987 resultados para modal transformation matrix


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A generalized top-spin analysis proposed some time ago in the context of the standard model and subsequently studied in varying contexts is now applied primarily to the case of e(+)e(-) -> t (tww) over bar with transversely polarized beams. This extends our recent work with new physics couplings of scalar (S) and tensor (T) types. We carry out a comprehensive analysis assuming only the electron beam to be transversely polarized, which is sufficient to probe these interactions, and also eliminates any azimuthal angular dependence due to the standard model or new physics of the vector (V) and axial-vector (A) type interactions. We then consider new physics of the general four-Fermi type of V and A type with both beams transversely polarized and discuss implications with longitudinal polarization as well. The generalized spin bases are all investigated in the presence of either longitudinal or transverse beam polarization to look for appreciable deviation from the SM prediction in case of the new physics. 90% confidence level limits are obtained on the interactions for the generalized spin bases with realistic integrated luminosity. In order to achieve this we present a general discussion based on helicity amplitudes and derive a general transformation matrix that enables us to treat the spin basis. We find that beamline basis combined with transverse polarization provides an excellent window of opportunity both for S, T and V, A new physics, followed by the off-diagonal basis. The helicity basis is shown to be the best in case of longitudinal polarization to look for new physics effects due to V and A. DOI: 10.1103/PhysRevD.86.114019

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Computer vision algorithms that use color information require color constant images to operate correctly. Color constancy of the images is usually achieved in two steps: first the illuminant is detected and then image is transformed with the chromatic adaptation transform ( CAT). Existing CAT methods use a single transformation matrix for all the colors of the input image. The method proposed in this paper requires multiple corresponding color pairs between source and target illuminants given by patches of the Macbeth color checker. It uses Delaunay triangulation to divide the color gamut of the input image into small triangles. Each color of the input image is associated with the triangle containing the color point and transformed with a full linear model associated with the triangle. Full linear model is used because diagonal models are known to be inaccurate if channel color matching functions do not have narrow peaks. Objective evaluation showed that the proposed method outperforms existing CAT methods by more than 21%; that is, it performs statistically significantly better than other existing methods.

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傍轴近似下的光学矩阵理论,可以简化光束传输计算过程,使光学系统设计更为方便。将ABCD变换矩阵方法引入到耦合光学系统的设计中,运用高斯光束的ABCD法则,详尽地给出了某一耦合方式下的半导体激光器耦合入单模光纤系统的设计;另一方面,对系统的耦合损耗与耦合距离的关系进行了理论计算,并把计算结果与最近的实验报道做了比较,它们基本相吻合,说明此方法是可行的、合理的。从整个设计及理论计算来看,ABCD矩阵方法减少了复杂的计算,从而简化了设计过程,与通常的衍射计算相比,它不失为一种方便、有效的方法,同时它对生产半导体

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O presente trabalho possui como objetivo central investigar a teoria acerca da origem da significação, presente na obra Ser e tempo, de Martin Heidegger, procurando mostrar em que medida a significação dos entes traz consigo a interpretação do conhecimento teórico como sendo uma transformação modal da relação semântica em que se movimenta medianamente o existente humano. Para tanto, procuraremos mostrar a partir da idéia de que existem dois extremos de um mesmo movimento de transformação semântica que caracterizam um processo de objetivação ou perda de sentido que a origem de sentido ou instância de produção de todos os conceitos e enunciados filosóficos reside no próprio ser-aí não como um sujeito cognoscente ou representacional, mas como um eu no sentido do si-mesmo próprio que, ao assumir a responsabilidade por seu ser, se mostra como sendo o ponto de vista modal a partir do qual é possível recorrer o sentido indo de encontro com sua própria atividade fundamental.

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Computer vision algorithms that use color information require color constant images to operate correctly. Color constancy of the images is usually achieved in two steps: first the illuminant is detected and then image is transformed with the chromatic adaptation transform ( CAT). Existing CAT methods use a single transformation matrix for all the colors of the input image. The method proposed in this paper requires multiple corresponding color pairs between source and target illuminants given by patches of the Macbeth color checker. It uses Delaunay triangulation to divide the color gamut of the input image into small triangles. Each color of the input image is associated with the triangle containing the color point and transformed with a full linear model associated with the triangle. Full linear model is used because diagonal models are known to be inaccurate if channel color matching functions do not have narrow peaks. Objective evaluation showed that the proposed method outperforms existing CAT methods by more than 21%; that is, it performs statistically significantly better than other existing methods.

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本文介绍了一种非接触式(LW-1型)机器人重复位姿精度检测系统.该系统采用电涡流传感器作为位置信息传感器.以这种传感器的检测性能为基础,研究设计了相应的传感器测量结构、数学模型和坐标变换求解方法,使系统技术指标及使用性能达到了检测机器人重复位姿精度的实用要求.该系统具有鲁棒性强、设计合理、结构简单、造价低廉等特点,可以满足我国现阶段在机器人学研究和机器人开发应用方面的需求

