964 resultados para discriminants of number fields
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Title from cover.
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Description based on: X-940, published in Jan. 1964; title from cover.
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Los procesos actuales han revitalizado el debate en torno al populismo en América Latina; no obstante, el estatus teórico de la categoría está lejos de ser clarificado. En este contexto, el artículo propone una contribución a la teoría política del populismo a partir de la perspectiva abierta por Ernesto Laclau, a la vez que avanza en la definición de campos funcionales al análisis político: el populismo como discurso, como construcción del sujeto político y como inclusión de lo excluido en el orden social. A partir de estos desarrollos, en la segunda parte del artículo se utilizan estos aportes para analizar el proceso político actual en Argentina, a saber, el fenómeno del kirchnerismo
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Use of nonlinear parameter estimation techniques is now commonplace in ground water model calibration. However, there is still ample room for further development of these techniques in order to enable them to extract more information from calibration datasets, to more thoroughly explore the uncertainty associated with model predictions, and to make them easier to implement in various modeling contexts. This paper describes the use of pilot points as a methodology for spatial hydraulic property characterization. When used in conjunction with nonlinear parameter estimation software that incorporates advanced regularization functionality (such as PEST), use of pilot points can add a great deal of flexibility to the calibration process at the same time as it makes this process easier to implement. Pilot points can be used either as a substitute for zones of piecewise parameter uniformity, or in conjunction with such zones. In either case, they allow the disposition of areas of high and low hydraulic property value to be inferred through the calibration process, without the need for the modeler to guess the geometry of such areas prior to estimating the parameters that pertain to them. Pilot points and regularization can also be used as an adjunct to geostatistically based stochastic parameterization methods. Using the techniques described herein, a series of hydraulic property fields can be generated, all of which recognize the stochastic characterization of an area at the same time that they satisfy the constraints imposed on hydraulic property values by the need to ensure that model outputs match field measurements. Model predictions can then be made using all of these fields as a mechanism for exploring predictive uncertainty.
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Radio-frequency ( RF) coils are designed such that they induce homogeneous magnetic fields within some region of interest within a magnetic resonance imaging ( MRI) scanner. Loading the scanner with a patient disrupts the homogeneity of these fields and can lead to a considerable degradation of the quality of the acquired image. In this paper, an inverse method is presented for designing RF coils, in which the presence of a load ( patient) within the MRI scanner is accounted for in the model. To approximate the finite length of the coil, a Fourier series expansion is considered for the coil current density and for the induced fields. Regularization is used to solve this ill-conditioned inverse problem for the unknown Fourier coefficients. That is, the error between the induced and homogeneous target fields is minimized along with an additional constraint, chosen in this paper to represent the curvature of the coil windings. Smooth winding patterns are obtained for both unloaded and loaded coils. RF fields with a high level of homogeneity are obtained in the unloaded case and a limit to the level of homogeneity attainable is observed in the loaded case.
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This work of thesis wants to present a dissertation of the wide range of modern dense matching algorithms, which are spreading in different application and research fields, with a particular attention to the innovative “Semi-Global” matching techniques. The choice of develop a semi-global numerical code was justified by the need of getting insight on the variables and strategies that affect the algorithm performances with the primary objective of maximizing the method accuracy and efficiency, and the results level of completeness. The dissertation will consist in the metrological characterization of the proprietary implementation of the semi-global matching algorithm, evaluating the influence of several matching variables and functions implemented in the process and comparing the accuracy and completeness of different results (digital surface models, disparity maps and 2D displacement fields) obtained using our code and other commercial and open-source matching programs in a wide variety of application fields.
