14,346 research outputs found
Audio-visual multi-modality driven hybrid feature learning model for crowd analysis and classification
The high pace emergence in advanced software systems, low-cost hardware and decentralized cloud computing technologies have broadened the horizon for vision-based surveillance, monitoring and control. However, complex and inferior feature learning over visual artefacts or video streams, especially under extreme conditions confine majority of the at-hand vision-based crowd analysis and classification systems. Retrieving event-sensitive or crowd-type sensitive spatio-temporal features for the different crowd types under extreme conditions is a highly complex task. Consequently, it results in lower accuracy and hence low reliability that confines existing methods for real-time crowd analysis. Despite numerous efforts in vision-based approaches, the lack of acoustic cues often creates ambiguity in crowd classification. On the other hand, the strategic amalgamation of audio-visual features can enable accurate and reliable crowd analysis and classification. Considering it as motivation, in this research a novel audio-visual multi-modality driven hybrid feature learning model is developed for crowd analysis and classification. In this work, a hybrid feature extraction model was applied to extract deep spatio-temporal features by using Gray-Level Co-occurrence Metrics (GLCM) and AlexNet transferrable learning model. Once extracting the different GLCM features and AlexNet deep features, horizontal concatenation was done to fuse the different feature sets. Similarly, for acoustic feature extraction, the audio samples (from the input video) were processed for static (fixed size) sampling, pre-emphasis, block framing and Hann windowing, followed by acoustic feature extraction like GTCC, GTCC-Delta, GTCC-Delta-Delta, MFCC, Spectral Entropy, Spectral Flux, Spectral Slope and Harmonics to Noise Ratio (HNR). Finally, the extracted audio-visual features were fused to yield a composite multi-modal feature set, which is processed for classification using the random forest ensemble classifier. The multi-class classification yields a crowd-classification accurac12529y of (98.26%), precision (98.89%), sensitivity (94.82%), specificity (95.57%), and F-Measure of 98.84%. The robustness of the proposed multi-modality-based crowd analysis model confirms its suitability towards real-world crowd detection and classification tasks
Protein-DNA binding sites prediction based on pre-trained protein language model and contrastive learning
Protein-DNA interaction is critical for life activities such as replication,
transcription, and splicing. Identifying protein-DNA binding residues is
essential for modeling their interaction and downstream studies. However,
developing accurate and efficient computational methods for this task remains
challenging. Improvements in this area have the potential to drive novel
applications in biotechnology and drug design. In this study, we propose a
novel approach called CLAPE, which combines a pre-trained protein language
model and the contrastive learning method to predict DNA binding residues. We
trained the CLAPE-DB model on the protein-DNA binding sites dataset and
evaluated the model performance and generalization ability through various
experiments. The results showed that the AUC values of the CLAPE-DB model on
the two benchmark datasets reached 0.871 and 0.881, respectively, indicating
superior performance compared to other existing models. CLAPE-DB showed better
generalization ability and was specific to DNA-binding sites. In addition, we
trained CLAPE on different protein-ligand binding sites datasets, demonstrating
that CLAPE is a general framework for binding sites prediction. To facilitate
the scientific community, the benchmark datasets and codes are freely available
at https://github.com/YAndrewL/clape
Continual Learning, Fast and Slow
According to the Complementary Learning Systems (CLS)
theory~\cite{mcclelland1995there} in neuroscience, humans do effective
\emph{continual learning} through two complementary systems: a fast learning
system centered on the hippocampus for rapid learning of the specifics,
individual experiences; and a slow learning system located in the neocortex for
the gradual acquisition of structured knowledge about the environment.
Motivated by this theory, we propose \emph{DualNets} (for Dual Networks), a
general continual learning framework comprising a fast learning system for
supervised learning of pattern-separated representation from specific tasks and
a slow learning system for representation learning of task-agnostic general
representation via Self-Supervised Learning (SSL). DualNets can seamlessly
incorporate both representation types into a holistic framework to facilitate
better continual learning in deep neural networks. Via extensive experiments,
we demonstrate the promising results of DualNets on a wide range of continual
learning protocols, ranging from the standard offline, task-aware setting to
the challenging online, task-free scenario. Notably, on the
CTrL~\cite{veniat2020efficient} benchmark that has unrelated tasks with vastly
different visual images, DualNets can achieve competitive performance with
existing state-of-the-art dynamic architecture
strategies~\cite{ostapenko2021continual}. Furthermore, we conduct comprehensive
ablation studies to validate DualNets efficacy, robustness, and scalability.
