Joel Perca
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Peer-reviewed

Publications

Computer Graphics Forum, vol. 45, no. 3 (Proc. EuroVis 2026)

UrbanClipAtlas: A Visual Analytics Framework for Event and Scene Retrieval in Urban Videos

Joel Perca, Luis Sante Taipe, Juanpablo Heredia, João Rulff, Claudio Silva, Jorge Poco

A visual analytics system for exploring long urban videos recorded at street intersections. It segments recordings into clips, describes them with a vision-language model and indexes them for semantic retrieval, combining retrieval-augmented generation with taxonomy-aware entity extraction and video grounding. A knowledge graph aligns the language model output with detected objects and trajectories, so every answer can be visually grounded and verified. Evaluated on the StreetAware dataset through case studies on hazardous scenarios and pedestrian crossing dynamics.

Presented at EuroVis 2026 — Nottingham, UK — June 2026

PythonVision-Language ModelsRetrieval-Augmented GenerationKnowledge GraphsLangChainSvelteDockerWebSockets

First author · Published

Computers & Graphics (Proc. SIBGRAPI 2025)

STRive: An association rule-based system for the exploration of spatiotemporal categorical data

Mauro Diaz, Luis Sante Taipe, Joel Perca, João Da Silva, Nivan Ferreira, Jorge Poco

A system for mining and exploring association rules over spatiotemporal categorical data. It pairs rule generation and rule clustering with an interactive interface offering two analysis modes — one at the cluster level, one at the individual rule level — connected through coordinated views. Demonstrated through case studies on fatal vehicle accidents and urban crime.

TypeScriptD3.jsPythonscikit-learnAssociation Rule MiningSpatiotemporal Data

Co-author (visualization platform) · Published

Engineering work

Projects

Product/Platform

Podchy

Featured

Kubernetes-based Code as a Service platform to run code via web UI.

KubernetesPythonTypeScriptDockerCI/CD (GitHub Actions)GCP
  • Microservices-based architecture with scaling criteria.
  • Deployment on Google Cloud Platform with CI/CD.

System

Lamport

Featured

Attendance system (Django/React/TypeScript) for a conference; team lead and deployment.

Django REST FrameworkReactTypeScriptDockerGCP
  • Microservices-based architecture with scaling criteria.
  • Deployment on Google Cloud Platform with CI/CD.

Web App

Chronious

Time tracking web app with NestJS, MongoDB, React, and TypeScript.

Node.jsNestJSMongoDBReactTypeScript

Open Source

Estela / Estela-CLI

Platform for managing scraping jobs; contributions across backend, frontend, and CLI.

DjangoDjango REST FrameworkReactTypeScriptKubernetesPython