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Sample records for statistical moment invariants

  1. Blurred image recognition by Legendre moment invariants.

    Science.gov (United States)

    Zhang, Hui; Shu, Huazhong; Han, Guoniu N; Coatrieux, Gouenou; Luo, Limin; Coatrieux, Jean Louis

    2010-03-01

    Processing blurred images is a key problem in many image applications. Existing methods to obtain blur invariants which are invariant with respect to centrally symmetric blur are based on geometric moments or complex moments. In this paper, we propose a new method to construct a set of blur invariants using the orthogonal Legendre moments. Some important properties of Legendre moments for the blurred image are presented and proved. The performance of the proposed descriptors is evaluated with various point-spread functions and different image noises. The comparison of the present approach with previous methods in terms of pattern recognition accuracy is also provided. The experimental results show that the proposed descriptors are more robust to noise and have better discriminative power than the methods based on geometric or complex moments.

  2. Maximum Entropy Moment Systems and Galilean Invariance

    OpenAIRE

    Junk, Michael; Unterreiter, Andreas

    2001-01-01

    In this article, we investigate the maximum entropy moment closure in gas dynamics. We show that the usual choice of polynomial weight functions may lead to hyperbolic systems with an unpleasant state space: equilibrium states are boundary points with possibly singular fluxes. In order to avoid singularities, the necessary arises to find weight functions which growing sub-quadratically at infinity. Unfortunately, this requirement leads to a conflict with Galilean invariance of the moment syst...

  3. Multidistortion-invariant image recognition with radial harmonic Fourier moments.

    Science.gov (United States)

    Ren, Haiping; Ping, Ziliang; Bo, Wurigen; Wu, Wenkai; Sheng, Yunlong

    2003-04-01

    We propose radial harmonic Fourier moments, which are shifting, scaling, rotation, and intensity invariant. Compared with Chebyshev-Fourier moments, the new moments have superior performance near the origin and better ability to describe small images in terms of image-reconstruction errors and noise sensitivity. A multidistortion-invariant pattern-recognition experiment was performed with radial harmonic Fourier moments.

  4. A Unified Methodology for Computing Accurate Quaternion Color Moments and Moment Invariants.

    Science.gov (United States)

    Karakasis, Evangelos G; Papakostas, George A; Koulouriotis, Dimitrios E; Tourassis, Vassilios D

    2014-02-01

    In this paper, a general framework for computing accurate quaternion color moments and their corresponding invariants is proposed. The proposed unified scheme arose by studying the characteristics of different orthogonal polynomials. These polynomials are used as kernels in order to form moments, the invariants of which can easily be derived. The resulted scheme permits the usage of any polynomial-like kernel in a unified and consistent way. The resulted moments and moment invariants demonstrate robustness to noisy conditions and high discriminative power. Additionally, in the case of continuous moments, accurate computations take place to avoid approximation errors. Based on this general methodology, the quaternion Tchebichef, Krawtchouk, Dual Hahn, Legendre, orthogonal Fourier-Mellin, pseudo Zernike and Zernike color moments, and their corresponding invariants are introduced. A selected paradigm presents the reconstruction capability of each moment family, whereas proper classification scenarios evaluate the performance of color moment invariants.

  5. Wavelet-based moment invariants for pattern recognition

    Science.gov (United States)

    Chen, Guangyi; Xie, Wenfang

    2011-07-01

    Moment invariants have received a lot of attention as features for identification and inspection of two-dimensional shapes. In this paper, two sets of novel moments are proposed by using the auto-correlation of wavelet functions and the dual-tree complex wavelet functions. It is well known that the wavelet transform lacks the property of shift invariance. A little shift in the input signal will cause very different output wavelet coefficients. The autocorrelation of wavelet functions and the dual-tree complex wavelet functions, on the other hand, are shift-invariant, which is very important in pattern recognition. Rotation invariance is the major concern in this paper, while translation invariance and scale invariance can be achieved by standard normalization techniques. The Gaussian white noise is added to the noise-free images and the noise levels vary with different signal-to-noise ratios. Experimental results conducted in this paper show that the proposed wavelet-based moments outperform Zernike's moments and the Fourier-wavelet descriptor for pattern recognition under different rotation angles and different noise levels. It can be seen that the proposed wavelet-based moments can do an excellent job even when the noise levels are very high.

  6. Electric dipole moments with and beyond flavor invariants

    OpenAIRE

    Christopher Smith; Selim Touati

    2017-01-01

    In this paper, the flavor structure of quark and lepton electric dipole moments in the SM and beyond is investigated using tools inspired from Minimal Flavor Violation. While Jarlskog-like flavor invariants are adequate for estimating CP-violation from closed fermion loops, non-invariant structures arise from rainbow-like processes. Our goal is to systematically construct these latter flavor structures in the quark and lepton sectors, assuming different mechanisms for generating neutrino mass...

  7. Electric dipole moments with and beyond flavor invariants

    OpenAIRE

    Smith, Christopher; Touati, Selim

    2017-01-01

    In this paper, the flavor structure of quark and lepton electric dipole moments in the SM and beyond is investigated using tools inspired from Minimal Flavor Violation. While Jarlskog-like flavor invariants are adequate for estimating CP -violation from closed fermion loops, non-invariant structures arise from rainbow-like processes. Our goal is to systematically construct these latter flavor structures in the quark and lepton sectors, assuming different mechanisms for generating neutrino mas...

  8. Rotation invariants from Gaussian-Hermite moments of color images

    Czech Academy of Sciences Publication Activity Database

    Yang, B.; Suk, Tomáš; Flusser, Jan; Shi, Z.; Chen, X.

    2018-01-01

    Roč. 143, č. 1 (2018), s. 282-291 ISSN 0165-1684 R&D Projects: GA ČR GA15-16928S Institutional support: RVO:67985556 Keywords : Color images * Object recognition * Rotation invariants * Gaussian–Hermite moments * Joint invariants Subject RIV: JD - Computer Applications, Robotics Impact factor: 3.110, year: 2016 http:// library .utia.cas.cz/separaty/2017/ZOI/suk-0479748.pdf

  9. Projection Operators and Moment Invariants to Image Blurring

    Czech Academy of Sciences Publication Activity Database

    Flusser, Jan; Suk, Tomáš; Boldyš, Jiří; Zitová, Barbara

    2015-01-01

    Roč. 37, č. 4 (2015), s. 786-802 ISSN 0162-8828 R&D Projects: GA ČR GA13-29225S; GA ČR GAP103/11/1552 Institutional support: RVO:67985556 Keywords : Blurred image * N-fold rotation symmetry * projection operators * image moments * moment invariants * blur invariants * object recognition Subject RIV: JD - Computer Applications, Robotics Impact factor: 6.077, year: 2015 http://library.utia.cas.cz/separaty/2014/ZOI/flusser-0434521.pdf

  10. Rotation invariants of vector fields from orthogonal moments

    Czech Academy of Sciences Publication Activity Database

    Yang, B.; Kostková, Jitka; Flusser, Jan; Suk, Tomáš; Bujack, R.

    2018-01-01

    Roč. 74, č. 1 (2018), s. 110-121 ISSN 0031-3203 R&D Projects: GA ČR GA15-16928S Institutional support: RVO:67985556 Keywords : Vector field * Total rotation * Invariants * Gaussian–Hermite moments * Zernike moments * Numerical stability Subject RIV: JD - Computer Applications, Robotics Impact factor: 4.582, year: 2016 http:// library .utia.cas.cz/separaty/2017/ZOI/flusser-0478329.pdf

  11. Statistical Inference Based on L-Moments

    Directory of Open Access Journals (Sweden)

    Tereza Šimková

    2017-03-01

    Full Text Available To overcome drawbacks of central moments and comoment matrices usually used to characterize univariate and multivariate distributions, respectively, their generalization, termed L-moments, has been proposed. L-moments of all orders are defined for any random variable or vector with finite mean. L-moments have been widely employed in the past 20 years in statistical inference. The aim of the paper is to present the review of the theory of L-moments and to illustrate their application in parameter estimating and hypothesis testing. The problem of estimating the three-parameter generalized Pareto distribution’s (GPD parameters that is generally used in modelling extreme events is considered. A small simulation study is performed to show the superiority of the L-moment method in some cases. Because nowadays L-moments are often employed in estimating extreme events by regional approaches, the focus is on the key assumption of index-flood based regional frequency analysis (RFA, that is homogeneity testing. The benefits of the nonparametric L-moment homogeneity test are implemented on extreme meteorological events observed in the Czech Republic.

  12. Quantitative characterization and comparison of precipitate and grain shape in Nickel -base superalloys using moment invariants

    Science.gov (United States)

    Callahan, Patrick Gregory

    to describe 3-D shapes using 2-D moment invariants. To do this we characterize 2-D sections of a 3-D microstructure using 2-D moment invariants. The statistical distribution of 2-D moment invariants from the sections are compared to a library of density maps produced from different shapes. The sectioning plane is random so each group of particles produces a statistical distribution of 2-D moments that can represent a microstructure. Then we show three example applications: determination of a 3-D shape by computing the Hellinger distance between moment invariant density maps derived from random 2-D section micrographs and the density map database; automated detection and quantification of rafting in cuboidal microstructures; and quantitative comparison of pairs of microstructures.

  13. ATS drugs molecular structure representation using refined 3D geometric moment invariants

    Czech Academy of Sciences Publication Activity Database

    Pratama, S. F.; Muda, A. K.; Choo, J. H.; Flusser, Jan; Abraham, A.

    2017-01-01

    Roč. 55, č. 10 (2017), s. 1951-1963 ISSN 0259-9791 R&D Projects: GA ČR GA15-16928S Institutional support: RVO:67985556 Keywords : 3D moment invariants * Geometric moment invariants * ATS drugs * Molecular similarity * Molecular descriptors Subject RIV: JD - Computer Applications, Robotics Impact factor: 1.308, year: 2016 http://library.utia.cas.cz/separaty/2017/ZOI/flusser-0479217.pdf

  14. Mechanical Fault Diagnosis Using Color Image Recognition of Vibration Spectrogram Based on Quaternion Invariable Moment

    Directory of Open Access Journals (Sweden)

    Liang Hua

    2015-01-01

    Full Text Available Automatic extraction of time-frequency spectral image of mechanical faults can be achieved and faults can be identified consequently when rotating machinery spectral image processing technology is applied to fault diagnosis, which is an advantage. Acquired mechanical vibration signals can be converted into color time-frequency spectrum images by the processing of pseudo Wigner-Ville distribution. Then a feature extraction method based on quaternion invariant moment was proposed, combining image processing technology and multiweight neural network technology. The paper adopted quaternion invariant moment feature extraction method and gray level-gradient cooccurrence matrix feature extraction method and combined them with geometric learning algorithm and probabilistic neural network algorithm, respectively, and compared the recognition rates of rolling bearing faults. The experimental results show that the recognition rates of quaternion invariant moment are higher than gray level-gradient cooccurrence matrix in the same recognition method. The recognition rates of geometric learning algorithm are higher than probabilistic neural network algorithm in the same feature extraction method. So the method based on quaternion invariant moment geometric learning and multiweight neural network is superior. What is more, this algorithm has preferable generalization performance under the condition of fewer samples, and it has practical value and acceptation on the field of fault diagnosis for rotating machinery as well.

  15. The Statistical Model with Interpartial Scalar Conformally Invariant Interaction

    CERN Document Server

    Ignat'ev, Yurii

    2015-01-01

    A closed mathematical model of the statistical self-gravitating system of scalar charged particles for conformal invariant scalar interactions is constructed on the basis of relativistic kinetics and gravitation theory. Asymptotic properties of the model are investigated in the ultrarelativistic limit. It is shown, that scalar charge density automatically generates scalar field effective mass and the value of this mass is found. In the paper it is proved the asymptotic conformal invariance of constitutive equations in case of homogenous isotropic Universe. Also it is proved the asymptotic conformal invariance of field equations at the early stages of cosmological evolution.

  16. Gray-scale moment invariants for airborne mine detection, discrimination and false alarm mitigation

    Science.gov (United States)

    Sriram, Pradeep; Agarwal, Sanjeev; Mitchell, O. Robert

    2002-08-01

    Shape features based on gray-scale moment invariants are presented for airborne mine detection and discrimination. Eleven shape features are obtained by translation, rotation and contrast normalization of the fourth-order gray-scale moments. Mahalanobis distance between an observed and true (average) shape feature vector is used as a shape metric. Covariance matrix corresponding to the average shape feature vector is obtained analytically using an additive and multiplicative noise model for the MWIR image. Effectiveness of gray scale moment invariant shape features for mine discrimination and false alarm mitigation is shown using MWIR imagery collected for LAMD-I program in May 2000. Successful implementation of the features in an airborne detection depends on the consistency of these shape features over time with change in factors such as solar illumination, ageing, clouds and environmental conditions. A study of the variability of gray-scale moment invariant-based shape features with time is conducted using MWIR time-sequenced imagery acquired in June-July 1998 by E-OIR.

  17. Measuring University Students' Approaches to Learning Statistics: An Invariance Study

    Science.gov (United States)

    Chiesi, Francesca; Primi, Caterina; Bilgin, Ayse Aysin; Lopez, Maria Virginia; del Carmen Fabrizio, Maria; Gozlu, Sitki; Tuan, Nguyen Minh

    2016-01-01

    The aim of the current study was to provide evidence that an abbreviated version of the Approaches and Study Skills Inventory for Students (ASSIST) was invariant across different languages and educational contexts in measuring university students' learning approaches to statistics. Data were collected on samples of university students attending…

  18. Determination of rotation angle based on invariant moment and MADALINE for HGA grasping

    Directory of Open Access Journals (Sweden)

    Nares Pokasap

    2014-06-01

    Full Text Available To proposed a new adaptive intelligent system for a robot work cell that can visually track and intercept an invariant stationary HGA feature undergoing arbitrary orientation anywhere along its predicted trajectory within the robot’s workspace is presented in this paper. A combination of the seven invariant moment technique, image feature technique and the MADALINE network are used for identifying the stationary HGA at any rotation angle without overlapping and generating the predicted robot trajectory respectively. An invariant moment that has system for a scale, translation and orientation are calculated for each significant region in the input images. Inertial ellipse is determining for angle rotation that compare against to the accepted orientation that required. The result shown that, the relationship between the visual feedback image data and the control command for changing the axis motion shows deviation of robot placing less than 2% by the MADALINE network for intercepting stationary HGA at any rotation angle. The location and image features of these HGAs need not be preprogrammed, marked and known before, and any change in a task is possible without changing the robot program. Finally, this novel method can improve the hard disk drive (HDD assembly process productivity.

  19. Statistical mechanics of reparametrization invariant systems. Takes Three to Tango

    CERN Document Server

    Josset, Thibaut; Rovelli, Carlo

    2015-01-01

    It is notoriously difficult to apply statistical mechanics to generally covariant systems, because the notions of time, energy and equilibrium are seriously modified in this context. We discuss the conditions under which weaker versions of these notions can be defined, sufficient for statistical mechanics. We focus on reparametrization invariant systems without additional gauges. The key idea is to reconstruct statistical mechanics from the ergodic theorem. We find that a suitable split of the system into two non-interacting components is sufficient for generalizing statistical mechanics. While equilibrium acquires sense only when the system admits a suitable split into three weakly interacting components ---roughly: a clock and two systems among which a generalization of energy is equi-partitioned. The key property that allows the application of statistical mechanics and thermodynamics is an additivity condition of such generalized energy.

  20. Statistical analysis of complex systems with nonclassical invariant measures

    KAUST Repository

    Fratalocchi, Andrea

    2011-02-28

    I investigate the problem of finding a statistical description of a complex many-body system whose invariant measure cannot be constructed stemming from classical thermodynamics ensembles. By taking solitons as a reference system and by employing a general formalism based on the Ablowitz-Kaup-Newell-Segur scheme, I demonstrate how to build an invariant measure and, within a one-dimensional phase space, how to develop a suitable thermodynamics. A detailed example is provided with a universal model of wave propagation, with reference to a transparent potential sustaining gray solitons. The system shows a rich thermodynamic scenario, with a free-energy landscape supporting phase transitions and controllable emergent properties. I finally discuss the origin of such behavior, trying to identify common denominators in the area of complex dynamics.

  1. An invariant approach to statistical analysis of shapes

    CERN Document Server

    Lele, Subhash R

    2001-01-01

    INTRODUCTIONA Brief History of MorphometricsFoundations for the Study of Biological FormsDescription of the data SetsMORPHOMETRIC DATATypes of Morphometric DataLandmark Homology and CorrespondenceCollection of Landmark CoordinatesReliability of Landmark Coordinate DataSummarySTATISTICAL MODELS FOR LANDMARK COORDINATE DATAStatistical Models in GeneralModels for Intra-Group VariabilityEffect of Nuisance ParametersInvariance and Elimination of Nuisance ParametersA Definition of FormCoordinate System Free Representation of FormEst

  2. Transformation de Fourier et moments invariants appliqués à la reconnaissance des caractères Tifinaghe

    Directory of Open Access Journals (Sweden)

    Rachid El Ayachi

    2012-03-01

    Full Text Available Optical Character Recognition OCR is a tool that aims to provide opportunities for computers to read characters without human intervention. The objective of OCR is characterization of a character by invariant descriptors in translation, rotation and scaling. In this paper, the OCR developed use invariant moments and Fourier transform in extraction phase. In the recognition phase, dynamic programming and neural network are adopted. All tests are applied on Tifinaghe printed characters.

  3. Rotation and Noise Invariant Near-Infrared Face Recognition by means of Zernike Moments and Spectral Regression Discriminant Analysis

    Czech Academy of Sciences Publication Activity Database

    Farokhi, S.; Shamsuddin, S. M.; Flusser, Jan; Sheikh, U. U.; Khansari, M.; Jafari-Khouzani, K.

    2013-01-01

    Roč. 22, č. 1 (2013), s. 1-11 ISSN 1017-9909 R&D Projects: GA ČR GAP103/11/1552 Keywords : face recognition * infrared imaging * image moments Subject RIV: JD - Computer Applications, Robotics Impact factor: 0.850, year: 2013 http://library.utia.cas.cz/separaty/2013/ZOI/flusser-rotation and noise invariant near-infrared face recognition by means of zernike moments and spectral regression discriminant analysis.pdf

  4. Statistical translation invariance protects a topological insulator from interactions

    Science.gov (United States)

    Milsted, A.; Seabra, L.; Fulga, I. C.; Beenakker, C. W. J.; Cobanera, E.

    2015-08-01

    We investigate the effect of interactions on the stability of a disordered, two-dimensional topological insulator realized as an array of nanowires or chains of magnetic atoms on a superconducting substrate. The Majorana zero-energy modes present at the ends of the wires overlap, forming a dispersive edge mode with thermal conductance determined by the central charge c of the low-energy effective field theory of the edge. We show numerically that, in the presence of disorder, the c =1 /2 Majorana edge mode remains delocalized up to extremely strong attractive interactions, while repulsive interactions drive a transition to a c =3 /2 edge phase localized by disorder. The absence of localization for strong attractive interactions is explained by a self-duality symmetry of the statistical ensemble of disorder configurations and of the edge interactions, originating from translation invariance on the length scale of the underlying mesoscopic array.

  5. Moment Invariant Features Extraction for Hand Gesture Recognition of Sign Language based on SIBI

    Directory of Open Access Journals (Sweden)

    Angga Rahagiyanto

    2017-07-01

    Full Text Available Myo Armband became an immersive technology to help deaf people for communication each other. The problem on Myo sensor is unstable clock rate. It causes the different length data for the same period even on the same gesture. This research proposes Moment Invariant Method to extract the feature of sensor data from Myo. This method reduces the amount of data and makes the same length of data. This research is user-dependent, according to the characteristics of Myo Armband. The testing process was performed by using alphabet A to Z on SIBI, Indonesian Sign Language, with static and dynamic finger movements. There are 26 class of alphabets and 10 variants in each class. We use min-max normalization for guarantying the range of data. We use K-Nearest Neighbor method to classify dataset. Performance analysis with leave-one-out-validation method produced an accuracy of 82.31%. It requires a more advanced method of classification to improve the performance on the detection results.

  6. Statistical Estimation and Clustering of Group-invariant Orientation Parameters

    CERN Document Server

    Chen, Yu-Hui; Newstadt, Gregory; DeGraef, Marc; Simmons, Jeffrey; Hero, Alfred

    2015-01-01

    We treat the problem of estimation of orientation parameters whose values are invariant to transformations from a spherical symmetry group. Previous work has shown that any such group-invariant distribution must satisfy a restricted finite mixture representation, which allows the orientation parameter to be estimated using an Expectation Maximization (EM) maximum likelihood (ML) estimation algorithm. In this paper, we introduce two parametric models for this spherical symmetry group estimation problem: 1) the hyperbolic Von Mises Fisher (VMF) mixture distribution and 2) the Watson mixture distribution. We also introduce a new EM-ML algorithm for clustering samples that come from mixtures of group-invariant distributions with different parameters. We apply the models to the problem of mean crystal orientation estimation under the spherically symmetric group associated with the crystal form, e.g., cubic or octahedral or hexahedral. Simulations and experiments establish the advantages of the extended EM-VMF and ...

  7. Invariants

    Indian Academy of Sciences (India)

    removed two cells of the same color. Whenever you are putting a 2 × 1 rectangle you are covering one black and one white cell. So the total number of white cells you have covered minus the total number of black cells you have covered after putting some 2 × 1 rectangles is always zero. So this difference is an invariant! You.

  8. Invariant hip moment pattern while walking with a robotic hip exoskeleton

    Science.gov (United States)

    Lewis, Cara L.; Ferris, Daniel P.

    2011-01-01

    Robotic lower limb exoskeletons hold significant potential for gait assistance and rehabilitation; however, we have a limited understanding of how people adapt to walking with robotic devices. The purpose of this study was to test the hypothesis that people reduce net muscle moments about their joints when robotic assistance is provided. This reduction in muscle moment results in a total joint moment (muscle plus exoskeleton) that is the same as the moment without the robotic assistance despite potential differences in joint angles. To test this hypothesis, eight healthy subjects trained with the robotic hip exoskeleton while walking on a force-measuring treadmill. The exoskeleton provided hip flexion assistance from approximately 33% to 53% of the gait cycle. We calculated the root mean squared difference (RMSD) between the average of data from the last 15 minutes of the powered condition and the unpowered condition. After completing three 30-minute training sessions, the hip exoskeleton provided 27% of the total peak hip flexion moment during gait. Despite this substantial contribution from the exoskeleton, subjects walked with a total hip moment pattern (muscle plus exoskeleton) that was almost identical and more similar to the unpowered condition than the hip angle pattern (hip moment RMSD 0.027, angle RMSD 0.134, p<0.001). The angle and moment RMSD were not different for the knee and ankle joints. These findings support the concept that people adopt walking patterns with similar joint moment patterns despite differences in hip joint angles for a given walking speed. PMID:21333995

  9. Recurrence relations for inverse and ratio moments of generalized order statistics from doubly truncated

    Directory of Open Access Journals (Sweden)

    Eldesoky E. Afify

    2013-05-01

    Full Text Available In this article, some recurrence relations of inverse and ratio moments for generalized order statistics from doubly truncated and non-truncated generalized exponential distribution are derived. From our results, we deduce the recurrence relations for single and product moments of generalized order statistics from general class distribution obtained by Haseeb and Hassan (2004, also we deduce the recurrence relations for single and product moments of order statistics from generalized exponential distribution obtained by Saran and Pushkarna (2000.

  10. Computing the Moments of Order Statistics from Truncated Pareto Distributions Based on the Conditional Expectation

    Directory of Open Access Journals (Sweden)

    Gökhan Gökdere

    2014-05-01

    Full Text Available In this paper, closed form expressions for the moments of the truncated Pareto order statistics are obtained by using conditional distribution. We also derive some results for the moments which will be useful for moment computations based on ordered data.

  11. Low-level contrast statistics are diagnostic of invariance of natural textures.

    Science.gov (United States)

    Groen, Iris I A; Ghebreab, Sennay; Lamme, Victor A F; Scholte, H Steven

    2012-01-01

    Texture may provide important clues for real world object and scene perception. To be reliable, these clues should ideally be invariant to common viewing variations such as changes in illumination and orientation. In a large image database of natural materials, we found textures with low-level contrast statistics that varied substantially under viewing variations, as well as textures that remained relatively constant. This led us to ask whether textures with constant contrast statistics give rise to more invariant representations compared to other textures. To test this, we selected natural texture images with either high (HV) or low (LV) variance in contrast statistics and presented these to human observers. In two distinct behavioral categorization paradigms, participants more often judged HV textures as "different" compared to LV textures, showing that textures with constant contrast statistics are perceived as being more invariant. In a separate electroencephalogram (EEG) experiment, evoked responses to single texture images (single-image ERPs) were collected. The results show that differences in contrast statistics correlated with both early and late differences in occipital ERP amplitude between individual images. Importantly, ERP differences between images of HV textures were mainly driven by illumination angle, which was not the case for LV images: there, differences were completely driven by texture membership. These converging neural and behavioral results imply that some natural textures are surprisingly invariant to illumination changes and that low-level contrast statistics are diagnostic of the extent of this invariance.

  12. Statistical moments in superposition models and strongly intensive measures

    Science.gov (United States)

    Broniowski, Wojciech; Olszewski, Adam

    2017-06-01

    First, we present a concise glossary of formulas for composition of standard, cumulant, factorial, and factorial cumulant moments in superposition (compound) models, where final particles are created via independent emission from a collection of sources. Explicit mathematical formulas for the composed moments are given to all orders. We discuss the composition laws for various types of moments via the generating-function methods and list the formulas for the unfolding of the unwanted fluctuations. Second, the technique is applied to the difference of the scaled multiplicities of two particle types. This allows for a systematic derivation and a simple algebraic interpretation of the so-called strongly intensive fluctuation measures. With the help of the formalism we obtain several new strongly intensive measures involving higher-rank moments. The reviewed as well as the new results may be useful in investigations of mechanisms of particle production and event-by-event fluctuations in high-energy nuclear and hadronic collisions, and in particular in the search for signatures of the QCD phase transition at a finite baryon density.

  13. Convergence rates for arbitrary statistical moments of random quantum circuits.

    Science.gov (United States)

    Brown, Winton G; Viola, Lorenza

    2010-06-25

    We consider a class of random quantum circuits where at each step a gate from a universal set is applied to a random pair of qubits, and determine how quickly averages of arbitrary finite-degree polynomials in the matrix elements of the resulting unitary converge to Haar measure averages. This is accomplished by mapping the superoperator that describes t order moments on n qubits to a multilevel SU(4^{t}) Lipkin-Meshkov-Glick Hamiltonian. We show that, for arbitrary fixed t, the ground-state manifold is exactly spanned by factorized eigenstates and, under the assumption that a mean-field ansatz accurately describes the low-lying excitations, the spectral gap scales as 1/n in the thermodynamic limit. Our results imply that random quantum circuits yield an efficient implementation of ϵ approximate unitary t designs.

  14. Higher-Order Moment Characterisation of Rogue Wave Statistics in Supercontinuum Generation

    DEFF Research Database (Denmark)

    Sørensen, Simon Toft; Bang, Ole; Wetzel, Benjamin

    2012-01-01

    The noise characteristics of supercontinuum generation are characterized using higherorder statistical moments. Measures of skew and kurtosis, and the coefficient of variation allow quantitative identification of spectral regions dominated by rogue wave like behaviour....

  15. Describing supercontinuum noise and rogue wave statistics using higher-order moments

    DEFF Research Database (Denmark)

    Sørensen, Simon Toft; Bang, Ole; Wetzel, Benjamin

    2012-01-01

    We show that the noise properties of fiber supercontinuum generation and the appearance of long-tailed “rogue wave” statistics can be accurately quantified using statistical higher-order central moments. Statistical measures of skew and kurtosis, as well as the coefficient of variation provide im...

  16. Higher order moment description of supercontinuum noise and rogue wave statistics

    DEFF Research Database (Denmark)

    Sørensen, Simon Toft; Bang, Ole; Dudley, John M.

    We quantify the noise properties of supercontinuum (SC) generation in optical fibers using higher-order central moments. The higher-order moments quantify not only the mean and variance of a distribution, but also the asymmetry and the presence of long tails, and are thus particularly useful...... for identifying regions of long-tailed rogue wave like behaviour. By carrying out multiple numerical simulations in the presence of noise, we demonstrate that the statistical moments of Coefficient of Variation, Skew and Kurtosis provide the necessary rigorous measure of the SC histograms to yield a clear means...

  17. Statistical mechanics of reparametrization-invariant systems. It takes three to tango.

    Science.gov (United States)

    Chirco, Goffredo; Josset, Thibaut; Rovelli, Carlo

    2016-02-01

    It is notoriously difficult to apply statistical mechanics to generally covariant systems, because the notions of time, energy, and equilibrium are seriously modified in this context. We discuss the conditions under which weaker versions of these notions can be defined, sufficient for statistical mechanics. We focus on reparametrization-invariant systems without additional gauges. The key is to reconstruct statistical mechanics from the ergodic theorem. We find that a suitable split of the system into two non interacting components is sufficient for generalizing statistical mechanics. While equilibrium acquires sense only when the system admits a suitable split into three weakly interacting components—roughly: a clock and two systems among which a generalization of energy is equi-partitioned. This allows the application of statistical mechanics and thermodynamics as an additivity condition of such generalized energy.

  18. Analysis of the Statistical Moments of the Scintillation Light Distribution With dSiPMs

    Science.gov (United States)

    Conde, P.; González, A. J.; González, A.; Hernández, L.; Bellido, P.; Crespo, E.; Iborra, A.; Moliner, L.; Rigla, J. P.; Rodrìguez-Álvarez, M. J.; Sánchez, F.; Seimetz, M.; Soriano, A.; Vidal, L. F.; Benlloch, J. M.

    2015-10-01

    In γ-ray detectors, monolithic scintillation crystals offer the possibility of preserving the scintillation light distribution especially when painted black. The statistical moments of this distribution provide accurate information on the three photon impact coordinates, including their depth of interaction (DOI). Digital SiPMs (dSiPMs) return digital information based on pixels about the collected light distribution, since the signal is a digital sum of the trigger bins. In this work we present, for the first time, an accurate analysis of the statistical moments of the light distribution using monolithic painted black crystals and state-of-the-art dSiPMs. Two 32.6 ×32.6 mm2 monolithic LYSO crystals covering the entire photodetectors area have been used in coincidence with 10 mm in thickness. The photosensor tiles were kept at a stable temperature of T = 20 °C. Energy resolution of about 18% was reached in relation to the zeroth moment. The first moment, related to the impact position, determined a spatial resolution of about 3 mm near the crystal center, but quadratically degrading towards the crystal borders. The DOI resolution, measured by means of the second moment, was found to be nearing 4 mm in the crystal center region. The third order moment, the so-called skewness, is related to the degree of truncation and once calibrated minimizes the compression effects. A corrected spatial resolution of about 3 mm was then measured for the entire crystal surface. DOI resolution improved at the crystal's center, reaching 3.5 mm, but a degradation towards the borders remained due to truncation of the scintillation light distribution.

  19. Multi-fidelity stochastic collocation method for computation of statistical moments

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Xueyu, E-mail: xueyu-zhu@uiowa.edu [Department of Mathematics, University of Iowa, Iowa City, IA 52242 (United States); Linebarger, Erin M., E-mail: aerinline@sci.utah.edu [Department of Mathematics, University of Utah, Salt Lake City, UT 84112 (United States); Xiu, Dongbin, E-mail: xiu.16@osu.edu [Department of Mathematics, The Ohio State University, Columbus, OH 43210 (United States)

    2017-07-15

    We present an efficient numerical algorithm to approximate the statistical moments of stochastic problems, in the presence of models with different fidelities. The method extends the multi-fidelity approximation method developed in . By combining the efficiency of low-fidelity models and the accuracy of high-fidelity models, our method exhibits fast convergence with a limited number of high-fidelity simulations. We establish an error bound of the method and present several numerical examples to demonstrate the efficiency and applicability of the multi-fidelity algorithm.

  20. On the Densities of the Scale-Invariant Statistics of the Multiple and ...

    African Journals Online (AJOL)

    This work examines both the elliptically contoured Wishart density and the resulting density of the total correlation coefficient, and reaffirms the invariance property of the squared sampled multiple correlation coefficient. This invariance property is then exploited to show that the densities of the multiple correlation coefficients ...

  1. Assessment of drug disposition in the perfused rat brain by statistical moment analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sakane, T.; Nakatsu, M.; Yamamoto, A.; Hashida, M.; Sezaki, H.; Yamashita, S.; Nadai, T. (Faculty of Pharmaceutical Sciences, Setsunan University, Osaka (Japan))

    1991-06-01

    Drug disposition in the brain was investigated by statistical moment analysis using an improved in situ brain perfusion technique. The right cerebral hemisphere of the rat was perfused in situ. The drug and inulin were injected into the right internal carotid artery as a rapid bolus and the venous outflow curve at the posterior facial vein was obtained. The infusion rate was adjusted to minimize the flow of perfusion fluid into the left hemisphere. The obtained disposition parameters were characteristics and considered to reflect the physicochemical properties of each drug. Antipyrine showed a small degree of initial uptake. Therefore, its apparent distribution volume (Vi) and apparent intrinsic clearance (CLint,i) were small. Diazepam showed large degrees of both influx and efflux and, thus, a large Vi. Water showed parameters intermediate between those of antipyrine and those of diazepam. Imipramine, desipramine, and propranolol showed a large CLint,i compared with those of the other drugs. The extraction ratio of propranolol significantly decreased with increasing concentrations of unlabeled propranolol in the perfusion fluid. These findings may be explained partly by the tissue binding of these drugs. In conclusion, the present method is useful for studying drug disposition in the brain.

  2. Assessment of Seismic Vulnerability of Steel and RC Moment Buildings Using HAZUS and Statistical Methodologies

    Directory of Open Access Journals (Sweden)

    Iman Mansouri

    2017-01-01

    Full Text Available Designer engineers have always the serious challenge regarding the choice of the kind of structures to use in the areas with significant seismic activities. Development of fragility curve provides an opportunity for designers to select a structure that will have the least fragility. This paper presents an investigation into the seismic vulnerability of both steel and reinforced concrete (RC moment frames using fragility curves obtained by HAZUS and statistical methodologies. Fragility curves are employed for several probability parameters. Fragility curves are used to assess several probability parameters. Furthermore, it examines whether the probability of the exceedence of the damage limit state is reduced as expected. Nonlinear dynamic analyses of five-, eight-, and twelve-story frames are carried out using Perform 3D. The definition of damage states is based on the descriptions provided by HAZUS, which gives the limit states and the associated interstory drift limits for structures. The fragility curves show that the HAZUS procedure reduces probability of damage, and this reduction is higher for RC frames. Generally, the RC frames have higher fragility compared to steel frames.

  3. High Energy Laser Beam Propagation in the Atmosphere: The Integral Invariants of the Nonlinear Parabolic Equation and the Method of Moments

    Science.gov (United States)

    Manning, Robert M.

    2012-01-01

    The method of moments is used to define and derive expressions for laser beam deflection and beam radius broadening for high-energy propagation through the Earth s atmosphere. These expressions are augmented with the integral invariants of the corresponding nonlinear parabolic equation that describes the electric field of high-energy laser beam to propagation to yield universal equations for the aforementioned quantities; the beam deflection is a linear function of the propagation distance whereas the beam broadening is a quadratic function of distance. The coefficients of these expressions are then derived from a thin screen approximation solution of the nonlinear parabolic equation to give corresponding analytical expressions for a target located outside the Earth s atmospheric layer. These equations, which are graphically presented for a host of propagation scenarios, as well as the thin screen model, are easily amenable to the phase expansions of the wave front for the specification and design of adaptive optics algorithms to correct for the inherent phase aberrations. This work finds application in, for example, the analysis of beamed energy propulsion for space-based vehicles.

  4. Classical and Quantum Models in Non-Equilibrium Statistical Mechanics: Moment Methods and Long-Time Approximations

    Directory of Open Access Journals (Sweden)

    Ramon F. Alvarez-Estrada

    2012-02-01

    Full Text Available We consider non-equilibrium open statistical systems, subject to potentials and to external “heat baths” (hb at thermal equilibrium at temperature T (either with ab initio dissipation or without it. Boltzmann’s classical equilibrium distributions generate, as Gaussian weight functions in momenta, orthogonal polynomials in momenta (the position-independent Hermite polynomialsHn’s. The moments of non-equilibrium classical distributions, implied by the Hn’s, fulfill a hierarchy: for long times, the lowest moment dominates the evolution towards thermal equilibrium, either with dissipation or without it (but under certain approximation. We revisit that hierarchy, whose solution depends on operator continued fractions. We review our generalization of that moment method to classical closed many-particle interacting systems with neither a hb nor ab initio dissipation: with initial states describing thermal equilibrium at T at large distances but non-equilibrium at finite distances, the moment method yields, approximately, irreversible thermalization of the whole system at T, for long times. Generalizations to non-equilibrium quantum interacting systems meet additional difficulties. Three of them are: (i equilibrium distributions (represented through Wigner functions are neither Gaussian in momenta nor known in closed form; (ii they may depend on dissipation; and (iii the orthogonal polynomials in momenta generated by them depend also on positions. We generalize the moment method, dealing with (i, (ii and (iii, to some non-equilibrium one-particle quantum interacting systems. Open problems are discussed briefly.

  5. Statistical thermodynamics and magnetic moments of Landau quantized group VI dichalcogenides

    Science.gov (United States)

    Horing, Norman J. M.

    2018-02-01

    This work is focused on the determination of the Helmholtz free energy and the magnetic moments of the ‘Dirac-like’ group VI dichalcogenides subject to Landau quantization. We employ a technique described by Wilson to relate the free energy to the Green’s function for the dichalcogenides in a high magnetic field, which was recently evaluated explicitly in terms of elementary functions. In the course of this analysis, the partition function is determined as a function of the magnetic field as well. The results exhibit the role of the quantizing magnetic field in the Helmholtz free energy at arbitrary temperature, and they are also employed to obtain the magnetic moments of the dichalcogenides. Explicit analytic formulas characteristic of de Haas–van Alphen oscillatory phenomenology are presented in the degenerate limit, and nondegenerate Landau quantization effects are also presented for the dichalcogenide magnetic moments.

  6. De-trending of wind speed variance based on first-order and second-order statistical moments only

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.; Hansen, Kurt Schaldemose

    2014-01-01

    of arbitrary types of time series. The second model uses the full set of information and includes thus additionally observed wind speed standard deviations to estimate the effect of ensemble mean non-stationarities on wind speed standard deviations. This model takes advantage of a simple physical relationship...... that the model constraint, introduced by the physical link between the first and second statistical moments, proves very efficient in the present context. Copyright © 2013 John Wiley & Sons, Ltd....

  7. Open statistical ensemble: new properties (scale invariance, application to small systems, meaning of surface particles, etc.)

    OpenAIRE

    Zaskulnikov, V. M.

    2010-01-01

    A new statistical ensemble is examined using the example of classical one-component simple fluid. It's logical to call it an open ensemble, because its peculiarity is the inclusion in the consideration some surrounding area. Calculations point to the necessity of taking into account the restricting surface, exactly when the system is not separated by anything from the bath, and the whole medium is uniform. The "surface tension coefficient", included in the partition function corresponds to th...

  8. Statistical properties of a filtered Poisson process with additive random noise: Distributions, correlations and moment estimation

    CERN Document Server

    Theodorsen, Audun; Rypdal, Martin

    2016-01-01

    The filtered Poisson process is often used as a reference model for intermittent fluctuations in physical systems. Here, this process is extended by adding a noise term, either as a purely additive term to the process or as a dynamical term in a stochastic differential equation. The moments, probability density function, auto- correlation function and power spectral density are derived and used to compare the effects of the different noise terms. Monte-Carlo studies of synthetic time series are used to investigate the accuracy of parameter estimation and to identify methods for separating the noise types. It is shown that the probability density function and the three lowest moments provide accurate estimations of the parameters, but are unable to separate the noise types. The auto-correlation function and the power spectral density also provide methods for estimating the model parameters, as well as being capable of determining the noise type. The number of times the signal passes a prescribed threshold in t...

  9. Recurrence Relations for Moments of Order Statistics from the Lindley Distribution with General Multiply Type-II Censored Sample

    Directory of Open Access Journals (Sweden)

    Bander Al-Zahrani

    2014-05-01

    Full Text Available In this paper, we derive the recurrence relations for the moments of function of single and two order statistics from Lindley distribution. We also consider the maximum likelihood estimation (MLE of the parameter of the distribution based on multiply type-II censoring. However maximum likelihood estimator does not have an explicit form for the involved parameter. In order to compute the MLE of the parameter, Monte Carlo simulation is used. A comparative study is presented between classical MLE and MLE from multiply type-II censored sample.

  10. Moment evolution and level-crossing statistics in dichotomous and multilevel flows with time-dependent control parameters

    Science.gov (United States)

    Nicolis, G.; Balakrishnan, V.; Nicolis, C.

    2002-05-01

    We study the dynamics of the first two moments and of threshold crossings by the stochastic trajectory in dichotomous diffusion =ξ(t), where ξ(t) is a dichotomous Markov process. The transition rate of the latter is regarded as a control parameter and allowed to have specified time variations. The stabilizing or destabilizing effect of this variation is demonstrated, and qualitative changes in the statistical properties of the system are shown to occur. The analysis is then extended to linear dichotomous flow, and to a generalization of dichotomous diffusion in which x is driven by a multilevel Markov noise.

  11. [Establishment of the mathematic model of total quantum statistical moment standard similarity for application to medical theoretical research].

    Science.gov (United States)

    He, Fu-yuan; Deng, Kai-wen; Huang, Sheng; Liu, Wen-long; Shi, Ji-lian

    2013-09-01

    The paper aims to elucidate and establish a new mathematic model: the total quantum statistical moment standard similarity (TQSMSS) on the base of the original total quantum statistical moment model and to illustrate the application of the model to medical theoretical research. The model was established combined with the statistical moment principle and the normal distribution probability density function properties, then validated and illustrated by the pharmacokinetics of three ingredients in Buyanghuanwu decoction and of three data analytical method for them, and by analysis of chromatographic fingerprint for various extracts with different solubility parameter solvents dissolving the Buyanghanwu-decoction extract. The established model consists of four mainly parameters: (1) total quantum statistical moment similarity as ST, an overlapped area by two normal distribution probability density curves in conversion of the two TQSM parameters; (2) total variability as DT, a confidence limit of standard normal accumulation probability which is equal to the absolute difference value between the two normal accumulation probabilities within integration of their curve nodical; (3) total variable probability as 1-Ss, standard normal distribution probability within interval of D(T); (4) total variable probability (1-beta)alpha and (5) stable confident probability beta(1-alpha): the correct probability to make positive and negative conclusions under confident coefficient alpha. With the model, we had analyzed the TQSMS similarities of pharmacokinetics of three ingredients in Buyanghuanwu decoction and of three data analytical methods for them were at range of 0.3852-0.9875 that illuminated different pharmacokinetic behaviors of each other; and the TQSMS similarities (ST) of chromatographic fingerprint for various extracts with different solubility parameter solvents dissolving Buyanghuanwu-decoction-extract were at range of 0.6842-0.999 2 that showed different constituents

  12. Parametric Study of Urban-Like Topographic Statistical Moments Relevant to a Priori Modelling of Bulk Aerodynamic Parameters

    Science.gov (United States)

    Zhu, Xiaowei; Iungo, G. Valerio; Leonardi, Stefano; Anderson, William

    2017-02-01

    For a horizontally homogeneous, neutrally stratified atmospheric boundary layer (ABL), aerodynamic roughness length, z_0, is the effective elevation at which the streamwise component of mean velocity is zero. A priori prediction of z_0 based on topographic attributes remains an open line of inquiry in planetary boundary-layer research. Urban topographies - the topic of this study - exhibit spatial heterogeneities associated with variability of building height, width, and proximity with adjacent buildings; such variability renders a priori, prognostic z_0 models appealing. Here, large-eddy simulation (LES) has been used in an extensive parametric study to characterize the ABL response (and z_0) to a range of synthetic, urban-like topographies wherein statistical moments of the topography have been systematically varied. Using LES results, we determined the hierarchical influence of topographic moments relevant to setting z_0. We demonstrate that standard deviation and skewness are important, while kurtosis is negligible. This finding is reconciled with a model recently proposed by Flack and Schultz (J Fluids Eng 132:041203-1-041203-10, 2010), who demonstrate that z_0 can be modelled with standard deviation and skewness, and two empirical coefficients (one for each moment). We find that the empirical coefficient related to skewness is not constant, but exhibits a dependence on standard deviation over certain ranges. For idealized, quasi-uniform cubic topographies and for complex, fully random urban-like topographies, we demonstrate strong performance of the generalized Flack and Schultz model against contemporary roughness correlations.

  13. Peak hip and knee joint moments during a sit-to-stand movement are invariant to the change of seat height within the range of low to normal seat height.

