330 research outputs found
Collective Dynamics of Swarms with a New Attraction/Repulsion Function
We specify an “individual-based” continuous-time model for swarm aggregation in -dimensional Euclidean space. We show that the swarm is completely stable, and the center of the swarm is stationary. Numerical simulations indicate that the individuals will form a stable and cohesive swarm, and under the attraction/repulsion function, the bound of the swarm size will increase as the number of individuals increases
Real-Time Illegal Parking Detection System Based on Deep Learning
The increasing illegal parking has become more and more serious. Nowadays the
methods of detecting illegally parked vehicles are based on background
segmentation. However, this method is weakly robust and sensitive to
environment. Benefitting from deep learning, this paper proposes a novel
illegal vehicle parking detection system. Illegal vehicles captured by camera
are firstly located and classified by the famous Single Shot MultiBox Detector
(SSD) algorithm. To improve the performance, we propose to optimize SSD by
adjusting the aspect ratio of default box to accommodate with our dataset
better. After that, a tracking and analysis of movement is adopted to judge the
illegal vehicles in the region of interest (ROI). Experiments show that the
system can achieve a 99% accuracy and real-time (25FPS) detection with strong
robustness in complex environments.Comment: 5pages,6figure
Evolution of interactions and cooperation in the spatial prisoner's dilemma game
We study the evolution of cooperation in the spatial prisoner's dilemma game
where players are allowed to establish new interactions with others. By
employing a simple coevolutionary rule entailing only two crucial parameters,
we find that different selection criteria for the new interaction partners as
well as their number vitally affect the outcome of the game. The resolution of
the social dilemma is most probable if the selection favors more successful
players and if their maximally attainable number is restricted. While the
preferential selection of the best players promotes cooperation irrespective of
game parametrization, the optimal number of new interactions depends somewhat
on the temptation to defect. Our findings reveal that the "making of new
friends" may be an important activity for the successful evolution of
cooperation, but also that partners must be selected carefully and their number
limited.Comment: 14 pages, 6 figures; accepted for publication in PLoS ON
Autonomous Optimization of Swimming Gait in a Fish Robot With Multiple Onboard Sensors
Autonomous gait optimization is an essential survival ability for mobile robots. However, it remains a challenging task for underwater robots. This paper addresses this problem for the locomotion of a bio-inspired robotic fish and aims at identifying fast swimming gait autonomously by the robot. Our approach for learning locomotion controllers mainly uses three components: 1) a biological concept of central pattern generator to obtain specific gaits; 2) an onboard sensory processing center to discover the environment and to evaluate the swimming gait; and 3) an evolutionary algorithm referred to as particle swarm optimization. A key aspect of our approach is the swimming gait of the robot is optimized autonomously, equivalent to that the robot is able to navigate and evaluate its swimming gait in the environment by the onboard sensors, and simultaneously run a built-in evolutionary algorithm to optimize its locomotion all by itself. Forward speed optimization experiments conducted on the robotic fish demonstrate the effectiveness of the developed autonomous optimization system. The latest results show that our robotic fish attained a maximum swimming speed of 1.011 BL/s (40.42 cm/s) through autonomous gait optimization, faster than any of the robot's previously recorded speeds
Graded extensions in K[Q, sigma]
Let V be a total valuation ring of a division ring K, Q be the additive group
of the rational numbers, Aut(K) be the group of automorphisms of K. Let sigma
be a group homomorphism from Q to Aut(K). Let K[Q, sigma ] be the skew group
ring of Q over K. In this paper, we classify graded extensions of V in K[Q,
sigma] into two types and study the structure of them
- …