Swarm Synergy: A Silent Way of Forming Community

In this paper, we introduce a novel swarm application, swarm synergy, where robots in a swarm intend to form communities. Each robot is considered to make independent decisions without any communication capability (silent agent). The proposed algorithm is based on parameters local to individual robots. Engaging scenarios are studied where the silent robots form communities without the preset conditions on the number of communities, community size, goal location of each community, and specific members in the community. Our approach allows silent robots to achieve this self-organized swarm behavior using only sensory inputs from the environment. The algorithm facilitates the formation of multiple swarm communities at arbitrary locations with unspecified goal locations. We further infer the behavior of swarm synergy to ensure the anonymity/untraceability of both robots and communities. The robots intend to form a community by sensing the neighbors, creating synergy in a bounded environment. The time to achieve synergy depends on the environment boundary and the onboard sensor's field of view. Compared to the state-of-art with similar objectives, the proposed communication-free swarm synergy shows comparative time to synergize with untraceability features.Comment: 8 Pages, 8 figures, 6 tables, pre-print versio

Multi-agent Collision Avoidance Using Interval Analysis and Symbolic Modelling with its Application to the Novel Polycopter

Coordination is fundamental component of autonomy when a system is defined by multiple mobile agents. For unmanned aerial systems (UAS), challenges originate from their low-level systems, such as their flight dynamics, which are often complex. The thesis begins by examining these low-level dynamics in an analysis of several well known UAS using a novel symbolic component-based framework. It is shown how this approach is used effectively to define key model and performance properties necessary of UAS trajectory control. This is demonstrated initially under the context of linear quadratic regulation (LQR) and model predictive control (MPC) of a quadcopter. The symbolic framework is later extended in the proposal of a novel UAS platform, referred to as the ``Polycopter" for its morphing nature. This dual-tilt axis system has unique authority over is thrust vector, in addition to an ability to actively augment its stability and aerodynamic characteristics. This presents several opportunities in exploitative control design. With an approach to low-level UAS modelling and control proposed, the focus of the thesis shifts to investigate the challenges associated with local trajectory generation for the purpose of multi-agent collision avoidance. This begins with a novel survey of the state-of-the-art geometric approaches with respect to performance, scalability and tolerance to uncertainty. From this survey, the interval avoidance (IA) method is proposed, to incorporate trajectory uncertainty in the geometric derivation of escape trajectories. The method is shown to be more effective in ensuring safe separation in several of the presented conditions, however performance is shown to deteriorate in denser conflicts. Finally, it is shown how by re-framing the IA problem, three dimensional (3D) collision avoidance is achieved. The novel 3D IA method is shown to out perform the original method in three conflict cases by maintaining separation under the effects of uncertainty and in scenarios with multiple obstacles. The performance, scalability and uncertainty tolerance of each presented method is then examined in a set of scenarios resembling typical coordinated UAS operations in an exhaustive Monte-Carlo analysis

Eye quietness and quiet eye in expert and novice golf performance: an electrooculographic analysis

Quiet eye (QE) is the final ocular fixation on the target of an action (e.g., the ball in golf putting). Camerabased eye-tracking studies have consistently found longer QE durations in experts than novices; however, mechanisms underlying QE are not known. To offer a new perspective we examined the feasibility of measuring the QE using electrooculography (EOG) and developed an index to assess ocular activity across time: eye quietness (EQ). Ten expert and ten novice golfers putted 60 balls to a 2.4 m distant hole. Horizontal EOG (2ms resolution) was recorded from two electrodes placed on the outer sides of the eyes. QE duration was measured using a EOG voltage threshold and comprised the sum of the pre-movement and post-movement initiation components. EQ was computed as the standard deviation of the EOG in 0.5 s bins from –4 to +2 s, relative to backswing initiation: lower values indicate less movement of the eyes, hence greater quietness. Finally, we measured club-ball address and swing durations. T-tests showed that total QE did not differ between groups (p = .31); however, experts had marginally shorter pre-movement QE (p = .08) and longer post-movement QE (p < .001) than novices. A group × time ANOVA revealed that experts had less EQ before backswing initiation and greater EQ after backswing initiation (p = .002). QE durations were inversely correlated with EQ from –1.5 to 1 s (rs = –.48 - –.90, ps = .03 - .001). Experts had longer swing durations than novices (p = .01) and, importantly, swing durations correlated positively with post-movement QE (r = .52, p = .02) and negatively with EQ from 0.5 to 1s (r = –.63, p = .003). This study demonstrates the feasibility of measuring ocular activity using EOG and validates EQ as an index of ocular activity. Its findings challenge the dominant perspective on QE and provide new evidence that expert-novice differences in ocular activity may reflect differences in the kinematics of how experts and novices execute skills

