Victoria
ChiNet: Deep Recurrent Convolutional Learning for Multimodal Spacecraft Pose Estimation
Rondao, Duarte, Aouf, Nabil, Richardson, Mark A.
This paper presents an innovative deep learning pipeline which estimates the relative pose of a spacecraft by incorporating the temporal information from a rendezvous sequence. It leverages the performance of long short-term memory (LSTM) units in modelling sequences of data for the processing of features extracted by a convolutional neural network (CNN) backbone. Three distinct training strategies, which follow a coarse-to-fine funnelled approach, are combined to facilitate feature learning and improve end-to-end pose estimation by regression. The capability of CNNs to autonomously ascertain feature representations from images is exploited to fuse thermal infrared data with red-green-blue (RGB) inputs, thus mitigating the effects of artefacts from imaging space objects in the visible wavelength. Each contribution of the proposed framework, dubbed ChiNet, is demonstrated on a synthetic dataset, and the complete pipeline is validated on experimental data.
Multi-Stage Graph Peeling Algorithm for Probabilistic Core Decomposition
Guo, Yang, Zhang, Xuekui, Esfahani, Fatemeh, Srinivasan, Venkatesh, Thomo, Alex, Xing, Li
Mining dense subgraphs where vertices connect closely with each other is a common task when analyzing graphs. A very popular notion in subgraph analysis is core decomposition. Recently, Esfahani et al. presented a probabilistic core decomposition algorithm based on graph peeling and Central Limit Theorem (CLT) that is capable of handling very large graphs. Their proposed peeling algorithm (PA) starts from the lowest degree vertices and recursively deletes these vertices, assigning core numbers, and updating the degree of neighbour vertices until it reached the maximum core. However, in many applications, particularly in biology, more valuable information can be obtained from dense sub-communities and we are not interested in small cores where vertices do not interact much with others. To make the previous PA focus more on dense subgraphs, we propose a multi-stage graph peeling algorithm (M-PA) that has a two-stage data screening procedure added before the previous PA. After removing vertices from the graph based on the user-defined thresholds, we can reduce the graph complexity largely and without affecting the vertices in subgraphs that we are interested in. We show that M-PA is more efficient than the previous PA and with the properly set filtering threshold, can produce very similar if not identical dense subgraphs to the previous PA (in terms of graph density and clustering coefficient).
HelpViz: Automatic Generation of Contextual Visual MobileTutorials from Text-Based Instructions
Zhong, Mingyuan, Li, Gang, Chi, Peggy, Li, Yang
We present HelpViz, a tool for generating contextual visual mobile tutorials from text-based instructions that are abundant on the web. HelpViz transforms text instructions to graphical tutorials in batch, by extracting a sequence of actions from each text instruction through an instruction parsing model, and executing the extracted actions on a simulation infrastructure that manages an array of Android emulators. The automatic execution of each instruction produces a set of graphical and structural assets, including images, videos, and metadata such as clicked elements for each step. HelpViz then synthesizes a tutorial by combining parsed text instructions with the generated assets, and contextualizes the tutorial to user interaction by tracking the user's progress and highlighting the next step. Our experiments with HelpViz indicate that our pipeline improved tutorial execution robustness and that participants preferred tutorials generated by HelpViz over text-based instructions. HelpViz promises a cost-effective approach for generating contextual visual tutorials for mobile interaction at scale.
Two-thirds of romantic couples start out as friends, study finds
If you've been having trouble finding love on dating apps, you might want to try dating one of your friends, a new study suggests. The study authors, based in British Columbia, Canada looked at data from just under 2,000 couples of different demographics. They found two thirds started out as just friends, suggesting that establishing a platonic connection with someone first is conducive to a solid romantic relationship later. The study suggests that the cliché of falling in love at first site – a frequent trope in the Hollywood movies of the silver screen – is slightly outdated in the 21st century. Built on a more solid foundation?
Uncertainty-Aware Learning for Improvements in Image Quality of the Canada-France-Hawaii Telescope
Gilda, Sankalp, Draper, Stark C., Fabbro, Sebastien, Mahoney, William, Prunet, Simon, Withington, Kanoa, Wilson, Matthew, Ting, Yuan-Sen, Sheinis, Andrew
We leverage state-of-the-art machine learning methods and a decade's worth of archival data from the Canada-France-Hawaii Telescope (CFHT) to predict observatory image quality (IQ) from environmental conditions and observatory operating parameters. Specifically, we develop accurate and interpretable models of the complex dependence between data features and observed IQ for CFHT's wide field camera, MegaCam. Our contributions are several-fold. First, we collect, collate and reprocess several disparate data sets gathered by CFHT scientists. Second, we predict probability distribution functions (PDFs) of IQ, and achieve a mean absolute error of $\sim0.07''$ for the predicted medians. Third, we explore data-driven actuation of the 12 dome ``vents'', installed in 2013-14 to accelerate the flushing of hot air from the dome. We leverage epistemic and aleatoric uncertainties in conjunction with probabilistic generative modeling to identify candidate vent adjustments that are in-distribution (ID) and, for the optimal configuration for each ID sample, we predict the reduction in required observing time to achieve a fixed SNR. On average, the reduction is $\sim15\%$. Finally, we rank sensor data features by Shapley values to identify the most predictive variables for each observation. Our long-term goal is to construct reliable and real-time models that can forecast optimal observatory operating parameters for optimization of IQ. Such forecasts can then be fed into scheduling protocols and predictive maintenance routines. We anticipate that such approaches will become standard in automating observatory operations and maintenance by the time CFHT's successor, the Maunakea Spectroscopic Explorer (MSE), is installed in the next decade.
