers of bilayer graphene yielded a transparent conducting
film with a sheet resistance of 180 {\Omega}_{\square} at a transmittance of
83%. In addition, bilayer graphene films transferred onto plastic substrate
showed remarkable robustness against bending, with sheet resistance change less
than 15% at 2.14% strain, a 20-fold improvement over commercial indium oxide
films.Comment: Published in Nanoscale, Nov. 2011 : http://www.rsc.org/nanoscal
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