Deterministic Models for Traffic Jams

We study several deterministic one-dimensional traffic models. For integer positions and velocities we find the typical high and low density phases separated by a simple transition. If positions and velocities are continuous variables the model shows self-organized criticality driven by the slowest car.Comment: 11 pages, latex, HLRZ preprint 46/93, UKAM-WP 93.13

Non-concave fundamental diagrams and phase transitions in a stochastic traffic cellular automaton

Within the class of stochastic cellular automata models of traffic flows, we look at the velocity dependent randomization variant (VDR-TCA) whose parameters take on a specific set of extreme values. These initial conditions lead us to the discovery of the emergence of four distinct phases. Studying the transitions between these phases, allows us to establish a rigorous classification based on their tempo-spatial behavioral characteristics. As a result from the system's complex dynamics, its flow-density relation exhibits a non-concave region in which forward propagating density waves are encountered. All four phases furthermore share the common property that moving vehicles can never increase their speed once the system has settled into an equilibrium

Programming patterns and development guidelines for Semantic Sensor Grids (SemSorGrid4Env)

The web of Linked Data holds great potential for the creation of semantic applications that can combine self-describing structured data from many sources including sensor networks. Such applications build upon the success of an earlier generation of 'rapidly developed' applications that utilised RESTful APIs. This deliverable details experience, best practice, and design patterns for developing high-level web-based APIs in support of semantic web applications and mashups for sensor grids. Its main contributions are a proposal for combining Linked Data with RESTful application development summarised through a set of design principles; and the application of these design principles to Semantic Sensor Grids through the development of a High-Level API for Observations. These are supported by implementations of the High-Level API for Observations in software, and example semantic mashups that utilise the API

Cellular Automata Models of Road Traffic

In this paper, we give an elaborate and understandable review of traffic cellular automata (TCA) models, which are a class of computationally efficient microscopic traffic flow models. TCA models arise from the physics discipline of statistical mechanics, having the goal of reproducing the correct macroscopic behaviour based on a minimal description of microscopic interactions. After giving an overview of cellular automata (CA) models, their background and physical setup, we introduce the mathematical notations, show how to perform measurements on a TCA model's lattice of cells, as well as how to convert these quantities into real-world units and vice versa. The majority of this paper then relays an extensive account of the behavioural aspects of several TCA models encountered in literature. Already, several reviews of TCA models exist, but none of them consider all the models exclusively from the behavioural point of view. In this respect, our overview fills this void, as it focusses on the behaviour of the TCA models, by means of time-space and phase-space diagrams, and histograms showing the distributions of vehicles' speeds, space, and time gaps. In the report, we subsequently give a concise overview of TCA models that are employed in a multi-lane setting, and some of the TCA models used to describe city traffic as a two-dimensional grid of cells, or as a road network with explicitly modelled intersections. The final part of the paper illustrates some of the more common analytical approximations to single-cell TCA models.Comment: Accepted for publication in "Physics Reports". A version of this paper with high-quality images can be found at: http://phdsven.dyns.cx (go to "Papers written"

Implementation and Deployment of a Library of the High-level Application Programming Interfaces (SemSorGrid4Env)

The high-level API service is designed to support rapid development of thin web applications and mashups beyond the state of the art in GIS, while maintaining compatibility with existing tools and expectations. It provides a fully configurable API, while maintaining a separation of concerns between domain experts, service administrators and mashup developers. It adheres to REST and Linked Data principles, and provides a novel bridge between standards-based (OGC O&M) and Semantic Web approaches. This document discusses the background motivations for the HLAPI (including experiences gained from any previously implemented versions), before moving onto specific details of the final implementation, including configuration and deployment instructions, as well as a full tutorial to assist mashup developers with using the exposed observation data

“INOVAÇÃO: A COMPREENSÃO DOS ENVOLVIDOS COM O ENSINO SUPERIOR EM BRASÍLIA”

Esta pesquisa tem por objetivo geral compreender os significados da inovação, no ensino superior, a partir dos atores envolvidos no processo: Universidades da cidade de Brasília, Ministério da Educação e Cultura e Ministério da Ciência, Tecnologia e Inovação. Buscou-se identificar, nas universidades da cidade de Brasília, elementos constituintes das políticas para a criação de inovações, através de seus documentos oficiais e no caso dos ministérios analisar pelas políticas, projetos e atos normativos como eles efetivamente destinam recursos e investem no desenvolvimento e implementação da temática. Buscou-se ainda compreender os potenciais e limites da Universidade no desenvolvimento do país, questionando o paradigma educacional vigente, sobretudo, na educação superior, fazendo uma relação entre educação, conceito de qualidade e perspectivas do mercado de trabalho. Procurou responder a uma necessidade atual da educação superior, qual seja a de preparar-se para as mudanças constantes e incertezas contínuas sobre o futuro e caminho do desenvolvimento e avanço econômico, social e político do país. Sendo assim, ela revelará que falta, portanto, entendimento sobre inovação na perspectiva de educação de qualidade