    Science.gov (United States)

    Yoshioka, Shinsuke; Nagano, Akinori; Hay, Dean C; Fukashiro, Senshi

    2014-03-12

    Previous studies have consistently reported that decreasing seat height increases the peak hip and knee joint moments; however, these findings may not apply to biomechanical changes at very low seat heights. The purpose of this study, therefore, was to examine the effect of a large range of seat heights on peak joint moments of the lower limb during a sit-to-stand (STS) movement. Eight healthy young subjects participated in this experiment. Each subject was instructed to stand up from six seat heights (10, 20, 30, 40, 50 and 60 cm). Joint moments were calculated with an inverse dynamics method. The sum of the hip and knee joint moments was used as the index to indicate the mechanical load of the STS movement. The effect of seat height on the mechanical load was examined with both analytical and experimental approaches. Through the analytical approach, it was revealed that the mechanical load of STS movements from low and normal seat heights (10 to 40 cm) always reaches its peak at or near the posture in which the thigh is horizontally positioned. This finding indicates that the peak value is invariant between the low and normal seat heights. Similar results were also found in the experimental approach. There were few significant differences in the peak mechanical load and the peak hip and knee joint moments between the low and normal seat heights, while they differed significantly between the low and high seat heights. This study concluded that, while the peak mechanical load and the peak hip and knee joint moments increase inversely to seat height within the range of high to normal seat height (60 to 40 cm), they are invariant to the change of seat height within the range of low to normal seat height (10 to 40 cm). These findings are useful for the design of chair, the improvement in the evaluation standard of minimum sit-to-stand height tests and the development of new muscular strength test.

  14. Upside/Downside statistical mechanics of nonequilibrium Brownian motion. I. Distributions, moments, and correlation functions of a free particle

    Science.gov (United States)

    Craven, Galen T.; Nitzan, Abraham

    2018-01-01

    Statistical properties of Brownian motion that arise by analyzing, separately, trajectories over which the system energy increases (upside) or decreases (downside) with respect to a threshold energy level are derived. This selective analysis is applied to examine transport properties of a nonequilibrium Brownian process that is coupled to multiple thermal sources characterized by different temperatures. Distributions, moments, and correlation functions of a free particle that occur during upside and downside events are investigated for energy activation and energy relaxation processes and also for positive and negative energy fluctuations from the average energy. The presented results are sufficiently general and can be applied without modification to the standard Brownian motion. This article focuses on the mathematical basis of this selective analysis. In subsequent articles in this series, we apply this general formalism to processes in which heat transfer between thermal reservoirs is mediated by activated rate processes that take place in a system bridging them.

  15. Detecting changes in ultrasound backscattered statistics by using Nakagami parameters: Comparisons of moment-based and maximum likelihood estimators.

    Science.gov (United States)

    Lin, Jen-Jen; Cheng, Jung-Yu; Huang, Li-Fei; Lin, Ying-Hsiu; Wan, Yung-Liang; Tsui, Po-Hsiang

    2017-05-01

    The Nakagami distribution is an approximation useful to the statistics of ultrasound backscattered signals for tissue characterization. Various estimators may affect the Nakagami parameter in the detection of changes in backscattered statistics. In particular, the moment-based estimator (MBE) and maximum likelihood estimator (MLE) are two primary methods used to estimate the Nakagami parameters of ultrasound signals. This study explored the effects of the MBE and different MLE approximations on Nakagami parameter estimations. Ultrasound backscattered signals of different scatterer number densities were generated using a simulation model, and phantom experiments and measurements of human liver tissues were also conducted to acquire real backscattered echoes. Envelope signals were employed to estimate the Nakagami parameters by using the MBE, first- and second-order approximations of MLE (MLE1 and MLE2, respectively), and Greenwood approximation (MLEgw) for comparisons. The simulation results demonstrated that, compared with the MBE and MLE1, the MLE2 and MLEgw enabled more stable parameter estimations with small sample sizes. Notably, the required data length of the envelope signal was 3.6 times the pulse length. The phantom and tissue measurement results also showed that the Nakagami parameters estimated using the MLE2 and MLEgw could simultaneously differentiate various scatterer concentrations with lower standard deviations and reliably reflect physical meanings associated with the backscattered statistics. Therefore, the MLE2 and MLEgw are suggested as estimators for the development of Nakagami-based methodologies for ultrasound tissue characterization. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Diagnostic Statistical Manual 5 Changes to the Autism Diagnostic Criteria: A Critical Moment for Occupational Therapists

    Directory of Open Access Journals (Sweden)

    Rondalyn Varney Whitney Ph.D., OT/L

    2012-11-01

    Full Text Available Changes in the soon to be released Diagnostic Statistical Manual (DSM – 5 (American Psychiatric Association, 2012 bring new opportunities for occupational therapy, but the profession must prepare for the impact these changes forecast. While well positioned to capitalize on newly defined specifications of Autism Spectrum Disorders (ASD and the elevation of sensory processing difficulties to a core feature of the disorder, the profession must be alert to the potential downside of the pending changes. The more stringentdiagnostic rubric will likely exclude a significant number of individuals currently eligible for therapeutic and academic services. Autism will be defined as a neurodevelopmental disorder that must be identifiable before early childhood (age 5, even if it is not detected until later as a result of environmental factors (minimal social demands, support from caretakers, etc.. The new diagnostic criteria will add the explicit recognition of sensory behaviors within a subdomain of stereotyped motor, verbal, and sensory-based behaviors and researchers suggest only 60% of those who currently meet the threshold for an autism spectrum diagnosis will continue to meet criteria under the new categorization. The proposed changes will likely encourage researchers to use greater specificity when recruiting sample populations and, as a result, help to determine interventions that are most advantageous for specific subtypes. Addressing sensory processing in thediagnostic criteria may authorize interventions aimed specifically towards reduction of sensory-related disabilities through remediation, environmental support, or parent education while simultaneously calling upon us to deliver evidence for Ayres’ sensory integration® (ASI approaches. The change also presents anurgent call to our profession to promote the unique scientific contributions occupational therapy makes for individuals with ASD, their families, and their educational contexts

  17. Face recognition using Krawtchouk moment

    Indian Academy of Sciences (India)

    Feature extraction is one of the important tasks in face recognition. Moments are widely used feature extractor due to their superior discriminatory power and geometrical invariance. Moments generally capture the global features of the image. This paper proposes Krawtchouk moment for feature extraction in face recognition ...

  18. Face recognition using Krawtchouk moment

    Indian Academy of Sciences (India)

    Abstract. Feature extraction is one of the important tasks in face recognition. Moments are widely used feature extractor due to their superior discriminatory power and geometrical invariance. Moments generally capture the global features of the image. This paper proposes Krawtchouk moment for feature extraction in face ...

  19. A Study of Moment Based Features on Handwritten Digit Recognition

    Directory of Open Access Journals (Sweden)

    Pawan Kumar Singh

    2016-01-01

    Full Text Available Handwritten digit recognition plays a significant role in many user authentication applications in the modern world. As the handwritten digits are not of the same size, thickness, style, and orientation, therefore, these challenges are to be faced to resolve this problem. A lot of work has been done for various non-Indic scripts particularly, in case of Roman, but, in case of Indic scripts, the research is limited. This paper presents a script invariant handwritten digit recognition system for identifying digits written in five popular scripts of Indian subcontinent, namely, Indo-Arabic, Bangla, Devanagari, Roman, and Telugu. A 130-element feature set which is basically a combination of six different types of moments, namely, geometric moment, moment invariant, affine moment invariant, Legendre moment, Zernike moment, and complex moment, has been estimated for each digit sample. Finally, the technique is evaluated on CMATER and MNIST databases using multiple classifiers and, after performing statistical significance tests, it is observed that Multilayer Perceptron (MLP classifier outperforms the others. Satisfactory recognition accuracies are attained for all the five mentioned scripts.

  20. Image Recognition Using Modified Zernike Moments

    Directory of Open Access Journals (Sweden)

    Min HUANG

    2014-03-01

    Full Text Available Zernike moments are complex moments with the orthogonal Zernike polynomials as kernel function, compared with other moments; Zernike moments have greater advantages in image rotation and low noise sensitivity. Because of the Zernike moments have image rotation invariance, and can construct arbitrary high order moments, it can be used for target recognition. In this paper, the Zernike moment algorithm is improved, which makes it having scale invariance in the processing of digital image. At last, an application of the improved Zernike moments in image recognition is given.

  1. Braiding statistics and link invariants of bosonic/fermionic topological quantum matter in 2+1 and 3+1 dimensions

    Science.gov (United States)

    Putrov, Pavel; Wang, Juven; Yau, Shing-Tung

    2017-09-01

    Topological Quantum Field Theories (TQFTs) pertinent to some emergent low energy phenomena of condensed matter lattice models in 2+1 and 3+1 dimensions are explored. Many of our TQFTs are highly-interacting without free quadratic analogs. Some of our bosonic TQFTs can be regarded as the continuum field theory formulation of Dijkgraaf-Witten twisted discrete gauge theories. Other bosonic TQFTs beyond the Dijkgraaf-Witten description and all fermionic TQFTs (namely the spin TQFTs) are either higher-form gauge theories where particles must have strings attached, or fermionic discrete gauge theories obtained by gauging the fermionic Symmetry-Protected Topological states (SPTs). We analytically calculate both the Abelian and non-Abelian braiding statistics data of anyonic particle and string excitations in these theories, where the statistics data can one-to-one characterize the underlying topological orders of TQFTs. Namely, we derive path integral expectation values of links formed by line and surface operators in these TQFTs. The acquired link invariants include not only the familiar Aharonov-Bohm linking number, but also Milnor triple linking number in 3 dimensions, triple and quadruple linking numbers of surfaces, and intersection number of surfaces in 4 dimensions. We also construct new spin TQFTs with the corresponding knot/link invariants of Arf(-Brown-Kervaire), Sato-Levine and others. We propose a new relation between the fermionic SPT partition function and the Rokhlin invariant. As an example, we can use these invariants and other physical observables, including ground state degeneracy, reduced modular Sxy and Txy matrices, and the partition function on RP3 manifold, to identify all ν ∈Z8 classes of 2+1 dimensional gauged Z2-Ising-symmetric Z2f -fermionic Topological Superconductors (realized by stacking ν layers of a pair of chiral and anti-chiral p-wave superconductors [ p + ip and p - ip], where boundary supports non-chiral Majorana-Weyl modes) with

  2. Invariant subspaces

    CERN Document Server

    Radjavi, Heydar

    2003-01-01

    This broad survey spans a wealth of studies on invariant subspaces, focusing on operators on separable Hilbert space. Largely self-contained, it requires only a working knowledge of measure theory, complex analysis, and elementary functional analysis. Subjects include normal operators, analytic functions of operators, shift operators, examples of invariant subspace lattices, compact operators, and the existence of invariant and hyperinvariant subspaces. Additional chapters cover certain results on von Neumann algebras, transitive operator algebras, algebras associated with invariant subspaces,

  3. Statistical analysis of annual maximum rainfall in North-East India: an application of LH-moments

    Science.gov (United States)

    Deka, Surobhi; Borah, Munindra; Kakaty, Sarat Chandra

    2011-05-01

    An attempt has been made to determine the best fitting distribution to describe the annual series of maximum daily rainfall data for the period 1966 to 2007 of nine distantly located stations in North East India. The LH-moments of order zero (L) to order four (L4) are used to estimate the parameters of three extreme value distributions viz. generalized extreme value distribution (GEV), generalized logistic distribution (GLD), and generalized Pareto distribution (GPD). The performances of the distributions are assessed by evaluating the relative bias (RBIAS) and relative root mean square error (RRMSE) of quantile estimates through Monte Carlo simulations. Then, the boxplot is used to show the location of the median and the associated dispersion of the data. Finally, it can be revealed from the results of boxplots that zero level of LH-moments of the generalized Pareto distribution would be appropriate to the majority of the stations for describing the annual maximum rainfall series in North East India.

  4. Real object recognition using moment invariants

    Indian Academy of Sciences (India)

    In this study, a computer vision system recognizing objects in captured images is estab- lished. The considering sensor can ... objects; a vision system insensitive to these changes is investigated. The organization of the ..... Ustun A 1999 Application of artificial neural networks to object recognition. MSc thesis, ITU Science.

  5. Real object recognition using moment invariants

    Indian Academy of Sciences (India)

    Author Affiliations. Muharrem Mercimek1 Kayhan Gulez1 Tarik Veli Mumcu1. Yildiz Technical University, Electrical-Electronics Faculty, Electrical Engineering Department, 34349 Besiktas-Istanbul, Turkey ...

  6. Chronometric Invariants

    CERN Document Server

    Zelmanov, Abraham

    2004-01-01

    This book introduces the mathematical apparatus of chronometric invariants (physical observable quantities) in the General Theory of Relativity, and also numerous results the mathematical apparatus found in relativistic cosmology (236 pages, 1 foto).

  7. Image Description using Radial Associated Laguerre Moments

    Directory of Open Access Journals (Sweden)

    Bojun Pan

    2015-08-01

    Full Text Available This study proposes a new set of moment functions for describing gray-level and color images based on the associated Laguerre polynomials, which are orthogonal over the whole right-half plane. Moreover, the mathematical frameworks of radial associated Laguerre moments (RALMs and associated rotation invariants are introduced. The proposed radial Laguerre invariants retain the basic form of disc-based moments, such as Zernike moments (ZMs, pseudo-Zernike moments (PZMs, Fourier-Mellin moments (OFMMs, and so on. Therefore, the rotation invariants of RALMs can be easily obtained. In addition, the study extends the proposed moments and invariants defined in a gray-level image to a color image using the algebra of quaternion to avoid losing some significant color information. Finally, the paper verifies the feature description capacities of the proposed moment function in terms of image reconstruction and invariant pattern recognition accuracy. Experimental results confirmed that the associated Laguerre moments (ALMs perform better than orthogonal OFMMs in both noise-free and noisy conditions.

  8. Invariant vacuum

    Science.gov (United States)

    Robles-Pérez, Salvador

    2017-11-01

    We apply the Lewis-Riesenfeld invariant method for the harmonic oscillator with time dependent mass and frequency to the modes of a charged scalar field that propagates in a curved, homogeneous and isotropic spacetime. We recover the Bunch-Davies vacuum in the case of a flat DeSitter spacetime, the equivalent one in the case of a closed DeSitter spacetime and the invariant vacuum in a curved spacetime that evolves adiabatically. In the three cases, it is computed the thermodynamical magnitudes of entanglement between the modes of the particles and antiparticles of the invariant vacuum, and the modification of the Friedmann equation caused by the existence of the energy density of entanglement. The amplitude of the vacuum fluctuations are also computed.

  9. Informatics Moments

    Science.gov (United States)

    Williams, Kate

    2012-01-01

    The informatics moment is the moment when a person seeks help in using some digital technology that is new to him or her. This article examines the informatics moment in people's everyday lives as they sought help at a branch public library. Four types of literacy were involved: basic literacy (reading and writing), computer literacy (use of a…

  10. Higher-order statistical moments and a procedure that detects potentially anomalous years as two alternative methods describing alterations in continuous environmental data

    Science.gov (United States)

    Arismendi, Ivan; Johnson, Sherri L.; Dunham, Jason

    2015-01-01

    Statistics of central tendency and dispersion may not capture relevant or desired characteristics of the distribution of continuous phenomena and, thus, they may not adequately describe temporal patterns of change. Here, we present two methodological approaches that can help to identify temporal changes in environmental regimes. First, we use higher-order statistical moments (skewness and kurtosis) to examine potential changes of empirical distributions at decadal extents. Second, we adapt a statistical procedure combining a non-metric multidimensional scaling technique and higher density region plots to detect potentially anomalous years. We illustrate the use of these approaches by examining long-term stream temperature data from minimally and highly human-influenced streams. In particular, we contrast predictions about thermal regime responses to changing climates and human-related water uses. Using these methods, we effectively diagnose years with unusual thermal variability and patterns in variability through time, as well as spatial variability linked to regional and local factors that influence stream temperature. Our findings highlight the complexity of responses of thermal regimes of streams and reveal their differential vulnerability to climate warming and human-related water uses. The two approaches presented here can be applied with a variety of other continuous phenomena to address historical changes, extreme events, and their associated ecological responses.

  11. Private Moments

    OpenAIRE

    Paul R. Reed; Carol J. Cumber

    2000-01-01

    In October, 1996 Private Moments, an adult novelty store, opened for business in Huntsville, Texas. Huntsville had no ordinances in place to prevent the opening of this type of business. In fact, the local Small Business Development Center provided guidance and assistance to Edward Delagarza, the founder and owner of Private Moments. Many of the Huntsville citizens, unhappy with the opening of Private Moments, approached the City Council requesting that it be closed immediately and asked for ...

  12. Hammersley’s harness process: Invariant distributions and height fluctuations

    OpenAIRE

    Seppäläinen, Timo; Zhai, Yun

    2017-01-01

    We study the invariant distributions of Hammersley’s serial harness process in all dimensions and height fluctuations in one dimension. Subject to mild moment assumptions there is essentially one unique invariant distribution, and all other invariant distributions are obtained by adding harmonic functions of the averaging kernel. We identify one Gaussian case where the invariant distribution is i.i.d. Height fluctuations in one dimension obey the stochastic heat equation with additive noise (...

  13. Retrieval of the raindrop size distribution from polarimetric radar data using double-moment normalisation

    Directory of Open Access Journals (Sweden)

    T. H. Raupach

    2017-07-01

    Full Text Available A new technique for estimating the raindrop size distribution (DSD from polarimetric radar data is proposed. Two statistical moments of the DSD are estimated from polarimetric variables, and the DSD is reconstructed using a double-moment normalisation. The technique takes advantage of the relative invariance of the double-moment normalised DSD. The method was tested using X-band radar data and networks of disdrometers in three different climatic regions. Radar-derived estimates of the DSD compare reasonably well to observations. In the three tested domains, in terms of DSD moments, rain rate, and characteristic drop diameter, the proposed method performs similarly to and often better than a state-of-the-art DSD-retrieval technique. The approach is flexible because no specific DSD model is prescribed. In addition, a method is proposed to treat noisy radar data to improve DSD-retrieval performance with radar measurements.

  14. Statistics

    CERN Document Server

    Hayslett, H T

    1991-01-01

    Statistics covers the basic principles of Statistics. The book starts by tackling the importance and the two kinds of statistics; the presentation of sample data; the definition, illustration and explanation of several measures of location; and the measures of variation. The text then discusses elementary probability, the normal distribution and the normal approximation to the binomial. Testing of statistical hypotheses and tests of hypotheses about the theoretical proportion of successes in a binomial population and about the theoretical mean of a normal population are explained. The text the

  15. Gauge-invariant two- and three- density correlators

    CERN Document Server

    Alexandrou, C; Tsapalis, A; Forcrand, Ph. de

    2003-01-01

    Gauge-invariant spatial correlations between two and three quarks inside a hadron are measured within quenched and unquenched QCD. These correlators provide information on the shape and multipole moments of the pion, the rho, the nucleon and the $\\Delta$.

  16. Temperature moments vs poison moments

    Energy Technology Data Exchange (ETDEWEB)

    Staebler, U.M.

    1947-05-19

    The excess reactivity available in an operating pile is absorbed in poison columns and horizontal rods. The temperature distribution of the pile is determined by the relative strengths and locations of the poison columns and the configuration of control rods used. A method for adjusting poison columns and rods to improve upon the pile`s temperature distribution is given in Document {number_sign}7-2654, ``Procedure for Improving Temperature Distribution via Rods and Columns,`` Wheeler and Menegus to Jordan, September 9, 1945. A relationship between poison moment (inhour lattice units) and temperature moments (per coat) was theoretically derived in the above document and has since been measured on several occasions on the basis of operating experience. A survey of recent operating data for the F Pile has been made by H. A. Gauper, Jr. with the intent of improving the method for obtaining the temperature and poison moments and relating changes in the two. This study was concerned with only the horizontal and vertical dipole moments. The results of Mr. Gauper`s investigation are summarized in this memorandum.

  17. Statistics

    Science.gov (United States)

    Links to sources of cancer-related statistics, including the Surveillance, Epidemiology and End Results (SEER) Program, SEER-Medicare datasets, cancer survivor prevalence data, and the Cancer Trends Progress Report.

  18. Collaborative Moments

    DEFF Research Database (Denmark)

    Hastrup, Kirsten Blinkenberg

    2017-01-01

    as an experiment in real time, where insights gained intersubjectively gradually shape up as knowledge through analysis. This line of thought is brought to bear on a discussion of collaboration between anthropologists, archaeologists, and biologists in North West Greenland. Through actual experiences from...... the field, this article shows how knowledge generated on the edge of one’s familiar disciplinary territory may both expand and intensify the anthropological field. Collaborative moments are seen to make new anthropological insights emerge through the co-presence of several analytical perspectives...

  19. Invariant Characteristics of Carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Simon Sherman

    Full Text Available Carcinogenic modeling is aimed at mathematical descriptions of cancer development in aging. In this work, we assumed that a small fraction of individuals in the population is susceptible to cancer, while the rest of the population is resistant to cancer. For individuals susceptible to cancer we adopted methods of conditional survival analyses. We performed computational experiments using data on pancreatic, stomach, gallbladder, colon and rectum, liver, and esophagus cancers from the gastrointestinal system collected for men and women in the SEER registries during 1975-2009. In these experiments, we estimated the time period effects, the birth cohort effects, the age effects and the population (unconditional cancer hazard rates. We also estimated the individual cancer presentation rates and the individual cancer resistance rates, which are, correspondingly, the hazard and survival rates conditioned on the susceptibility to cancer. The performed experiments showed that for men and women, patterns of the age effects, the individual cancer presentation rates and the individual cancer resistance rates are: (i intrinsic for each cancer subtype, (ii invariant to the place of living of the individuals diagnosed with cancer, and (iii well adjusted for the modifiable variables averaged at a given time period. Such specificity and invariability of the age effects, the individual cancer presentation rates and the individual cancer resistance rates suggest that these carcinogenic characteristics can be useful for predictive carcinogenic studies by methods of inferential statistics and for the development of novel strategies for cancer prevention.

  20. A filter bank for rotationally invariant image recognition

    African Journals Online (AJOL)

    2005-07-18

    Jul 18, 2005 ... Hu moments, noticed in [22], clearly indicates a need for further research. Shortly after. Hu's paper, a variety of invariant moments were proposed and analyzed [3, 4, 9, 10, 11,. 14, 18, 19, 20, 21, 22, 25 ..... [6] Han J & Kamber M, 2001, Data mining concepts and techniques, Morgan Kauf- mann Pub, London.

  1. Statistical analysis of high order moments is a turbulent boundary layer with strong density differences; Analyse statistique des moments d'ordre eleve dans une couche limite turbulente en presence de differences de densite importantes

    Energy Technology Data Exchange (ETDEWEB)

    Soudani, A. [Batna Univ., Dept. de Physique, Faculte des Sciences (Algeria); Bessaih, R. [Mentouri-Constantine Univ., Dept. de Genie Mecanique, Faculte des Sciences de l' Ingenieur (Algeria)

    2004-12-01

    The study of turbulent boundary layer with strong differences of density is important for the understanding of practical situations occurring for example in the cooling of turbine blades through the tangential injection of a different gas or in combustion. In order to study the fine structure of wall turbulence in the presence of significant variations of density, a statistical analysis of the experimental data, obtained in a wind tunnel, is carried out. The results show that the relaxation of the skewness factor of u'(S{sub u'}) is carried out more quickly in the external layer than close to the wall, as well for the air injection as for the helium injection. S{sub u'} grows close to the injection slot in an appreciable way and this increase is accentuated for the air injection than for the helium injection. This growth of the skewness factor close to the injection slot can be explained by the increase in the longitudinal convective flux of turbulent energy in this zone. The results show for the distribution of the flatness factor F{sub u'} that there is no significant effect of the density gradient on the intermittent structure of the instantaneous longitudinal velocity in the developed zone, x/{delta} {>=} 5. The statistical analysis carried out in this study shows that the helium injection in the boundary layer generates more violent ejections than in the case of air injection. This result is confirmed by the significant contribution of the ejections to turbulent mass flux.

  2. Technical Note: Higher-order statistical moments and a procedure that detects potentially anomalous years as two alternative methods describing alterations in continuous environmental data

    Science.gov (United States)

    I. Arismendi; S. L. Johnson; J. B. Dunham

    2015-01-01

    Statistics of central tendency and dispersion may not capture relevant or desired characteristics of the distribution of continuous phenomena and, thus, they may not adequately describe temporal patterns of change. Here, we present two methodological approaches that can help to identify temporal changes in environmental regimes. First, we use higher-order statistical...

  3. Computational invariant theory

    CERN Document Server

    Derksen, Harm

    2015-01-01

    This book is about the computational aspects of invariant theory. Of central interest is the question how the invariant ring of a given group action can be calculated. Algorithms for this purpose form the main pillars around which the book is built. There are two introductory chapters, one on Gröbner basis methods and one on the basic concepts of invariant theory, which prepare the ground for the algorithms. Then algorithms for computing invariants of finite and reductive groups are discussed. Particular emphasis lies on interrelations between structural properties of invariant rings and computational methods. Finally, the book contains a chapter on applications of invariant theory, covering fields as disparate as graph theory, coding theory, dynamical systems, and computer vision. The book is intended for postgraduate students as well as researchers in geometry, computer algebra, and, of course, invariant theory. The text is enriched with numerous explicit examples which illustrate the theory and should be ...

  4. A Many Particle Adiabatic Invariant

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    1999-01-01

    For a system of N charged particles moving in a homogeneous, sufficiently strong magnetic field, a many-particle adiabatic invariant constrains the collisional exchange of energy between the degrees of freedom perpendicular to and parallel to the magnetic field. A description of the phenomenon in...... in terms of Hamiltonian dynamics is given. The relation to the Equipartition Theorem of statistical Mechanics is briefly discussed....

  5. Apple Shape Classification Method Based on Wavelet Moment

    Directory of Open Access Journals (Sweden)

    Jiangsheng Gui

    2014-09-01

    Full Text Available Shape is not only an important indicator for assessing the grade of the apple, but also the important factors for increasing the value of the apple. In order to improve the apple shape classification accuracy rate, an approach for apple shape sorting based on wavelet moments was proposed, the image was first subjected to a normalization process using its regular moments to obtain scale and translation invariance, the rotation invariant wavelet moment features were then extracted from the scale and translation normalized images and the method of cluster analysis was used for finished the shape classification. This method performs better than traditional approaches such as Fourier descriptors and Zernike moments, because of that Wavelet moments can provide time-domain and frequency domain window, which was verified by experiments. The normal fruit shape, mild deformity and severe deformity classification accuracy is 86.21 %, 85.82 %, 90.81 % by our method.

  6. Comparing invariants of SK1

    OpenAIRE

    Wouters, Tim

    2010-01-01

    In this text, we compare several invariants of the reduced Whitehead group SK1 of a central simple algebra. For biquaternion algebras, we compare a generalised invariant of Suslin as constructed by the author in a previous article to an invariant introduced by Knus-Merkurjev-Rost-Tignol. Using explicit computations, we prove these invariants are essentially the same. We also prove the non-triviality of an invariant introduced by Kahn. To obtain this result, we compare Kahn's invariant to an i...

  7. Invariant sets for Windows

    CERN Document Server

    Morozov, Albert D; Dragunov, Timothy N; Malysheva, Olga V

    1999-01-01

    This book deals with the visualization and exploration of invariant sets (fractals, strange attractors, resonance structures, patterns etc.) for various kinds of nonlinear dynamical systems. The authors have created a special Windows 95 application called WInSet, which allows one to visualize the invariant sets. A WInSet installation disk is enclosed with the book.The book consists of two parts. Part I contains a description of WInSet and a list of the built-in invariant sets which can be plotted using the program. This part is intended for a wide audience with interests ranging from dynamical

  8. Algorithms in invariant theory

    CERN Document Server

    Sturmfels, Bernd

    2008-01-01

    J. Kung and G.-C. Rota, in their 1984 paper, write: "Like the Arabian phoenix rising out of its ashes, the theory of invariants, pronounced dead at the turn of the century, is once again at the forefront of mathematics". The book of Sturmfels is both an easy-to-read textbook for invariant theory and a challenging research monograph that introduces a new approach to the algorithmic side of invariant theory. The Groebner bases method is the main tool by which the central problems in invariant theory become amenable to algorithmic solutions. Students will find the book an easy introduction to this "classical and new" area of mathematics. Researchers in mathematics, symbolic computation, and computer science will get access to a wealth of research ideas, hints for applications, outlines and details of algorithms, worked out examples, and research problems.

  9. Relativistic gauge invariant potentials

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J.J. (Valladolid Univ. (Spain). Dept. de Fisica Teorica); Negro, J. (Valladolid Univ. (Spain). Dept. de Fisica Teorica); Olmo, M.A. del (Valladolid Univ. (Spain). Dept. de Fisica Teorica)

    1995-01-01

    A global method characterizing the invariant connections on an abelian principal bundle under a group of transformations is applied in order to get gauge invariant electromagnetic (elm.) potentials in a systematic way. So, we have classified all the elm. gauge invariant potentials under the Poincare subgroups of dimensions 4, 5, and 6, up to conjugation. It is paid attention in particular to the situation where these subgroups do not act transitively on the space-time manifold. We have used the same procedure for some galilean subgroups to get nonrelativistic potentials and study the way they are related to their relativistic partners by means of contractions. Some conformal gauge invariant potentials have also been derived and considered when they are seen as consequence of an enlargement of the Poincare symmetries. (orig.)

  10. Testing measurement invariance of the Learning Programme Management and Evaluation scale across academic achievement

    Directory of Open Access Journals (Sweden)

    Maelekanyo C. Mulaudzi

    2016-02-01

    Full Text Available Orientation: Measurement invariance is one of the most precarious aspects of the scale development process without which the interpretation of research findings on population subgroups may be ambiguous and even invalid. Besides tests for validity and reliability, measurement invariance represents the hallmark for psychometric compliance of a new measuring instrument and provides the basis for inference of research findings across a range of relevant population sub-groups.Research purpose: This study tested the measurement invariance of a Learning Programme Management and Evaluation (LPME scale across levels of academic achievement.Motivation for the study: It is important for any researcher involved in new scale development to ensure that the measurement instrument and its underlying constructs have proper structural alignment and that they both have the same level of meaning and significance across comparable heterogeneous groups.Research design, approach and method: A quantitative, non-experimental, cross-sectional survey design was used, and data were obtained from 369 participants who were selected from three public sector organisations using a probabilistic simple random sampling technique. The Statistical Package for Social Sciences and Analysis of Moment Structures software (versions 21.0.0 were used to analyse the data.Main findings: The findings show that all the four invariance models tested have achieved acceptable goodness-of-fit indices. Furthermore, the findings show that the factorial structure of the LPME scale and the meaning of its underlying constructs are invariant across different levels of academic achievement for human resource development (HRD practitioners and learners or apprentices involved in occupational learning programmes.Practical implications: The findings of this study suggest practical implications for HRD scholars as they are enabled to make informed decisional balance comparisons involving educational

  11. Stochastic Generalized Method of Moments

    KAUST Repository

    Yin, Guosheng

    2011-08-16

    The generalized method of moments (GMM) is a very popular estimation and inference procedure based on moment conditions. When likelihood-based methods are difficult to implement, one can often derive various moment conditions and construct the GMM objective function. However, minimization of the objective function in the GMM may be challenging, especially over a large parameter space. Due to the special structure of the GMM, we propose a new sampling-based algorithm, the stochastic GMM sampler, which replaces the multivariate minimization problem by a series of conditional sampling procedures. We develop the theoretical properties of the proposed iterative Monte Carlo method, and demonstrate its superior performance over other GMM estimation procedures in simulation studies. As an illustration, we apply the stochastic GMM sampler to a Medfly life longevity study. Supplemental materials for the article are available online. © 2011 American Statistical Association.

  12. Robust Affine Invariant Descriptors

    Directory of Open Access Journals (Sweden)

    Jianwei Yang

    2011-01-01

    Full Text Available An approach is developed for the extraction of affine invariant descriptors by cutting object into slices. Gray values associated with every pixel in each slice are summed up to construct affine invariant descriptors. As a result, these descriptors are very robust to additive noise. In order to establish slices of correspondence between an object and its affine transformed version, general contour (GC of the object is constructed by performing projection along lines with different polar angles. Consequently, affine in-variant division curves are derived. A slice is formed by points fall in the region enclosed by two adjacent division curves. To test and evaluate the proposed method, several experiments have been conducted. Experimental results show that the proposed method is very robust to noise.

  13. Modular Invariant Theory

    CERN Document Server

    Campbell, HEA

    2011-01-01

    This book covers the modular invariant theory of finite groups, the case when the characteristic of the field divides the order of the group, a theory that is more complicated than the study of the classical non-modular case. Largely self-contained, the book develops the theory from its origins up to modern results. It explores many examples, illustrating the theory and its contrast with the better understood non-modular setting. It details techniques for the computation of invariants for many modular representations of finite groups, especially the case of the cyclic group of prime order. It

  14. Anisotropic Weyl invariance

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Nadal, Guillem [Universidad de Buenos Aires, Buenos Aires (Argentina)

    2017-07-15

    We consider a non-relativistic free scalar field theory with a type of anisotropic scale invariance in which the number of coordinates ''scaling like time'' is generically greater than one. We propose the Cartesian product of two curved spaces, the metric of each space being parameterized by the other space, as a notion of curved background to which the theory can be extended. We study this type of geometries, and find a family of extensions of the theory to curved backgrounds in which the anisotropic scale invariance is promoted to a local, Weyl-type symmetry. (orig.)

  15. Electric multipole moments, topological multipole moment pumping, and chiral hinge states in crystalline insulators

    Science.gov (United States)

    Benalcazar, Wladimir A.; Bernevig, B. Andrei; Hughes, Taylor L.

    2017-12-01

    We extend the theory of dipole moments in crystalline insulators to higher multipole moments. As first formulated in Benalcazar et al. [Science 357, 61 (2017), 10.1126/science.aah6442], we show that bulk quadrupole and octupole moments can be realized in crystalline insulators. In this paper, we expand in great detail the theory presented previously [Benalcazar et al., Science 357, 61 (2017), 10.1126/science.aah6442] and extend it to cover associated topological pumping phenomena, and a class of three-dimensional (3D) insulator with chiral hinge states. We start by deriving the boundary properties of continuous classical dielectrics hosting only bulk dipole, quadrupole, or octupole moments. In quantum mechanical crystalline insulators, these higher multipole bulk moments manifest themselves by the presence of boundary-localized moments of lower dimension, in exact correspondence with the electromagnetic theory of classical continuous dielectrics. In the presence of certain symmetries, these moments are quantized, and their boundary signatures are fractionalized. These multipole moments then correspond to new symmetry-protected topological phases. The topological structure of these phases is described by "nested" Wilson loops, which we define. These Wilson loops reflect the bulk-boundary correspondence in a way that makes evident a hierarchical classification of the multipole moments. Just as a varying dipole generates charge pumping, a varying quadrupole generates dipole pumping, and a varying octupole generates quadrupole pumping. For nontrivial adiabatic cycles, the transport of these moments is quantized. An analysis of these interconnected phenomena leads to the conclusion that a new kind of Chern-type insulator exists, which has chiral, hinge-localized modes in 3D. We provide the minimal models for the quantized multipole moments, the nontrivial pumping processes, and the hinge Chern insulator, and describe the topological invariants that protect them.

  16. Pinch technique prescription to compute the electroweak corrections to the muon anomalous magnetic moment

    OpenAIRE

    Cabral-Rosetti, L.G.; Lopez Castro, G.; Pestieau, Jean

    2004-01-01

    We apply a simple prescription derived from the framework of the Pinch Technique formalism to check the calculation of the gauge-invariant one-loop bosonic electroweak corrections to the muon anomalous magnetic moment.

  17. Modular invariant gaugino condensation

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard, M.K.

    1991-05-09

    The construction of effective supergravity lagrangians for gaugino condensation is reviewed and recent results are presented that are consistent with modular invariance and yield a positive definite potential of the noscale type. Possible implications for phenomenology are briefly discussed. 29 refs.

  18. Invariant differential operators

    CERN Document Server

    Dobrev, Vladimir K

    2016-01-01

    With applications in quantum field theory, elementary particle physics and general relativity, this two-volume work studies invariance of differential operators under Lie algebras, quantum groups, superalgebras including infinite-dimensional cases, Schrödinger algebras, applications to holography. This first volume covers the general aspects of Lie algebras and group theory.

  19. A Hybrid Joint Moment Ratio Test for Financial Time Series

    NARCIS (Netherlands)

    Groenendijk, Patrick A.; Lucas, André; Vries, de Casper G.

    1998-01-01

    We advocate the use of absolute moment ratio statistics in conjunctionwith standard variance ratio statistics in order to disentangle lineardependence, non-linear dependence, and leptokurtosis in financial timeseries. Both statistics are computed for multiple return horizonssimultaneously, and the

  20. Skein Invariants of Links and Their State Sum Models

    Directory of Open Access Journals (Sweden)

    Louis H. Kauffman

    2017-10-01

    Full Text Available We present the new skein invariants of classical links, H [ H ] , K [ K ] and D [ D ] , based on the invariants of links, H, K and D, denoting the regular isotopy version of the Homflypt polynomial, the Kauffman polynomial and the Dubrovnik polynomial. The invariants are obtained by abstracting the skein relation of the corresponding invariant and making a new skein algorithm comprising two computational levels: first producing unlinked knotted components, then evaluating the resulting knots. The invariants in this paper, were revealed through the skein theoretic definition of the invariants Θ d related to the Yokonuma–Hecke algebras and their 3-variable generalization Θ , which generalizes the Homflypt polynomial. H [ H ] is the regular isotopy counterpart of Θ . The invariants K [ K ] and D [ D ] are new generalizations of the Kauffman and the Dubrovnik polynomials. We sketch skein theoretic proofs of the well-definedness and topological properties of these invariants. The invariants of this paper are reformulated into summations of the generating invariants (H, K, D on sublinks of the given link L, obtained by partitioning L into collections of sublinks. The first such reformulation was achieved by W.B.R. Lickorish for the invariant Θ and we generalize it to the Kauffman and Dubrovnik polynomial cases. State sum models are formulated for all the invariants. These state summation models are based on our skein template algorithm which formalizes the skein theoretic process as an analogue of a statistical mechanics partition function. Relationships with statistical mechanics models are articulated. Finally, we discuss physical situations where a multi-leveled course of action is taken naturally.

  1. Continuous Integrated Invariant Inference Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project will develop a new technique for invariant inference and embed this and other current invariant inference and checking techniques in an...

  2. Lepton dipole moments

    CERN Document Server

    Marciano, William J

    2010-01-01

    This book provides a self-contained description of the measurements of the magnetic dipole moments of the electron and muon, along with a discussion of the measurements of the fine structure constant, and the theory associated with magnetic and electric dipole moments. Also included are the searches for a permanent electric dipole moment of the electron, muon, neutron and atomic nuclei. The related topic of the transition moment for lepton flavor violating processes, such as neutrinoless muon or tauon decays, and the search for such processes are included as well. The papers, written by many o

  3. Updating neutrino magnetic moment constraints

    Directory of Open Access Journals (Sweden)

    B.C. Cañas

    2016-02-01

    Full Text Available In this paper we provide an updated analysis of the neutrino magnetic moments (NMMs, discussing both the constraints on the magnitudes of the three transition moments Λi and the role of the CP violating phases present both in the mixing matrix and in the NMM matrix. The scattering of solar neutrinos off electrons in Borexino provides the most stringent restrictions, due to its robust statistics and the low energies observed, below 1 MeV. Our new limit on the effective neutrino magnetic moment which follows from the most recent Borexino data is 3.1×10−11μB at 90% C.L. This corresponds to the individual transition magnetic moment constraints: |Λ1|≤5.6×10−11μB, |Λ2|≤4.0×10−11μB, and |Λ3|≤3.1×10−11μB (90% C.L., irrespective of any complex phase. Indeed, the incoherent admixture of neutrino mass eigenstates present in the solar flux makes Borexino insensitive to the Majorana phases present in the NMM matrix. For this reason we also provide a global analysis including the case of reactor and accelerator neutrino sources, presenting the resulting constraints for different values of the relevant CP phases. Improved reactor and accelerator neutrino experiments will be needed in order to underpin the full profile of the neutrino electromagnetic properties.

  4. Conformal invariance of curvature perturbation

    CERN Document Server

    Gong, Jinn-Ouk; Park, Wan Il; Sasaki, Misao; Song, Yong-Seon

    2011-01-01

    We show that in the single component situation all perturbation variables in the comoving gauge are conformally invariant to all perturbation orders. Generally we identify a special time slicing, the uniform-conformal transformation slicing, where all perturbations are again conformally invariant to all perturbation orders. We apply this result to the delta N formalism, and show its conformal invariance.

  5. Reducing Lookups for Invariant Checking

    DEFF Research Database (Denmark)

    Thomsen, Jakob Grauenkjær; Clausen, Christian; Andersen, Kristoffer Just

    2013-01-01

    This paper helps reduce the cost of invariant checking in cases where access to data is expensive. Assume that a set of variables satisfy a given invariant and a request is received to update a subset of them. We reduce the set of variables to inspect, in order to verify that the invariant is still...

  6. Conformal invariance of curvature perturbation

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Jinn-Ouk [Theory Division, CERN, CH-1211 Genève 23 (Switzerland); Hwang, Jai-chan [Department of Astronomy and Atmospheric Sciences, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Park, Wan Il; Sasaki, Misao; Song, Yong-Seon, E-mail: jinn-ouk.gong@cern.ch, E-mail: jchan@knu.ac.kr, E-mail: wipark@kias.re.kr, E-mail: misao@yukawa.kyoto-u.ac.jp, E-mail: ysong@kias.re.kr [Korea Institute for Advanced Study, Seoul 130-722 (Korea, Republic of)

    2011-09-01

    We show that in the single component situation all perturbation variables in the comoving gauge are conformally invariant to all perturbation orders. Generally we identify a special time slicing, the uniform-conformal transformation slicing, where all perturbations are again conformally invariant to all perturbation orders. We apply this result to the δN formalism, and show its conformal invariance.

  7. Invariants of DNA genomic signals

    Science.gov (United States)

    Cristea, Paul Dan A.

    2005-02-01

    For large scale analysis purposes, the conversion of genomic sequences into digital signals opens the possibility to use powerful signal processing methods for handling genomic information. The study of complex genomic signals reveals large scale features, maintained over the scale of whole chromosomes, that would be difficult to find by using only the symbolic representation. Based on genomic signal methods and on statistical techniques, the paper defines parameters of DNA sequences which are invariant to transformations induced by SNPs, splicing or crossover. Re-orienting concatenated coding regions in the same direction, regularities shared by the genomic material in all exons are revealed, pointing towards the hypothesis of a regular ancestral structure from which the current chromosome structures have evolved. This property is not found in non-nuclear genomic material, e.g., plasmids.

  8. Convex Graph Invariants

    Science.gov (United States)

    2010-12-02

    evaluating the function ΘP (A) for any fixed A,P is equivalent to solving the so-called Quadratic Assignment Problem ( QAP ), and thus we can employ various...tractable linear programming, spectral, and SDP relaxations of QAP [40, 11, 33]. In particular we discuss recent work [14] on exploiting group...symmetry in SDP relaxations of QAP , which is useful for approximately computing elementary convex graph invariants in many interesting cases. Finally in

  9. Galilei invariant molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hoermann, G. [Vienna Univ. (Austria). Mathematisches Inst.; Jaekel, C.D. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    1994-04-01

    We construct a C{sup *}-dynamical model for a chemical reaction. Galilei invariance of our nonrelativistic model is demonstrated by defining it directly on a Galilean space-time fibrebundle with C{sup *}-algebra valued fibre, i.e. without reference to any coordinate system. The existence of equilibrium states in this model is established and some of their properties are discussed. (orig.)

  10. The Effect of Differential Item Functioning in Anchor Items on Population Invariance of Equating

    Science.gov (United States)

    Huggins, Anne Corinne

    2014-01-01

    Invariant relationships in the internal mechanisms of estimating achievement scores on educational tests serve as the basis for concluding that a particular test is fair with respect to statistical bias concerns. Equating invariance and differential item functioning are both concerned with invariant relationships yet are treated separately in the…

  11. Moment graphs and representations

    DEFF Research Database (Denmark)

    Jantzen, Jens Carsten

    2012-01-01

    Moment graphs and sheaves on moment graphs are basically combinatorial objects that have be used to describe equivariant intersectiion cohomology. In these lectures we are going to show that they can be used to provide a direct link from this cohomology to the representation theory of simple Lie ...

  12. The moment problem

    CERN Document Server

    Schmüdgen, Konrad

    2017-01-01

    This advanced textbook provides a comprehensive and unified account of the moment problem. It covers the classical one-dimensional theory and its multidimensional generalization, including modern methods and recent developments. In both the one-dimensional and multidimensional cases, the full and truncated moment problems are carefully treated separately. Fundamental concepts, results and methods are developed in detail and accompanied by numerous examples and exercises. Particular attention is given to powerful modern techniques such as real algebraic geometry and Hilbert space operators. A wide range of important aspects are covered, including the Nevanlinna parametrization for indeterminate moment problems, canonical and principal measures for truncated moment problems, the interplay between Positivstellensätze and moment problems on semi-algebraic sets, the fibre theorem, multidimensional determinacy theory, operator-theoretic approaches, and the existence theory and important special topics of multidime...

  13. Multi-moment maps

    DEFF Research Database (Denmark)

    Swann, Andrew Francis; Madsen, Thomas Bruun

    2012-01-01

    We introduce a notion of moment map adapted to actions of Lie groups that preserve a closed three-form. We show existence of our multi-moment maps in many circumstances, including mild topological assumptions on the underlying manifold. Such maps are also shown to exist for all groups whose second...... and third Lie algebra Betti numbers are zero. We show that these form a special class of solvable Lie groups and provide a structural characterisation. We provide many examples of multi-moment maps for different geometries and use them to describe manifolds with holonomy contained in G(2) preserved by a two...

