Delhi Technological University

About: Delhi Technological University is a education organization based out in New Delhi, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 4427 authors who have published 6761 publications receiving 71035 citations. The organization is also known as: Delhi College of Engineering & DTU.

Explain Your Move: Understanding Agent Actions Using Specific and Relevant Feature Attribution

Abstract: As deep reinforcement learning (RL) is applied to more tasks, there is a need to visualize and understand the behavior of learned agents. Saliency maps explain agent behavior by highlighting the features of the input state that are most relevant for the agent in taking an action. Existing perturbation-based approaches to compute saliency often highlight regions of the input that are not relevant to the action taken by the agent. Our proposed approach, SARFA (Specific and Relevant Feature Attribution), generates more focused saliency maps by balancing two aspects (specificity and relevance) that capture different desiderata of saliency. The first captures the impact of perturbation on the relative expected reward of the action to be explained. The second downweighs irrelevant features that alter the relative expected rewards of actions other than the action to be explained. We compare SARFA with existing approaches on agents trained to play board games (Chess and Go) and Atari games (Breakout, Pong and Space Invaders). We show through illustrative examples (Chess, Atari, Go), human studies (Chess), and automated evaluation methods (Chess) that SARFA generates saliency maps that are more interpretable for humans than existing approaches. For the code release and demo videos, see this https URL.

Radiation characteristics of higher-order modes in microstrip ring antenna

Abstract: The results of the theoretical analysis of modal fields and radiation characteristics of the microstrip ring antenna are presented. Radiation patterns for the different modes are derived from the fringing fields at the inner and outer peripheries of the ring. Theoretical patterns are compared with experimental results at 1.8 GHz. The analyses show that the TM 1m -modes (m = 2, 4, 6,...) are suitable for broadband boresight antennas while TM 1m -modes (m = 1,3,...) may be used for narrowband boresight antennas.

Hexagonal Ceria Located at the Interface of Anatase/Rutile TiO2 Superstructure Optimized for High Activity under Combined UV and Visible-Light Irradiation

Abstract: The photocatalytic activity of the system critically depends on the catalyst’s architecture and composition. In a ceria–titania system a proper ratio and location of ceria on titania might be crucial to have an optimum level of physicochemical properties for efficient charge carrier generation and separation in the system to initiate redox reaction at its surface. Herein, a novel architecture of the ceria-doped TiO2 system has been developed to study its photoactivity and the mechanism of charge transfer. The photocatalytic activity with optimum cerium content Ce/Ti = 0.2 wt % shows the highest degradation of methylene blue under combined (UV + Vis) irradiation compared to the pristine titania. The obtained result shows that catalyst composition is an important parameter in modeling and optimizing the system to have the desired impact on photoactivity. The proposed unique architecture and composition combination appears to be an ideal model for design of novel photoactive materials having activity in a wi...