Essay 1: This paper studies tipping behaviour in the residential mobility of the native population inSweden between 1990 and 2007. Using regression discontinuity methods, we find that thegrowth in native population in a neighbourhood discontinuously drops once aneighbourhood’s immigrant share exceeds the identified tipping point. In the 1990s the dropcan be attributed both to increased out-migration of natives (native flight) and to thedecreased in-migration of natives (native avoidance) while native flight appears to be drivingthe segregation pattern between the years 2000 and 2007. Further, we find native migrationfrom neighbourhoods that have tipped is selective, in the sense that natives with a high levelof educational attainment are the most likely to move from such neighbourhood. We concludethat the native residential mobility has contributed to increased ethnic segregation but it alsoappears to have increased socio-economic segregation in Sweden between 1990 and 2007. Essay 2: This paper focuses on second-generation immigrants and analyses the short- and long-termeffects of immigrant and ethnic group concentration in childhood neighbourhood on earnings,unemployment, reliance on income support and educational attainment. The results show thata high immigrant concentration in a childhood neighbourhood is negatively associated witheconomic outcomes of both second-generation immigrants and natives. Ethnic groupconcentration seems to work in the opposite direction, improving economic outcomes forsecond-generation immigrants. Furthermore, the results highlight the importance of includingtime dynamics in any analysis of the effect of childhood neighbourhood ethnic compositionon economic outcomes.

Ekonomy i psychology po celém světě vždy zajímala otázka procesu lidského rozhodování. Eko- nomové zd·razňují význam teorie úžitku během rozhodování, kdežto psychologové se zaměřují na r·zné vnitřní a vnější stimuly ovlivňující naše rozhodnutí. Oba tyto přístupy m·žeme najít v be- haviorální ekonomií, kde oba koncepty mezi sebou těsně spolupracují. Znalost r·zných ekonomic- kých i psychologických faktor·, které ovlivňují náš výběr m·že být mimo jiné přínosná například ve výzkumu spropitného. Abychom našli r·zné d·vody pro placení spropitného, vytvořili jsme experiment ohledně výše spropitného u českých zákazník·. Procentuální výše spropitného byla zkoumána v závislosti na pohlaví obsluhy, velikosti skupiny, která navštívila restauraci, velikosti účtu na jednu osobu a také byl zkoumán vliv tří na sobě nezávislých intervencí. Tyto intervence byly zaměřeny na altruistické chování, reciprocitu a dobrou náladu zp·sobenou personalizací. Výsledky experimentu jsou překvapující a neshodují se s výsledky z předchozích experiment·. Bylo zjištěno, že intervence spojené s altruismem a reciprocitou mají negativní vliv na výši spro- pitného, avšak intervence spojená s personalizací nemá žádný vliv na spropitné. Ve výsledku se také poukazuje na klíčový vliv země, ve které je experiment proveden. 1

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-07-26T12:57:02Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) CRUZ, C K M.pdf: 6032813 bytes, checksum: 7efac88640dc87672373f58d5ea10713 (MD5) / Made available in DSpace on 2017-07-26T12:57:02Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) CRUZ, C K M.pdf: 6032813 bytes, checksum: 7efac88640dc87672373f58d5ea10713 (MD5) Previous issue date: 2016-01-29 / CNPQ / O presente trabalho teve por objetivo analisar os fatores de influência nos processos de tombamento e suas consequências na preservação do patrimônio material e arqueológico em quatro parques históricos da Região Metropolitana do Recife. A questão da busca por uma memória nacional vivida nas décadas de 1960 a 1980 aqui no Brasil exerceu uma forte influência nas escolhas de que bens patrimoniais constituíam exemplos da identidade formadora da União. Utilizando os processos de tombamento como norteadores, analisamos as estratégias de tombamento realizadas em Pernambuco, avaliamos o discurso político, ideológico que influenciou esses processos de tombamento e, por fim, analisamos as estratégias de tombamento e preservação do patrimônio arqueológico dos parques históricos e/ou arqueológicos do país onde o fator arqueológico foi o principal motivo para a realização do processo de tombamento. Para isso, traçamos um protocolo para análise das dimensões técnica, jurídica e social. E, a partir disso elencamos cinco elementos principais que nos permitiram relacionar os discursos e as ações preservacionistas a que foram submetidos esses patrimônios. Assim, obtivemos que os parques históricos em Pernambuco foram tombados a partir de iniciativa de pesquisadores a fim de evitar que as consequências do momento que o Brasil estava passando e a busca de um progresso que vê o patrimônio cultural como um empecilho os atingisse e que se perdessem alguns dos locais representativos da história da Restauração Pernambucana. Entretanto, a preservação desse patrimônio arqueológico necessita de ações conjuntas e efetivas com a participação da população para que se perdure para as futuras gerações. / The present study aimed to analyze the factors of influence on the processes of tipping and its consequences in the preservation of heritage material and archaeological in four parks of the metropolitan area of Recife. The question of the search for a national memory lived on the decades of 1960 to 1980 here in Brazil has exercised a strong influence on the choices of which assets constituted examples of the Union’s forming identity. Using the processes of tipping as guiding, we analyzed the tipping strategies held in Pernambuco, we evaluated the political discourse, that influenced these ideological processes tipping and, finally, we analyzed the strategies of tipping and preservation the archaeological heritage of historical and/or archaeological parks of the country where the archaeological factor was the main reason for the tumbling process. For this, designed a protocol for analysis of technical, legal and social dimensions. And, from that we highlighted five key elements that allowed us to relate the speeches and actions the preservationists that have submitted these assets. Thus, we obtained that the historical parks in Pernambuco were listed from researchers’ initiative in order to avoid the consequences of the moment that the Brazil was going through and the search of a progress that see the cultural heritage as a trammels that hit and that lost some of the local representative of the history of Pernambuco's Restoration. However, the preservation of this archaeological heritage requires joint and effective actions with the participation of the population to which they will endure for the future generations.