  14. Viability, invariance and applications

    CERN Document Server

    Carja, Ovidiu; Vrabie, Ioan I

    2007-01-01

    The book is an almost self-contained presentation of the most important concepts and results in viability and invariance. The viability of a set K with respect to a given function (or multi-function) F, defined on it, describes the property that, for each initial data in K, the differential equation (or inclusion) driven by that function or multi-function) to have at least one solution. The invariance of a set K with respect to a function (or multi-function) F, defined on a larger set D, is that property which says that each solution of the differential equation (or inclusion) driven by F and issuing in K remains in K, at least for a short time.The book includes the most important necessary and sufficient conditions for viability starting with Nagumo's Viability Theorem for ordinary differential equations with continuous right-hand sides and continuing with the corresponding extensions either to differential inclusions or to semilinear or even fully nonlinear evolution equations, systems and inclusions. In th...

  15. Permutationally invariant state reconstruction

    DEFF Research Database (Denmark)

    Moroder, Tobias; Hyllus, Philipp; Tóth, Géza

    2012-01-01

    Feasible tomography schemes for large particle numbers must possess, besides an appropriate data acquisition protocol, an efficient way to reconstruct the density operator from the observed finite data set. Since state reconstruction typically requires the solution of a nonlinear large-scale opti...... optimization, which has clear advantages regarding speed, control and accuracy in comparison to commonly employed numerical routines. First prototype implementations easily allow reconstruction of a state of 20 qubits in a few minutes on a standard computer.......-scale optimization problem, this is a major challenge in the design of scalable tomography schemes. Here we present an efficient state reconstruction scheme for permutationally invariant quantum state tomography. It works for all common state-of-the-art reconstruction principles, including, in particular, maximum...... likelihood and least squares methods, which are the preferred choices in today's experiments. This high efficiency is achieved by greatly reducing the dimensionality of the problem employing a particular representation of permutationally invariant states known from spin coupling combined with convex...

  16. The Kolmogorov-Obukhov Statistical Theory of Turbulence

    Science.gov (United States)

    Birnir, Björn

    2013-08-01

    In 1941 Kolmogorov and Obukhov postulated the existence of a statistical theory of turbulence, which allows the computation of statistical quantities that can be simulated and measured in a turbulent system. These are quantities such as the moments, the structure functions and the probability density functions (PDFs) of the turbulent velocity field. In this paper we will outline how to construct this statistical theory from the stochastic Navier-Stokes equation. The additive noise in the stochastic Navier-Stokes equation is generic noise given by the central limit theorem and the large deviation principle. The multiplicative noise consists of jumps multiplying the velocity, modeling jumps in the velocity gradient. We first estimate the structure functions of turbulence and establish the Kolmogorov-Obukhov 1962 scaling hypothesis with the She-Leveque intermittency corrections. Then we compute the invariant measure of turbulence, writing the stochastic Navier-Stokes equation as an infinite-dimensional Ito process, and solving the linear Kolmogorov-Hopf functional differential equation for the invariant measure. Finally we project the invariant measure onto the PDF. The PDFs turn out to be the normalized inverse Gaussian (NIG) distributions of Barndorff-Nilsen, and compare well with PDFs from simulations and experiments.

  17. Invariant and Absolute Invariant Means of Double Sequences

    Directory of Open Access Journals (Sweden)

    Abdullah Alotaibi

    2012-01-01

    Full Text Available We examine some properties of the invariant mean, define the concepts of strong σ-convergence and absolute σ-convergence for double sequences, and determine the associated sublinear functionals. We also define the absolute invariant mean through which the space of absolutely σ-convergent double sequences is characterized.

  18. Mobius invariant QK spaces

    CERN Document Server

    Wulan, Hasi

    2017-01-01

    This monograph summarizes the recent major achievements in Möbius invariant QK spaces. First introduced by Hasi Wulan and his collaborators, the theory of QK spaces has developed immensely in the last two decades, and the topics covered in this book will be helpful to graduate students and new researchers interested in the field. Featuring a wide range of subjects, including an overview of QK spaces, QK-Teichmüller spaces, K-Carleson measures and analysis of weight functions, this book serves as an important resource for analysts interested in this area of complex analysis. Notes, numerous exercises, and a comprehensive up-to-date bibliography provide an accessible entry to anyone with a standard graduate background in real and complex analysis.

  19. The search for permanent electric dipole moments, in particular for the one of the neutron

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    Nonzero permanent electric dipole moments (EDM) of fundamental systems like particles, nuclei, atoms or molecules violate parity and time reversal invariance. Invoking the CPT theorem, time reversal violation implies CP violation. Although CP-violation is implemented in the standard electro-weak theory, EDM generated this way remain undetectably small. However, this CP-violation also appears to fail explaining the observed baryon asymmetry of our universe. Extensions of the standard theory usually include new CP violating phases which often lead to the prediciton of larger EDM. EDM searches in different systems are complementary and various efforts worldwide are underway, but no finite value could be established yet. An improved search for the EDM of the neutron requires, among other things, much better statistics. At PSI, we are presently commissioning a new high intensity source of ultracold neutrons. At the same time, with an international collaboration, we are setting up for a new measurement of the ...

  20. Tau magnetic moment

    Science.gov (United States)

    González-Sprinberg, G. A.; Vidal, J.

    2017-10-01

    The τ lepton magnetic moment theoretical predictions and measurements are reviewed. While it is believed that such a high mass particle is a good candidate to show up new physics, this is not the case up to now. The magnetic moment of elementary fermions, and in particular the anomalous magnetic moment of the electron, had an historical impact both in relativistic quantum mechanics and in quantum field theories. Besides, many new physics models were discarded when confronted with these magnitudes. More recently, the discrepancy of the experiments and the theoretical predictions for the muon anomalous magnetic moment is still an open issue. For the τ lepton, instead, while the theoretical prediction is well known for the standard model and some new physics models, the data are very far of determining even its sign or the first figure. We will discuss the most important theoretical aspects of the τ magnetic moment, and also the current accepted measurements and future perspectives, in particular related to B-factories.

  1. Wigner distribution moments in fractional Fourier transform systems.

    Science.gov (United States)

    Bastiaans, Martin J; Alieva, Tatiana

    2002-09-01

    It is shown how all global Wigner distribution moments of arbitrary order in the output plane of a (generally anamorphic) two-dimensional fractional Fourier transform system can be expressed in terms of the moments in the input plane. Since Wigner distribution moments are identical to derivatives of the ambiguity function at the origin, a similar relation holds for these derivatives. The general input-output relationship is then broken down into a number of rotation-type input-output relationships between certain combinations of moments. It is shown how the Wigner distribution moments (or ambiguity function derivatives) can be measured as intensity moments in the output planes of a set of appropriate fractional Fourier transform systems and thus be derived from the corresponding fractional power spectra. The minimum number of (anamorphic) fractional power spectra that are needed for the determination of these moments is derived. As an important by-product we get a number of moment combinations that are invariant under (anamorphic) fractional Fourier transformation.

  2. Finite type invariants and fatgraphs

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Bene, Alex; Meilhan, Jean-Baptiste Odet Thierry

    2010-01-01

    –Murakami–Ohtsuki of the link invariant of Andersen–Mattes–Reshetikhin computed relative to choices determined by the fatgraph G; this provides a basic connection between 2d geometry and 3d quantum topology. For each fixed G, this invariant is shown to be universal for homology cylinders, i.e., G establishes an isomorphism...

  3. Scale invariance from phase transitions to turbulence

    CERN Document Server

    Lesne, Annick

    2012-01-01

    During a century, from the Van der Waals mean field description (1874) of gases to the introduction of renormalization group (RG techniques 1970), thermodynamics and statistical physics were just unable to account for the incredible universality which was observed in numerous critical phenomena. The great success of RG techniques is not only to solve perfectly this challenge of critical behaviour in thermal transitions but to introduce extremely useful tools in a wide field of daily situations where a system exhibits scale invariance. The introduction of scaling, scale invariance and universality concepts has been a significant turn in modern physics and more generally in natural sciences. Since then, a new "physics of scaling laws and critical exponents", rooted in scaling approaches, allows quantitative descriptions of numerous phenomena, ranging from phase transitions to earthquakes, polymer conformations, heartbeat rhythm, diffusion, interface growth and roughening, DNA sequence, dynamical systems, chaos ...

  4. Three +1 Faces of Invariance

    CERN Document Server

    Fayngold, Moses

    2010-01-01

    A careful look at an allegedly well-known century-old concept reveals interesting aspects in it that have generally avoided recognition in literature. There are four different kinds of physical observables known or proclaimed as relativistic invariants under space-time rotations. Only observables in the first three categories are authentic invariants, whereas the single "invariant" - proper length - in the fourth category is actually not an invariant. The proper length has little is anything to do with proper distance which is a true invariant. On the other hand, proper distance, proper time, and rest mass have more in common than usually recognized, and particularly, mass - time analogy opens another view of the twin paradox.

  5. Harmonic statistics

    Energy Technology Data Exchange (ETDEWEB)

    Eliazar, Iddo, E-mail: eliazar@post.tau.ac.il

    2017-05-15

    The exponential, the normal, and the Poisson statistical laws are of major importance due to their universality. Harmonic statistics are as universal as the three aforementioned laws, but yet they fall short in their ‘public relations’ for the following reason: the full scope of harmonic statistics cannot be described in terms of a statistical law. In this paper we describe harmonic statistics, in their full scope, via an object termed harmonic Poisson process: a Poisson process, over the positive half-line, with a harmonic intensity. The paper reviews the harmonic Poisson process, investigates its properties, and presents the connections of this object to an assortment of topics: uniform statistics, scale invariance, random multiplicative perturbations, Pareto and inverse-Pareto statistics, exponential growth and exponential decay, power-law renormalization, convergence and domains of attraction, the Langevin equation, diffusions, Benford’s law, and 1/f noise. - Highlights: • Harmonic statistics are described and reviewed in detail. • Connections to various statistical laws are established. • Connections to perturbation, renormalization and dynamics are established.

  6. Physical Invariants of Intelligence

    Science.gov (United States)

    Zak, Michail

    2010-01-01

    A program of research is dedicated to development of a mathematical formalism that could provide, among other things, means by which living systems could be distinguished from non-living ones. A major issue that arises in this research is the following question: What invariants of mathematical models of the physics of systems are (1) characteristic of the behaviors of intelligent living systems and (2) do not depend on specific features of material compositions heretofore considered to be characteristic of life? This research at earlier stages has been reported, albeit from different perspectives, in numerous previous NASA Tech Briefs articles. To recapitulate: One of the main underlying ideas is to extend the application of physical first principles to the behaviors of living systems. Mathematical models of motor dynamics are used to simulate the observable physical behaviors of systems or objects of interest, and models of mental dynamics are used to represent the evolution of the corresponding knowledge bases. For a given system, the knowledge base is modeled in the form of probability distributions and the mental dynamics is represented by models of the evolution of the probability densities or, equivalently, models of flows of information. At the time of reporting the information for this article, the focus of this research was upon the following aspects of the formalism: Intelligence is considered to be a means by which a living system preserves itself and improves its ability to survive and is further considered to manifest itself in feedback from the mental dynamics to the motor dynamics. Because of the feedback from the mental dynamics, the motor dynamics attains quantum-like properties: The trajectory of the physical aspect of the system in the space of dynamical variables splits into a family of different trajectories, and each of those trajectories can be chosen with a probability prescribed by the mental dynamics. From a slightly different perspective

  7. A filter bank for rotationally invariant image recognition

    Directory of Open Access Journals (Sweden)

    S Rodtook

    2005-12-01

    Full Text Available We present new rotation moment invariants based on multiresolution filter bank techniques. The multiresolution pyramid motivates our simple but efficient feature selection procedure based on the fuzzy C-mean clustering methodology combined with the Mahalanobis distance measure. The proposed procedure verifies an impact of random noise as well as an interesting, less known impact of noise due to spatial transformations. The recognition accuracy of the proposed technique has been tested with the Zernike moments, the Fourier-Mellin moments as well as with wavelet based schemes. The numerical experiments, with more than 30 000 images, demonstrate a tangible accuracy increase of about 3% for low level noise, 8% for the average level noise and 15% for high level noise.

  8. Moments of Negotiation

    NARCIS (Netherlands)

    Pieters, Jurgen

    2001-01-01

    'Moments of Negotiation' offers the first book-length and indepth analysis of the New Historicist reading method, which the American Shakespeare-scolar Stephen Greenblatt introduced at the beginning of the 1980s. Ever since, Greenblatt has been hailed as the prime representative of this movement,

  9. Three Moments in Jewish Philosophy

    OpenAIRE

    Stefan Goltzberg

    2013-01-01

    The purpose of this article is to offer a new periodization of Jewish philosophy and to reflect on the definition of Jewish philosophy. It will therefore deal with the characteristic style of each Jewish philosophy rather than with their content. I shall identify three moments in the history of Jewish philosophy: the Arab moment, the German moment, and the analytic moment; this last moment, largely unknown, will be studied more in depth. This paper does not aim to present an exhaustive panora...

  10. Experimental evidence of conformal invariance in soap film turbulent flows

    CERN Document Server

    Thalabard, S; Artana, G; Mininni, P D; Pouquet, A

    2010-01-01

    We present experimental evidence of statistical conformal invariance in isocontours of fluid thickness in experiments of two-dimensional turbulence using soap films. A Schlieren technique is used to visualize regions of the flow with constant film thickness, and association of isocontours with Schramm-L\\"owner evolution (SLE) is used to identify conformal invariance. In experiments where an inverse energy cascade develops, statistical evidence is consistent with such an association. The diffusivity of the associated one-dimensional Brownian process is close to 8/3, a value previously identified in isocontours of vorticity in high-resolution numerical simulations of two-dimensional turbulence (D. Bernard et al., Nature Phys. 2, 124, 2006). In experiments where the inverse energy cascade is not sufficiently developed, no statistical evidence of conformal invariance is found.

  11. On density of the Vassiliev invariants

    DEFF Research Database (Denmark)

    Røgen, Peter

    1999-01-01

    The main result is that the Vassiliev invariants are dense in the set of numeric knot invariants if and only if they separate knots.Keywords: Knots, Vassiliev invariants, separation, density, torus knots......The main result is that the Vassiliev invariants are dense in the set of numeric knot invariants if and only if they separate knots.Keywords: Knots, Vassiliev invariants, separation, density, torus knots...

  12. Invariant and semi-invariant probabilistic normed spaces

    Energy Technology Data Exchange (ETDEWEB)

    Ghaemi, M.B. [School of Mathematics Iran, University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of)], E-mail: mghaemi@iust.ac.ir; Lafuerza-Guillen, B. [Departamento de Estadistica y Matematica Aplicada, Universidad de Almeria, Almeria E-04120 (Spain)], E-mail: blafuerz@ual.es; Saiedinezhad, S. [School of Mathematics Iran, University of Science and Technology, Narmak, Tehran (Iran, Islamic Republic of)], E-mail: ssaiedinezhad@yahoo.com

    2009-10-15

    Probabilistic metric spaces were introduced by Karl Menger. Alsina, Schweizer and Sklar gave a general definition of probabilistic normed space based on the definition of Menger . We introduce the concept of semi-invariance among the PN spaces. In this paper we will find a sufficient condition for some PN spaces to be semi-invariant. We will show that PN spaces are normal spaces. Urysohn's lemma, and Tietze extension theorem for them are proved.

  13. Statistical Distance For Chaotic Maps

    CERN Document Server

    Johal, R S

    1998-01-01

    The purpose of this letter is to define a distance on the underlying phase space of a chaotic map, based on natural invariant density of the map. It is observed that for logistic map this distance is equivalent to Wootters' statistical distance. This distance becomes the Euclidean distance for a map with constant invariant density.

  14. Invariant measures in brain dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Boyarsky, Abraham [Department of Mathematics and Statistics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6 (Canada)]. E-mail: boyar@alcor.concordia.ca; Gora, Pawel [Department of Mathematics and Statistics, Concordia University, 1455 de Maisonneuve Blvd. West, Montreal, Quebec H3G 1M8 (Canada)]. E-mail: pgora@vax2.concordia.ca

    2006-10-02

    This note concerns brain activity at the level of neural ensembles and uses ideas from ergodic dynamical systems to model and characterize chaotic patterns among these ensembles during conscious mental activity. Central to our model is the definition of a space of neural ensembles and the assumption of discrete time ensemble dynamics. We argue that continuous invariant measures draw the attention of deeper brain processes, engendering emergent properties such as consciousness. Invariant measures supported on a finite set of ensembles reflect periodic behavior, whereas the existence of continuous invariant measures reflect the dynamics of nonrepeating ensemble patterns that elicit the interest of deeper mental processes. We shall consider two different ways to achieve continuous invariant measures on the space of neural ensembles: (1) via quantum jitters, and (2) via sensory input accompanied by inner thought processes which engender a 'folding' property on the space of ensembles.

  15. The invariant theory of matrices

    CERN Document Server

    Concini, Corrado De

    2017-01-01

    This book gives a unified, complete, and self-contained exposition of the main algebraic theorems of invariant theory for matrices in a characteristic free approach. More precisely, it contains the description of polynomial functions in several variables on the set of m\\times m matrices with coefficients in an infinite field or even the ring of integers, invariant under simultaneous conjugation. Following Hermann Weyl's classical approach, the ring of invariants is described by formulating and proving the first fundamental theorem that describes a set of generators in the ring of invariants, and the second fundamental theorem that describes relations between these generators. The authors study both the case of matrices over a field of characteristic 0 and the case of matrices over a field of positive characteristic. While the case of characteristic 0 can be treated following a classical approach, the case of positive characteristic (developed by Donkin and Zubkov) is much harder. A presentation of this case...

  16. Hidden scale invariance of metals

    DEFF Research Database (Denmark)

    Hummel, Felix; Kresse, Georg; Dyre, Jeppe C.

    2015-01-01

    Density functional theory (DFT) calculations of 58 liquid elements at their triple point show that most metals exhibit near proportionality between the thermal fluctuations of the virial and the potential energy in the isochoric ensemble. This demonstrates a general “hidden” scale invariance...... of iron and phosphorous are shown to increase at elevated pressures. Finally, we discuss how scale invariance explains the Grüneisen equation of state and a number of well-known empirical melting and freezing rules...

  17. Classification of simple current invariants

    CERN Document Server

    Gato-Rivera, Beatriz

    1992-01-01

    We summarize recent work on the classification of modular invariant partition functions that can be obtained with simple currents in theories with a center (Z_p)^k with p prime. New empirical results for other centers are also presented. Our observation that the total number of invariants is monodromy-independent for (Z_p)^k appears to be true in general as well. (Talk presented in the parallel session on string theory of the Lepton-Photon/EPS Conference, Geneva, 1991.)

  18. Redefining the political moment

    Directory of Open Access Journals (Sweden)

    James Arvanitakis

    2011-07-01

    Full Text Available On 16 February 2003, more than half a million people gathered in Sydney, Australia, as part of a global anti-war protest aimed at stopping the impending invasion of Iraq by the then US Administration. It is difficult to estimate how many millions marched on the coordinated protest, but it was by far the largest mobilization of a generation. Walking and chanting on the streets of Sydney that day, it seemed that a political moment was upon us. In a culture that rarely embraces large scale activism, millions around Australian demanded to be heard. The message was clear: if you do not hear us, we would be willing to bring down a government. The invasion went ahead, however, with the then Australian government, under the leadership of John Howard, being one of the loudest and staunchest supporters of the Bush Administrations drive to war. Within 18 months, anti-war activists struggled to have a few hundred participants take part in anti-Iraq war rallies, and the Howard Government was comfortably re-elected for another term. The political moment had come and gone, with both social commentators and many members of the public looking for a reason. While the conservative media was often the focus of analysis, this paper argues that in a time of late capitalism, the political moment is hollowed out by ‘Politics’ itself. That is to say, that formal political processes (or ‘Politics’ undermine the political practices that people participate in everyday (or ‘politics’. Drawing on an ongoing research project focusing on democracy and young people, I discuss how the concept of ’politics‘ has been destabilised and subsequently, the political moment has been displaced. This displacement has led to a re-definition of ‘political action’ and, I argue, the emergence of a different type of everyday politics.

  19. Distributions on unbounded moment spaces and random moment sequences

    OpenAIRE

    Dette, Holger; Nagel, Jan

    2012-01-01

    In this paper we define distributions on moment spaces corresponding to measures on the real line with an unbounded support. We identify these distributions as limiting distributions of random moment vectors defined on compact moment spaces and as distributions corresponding to random spectral measures associated with the Jacobi, Laguerre and Hermite ensemble from random matrix theory. For random vectors on the unbounded moment spaces we prove a central limit theorem where the centering vecto...

  20. Origin invariance in vibrational resonance Raman optical activity.

    Science.gov (United States)

    Vidal, Luciano N; Egidi, Franco; Barone, Vincenzo; Cappelli, Chiara

    2015-05-07

    A theoretical investigation on the origin dependence of the vibronic polarizabilities, isotropic and anisotropic rotational invariants, and scattering cross sections in Resonance Raman Optical Activity (RROA) spectroscopy is presented. Expressions showing the origin dependence of these polarizabilities were written in the resonance regime using the Franck-Condon (FC) and Herzberg-Teller (HT) approximations for the electronic transition moments. Differently from the far-from-resonance scattering regime, where the origin dependent terms cancel out when the rotational invariants are calculated, RROA spectrum can exhibit some origin dependence even for eigenfunctions of the electronic Hamiltonian. At the FC level, the RROA spectrum is completely origin invariant if the polarizabilities are calculated using a single excited state or for a set of degenerate states. Otherwise, some origin effects can be observed in the spectrum. At the HT level, RROA spectrum is origin dependent even when the polarizabilities are evaluated from a single excited state but the origin effect is expected to be small in this case. Numerical calculations performed for (S)-methyloxirane, (2R,3R)-dimethyloxirane, and (R)-4-F-2-azetidinone at both FC and HT levels using the velocity representation of the electric dipole and quadrupole transition moments confirm the predictions of the theory and show the extent of origin effects and the effectiveness of suggested ways to remove them.

  1. Score Function of Distribution and Revival of the Moment Method

    Czech Academy of Sciences Publication Activity Database

    Fabián, Zdeněk

    2016-01-01

    Roč. 45, č. 4 (2016), s. 1118-1136 ISSN 0361-0926 R&D Projects: GA MŠk(CZ) LG12020 Institutional support: RVO:67985807 Keywords : characteristics of distributions * data characteristics * general moment method * Huber moment estimator * parametric methods * score function Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.311, year: 2016

  2. On invariant submanifolds of (LCSn-manifolds

    Directory of Open Access Journals (Sweden)

    Absos Ali Shaikh

    2016-04-01

    Full Text Available The object of the present paper is to study the invariant submanifolds of (LCSn-manifolds. We study semiparallel and 2-semiparallel invariant submanifolds of (LCSn-manifolds. Among others we study 3-dimensional invariant submanifolds of (LCSn-manifolds. It is shown that every 3-dimensional invariant submanifold of a (LCSn-manifold is totally geodesic.

  3. Invariant Matsumoto metrics on homogeneous spaces

    OpenAIRE

    Salimi Moghaddam, H.R.

    2014-01-01

    In this paper we consider invariant Matsumoto metrics which are induced by invariant Riemannian metrics and invariant vector fields on homogeneous spaces, and then we give the flag curvature formula of them. Also we study the special cases of naturally reductive spaces and bi-invariant metrics. We end the article by giving some examples of geodesically complete Matsumoto spaces.

  4. Paul Callaghan luminous moments

    CERN Document Server

    Callaghan, Paul

    2013-01-01

    Acknowledged internationally for his ground-breaking scientific research in the field of magnetic resonance, Sir Paul Callaghan was a scientist and visionary with a rare gift for promoting science to a wide audience. He was named New Zealander of the Year in 2011. His death in early 2012 robbed New Zealand of an inspirational leader. Paul Callaghan: Luminous Moments brings together some of his most significant writing. Whether he describes his childhood in Wanganui, reflects on discovering the beauty of science, sets out New Zealand's future potential or discusses the experience of fa

  5. Moments in time

    Directory of Open Access Journals (Sweden)

    Marc eWittmann

    2011-10-01

    Full Text Available It has been suggested that perception and action can be understood as evolving in temporal epochs or sequential processing units. Successive events are fused into units forming a unitary experience or ‘psychological present’. Studies have identified several temporal integration levels on different time scales which are fundamental for our understanding of behaviour and subjective experience. In recent literature concerning the philosophy and neuroscience of consciousness these separate temporal processing levels are not always precisely distinguished. Therefore, empirical evidence from psychophysics and neuropsychology on these distinct temporal processing levels is presented and discussed within philosophical conceptualizations of time experience. On an elementary level, one can identify a functional moment, a basic temporal building block of perception in the range of milliseconds that defines simultaneity and succession. Below a certain threshold temporal order is not perceived, individual events are processed as co-temporal. On a second level, an experienced moment, which is based on temporal integration of up to a few seconds, has been reported in many qualitatively different experiments in perception and action. It has been suggested that this segmental processing mechanism creates temporal windows that provide a logistical basis for conscious representation and the experience of nowness. On a third level of integration, continuity of experience is enabled by working-memory in the range of multiple seconds allowing the maintenance of cognitive operations and emotional feelings, leading to mental presence, a temporal window of an individual’s experienced presence.

  6. A Hybrid Joint Moment Ratio Test for Financial Time Series

    NARCIS (Netherlands)

    P.A. Groenendijk (Patrick); A. Lucas (André); C.G. de Vries (Casper)

    1998-01-01

    textabstractWe advocate the use of absolute moment ratio statistics in conjunction with standard variance ratio statistics in order to disentangle linear dependence, non-linear dependence, and leptokurtosis in financial time series. Both statistics are computed for multiple return horizons

  7. Numeric invariants from multidimensional persistence

    Energy Technology Data Exchange (ETDEWEB)

    Skryzalin, Jacek [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Carlsson, Gunnar [Stanford Univ., Stanford, CA (United States)

    2017-05-19

    In this paper, we analyze the space of multidimensional persistence modules from the perspectives of algebraic geometry. We first build a moduli space of a certain subclass of easily analyzed multidimensional persistence modules, which we construct specifically to capture much of the information which can be gained by using multidimensional persistence over one-dimensional persistence. We argue that the global sections of this space provide interesting numeric invariants when evaluated against our subclass of multidimensional persistence modules. Lastly, we extend these global sections to the space of all multidimensional persistence modules and discuss how the resulting numeric invariants might be used to study data.

  8. A generalization of gauge invariance

    Science.gov (United States)

    Grigore, Dan-Radu

    2017-08-01

    We consider perturbative quantum field theory in the causal framework. Gauge invariance is, in this framework, an identity involving chronological products of the interaction Lagrangian; it expresses the fact that the scattering matrix must leave invariant the sub-space of physical states. We are interested in generalizations of such identity involving Wick sub-monomials of the interaction Lagrangian. The analysis can be performed by direct computation in the lower orders of perturbation theory; guided by these computations, we conjecture a generalization for arbitrary orders.

  9. Dark Coupling and Gauge Invariance

    CERN Document Server

    Gavela, M B; Mena, O; Rigolin, S

    2010-01-01

    We study a coupled dark energy-dark matter model in which the energy-momentum exchange is proportional to the Hubble expansion rate. The inclusion of its perturbation is required by gauge invariance. We derive the linear perturbation equations for the gauge invariant energy density contrast and velocity of the coupled fluids, and we determine the initial conditions. The latter turn out to be adiabatic for dark energy, when assuming adiabatic initial conditions for all the standard fluids. We perform a full Monte Carlo Markov Chain likelihood analysis of the model, using WMAP 7-year data.

  10. Test of charge conjugation invariance.

    Science.gov (United States)

    Nefkens, B M K; Prakhov, S; Gårdestig, A; Allgower, C E; Bekrenev, V; Briscoe, W J; Clajus, M; Comfort, J R; Craig, K; Grosnick, D; Isenhower, D; Knecht, N; Koetke, D; Koulbardis, A; Kozlenko, N; Kruglov, S; Lolos, G; Lopatin, I; Manley, D M; Manweiler, R; Marusić, A; McDonald, S; Olmsted, J; Papandreou, Z; Peaslee, D; Phaisangittisakul, N; Price, J W; Ramirez, A F; Sadler, M; Shafi, A; Spinka, H; Stanislaus, T D S; Starostin, A; Staudenmaier, H M; Supek, I; Tippens, W B

    2005-02-04

    We report on the first determination of upper limits on the branching ratio (BR) of eta decay to pi0pi0gamma and to pi0pi0pi0gamma. Both decay modes are strictly forbidden by charge conjugation (C) invariance. Using the Crystal Ball multiphoton detector, we obtained BR(eta-->pi0pi0gamma)pi0pi0pi0gamma)<6 x 10(-5) at the 90% confidence level, in support of C invariance of isovector electromagnetic interactions.

  11. Moments, positive polynomials and their applications

    CERN Document Server

    Lasserre, Jean Bernard

    2009-01-01

    Many important applications in global optimization, algebra, probability and statistics, applied mathematics, control theory, financial mathematics, inverse problems, etc. can be modeled as a particular instance of the Generalized Moment Problem (GMP) . This book introduces a new general methodology to solve the GMP when its data are polynomials and basic semi-algebraic sets. This methodology combines semidefinite programming with recent results from real algebraic geometry to provide a hierarchy of semidefinite relaxations converging to the desired optimal value. Applied on appropriate cones,

  12. Infinite invariant densities due to intermittency in a nonlinear oscillator

    Science.gov (United States)

    Meyer, Philipp; Kantz, Holger

    2017-08-01

    Dynamical intermittency is known to generate anomalous statistical behavior of dynamical systems, a prominent example being the Pomeau-Manneville map. We present a nonlinear oscillator, i.e., a physical model in continuous time, whose properties in terms of weak ergodity breaking and aging have a one-to-one correspondence to the properties of the Pomeau-Manneville map. So for both systems in a wide range of parameters no physical invariant density exists. We show how this regime can be characterized quantitatively using the techniques of infinite invariant densities and the Thaler-Dynkin limit theorem. We see how expectation values exhibit aging in terms of scaling in time.

  13. Infinite invariant densities due to intermittency in a nonlinear oscillator.

    Science.gov (United States)

    Meyer, Philipp; Kantz, Holger

    2017-08-01

    Dynamical intermittency is known to generate anomalous statistical behavior of dynamical systems, a prominent example being the Pomeau-Manneville map. We present a nonlinear oscillator, i.e., a physical model in continuous time, whose properties in terms of weak ergodity breaking and aging have a one-to-one correspondence to the properties of the Pomeau-Manneville map. So for both systems in a wide range of parameters no physical invariant density exists. We show how this regime can be characterized quantitatively using the techniques of infinite invariant densities and the Thaler-Dynkin limit theorem. We see how expectation values exhibit aging in terms of scaling in time.

  14. Invariant Classification of Gait Types

    DEFF Research Database (Denmark)

    Fihl, Preben; Moeslund, Thomas B.

    2008-01-01

    This paper presents a method of classifying human gait in an invariant manner based on silhouette comparison. A database of artificially generated silhouettes is created representing the three main types of gait, i.e. walking, jogging, and running. Silhouettes generated from different camera angles...

  15. Lie groups and invariant theory

    CERN Document Server

    Vinberg, Ernest

    2005-01-01

    This volume, devoted to the 70th birthday of A. L. Onishchik, contains a collection of articles by participants in the Moscow Seminar on Lie Groups and Invariant Theory headed by E. B. Vinberg and A. L. Onishchik. The book is suitable for graduate students and researchers interested in Lie groups and related topics.

  16. The constant electric field effect on the dipole moment of a comb-like polymer with chromophore groups in side chains

    Directory of Open Access Journals (Sweden)

    Tamara P. Stepanova

    2015-03-01

    Full Text Available The study of conformational properties and tendency to association for chromophore-containing comb-like copolymer of β-(3,4-dicyanophenylazobenzenethyazole methacrylate (A and amylmethacrylate (B (1:1 has been carried out. The copolymer AB is of particular interest because of non-linear optical properties of its films. Dielectric permittivity and dipole moment temperature dependences in dilute cyclohexanone solutions in the temperature range from 20 to 70 °С, in the electric field E ≤ 104 V/cm were investigated by means of static dielectric polarization. It was shown that temperature and concentration dependences of dielectric permittivity for the solvent, copolymer AB, monomer A and polymer B were linear indicating low molecular interactions at temperatures and fields used. The invariable stoichiometry of components in solution for concentration lower than 10–3 mol/mol was proved. The values of dielectric permittivity were extrapolated to infinite dilution and increments α=(Δɛ12/Δx2x2=0 were calculated. The solvent dipole moments were calculated in terms of the Onsager theory whereas dipole moments of AB, A and B were calculated in terms of the Backingham statistical theory of dielectric polarization. Intramacromolecular conformational transition was found to be at ∼40 °C. Dipole moment of A was shown to increase with both temperature and electric field strength. Copolymer side chains trans-location takes place due to intramacromolecular association resulting in the compensation of dipole moments and Kirkwood factor g ≈ 0.6. The association of A units increases in the electric field reducing the dipole moment per monomer unit significantly and g values approximately twice.

  17. Score-based tests of measurement invariance: Use in practice

    Directory of Open Access Journals (Sweden)

    Ting eWang

    2014-05-01

    Full Text Available In this paper, we consider a family of recently-proposed measurement invariance tests that are based on the scores of a fitted model. This family can be used to test for measurement invariance w.r.t. a continuous auxiliary variable, without pre-specification of subgroups. Moreover, the family can be used when one wishes to test for measurement invariance w.r.t. an ordinal auxiliary variable, yielding test statistics that are sensitive to violations that are monotonically related to the ordinal variable (and less sensitive to non-monotonic violations. The paper is specifically aimed at potential users of the tests who may wish to know (i how the tests can be employed for their data, and (ii whether the tests can accurately identify specific models parameters that violate measurement invariance (possibly in the presence of model misspecification. After providing an overview of the tests, we illustrate their general use via the R packages lavaan and strucchange. We then describe two novel simulations that provide evidence of the tests' practical abilities. As a whole, the paper provides researchers with the tools and knowledge needed to apply these tests to general measurement invariance scenarios.

  18. Analytical Derivation of Moment Equations in Stochastic Chemical Kinetics

    Science.gov (United States)

    Sotiropoulos, Vassilios; Kaznessis, Yiannis N.

    2011-01-01

    The master probability equation captures the dynamic behavior of a variety of stochastic phenomena that can be modeled as Markov processes. Analytical solutions to the master equation are hard to come by though because they require the enumeration of all possible states and the determination of the transition probabilities between any two states. These two tasks quickly become intractable for all but the simplest of systems. Instead of determining how the probability distribution changes in time, we can express the master probability distribution as a function of its moments, and, we can then write transient equations for the probability distribution moments. In 1949, Moyal defined the derivative, or jump, moments of the master probability distribution. These are measures of the rate of change in the probability distribution moment values, i.e. what the impact is of any given transition between states on the moment values. In this paper we present a general scheme for deriving analytical moment equations for any N-dimensional Markov process as a function of the jump moments. Importantly, we propose a scheme to derive analytical expressions for the jump moments for any N-dimensional Markov process. To better illustrate the concepts, we focus on stochastic chemical kinetics models for which we derive analytical relations for jump moments of arbitrary order. Chemical kinetics models are widely used to capture the dynamic behavior of biological systems. The elements in the jump moment expressions are a function of the stoichiometric matrix and the reaction propensities, i.e the probabilistic reaction rates. We use two toy examples, a linear and a non-linear set of reactions, to demonstrate the applicability and limitations of the scheme. Finally, we provide an estimate on the minimum number of moments necessary to obtain statistical significant data that would uniquely determine the dynamics of the underlying stochastic chemical kinetic system. The first two moments

  19. Invariant manifolds near hyperbolic fixed points

    NARCIS (Netherlands)

    Homburg, A.J.

    2006-01-01

    Abstract: In these notes, we discuss obstructions to the existence of local invariant manifolds of some smoothness class, near hyperbolic fixed points of diffeomorphisms. We present an elementary construction for continuously differentiable invariant manifolds that are not necessarily normally

  20. Constructing Invariant Fairness Measures for Surfaces

    DEFF Research Database (Denmark)

    Gravesen, Jens; Ungstrup, Michael

    1998-01-01

    of the size of this vector field is used as the fairness measure on the family.Six basic 3rd order invariants satisfying two quadratic equations are defined. They form a complete set in the sense that any invariant 3rd order function can be written as a function of the six basic invariants together...

  1. Invariance for Single Curved Manifold

    KAUST Repository

    Castro, Pedro Machado Manhaes de

    2012-08-01

    Recently, it has been shown that, for Lambert illumination model, solely scenes composed by developable objects with a very particular albedo distribution produce an (2D) image with isolines that are (almost) invariant to light direction change. In this work, we provide and investigate a more general framework, and we show that, in general, the requirement for such in variances is quite strong, and is related to the differential geometry of the objects. More precisely, it is proved that single curved manifolds, i.e., manifolds such that at each point there is at most one principal curvature direction, produce invariant is surfaces for a certain relevant family of energy functions. In the three-dimensional case, the associated energy function corresponds to the classical Lambert illumination model with albedo. This result is also extended for finite-dimensional scenes composed by single curved objects. © 2012 IEEE.

  2. Homotopy invariants of Gauss words

    OpenAIRE

    Gibson, Andrew

    2009-01-01

    By defining combinatorial moves, we can define an equivalence relation on Gauss words called homotopy. In this paper we define a homotopy invariant of Gauss words. We use this to show that there exist Gauss words that are not homotopically equivalent to the empty Gauss word, disproving a conjecture by Turaev. In fact, we show that there are an infinite number of equivalence classes of Gauss words under homotopy.

  3. Scale invariance and universality of economic fluctuations

    Science.gov (United States)

    Stanley, H. E.; Amaral, L. A. N.; Gopikrishnan, P.; Plerou, V.

    2000-08-01

    In recent years, physicists have begun to apply concepts and methods of statistical physics to study economic problems, and the neologism “econophysics” is increasingly used to refer to this work. Much recent work is focused on understanding the statistical properties of time series. One reason for this interest is that economic systems are examples of complex interacting systems for which a huge amount of data exist, and it is possible that economic time series viewed from a different perspective might yield new results. This manuscript is a brief summary of a talk that was designed to address the question of whether two of the pillars of the field of phase transitions and critical phenomena - scale invariance and universality - can be useful in guiding research on economics. We shall see that while scale invariance has been tested for many years, universality is relatively less frequently discussed. This article reviews the results of two recent studies - (i) The probability distribution of stock price fluctuations: Stock price fluctuations occur in all magnitudes, in analogy to earthquakes - from tiny fluctuations to drastic events, such as market crashes. The distribution of price fluctuations decays with a power-law tail well outside the Lévy stable regime and describes fluctuations that differ in size by as much as eight orders of magnitude. (ii) Quantifying business firm fluctuations: We analyze the Computstat database comprising all publicly traded United States manufacturing companies within the years 1974-1993. We find that the distributions of growth rates is different for different bins of firm size, with a width that varies inversely with a power of firm size. Similar variation is found for other complex organizations, including country size, university research budget size, and size of species of bird populations.

  4. Higher moments method for generalized Pareto distribution in flood frequency analysis

    Science.gov (United States)

    Zhou, C. R.; Chen, Y. F.; Huang, Q.; Gu, S. H.

    2017-08-01

    The generalized Pareto distribution (GPD) has proven to be the ideal distribution in fitting with the peak over threshold series in flood frequency analysis. Several moments-based estimators are applied to estimating the parameters of GPD. Higher linear moments (LH moments) and higher probability weighted moments (HPWM) are the linear combinations of Probability Weighted Moments (PWM). In this study, the relationship between them will be explored. A series of statistical experiments and a case study are used to compare their performances. The results show that if the same PWM are used in LH moments and HPWM methods, the parameter estimated by these two methods is unbiased. Particularly, when the same PWM are used, the PWM method (or the HPWM method when the order equals 0) shows identical results in parameter estimation with the linear Moments (L-Moments) method. Additionally, this phenomenon is significant when r ≥ 1 that the same order PWM are used in HPWM and LH moments method.

  5. Scale invariance implies conformal invariance for the three-dimensional Ising model.

    Science.gov (United States)

    Delamotte, Bertrand; Tissier, Matthieu; Wschebor, Nicolás

    2016-01-01

    Using the Wilson renormalization group, we show that if no integrated vector operator of scaling dimension -1 exists, then scale invariance implies conformal invariance. By using the Lebowitz inequalities, we prove that this necessary condition is fulfilled in all dimensions for the Ising universality class. This shows, in particular, that scale invariance implies conformal invariance for the three-dimensional Ising model.

  6. Higher topological invariants of magnetic field lines: observational aspects

    Science.gov (United States)

    Illarionov, Egor; Smirnov, Alexander; Georgoulis, Manolis K.; Sokoloff, Dmitry; Akhmet'ev, Peter

    Topology of magnetic field lines is directly involved in magnetohydrodynamic (MHD) theorems and equations. Being an invariant of motion in ideal MHD conditions, the magnetic field-line topology is a natural obstacle to the relaxation of magnetic field into a current-free (potential) field and contrariwise limits a dynamo generation. Usage of these conservational laws and writing of numerical relations require a quantification of topology. One of the simplest existing measures of magnetic topology is the mutual magnetic helicity, that expresses the combined action of interaction and linkage between different magnetic field lines. For practical purposes there exists the revised concept of relative magnetic helicity, that allows to estimate the complexity of field-line topology in case of open volume, i.e. when magnetic lines cross the boundaries of given 3D region. At the same time this concept remains a simple interpretation of linkage number in terms of individual lines. Our point however is that magnetic helicity is far from being unique or comprehensive quantification of magnetic field-line topology. To improve the situation we introduce a set of higher invariants which extends the idea of relative helicity and provides a new means to describe the magnetic field-line topology. To practically study the possibility of implementation of higher topological invariants we reconstruct several moments of mutual helicity from observed solar vector magnetograms with extrapolated magnetic field above the photosphere and discuss to what extent such knowledge could be instructive for understanding of the solar magnetic field evolution.

  7. Disformal invariance of curvature perturbation

    Energy Technology Data Exchange (ETDEWEB)

    Motohashi, Hayato [Kavli Institute for Cosmological Physics, The University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois, 60637 (United States); White, Jonathan, E-mail: motohashi@kicp.uchicago.edu, E-mail: jwhite@post.kek.jp [Research Center for the Early Universe (RESCEU), The University of Tokyo, Hongo 7-3-1, Tokyo, 113-0033 Japan (Japan)

    2016-02-01

    We show that under a general disformal transformation the linear comoving curvature perturbation is not identically invariant, but is invariant on superhorizon scales for any theory that is disformally related to Horndeski's theory. The difference between disformally related curvature perturbations is found to be given in terms of the comoving density perturbation associated with a single canonical scalar field. In General Relativity it is well-known that this quantity vanishes on superhorizon scales through the Poisson equation that is obtained on combining the Hamiltonian and momentum constraints, and we confirm that a similar result holds for any theory that is disformally related to Horndeski's scalar-tensor theory so long as the invertibility condition for the disformal transformation is satisfied. We also consider the curvature perturbation at full nonlinear order in the unitary gauge, and find that it is invariant under a general disformal transformation if we assume that an attractor regime has been reached. Finally, we also discuss the counting of degrees of freedom in theories disformally related to Horndeski's.

  8. Magnetic Moment of $^{59}$Cu

    CERN Multimedia

    2002-01-01

    Experiment IS358 uses the intense and pure beams of copper isotopes provided by the ISOLDE RILIS (resonance ionization laser ion source). The isotopes are implanted and oriented in the low temperature nuclear orientation set-up NICOLE. Magnetic moments are measured by $\\beta$-NMR. Copper (Z=29), with a single proton above the proton-magic nickel isotopes provides an ideal testground for precise shell model calculations of magnetic moments and their experimental verification. In the course of our experiments we already determined the magnetic moments of $^{67}$Ni, $^{67}$Cu, $^{68g}$Cu, $^{69}$Cu and $^{71}$Cu which provide important information on the magicity of the N=40 subshell closure. In 2001 we plan to conclude our systematic investigations by measuring the magnetic moment of the neutron-deficient isotope $^{59}$Cu. This will pave the way for a subsequent study of the magnetic moment of $^{57}$Cu with a complementary method.

  9. Chronometric Invariance and String Theory

    Science.gov (United States)

    Pollock, M. D.

    The Einstein-Hilbert Lagrangian R is expressed in terms of the chronometrically invariant quantities introduced by Zel'manov for an arbitrary four-dimensional metric gij. The chronometrically invariant three-space is the physical space γαβ = -gαβ+e2ϕ γαγβ, where e2ϕ = g00 and γα = g0α/g00, and whose determinant is h. The momentum canonically conjugate to γαβ is π α β =-√ {h}(Kα β -γ α β K), where Kα β =½ ∂ tγ α β and ∂t≡e-ϕ∂0 is the chronometrically invariant derivative with respect to time. The Wheeler-DeWitt equation for the wave function Ψ is derived. For a stationary space-time, such as the Kerr metric, παβ vanishes, implying that there is then no dynamics. The most symmetric, chronometrically-invariant space, obtained after setting ϕ = γα = 0, is Rα β =-λ (t)δ α β , where δαβ is constant and has curvature k. From the Friedmann and Raychaudhuri equations, we find that λ is constant only if k=1 and the source is a perfect fluid of energy-density ρ and pressure p=(γ-1)ρ, with adiabatic index γ=2/3, which is the value for a random ensemble of strings, thus yielding a three-dimensional de Sitter space embedded in four-dimensional space-time. Furthermore, Ψ is only invariant under the time-reversal operator {T} if γ=2/(2n-1), where n is a positive integer, the first two values n=1,2 defining the high-temperature and low-temperature limits ρ T±2, respectively, of the heterotic superstring theory, which are thus dual to one another in the sense T↔1/2π2α‧T.

