Oceania
Towards Knowledgeable Supervised Lifelong Learning Systems
Benavides-Prado, Diana (The University of Auckland) | Koh, Yun Sing | Riddle, Patricia
Learning a sequence of tasks is a long-standing challenge in machine learning. This setting applies to learning systems that observe examples of a range of tasks at different points in time. A learning system should become more knowledgeable as more related tasks are learned. Although the problem of learning sequentially was acknowledged for the first time decades ago, the research in this area has been rather limited. Research in transfer learning, multitask learning, metalearning and deep learning has studied some challenges of these kinds of systems. Recent research in lifelong machine learning and continual learning has revived interest in this problem. We propose Proficiente, a full framework for long-term learning systems. Proficiente relies on knowledge transferred between hypotheses learned with Support Vector Machines. The first component of the framework is focused on transferring forward selectively from a set of existing hypotheses or functions representing knowledge acquired during previous tasks to a new target task. A second component of Proficiente is focused on transferring backward, a novel ability of long-term learning systems that aim to exploit knowledge derived from recent tasks to encourage refinement of existing knowledge. We propose a method that transfers selectively from a task learned recently to existing hypotheses representing previous tasks. The method encourages retention of existing knowledge whilst refining. We analyse the theoretical properties of the proposed framework. Proficiente is accompanied by an agnostic metric that can be used to determine if a long-term learning system is becoming more knowledgeable. We evaluate Proficiente in both synthetic and real-world datasets, and demonstrate scenarios where knowledgeable supervised learning systems can be achieved by means of transfer.
Australian military gets first drone that can fly with artificial intelligence
Hong Kong (CNN)Australia has its first "loyal wingman." Boeing Australia presented the country's Air Force on Tuesday with a prototype of a jet-powered drone that they hope will one day fly alongside manned warplanes while bringing artificial intelligence to the battlefield. The Loyal Wingman, at 38-foot-long (11.5 meters) and with a range of 2,000 miles (3,218.6 kilometers), will "use artificial intelligence to fly independently, or in support of manned aircraft, while maintaining safe distance between other aircraft," according to Boeing's website on the project. The drones will be able to engage in electronic warfare as well as intelligence, reconnaissance and surveillance missions and swap quickly between those roles, according to Boeing. The aircraft delivered in Sydney on Tuesday is the first of three prototypes Boeing is producing.
A Global Benchmark of Algorithms for Segmenting Late Gadolinium-Enhanced Cardiac Magnetic Resonance Imaging
Xiong, Zhaohan, Xia, Qing, Hu, Zhiqiang, Huang, Ning, Bian, Cheng, Zheng, Yefeng, Vesal, Sulaiman, Ravikumar, Nishant, Maier, Andreas, Yang, Xin, Heng, Pheng-Ann, Ni, Dong, Li, Caizi, Tong, Qianqian, Si, Weixin, Puybareau, Elodie, Khoudli, Younes, Geraud, Thierry, Chen, Chen, Bai, Wenjia, Rueckert, Daniel, Xu, Lingchao, Zhuang, Xiahai, Luo, Xinzhe, Jia, Shuman, Sermesant, Maxime, Liu, Yashu, Wang, Kuanquan, Borra, Davide, Masci, Alessandro, Corsi, Cristiana, de Vente, Coen, Veta, Mitko, Karim, Rashed, Preetha, Chandrakanth Jayachandran, Engelhardt, Sandy, Qiao, Menyun, Wang, Yuanyuan, Tao, Qian, Nunez-Garcia, Marta, Camara, Oscar, Savioli, Nicolo, Lamata, Pablo, Zhao, Jichao
Segmentation of cardiac images, particularly late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) widely used for visualizing diseased cardiac structures, is a crucial first step for clinical diagnosis and treatment. However, direct segmentation of LGE-MRIs is challenging due to its attenuated contrast. Since most clinical studies have relied on manual and labor-intensive approaches, automatic methods are of high interest, particularly optimized machine learning approaches. To address this, we organized the "2018 Left Atrium Segmentation Challenge" using 154 3D LGE-MRIs, currently the world's largest cardiac LGE-MRI dataset, and associated labels of the left atrium segmented by three medical experts, ultimately attracting the participation of 27 international teams. In this paper, extensive analysis of the submitted algorithms using technical and biological metrics was performed by undergoing subgroup analysis and conducting hyper-parameter analysis, offering an overall picture of the major design choices of convolutional neural networks (CNNs) and practical considerations for achieving state-of-the-art left atrium segmentation. Results show the top method achieved a dice score of 93.2% and a mean surface to a surface distance of 0.7 mm, significantly outperforming prior state-of-the-art. Particularly, our analysis demonstrated that double, sequentially used CNNs, in which a first CNN is used for automatic region-of-interest localization and a subsequent CNN is used for refined regional segmentation, achieved far superior results than traditional methods and pipelines containing single CNNs. This large-scale benchmarking study makes a significant step towards much-improved segmentation methods for cardiac LGE-MRIs, and will serve as an important benchmark for evaluating and comparing the future works in the field.
Predictive Modeling of ICU Healthcare-Associated Infections from Imbalanced Data. Using Ensembles and a Clustering-Based Undersampling Approach
Sánchez-Hernández, Fernando, Ballesteros-Herráez, Juan Carlos, Kraiem, Mohamed S., Sánchez-Barba, Mercedes, Moreno-García, María N.
