Jozef Grycz (1890-1954) – An Appreciation

Introduction to the life and works of Jozef Grycz, one of the founders of modern Polish libraries and librarianshi

Exploring the Benefits of Teams in Multiagent Learning

For problems requiring cooperation, many multiagent systems implement solutions among either individual agents or across an entire population towards a common goal. Multiagent teams are primarily studied when in conflict; however, organizational psychology (OP) highlights the benefits of teams among human populations for learning how to coordinate and cooperate. In this paper, we propose a new model of multiagent teams for reinforcement learning (RL) agents inspired by OP and early work on teams in artificial intelligence. We validate our model using complex social dilemmas that are popular in recent multiagent RL and find that agents divided into teams develop cooperative pro-social policies despite incentives to not cooperate. Furthermore, agents are better able to coordinate and learn emergent roles within their teams and achieve higher rewards compared to when the interests of all agents are aligned.Comment: 10 pages, 6 figures, Published at IJCAI 2022. arXiv admin note: text overlap with arXiv:2204.0747

Towards a Better Understanding of Learning with Multiagent Teams

While it has long been recognized that a team of individual learning agents can be greater than the sum of its parts, recent work has shown that larger teams are not necessarily more effective than smaller ones. In this paper, we study why and under which conditions certain team structures promote effective learning for a population of individual learning agents. We show that, depending on the environment, some team structures help agents learn to specialize into specific roles, resulting in more favorable global results. However, large teams create credit assignment challenges that reduce coordination, leading to large teams performing poorly compared to smaller ones. We support our conclusions with both theoretical analysis and empirical results.Comment: 15 pages, 11 figures, published at the International Joint Conference on Artificial Intelligence (IJCAI) in 202

What would Jaws do? The tyranny of film and the relationship between gaze and higher-level narrative film comprehension

What is the relationship between film viewers’ eye movements and their film comprehension? Typical Hollywood movies induce strong attentional synchrony—most viewers look at the same things at the same time. Thus, we asked whether film viewers’ eye movements would differ based on their understanding—the mental model hypothesis—or whether any such differences would be overwhelmed by viewers’ attentional synchrony—the tyranny of film hypothesis. To investigate this question, we manipulated the presence/absence of prior film context and measured resulting differences in film comprehension and eye movements. Viewers watched a 12-second James Bond movie clip, ending just as a critical predictive inference should be drawn that Bond’s nemesis, “Jaws,” would fall from the sky onto a circus tent. The No-context condition saw only the 12-second clip, but the Context condition also saw the preceding 2.5 minutes of the movie before seeing the critical 12-second portion. Importantly, the Context condition viewers were more likely to draw the critical inference and were more likely to perceive coherence across the entire 6 shot sequence (as shown by event segmentation), indicating greater comprehension. Viewers’ eye movements showed strong attentional synchrony in both conditions as compared to a chance level baseline, but smaller differences between conditions. Specifically, the Context condition viewers showed slightly, but significantly, greater attentional synchrony and lower cognitive load (as shown by fixation probability) during the critical first circus tent shot. Thus, overall, the results were more consistent with the tyranny of film hypothesis than the mental model hypothesis. These results suggest the need for a theory that encompasses processes from the perception to the comprehension of film

Observations on abundance of bluntnose sixgill sharks, Hexanchus griseus, in an urban waterway in the Salish Sea, 2003-2012

The bluntnose sixgill shark, Hexanchus griseus, is a widely distributed but poorly understood large, apex predator. Anecdotal reports of diver-shark encounters in the late 1990’s and early 2000’s in the Pacific Northwest stimulated interest in the normally deep-dwelling shark and the reason for its presence in the shallow waters of the Salish Sea. Analysis of underwater video documenting sharks at the Seattle Aquarium’s sixgill research site on Seattle’s waterfront and mark-recapture techniques were used to identify individual sharks to answer simple questions about abundance and seasonality. Temporal changes in relative abundance in Puget Sound were reported from a controlled study site from 2003-2012. At the Seattle Aquarium study site, 45 sixgills were observed and tagged with modified Floy visual marker tags, along with an estimated 116 observations of untagged sharks. Mark/Recapture statistical model estimates based on video observations ranged from a high of 98 sharks observed in July of 2004 to a low of 0 sharks observed in several research events from 2008-2012. Both analyses found sixgills significantly more abundant in the summer months at the Aquarium’s research station from 2003-2005 than at any other time during the study

Relative Abundance of Sixgill Sharks (Hexanchus griseus) in Elliott Bay, Seattle, Washington

The Sixgill Shark Research Project is designed to address gaps in the body of scientific knowledge on bluntnose sixgill sharks (Hexanchus griseus) in Puget Sound. This project utilizes three interwoven techniques: (1) genetics research, (2) visual marker tagging, and (3) video analysis. Seattle Aquarium biologists monitor sixgill shark sightings reported by local divers (since 1999) and study their relative abundance in Elliott Bay under the Aquarium’s pier (since 2003). Here we report on our findings of relative abundance. Bluntnose sixgills are a species of conservation concern. Sixgills are listed as “near threatened” on the IUCN Red List. Living mainly at abyssal depths but also in the shallow waters of the Salish Sea, sixgills are thought to be long-lived and slow-growing, and appear to have established movement corridors and home ranges that remain relatively fixed over time. As apex predators they are important members of marine communities; and, owing to their life history characteristics such as a slow rate of maturity and low reproductive rates, are thought to be extremely vulnerable to exploitation. Here we present our findings of relative abundance of sixgill sharks in Elliot Bay during the two time periods that the research was conducted: 2003-2005 and 2008-2015. We present the number of individual sharks seen each night, number of sharks tagged, number of returning tagged sharks, sex ratios, estimated number of sixgills residing in Elliott Bay (using capture-mark-recapture techniques), and seasonal and long-term trends in abundance

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