657 research outputs found
Medical Image Analysis using Deep Relational Learning
In the past ten years, with the help of deep learning, especially the rapid
development of deep neural networks, medical image analysis has made remarkable
progress. However, how to effectively use the relational information between
various tissues or organs in medical images is still a very challenging
problem, and it has not been fully studied. In this thesis, we propose two
novel solutions to this problem based on deep relational learning. First, we
propose a context-aware fully convolutional network that effectively models
implicit relation information between features to perform medical image
segmentation. The network achieves the state-of-the-art segmentation results on
the Multi Modal Brain Tumor Segmentation 2017 (BraTS2017) and Multi Modal Brain
Tumor Segmentation 2018 (BraTS2018) data sets. Subsequently, we propose a new
hierarchical homography estimation network to achieve accurate medical image
mosaicing by learning the explicit spatial relationship between adjacent
frames. We use the UCL Fetoscopy Placenta dataset to conduct experiments and
our hierarchical homography estimation network outperforms the other
state-of-the-art mosaicing methods while generating robust and meaningful
mosaicing result on unseen frames.Comment: arXiv admin note: substantial text overlap with arXiv:2007.0778
Generating EDU Extracts for Plan-Guided Summary Re-Ranking
Two-step approaches, in which summary candidates are generated-then-reranked
to return a single summary, can improve ROUGE scores over the standard
single-step approach. Yet, standard decoding methods (i.e., beam search,
nucleus sampling, and diverse beam search) produce candidates with redundant,
and often low quality, content. In this paper, we design a novel method to
generate candidates for re-ranking that addresses these issues. We ground each
candidate abstract on its own unique content plan and generate distinct
plan-guided abstracts using a model's top beam. More concretely, a standard
language model (a BART LM) auto-regressively generates elemental discourse unit
(EDU) content plans with an extractive copy mechanism. The top K beams from the
content plan generator are then used to guide a separate LM, which produces a
single abstractive candidate for each distinct plan. We apply an existing
re-ranker (BRIO) to abstractive candidates generated from our method, as well
as baseline decoding methods. We show large relevance improvements over
previously published methods on widely used single document news article
corpora, with ROUGE-2 F1 gains of 0.88, 2.01, and 0.38 on CNN / Dailymail, NYT,
and Xsum, respectively. A human evaluation on CNN / DM validates these results.
Similarly, on 1k samples from CNN / DM, we show that prompting GPT-3 to follow
EDU plans outperforms sampling-based methods by 1.05 ROUGE-2 F1 points. Code to
generate and realize plans is available at
https://github.com/griff4692/edu-sum.Comment: ACL 202
Disentangling rodent behaviors to improve automated behavior recognition
Automated observation and analysis of behavior is important to facilitate progress in many fields of science. Recent developments in deep learning have enabled progress in object detection and tracking, but rodent behavior recognition struggles to exceed 75–80% accuracy for ethologically relevant behaviors. We investigate the main reasons why and distinguish three aspects of behavior dynamics that are difficult to automate. We isolate these aspects in an artificial dataset and reproduce effects with the state-of-the-art behavior recognition models. Having an endless amount of labeled training data with minimal input noise and representative dynamics will enable research to optimize behavior recognition architectures and get closer to human-like recognition performance for behaviors with challenging dynamics
Optimization of neural networks for deep learning and applications to CT image segmentation
[eng] During the last few years, AI development in deep learning has been going so fast that even important researchers, politicians, and entrepreneurs are signing petitions to try to slow it down. The newest methods for natural language processing and image generation are achieving results so unbelievable that people are seriously starting to think they can be dangerous for society. In reality, they are not dangerous (at the moment) even if we have to admit we reached a point where we have no more control over the flux of data inside the deep networks. It is impossible to open a modern
deep neural network and interpret how it processes the information and, in many cases, explain how or why it gives back that particular result. One of the goals of this doctoral work has been to study the behavior of weights in convolutional neural networks and in transformers. We hereby present a work that demonstrates how to invert 3x3 convolutions after training a neural network able to learn how to classify images, with the future aim of having precisely invertible convolutional neural networks. We demonstrate that a simple network can learn to classify images on an open-source dataset without loss in accuracy, with respect to a non-invertible one. All that with the ability to reconstruct the original image without detectable error
(on 8-bit images) in up to 20 convolutions stacked in a row. We present a thorough comparison between our method and the standard. We tested the
performances of the five most used transformers for image classification on an open- source dataset. Studying the embedded matrices, we have been
able to provide two criteria that can help transformers learn with a training time reduction of up to 30% and with no impact on classification accuracy.
The evolution of deep learning techniques is also touching the field of digital health. With tens of thousands of new start-ups and more than 1B $ of investments only in the last year, this field is growing rapidly and promising to revolutionize healthcare. In this thesis, we present several neural networks for the segmentation of lungs, lung nodules, and areas affected by pneumonia induced by COVID-19, in chest CT scans. The architecturesm we used are all residual convolutional neural networks inspired by UNet and Inception. We customized them with novel loss functions and layers
studied to achieve high performances on these particular applications. The errors on the surface of nodule segmentation masks are not over 1mm in more than 99% of the cases. Our algorithm for COVID-19 lesion detection has a specificity of 100% and overall accuracy of 97.1%. In general, it surpasses the state-of-the-art in all the considered statistics, using UNet as a benchmark. Combining these with other algorithms able to detect and predict lung cancer, the whole work was presented in a European innovation program and judged of high interest by worldwide experts.
