Africa
Using Machine Learning to Anticipate Tipping Points and Extrapolate to Post-Tipping Dynamics of Non-Stationary Dynamical Systems
In this paper we consider the machine learning (ML) task of predicting tipping point transitions and long-term post-tipping-point behavior associated with the time evolution of an unknown (or partially unknown), non-stationary, potentially noisy and chaotic, dynamical system. We focus on the particularly challenging situation where the past dynamical state time series that is available for ML training predominantly lies in a restricted region of the state space, while the behavior to be predicted evolves on a larger state space set not fully observed by the ML model during training. In this situation, it is required that the ML prediction system have the ability to extrapolate to different dynamics past that which is observed during training. We investigate the extent to which ML methods are capable of accomplishing useful results for this task, as well as conditions under which they fail. In general, we found that the ML methods were surprisingly effective even in situations that were extremely challenging, but do (as one would expect) fail when ``too much" extrapolation is required. For the latter case, we investigate the effectiveness of combining the ML approach with conventional modeling based on scientific knowledge, thus forming a hybrid prediction system which we find can enable useful prediction even when its ML-based and knowledge-based components fail when acting alone. We also found that achieving useful results may require using very carefully selected ML hyperparameters and we propose a hyperparameter optimization strategy to address this problem. The main conclusion of this paper is that ML-based approaches are promising tools for predicting the behavior of non-stationary dynamical systems even in the case where the future evolution (perhaps due to the crossing of a tipping point) includes dynamics on a set outside of that explored by the training data.
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You might not notice it, but you've likely adopted artificial intelligence into your daily life. It can be as simple as personalizing your news feeds, searching for products on shopping sites or voice-to-text conversion on smartphones. It can also be applied to more sophisticated tasks like predicting court outcomes in cases involving employment law or used for robotic welding applications. The transformative power of AI is also an economic growth driver, which is why the Canadian government has given the green light to advancing the country's AI strategy. According to a recent announcement from Minister of Innovation, Science and Industry François-Philippe Champagne, more than $443 million in Budget 2021 is designated for the second phase of the pan-Canadian Artificial Intelligence Strategy.
5 Ws of artificial intelligence in developing countries - Dataconomy
We explained the 5 Ws of artificial intelligence in developing countries. In recent years, artificial intelligence hasn't had a very favorable reputation overall. It is considered a threat to human employment opportunities even though we use artificial intelligence in everyday life. Is artificial intelligence better than human intelligence? The answer to this question will differ from person to person, but there is something that cannot be denied.
Prediction of Dilatory Behavior in eLearning: A Comparison of Multiple Machine Learning Models
Imhof, Christof, Comsa, Ioan-Sorin, Hlosta, Martin, Parsaeifard, Behnam, Moser, Ivan, Bergamin, Per
Procrastination, the irrational delay of tasks, is a common occurrence in online learning. Potential negative consequences include higher risk of drop-outs, increased stress, and reduced mood. Due to the rise of learning management systems and learning analytics, indicators of such behavior can be detected, enabling predictions of future procrastination and other dilatory behavior. However, research focusing on such predictions is scarce. Moreover, studies involving different types of predictors and comparisons between the predictive performance of various methods are virtually non-existent. In this study, we aim to fill these research gaps by analyzing the performance of multiple machine learning algorithms when predicting the delayed or timely submission of online assignments in a higher education setting with two categories of predictors: subjective, questionnaire-based variables and objective, log-data based indicators extracted from a learning management system. The results show that models with objective predictors consistently outperform models with subjective predictors, and a combination of both variable types perform slightly better. For each of these three options, a different approach prevailed (Gradient Boosting Machines for the subjective, Bayesian multilevel models for the objective, and Random Forest for the combined predictors). We conclude that careful attention should be paid to the selection of predictors and algorithms before implementing such models in learning management systems.
Is Neuro-Symbolic AI Meeting its Promise in Natural Language Processing? A Structured Review
Hamilton, Kyle, Nayak, Aparna, Božić, Bojan, Longo, Luca
Advocates for Neuro-Symbolic Artificial Intelligence (NeSy) assert that combining deep learning with symbolic reasoning will lead to stronger AI than either paradigm on its own. As successful as deep learning has been, it is generally accepted that even our best deep learning systems are not very good at abstract reasoning. And since reasoning is inextricably linked to language, it makes intuitive sense that Natural Language Processing (NLP), would be a particularly well-suited candidate for NeSy. We conduct a structured review of studies implementing NeSy for NLP, with the aim of answering the question of whether NeSy is indeed meeting its promises: reasoning, out-of-distribution generalization, interpretability, learning and reasoning from small data, and transferability to new domains. We examine the impact of knowledge representation, such as rules and semantic networks, language structure and relational structure, and whether implicit or explicit reasoning contributes to higher promise scores. We find that systems where logic is compiled into the neural network lead to the most NeSy goals being satisfied, while other factors such as knowledge representation, or type of neural architecture do not exhibit a clear correlation with goals being met. We find many discrepancies in how reasoning is defined, specifically in relation to human level reasoning, which impact decisions about model architectures and drive conclusions which are not always consistent across studies. Hence we advocate for a more methodical approach to the application of theories of human reasoning as well as the development of appropriate benchmarks, which we hope can lead to a better understanding of progress in the field. We make our data and code available on github for further analysis.
