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Modos deslizantes discretos em sistemas incertos com atraso na computação do sinal de controle

Caun, Alessandro da Ponte
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 94 f. : il.
POR
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Engenharia Elétrica - FEIS; Este trabalho apresenta uma nova estratégia de controle discreto. A técnica é baseada em Modos Deslizantes Discretos, utilizando uma lei de controle suave. Quando um algoritmo de controle é implementado em um computador digital, existe um atraso no tempo de computação, devido ao tempo de execução das instruções. Neste trabalho, vamos assumir que estes atrasos são constantes e menores que um período de amostragem. A presença do atraso no tempo de computação não apenas reduz a estabilidade e robustez, mas também degrada a performance de controle. O novo controlador proposto é projetado para atuar na presença destes atrasos, melhorando substancialmente o desempenho do controle. Outra propriedade importante deste controlador é a possibilidade de trabalhar com períodos de amostragem mais altos, garantindo o uso de freqüências mais baixas de processamento, ou seja, proporcionando uma economia do hardware de atuação. A nova lei de controle proposta foi aplicada na estabilização de quatro sistemas incertos e de natureza instável: Sistema Bola e Viga, Sistema Pêndulo Invertido Linear, Sistema Pêndulo Invertido Rotacional e Sistema Pêndulo Invertido Rotacional Duplo. Resultados das simulações são apresentados e comparados com resultados de outro controlador de Modo Deslizante...

A comprehensive evaluation of the PRESAGE∕optical-CT 3D dosimetry system

Sakhalkar, H. S.; Adamovics, J.; Ibbott, G.; Oldham, M.
Fonte: American Association of Physicists in Medicine Publicador: American Association of Physicists in Medicine
Tipo: Artigo de Revista Científica
EN
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This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco-dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical-CT scanner (OCTOPUS 5× scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head-and-neck (H&N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields (1×3 cm2) impinging on the flat circular face of the dosimeter. A repetitious sequence of three dose levels (4, 2.88, and 1.28 Gy) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS 5× commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to ∼2%) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference...

FRODOCK: a new approach for fast rotational protein–protein docking

Garzon, José Ignacio; Lopéz-Blanco, José Ramón; Pons, Carles; Kovacs, Julio; Abagyan, Ruben; Fernandez-Recio, Juan; Chacon, Pablo
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
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Motivation: Prediction of protein–protein complexes from the coordinates of their unbound components usually starts by generating many potential predictions from a rigid-body 6D search followed by a second stage that aims to refine such predictions. Here, we present and evaluate a new method to effectively address the complexity and sampling requirements of the initial exhaustive search. In this approach we combine the projection of the interaction terms into 3D grid-based potentials with the efficiency of spherical harmonics approximations to accelerate the search. The binding energy upon complex formation is approximated as a correlation function composed of van der Waals, electrostatics and desolvation potential terms. The interaction-energy minima are identified by a novel, fast and exhaustive rotational docking search combined with a simple translational scanning. Results obtained on standard protein–protein benchmarks demonstrate its general applicability and robustness. The accuracy is comparable to that of existing state-of-the-art initial exhaustive rigid-body docking tools, but achieving superior efficiency. Moreover, a parallel version of the method performs the docking search in just a few minutes, opening new application opportunities in the current ‘omics’ world.

Fast Approximations of the Rotational Diffusion Tensor and their Application to Structural Assembly of Molecular Complexes

Berlin, Konstantin; O’Leary, Dianne P.; Fushman, David
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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We present and evaluate a rigid-body, deterministic, molecular docking method, called ELMDOCK, that relies solely on the three-dimensional structure of the individual components and the overall rotational diffusion tensor of the complex, obtained from nuclear spin-relaxation measurements. We also introduce a docking method, called ELMPATIDOCK, derived from ELMDOCK and based on the new concept of combining the shape-related restraints from rotational diffusion with those from residual dipolar couplings, along with ambiguous contact/interface-related restraints obtained from chemical shift perturbations. ELMDOCK and ELMPATIDOCK use two novel approximations of the molecular rotational diffusion tensor that allow computationally efficient docking. We show that these approximations are accurate enough to properly dock the two components of a complex without the need to recompute the diffusion tensor at each iteration step. We analyze the accuracy, robustness, and efficiency of these methods using synthetic relaxation data for a large variety of protein-protein complexes. We also test our method on three protein systems for which the structure of the complex and experimental relaxation data are available, and analyze the effect of flexible unstructured tails on the outcome of docking. Additionally...