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Este estudo está circunscrito em Folkcomunicação, na área da Comunicação Social, e faz uma experiência de análise da obra literária de Luiz Beltrão, no sentido de verificar em que medida essa obra engendra elementos também constantes em seus estudos de Folkcomunicação, a saber, dentro de sua Teoria da Comunicação dos Excluídos (1967). Para este estudo foram selecionados contos e romances com o objetivo de se encontrar no texto literário marcas identificadoras da Folkcomunicação, já que a própria trama narrativa de Luiz Beltrão se dá, freqüentemente, na presença do embate político-ideológico entre cultura acadêmica e cultura popular, salientando ainda diferenças sociais extremadas. Em sua obra literária Beltrão tece narrativas com eventos que descrevem a realidade de indivíduos oprimidos, descortinando o quotidiano das gentes das classes desfavorecidas, sempre no confronto e em demanda com forças dos poderes políticos e sociais. Com apoio teórico de Bourdieu (2004), que postula a teoria dos campos e desenvolve o conceito de habitus, levanta-se um conjunto de crenças e práticas sociais que concretizam a identidade dos indivíduos em sociedade, particularmente no grupo dos excluídos. Assim, a pesquisa tem por objetivo verificar se na obra literária de LB elementos da Folkcomunicação já estavam presentes, conforme postulam as hipóteses aqui levantadas. Os resultados obtidos apontam que serão necessários outros estudos de análise para que se possam confirmar plenamente as hipóteses levantadas; no entanto, ficam evidentes as escolhas do autor sempre voltadas para os grupos sociais excluídos, sem voz social de relevo no universo comunicacional.(AU)
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No campo científico, a busca por uma maior compreensão acerca de bem-estar no âmbito do trabalho é a tônica do momento, reunindo estudiosos das mais diferentes áreas que demonstram interesse pelo tema. No contexto empresarial, o papel dos programas de promoção da saúde e qualidade de vida torna-se marcante quando se deseja o crescimento da produtividade e do bem-estar dos trabalhadores, considerando a obtenção de resultados crescentes, pela empresa, como fundamentais para que as melhorias nas condições, organização e relações de trabalho ocorram permanentemente. Ou seja, as empresas entendem que com o investimento nesses programas a produtividade deve aumentar, gerando recursos, para que esta se sinta estimulada a continuar investindo no bem-estar dos empregados. Este estudo teve como objetivo promover uma análise sobre as relações entre bem-estar no trabalho, representado por satisfação com o trabalho, envolvimento com o trabalho e comprometimento organizacional afetivo; e freqüência a programas organizacionais de promoção da saúde. A amostra foi constituída por 117 trabalhadores de uma indústria multinacional química e farmacêutica, situada na Grande São Paulo, sendo 53 do sexo masculino e 64 do sexo feminino, com idade média de 30,28 anos, dos quais 63 eram solteiros, 46 casados e oito registram outro estado civil. Para desenvolvimento deste estudo, utilizou-se como instrumento um questionário composto por quatro escalas que mediram satisfação no trabalho, envolvimento com o trabalho, comprometimento organizacional afetivo e freqüência de participação em programas de promoção da saúde, realizados na empresa. Todos os dados recolhidos por meio do instrumento eram numéricos, o que permitiu sua análise eletrônica pelo SPSS, versão 13.0 para Windows. Nessa categoria de dados incluem-se os de descrição da amostra, os referentes a bem-estar no trabalho e freqüência aos programas de promoção da saúde. Foi criado um banco de dados para realização das análises descritivas (freqüências, percentuais, médias e desvios-padrão) e de correlação bivariada (r de Pearson). Os dados que permitiram descrever os programas de promoção da saúde promovidos pela empresa foram obtidos por meio de entrevista com a gerente de responsabilidade social, análise do relatório da empresa e de folhetos elaborados para divulgação e registro desses programas. Um total de cinco categorias de programas foi identificado: benefícios, atividades físicas, saúde, atividades culturais/lazer e ações comunitárias. A maior freqüência aos programas ocorreu na categoria benefícios, pela presença constante no restaurante da empresa. Os resultados deste estudo revelaram que grande parcela do bem-estar no trabalho especialmente no que tange o envolvimento com o trabalho, comprometimento afetivo com a organização, bem como satisfações com os colegas, com a chefia e com o próprio trabalho praticamente independe dos programas de promoção da saúde promovidos pela empresa. Por outro lado, participação em programas de promoção da saúde que incluem as categorias de benefícios, saúde e ações comunitárias, relacionou-se a satisfações com promoções e com salário
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Recently, there has been a considerable research activity in extending topographic maps of vectorial data to more general data structures, such as sequences or trees. However, the representational capabilities and internal representations of the models are not well understood. We rigorously analyze a generalization of the Self-Organizing Map (SOM) for processing sequential data, Recursive SOM (RecSOM [1]), as a non-autonomous dynamical system consisting off a set of fixed input maps. We show that contractive fixed input maps are likely to produce Markovian organizations of receptive fields o the RecSOM map. We derive bounds on parameter $\beta$ (weighting the importance of importing past information when processing sequences) under which contractiveness of the fixed input maps is guaranteed.
