Energy
Zermelo's problem: Optimal point-to-point navigation in 2D turbulent flows using Reinforcement Learning
Biferale, Luca, Bonaccorso, Fabio, Buzzicotti, Michele, Di Leoni, Patricio Clark, Gustavsson, Kristian
To find the path that minimizes the time to navigate between two given points in a fluid flow is known as the Zermelo's problem. Here, we investigate it by using a Reinforcement Learning (RL) approach for the case of a vessel which has a slip velocity with fixed intensity, V_s, but variable direction and navigating in a 2D turbulent sea. We use an Actor-Critic RL algorithm, and compare the results with strategies obtained analytically from continuous Optimal Navigation (ON) protocols. We show that for our application, ON solutions are unstable for the typical duration of the navigation process, and are therefore not useful in practice. On the other hand, RL solutions are much more robust with respect to small changes in the initial conditions and to external noise, and are able to find optimal trajectories even when V_s is much smaller than the maximum flow velocity. Furthermore, we show how the RL approach is able to take advantage of the flow properties in order to reach the target, especially when the steering speed is small.
Boosting Resolution and Recovering Texture of micro-CT Images with Deep Learning
Da Wang, Ying, Armstrong, Ryan T., Mostaghimi, Peyman
Digital Rock Imaging is constrained by detector hardware, and a trade-off between the image field of view (FOV) and the image resolution must be made. This can be compensated for with super resolution (SR) techniques that take a wide FOV, low resolution (LR) image, and super resolve a high resolution (HR), high FOV image. The Enhanced Deep Super Resolution Generative Adversarial Network (EDSRGAN) is trained on the Deep Learning Digital Rock Super Resolution Dataset, a diverse compilation 12000 of raw and processed uCT images. The network shows comparable performance of 50% to 70% reduction in relative error over bicubic interpolation. GAN performance in recovering texture shows superior visual similarity compared to SRCNN and other methods. Difference maps indicate that the SRCNN section of the SRGAN network recovers large scale edge (grain boundaries) features while the GAN network regenerates perceptually indistinguishable high frequency texture. Network performance is generalised with augmentation, showing high adaptability to noise and blur. HR images are fed into the network, generating HR-SR images to extrapolate network performance to sub-resolution features present in the HR images themselves. Results show that under-resolution features such as dissolved minerals and thin fractures are regenerated despite the network operating outside of trained specifications. Comparison with Scanning Electron Microscope images shows details are consistent with the underlying geometry of the sample. Recovery of textures benefits the characterisation of digital rocks with a high proportion of under-resolution micro-porous features, such as carbonate and coal samples. Images that are normally constrained by the mineralogy of the rock (coal), by fast transient imaging (waterflooding), or by the energy of the source (microporosity), can be super resolved accurately for further analysis downstream.
Feature-driven Improvement of Renewable Energy Forecasting and Trading
Muñoz, Miguel Á., Morales, Juan M., Pineda, Salvador
Inspired from recent insights into the common ground of machine learning, optimization and decision-making, this paper proposes an easy-to-implement, but effective procedure to enhance both the quality of renewable energy forecasts and the competitive edge of renewable energy producers in electricity markets with a dual-price settlement of imbalances. The quality and economic gains brought by the proposed procedure essentially stem from the utilization of valuable predictors (also known as features) in a data-driven newsvendor model that renders a computationally inexpensive linear program. We illustrate the proposed procedure and numerically assess its benefits on a realistic case study that considers the aggregate wind power production in the Danish DK1 bidding zone as the variable to be predicted and traded. Within this context, our procedure leverages, among others, spatial information in the form of wind power forecasts issued by transmission system operators (TSO) in surrounding bidding zones and publicly available in online platforms. We show that our method is able to improve the quality of the wind power forecast issued by the Danish TSO by several percentage points (when measured in terms of the mean absolute or the root mean square error) and to significantly reduce the balancing costs incurred by the wind power producer.
Towards Blockchain-based Multi-Agent Robotic Systems: Analysis, Classification and Applications
Afanasyev, Ilya, Kolotov, Alexander, Rezin, Ruslan, Danilov, Konstantin, Mazzara, Manuel, Chakraborty, Subham, Kashevnik, Alexey, Chechulin, Andrey, Kapitonov, Aleksandr, Jotsov, Vladimir, Topalov, Andon, Shakev, Nikola, Ahmed, Sevil
This is known as cloud computing, distributed planning and management, and the classical Blockchain Trilemma - when it comes to the distributed ledgers provides and optimistic outlook towards choice two of the three between decentralization, scalability increasingly popular technological solutions such as the Internet and security [12]. One of the scaling methods that does not of Robotic Things (IoRT) [1], [2], [3], [4], [5] and the compromise security or decentralization is called sharding, Blockchain-based Multi-Agent Robotic Systems (MARS) [6], which involves fragmentation of the available dataset into [7], [8], [9]. It is known that one of the important problems smaller datasets called shards [11], [12]. Although multi-agent in developing multi-robot systems is the design of strategies robotic systems (MARS) are not so critical to scalability and for their coordination in such a way that the robots could speed as the financial and big data-based systems, they are effectively perform their operations and reasonably coordinate nevertheless also very sensitive to delays and throughput of the task allocation among themselves [10]. Real-world scenarios the information channels at data exchange between agents.