On the Use of Sensor Fusion to Reduce the Impact of Rotational and Additive Noise in Human Activity Recognition

Banos, Oresti; Damas, Miguel; Pomares, Hector; Rojas, Ignacio
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 11/06/2012 EN
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26.16%
The main objective of fusion mechanisms is to increase the individual reliability of the systems through the use of the collectivity knowledge. Moreover, fusion models are also intended to guarantee a certain level of robustness. This is particularly required for problems such as human activity recognition where runtime changes in the sensor setup seriously disturb the reliability of the initial deployed systems. For commonly used recognition systems based on inertial sensors, these changes are primarily characterized as sensor rotations, displacements or faults related to the batteries or calibration. In this work we show the robustness capabilities of a sensor-weighted fusion model when dealing with such disturbances under different circumstances. Using the proposed method, up to 60% outperformance is obtained when a minority of the sensors are artificially rotated or degraded, independent of the level of disturbance (noise) imposed. These robustness capabilities also apply for any number of sensors affected by a low to moderate noise level. The presented fusion mechanism compensates the poor performance that otherwise would be obtained when just a single sensor is considered.

Comparison between Different Methods for Biomechanical Assessment of Ex Vivo Fracture Callus Stiffness in Small Animal Bone Healing Studies

Steiner, Malte; Volkheimer, David; Meyers, Nicholaus; Wehner, Tim; Wilke, Hans-Joachim; Claes, Lutz; Ignatius, Anita
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 17/03/2015 EN
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For ex vivo measurements of fracture callus stiffness in small animals, different test methods, such as torsion or bending tests, are established. Each method provides advantages and disadvantages, and it is still debated which of those is most sensitive to experimental conditions (i.e. specimen alignment, directional dependency, asymmetric behavior). The aim of this study was to experimentally compare six different testing methods regarding their robustness against experimental errors. Therefore, standardized specimens were created by selective laser sintering (SLS), mimicking size, directional behavior, and embedding variations of respective rat long bone specimens. For the latter, five different geometries were created which show shifted or tilted specimen alignments. The mechanical tests included three-point bending, four-point bending, cantilever bending, axial compression, constrained torsion, and unconstrained torsion. All three different bending tests showed the same principal behavior. They were highly dependent on the rotational direction of the maximum fracture callus expansion relative to the loading direction (creating experimental errors of more than 60%), however small angular deviations (<15°) were negligible. Differences in the experimental results between the bending tests originate in their respective location of maximal bending moment induction. Compared to four-point bending...

Locally oriented optical flow computation

Niu, Y.; Dick, A.; Brooks, M.
Fonte: IEEE-Inst Electrical Electronics Engineers Inc Publicador: IEEE-Inst Electrical Electronics Engineers Inc
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
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This paper proposes the use of an adaptive locally oriented coordinate frame when calculating an optical flow field. The coordinate frame is aligned with the least curvature direction in a local window about each pixel. This has advantages to both fitting the flow field to the image data and in imposing smoothness constraints between neighboring pixels. In terms of fitting, robustness is obtained to a wider variety of image motions due to the extra invariance provided by the coordinate frame. Smoothness constraints are naturally propagated along image boundaries which often correspond to motion boundaries. In addition, moving objects can be efficiently segmented in the least curvature direction. We show experimentally the benefits of the method and demonstrate robustness to fast rotational motion, such as what often occurs in human motion.; Yan Niu, Anthony Dick and Michael Brooks

On the Use of Sensor Fusion to Reduce the Impact of Rotational and Additive Noise in Human Activity Recognition

Ba??os Legr??n, Oresti; Damas Hermoso, Miguel; Pomares Cintas, H??ctor; Rojas Ruiz, Ignacio
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
ENG
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This article belongs to the Special Issue Select papers from UCAmI 2011 - the 5th International Symposium on Ubiquitous Computing and Ambient Intelligence (UCAmI'11).; The main objective of fusion mechanisms is to increase the individual reliability of the systems through the use of the collectivity knowledge. Moreover, fusion models are also intended to guarantee a certain level of robustness. This is particularly required for problems such as human activity recognition where runtime changes in the sensor setup seriously disturb the reliability of the initial deployed systems. For commonly used recognition systems based on inertial sensors, these changes are primarily characterized as sensor rotations, displacements or faults related to the batteries or calibration. In this work we show the robustness capabilities of a sensor-weighted fusion model when dealing with such disturbances under different circumstances. Using the proposed method, up to 60% outperformance is obtained when a minority of the sensors are artificially rotated or degraded, independent of the level of disturbance (noise) imposed. These robustness capabilities also apply for any number of sensors affected by a low to moderate noise level. The presented fusion mechanism compensates the poor performance that otherwise would be obtained when just a single sensor is considered.

