Goto

Collaborating Authors

 Atlantic Ocean


MaxFloodCast: Ensemble Machine Learning Model for Predicting Peak Inundation Depth And Decoding Influencing Features

arXiv.org Artificial Intelligence

Timely, accurate, and reliable information is essential for decision-makers, emergency managers, and infrastructure operators during flood events. This study demonstrates a proposed machine learning model, MaxFloodCast, trained on physics-based hydrodynamic simulations in Harris County, offers efficient and interpretable flood inundation depth predictions. Achieving an average R-squared of 0.949 and a Root Mean Square Error of 0.61 ft on unseen data, it proves reliable in forecasting peak flood inundation depths. Validated against Hurricane Harvey and Storm Imelda, MaxFloodCast shows the potential in supporting near-time floodplain management and emergency operations. The model's interpretability aids decision-makers in offering critical information to inform flood mitigation strategies, to prioritize areas with critical facilities and to examine how rainfall in other watersheds influences flood exposure in one area. The MaxFloodCast model enables accurate and interpretable inundation depth predictions while significantly reducing computational time, thereby supporting emergency response efforts and flood risk management more effectively.


Diffusion-based Visual Counterfactual Explanations -- Towards Systematic Quantitative Evaluation

arXiv.org Artificial Intelligence

Latest methods for visual counterfactual explanations (VCE) harness the power of deep generative models to synthesize new examples of high-dimensional images of impressive quality. However, it is currently difficult to compare the performance of these VCE methods as the evaluation procedures largely vary and often boil down to visual inspection of individual examples and small scale user studies. In this work, we propose a framework for systematic, quantitative evaluation of the VCE methods and a minimal set of metrics to be used. We use this framework to explore the effects of certain crucial design choices in the latest diffusion-based generative models for VCEs of natural image classification (ImageNet). We conduct a battery of ablation-like experiments, generating thousands of VCEs for a suite of classifiers of various complexity, accuracy and robustness. Our findings suggest multiple directions for future advancements and improvements of VCE methods. By sharing our methodology and our approach to tackle the computational challenges of such a study on a limited hardware setup (including the complete code base), we offer a valuable guidance for researchers in the field fostering consistency and transparency in the assessment of counterfactual explanations.


Mass evacuation ordered as Russian forces intensify offensive in Ukraine

FOX News

Fox News Flash top headlines are here. Check out what's clicking on Foxnews.com. Ukrainian authorities ordered a mandatory evacuation Thursday of nearly 12,000 civilians from 37 towns and villages in the eastern Kharkiv region, where Russian forces reportedly are making a concerted effort to punch through the front line. The local military administration in Kharkiv's Kupiansk district said residents must comply with the evacuation order or sign a document saying they would stay at their own risk. Ukrainian Deputy Defense Minister Hanna Maliar had said the previous day that "the intensity of combat and enemy shelling is high" in the area.


Russia faces 'great dilemma' as Ukraine puts Moscow on the defensive

Al Jazeera

Bogged down in small-scale infantry attacks and incremental advances, Ukraine sought to gain an advantage in the 76th week of the war by attacking Russian shipping at range and was accused of drone strikes targeting Moscow. Drone footage Ukraine released on August 4 showed the prow of a surface drone approaching the Olenegorsky Gornyak, a Ropucha-class Russian landing ship, before going blank at contact range. The attack happened just outside Novorossiysk harbour, supposedly a safe port on the eastern edge of the Black Sea, to which Russia had relocated much of its navy fleet based in Sevastopol after Ukraine sank its Black Sea flagship in May. Daylight footage showed the Olenegorsky Gornyak listing severely to port as it was towed to Novorossiysk harbour. "This poses a great dilemma for the Russians," wrote Phillips O'Brien, professor of strategy at St Andrews University.


Russia says 13 Ukrainian drones downed on way to attack Sevastopol, Moscow

Al Jazeera

Russian forces took down more than a dozen Ukrainian drones flying towards the capital Moscow and the city of Sevastopol in the annexed Crimean peninsula, according to the country's defence ministry. The attack on Moscow on Thursday is the latest in a series of Ukrainian drone raids deep inside Russian territory. The defence ministry said in a statement that two drones "flying in the direction of the city of Moscow were destroyed", while 11 others were brought down near the city of Sevastopol. Two of the Ukrainian drones were "hit by on-duty anti-aircraft defence equipment, another nine were suppressed by means of electronic warfare and crashed in the Black Sea before reaching the target", the ministry said of the attack. There was no immediate comment from Ukraine.


