948 resultados para blur distortion
Resumo:
O estudo realizou um diagnóstico ambiental na Ribeira da Barca, Concelho de Santa Catarina, Ilha de Santiago, no sentido de se identificar, avaliar, e caracterizar as alterações na paisagem, causadas pelas actividades extractivas nas crateras da Ribeira da Barca, estimar a quantidade de inertes extraídas ao longo do tempo. O trabalho de levantamento de campo foi realizado entre Novembro de 2010 e Maio de 2011. A paisagem estudada enquadra-se bem num processo de transformação por acções antropogénicas negativas, relativamente à extracção ao comércio de areia e brita. O leito da ribeira apresenta-se totalmente esburacado, com cavas de dimensões que variam desde de 2,6 m até 46,90 m de comprimento, largura de 2,90m até 28,10 m; altura/profundidade de 0,12 m até 2,70 m , provocando uma distorção no carácter visual de todo o leito. Das vinte e três (23) cavas monitorizadas durante seis meses de estudo 26,1% das cavas (cerca de 6), tiveram uma evolução considerável, em termos de comprimento, largura e altura/profundidade; 34,8% (cerca de 8) tiveram uma evolução menos considerável; 39,1% das cavas (cerca de 9 ) não evoluíram. Torna-se necessária adequar uma estratégia que possa agir de forma "positiva" baseada num processo de recuperação da paisagem.
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For many goods (such as experience goods or addictive goods), consumers preferences may change over time. In this paper, we examine a monopolist s optimal pricing schedule when current consumption can affect a consumer s valuation in the future and valuations are unobservable. We assume that consumers are anonymous, i.e. the monopolist can t observe a consumer s past consumption history. For myopic consumers, the optimal consumption schedule is distorted upwards, involving substantial discounts for low valuation types. This pushes low types into higher valuations, from which rents can be extracted.For forward looking consumers, there may be a further upward distortion of consumption due to a reversal of the adverse selection effect; low valuation consumers now have a strong interest in consumption in order to increase their valuations. Firms will find it profitable to educate consumers and encourage forward looking behavior.
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O presente trabalho cujo título é Implementação do ABC numa empresa prestadora de serviços de Saúde, tem como finalidade a obtenção do grau de licenciatura em Contabilidade e Administração e tem como principal objectivo a implementação do método ABC numa pequena e média empresa de prestação de serviços de saúde, como um instrumento de apoio á gestão. Para a introdução da Contabilidade de Gestão na empresa, há que se escolher um método/sistema de apuramento de gastos que espelha a realidade da empresa, e de uma certa forma o ABC é o método ideal para apuramento de resultados sem distorções. O ABC (Activity-Based Cost) apura os resultados através da relação de causa-efeito, considerando que as actividades é que geram gastos e os objectos de custeio é que consomem as actividades. É aplicável tanto nas empresas industriais como nas empresas prestadoras de serviços, apesar de inicialmente ter sido concebido para as empresas industrias, isto é, para as grandes empresas devido aos avultados recursos financeiros e humanos como também pelo tempo necessário para a sua implementação. Mas o modelo matricial apresentado por Roztcki et al (1999) permite a aplicação deste método nas PME com poucos recursos financeiros e de tempo, utilizando uma folha de cálculo no Excel. Será este modelo a ser proposto e poderá ser implementado na clínica. O modelo apresentado foi testado num estudo de caso realizado numa clínica. Com a realização dos testes foi detectado algumas dificuldades e limitações, as maiores dificuldades encontradas foram a identificação das actividades e dos cost drivers, devido à complexidade do sector. A implementação foi concluída com sucesso, proporcionando informações detalhadas dos gastos dos produtos/serviços prestados em toda a clínica. This work was done as a requisite for obtaining a degree in Accounting and Administration, and is titled “The Implementation of ABC – Activity Based Cost in a company that provides health services”. Its main purpose is to analyze the implementation of ABC method in a small and medium-sized enterprise which provides health services to support decision making by the Managers. To adopt management accounting in a company, it’s necessary to choose a cost qualifying system that reflects the reality of the company and in a certain way ABC is the method which can determine the results without any distortion. ABC (Activity-Based Cost) determines the results through cause-and-effect relationship, whereas the activities generate spending while costing objects consume the activities. It’s applicable both in industrial companies as in services providers, although it was initially designed for industrial companies, that is, to large companies, due to the huge financial and human resources existent as well as by the time required for its implementation. But the matrix model presented by Roztckiet al (1999) allows application of this method in small and medium-sized enterprises with limited financial resources and time, using a spreadsheet in Excel. This model will be proposed and could be implemented in any clinic. The model was tested in a case study, undertaken in a private clinic. With the realization of the tests, some problems and limitations were detected, and the major difficulties encountered were the identification of activities and cost drivers, due to the complexity of the sector. The implementation was completed successfully, providing detailed information of the products services spending throughout the clinic.
