Suchergebnisse

Nach Naturkatastrophen, wie beispielsweise Erdbeben, Wirbelstürmen, Flutwellen oder auch nach durch den Menschen verursachten Katastrophen wie Terroranschlägen oder Unfällen, ist es sehr wichtig die Ersthelfer zu organisieren. Hierfür ist eine Kommunikationsinfrastruktur, welche zum Beispiel Basisstationen für Mobilfunknetze enthält, von entscheidender Bedeutung. Diese Infrastruktur kann durch die Katastrophe jedoch schwer beeinträchtigt oder vollkommen zerstört sein. Heutzutage sind Ersthelfer als auch Opfer üblicherweise mit leistungsfähigen mobilen Endgeräten, wie Smartphones oder Notebooks, ausgerüstet. Diese mobilen Endgeräte, welche über eine Vielzahl von Netzzugangstechnologien verfügen, können zu einem sogenannten Ad-hoc-Netzwerk zusammengeschlossen werden und bilden anschließend eine infrastrukturlose Kommunikationsbasis. Die Leistungsfähigkeit von kabellosen Ad-hoc-Netzwerken ist dabei stark von der Anzahl bekannter Verbindungen im Netz abhängig. Diese Verbindungen, auch Routen genannt, werden durch das verwendete Routingprotokoll gesucht und ständig aktualisiert. Hierzu stehen verschiedenartige Routingprotokolle zur Verfügung, welche Topologieinformationen zwischen den einzelnen Knoten eines Netzwerks austauschen. Für kabellose Ad-hoc-Netzwerke sind hierfür zahlreiche Routingprotokolle verfügbar, jedoch sind diese bereits existierenden Protokolle nur eingeschränkt für hochdynamische mobile Ad-hoc-Netzwerke geeignet. Dies liegt darin begründet, dass sie nicht in der Lage sind, sich an große Änderungen im Netzwerk anzupassen. In Katastrophenszenarien können allerdings hochdynamische Netzwerke vorkommen, in welchen beispielsweise die Größe des Netzes zwischen einigen wenigen und einigen hundert Knoten schwankt oder sich die Knotengeschwindigkeit von statischen bis hin zu hochmobilen Knoten verändert. Die vorliegende Arbeit präsentiert einen adaptiven Ansatz, welcher in der Lage ist, die gegebenen Parameter des Netzwerks in einer dezentralen Weise zu ermitteln und anschließend das verwendete Routingprotokoll während der Laufzeit zu wechseln, um somit das Routing sehr flexibel an die Gegebenheiten des Netzwerks anzupassen.

Governance networks play an increasingly important role in ecosystem management. The collaboration within these governance networks can be formalized or informal, top-down or bottom-up, and designed or self-organized. Informal self-organized governance networks may increase legitimacy if a variety of stakeholders are involved, but at the same time, accountability becomes blurred when decisions are taken. Basically, democratic accountability refers to ways in which citizens can control their government and the mechanisms for doing so. Scholars in ecosystem management are generally positive to policy/governance networks and emphasize its potential for enhancing social learning, adaptability, and resilience in social-ecological systems. Political scientists, on the other hand, have emphasized the risk that the public interest may be threatened by governance networks. I describe and analyze the multilevel governance network of Kristianstads Vattenrike Biosphere Reserve (KVBR) in Southern Sweden, with the aim of understanding whether and how accountability is secured in the governance network and its relation to representative democracy. The analysis suggests that the governance network of KVBR complements representative democracy. It deals mainly with low politics; the learning and policy directions are developed in the governance network, but the decisions are embedded in representative democratic structures. Because several organizations and agencies co-own the process and are committed to the outcomes, there is a shared or extended accountability. A recent large investment in KVBR caused a major crisis at the municipal level, fueled by the financial crisis. The higher levels of the governance network, however, served as a social memory and enhanced resilience of the present biosphere development trajectory. For self-organized networks, legitimacy is the bridge between adaptability and accountability; accountability is secured as long as the adaptive governance network performs well, i.e., is perceived as legitimate. Governing and ensuring accountability of governance networks, without hampering their flexibility, adaptability, and innovativeness, represents a new challenge for the modern state. ; authorCount :1

Computer network security is a very serious concern in many commercial, industrial, and military environments. This paper proposes a new computer network security approach defined by self-organized agent swarms (SOMAS) which provides a novel computer network security management framework based upon desired overall system behaviors. The SOMAS structure evolves based upon the partially observable Markov decision process (POMDP) formal model and the more complex Interactive-POMDP and Decentralized-POMDP models, which are augmented with a new F(*-POMDP) model. Example swarm specific and network based behaviors are formalized and simulated. This paper illustrates through various statistical testing techniques, the significance of this proposed SOMAS architecture, and the effectiveness of self-organization and entangled hierarchies.

