arXiv subjects

Hisanao Akima

Publications and source records attributed to Hisanao Akima.

3 recordsLinked to original sources

arXiv2024

HICO-DET-SG and V-COCO-SG: New Data Splits for Evaluating the Systematic Generalization Performance of Human-Object Interaction Detection Models

Human-Object Interaction (HOI) detection is a task to localize humans and objects in an image and predict the interactions in human-object pairs. In real-world scenarios, HOI detection models need systematic generalization, i.e., generalization to novel combinations of objects and interactions, because the train data are expected to cover a limited portion of all possible combinations. To evaluate the systematic generalization performance of HOI detection models, we created two new sets of HOI detection data splits named HICO-DET-SG and V-COCO-SG based on the HICO-DET and V-COCO datasets, respectively. When evaluated on the new data splits, HOI detection models with various characteristics performed much more poorly than when evaluated on the original splits. This shows that systematic generalization is a challenging goal in HOI detection. By analyzing the evaluation results, we also gain insights for improving the systematic generalization performance and identify four possible future research directions. We hope that our new data splits and presented analysis will encourage further research on systematic generalization in HOI detection.

cs.CV↗

arXiv2023

Accuracy Improvement Technique of DNN for Accelerating CFD Simulator

There is a Computational fluid dynamics (CFD) method of incorporating the DNN inference to reduce the computational cost. The reduction is realized by replacing some calculations by DNN inference. The cost reduction depends on the implementation method of the DNN and the accuracy of the DNN inference. Thus, we propose two techniques suitable to infer flow field on the CFD grid. The first technique is to infer the flow field of the steady state from the airfoil shape. We use the position on the coordinates of the grid point and the distance from the surface of the airfoil as input information for the DNN. The second method uses the customized mean square error as a loss function. The size of the associated area for each grid point was multiplied by the square error. This method compensates for the effect caused by the size of the associated area of nonuniform allocation of grid points. The evaluation results show that the CFD incorporated first technique achieves 1.7x speedup against the CFD without DNN, while maintaining equivalent result quality. By implementing the second technique, the CFD realized further 2.3x speed up against the CFD with first technique only.

physics.flu-dyn↗

arXiv2007

Stochastic resonance in a single electron turnstile

In this paper, we report stochastic resonance (SR) in a single electron turnstile. It has been known that SR emerges by the cooperation of a weak periodic signal and noise in a bistable system. A periodic signal produces switching between two stable states by lowering the potential barrier. Even if the amplitude of the signal is not large enough to make the potential barrier disappear, the switching can occur with the help of noise. As a result, an output signal-to-noise ratio (SNR), which shows how much the switching is synchronized with the signal, can be enhanced by increasing the noise. We have formulated the SR in a single electron turnstile into the adiabatic two-state theory of McNamara-Wiesenfeld and confirmed its manifestation by numerical simulation. These results could be applied to detection of the periodic motion of very small electric charge under noisy environment.

quant-ph↗