The problem of dynamic autonomous agent placement for tracking moving targets arises in many real-life applications, such as rescue operations, security, surveillance, and reconnaissance. The objective of this thesis is to develop a distributed hierarchical approach to address this problem. After the approach is developed, it is tested on a number of urban surveillance scenarios. The proposed approach views the placement problem as a multi-tiered architecture entailing modules for low-level sensor data preprocessing and fusion, decentralized decision support, knowledge building, and centralized decision support. This thesis focuses upon the modules of decentralized decision support and knowledge building. The decentralized decision support module requires a great deal of coordination among agents to achieve the mission objectives. The module entails two classes of distributed algorithms: non-model-based algorithms and model-based algorithms. The first class is used as a place holder while a model is built to describe agents knowledge about target behaviors. After the model is built and evaluated, agents switch to the model-based algorithms. To apply the approach to urban environments, urban terrain zones are classified, and the problem is mathematically formulated for two different types of urban terrain, namely low-rise, widely spaced and high-rise, closely spaced zones. An instance of each class of algorithms is developed for each of the two types of urban terrain. The algorithms are designed to run in a distributed fashion to address scalability and fault tolerance issues. The class of model-based algorithms includes a distributed model-based algorithm for dealing with evasive targets. The algorithm is designed to improve its performance over time as it learns from past experience how to deal with evasive targets. Apart from the algorithms, a model estimation module is developed to build motion models online from sensor observations. The approach is evaluated through a set of simulation experiments inspired from real-life scenarios. Experimental results reveal the superiority of the developed algorithms over existing ones and the applicability of the online model-building method. Therefore, it is concluded that the overall distributed approach is capable of handling agent placement or surveillance applications in urban environments among other applications.

With the achievement of autonomous flight for small unmanned aircraft, currently ongoing research is expanding the capabilities of systems utilizing such vehicles for various tasks. This allows shifting the research focus from the individual systems to task execution benefits resulting from interaction and collaboration of several aircraft. Given that some available high-fidelity simulations do not yet support multi-vehicle scenarios, the presented work introduces a framework which allows several individual single-vehicle simulations to be combined into a larger multi-vehicle scenario with little to no special requirements towards the single-vehicle systems. The created multi-vehicle system offers real-time software-in-the-loop simulations of swarms of vehicles across multiple hosts and enables a single operator to command and control a swarm of unmanned aircraft beyond line-of-sight in geometrically correct two-dimensional cluttered environments through a multi-hop network of data-relaying intermediaries. This dissertation presents the main aspects of the developed system: the underlying software framework and application programming interface, the utilized inter- and intra-system communication architecture, the graphical user interface, and implemented algorithms and operator aid heuristics to support the management and placement of the vehicles. The effectiveness of the aid heuristics is validated through a human subject study which showed that the provided operator support systems significantly improve the operators' performance in a simulated first responder scenario. The presented software is released under the Apache License 2.0 and, where non-open-source parts are used, software packages with free academic licenses have been chosen--resulting in a framework that is completely free for academic research.

Due to their small size, relative covertness, and high maneuverability, micro rotorcraft are ideal for a plethora of civilian and military applications in an urban environment such as, surveillance, monitoring, mapping, and search and rescue. It is envisioned that these vehicles will operate indoors confined complex spaces, and outside near the ground—among buildings and other obstacles. The aerodynamic velocity fields in these areas are notoriously complex with the mean winds varying spatially and temporally with sharp changes in wind magnitude and direction over small distances. This results in velocity perturbations which are on the same order of magnitude as the maximum flight speeds of micro rotorcraft leading to stall, large attitude perturbations, and loss of control; thus preventing micro rotorcraft from carrying out even the most basic missions. This dissertation starts to fill the void in the literature on this topic by assessing how to design a micro coaxial helicopter with improved gust response in complex urban environments. Both experimental flight tests and modeling and simulation tools are developed and executed to analytically understand the challenges and potential solutions to enable rotorcraft to operate efficiently and robustly in urban environments. A set of performance metrics were developed to provide a framework to assess mission-level performance of micro rotorcraft in both flight experiments and simulation trade studies. A high fidelity dynamic model of a coaxial helicopter was developed to accurately simulate vehicle response to urban wind disturbances. The model was validated using flight experiments in a motion capture facility. Additionally, a dynamic inversion based Gust Rejection Control architecture was developed for the dynamic simulation which included a novel wind estimation algorithm that was utilized to improve controller performance and create a flight envelope protection scheme. The high fidelity dynamic model was employed to perform a variety of trade studies to: analyze vehicle response to prototypical urban wind kernels, understand the affect of wind estimation on the control architecture, assess the level of model fidelity required to adequately simulate vehicle response to urban winds, and identify key platform design parameter trends to improve wind disturbance capabilities. Overall the results show the challenges micro rotorcraft face in urban environments while highlighting some trends that can be helpful for future design and analysis efforts.