AbstractUrban street networks of unplanned or self-organized cities typically exhibit astonishing scale-free patterns. This scale-freeness can be shown, within the maximum entropy formalism (MaxEnt), as the manifestation of a fluctuating system that preserves on average some amount of information. Monte Carlo methods that can further this perspective are cruelly missing. Here we adapt to self-organized urban street networks the Metropolis algorithm. The "coming to equilibrium" distribution is established with MaxEnt by taking scale-freeness as prior hypothesis along with symmetry-conservation arguments. The equilibrium parameter is the scaling; its concomitant extensive quantity is, assuming our lack of knowledge, an amount of information. To design an ergodic dynamics, we disentangle the state-of-the-art street generating paradigms based on non-overlapping walks into layout-at-junction dynamics. Our adaptation reminisces the single-spin-flip Metropolis algorithm for Ising models. We thus expect Metropolis simulations to reveal that self-organized urban street networks, besides sustaining scale-freeness over a wide range of scalings, undergo a crossover as scaling varies—literature argues for a small-world crossover. Simulations for Central London are consistent against the state-of-the-art outputs over a realistic range of scaling exponents. Our illustrative Watts–Strogatz phase diagram with scaling as rewiring parameter demonstrates a small-world crossover curving within the realistic window 2–3; it also shows that the state-of-the-art outputs underlie relatively large worlds. Our Metropolis adaptation to self-organized urban street networks thusly appears as a scaling variant of the Watts–Strogatz model. Such insights may ultimately allow the urban profession to anticipate self-organization or unplanned evolution of urban street networks.

The limitation of capitalist principles and ethics has long been an issue for self-organized enterprises. Even though capitalist modes of labor organization, administration, and management are expelled from the workplace, issues of growth, investment, production, and circulation remain exposed to dominant forms of production. Nevertheless, communities of solidarity, along with spatial and techno-material settings, constitute the infrastructure of commoning practices in those endeavors. We compare the cases of the factory occupation movement in Argentina and the occupation of the Vio.Me. factory in Greece (2010), where a shift to self-organization emerged in the context of the Argentinian and Greek economic crises. We focus on struggles revolving around the use and ownership of spatial-material infrastructure and the production of use-values, highlighting the emancipatory potential of self-organization. Space and objects appear as a contested terrain, while at the same time, material settings are transformed, through the collectives' participation in networks of distribution and solidarity.

AbstractMovements and groups abound in modern society. Sometimes, a movement or group succeeds in mobilizing a large section of the population and thoroughly knitting it together, by building a pervasive subculture and by setting up a vast interrelated network of organizations, resulting in a seemingly impenetrable and powerful bloc. This happened to different degrees in most Western countries, including the United States and Canada. It is also occurring now in the non-Western world. Belgium and the Netherlands were particularly affected by extensive bloc building. In both countries, Catholic, Socialist, and Liberal pillars – plus a Protestant pillar in the Netherlands – divided society and determined political and social life from the late nineteenth century up to the late twentieth century. As a consequence, the phenomenon has been studied there more thoroughly and under a specific label, 'verzuiling' (pillarization). The first section of this article offers a review of pillarization theory in the Netherlands, Belgium and elsewhere. In the second part, to advance the study of organized blocs all over the world, I argue for a broad, international perspective on pillarization against the particularistic tendencies of many pillarization researchers, especially in the Netherlands. In a shorter third part, I address the isolation of pillarization theory from general sociological theory. Self-reinforcing processes of segregation and organization in large population groupings were and still are a common feature in the modern world. They have resulted in more than one case in divided societies.

