Fractal geometry of aggregate snowflakes revealed by triple wavelength radar measurements

Radar reflectivity measurements from three different wavelengths are used to retrieve information about the shape of aggregate snowflakes in deep stratiform ice clouds. Dual-wavelength ratios are calculated for different shape models and compared to observations at 3, 35 and 94 GHz. It is demonstrated that many scattering models, including spherical and spheroidal models, do not adequately describe the aggregate snowflakes that are observed. The observations are consistent with fractal aggregate geometries generated by a physically-based aggregation model. It is demonstrated that the fractal dimension of large aggregates can be inferred directly from the radar data. Fractal dimensions close to 2 are retrieved, consistent with previous theoretical models and in-situ observations.

Understanding the link between single cell and population scale responses of Escherichia coli in differing ligand gradients

We formulate an agent-based population model of Escherichia coli cells which incorporates a description of the chemotaxis signalling cascade at the single cell scale. The model is used to gain insight into the link between the signalling cascade dynamics and the overall population response to differing chemoattractant gradients. Firstly, we consider how the observed variation in total (phosphorylated and unphosphorylated) signalling protein concentration affects the ability of cells to accumulate in differing chemoattractant gradients. Results reveal that a variation in total cell protein concentration between cells may be a mechanism for the survival of cell colonies across a wide range of differing environments. We then study the response of cells in the presence of two different chemoattractants.In doing so we demonstrate that the population scale response depends not on the absolute concentration of each chemoattractant but on the sensitivity of the chemoreceptors to their respective concentrations. Our results show the clear link between single cell features and the overall environment in which cells reside.

Metallicity effects on the modified wind momentum of CSPN

Recent investigations on the central stars of planetary nebulae (CSPN) indicate that the masses based on model atmospheres can be much larger than the masses derived from theoretical mass-luminosity relations. Also, the dispersion in the relation between the modified wind momentum and the luminosity depends on the mass spread of the CSPN, and is larger than observed in massive hot stars. Since the wind characteristics probably depend on the metallicity, we analyze the effects on the modified wind momentum by considering the dispersion in this quantity caused by the stellar metallicity. Our CSPN masses are based on a relation between the core mass and the nebular abundances. We conclude that these masses agree with the known mass distribution both for CSPN and white dwarfs, and that the spread in the modified wind momentum can be explained by the observed metallicity variations.

Multi-agent simulation of sawmill yard operations

This paper reports the findings of using multi-agent based simulation model to evaluate the sawmill yard operations within a large privately owned sawmill in Sweden, Bergkvist Insjön AB in the current case. Conventional working routines within sawmill yard threaten the overall efficiency and thereby limit the profit margin of sawmill. Deploying dynamic work routines within the sawmill yard is not readily feasible in real time, so discrete event simulation model has been investigated to be able to report optimal work order depending on the situations. Preliminary investigations indicate that the results achieved by simulation model are promising. It is expected that the results achieved in the current case will support Bergkvist-Insjön AB in making optimal decisions by deploying efficient work order in sawmill yard.

Transformação tecnológica e estratégia competitiva: um estudo multicaso

O objetivo principal desta pesquisa é investigar como a inovação tecnológica ajuda a moldar estratégias, para obtenção de vantagens competitivas sustentáveis, em um contexto de globalização. Com base em extensa revisão bibliográfica, compreendendo competitividade, tecnologia, estratégia e alianças estratégicas é explorado o fenômeno da inovação tecnológica e sua inserção na gestão estratégica de quatro empresas dos setores de celulose, siderurgia, químico-farmacêutico e de aplicações médicas da energia nuclear. Inicialmente, o conceito de competitividade e a estrutura industrial brasileira são analisados a luz de três modelos distintos. Também é realizada uma avaliação do conceito de competências essenciais das organizações e arquiteturas estratégicas. Posteriormente é avaliada a relação entre vantagem competitiva e inovação tecnológica e as dimensões estratégicas da tecnologia. Finalmente são descritas as escolas de pensamento estratégico e as relações entre alianças estratégicas e transferência de tecnologia. São analisadas as características estruturais e competitivas de cada um dos setores estudados, bem como apresentados perfis das empresas representantes de cada setor. Os dados de cada uma das empresas foram obtidos por meio de entrevistas semi-estruturadas. Os resultados são analisados individualmente e posteriormente consolidados. Os resultados do estudo permitiram identificar que a variável tecnológica é inserida na gestão estratégica das empresas em três níveis distintos. O primeiro nível é o de análise; o segundo é o de decisões estratégicas e finalmente o terceiro nível é o de implementação estratégica. Também foram identificadas as fontes de tecnologia normalmente utilizadas pelas organizações objeto do estudo. Por fim, é sugerido que o modelo de estrutura industrial de Porter pode receber contribuições no sentido de incorporar as estratégias cooperativas das empresas por meio de indicadores de cooperatividade.