Le paradigme d'Internet des objets (IdO) envisage d'augmenter l'Internet actuel avec un grand nombre de dispositifs intelligents communicants. Les réseaux de capteurs sans fil (RCsF) déploient les appareils fonctionnant sur les approvisionnements énergétiques maigres et mesurent les phénomènes environnementaux (comme la température, la radioactivité, ou CO2). Les applications populaires de réseaux de capteurs sans fil comprennent la surveillance, la télémétrie et la prévention des catastrophes naturelles. Les majeurs défis de réseaux de capteurs consistent à: comment obtenir l'efficacité énergétique? Comment surmonter les déficiences de support sans fil? et comment les faire fonctionner d'une manière auto-organisée? L'intégration de réseaux de capteurs dans IoD s'appuiera sur un ensemble de standards ouverts qui s'efforcent d'offrir le passage à l'échelle, la fiabilité dans une variété des conditions, et les scénarios d'exploitation. Néanmoins, les standards dans leur état actuel ont des problèmes d'interopérabilité et peuvent bénéficier de nouvelles améliorations. Les contributions de la thèse sont les suivantes: • Nous avons mené une analyse expérimentale et identifié les caractéristiques d'un environnement de réseau de capteurs. Notre analyse a porté sur la modélisation des liens et la dynamique du réseau, ainsi que la corrélation des liens avec les paramètres environnementaux. L'étude analytique nous a permis d'identifier les principales faiblesses de l'environnement du RCsF et a permis aussi d'obtenir une meilleure compréhension de la dynamique de lien radio et le voisinage des nœuds. • Nous avons confrontés la question de l'interopérabilité des deux principaux standards - IEEE 802.15.4 dans la couche de contrôle d'accès au medium, et RPL dans la couche de transport. Nous proposons d'adapter la structure originale de cluster tree et de construire un framework élégant, qui permettra le fonctionnement conjoint de l'IEEE 802.15.4 et RPL sans l'apparition des collisions. En outre, nous évaluons à travers de nombreuses simulations les deux algorithmes distribués d'attribution de slots. Ces algorithmes permettront d'atteindre un fonctionnement presque sans collisions. • Nous proposons une solution inter-couche distribuée dans le but de construire une topologie afin que IEEE 802.15.4 et RPL puissent fonctionner ensemble. Notre algorithme auto-organisé obtient une structure topologique obéissante aux recommandations globales, cela, par la seule utilisation des métriques mesurées localement. De nombreuses simulations démontrent les avantages de la structure résultante en termes de convergence de temps, de stabilité, et d'efficacité énergétique dans le long terme. Les simulations démontrent aussi un impact positif sur les performances de routage. • Nous proposons un ensemble de nouveaux mécanismes qui permettront d'améliorer les performances de RPL et d'utiliser la Qualité de Service pour gérer les problèmes de trafic sensible. Notre extension de routage opportuniste et multi-chemin contribue à améliorer la livraison des paquets avant une date limite, tout en minimisant le surcout et la consommation d'énergie par rapport à la version de base de RPL. / Internet of Things (IoT) paradigm envisages expanding the current Internet with a huge number of the intelligent communicating devices. Wireless Sensor Networks (WSN) deploys the devices running on the meager energy supplies, and measuring environmental phenomena (like temperature, radioactivity, or CO2). WSN popular applications include monitoring, telemetry, and natural disaster prevention. Major WSN challenges are how to allow energy efficiency, overcome impairments of wireless medium, and operate in the self-organized manner. The WSN integrating IoT will rely on a set of the open standards striving to offer scalability, reliability in a variety of the operating scenarios and conditions. Nevertheless, the current state of the standards has interoperability issues and can benefit from further improvements. The contributions of the thesis work are: • We conducted an experimental analysis and characterization of a WSN environment. Our analysis included the link characterization, correlation with environmental parameters as well as network dynamics. Analytical study allowed us to identify key weaknesses of the WSN environment as well a get a better understanding of the dynamics—both link and node neighborhood related. • We confront the interoperability issue of the leading IEEE 802.15.4 standard on the Medium Access Control layer and RPL standard on the transport layer. We propose to accommodate the original cluster-tree structure and to build an elegant framework for collision free multi-hop operation of the IEEE 802.15.4 that will allow RPL to run on top of it. Furthermore, we evaluate through extensive simulations two distributed schemes that achieve near collision free self-organization of the nodes. • We propose a distributed cross-layer convergecast topology construction within the joint IEEE 802.15.4 and RPL framework. Self-organization scheme obtains a topological structure obeying the global recommendations by the sole use of locally measured metrics. Extensive simulations demonstrate the advantages of the resulting structure in terms of convergence time, stability, and energy efficiency in long term and a positive impact on the routing performances. • We propose a set of new mechanisms that will improve RPL performances and enable Quality of Service operation that will handle delay sensitive traffic. Our multi-path opportunistic routing extension helps to improve packet delivery before a deadline, while minimizing overhead and energy consumption compared to the basic version of RPL.STAR