Early detection of patients vulnerable to infections acquired in the hospital environment is a challenge in current health systems given the impact that such infections have on patient mortality and healthcare costs. This work is focused on both the identification of risk factors and the prediction of healthcare-associated infections in intensive-care units by means of machine-learning methods. The aim is to support decision making addressed at reducing the incidence rate of infections. In this field, it is necessary to deal with the problem of building reliable classifiers from imbalanced datasets. We propose a clustering-based undersampling strategy to be used in combination with ensemble classifiers. A comparative study with data from 4616 patients was conducted in order to validate our proposal. We applied several single and ensemble classifiers both to the original dataset and to data preprocessed by means of different resampling methods. The results were analyzed by means of classic and recent metrics specifically designed for imbalanced data classification. They revealed that the proposal is more efficient in comparison with other approaches.
Variance Constrained Autoencoding
Braithwaite, D. T., O'Connor, M., Kleijn, W. B.
Recent state-of-the-art autoencoder based generative models have an encoder-decoder structure and learn a latent representation with a pre-defined distribution that can be sampled from. Implementing the encoder networks of these models in a stochastic manner provides a natural and common approach to avoid overfitting and enforce a smooth decoder function. However, we show that for stochastic encoders, simultaneously attempting to enforce a distribution constraint and minimising an output distortion leads to a reduction in generative and reconstruction quality. In addition, attempting to enforce a latent distribution constraint is not reasonable when performing disentanglement. Hence, we propose the variance-constrained autoencoder (VCAE), which only enforces a variance constraint on the latent distribution. Our experiments show that VCAE improves upon Wasserstein Autoencoder and the Variational Autoencoder in both reconstruction and generative quality on MNIST and CelebA. Moreover, we show that VCAE equipped with a total correlation penalty term performs equivalently to FactorVAE at learning disentangled representations on 3D-Shapes while being a more principled approach.
Can a powerful neural network be a teacher for a weaker neural network?
Landro, Nicola, Gallo, Ignazio, La Grassa, Riccardo
The transfer learning technique is widely used to learning in one context and applying it to another, i.e. the capacity to apply acquired knowledge and skills to new situations. But is it possible to transfer the learning from a deep neural network to a weaker neural network? Is it possible to improve the performance of a weak neural network using the knowledge acquired by a more powerful neural network? In this work, during the training process of a weak network, we add a loss function that minimizes the distance between the features previously learned from a strong neural network with the features that the weak network must try to learn. To demonstrate the effectiveness and robustness of our approach, we conducted a large number of experiments using three known datasets and demonstrated that a weak neural network can increase its performance if its learning process is driven by a more powerful neural network.
Detecting sudden and gradual drifts in business processes from execution traces
Maaradji, Abderrahmane, Dumas, Marlon, La Rosa, Marcello, Ostovar, Alireza
Business processes are prone to unexpected changes, as process workers may suddenly or gradually start executing a process differently in order to adjust to changes in workload, season, or other external factors. Early detection of business process changes enables managers to identify and act upon changes that may otherwise affect process performance. Business process drift detection refers to a family of methods to detect changes in a business process by analyzing event logs extracted from the systems that support the execution of the process. Existing methods for business process drift detection are based on an explorative analysis of a potentially large feature space and in some cases they require users to manually identify specific features that characterize the drift. Depending on the explored feature space, these methods miss various types of changes. Moreover, they are either designed to detect sudden drifts or gradual drifts but not both. This paper proposes an automated and statistically grounded method for detecting sudden and gradual business process drifts under a unified framework. An empirical evaluation shows that the method detects typical change patterns with significantly higher accuracy and lower detection delay than existing methods, while accurately distinguishing between sudden and gradual drifts.
Does Imagenet Pretraining work for Chest Radiography Images(COVID-19)?
An enemy with which we are befuddled. And unless you were living under a rock for the past couple of months(like Jared Leto), you know what I'm talking about – COVID-19. Whether you turn on the news, or scroll through social media, the majority of information that you take in nowadays is about the SARS-COV2 virus, or the Novel Corona Virus. But among all the negativity, there was a sliver of light shining through. When faced with a common enemy, mankind united across borders(for the most part; there are bad apples always) to help each other tide over the current assault. Scientists, who are the heroes of the day, doubled down to find a cure, vaccine, and a million other things which helps in the battle against COVID-19.
The story of Draganfly's 'pandemic drone' - DroneDJ
If anyone knows the name "Draganfly," it may be from an unfortunate news story from last week. The Canadian company's plan to test a coronavirus-monitoring "pandemic drone" in Westport, Connecticut, came to a halt when anxious citizens and civil rights advocates got wind of it. But that was just one town. The company says it has many other takers, and that the pandemic drone is far from dead. News site VentureBeat has a great in-depth look at the drone company's COVID-19 work that is well worth a thorough read.
How COVID-19 is changing the future of eye care
The rapid uptake of telehealth services to stop the spread of coronavirus is adding impetus to research to develop innovative new ways of diagnosing and monitoring patients with eye disease. As the COVID-19 pandemic has spurred Australia's health care practitioners to replace many routine face-to-face appointments with phone or video consultations – telehealth has moved into the mainstream. CERA researchers are leading major projects to develop innovative new diagnostic tools that can be used in the home or outside of traditional eye clinic settings. They predict the shift to telehealth services will continue to gather pace after the COVID-19 pandemic has ended. CERA Deputy Director Associate Professor Peter van Wijngaarden is leading research to develop a simple eye test to detect the early signs Alzheimer's disease.