With this work, we set the basis for the future development of better AI tools in healthcare and scientific investigation into the fundamentals of deep learning.[spa] Durante los últimos años, el desarrollo de la IA en el aprendizaje profundo ha ido tan rápido que Incluso importantes investigadores, polÃticos y empresarios están firmando peticiones para intentar para ralentizarlo. Los métodos más nuevos para el procesamiento y la generación de imágenes y lenguaje natural, están logrando resultados tan increÃbles que la gente está empezando a preocuparse seriamente. Pienso que pueden ser peligrosos para la sociedad. En realidad, no son peligrosos (al menos de momento) incluso si tenemos que admitir que llegamos a un punto en el que ya no tenemos control sobre el flujo de datos dentro de las redes profundas. Es imposible abrir una moderna red neuronal profunda e interpretar cómo procesa la información y, en muchos casos, explique cómo o por qué devuelve ese resultado en particular, uno de los objetivos de este doctorado.
El trabajo ha consistido en estudiar el comportamiento de los pesos en redes neuronales convolucionales y en transformadores. Por la presente presentamos un trabajo que demuestra cómo invertir 3x3 convoluciones después de entrenar una red neuronal capaz de aprender a clasificar imágenes, con el objetivo futuro de tener redes neuronales convolucionales precisamente invertibles. Nosotros queremos demostrar que una red simple puede aprender a clasificar imágenes en un código abierto conjunto de datos sin pérdida de precisión, con respecto a uno no invertible. Todo eso con la capacidad de reconstruir la imagen original sin errores detectables (en imágenes de 8 bits) en hasta 20 convoluciones apiladas en fila. Presentamos una exhaustiva comparación entre nuestro método y el estándar. Probamos las prestaciones de los cinco transformadores más utilizados para la clasificación de imágenes en abierto. conjunto de datos de origen. Al estudiar las matrices incrustadas, hemos sido capaz de proporcionar dos criterios que pueden ayudar a los transformadores a aprender con un tiempo de capacitación reducción de hasta el 30% y sin impacto en la precisión de la clasificación.
La evolución de las técnicas de aprendizaje profundo también está afectando al campo de la salud digital. Con decenas de miles de nuevas empresas y más de mil millones de dólares en inversiones sólo en el año pasado, este campo está creciendo rápidamente y promete revolucionar la atención médica. En esta tesis, presentamos varias redes neuronales para la segmentación de pulmones, nódulos pulmonares, y zonas afectadas por neumonÃa inducida por COVID-19, en tomografÃas computarizadas de tórax. La arquitectura que utilizamos son todas redes neuronales convolucionales residuales inspiradas en UNet. Las personalizamos con nuevas funciones y capas de pérdida, estudiado para lograr altos rendimientos en estas aplicaciones particulares. Los errores en la superficie de las máscaras de segmentación de los nódulos no supera 1 mm en más del 99% de los casos. Nuestro algoritmo para la detección de lesiones de COVID-19 tiene una especificidad del 100% y en general precisión del 97,1%. En general supera el estado del arte en todos los aspectos considerados, estadÃsticas, utilizando UNet como punto de referencia. Combinando estos con otros algoritmos capaces de detectar y predecir el cáncer de pulmón, todo el trabajo se presentó en una innovación europea programa y considerado de gran interés por expertos de todo el mundo.