  10. Position-invariant, rotation-invariant, and scale-invariant process for binary image recognition.

    Science.gov (United States)

    Levkovitz, J; Oron, E; Tur, M

    1997-05-10

    A novel recognition process is presented that is invariant under position, rotation, and scale changes. The recognition process is based on the Fang-Häusler transform [Appl. Opt. 29, 704 (1990)] and is applied to the autoconvolved image, rather than to the image itself. This makes the recognition process sensitive not only to the image histogram but also to its detailed pattern, resulting in a more reliable process that is also applicable to binary images. The proposed recognition process is demonstrated, by use of a fast algorithm, on several types of binary images with a real transform kernel, which contains amplitude, as well as phase, information. Good recognition is achieved for both synthetic and scanned images. In addition, it is shown that the Fang-Hausler transform is also invariant under a general affine transformation of the spatial coordinates.

  11. Gauge Invariance and Broken Symmetries in Anyon Superfluids

    Science.gov (United States)

    Boyanovsky, Daniel

    We review aspects of broken symmetry and the nature of long range order in theories of anyons starting with bosons with a statistical interaction. We introduce a novel gauge invariant quantization scheme that allows the identification of local and gauge invariant order parameters. The connection between spin and statistics is reviewed and the consequences of broken symmetries in the anyon representation are discussed. An anyon gas is studied in the Bogoliubov approximation, it is determined that the ground state is a condensate of charge-flux composites with “quasi-long-range order” at zero temperature, a “weak” gap in the spectrum and finite helicity modulus. The system is disordered at nonzero temperatures. The disorder is not caused by Goldstone bosons but by the strong infrared behavior arising from the Coulomb interaction induced by the long-range statistical interaction. The properties of topological vortices in nonrelativistic and in relativistic Landau-Ginzburg theories are studied in detail. We study the physics of the mean-field ansatz and quasi-long range order in a simple exactly soluble relativistic model. This model exhibits a novel phenomenon of charge redistribution to the boundaries and restoration of translational invariance in the infinite volume limit. It also illuminates the physics of quasi-long-range order with a gap in the spectrum, statistical charge polarization by external magnetic fields and the role of “large” gauge transformations.

  12. Iris Recognition Using Image Moments and k-Means Algorithm

    Directory of Open Access Journals (Sweden)

    Yaser Daanial Khan

    2014-01-01

    Full Text Available This paper presents a biometric technique for identification of a person using the iris image. The iris is first segmented from the acquired image of an eye using an edge detection algorithm. The disk shaped area of the iris is transformed into a rectangular form. Described moments are extracted from the grayscale image which yields a feature vector containing scale, rotation, and translation invariant moments. Images are clustered using the k-means algorithm and centroids for each cluster are computed. An arbitrary image is assumed to belong to the cluster whose centroid is the nearest to the feature vector in terms of Euclidean distance computed. The described model exhibits an accuracy of 98.5%.

  13. Iris recognition using image moments and k-means algorithm.

    Science.gov (United States)

    Khan, Yaser Daanial; Khan, Sher Afzal; Ahmad, Farooq; Islam, Saeed

    2014-01-01

    This paper presents a biometric technique for identification of a person using the iris image. The iris is first segmented from the acquired image of an eye using an edge detection algorithm. The disk shaped area of the iris is transformed into a rectangular form. Described moments are extracted from the grayscale image which yields a feature vector containing scale, rotation, and translation invariant moments. Images are clustered using the k-means algorithm and centroids for each cluster are computed. An arbitrary image is assumed to belong to the cluster whose centroid is the nearest to the feature vector in terms of Euclidean distance computed. The described model exhibits an accuracy of 98.5%.

  14. Exact lower and upper bounds on stationary moments in stochastic biochemical systems

    Science.gov (United States)

    Ghusinga, Khem Raj; Vargas-Garcia, Cesar A.; Lamperski, Andrew; Singh, Abhyudai

    2017-08-01

    In the stochastic description of biochemical reaction systems, the time evolution of statistical moments for species population counts is described by a linear dynamical system. However, except for some ideal cases (such as zero- and first-order reaction kinetics), the moment dynamics is underdetermined as lower-order moments depend upon higher-order moments. Here, we propose a novel method to find exact lower and upper bounds on stationary moments for a given arbitrary system of biochemical reactions. The method exploits the fact that statistical moments of any positive-valued random variable must satisfy some constraints that are compactly represented through the positive semidefiniteness of moment matrices. Our analysis shows that solving moment equations at steady state in conjunction with constraints on moment matrices provides exact lower and upper bounds on the moments. These results are illustrated by three different examples—the commonly used logistic growth model, stochastic gene expression with auto-regulation and an activator-repressor gene network motif. Interestingly, in all cases the accuracy of the bounds is shown to improve as moment equations are expanded to include higher-order moments. Our results provide avenues for development of approximation methods that provide explicit bounds on moments for nonlinear stochastic systems that are otherwise analytically intractable.

  15. Quantum Weyl invariance and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Dabholkar, Atish, E-mail: atish@ictp.it [International Centre for Theoretical Physics, ICTP-UNESCO, Strada Costiera 11, Trieste 34151 (Italy); Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7589, LPTHE, F-75005, Paris (France)

    2016-09-10

    Equations for cosmological evolution are formulated in a Weyl invariant formalism to take into account possible Weyl anomalies. Near two dimensions, the renormalized cosmological term leads to a nonlocal energy-momentum tensor and a slowly decaying vacuum energy. A natural generalization to four dimensions implies a quantum modification of Einstein field equations at long distances. It offers a new perspective on time-dependence of couplings and naturalness with potentially far-reaching consequences for the cosmological constant problem, inflation, and dark energy.

  16. Traveling salesman problem, conformal invariance, and dense polymers.

    Science.gov (United States)

    Jacobsen, J L; Read, N; Saleur, H

    2004-07-16

    We propose that the statistics of the optimal tour in the planar random Euclidean traveling salesman problem is conformally invariant on large scales. This is exhibited in the power-law behavior of the probabilities for the tour to zigzag repeatedly between two regions, and in subleading corrections to the length of the tour. The universality class should be the same as for dense polymers and minimal spanning trees. The conjectures for the length of the tour on a cylinder are tested numerically.

  17. The Electric Dipole Moment of the Electron

    Science.gov (United States)

    Commins, Eugene D.; Demille, David

    The following sections are included: * Introduction * Overview of relevant particle theory * Electron EDM in the Standard Model * Electron EDM in extensions of the Standard Model * Introduction to experimental basis for electron EDM searches * Other sources of atomic and molecular EDMs * Theoretical Basis of Electron EDM Experiments * Proper-Lorentz-invariant EDM Lagrangian density * Schiff's theorem * Enhancement factors for paramagnetic atoms * Is there a simple intuitive explanation for the Sandars effect? * P,T-odd electron-nucleon interaction * Paramagnetic molecules * Electron EDM Experiments * General overview * A simple model experiment * Noise * Systematic errors * The Berkeley thallium atomic beam experiment * Cesium optical pumping experiments * Cesium optical trap experiments * The francium optical trap experiment * The YbF experiment * The PbO experiment * The ThO experiment * The proposed HfF+ experiment * Electron EDM solid-state experiments * Basic ideas * The Indiana GGG experiment * The Amherst GdIG experiment * Atomic T,P-odd polarizability. Molecular T,P-odd magnetic moment * Acknowledgments * References

  18. Time reversal invariance in polarized neutron decay

    Energy Technology Data Exchange (ETDEWEB)

    Wasserman, Eric G. [Harvard Univ., Cambridge, MA (United States)

    1994-03-01

    An experiment to measure the time reversal invariance violating (T-violating) triple correlation (D) in the decay of free polarized neutrons has been developed. The detector design incorporates a detector geometry that provides a significant improvement in the sensitivity over that used in the most sensitive of previous experiments. A prototype detector was tested in measurements with a cold neutron beam. Data resulting from the tests are presented. A detailed calculation of systematic effects has been performed and new diagnostic techniques that allow these effects to be measured have been developed. As the result of this work, a new experiment is under way that will improve the sensitivity to D to 3 x 10-4 or better. With higher neutron flux a statistical sensitivity of the order 3 x 10-5 is ultimately expected. The decay of free polarized neutrons (n → p + e + $\\bar{v}$e) is used to search for T-violation by measuring the triple correlation of the neutron spin polarization, and the electron and proton momenta (σn • pp x pe). This correlation changes sign under reversal of the motion. Since final state effects in neutron decay are small, a nonzero coefficient, D, of this correlation indicates the violation of time reversal invariance. D is measured by comparing the numbers of coincidences in electron and proton detectors arranged symmetrically about a longitudinally polarized neutron beam. Particular care must be taken to eliminate residual asymmetries in the detectors or beam as these can lead to significant false effects. The Standard Model predicts negligible T-violating effects in neutron decay. Extensions to the Standard Model include new interactions some of which include CP-violating components. Some of these make first order contributions to D.

  19. On moments-based Heisenberg inequalities

    Science.gov (United States)

    Zozor, Steeve; Portesi, Mariela; Sanchez-Moreno, Pablo; Dehesa, Jesus S.

    2011-03-01

    In this paper we revisit the quantitative formulation of the Heisenberg uncertainty principle. The primary version of this principle establishes the impossibility of refined simultaneous measurement of position x and momentum u for a (1-dimensional) quantum particle in terms of variances: ⩾1/4. Since this inequality applies provided each variance exists, some authors proposed entropic versions of this principle as an alternative (employing Shannon's or Rényi's entropies). As another alternative, we consider moments-based formulations and show that inequalities involving moments of orders other than 2 can be found. Our procedure is based on the Rényi entropic versions of the Heisenberg relation together with the search for the maximal entropy under statistical moments' constraints ( and ). Our result improves a relation proposed very recently by Dehesa et al.. [1] where the same approach was used but starting with the Shannon version of the entropic uncertainty relation. Furthermore, we show that when a =b, the best bound we can find with our approach coincides with that of Ref. [1] and, in addition, for a = b = 2 the variance-based Heisenberg relation is recovered. Finally, we illustrate our results in the cases of d-dimensional hydrogenic systems.

  20. Statistical multipole formulations for shielding problems

    Directory of Open Access Journals (Sweden)

    K. Körber

    2012-09-01

    Full Text Available A multipole-based method is presented for modelling an electromagnetic field with small statistical variations inside an arbitrary enclosure. The accurate computation of the statistics of the field components from the statistical moments of the multipole amplitudes is demonstrated for two- and three-dimensional examples. To obtain the statistics of quantities which depend non-linearly on the field components, higher-order statistical moments of the latter are required.

  1. Transformation Invariant Control of Voxel-Wise False Discovery Rate

    Science.gov (United States)

    Li, Junning; Shi, Yonggang; Toga, Arthur W.

    2016-01-01

    Multiple testing for statistical maps remains a critical and challenging problem in brain mapping. Since the false discovery rate (FDR) criterion was introduced to the neuroimaging community a decade ago, many variations have been proposed, mainly to enhance detection power. However, a fundamental geometrical property known as transformation invariance has not been adequately addressed, especially for the voxel-wise FDR. Correction of multiple testing applied after spatial transformation is not necessarily equivalent to transformation applied after correction in the original space. Without the invariance property, assigning different testing spaces will yield different results. We find that normalized residuals of linear models with Gaussian noises are uniformly distributed on a unit high-dimensional sphere, independent of t-statistics and F-statistics. By defining volumetric measure in the hyper-spherical space mapped by normalized residuals, instead of the image’s Euclidean space, we can achieve invariant control of the FDR under diffeomorphic transformation. This hyper-spherical measure also reflects intrinsic “volume of randomness” in signals. Experiments with synthetic, semi-synthetic and real images demonstrate that our method significantly reduces FDR inconsistency introduced by the choice of testing spaces. PMID:27101602

  2. Age-invariant face recognition.

    Science.gov (United States)

    Park, Unsang; Tong, Yiying; Jain, Anil K

    2010-05-01

    One of the challenges in automatic face recognition is to achieve temporal invariance. In other words, the goal is to come up with a representation and matching scheme that is robust to changes due to facial aging. Facial aging is a complex process that affects both the 3D shape of the face and its texture (e.g., wrinkles). These shape and texture changes degrade the performance of automatic face recognition systems. However, facial aging has not received substantial attention compared to other facial variations due to pose, lighting, and expression. We propose a 3D aging modeling technique and show how it can be used to compensate for the age variations to improve the face recognition performance. The aging modeling technique adapts view-invariant 3D face models to the given 2D face aging database. The proposed approach is evaluated on three different databases (i.g., FG-NET, MORPH, and BROWNS) using FaceVACS, a state-of-the-art commercial face recognition engine.

  3. A Local Galilean Invariant Thermostat.

    Science.gov (United States)

    Groot, Robert D

    2006-05-01

    The thermostat introduced recently by Stoyanov and Groot (J. Chem. Phys. 2005, 122, 114112) is analyzed for inhomogeneous systems. This thermostat has one global feature, because the mean temperature used to drive the system toward equilibrium is a global average. The consequence is that the thermostat locally conserves energy rather than temperature. Thus, local temperature variations can be long-lived, although they do average out by thermal diffusion. To obtain a faster local temperature equilibration, a truly local thermostat must be introduced. To conserve momentum and, hence, to simulate hydrodynamic interactions, the thermostat must be Galilean invariant. Such a local Galilean invariant thermostat is studied here. It is shown that, by defining a local temperature on each particle, the ensemble is locally isothermal. The local temperature is obtained from a local square velocity average around each particle. Simulations on the ideal gas show that this local Nosé-Hoover algorithm has a similar artifact as dissipative particle dynamics:  the ideal gas pair correlation function is slightly distorted. This is attributed to the fact that the thermostat compensates fluctuations that are natural within a small cluster of particles. When the cutoff range rc for the square velocity average is increased, systematic errors decrease proportionally to rc(-)(3/2); hence, the systematic error can be made arbitrary small.

  4. Inquiry-Based Science: Turning Teachable Moments into Learnable Moments

    Science.gov (United States)

    Haug, Berit S.

    2014-02-01

    This study examines how an inquiry-based approach to teaching and learning creates teachable moments that can foster conceptual understanding in students, and how teachers capitalize upon these moments. Six elementary school teachers were videotaped as they implemented an integrated inquiry-based science and literacy curriculum in their classrooms. In this curriculum, science inquiry implies that students search for evidence in order to make and revise explanations based on the evidence found and through critical and logical thinking. Furthermore, the curriculum material is designed to address science key concepts multiple times through multiple modalities (do it, say it, read it, write it). Two types of teachable moments were identified: planned and spontaneous. Results suggest that the consolidation phases of inquiry, when students reinforce new knowledge and connect their empirical findings to theory, can be considered as planned teachable moments. These are phases of inquiry during which the teacher should expect, and be prepared for, student utterances that create opportunities to further student learning. Spontaneous teachable moments are instances when the teacher must choose to either follow the pace of the curriculum or adapt to the students' need. One implication of the study is that more teacher support is required in terms of how to plan for and effectively utilize the consolidation phases of inquiry.

  5. Statistical Moments in Variable Density Incompressible Mixing Flows

    Science.gov (United States)

    2015-08-28

    59]. The algorithm uses an approximate projection method [16] with the interface modeled with the Immersed Boundary Method ( IBM ), as spread via a nu...and B. C. Watson . Taylor instability of finite surface waves. J. Fluid Mech., 7:177–193, 1960. [32] E. Fermi. Taylor instability of an

  6. Multispectral and hyperspectral images invariant to illumination

    OpenAIRE

    Yazdani Salekdeh, Amin

    2011-01-01

    In this thesis a novel method is proposed that makes use of multispectral and hyperspectral image data to generate a novel photometric-invariant spectral image. For RGB colour image, an illuminant-invariant image was constructed independent of the illuminant and shading. To generate this image either a set of calibration images was required, or entropy information from a single image was used. For spectral images we show that photometric-invariant image formation is in essence greatly simplif...

  7. Invariant texture segmentation via circular gabor filter

    OpenAIRE

    ZHANG, Jianguo; Tan, Tieniu

    2002-01-01

    International audience; In this paper, we focus on invariant texture segmentation, and propose a new method using circular Gabor filters (CGF) for rotation invariant texture segmentation. The traditional Gabor function is modified into a circular symmetric version. The rotation invariant texture features are achieved via the channel output of the CGF. A new scheme of the selection of Gabor parameters is also proposed for texture segmentation. Experiments show the efficacy of this method

  8. Effect of reverse shoulder design philosophy on muscle moment arms.

    Science.gov (United States)

    Hamilton, Matthew A; Diep, Phong; Roche, Chris; Flurin, Pierre Henri; Wright, Thomas W; Zuckerman, Joseph D; Routman, Howard

    2015-04-01

    This study analyzes the muscle moment arms of three different reverse shoulder design philosophies using a previously published method. Digital bone models of the shoulder were imported into a 3D modeling software and markers placed for the origin and insertion of relevant muscles. The anatomic model was used as a baseline for moment arm calculations. Subsequently, three different reverse shoulder designs were virtually implanted and moment arms were analyzed in abduction and external rotation. The results indicate that the lateral offset between the joint center and the axis of the humerus specific to one reverse shoulder design increased the external rotation moment arms of the posterior deltoid relative to the other reverse shoulder designs. The other muscles analyzed demonstrated differences in the moment arms, but none of the differences reached statistical significance. This study demonstrated how the combination of variables making up different reverse shoulder designs can affect the moment arms of the muscles in different and statistically significant ways. The role of humeral offset in reverse shoulder design has not been previously reported and could have an impact on external rotation and stability achieved post-operatively. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  9. Invariance principle and model reduction for the Fokker-Planck equation.

    Science.gov (United States)

    Karlin, I V

    2016-11-13

    The principle of dynamic invariance is applied to obtain closed moment equations from the Fokker-Planck kinetic equation. The analysis is carried out to explicit formulae for computation of the lowest eigenvalue and of the corresponding eigenfunction for arbitrary potentials.This article is part of the themed issue 'Multiscale modelling at the physics-chemistry-biology interface'. © 2016 The Author(s).

  10. Wilson loop invariants from WN conformal blocks

    Directory of Open Access Journals (Sweden)

    Oleg Alekseev

    2015-12-01

    Full Text Available Knot and link polynomials are topological invariants calculated from the expectation value of loop operators in topological field theories. In 3D Chern–Simons theory, these invariants can be found from crossing and braiding matrices of four-point conformal blocks of the boundary 2D CFT. We calculate crossing and braiding matrices for WN conformal blocks with one component in the fundamental representation and another component in a rectangular representation of SU(N, which can be used to obtain HOMFLY knot and link invariants for these cases. We also discuss how our approach can be generalized to invariants in higher-representations of WN algebra.

  11. Scale invariance in road networks.

    Science.gov (United States)

    Kalapala, Vamsi; Sanwalani, Vishal; Clauset, Aaron; Moore, Cristopher

    2006-02-01

    We study the topological and geographic structure of the national road networks of the United States, England, and Denmark. By transforming these networks into their dual representation, where roads are vertices and an edge connects two vertices if the corresponding roads ever intersect, we show that they exhibit both topological and geographic scale invariance. That is, we show that for sufficiently large geographic areas, the dual degree distribution follows a power law with exponent 2.2< or = alpha < or =2.4, and that journeys, regardless of their length, have a largely identical structure. To explain these properties, we introduce and analyze a simple fractal model of road placement that reproduces the observed structure, and suggests a testable connection between the scaling exponent and the fractal dimensions governing the placement of roads and intersections.

  12. Modular invariance and entanglement entropy

    Energy Technology Data Exchange (ETDEWEB)

    Lokhande, Sagar Fakirchand; Mukhi, Sunil [Indian Institute of Science Education and Research,Homi Bhabha Rd, Pashan, Pune 411 008 (India)

    2015-06-17

    We study the Rényi and entanglement entropies for free 2d CFT’s at finite temperature and finite size, with emphasis on their properties under modular transformations of the torus. We address the issue of summing over fermion spin structures in the replica trick, and show that the relation between entanglement and thermal entropy determines two different ways to perform this sum in the limits of small and large interval. Both answers are modular covariant, rather than invariant. Our results are compared with those for a free boson at unit radius in the two limits and complete agreement is found, supporting the view that entanglement respects Bose-Fermi duality. We extend our computations to multiple free Dirac fermions having correlated spin structures, dual to free bosons on the Spin(2d) weight lattice.

  13. Negation switching invariant signed graphs

    Directory of Open Access Journals (Sweden)

    Deepa Sinha

    2014-04-01

    Full Text Available A signed graph (or, $sigraph$ in short is a graph G in which each edge x carries a value $\\sigma(x \\in \\{-, +\\}$ called its sign. Given a sigraph S, the negation $\\eta(S$ of the sigraph S is a sigraph obtained from S by reversing the sign of every edge of S. Two sigraphs $S_{1}$ and $S_{2}$ on the same underlying graph are switching equivalent if it is possible to assign signs `+' (`plus' or `-' (`minus' to vertices of $S_{1}$ such that by reversing the sign of each of its edges that has received opposite signs at its ends, one obtains $S_{2}$. In this paper, we characterize sigraphs which are negation switching invariant and also see for what sigraphs, S and $\\eta (S$ are signed isomorphic.

  14. Quadrupole moment of 203Fr

    Science.gov (United States)

    Wilkins, S. G.; Lynch, K. M.; Billowes, J.; Binnersley, C. L.; Bissell, M. L.; Cocolios, T. E.; Goodacre, T. Day; de Groote, R. P.; Farooq-Smith, G. J.; Flanagan, K. T.; Franchoo, S.; Ruiz, R. F. Garcia; Gins, W.; Heylen, H.; Koszorús, Á.; Neyens, G.; Stroke, H. H.; Vernon, A. R.; Wendt, K. D. A.; Yang, X. F.

    2017-09-01

    The spectroscopic electric quadrupole moment of the neutron-deficient francium isotope 203Fr was measured by using high-resolution collinear resonance ionization spectroscopy (CRIS) at the CERN Isotope Separation On-Line Device (ISOLDE) facility. A remeasurement of the 207Fr quadrupole moment was also performed, resulting in a departure from the established literature value. A sudden increase in magnitude of the 203Fr quadrupole moment, with respect to the general trend in the region, points to an onset of static deformation at N =116 in the 87Fr isotopic chain. Calculation of the static and total deformation parameters show that the increase in static deformation only cannot account for the observed departure of its relative charge radius from the 82Pb chain.

  15. Moment Distributions of Phase Type

    DEFF Research Database (Denmark)

    Bladt, Mogens; Nielsen, Bo Friis

    In this paper we prove that the class of distributions on the positive reals with a rational Laplace transform, also known as matrix-exponential distributions, is closed under formation of moment distributions. In particular, the results are hence valid for the well known class of phase-type dist......In this paper we prove that the class of distributions on the positive reals with a rational Laplace transform, also known as matrix-exponential distributions, is closed under formation of moment distributions. In particular, the results are hence valid for the well known class of phase...

  16. Method of moments in electromagnetics

    CERN Document Server

    Gibson, Walton C

    2007-01-01

    Responding to the need for a clear, up-to-date introduction to the field, The Method of Moments in Electromagnetics explores surface integral equations in electromagnetics and presents their numerical solution using the method of moments (MOM) technique. It provides the numerical implementation aspects at a nuts-and-bolts level while discussing integral equations and electromagnetic theory at a higher level. The author covers a range of topics in this area, from the initial underpinnings of the MOM to its current applications. He first reviews the frequency-domain electromagnetic theory and t

  17. Borromean surgery formula for the Casson invariant

    DEFF Research Database (Denmark)

    Meilhan, Jean-Baptiste Odet Thierry

    2008-01-01

    It is known that every oriented integral homology 3-sphere can be obtained from S3 by a finite sequence of Borromean surgeries. We give an explicit formula for the variation of the Casson invariant under such a surgery move. The formula involves simple classical invariants, namely the framing, li...

  18. Numerical Approximation of Normally Hyperbolic Invariant Manifolds

    NARCIS (Netherlands)

    Broer, Henk; Hagen, Aaron; Vegter, Gert

    2003-01-01

    This paper deals with the numerical continuation of invariant manifolds, regardless of the restricted dynamics. Typically, invariant manifolds make up the skeleton of the dynamics of phase space. Examples include limit sets, co-dimension 1 manifolds separating basins of attraction (separatrices),

  19. Invariant Ordering of Item-Total Regressions

    Science.gov (United States)

    Tijmstra, Jesper; Hessen, David J.; van der Heijden, Peter G. M.; Sijtsma, Klaas

    2011-01-01

    A new observable consequence of the property of invariant item ordering is presented, which holds under Mokken's double monotonicity model for dichotomous data. The observable consequence is an invariant ordering of the item-total regressions. Kendall's measure of concordance "W" and a weighted version of this measure are proposed as measures for…

  20. Scale invariant Volkov–Akulov supergravity

    Directory of Open Access Journals (Sweden)

    S. Ferrara

    2015-10-01

    Full Text Available A scale invariant goldstino theory coupled to supergravity is obtained as a standard supergravity dual of a rigidly scale-invariant higher-curvature supergravity with a nilpotent chiral scalar curvature. The bosonic part of this theory describes a massless scalaron and a massive axion in a de Sitter Universe.

  1. The invariator principle in convex geometry

    DEFF Research Database (Denmark)

    Thórisdóttir, Ólöf; Kiderlen, Markus

    The invariator principle is a measure decomposition that was rediscovered in local stereology in 2005 and has since been used widely in the stereological literature. We give an exposition of invariator related results where existing formulae are generalized and new ones proposed. In particular, w...

  2. Quiet Moment around the Campfire

    Centers for Disease Control (CDC) Podcasts

    2014-06-18

    Byron Breedlove reads his essay, "Quiet Moment around the Campfire," about the art of Frederic Remington and the transmission of pathogens as frontiers expand.  Created: 6/18/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 6/19/2014.

  3. Measuring the Moment of Inertia

    Science.gov (United States)

    Lehmberg, George L.

    1978-01-01

    Two physics experiments are described, One, involving a laboratory cart accelerated along a level surface, examines the concept of inertial mass in translation and the other, using a solid cylinder, measures the moment of inertia of a wheel. Equations and illustrations are included. (MA)

  4. Particle electric dipole-moments

    Energy Technology Data Exchange (ETDEWEB)

    Pendlebury, J.M. [Sussex Univ., Brighton (United Kingdom)

    1997-04-01

    The incentive to detect particle electric dipole-moments, as a window on time-reversal violation, remains undiminished. Efforts to improve the measurements for the neutron, the electron and some nuclei are still making rapid progress as more powerful experimental methods are brought to bear. A new measurement for the neutron at ILL is presented. (author). 7 refs.

  5. Fantastic Learning Moments and Where to Find Them.

    Science.gov (United States)

    Sheng, Alexander Y; Sullivan, Ryan; Kleber, Kara; Mitchell, Patricia M; Liu, James H; McGreevy, Jolion; McCabe, Kerry; Atema, Annemieke; Schneider, Jeffrey I

    2018-01-01

    Experiential learning is crucial for the development of all learners. Literature exploring how and where experiential learning happens in the modern clinical learning environment is sparse. We created a novel, web-based educational tool called "Learning Moment" (LM) to foster experiential learning among our learners. We used data captured by LM as a research database to determine where learning experiences were occuring within our emergency department (ED). We hypothesized that these moments would occur more frequently at the physician workstations as opposed to the bedside. We implemented LM at a single ED's medical student clerkship. The platform captured demographic data including the student's intended specialty and year of training as well as "learning moments," defined as logs of learner self-selected learning experiences that included the clinical "pearl," clinical scenario, and location where the "learning moment" occurred. We presented data using descriptive statistics with frequencies and percentages. Locations of learning experiences were stratified by specialty and training level. A total of 323 "learning moments" were logged by 42 registered medical students (29 fourth-year medical students (MS 4) and 13 MS 3 over a six-month period. Over half (52.4%) intended to enter the field of emergency medicine (EM). Of these "learning moments," 266 included optional location data. The most frequently reported location was patient rooms (135 "learning moments", 50.8%). Physician workstations hosted the second most frequent "learning moments" (67, 25.2%). EM-bound students reported 43.7% of "learning moments" happening in patient rooms, followed by workstations (32.8%). On the other hand, non EM-bound students reported that 66.3% of "learning moments" occurred in patient rooms and only 8.4% at workstations (plearning cycle for our learners. In our environment, patient rooms represented the most frequent location of "learning moments," followed by physician

  6. Precise asymptotics for complete moment convergence in Hilbert ...

    Indian Academy of Sciences (India)

    (Math. Sci.) Vol. 122, No. 1, February 2012, pp. 87–97. c Indian Academy of Sciences. Precise asymptotics for complete moment convergence in Hilbert spaces ... School of Statistics and Mathematics, Zhejiang Gongshang University, .... Now we start to introduce some Propositions, and the proof of our main result is based.

  7. Searches for permanent electric dipole moments in Radium isotopes

    OpenAIRE

    Willmann, L.; Jungmann, K.; Wilschut, H. W.

    2010-01-01

    Permanent electric dipole moments are uniquely sensitive to sources of T and P violation in fundamental interactions. In particular radium isotopes offer the largest intrinsic sensitivity. We want to explore the prospects for utilizing the high intense beams from HIE-ISOLDE to boost the statistical sensitivity of search for EDMs in atomic radium.

  8. Searches for permanent electric dipole moments in Radium isotopes

    NARCIS (Netherlands)

    Willmann, L.; Jungmann, K.; Wilschut, H.W.

    2010-01-01

    Permanent electric dipole moments are uniquely sensitive to sources of T and P violation in fundamental interactions. In particular radium isotopes offer the largest intrinsic sensitivity. We want to explore the prospects for utilizing the high intense beams from HIE-ISOLDE to boost the statistical

  9. Negative electric susceptibility and magnetism from translational invariance and rotational invariance

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Je Huan, E-mail: koo@kw.ac.kr

    2015-02-01

    In this work we investigate magnetic effects in terms of the translational and rotational invariances of magnetisation. Whilst Landau-type diamagnetism originates from translational invariance, a new diamagnetism could result from rotational invariance. Translational invariance results in only conventional Landau-type diamagnetism, whereas rotational invariance can induce a paramagnetic susceptibility for localised electrons and also a new kind of diamagnetism that is specific to conducting electrons. In solids, the moving electron shows a paramagnetic susceptibility but the surrounding screening of electrons may produce a new diamagnetic response by Lenz's law, resulting in a total susceptibility that tends to zero. For electricity, similar behaviours are obtained. We also derive the DC-type negative electric susceptibility via two methods in analogy with Landau diamagnetism. - Highlights: • The translational invariance of magnetisation. • The rotational invariance of magnetisation. • An electron attached to an electric vortex. • A kind of Landau paramagnetism. • A kind of Pauli diamagnetism.

  10. A scale invariance criterion for LES parametrizations

    Directory of Open Access Journals (Sweden)

    Urs Schaefer-Rolffs

    2015-01-01

    Full Text Available Turbulent kinetic energy cascades in fluid dynamical systems are usually characterized by scale invariance. However, representations of subgrid scales in large eddy simulations do not necessarily fulfill this constraint. So far, scale invariance has been considered in the context of isotropic, incompressible, and three-dimensional turbulence. In the present paper, the theory is extended to compressible flows that obey the hydrostatic approximation, as well as to corresponding subgrid-scale parametrizations. A criterion is presented to check if the symmetries of the governing equations are correctly translated into the equations used in numerical models. By applying scaling transformations to the model equations, relations between the scaling factors are obtained by demanding that the mathematical structure of the equations does not change.The criterion is validated by recovering the breakdown of scale invariance in the classical Smagorinsky model and confirming scale invariance for the Dynamic Smagorinsky Model. The criterion also shows that the compressible continuity equation is intrinsically scale-invariant. The criterion also proves that a scale-invariant turbulent kinetic energy equation or a scale-invariant equation of motion for a passive tracer is obtained only with a dynamic mixing length. For large-scale atmospheric flows governed by the hydrostatic balance the energy cascade is due to horizontal advection and the vertical length scale exhibits a scaling behaviour that is different from that derived for horizontal length scales.

  11. Feedback-Driven Dynamic Invariant Discovery

    Science.gov (United States)

    Zhang, Lingming; Yang, Guowei; Rungta, Neha S.; Person, Suzette; Khurshid, Sarfraz

    2014-01-01

    Program invariants can help software developers identify program properties that must be preserved as the software evolves, however, formulating correct invariants can be challenging. In this work, we introduce iDiscovery, a technique which leverages symbolic execution to improve the quality of dynamically discovered invariants computed by Daikon. Candidate invariants generated by Daikon are synthesized into assertions and instrumented onto the program. The instrumented code is executed symbolically to generate new test cases that are fed back to Daikon to help further re ne the set of candidate invariants. This feedback loop is executed until a x-point is reached. To mitigate the cost of symbolic execution, we present optimizations to prune the symbolic state space and to reduce the complexity of the generated path conditions. We also leverage recent advances in constraint solution reuse techniques to avoid computing results for the same constraints across iterations. Experimental results show that iDiscovery converges to a set of higher quality invariants compared to the initial set of candidate invariants in a small number of iterations.

  12. Comment on ``Pairing interaction and Galilei invariance''

    Science.gov (United States)

    Arias, J. M.; Gallardo, M.; Gómez-Camacho, J.

    1999-05-01

    A recent article by Dussel, Sofia, and Tonina studies the relation between Galilei invariance and dipole energy weighted sum rule (EWSR). The authors find that the pairing interaction, which is neither Galilei nor Lorentz invariant, produces big changes in the EWSR and in effective masses of the nucleons. They argue that these effects of the pairing force could be realistic. In this Comment we stress the validity of Galilei invariance to a very good approximation in this context of low-energy nuclear physics and show that the effective masses and the observed change in the EWSR for the electric dipole operator relative to its classical value are compatible with this symmetry.

  13. Stability and Invariance of Psychopathic Traits from Late Adolescence to Young Adulthood

    Science.gov (United States)

    Neumann, Craig; Wampler, Megan; Taylor, Jeanette; Blonigen, Daniel M.; Iacono, William G.

    2011-01-01

    The current study examined the longitudinal stability and invariance of psychopathic traits in a large community sample of male twins from ages 17 to 23. Participants were assessed across six years to gauge the stability and measurement invariance of the Minnesota Temperament Inventory (MTI), a Cleckley-based measure of psychopathic personality traits, and how family functioning and externalizing behavior were linked to these traits. A latent variable approach was used to model the structure of the MTI and provide a statistical test of measurement invariance across time. The results revealed support for invariance and moderate to strong stability of the MTI factors, which showed significant associations with the external correlates in late adolescence but not early adulthood. PMID:21572537

  14. Stability and Invariance of Psychopathic Traits from Late Adolescence to Young Adulthood.

    Science.gov (United States)

    Neumann, Craig; Wampler, Megan; Taylor, Jeanette; Blonigen, Daniel M; Iacono, William G

    2011-04-01

    The current study examined the longitudinal stability and invariance of psychopathic traits in a large community sample of male twins from ages 17 to 23. Participants were assessed across six years to gauge the stability and measurement invariance of the Minnesota Temperament Inventory (MTI), a Cleckley-based measure of psychopathic personality traits, and how family functioning and externalizing behavior were linked to these traits. A latent variable approach was used to model the structure of the MTI and provide a statistical test of measurement invariance across time. The results revealed support for invariance and moderate to strong stability of the MTI factors, which showed significant associations with the external correlates in late adolescence but not early adulthood.

  15. Moment of truth for CMS

    CERN Multimedia

    2006-01-01

    One of the first events reconstructed in the Muon Drift Tubes, the Hadron Calorimeter and elements of the Silicon Tracker (TK) at 3 Tesla. The atmosphere in the CMS control rooms was electric. Everbody was at the helm for the first full-scale testing of the experiment. This was a crunch moment for the entire collaboration. On Tuesday, 22 August the magnet attained almost its nominal power of 4 Tesla! At the same moment, in a tiny improvised control room, the physicists were keyed up to test the entire detector system for the first time. The first cosmic ray tracks appeared on their screens in the week of 15 August. The tests are set to continue for several weeks more until the first CMS components are lowered into their final positions in the cavern.

  16. General moment theorems for nondistinct unrestricted partitions

    Science.gov (United States)

    Coons, Michael; Kirsten, Klaus

    2009-01-01

    A well-known result from Hardy and Ramanujan ["Aysmptotic formulae in combinatory analysis," Proc. Lond. Math. Soc. 17, 75 (1918)] gives an asymptotic expression for the number of possible ways to express an integer as the sum of smaller integers. In this vein, we consider the general partitioning problem of writing an integer n as a sum of summands from a given sequence Λ of nondecreasing integers. Under suitable assumptions on the sequence Λ, we obtain results using associated zeta functions and saddle-point techniques. We also calculate higher moments of the sequence Λ as well as the expected number of summands. Applications are made to various sequences, including those of Barnes and Epstein types. These results are of potential interest in statistical mechanics in the context of Bose-Einstein condensation.

  17. Modified dispersion relations, inflation, and scale invariance

    Science.gov (United States)

    Bianco, Stefano; Friedhoff, Victor Nicolai; Wilson-Ewing, Edward

    2018-02-01

    For a certain type of modified dispersion relations, the vacuum quantum state for very short wavelength cosmological perturbations is scale-invariant and it has been suggested that this may be the source of the scale-invariance observed in the temperature anisotropies in the cosmic microwave background. We point out that for this scenario to be possible, it is necessary to redshift these short wavelength modes to cosmological scales in such a way that the scale-invariance is not lost. This requires nontrivial background dynamics before the onset of standard radiation-dominated cosmology; we demonstrate that one possible solution is inflation with a sufficiently large Hubble rate, for this slow roll is not necessary. In addition, we also show that if the slow-roll condition is added to inflation with a large Hubble rate, then for any power law modified dispersion relation quantum vacuum fluctuations become nearly scale-invariant when they exit the Hubble radius.

  18. Invariant Measures of Genetic Recombination Processes

    Science.gov (United States)

    Akopyan, Arseniy V.; Pirogov, Sergey A.; Rybko, Aleksandr N.

    2015-07-01

    We construct a non-linear Markov process connected with a biological model of a bacterial genome recombination. The description of invariant measures of this process gives us the solution of one problem in elementary probability theory.

  19. Testing Lorentz invariance of dark matter

    CERN Document Server

    Blas, Diego; Sibiryakov, Sergey

    2012-01-01

    We study the possibility to constrain deviations from Lorentz invariance in dark matter (DM) with cosmological observations. Breaking of Lorentz invariance generically introduces new light gravitational degrees of freedom, which we represent through a dynamical timelike vector field. If DM does not obey Lorentz invariance, it couples to this vector field. We find that this coupling affects the inertial mass of small DM halos which no longer satisfy the equivalence principle. For large enough lumps of DM we identify a (chameleon) mechanism that restores the inertial mass to its standard value. As a consequence, the dynamics of gravitational clustering are modified. Two prominent effects are a scale dependent enhancement in the growth of large scale structure and a scale dependent bias between DM and baryon density perturbations. The comparison with the measured linear matter power spectrum in principle allows to bound the departure from Lorentz invariance of DM at the per cent level.

  20. Testing Lorentz invariance of dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Blas, Diego [Theory Group, Physics Department, CERN, CH-1211 Geneva 23 (Switzerland); Ivanov, Mikhail M.; Sibiryakov, Sergey, E-mail: diego.blas@cern.ch, E-mail: mm.ivanov@physics.msu.ru, E-mail: sibir@inr.ac.ru [Faculty of Physics, Moscow State University, Vorobjevy Gory, 119991 Moscow (Russian Federation)

    2012-10-01

    We study the possibility to constrain deviations from Lorentz invariance in dark matter (DM) with cosmological observations. Breaking of Lorentz invariance generically introduces new light gravitational degrees of freedom, which we represent through a dynamical timelike vector field. If DM does not obey Lorentz invariance, it couples to this vector field. We find that this coupling affects the inertial mass of small DM halos which no longer satisfy the equivalence principle. For large enough lumps of DM we identify a (chameleon) mechanism that restores the inertial mass to its standard value. As a consequence, the dynamics of gravitational clustering are modified. Two prominent effects are a scale dependent enhancement in the growth of large scale structure and a scale dependent bias between DM and baryon density perturbations. The comparison with the measured linear matter power spectrum in principle allows to bound the departure from Lorentz invariance of DM at the per cent level.

  1. Ermakov–Lewis invariants and Reid systems

    Energy Technology Data Exchange (ETDEWEB)

    Mancas, Stefan C., E-mail: stefan.mancas@erau.edu [Department of Mathematics, Embry-Riddle Aeronautical University, Daytona Beach, FL 32114-3900 (United States); Rosu, Haret C., E-mail: hcr@ipicyt.edu.mx [IPICyT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San José 2055, Col. Lomas 4a Sección, 78216 San Luis Potosí, S.L.P. (Mexico)

    2014-06-13

    Reid's mth-order generalized Ermakov systems of nonlinear coupling constant α are equivalent to an integrable Emden–Fowler equation. The standard Ermakov–Lewis invariant is discussed from this perspective, and a closed formula for the invariant is obtained for the higher-order Reid systems (m≥3). We also discuss the parametric solutions of these systems of equations through the integration of the Emden–Fowler equation and present an example of a dynamical system for which the invariant is equivalent to the total energy. - Highlights: • Reid systems of order m are connected to Emden–Fowler equations. • General expressions for the Ermakov–Lewis invariants both for m=2 and m≥3 are obtained. • Parametric solutions of the Emden–Fowler equations related to Reid systems are obtained.

  2. Numerical considerations in computing invariant subspaces

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J.J. (Tennessee Univ., Knoxville, TN (USA). Dept. of Computer Science Oak Ridge National Lab., TN (USA)); Hammarling, S. (Numerical Algorithms Group Ltd., Oxford (UK)); Wilkinson, J.H. (Oak Ridge National Lab., TN (USA))

    1990-11-01

    This paper describes two methods for computing the invariant subspace of a matrix. The first involves using transformations to interchange the eigenvalues; the second involves direct computation of the vectors. 10 refs.

  3. Gauge invariance for a whole Abelian model

    Science.gov (United States)

    Chauca, J.; Doria, R.; Soares, W.

    2012-10-01

    Light invariance is a fundamental principle for physics be done. It generates Maxwell equations, relativity, Lorentz group. However there is still space for a fourth picture be developed which is to include fields with same Lorentz nature. It brings a new room for field theory. It says that light invariance does not work just to connect space and time but it also associates different fields with same nature. Thus for the (1/2,1/2) representation there is a fields family {AμI} to be studied. This means that given such fields association one should derive its corresponding gauge theory. This is the effort at this work. Show that there is a whole gauge theory to cover these fields relationships. Considering the abelian case, prove its gauge invariance. It yields the kinetic, massive, trilinear and quadrilinear gauge invariant terms.

  4. Gauge invariance for a whole Abelian model

    Energy Technology Data Exchange (ETDEWEB)

    Chauca, J.; Doria, R.; Soares, W. [CBPF, Rio de Janeiro (Brazil); Aprendanet, Petropolis, 25600 (Brazil)

    2012-09-24

    Light invariance is a fundamental principle for physics be done. It generates Maxwell equations, relativity, Lorentz group. However there is still space for a fourth picture be developed which is to include fields with same Lorentz nature. It brings a new room for field theory. It says that light invariance does not work just to connect space and time but it also associates different fields with same nature. Thus for the ((1/2),(1/2)) representation there is a fields family {l_brace}A{sub {mu}I}{r_brace} to be studied. This means that given such fields association one should derive its corresponding gauge theory. This is the effort at this work. Show that there is a whole gauge theory to cover these fields relationships. Considering the abelian case, prove its gauge invariance. It yields the kinetic, massive, trilinear and quadrilinear gauge invariant terms.

  5. On invariant measures of nonlinear Markov processes

    Directory of Open Access Journals (Sweden)

    N. U. Ahmed

    1993-01-01

    Full Text Available We consider a nonlinear (in the sense of McKean Markov process described by a stochastic differential equations in Rd. We prove the existence and uniqueness of invariant measures of such process.

  6. Galilean invariance in 2+1 dimensions

    OpenAIRE

    Brihaye, Y.; Gonera, C.; Giller, S; Kosinski, P.

    1995-01-01

    The Galilean invariance in three dimensional space-time is considered. It appears that the Galilei group in 2+1 dimensions posses a three-parameter family of projective representations. Their physical interpretation is discussed in some detail.

