Deterministic Symmetry Breaking in Ring Networks

We study a distributed coordination mechanism for uniform agents located on a circle. The agents perform their actions in synchronised rounds. At the beginning of each round an agent chooses the direction of its movement from clockwise, anticlockwise, or idle, and moves at unit speed during this round. Agents are not allowed to overpass, i.e., when an agent collides with another it instantly starts moving with the same speed in the opposite direction (without exchanging any information with the other agent). However, at the end of each round each agent has access to limited information regarding its trajectory of movement during this round. We assume that $n$ mobile agents are initially located on a circle unit circumference at arbitrary but distinct positions unknown to other agents. The agents are equipped with unique identifiers from a fixed range. The {\em location discovery} task to be performed by each agent is to determine the initial position of every other agent. Our main result states that, if the only available information about movement in a round is limited to %information about distance between the initial and the final position, then there is a superlinear lower bound on time needed to solve the location discovery problem. Interestingly, this result corresponds to a combinatorial symmetry breaking problem, which might be of independent interest. If, on the other hand, an agent has access to the distance to its first collision with another agent in a round, we design an asymptotically efficient and close to optimal solution for the location discovery problem.Comment: Conference version accepted to ICDCS 201

Classical Engineering Systems Provide Behavioral Analog for Ephemeral Insect and Plant Biomechanics

In this dissertation we consider ephemeral behaviors of two small-scale living systems, mosquitoes and citrus fruit reservoirs. While these two systems share few obvious commonalities, they both express life events that are complex and conclude within approximately 50 milliseconds. We utilize high-speed videography, between 1,000-16,000 fps, to detail how complex behavior can be modeled as classical engineering systems. Beginning with the larger organism we assessed the landing and takeoff behavior of Aedes aegypti mosquitoes to ascertain the secrets of their covert interaction with humans. At takeoff, mosquitoes decrease pushing contact time with substrates of low friction through a modified takeoff behavior of striking the substrate with a hind-leg prior to a classic push phase. We propose a 2D analog where the striking leg acts as a rotating cantilever about a fixed end that generates upward momentum with a small penalty in body rotation. Landing mosquitoes are filmed in 2D and modeled as a mass-spring-damper system whose natural frequency, damping coefficient, ratio, and spring constant are determined experimentally and validated through a nonlinear least square solver fitting of the free vibration ODE\u27s general solution. Results indicate mosquitoes behave as an underdamped system to scrub their incoming momentum through extending impact duration, effectively reducing temporal impact force. Shrinking in scale we proceed to characterize citrus reservoir rupture as a passive system capable of microjetting oil through expanding orifices at accelerations greater than 5000 gravities. Citrus reservoirs are modeled as ellipsoidal pressure vessels capped by a thin membrane of contrasting stiffness to the surrounding ductile compressible albedo

Philosophical foundations of the Death and Anti-Death discussion

Perhaps there has been no greater opportunity than in this “VOLUME FIFTEEN of our Death And Anti-Death set of anthologies” to write about how might think about life and how to avoid death. There are two reasons to discuss “life”, the first being enhancing our understanding of who we are and why we may be here in the Universe. The second is more practical: how humans meet the physical challenges brought about by the way they have interacted with their environment. Many persons discussing “life” beg the question about what “life” is. Surely, when one discusses how to overcome its opposite, death, they are not referring to another “living” thing such as a plant. There seems to be a commonality, though, and it is this commonality is one needing elaboration. It ostensibly seems to be the boundary condition separating what is completely passive (inert) from what attempts to maintain its integrity, as well as fulfilling other conditions we think “life” has. In our present discussion, there will be a reminder that it by no means has been unequivocally established what life really is by placing quotes around the word, namely, “life”. Consider it a tag representing a bundle of philosophical ideas that will be unpacked in this paper

Fire ant self-assemblages

Fire ants link their legs and jaws together to form functional structures called self- assemblages. Examples include floating rafts, towers, bridges, and bivouacs. We investigate these self-assemblages of fire ants. Our studies are motivated in part by the vision of providing guidance for programmable robot swarms. The goal for such systems is to develop a simple programmable element from which complex patterns or behaviors emerge on the collective level. Intelligence is decentralized, as is the case with social insects such as fire ants. In this combined experimental and theoretical study, we investigate the construction of two fire ant self-assemblages that are critical to the colony’s survival: the raft and the tower. Using time-lapse photography, we record the construction processes of rafts and towers in the laboratory. We identify and characterize individual ant behaviors that we consistently observe during assembly, and incorporate these behaviors into mathematical models of the assembly process. Our models accurately predict both the assemblages’ shapes and growth patterns, thus providing evidence that we have identified and analyzed the key mechanisms for these fire ant self-assemblages. We also develop novel techniques using scanning electron microscopy and micro-computed tomography scans to visualize and quantify the internal structure and packing properties of live linked fire ants. We compare our findings to packings of dead ants and similarly shaped granular material packings to understand how active arranging affects ant spacing and orientation. We find that ants use their legs to increase neighbor spacing and hence reduce their packing density by one-third compared to packings of dead ants. Also, we find that live ants do not align themselves in parallel with nearest neighbors as much as dead ants passively do. Our main contribution is the development of parsimonious mathematical models of how the behaviors of individuals result in the collective construction of fire ant assemblages. The models posit only simple observed behaviors based on local information, yet their mathe- matical analysis yields accurate predictions of assemblage shapes and construction rates for a wide range of ant colony sizes.Ph.D

