We introduce basic behaviors as primitives for control and learning in situated, embodied agents interacting in complex domains. We propose methods for selecting, formally specifying, algorithmically implementing, empirically evaluating, and combining behaviors from a basic set. We also introduce a general methodology for automatically constructing higher--level behaviors by learning to select from this set. Based on a formulation of reinforcement learning using conditions, behaviors, and shaped reinforcement, out approach makes behavior selection learnable in noisy, uncertain environments with stochastic dynamics. All described ideas are validated with groups of up to 20 mobile robots performing safe--wandering, following, aggregation, dispersion, homing, flocking, foraging, and learning to forage.

The recent breakthroughs in communication technologies have reintroduced the user to Internet. Media consumers became empowered with the capabality to produce, and will gradually shift from the traditional role of an audience to generate content, compete with mainstream media and construct new social and cultural realities. The impact user-generated-content is having over individuals and groups is still ambiguous and requires a better understanding of both the nature of UGC and the particularity of social media platforms as a channel. The pupose of this paper is to further the discussion on how user-generated-content impact audiences in terms of opinion and behavior, particularly during periods of crisis.

Social insects are used as models for understanding the evolution of sociality because they show seemingly complex behavioral and physiological traits that enforce group cohesion, collective organization, and group level reproduction. Social organization in insect societies requires workers to share information. Information sharing allows workers to efficiently perform and switch among tasks to meet colony needs. For many species that nest in preformed cavities, colony growth results in crowding inside the nest which can affect colony productivity and fitness. How does colony size and social density affect individual and collective behavior? Using a combination of laboratory and field experiments, I have begun to answer this question. In Temnothorax rugatulus ants, high social density resulted in greater colony energy use. In addition, larger colonies used proportionally less energy compared to smaller colonies, but showed reduced brood production. These results indicate that the way colonies use energy changes with social density and group size. In analyzing the effects of colony size and density on worker behavior, I found that high density increased worker connectivity and information sharing. Workers in larger colonies showed less connectivity compared to workers in smaller colonies. Interestingly, workers with more interactions spent less time in brood care. This study shows that workers' access to information and the overall pattern of information flow are affected by social density and colony size, and changes in worker connectivity can influence task behavior. The next study shows that field colonies maintained a relatively constant level of intranidal density irrespective of colony size; this suggests that Temnothorax ants actively regulate social density. When colonies were established in high density nests, they showed greater foraging and scouting activities, and this led to a higher probability for becoming polydomous, i.e., occupying multiple nests. When polydomy occurred, colonies divided evenly between two nests, but distributed fewer, heavier workers and brood to the supplemental nests. Taken together, the first four studies indicate that social density is an important colony phenotype that affects individual and collective behavior and energetics in ants, and the collective management of social density may be a group adaptation in ants and other social insects. Lastly, because crowding affects polydomy behavior, the final two experiments tested whether colony emigration and nest construction and dispersion, two strategies for reducing intranidal crowding, are influenced by food distribution. Temnothorax colonies preferred to emigrate to nests positioned closer to food, and weaver ants (Oecophylla smaragdina) positioned newly constructed nests in food-rich areas. Furthermore, weaver ants used the newly constructed nests to more rapidly retrieve and safeguard valuable food items. Thus, strategic emigrations and adaptive nest dispersion can remedy intranidal crowding and at the same time allow growing colonies to acquire adequate food to meet colony needs.

Thesis (Ph. D.)--University of California, San Diego, 2003. / Vita. Includes bibliographical references (leaves 270-281).

Thesis (M.A.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (leaves 84-86). Also available via the World Wide Web.

Thesis (M.A.) - Carleton University, 2007. / Includes bibliographical references (p. 110-117). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Tennessee, Knoxville, 2008. / Title from title page screen (viewed on Sept. 10, 2009). Thesis advisor: Bruce Ralston. Vita. Includes bibliographical references.

Thesis (M.A.)--Miami University, Dept. of Psychology, 2007. / Title from first page of PDF document. Includes bibliographical references (p. 21-23).

vii, 95 p. : ill. A print copy of this title is available through the UO Libraries under the call numbers: KNIGHT HB846.5 .C76 2000 / By traditional economic reasoning, the production and sale of private goods is assumed to be efficient in a pure market because only the owners of privately held goods can access and enjoy them. In contrast, public goods are likely to be under supplied, because individuals can free ride on the contributions of others. Citizens can solve the free rider problem either spontaneously or through the use of coercive tools such as taxation. However, such solutions will rarely be efficient. An alternative solution, seldom studied by political scientists, is the formation of clubs. Clubs exist to provide semi-public goods to their members. If only contributing members of a club can access its product (the club good), the club should be free of the free-rider problem. Because club goods are finite and rivalrous, clubs are subject to "crowding effects"; that is, per-member benefits will decline if clubs grow too large. Clubs can minimize this crowding by limiting the size of their membership. Clubs are traditionally formulated as consumer- driven arrangements, driven solely by the wealth-maximizing preferences of their memberships and not by external concerns. In an experimental setting, this dissertation demonstrates that clubs also tolerate crowding if club membership is the sole source of some club good for otherwise excluded individuals. Club members can minimize the effects of this crowding by making multilateral promises not to overuse the club good. This means that clubs members do consider the social ramifications of the club's membership policies, and those membership policies respond to government action (specifically, the presence of other funding for excluded individuals). This has implications for both the study of clubs and the associations that resemble them: firms, coalitions, and communities. / Committee in charge: Dr. John Orbell, Chair; Dr. Holly Arrow; Dr. Bill Harbaugh; Dr. Ron Mitchell

abstract: For interspecific mutualisms, the behavior of one partner can influence the fitness of the other, especially in the case of symbiotic mutualisms where partners live in close physical association for much of their lives. Behavioral effects on fitness may be particularly important if either species in these long-term relationships displays personality. Animal personality is defined as repeatable individual differences in behavior, and how correlations among these consistent traits are structured is termed behavioral syndromes. Animal personality has been broadly documented across the animal kingdom but is poorly understood in the context of mutualisms. My dissertation focuses on the structure, causes, and consequences of collective personality in Azteca constructor colonies that live in Cecropia trees, one of the most successful and prominent mutualisms of the neotropics. These pioneer plants provide hollow internodes for nesting and nutrient-rich food bodies; in return, the ants provide protection from herbivores and encroaching vines. I first explored the structure of the behavioral syndrome by testing the consistency and correlation of colony-level behavioral traits under natural conditions in the field. Traits were both consistent within colonies and correlated among colonies revealing a behavioral syndrome along a docile-aggressive axis. Host plants of more active, aggressive colonies had less leaf damage, suggesting a link between a colony personality and host plant health. I then studied how aspects of colony sociometry are intertwined with their host plants by assessing the relationship among plant growth, colony growth, colony structure, ant morphology, and colony personality. Colony personality was independent of host plant measures like tree size, age, volume. Finally, I tested how colony personality influenced by soil nutrients by assessing personality in the field and transferring colonies to plants the greenhouse under different soil nutrient treatments. Personality was correlated with soil nutrients in the field but was not influenced by soil nutrient treatment in the greenhouse. This suggests that soil nutrients interact with other factors in the environment to structure personality. This dissertation demonstrates that colony personality is an ecologically relevant phenomenon and an important consideration for mutualism dynamics. / Dissertation/Thesis / Doctoral Dissertation Biology 2018