  7. Factorial invariance of the Adult State Hope Scale

    Directory of Open Access Journals (Sweden)

    Petrus Nel

    2014-02-01

    Full Text Available Orientation: Given the interest in the impact of positive psychology on employees, it is imperative to use reliable and valid instruments to operationalise positive-psychology constructs. One such construct is hope.Research purpose: The purpose of the study was to assess the degree of factorial invariance across race and gender by using a sample of aspiring chartered accountants.Motivation for the study: Previous research on the hope construct and associated measuring instruments have been conducted, using homogenous samples from Westernised cultures. Researchers need to be careful to assume that hope looks and behaves in exactly the same manner across cultures and groups.Research approach, design and method: A cross-sectional quantitative research design was used. A sample of 295 aspiring chartered accountants participated in the study. Exploratory factor analysis was used to determine the degree of factor similarity across groups, utilising Tucker’s coefficient of congruence. To supplement the exploratory factor analysis, a series of increasingly restrictive multi-group analyses were conducted to test the invariance of model parameters across the groups.Main findings: No significant differences were found in the factor patterns for the agency and pathways factors for (1 the white and designated groups and (2 females and males.Practical/managerial implications: Evidence related to factorial invariance was found. This should inform researchers and practitioners that both pathways and agency look similar across racial and gender groups.Contribution/value-add: Researchers are urged to use various statistical techniques, in combination, to determine the degree of factorial invariance across groups.

  8. Inference in partially identified models with many moment inequalities using Lasso

    DEFF Research Database (Denmark)

    Bugni, Federico A.; Caner, Mehmet; Kock, Anders Bredahl

    This paper considers the problem of inference in a partially identified moment (in)equality model with possibly many moment inequalities. Our contribution is to propose a novel two-step new inference method based on the combination of two ideas. On the one hand, our test statistic and critical...

  9. Fibred knots and twisted Alexander invariants

    OpenAIRE

    Cha, Jae Choon

    2001-01-01

    We introduce a new algebraic topological technique to detect non-fibred knots in the three sphere using the twisted Alexander invariants. As an application, we show that for any Seifert matrix of a knot with a nontrivial Alexander polynomial, there exist infinitely many non-fibered knots with the given Seifert matrix. We illustrate examples of knots that have trivial Alexander polynomials but do not have twisted Alexander invariants of fibred knots.

  10. Pinning down top dipole moments with ultra-boosted tops

    CERN Document Server

    Aguilar-Saavedra, Juan A.; Mangano, Michelangelo L.

    2015-01-01

    We investigate existing and future hadron-collider constraints on the top dipole chromomagnetic and chromoelectric moments, two quantities that are expected to be modified in the presence of new physics. We focus first on recent measurements of the inclusive top pair production cross section at the Tevatron and at the Large Hadron Collider. We then analyse the role of top-antitop events produced at very large invariant masses, in the context of the forthcoming 13-14 TeV runs of the LHC, and at a future 100 TeV proton-proton collider. In this latter case, the selection of semileptonic decays to hard muons allows to tag top quarks boosted to the multi-TeV regime, strongly reducing the QCD backgrounds and leading to a significant improvement in the sensitivity to anomalous top couplings.

  11. Fractal transforms and feature invariance

    NARCIS (Netherlands)

    B.A.M. Schouten (Ben); P.M. de Zeeuw (Paul)

    2000-01-01

    htmlabstractIn this paper, fractal transforms are employed with the aim of image recognition. It is known that such transforms are highly sensitive to distortions like a small shift of an image. However, by using features based on statistics kept during the actual decomposition we can derive

  12. Moment Closure for the Stochastic Logistic Model

    National Research Council Canada - National Science Library

    Singh, Abhyudai; Hespanha, Joao P

    2006-01-01

    ..., which we refer to as the moment closure function. In this paper, a systematic procedure for constructing moment closure functions of arbitrary order is presented for the stochastic logistic model...

  13. Nuclear Quadrupole Moments and Nuclear Shell Structure

    Science.gov (United States)

    Townes, C. H.; Foley, H. M.; Low, W.

    1950-06-23

    Describes a simple model, based on nuclear shell considerations, which leads to the proper behavior of known nuclear quadrupole moments, although predictions of the magnitudes of some quadrupole moments are seriously in error.

  14. Towards a high-precision measurement of the antiproton magnetic moment

    CERN Document Server

    Smorra, C.; Franke, K.; Matsuda, Y.; Mooser, A.; Nagahama, H.; Ospelkaus, C.; Quint, W.; Schneider, G.; Van Gorp, S.; Walz, J.; Yamazaki, Y.; Ulmer, S.

    2014-01-01

    The recent observation of single spins flips with a single proton in a Penning trap opens the way to measure the proton magnetic moment with high precision. Based on this success, which has been achieved with our apparatus at the University of Mainz, we demonstrated recently the first application of the so called double Penning-trap method with a single proton. This is a major step towards a measurement of the proton magnetic moment with ppb precision. To apply this method to a single trapped antiproton our collaboration is currently setting up a companion experiment at the antiproton decelerator of CERN. This effort is recognized as the Baryon Antibaryon Symmetry Experiment (BASE). A comparison of both magnetic moment values will provide a stringent test of CPT invariance with baryons.

  15. Defining moments in leadership character development.

    Science.gov (United States)

    Bleich, Michael R

    2015-06-01

    Critical moments in life define one's character and clarify true values. Reflective leadership is espoused as an important practice for transformational leaders. Professional development educators can help surface and explore defining moments, strengthen leadership behavior with defining moments as a catalyst for change, and create safe spaces for leaders to expand their leadership capacity. Copyright 2015, SLACK Incorporated.

  16. On the interpretation of the support moment

    NARCIS (Netherlands)

    Hof, AL

    2000-01-01

    It has been suggested by Winter (J. Biomech. 13 (1980) 923-927) that the 'support moment', the sum of the sagittal extension moments, shows less variability in walking than any of the joint moments separately. A simple model is put forward to explain this finding. It is proposed to reformulate the

  17. The Krein condition for the moment problem

    DEFF Research Database (Denmark)

    Pedersen, Henrik Laurberg

    2005-01-01

    In this paper, we describe a class of Wiener functionals that are `indeterminate by their moments', that is, whose distributions are not uniquely determined by their moments. In particular, it is proved that the integral of a geometric Brownian motion is indeterminate by its moments and, moreover...

  18. Electric and Magnetic Dipole Moments

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    The stringent limit on the electric dipole moment of the neutron forced the issue on the strong CP-problem. The most elegant solution of which is the axion field proposed by Peccei and Quinn. The current limit on the QCD parameter theta coming from the limit on the neutron EDM is of order 10-10. I am going to describe the present status on the neutron EDM searches and further prospects on getting down to theta_qcd sensitivity of 10-13 with the new deuteron EDM in storage rings proposal. For completeness the current status and prospects of the muon g-2 experiment will also be given.

  19. Multifractals embedded in short time series: An unbiased estimation of probability moment

    Science.gov (United States)

    Qiu, Lu; Yang, Tianguang; Yin, Yanhua; Gu, Changgui; Yang, Huijie

    2016-12-01

    An exact estimation of probability moments is the base for several essential concepts, such as the multifractals, the Tsallis entropy, and the transfer entropy. By means of approximation theory we propose a new method called factorial-moment-based estimation of probability moments. Theoretical prediction and computational results show that it can provide us an unbiased estimation of the probability moments of continuous order. Calculations on probability redistribution model verify that it can extract exactly multifractal behaviors from several hundred recordings. Its powerfulness in monitoring evolution of scaling behaviors is exemplified by two empirical cases, i.e., the gait time series for fast, normal, and slow trials of a healthy volunteer, and the closing price series for Shanghai stock market. By using short time series with several hundred lengths, a comparison with the well-established tools displays significant advantages of its performance over the other methods. The factorial-moment-based estimation can evaluate correctly the scaling behaviors in a scale range about three generations wider than the multifractal detrended fluctuation analysis and the basic estimation. The estimation of partition function given by the wavelet transform modulus maxima has unacceptable fluctuations. Besides the scaling invariance focused in the present paper, the proposed factorial moment of continuous order can find its various uses, such as finding nonextensive behaviors of a complex system and reconstructing the causality relationship network between elements of a complex system.

  20. DDF and Pohlmeyer invariants of (super)string

    OpenAIRE

    Schreiber, Urs

    2004-01-01

    We show how the Pohlmeyer invariants of the bosonic string are expressible in terms of DDF invariants. Quantization of the DDF observables in the usual way yields a consistent quantization of the algebra of Pohlmeyer invariants. Furthermore it becomes straightforward to generalize the Pohlmeyer invariants to the superstring as well as to all backgrounds which allow a free field realization of the worldsheet theory.

  1. Invariant geodynamical information in geometric geodetic measurements

    Science.gov (United States)

    Xu, Peiliang; Shimada, Seiichi; Fujii, Yoichiro; Tanaka, Torao

    2000-08-01

    Repeated geodetic measurements have been used to extract geodynamical quantities such as displacements, velocities of movement and crustal strains. Historical geodetic networks, especially those established before the space geodetic era, were, and still are, very important in providing a unique insight into the (local or regional) historical deformation state of the Earth. For the geodetic network without a tie to an external reference frame, free network adjustment methods have been widely applied to derive geodynamical quantities. Currently, it is commonly accepted that absolute displacements cannot be uniquely determined from triangulation/trilateration measurements, but relative displacements can be found uniquely if the geodetic network is geometrically overdetermined (see e.g. Segall & Matthews 1988). Strain tensors were derived using the coordinate method and were reported to be uniquely determined. We have carried out a theoretical analysis of invariant geodynamical information in geometric geodetic observations and concluded: (1) that relative displacements are not invariant quantities and thus cannot be uniquely determined from the geodetic network without a tie to an external reference frame; and (2) the components of the strain tensors are not all invariant and thus cannot individually be determined uniquely from the network. However, certain combinations of strain components are indeed invariant and can be uniquely determined from geometric geodetic measurements. The theory of invariant information is then applied to the analysis of the Tokai first-order triangulation/trilateration network spanning an interval of more than 100yr. The results show that the normal and principal strains are significantly affected by the unknown scaling biases and orientation differences; thus any attempt at geophysical interpretation of these quantities must be exercised with great care. If the scaling bias and the orientation difference are small, the shear strain is

  2. Generalized method of moments for estimating parameters of stochastic reaction networks.

    Science.gov (United States)

    Lück, Alexander; Wolf, Verena

    2016-10-21

    Discrete-state stochastic models have become a well-established approach to describe biochemical reaction networks that are influenced by the inherent randomness of cellular events. In the last years several methods for accurately approximating the statistical moments of such models have become very popular since they allow an efficient analysis of complex networks. We propose a generalized method of moments approach for inferring the parameters of reaction networks based on a sophisticated matching of the statistical moments of the corresponding stochastic model and the sample moments of population snapshot data. The proposed parameter estimation method exploits recently developed moment-based approximations and provides estimators with desirable statistical properties when a large number of samples is available. We demonstrate the usefulness and efficiency of the inference method on two case studies. The generalized method of moments provides accurate and fast estimations of unknown parameters of reaction networks. The accuracy increases when also moments of order higher than two are considered. In addition, the variance of the estimator decreases, when more samples are given or when higher order moments are included.

  3. Regional frequency analysis of extreme rainfalls using partial L moments method

    Science.gov (United States)

    Zakaria, Zahrahtul Amani; Shabri, Ani

    2013-07-01

    An approach based on regional frequency analysis using L moments and LH moments are revisited in this study. Subsequently, an alternative regional frequency analysis using the partial L moments (PL moments) method is employed, and a new relationship for homogeneity analysis is developed. The results were then compared with those obtained using the method of L moments and LH moments of order two. The Selangor catchment, consisting of 37 sites and located on the west coast of Peninsular Malaysia, is chosen as a case study. PL moments for the generalized extreme value (GEV), generalized logistic (GLO), and generalized Pareto distributions were derived and used to develop the regional frequency analysis procedure. PL moment ratio diagram and Z test were employed in determining the best-fit distribution. Comparison between the three approaches showed that GLO and GEV distributions were identified as the suitable distributions for representing the statistical properties of extreme rainfall in Selangor. Monte Carlo simulation used for performance evaluation shows that the method of PL moments would outperform L and LH moments methods for estimation of large return period events.

  4. Moment-to-moment dynamics of ADHD behaviour

    Directory of Open Access Journals (Sweden)

    Aase Heidi

    2005-08-01

    learning long behavioural sequences may ultimately lead to deficient development of verbally governed behaviour and self control. The study represents a new approach to analyzing the moment-to-moment dynamics of behaviour, and provides support for the theory that reinforcement processes are altered in ADHD.

  5. Predicting Robust Learning with the Visual Form of the Moment-by-Moment Learning Curve

    Science.gov (United States)

    Baker, Ryan S.; Hershkovitz, Arnon; Rossi, Lisa M.; Goldstein, Adam B.; Gowda, Sujith M.

    2013-01-01

    We present a new method for analyzing a student's learning over time for a specific skill: analysis of the graph of the student's moment-by-moment learning over time. Moment-by-moment learning is calculated using a data-mined model that assesses the probability that a student learned a skill or concept at a specific time during learning (Baker,…

  6. The magnetic moments of the proton and the antiproton

    CERN Document Server

    Ulmer, S.; Blaum, K.; Braeuninger, S.; Franke, K.; Kracke, H.; Leiteritz, C.; Matsuda, Y.; Nagahama, H.; Ospelkaus, C.; Rodegheri, C.C.; Quint, W.; Schneider, G.; Smorra, C.; Van Gorp, S.; Walz, J.; Yamazaki, Y.

    2014-01-01

    Recent exciting progress in the preparation and manipulation of the motional quantum states of a single trapped proton enabled the first direct detection of the particle's spin state. Based on this success the proton magnetic moment $\\mu_p$ was measured with ppm precision in a Penning trap with a superimposed magnetic field inhomogeneity. An improvement by an additional factor of 1000 in precision is possible by application of the so-called double Penning trap technique. In a recent paper we reported the first demonstration of this method with a single trapped proton, which is a major step towards the first direct high-precision measurement of $\\mu_p$. The techniques required for the proton can be directly applied to measure the antiproton magnetic moment $\\mu_{\\bar{p}}$. An improvement in precision of $\\mu_{\\bar{p}}$ by more than three orders of magnitude becomes possible, which will provide one of the most sensitive tests of CPT invariance. To achieve this research goal we are currently setting up the Baryo...

  7. Iterative PET Image Reconstruction Using Translation Invariant Wavelet Transform.

    Science.gov (United States)

    Zhou, Jian; Senhadji, Lotfi; Coatrieux, Jean-Louis; Luo, Limin

    2009-02-01

    The present work describes a Bayesian maximum a posteriori (MAP) method using a statistical multiscale wavelet prior model. Rather than using the orthogonal discrete wavelet transform (DWT), this prior is built on the translation invariant wavelet transform (TIWT). The statistical modeling of wavelet coefficients relies on the generalized Gaussian distribution. Image reconstruction is performed in spatial domain with a fast block sequential iteration algorithm. We study theoretically the TIWT MAP method by analyzing the Hessian of the prior function to provide some insights on noise and resolution properties of image reconstruction. We adapt the key concept of local shift invariance and explore how the TIWT MAP algorithm behaves with different scales. It is also shown that larger support wavelet filters do not offer better performance in contrast recovery studies. These theoretical developments are confirmed through simulation studies. The results show that the proposed method is more attractive than other MAP methods using either the conventional Gibbs prior or the DWT-based wavelet prior.

  8. Two signatures of implicit intergroup attitudes: developmental invariance and early enculturation.

    Science.gov (United States)

    Dunham, Yarrow; Chen, Eva E; Banaji, Mahzarin R

    2013-06-01

    Long traditions in the social sciences have emphasized the gradual internalization of intergroup attitudes and the putatively more basic tendency to prefer the groups to which one belongs. In four experiments (N = 883) spanning two cultures and two status groups within one of those cultures, we obtained new evidence that implicit intergroup attitudes emerge in young children in a form indistinguishable from adult attitudes. Strikingly, this invariance from childhood to adulthood holds for members of socially dominant majorities, who consistently favor their in-group, as well as for members of a disadvantaged minority, who, from the early moments of race-based categorization, do not show a preference for their in-group. Far from requiring a protracted period of internalization, implicit intergroup attitudes are characterized by early enculturation and developmental invariance.

  9. Power properties of invariant tests for spatial autocorrelation in linear regression

    NARCIS (Netherlands)

    Martellosio, F.

    2006-01-01

    Many popular tests for residual spatial autocorrelation in the context of the linear regression model belong to the class of invariant tests. This paper derives a number of exact properties of the power function of such tests. In particular, we extend the work of Krämer (2005, Journal of Statistical

  10. Gauge-Invariant Formulation of Circular Dichroism.

    Science.gov (United States)

    Raimbault, Nathaniel; de Boeij, Paul L; Romaniello, Pina; Berger, J A

    2016-07-12

    Standard formulations of magnetic response properties, such as circular dichroism spectra, are plagued by gauge dependencies, which can lead to unphysical results. In this work, we present a general gauge-invariant and numerically efficient approach for the calculation of circular dichroism spectra from the current density. First we show that in this formulation the optical rotation tensor, the response function from which circular dichroism spectra can be obtained, is independent of the origin of the coordinate system. We then demonstrate that its trace is independent of the gauge origin of the vector potential. We also show how gauge invariance can be retained in practical calculations with finite basis sets. As an example, we explain how our method can be applied to time-dependent current-density-functional theory. Finally, we report gauge-invariant circular dichroism spectra obtained using the adiabatic local-density approximation. The circular dichroism spectra we thus obtain are in good agreement with experiment.

  11. Spontaneous breaking of continuous translational invariance

    Science.gov (United States)

    Watanabe, Haruki; Brauner, Tomáš

    2012-04-01

    Unbroken continuous translational invariance is often taken as a basic assumption in discussions of spontaneous symmetry breaking (SSB), which singles out SSB of translational invariance itself as an exceptional case. We present a framework that allows us to treat translational invariance on the same footing as other symmetries. It is shown that existing theorems on SSB can be straightforwardly extended to this general case. As a concrete application, we analyze the Nambu-Goldstone modes in a (ferromagnetic) supersolid. We prove on the ground of the general theorems that the Bogoliubov mode stemming from a spontaneously broken internal U(1) symmetry and the longitudinal phonon due to a crystalline order are distinct physical modes.

  12. Invariant death [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Steven A. Frank

    2016-08-01

    Full Text Available In nematodes, environmental or physiological perturbations alter death’s scaling of time. In human cancer, genetic perturbations alter death’s curvature of time. Those changes in scale and curvature follow the constraining contours of death’s invariant geometry. I show that the constraints arise from a fundamental extension to the theories of randomness, invariance and scale. A generalized Gompertz law follows. The constraints imposed by the invariant Gompertz geometry explain the tendency of perturbations to stretch or bend death’s scaling of time. Variability in death rate arises from a combination of constraining universal laws and particular biological processes.

  13. Differential invariants in nonclassical models of hydrodynamics

    Science.gov (United States)

    Bublik, Vasily V.

    2017-10-01

    In this paper, differential invariants are used to construct solutions for equations of the dynamics of a viscous heat-conducting gas and the dynamics of a viscous incompressible fluid modified by nanopowder inoculators. To describe the dynamics of a viscous heat-conducting gas, we use the complete system of Navier—Stokes equations with allowance for heat fluxes. Mathematical description of the dynamics of liquid metals under high-energy external influences (laser radiation or plasma flow) includes, in addition to the Navier—Stokes system of an incompressible viscous fluid, also heat fluxes and processes of nonequilibrium crystallization of a deformable fluid. Differentially invariant solutions are a generalization of partially invariant solutions, and their active study for various models of continuous medium mechanics is just beginning. Differentially invariant solutions can also be considered as solutions with differential constraints; therefore, when developing them, the approaches and methods developed by the science schools of academicians N. N. Yanenko and A. F. Sidorov will be actively used. In the construction of partially invariant and differentially invariant solutions, there are overdetermined systems of differential equations that require a compatibility analysis. The algorithms for reducing such systems to involution in a finite number of steps are described by Cartan, Finikov, Kuranishi, and other authors. However, the difficultly foreseeable volume of intermediate calculations complicates their practical application. Therefore, the methods of computer algebra are actively used here, which largely helps in solving this difficult problem. It is proposed to use the constructed exact solutions as tests for formulas, algorithms and their software implementations when developing and creating numerical methods and computational program complexes. This combination of effective numerical methods, capable of solving a wide class of problems, with

  14. The Uniqueness of -Matrix Graph Invariants

    Science.gov (United States)

    Dehmer, Matthias; Shi, Yongtang

    2014-01-01

    In this paper, we examine the uniqueness (discrimination power) of a newly proposed graph invariant based on the matrix defined by Randić et al. In order to do so, we use exhaustively generated graphs instead of special graph classes such as trees only. Using these graph classes allow us to generalize the findings towards complex networks as they usually do not possess any structural constraints. We obtain that the uniqueness of this newly proposed graph invariant is approximately as low as the uniqueness of the Balaban index on exhaustively generated (general) graphs. PMID:24392099

  15. Galilean invariant resummation schemes of cosmological perturbations

    Science.gov (United States)

    Peloso, Marco; Pietroni, Massimo

    2017-01-01

    Many of the methods proposed so far to go beyond Standard Perturbation Theory break invariance under time-dependent boosts (denoted here as extended Galilean Invariance, or GI). This gives rise to spurious large scale effects which spoil the small scale predictions of these approximation schemes. By using consistency relations we derive fully non-perturbative constraints that GI imposes on correlation functions. We then introduce a method to quantify the amount of GI breaking of a given scheme, and to correct it by properly tailored counterterms. Finally, we formulate resummation schemes which are manifestly GI, discuss their general features, and implement them in the so called Time-Flow, or TRG, equations.

  16. Application of invariant embedding to reactor physics

    CERN Document Server

    Shimizu, Akinao; Parsegian, V L

    1972-01-01

    Application of Invariant Embedding to Reactor Physics describes the application of the method of invariant embedding to radiation shielding and to criticality calculations of atomic reactors. The authors intend to show how this method has been applied to realistic problems, together with the results of applications which will be useful to shielding design. The book is organized into two parts. Part A deals with the reflection and transmission of gamma rays by slabs. The chapters in this section cover topics such as the reflection and transmission problem of gamma rays; formulation of the probl

  17. Symmetric form-invariant dual Pearcey beams.

    Science.gov (United States)

    Ren, Zhijun; Fan, Changjiang; Shi, Yile; Chen, Bo

    2016-08-01

    We introduce another type of Pearcey beam, namely, dual Pearcey (DP) beams, based on the Pearcey function of catastrophe theory. DP beams are experimentally generated by applying Fresnel diffraction of bright elliptic rings. Form-invariant Bessel distribution beams can be regarded as a special case of DP beams. Subsequently, the basic propagation characteristics of DP beams are identified. DP beams are the result of the interference of two half DP beams instead of two classical Pearcey beams. Moreover, we also verified that half DP beams (including special-case parabolic-like beams) generated by half elliptical rings (circular rings) are a new member of the family of form-invariant beams.

  18. Difference spaces and invariant linear forms

    CERN Document Server

    Nillsen, Rodney

    1994-01-01

    Difference spaces arise by taking sums of finite or fractional differences. Linear forms which vanish identically on such a space are invariant in a corresponding sense. The difference spaces of L2 (Rn) are Hilbert spaces whose functions are characterized by the behaviour of their Fourier transforms near, e.g., the origin. One aim is to establish connections between these spaces and differential operators, singular integral operators and wavelets. Another aim is to discuss aspects of these ideas which emphasise invariant linear forms on locally compact groups. The work primarily presents new results, but does so from a clear, accessible and unified viewpoint, which emphasises connections with related work.

  19. Conformal invariants topics in geometric function theory

    CERN Document Server

    Ahlfors, Lars V

    2010-01-01

    Most conformal invariants can be described in terms of extremal properties. Conformal invariants and extremal problems are therefore intimately linked and form together the central theme of this classic book which is primarily intended for students with approximately a year's background in complex variable theory. The book emphasizes the geometric approach as well as classical and semi-classical results which Lars Ahlfors felt every student of complex analysis should know before embarking on independent research. At the time of the book's original appearance, much of this material had never ap

  20. Invariant distances and metrics in complex analysis

    CERN Document Server

    Jarnicki, Marek

    2013-01-01

    As in the field of ""Invariant Distances and Metrics in Complex Analysis"" there was and is a continuous progress this is the second extended edition of the corresponding monograph. This comprehensive book is about the study of invariant pseudodistances (non-negative functions on pairs of points) and pseudometrics (non-negative functions on the tangent bundle) in several complex variables. It is an overview over a highly active research area at the borderline between complex analysis, functional analysis and differential geometry. New chapters are covering the Wu, Bergman and several other met

  1. The decomposition of global conformal invariants

    CERN Document Server

    Alexakis, Spyros

    2012-01-01

    This book addresses a basic question in differential geometry that was first considered by physicists Stanley Deser and Adam Schwimmer in 1993 in their study of conformal anomalies. The question concerns conformally invariant functionals on the space of Riemannian metrics over a given manifold. These functionals act on a metric by first constructing a Riemannian scalar out of it, and then integrating this scalar over the manifold. Suppose this integral remains invariant under conformal re-scalings of the underlying metric. What information can one then deduce about the Riemannian scalar? Dese

  2. Dihadron fragmentation functions for large invariant mass.

    Science.gov (United States)

    Zhou, J; Metz, A

    2011-04-29

    Using perturbative quantum chromodynamics, we compute dihadron fragmentation functions for a large invariant mass of the dihadron pair. The main focus is on the interference fragmentation function H(1)(∢), which plays an important role in spin physics of the nucleon. Our calculation also reveals that H(1)(∢) and the Collins fragmentation function have closely related underlying dynamics. By considering semi-inclusive deep-inelastic scattering, we further show that collinear factorization in terms of dihadron fragmentation functions and collinear factorization in terms of single-hadron fragmentation functions provide the same result in the region of intermediate invariant mass.

  3. Invariant measures on multimode quantum Gaussian states

    Energy Technology Data Exchange (ETDEWEB)

    Lupo, C. [School of Science and Technology, Universita di Camerino, I-62032 Camerino (Italy); Mancini, S. [School of Science and Technology, Universita di Camerino, I-62032 Camerino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); De Pasquale, A. [NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, I-56126 Pisa (Italy); Facchi, P. [Dipartimento di Matematica and MECENAS, Universita di Bari, I-70125 Bari (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy); Florio, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy); Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Piazza del Viminale 1, I-00184 Roma (Italy); Dipartimento di Fisica and MECENAS, Universita di Bari, I-70126 Bari (Italy); Pascazio, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy); Dipartimento di Fisica and MECENAS, Universita di Bari, I-70126 Bari (Italy)

    2012-12-15

    We derive the invariant measure on the manifold of multimode quantum Gaussian states, induced by the Haar measure on the group of Gaussian unitary transformations. To this end, by introducing a bipartition of the system in two disjoint subsystems, we use a parameterization highlighting the role of nonlocal degrees of freedom-the symplectic eigenvalues-which characterize quantum entanglement across the given bipartition. A finite measure is then obtained by imposing a physically motivated energy constraint. By averaging over the local degrees of freedom we finally derive the invariant distribution of the symplectic eigenvalues in some cases of particular interest for applications in quantum optics and quantum information.

  4. Condition for invariant spectrum of an electromagnetic wave scattered from an anisotropic random media.

    Science.gov (United States)

    Li, Jia; Wu, Pinghui; Chang, Liping

    2015-08-24

    Within the accuracy of the first-order Born approximation, sufficient conditions are derived for the invariance of spectrum of an electromagnetic wave, which is generated by the scattering of an electromagnetic plane wave from an anisotropic random media. We show that the following restrictions on properties of incident fields and the anisotropic media must be simultaneously satisfied: 1) the elements of the dielectric susceptibility matrix of the media must obey the scaling law; 2) the spectral components of the incident field are proportional to each other; 3) the second moments of the elements of the dielectric susceptibility matrix of the media are inversely proportional to the frequency.

  5. Impact of Not Addressing Partially Cross-Classified Multilevel Structure in Testing Measurement Invariance: A Monte Carlo Study

    OpenAIRE

    Im, Myung H.; Kim, Eun S.; Kwok, Oi-Man; Yoon, Myeongsun; Willson, Victor L.

    2016-01-01

    In educational settings, researchers are likely to encounter multilevel data with cross-classified structure. However, due to the lack of familiarity and limitations of statistical software for cross-classified modeling, most researchers adopt less optimal approaches to analyze cross-classified multilevel data in testing measurement invariance. We conducted two Monte Carlo studies to investigate the performances of testing measurement invariance with cross-classified multilevel data when the ...

  6. Investigating spousal influence using moment-to-moment affect data from marital conflict.

    Science.gov (United States)

    Madhyastha, Tara M; Hamaker, Ellen L; Gottman, John M

    2011-04-01

    Gottman and colleagues proposed using a dynamical systems model to study dyadic interaction in marriage. In this model, each spouse's affect in each 6-s window is described as a function of an uninfluenced linear steady state and a nonlinear influence function of the partner's affect in the previous window. Recently, an alternative parameter estimation procedure for the equations of marriage was introduced, which is based on threshold autoregressive models. We apply this estimation procedure to data from a study of couples (N = 124) and newlyweds (N = 130) to compare different forms of spousal influence using the Bayesian information criterion. Although results show some statistically significant evidence for influence, this is only slightly greater than what would be expected by random association. One model of influence does not fit all couples. This suggests that for many people initial state and emotional inertia dictate the outcome of the conflict discussion far more than the moment-to-moment affect of the spouse. This latter finding is in conflict with most models of couples' interaction, which suggest that the outcome of conflict discussions are determined by the nature of the couples' mutual influence processes.

  7. A blur-invariant local feature for motion blurred image matching

    Science.gov (United States)

    Tong, Qiang; Aoki, Terumasa

    2017-07-01

    Image matching between a blurred (caused by camera motion, out of focus, etc.) image and a non-blurred image is a critical task for many image/video applications. However, most of the existing local feature schemes fail to achieve this work. This paper presents a blur-invariant descriptor and a novel local feature scheme including the descriptor and the interest point detector based on moment symmetry - the authors' previous work. The descriptor is based on a new concept - center peak moment-like element (CPME) which is robust to blur and boundary effect. Then by constructing CPMEs, the descriptor is also distinctive and suitable for image matching. Experimental results show our scheme outperforms state of the art methods for blurred image matching

  8. Enhanced violation of the Lorentz invariance and Einstein's equivalence principle in nuclei and atoms

    CERN Document Server

    Flambaum, V V

    2016-01-01

    Local Lorentz Invariance violating (LLIV) and Einstein equivalence principle violating (EEPV) effects in atomic experiments are discussed. The LLIV and EEPV effects are strongly enhanced in the narrow 7.8 eV transition in 229Th nucleus. Nuclear LLIV tensors are expressed in terms of the experimental values of nuclear quadrupole moments. There is enhancement in nuclei where the quadrupole moments and LLIV tensors have collective nature. Calculations for nuclei of experimental interest 21Ne, 173Yb, 133Cs, 85Rb, 87Rb, 20Hg, 9Be and 131Xe have been performed. The results for 21Ne are used to improve the limits on the proton LLIV constants by 5 orders of magnitude and on the neutron LLIV constants by 1 order of magnitude.

  9. Solving moment hierarchies for chemical reaction networks

    Science.gov (United States)

    Krishnamurthy, Supriya; Smith, Eric

    2017-10-01

    The study of chemical reaction networks (CRN’s) is a very active field. Earlier well-known results (Feinberg 1987 Chem. Enc. Sci. 42 2229, Anderson et al 2010 Bull. Math. Biol. 72 1947) identify a topological quantity called deficiency, for any CRN, which, when exactly equal to zero, leads to a unique factorized steady-state for these networks. No results exist however for the steady states of non-zero-deficiency networks. In this paper, we show how to write the full moment-hierarchy for any non-zero-deficiency CRN obeying mass-action kinetics, in terms of equations for the factorial moments. Using these, we can recursively predict values for lower moments from higher moments, reversing the procedure usually used to solve moment hierarchies. We show, for non-trivial examples, that in this manner we can predict any moment of interest, for CRN’s with non-zero deficiency and non-factorizable steady states.

  10. Spermatogonium image recognition using Zernike moments.

    Science.gov (United States)

    Liyun, Wang; Hefei, Ling; Fuhao, Zou; Zhengding, Lu; Zhendi, Wang

    2009-07-01

    The automatic identification and classification of spermatogonium images is a very important issue in biomedical engineering research. This paper proposes a scheme for spermatogonium recognition, in which Zernike moments are used to represent image features. First of all, the mathematical morphology method is employed to extract the intact individual cell in every image, and then we normalize these binary images. Then, Zernike moments are calculated from these normalized images, followed by recognizing the spermatogonia through computing similarity of vectors composed with Zernike moments using Euclidean distance. Experimental results demonstrate that the proposed method, based on Zernike moments, outperforms two well-known methods, namely those based on Hu moments and boundary moments. This method has stronger distinguishing ability, showing better performance in discriminating cell images whether belong to the same cell.

  11. Impact of Not Addressing Partially Cross-Classified Multilevel Structure in Testing Measurement Invariance: A Monte Carlo Study.

    Science.gov (United States)

    Im, Myung H; Kim, Eun S; Kwok, Oi-Man; Yoon, Myeongsun; Willson, Victor L

    2016-01-01

    In educational settings, researchers are likely to encounter multilevel data with cross-classified structure. However, due to the lack of familiarity and limitations of statistical software for cross-classified modeling, most researchers adopt less optimal approaches to analyze cross-classified multilevel data in testing measurement invariance. We conducted two Monte Carlo studies to investigate the performances of testing measurement invariance with cross-classified multilevel data when the noninvarinace is at the between-level: (a) the impact of ignoring crossed factor using conventional multilevel confirmatory factor analysis (MCFA) which assumes hierarchical multilevel data in testing measurement invariance and (b) the adequacy of the cross-classified multiple indicators multiple causes (MIMIC) models with cross-classified data. We considered two design factors, intraclass correlation (ICC) and magnitude of non-invariance. Generally, MCFA demonstrated very low statistical power to detect non-invariance. The low power was plausibly related to the underestimated factor loading differences and the underestimated ICC due to the redistribution of the variance component from the ignored crossed factor. The results demonstrated possible incorrect statistical inferences with conventional MCFA analyses that assume multilevel data as hierarchical structure for testing measurement invariance with cross-classified data (non-hierarchical structure). On the contrary, the cross-classified MIMIC model demonstrated acceptable performance with cross-classified data.

  12. Impact of Not Fully Addressing Cross-Classified Multilevel Structure in Testing Measurement Invariance: A Monte Carlo Study

    Directory of Open Access Journals (Sweden)

    Myung Hee eIm

    2016-03-01

    Full Text Available In educational settings, researchers are likely to encounter multilevel data with cross-classified structure. However, due to the lack of familiarity and limitations of statistical software for cross-classified modeling, most researchers adopt less optimal approaches to analyze cross-classified multilevel data in testing measurement invariance. We conducted two Monte Carlo studies to investigate the performances of testing measurement invariance with cross-classified multilevel data when the noninvarinace is at the between-level: (a the impact of ignoring crossed factor using conventional multilevel confirmatory factor analysis (MCFA which assumes hierarchical multilevel data in testing measurement invariance and (b the adequacy of the cross-classified multiple indicators multiple causes (MIMIC models with cross-classified data. We considered two design factors, intraclass correlation (ICC and magnitude of non-invariance. Generally, MCFA demonstrated very low statistical power to detect non-invariance. The low power was plausibly related to the underestimated factor loading differences and the underestimated ICC due to the redistribution of the variance component from the ignored crossed factor. The results demonstrated possible incorrect statistical inferences with conventional MCFA analyses that assume multilevel data as hierarchical structure for testing measurement invariance with cross-classified data (non-hierarchical structure. On the contrary, the cross-classified MIMIC model demonstrated acceptable performance with cross-classified data.

  13. Muon Dipole Moment Experiments Interpretation and Prospects

    CERN Document Server

    Feng, J L; Shadmi, Y; Feng, Jonathan L; Matchev, Konstantin T.; Shadmi, Yael

    2001-01-01

    We examine the prospects for discovering new physics through muon dipole moments. The current deviation in $g_{\\mu}-2$ may be due entirely to the muon's {\\em electric} dipole moment. We note that the precession frequency in the proposed BNL muon EDM experiment is also subject to a similar ambiguity, but this can be resolved by up-down asymmetry measurements. We then review the theoretical expectations for the muon's electric dipole moment in supersymmetric models.

  14. Applications of Generalized Method of Moments Estimation

    OpenAIRE

    Wooldridge, Jeffrey M.

    2001-01-01

    I describe how the method of moments approach to estimation, including the more recent generalized method of moments (GMM) theory, can be applied to problems using cross section, time series, and panel data. Method of moments estimators can be attractive because in many circumstances they are robust to failures of auxiliary distributional assumptions that are not needed to identify key parameters. I conclude that while sophisticated GMM estimators are indispensable for complicated estimation ...

  15. Invariance Properties for General Diagnostic Classification Models

    Science.gov (United States)

    Bradshaw, Laine P.; Madison, Matthew J.

    2016-01-01

    In item response theory (IRT), the invariance property states that item parameter estimates are independent of the examinee sample, and examinee ability estimates are independent of the test items. While this property has long been established and understood by the measurement community for IRT models, the same cannot be said for diagnostic…

  16. Local Unitary Invariants of Quantum States

    Science.gov (United States)

    Cui, Meiyu; Chang, Jingmei; Zhao, Ming-Jing; Huang, Xiaofen; Zhang, Tinggui

    2017-11-01

    We study the equivalence of mixed states under local unitary transformations. First we express quantum states in Bloch representation. Then based on the coefficient matrices, some invariants are constructed. This method and results can be extended to multipartite high dimensional system.

  17. Joint local quasinilpotence and common invariant subspaces

    Indian Academy of Sciences (India)

    . In fact the intersection of the sets. QTi = {x ∈ X, such that Ti is locally quasinilpotent at x}, is a common invariant manifold. However if T1,...,TN are not commuting, the problem becomes more complicated. Example. Let T1,T2 be two operators ...

  18. Discrete Groups, Expanding Graphs and Invariant Measures

    CERN Document Server

    Lubotzky, Alexander

    2009-01-01

    Presents the solutions to two problems: the first is the construction of expanding graphs - graphs which are of fundamental importance for communication networks and computer science, and the second is the Ruziewicz problem concerning the finitely additive invariant measures on spheres

  19. Topologically left invariant means on semigroup algebras

    Indian Academy of Sciences (India)

    Let M ( S ) be the Banach algebra of all bounded regular Borel measures on a locally compact Hausdorff semitopological semigroup with variation norm and convolution as multiplication. We obtain necessary and sufficient conditions for M ( S ) ∗ to have a topologically left invariant mean.

  20. Automatic invariant detection in dynamic web applications

    NARCIS (Netherlands)

    Groeneveld, F.; Mesbah, A.; Van Deursen, A.

    2010-01-01

    The complexity of modern web applications increases as client-side JavaScript and dynamic DOM programming are used to offer a more interactive web experience. In this paper, we focus on improving the dependability of such applications by automatically inferring invariants from the client-side and

  1. Invariant metric for nonlinear symplectic maps

    Indian Academy of Sciences (India)

    In this paper, we construct an invariant metric in the space of homogeneous polynomials of a given degree (≥ 3). The homogeneous polynomials specify a nonlinear symplectic map which in turn represents a Hamiltonian system. By minimizing the norm constructed out of this metric as a function of system parameters, we ...

  2. Holography for chiral scale-invariant models

    NARCIS (Netherlands)

    Caldeira Costa, R.N.; Taylor, M.

    2011-01-01

    Deformation of any d-dimensional conformal field theory by a constant null source for a vector operator of dimension (d + z -1) is exactly marginal with respect to anisotropic scale invariance, of dynamical exponent z. The holographic duals to such deformations are AdS plane waves, with z=2 being

  3. Holography for chiral scale-invariant models

    NARCIS (Netherlands)

    Caldeira Costa, R.N.; Taylor, M.

    2010-01-01

    Deformation of any d-dimensional conformal field theory by a constant null source for a vector operator of dimension (d + z -1) is exactly marginal with respect to anisotropic scale invariance, of dynamical exponent z. The holographic duals to such deformations are AdS plane waves, with z=2 being

  4. A functional LMO invariant for Lagrangian cobordisms

    DEFF Research Database (Denmark)

    Cheptea, Dorin; Habiro, Kazuo; Massuyeau, Gwénaël

    2008-01-01

    Lagrangian cobordisms are three-dimensional compact oriented cobordisms between once-punctured surfaces, subject to some homological conditions. We extend the Le–Murakami–Ohtsuki invariant of homology three-spheres to a functor from the category of Lagrangian cobordisms to a certain category...

  5. Algorithms for computing normally hyperbolic invariant manifolds

    NARCIS (Netherlands)

    Broer, H.W.; Osinga, H.M.; Vegter, G.

    An effcient algorithm is developed for the numerical computation of normally hyperbolic invariant manifolds, based on the graph transform and Newton's method. It fits in the perturbation theory of discrete dynamical systems and therefore allows application to the setting of continuation. A

  6. A versatile algorithm for computing invariant manifolds

    NARCIS (Netherlands)

    Broer, H. W.; Hagen, A.; Vegter, G.; Gorban, AN; Kazantzis, NK; Kevrekidis, IG; Ottinger, HC; Theodoropoulos, C

    2006-01-01

    This paper deals with the numerical computation of invariant manifolds using a method of discretizing global manifolds. It provides a geometrically natural algorithm that converges regardless of the restricted dynamics. Common examples of such manifolds include limit sets, co-dimension 1 manifolds

  7. Adaptivity and group invariance in mathematical morphology

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2009-01-01

    The standard morphological operators are (i) defined on Euclidean space, (ii) based on structuring elements, and (iii) invariant with respect to translation. There are several ways to generalise this. One way is to make the operators adaptive by letting the size or shape of structuring elements

  8. Invariant metric for nonlinear symplectic maps

    Indian Academy of Sciences (India)

    Abstract. In this paper, we construct an invariant metric in the space of homogeneous polynomials of a given degree ( 3). The homogeneous polynomials specify a nonlinear symplectic map which in turn represents a Hamiltonian system. By minimizing the norm constructed out of this metric as a function of system ...

  9. Spectral properties of supersymmetric shape invariant potentials

    Indian Academy of Sciences (India)

    oscillator-type spectral properties (picket fence) in unfolded spectrum although the folded spectrum is completely random and uncorrelated. We conjecture this as the reflection of shape invariance symmetry in the spectral properties. The paper is organized as follows. We will introduce sl algebra and the method.

  10. Commentary: Visual object recognition: building invariant ...

    Indian Academy of Sciences (India)

    2008-11-13

    Nov 13, 2008 ... http://www.ias.ac.in/article/fulltext/jbsc/033/05/0639-0642. Keywords. Interferotemporal cortex; object invariance; object recognition; positional tolerance; saccadic eye movements. Author Affiliations. Duje Tadin1 Raphael Pinaud1. Department of Brain and Cognitive Sciences and Center for Visual Science, ...

  11. A Sim(2 invariant dimensional regularization

    Directory of Open Access Journals (Sweden)

    J. Alfaro

    2017-09-01

    Full Text Available We introduce a Sim(2 invariant dimensional regularization of loop integrals. Then we can compute the one loop quantum corrections to the photon self energy, electron self energy and vertex in the Electrodynamics sector of the Very Special Relativity Standard Model (VSRSM.

  12. Performance evaluation of local colour invariants

    NARCIS (Netherlands)

    Burghouts, G.J.; Geusebroek, J.M.

    2009-01-01

    In this paper, we compare local colour descriptors to grey-value descriptors. We adopt the evaluation framework of Mikolayzcyk and Schmid. We modify the framework in several ways. We decompose the evaluation framework to the level of local grey-value invariants on which common region descriptors are

  13. Statistical Physics for Cosmic Structures

    CERN Document Server

    Gabrielli, Andrea

    2004-01-01

    The physics of scale-invariant and complex systems is a novel interdisciplinary field. Its ideas allow us to look at natural phenomena in a radically new and original way, eventually leading to unifying concepts independent of the detailed structure of the systems. The objective is the study of complex, scale-invariant, and more general stochastic structures that appear both in space and time in a vast variety of natural phenomena, which exhibit new types of collective behaviors, and the fostering of their understanding. This book has been conceived as a methodological monograph in which the main methods of modern statistical physics for cosmological structures and density fields (galaxies, Cosmic Microwave Background Radiation, etc.) are presented in detail. The main purpose is to present clearly, to a workable level, these methods, with a certain mathematical accuracy, providing also some paradigmatic examples of applications. This should result in a new and more general framework for the statistical analys...

  14. Experimental Study of Quantum Graphs With and Without Time-Reversal Invariance

    Science.gov (United States)

    Anlage, Steven Mark; Fu, Ziyuan; Koch, Trystan; Antonsen, Thomas; Ott, Edward

    An experimental setup consisting of a microwave network is used to simulate quantum graphs. The random coupling model (RCM) is applied to describe the universal statistical properties of the system with and without time-reversal invariance. The networks which are large compared to the wavelength, are constructed from coaxial cables connected by T junctions, and by making nodes with circulators time-reversal invariance for microwave propagation in the networks can be broken. The results of experimental study of microwave networks with and without time-reversal invariance are presented both in frequency domain and time domain. With the measured S-parameter data of two-port networks, the impedance statistics and the nearest-neighbor spacing statistics are examined. Moreover, the experiments of time reversal mirrors for networks demonstrate that the reconstruction quality can be used to quantify the degree of the time-reversal invariance for wave propagation. Numerical models of networks are also presented to verify the time domain experiments. We acknowledge support under contract AFOSR COE Grant FA9550-15-1-0171 and the ONR Grant N000141512134.