Luontoa jäljittelevän pallorobotin kehittäminen planeettatutkimukseen

Planeetoille suuntautuvat tutkimusmatkat tähtäävät usein maaperänäytteiden keräämiseen ja tutkimiseen, usein myös näytteiden palauttamiseen Maahan tarkempia tutkimuksia varten. Äskettäiset Marsiin suuntautuneet robottimissiot ovat osoittaneet liikkuvien robottien kyvyn suorittaa tutkimustehtäviä. Vieraalla planeetalla robotin liikkumiskyky on tarpeen tutkittavan alueen laajentamiseksi ja tutkimusten kohdentamiseksi haluttuihin tieteellisesti kiinnostavimpiin kohteisiin. Luonnon kehittämiä ratkaisuja jäljittelevä liikkumistapa saattaa tarjota liikkuvalle robotille nykyisiä parempaa mukautumis- ja viansietokykyä. Tämä tutkimustyö etsii luonnosta uusia innovaatioita ja tähtää uudenlaisten joustavien ja tehokkaiden liikkumistapojen kehittämiseen liikkuville roboteille. Erityisesti työ keskittyy pallomaisen, aro-ohdakkeen mukaan englanniksi 'Thistle':ksi nimetyn, robotin määrittelyyn ja alustavaan kehitystyöhön. Tutkimus käsittelee myös keinoja hyödyntää liikkumisessa Marsin paikallisia energialähteitä, kuten tuuli- ja lämpöenergiaa. Useita erilaisia energiankeruutapoja esitellään ja arvioidaan. Vaikka kaikki tutkitut konseptit eivät heti vaikuta toteuttamiskelpoisilta, on ne kuitenkin esitelty mitään pois jättämättä, jotta ne voisivat olla innoittajina tuleville uusille asiaan liittyville tutkimuksille.Planetary exploration missions often aim to carry out in-situ analysis and possibly return samples to Earth for more thorough examination. Recent robotic missions to Mars have demonstrated effectiveness of robotic exploration of planetary surface. Purpose of a mobile robot on planet surface is to enlarge the area to be investigated, and to concentrate investigations on subjects with most scientific interest. The application of biomimetic locomotion to the Martian surface offers the possibility of increased robustness and failure tolerance of a mobile robot. This study searches for new innovations from nature and aims to develop a novel system to provide robust and efficient locomotion system to be used for exploring surface of foreign planets. Especially this work describes definition and conceptual development of a rolling robot -later called 'The Thistle' mimicking a Russian Thistle -plant. The study considers locomotion and power generation methods that would utilize local power generation resources like wind or heat. This study involves the identification and conceptual development of innovative concepts for planetary surface locomotion and energy collection. Several concepts are presented and evaluated. Considering nature of the study, although evaluation reveals some concepts probably not adequate, these are not removed from the thesis, but are left here for the interest and further inspiration of the reader

Autonomous, Collaborative, Unmanned Aerial Vehicles for Search and Rescue

Search and Rescue is a vitally important subject, and one which can be improved through the use of modern technology. This work presents a number of advances aimed towards the creation of a swarm of autonomous, collaborative, unmanned aerial vehicles for land-based search and rescue. The main advances are the development of a diffusion based search strategy for route planning, research into GPS (including the Durham Tracker Project and statistical research into altitude errors), and the creation of a relative positioning system (including discussion of the errors caused by fast-moving units). Overviews are also given of the current state of research into both UAVs and Search and Rescue

Cyber-Human Systems, Space Technologies, and Threats

CYBER-HUMAN SYSTEMS, SPACE TECHNOLOGIES, AND THREATS is our eighth textbook in a series covering the world of UASs / CUAS/ UUVs / SPACE. Other textbooks in our series are Space Systems Emerging Technologies and Operations; Drone Delivery of CBNRECy – DEW Weapons: Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD); Disruptive Technologies with applications in Airline, Marine, Defense Industries; Unmanned Vehicle Systems & Operations On Air, Sea, Land; Counter Unmanned Aircraft Systems Technologies and Operations; Unmanned Aircraft Systems in the Cyber Domain: Protecting USA’s Advanced Air Assets, 2nd edition; and Unmanned Aircraft Systems (UAS) in the Cyber Domain Protecting USA’s Advanced Air Assets, 1st edition. Our previous seven titles have received considerable global recognition in the field. (Nichols & Carter, 2022) (Nichols, et al., 2021) (Nichols R. K., et al., 2020) (Nichols R. , et al., 2020) (Nichols R. , et al., 2019) (Nichols R. K., 2018) (Nichols R. K., et al., 2022)https://newprairiepress.org/ebooks/1052/thumbnail.jp