arc length
- North America > United States > Massachusetts > Middlesex County > Cambridge (0.14)
- Oceania > Australia (0.04)
- Asia > China > Jiangsu Province > Nanjing (0.04)
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Estimating the Arc Length of the Optimal ROC Curve and Lower Bounding the Maximal AUC
In this paper, we show the arc length of the optimal ROC curve is an $f$-divergence. By leveraging this result, we express the arc length using a variational objective and estimate it accurately using positive and negative samples. We show this estimator has a non-parametric convergence rate $O_p(n^{-\beta/4})$ ($\beta \in (0,1]$ depends on the smoothness). Using the same technique, we show the surface area sandwiched between the optimal ROC curve and the diagonal can be expressed via a similar variational objective. These new insights lead to a novel two-step classification procedure that maximizes an approximate lower bound of the maximal AUC. Experiments on CIFAR-10 datasets show the proposed two-step procedure achieves good AUC performance in imbalanced binary classification tasks.
- North America > United States > Massachusetts > Middlesex County > Cambridge (0.14)
- Oceania > Australia (0.04)
- Asia > China > Jiangsu Province > Nanjing (0.04)
- (3 more...)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
- Asia > Middle East > Jordan (0.04)
- Information Technology > Artificial Intelligence > Machine Learning > Statistical Learning (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Performance Analysis > Accuracy (1.00)
- Information Technology > Data Science (0.93)
- Information Technology > Artificial Intelligence > Representation & Reasoning (0.93)
Uncertainty-Aware Perception-Based Control for Autonomous Racing
Trisovic, Jelena, Carron, Andrea, Zeilinger, Melanie N.
--Autonomous systems operating in unknown environments often rely heavily on visual sensor data, yet making safe and informed control decisions based on these measurements remains a significant challenge. T o facilitate the integration of perception and control in autonomous vehicles, we propose a novel perception-based control approach that incorporates road estimation, quantification of its uncertainty, and uncertainty-aware control based on this estimate. At the core of our method is a parametric road curvature model, optimized using visual measurements of the road through a constrained nonlinear optimization problem. This process ensures adherence to constraints on both model parameters and curvature. By leveraging the Frenet frame formulation, we embed the estimated track curvature into the system dynamics, allowing the controller to explicitly account for perception uncertainty and enhancing robustness to estimation errors based on visual input. We validate our approach in a simulated environment, using a high-fidelity 3D rendering engine, and demonstrate its effectiveness in achieving reliable and uncertainty-aware control for autonomous racing. Robots increasingly rely on visual feedback to navigate and operate in unknown, complex environments. Recent advances demonstrate the potential of visual perception for control tasks [1], [2], enabling robots to make decisions based on high-dimensional sensory inputs. However, safe deployment of autonomous systems requires robust handling of uncertainty throughout the autonomy stack, including perception, planning, and control, to ensure reliability in dynamic and unpredictable settings. Most existing perception-based control methods, however, assume perfect perception and treat its outputs as certain and fully reliable [2], [3]. This decoupled design of the modules can lead to compounding error and cascading failures in safety-critical applications.
- Europe > Switzerland > Zürich > Zürich (0.04)
- North America > United States > California > Alameda County > Berkeley (0.04)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.04)
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- Automobiles & Trucks (1.00)
- Transportation > Ground > Road (0.46)
Estimating the Arc Length of the Optimal ROC Curve and Lower Bounding the Maximal AUC
In this paper, we show the arc length of the optimal ROC curve is an f -divergence. By leveraging this result, we express the arc length using a variational objective and estimate it accurately using positive and negative samples. We show this estimator has a non-parametric convergence rate O_p(n {-\beta/4}) ( \beta \in (0,1] depends on the smoothness). Using the same technique, we show the surface area sandwiched between the optimal ROC curve and the diagonal can be expressed via a similar variational objective. These new insights lead to a novel two-step classification procedure that maximizes an approximate lower bound of the maximal AUC.
Projected random forests and conformal prediction of circular data
F., Paulo C. Marques, Artes, Rinaldo, Graziadei, Helton
We apply split conformal prediction techniques to regression problems with circular responses by introducing a suitable conformity score, leading to prediction sets with adaptive arc length and finite-sample coverage guarantees for any circular predictive model under exchangeable data. Leveraging the high performance of existing predictive models designed for linear responses, we analyze a general projection procedure that converts any linear response regression model into one suitable for circular responses. When random forests serve as basis models in this projection procedure, we harness the out-of-bag dynamics to eliminate the necessity for a separate calibration sample in the construction of prediction sets. For synthetic and real datasets the resulting projected random forests model produces more efficient out-of-bag conformal prediction sets, with shorter median arc length, when compared to the split conformal prediction sets generated by two existing alternative models.
- Europe > Austria > Vienna (0.14)
- South America > Brazil > São Paulo (0.04)
- South America > Brazil > Rio de Janeiro > Rio de Janeiro (0.04)
- Africa > Cabo Verde > Praia > Praia (0.04)
- Information Technology > Artificial Intelligence > Machine Learning > Decision Tree Learning (0.96)
- Information Technology > Artificial Intelligence > Machine Learning > Ensemble Learning (0.86)
- Information Technology > Artificial Intelligence > Machine Learning > Statistical Learning > Regression (0.48)
An iterative closest point algorithm for marker-free 3D shape registration of continuum robots
Hoffmann, Matthias K., Mühlenhoff, Julian, Ding, Zhaoheng, Sattel, Thomas, Flaßkamp, Kathrin
Continuum robots have emerged as a promising technology in the medical field due to their potential of accessing deep sited locations of the human body with low surgical trauma. When deriving physics-based models for these robots, evaluating the models poses a significant challenge due to the difficulty in accurately measuring their intricate shapes. In this work, we present an optimization based 3D shape registration algorithm for estimation of the backbone shape of slender continuum robots as part of a pho togrammetric measurement. Our approach to estimating the backbones optimally matches a parametric three-dimensional curve to images of the robot. Since we incorporate an iterative closest point algorithm into our method, we do not need prior knowledge of the robots position within the respective images. In our experiments with artificial and real images of a concentric tube continuum robot, we found an average maximum deviation of the reconstruction from simulation data of 0.665 mm and 0.939 mm from manual measurements. These results show that our algorithm is well capable of producing high accuracy positional data from images of continuum robots.
Contrasting Linguistic Patterns in Human and LLM-Generated Text
Muñoz-Ortiz, Alberto, Gómez-Rodríguez, Carlos, Vilares, David
We conduct a quantitative analysis contrasting human-written English news text with comparable large language model (LLM) output from 4 LLMs from the LLaMa family. Our analysis spans several measurable linguistic dimensions, including morphological, syntactic, psychometric and sociolinguistic aspects. The results reveal various measurable differences between human and AI-generated texts. Among others, human texts exhibit more scattered sentence length distributions, a distinct use of dependency and constituent types, shorter constituents, and more aggressive emotions (fear, disgust) than LLM-generated texts. LLM outputs use more numbers, symbols and auxiliaries (suggesting objective language) than human texts, as well as more pronouns. The sexist bias prevalent in human text is also expressed by LLMs.
- North America > United States > Washington > King County > Seattle (0.04)
- North America > United States > Texas > Travis County > Austin (0.04)
- North America > United States > New York (0.04)
- (6 more...)