abstract: Complex dynamical systems are the kind of systems with many interacting components that usually have nonlinear dynamics. Those systems exist in a wide range of disciplines, such as physical, biological, and social fields. Those systems, due to a large amount of interacting components, tend to possess very high dimensionality. Additionally, due to the intrinsic nonlinear dynamics, they have tremendous rich system behavior, such as bifurcation, synchronization, chaos, solitons. To develop methods to predict and control those systems has always been a challenge and an active research area. My research mainly concentrates on predicting and controlling tipping points (saddle-node bifurcation) in complex ecological systems, comparing linear and nonlinear control methods in complex dynamical systems. Moreover, I use advanced artificial neural networks to predict chaotic spatiotemporal dynamical systems. Complex networked systems can exhibit a tipping point (a “point of no return”) at which a total collapse occurs. Using complex mutualistic networks in ecology as a prototype class of systems, I carry out a dimension reduction process to arrive at an effective two-dimensional (2D) system with the two dynamical variables corresponding to the average pollinator and plant abundances, respectively. I demonstrate that, using 59 empirical mutualistic networks extracted from real data, our 2D model can accurately predict the occurrence of a tipping point even in the presence of stochastic disturbances. I also develop an ecologically feasible strategy to manage/control the tipping point by maintaining the abundance of a particular pollinator species at a constant level, which essentially removes the hysteresis associated with tipping points. Besides, I also find that the nodal importance ranking for nonlinear and linear control exhibits opposite trends: for the former, large degree nodes are more important but for the latter, the importance scale is tilted towards the small-degree nodes, suggesting strongly irrelevance of linear controllability to these systems. Focusing on a class of recurrent neural networks - reservoir computing systems that have recently been exploited for model-free prediction of nonlinear dynamical systems, I uncover a surprising phenomenon: the emergence of an interval in the spectral radius of the neural network in which the prediction error is minimized. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2020

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The adoptation of environmentally friendly behaviour is rather slow, although the climate crisis is pressing. This thesis aims to understand the slow adoption of environmentally friendly behaviour, specifically focusing on vegetarianism and veganism, by employing social network analysis. By simulating interactions within an agent-based model, the study explores different mechanisms that hinder the diffusion of these behaviours. The research findings highlight the significance of the complexity of the contagion in shaping the speed and extent of the diffusion process. While minimally complex contagions are able to infect half of the network on average, vegetarianism and veganism do not spread, due to their complexity. Additionally, the initial number of vegetarians/ vegans was found to be the main driver of infection speed, besides inter-connectedness. The study also explores the possibility of a social tipping point, a critical threshold at which the diffusion process accelerates or reaches a critical mass. However, the research did not observe a tipping point in the adoption of vegetarianism and veganism. By examining the slow adoption of vegetarianism and veganism as a complex contagion, this research contributes to the comprehension of concrete network effect. The findings provide valuable insights for designing interventions and strategies to promote the widespread adoption of vegetarianism, veganism, and other environmentally friendly practices.

Secondary administrative and leadership teams continuously search for practices that bolster cultural proficiency to address increasingly diverse student cohorts. This qualitative case study identifies the culturally responsive school leadership (CRSL) behaviors and expressions of 24 high school administrative and leadership team members in a suburban school district in Utah. Data reveals how each team demonstrates the behaviors and expressions of CRSL framework and how these behaviors and expressions position each school on the culturally proficient continuum. Superimposing the CRSL behaviors and expressions on the cultural proficiency continuum provides a current reality for administrative and leadership teams to assess their tipping points and how to move toward cultural proficiency.