The best Alexa-compatible Prime Day deals of 2019
Alexa-enabled devices like the Echo or Echo Dot can be used to control smart home products such as the Ring Alarm Kit. If you make a purchase by clicking one of our links, we may earn a small share of the revenue. Our picks and opinions are independent from USA TODAY's newsroom and any business incentives. Prime Day is a great opportunity to find money-saving deals on smart home products that can be controlled using Amazon Alexa on your Echo device. From smart doorbells to pressure cookers, here are the best Alexa-compatible Prime Day deals of 2019.
Strategic sovereignty: How Europe can regain the capacity to act
As the world descends into geopolitical competition, other powers increasingly challenge European countries' ability to defend their interests and values. Russia is willing to weaponise energy supplies, cyber capabilities, and disinformation; China invests strategically and uses state capitalism to skew the market; Turkey instrumentalises migration; Saudi Arabia leverages its energy resources. And the Trump administration is willing to exploit European dependence on the transatlantic security alliance and the dollar to achieve short-term policy goals. What unites these disparate powers is their unwillingness to separate the functioning of the global economy from political and security competition. The EU has the market power, defence spending, and diplomatic heft to end this vulnerability and restore sovereignty to its member states.
The best of both worlds: How to solve real problems on modern quantum computers
In recent years, quantum devices have become available that enable researchers--for the first time--to use real quantum hardware to begin to solve scientific problems. However, in the near term, the number and quality of qubits (the basic unit of quantum information) for quantum computers are expected to remain limited, making it difficult to use these machines for practical applications. A hybrid quantum and classical approach may be the answer to tackling this problem with existing quantum hardware. Researchers at the U.S. Department of Energy's (DOE) Argonne National Laboratory and Los Alamos National Laboratory, along with researchers at Clemson University and Fujitsu Laboratories of America, have developed hybrid algorithms to run on quantum machines and have demonstrated them for practical applications using IBM quantum computers (see below for description of Argonne's role in the IBM Q Hub at Oak Ridge National Laboratory [ORNL]) and a D-Wave quantum computer. "This approach will enable researchers to use near-term quantum computers to solve applications that support the DOE mission. For example, it can be applied to find community structures in metabolic networks or a microbiome," says Yuri Alexeev, principal project specialist, Computational Science division The team's work is presented in an article entitled "A Hybrid Approach for Solving Optimization Problems on Small Quantum Computers" that appears in the June 2019 issue of the Institute of Electrical and Electronics Engineers (IEEE) Computer Magazine.
Parametric generation of conditional geological realizations using generative neural networks
Chan, Shing, Elsheikh, Ahmed H.
Deep learning techniques are increasingly being considered for geological applications where -- much like in computer vision -- the challenges are characterized by high-dimensional spatial data dominated by multipoint statistics. In particular, a novel technique called generative adversarial networks has been recently studied for geological parametrization and synthesis, obtaining very impressive results that are at least qualitatively competitive with previous methods. The method obtains a neural network parametrization of the geology -- so-called a generator -- that is capable of reproducing very complex geological patterns with dimensionality reduction of several orders of magnitude. Subsequent works have addressed the conditioning task, i.e. using the generator to generate realizations honoring spatial observations (hard data). The current approaches, however, do not provide a parametrization of the conditional generation process. In this work, we propose a method to obtain a parametrization for direct generation of conditional realizations. The main idea is to simply extend the existing generator network by stacking a second inference network that learns to perform the conditioning. This inference network is a neural network trained to sample a posterior distribution derived using a Bayesian formulation of the conditioning task. The resulting extended neural network thus provides the conditional parametrization. Our method is assessed on a benchmark image of binary channelized subsurface, obtaining very promising results for a wide variety of conditioning configurations.
Unsupervised Fault Detection in Varying Operating Conditions
Training data-driven approaches for complex industrial system health monitoring is challenging. When data on faulty conditions are rare or not available, the training has to be performed in a unsupervised manner. In addition, when the observation period, used for training, is kept short, to be able to monitor the system in its early life, the training data might not be representative of all the system normal operating conditions. In this paper, we propose five approaches to perform fault detection in such context. Two approaches rely on the data from the unit to be monitored only: the baseline is trained on the early life of the unit. An incremental learning procedure tries to learn new operating conditions as they arise. Three other approaches take advantage of data from other similar units within a fleet. In two cases, units are directly compared to each other with similarity measures, and the data from similar units are combined in the training set. We propose, in the third case, a new deep-learning methodology to perform, first, a feature alignment of different units with an Unsupervised Feature Alignment Network (UFAN). Then, features of both units are combined in the training set of the fault detection neural network. The approaches are tested on a fleet comprising 112 units, observed over one year of data. All approaches proposed here are an improvement to the baseline, trained with two months of data only. As units in the fleet are found to be very dissimilar, the new architecture UFAN, that aligns units in the feature space, is outperforming others.
A Decade of Accelerated Computing Augurs Well For GPUs
While accelerators have been around for some time to boost the performance of simulation and modeling applications, accelerated computing didn't gain traction for most people until the commercialization of the Tesla line of GPUs for general computing by Nvidia. This year marked the tenth annual Nvidia GPU Technology Conference (GTC). I have been to all but one starting with the inaugural event in 2009. Back then it was a much smaller group. Attendance has leaped 10X with this year's meeting attracting over 9,000 participants.