arXiv subjects

Luigi Marini

Publications and source records attributed to Luigi Marini.

4 recordsLinked to original sources

arXiv2026

Circumpolar Wall-to-Wall Detection of Retrogressive Thaw Slumps with Scarce Labels and Extreme Class Imbalance

Retrogressive thaw slumps (RTS) are among the most dynamic ground deformations caused by permafrost thaw. Abrupt thaw processes such as RTS could roughly double the contribution of permafrost thaw to climate warming, and already threaten a third of Arctic infrastructure. Circumpolar RTS mapping has advanced quickly, yet released inventories together cover only part of the permafrost region. RTS occupy only 0.1-0.5% of image tiles and labels are costly, so a detector must be designed and evaluated as a rare-target problem. We therefore developed a deep learning system and mapped 20.68 M square kilometres of circumpolar permafrost using 41.6 M tiles of 4.8 m PlanetScope imagery. Training used 22,259 tiles with 2,609 RTS instances in 1,718 of them, and the model was tuned through 172 controlled experiments. A convolutional network matched every alternative tested, including multimodal fusion, foundation-model encoders and masked-autoencoder pretraining, each at far more compute for similar or worse results. Labelled data moved performance most, and a foundation model's advantage appeared only when labels were scarce. Tested once on held-out ecoregions at the real-world prevalence of 0.1-0.5%, the final model achieved an area under the precision-recall curve of 0.812-0.855, an object precision of 0.854 and F1 of 0.644. Deployed wall-to-wall, the model produced a circumpolar map of 19,068 high-confidence detections whose sampled precision ranges from 0.54 to 0.90 by size class. We present an evaluation protocol for rare targets, a controlled account of what governs accuracy under scarce labels, and the circumpolar RTS map the validated model produced.

cs.CV↗

arXiv2023

Self-Supervised Masked Digital Elevation Models Encoding for Low-Resource Downstream Tasks

The lack of quality labeled data is one of the main bottlenecks for training Deep Learning models. As the task increases in complexity, there is a higher penalty for overfitting and unstable learning. The typical paradigm employed today is Self-Supervised learning, where the model attempts to learn from a large corpus of unstructured and unlabeled data and then transfer that knowledge to the required task. Some notable examples of self-supervision in other modalities are BERT for Large Language Models, Wav2Vec for Speech Recognition, and the Masked AutoEncoder for Vision, which all utilize Transformers to solve a masked prediction task. GeoAI is uniquely poised to take advantage of the self-supervised methodology due to the decades of data collected, little of which is precisely and dependably annotated. Our goal is to extract building and road segmentations from Digital Elevation Models (DEM) that provide a detailed topography of the earths surface. The proposed architecture is the Masked Autoencoder pre-trained on ImageNet (with the limitation that there is a large domain discrepancy between ImageNet and DEM) with an UperNet Head for decoding segmentations. We tested this model with 450 and 50 training images only, utilizing roughly 5% and 0.5% of the original data respectively. On the building segmentation task, this model obtains an 82.1% Intersection over Union (IoU) with 450 Images and 69.1% IoU with only 50 images. On the more challenging road detection task the model obtains an 82.7% IoU with 450 images and 73.2% IoU with only 50 images. Any hand-labeled dataset made today about the earths surface will be immediately obsolete due to the constantly changing nature of the landscape. This motivates the clear necessity for data-efficient learners that can be used for a wide variety of downstream tasks.

cs.CV↗

arXiv2015

Standing Together for Reproducibility in Large-Scale Computing: Report on reproducibility@XSEDE

This is the final report on reproducibility@xsede, a one-day workshop held in conjunction with XSEDE14, the annual conference of the Extreme Science and Engineering Discovery Environment (XSEDE). The workshop's discussion-oriented agenda focused on reproducibility in large-scale computational research. Two important themes capture the spirit of the workshop submissions and discussions: (1) organizational stakeholders, especially supercomputer centers, are in a unique position to promote, enable, and support reproducible research; and (2) individual researchers should conduct each experiment as though someone will replicate that experiment. Participants documented numerous issues, questions, technologies, practices, and potentially promising initiatives emerging from the discussion, but also highlighted four areas of particular interest to XSEDE: (1) documentation and training that promotes reproducible research; (2) system-level tools that provide build- and run-time information at the level of the individual job; (3) the need to model best practices in research collaborations involving XSEDE staff; and (4) continued work on gateways and related technologies. In addition, an intriguing question emerged from the day's interactions: would there be value in establishing an annual award for excellence in reproducible research?

cs.DC↗

arXiv2009

Embedding Data within Knowledge Spaces

The promise of e-Science will only be realized when data is discoverable, accessible, and comprehensible within distributed teams, across disciplines, and over the long-term--without reliance on out-of-band (non-digital) means. We have developed the open-source Tupelo semantic content management framework and are employing it to manage a wide range of e-Science entities (including data, documents, workflows, people, and projects) and a broad range of metadata (including provenance, social networks, geospatial relationships, temporal relations, and domain descriptions). Tupelo couples the use of global identifiers and resource description framework (RDF) statements with an aggregatable content repository model to provide a unified space for securely managing distributed heterogeneous content and relationships.

cs.AI↗