Con este trabajo, sentamos las bases para el futuro desarrollo de mejores herramientas de IA en Investigación sanitaria y cientÃfica sobre los fundamentos del aprendizaje profundo
30th European Congress on Obesity (ECO 2023)
This is the abstract book of 30th European Congress on Obesity (ECO 2023
Seamless Multimodal Biometrics for Continuous Personalised Wellbeing Monitoring
Artificially intelligent perception is increasingly present in the lives of
every one of us. Vehicles are no exception, (...) In the near future, pattern
recognition will have an even stronger role in vehicles, as self-driving cars
will require automated ways to understand what is happening around (and within)
them and act accordingly. (...) This doctoral work focused on advancing
in-vehicle sensing through the research of novel computer vision and pattern
recognition methodologies for both biometrics and wellbeing monitoring. The
main focus has been on electrocardiogram (ECG) biometrics, a trait well-known
for its potential for seamless driver monitoring. Major efforts were devoted to
achieving improved performance in identification and identity verification in
off-the-person scenarios, well-known for increased noise and variability. Here,
end-to-end deep learning ECG biometric solutions were proposed and important
topics were addressed such as cross-database and long-term performance,
waveform relevance through explainability, and interlead conversion. Face
biometrics, a natural complement to the ECG in seamless unconstrained
scenarios, was also studied in this work. The open challenges of masked face
recognition and interpretability in biometrics were tackled in an effort to
evolve towards algorithms that are more transparent, trustworthy, and robust to
significant occlusions. Within the topic of wellbeing monitoring, improved
solutions to multimodal emotion recognition in groups of people and
activity/violence recognition in in-vehicle scenarios were proposed. At last,
we also proposed a novel way to learn template security within end-to-end
models, dismissing additional separate encryption processes, and a
self-supervised learning approach tailored to sequential data, in order to
ensure data security and optimal performance. (...)Comment: Doctoral thesis presented and approved on the 21st of December 2022
to the University of Port
Workshop Proceedings of the 12th edition of the KONVENS conference
The 2014 issue of KONVENS is even more a forum for exchange: its main topic is the interaction between Computational Linguistics and Information Science, and the synergies such interaction, cooperation and integrated views can produce. This topic at the crossroads of different research traditions which deal with natural language as a container of knowledge, and with methods to extract and manage knowledge that is linguistically represented is close to the heart of many researchers at the Institut für Informationswissenschaft und Sprachtechnologie of Universität Hildesheim: it has long been one of the institute’s research topics, and it has received even more attention over the last few years
A Novel Information-Theoretic Objective to Disentangle Representations for Fair Classification
One of the pursued objectives of deep learning is to provide tools that learn
abstract representations of reality from the observation of multiple contextual
situations. More precisely, one wishes to extract disentangled representations
which are (i) low dimensional and (ii) whose components are independent and
correspond to concepts capturing the essence of the objects under consideration
(Locatello et al., 2019b). One step towards this ambitious project consists in
learning disentangled representations with respect to a predefined (sensitive)
attribute, e.g., the gender or age of the writer. Perhaps one of the main
application for such disentangled representations is fair classification.
Existing methods extract the last layer of a neural network trained with a loss
that is composed of a cross-entropy objective and a disentanglement
regularizer. In this work, we adopt an information-theoretic view of this
problem which motivates a novel family of regularizers that minimizes the
mutual information between the latent representation and the sensitive
attribute conditional to the target. The resulting set of losses, called
CLINIC, is parameter free and thus, it is easier and faster to train. CLINIC
losses are studied through extensive numerical experiments by training over 2k
neural networks. We demonstrate that our methods offer a better
disentanglement/accuracy trade-off than previous techniques, and generalize
better than training with cross-entropy loss solely provided that the
disentanglement task is not too constraining.Comment: Findings AACL 202
Measuring the impact of COVID-19 on hospital care pathways
Care pathways in hospitals around the world reported significant disruption during the recent COVID-19 pandemic but measuring the actual impact is more problematic. Process mining can be useful for hospital management to measure the conformance of real-life care to what might be considered normal operations. In this study, we aim to demonstrate that process mining can be used to investigate process changes associated with complex disruptive events. We studied perturbations to accident and emergency (A &E) and maternity pathways in a UK public hospital during the COVID-19 pandemic. Co-incidentally the hospital had implemented a Command Centre approach for patient-flow management affording an opportunity to study both the planned improvement and the disruption due to the pandemic. Our study proposes and demonstrates a method for measuring and investigating the impact of such planned and unplanned disruptions affecting hospital care pathways. We found that during the pandemic, both A &E and maternity pathways had measurable reductions in the mean length of stay and a measurable drop in the percentage of pathways conforming to normative models. There were no distinctive patterns of monthly mean values of length of stay nor conformance throughout the phases of the installation of the hospital’s new Command Centre approach. Due to a deficit in the available A &E data, the findings for A &E pathways could not be interpreted
CompA: Addressing the Gap in Compositional Reasoning in Audio-Language Models
A fundamental characteristic of audio is its compositional nature.
Audio-language models (ALMs) trained using a contrastive approach (e.g., CLAP)
that learns a shared representation between audio and language modalities have
improved performance in many downstream applications, including zero-shot audio
classification, audio retrieval, etc. However, the ability of these models to
effectively perform compositional reasoning remains largely unexplored and
necessitates additional research. In this paper, we propose CompA, a collection
of two expert-annotated benchmarks with a majority of real-world audio samples,
to evaluate compositional reasoning in ALMs. Our proposed CompA-order evaluates
how well an ALM understands the order or occurrence of acoustic events in
audio, and CompA-attribute evaluates attribute binding of acoustic events. An
instance from either benchmark consists of two audio-caption pairs, where both
audios have the same acoustic events but with different compositions. An ALM is
evaluated on how well it matches the right audio to the right caption. Using
this benchmark, we first show that current ALMs perform only marginally better
than random chance, thereby struggling with compositional reasoning. Next, we
propose CompA-CLAP, where we fine-tune CLAP using a novel learning method to
improve its compositional reasoning abilities. To train CompA-CLAP, we first
propose improvements to contrastive training with composition-aware hard
negatives, allowing for more focused training. Next, we propose a novel modular
contrastive loss that helps the model learn fine-grained compositional
understanding and overcomes the acute scarcity of openly available
compositional audios. CompA-CLAP significantly improves over all our baseline
models on the CompA benchmark, indicating its superior compositional reasoning
capabilities.Comment: Pre-print under revie
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