Ascenção e queda do provimento de acesso gratuito à Internet no Brasil: o papel dos modelos de negócio

This research was commenced with the idea to promote an strategic evaluation of the sustentability of the free Internet access, analysing its process of value creation, its sources of revenue generation, its business models development as well as its capacity to generate adequated returns to the investors. It was concluded that the free Internet access is not dead. Indeed, what has occoured was a migration from a model completely based on delivering a single service, generally dependent of publicity sells revenues, to a hibrid based business model with different types of services and with revenues been generated from multiple sources. Nevertheless, not all players were capable to evolute their business models and survive, what occasioned a huge number of fails, mergers and acquisitions, resulting in a concentration all over the segment.

Gestão por resultados: proposta de desdobramento da estratégia e criação de incentivos para o alcance das metas na Prefeitura do Município de Osasco

Desde 2013, a Prefeitura do Município de Osasco iniciou a implantação de um modelo de gestão por resultados, com a utilização da metodologia do Balanced Scorecard (BSC) e a celebração de Acordos de Resultados entre o prefeito e respectivos secretários. A dissertação objetivou, inicialmente, responder à demanda da Secretaria de Planejamento e Gestão (Seplag), de realizar diagnóstico e propor soluções de incentivos prioritariamente não financeiros para estimular os funcionários a perseguirem o cumprimento dos objetivos e metas contidos no planejamento estratégico da prefeitura. Neste sentido, buscou-se estabelecer um modelo conceitual para embasar a adoção de políticas de reconhecimento no trabalho, especialmente no âmbito da gestão pública. Adicionalmente, verificou-se a necessidade de agregar dois novos objetivos àquele proposto de início: (1) avaliar o nível de disseminação e desdobramento até as equipes de ponta das metas estratégicas pactuadas nos Acordos de Resultados, utilizando-se como referência a metodologia do BSC; (2) verificar o nível de aderência do modelo de gestão atualmente praticado pela prefeitura de Osasco aos preceitos da chamada Nova Gestão Pública (NGP). Ao final, são propostas ações para o aperfeiçoamento e continuidade do modelo de gestão adotado.

Análise e proposta de aprimoramento para a gestão da Sabina Escola Parque do Conhecimento

Este trabalho teve como objetivo principal buscar, por meio de benchmarking, um modelo mais apropriado de gestão para o equipamento público Sabina Escola Parque do Conhecimento – localizado na cidade de Santo André-São Paulo –, cuja finalidade é ser uma extensão lúdica e prática do ambiente escolar. Para isso, avaliaram-se os modelos de gestão aplicados em equipamentos públicos similares, isto é, que também fornecem serviços educacionais e ambientais inovadores. Os equipamentos públicos escolhidos para compor a análise foram: Museu Catavento, Plug Minas e Aquário Municipal de Santos, situados, respectivamente, nas cidades de São Paulo, Belo Horizonte e Santos. Para alcançar esse objetivo, recorreu-se a um estudo investigativo, que compreendeu pesquisa bibliográfica e documental, visitas técnicas, coleta de dados quantitativos sobre os equipamentos e suas respectivas localidades, bem como entrevistas com os gestores desses atrativos e com responsáveis por órgãos governamentais relacionados. A partir disso, e com auxílio da análise SWOT, foram elaboradas algumas propostas para melhorar a gestão da Sabina Escola Parque: implantar um modelo de gestão por resultados, implementar parcerias formalizadas por meio de contrato de gestão com entidade qualificada, como as Organizações Sociais, incrementar as receitas, melhorar a eficiência das despesas, dentre outras.

Controlador em modo dual adaptativo robusto - DMARC

The so-called Dual Mode Adaptive Robust Control (DMARC) is proposed. The DMARC is a control strategy which interpolates the Model Reference Adaptive Control (MRAC) and the Variable Structure Model Reference Adaptive Control (VS-MRAC). The main idea is to incorporate the transient performance advantages of the VS-MRAC controller with the smoothness control signal in steady-state of the MRAC controller. Two basic algorithms are developed for the DMARC controller. In the first algorithm the controller's adjustment is made, in real time, through the variation of a parameter in the adaptation law. In the second algorithm the control law is generated, using fuzzy logic with Takagi-Sugeno s model, to obtain a combination of the MRAC and VS-MRAC control laws. In both cases, the combined control structure is shown to be robust to the parametric uncertainties and external disturbances, with a fast transient performance, practically without oscillations, and a smoothness steady-state control signal

Uma abordagem comportamental para inserção de robôs em ambientes culturais

In this work, we propose methodologies and computer tools to insert robots in cultural environments. The basic idea is to have a robot in a real context (a cultural space) that can represent an user connected to the system through Internet (visitor avatar in the real space) and that the robot also have its representation in a Mixed Reality space (robot avatar in the virtual space). In this way, robot and avatar are not simply real and virtual objects. They play a more important role in the scenery, interfering in the process and taking decisions. In order to have this service running, we developed a module composed by a robot, communication tools and ways to provide integration of these with the virtual environment. As welI we implemented a set of behaviors with the purpose of controlling the robot in the real space. We studied available software and hardware tools for the robotics platform used in the experiments, as welI we developed test routines to determine their potentialities. Finally, we studied the behavior-based control model, we planned and implemented alI the necessary behaviors for the robot integration to the real and virtual cultural spaces. Several experiments were conducted, in order to validate the developed methodologies and tools