Rotational properties of $^{252, 253, 254}$No. Influence of pairing correlations

Duguet, T.; Bonche, P.; Heenen, P. -H.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 15/05/2000
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Rotational bands of $^{252, 253, 254}$No and the fission barriers of $^{254}$No at spin 0$\hbar$ and 20$\hbar$ are calculated with the Hartree-Fock-Bogolyubov theory and the Lipkin-Nogami approximate particle number projection. The SLy4 Skyrme force is used in the particle-hole channel. A zero-range force with and without density-dependence is used in the particle-particle channel. The experimental ground state deformation (${\cal{Q}}_{20}$ = 32.8 b) is reproduced as well as the increase of the dynamical moment of inertia with frequency both for $^{252}$No and $^{254}$No. The rotational band of $^{253}$No is also calculated. Fission barriers of $^{254}$No at spin 0$\hbar$ and 20$\hbar$ show the robustness of shell-corrections against rotation in these heavy nuclei.; Comment: 19 pages, 10 figures, Latex file

Collective rotation from ab initio theory

Caprio, M. A.; Maris, P.; Vary, J. P.; Smith, R.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 31/08/2015
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Through ab initio approaches in nuclear theory, we may now seek to quantitatively understand the wealth of nuclear collective phenomena starting from the underlying internucleon interactions. No-core configuration interaction (NCCI) calculations for p-shell nuclei give rise to rotational bands, as evidenced by rotational patterns for excitation energies, electromagnetic moments, and electromagnetic transitions. In this review, NCCI calculations of 7-9Be are used to illustrate and explore ab initio rotational structure, and the resulting predictions for rotational band properties are compared with experiment. We highlight the robustness of ab initio rotational predictions across different choices for the internucleon interaction.; Comment: 34 pages, 19 figures; to be published in Int. J. Mod. Phys. E

Invariant texture analysis through Local Binary Patterns

Nava, Rodrigo; Cristóbal, Gabriel; Escalante-Ramírez, Boris
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/11/2011
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In many image processing applications, such as segmentation and classification, the selection of robust features descriptors is crucial to improve the discrimination capabilities in real world scenarios. In particular, it is well known that image textures constitute power visual cues for feature extraction and classification. In the past few years the local binary pattern (LBP) approach, a texture descriptor method proposed by Ojala et al., has gained increased acceptance due to its computational simplicity and more importantly for encoding a powerful signature for describing textures. However, the original algorithm presents some limitations such as noise sensitivity and its lack of rotational invariance which have led to many proposals or extensions in order to overcome such limitations. In this paper we performed a quantitative study of the Ojala's original LBP proposal together with other recently proposed LBP extensions in the presence of rotational, illumination and noisy changes. In the experiments we have considered two different databases: Brodatz and CUReT for different sizes of LBP masks. Experimental results demonstrated the effectiveness and robustness of the described texture descriptors for images that are subjected to geometric or radiometric changes.; Comment: 7 figures...

Predictions for the CO emission of galaxies from a coupled simulation of galaxy formation and photon dominated regions

Lagos, Claudia del P.; Bayet, Estelle; Baugh, Carlton M.; Lacey, Cedric G.; Bell, Tom; Fanidakis, Nikolaos; Geach, James
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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We combine the galaxy formation model GALFORM with the Photon Dominated Region code UCL_PDR to study the emission from the rotational transitions of 12CO (CO) in galaxies from z=0 to z=6 in the Lambda CDM framework. GALFORM is used to predict the molecular (H2) and atomic hydrogen (HI) gas contents of galaxies using the pressure-based empirical star formation relation of Blitz & Rosolowsky. From the predicted H2 mass and the conditions in the interstellar medium, we estimate the CO emission in the rotational transitions 1-0 to 10-9 by applying the UCL_PDR model to each galaxy. We find that deviations from the Milky-Way CO-H2 conversion factor come mainly from variations in metallicity, and in the average gas and star formation rate surface densities. In the local universe, the model predicts a CO(1-0) luminosity function (LF), CO-to-total infrared (IR) luminosity ratios for multiple CO lines and a CO spectral line energy distribution (SLED) which are in good agreement with observations of luminous and ultra-luminous IR galaxies. At high redshifts, the predicted CO SLED of the brightest IR galaxies reproduces the shape and normalization of the observed CO SLED. The model predicts little evolution in the CO-to-IR luminosity ratio for different CO transitions...

