Methods, techniques and instruments of data collection in European Countries

Tese de mestrado. Engenharia Civil - Especialização em Infraestruturas de Transporte. Universidade do Porto. Faculdade de Engenharia. 201

Predicting space occupancy for street paid parking

This dissertation discusses how to develop a prediction method for on-street parking space availability, using only historical occupancy data collected from on-street multi-space parking meters. It is analyzed how to transform the raw data into a dataset representing the occupancy and how can this information be used to detect when the parking spaces on a street are Vacant or Full. Attributes like weather conditions and holidays are added to the data, giving them more context and comprehension. After the data preparation and analysis, a prediction model is developed using machinelearning techniques that can forecast the availability of the parking spaces on a street at a specific day and on a given moment. For that, a classification method is implemented based on decision trees and neural networks, comparing both methods regarding results and development time. Particular attention is given to the algorithm parameters, to achieve the right balance between accuracy and computational time. The developed model proved effective, correctly capturing the different behavior of each street through the different weeks, and returning results useful to drivers searching for parking and to the business owners while monitoring their parking investments and returns.Esta dissertação apresenta como pode ser desenvolvido um método para previsão de disponibilidade de lugares de estacionamento em rua, utilizando dados históricos obtidos através de parquímetros de controlo a múltiplos lugares. É analisado como os dados em bruto dos parquímetros podem ser transformados num conjunto de dados que represente qual a ocupação dos lugares, e posteriormente como esta informação pode ser utilizada para detetar se o estacionamento em uma rua está livre ou ocupado. São adicionados também mais alguns atributos, como por exemplo informação sobre as condições meteorológicas ou que dias são feriados, dando mais algum contexto e compreensão à informação já existente. Após a preparação e análise dos dados, é desenvolvido um método de previsão utilizando técnicas de aprendizagem automática de modo a que seja possível saber qual a disponibilidade de estacionamento em uma rua, a um dia específico e a um determinado momento. Para isso, foi implementado um método de classificação baseado em árvores de decisão e redes neuronais, comparando ambos os métodos do ponto de vista dos resultados e do tempo de desenvolvimento. Foi dada especial atenção aos parâmetros utilizados em cada algoritmo, de modo a que haja um balanço entre a precisão e tempo de computação. O modelo desenvolvido mostrou ser eficaz, captando corretamente o comportamento de cada rua nas diferentes semanas, devolvendo resultados uteis aos condutores que procurem lugares de estacionamento e aos proprietários do negócio por lhes permitir monitorizar o desempenho dos seus investimentos em parques de estacionamento e qual o retorno

Transformações lineares e isomorfismos: um exemplo em criptografia

TCCP (especialização) - Universidade Federal de Santa Catarina

Conillon: Distributed computing platform for desktop grids

Grid computing enables organizations to integrate and share sets of heterogeneous resources into one synergetic and powerful system, in order to deliver e ciency and processing performance to demanding parallel applications. The aggregation and the coordination of these resources need to be integrated in a set of tools and protocols that reduce their complexity. Resource allocation is performed by a centralized manager that has complete knowledge of system state. Conillon is a distributed computing platform that manages and coordinates a set of actors. This platform enables heterogeneous workstations to function as part of a distributed system. Conillon is a lightweight, simple to use, and yet allows any number of di erent applications to be deployed and executed in parallel. Our platform maximizes the resource utilization in bene t of the demanding parallel applications. Parallel applications developers have access to a set of tools that simpli es the development process and the creation of tasks. The complexity related to the scheduling, distribution, and fault tolerant management of tasks is shielded from the programmer. Conillom platform has an integrated set of programms that work synergistically delivering a positivo ratio between e ciency and processing performance. We present our platform in detail as well as the results of extensive experiments about perfor- mance. The platform behaved relatively well and achieves an average speed up of up to x1.9 on the time needed to complete a job each time the computational resources are doubled.A computação paralela permite integrar e partilhar um conjunto de recursos heterogéneos num sistema poderoso e sinergético, de forma a poder disponibilizar e ciência e desempenho de processamento às aplicações paralelas. A agregação e coordenação destes recursos devem integrados num conjunto de ferramentas e protocolos que reduzam a complexidade inerente. A alocação de recursos é realizada por um gestor centralizado que tem conhecimento de todo o estado do sistema. Foi desenvolvida uma plataforma de computação distribuída, o Conillon, que coordena e gere um conjunto de participantes. A nossa plataforma permite que estações de trabalho heterogéneas façam parte de um sistema distribuído. A plataforma Conillon é simples, ocupando poucos recursos no entanto permite que múltiplas e distintas aplicações sejam executadas em paralelo. A plataforma maximiza a utilização de recursos em benefício das exigentes aplicações paralelas. Os programadores de aplicações paralelas têm acesso a um conjunto de ferramentas simples para criação de tarefas. A complexidade relacionada com o escalonamento, distribuição e tolerância a falhas é encapsulada do programador. A plataforma Conillon tem um conjunto integrado de programas que funcionam sinergicamente, entregando um rácio positivo entre e ciência e performance de computação. Neste trabalho presentamos a nossa plataforma em detalhe, bem como os resultados de testes extensivos sobre performance. A plataforma comporta-se relativamente bem, alcançando uma acelera ção de até 1.9x no tempo necessário para terminar um serviço sempre que o número de recursos computacionais é duplicado

Serviço de vídeo a pedido através da Internet

O presente téxto tem o objectivo de introduzir os conceitos relacionados com a transmissão de vídeo através da Internet. Através da realização, implementação e estudo de uma plataforma de suporte ao serviço de vídeo a pedido, analisam-se os principais problemas inerentes à concepção de um serviço deste tipo. Apresenta-se uma solução para um clube de vídeo on-line, mostrando uma implementação possível para o serviço de vídeo em tempo real. Por fim fazem-se as conclusões e enumeram-se algumas direcções para melhorar a qualidade do serviço

