The self-organized nest construction behaviors of European paper wasps (Polistes dominula) show potential for adoption in artificial intelligence and robotic systems where centralized control proves challenging. However, P. dominula nest construction mechanisms are not fully understood. The goal of this research was to investigate how P. dominula nest structures stimulate worker actions. Simulation utilities were constructed in C++, C#, and Python. Two models from previous work, a three-dimensional model with weighted actions and a two-dimensional model with simple rule-based actions, were combined in a three-dimensional model with simple rules. Nest construction was simulated with a random selection rule, an age-based rule, a height requirement rule, and a height difference rule. Real and idealized nest data were used to evaluate simulated nests. Structures generated with age- and height-based rules showed more correlation with real and idealized nest structures than randomly-generated structures.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20790号 / 医博第4290号 / 新制||医||1025(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 高橋 淳, 教授 井上 治久, 教授 林 康紀 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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京都大学 / 新制・課程博士 / 博士(工学) / 甲第24614号 / 工博第5120号 / 新制||工||1979(附属図書館) / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 邑瀬 邦明, 教授 宇田 哲也, 教授 作花 哲夫 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Human mobility is central to socioeconomic interactions in modern society. Unprecedented reliance on individual transportation has resulted in widespread challenges globally, including congestion, emissions, and socioeconomic inequalities. These issues are anticipated to worsen with climate change, presenting a significant risk to human civilization. Notably, human mobility accounts for over 15% of total carbon emissions, with the bulk stemming from private transportation. Therefore, there is a pressing need to transition to sustainable alternatives like public transport to address these challenges effectively. Public transport comprises a complex system with multiple interacting parts, including users, drivers, service providers, and evolving urban infrastructure. The interactions among these elements give rise to multiple self-organized states, which play a pivotal role in determining the attractiveness and efficiency of public transport systems. In this thesis, we combine tools from network dynamics, statistical physics, nonlinear dynamics, transport science, and data analysis to understand emergent behavior in public transport worldwide. Public transport infrastructure highlights the disparities in cities across the globe. Developed countries in the Global North generally feature centrally organized formal transport systems, while developing nations in the Global South are served by informal transport operated by private individuals. In our study of complex self-organized states within both formal and informal transport, we explore how self-organization enhances mode attractiveness in some contexts whereas it may reduce ridership in others. We find that in urbanizing cities with formal transport, the interaction between users and service providers can lead to sub-optimal transport outcomes. With the rise of app-based technologies, on-demand transport services like bike taxis are becoming increasingly popular within cities in the Global South. Our results suggest that as congestion grows, a transition may occur, leading users to shift from shared transport to single-passenger options like bike taxis. Finally, our analysis of transport systems in cities across the globe shows that informal transport often self-organizes into more efficient route structures compared to formal transport, indicating that lessons from these informal systems could lead to the improvement of formal transport systems. Our findings provide a foundation for developing intervention strategies to enhance public transportation, by bridging the gap between physics, graph theory, transportation research, data science, and public policy. The results offer valuable insights into reducing congestion and emissions, contributing to a more sustainable and livable urban future, while highlighting the importance of further studies into the collective dynamics of human mobility systems. / Die menschliche Mobilität ist für die sozioökonomischen Interaktionen in der modernen Gesellschaft von zentraler Bedeutung. Die beispiellose Abhängigkeit vom Individualverkehr hat weltweit zu weitreichenden Problemen geführt, darunter Verkehrsstaus, Emissionen und sozioökonomischen Ungleichheiten. Es wird erwartet, dass sich diese Probleme mit dem Klimawandel noch verschärfen werden, was ein erhebliches Risiko für die menschliche Zivilisation darstellt. Vor allem die menschliche Mobilität ist für über 15% der gesamten Kohlenstoffemissionen verantwortlich, wobei der Großteil auf den Individualverkehr entfällt. Daher besteht die dringende Notwendigkeit, auf nachhaltige Alternativen wie den öffentlichen Verkehr umzusteigen, um diesen Herausforderungen wirksam zu begegnen. Der öffentliche Verkehr ist ein komplexes System mit zahlreichen interagierenden Komponenten, darunter Nutzer, Fahrer, Dienstleister und die sich entwickelnde städtische Infrastruktur. Die Wechselwirkungen zwischen diesen Elementen