Oceania
Automatic Forecasting using Gaussian Processes
Corani, Giorgio, Benavoli, Alessio, Augusto, Joao, Zaffalon, Marco
Automatic forecasting is the task of receiving a time series and returning a forecast for the next time steps without any human intervention. We propose an approach for automatic forecasting based on Gaussian Processes (GPs). So far, the main limits of GPs on this task have been the lack of a criterion for the selection of the kernel and the long times required for training different competing kernels. We design a fixed additive kernel, which contains the components needed to model most time series. During training the unnecessary components are made irrelevant by automatic relevance determination. We assign priors to each hyperparameter. We design the priors by analyzing a separate set of time series through a hierarchical GP. The resulting model performs very well on different types of time series, being competitive or outperforming the state-of-the-art approaches.Thanks to the priors, we reliably estimate the parameters with a single restart; this speedup makes the model efficient to train and suitable for processing a large number of time series.
Feds Charge Chinese Hackers With Ripping Off Video Game Loot From 9 Companies
For years, a group of Chinese hackers known variously as Barium, Winnti, or APT41 has carried out a unique mix of sophisticated hacking activities that has puzzled the cybersecurity researchers tracking them. At times they appear focused on the usual state-sponsored espionage, believed to be working in the service of the Chinese Ministry of State Security. At other times their attacks looked more like traditional cybercrime. Now a set of federal indictments has called out those intruders by name, and cast their activities in a new light. Five Chinese hackers are accused of a sprawling scheme to break into the networks of hundreds of global companies in a broad range of industries, as well as think tanks, universities, foreign government agencies, and the accounts of Hong Kong government officials and pro-democracy activists.
The best-paid jobs for women
If you're looking for jobs that are trending for women right now, then careers with a technical focus are where it's at. But if you want the highest paying jobs, then health still has it. According to the latest data from the Australian Tax Office for 2017–18, seven of the top 10 highest paid occupations for women went to highly skilled careers in the medical profession. Among these the average female anaesthetist earned $314,306 a year, while the average female neurosurgeon took home $308,329. Female plastic and reconstructive surgeons earned $302,329, female gynaecologists $301,431 and female cardiologists $290,932. More from Financy: 'Demoralised': Women hit back over emergency super guilt By contrast, the average annual salary for women working across the healthcare sector stood at just $78,000 as of May, which is about the same amount as the average clinical female nurse earns a year.
AI Is Making Our Lives Better In Weird And Wonderful Ways, Here's How
When some people hear the term'artificial intelligence' their initial reaction is to imagine a dystopian future where robots have risen up and overthrown humanity. The truth is, application of AI technology in our day-to-day lives is a lot less sinister. It might not be long before these technologies become common in our everyday lives. It's currently assisting with medical diagnosis, the creation of autonomous cars and to help improve businesses by analysing data and creating accurate forecasts of client or market behaviour. The application of AI is becoming more and more popular in businesses worldwide, with the potential to improve our lives in unexpected ways.
Improving Delay Based Reservoir Computing via Eigenvalue Analysis
Köster, Felix, Yanchuk, Serhiy, Lüdge, Kathy
We analyze the reservoir computation capability of the Lang-Kobayashi system by comparing the numerically computed recall capabilities and the eigenvalue spectrum. We show that these two quantities are deeply connected, and thus the reservoir computing performance is predictable by analyzing the eigenvalue spectrum. Our results suggest that any dynamical system used as a reservoir can be analyzed in this way as long as the reservoir perturbations are sufficiently small. Optimal performance is found for a system with the eigenvalues having real parts close to zero and off-resonant imaginary parts.
Brain tumour segmentation using cascaded 3D densely-connected U-net
Ghaffari, Mina, Sowmya, Arcot, Oliver, Ruth
Accurate brain tumour segmentation is a crucial step towards improving disease diagnosis and proper treatment planning. In this paper, we propose a deep-learning based method to segment a brain tumour into its subregions: whole tumour, tumour core and enhancing tumour. The proposed architecture is a 3D convolutional neural network based on a variant of the U-Net architecture of Ronneberger et al. [17] with three main modifications: (i) a heavy encoder, light decoder structure using residual blocks (ii) employment of dense blocks instead of skip connections, and (iii) utilization of self-ensembling in the decoder part of the network. The network was trained and tested using two different approaches: a multitask framework to segment all tumour subregions at the same time, and a three-stage cascaded framework to segment one subregion at a time. An ensemble of the results from both frameworks was also computed. To address the class imbalance issue, appropriate patch extraction was employed in a pre-processing step. Connected component analysis was utilized in the post-processing step to reduce the false positive predictions. Experimental results on the BraTS20 validation dataset demonstrates that the proposed model achieved average Dice Scores of 0.90, 0.82, and 0.78 for whole tumour, tumour core and enhancing tumour respectively. Keywords: Brain tumour segmentation, · Multimodal MRI, · Cascaded network, · Densely connected CNN.