Tiergemeinschaften im offenen Ozean: ein theoretischer Ansatz

Many aspects of the behavioural ecology of oceanic predators are little understood due to difficulties related to costs and reduced accessibility of their habitat. Often only certain parts and factors of an ecosystem can be studied. Hence it is important to compile results of previous research so as to extract the most possible information from what is available. In the scope of this study a review of animal grouping in the oceanic environment identified possible evolutionary drivers towards congregation in cetacea which were then quantitatively evaluated by a meta-analysis of group size correlations with a number of ecological and behavioural parameters, including habitat range, migration behaviour, prey composition, foraging depth and predation risk. The latter was quantified based on vertical and horizontal overlap of cetacea habitat with that of their predators, and from both, the probability of attack during an encounter with a predator and attack fatality. Tuna-dolphin associations were qualitatively analysed with regard to fitness benefits related to predation risk, foraging and improved navigation accuracy.Durch hohe Kosten verbunden mit der Erforschung der Hochsee und geringe Zugänglichkeit dieser Gebiete sind viele verhaltensökologische Aspekte ozeanischer Prädatoren kaum bekannt. Oft können nur Teile und bestimmte Faktoren eines Ökosystems untersucht werden. Dadurch ist es wichtig Resultate vergangener Studien so effizient wie möglich zu kompilieren um mit den Informationen die verfügbar sind den größtmöglichen Einblick zu gewinnen. Im Rahmen dieser Arbeit wurde ein Review über das Gruppenverhalten in Hochseegewässern angefertigt, der mögliche evolutionäre Haupteinflussfaktoren identifiziert. Diese sind dann quantitativ im Rahmen einer Meta-analyse von Korrelationen zwischen Gruppengröße und verschiedenen ökologischen und verhaltensspezifischen Parametern ausgewertet worden. Diese sind unter anderem Ausbreitungs- und Migrationsverhalten, Nahrungszusammensetzung, Nahrungstiefe und Prädationsgefahr. Letztere wurde auf der Basis von der Überlappung zwischen Räuber- und Beutehabitat, der Wahrscheinlichkeit, dass das Zusammentreffen mit einem Prädator zu einem Angriff führt und der Letalität eines solchen Angriffs quantifiziert. Thunfisch-Delphin Gemeinschaften sind im Hinblick auf mit der Ernährung, der Navigationspräzision und der Prädationsgefahr zusammenhängende Fitnessvorteile qualitativ untersucht worden

Divergence in Architectural Research

ConCave Ph.D. Symposium 2020: Divergence in Architectural Research, March 5-6, 2020, Georgia Institute of Technology, Atlanta, GA.The essays in this volume have come together under the theme “Divergence in Architectural Research” and present a snapshot of Ph.D. research being conducted in over thirty architectural research institutions, representing fourteen countries around the world. These essays also provide a window into the presentations and discussions that took place March 5-6, 2020, during the ConCave Ph.D. Symposium “Divergence in Architectural Research,” under the auspices of the School of Architecture, Georgia Institute of Technology, in Atlanta, Georgia. On a preliminary reading, the essays respond to the call of divergence by doing just that; they present the great diversity of research topics, methodologies, and practices currently found under the umbrella of “architectural research.” They inform inquiry within architectural programs and across disciplinary concentrations, and also point to the ways that the academy, research methodologies, and the design profession are evolving and encroaching upon one another, with the unspoken hope of encouraging new relationships, reconfiguring previous assumptions about the discipline, and interweaving research and practice