The baryonic Tully-Fisher Relation predicted by cold dark matter cosmogony

Desmond, Harry
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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16.07%
Providing a theoretical basis for the baryonic Tully-Fisher Relation (BTFR; baryonic mass vs rotational velocity in spiral galaxies) in the LCDM paradigm has proved problematic. Simple calculations suggest too low a slope and too high a scatter, and recent semi-analytic models and numerical galaxy simulations typically fail to reproduce some aspects of the relation. Furthermore, the assumptions underlying one model are often inconsistent with those behind another. This paper aims to develop a rigorous prediction for the BTFR in the context of LCDM, using only a priori expected effects and relations, a minimum of theoretical assumptions, and no free parameters. The robustness of the relation to changes in key galactic parameters will be explored. I adopt a modular approach, taking each of the stand alone galaxy relations necessary for constructing the BTFR from up-to-date numerical simulations of dark halos. These relations -- and their expected scatter -- are used to describe model spirals with a range of masses, resulting in a band in the space of the BTFR that represents the current best guess for the LCDM prediction. Consistent treatment of expected LCDM effects goes a large way towards reconciling the naive slope-3 LCDM prediction with the data...

On the robustness of the ammonia thermometer

Maret, Sebastien; Faure, Alexandre; Scifoni, Emanuele; Wiesenfeld, Laurent
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 24/06/2009
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25.9%
Ammonia inversion lines are often used as probes of the physical conditions in the dense ISM. The excitation temperature between the first two para metastable (rotational) levels is an excellent probe of the gas kinetic temperature. However, the calibration of this ammonia thermometer depends on the accuracy of the collisional rates with H2. Here we present new collisional rates for ortho-NH3 and para-NH3 colliding with para-H2 (J=0) and we investigate the effects of these new rates on the excitation of ammonia. Scattering calculations employ a new, high accuracy, potential energy surface computed at the coupled-cluster CCSD(T) level with a basis set extrapolation procedure. Rates are obtained for all transitions involving ammonia levels with J <= 3 and for kinetic temperatures in the range 5-100 K. We find that the calibration curve of the ammonia thermometer -- which relates the observed excitation temperature between the first two para metastable levels to the gas kinetic temperature -- does not change significantly when these new rates are used. Thus, the calibration of ammonia thermometer appears to be robust. Effects of the new rates on the excitation temperature of inversion and rotation-inversion transitions are also found to be small.; Comment: Accepted for publication in the MNRAS

Coherent spin-rotational dynamics of oxygen super rotors

Milner, Alexander A.; Korobenko, Aleksey; Milner, Valery
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/06/2014
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26.33%
We use state- and time-resolved coherent Raman spectroscopy to study the rotational dynamics of oxygen molecules in ultra-high rotational states. While it is possible to reach rotational quantum numbers up to $N \approx 50$ by increasing the gas temperature to 1500 K, low population levels and gas densities result in correspondingly weak optical response. By spinning O$_2$ molecules with an optical centrifuge, we efficiently excite extreme rotational states with $N\leqslant 109$ in high-density room temperature ensembles. Fast molecular rotation results in the enhanced robustness of the created rotational wave packets against collisions, enabling us to observe the effects of weak spin-rotation coupling in the coherent rotational dynamics of oxygen. The decay rate of spin-rotation coherence due to collisions is measured as a function of the molecular angular momentum and explained in terms of the general scaling law. We find that at high values of $N$, the rotational decoherence of oxygen is much faster than that of the previously studied non-magnetic nitrogen molecules. This may suggest a different mechanism of rotational relaxation in paramagnetic gases.; Comment: 10 pages, 5 figures

Field-free long-lived alignment of molecules in extreme rotational states

Milner, A. A.; Korobenko, A.; Milner, V.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 06/09/2015
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26.21%
We introduce a new optical tool - a "two-dimensional optical centrifuge", capable of aligning molecules in extreme rotational states. Unlike the conventional centrifuge, which confines the molecules in the plane of their rotation, its two-dimensional version aligns the molecules along a well-defined axis, similarly to the effect of a single linearly polarized laser pulse, but at a much higher level of rotational excitation. The increased robustness of ultra-high rotational states with respect to collisions results in a longer life time of the created alignment in dense media, offering new possibilities for studying and utilizing aligned molecular ensembles under ambient conditions.