  15. Complex-linear invariants of biochemical networks.

    Science.gov (United States)

    Karp, Robert L; Pérez Millán, Mercedes; Dasgupta, Tathagata; Dickenstein, Alicia; Gunawardena, Jeremy

    2012-10-21

    The nonlinearities found in molecular networks usually prevent mathematical analysis of network behaviour, which has largely been studied by numerical simulation. This can lead to difficult problems of parameter determination. However, molecular networks give rise, through mass-action kinetics, to polynomial dynamical systems, whose steady states are zeros of a set of polynomial equations. These equations may be analysed by algebraic methods, in which parameters are treated as symbolic expressions whose numerical values do not have to be known in advance. For instance, an "invariant" of a network is a polynomial expression on selected state variables that vanishes in any steady state. Invariants have been found that encode key network properties and that discriminate between different network structures. Although invariants may be calculated by computational algebraic methods, such as Gröbner bases, these become computationally infeasible for biologically realistic networks. Here, we exploit Chemical Reaction Network Theory (CRNT) to develop an efficient procedure for calculating invariants that are linear combinations of "complexes", or the monomials coming from mass action. We show how this procedure can be used in proving earlier results of Horn and Jackson and of Shinar and Feinberg for networks of deficiency at most one. We then apply our method to enzyme bifunctionality, including the bacterial EnvZ/OmpR osmolarity regulator and the mammalian 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase glycolytic regulator, whose networks have deficiencies up to four. We show that bifunctionality leads to different forms of concentration control that are robust to changes in initial conditions or total amounts. Finally, we outline a systematic procedure for using complex-linear invariants to analyse molecular networks of any deficiency. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Dimensional analysis using toric ideals: primitive invariants.

    Directory of Open Access Journals (Sweden)

    Mark A Atherton

    Full Text Available Classical dimensional analysis in its original form starts by expressing the units for derived quantities, such as force, in terms of power products of basic units [Formula: see text] etc. This suggests the use of toric ideal theory from algebraic geometry. Within this the Graver basis provides a unique primitive basis in a well-defined sense, which typically has more terms than the standard Buckingham approach. Some textbook examples are revisited and the full set of primitive invariants found. First, a worked example based on convection is introduced to recall the Buckingham method, but using computer algebra to obtain an integer [Formula: see text] matrix from the initial integer [Formula: see text] matrix holding the exponents for the derived quantities. The [Formula: see text] matrix defines the dimensionless variables. But, rather than this integer linear algebra approach it is shown how, by staying with the power product representation, the full set of invariants (dimensionless groups is obtained directly from the toric ideal defined by [Formula: see text]. One candidate for the set of invariants is a simple basis of the toric ideal. This, although larger than the rank of [Formula: see text], is typically not unique. However, the alternative Graver basis is unique and defines a maximal set of invariants, which are primitive in a simple sense. In addition to the running example four examples are taken from: a windmill, convection, electrodynamics and the hydrogen atom. The method reveals some named invariants. A selection of computer algebra packages is used to show the considerable ease with which both a simple basis and a Graver basis can be found.

  17. A Circular Statistical Method for Extracting Rotation Measures

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    . IPA from data. This procedure is based on maximum likelihood for distributions defined to be invariant under angular coordinate changes. The von Mises (vM) dis- tribution serves as a prototype for the statistical fluctuations for circular data.

  18. Kant’s Machiavellian Moment

    Directory of Open Access Journals (Sweden)

    Jay Foster

    2015-11-01

    Full Text Available At least two recent collections of essays – Postmodernism and the Enlightenment (2001 and What’s Left of Enlightenment?: A Postmodern Question (2001 – have responded to postmodern critiques of Enlightenment by arguing that Enlightenment philosophes themselves embraced a number of post-modern themes. This essay situates Kant’s essay Was ist Aufklärung (1784 in the context of this recent literature about the appropriate characterization of modernity and the Enlightenment. Adopting an internalist reading of Kant’s Aufklärung essay, this paper observes that Kant is surprisingly ambivalent about who might be Enlightened and unspecific about when Enlightenment might be achieved. The paper argues that this is because Kant is concerned less with elucidating his concept of Enlightenment and more with characterizing a political condition that might provide the conditions for the possibility of Enlightenment. This paper calls this political condition modernity and it is achieved when civil order can be maintained alongside fractious and possibly insoluble public disagreement about matters of conscience, including the nature and possibility of Enlightenment. Thus, the audience for the Aufklärung essay is not the tax collector, soldier or clergyman, but rather the sovereign. Kant enjoins and advises the prince that discord and debate about matters of conscience need not entail any political unrest or upheaval. It is in this restricted (Pocockian sense that the Enlightenment essay is Kant’s Machiavellian moment.

  19. Dualities between Scale Invariant and Magnitude Invariant Perturbation Spectra in Inflationary/Bouncing Cosmos

    CERN Document Server

    Li, Chonghong

    2012-01-01

    We study cosmological perturbation spectra using the dynamical equations of gauge invariant perturbations with a generalized blue/red-shift term. Combined with the power-law index of cosmological background, {\

  20. Evaluation of scaling invariance embedded in short time series.

    Directory of Open Access Journals (Sweden)

    Xue Pan

    Full Text Available Scaling invariance of time series has been making great contributions in diverse research fields. But how to evaluate scaling exponent from a real-world series is still an open problem. Finite length of time series may induce unacceptable fluctuation and bias to statistical quantities and consequent invalidation of currently used standard methods. In this paper a new concept called correlation-dependent balanced estimation of diffusion entropy is developed to evaluate scale-invariance in very short time series with length ~10(2. Calculations with specified Hurst exponent values of 0.2,0.3,...,0.9 show that by using the standard central moving average de-trending procedure this method can evaluate the scaling exponents for short time series with ignorable bias (≤0.03 and sharp confidential interval (standard deviation ≤0.05. Considering the stride series from ten volunteers along an approximate oval path of a specified length, we observe that though the averages and deviations of scaling exponents are close, their evolutionary behaviors display rich patterns. It has potential use in analyzing physiological signals, detecting early warning signals, and so on. As an emphasis, the our core contribution is that by means of the proposed method one can estimate precisely shannon entropy from limited records.

  1. Likelihood devices in spatial statistics

    NARCIS (Netherlands)

    Zwet, E.W. van

    1999-01-01

    One of the main themes of this thesis is the application to spatial data of modern semi- and nonparametric methods. Another, closely related theme is maximum likelihood estimation from spatial data. Maximum likelihood estimation is not common practice in spatial statistics. The method of moments

  2. Pixel-wise orthogonal decomposition for color illumination invariant and shadow-free image.

    Science.gov (United States)

    Qu, Liangqiong; Tian, Jiandong; Han, Zhi; Tang, Yandong

    2015-02-09

    In this paper, we propose a novel, effective and fast method to obtain a color illumination invariant and shadow-free image from a single outdoor image. Different from state-of-the-art methods for shadow-free image that either need shadow detection or statistical learning, we set up a linear equation set for each pixel value vector based on physically-based shadow invariants, deduce a pixel-wise orthogonal decomposition for its solutions, and then get an illumination invariant vector for each pixel value vector on an image. The illumination invariant vector is the unique particular solution of the linear equation set, which is orthogonal to its free solutions. With this illumination invariant vector and Lab color space, we propose an algorithm to generate a shadow-free image which well preserves the texture and color information of the original image. A series of experiments on a diverse set of outdoor images and the comparisons with the state-of-the-art methods validate our method.

  3. The Tripod School Climate Index: An Invariant Measure of School Safety and Relationships.

    Science.gov (United States)

    Phillips, Sarah Fierberg; Rowley, Jacob F S

    2016-03-01

    Recently revised standards for social work practice in schools encourage data-informed school climate interventions that implicitly require invariant measures of school climate. Invariant measures have the same meaning, scale, and origin across different groups of respondents. Although noninvariant measures bias statistical analyses and can lead users to erroneous conclusions, most school climate measures have not been tested for invariance. This study examines the invariance of the Tripod School Climate Index. Exploratory, confirmatory, and multiple-group confirmatory factor analyses were conducted on data collected from 66,531 students across 222 schools. Results indicate that the index is an excellent fit for the data and invariant by student grade level, demographic background, prior achievement, and dropout risk. Results imply that student responses can be validly aggregated to create school-level scores. The index will not bias studies of school climate interventions or bivariate analyses comparing perceptions of school climate across subgroups of students attending the same school. Given the centrality of school climate interventions to social work practice in schools and the consequences of noninvariance, the development of an index with these properties is an important contribution to the field.

  4. Dynamical and scale invariance of charged particles slipping on a rough surface with periodic excitation

    Science.gov (United States)

    Zhang, Hao; Luo, Pengcheng; Ding, Huifang

    2017-07-01

    This letter deals with the dynamical and scaling invariance of charged particles slipping on a rough surface with periodic excitation. A variant of the Fermi-Ulam model (FUM) is proposed to describe the transport behavior of the particles when the electric field force Fe is smaller or larger than the friction force Ff, i.e., A 0. For these two cases, the stability of fixed points is analyzed with the help of the eigenvalue analysis method, and further the invariant manifolds are constructed to investigate the dynamical invariance such as energy diffusion for some initial conditions in the case A > 0 and decay process in the case A law of the statistical behavior. It follows that both the FA phenomenon for A > 0 and the velocity decay process for A < 0 satisfy scaling invariance with respect to the nondimensional acceleration A. Besides, for A < 0, the transient number nx is proposed to evaluate the speed of the velocity decay process. More importantly, nx is found to possess the attribute of scaling invariance with respect to both the initial velocity V0 and the nondimensional acceleration A. These results are very useful for the in-depth understanding of the energy transport properties of charged particle systems.

  5. Overview of quantitative measurement methods. Equivalence, invariance, and differential item functioning in health applications.

    Science.gov (United States)

    Teresi, Jeanne A

    2006-11-01

    Reviewed in this article are issues relating to the study of invariance and differential item functioning (DIF). The aim of factor analyses and DIF, in the context of invariance testing, is the examination of group differences in item response conditional on an estimate of disability. Discussed are parameters and statistics that are not invariant and cannot be compared validly in crosscultural studies with varying distributions of disability in contrast to those that can be compared (if the model assumptions are met) because they are produced by models such as linear and nonlinear regression. The purpose of this overview is to provide an integrated approach to the quantitative methods used in this special issue to examine measurement equivalence. The methods include classical test theory (CTT), factor analytic, and parametric and nonparametric approaches to DIF detection. Also included in the quantitative section is a discussion of item banking and computerized adaptive testing (CAT). Factorial invariance and the articles discussing this topic are introduced. A brief overview of the DIF methods presented in the quantitative section of the special issue is provided together with a discussion of ways in which DIF analyses and examination of invariance using factor models may be complementary. Although factor analytic and DIF detection methods share features, they provide unique information and can be viewed as complementary in informing about measurement equivalence.

  6. Measuring Statistics Anxiety: Cross-Country Validity of the Statistical Anxiety Scale (SAS)

    Science.gov (United States)

    Chiesi, Francesca; Primi, Caterina; Carmona, Jose

    2011-01-01

    The aim of the research was to test the psychometric properties of the Italian version of the Vigil-Colet et al.'s Statistical Anxiety Scale (SAS), taking into account evidences based on (a) internal structure (factorial structure and cross-country invariance) and (b) relationships to other variables (the statistics anxiety's nomological network).…

  7. Monopole classes and Perelman's invariant of four-manifolds

    OpenAIRE

    Kotschick, D.

    2006-01-01

    We calculate Perelman's invariant for compact complex surfaces and a few other smooth four-manifolds. We also prove some results concerning the dependence of Perelman's invariant on the smooth structure.

  8. Closed forms and multi-moment maps

    DEFF Research Database (Denmark)

    Madsen, Thomas Bruun; Swann, Andrew Francis

    We extend the notion of multi-moment map to geometries defined by closed forms of arbitrary degree. We give fundamental existence and uniqueness results and discuss a number of essential examples, including geometries related to special holonomy. For forms of degree four, multi-moment maps...

  9. Teachable Moment: Google Earth Takes Us There

    Science.gov (United States)

    Williams, Ann; Davinroy, Thomas C.

    2015-01-01

    In the current educational climate, where clearly articulated learning objectives are required, it is clear that the spontaneous teachable moment still has its place. Authors Ann Williams and Thomas Davinroy think that instructors from almost any discipline can employ Google Earth as a tool to take advantage of teachable moments through the…

  10. How to Introduce the Magnetic Dipole Moment

    Science.gov (United States)

    Bezerra, M.; Kort-Kamp, W. J. M.; Cougo-Pinto, M. V.; Farina, C.

    2012-01-01

    We show how the concept of the magnetic dipole moment can be introduced in the same way as the concept of the electric dipole moment in introductory courses on electromagnetism. Considering a localized steady current distribution, we make a Taylor expansion directly in the Biot-Savart law to obtain, explicitly, the dominant contribution of the…

  11. Magnetic moment of single layer graphene rings

    Science.gov (United States)

    Margulis, V. A.; Karpunin, V. V.; Mironova, K. I.

    2018-01-01

    Magnetic moment of single layer graphene rings is investigated. An analytical expression for the magnetic moment as a function of the magnetic field flux through the one-dimensional quantum rings is obtained. This expression has the oscillation character. The oscillation period is equal to one flux quanta.

  12. Closed forms and multi-moment maps

    DEFF Research Database (Denmark)

    Madsen, Thomas Bruun; Swann, Andrew Francis

    2013-01-01

    We extend the notion of multi-moment map to geometries defined by closed forms of arbitrary degree. We give fundamental existence and uniqueness results and discuss a number of essential examples, including geometries related to special holonomy. For forms of degree four, multi-moment maps are gu...

  13. Statistics for Finance

    DEFF Research Database (Denmark)

    Lindström, Erik; Madsen, Henrik; Nielsen, Jan Nygaard

    Statistics for Finance develops students’ professional skills in statistics with applications in finance. Developed from the authors’ courses at the Technical University of Denmark and Lund University, the text bridges the gap between classical, rigorous treatments of financial mathematics...... that rarely connect concepts to data and books on econometrics and time series analysis that do not cover specific problems related to option valuation. The book discusses applications of financial derivatives pertaining to risk assessment and elimination. The authors cover various statistical...... and mathematical techniques, including linear and nonlinear time series analysis, stochastic calculus models, stochastic differential equations, Itō’s formula, the Black–Scholes model, the generalized method-of-moments, and the Kalman filter. They explain how these tools are used to price financial derivatives...

  14. Cancer Statistics

    Science.gov (United States)

    ... What Is Cancer? Cancer Statistics Cancer Disparities Cancer Statistics Cancer has a major impact on society in ... success of efforts to control and manage cancer. Statistics at a Glance: The Burden of Cancer in ...

  15. Caregiving Statistics

    Science.gov (United States)

    ... Coping with Alzheimer’s COPD Caregiving Take Care! Caregiver Statistics Statistics on Family Caregivers and Family Caregiving Caregiving Population ... Health Care Caregiver Self-Awareness State by State Statistics Caregiving Population The value of the services family ...

  16. On the probability density function and characteristic function moments of image steganalysis in the log prediction error wavelet subband

    Science.gov (United States)

    Bao, Zhenkun; Li, Xiaolong; Luo, Xiangyang

    2017-01-01

    Extracting informative statistic features is the most essential technical issue of steganalysis. Among various steganalysis methods, probability density function (PDF) and characteristic function (CF) moments are two important types of features due to the excellent ability for distinguishing the cover images from the stego ones. The two types of features are quite similar in definition. The only difference is that the PDF moments are computed in the spatial domain, while the CF moments are computed in the Fourier-transformed domain. Then, the comparison between PDF and CF moments is an interesting question of steganalysis. Several theoretical results have been derived, and CF moments are proved better than PDF moments in some cases. However, in the log prediction error wavelet subband of wavelet decomposition, some experiments show that the result is opposite and lacks a rigorous explanation. To solve this problem, a comparison result based on the rigorous proof is presented: the first-order PDF moment is proved better than the CF moment, while the second-order CF moment is better than the PDF moment. It tries to open the theoretical discussion on steganalysis and the question of finding suitable statistical features.

  17. Conformal projective invariants in the problem of image recognition.

    Directory of Open Access Journals (Sweden)

    Надежда Григорьевна Коновенко

    2014-11-01

    Full Text Available In this paper we reduce local classification of differential 1-forms on the plane with respect to group SL_2(C of Mobius transformations. We find the field of rational conformal differential invariants and show that the field is generated by two differential invariant derivations and by differential invariants of the first and second orders.

  18. Invariant Einstein metrics on Ledger-Obata spaces

    OpenAIRE

    Chen, Zhiqi; Nikonorov, Yuriĭ; Nikonorova, Yulia

    2016-01-01

    In this paper, we study invariant Einstein metrics on Ledger-Obata spaces $F^m/\\operatorname{diag}(F)$. In particular, we classify invariant Einstein metrics on $F^4/\\operatorname{diag}(F)$ and estimate the number of invariant Einstein metrics on general Ledger-Obata spaces $F^{m}/\\operatorname{diag}(F)$.

  19. Generalized scale invariance, clouds and radiative transfer on multifractal clouds

    Energy Technology Data Exchange (ETDEWEB)

    Lovejoy, S.; Schertzer, D. [Univ. Pierre et Marie Curie, Paris (France)

    1995-09-01

    Recent systematic satellite studies (LANDSAT, AVHRR, METEOSAT) of cloud radiances using (isotropic) energy spectra have displayed excellent scaling from at least about 300m to about 4000km, even for individual cloud pictures. At first sight, this contradicts the observed diversity of cloud morphology, texture and type. The authors argue that the explanation of this apparent paradox is that the differences are due to anisotropy, e.g. differential stratification and rotation. A general framework for anisotropic scaling expressed in terms of isotropic self-similar scaling and fractals and multifractals is needed. Schertzer and Lovejoy have proposed Generalized Scale Invariance (GSI) in response to this need. In GSI, the statistics of the large and small scales of system can be related to each other by a scale changing operator T{sub {lambda}} which depends only on the scale ratio {lambda}{sub i} there is no characteristic size. 3 refs., 1 fig.

  20. Molecular electric moments calculated by using natural orbital functional theory

    CERN Document Server

    Mitxelena, Ion

    2016-01-01

    The molecular electric dipole, quadrupole and octupole moments of a selected set of 21 spin-compensated molecules are determined employing the extended version of the Piris natural orbital functional 6 (PNOF6), using the triple-$\\zeta$ Gaussian basis set with polarization functions developed by Sadlej, at the experimental geometries. The performance of the PNOF6 is established by carrying out a statistical analysis of the mean absolute errors with respect to the experiment. The calculated PNOF6 electric moments agree satisfactorily with the corresponding experimental data, and are in good agreement with the values obtained by accurate ab initio methods, namely, the coupled-cluster single and doubles (CCSD) and multi-reference single and double excitation configuration interaction (MRSD-CI) methods.

  1. Hamiltonian reductions of the one-dimensional Vlasov equation using phase-space moments

    Science.gov (United States)

    Chandre, C.; Perin, M.

    2016-03-01

    We consider Hamiltonian closures of the Vlasov equation using the phase-space moments of the distribution function. We provide some conditions on the closures imposed by the Jacobi identity. We completely solve some families of examples. As a result, we show that imposing that the resulting reduced system preserves the Hamiltonian character of the parent model shapes its phase space by creating a set of Casimir invariants as a direct consequence of the Jacobi identity. We exhibit three main families of Hamiltonian models with two, three, and four degrees of freedom aiming at modeling the complexity of the bunch of particles in the Vlasov dynamics.

  2. A Family of Invariant Stress Surfaces

    DEFF Research Database (Denmark)

    Krenk, S.

    contour is given in explicit form. Several special cases are considered: a generalized Drucker-Prager criterion with straight generators and a smooth triangular deviatoric contour, surfaces with parabolic compression and tension generators, and the Lade failure surface for cohesionless soils. The use......A family of invariant stress surfaces with a cubic dependence on the deviatoric stress components is expressed as a linear combination of the second and third deviatori stress invariants. A simple geometric derivation demonstrates the convexity of the contours in the deviatoric plane. An explicit...... representation of the deviatoric contours in terms of a size and a shape parameter is given. The shape parameter effects a continuous transition from a triangle to a circle in the deviatoric plane. An explicit format in terms of the triaxial compresson and tension generators is derived, and the plane stress...

  3. The geometric Hopf invariant and surgery theory

    CERN Document Server

    Crabb, Michael

    2017-01-01

    Written by leading experts in the field, this monograph provides homotopy theoretic foundations for surgery theory on higher-dimensional manifolds. Presenting classical ideas in a modern framework, the authors carefully highlight how their results relate to (and generalize) existing results in the literature. The central result of the book expresses algebraic surgery theory in terms of the geometric Hopf invariant, a construction in stable homotopy theory which captures the double points of immersions. Many illustrative examples and applications of the abstract results are included in the book, making it of wide interest to topologists. Serving as a valuable reference, this work is aimed at graduate students and researchers interested in understanding how the algebraic and geometric topology fit together in the surgery theory of manifolds. It is the only book providing such a wide-ranging historical approach to the Hopf invariant, double points and surgery theory, with many results old and new. .

  4. Scale-invariant nonlinear optics in gases

    CERN Document Server

    Heyl, C M; Miranda, M; Louisy, M; Kovacs, K; Tosa, V; Balogh, E; Varjú, K; L'Huillier, A; Couairon, A; Arnold, C L

    2015-01-01

    Nonlinear optical methods are becoming ubiquitous in many areas of modern photonics. They are, however, often limited to a certain range of input parameters, such as pulse energy and average power, since restrictions arise from, for example, parasitic nonlinear effects, damage problems and geometrical considerations. Here, we show that many nonlinear optics phenomena in gaseous media are scale-invariant if spatial coordinates, gas density and laser pulse energy are scaled appropriately. We develop a general scaling model for (3+1)-dimensional wave equations, demonstrating the invariant scaling of nonlinear pulse propagation in gases. Our model is numerically applied to high-order harmonic generation and filamentation as well as experimentally verified using the example of pulse post-compression via filamentation. Our results provide a simple recipe for up-or downscaling of nonlinear processes in gases with numerous applications in many areas of science.

  5. Actions and invariants of algebraic groups

    CERN Document Server

    Ferrer Santos, Walter

    2005-01-01

    Actions and Invariants of Algebraic Groups presents a self-contained introduction to geometric invariant theory that links the basic theory of affine algebraic groups to Mumford''s more sophisticated theory. The authors systematically exploit the viewpoint of Hopf algebra theory and the theory of comodules to simplify and compactify many of the relevant formulas and proofs.The first two chapters introduce the subject and review the prerequisites in commutative algebra, algebraic geometry, and the theory of semisimple Lie algebras over fields of characteristic zero. The authors'' early presentation of the concepts of actions and quotients helps to clarify the subsequent material, particularly in the study of homogeneous spaces. This study includes a detailed treatment of the quasi-affine and affine cases and the corresponding concepts of observable and exact subgroups.Among the many other topics discussed are Hilbert''s 14th problem, complete with examples and counterexamples, and Mumford''s results on quotien...

  6. A Gauge Invariant Regulator for the ERG

    Science.gov (United States)

    Arnone, S.; Kubyshin, Yu. A.; Morris, T. R.; Tighe, J. F.

    A gauge invariant regularisation for dealing with pure Yang-Mills theories within the exact renormalization group approach is proposed. It is based on the regularisation via covariant higher derivatives and includes auxiliary Pauli-Villars fields which amounts to a spontaneously broken SU(N|N) super-gauge theory. We demonstrate perturbatively that the extended theory is ultra-violet finite in four dimensions and argue that it has a sensible limit when the regularization cutoff is removed.

  7. Liaison, Schottky Problem and Invariant Theory

    CERN Document Server

    Alonso, Maria Emilia; Mallavibarrena, Raquel; Sols, Ignacio

    2010-01-01

    This volume is a homage to the memory of the Spanish mathematician Federico Gaeta (1923-2007). Apart from a historical presentation of his life and interaction with the classical Italian school of algebraic geometry, the volume presents surveys and original research papers on the mathematics he studied. Specifically, it is divided into three parts: linkage theory, Schottky problem and invariant theory. On this last topic a hitherto unpublished article by Federico Gaeta is also included.

  8. Size-change termination and transition invariants

    DEFF Research Database (Denmark)

    Heizmann, Matthias; Jones, Neil; Podelski, Andreas

    2010-01-01

    Two directions of recent work on program termination use the concepts of size-change termination resp. transition invariants. The difference in the setting has as consequence the inherent incomparability of the analysis and verification methods that result from this work. Yet, in order to facilit...... to facilitate the crossover of ideas and techniques in further developments, it seems interesting to identify which aspects in the respective formal foundation are related. This paper presents initial results in this direction....

  9. Simplified topological invariants for interacting insulators

    OpenAIRE

    Zhong Wang; Shou-Cheng Zhang

    2012-01-01

    We propose general topological order parameters for interacting insulators in terms of the Green’s function at zero frequency. They provide a unified description of various interacting topological insulators including the quantum anomalous Hall insulators and the time-reversal-invariant insulators in four, three, and two dimensions. Since only the Green’s function at zero frequency is used, these topological order parameters can be evaluated efficiently by most numerical and analytical algori...

  10. Overdispersion in nuclear statistics

    Energy Technology Data Exchange (ETDEWEB)

    Semkow, Thomas M. [State University of New York, Albany, NY (United States)

    1999-02-11

    The modern statistical distribution theory is applied to the development of the overdispersion theory in ionizing-radiation statistics for the first time. The physical nuclear system is treated as a sequence of binomial processes, each depending on a characteristic probability, such as probability of decay, detection, etc. The probabilities fluctuate in the course of a measurement, and the physical reasons for that are discussed. If the average values of the probabilities change from measurement to measurement, which originates from the random Lexis binomial sampling scheme, then the resulting distribution is overdispersed. The generating functions and probability distribution functions are derived, followed by a moment analysis. The Poisson and Gaussian limits are also given. The distribution functions belong to a family of generalized hypergeometric factorial moment distributions by Kemp and Kemp, and can serve as likelihood functions for the statistical estimations. An application to radioactive decay with detection is described and working formulae are given, including a procedure for testing the counting data for overdispersion. More complex experiments in nuclear physics (such as solar neutrino) can be handled by this model, as well as distinguishing between the source and background.

  11. Breast cancer diagnosis in digitized mammograms using curvelet moments.

    Science.gov (United States)

    Dhahbi, Sami; Barhoumi, Walid; Zagrouba, Ezzeddine

    2015-09-01

    Feature extraction is a key issue in designing a computer aided diagnosis system. Recent researches on breast cancer diagnosis have reported the effectiveness of multiscale transforms (wavelets and curvelets) for mammogram analysis and have shown the superiority of curvelet transform. However, the curse of dimensionality problem arises when using the curvelet coefficients and therefore a reduction method is required to extract a reduced set of discriminative features. This paper deals with this problem and proposes a feature extraction method based on curvelet transform and moment theory for mammogram description. First, we performed discrete curvelet transform and we computed the four first-order moments from curvelet coefficients distribution. Hence, two feature sets can be obtained: moments from each band and moments from each level. In this work, both sets are studied. Then, the t-test ranking technique was applied to select the best features from each set. Finally, a k-nearest neighbor classifier was used to distinguish between normal and abnormal breast tissues and to classify tumors as malignant or benign. Experiments were performed on 252 mammograms from the Mammographic Image Analysis Society (mini-MIAS) database using the leave-one-out cross validation as well as on 11553 mammograms from the Digital Database for Screening Mammography (DDSM) database using 2×5-fold cross validation. Experimental results prove the effectiveness and the superiority of curvelet moments for mammogram analysis. Indeed, results on the mini-MIAS database show that curvelet moments yield an accuracy of 91.27% (resp. 81.35 %) with 10 (resp. 8) features for abnormality (resp. malignancy) detection. In addition, empirical comparisons of the proposed method against state-of-the-art curvelet-based methods on the DDSM database show that the suggested method does not only lead to a more reduced feature set, but it also statistically outperforms all the compared methods in terms of

  12. WRIST SALVAGE PROCEDURES ALTER MOMENT ARMS OF THE PRIMARY WRIST MUSCLES

    Science.gov (United States)

    Nichols, Jennifer A.; Bednar, Michael S.; Havey, Robert M.; Murray, Wendy M.

    2015-01-01

    Background Proximal row carpectomy and scaphoid-excision four-corner fusion are salvage procedures that relieve pain by removing arthritic joint surfaces. While numerous studies have examined how these procedures affect joint motion, few have examined how they influence muscle mechanical actions. This study examines whether muscle moment arms change after these procedures. Methods Moment arms of primary wrist muscles were measured in 8 cadaveric specimens using the tendon excursion method. In each specimen, moment arms were measured for two degrees of freedom (flexion-extension and radial-ulnar deviation) and three conditions (nonimpaired, scaphoid-excision four-corner fusion, and proximal row carpectomy). For each muscle and degree of freedom, moment arm versus joint angle curves for the three conditions were statistically compared. Findings Wrist salvage procedures significantly alter moment arms of the primary wrist muscles. Proximal row carpectomy primarily alters flexion-extension moment arms, while scaphoid-excision four-corner fusion primarily alters radial-ulnar deviation moment arms. Both procedures also alter the balance between agonist and antagonist wrist muscles. Following proximal row carpectomy, wrist extensors have smaller moment arms in extended postures. Following scaphoid-excision four-corner fusion, radial deviators have larger moment arms throughout radial-ulnar deviation. Interpretation Different moment arms indicate that different forces are required to complete the same tasks in nonimpaired and surgically altered wrists. The altered muscle moment arms likely contribute to post-operative impairments. Understanding how salvage procedures alter muscle mechanical actions is a critical first step toward identifying the cause of post-operative impairments and is necessary to develop effective interventions to augment deficient muscles and improve overall function. PMID:25843482

  13. Astroparticle Physics Tests of Lorentz Invariance Violation

    Science.gov (United States)

    Lang, R. G.; de Souza, V.

    2017-06-01

    Testing Lorentz invariance is essential as it is one of the pillars of modern physics. Moreover, its violation is foreseen in several popular Quantum Gravity models. Several authors study the effects of Lorentz invariance violation (LIV) in the propagation of ultra-high energy cosmic rays. These particles are the most energetic events ever detected and therefore represent a promising framework to test LIV. In this work we present an analytic calculation of the inelasticity for any a + b → c + d interaction using first order perturbation in the dispersion relation that violates Lorentz invariance. The inelasticity can be calculated by solving a third-order polynomial equation containing: a) the kinematics of the interaction, b) the LIV term for each particle and c) the geometry of the interaction. We use the inelasticity we calculate to investigate the proton propagation in the intergalactic media. The photopion production of the proton interaction with the CMB is taken into account using the inelasticity and the attenuation length in different LIV scenarios. We show how the allowed phase space for the photopion production changes when LIV is considered for the interaction. The calculations presented here are going to be extended in order to calculated the modified ultra-high energy cosmic rays spectrum and compare it to the data.

  14. Permutation-invariant distance between atomic configurations

    Energy Technology Data Exchange (ETDEWEB)

    Ferré, Grégoire; Maillet, Jean-Bernard [CEA, DAM, DIF, F-91297 Arpajon (France); Stoltz, Gabriel [Université Paris-Est, CERMICS (ENPC), INRIA, F-77455 Marne-la-Vallée (France)

    2015-09-14

    We present a permutation-invariant distance between atomic configurations, defined through a functional representation of atomic positions. This distance enables us to directly compare different atomic environments with an arbitrary number of particles, without going through a space of reduced dimensionality (i.e., fingerprints) as an intermediate step. Moreover, this distance is naturally invariant through permutations of atoms, avoiding the time consuming associated minimization required by other common criteria (like the root mean square distance). Finally, the invariance through global rotations is accounted for by a minimization procedure in the space of rotations solved by Monte Carlo simulated annealing. A formal framework is also introduced, showing that the distance we propose verifies the property of a metric on the space of atomic configurations. Two examples of applications are proposed. The first one consists in evaluating faithfulness of some fingerprints (or descriptors), i.e., their capacity to represent the structural information of a configuration. The second application concerns structural analysis, where our distance proves to be efficient in discriminating different local structures and even classifying their degree of similarity.

  15. Volumetric Image Registration From Invariant Keypoints.

    Science.gov (United States)

    Rister, Blaine; Horowitz, Mark A; Rubin, Daniel L

    2017-10-01

    We present a method for image registration based on 3D scale- and rotation-invariant keypoints. The method extends the scale invariant feature transform (SIFT) to arbitrary dimensions by making key modifications to orientation assignment and gradient histograms. Rotation invariance is proven mathematically. Additional modifications are made to extrema detection and keypoint matching based on the demands of image registration. Our experiments suggest that the choice of neighborhood in discrete extrema detection has a strong impact on image registration accuracy. In head MR images, the brain is registered to a labeled atlas with an average Dice coefficient of 92%, outperforming registration from mutual information as well as an existing 3D SIFT implementation. In abdominal CT images, the spine is registered with an average error of 4.82 mm. Furthermore, keypoints are matched with high precision in simulated head MR images exhibiting lesions from multiple sclerosis. These results were achieved using only affine transforms, and with no change in parameters across a wide variety of medical images. This paper is freely available as a cross-platform software library.

  16. Regional analysis of annual maximum rainfall using TL-moments method

    Science.gov (United States)

    Shabri, Ani Bin; Daud, Zalina Mohd; Ariff, Noratiqah Mohd

    2011-06-01

    Information related to distributions of rainfall amounts are of great importance for designs of water-related structures. One of the concerns of hydrologists and engineers is the probability distribution for modeling of regional data. In this study, a novel approach to regional frequency analysis using L-moments is revisited. Subsequently, an alternative regional frequency analysis using the TL-moments method is employed. The results from both methods were then compared. The analysis was based on daily annual maximum rainfall data from 40 stations in Selangor Malaysia. TL-moments for the generalized extreme value (GEV) and generalized logistic (GLO) distributions were derived and used to develop the regional frequency analysis procedure. TL-moment ratio diagram and Z-test were employed in determining the best-fit distribution. Comparison between the two approaches showed that the L-moments and TL-moments produced equivalent results. GLO and GEV distributions were identified as the most suitable distributions for representing the statistical properties of extreme rainfall in Selangor. Monte Carlo simulation was used for performance evaluation, and it showed that the method of TL-moments was more efficient for lower quantile estimation compared with the L-moments.

  17. Statistics for Finance

    DEFF Research Database (Denmark)

    Lindström, Erik; Madsen, Henrik; Nielsen, Jan Nygaard

    that rarely connect concepts to data and books on econometrics and time series analysis that do not cover specific problems related to option valuation. The book discusses applications of financial derivatives pertaining to risk assessment and elimination. The authors cover various statistical...... and mathematical techniques, including linear and nonlinear time series analysis, stochastic calculus models, stochastic differential equations, Itō’s formula, the Black–Scholes model, the generalized method-of-moments, and the Kalman filter. They explain how these tools are used to price financial derivatives...

  18. A reanalysis of Lord's statistical treatment of football numbers

    NARCIS (Netherlands)

    Zand Scholten, A.; Borsboom, D.

    2009-01-01

    Stevens’ theory of admissible statistics [Stevens, S. S. (1946). On the theory of scales of measurement. Science, 103, 677680] states that measurement levels should guide the choice of statistical test, such that the truth value of statements based on a statistical analysis remains invariant under

  19. Model reduction using the Vorobyev moment problem

    Science.gov (United States)

    Strakoš, Zdeněk

    2009-07-01

    Given a nonsingular complex matrix and complex vectors v and w of length N, one may wish to estimate the quadratic form w * A - 1 v, where w * denotes the conjugate transpose of w. This problem appears in many applications, and Gene Golub was the key figure in its investigations for decades. He focused mainly on the case A Hermitian positive definite (HPD) and emphasized the relationship of the algebraically formulated problems with classical topics in analysis - moments, orthogonal polynomials and quadrature. The essence of his view can be found in his contribution Matrix Computations and the Theory of Moments, given at the International Congress of Mathematicians in Zürich in 1994. As in many other areas, Gene Golub has inspired a long list of coauthors for work on the problem, and our contribution can also be seen as a consequence of his lasting inspiration. In this paper we will consider a general mathematical concept of matching moments model reduction, which as well as its use in many other applications, is the basis for the development of various approaches for estimation of the quadratic form above. The idea of model reduction via matching moments is well known and widely used in approximation of dynamical systems, but it goes back to Stieltjes, with some preceding work done by Chebyshev and Heine. The algebraic moment matching problem can for A HPD be formulated as a variant of the Stieltjes moment problem, and can be solved using Gauss-Christoffel quadrature. Using the operator moment problem suggested by Vorobyev, we will generalize model reduction based on matching moments to the non-Hermitian case in a straightforward way. Unlike in the model reduction literature, the presented proofs follow directly from the construction of the Vorobyev moment problem.

  20. A parts-per-billion measurement of the antiproton magnetic moment.

    Science.gov (United States)

    Smorra, C; Sellner, S; Borchert, M J; Harrington, J A; Higuchi, T; Nagahama, H; Tanaka, T; Mooser, A; Schneider, G; Bohman, M; Blaum, K; Matsuda, Y; Ospelkaus, C; Quint, W; Walz, J; Yamazaki, Y; Ulmer, S

    2017-10-18

    Precise comparisons of the fundamental properties of matter-antimatter conjugates provide sensitive tests of charge-parity-time (CPT) invariance, which is an important symmetry that rests on basic assumptions of the standard model of particle physics. Experiments on mesons, leptons and baryons have compared different properties of matter-antimatter conjugates with fractional uncertainties at the parts-per-billion level or better. One specific quantity, however, has so far only been known to a fractional uncertainty at the parts-per-million level: the magnetic moment of the antiproton, . The extraordinary difficulty in measuring with high precision is caused by its intrinsic smallness; for example, it is 660 times smaller than the magnetic moment of the positron. Here we report a high-precision measurement of in units of the nuclear magneton μN with a fractional precision of 1.5 parts per billion (68% confidence level). We use a two-particle spectroscopy method in an advanced cryogenic multi-Penning trap system. Our result  = -2.7928473441(42)μN (where the number in parentheses represents the 68% confidence interval on the last digits of the value) improves the precision of the previous best measurement by a factor of approximately 350. The measured value is consistent with the proton magnetic moment, μp = 2.792847350(9)μN, and is in agreement with CPT invariance. Consequently, this measurement constrains the magnitude of certain CPT-violating effects to below 1.8 × 10-24 gigaelectronvolts, and a possible splitting of the proton-antiproton magnetic moments by CPT-odd dimension-five interactions to below 6 × 10-12 Bohr magnetons.

  1. Moment of inertia in elliptical quantum dots

    Science.gov (United States)

    Serra, Llorenç; Puente, Antonio; Lipparini, Enrico

    The moment of inertia of deformed quantum dots and its experimental relevance in relation to the dot spectroscopic features is theoretically investigated. A strong link to the low-energy orbital current mode that manifests in the magnetic dipole (M1) spectrum is stressed. The moment of inertia is obtained by solving the cranked Kohn-Sham equations within the local-spin-density approximation and the results discussed in comparison with the predictions of an analytical non-interacting model. The results as a function of deformation and size indicate that the existence of spin transitions in the dot ground state has an important effect on the moment of inertia.

  2. A cohomological framework for homotopy moment maps

    Science.gov (United States)

    Frégier, Yaël; Laurent-Gengoux, Camille; Zambon, Marco

    2015-11-01

    Given a Lie group acting on a manifold M preserving a closed n + 1-form ω, the notion of homotopy moment map for this action was introduced in Fregier (0000), in terms of L∞-algebra morphisms. In this note we describe homotopy moment maps as coboundaries of a certain complex. This description simplifies greatly computations, and we use it to study various properties of homotopy moment maps: their relation to equivariant cohomology, their obstruction theory, how they induce new ones on mapping spaces, and their equivalences. The results we obtain extend some of the results of Fregier (0000).

  3. Moment analysis of hadronic vacuum polarization

    Energy Technology Data Exchange (ETDEWEB)

    Rafael, Eduardo de

    2014-09-07

    I suggest a new approach to the determination of the hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment of the muon a{sub μ}{sup HVP} in lattice QCD. It is based on properties of the Mellin transform of the hadronic spectral function and their relation to the HVP self-energy in the Euclidean. I show how a{sub μ}{sup HVP} is very well approximated by a few moments associated to this Mellin transform and how these moments can be evaluated in lattice QCD, providing thus a series of tests when compared with the corresponding determinations using experimental data.

  4. Binomial moment equations for stochastic reaction systems.

    Science.gov (United States)

    Barzel, Baruch; Biham, Ofer

    2011-04-15

    A highly efficient formulation of moment equations for stochastic reaction networks is introduced. It is based on a set of binomial moments that capture the combinatorics of the reaction processes. The resulting set of equations can be easily truncated to include moments up to any desired order. The number of equations is dramatically reduced compared to the master equation. This formulation enables the simulation of complex reaction networks, involving a large number of reactive species much beyond the feasibility limit of any existing method. It provides an equation-based paradigm to the analysis of stochastic networks, complementing the commonly used Monte Carlo simulations.

  5. Moment analysis of hadronic vacuum polarization

    Directory of Open Access Journals (Sweden)

    Eduardo de Rafael

    2014-09-01

    Full Text Available I suggest a new approach to the determination of the hadronic vacuum polarization (HVP contribution to the anomalous magnetic moment of the muon aμHVP in lattice QCD. It is based on properties of the Mellin transform of the hadronic spectral function and their relation to the HVP self-energy in the Euclidean. I show how aμHVP is very well approximated by a few moments associated to this Mellin transform and how these moments can be evaluated in lattice QCD, providing thus a series of tests when compared with the corresponding determinations using experimental data.

  6. A new affine-invariant image matching method based on SIFT

    Science.gov (United States)

    Wang, Peng-cheng; Chen, Qian; Chen, Hai-xin; Cheng, Hong-chang; Gong, Zhen-fei

    2013-09-01

    Local invariant feature extraction, as one of the main problems in the field of computer vision, has been widely applied to image matching, splicing and target recognition etc. Lowe's scale invariant feature transform (known as SIFT) algorithm has attracted much attention due to its invariance to scale, rotation and illumination. However, SIFT is not robust to affine deformations, because it is based on the DoG detector which extracts keypoints in a circle region. Besides, the feature descriptor is represented by a 128-dimensional vector, which means that the algorithm complexity is extremely large especially when there is a great quantity of keypoints in the image. In this paper, a new feature descriptor, which is robust to affine deformations, is proposed. Considering that circles turn to be ellipses after affine deformations, some improvements have been made. Firstly, the Gaussian image pyramids are constructed by convoluting the source image and the elliptical Gaussian kernel with two volatile parameters, orientation and eccentricity. In addition, the two parameters are discretely selected in order to imitate the possibilities of the affine deformation, which can make sure that anisotropic regions are transformed into isotropic ones. Next, all extreme points can be extracted as the candidates for the affine-invariant keypoints in the image pyramids. After accurate keypoints localization is performed, the secondary moment of the keypoints' neighborhood is calculated to identify the elliptical region which is affineinvariant, the same as SIFT, the main orientation of the keypoints can be determined and the feature descriptor is generated based on the histogram constructed in this region. At last, the PCA method for the 128-dimensional descriptor's reduction is used to improve the computer calculating efficiency. The experiments show that this new algorithm inherits all SIFT's original advantages, and has a good resistance to affine deformations; what's more, it

  7. Earth's magnetic moment during geomagnetic reversals

    Science.gov (United States)

    Sokoloff, D. D.

    2017-11-01

    The behavior of the dipole magnetic moment of the geomagnetic field during the reversals is considered. By analogy with the reversals of the magnetic field of the Sun, the scenario is suggested in which during the reversal the mean dipole moment becomes zero, whereas the instantaneous value of the dipole magnetic moment remains nonzero and the corresponding vector rotates from the vicinity of one geographical pole to the other. A thorough discussion concerning the definition of the mean magnetic moment, which is used in this concept, is presented. Since the behavior of the geomagnetic field during the reversal is far from stationary, the ensemble average instead of the time average has to be considered.

  8. Nonredundant Single-Gimbaled Control Moment Gyroscopes

    Science.gov (United States)

    2012-04-01

    p. 79. [3] Kennel , H. F., “Steering Law for Parallel Mounted Double-Gimbaled Control Moment Gyros,” NASATM-X-64930, 1975, p. 34. [4] Colburn, B. K...NASATM-X-64926, 1975. [6] Kennel , H. F., “Steering Law for Parallel Mounted Double-Gimbaled Control Moment Gyros,” NASATM-X-82390, 1981, p. 22. Fig. 16

  9. Variational approach to the moment of inertia

    Energy Technology Data Exchange (ETDEWEB)

    Stringari, S.; Lipparini, E.

    1980-08-01

    We derive an approximate expression for the moment of inertia theta in the framework of the cranked Hartree-Fock theory. Our method allows for a detailed study of the role of spin-orbit and two-body nuclear potentials. In particular it is shown that in /sup 20/Ne the two-body interaction lowers by 30% the rigid value of theta. The irrotational and rigid values for the moment of inertia are obtained as special cases of the present approach.

  10. Link between chips and cutting moments evolution

    CERN Document Server

    Cahuc, Olivier; Gérard, Alain; 10.4028/WWW.scientific.net/AMR.423.89

    2012-01-01

    The better understanding of the material cutting process has been shown with the benefit of the forces and moments measurement since some years ago. In paper, simultaneous six mechanical components and chip orientation measurements were realized during turning tests. During these tests, the influence of the depth of cut or feed rate has been observed and a link between the chip orientation and the moment vector orientation or the central axis characteristics has been shown.