Code will be made available at \url{https://github.com/phquang/DualNet}.Comment: arXiv admin note: substantial text overlap with arXiv:2110.0017
Designing a Direct Feedback Loop between Humans and Convolutional Neural Networks through Local Explanations
The local explanation provides heatmaps on images to explain how
Convolutional Neural Networks (CNNs) derive their output. Due to its visual
straightforwardness, the method has been one of the most popular explainable AI
(XAI) methods for diagnosing CNNs. Through our formative study (S1), however,
we captured ML engineers' ambivalent perspective about the local explanation as
a valuable and indispensable envision in building CNNs versus the process that
exhausts them due to the heuristic nature of detecting vulnerability. Moreover,
steering the CNNs based on the vulnerability learned from the diagnosis seemed
highly challenging. To mitigate the gap, we designed DeepFuse, the first
interactive design that realizes the direct feedback loop between a user and
CNNs in diagnosing and revising CNN's vulnerability using local explanations.
DeepFuse helps CNN engineers to systemically search "unreasonable" local
explanations and annotate the new boundaries for those identified as
unreasonable in a labor-efficient manner. Next, it steers the model based on
the given annotation such that the model doesn't introduce similar mistakes. We
conducted a two-day study (S2) with 12 experienced CNN engineers. Using
DeepFuse, participants made a more accurate and "reasonable" model than the
current state-of-the-art. Also, participants found the way DeepFuse guides
case-based reasoning can practically improve their current practice. We provide
implications for design that explain how future HCI-driven design can move our
practice forward to make XAI-driven insights more actionable.Comment: 32 pages, 6 figures, 5 tables. Accepted for publication in the
Proceedings of the ACM on Human-Computer Interaction (PACM HCI), CSCW 202
Automatic Caption Generation for Aerial Images: A Survey
Aerial images have attracted attention from researcher community since long time. Generating a caption for an aerial image describing its content in comprehensive way is less studied but important task as it has applications in agriculture, defence, disaster management and many more areas. Though different approaches were followed for natural image caption generation, generating a caption for aerial image remains a challenging task due to its special nature. Use of emerging techniques from Artificial Intelligence (AI) and Natural Language Processing (NLP) domains have resulted in generation of accepted quality captions for aerial images. However lot needs to be done to fully utilize potential of aerial image caption generation task. This paper presents detail survey of the various approaches followed by researchers for aerial image caption generation task. The datasets available for experimentation, criteria used for performance evaluation and future directions are also discussed
Joint Dropout: Improving Generalizability in Low-Resource Neural Machine Translation through Phrase Pair Variables
Despite the tremendous success of Neural Machine Translation (NMT), its
performance on low-resource language pairs still remains subpar, partly due to
the limited ability to handle previously unseen inputs, i.e., generalization.
In this paper, we propose a method called Joint Dropout, that addresses the
challenge of low-resource neural machine translation by substituting phrases
with variables, resulting in significant enhancement of compositionality, which
is a key aspect of generalization. We observe a substantial improvement in
translation quality for language pairs with minimal resources, as seen in BLEU
and Direct Assessment scores. Furthermore, we conduct an error analysis, and
find Joint Dropout to also enhance generalizability of low-resource NMT in
terms of robustness and adaptability across different domainsComment: Accepted at MT Summit 202
Fault diagnosis in aircraft fuel system components with machine learning algorithms
There is a high demand and interest in considering the social and environmental effects of the component’s lifespan. Aircraft are one of the most high-priced
businesses that require the highest reliability and safety constraints. The complexity of aircraft systems designs also has advanced rapidly in the last decade. Consequently, fault detection, diagnosis and modification/ repair procedures are becoming more challenging. The presence of a fault within an aircraft system can result in changes to system performances and cause operational downtime or accidents in a worst-case scenario.
The CBM method that predicts the state of the equipment based on data collected is widely used in aircraft MROs. CBM uses diagnostics and prognostics models
to make decisions on appropriate maintenance actions based on the Remaining Useful Life (RUL) of the components.
The aircraft fuel system is a crucial system of aircraft, even a minor failure in the fuel system can affect the aircraft's safety greatly. A failure in the fuel system that
impacts the ability to deliver fuel to the engine will have an immediate effect on system performance and safety. There are very few diagnostic systems that
monitor the health of the fuel system and even fewer that can contain detected faults. The fuel system is crucial for the operation of the aircraft, in case of failure,
the fuel in the aircraft will become unusable/unavailable to reach the destination.
It is necessary to develop fault detection of the aircraft fuel system. The future aircraft fuel system must have the function of fault detection. Through the information of sensors and Machine Learning Techniques, the aircraft fuel system’s fault type can be detected in a timely manner.