Thesis (MTech (Town and Regional Planning))--Cape Technikon, Cape Town, 2004 / Urban environments are by their very nature vastly complex with regard to the way they operate and how they perform in terms of quality of life. The influence of public transportation on the urban environment was highlighted by the erstwhile South African Minister of Transport, Mr Abdulah Mohamed Omar (Department of Transport 1999) when he said that in order to ensure sustainable urban environments, public transportation needs to be the preferred mode of motorised transportation in our cities. In order for this target to be reached, as set by the Minister, it is clearly necessary that the public transportation system operates at its optimal level and that existing deficiencies be identified and addressed. One typical, under-achieving element in the public transportation systems of cities in the developing world is in fact the Public Transport Interchange (PTI). The quality of PTls and their surrounding urban environments has been seriously neglected and ignored in the past. Evidence strongly suggests that PTls have the potential to provide fundamental preconditions for social and economic development locally and in some instances in the wider metropolitan context. For this potential to be realised, a set of performance measures needs to be identified specifically for PTls as an evaluating tool and to guide upgrades and new developments. However, before such performance measures can be proposed, a full understanding of what a positive urban living environment could be in the context of PTls, needs to be developed. In summary, the objective of this research project is to address the existing shortcomings associated with Public Transport Interchanges by setting performance indicators for evaluating and developing PTls in the developing world context, with specific emphasis on Cape Town, South Africa.

O objetivo desta pesquisa consiste em descrever as táticas e estratégias, desenvolvidas nas práticas cotidianas das pessoas que se encontram trabalhando como motoboys, na cidade de São Paulo (Brasil), para encontrarem alternativas e continuarem nessa atividade, diante de todas as adversidades da profissão e das contingências do espaço urbano. Levamos em consideração as ações produzidas por dois grupos de motoboys: o Canal Motoboy, que busca se organizar coletivamente, a partir de um projeto artístico, e produzir uma nova realidade para si e para a sua categoria profissional; e os motoboys de um grupo farmacêutico, que ganham a vida fazendo entregas de remédios pela grande São Paulo. O referencial teórico fundamenta-se em autores como Certeau, Sato, Santos e Oliva. Em termos metodológicos, valho-me da abordagem etnográfica, o que me levou a estabelecer uma convivência junto aos grupos de motoboys: com o Canal Motoboy, mantive uma convivência prolongada de mais de seis meses, no ano de 2007, frequentando, semanalmente, suas reuniões; com os motoqueiros do grupo farmacêutico, estabeleci uma convivência diária de duas semanas, em uma segunda etapa do campo, que se realizou no mês de julho de 2010. Os resultados apontam para a produção de táticas e estratégias nas práticas cotidianas que visam a estabelecer uma equilibração de forças entre os motoqueiros e o espaço da cidade: os motoboys ressignificam o espaço que se forma entre os carros, nas ruas, as determinações legais para o exercício de suas atividades de trabalho, os preconceitos sociais sobre a categoria, sua importância para o fluxo de coisas, na cidade, e tentam cumprir suas atribuições, buscando evitar os riscos dos acidentes de trânsito. Pudemos constatar, também, as articulações dos motoboys diante dos interesses de diversos setores sociais e econômicos que procuraram unir-se a eles, como: ONGs, associações da categoria, sindicatos, universidades, centros de pesquisas e empresas do setor motociclístico. Como trabalhadores onipresentes em uma das maiores metrópoles do mundo, os motoboys são alvos de interesses diversos e alguns procuram encontrar vantagens nessa situação, para se estruturarem enquanto uma rede social. Observamos ainda que os motoqueiros descrevem suas atividades cotidianas como uma luta pela sobrevivência, diante das contingências do espaço da cidade / The objective of this study is to describe the tactics and strategies found in the daily practices of people who work as couriers in São Paulo (Brazil), to find alternatives while continuing to deal with adersities of the profession and the continguencies of urban space. We consider the actions of two distinct groups of couriers: (1) Canal Motoboy, which collectively organizes an artistic project to create a new reality for themselves and their profession; and (2) a pharmaceutical group, which makes a living by delivering medicine in Metropolitan São Paulo. The theoretical reference is based on authors, such as Certeau, Sato, Santos, and Oliva. In terms of methods, we used an ethnographic approach, which led us to establish a joint-living situation with the courier groups: with Canal Motoboy, a prolonged stay of more than six months in 2007, attending their meetings on a weekly basis; and with the bikers from the pharmaceurical group, an established daily-living situation for two weeks during the latter part of the field study held in July, 2010. The results point to the innovation of tactics and strategies in daily practices, aimed to balance the forces between the bikers and the urban space: these couriers redefined this space, made of cars on the streets, the legal frameworks that determine work ethics, the social prejudices surrounding the issue, its importance to the flow of things in the city and its attempt to fulfill its mission, all while avoiding lethal traffic accidents. We have seen, also, the shared interests of diverse social and economic sectors that have sought to unite in this movement: NGOs, workers associations, unions, universities, research centers and companies that make up the motorcycle industry. As ubiquitous workers in one of the largest metropolises in the world, couriers are targets of diverse interests and anyone looking for a chance to take advantage of the situation, while structuring a social network. We acknowledge the bikers for their daily activities, which they define as a fight for survival amongst constingencies in the urban space