Rotational Quantum Impurities in a Metal: Stability of the 2-Channel Kondo Fixed Point in a Magnetic Field

Ballmann, Katinka; Kroha, Johann
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 01/02/2012
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26.07%
A three-level system with partially broken SU(3) symmetry immersed in a metal, comprised of a unique non-interacting ground state and two-fold degenerate excited states, exhibits a stable two-channel Kondo fixed point within a wide range of parameters, as has been shown in previous work. Such systems can, for instance, be realized by protons dissolved in a metal and bound in the interstitial space of the host lattice, where the degeneracy of excited rotational states is guaranteed by the space inversion symmetry of the lattice. We analyze the robustness of the 2CK fixed point with respect to a level splitting of the excited states and discuss how this may explain the behavior of the well-known dI/dV spectra measured by Ralph and Buhrman on ultrasmall quantum point contacts in a magnetic field.; Comment: 7 pages, 3 figures; to appear in Ann. Physik (Berlin)

The drive system of the Major Atmospheric Gamma-ray Imaging Cherenkov Telescope

Bretz, T.; Dorner, D.; Wagner, R. M.; Sawallisch, P.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 27/10/2008
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The MAGIC telescope is an imaging atmospheric Cherenkov telescope, designed to observe very high energy gamma-rays while achieving a low energy threshold. One of the key science goals is fast follow-up of the enigmatic and short lived gamma-ray bursts. The drive system for the telescope has to meet two basic demands: (1) During normal observations, the 72-ton telescope has to be positioned accurately, and has to track a given sky position with high precision at a typical rotational speed in the order of one revolution per day. (2) For successfully observing GRB prompt emission and afterglows, it has to be powerful enough to position to an arbitrary point on the sky within a few ten seconds and commence normal tracking immediately thereafter. To meet these requirements, the implementation and realization of the drive system relies strongly on standard industry components to ensure robustness and reliability. In this paper, we describe the mechanical setup, the drive control and the calibration of the pointing, as well as present measurements of the accuracy of the system. We show that the drive system is mechanically able to operate the motors with an accuracy even better than the feedback values from the axes. In the context of future projects...

Compass rose: A rotational robust signature for optical flow computation

Niu, Y.; Dick, A.; Brooks, M.
Fonte: IEEE Publicador: IEEE
Tipo: Artigo de Revista Científica
Publicado em //2014 EN
Relevância na Pesquisa
36.07%
This paper proposes a new image signature, called Compass Rose, which is particularly suited to optical flow computation. It is differentiable, fast to compute, and robust to additive illumination changes, translation, and fast rotation. We design a sparse flow computation system based on the invariance of the Compass Rose signatures. This is then extended to dense motion estimation by the addition of an optional diffusion step. Quantitative testing on several benchmark sequences shows the Compass Rose attains higher accuracy than the traditional flow signatures under a range of conditions. Finally, we demonstrate its application to human motion estimation, which is challenging for optical flow methods due to fast limb rotation.; Yan Niu, Anthony Dick, and Michael Brooks

Characterization of Energy Confinement in Net-current Free Plasmas using the Extended International Stellarator Database

Yamada, Y; Harris, Jeffrey; Dinklage, Andreas; Ascasibar, E; Sano, F; Talmadge, J; Stroth, U; Kus, A; Murakami, S; Yokoyama, M; Beidler, C; Tribaldos, V; Watanabe, K; Suzuki, Y; Okamura, S
Fonte: IOP Publishing Publicador: IOP Publishing
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
25.9%
International collaboration on development of a stellarator confinement database has progressed. More than 3000 data points from nine major stellarator experiments have been compiled. Robust dependences of the energy confinement time on the density and the heating power have been confirmed. Dependences on other operational parameters, i.e. the major and minor radii, magnetic field and the rotational transform , have been evaluated using inter-machine analyses. In order to express the energy confinement in a unified scaling law, systematic differences in each subgroup are quantified. An a posteriori approach using a confinement enhancement factor on ISS95 as a renormalizing configuration- dependent parameter yields a new scaling expression ISS04; . Gyro-Bohm characteristic similar to ISS95 has been confirmed for the extended database with a wider range of plasma parameters and magnetic configurations than in the study of ISS95. It has also been discovered that there is a systematic offset of energy confinement between magnetic configurations, and its measure correlates with the effective helical ripple of the external stellarator field. Full documentation of the International Stellarator Confinement Database is available at http://iscdb.nifs.ac.jp/ and http://www.ipp.mpg.de/ISS.