This thesis discusses the application of a Data-driven technique to analyse the healthy and faulty data collected using the aircraft fuel system model, which is
similar to Boeing-777. The data is collected is processed through Machine learning Techniques and the results are comparedPhD in Manufacturin
Improving diagnostic procedures for epilepsy through automated recording and analysis of patients’ history
Transient loss of consciousness (TLOC) is a time-limited state of profound cognitive impairment characterised by amnesia, abnormal motor control, loss of responsiveness, a short duration and complete recovery. Most instances of TLOC are caused by one of three health conditions: epilepsy, functional (dissociative) seizures (FDS), or syncope. There is often a delay before the correct diagnosis is made and 10-20% of individuals initially receive an incorrect diagnosis. Clinical decision tools based on the endorsement of TLOC symptom lists have been limited to distinguishing between two causes of TLOC. The Initial Paroxysmal Event Profile (iPEP) has shown promise but was demonstrated to have greater accuracy in distinguishing between syncope and epilepsy or FDS than between epilepsy and FDS. The objective of this thesis was to investigate whether interactional, linguistic, and communicative differences in how people with epilepsy and people with FDS describe their experiences of TLOC can improve the predictive performance of the iPEP. An online web application was designed that collected information about TLOC symptoms and medical history from patients and witnesses using a binary questionnaire and verbal interaction with a virtual agent. We explored potential methods of automatically detecting these communicative differences, whether the differences were present during an interaction with a VA, to what extent these automatically detectable communicative differences improve the performance of the iPEP, and the acceptability of the application from the perspective of patients and witnesses. The two feature sets that were applied to previous doctor-patient interactions, features designed to measure formulation effort or detect semantic differences between the two groups, were able to predict the diagnosis with an accuracy of 71% and 81%, respectively. Individuals with epilepsy or FDS provided descriptions of TLOC to the VA that were qualitatively like those observed in previous research. Both feature sets were effective predictors of the diagnosis when applied to the web application recordings (85.7% and 85.7%). Overall, the accuracy of machine learning models trained for the threeway classification between epilepsy, FDS, and syncope using the iPEP responses from patients that were collected through the web application was worse than the performance observed in previous research (65.8% vs 78.3%), but the performance was increased by the inclusion of features extracted from the spoken descriptions on TLOC (85.5%). Finally, most participants who provided feedback reported that the online application was acceptable. These findings suggest that it is feasible to differentiate between people with epilepsy and people with FDS using an automated analysis of spoken seizure descriptions. Furthermore, incorporating these features into a clinical decision tool for TLOC can improve the predictive performance by improving the differential diagnosis between these two health conditions. Future research should use the feedback to improve the design of the application and increase perceived acceptability of the approach
Beam scanning by liquid-crystal biasing in a modified SIW structure
A fixed-frequency beam-scanning 1D antenna based on Liquid Crystals (LCs) is designed for application in 2D scanning with lateral alignment. The 2D array environment imposes full decoupling of adjacent 1D antennas, which often conflicts with the LC requirement of DC biasing: the proposed design accommodates both. The LC medium is placed inside a Substrate Integrated Waveguide (SIW) modified to work as a Groove Gap Waveguide, with radiating slots etched on the upper broad wall, that radiates as a Leaky-Wave Antenna (LWA). This allows effective application of the DC bias voltage needed for tuning the LCs. At the same time, the RF field remains laterally confined, enabling the possibility to lay several antennas in parallel and achieve 2D beam scanning. The design is validated by simulation employing the actual properties of a commercial LC medium
Evaluation of different segmentation-based approaches for skin disorders from dermoscopic images
Treballs Finals de Grau d'Enginyeria Biomèdica. Facultat de Medicina i Ciències de la Salut. Universitat de Barcelona. Curs: 2022-2023. Tutor/Director: Sala Llonch, Roser, Mata Miquel, Christian, Munuera, JosepSkin disorders are the most common type of cancer in the world and the incident has been lately increasing over the past decades. Even with the most complex and advanced technologies, current image acquisition systems do not permit a reliable identification of the skin lesion by visual examination due to the challenging structure of the malignancy. This promotes the need for the implementation of automatic skin lesion segmentation methods in order to assist in physicians’ diagnostic when determining the lesion's region and to serve as a preliminary step for the classification of the skin lesion. Accurate and precise segmentation is crucial for a rigorous screening and monitoring of the disease's progression.
For the purpose of the commented concern, the present project aims to accomplish a state-of-the-art review about the most predominant conventional segmentation models for skin lesion segmentation, alongside with a market analysis examination. With the rise of automatic segmentation tools, a wide number of algorithms are currently being used, but many are the drawbacks when employing them for dermatological disorders due to the high-level presence of artefacts in the image acquired.
In light of the above, three segmentation techniques have been selected for the completion of the work: level set method, an algorithm combining GrabCut and k-means methods and an intensity automatic algorithm developed by Hospital Sant Joan de DĂ©u de Barcelona research group. In addition, a validation of their performance is conducted for a further implementation of them in clinical training. The proposals, together with the got outcomes, have been accomplished by means of a publicly available skin lesion image database
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