Unlike equilibrium systems, where it is possible to study the impact of endogenous and exogenous perturbations using fluctuation-dissipation theorems, it is difficult to understand and predict the impact of shocks in out-of-equilibrium systems. This thesis tries to uncover and quantify the epidemic processes in out-of-equilibrium self-organizing systems of both endogenous and exogenous origin. We address the questions using massive datasets from social, biological, and physical systems and quantify the endogenous and exogenous origin of contagion. We further extend our discussion on how to build robust data aggregation systems to obtain and process large datasets to better understand the out of equilibrium systems. In the first part of the thesis, we study the active systems of YouTube with ∼ 2 billion active users watching billions of videos, and a Scholarly network, with ∼ 200 Million articles with ∼1.6 Billion citation links.We mine these massive datasets to uncover epidemic processes that impact individual productivity and success.We quantify the epidemic processes in these self-organizing systems to validate their endogenous origin. We further show how the endogenously fueled exuberance within the network participants tend to synchronize both the individual productivity and success patterns. The second part of the thesis examines hundreds of thousands of performances in international cricket to show that the performance sequence can be efficiently modeled as an epidemic process. With a number of statistical analyses, we provide convincing evidence for the presence of hot-hand effect that is success breeds success, implying large value of endogeneity in the game of cricket. Again we show the presence of a predictable performance sequence, in individual careers. However, we further uncover that the game itself aggregates and digests the information in such a way that the overall team performance and game outcome becomes unpredictable. The third part of the thesis investigates the Earth's crust as an out-of-equilibrium system. With the help of an augmented Epidemic-Type Aftershock Sequence (ETAS) model that offers a direct path to thoroughly investigate the response of this self-organizing system to the exogenous (background earthquakes) and endogenous (aftershock earthquake sequence) shocks, we quantify the distance of the earthquake catalogs from the criticality. We show that our model that accounts specifically for spatial variation of background rate (μ(x,y)) of events outperforms the standard ETAS model with uniform μ. Interestingly, the relatively low value of branching ratio (n < 1) in the superior ETAS model suggests the crust is not be operating at a critical point, as it has been believed for a long time. The fourth part of the thesis considers the society we live in as an out-of-equilibrium self-organizing system, where we are constantly exposed to infectious pathogens. The pathogens trigger epidemic of infectious diseases at all magnitudes. The pandemic due to the SARS-CoV2 virus is one such examples. The virus causing the disease is very efficient in transmitting from human to human. We thus model the epidemic process with the help of a probabilistic contagion model with inhomogeneous source terms that takes into account both endogenous (human to human) and exogenous (contaminated surfaces) modes of transmission. We use a number of Bayesian tools to effectively estimate the impact of governmental interventions (namely exogenous shocks) on epidemic progression during this period.

3 pages, 4 figures. ; We have grown self-organized InSb quantum dots on semi-insulating InP (001) substrates by molecular beam epitaxy. We studied the size dependency of the uncapped InSb quantum dots on the nominal thickness of the deposited InSb by atomic force microscopy. The dot sizes have a pronounced minimum at about 2.2 monolayers of InSb. After a nominal thickness of 3.2 monolayers we observe a drastic change of the dot shape, from quantum dots to quantum dashes. From there on the dots grow in a quasicylindric shape aligned in the (110) direction. ; The authors would like to acknowledge gratefully financial support from the European Union (HCM, Network CT930349). ; Peer reviewed

Scheduling plays an important role in the companies' competiveness, dealing with complex combinatorial problems subject to uncertainty and emergence. In particular, in the ramp-up phase of small lot-sizes of complex products, scheduling is more demanding, e.g. due to late requests and immature technology products and processes. This paper presents the principles of a distributed scheduling architecture based on holonic and swarm principles and implemented using multi-agent system technology. In particular, it is described the coordination among the network of the swarm of schedulers and analysed the impact of embedded self-organization mechanisms. ; The research leading to these results has received funding from the European Union Seventh Framework Programme FP7 ARUM project, under grant agreement n° 314056. ; info:eu-repo/semantics/publishedVersion

Abstract. A novel method of data processing – a structural functions curvature analysis method – was applied to the time series of seismodeformation monitoring of Baikal rift zone from April to November 2008, revealing the unique features of monitoring variable behaviour that can be considered as a revelation of precursors to the intensive South-Biakal earthquake (M=6.3, at 09:31 on 27 August 2008). The idea of a new approach leans upon basic ideas of modern physics of self-organized criticality and open non-equilibrium systems in general.