81 research outputs found
Action valuation of on- and off-ball soccer players based on multi-agent deep reinforcement learning
Analysis of invasive sports such as soccer is challenging because the game
situation changes continuously in time and space, and multiple agents
individually recognize the game situation and make decisions. Previous studies
using deep reinforcement learning have often considered teams as a single agent
and valued the teams and players who hold the ball in each discrete event. Then
it was challenging to value the actions of multiple players, including players
far from the ball, in a spatiotemporally continuous state space. In this paper,
we propose a method of valuing possible actions for on- and off-ball soccer
players in a single holistic framework based on multi-agent deep reinforcement
learning. We consider a discrete action space in a continuous state space that
mimics that of Google research football and leverages supervised learning for
actions in reinforcement learning. In the experiment, we analyzed the
relationships with conventional indicators, season goals, and game ratings by
experts, and showed the effectiveness of the proposed method. Our approach can
assess how multiple players move continuously throughout the game, which is
difficult to be discretized or labeled but vital for teamwork, scouting, and
fan engagement.Comment: 12 pages, 4 figure
Runner re-identification from single-view video in the open-world setting
In many sports, player re-identification is crucial for automatic video
processing and analysis. However, most of the current studies on player
re-identification in multi- or single-view sports videos focus on
re-identification in the closed-world setting using labeled image dataset, and
player re-identification in the open-world setting for automatic video analysis
is not well developed. In this paper, we propose a runner re-identification
system that directly processes single-view video to address the open-world
setting. In the open-world setting, we cannot use labeled dataset and have to
process video directly. The proposed system automatically processes raw video
as input to identify runners, and it can identify runners even when they are
framed out multiple times. For the automatic processing, we first detect the
runners in the video using the pre-trained YOLOv8 and the fine-tuned
EfficientNet. We then track the runners using ByteTrack and detect their shoes
with the fine-tuned YOLOv8. Finally, we extract the image features of the
runners using an unsupervised method using the gated recurrent unit autoencoder
model. To improve the accuracy of runner re-identification, we use dynamic
features of running sequence images. We evaluated the system on a running
practice video dataset and showed that the proposed method identified runners
with higher accuracy than one of the state-of-the-art models in unsupervised
re-identification. We also showed that our unsupervised running dynamic feature
extractor was effective for runner re-identification. Our runner
re-identification system can be useful for the automatic analysis of running
videos.Comment: 18 pages, 8 figure
Adaptive action supervision in reinforcement learning from real-world multi-agent demonstrations
Modeling of real-world biological multi-agents is a fundamental problem in
various scientific and engineering fields. Reinforcement learning (RL) is a
powerful framework to generate flexible and diverse behaviors in cyberspace;
however, when modeling real-world biological multi-agents, there is a domain
gap between behaviors in the source (i.e., real-world data) and the target
(i.e., cyberspace for RL), and the source environment parameters are usually
unknown. In this paper, we propose a method for adaptive action supervision in
RL from real-world demonstrations in multi-agent scenarios. We adopt an
approach that combines RL and supervised learning by selecting actions of
demonstrations in RL based on the minimum distance of dynamic time warping for
utilizing the information of the unknown source dynamics. This approach can be
easily applied to many existing neural network architectures and provide us
with an RL model balanced between reproducibility as imitation and
generalization ability to obtain rewards in cyberspace. In the experiments,
using chase-and-escape and football tasks with the different dynamics between
the unknown source and target environments, we show that our approach achieved
a balance between the reproducibility and the generalization ability compared
with the baselines. In particular, we used the tracking data of professional
football players as expert demonstrations in football and show successful
performances despite the larger gap between behaviors in the source and target
environments than the chase-and-escape task.Comment: 14 pages, 5 figure
Peplomycin-induced DNA repair synthesis in permeable mouse ascites sarcoma cells.
DNA repair synthesis induced in permeable mouse ascites sarcoma cells by peplomycin, an antitumor antibiotic, was studied. Mouse ascites sarcoma (SR-C3H/He) cells were permeabilized with a low concentration of Triton X-100 in an isotonic condition. Permeable cells were treated with an appropriate concentration of peplomycin to introduce single-strand breaks in permeable cell DNA. DNA repair synthesis in peplomycin-treated permeable cells was measured by incubating the cells with four deoxynucleoside triphosphates in an appropriate buffer system. The DNA repair synthesis was enhanced by ATP and NaCl at near physiological concentrations. More than 90% of DNA synthesis in the present system depended on the peplomycin-treatment. The repair nature of the DNA synthesis was confirmed by a BrdUMP density shift technique. The repair patches were largely completed and ligated in the presence of ATP. Analyses using selective inhibitors for DNA polymerases showed that both DNA polymerase Beta and aphidicolin-sensitive DNA polymerases (DNA polymerase alpha and/or delta) were involved in the repair DNA synthesis.</P></p
The Institutional Presidency from a Comparative Perspective: Argentina and Brazil since the 1980s
This paper focuses on the evolution of the institutional presidency - meaning the cluster of agencies that directly support the chief of the executive - in Argentina and Brazil since their redemocratization in the 1980s. It investigates what explains the changes that have come about regarding the size of the institutional presidency and the types of agency that form it. Following the specialized literature, we argue that the growth of the institutional presidency is connected to developments occurring in the larger political system - that is, to the political challenges that the various presidents of the two countries have faced. Presidents adjust the format and mandate of the different agencies under their authority so as to better manage their relations with the political environment. In particular, we argue that the type of government (coalition or single-party) has had consequences for the structure of the presidency or, in other words, that different cabinet structures pose different challenges to presidents. This factor has not played a significant role in presidency-related studies until now, which have hitherto mostly been based on the case of the United States. Our empirical references, the presidencies of Argentina and Brazil, typical cases of coalitional as well as single-party presidentialism respectively allow us to show the impact of the type of government on the number and type of presidential agencies
- …