Através de uma abordagem analítica entre dois modelos geomorfológicos elaborados por ROSS (1994) e pelo INPE (CREPANI et. al, 1996), foi estabelecida uma comparação entre variáveis relacionadas a aspectos capitais de ambos - critérios utilizados para a definição das unidades de paisagem e importância da variável relevo e um aspecto relacionado à aplicabilidade a adequação aos ambientes urbanos. Por apresentar uma diversidade de usos e ocorrência de áreas urbanas e preservadas, a bacia do córrego do Bispo, localizada na zona norte do município de São Paulo, foi escolhida como área teste. Estes modelos apresentaram boa aplicabilidade em ambientes preservados, destacando-se o modelo de Ross, que é mais eficaz em termos de previsibilidade. Em relação às áreas urbanas os modelos apresentaram resultados semelhantes, na medida em que diagnosticam fragilidades ambientais para áreas de ocupação não consolidadas e apresentam limitações em relação às áreas de ocupação consolidadas. Objetivando ainda uma contribuição ao modelo de Ross em nível experimental, incorporou-se a classificação de vertentes de RUEH (1975) baseada na geometria destas, à variável relevo do primeiro. Como resultado, foram obtidas diferenças significativas para algumas áreas em relação ao modelo originalmente proposto por Ross. / An analytical approach between two geomorfphologic models elaborated by ROSS (1994) and INPE (CREPANI et. al, 1996), a comparison was estabilished between two variables related to capital aspects of both the criteria for the definition of landscape units, the importance of variable relief and its appliance to urban environments. For presenting a huge diversity of land uses and preserved urban areas, Córrego do Bispo basin located in north zone of São Paulo has been chosen as an experimental area. These models have shown a good applicability in preserved environmental, emphasizing specially Ross model, which is more useful in terms of predictability. Both models presented similar results in urban areas, while they make diagnostics of environmental fragilities to areas of non-consolidated occupation and presented restrictions about consolidated occupation areas. Also intending to contribute to Ross model in an experimental level, the slope classification of RUEH (1975) was included, based in its geometry to variable relief of Ross model. As a result, meaningful differences were obtained for some areas in relation to the model originally proposed by Ross.

Microplastics (MPs) constitute a risk to both human and environmental health. It is vital to identify sources and pathways to take the necessary action and limit the number of MPs in our environments. However, we currently have a limited understanding regarding MPs' variation with time in urban environments in an indoor setting. This knowledge gap is partly due to the absence of standard sampling procedures, and there is a need to develop reliable sampling techniques. This study evaluates the effectivity of a novel tape-lifting method developed for sampling MPs from various urban surfaces and applies this technique to measure weekly trends in artificial polymer deposition within an indoor environment at Umeå University. Two stone floor surfaces were sampled repeatedly on eight occasions over three weeks. Recovered MPs were identified in a microscope and categorized after shape: fibers or fragments. My developed tape-lifting method showed high MP recoveries (on average 100 ±4%) for the majority of the tested indoor surfaces (floors and tables). However, the method proved less functional for outdoor substrates (asphalt), where the recovery was significantly lower (on average, 48% ± 17). In my monitoring of MPs, I found that the deposition rate of fibers did not significantly differ between the two sampling sites or change over the three weeks. In contrast, MPs of fragment-type varied both between sampling sites and as a function of time. Here, the MP deposition rate was, on average, nearly two times higher at one of the sites, indicating substantial spatial variation. Regarding temporal variation, fragmented MPs showed an overall decrease in the number of deposited fragments over the three-week period. Interestingly the lack of variation in fibrous MPs indicates a dominating input source of fibers that is both homogenous for the room and static with time. In contrast, a specific source that is also time-sensitive appears to influence the dispersal pattern of fragmented MPs. My findings highlight the need to consider the temporal dimension of MP contamination and for research focusing on the relationship between fragmented MPs and their sources in indoor environments.

