948 resultados para Sarpi, Paolo, 1552-1626


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由第一类零阶贝塞尔函数的级数展开推导出波结构函数在任意湍流条件下的近似表达式。由广义惠更斯菲涅耳原理、随高度变化的Hufnagel-Valley湍流廓线模型以及波结构函数在任意湍流条件下的近似表达式,导出了斜程传输时准单色高斯谢尔光束互相干函数的解析式。然后,利用表征光束时间相干性的纵向相干长度(可由互相干函数导出),研究了斜程传输时大气湍流对准单色高斯谢尔光束时间相干性的影响。研究结果表明,准单色高斯谢尔光束的时间相干性在整个斜程传输过程中保持不变。最后,对该结果在物理上给予了定性解释。

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Intrinsically fuzzy morphological erosion and dilation are extended to a total of eight operations that have been formulated in terms of a single morphological operation--biased dilation. Based on the spatial coding of a fuzzy variable, a bidirectional projection concept is proposed. Thus, fuzzy logic operations, arithmetic operations, gray-scale dilation, and erosion for the extended intrinsically fuzzy morphological operations can be included in a unified algorithm with only biased dilation and fuzzy logic operations. To execute this image algebra approach we present a cellular two-layer processing architecture that consists of a biased dilation processor and a fuzzy logic processor. (C) 1996 Optical Society of America

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A highly uniform multiwavelength erbium-doped fiber ring laser with an intracavity sine phase modulator is demonstrated. The flat output spectrum is achieved by optimizing the cavity structure, modulation amplitude, and frequency of the sine phase modulator. Fifteen lasing lines with wavelength spacing of 0.9 nm appear simultaneously and stably with power differences less than 2 dB and side-mode suppression ratio higher than 32 dB. In addition, the proposed cavity can support unidirectional operation without optical isolators. An output power difference of about 20 dB is realized between the counterclockwise and clockwise directions, which is almost independent of the pump power and lasing wavelengths. (c) 2005 Society of Photo-Optical Instrumentation Engineers.

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En fecha tan temprana como 1622 aparece en Inglaterra la primera publicación periódica. Ese mismo año Ben Jonson, escritor teatral contemporáneo de William Shakespeare, compone una mascarada, la primera obra literaria que alude al fenómeno del periodismo. Cuatro años después, en 1626, escribe y hace representar toda una comedia cuyo tema central y escenario es un periódico. Por primera vez en español damos ahora en traducción ambas obras, Noticias del Nuevo Mundo descubierto en la Luna (News from the New World discover’d in the Moon) y El comercio de noticias (The staple of news). Especialmente esta última es, además de una apreciable pieza dramática, un excelente retrato de un fenómeno emergente que no solamente describe las características del incipiente periodismo, sino además una reflexión sobre cuestiones tales como la democracia, la participación ciudadana, la monarquía, la estructura empresarial o los derechos de autor. La obra de Jonson es el retrato de una época oscura, apenas dos décadas de albores del periodismo, y su literatura es la única capaz de devolvernos algo de su efímero esplendor. Pero es también el retrato de una profesión cuyas principales características, que el escalpelo crítico de Jonson tan ácidamente pone de manifiesto, siguen siendo contemporáneas. Con sus casi cuatro siglos de solera, en la oficina de noticias que Jonson nos pinta está teniendo lugar una escena que no ha perdido su vigencia.

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为研究周期相位调制光束的放大特性,在分析激光放大介质跃迁谱线线型对损耗、受激辐射截面及饱和能量密度等参量影响的基础上,改进了原先的脉冲放大模型。以Nd:YLF放大器为例,实验中获得的时间波形调制周期约为300ps,与计算结果330ps吻合较好;同时依据该模型计算分析了影响放大输出时间波形的主要因素,入射光场中心频率与跃迁谱线中心频率的匹配能有效降低相位调制-振幅调制(PM—AM)效应,为抑制该效应提供了依据。