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Kahneman and Tversky asserted a fundamental asymmetry between gains and losses, namely a reflection effect which occurs when an individual prefers a sure gain of $ pz to anuncertain gain of $ z with probability p, while preferring an uncertain loss of $z with probability p to a certain loss of $ pz.We focus on this class of choices (actuarially fair), and explore the extent to which thereflection effect, understood as occurring at a range of wealth levels, is compatible with single-self preferences.We decompose the reflection effect into two components, a probability switch effect,which is compatible with single-self preferences, and a translation effect, which is not. To argue the first point, we analyze two classes of single-self, nonexpected utility preferences, which we label homothetic and weakly homothetic. In both cases, we characterize the switch effect as well as the dependence of risk attitudes on wealth.We also discuss two types of utility functions of a form reminiscent of expected utility but with distorted probabilities. Type I always distorts the probability of the worst outcome downwards, yielding attraction to small risks for all probabilities. Type II distorts low probabilities upwards, and high probabilities downwards, implying risk aversion when the probability of the worst outcome is low. By combining homothetic or weak homothetic preferences with Type I or Type II distortion functions, we present four explicit examples: All four display a switch effect and, hence, a form of reflection effect consistent a single self preferences.
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The paper reports results on the effects of stylized stabilization policies on endogenously created fluctuations. A simple monetary model with intertemporally optimizing agents is considered. Fluctuations in output may occur due to fluctuations in labor supply which are again caused by volatile expectations which are ``self fulfilling'', i.e. correct given the model. It turns out that stabilization policies that are sufficiently countercyclical in the sense that government spending (on transfers or demand) depends sufficiently strongly negatively on GNP-increases can stabilize the economy at a monetary steadystate for an arbitrarily low degree of distortion of that steady state. Such stabilization has unambiguously good welfare effects and can be achieved without features such as positive lump sum taxation or negative income taxation as part of the stabilization policy.
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We present a model of price discrimination where a monopolistfaces a consumer who is privately informed about thedistribution of his valuation for an indivisible unit ofgood but has yet to learn privately the actual valuation.The monopolist sequentially screens the consumer with amenu of contracts:the consumer self-selects once by choosing a contract andthen self-selects again when he learns the actual valuation. A deterministic sequential mechanism is a menu of refundcontracts, each consisting of an advance payment and a refundamount in case of no consumption, but sequential mechanismsmay involve randomization.We characterize the optimal sequential mechanism when someconsumer types are more eager in the sense of first-orderstochastic dominance, and when some types face greatervaluation uncertainty in the sense of mean-preserving-spread.We show that it can be optimal to subsidize consumer typeswith smaller valuation uncertainty (through low refund, as inairplane ticket pricing) in order to reduce the rent to thosewith greater uncertainty. The size of distortion depends bothon the type distribution and on how informative the consumer'sinitial private knowledge is about his valuation, but noton how much he initially knows about the valuation per se.
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We consider adaptive sequential lossy coding of bounded individual sequences when the performance is measured by the sequentially accumulated mean squared distortion. Theencoder and the decoder are connected via a noiseless channel of capacity $R$ and both are assumed to have zero delay. No probabilistic assumptions are made on how the sequence to be encoded is generated. For any bounded sequence of length $n$, the distortion redundancy is defined as the normalized cumulative distortion of the sequential scheme minus the normalized cumulative distortion of the best scalarquantizer of rate $R$ which is matched to this particular sequence. We demonstrate the existence of a zero-delay sequential scheme which uses common randomization in the encoder and the decoder such that the normalized maximum distortion redundancy converges to zero at a rate $n^{-1/5}\log n$ as the length of the encoded sequence $n$ increases without bound.
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On the basis of the experiments carried out over various years, it was concluded that (1) grayling Thymallus thymallus and brown trout Salmo trutta are resistant to temperature-induced sex reversal at ecologically relevant temperatures, (2) environmental sex reversal is unlikely to cause the persistent sex ratio distortion observed in at least one of the study populations and (3) sex-specific tolerance of temperature-related stress may be the cause of distorted sex ratios in populations of T. thymallus or S. trutta.