Cholesterol-based compounds: Recent advances in synthesis and applications

This review reports on the latest developments (since 2014) in the chemistry of cholesterol and its applications in different research fields. These applications range from drug delivery or bioimaging applications to cholesterol-based liquid crystals and gelators. A brief overview of the most recent synthetic procedures to obtain new cholesterol derivatives is also provided, as well as the latest anticancer, antimicrobial, and antioxidant new cholesterol-based derivatives. This review discusses not only the synthetic details of the preparation of new cholesterol derivatives or conjugates, but also gives a short summary concerning the specific application of such compoundsThanks are due to the University of Aveiro, Instituto Politécnico de Bragança, FCT/MEC for financial support of the QOPNA (FCT UID/QUI/00062/2013) and CIMO (UID/AGR/00690/2013) research units, through national funds, and where applicable cofinanced by the FEDER, within the PT2020 Partnership Agreement; and also to the Portuguese NMR Network. This work was also supported by the Integrated Programme of SR&TD “pAGE–Protein aggregation Across the Lifespan” (reference CENTRO-01-0145-FEDER-000003), co-funded by the Centro 2020 program, Portugal 2020, European Union, through the European Regional Development Fund. H. M. T. Albuquerque thanks the pAGE project for his Post-Doc grant (BPD/UI98/4861/2017).info:eu-repo/semantics/publishedVersio

Non-hexagonal-ring defects and structures induced by strain in graphene and in functionalized graphene

We perform {\textit ab initio} calculations for the strain-induced formation of non-hexagonal-ring defects in graphene, graphane (planar CH), and graphenol (planar COH). We find that the simplest of such topological defects, the Stone-Wales defect, acts as a seed for strain-induced dissociation and multiplication of topological defects. Through the application of inhomogeneous deformations to graphene, graphane and graphenol with initially small concentrations of pentagonal and heptagonal rings, we obtain several novel stable structures that possess, at the same time, large concentrations of non-hexagonal rings (from fourfold to elevenfold) and small formation energies

Chalcones as versatile synthons for the synthesis of 5- and 6-membered nitrogen heterocylces

Chalcones belong to the flavonoid family which constitutes one of the major classes of naturally occurring oxygen heterocyclic compounds. The alpha,beta-unsaturated carbonyl system of chalcones possesses two electrophilic reactive centers allowing them to participate in addition reactions via attack to the carbonyl group (1,2-addition) or involving the beta-carbon (1,4-conjugate addition), leading to the synthesis of promising bioactive heterocyclic compounds. The purpose of this review is to present a systematic survey of the most recent literature that uses chalcones in the synthesis of biologically active 5- and 6-membered nitrogen heterocycles such as pyrroles, indoles, isoxazoles, imidazoles, pyrazoles, indazoles, triazoles, tetrazoles, pyridines and pyrimidines. Efficiency, easy-to-handle and cheap reagents, alternative heating conditions and greener protocols will be highlighted. In this review we will cover the literature since the beginning of the 21st century in more than 400 publications.PEst-C/QUI/UI0062/2013 FCOMP-01-0124-FEDER-03729

Synthesis of 2-{2-[5(4)-aryl-2H-[1,2,3]-triazol-4(5)-yl]vinyl}chromen-4-ones

Chromones are a family of oxygen-containing heterocyclic compounds that have been shown particular relevant biological activity. In what concerns to 2-methylchromones, their reactivity is well-known and allowed to exploit many different kinds of chemical reactions. The acidic character of the 2-methyl group, due to the low electron density at C-2 caused by carbonyl group enable this class of compounds to undergo oxidation, photolysis, cycloaddition and condensation reactionsUniversity of Aveiro, Funda9ao para a Ciencia e Tecnologia (FCT, Portugal), European Union, QREN, FEDER and COMPETE for funding the QOPNA Research Unit (project PEst-C/QUI/UI0062/2011) and the Portuguese National NMR Network. Hello Albuquerque also thanks FCT for his fellowship (SFRH/Bl/51556/2011 )

Nitromethane conjugate addition to 2-[(1E,3E)-4-arylbuta-1,3-dien-1-yl]-4Hchromen- 4-ones

Chromone are a group of oxygen-containing heterocycles, which are often associated to important biological activities.1 Chromone derivatives are also seen as interesting scaffolds to input further functionalizations,2 most of them through chemical transformations such as oxidation, condensation, Diels-Alder or conjugate addition. Conjugate addition of carbon nucleophiles to electron-deficient alkenes is one of the most important methods available for carbon–carbon bond-forming reactions. A wide range of carbon nucleophiles easily undergo conjugate addition with various substrates such as chalcones, cinnamylideneacetophenones or styrylchromones. Following previous work of our research group involving the 1,6-conjugate addition of nitromethane to (E)-2- styrylchromones,3 herein we report the first reactivity studies in the nitromethane conjugate addition to the extended unsaturated π-system of 2-[(1E,3E)-4-arylbuta-1,3-dien-1-yl]-4H-chromen-4-ones 1 (Scheme 1). The DBU catalyzed nitromethane addition reaction afforded the corresponding β-(nitromethyl)chromones 2 (1,6-conjugate addition) as major products. (E)-5'-(Nitromethyl)-3'-styryl-[1,1'-biphenyl]-2-ol 3 and 3'-aryl-2'-nitro-5'-(nitromethyl)spiro [chromane- 2,1'-cyclohexan]-4-one 4 derivatives were also isolated as minor products, which result from the addition of two nitromethane molecules, through tandem processes.info:eu-repo/semantics/publishedVersio