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The thesis investigates the properties of two trends or time series which formed a:part of the Co-Citation bibliometric model "X~Ray Crystallography and Protein Determination in 1978, 1980 and 1982". This model was one of several created for the 1983 ABRC Science Policy Study which aimed to test the utility of bibliometric models in a national science policy context. The outcome of the validation part of that study proved to be especially favourable concerning the utility of trend data, which purport to model the development of speciality areas in science over time. This assessment could have important implications for the use of such data in policy formulation. However one possible problem with the Science Policy Study's conclusions was that insufficient time was available in the study for an in-depth analysis of the data. The thesis aims to continue the validation begun in the ABRC study by providing a detailed.examination of the characteristics of the data contained in the Trends numbered 11 and 44 in the model. A novel methodology for the analysis of the properties of the trends with respect to their literature content is presented. This is followed by an assessment based on questionnaire and interview data, of the ability of Trend 44 to realistically model the historical development of the field of mobile genetic elements research over time, with respect to its scientific content and the activities of its community of researchers. The results of these various analyses are then used to evaluate the strenghts and weaknesses of a trend or time series approach to the modelling of the activities of scientifiic fields. A critical evaluation of the origins of the discovered strengths and weaknesses.in the assumptions underlying the techniques used to generate trends from co-citation data is provided. Possible improvements. to the modelling techniques are discussed.
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We experimentally demonstrate performance enhancements enabled by weighted digital back propagation method for 28 Gbaud PM-16QAM transmission systems, over a 250 km ultra-large area fibre, using only one back-propagation step for the entire link, enabling up to 3 dB improvement in power tolerance with respect to linear compensation only. We observe that this is roughly the same improvement that can be obtained with the conventional, computationally heavy, non-weighted digital back propagation compensation with one step per span. As a further benchmark, we analyze performance improvement as a function of number of steps, and show that the performance improvement saturates at approximately 20 steps per span, at which a 5 dB improvement in power tolerance is obtained with respect to linear compensation only. Furthermore, we show that coarse-step self-phase modulation compensation is inefficient in wavelength division multiplexed transmission.
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We experimentally demonstrate performance enhancements enabled by weighted digital back propagation method for 28 Gbaud PM-16QAM transmission systems, over a 250 km ultra-large area fibre, using only one back-propagation step for the entire link, enabling up to 3 dB improvement in power tolerance with respect to linear compensation only. We observe that this is roughly the same improvement that can be obtained with the conventional, computationally heavy, non-weighted digital back propagation compensation with one step per span. As a further benchmark, we analyze performance improvement as a function of number of steps, and show that the performance improvement saturates at approximately 20 steps per span, at which a 5 dB improvement in power tolerance is obtained with respect to linear compensation only. Furthermore, we show that coarse-step self-phase modulation compensation is inefficient in wavelength division multiplexed transmission.
