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Latent Preserving Generative Adversarial Network for Imbalance classification

arXiv.org Artificial Intelligence

Many real-world classification problems have imbalanced frequency of class labels; a well-known issue known as the "class imbalance" problem. Classic classification algorithms tend to be biased towards the majority class, leaving the classifier vulnerable to misclassification of the minority class. While the literature is rich with methods to fix this problem, as the dimensionality of the problem increases, many of these methods do not scale-up and the cost of running them become prohibitive. In this paper, we present an end-to-end deep generative classifier. We propose a domain-constraint autoencoder to preserve the latent-space as prior for a generator, which is then used to play an adversarial game with two other deep networks, a discriminator and a classifier. Extensive experiments are carried out on three different multi-class imbalanced problems and a comparison with state-of-the-art methods. Experimental results confirmed the superiority of our method over popular algorithms in handling high-dimensional imbalanced classification problems. Our code is available on https://github.com/TanmDL/SLPPL-GAN.


Autonomous Delivery of Multiple Packages Using Single Drone in Urban Airspace

arXiv.org Artificial Intelligence

Examples of these applications include public security, remote sensing, surveillance, photography, and delivery of goods [2]. The continual growth of e-commerce, especially during the COVID-19 pandemic, has revolutionized the way customers acquire goods and services [3]. The ubiquity of drones in the sky has prompted an increasing interest of several e-commerce companies such as UPS, Flytrex, and Amazon Prime Air to use drones for package delivery [4]. Several countries have used drones for safe and contactless deliveries during the pandemic lockdowns [5]. Drone delivery is highly desired in urban areas to reduce delivery time and traffic congestion on roads by utilizing urban airspace [6]. The recent developments in drone technology show that drones can carry multiple packages [7]. Therefore, a drone can serve more than one customer in one trip.


ProBoost: a Boosting Method for Probabilistic Classifiers

arXiv.org Artificial Intelligence

ProBoost, a new boosting algorithm for probabilistic classifiers, is proposed in this work. This algorithm uses the epistemic uncertainty of each training sample to determine the most challenging/uncertain ones; the relevance of these samples is then increased for the next weak learner, producing a sequence that progressively focuses on the samples found to have the highest uncertainty. In the end, the weak learners' outputs are combined into a weighted ensemble of classifiers. Three methods are proposed to manipulate the training set: undersampling, oversampling, and weighting the training samples according to the uncertainty estimated by the weak learners. Furthermore, two approaches are studied regarding the ensemble combination. The weak learner herein considered is a standard convolutional neural network, and the probabilistic models underlying the uncertainty estimation use either variational inference or Monte Carlo dropout. The experimental evaluation carried out on MNIST benchmark datasets shows that ProBoost yields a significant performance improvement. The results are further highlighted by assessing the relative achievable improvement, a metric proposed in this work, which shows that a model with only four weak learners leads to an improvement exceeding 12% in this metric (for either accuracy, sensitivity, or specificity), in comparison to the model learned without ProBoost.


An overview of deep learning techniques for epileptic seizures detection and prediction based on neuroimaging modalities: Methods, challenges, and future works

arXiv.org Artificial Intelligence

Epilepsy is a disorder of the brain denoted by frequent seizures. The symptoms of seizure include confusion, abnormal staring, and rapid, sudden, and uncontrollable hand movements. Epileptic seizure detection methods involve neurological exams, blood tests, neuropsychological tests, and neuroimaging modalities. Among these, neuroimaging modalities have received considerable attention from specialist physicians. One method to facilitate the accurate and fast diagnosis of epileptic seizures is to employ computer-aided diagnosis systems (CADS) based on deep learning (DL) and neuroimaging modalities. This paper has studied a comprehensive overview of DL methods employed for epileptic seizures detection and prediction using neuroimaging modalities. First, DL-based CADS for epileptic seizures detection and prediction using neuroimaging modalities are discussed. Also, descriptions of various datasets, preprocessing algorithms, and DL models which have been used for epileptic seizures detection and prediction have been included. Then, research on rehabilitation tools has been presented, which contains brain-computer interface (BCI), cloud computing, internet of things (IoT), hardware implementation of DL techniques on field-programmable gate array (FPGA), etc. In the discussion section, a comparison has been carried out between research on epileptic seizure detection and prediction. The challenges in epileptic seizures detection and prediction using neuroimaging modalities and DL models have been described. In addition, possible directions for future works in this field, specifically for solving challenges in datasets, DL, rehabilitation, and hardware models, have been proposed. The final section is dedicated to the conclusion which summarizes the significant findings of the paper.


ASTra: A Novel Algorithm-Level Approach to Imbalanced Classification

arXiv.org Artificial Intelligence

This paper addresses the challenge of handling extreme class imbalance, defined here as a situation in which negative examples, conventionally the majority, outnumber positive examples, usually the ones of most interest, by a factor of 500 or more (in other words, have an imbalance ratio (IR) 500). Such problems are not in fact uncommon, and arise in application areas such as fraud detection [1] and cheminformatics [2]. We make use of two methods, that tackle different, but complementary, aspects of the class imbalance problem: ASTra, a novel, adaptive, asymmetric output layer activation function, which makes the correct classification of minority examples easier. A loss function based on an approximated confusion matrix, which aggressively targets the misclassification of minority examples. Our proposed methods have the advantage of being easy to implement and integrate into the workflow of any model that makes binary predictions normally generated by a sigmoid activation (transfer) function. In addition, the paper presents a new means of monitoring training and validation performance, especially valuable in cases of high class imbalance, that could potentially be used with any training regime, independently of the proposed methods.


