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Pumped Hydro Energy Storage Is Having a Renaissance

WIRED

As the world looks to incorporate more renewables into energy grids, centuries-old systems that can balance supply and demand are being reappraised and innovated upon.


Hybrid Cross-domain Robust Reinforcement Learning

Van, Linh Le Pham, Nguyen, Minh Hoang, Le, Hung, Tran, Hung The, Gupta, Sunil

arXiv.org Artificial Intelligence

Robust reinforcement learning (RL) aims to learn policies that remain effective despite uncertainties in its environment, which frequently arise in real-world applications due to variations in environment dynamics. The robust RL methods learn a robust policy by maximizing value under the worst-case models within a predefined uncertainty set. Offline robust RL algorithms are particularly promising in scenarios where only a fixed dataset is available and new data cannot be collected. However, these approaches often require extensive offline data, and gathering such datasets for specific tasks in specific environments can be both costly and time-consuming. Using an imperfect simulator offers a faster, cheaper, and safer way to collect data for training, but it can suffer from dynamics mismatch. In this paper, we introduce HYDRO, the first Hybrid Cross-Domain Robust RL framework designed to address these challenges. HYDRO utilizes an online simulator to complement the limited amount of offline datasets in the non-trivial context of robust RL. By measuring and minimizing performance gaps between the simulator and the worst-case models in the uncertainty set, HYDRO employs novel uncertainty filtering and prioritized sampling to select the most relevant and reliable simulator samples. Our extensive experiments demonstrate HYDRO's superior performance over existing methods across various tasks, underscoring its potential to improve sample efficiency in offline robust RL.


Random Walk Guided Hyperbolic Graph Distillation

Long, Yunbo, Xu, Liming, Schoepf, Stefan, Brintrup, Alexandra

arXiv.org Artificial Intelligence

Graph distillation (GD) is an effective approach to extract useful information from large-scale network structures. However, existing methods, which operate in Euclidean space to generate condensed graphs, struggle to capture the inherent tree-like geometry of real-world networks, resulting in distilled graphs with limited task-specific information for downstream tasks. Furthermore, these methods often fail to extract dynamic properties from graphs, which are crucial for understanding information flow and facilitating graph continual learning. This paper presents the Hyperbolic Graph Distillation with Random Walks Optimization (HyDRO), a novel graph distillation approach that leverages hyperbolic embeddings to capture complex geometric patterns and optimize the spectral gap in hyperbolic space. Experiments show that HyDRO demonstrates strong task generalization, consistently outperforming state-of-the-art methods in both node classification and link prediction tasks. HyDRO also effectively preserves graph random walk properties, producing condensed graphs that achieve enhanced performance in continual graph learning. Additionally, HyDRO achieves competitive results on mainstream graph distillation benchmarks, while maintaining a strong balance between privacy and utility, and exhibiting robust resistance to noises.


Hydro: Adaptive Query Processing of ML Queries

Kakkar, Gaurav Tarlok, Cao, Jiashen, Sengupta, Aubhro, Arulraj, Joy, Kim, Hyesoon

arXiv.org Artificial Intelligence

Query optimization in relational database management systems (DBMSs) is critical for fast query processing. The query optimizer relies on precise selectivity and cost estimates to effectively optimize queries prior to execution. While this strategy is effective for relational DBMSs, it is not sufficient for DBMSs tailored for processing machine learning (ML) queries. In ML-centric DBMSs, query optimization is challenging for two reasons. First, the performance bottleneck of the queries shifts to user-defined functions (UDFs) that often wrap around deep learning models, making it difficult to accurately estimate UDF statistics without profiling the query. This leads to inaccurate statistics and sub-optimal query plans. Second, the optimal query plan for ML queries is data-dependent, necessitating DBMSs to adapt the query plan on the fly during execution. So, a static query plan is not sufficient for such queries. In this paper, we present Hydro, an ML-centric DBMS that utilizes adaptive query processing (AQP) for efficiently processing ML queries. Hydro is designed to quickly evaluate UDF-based query predicates by ensuring optimal predicate evaluation order and improving the scalability of UDF execution. By integrating AQP, Hydro continuously monitors UDF statistics, routes data to predicates in an optimal order, and dynamically allocates resources for evaluating predicates. We demonstrate Hydro's efficacy through four illustrative use cases, delivering up to 11.52x speedup over a baseline system.


The Water Health Open Knowledge Graph

Carletti, Gianluca, Giulianelli, Elio, Lippolis, Anna Sofia, Lodi, Giorgia, Nuzzolese, Andrea Giovanni, Picone, Marco, Settanta, Giulio

arXiv.org Artificial Intelligence

Recently, an increasing interest in the management of water and health resources has been recorded. This interest is fed by the global sustainability challenges posed to the humanity that have water scarcity and quality at their core. Thus, the availability of effective, meaningful and open data is crucial to address those issues in the broader context of the Sustainable Development Goals of clean water and sanitation as targeted by the United Nations. In this paper, we present the Water Health Open Knowledge Graph (WHOW-KG) along with its design methodology and analysis on impact. WHOW-KG is a semantic knowledge graph that models data on water consumption, pollution, infectious disease rates and drug distribution. The WHOW-KG is developed in the context of the EU-funded WHOW (Water Health Open Knowledge) project and aims at supporting a wide range of applications: from knowledge discovery to decision-making, making it a valuable resource for researchers, policymakers, and practitioners in the water and health domains. The WHOW-KG consists of a network of five ontologies and related linked open data, modelled according to those ontologies.


What Does The Future Of RPA Look Like? - Express Computer

#artificialintelligence

Around the world, the lockdown measures to contain the pandemic have led to economic contraction and a significant drop in energy consumption including electricity, gas, and oil. CEOs, experts, and policymakers are still taking stock of the impact of COVID-19 on the energy landscape and what it means for the ongoing transition to sustainable energy. In India, the renewable sector, including large hydro, accounted for 15.6 percent of the generation in January, which is a lean season for hydro. Solar, wind, small hydro, biomass i.e officially referred to as Renewable Energy in India ― contributed 9.11 percent, up from 8.55 percent in the same period last year. Renewable energy provides an opportunity for building back better' as many people all over the world believe that the coronavirus pandemic is a result of us not being responsible for the environment.


Column: Can AI solve renewable energy's problems? India may show the way - Reuters

#artificialintelligence

LAUNCESTON, Australia (Reuters) - One of humankind's most enduring weaknesses is to assume that the way things are presently will somehow persist into the future, and that current trends are inexorable. This thinking is behind the often repeated view that renewable energy sources such as wind and solar cannot replace thermal electricity generation such as coal and natural gas. Presently, it is correct that the most significant weakness of these renewables is that they are intermittent, meaning they don't generate close to their installed capacity and cause instability in electricity grids. While storage through batteries or pumped hydro is often touted as a solution to the drawbacks of wind and solar, there are other emerging technologies that may well make renewables more effective. One of those is harnessing artificial intelligence (AI) to improve the efficiency of wind and solar by using machine learning programmes to enhance predictability of generation and grid stability.