führen zu zahlreichen selbstorganisierten Zuständen, die eine zentrale Rolle bei der Bestimmung der Attraktivität und Effizienz von öffentlichen Verkehrssystemen spielen. In dieser Arbeit kombinieren wir Werkzeuge aus der Netzwerkdynamik, der statistischen Physik, der nichtlinearen Dynamik, der Verkehrswissenschaft und der Statistik, um das emergente Verhalten im öffentlichen Verkehr weltweit zu verstehen. Die Infrastruktur des öffentlichen Verkehrs verdeutlicht die Ungleichheiten in den Städten der Welt. In den Industrieländern des globalen Nordens gibt es in der Regel zentral organisierte formale Verkehrssysteme, während in den Entwicklungsländern des globalen Südens der informelle Verkehr von Privatpersonen betrieben wird. In unserer Studie über komplexe selbstorganisierte Zustände sowohl im formellen als auch im informellen Verkehr untersuchen wir, wie die Selbstorganisation die Attraktivität der Verkehrsmittel in einigen Kontexten erhöht, während sie in anderen die Fahrgastzahlen verringern kann. Wir stellen fest, dass in Städten mit formellem Verkehr die Interaktion zwischen Nutzern und Dienstleistern zu suboptimalen Verkehrsergebnissen führen kann. Mit dem Aufkommen von App-basierten Technologien werden On-Demand-Verkehrsdienste wie Fahrradtaxis in Städten des globalen Südens immer beliebter. Unsere Ergebnisse deuten darauf hin, dass mit zunehmender Überlastung ein Übergang stattfinden kann, der die Nutzer dazu veranlasst, von gemeinsam genutzten Verkehrsmitteln auf Einzelpersonenoptionen wie Fahrradtaxis umzusteigen. Schließlich zeigt unsere Analyse von Verkehrssystemen in Städten auf der ganzen Welt, dass sich der informelle Verkehr im Vergleich zum formellen Verkehr oft selbst in effizienteren Routenstrukturen organisiert, was darauf hindeutet, dass Lehren aus diesen informellen Systemen zur Verbesserung formeller Verkehrssysteme führen könnten. Unsere Ergebnisse bieten eine Grundlage für die Entwicklung von Interventionsstrategien zur Verbesserung des öffentlichen Verkehrs, indem sie die Lücke zwischen Physik, Graphentheorie, Verkehrsforschung, Datenwissenschaft und öffentlicher Politik schließen. Die Ergebnisse bieten wertvolle Einblicke in die Reduzierung von Staus und Emissionen und tragen so zu einer nachhaltigeren und lebenswerteren urbanen Zukunft bei.

This study is the result of a two-year long minor field study project of informal settlements in Buenos Aires, Argentina. The aim was to analyse the concept of disaster resilience by describing possible contemporary complications in both theory and practice related to resilience and risks of informal settlements in Buenos Aires. For this reason I have applied the theoretical concept of resilience used by United Nations International Strategy for Disaster Reduction (UNISDR). The research has been conducted in two local settings of informal settlements by using a qualitative case study approach of semi-structured interviews and observations. The chosen area of empirics has been limited to local voluntary and political organisations in a context of self-organization were all chosen interviewees have some relation to either projects or organizations in the area. The results show that local context of functionality depends on different political strategies that can either restrict or assist the process of resilience, which can occur on both individual and collective levels of community. In this context resistance to natural hazards becomes contradictive in absence of prevention when resilience is achieved without even touching high levels of vulnerability such as drugs and violence. In this setting United Nations stands before a change of paradigms in either continuing to manage disasters or change focus to manage underlying drivers of risks. / Este estudio es el resultado de un proyecto de dos años de un estudio de campo menor sobre los asentamientos informales en Buenos Aires, Argentina. El propósito fue analizar el concepto de resiliencia de los desastres, describiendo las posibles complicaciones contemporáneos tanto en la teoría y la práctica, en relación con la resiliencia y los riesgos de los asentamientos informales en Buenos Aires. Por esta razón he aplicado el concepto teórico de la resiliencia utilizada por la Estrategia Internacional para la Reducción de Desastres de las Naciones Unidas (UNISDR). La investigación se ha realizado en dos configuraciones locales de los asentamientos informales, mediante el uso de un enfoque de estudio de caso cualitativo de observaciones y entrevistas semi-estructuradas. El área elegida de análisis empírico se ha limitado a las organizaciones locales de voluntarios y políticos en un contexto de auto-organización, donde todos los entrevistados han sido elegidos porque tienen alguna relación con cualquiera de los proyectos u organizaciones de la zona. Los resultados muestran que el contexto local de la funcionalidad depende de diferentes estrategias políticas que pueden restringir o asistir al proceso de resiliencia, esto puede ocurrir en ambos niveles individuales y colectivos de la comunidad. En este contexto, la resistencia a las amenazas naturales se vuelve contradictorio por la ausencia de la prevención, cuando se alcanza la capacidad de resiliencia sin tocar los altos niveles de vulnerabilidad, como las drogas y la violencia. En este escenario las Naciones Unidas se encuentra ante un cambio de paradigma, ya sea continuar para gestionar los desastres o cambiar de enfoque para gestionar los  factores subyacentes de los riesgos. / Minor Field Study