AI Favors Autocracy, But Democracies Can Still Fight Back
As Ben Buchanan and Andrew Imbrie note in their recent book, "AI's [artificial intelligence's] new capabilities are both marvels and distractions." The marvel versus distraction dichotomy is an interesting one: due to the two possible natures of AI, the question of whether advances in AI will favor autocracies or democracies has come to the forefront of the tech and global power debate. On the one hand, AI has the potential to tackle some of the world's most challenging social problems, such as issues related to healthcare, the environment, and crisis response, leading some to believe that democracies will wield AI to create a future for human good. On the other hand, some fear AI-enabled surveillance, information campaigns, and cyber operations will empower existing tyrants and produce new ones, leading to a future where autocracies thrive and democracies struggle. By examining how advances in AI capabilities in the near future could benefit autocracies and democracies, as well as how these advances could benefit both, I believe that AI is likely to favor autocracies in the near term, but under one necessary condition: that democracies are negligent in their response to autocracies' destructive use of AI.
We're Dangerously Close to Giving Big Tech Control Of Our Thoughts
Elon Musk has proclaimed himself to be a "free speech absolutist" though reports of the way employees of his companies have been treated when exercising their free speech rights to criticise him might indicate that his commitment to free speech has its limits. But as Musk's bid to takeover Twitter progresses in fits and starts, the potential for anyone to access and control billions of opinions around the world for the right sum should focus all our minds on the need to protect an almost forgotten right--the right to freedom of thought. In 1942 the U.S. Supreme Court wrote "Freedom to think is absolute of its own nature, the most tyrannical government is powerless to control the inward workings of the mind." The assumption that getting inside our heads is a practical impossibility may have prevented lawyers and legislators from dwelling too much on putting in place regulation that protects our inner lives. But it has not stopped powerful people trying to access and control our minds for centuries.
Variational Bayesian inference for CP tensor completion with side information
Budzinskiy, Stanislav, Zamarashkin, Nikolai
We propose a message passing algorithm, based on variational Bayesian inference, for low-rank tensor completion with automatic rank determination in the canonical polyadic format when additional side information (SI) is given. The SI comes in the form of low-dimensional subspaces the contain the fiber spans of the tensor (columns, rows, tubes, etc.). We validate the regularization properties induced by SI with extensive numerical experiments on synthetic and real-world data and present the results about tensor recovery and rank determination. The results show that the number of samples required for successful completion is significantly reduced in the presence of SI. We also discuss the origin of a bump in the phase transition curves that exists when the dimensionality of SI is comparable with that of the tensor.
A Temporal Extension of Latent Dirichlet Allocation for Unsupervised Acoustic Unit Discovery
van der Merwe, Werner, Kamper, Herman, Preez, Johan du
Latent Dirichlet allocation (LDA) is widely used for unsupervised topic modelling on sets of documents. No temporal information is used in the model. However, there is often a relationship between the corresponding topics of consecutive tokens. In this paper, we present an extension to LDA that uses a Markov chain to model temporal information. We use this new model for acoustic unit discovery from speech. As input tokens, the model takes a discretised encoding of speech from a vector quantised (VQ) neural network with 512 codes. The goal is then to map these 512 VQ codes to 50 phone-like units (topics) in order to more closely resemble true phones. In contrast to the base LDA, which only considers how VQ codes co-occur within utterances (documents), the Markov chain LDA additionally captures how consecutive codes follow one another. This extension leads to an increase in cluster quality and phone segmentation results compared to the base LDA. Compared to a recent vector quantised neural network approach that also learns 50 units, the extended LDA model performs better in phone segmentation but worse in mutual information.
Interactive Physically-Based Simulation of Roadheader Robot
Hou, Shengzhe, Lu, Xinming, Gao, Wenli, Jiang, Shuai, Zhang, Xingli
Roadheader is an engineering robot widely used in underground engineering and mining industry. Interactive dynamics simulation of roadheader is a fundamental problem in unmanned excavation and virtual reality training. However, current research is only based on traditional animation techniques or commercial game engines. There are few studies that apply real-time physical simulation of computer graphics to the field of roadheader robot. This paper aims to present an interactive physically-based simulation system of roadheader robot. To this end, an improved multibody simulation method based on generalized coordinates is proposed. First, our simulation method describes robot dynamics based on generalized coordinates. Compared to state-of-the-art methods, our method is more stable and accurate. Numerical simulation results showed that our method has significantly less error than the game engine in the same number of iterations. Second, we adopt the symplectic Euler integrator instead of the conventional fourth-order Runge-Kutta (RK4) method for dynamics iteration. Compared with other integrators, our method is more stable in energy drift during long-term simulation. The test results showed that our system achieved real-time interaction performance of 60 frames per second (fps). Furthermore, we propose a model format for geometric and robotics modeling of roadheaders to implement the system. Our interactive simulation system of roadheader meets the requirements of interactivity, accuracy and stability.