  11. Magnetic Johnson Noise Constraints on Electron Electric Dipole Moment Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Munger, C.

    2004-11-18

    Magnetic fields from statistical fluctuations in currents in conducting materials broaden atomic linewidths by the Zeeman effect. The constraints so imposed on the design of experiments to measure the electric dipole moment of the electron are analyzed. Contrary to the predictions of Lamoreaux [S.K. Lamoreaux, Phys. Rev. A60, 1717(1999)], the standard material for high-permeability magnetic shields proves to be as significant a source of broadening as an ordinary metal. A scheme that would replace this standard material with ferrite is proposed.

  12. Statistical theory and inference

    CERN Document Server

    Olive, David J

    2014-01-01

    This text is for  a one semester graduate course in statistical theory and covers minimal and complete sufficient statistics, maximum likelihood estimators, method of moments, bias and mean square error, uniform minimum variance estimators and the Cramer-Rao lower bound, an introduction to large sample theory, likelihood ratio tests and uniformly most powerful  tests and the Neyman Pearson Lemma. A major goal of this text is to make these topics much more accessible to students by using the theory of exponential families. Exponential families, indicator functions and the support of the distribution are used throughout the text to simplify the theory. More than 50 ``brand name" distributions are used to illustrate the theory with many examples of exponential families, maximum likelihood estimators and uniformly minimum variance unbiased estimators. There are many homework problems with over 30 pages of solutions.

  13. Superluminality in dilatationally invariant generalized Galileon theories

    Science.gov (United States)

    Kolevatov, R. S.

    2015-12-01

    We consider small perturbations about homogeneous backgrounds in dilatationally invariant Galileon models. The issues we address are stability (absence of ghosts and gradient instabilities) and superluminality. We show that in the Minkowski background, it is possible to construct the Lagrangian in such a way that any homogeneous Galileon background solution is stable and small perturbations about it are subluminal. On the other hand, in the case of Friedmann-Lemaitre-Robertson-Walker (FLRW) backgrounds, for any Lagrangian functions there exist homogeneous background solutions to the Galileon equation of motion and time dependence of the scale factor, such that the stability conditions are satisfied, but the Galileon perturbations propagate with superluminal speed.

  14. Constructing invariant fairness measures for surfaces

    DEFF Research Database (Denmark)

    Gravesen, Jens; Ungstrup, Michael

    2002-01-01

    The paper proposes a rational method to derive fairness measures for surfaces. It works in cases where isophotes, reflection lines, planar intersection curves, or other curves are used to judge the fairness of the surface. The surface fairness measure is derived by demanding that all the given cu...... of curves. Six basic third order invariants by which the fairing measures can be expressed are defined. Furthermore, the geometry of a plane intersection curve is studied, and the variation of the total, the normal, and the geodesic curvature and the geodesic torsion is determined....

  15. Translational invariant shell model for Λ hypernuclei

    Directory of Open Access Journals (Sweden)

    Jolos R.V.

    2016-01-01

    Full Text Available We extend shell model for Λ hypernuclei suggested by Gal and Millener by including 2ћω excitations in the translation invariant version to estimate yields of different hyperfragments from primary p-shell hypernuclei. We are inspired by the first successful experiment done at MAMI which opens way to study baryon decay of hypernuclei. We use quantum numbers of group SU(4, [f], and SU(3, (λμ, to classify basis wave functions and calculate coefficients of fractional parentage.

  16. Topologically left invariant means on semigroup algebras

    Indian Academy of Sciences (India)

    -compact in M(S)∗∗ . We define the semiflow (M0(S), ) by putting ρ(µ,F) = µF for µ ∈ M(S) and F ∈. M(S)∗∗ . By hypothesis, there exists M ∈ that is fixed under the action of M0(S), that is µM = M for every µ ∈ M0(S). It follows that M is a topologically left invariant mean on M(S)∗ . This completes our proof. 2. A right action of ...

  17. Lattice Boltzmann method with restored Galilean invariance.

    Science.gov (United States)

    Prasianakis, N I; Karlin, I V; Mantzaras, J; Boulouchos, K B

    2009-06-01

    An isothermal model on the standard two-dimension nine-velocity lattice (D2Q9) is proposed and analyzed. It originates from the thermal model with energy conservation introduced by N. I. Prasianakis and I. V. Karlin [Phys. Rev. E 76, 016702 (2007)]. The isothermal and the thermal equivalent models are tested through the simulation of the decay of a shear wave and of a temperature wave. Both are shown to be Galilean invariant, reference temperature independent, and rotational isotropic through the measurement of the transport coefficients on a rotated moving frame of reference.

  18. Origin of gauge invariance in string theory

    Science.gov (United States)

    Horowitz, G. T.; Strominger, A.

    1986-01-01

    A first quantization of the space-time embedding Chi exp mu and the world-sheet metric rho of the open bosonic string. The world-sheet metric rho decouples from S-matrix elements in 26 dimensions. This formulation of the theory naturally includes 26-dimensional gauge transformations. The gauge invariance of S-matrix elements is a direct consequence of the decoupling of rho. Second quantization leads to a string field Phi(Chi exp mu, rho) with a gauge-covariant equation of motion.

  19. Hidden Scale Invariance in Condensed Matter

    DEFF Research Database (Denmark)

    Dyre, J. C.

    2014-01-01

    . This means that the phase diagram becomes effectively one-dimensional with regard to several physical properties. Liquids and solids with isomorphs include most or all van der Waals bonded systems and metals, as well as weakly ionic or dipolar systems. On the other hand, systems with directional bonding...... (hydrogen bonds or covalent bonds) or strong Coulomb forces generally do not exhibit hidden scale invariance. The article reviews the theory behind this picture of condensed matter and the evidence for it coming from computer simulations and experiments...

  20. Visual Distinctness Determined by Partially Invariant Features

    Science.gov (United States)

    2000-03-01

    DISTINCTNESS DETERMINED BY PARTIALLY INVARIANT FEATURES. J.A. Garcia, J. Fdez-Valdivia Departamento de Ciencias de la Computacion e I.A. Univ. de Granada...E.T.S. de Ingenieria Informatica. 18071 Granada. Spain E-mail: jagsadecsai.ugr.es, J.Fdez-Valdivia@decsai.ugr.es Xose R. Fdez-Vidal Departamento de... Fisica Aplicada. Univ. de Santiago de Compostela. Facultad de Fisica . 15706 Santiago de Compostela. Spain E-mail: faxose@usc.es Rosa Rodriguez-Sanchez

  1. Monomial codes seen as invariant subspaces

    Directory of Open Access Journals (Sweden)

    García-Planas María Isabel

    2017-08-01

    Full Text Available It is well known that cyclic codes are very useful because of their applications, since they are not computationally expensive and encoding can be easily implemented. The relationship between cyclic codes and invariant subspaces is also well known. In this paper a generalization of this relationship is presented between monomial codes over a finite field and hyperinvariant subspaces of n under an appropriate linear transformation. Using techniques of Linear Algebra it is possible to deduce certain properties for this particular type of codes, generalizing known results on cyclic codes.

  2. Invariant measures of mass migration processes

    Czech Academy of Sciences Publication Activity Database

    Fajfrová, Lucie; Gobron, T.; Saada, E.

    2016-01-01

    Roč. 21, č. 1 (2016), s. 1-52, č. článku 60. ISSN 1083-6489 R&D Projects: GA ČR GAP201/12/2613; GA ČR(CZ) GA16-15238S Institutional support: RVO:67985556 Keywords : interacting particle systems * product invariant measures * zero range process * target process * mass migration process * condensation Subject RIV: BA - General Mathematics Impact factor: 0.904, year: 2016 http://library.utia.cas.cz/separaty/2016/SI/fajfrova-0464455.pdf

  3. Conformal invariance in quantum field theory

    CERN Document Server

    Todorov, Ivan T; Petkova, Valentina B

    1978-01-01

    The present volume is an extended and up-to-date version of two sets of lectures by the first author and it reviews more recent work. The notes aim to present a self-contained exposition of a constructive approach to conformal invariant quantum field theory. Other parts in application of the conformal group to quantum physics are only briefly mentioned. The relevant mathematical material (harmonic analysis on Euclidean conformal groups) is briefly summarized. A new exposition of physical applications is given, which includes an explicit construction of the vacuum operator product expansion for the free zero mass fields.

  4. Loop quasi-invariant chunk detection

    DEFF Research Database (Denmark)

    Moyen, Jean-Yves; Rubiano, Thomas; Seiller, Thomas

    2017-01-01

    Several techniques for analysis and transformations are used in compilers. Among them, the peeling of loops for hoisting quasi-invariants can be used to optimize generated code, or simply ease developers’ lives. In this paper, we introduce a new concept of dependency analysis borrowed from...... the computational complexity of the overall program can be decreased. In this paper, we introduce the theory around this concept and present a prototype analysis pass implemented on LLVM. We already implemented a proof of concept on a toy C parser (https://github.com/ThomasRuby/LQICM_On_C_Toy_Parser) analysing...

  5. Descriptive statistics.

    Science.gov (United States)

    Shi, Runhua; McLarty, Jerry W

    2009-10-01

    In this article, we introduced basic concepts of statistics, type of distributions, and descriptive statistics. A few examples were also provided. The basic concepts presented herein are only a fraction of the concepts related to descriptive statistics. Also, there are many commonly used distributions not presented herein, such as Poisson distributions for rare events and exponential distributions, F distributions, and logistic distributions. More information can be found in many statistics books and publications.

  6. Reparametrization Invariance, the controversial extraction of $\\alpha$ from $B\\to\\pi\\pi$ and New Physics

    OpenAIRE

    Botella, Francisco J.; Nebot, Miguel

    2007-01-01

    The extraction of the weak phase $\\alpha$ from $B\\to\\pi\\pi$ decays has been controversial from a statistical point of view, as the frequentist vs. bayesian confrontation shows. We analyse several relevant questions which have not deserved full attention and pervade the extraction of $\\alpha$. Reparametrization Invariance proves appropriate to understand those issues. We show that some Standard Model inspired parametrizations can be senseless or inadequate if they go beyond the minimal Gronau ...

  7. Indoor Location Sensing with Invariant Wi-Fi Received Signal Strength Fingerprinting

    Directory of Open Access Journals (Sweden)

    Mohd Nizam Husen

    2016-11-01

    Full Text Available A method of location fingerprinting based on the Wi-Fi received signal strength (RSS in an indoor environment is presented. The method aims to overcome the RSS instability due to varying channel disturbances in time by introducing the concept of invariant RSS statistics. The invariant RSS statistics represent here the RSS distributions collected at individual calibration locations under minimal random spatiotemporal disturbances in time. The invariant RSS statistics thus collected serve as the reference pattern classes for fingerprinting. Fingerprinting is carried out at an unknown location by identifying the reference pattern class that maximally supports the spontaneous RSS sensed from individual Wi-Fi sources. A design guideline is also presented as a rule of thumb for estimating the number of Wi-Fi signal sources required to be available for any given number of calibration locations under a certain level of random spatiotemporal disturbances. Experimental results show that the proposed method not only provides 17% higher success rate than conventional ones but also removes the need for recalibration. Furthermore, the resolution is shown finer by 40% with the execution time more than an order of magnitude faster than the conventional methods. These results are also backed up by theoretical analysis.

  8. Indoor Location Sensing with Invariant Wi-Fi Received Signal Strength Fingerprinting.

    Science.gov (United States)

    Husen, Mohd Nizam; Lee, Sukhan

    2016-11-11

    A method of location fingerprinting based on the Wi-Fi received signal strength (RSS) in an indoor environment is presented. The method aims to overcome the RSS instability due to varying channel disturbances in time by introducing the concept of invariant RSS statistics. The invariant RSS statistics represent here the RSS distributions collected at individual calibration locations under minimal random spatiotemporal disturbances in time. The invariant RSS statistics thus collected serve as the reference pattern classes for fingerprinting. Fingerprinting is carried out at an unknown location by identifying the reference pattern class that maximally supports the spontaneous RSS sensed from individual Wi-Fi sources. A design guideline is also presented as a rule of thumb for estimating the number of Wi-Fi signal sources required to be available for any given number of calibration locations under a certain level of random spatiotemporal disturbances. Experimental results show that the proposed method not only provides 17% higher success rate than conventional ones but also removes the need for recalibration. Furthermore, the resolution is shown finer by 40% with the execution time more than an order of magnitude faster than the conventional methods. These results are also backed up by theoretical analysis.

  9. A Great Moment for Astronomy

    Science.gov (United States)

    1998-05-01

    illustrates how the appearance of a stellar image at the focal plane is fully controllable. Fast and thorough optical adjustment ensures the best possible optical quality at all times . 9. Image Quality of the VLT This diagram demonstrates that First Light specifications have been fully met and, more impressively, that the actual VLT performance is sometimes already within the more stringent specifications that were expected to be fulfilled only three years from now. The final steps before "First Light" The final, critical testing phase commenced with the installation of the 8.2-m primary (at that time still uncoated) Zerodur mirror and 1.1-m secondary Beryllium mirror during the second half of April. The optics were then gradually brought into position during carefully planned, successive adjustments. Due to the full integration of an advanced, active control system into the VLT concept, this delicate process went amazingly fast, especially when compared to other ground-based telescopes. It included a number of short test exposures in early May, first with the Guide Camera that is used to steer the telescope. Later, some exposures were made with the Test Camera mounted just below the main mirror at the Cassegrain Focus, in a central space inside the mirror cell. It will continue to be used during the upcoming Commissioning Phase, until the first major instruments (FORS and ISAAC) are attached to the UT1, later in 1998. The 8.2-m mirror was successfully aluminized at the Paranal Mirror Coating facility on May 20 and was reattached to the telescope tube the day thereafter, cf. ESO PR Photos 13a-e/98 and ESO PR Photos 14a-i/98. Further test exposures were then made to check the proper functioning of the telescope mechanics, optics and electronics. This has lead up to the moment of First Light , i.e. the time when the telescope is considered able to produce the first, astronomically useful images. Despite an intervening spell of bad atmospheric conditions, this important event

  10. Gauge-invariant Aharonov-Bohm streamlines

    Science.gov (United States)

    Berry, M. V.

    2017-10-01

    The phase gradient of the wave describing the Aharonov-Bohm effect (AB) is proportional to the local canonical momentum. This vector field contains vortices (phase singularities), whose strengths cannot be detected in quantum mechanics because they increase (discontinuously) with the magnetic flux, violating gauge invariance. The analogous quantity which is gauge-invariant is the kinetic momentum field, proportional to the local electron velocity. Investigation of the streamlines (integral curves) of this velocity field reveals that as the flux increases from 0 to 1/2 (in quantum units), a vortex V is generated at the flux line, accompanied by a stagnation point (saddle) S that emerges from V and then collapses back into V. The VS pair is always small: the maximum distance between V and S is approximately 0.0209 de Broglie wavelengths. The VS phenomenon survives generalization to a superposition of AB waves. If the flux is confined within an impenetrable tube of radius R, S persists if R  <  0.004 de Broglie wavelengths, and is swallowed by the tube for larger R. An experiment is envisaged.

  11. Natural inflation with hidden scale invariance

    Directory of Open Access Journals (Sweden)

    Neil D. Barrie

    2016-05-01

    Full Text Available We propose a new class of natural inflation models based on a hidden scale invariance. In a very generic Wilsonian effective field theory with an arbitrary number of scalar fields, which exhibits scale invariance via the dilaton, the potential necessarily contains a flat direction in the classical limit. This flat direction is lifted by small quantum corrections and inflation is realised without need for an unnatural fine-tuning. In the conformal limit, the effective potential becomes linear in the inflaton field, yielding to specific predictions for the spectral index and the tensor-to-scalar ratio, being respectively: ns−1≈−0.025(N⋆60−1 and r≈0.0667(N⋆60−1, where N⋆≈30–65 is a number of efolds during observable inflation. This predictions are in reasonable agreement with cosmological measurements. Further improvement of the accuracy of these measurements may turn out to be critical in falsifying our scenario.

  12. Multi-Centered Invariants, Plethysm and Grassmannians

    CERN Document Server

    Cacciatori, Sergio L.; van Geemen, Bert

    2013-01-01

    Motivated by multi-centered black hole solutions of Maxwell-Einstein theories of (super)gravity in D=4 space-time dimensions, we develop some general methods, that can be used to determine all homogeneous invariant polynomials on the irreducible (SL_h(p,R) x G4)-representation (p,R), where p denotes the number of centers, and SL_h(p,R) is the "horizontal" symmetry of the system, acting upon the indices labelling the centers. The black hole electric and magnetic charges sit in the symplectic representation R of the generalized electric-magnetic (U-)duality group G4. We start with an algebraic approach based on classical invariant theory, using Schur polynomials and the Cauchy formula. Then, we perform a geometric analysis, involving Grassmannians, Pluecker coordinates, and exploiting Bott's Theorem. We focus on non-degenerate groups G4 "of type E7" relevant for (super)gravities whose (vector multiplets') scalar manifold is a symmetric space. In the triality-symmetric stu model of N=2 supergravity, we explicitl...

  13. Definition of fractal topography to essential understanding of scale-invariance

    Science.gov (United States)

    Jin, Yi; Wu, Ying; Li, Hui; Zhao, Mengyu; Pan, Jienan

    2017-01-01

    Fractal behavior is scale-invariant and widely characterized by fractal dimension. However, the cor-respondence between them is that fractal behavior uniquely determines a fractal dimension while a fractal dimension can be related to many possible fractal behaviors. Therefore, fractal behavior is independent of the fractal generator and its geometries, spatial pattern, and statistical properties in addition to scale. To mathematically describe fractal behavior, we propose a novel concept of fractal topography defined by two scale-invariant parameters, scaling lacunarity (P) and scaling coverage (F). The scaling lacunarity is defined as the scale ratio between two successive fractal generators, whereas the scaling coverage is defined as the number ratio between them. Consequently, a strictly scale-invariant definition for self-similar fractals can be derived as D = log F /log P. To reflect the direction-dependence of fractal behaviors, we introduce another parameter Hxy, a general Hurst exponent, which is analytically expressed by Hxy = log Px/log Py where Px and Py are the scaling lacunarities in the x and y directions, respectively. Thus, a unified definition of fractal dimension is proposed for arbitrary self-similar and self-affine fractals by averaging the fractal dimensions of all directions in a d-dimensional space, which . Our definitions provide a theoretical, mechanistic basis for understanding the essentials of the scale-invariant property that reduces the complexity of modeling fractals. PMID:28436450

  14. Scale-invariant structure of energy fluctuations in real earthquakes

    Science.gov (United States)

    Wang, Ping; Chang, Zhe; Wang, Huanyu; Lu, Hong

    2017-11-01

    Earthquakes are obviously complex phenomena associated with complicated spatiotemporal correlations, and they are generally characterized by two power laws: the Gutenberg-Richter (GR) and the Omori-Utsu laws. However, an important challenge has been to explain two apparently contrasting features: the GR and Omori-Utsu laws are scale-invariant and unaffected by energy or time scales, whereas earthquakes occasionally exhibit a characteristic energy or time scale, such as with asperity events. In this paper, three high-quality datasets on earthquakes were used to calculate the earthquake energy fluctuations at various spatiotemporal scales, and the results reveal the correlations between seismic events regardless of their critical or characteristic features. The probability density functions (PDFs) of the fluctuations exhibit evidence of another scaling that behaves as a q-Gaussian rather than random process. The scaling behaviors are observed for scales spanning three orders of magnitude. Considering the spatial heterogeneities in a real earthquake fault, we propose an inhomogeneous Olami-Feder-Christensen (OFC) model to describe the statistical properties of real earthquakes. The numerical simulations show that the inhomogeneous OFC model shares the same statistical properties with real earthquakes.

  15. Cotton-Type and Joint Invariants for Linear Elliptic Systems

    Science.gov (United States)

    Aslam, A.; Mahomed, F. M.

    2013-01-01

    Cotton-type invariants for a subclass of a system of two linear elliptic equations, obtainable from a complex base linear elliptic equation, are derived both by spliting of the corresponding complex Cotton invariants of the base complex equation and from the Laplace-type invariants of the system of linear hyperbolic equations equivalent to the system of linear elliptic equations via linear complex transformations of the independent variables. It is shown that Cotton-type invariants derived from these two approaches are identical. Furthermore, Cotton-type and joint invariants for a general system of two linear elliptic equations are also obtained from the Laplace-type and joint invariants for a system of two linear hyperbolic equations equivalent to the system of linear elliptic equations by complex changes of the independent variables. Examples are presented to illustrate the results. PMID:24453871

  16. On logarithmic extensions of local scale-invariance

    Energy Technology Data Exchange (ETDEWEB)

    Henkel, Malte, E-mail: malte.henkel@ijl.nancy-universite.fr [Groupe de Physique Statistique, Département de Physique de la Matière et des Matériaux, Institut Jean Lamour (CNRS UMR 7198), Université de Lorraine Nancy, B.P. 70239, F-54506 Vandoeuvre lès Nancy Cedex (France)

    2013-04-11

    Ageing phenomena far from equilibrium naturally present dynamical scaling and in many situations this may be generalised to local scale-invariance. Generically, the absence of time-translation-invariance implies that each scaling operator is characterised by two independent scaling dimensions. Building on analogies with logarithmic conformal invariance and logarithmic Schrödinger-invariance, this work proposes a logarithmic extension of local scale-invariance, without time-translation-invariance. Carrying this out requires in general to replace both scaling dimensions of each scaling operator by Jordan cells. Co-variant two-point functions are derived for the most simple case of a two-dimensional logarithmic extension. Their form is compared to simulational data for autoresponse functions in several universality classes of non-equilibrium ageing phenomena.

  17. Conformal Invariance in the Long-Range Ising Model

    CERN Document Server

    Paulos, Miguel F; van Rees, Balt C; Zan, Bernardo

    2016-01-01

    We consider the question of conformal invariance of the long-range Ising model at the critical point. The continuum description is given in terms of a nonlocal field theory, and the absence of a stress tensor invalidates all of the standard arguments for the enhancement of scale invariance to conformal invariance. We however show that several correlation functions, computed to second order in the epsilon expansion, are nontrivially consistent with conformal invariance. We proceed to give a proof of conformal invariance to all orders in the epsilon expansion, based on the description of the long-range Ising model as a defect theory in an auxiliary higher-dimensional space. A detailed review of conformal invariance in the d-dimensional short-range Ising model is also included and may be of independent interest.

  18. Conformal invariance in the long-range Ising model

    Directory of Open Access Journals (Sweden)

    Miguel F. Paulos

    2016-01-01

    Full Text Available We consider the question of conformal invariance of the long-range Ising model at the critical point. The continuum description is given in terms of a nonlocal field theory, and the absence of a stress tensor invalidates all of the standard arguments for the enhancement of scale invariance to conformal invariance. We however show that several correlation functions, computed to second order in the epsilon expansion, are nontrivially consistent with conformal invariance. We proceed to give a proof of conformal invariance to all orders in the epsilon expansion, based on the description of the long-range Ising model as a defect theory in an auxiliary higher-dimensional space. A detailed review of conformal invariance in the d-dimensional short-range Ising model is also included and may be of independent interest.

  19. Conformal invariance in the long-range Ising model

    Energy Technology Data Exchange (ETDEWEB)

    Paulos, Miguel F. [CERN, Theory Group, Geneva (Switzerland); Rychkov, Slava, E-mail: slava.rychkov@lpt.ens.fr [CERN, Theory Group, Geneva (Switzerland); Laboratoire de Physique Théorique de l' École Normale Supérieure (LPTENS), Paris (France); Faculté de Physique, Université Pierre et Marie Curie (UPMC), Paris (France); Rees, Balt C. van [CERN, Theory Group, Geneva (Switzerland); Zan, Bernardo [Institute of Physics, Universiteit van Amsterdam, Amsterdam (Netherlands)

    2016-01-15

    We consider the question of conformal invariance of the long-range Ising model at the critical point. The continuum description is given in terms of a nonlocal field theory, and the absence of a stress tensor invalidates all of the standard arguments for the enhancement of scale invariance to conformal invariance. We however show that several correlation functions, computed to second order in the epsilon expansion, are nontrivially consistent with conformal invariance. We proceed to give a proof of conformal invariance to all orders in the epsilon expansion, based on the description of the long-range Ising model as a defect theory in an auxiliary higher-dimensional space. A detailed review of conformal invariance in the d-dimensional short-range Ising model is also included and may be of independent interest.

  20. Measurement of magnetic moment via optical transmission

    Science.gov (United States)

    Heidsieck, Alexandra; Schmid, Daniel; Gleich, Bernhard

    2016-03-01

    The magnetic moment of nanoparticles is an important property for drug targeting and related applications as well as for the simulation thereof. However, the measurement of the magnetic moment of nanoparticles, nanoparticle-virus-complexes or microspheres in solution can be difficult and often yields unsatisfying or incomparable results. To measure the magnetic moment, we designed a custom measurement device including a magnetic set-up to observe nanoparticles indirectly via light transmission in solution. We present a simple, cheap device of manageable size, which can be used in any laboratory as well as a novel evaluation method to determine the magnetic moment of nanoparticles via the change of the optical density of the particle suspension in a well-defined magnetic gradient field. In contrast to many of the established measurement methods, we are able to observe and measure the nanoparticle complexes in their natural state in the respective medium. The nanoparticles move along the magnetic gradient and thereby away from the observation point. Due to this movement, the optical density of the fluid decreases and the transmission increases over time at the measurement location. By comparing the measurement with parametric simulations, we can deduce the magnetic moment from the observed behavior.

  1. The Kubelka-Munk Theory for Color Image Invariant Properties

    OpenAIRE

    Geusebroek, J.M.; Gevers, Th.; Smeulders, A.W.M.

    2002-01-01

    A fundamental problem in color image processing is the integration of the physical laws of light reflection into image processing results, the probem known as photometric invariance. The derivation of object properties from color images yields the extraction of geometric and photometric invariants from color images. Photometric invariance is to be derived from the physics of refelection. In this paper, we rehearse the results from radiative transfer theory to model the reflection and transmis...

  2. Localization of Compact Invariant Sets of the Lorenz'1984 System

    OpenAIRE

    Kh. M. Ramazanova

    2015-01-01

    Localization of compact invariant sets of a dynamical system is one way to conduct a qualitative analysis of dynamical system. The localization task is aimed at evaluating the location of invariant compact sets of systems, which are equilibrium, periodic trajectories, attractors and repellers, and invariant tori. Such sets and their properties largely determine the structure of the phase portrait of the system. For this purpose, one can use a localization set, i.e. a set in the phase space of...

  3. Dimuon Level-1 invariant mass in 2017 data

    CERN Document Server

    CMS Collaboration

    2018-01-01

    This document shows the Level-1 (L1) dimuon invariant mass with and without L1 muon track extrapolation to the collision vertex and how it compares with the offline reconstructed dimuon invariant mass. The plots are made with the data sample collected in 2017. The event selection, the matching algorithm and the results of the L1 dimuon invariant mass are described in the next pages.

  4. Semi-invariant submanifolds of (g, F-manifolds

    Directory of Open Access Journals (Sweden)

    Novac-Claudiu Chiriac

    2010-09-01

    Full Text Available We introduce (g,F-manifolds and initiate a study of their semi-invariant submanifolds. These submanifolds are generalizations of CR-submanifolds of Kaehler manifolds. We obtain necessary and sufficient conditions for the integrability of distributions on a semi-invariant submanifold and study the geometry of foliations defined by these distributions. In particular, for a large class of (g,F-manifolds we prove the existence of a natural foliation on their semi-invariant submanifolds.

  5. Investigating Measurement Invariance in Computer-Based Personality Testing: The Impact of Using Anchor Items on Effect Size Indices

    Science.gov (United States)

    Egberink, Iris J. L.; Meijer, Rob R.; Tendeiro, Jorge N.

    2015-01-01

    A popular method to assess measurement invariance of a particular item is based on likelihood ratio tests with all other items as anchor items. The results of this method are often only reported in terms of statistical significance, and researchers proposed different methods to empirically select anchor items. It is unclear, however, how many…

  6. Attention-Deficit/Hyperactivity Disorder and Sluggish Cognitive Tempo throughout Childhood: Temporal Invariance and Stability from Preschool through Ninth Grade

    Science.gov (United States)

    Leopold, Daniel R.; Christopher, Micaela E.; Burns, G. Leonard; Becker, Stephen P.; Olson, Richard K.; Willcutt, Erik G.

    2016-01-01

    Background: Although multiple cross-sectional studies have shown symptoms of sluggish cognitive tempo (SCT) and attention-deficit/hyperactivity disorder (ADHD) to be statistically distinct, studies have yet to examine the temporal stability and measurement invariance of SCT in a longitudinal sample. To date, only six studies have assessed SCT…

  7. Deviation from power law of the global seismic moment distribution

    Science.gov (United States)

    Serra, Isabel; Corral, Álvaro

    2017-01-01

    The distribution of seismic moment is of capital interest to evaluate earthquake hazard, in particular regarding the most extreme events. We make use of likelihood-ratio tests to compare the simple Gutenberg-Richter power-law (PL) distribution with two statistical models that incorporate an exponential tail, the so-called tapered Gutenberg-Richter (Tap) and the truncated gamma, when fitted to the global CMT earthquake catalog. Although the Tap distribution does not introduce any significant improvement of fit respect the PL, the truncated gamma does. Simulated samples of this distribution, with parameters β = 0.68 and mc = 9.15 and reshuffled in order to mimic the time occurrence of the order statistics of the empirical data, are able to explain the temporal heterogeneity of global seismicity both before and after the great Sumatra-Andaman earthquake of 2004.

  8. Metric Ranking of Invariant Networks with Belief Propagation

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Changxia [Xi' an Jiaotong University, China; Ge, Yong [University of North Carolina, Charlotte; Song, Qinbao [Xi' an Jiaotong University, China; Ge, Yuan [Anhui Polytechnic University, China; Omitaomu, Olufemi A [ORNL

    2014-01-01

    The management of large-scale distributed information systems relies on the effective use and modeling of monitoring data collected at various points in the distributed information systems. A promising approach is to discover invariant relationships among the monitoring data and generate invariant networks, where a node is a monitoring data source (metric) and a link indicates an invariant relationship between two monitoring data. Such an invariant network representation can help system experts to localize and diagnose the system faults by examining those broken invariant relationships and their related metrics, because system faults usually propagate among the monitoring data and eventually lead to some broken invariant relationships. However, at one time, there are usually a lot of broken links (invariant relationships) within an invariant network. Without proper guidance, it is difficult for system experts to manually inspect this large number of broken links. Thus, a critical challenge is how to effectively and efficiently rank metrics (nodes) of invariant networks according to the anomaly levels of metrics. The ranked list of metrics will provide system experts with useful guidance for them to localize and diagnose the system faults. To this end, we propose to model the nodes and the broken links as a Markov Random Field (MRF), and develop an iteration algorithm to infer the anomaly of each node based on belief propagation (BP). Finally, we validate the proposed algorithm on both realworld and synthetic data sets to illustrate its effectiveness.

  9. Binary optical filters for scale invariant pattern recognition

    Science.gov (United States)

    Reid, Max B.; Downie, John D.; Hine, Butler P.

    1992-01-01

    Binary synthetic discriminant function (BSDF) optical filters which are invariant to scale changes in the target object of more than 50 percent are demonstrated in simulation and experiment. Efficient databases of scale invariant BSDF filters can be designed which discriminate between two very similar objects at any view scaled over a factor of 2 or more. The BSDF technique has considerable advantages over other methods for achieving scale invariant object recognition, as it also allows determination of the object's scale. In addition to scale, the technique can be used to design recognition systems invariant to other geometric distortions.

  10. Experimental Design for Testing Local Lorentz Invariance Violations in Gravity

    Science.gov (United States)

    Chen, Ya-Fen; Tan, Yu-Jie; Shao, Cheng-Gang

    2017-09-01

    Local Lorentz invariance is an important component of General Relativity. Testing for Local Lorentz invariance can not only probe the foundation stone of General Relativity but also help to explore the unified theory for General Relativity and quantum mechanics. In this paper, we search the Local Lorentz invariance violation associated with operators of mass dimension d=6 in the pure-gravity sector with short-range gravitational experiments. To enlarge the Local Lorentz invariance violation signal effectively, we design a new experiment in which the constraints of all fourteen violation coefficients may be improved by about one order of magnitude

  11. Statistical physics

    CERN Document Server

    Sadovskii, Michael V

    2012-01-01

    This volume provides a compact presentation of modern statistical physics at an advanced level. Beginning with questions on the foundations of statistical mechanics all important aspects of statistical physics are included, such as applications to ideal gases, the theory of quantum liquids and superconductivity and the modern theory of critical phenomena. Beyond that attention is given to new approaches, such as quantum field theory methods and non-equilibrium problems.

  12. Statistical distributions

    CERN Document Server

    Forbes, Catherine; Hastings, Nicholas; Peacock, Brian J.

    2010-01-01

    A new edition of the trusted guide on commonly used statistical distributions Fully updated to reflect the latest developments on the topic, Statistical Distributions, Fourth Edition continues to serve as an authoritative guide on the application of statistical methods to research across various disciplines. The book provides a concise presentation of popular statistical distributions along with the necessary knowledge for their successful use in data modeling and analysis. Following a basic introduction, forty popular distributions are outlined in individual chapters that are complete with re

  13. Statistical methods

    CERN Document Server

    Szulc, Stefan

    1965-01-01

    Statistical Methods provides a discussion of the principles of the organization and technique of research, with emphasis on its application to the problems in social statistics. This book discusses branch statistics, which aims to develop practical ways of collecting and processing numerical data and to adapt general statistical methods to the objectives in a given field.Organized into five parts encompassing 22 chapters, this book begins with an overview of how to organize the collection of such information on individual units, primarily as accomplished by government agencies. This text then

  14. Statistical optics

    CERN Document Server

    Goodman, Joseph W

    2015-01-01

    This book discusses statistical methods that are useful for treating problems in modern optics, and the application of these methods to solving a variety of such problems This book covers a variety of statistical problems in optics, including both theory and applications.  The text covers the necessary background in statistics, statistical properties of light waves of various types, the theory of partial coherence and its applications, imaging with partially coherent light, atmospheric degradations of images, and noise limitations in the detection of light. New topics have been introduced i

  15. Pengenalan Pose Tangan Menggunakan HuMoment

    Directory of Open Access Journals (Sweden)

    Dina Budhi Utami

    2017-02-01

    Full Text Available Computer vision yang didasarkan pada pengenalan bentuk memiliki banyak potensi dalam interaksi manusia dan komputer. Pose tangan dapat dijadikan simbol interaksi manusia dengan komputer seperti halnya pada penggunaan berbagai pose tangan pada bahasa isyarat. Berbagai pose tangan dapat digunakan untuk menggantikan fungsi mouse, untuk mengendalikan robot, dan sebagainya. Penelitian ini difokuskan pada pembangunan sistem pengenalan pose tangan menggunakan HuMoment. Proses pengenalan pose tangan dimulai dengan melakukan segmentasi citra masukan untuk menghasilkan citra ROI (Region of Interest yaitu area telapak tangan. Selanjutnya dilakukan proses deteksi tepi. Kemudian dilakukan ekstraksi nilai HuMoment. Nilai HuMoment dikuantisasikan ke dalam bukukode yang dihasilkan dari proses pelatihan menggunakan K-Means. Proses kuantisasi dilakukan dengan menghitung nilai Euclidean Distance terkecil antara nilai HuMomment citra masukan dan bukukode. Berdasarkan hasil penelitian, nilai akurasi sistem dalam mengenali pose tangan adalah 88.57%.

  16. The anomalous magnetic moment of the muon

    CERN Document Server

    Jegerlehner, Friedrich

    2017-01-01

    This research monograph covers extensively the theory of the muon anomalous magnetic moment and provides estimates of the theoretical uncertainties. The muon anomalous magnetic moment is one of the most precisely measured quantities in elementary particle physics and provides one of the most stringent tests of relativistic quantum field theory as a fundamental theoretical framework. It allows for an extremely precise check of the standard model of elementary particles and of its limitations. This book reviews the present state of knowledge of the anomalous magnetic moment a=(g-2)/2 of the muon. Recent experiments at the Brookhaven National Laboratory now reach the unbelievable precision of 0.5 parts per million, improving the accuracy of previous g-2 experiments at CERN by a factor of 14. In addition, quantum electrodynamics and electroweak and hadronic effects are reviewed. Since non-perturbative hadronic effects play a key role for the precision test, their evaluation is described in detail. Perspectives fo...

  17. A corrector for spacecraft calculated electron moments

    Directory of Open Access Journals (Sweden)

    J. Geach

    2005-03-01

    Full Text Available We present the application of a numerical method to correct electron moments calculated on-board spacecraft from the effects of potential broadening and energy range truncation. Assuming a shape for the natural distribution of the ambient plasma and employing the scalar approximation, the on-board moments can be represented as non-linear integral functions of the underlying distribution. We have implemented an algorithm which inverts this system successfully over a wide range of parameters for an assumed underlying drifting Maxwellian distribution. The outputs of the solver are the corrected electron plasma temperature Te, density Ne and velocity vector Ve. We also make an estimation of the temperature anisotropy A of the distribution. We present corrected moment data from Cluster's PEACE experiment for a range of plasma environments and make comparisons with electron and ion data from other Cluster instruments, as well as the equivalent ground-based calculations using full 3-D distribution PEACE telemetry.

  18. Magnetic Moment Distribution in Layered Materials

    Science.gov (United States)

    Nicholson, D. M. C.; Zhang, X.-G.; Wang, Y.; Shelton, W. A.; Butler, W. H.; Stocks, G. M.; MacLaren, J. M.

    1996-03-01

    Thin layers of magnetic material surrounded by non-magnetic layers display a reduced moment per atom relative to the bulk magnetic material. Plots of sturation magnetization versus magnetic layer thickness can be explained in terms of magnetically dead layers at interfaces. First principles calculations indicate a more complex distribution of magnetic moments. Moment distributions calculated in the local density approximation restricted to colinear spins and with unrestricted spin orientations will be presented for Cu/Ni/Cu, Cu/permalloy/Cu, and Mo/Ni/Mo structures. Work supported by Division of Materials Science, the Mathematical Information and Computational Science Division of the Office of Computational Technology Research, and by the Assistant Secretary of Defence Programs, Technology Management Group, Technology Transfer Initiative, US DOE under subcontract DEAC05-84OR21400 with Martin-Marietta Energy Systems, Inc.

  19. Spin and orbital moments in actinide compounds

    DEFF Research Database (Denmark)

    Lebech, B.; Wulff, M.; Lander, G.H.

    1991-01-01

    The extended spatial distribution of both the transition-metal 3d electrons and the actinide 5f electrons results in a strong interaction between these electron states when the relevant elements are alloyed. A particular interesting feature of this hybridization, which is predicted by single-electron...... band-structure calculations, is that the orbital moments of the actinide 5f electrons are considerably reduced from the values anticipated by a simple application of Hund's rules. To test these ideas, and thus to obtain a measure of the hybridization, we have performed a series of neutron scattering...... experiments designed to determine the magnetic moments at the actinide and transition-metal sublattice sites in compounds such as UFe2, NpCo2, and PuFe2 and to separate the spin and orbital components at the actinide sites. The results show, indeed, that the ratio of the orbital to spin moment is reduced...

  20. Magnetic moment nonconservation in magnetohydrodynamic turbulence models.

    Science.gov (United States)

    Dalena, S; Greco, A; Rappazzo, A F; Mace, R L; Matthaeus, W H

    2012-07-01

    The fundamental assumptions of the adiabatic theory do not apply in the presence of sharp field gradients or in the presence of well-developed magnetohydrodynamic turbulence. For this reason, in such conditions the magnetic moment μ is no longer expected to be constant. This can influence particle acceleration and have considerable implications in many astrophysical problems. Starting with the resonant interaction between ions and a single parallel propagating electromagnetic wave, we derive expressions for the magnetic moment trapping width Δμ (defined as the half peak-to-peak difference in the particle magnetic moments) and the bounce frequency ω(b). We perform test-particle simulations to investigate magnetic moment behavior when resonance overlapping occurs and during the interaction of a ring-beam particle distribution with a broadband slab spectrum. We find that the changes of magnetic moment and changes of pitch angle are related when the level of magnetic fluctuations is low, δB/B(0) = (10(-3),10(-2)), where B(0) is the constant and uniform background magnetic field. Stochasticity arises for intermediate fluctuation values and its effect on pitch angle is the isotropization of the distribution function f(α). This is a transient regime during which magnetic moment distribution f(μ) exhibits a characteristic one-sided long tail and starts to be influenced by the onset of spatial parallel diffusion, i.e., the variance grows linearly in time as in normal diffusion. With strong fluctuations f(α) becomes completely isotropic, spatial diffusion sets in, and the f(μ) behavior is closely related to the sampling of the varying magnetic field associated with that spatial diffusion.

  1. Multipeakons and the Classical Moment Problem

    CERN Document Server

    Beals, R; Szmigielski, J; Beals, Richard

    1999-01-01

    Classical results of Stieltjes are used to obtain explicit formulas for the peakon-antipeakon solutions of the Camassa-Holm equation. The closed form solution is expressed in terms of the orthogonal polynomials of the related classical moment problem. It is shown that collisions occur only in peakon-antipeakon pairs, and the details of the collisions are analyzed using results {}from the moment problem. A sharp result on the steepening of the slope at the time of collision is given. Asymptotic formulas are given, and the scattering shifts are calculated explicitly

  2. Moment distributions of phase-type

    DEFF Research Database (Denmark)

    Bladt, Mogens; Nielsen, Bo Friis

    2012-01-01

    of the age an residual life-time, is also phase-type distributed. Moreover, we give some explicit representations. The spread is known to have a first order moment distribution. If X is a positive random variable and ?i is its i'th moment, then the function fi(x) = xif(x)/?i is a density function......-normal, Pareto and gamma distributions. We provide explicit representations for both the matrix-exponential class and for the phase-type distributions, where the latter class may also use the former representations, but for various reasons it is desirable to establish a phase-type representation when dealing...

  3. Duality violations in τ hadronic spectral moments

    Science.gov (United States)

    Boito, D. R.; Catà, O.; Golterman, M.; Jamin, M.; Maltman, K.; Osborne, J.; Peris, S.

    2011-09-01

    Evidence is presented for the necessity of including duality violations in a consistent description of spectral function moments employed in the precision determination of α from τ decay. A physically motivated ansatz for duality violations in the spectral functions enables us to perform fits to spectral moments employing both pinched and unpinched weights. We describe our analysis strategy and provide some preliminary findings. Final numerical results await completion of an ongoing re-determination of the ALEPH covariance matrices incorpo-rating correlations due to the unfolding procedure which are absent from the currently posted versions. To what extent this issue affects existing analyses and our own work will require further study.

  4. The physics of the second-order gyrokinetic magnetohydrodynamic Hamiltonian: μ conservation, Galilean invariance, and ponderomotive potential

    Energy Technology Data Exchange (ETDEWEB)

    Krommes, J. A. [Plasma Physics Laboratory, Princeton University, MS 28, P.O. Box 451, Princeton, New Jersey 08543–0451 (United States)

    2013-12-15

    Some physical interpretations are given of the well-known second-order gyrokinetic Hamiltonian in the magnetohydrodynamic limit. Its relations to the conservation of the true (Galilean-invariant) magnetic moment and fluid nonlinearities are described. Subtleties about its derivation as a cold-ion limit are explained; it is important to take that limit in the frame moving with the E×B velocity. The discussion also provides some geometric understanding of certain well-known Lie generating functions, and it makes contact with general discussions of ponderomotive potentials and the thermodynamics of dielectric media.

  5. Azimuthal Angle Distribution in $B \\to K^* (\\to K \\pi) \\ell^+ \\ell^- $ at low invariant $m_{\\ell^+ \\ell^-}$ Region

    CERN Document Server

    Kim, C S; Lü, C D; Morozumi, T; Kim, Yeong Gyun; Lu, Cai-Dian; Morozumi, Takuya

    2000-01-01

    We present the angular distribution of the rare B decay, $B \\to K^* (\\to K invariant mass region of dileptons, we can probe new physics effects efficiently. In particular, this distribution is found to be quite sensitive to the ratio of the contributions from two independent magnetic moment operators, which also contribute to $B \\to K^* \\gamma$. Therefore, our method can be very useful when new physics is introduced without changing the total decay rate of the $b \\to s \\gamma$. The angular distributions are compared with the predictions of the standard model, and are shown for the cases when the afore-mentioned ratio is different from the standard model prediction.

  6. Gauge invariance and Weyl-polymer quantization

    CERN Document Server

    Strocchi, Franco

    2016-01-01

    The book gives an introduction to Weyl non-regular quantization suitable for the description of physically interesting quantum systems, where the traditional Dirac-Heisenberg quantization is not applicable.  The latter implicitly assumes that the canonical variables describe observables, entailing necessarily the regularity of their exponentials (Weyl operators). However, in physically interesting cases -- typically in the presence of a gauge symmetry -- non-observable canonical variables are introduced for the description of the states, namely of the relevant representations of the observable algebra. In general, a gauge invariant ground state defines a non-regular representation of the gauge dependent Weyl operators, providing a mathematically consistent treatment of familiar quantum systems -- such as the electron in a periodic potential (Bloch electron), the Quantum Hall electron, or the quantum particle on a circle -- where the gauge transformations are, respectively, the lattice translations, the magne...