Synthesising Reinforcement Learning Policies through Set-Valued Inductive Rule Learning
Coppens, Youri, Steckelmacher, Denis, Jonker, Catholijn M., Nowé, Ann
Today's advanced Reinforcement Learning algorithms produce black-box policies, that are often difficult to interpret and trust for a person. We introduce a policy distilling algorithm, building on the CN2 rule mining algorithm, that distills the policy into a rule-based decision system. At the core of our approach is the fact that an RL process does not just learn a policy, a mapping from states to actions, but also produces extra meta-information, such as action values indicating the quality of alternative actions. This meta-information can indicate whether more than one action is near-optimal for a certain state. We extend CN2 to make it able to leverage knowledge about equally-good actions to distill the policy into fewer rules, increasing its interpretability by a person. Then, to ensure that the rules explain a valid, non-degenerate policy, we introduce a refinement algorithm that fine-tunes the rules to obtain good performance when executed in the environment. We demonstrate the applicability of our algorithm on the Mario AI benchmark, a complex task that requires modern reinforcement learning algorithms including neural networks. The explanations we produce capture the learned policy in only a few rules, that allow a person to understand what the black-box agent learned.
Batter up! EA Sports gets back into baseball video games with 'Super Mega Baseball' studio deal
EA Sports has made an acquisition that gets it back into baseball video games. The sports game division of Electronic Arts is adding to its lineup Metalhead Software, a Victoria, British Columbia, studio that makes Super Mega Baseball video games. "Super Mega Baseball 3," released in March 2020, has an arcade look, but "it's a really well-made game," EA Sports executive vice president and general manager Cam Weber told USA TODAY. It plays like a simulation under the hood. One of the largest video game publishers in the U.S., EA posted revenue of $5.5 billion in fiscal year 2020.
One Billion Audio Sounds from GPU-enabled Modular Synthesis
Turian, Joseph, Shier, Jordie, Tzanetakis, George, McNally, Kirk, Henry, Max
We release synth1B1, a multi-modal audio corpus consisting of 1 billion 4-second synthesized sounds, which is 100x larger than any audio dataset in the literature. Each sound is paired with the corresponding latent parameters used to generate it. synth1B1 samples are deterministically generated on-the-fly 16200x faster than real-time (714MHz) on a single GPU using torchsynth (https://github.com/torchsynth/torchsynth), an open-source modular synthesizer we release. Additionally, we release two new audio datasets: FM synth timbre (https://zenodo.org/record/4677102) and subtractive synth pitch (https://zenodo.org/record/4677097). Using these datasets, we demonstrate new rank-based synthesizer-motivated evaluation criteria for existing audio representations. Finally, we propose novel approaches to synthesizer hyperparameter optimization, and demonstrate how perceptually-correlated auditory distances could enable new applications in synthesizer design.
Selective Survey: Most Efficient Models and Solvers for Integrative Multimodal Transport
Matei, Oliviu, Rudolf, Erdei, Pintea, Camelia-M.
In the family of Intelligent Transportation Systems (ITS), Multimodal Transport Systems (MMTS) have placed themselves as a mainstream transportation mean of our time as a feasible integrative transportation process. The Global Economy progressed with the help of transportation. The volume of goods and distances covered have doubled in the last ten years, so there is a high demand of an optimized transportation, fast but with low costs, saving resources but also safe, with low or zero emissions. Thus, it is important to have an overview of existing research in this field, to know what was already done and what is to be studied next. The main objective is to explore a beneficent selection of the existing research, methods and information in the field of multimodal transportation research, to identify industry needs and gaps in research and provide context for future research. The selective survey covers multimodal transport design and optimization in terms of: cost, time, and network topology. The multimodal transport theoretical aspects, context and resources are also covering various aspects. The survey's selection includes nowadays best methods and solvers for Intelligent Transportation Systems (ITS). The gap between theory and real-world applications should be further solved in order to optimize the global multimodal transportation system.
On the Evolvability of Monotone Conjunctions with an Evolutionary Mutation Mechanism
Valiant (2009) introduced a framework for a quantitative approach to evolution, called evolvability. The idea is, roughly, that there is an ideal behavior in every environment and the feedback that the various organisms receive during evolution indicates how close their behavior is to ideal. Ultimately, evolvability aims at modeling and explaining mechanisms that allow near-optimal behavior of organisms while exploiting realistic computational resources. Due to a result by Feldman (2008), evolvability is equivalent to learning in the correlational statistical query (CSQ) model (Bshouty & Feldman, 2002). Thus, evolvability algorithms correspond to a special type of local search learning algorithms that fall under the umbrella of the probably approximately correct (PAC) model of learning (Valiant, 1984).