From a visual standpoint it is often easy to point out whether a system is considered to be self-organizing or not, though a quantitative approach would be more helpful. Information theory, as introduced by Shannon, provides the right tools not only quantify self-organization, but also to investigate it in relation to the information processing performed by individual agents within a collective. This thesis sets out to introduce methods to quantify spatial self-organization in collective systems in the continuous domain as a means to investigate morphogenetic processes. In biology, morphogenesis denotes the development of shapes and form, for example embryos, organs or limbs. Here, I will introduce methods to quantitatively investigate shape formation in stochastic particle systems. In living organisms, self-organization, like the development of an embryo, is a guided process, predetermined by the genetic code, but executed in an autonomous decentralized fashion. Information is processed by the individual agents (e.g. cells) engaged in this process. Hence, information theory can be deployed to study such processes and connect self-organization and information processing. The existing concepts of observer based self-organization and relevant information will be used to devise a framework for the investigation of guided spatial self-organization. Furthermore, local information transfer plays an important role for processes of self-organization. In this context, the concept of synergy has been getting a lot attention lately. Synergy is a formalization of the idea that for some systems the whole is more than the sum of its parts and it is assumed that it plays an important role in self-organization, learning and decision making processes. In this thesis, a novel measure of synergy will be introduced, that addresses some of the theoretical problems that earlier approaches posed.

<p>The behavior of fibers suspended in a flow between two counter-rotating discs has been studied experimentally. This is inspired by the refining process in the papermaking process where cellulose fibers are ground between discs in order to change performance in the papermaking process and/or qualities of the final paper product.</p><p>To study the fiber behavior in a counter-rotating flow, an experimental set-up with two glass discs was built. A CCD-camera was used to capture images of the fibers in the flow. Image analysis based on the concept of steerable filters extracted the position and orientation of the fibers in the plane of the discs. Experiments were performed for gaps of 0.1-0.9 fiber lengths, and for equal absolute values of the angular velocities for the upper and lower disc. The aspect ratios of the fibers were 7, 14 and 28.</p><p>Depending on the angular velocity of the discs and the gap between them, the fibers were found to organize themselves in fiber trains. A fiber train is a set of fibers positioned one after another in the tangential direction with a close to constant fiber-to-fiber distance. In the fiber trains, each individual fiber is aligned in the radial direction (i.e. normal to the main direction of the train).</p><p>The experiments show that the number of fibers in a train increases as the gap between the discs decreases. Also, the distance between the fibers in a train decreases as the length of the train increases, and the results for short trains are in accordance with previous numerical results in two dimensions.Furthermore, the results of different aspect ratios imply that there are three-dimensional fiber end-effects that are important for the forming of fiber trains.</p>

<p>Advanced architectures for cluster-based services that have been recently proposed allow for service differentiation, server overload control and high utilization of resources. These systems, however, rely on centralized functions, which limit their ability to scale and to tolerate faults. In addition, they do not have built-in architectural support for automatic reconfiguration in case of failures or addition/removal of system components.</p><p>Recent research in peer-to-peer systems and distributed management has demonstrated the potential benefits of decentralized over centralized designs: a decentralized design can reduce the configuration complexity of a system and increase its scalability and fault tolerance.</p><p>This research focuses on introducing self-management capabilities into the design of cluster-based services. Its intended benefits are to make service platforms dynamically adapt to the needs of customers and to environment changes, while giving the service providers the capability to adjust operational policies at run-time.</p><p>We have developed a decentralized design that efficiently allocates resources among multiple services inside a server cluster. The design combines the advantages of both centralized and decentralized architectures. It allows associating a set of QoS objectives with each service. In case of overload or failures, the quality of service degrades in a controllable manner. We have evaluated the performance of our design through extensive simulations. The results have been compared with performance characteristics of ideal systems.</p>