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Many regions of the Amazon are experiencing drastic changes as deforestation and climate change drive the world’s largest continuous rainforest towards a ‘tipping point’. These disturbances are changing natural cycles that once past a critical threshold, will mark an unstoppable transition to an altered ecosystem. Losing areas of the Amazon rainforest will have implications for the global climate, global carbon budget, and global hydrological regimes. Scholars have projected these tipping points for areas of the eastern Amazon rainforest, but much less scholarship focuses on the headwaters of the Western Amazon, an area of great cultural and biological importance. Ecuador is one such country. This study aims to model a tipping point for the Ecuadorian Amazon by investigating the potential outcomes of a warming climate and land cover change through 1. a comprehensive review of regional circulation models and global circulation models in the Ecuadorian Amazon, 2. a comprehensive review of anthropogenic disturbances in the Ecuadorian Amazon and their impact on communities, soil, flora and fauna, and 3. A model projecting the deforestation tipping point of the Ecuadorian Amazon. The results of my study will identify patterns of forest loss and provide quantitative assessments of potential ‘tipping points’ in a future Ecuadorian Amazon. The methods and model created herein can be used by future researchers to evaluate regional drivers of deforestation and predict land cover change under future scenarios.

Der technologische Fortschritt hat in jüngster Zeit zu einer großen Zahl von Zeitreihenmessdaten über komplexe dynamische Systeme wie das Klimasystem, das Gehirn oder das globale ökonomische System geführt. Beispielsweise treten im Klimasystem Prozesse wie El Nino-Southern Oscillation (ENSO) mit dem indischen Monsun auf komplexe Art und Weise durch Telekonnektionen und Rückkopplungen in Wechselwirkung miteinander. Die Analyse der Messdaten zur Rekonstruktion der diesen Wechselwirkungen zugrunde liegenden kausalen Mechanismen ist eine Möglichkeit komplexe Systeme zu verstehen, insbesondere angesichts der unendlich-dimensionalen Komplexität der physikalischen Prozesse. Diese Dissertation verfolgt zwei Hauptfragen: (i) Wie können, ausgehend von multivariaten Zeitreihen, kausale Wechselwirkungen praktisch detektiert werden? (ii) Wie kann die Stärke kausaler Wechselwirkungen zwischen mehreren Prozessen in klar interpretierbarer Weise quantifiziert werden? Im ersten Teil der Arbeit werden die Theorie zur Detektion und Quantifikation nichtlinearer kausaler Wechselwirkungen (weiter-)entwickelt und wichtige Aspekte der Schätztheorie untersucht. Zur Quantifikation kausaler Wechselwirkungen wird ein physikalisch motivierter, informationstheoretischer Ansatz vorgeschlagen, umfangreich numerisch untersucht und durch analytische Resultate untermauert. Im zweiten Teil der Arbeit werden die entwickelten Methoden angewandt, um Hypothesen über kausale Wechselwirkungen in Klimadaten der vergangenen hundert Jahre zu testen und zu generieren. In einem zweiten, eher explorativen Schritt wird ein globaler Luftdruck-Datensatz analysiert, um wichtige treibende Prozesse in der Atmosphäre zu identifizieren. Abschließend wird aufgezeigt, wie die Quantifizierung von Wechselwirkungen Aufschluss über mögliche qualitative Veränderungen in der Klimadynamik (Kipppunkte) geben kann und wie kausal treibende Prozesse zur optimalen Vorhersage von Zeitreihen genutzt werden können. / Today''s scientific world produces a vastly growing and technology-driven abundance of time series data of such complex dynamical systems as the Earth''s climate, the brain, or the global economy. In the climate system multiple processes (e.g., El Nino-Southern Oscillation (ENSO) or the Indian Monsoon) interact in a complex, intertwined way involving teleconnections and feedback loops. Using the data to reconstruct the causal mechanisms underlying these interactions is one way to better understand such complex systems, especially given the infinite-dimensional complexity of the underlying physical equations. In this thesis, two main research questions are addressed: (i) How can general causal interactions be practically detected from multivariate time series? (ii) How can the strength of causal interactions between multiple processes be quantified in a well-interpretable way? In the first part of this thesis, the theory of detecting and quantifying general (linear and nonlinear) causal interactions is developed alongside with the important practical issues of estimation. To quantify causal interactions, a physically motivated, information-theoretic formalism is introduced. The formalism is extensively tested numerically and substantiated by rigorous mathematical results. In the second part of this thesis, the novel methods are applied to test and generate hypotheses on causal interactions in climate time series covering the 20th century up to the present. The results yield insights on an understanding of the Walker circulation and teleconnections of the ENSO system, for example with the Indian Monsoon. Further, in an exploratory way, a global surface pressure dataset is analyzed to identify key processes that drive and govern interactions in the global atmosphere. Finally, it is shown how quantifying interactions can be used to determine possible structural changes, termed tipping points, and as optimal predictors, here applied to the prediction of ENSO.