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Esta pesquisa tem como ponto de partida a abordagem que o filósofo francês Gilles Deleuze (1925-1995) faz da pintura, e concentra-se na argumentação desenvolvida em seu livro Francis Bacon, logique de la sensation. Além da análise lógica e conceitual da sensação, privilegia-se aqui o enfoque deleuziano do processo pictórico de Francis Bacon, naquilo em que este envolve a manipulação do acaso , e busca-se relacioná-lo com a questão do enfrentamento do caos , tal como se apresenta no livro de Deleuze e Félix Guattari Quest- ce que la philosophie? Neste trabalho é de grande importância a compreens ão do problema da representação na obra deleuziana. Trata-se de pensar em como este problema se traduz na destruição dos clichês e da recognição, mas sobretudo na afirmação das forças da vida, da criação, da diferença e da liberdade.

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The dynamic interaction of limb segments during movements that involve multiple joints creates torques in one joint due to motion about another. Evidence shows that such interaction torques are taken into account during the planning or control of movement in humans. Two alternative hypotheses could explain the compensation of these dynamic torques. One involves the use of internal models to centrally compute predicted interaction torques and their explicit compensation through anticipatory adjustment of descending motor commands. The alternative, based on the equilibrium-point hypothesis, claims that descending signals can be simple and related to the desired movement kinematics only, while spinal feedback mechanisms are responsible for the appropriate creation and coordination of dynamic muscle forces. Partial supporting evidence exists in each case. However, until now no model has explicitly shown, in the case of the second hypothesis, whether peripheral feedback is really sufficient on its own for coordinating the motion of several joints while at the same time accommodating intersegmental interaction torques. Here we propose a minimal computational model to examine this question. Using a biomechanics simulation of a two-joint arm controlled by spinal neural circuitry, we show for the first time that it is indeed possible for the neuromusculoskeletal system to transform simple descending control signals into muscle activation patterns that accommodate interaction forces depending on their direction and magnitude. This is achieved without the aid of any central predictive signal. Even though the model makes various simplifications and abstractions compared to the complexities involved in the control of human arm movements, the finding lends plausibility to the hypothesis that some multijoint movements can in principle be controlled even in the absence of internal models of intersegmental dynamics or learned compensatory motor signals.

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Learning to perceive is faced with a classical paradox: if understanding is required for perception, how can we learn to perceive something new, something we do not yet understand? According to the sensorimotor approach, perception involves mastery of regular sensorimotor co-variations that depend on the agent and the environment, also known as the "laws" of sensorimotor contingencies (SMCs). In this sense, perception involves enacting relevant sensorimotor skills in each situation. It is important for this proposal that such skills can be learned and refined with experience and yet up to this date, the sensorimotor approach has had no explicit theory of perceptual learning. The situation is made more complex if we acknowledge the open-ended nature of human learning. In this paper we propose Piaget's theory of equilibration as a potential candidate to fulfill this role. This theory highlights the importance of intrinsic sensorimotor norms, in terms of the closure of sensorimotor schemes. It also explains how the equilibration of a sensorimotor organization faced with novelty or breakdowns proceeds by re-shaping pre-existing structures in coupling with dynamical regularities of the world. This way learning to perceive is guided by the equilibration of emerging forms of skillful coping with the world. We demonstrate the compatibility between Piaget's theory and the sensorimotor approach by providing a dynamical formalization of equilibration to give an explicit micro-genetic account of sensorimotor learning and, by extension, of how we learn to perceive. This allows us to draw important lessons in the form of general principles for open-ended sensorimotor learning, including the need for an intrinsic normative evaluation by the agent itself. We also explore implications of our micro-genetic account at the personal level.