Towards true discovery of the differential equations

arXiv.org Artificial Intelligence

Differential equation discovery, a machine learning subfield, is used to develop interpretable models, particularly in nature-related applications. By expertly incorporating the general parametric form of the equation of motion and appropriate differential terms, algorithms can autonomously uncover equations from data. This paper explores the prerequisites and tools for independent equation discovery without expert input, eliminating the need for equation form assumptions. We focus on addressing the challenge of assessing the adequacy of discovered equations when the correct equation is unknown, with the aim of providing insights for reliable equation discovery without prior knowledge of the equation form.


A Universal Question-Answering Platform for Knowledge Graphs

arXiv.org Artificial Intelligence

Knowledge from diverse application domains is organized as knowledge graphs (KGs) that are stored in RDF engines accessible in the web via SPARQL endpoints. Expressing a well-formed SPARQL query requires information about the graph structure and the exact URIs of its components, which is impractical for the average user. Question answering (QA) systems assist by translating natural language questions to SPARQL. Existing QA systems are typically based on application-specific human-curated rules, or require prior information, expensive pre-processing and model adaptation for each targeted KG. Therefore, they are hard to generalize to a broad set of applications and KGs. In this paper, we propose KGQAn, a universal QA system that does not need to be tailored to each target KG. Instead of curated rules, KGQAn introduces a novel formalization of question understanding as a text generation problem to convert a question into an intermediate abstract representation via a neural sequence-to-sequence model. We also develop a just-in-time linker that maps at query time the abstract representation to a SPARQL query for a specific KG, using only the publicly accessible APIs and the existing indices of the RDF store, without requiring any pre-processing. Our experiments with several real KGs demonstrate that KGQAn is easily deployed and outperforms by a large margin the state-of-the-art in terms of quality of answers and processing time, especially for arbitrary KGs, unseen during the training.


Character-level NMT and language similarity

arXiv.org Artificial Intelligence

We explore the effectiveness of character-level neural machine translation using Transformer architecture for various levels of language similarity and size of the training dataset on translation between Czech and Croatian, German, Hungarian, Slovak, and Spanish. We evaluate the models using automatic MT metrics and show that translation between similar languages benefits from character-level input segmentation, while for less related languages, character-level vanilla Transformer-base often lags behind subword-level segmentation. We confirm previous findings that it is possible to close the gap by finetuning the already trained subword-level models to character-level.


Towards Machine Learning-based Fish Stock Assessment

arXiv.org Artificial Intelligence

The accurate assessment of fish stocks is crucial for sustainable fisheries management. However, existing statistical stock assessment models can have low forecast performance of relevant stock parameters like recruitment or spawning stock biomass, especially in ecosystems that are changing due to global warming and other anthropogenic stressors. In this paper, we investigate the use of machine learning models to improve the estimation and forecast of such stock parameters. We propose a hybrid model that combines classical statistical stock assessment models with supervised ML, specifically gradient boosted trees. Our hybrid model leverages the initial estimate provided by the classical model and uses the ML model to make a post-hoc correction to improve accuracy. We experiment with five different stocks and find that the forecast accuracy of recruitment and spawning stock biomass improves considerably in most cases.


Democratising AI: Multiple Meanings, Goals, and Methods

arXiv.org Artificial Intelligence

Numerous parties are calling for the democratisation of AI, but the phrase is used to refer to a variety of goals, the pursuit of which sometimes conflict. This paper identifies four kinds of AI democratisation that are commonly discussed: (1) the democratisation of AI use, (2) the democratisation of AI development, (3) the democratisation of AI profits, and (4) the democratisation of AI governance. Numerous goals and methods of achieving each form of democratisation are discussed. The main takeaway from this paper is that AI democratisation is a multifarious and sometimes conflicting concept that should not be conflated with improving AI accessibility. If we want to move beyond ambiguous commitments to democratising AI, to productive discussions of concrete policies and trade-offs, then we need to recognise the principal role of the democratisation of AI governance in navigating tradeoffs and risks across decisions around use, development, and profits.