Oceania
Robust Deep Reinforcement Learning for Extractive Legal Summarization
Nguyen, Duy-Hung, Nguyen, Bao-Sinh, Nghiem, Nguyen Viet Dung, Le, Dung Tien, Khatun, Mim Amina, Nguyen, Minh-Tien, Le, Hung
Automatic summarization of legal texts is an important and still a challenging task since legal documents are often long and complicated with unusual structures and styles. Recent advances of deep models trained end-to-end with differentiable losses can well-summarize natural text, yet when applied to the legal domain, they show limited results. In this paper, we propose to use reinforcement learning to train current deep summarization models to improve their performance in the legal domain. To this end, we adopt proximal policy optimization methods and introduce novel reward functions that encourage the generation of candidate summaries satisfying both lexical and semantic criteria. We apply our method to training different summarization backbones and observe a consistent and significant performance gain across three public legal datasets.
Efficient Hierarchical Bayesian Inference for Spatio-temporal Regression Models in Neuroimaging
Hashemi, Ali, Gao, Yijing, Cai, Chang, Ghosh, Sanjay, Müller, Klaus-Robert, Nagarajan, Srikantan S., Haufe, Stefan
Several problems in neuroimaging and beyond require inference on the parameters of multi-task sparse hierarchical regression models. Examples include M/EEG inverse problems, neural encoding models for task-based fMRI analyses, and climate science. In these domains, both the model parameters to be inferred and the measurement noise may exhibit a complex spatio-temporal structure. Existing work either neglects the temporal structure or leads to computationally demanding inference schemes. Overcoming these limitations, we devise a novel flexible hierarchical Bayesian framework within which the spatio-temporal dynamics of model parameters and noise are modeled to have Kronecker product covariance structure. Inference in our framework is based on majorization-minimization optimization and has guaranteed convergence properties. Our highly efficient algorithms exploit the intrinsic Riemannian geometry of temporal autocovariance matrices. For stationary dynamics described by Toeplitz matrices, the theory of circulant embeddings is employed. We prove convex bounding properties and derive update rules of the resulting algorithms. On both synthetic and real neural data from M/EEG, we demonstrate that our methods lead to improved performance.
First AI white paper calls for major measures and investment in artificial intelligence research - NZ Herald
If New Zealand does not invest in artificial intelligence research, its AI capabilities will only be efficient software running in the cloud of large overseas companies, creating risk for the country's technology and data sovereignty independence. This is a conclusion of the first white paper issued by New Zealand's Artificial Intelligence Researchers Association, which says our universities and research institutes have very strong AI research with "huge breadth and potential". "It is imperative to create and invest in an AI ecosystem where industry and research organisations can work together more closely for the benefit of Aotearoa New Zealand," said the paper. AI was profoundly changing how people live and work, and its cumulative impact was likely to be comparable to transformative technologies such as electricity or the internet. "As a result it is imperative that we take a strategic approach to realising the potential benefits offered by AI and to protecting people against the potential risks," the paper said.
New Zealand First's AI White Paper Urges Investing in Artificial Intelligence Research
In terms of creating world-leading AI businesses, nurturing a pool of talented AI engineers, applying AI technologies to our government, agriculture, manufacturing, and service industries, and holding a meaningful national debate on the broader implications for society, the rapid development of AI technologies presents major opportunities and challenges for New Zealand. Hence, New Zealand must engage actively with AI now to ensure its future success. If New Zealand does not invest in artificial intelligence research, its AI capabilities will be limited to efficient software running on the clouds of giant multinational corporations, jeopardising the country's technological and data sovereignty. This was confirmed in the publication of New Zealand's first white paper, which claims that the country's universities and research institutes have "great breadth and potential" in AI research. The white paper recognised the importance of AI and emphasised the importance of establishing and investing in an AI ecosystem in which industry and research organisations can collaborate more closely for the benefit of Aotearoa New Zealand.
Flexible Bayesian Nonlinear Model Configuration
Hubin, Aliaksandr | Storvik, Geir (University of Oslo) | Frommlet, Florian (Medical University of Vienna)
Regression models are used in a wide range of applications providing a powerful scientific tool for researchers from different fields. Linear, or simple parametric, models are often not sufficient to describe complex relationships between input variables and a response. Such relationships can be better described through flexible approaches such as neural networks, but this results in less interpretable models and potential overfitting. Alternatively, specific parametric nonlinear functions can be used, but the specification of such functions is in general complicated. In this paper, we introduce a flexible approach for the construction and selection of highly flexible nonlinear parametric regression models. Nonlinear features are generated hierarchically, similarly to deep learning, but have additional flexibility on the possible types of features to be considered. This flexibility, combined with variable selection, allows us to find a small set of important features and thereby more interpretable models. Within the space of possible functions, a Bayesian approach, introducing priors for functions based on their complexity, is considered. A genetically modified mode jumping Markov chain Monte Carlo algorithm is adopted to perform Bayesian inference and estimate posterior probabilities for model averaging. In various applications, we illustrate how our approach is used to obtain meaningful nonlinear models. Additionally, we compare its predictive performance with several machine learning algorithms.