Uma plataforma de integração de middleware para computação ubíqua

One of the current challenges of Ubiquitous Computing is the development of complex applications, those are more than simple alarms triggered by sensors or simple systems to configure the environment according to user preferences. Those applications are hard to develop since they are composed by services provided by different middleware and it is needed to know the peculiarities of each of them, mainly the communication and context models. This thesis presents OpenCOPI, a platform which integrates various services providers, including context provision middleware. It provides an unified ontology-based context model, as well as an environment that enable easy development of ubiquitous applications via the definition of semantic workflows that contains the abstract description of the application. Those semantic workflows are converted into concrete workflows, called execution plans. An execution plan consists of a workflow instance containing activities that are automated by a set of Web services. OpenCOPI supports the automatic Web service selection and composition, enabling the use of services provided by distinct middleware in an independent and transparent way. Moreover, this platform also supports execution adaptation in case of service failures, user mobility and degradation of services quality. The validation of OpenCOPI is performed through the development of case studies, specifically applications of the oil industry. In addition, this work evaluates the overhead introduced by OpenCOPI and compares it with the provided benefits, and the efficiency of OpenCOPI s selection and adaptation mechanism

Identificação e comparação entre controle preditivo com modelo não linear e PI sintonizados com PSO em sistema de separação gravitacional de águia-óleo

The separation methods are reduced applications as a result of the operational costs, the low output and the long time to separate the uids. But, these treatment methods are important because of the need for extraction of unwanted contaminants in the oil production. The water and the concentration of oil in water should be minimal (around 40 to 20 ppm) in order to take it to the sea. Because of the need of primary treatment, the objective of this project is to study and implement algorithms for identification of polynomial NARX (Nonlinear Auto-Regressive with Exogenous Input) models in closed loop, implement a structural identification, and compare strategies using PI control and updated on-line NARX predictive models on a combination of three-phase separator in series with three hydro cyclones batteries. The main goal of this project is to: obtain an optimized process of phase separation that will regulate the system, even in the presence of oil gushes; Show that it is possible to get optimized tunings for controllers analyzing the mesh as a whole, and evaluate and compare the strategies of PI and predictive control applied to the process. To accomplish these goals a simulator was used to represent the three phase separator and hydro cyclones. Algorithms were developed for system identification (NARX) using RLS(Recursive Least Square), along with methods for structure models detection. Predictive Control Algorithms were also implemented with NARX model updated on-line, and optimization algorithms using PSO (Particle Swarm Optimization). This project ends with a comparison of results obtained from the use of PI and predictive controllers (both with optimal state through the algorithm of cloud particles) in the simulated system. Thus, concluding that the performed optimizations make the system less sensitive to external perturbations and when optimized, the two controllers show similar results with the assessment of predictive control somewhat less sensitive to disturbances

Controle adaptativo por modelo de referencia e estrutura variável discreto no tempo

With the technology progess, embedded systems using adaptive techniques are being used frequently. One of these techniques is the Variable Structure Model- Reference Adaptive Control (VS-MRAC). The implementation of this technique in embedded systems, requires consideration of a sampling period which if not taken into consideration, can adversely affect system performance and even takes the system to instability. This work proposes a stability analysis of a discrete-time VS-MRAC accomplished for SISO linear time-invariant plants with relative degree one. The aim is to analyse the in uence of the sampling period in the system performance and the relation of this period with the chattering and system instability

Desenvolvimento de uma proposta de educação sexual para adolescentes

O objetivo geral do presente estudo foi descrever a experiência de construção e aplicação de uma proposta pedagógica no campo da educação sexual, fundamentada em algumas premissas contidas na concepção de Paulo Freire, visando atender adolescentes de uma comunidade carente do interior paulista. A partir dos questionamentos iniciais levantados pelos jovens foram realizados quatro encontros focando questões sobre sexualidade, anatomia e fisiologia humana, métodos anticoncepcionais e DST/Aids. Com a realização desse trabalho, os jovens tiveram oportunidade de participar de um processo educativo que possibilitou, pelo resgate de suas próprias experiências e crenças, a reflexão sobre sua autonomia na vivência de uma sexualidade saudável, respeitando a si próprio e ao outro.

Rural-urban migration in D-dimensional lattices

The rural-urban migration phenomenon is analyzed by using an agent-based computational model. Agents are placed on lattices which dimensions varying from d = 2 up to d = 7. The localization of the agents in the lattice defines that their social neighborhood (rural or urban) is not related to their spatial distribution. The effect of the dimension of lattice is studied by analyzing the variation of the main parameters that characterizes the migratory process. The dynamics displays strong effects even for around one million of sites, in higher dimensions (d = 6, 7).