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Thema der vorliegenden Arbeit ist die Bestimmung von Basen von Räumen spezieller harmonischer 2-Koketten auf Bruhat-Tits-Gebäuden der PGL(3) über Funktionenkörpern. Hierzu wird der Raum der speziellen harmonischen 2-Koketten auf dem Bruhat-Tits-Gebäude der PGL(3) zunächst mit gewissen komplexen Linearkombinationen von 2-Simplizes des Quotientenkomplexes, sogenannten geschlossenen Flächen, identifiziert und anschließend durch verallgemeinerte Modulsymbole beschrieben. Die Darstellung der Gruppe der Modulsymbole durch Erzeuger und Relationen ermöglicht die Bestimmung einer endlichen Basis des Raums der speziellen harmonischen 2-Koketten. Die so gewonnenen Erkenntnisse können zur Untersuchung von Hecke-Operatoren auf speziellen harmonischen 2-Koketten genutzt werden. Mithilfe des hergeleiteten Isomorphismus zwischen dem Raum der speziellen harmonischen 2-Koketten und dem Raum der geschlossenen Flächen wird die Theorie der Hecke-Operatoren auf den Raum der geschlossenen Flächen übertragen. Dies ermöglicht die Berechnung von Abbildungsmatrizen der Hecke-Operatoren auf dem Raum der harmonischen 2-Koketten durch die Auswertung auf den geschlossenen Flächen.

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Emission line ratios have been essential for determining physical parameters such as gas temperature and density in astrophysical gaseous nebulae. With the advent of panoramic spectroscopic devices, images of regions with emission lines related to these physical parameters can, in principle, also be produced. We show that, with observations from modern instruments, it is possible to transform images taken from density-sensitive forbidden lines into images of emission from high- and low-density clouds by applying a transformation matrix. In order to achieve this, images of the pairs of density-sensitive lines as well as the adjacent continuum have to be observed and combined. We have computed the critical densities for a series of pairs of lines in the infrared, optical, ultraviolet and X-rays bands, and calculated the pair line intensity ratios in the high- and low-density limit using a four- and five-level atom approximation. In order to illustrate the method, we applied it to Gemini Multi-Object Spectrograph (GMOS) Integral Field Unit (GMOS-IFU) data of two galactic nuclei. We conclude that this method provides new information of astrophysical interest, especially for mapping low- and high-density clouds; for this reason, we call it `the ld/hd imaging method`.

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The objective of this paper is to show an alternative methodology to calculate transmission-line parameters per unit length. With this methodology, the transmission-line parameters can be obtained starting from impedances measured in one terminal of the line. First, the article shows the classical methodology to calculate frequency-dependent transmission-line parameters by using Carson's and Pollaczeck's equations for representing the ground effect and Bessel's functions to represent the skin effect. After that, a new procedure is shown to calculate frequency-dependent transmission-line parameters directly from currents and voltages of an existing line. Then, this procedure is applied in a two-phase and a three-phase transmission line whose parameters have been previously calculated by using the classical methodology. Finally, the results obtained by using the new procedure and by using the classical methodology are compared. The article shows simulations results for a typical frequency spectrum of switching transients (10 Hz to 10 kHz).

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The objective of this paper is to show an alternative methodology to calculate transmission line parameters per unit length. With this methodology the transmission line parameters can be obtained starting from the phase currents and voltages in one terminal of the line. First, the article shows the classical methodology to calculate frequency dependent transmission line parameters by using Carson's and Pollaczeck's equations for representing the ground effect and Bessel's functions to represent the skin effect. After that, it is shown a new procedure to calculate frequency dependent transmission line parameters directly from currents and voltages of the line that is already built. Then, this procedure is applied in a two-phase transmission line whose parameters have been previously calculated by using the classical methodology. Finally, the results obtained by using the new procedure and by using the classical methodology are compared. ©2005 IEEE.

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A transmission line digital model is developed direct in the phase and time domains. The successive modal transformations considered in the three-phase representation are simplified and then the proposed model can be easily applied to several operation condition based only on the previous knowing of the line parameters, without a thorough theoretical knowledge of modal analysis. The proposed model is also developed based on lumped elements, providing a complete current and voltage profile at any point of the transmission system. This model makes possible the modeling of non-linear power devices and electromagnetic phenomena along the transmission line using simple electric circuit components, representing a great advantage when compared to several models based on distributed parameters and inverse transforms. In addition, an efficient integration method is proposed to solve the system of differential equations resulted from the line modeling by lumped elements, thereby making possible simulations of transient and steady state using a wide and constant integration step. © 2012 IEEE.

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This paper presents a method for analyzing electromagnetic transients using real transformation matrices in three-phase systems considering the presence of ground wires. So, for the Z and Y matrices that represent the transmission line, the characteristics of ground wires are not implied in the values related to the phases. A first approach uses a real transformation matrix for the entire frequency range considered in this case. This transformation matrix is an approximation to the exact transformation matrix. For those elements related to the phases of the considered system, the transformation matrix is composed of the elements of Clarke's matrix. In part related to the ground wires, the elements of the transformation matrix must establish a relationship with the elements of the phases considering the establishment of a single homopolar reference in the mode domain. In the case of three-phase lines with the presence of two ground wires, it is unable to get the full diagonalization of the matrices Z and Y in the mode domain. This leads to the second proposal for the composition of real transformation matrix: obtain such transformation matrix from the multiplication of two real and constant matrices. In this case, the inclusion of a second matrix had the objective to minimize errors from the first proposal for the composition of the transformation matrix mentioned. © 2012 IEEE.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)