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The development of statistical models for forensic fingerprint identification purposes has been the subject of increasing research attention in recent years. This can be partly seen as a response to a number of commentators who claim that the scientific basis for fingerprint identification has not been adequately demonstrated. In addition, key forensic identification bodies such as ENFSI [1] and IAI [2] have recently endorsed and acknowledged the potential benefits of using statistical models as an important tool in support of the fingerprint identification process within the ACE-V framework. In this paper, we introduce a new Likelihood Ratio (LR) model based on Support Vector Machines (SVMs) trained with features discovered via morphometric and spatial analyses of corresponding minutiae configurations for both match and close non-match populations often found in AFIS candidate lists. Computed LR values are derived from a probabilistic framework based on SVMs that discover the intrinsic spatial differences of match and close non-match populations. Lastly, experimentation performed on a set of over 120,000 publicly available fingerprint images (mostly sourced from the National Institute of Standards and Technology (NIST) datasets) and a distortion set of approximately 40,000 images, is presented, illustrating that the proposed LR model is reliably guiding towards the right proposition in the identification assessment of match and close non-match populations. Results further indicate that the proposed model is a promising tool for fingerprint practitioners to use for analysing the spatial consistency of corresponding minutiae configurations.
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Transcatheter stent-valve implantation in stenosed congenital bicuspid aortic valves is under debate. Heavily calcified elliptic bicuspid valves represent a contraindication to catheter-based valve therapies because of a risk of stent-valve displacement, distortion, or malfunctioning after the implantation. In this case report we illustrate our experience with a patient suffering from stenosed congenital bicuspid aortic valve who successfully underwent a transapical 26-mm Edwards Sapien stent-valve (Edwards Lifesciences Inc, Irvine, CA) implantation. Postoperative distortion, malfunctioning, and paravalvular leaks were not detected.
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When preparing an article on image restoration in astronomy, it is obvious that some topics have to be dropped to keep the work at reasonable length. We have decided to concentrate on image and noise models and on the algorithms to find the restoration. Topics like parameter estimation and stopping rules are also commented on. We start by describing the Bayesian paradigm and then proceed to study the noise and blur models used by the astronomical community. Then the prior models used to restore astronomical images are examined. We describe the algorithms used to find the restoration for the most common combinations of degradation and image models. Then we comment on important issues such as acceleration of algorithms, stopping rules, and parameter estimation. We also comment on the huge amount of information available to, and made available by, the astronomical community.
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This paper describes the development and applications of a super-resolution method, known as Super-Resolution Variable-Pixel Linear Reconstruction. The algorithm works combining different lower resolution images in order to obtain, as a result, a higher resolution image. We show that it can make significant spatial resolution improvements to satellite images of the Earth¿s surface allowing recognition of objects with size approaching the limiting spatial resolution of the lower resolution images. The algorithm is based on the Variable-Pixel Linear Reconstruction algorithm developed by Fruchter and Hook, a well-known method in astronomy but never used for Earth remote sensing purposes. The algorithm preserves photometry, can weight input images according to the statistical significance of each pixel, and removes the effect of geometric distortion on both image shape and photometry. In this paper, we describe its development for remote sensing purposes, show the usefulness of the algorithm working with images as different to the astronomical images as the remote sensing ones, and show applications to: 1) a set of simulated multispectral images obtained from a real Quickbird image; and 2) a set of multispectral real Landsat Enhanced Thematic Mapper Plus (ETM+) images. These examples show that the algorithm provides a substantial improvement in limiting spatial resolution for both simulated and real data sets without significantly altering the multispectral content of the input low-resolution images, without amplifying the noise, and with very few artifacts.
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We study the strategic interaction between a decision maker who needs to take a binary decision but is uncertain about relevant facts and an informed expert who can send a message to the decision maker but has a preference over the decision.We show that the probability that the expert can persuade the decision maker to take the expert's preferred decision is a hump-shaped function of his costs of sending dishonest messages.
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An unusual case of localized amyloid light-chain (AL) amyloidosis and extramedullary plasmacytoma of the mitral valve is described. The worsening of a mitral regurgitation led to investigations and surgery. The valve presented marked distortion and thickening by type AL amyloid associated with a monotypic CD138+ immunoglobulin lambda plasma cell proliferation. Systemic staging showed a normal bone marrow and no evidence of amyloid deposition in other localizations. The patient's outcome after mitral valve replacement was excellent. To our knowledge, this is the first description of a localized AL amyloidosis as well as of a primary extramedullary plasmacytoma of the mitral valve.
Resumo:
Multiexponential decays may contain time-constants differing in several orders of magnitudes. In such cases, uniform sampling results in very long records featuring a high degree of oversampling at the final part of the transient. Here, we analyze a nonlinear time scale transformation to reduce the total number of samples with minimum signal distortion, achieving an important reduction of the computational cost of subsequent analyses. We propose a time-varying filter whose length is optimized for minimum mean square error