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Shuhan Ge

Publications and source records attributed to Shuhan Ge.

2 recordsLinked to original sources

REKEY: Metadata-Grounded Visual-Key Regeneration for Contamination-Resilient VQA Evaluation

Static visual question answering (VQA) benchmarks age quickly: Once the items leak into training corpora, scores can reflect memorization rather than genuine visual ability, thus obscuring real progress. Rebuilding high-quality benchmarks such as V*Bench requires substantial human annotation, yet each static release can quickly become another leaked artifact. We propose ReKey, a live benchmark protocol that randomly regenerates the answer-bearing local detail, or visual key, in real images at evaluation time. Using human-validated edit slots, ReKey samples fresh instances with new answers, construction-grounded labels, and controlled visual-search difficulty. On V*Bench, the ReKey regenerated benchmark reveals a sharp score jump across eight frontier vision-language models (VLMs): The original items score 9.5--18.8 percentage points higher than the regenerated variants. By making the visual key renewable, ReKey keeps evaluation fresh as models and training data evolve.

cs.CV

Quantifying real-world energy use and CO2 emissions of electric vehicles via a city-scale bottom-up framework

Although electric vehicles (EVs) are scaling rapidly, city-scale evidence on real-world operational energy use and carbon dioxide (CO2) emissions from EVs remains limited. Using Shanghai as a case study, this study develops a bottom-up framework covering all EV models registered between July 2022 and December 2024 to quantify model-specific real-world energy intensity, the operational energy mix, and associated CO2 emissions. The results indicate that (1) pronounced and systematic underestimation by test-cycle values: on average, real-world use is 20.8% greater for battery electric vehicles (BEVs) and ~55% greater for plug-in hybrid electric vehicles (PHEVs), whereas extended-range EVs (EREVs) show the largest gaps, as many models consume 3.75 times more energy than their official data suggest. (2) From 2022-2024, electricity supplies more than 70% of operational energy, and power-sector emissions dominate EV operational CO2, contributing 75.3%, 85.7% and 87.0% in 2022, 2023 and 2024, respectively. (3) BEVs achieve the greatest absolute mitigation under current policies, with 1,834 kilotons (kt) of CO2 in 2035, modest benefits from PHEVs, and strong gains for EREVs under more ambitious policies (up to 2,122 kt of CO2 in 2035). These findings underscore the need to align fleet electrification with grid decarbonization, alleviate congestion, improve charging accessibility, and narrow test-cycle versus on-road performance gaps to fully realize the climate benefits of EVs in megacities.

physics.soc-ph