GLUCOSE: GeneraLized and COntextualized Story Explanations
Mostafazadeh, Nasrin, Kalyanpur, Aditya, Moon, Lori, Buchanan, David, Berkowitz, Lauren, Biran, Or, Chu-Carroll, Jennifer
When humans read or listen, they make implicit commonsense inferences that frame their understanding of what happened and why. As a step toward AI systems that can build similar mental models, we introduce GLUCOSE, a large-scale dataset of implicit commonsense causal knowledge, encoded as causal mini-theories about the world, each grounded in a narrative context. To construct GLUCOSE, we drew on cognitive psychology to identify ten dimensions of causal explanation, focusing on events, states, motivations, and emotions. Each GLUCOSE entry includes a story-specific causal statement paired with an inference rule generalized from the statement. This paper details two concrete contributions: First, we present our platform for effectively crowdsourcing GLUCOSE data at scale, which uses semi-structured templates to elicit causal explanations. Using this platform, we collected 440K specific statements and general rules that capture implicit commonsense knowledge about everyday situations. Second, we show that existing knowledge resources and pretrained language models do not include or readily predict GLUCOSE's rich inferential content. However, when state-of-the-art neural models are trained on this knowledge, they can start to make commonsense inferences on unseen stories that match humans' mental models.
Minimize Exposure Bias of Seq2Seq Models in Joint Entity and Relation Extraction
Zhang, Haoran, Liu, Qianying, Fan, Aysa Xuemo, Ji, Heng, Zeng, Daojian, Cheng, Fei, Kawahara, Daisuke, Kurohashi, Sadao
Joint entity and relation extraction aims to extract relation triplets from plain text directly. Prior work leverages Sequence-to-Sequence (Seq2Seq) models for triplet sequence generation. However, Seq2Seq enforces an unnecessary order on the unordered triplets and involves a large decoding length associated with error accumulation. These introduce exposure bias, which may cause the models overfit to the frequent label combination, thus deteriorating the generalization. We propose a novel Sequence-to-Unordered-Multi-Tree (Seq2UMTree) model to minimize the effects of exposure bias by limiting the decoding length to three within a triplet and removing the order among triplets. We evaluate our model on two datasets, DuIE and NYT, and systematically study how exposure bias alters the performance of Seq2Seq models. Experiments show that the state-of-the-art Seq2Seq model overfits to both datasets while Seq2UMTree shows significantly better generalization. Our code is available at https://github.com/WindChimeRan/OpenJERE .
Incompatibilities Between Iterated and Relevance-Sensitive Belief Revision
Aravanis, Theofanis (University of Patras) | Peppas, Pavlos (University of Patras, Greece) | Williams, Mary-Anne (University of Technology Sydney, Australia)
The AGM paradigm for belief change, as originally introduced by Alchourrón, Gärdenfors and Makinson, lacks any guidelines for the process of iterated revision. One of the most influential work addressing this problem is Darwiche and Pearl's approach (DP approach, for short), which, despite its well-documented shortcomings, remains to this date the most dominant. In this article, we make further observations on the DP approach. In particular, we prove that the DP postulates are, in a strong sense, inconsistent with Parikh's relevance-sensitive axiom (P), extending previous initial conflicts. Immediate consequences of this result are that an entire class of intuitive revision operators, which includes Dalal's operator, violates the DP postulates, as well as that the Independence postulate and Spohn's conditionalization are inconsistent with axiom (P). The whole study, essentially, indicates that two fundamental aspects of the revision process, namely, iteration and relevance, are in deep conflict, and opens the discussion for a potential reconciliation towards a comprehensive formal framework for knowledge dynamics.
Transformer Based Multi-Source Domain Adaptation
Wright, Dustin, Augenstein, Isabelle
In practical machine learning settings, the data on which a model must make predictions often come from a different distribution than the data it was trained on. Here, we investigate the problem of unsupervised multi-source domain adaptation, where a model is trained on labelled data from multiple source domains and must make predictions on a domain for which no labelled data has been seen. Prior work with CNNs and RNNs has demonstrated the benefit of mixture of experts, where the predictions of multiple domain expert classifiers are combined; as well as domain adversarial training, to induce a domain agnostic representation space. Inspired by this, we investigate how such methods can be effectively applied to large pretrained transformer models. We find that domain adversarial training has an effect on the learned representations of these models while having little effect on their performance, suggesting that large transformer-based models are already relatively robust across domains. Additionally, we show that mixture of experts leads to significant performance improvements by comparing several variants of mixing functions, including one novel mixture based on attention. Finally, we demonstrate that the predictions of large pretrained transformer based domain experts are highly homogenous, making it challenging to learn effective functions for mixing their predictions.