The consequences of recent flooding and extreme rain events have highlighted the importance of proper urban planning and preventative measures for storm water management. As cities become more urbanized the significance of permeable surfaces such as parks and other urban green spaces increases which infiltrate the water into the ground. Agricultural research has for many years emphasized the effect of compaction on soil parameters and how, not only the crop yield reduces but also how the infiltration decreases. This thesis aims to study how the infiltration rate, bulk density and soil resistance changes with compaction through field experiments where a vehicle is let to roll over an urban green area. The thesis will also simulate rainfall over five theoretical soils that can be found in urban environments exposed to compaction to determine what significance compaction has on surface runoff. The modelling software HYDRUS-1D will be used so simulate rain fall events on the different soils. The rain events simulated will be based on the five hyetographs that best represent Sweden’s rain events, based on historical data. A CDS rain will be simulated as well. They will be simulated for a 2, 10 and 100 year return period. A literature study will also be conducted to determine how relevant freeze-thaw cycles are to the soil parameters. It is since previously known that freeze-thaw cycles can improve aggregate stability, increase soil particle fragmentation which can lead to less soil penetration resistance and even partially return the soil conditions to those prior to compaction, but the process does not extend to layers beyond 40 cm. The field experiment results showed a clear decrease in infiltration rate with increasing number of vehicle passes. There was no clear correlation between bulk density and the number of vehicle passes. This result is attributed to the relatively light weight of the vehicle used as well as the heterogeneity of the soil. The cone penetration measurements showed an increasing resistance with increasing number of vehicle passes for only one of the three measured sites, with the most resistance being measured in a pathway on the green area. The insignificant results of one of the two other sites are attributed to wet weather conditions and unknown underlying material. The HYDRUS 1D simulations showed that a higher sand content mitigates the effects of soil compaction and leads to less runoff. The soil classified as sand (93% sand) had no runoff, the loamy sand (80% sand) had mild runoff. When comparing a sandy loam (60% sand) and a clay soil it is concluded that the sandy loam is more sensitive to soil compaction as more compaction leads to more runoff compared to the non-compacted scenario. The clay soil has little variation between the compaction scenarios but has generally more surface runoff in total. Soil texture therefor affects the surface runoff more than soil compaction. Most amount of runoff was generated by the two hyetographs which had a late peak intensity, most likely due to the soil already being saturated when the peak occurs. The runoff also increases with the return period of the rain event for both the hyetographs and the CDS rain.

This paper examines peri-urban space existing separate from the urban fabric and often in between urban and rural landscapes. This is a largely neglected area and often considered by each side as belonging to the other. Contemporary studies identify two sides associated with the rural-urban fringe: the expanding built settlements and ebbing countryside, ignoring significance and the circumstance of the spaces. The peri-urban fringe is a planning opportunity, which provides services beyond simple human habitat or wasteland of undesirable function. Through this study I intend to present the peri-urban interface as an intricate element of the urban infrastructure. This paper examines a series of case studies, which display peri-urban land-use planning and design through established areas, boundaries, and buffers spanning North America, Western Europe and Australia. Each area is examined to determine scope, program, and ecological and social impacts. The data informs positive and negative impacts within the peri-urban area. The peri-urban fringe spaces take on many forms and functions. Successful sites enrich the associated urban communities, whereas unsuccessful sites, which often exist in conflict with abutting environments, reduce quality of life and essential ecological processes. The peri-urban interface varies with many scales and circumstances, which affect quality of life for the urban population. Planning in the PUI is essential in promoting healthy populations and ecologies. Scale, program and accessibility determine how effectiveness of a peri-urban interface. Through this study, I want to identify significant value of the peri-urban interface as an opportunity and asset for the urban landscape. / Master of Landscape Architecture