Ideal isotropic auxetic networks from random networks

Auxetic materials are characterized by a negative Poisson's ratio, $\mathrm{\nu}$. As the Poisson's ratio becomes negative and approaches the lower isotropic mechanical limit of $\mathrm{\nu = -1}$, materials show enhanced resistance to impact and shear, making them suitable for applications ranging from robotics to impact mitigation. Past experimental efforts aimed at reaching the $\mathrm{\nu = -1}$ limit have resulted in highly anisotropic materials, which show a negative Poisson's ratio only when subjected to deformations along specific directions. Isotropic designs have only attained moderately auxetic behavior, or have led to structures that cannot be manufactured in 3D. Here, we present a design strategy to create isotropic structures from disordered networks that leads to Poisson's ratios as low as $\mathrm{\nu = -0.98}$. The materials conceived through this approach are successfully fabricated in the laboratory and behave as predicted. The Poisson's ratio $\mathrm{\nu}$ is found to depend on network structure and bond strengths; this sheds light on the structural motifs that lead to auxetic behavior. The ideas introduced here can be generalized to 3D, a wide range of materials, and a spectrum of length scales, thereby providing a general platform that could impact technology.Comment: 16 pages, 6 figure

Breakdown and recovery in traffic flow models

Most car-following models show a transition from laminar to ``congested'' flow and vice versa. Deterministic models often have a density range where a disturbance needs a sufficiently large critical amplitude to move the flow from the laminar into the congested phase. In stochastic models, it may be assumed that the size of this amplitude gets translated into a waiting time, i.e.\ until fluctuations sufficiently add up to trigger the transition. A recently introduced model of traffic flow however does not show this behavior: in the density regime where the jam solution co-exists with the high-flow state, the intrinsic stochasticity of the model is not sufficient to cause a transition into the jammed regime, at least not within relevant time scales. In addition, models can be differentiated by the stability of the outflow interface. We demonstrate that this additional criterion is not related to the stability of the flow. The combination of these criteria makes it possible to characterize commonalities and differences between many existing models for traffic in a new way

Desodorização de efluentes líquidos tratados em leito de zona de raízes: “wetlands”

<div align="justify">A zona de raízes é um sistema que utiliza as raízes das plantas (macrófitas) no tratamento de efluentes líquidos domésticos. Os mecanismos envolvidos (físicos, químicos e biológicos) de estabilização da matéria orgânica do efluente e compostos odorantesenvolvem principalmente os elementos constituintes do meio (solo, microrganismos e plantas). O presente trabalho utiliza-se daolfatometria (técnica de análise de odores) como ferramenta na avaliação da desodorização de efluentes líquidos tratados em umaestação de tratamento de esgoto por zona de raízes (ETEZR) em uma comunidade rural do município de Irati (PR). Para umamelhor avaliação da eficácia da desodorização, os odores (de antes e depois do tratamento na estação) foram avaliados nas trêscategorias olfatométricas (intensidade, caráter e hedonicidade) de acordo com normas européias. Os resultados apontaram que oefluente tratado ainda apresentava níveis de odor perceptíveis mesmo após redução significativa na sua intensidade (a redução noquesito “muito forte” foi de 89,3% entre os efluentes de entrada e saída da estação de macrófitas). Além disso, o caráter odoranteclassificado como “ofensivo” foi o mais citado pelo júri nos dois efluentes (entrada e saída, com 91% e 40% do número derespostas, respectivamente); entretanto, nesse mesmo quesito, o efluente tratado apresentou odores menos “agressivos” e bemmenos desagradáveis. De um modo geral, a estação proposta mostrou-se eficaz na estabilização de compostos odorantescomumente liberados na degradação biológica anaeróbia em tratamentos dessa natureza.<br><br>Abstract The wetland is a system that uses the roots plants (macrophyte) in the domestic wastewater treatment.The mechanisms (physical, chemical and biological ones) oforganic matter stabilization of effluent and odorouscompounds (commonly found in anaerobic biologicaldegradation) involve soil, microorganisms and plants. This work uses olfactometry (technical of odors analysis) as toolin the evaluation of the odor remotion of sewage treated byRoot Zone Sewage Treatment Station (RZSTS) in an ruralcommunity of Irati City (Brazil). For a better evaluation ofthe effectiveness of the odor remotion, the odors (rather anddownstream treatment) has been evaluated in the threeolfactometric categories (intensity, character and hedonictone), according to European standards. The results hadpointed that wastewater treated still presented perceivablelevels of odor even after significant reduction in intensity(the reduction in the category “very strong” was 89,3%between the entrance and outlet wastewater of themacrophyes station). Moreover, “offensive” category wascited by the jury in the two effluent (entrance and outlet one,with 91% and 40% of answers, respectively); however, inthis same question, the wastewater treated presented lessaggressive and unpleasant odors. In a general way, thestation proposed revealed efficiency in odorous compoundsstabilization by anaerobic biological degradation.</div

Social organization in the Minority Game model

We study the role of imitation within the Minority Game model of market. The players can exchange information locally, which leads to formation of groups which act as if they were single players. Coherent spatial areas of rich and poor agents result. We found that the global effectivity is optimized at certain value of the imitation probability, which decreases with increasing memory length. The social tensions are suppressed for large imitation probability, but generally the requirements of high global effectivity and low social tensions are in conflict.Comment: 6 pages, 7 figures, submitted to Physica