FLIX: A Simple and Communication-Efficient Alternative to Local Methods in Federated Learning
Gasanov, Elnur, Khaled, Ahmed, Horváth, Samuel, Richtárik, Peter
Federated Learning (FL) is an increasingly popular machine learning paradigm in which multiple nodes try to collaboratively learn under privacy, communication and multiple heterogeneity constraints. A persistent problem in federated learning is that it is not clear what the optimization objective should be: the standard average risk minimization of supervised learning is inadequate in handling several major constraints specific to federated learning, such as communication adaptivity and personalization control. We identify several key desiderata in frameworks for federated learning and introduce a new framework, FLIX, that takes into account the unique challenges brought by federated learning. FLIX has a standard finite-sum form, which enables practitioners to tap into the immense wealth of existing (potentially non-local) methods for distributed optimization. Through a smart initialization that does not require any communication, FLIX does not require the use of local steps but is still provably capable of performing dissimilarity regularization on par with local methods. We give several algorithms for solving the FLIX formulation efficiently under communication constraints. Finally, we corroborate our theoretical results with extensive experimentation.
Component Transfer Learning for Deep RL Based on Abstract Representations
van Driessel, Geoffrey, Francois-Lavet, Vincent
In this work we investigate a specific transfer learning approach for deep reinforcement learning in the context where the internal dynamics between two tasks are the same but the visual representations differ. We learn a low-dimensional encoding of the environment, meant to capture summarizing abstractions, from which the internal dynamics and value functions are learned. Transfer is then obtained by freezing the learned internal dynamics and value functions, thus reusing the shared low-dimensional embedding space. When retraining the encoder for transfer, we make several observations: (i) in some cases, there are local minima that have small losses but a mismatching embedding space, resulting in poor task performance and (ii) in the absence of local minima, the output of the encoder converges in our experiments to the same embedding space, which leads to a fast and efficient transfer as compared to learning from scratch. The local minima are caused by the reduced degree of freedom of the optimization process caused by the frozen models. We also find that the transfer performance is heavily reliant on the base model; some base models often result in a successful transfer, whereas other base models often result in a failing transfer.
DLVGen: A Dual Latent Variable Approach to Personalized Dialogue Generation
Lee, Jing Yang, Lee, Kong Aik, Gan, Woon Seng
The generation of personalized dialogue is vital to natural and human-like conversation. Typically, personalized dialogue generation models involve conditioning the generated response on the dialogue history and a representation of the persona/personality of the interlocutor. As it is impractical to obtain the persona/personality representations for every interlocutor, recent works have explored the possibility of generating personalized dialogue by finetuning the model with dialogue examples corresponding to a given persona instead. However, in real-world implementations, a sufficient number of corresponding dialogue examples are also rarely available. Hence, in this paper, we propose a Dual Latent Variable Generator (DLVGen) capable of generating personalized dialogue in the absence of any persona/personality information or any corresponding dialogue examples. Unlike prior work, DLVGen models the latent distribution over potential responses as well as the latent distribution over the agent's potential persona. During inference, latent variables are sampled from both distributions and fed into the decoder. Empirical results show that DLVGen is capable of generating diverse responses which accurately incorporate the agent's persona.
Paris-CARLA-3D: A Real and Synthetic Outdoor Point Cloud Dataset for Challenging Tasks in 3D Mapping
Deschaud, Jean-Emmanuel, Duque, David, Richa, Jean Pierre, Velasco-Forero, Santiago, Marcotegui, Beatriz, Goulette, and François
Paris-CARLA-3D is a dataset of several dense colored point clouds of outdoor environments built by a mobile LiDAR and camera system. The data are composed of two sets with synthetic data from the open source CARLA simulator (700 million points) and real data acquired in the city of Paris (60 million points), hence the name Paris-CARLA-3D. One of the advantages of this dataset is to have simulated the same LiDAR and camera platform in the open source CARLA simulator as the one used to produce the real data. In addition, manual annotation of the classes using the semantic tags of CARLA was performed on the real data, allowing the testing of transfer methods from the synthetic to the real data. The objective of this dataset is to provide a challenging dataset to evaluate and improve methods on difficult vision tasks for the 3D mapping of outdoor environments: semantic segmentation, instance segmentation, and scene completion. For each task, we describe the evaluation protocol as well as the experiments carried out to establish a baseline.
Towards Improving Embedding Based Models of Social Network Alignment via Pseudo Anchors
Yan, Zihan, Liu, Li, Li, Xin, Cheung, William K., Zhang, Youmin, Liu, Qun, Wang, Guoyin
Social network alignment aims at aligning person identities across social networks. Embedding based models have been shown effective for the alignment where the structural proximity preserving objective is typically adopted for the model training. With the observation that ``overly-close'' user embeddings are unavoidable for such models causing alignment inaccuracy, we propose a novel learning framework which tries to enforce the resulting embeddings to be more widely apart among the users via the introduction of carefully implanted pseudo anchors. We further proposed a meta-learning algorithm to guide the updating of the pseudo anchor embeddings during the learning process. The proposed intervention via the use of pseudo anchors and meta-learning allows the learning framework to be applicable to a wide spectrum of network alignment methods. We have incorporated the proposed learning framework into several state-of-the-art models. Our experimental results demonstrate its efficacy where the methods with the pseudo anchors implanted can outperform their counterparts without pseudo anchors by a fairly large margin, especially when there only exist very few labeled anchors.