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The notion of information processing has dominated the study of the mind for over six decades. However, before the advent of cognitivism, one of the most prominent theoretical ideas was that of Habit. This is a concept with a rich and complex history, which is again starting to awaken interest, following recent embodied, enactive critiques of computationalist frameworks. We offer here a very brief history of the concept of habit in the form of a genealogical network-map. This serves to provide an overview of the richness of this notion and as a guide for further re-appraisal. We identify 77 thinkers and their influences, and group them into seven schools of thought. Two major trends can be distinguished. One is the associationist trend, starting with the work of Locke and Hume, developed by Hartley, Bain, and Mill to be later absorbed into behaviorism through pioneering animal psychologists (Morgan and Thorndike). This tradition conceived of habits atomistically and as automatisms (a conception later debunked by cognitivism). Another historical trend we have called organicism inherits the legacy of Aristotle and develops along German idealism, French spiritualism, pragmatism, and phenomenology. It feeds into the work of continental psychologists in the early 20th century, influencing important figures such as Merleau-Ponty, Piaget, and Gibson. But it has not yet been taken up by mainstream cognitive neuroscience and psychology. Habits, in this tradition, are seen as ecological, self-organizing structures that relate to a web of predispositions and plastic dependencies both in the agent and in the environment. In addition, they are not conceptualized in opposition to rational, volitional processes, but as transversing a continuum from reflective to embodied intentionality. These are properties that make habit a particularly attractive idea for embodied, enactive perspectives, which can now re-evaluate it in light of dynamical systems theory and complexity research.

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Os processos estocásticos com ruído branco multiplicativo são objeto de atenção constante em uma grande área da pesquisa científica. A variedade de prescrições possíveis para definir matematicamente estes processos oferece um obstáculo ao desenvolvimento de ferramentas gerais para seu tratamento. Na presente tese, estudamos propriedades de equilíbrio de processos markovianos com ruído branco multiplicativo. Para conseguirmos isto, definimos uma transformação de reversão temporal de tais processos levando em conta que a distribuição estacionária de probabilidade depende da prescrição. Deduzimos um formalismo funcional visando obter o funcional gerador das funções de correlação e resposta de um processo estocástico multiplicativo representado por uma equação de Langevin. Ao representar o processo estocástico neste formalismo (de Grassmann) funcional eludimos a necessidade de fixar uma prescrição particular. Neste contexto, analisamos as propriedades de equilíbrio e estudamos as simetrias ocultas do processo. Mostramos que, usando uma definição apropriada da distribuição de equilíbrio e considerando a transformação de reversão temporal adequada, as propriedades usuais de equilíbrio são satisfeitas para qualquer prescrição. Finalmente, apresentamos uma dedução detalhada da formulação supersimétrica covariante de um processo markoviano com ruído branco multiplicativo e estudamos algumas das relações impostas pelas funções de correlação através das identidades de Ward-Takahashi.

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Esta dissertação visa a leitura do texto dramático António Marinheiro (O Édipo de Alfama) de Bernardo Santareno, tendo como ponto de partida Édipo Rei de Sófocles. Os fundamentos teóricos para a interpretação desses textos são a obra freudiana e o ensino de Jacques Lacan. Santareno retira as suas personagens do interior das muralhas de Tebas para colocá-las em Alfama, bairro de Lisboa, na segunda metade do século XX. Nesse novo cenário, o fado, o vinho e a taberna compõem os costumes tipicamente portugueses. Escolhemos dois filmes, Édipo Rei de Pier Paolo Pasolini e Incêndios de Denis Villeneuve, para fazer uma leitura comparativa com as peças de Sófocles e de Bernardo Santareno. O início do filme de Pasolini ocorre em uma cidade pequena ao norte da Itália e depois se transfere para a Grécia antiga onde se passa a tragédia de Sófocles. Incêndios é uma adaptação da peça do libanês Wadji Mouawad e retrata a guerra civil do Líbano, a intolerância religiosa, estupro, incesto e genocídio

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提出一种获取平面光学元件光圈数的方法。通过确定一幅干涉条纹图像中三块测试区域及相应的搜索区域,寻找条纹弯曲量的平均值和相应条纹间距的平均值,根据测试区域对应的权重系数,得到被测平面光学元件光圈数的最佳估计值。通过测量标准光圈并比较目视判读结果,得到最大相对误差为5%。实验结果表明,该方法提高了处理干涉条纹图像的适应性,并可替代人工目视判读干涉条纹图像。