Scalable Adversarial Online Continual Learning

arXiv.org Artificial Intelligence

Adversarial continual learning is effective for continual learning problems because of the presence of feature alignment process generating task-invariant features having low susceptibility to the catastrophic forgetting problem. Nevertheless, the ACL method imposes considerable complexities because it relies on task-specific networks and discriminators. It also goes through an iterative training process which does not fit for online (one-epoch) continual learning problems. This paper proposes a scalable adversarial continual learning (SCALE) method putting forward a parameter generator transforming common features into task-specific features and a single discriminator in the adversarial game to induce common features. The training process is carried out in meta-learning fashions using a new combination of three loss functions. SCALE outperforms prominent baselines with noticeable margins in both accuracy and execution time.


Rice Leaf Disease Classification and Detection Using YOLOv5

arXiv.org Artificial Intelligence

A staple food in more than a hundred nations worldwide is rice (Oryza sativa). The cultivation of rice is vital to global economic growth. However, the main issue facing the agricultural industry is rice leaf disease. The quality and quantity of the crops have declined, and this is the main cause. As farmers in any country do not have much knowledge about rice leaf disease, they cannot diagnose rice leaf disease properly. That's why they cannot take proper care of rice leaves. As a result, the production is decreasing. From literature survey, it has seen that YOLOv5 exhibit the better result compare to others deep learning method. As a result of the continual advancement of object detection technology, YOLO family algorithms, which have extraordinarily high precision and better speed have been used in various scene recognition tasks to build rice leaf disease monitoring systems. We have annotate 1500 collected data sets and propose a rice leaf disease classification and detection method based on YOLOv5 deep learning. We then trained and evaluated the YOLOv5 model. The simulation outcomes show improved object detection result for the augmented YOLOv5 network proposed in this article. The required levels of recognition precision, recall, mAP value, and F1 score are 90\%, 67\%, 76\%, and 81\% respectively are considered as performance metrics.


Conditional Independence Testing via Latent Representation Learning

arXiv.org Artificial Intelligence

Detecting conditional independencies plays a key role in several statistical and machine learning tasks, especially in causal discovery algorithms. In this study, we introduce LCIT (Latent representation based Conditional Independence Test)-a novel non-parametric method for conditional independence testing based on representation learning. Our main contribution involves proposing a generative framework in which to test for the independence between X and Y given Z, we first learn to infer the latent representations of target variables X and Y that contain no information about the conditioning variable Z. The latent variables are then investigated for any significant remaining dependencies, which can be performed using the conventional partial correlation test. The empirical evaluations show that LCIT outperforms several state-of-the-art baselines consistently under different evaluation metrics, and is able to adapt really well to both non-linear and high-dimensional settings on a diverse collection of synthetic and real data sets.


Decoupled Dynamic Spatial-Temporal Graph Neural Network for Traffic Forecasting

arXiv.org Artificial Intelligence

We all depend on mobility, and vehicular transportation affects the daily lives of most of us. Thus, the ability to forecast the state of traffic in a road network is an important functionality and a challenging task. Traffic data is often obtained from sensors deployed in a road network. Recent proposals on spatial-temporal graph neural networks have achieved great progress at modeling complex spatial-temporal correlations in traffic data, by modeling traffic data as a diffusion process. However, intuitively, traffic data encompasses two different kinds of hidden time series signals, namely the diffusion signals and inherent signals. Unfortunately, nearly all previous works coarsely consider traffic signals entirely as the outcome of the diffusion, while neglecting the inherent signals, which impacts model performance negatively. To improve modeling performance, we propose a novel Decoupled Spatial-Temporal Framework (DSTF) that separates the diffusion and inherent traffic information in a data-driven manner, which encompasses a unique estimation gate and a residual decomposition mechanism. The separated signals can be handled subsequently by the diffusion and inherent modules separately. Further, we propose an instantiation of DSTF, Decoupled Dynamic Spatial-Temporal Graph Neural Network (D2STGNN), that captures spatial-temporal correlations and also features a dynamic graph learning module that targets the learning of the dynamic characteristics of traffic networks. Extensive experiments with four real-world traffic datasets demonstrate that the framework is capable of advancing the state-of-the-art.


Machine learning model uses social media for more accurate wildfire monitoring

#artificialintelligence

Scientists have developed a new machine learning model that uses social media data to predict and monitor wildfires more accurately in real-time. Data scientists from Imperial's Data Science Institute used machine learning - a subfield of artificial intelligence where computers learn from data and statistics, in a wildfire prediction model. In this new model, they combined social media data and geophysical satellite data to predict wildfire characteristics with high accuracy. The study, published in the Journal of Computational Social Science, demonstrates how social media could be key to making more informed, socially driven decisions which could help disaster management teams to identify areas of immediate danger. The intensity of wildfires and wildfire season length is increasing due to climate change, causing greater threats to populations worldwide.