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Editorial: The 2015 BCLA annual conference was another fantastic affair. It was the first time the conference was held in the beautiful city of Liverpool. The venue was great and the programme was excellent. The venue overlooked the River Mersey and many of the hotels were local boutique hotels. I stayed in one which was formerly the offices of White Star Liners—where the RMS Titanic was originally registered. The hotel decor was consistent with its historic significance. The BCLA gala dinner was held in the hugely impressive Anglican Cathedral with entertainment from a Beatles tribute band. That will certainly be a hard act to follow at the next conference in 2017. Brian Tompkins took the reigns as the new BCLA president. Professor Fiona Stapleton was the recipient of the BCLA Gold Medal Award. The winner of the poster competition was Dorota Szczesna-Iskander with a poster entitled ‘Dry Contact lens poor wettability and visual performance’. Second place was Renee Reeder with her poster entitled ‘Abnormal Rosacea as a differential diagnosis in corneal scarring’. And third place was Maria Jesus Gonzalez-Garcia with her poster entitled ‘Dry Effect of the Environmental Conditions on Tear Inflammatory Mediators Concentration in Contact Lens Wearers’. The photographic competition winner was Professor Wolfgang Sickenberger from Jena in Germany. The Editorial Panel of CLAE met at the BCLA conference for their first biannual meeting. The journal metrics were discussed. In terms of number of submissions of new papers CLAE seems to have plateaued after seeing a rapid growth in the number of submissions over the last few years. The increase over the last few years could be attributed to the fact that CLAE was awarded an impact factor for the first time in 2012. This year it seems that impact factors across nearly all ophthalmic related journals has dropped. This could in part be due to the fact that last year was a ‘Research Exercise Framework (REF) year for UK universities, where they are judged on quality of their research output. The next REF is in 2020 so we may see changes nearing that time. Looking at article downloads, there seems to be a continued rise in figures. Currently CLAE attracts around 85,000 downloads per year (this is an increase of around 10,000 per year for the last few years) and the 2015 prediction is 120,000! With this in mind and with other contributing factors too, the BCLA has decided to move to online delivery of CLAE to its members starting from issue 5 of 2015. Some members do like to flick through the pages of a hard copy of the journal so members will still have the option of receiving a hard copy through the post but the default journal delivery method will now be online. The BCLA office will send various alerts and content details to members email addresses. To access CLAE online you will need to log in via the BCLA web page, currently you then click on ‘Resources’ and then under ‘Free and Discounted Publications’ you will see CLAE. This actually takes you to CLAE’s own webpage (www.contactlensjournal.com) but you need to log in via the BCLA web page. The BCLA plans to change these weblinks so that from the BCLA web page you can link to the journal website much more easily and you have the choice of going directly into the general website for CLAE or straight to the current issue. In 2016 you will see an even easier way of accessing CLAE online as the BCLA will launch a CLAE application for mobile devices where the journal can be downloaded as a ‘flick-book’. This is a great way of bringing CLAE into the modern era where people access their information in newer ways. For many the BCLA conference was part of a very busy conference week as it was preceded by the International Association of Contact Lens Educators’ (IACLE) Third World Congress, held in Manchester on the 4 days before the BCLA conference. The first and second IACE World Congresses were held in Waterloo, Canada in 1994 and 2000 respectively and hosted by Professor Des Fonn. Professor Fonn was the recipient of the first ever IACLE lifetime achievement award. The Third IACLE World Congress saw more than 100 contact lens educators and industry representatives from around 30 countries gather in the UK for the four-day event, hosted by The University of Manchester. Delegates gained hands-on experience of innovations in teaching, such as learning delivery systems, the use of iPads in the classroom and for creating ePub content, and augmented and virtual reality technologies. IACLE members around the world also took part via a live online broadcast. The Third IACLE World Congress was made possible by the generous support of Sponsors Alcon, CooperVision and Johnson & Johnson Vision Care., for more information look at the IACLE web page (www.iacle.org).
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Learning to Research Researching to Learn explores the integration of research into teaching and learning at all levels of higher education. The chapters draw on the long and ongoing debate about the teaching research nexus in universities. Although the vast majority of academics believe that there is an important and valuable link between teaching and research, the precise nature of this relationship continues to be contested. The book includes chapters that showcase innovative ways of learning to research; how research is integrated into coursework teaching; how students learn the processes of research, and how universities are preparing students to engage with the world. The chapters also showcase innovative ways of researching to learn, exploring how students learn through doing research, how they conceptualise the knowledge of their fields of study through the processes of doing research, and how students experiment and reflect on the results produced. These are the key issues addressed by this anthology, as it brings together analyses of the ways in which university teachers are developing research skills in their students, creating enquiry-based approaches to teaching, and engaging in education research themselves. The studies here explore the links between teaching, learning and research in a range of contexts, from pre-enrolment through to academic staff development, in Australia, the UK, the US, Singapore and Denmark. Through a rich array of theoretical and methodological approaches, the collection seeks to further our understanding of how universities can play an effective role in educating graduates suited to the twenty-first century