  7. Blocks of finite groups and their invariants

    CERN Document Server

    Sambale, Benjamin

    2014-01-01

    Providing a nearly complete selection of up-to-date methods and results on block invariants with respect to their defect groups, this book covers the classical theory pioneered by Brauer, the modern theory of fusion systems introduced by Puig, the geometry of numbers developed by Minkowski, the classification of finite simple groups, and various computer assisted methods. In a powerful combination, these tools are applied to solve many special cases of famous open conjectures in the representation theory of finite groups. Most of the material is drawn from peer-reviewed journal articles, but there are also new previously unpublished results. In order to make the text self-contained, detailed proofs are given whenever possible. Several tables add to the text's usefulness as a reference. The book is aimed at experts in group theory or representation theory who may wish to make use of the presented ideas in their research.

  8. Spiking models for level-invariant encoding

    Directory of Open Access Journals (Sweden)

    Romain eBrette

    2012-01-01

    Full Text Available Levels of ecological sounds vary over several orders of magnitude,but the firing rate and membrane potential of a neuron are much more limited in range.In binaural neurons of the barn owl, tuning to interaural delays is independent oflevel differences. Yet a monaural neuron with a fixed threshold should fire earlier in responseto louder sounds, which would disrupt the tuning of these neurons. %, resulting in shifts in delay tuning for interaural level differences.How could spike timing be independent of input level?Here I derive theoretical conditions for a spiking model tobe insensitive to input level.The key property is a dynamic change in spike threshold.I then show how level invariance can be physiologically implemented,with specific ionic channel properties.It appears that these ingredients are indeed present inmonaural neurons of the sound localization pathway of birds and mammals.

  9. Kahler stabilized, modular invariant heterotic string models

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard, Mary K.; Gaillard, Mary K.; Nelson, Brent D.

    2007-03-19

    We review the theory and phenomenology of effective supergravity theories based on orbifold compactifications of the weakly-coupled heterotic string. In particular, we consider theories in which the four-dimensional theory displays target space modular invariance and where the dilatonic mode undergoes Kahler stabilization. A self-contained exposition of effective Lagrangian approaches to gaugino condensation and heterotic string theory is presented, leading to the development of the models of Binétruy, Gaillard and Wu. Various aspects of the phenomenology of this class of models are considered. These include issues of supersymmetry breaking and superpartner spectra, the role of anomalous U(1) factors, issues of flavor and R-parity conservation, collider signatures, axion physics, and early universe cosmology. For the vast majority of phenomenological considerations the theories reviewed here compare quite favorably to other string-derived models in the literature. Theoretical objections to the framework and directions for further research are identified and discussed.

  10. Multivariate dice recognition using invariant features

    Science.gov (United States)

    Hsu, Gee-Sern; Peng, Hsiao-Chia; Yeh, Shang-Min; Lin, Chyi-Yeu

    2013-04-01

    A system is proposed for automatic reading of the number of dots on dice in general table game settings. Different from previous dice recognition systems that recognize dice of a specific color using a single top-view camera in an enclosure with controlled settings, the proposed one uses multiple cameras to recognize dice of various colors and under uncontrolled conditions. It is composed of three modules. Module-1 locates the dice using the gradient-conditioned color segmentation, proposed, to segment dice of arbitrary colors from the background. Module-2 exploits the local invariant features good for building homographies, giving a solution to segment the top faces of the dice. To identify the dots on the segmented top faces, a maximally stable extremal region detector is embedded in module-3 for its consistency in locating the dot region. Experiments show that the proposed system performs satisfactorily in various test conditions.

  11. Positively invariant manifolds: concept and applications

    Science.gov (United States)

    Sazhin, Sergei S.; Shchepakina, Elena; Sobolev, Vladimir

    2017-02-01

    In many applications of the system order reduction models, including those focused on spray ignition and combustion processes, it is assumed that all functions in corresponding differential equations are Lipschitzian. This assumption has not been checked in most cases and the cases when these functions were non-Lipschitzian have sometimes been overlooked. This allows us to question the results of application of the conventional theory of integral manifolds to some such systems. The aim of this paper is to demonstrate that even in the case of singular perturbed systems with non-Lipschitzian nonlinearities the order reduction can be performed, using a new concept of positively invariant manifolds. This is illustrated by several examples including the problem of heating, evaporation, ignition and combustion of Diesel fuel sprays.

  12. Rotationally invariant ensembles of integrable matrices.

    Science.gov (United States)

    Yuzbashyan, Emil A; Shastry, B Sriram; Scaramazza, Jasen A

    2016-05-01

    We construct ensembles of random integrable matrices with any prescribed number of nontrivial integrals and formulate integrable matrix theory (IMT)-a counterpart of random matrix theory (RMT) for quantum integrable models. A type-M family of integrable matrices consists of exactly N-M independent commuting N×N matrices linear in a real parameter. We first develop a rotationally invariant parametrization of such matrices, previously only constructed in a preferred basis. For example, an arbitrary choice of a vector and two commuting Hermitian matrices defines a type-1 family and vice versa. Higher types similarly involve a random vector and two matrices. The basis-independent formulation allows us to derive the joint probability density for integrable matrices, similar to the construction of Gaussian ensembles in the RMT.

  13. The Mond Limit from Spacetime Scale Invariance

    Science.gov (United States)

    Milgrom, Mordehai

    2009-06-01

    The modified Newtonian dynamics (MOND) limit is shown to follow from a requirement of spacetime scale invariance of the equations of motion for nonrelativistic, purely gravitational systems, i.e., invariance of the equations of motion under (t, r) → (λt, λr) in the limit a 0 → ∞. It is suggested that this should replace the definition of the MOND limit based on the low-acceleration behavior of a Newtonian-MOND interpolating function. In this way, the salient, deep-MOND results—asymptotically flat rotation curves, the mass-rotational-speed relation (baryonic Tully-Fisher relation), the Faber-Jackson relation, etc.,—follow from a symmetry principle. For example, asymptotic flatness of rotation curves reflects the fact that radii change under scaling, while velocities do not. I then comment on the interpretation of the deep-MOND limit as one of "zero mass": rest masses, whose presence obstructs scaling symmetry, become negligible compared to the "phantom," dynamical masses—those that some would attribute to dark matter. Unlike the former masses, the latter transform in a way that is consistent with the symmetry. Finally, I discuss the putative MOND-cosmology connection in light of another, previously known symmetry of the deep-MOND limit. In particular, it is suggested that MOND is related to the asymptotic de Sitter geometry of our universe. It is conjectured, for example that in an exact de Sitter cosmos, deep-MOND physics would exactly apply to local systems. I also point out, in this connection, the possible relevance of a de Sitter-conformal-field-theory (dS/CFT) duality.

  14. Constructing three emotion knowledge tests from the invariant measurement approach

    Directory of Open Access Journals (Sweden)

    Ana R. Delgado

    2017-09-01

    Full Text Available Background Psychological constructionist models like the Conceptual Act Theory (CAT postulate that complex states such as emotions are composed of basic psychological ingredients that are more clearly respected by the brain than basic emotions. The objective of this study was the construction and initial validation of Emotion Knowledge measures from the CAT frame by means of an invariant measurement approach, the Rasch Model (RM. Psychological distance theory was used to inform item generation. Methods Three EK tests—emotion vocabulary (EV, close emotional situations (CES and far emotional situations (FES—were constructed and tested with the RM in a community sample of 100 females and 100 males (age range: 18–65, both separately and conjointly. Results It was corroborated that data-RM fit was sufficient. Then, the effect of type of test and emotion on Rasch-modelled item difficulty was tested. Significant effects of emotion on EK item difficulty were found, but the only statistically significant difference was that between “happiness” and the remaining emotions; neither type of test, nor interaction effects on EK item difficulty were statistically significant. The testing of gender differences was carried out after corroborating that differential item functioning (DIF would not be a plausible alternative hypothesis for the results. No statistically significant sex-related differences were found out in EV, CES, FES, or total EK. However, the sign of d indicate that female participants were consistently better than male ones, a result that will be of interest for future meta-analyses. Discussion The three EK tests are ready to be used as components of a higher-level measurement process.

  15. Scan Statistics

    CERN Document Server

    Glaz, Joseph

    2009-01-01

    Suitable for graduate students and researchers in applied probability and statistics, as well as for scientists in biology, computer science, pharmaceutical science and medicine, this title brings together a collection of chapters illustrating the depth and diversity of theory, methods and applications in the area of scan statistics.

  16. Practical Statistics

    CERN Document Server

    Lyons, L.

    2016-01-01

    Accelerators and detectors are expensive, both in terms of money and human effort. It is thus important to invest effort in performing a good statistical anal- ysis of the data, in order to extract the best information from it. This series of five lectures deals with practical aspects of statistical issues that arise in typical High Energy Physics analyses.

  17. The use of latent variable mixture models to identify invariant items in test construction.

    Science.gov (United States)

    Sawatzky, Richard; Russell, Lara B; Sajobi, Tolulope T; Lix, Lisa M; Kopec, Jacek; Zumbo, Bruno D

    2017-08-23

    Patient-reported outcome measures (PROMs) are frequently used in heterogeneous patient populations. PROM scores may lead to biased inferences when sources of heterogeneity (e.g., gender, ethnicity, and social factors) are ignored. Latent variable mixture models (LVMMs) can be used to examine measurement invariance (MI) when sources of heterogeneity in the population are not known a priori. The goal of this article is to discuss the use of LVMMs to identify invariant items within the context of test construction. The Draper-Lindely-de Finetti (DLD) framework for the measurement of latent variables provides a theoretical context for the use of LVMMs to identify the most invariant items in test construction. In an expository analysis using 39 items measuring daily activities, LVMMs were conducted to compare 1- and 2-class item response theory models (IRT). If the 2-class model had better fit, item-level logistic regression differential item functioning (DIF) analyses were conducted to identify items that were not invariant. These items were removed and LVMMs and DIF testing repeated until all remaining items showed MI. The 39 items had an essentially unidimensional measurement structure. However, a 1-class IRT model resulted in many statistically significant bivariate residuals, indicating suboptimal fit due to remaining local dependence. A 2-class LVMM had better fit. Through subsequent rounds of LVMMs and DIF testing, nine items were identified as being most invariant. The DLD framework and the use of LVMMs have significant potential for advancing theoretical developments and research on item selection and the development of PROMs for heterogeneous populations.

  18. Moments, Mixed Methods, and Paradigm Dialogs

    Science.gov (United States)

    Denzin, Norman K.

    2010-01-01

    I reread the 50-year-old history of the qualitative inquiry that calls for triangulation and mixed methods. I briefly visit the disputes within the mixed methods community asking how did we get to where we are today, the period of mixed-multiple-methods advocacy, and Teddlie and Tashakkori's third methodological moment. (Contains 10 notes.)

  19. Using Aha! Moments to Understand Leadership Theory

    Science.gov (United States)

    Moore, Lori L.; Lewis, Lauren J.

    2012-01-01

    As Huber (2002) noted, striving to understand how leadership is taught and learned is both a challenge and an opportunity facing leadership educators. This article describes the "Leadership Aha! Moment" assignment used in a leadership theory course to help students recognize the intersection of leadership theories and their daily lives while…

  20. Anomalous magnetic moment and Compton wavelength

    OpenAIRE

    Heyrovska, Raji

    2004-01-01

    The relativistic and quantum theoretical explanations of the magnetic moment anomaly of the electron (or proton) show that it is a complicated function of the fine structure constant. In this work, a simple non-relativistic approach shows that the translational motion of the particle during its spin is responsible for the observed effects.

  1. The isotopic dipole moment of HDO

    Energy Technology Data Exchange (ETDEWEB)

    Assafrao, Denise; Mohallem, Jose R [Laboratorio de Atomos e Moleculas Especiais, Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, CP 702, 30123-970, Belo Horizonte, MG (Brazil)

    2007-03-14

    An adiabatic variational approximation is used to study the monodeuterated water molecule, HDO, accounting for the isotopic effect. The isotopic dipole moment, pointing from D to H, is then calculated for the first time, yielding (1.5 {+-} 0.1) x 10{sup -3} Debye, being helpful in the interpretation of experiments. (fast track communication)

  2. "To Value Every Child in the Moment"

    Science.gov (United States)

    Armstrong, Michael

    2014-01-01

    This article takes as its starting point the assertion that the purpose of primary education is to value every child in the moment. The author examines one particular story by a six-year-old girl as an example of what this assertion implies, and of its significance for teaching and learning within the primary school.

  3. The Doubling Moment: Resurrecting Edgar Allan Poe

    Science.gov (United States)

    Minnick, J. Bradley; Mergil, Fernando

    2008-01-01

    This article expands upon Jeffrey Wilhelm's and Brian Edmiston's (1998) concept of a doubling of viewpoints by encouraging middle level students to use dramatization to take on multiple perspectives, to pose interpretive questions, and to enhance critical inquiry from inside and outside of texts. The doubling moment is both the activation of…

  4. Scale factor correction for Gaussian beam truncation in second moment beam radius measurements

    Science.gov (United States)

    Hofer, Lucas R.; Dragone, Rocco V.; MacGregor, Andrew D.

    2017-04-01

    Charged-couple devices (CCD) and complementary metal oxide semiconductor (CMOS) image sensors, in conjunction with the second moment radius analysis method, are effective tools for determining the radius of a laser beam. However, the second moment method heavily weights sensor noise, which must be dealt with using a thresholding algorithm and a software aperture. While these noise reduction methods lower the random error due to noise, they simultaneously generate systematic error by truncating the Gaussian beam's edges. A scale factor that is invariant to beam ellipticity and corrects for the truncation of the Gaussian beam due to thresholding and the software aperture has been derived. In particular, simulations showed an order of magnitude reduction in measured beam radius error when using the scale factor-irrespective of beam ellipticity-and further testing with real beam data demonstrated that radii corrected by the scale factor are independent of the noise reduction parameters. Thus, through use of the scale factor, the accuracy of beam radius measurements made with a CCD or CMOS sensor and the second moment are significantly improved.

  5. Differential branching fraction and angular moments analysis of the decay $B^0 \\to K^+ \\pi^- \\mu^+ \\mu^-$ in the $K^*_{0,2}(1430)^0$ region

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Baszczyk, Mateusz; Batozskaya, Varvara; Batsukh, Baasansuren; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Bel, Lennaert; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bertolin, Alessandro; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Bird, Thomas; Birnkraut, Alex; Bitadze, Alexander; Bizzeti, Andrea; Blake, Thomas; Blanc, Frederic; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borgheresi, Alessio; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cavallero, Giovanni; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chobanova, Veronika; Chrzaszcz, Marcin; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dall'Occo, Elena; Dalseno, Jeremy; David, Pieter; Davis, Adam; De Aguiar Francisco, Oscar; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Demmer, Moritz; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Dungs, Kevin; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Déléage, Nicolas; Easo, Sajan; Ebert, Marcus; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fay, Robert; Fazzini, Davide; Ferguson, Dianne; Fernandez Albor, Victor; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fohl, Klaus; Fontana, Marianna; Fontanelli, Flavio; Forshaw, Dean Charles; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Furfaro, Emiliano; Färber, Christian; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Garsed, Philip John; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, V.V.; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Griffith, Peter; Grillo, Lucia; Gruberg Cazon, Barak Raimond; Grünberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Göbel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; Hatch, Mark; He, Jibo; Head, Timothy; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hombach, Christoph; Hopchev, P H; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hussain, Nazim; Hutchcroft, David; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kecke, Matthieu; Kelsey, Matthew; Kenyon, Ian; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Koliiev, Serhii; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Kozachuk, Anastasiia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krokovny, Pavel; Kruse, Florian; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kurek, Krzysztof; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Leflat, Alexander; Lefrançois, Jacques; Lefèvre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Liu, Xuesong; Loh, David; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Maev, Oleg; Maguire, Kevin; Malde, Sneha; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massacrier, Laure Marie; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; Meadows, Brian; Meier, Frank; Meissner, Marco; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Minard, Marie-Noelle; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Monroy, Ignacio Alberto; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Mussini, Manuel; Müller, Dominik; Müller, Janine; Müller, Katharina; Müller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Otalora Goicochea, Juan Martin; Otto, Adam; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pikies, Malgorzata; Pinci, Davide; Pistone, Alessandro; Piucci, Alessio; Playfer, Stephen; Plo Casasus, Maximo; Poikela, Tuomas; Polci, Francesco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Poslavskii, Stanislav; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Rachwal, Bartolomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vicente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rodriguez Perez, Pablo; Rogozhnikov, Alexey; Roiser, Stefan; Romanovskiy, Vladimir; Romero Vidal, Antonio; Ronayne, John William; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schubert, Konstantin; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Eluned; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavorima; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Syropoulos, Vasileios; Szczekowski, Marek; Szumlak, Tomasz; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Toriello, Francis; Tournefier, Edwige; Tourneur, Stephane; Trabelsi, Karim; Traill, Murdo; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valassi, Andrea; Valat, Sebastien; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Vernet, Maxime; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Vázquez Sierra, Carlos; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wang, Jianchun; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Matthew; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wraight, Kenneth; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhang, Yu; Zhelezov, Alexey; Zheng, Yangheng; Zhokhov, Anatoly; Zhu, Xianglei; Zhukov, Valery; Zucchelli, Stefano

    2016-12-15

    Measurements of the differential branching fraction and angular moments of the decay $B^0 \\to K^+ \\pi^- \\mu^+ \\mu^-$ in the $K^*_{0,2}(1430)^0$ in the $K^+\\pi^-$ invariant mass range $1330 < m (K^+ \\pi^-) <1530~ \\text{MeV}/c^2$ are presented. Proton-proton collision data are used, corresponding to an integrated luminosity of 3 fb$^{-1}$ collected by the LHCb experiment. Differential branching fraction measurements are reported in five bins of the invariant mass squared of the dimuon system, $q^2$, between 0.1 and 8.0 $\\text{GeV}^2/c^4$. For the first time, an angular analysis sensitive to the S-, P- and D-wave contributions of this rare decay is performed. The set of 40 normalised angular moments describing the decay is presented for the $q^2$ range $1.1-6.0 \\text{GeV}^2/c^4$.

  6. The Scale Invariant Synchrotron Jet of Flat Spectrum Radio Quasars

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... In this paper, the scale invariance of the synchrotron jet of Flat Spectrum Radio Quasars has been studied using a sample of combined sources from FKM04 and from SDSS DR3 catalogue. Since the research of scale invariance has been focused on sub-Eddington cases that can be fitted onto the ...

  7. The Scale Invariant Synchrotron Jet of Flat Spectrum Radio Quasars ...

    Indian Academy of Sciences (India)

    Abstract. In this paper, the scale invariance of the synchrotron jet of Flat. Spectrum Radio Quasars has been studied using a sample of combined sources from FKM04 and from SDSS DR3 catalogue. Since the research of scale invariance has been focused on sub-Eddington cases that can be fitted onto the fundamental ...

  8. Conservation Laws and Invariant Measures in Surjective Cellular Automata

    NARCIS (Netherlands)

    Kari, J.; Taati, S.

    2011-01-01

    We discuss a close link between two seemingly different topics studied in the cellular automata literature: additive conservation laws and invariant probability measures. We provide an elementary proof of a simple correspondence between invariant full-support Bernoulli measures and interaction-free

  9. Conservation Laws and Invariant Measures in Surjective Cellular Automata

    NARCIS (Netherlands)

    Kari, Jarkko; Taati, Siamak

    2012-01-01

    We discuss a close link between two seemingly different topics studied in the cellular automata literature: additive conservation laws and invariant probability measures. We provide an elementary proof of a simple correspondence between invariant full-support Bernoulli measures and interaction-free

  10. The Kubelka-Munk Theory for Color Image Invariant Properties

    NARCIS (Netherlands)

    Geusebroek, J.M.; Gevers, Th.; Smeulders, A.W.M.

    2002-01-01

    A fundamental problem in color image processing is the integration of the physical laws of light reflection into image processing results, the probem known as photometric invariance. The derivation of object properties from color images yields the extraction of geometric and photometric invariants

  11. Rephasing invariants of the Cabibbo-Kobayashi- Maskawa matrix

    Science.gov (United States)

    Pérez R., H.; Kielanowski, P.; Juárez W., S. R.

    2016-03-01

    The paper is motivated by the importance of the rephasing invariance of the CKM (Cabibbo-Kobayashi-Maskawa) matrix observables. These observables appear in the discussion of the CP violation in the standard model (Jarlskog invariant) and also in the renormalization group equations for the quark Yukawa couplings. Our discussion is based on the general phase invariant monomials built out of the CKM matrix elements and their conjugates. We show that there exist 30 fundamental phase invariant monomials and 18 of them are a product of 4 CKM matrix elements and 12 are a product of 6 CKM matrix elements. In the main theorem we show that a general rephasing invariant monomial can be expressed as a product of at most five factors: four of them are fundamental phase invariant monomials and the fifth factor consists of powers of squares of absolute values of the CKM matrix elements. We also show that the imaginary part of any rephasing invariant monomial is proportional to the Jarlskog's invariant J or is 0.

  12. On a class of invariant algebraic curves for Kukles systems

    Directory of Open Access Journals (Sweden)

    Osvaldo Osuna

    2016-08-01

    Full Text Available In this paper we give a new upper bound for the degree of a class of transversal to infinity invariant algebraic curves for polynomial Kukles systems of arbitrary degree. Moreover, we prove that a quadratic Kukles system having at least one transversal to infinity invariant algebraic curve is integrable.

  13. Invariants for the construction of a handshake register

    NARCIS (Netherlands)

    Hesselink, Wim H.

    1998-01-01

    Tromp's construction of a waitfree atomic register for one writing process and one reading process is presented and proved by means of ghost variables and invariants. Preservation of the invariants is proved mechanically. This approach can be compared with the original proof based on the partial

  14. Testing measurement invariance of the GHQ-28 in stroke patients.

    Science.gov (United States)

    Munyombwe, Theresa; West, Robert M; Hill, Kate

    2015-08-01

    In order to combine self-reported measures data from multiple studies to conduct an integrated data analysis, the construct measured must have the same meaning across the studies. This study investigated the measurement invariance of the General Health questionnaire (GHQ-28) in two stroke studies before combining the data for an integrative data analysis. The study used data from the Stroke Outcomes Study 1 (SOS1, n = 448) and second Stroke Outcomes Study (SOS2, n = 585). The initial analysis was a confirmatory factor analysis (CFA) for each study separately to confirm the four-factor structure of GHQ-28 questionnaire. Multi-group confirmatory factor analysis (MG-CFA) was used to assess the measurement invariance of the GHQ-28 questionnaire in the two stroke cohorts. Measurement invariance at configural invariance (same items associated with same factor across groups); factor loading invariance (equal factor loadings across groups) and scalar invariance (equal intercepts across groups) was examined. CFA supported all three invariances measured. Results showed that the GHQ-28 questionnaire has comparable measurement properties in the SOS1 and SOS2 stroke studies. Strong measurement invariance was established, and based on the results from this study, integrative data analysis of GHQ-28 scores from the two stroke studies is merited.

  15. Improving measurement-invariance assessments: correcting entrenched testing deficiencies

    OpenAIRE

    Hayduk, Leslie A

    2016-01-01

    Background Factor analysis historically focused on measurement while path analysis employed observed variables as though they were error-free. When factor- and path-analysis merged as structural equation modeling, factor analytic notions dominated measurement discussions ? including assessments of measurement invariance across groups. The factor analytic tradition fostered disregard of model testing and consequently entrenched this deficiency in measurement invariance assessments. Discussion ...

  16. Testing for Factorial Invariance in the Context of Construct Validation

    Science.gov (United States)

    Dimitrov, Dimiter M.

    2010-01-01

    This article describes the logic and procedures behind testing for factorial invariance across groups in the context of construct validation. The procedures include testing for configural, measurement, and structural invariance in the framework of multiple-group confirmatory factor analysis (CFA). The "forward" (sequential constraint imposition)…

  17. Factorial Invariance in Multiple Populations: A Multiple Testing Procedure

    Science.gov (United States)

    Raykov, Tenko; Marcoulides, George A.; Millsap, Roger E.

    2013-01-01

    A multiple testing method for examining factorial invariance for latent constructs evaluated by multiple indicators in distinct populations is outlined. The procedure is based on the false discovery rate concept and multiple individual restriction tests and resolves general limitations of a popular factorial invariance testing approach. The…

  18. Conformal invariance in the long-range Ising model

    NARCIS (Netherlands)

    Paulos, M.F.; Rychkov, S.; van Rees, B.C.; Zan, B.

    We consider the question of conformal invariance of the long-range Ising model at the critical point. The continuum description is given in terms of a nonlocal field theory, and the absence of a stress tensor invalidates all of the standard arguments for the enhancement of scale invariance to

  19. Galilean and dynamical invariance of entanglement in particle scattering.

    Science.gov (United States)

    Harshman, N L; Wickramasekara, S

    2007-02-23

    Particle systems admit a variety of tensor product structures (TPSs) depending on the algebra of observables chosen for analysis. Global symmetry transformations and dynamical transformations may be resolved into local unitary operators with respect to certain TPSs and not with respect to others. Symmetry-invariant and dynamical-invariant TPSs are defined and various notions of entanglement are considered for scattering states.

  20. Galilean invariance and vertex renormalization in turbulence theory.

    Science.gov (United States)

    McComb, W D

    2005-03-01

    The Navier-Stokes equation is invariant under Galilean transformation of the instantaneous velocity field. However, the total velocity transformation is effected by transformation of the mean velocity alone. For a constant mean velocity, the equation of motion for the fluctuating velocity is automatically Galilean invariant in the comoving frame, and vertex renormalization is not constrained by this symmetry.

  1. Galilean invariance and homogeneous anisotropic randomly stirred flows.

    Science.gov (United States)

    Berera, Arjun; Hochberg, David

    2005-11-01

    The Ward-Takahashi identities for incompressible flow implied by Galilean invariance are derived for the randomly forced Navier-Stokes equation, in which both the mean and fluctuating velocity components are explicitly present. The consequences of the Galilean invariance for the vertex renormalization are drawn from this identity.

  2. Chronometrically invariant variations in the Einstein gravitation theory

    Energy Technology Data Exchange (ETDEWEB)

    Zelmanov, A.L.; Khabikov, Z.R.

    1983-01-01

    Attention is given to chronometrically invariant variations (which in general are infinitely small) of first order. It is noted that infinitely small chronometrically invariant variations can be applied in the problem of gravitational instability, the theory of gravitational waves, and the theory of bimetric formalism.

  3. Rephasing invariants of the Cabibbo-Kobayashi- Maskawa matrix

    Energy Technology Data Exchange (ETDEWEB)

    Pérez R, H.; Kielanowski, P., E-mail: kiel@fis.cinvestav.mx [Departamento de Física, Centro de Investigación y de Estudios Avanzados, 07000 México D.F. (Mexico); Juárez W, S. R., E-mail: rebeca@esfm.ipn.mx [Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, U.P. “Adolfo López Mateos,” C.P. 07738 México D.F. (Mexico)

    2016-03-15

    The paper is motivated by the importance of the rephasing invariance of the CKM (Cabibbo-Kobayashi-Maskawa) matrix observables. These observables appear in the discussion of the CP violation in the standard model (Jarlskog invariant) and also in the renormalization group equations for the quark Yukawa couplings. Our discussion is based on the general phase invariant monomials built out of the CKM matrix elements and their conjugates. We show that there exist 30 fundamental phase invariant monomials and 18 of them are a product of 4 CKM matrix elements and 12 are a product of 6 CKM matrix elements. In the main theorem we show that a general rephasing invariant monomial can be expressed as a product of at most five factors: four of them are fundamental phase invariant monomials and the fifth factor consists of powers of squares of absolute values of the CKM matrix elements. We also show that the imaginary part of any rephasing invariant monomial is proportional to the Jarlskog’s invariant J or is 0.

  4. Stable calculations for unstable particles: restoring gauge invariance

    NARCIS (Netherlands)

    Argyres, E.N.; Beenakker, W.; van Oldenborgh, G.J.; Denner, A.; Dittmaier, S.; Hoogland, J.K.; Kleiss, R.H.P.; Papadopoulos, C.G.; Passarino, G.

    1995-01-01

    We discuss theoretical and phenomenological aspects of the use of boson propagators with energy-dependent widths in predictions for high-energy scattering processes. In general, gauge invariance is violated in such calculations. We discuss several approaches to restore gauge invariance, necessary

  5. Semiconductor statistics

    CERN Document Server

    Blakemore, J S

    1962-01-01

    Semiconductor Statistics presents statistics aimed at complementing existing books on the relationships between carrier densities and transport effects. The book is divided into two parts. Part I provides introductory material on the electron theory of solids, and then discusses carrier statistics for semiconductors in thermal equilibrium. Of course a solid cannot be in true thermodynamic equilibrium if any electrical current is passed; but when currents are reasonably small the distribution function is but little perturbed, and the carrier distribution for such a """"quasi-equilibrium"""" co

  6. Statistics Clinic

    Science.gov (United States)

    Feiveson, Alan H.; Foy, Millennia; Ploutz-Snyder, Robert; Fiedler, James

    2014-01-01

    Do you have elevated p-values? Is the data analysis process getting you down? Do you experience anxiety when you need to respond to criticism of statistical methods in your manuscript? You may be suffering from Insufficient Statistical Support Syndrome (ISSS). For symptomatic relief of ISSS, come for a free consultation with JSC biostatisticians at our help desk during the poster sessions at the HRP Investigators Workshop. Get answers to common questions about sample size, missing data, multiple testing, when to trust the results of your analyses and more. Side effects may include sudden loss of statistics anxiety, improved interpretation of your data, and increased confidence in your results.

  7. Electric potential invariants and ions-in-molecules effective potentials for molecular Rydberg states

    Science.gov (United States)

    Coy, Stephen L.; Grimes, David D.; Zhou, Yan; Field, Robert W.; Wong, Bryan M.

    2016-12-01

    The dependence of multipole moments and polarizabilities on external fields appears in many applications including biomolecular molecular mechanics, optical non-linearity, nanomaterial calculations, and the perturbation of spectroscopic signatures in atomic clocks. Over a wide range of distances, distributed multipole and polarizability potentials can be applied to obtain the variation of atom-centered atoms-in-molecules electric properties like bonding-quenched polarizability. For cylindrically symmetric charge distributions, we examine single-center and atom-centered effective polarization potentials in a non-relativistic approximation for Rydberg states. For ions, the multipole expansion is strongly origin-dependent, but we note that origin-independent invariants can be defined. The several families of invariants correspond to optimized representations differing by origin and number of terms. Among them, a representation at the center of dipole polarizability optimizes the accuracy of the potential with terms through 1/r4. We formulate the single-center expansion in terms of polarization-modified effective multipole moments, defining a form related to the source-multipole expansion of Brink and Satchler. Atom-centered potentials are an origin independent alternative but are limited both by the properties allowed at each center and by the neglected effects like bond polarizability and charge flow. To enable comparisons between single-center effective potentials in Cartesian or spherical form and two-center effective potentials with differing levels of mutual induction between atomic centers, we give analytical expressions for the bond-length and origin-dependence of multipole and polarizability terms projected in the multipole and polarizability expansion of Buckingham. The atom-centered potentials can then be used with experimental data and ab initio calculations to estimate atoms-in-molecules properties. Some results are given for BaF+ and HF showing the

  8. Position and rotation-invariant pattern recognition system by binary rings masks

    Science.gov (United States)

    Solorza, S.; Álvarez-Borrego, J.

    2015-06-01

    In this paper, algorithms invariant to position, rotation, noise and non-homogeneous illumination are presented. Here, several manners are studied to generate binary rings mask filters and the corresponding signatures associated to each image. Also, in this work it is shown that digital systems, which are based on the ?-law non-linear correlation, are ?-invariant for ?. The methodologies are tested using greyscale fossil diatoms digital images (real images), and considering the great similarity between those images the results obtained are excellent. The box plot statistical analysis and the computational cost times yield that the Bessel rings masks are the best option when the images contain a homogeneous illumination and the Fourier masks digital system is the right selection when the non-homogeneous illumination and noise is presented in the images.

  9. Compact storage ring to search for the muon electric dipole moment

    NARCIS (Netherlands)

    Adelmann, A.; Kirch, K.; Onderwater, C. J. G.; Schietinger, T.

    We present the concept of a compact storage ring of less than 0.5 m orbit radius to search for the electric dipole moment (EDM) of the muon (d(mu)) by adapting the 'frozen spin' method. At existing muon facilities a statistics limited sensitivity of d(mu) similar to 7 x 10(-23) e cm can be achieved

  10. CMS Statistics

    Data.gov (United States)

    U.S. Department of Health & Human Services — The CMS Center for Strategic Planning produces an annual CMS Statistics reference booklet that provides a quick reference for summary information about health...

  11. WPRDC Statistics

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — Data about the usage of the WPRDC site and its various datasets, obtained by combining Google Analytics statistics with information from the WPRDC's data portal.

  12. Accident Statistics

    Data.gov (United States)

    Department of Homeland Security — Accident statistics available on the Coast Guard’s website by state, year, and one variable to obtain tables and/or graphs. Data from reports has been loaded for...

  13. Image Statistics

    Energy Technology Data Exchange (ETDEWEB)

    Wendelberger, Laura Jean [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-08

    In large datasets, it is time consuming or even impossible to pick out interesting images. Our proposed solution is to find statistics to quantify the information in each image and use those to identify and pick out images of interest.

  14. Multiparametric statistics

    CERN Document Server

    Serdobolskii, Vadim Ivanovich

    2007-01-01

    This monograph presents mathematical theory of statistical models described by the essentially large number of unknown parameters, comparable with sample size but can also be much larger. In this meaning, the proposed theory can be called "essentially multiparametric". It is developed on the basis of the Kolmogorov asymptotic approach in which sample size increases along with the number of unknown parameters.This theory opens a way for solution of central problems of multivariate statistics, which up until now have not been solved. Traditional statistical methods based on the idea of an infinite sampling often break down in the solution of real problems, and, dependent on data, can be inefficient, unstable and even not applicable. In this situation, practical statisticians are forced to use various heuristic methods in the hope the will find a satisfactory solution.Mathematical theory developed in this book presents a regular technique for implementing new, more efficient versions of statistical procedures. ...

  15. Trichomoniasis Statistics

    Science.gov (United States)

    ... Search Form Controls Cancel Submit Search the CDC Trichomoniasis Note: Javascript is disabled or is not supported ... Twitter STD on Facebook Sexually Transmitted Diseases (STDs) Trichomoniasis Statistics Recommend on Facebook Tweet Share Compartir In ...

  16. Reversible Statistics

    DEFF Research Database (Denmark)

    Tryggestad, Kjell

    2004-01-01

    The study aims is to describe how the inclusion and exclusion of materials and calculative devices construct the boundaries and distinctions between statistical facts and artifacts in economics. My methodological approach is inspired by John Graunt's (1667) Political arithmetic and more recent work...... within constructivism and the field of Science and Technology Studies (STS). The result of this approach is here termed reversible statistics, reconstructing the findings of a statistical study within economics in three different ways. It is argued that all three accounts are quite normal, albeit...... in different ways. The presence and absence of diverse materials, both natural and political, is what distinguishes them from each other. Arguments are presented for a more symmetric relation between the scientific statistical text and the reader. I will argue that a more symmetric relation can be achieved...

  17. An Invariant-Preserving ALE Method for Solids under Extreme Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Sambasivan, Shiv Kumar [Los Alamos National Laboratory; Christon, Mark A [Los Alamos National Laboratory

    2012-07-17

    We are proposing a fundamentally new approach to ALE methods for solids undergoing large deformation due to extreme loading conditions. Our approach is based on a physically-motivated and mathematically rigorous construction of the underlying Lagrangian method, vector/tensor reconstruction, remapping, and interface reconstruction. It is transformational because it deviates dramatically from traditionally accepted ALE methods and provides the following set of unique attributes: (1) a three-dimensional, finite volume, cell-centered ALE framework with advanced hypo-/hyper-elasto-plastic constitutive theories for solids; (2) a new physically and mathematically consistent reconstruction method for vector/tensor fields; (3) advanced invariant-preserving remapping algorithm for vector/tensor quantities; (4) moment-of-fluid (MoF) interface reconstruction technique for multi-material problems with solids undergoing large deformations. This work brings together many new concepts, that in combination with emergent cell-centered Lagrangian hydrodynamics methods will produce a cutting-edge ALE capability and define a new state-of-the-art. Many ideas in this work are new, completely unexplored, and hence high risk. The proposed research and the resulting algorithms will be of immediate use in Eulerian, Lagrangian and ALE codes under the ASC program at the lab. In addition, the research on invariant preserving reconstruction/remap of tensor quantities is of direct interest to ongoing CASL and climate modeling efforts at LANL. The application space impacted by this work includes Inertial Confinement Fusion (ICF), Z-pinch, munition-target interactions, geological impact dynamics, shock processing of powders and shaped charges. The ALE framework will also provide a suitable test-bed for rapid development and assessment of hypo-/hyper-elasto-plastic constitutive theories. Today, there are no invariant-preserving ALE algorithms for treating solids with large deformations. Therefore

  18. Joint confidence region estimation of L-moment ratios with an extension to right censored data.

    Science.gov (United States)

    Wang, Dongliang; Hutson, Alan D

    L-moments, defined as specific linear combinations of expectations of order statistics, have been advocated by Hosking [7] and others in the literature as meaningful replacements to that of classic moments in a wide variety of applications. One particular use of L-moments is to classify distributions based on the so-called L-skewness and L-kurtosis measures and given by an L-moment ratio diagram. This method parallels the classic moment-based plot of skewness and kurtosis corresponding to the Pearson system of distributions. In general, these methods have been more descriptive in nature and failed to consider the corresponding variation and covariance of the point estimators. In this note, we propose two procedures to estimate the 100(1 - α)% joint confidence region of L-skewness and L-kurtosis, given both complete and censored data. The procedures are derived based on asymptotic normality of L-moment estimators or through a novel empirical characteristic function (c.f.) approach. Simulation results are provided for comparing the performance of these procedures in terms of their respective coverage probabilities. The new and novel c.f.-based confidence region provided superior coverage probability as compared to the standard bootstrap procedure across all parameter settings. The proposed methods are illustrated via an application to a complete Buffalo snow fall data set and to a censored breast cancer data set, respectively.

  19. Vital statistics

    CERN Document Server

    MacKenzie, Dana

    2004-01-01

    The drawbacks of using 19th-century mathematics in physics and astronomy are illustrated. To continue with the expansion of the knowledge about the cosmos, the scientists will have to come in terms with modern statistics. Some researchers have deliberately started importing techniques that are used in medical research. However, the physicists need to identify the brand of statistics that will be suitable for them, and make a choice between the Bayesian and the frequentists approach. (Edited abstract).

  20. Incorporating forcing terms in cascaded lattice Boltzmann approach by method of central moments.

    Science.gov (United States)

    Premnath, Kannan N; Banerjee, Sanjoy

    2009-09-01

    Cascaded lattice Boltzmann method (cascaded-LBM) employs a class of collision operators aiming to stabilize computations and remove certain modeling artifacts for simulation of fluid flow on lattice grids with sizes arbitrarily larger than the smallest physical dissipation length scale [Geier, Phys. Rev. E 63, 066705 (2006)]. It achieves this and distinguishes from other collision operators, such as in the standard single or multiple relaxation-time approaches, by performing relaxation process due to collisions in terms of moments shifted by the local hydrodynamic fluid velocity, i.e., central moments, in an ascending order by order at different relaxation rates. In this paper, we propose and derive source terms in the cascaded-LBM to represent the effect of external or internal forces on the dynamics of fluid motion. This is essentially achieved by matching the continuous form of the central moments of the source or forcing terms with its discrete version. Different forms of continuous central moments of sources, including one that is obtained from a local Maxwellian, are considered in this regard. As a result, the forcing terms obtained in this formulation are Galilean invariant by construction. To alleviate lattice artifacts due to forcing terms in the emergent macroscopic fluid equations, they are proposed as temporally semi-implicit and second order, and the implicitness is subsequently effectively removed by means of a transformation to facilitate computation. It is shown that the impressed force field influences the cascaded collision process in the evolution of the transformed distribution function. The method of central moments along with the associated orthogonal properties of the moment basis completely determines the analytical expressions for the source terms as a function of the force and macroscopic velocity fields. In contrast to the existing forcing schemes, it is found that they involve higher-order terms in velocity space. It is shown that the

  1. Learning to Be (In)Variant: Combining Prior Knowledge and Experience to Infer Orientation Invariance in Object Recognition

    Science.gov (United States)

    Austerweil, Joseph L.; Griffiths, Thomas L.; Palmer, Stephen E.

    2017-01-01

    How does the visual system recognize images of a novel object after a single observation despite possible variations in the viewpoint of that object relative to the observer? One possibility is comparing the image with a prototype for invariance over a relevant transformation set (e.g., translations and dilations). However, invariance over…

  2. Determining and correcting "moment bias" in gradient polymer elution chromatography.

    Science.gov (United States)

    Striegel, André M

    2003-05-09

    Gradient polymer elution chromatography (GPEC) is rapidly becoming the analytical method of choice for determining the chemical composition distribution (CCD) of synthetic polymers. GPEC can be performed in traditional (strict precipitation-redissolution mechanism) or interactive (normal- and reversed-phase) modes, and results may be qualitative, semi-quantitative, or fully quantitative. Quantitative approaches have thus far relied on colligative or end group techniques for determining the values of standards used in constructing the GPEC calibration curve. While the values obtained from said methods are number-averages, they are assigned to the peak apexes of the standards (i.e. assigned as peak averages). This creates a determinate error in the quantitation, referred to herein as "moment bias". In this paper we determine moment bias for a series of styrene-acrylonitrile (SAN) copolymers, where the distribution and averages of the AN% have been measured using normal-phase (NP) GPEC. We also correct for the effect via statistical treatment of the chromatographic data.

  3. Polynomial probability distribution estimation using the method of moments

    Science.gov (United States)

    Mattsson, Lars; Rydén, Jesper

    2017-01-01

    We suggest a procedure for estimating Nth degree polynomial approximations to unknown (or known) probability density functions (PDFs) based on N statistical moments from each distribution. The procedure is based on the method of moments and is setup algorithmically to aid applicability and to ensure rigor in use. In order to show applicability, polynomial PDF approximations are obtained for the distribution families Normal, Log-Normal, Weibull as well as for a bimodal Weibull distribution and a data set of anonymized household electricity use. The results are compared with results for traditional PDF series expansion methods of Gram–Charlier type. It is concluded that this procedure is a comparatively simple procedure that could be used when traditional distribution families are not applicable or when polynomial expansions of probability distributions might be considered useful approximations. In particular this approach is practical for calculating convolutions of distributions, since such operations become integrals of polynomial expressions. Finally, in order to show an advanced applicability of the method, it is shown to be useful for approximating solutions to the Smoluchowski equation. PMID:28394949

  4. Polynomial probability distribution estimation using the method of moments.

    Science.gov (United States)

    Munkhammar, Joakim; Mattsson, Lars; Rydén, Jesper

    2017-01-01

    We suggest a procedure for estimating Nth degree polynomial approximations to unknown (or known) probability density functions (PDFs) based on N statistical moments from each distribution. The procedure is based on the method of moments and is setup algorithmically to aid applicability and to ensure rigor in use. In order to show applicability, polynomial PDF approximations are obtained for the distribution families Normal, Log-Normal, Weibull as well as for a bimodal Weibull distribution and a data set of anonymized household electricity use. The results are compared with results for traditional PDF series expansion methods of Gram-Charlier type. It is concluded that this procedure is a comparatively simple procedure that could be used when traditional distribution families are not applicable or when polynomial expansions of probability distributions might be considered useful approximations. In particular this approach is practical for calculating convolutions of distributions, since such operations become integrals of polynomial expressions. Finally, in order to show an advanced applicability of the method, it is shown to be useful for approximating solutions to the Smoluchowski equation.

  5. Implications of conformal invariance in momentum space

    Science.gov (United States)

    Bzowski, Adam; McFadden, Paul; Skenderis, Kostas

    2014-03-01

    We present a comprehensive analysis of the implications of conformal invariance for 3-point functions of the stress-energy tensor, conserved currents and scalar operators in general dimension and in momentum space. Our starting point is a novel and very effective decomposition of tensor correlators which reduces their computation to that of a number of scalar form factors. For example, the most general 3-point function of a conserved and traceless stress-energy tensor is determined by only five form factors. Dilatations and special conformal Ward identities then impose additional conditions on these form factors. The special conformal Ward identities become a set of first and second order differential equations, whose general solution is given in terms of integrals involving a product of three Bessel functions (`triple- K integrals'). All in all, the correlators are completely determined up to a number of constants, in agreement with well-known position space results. In odd dimensions 3-point functions are finite without renormalisation while in even dimensions non-trivial renormalisation in required. In this paper we restrict ourselves to odd dimensions. A comprehensive analysis of renormalisation will be discussed elsewhere. This paper contains two parts that can be read independently of each other. In the first part, we explain the method that leads to the solution for the correlators in terms of triple- K integrals while the second part contains a self-contained presentation of all results. Readers interested only in results may directly consult the second part of the paper.

  6. Non-Local Translationally Invariant Nuclear Density

    Science.gov (United States)

    Gennari, Michael; Calci, Angelo; Vorabbi, Matteo; Navratil, Petr

    2017-09-01

    Nonlocal nuclear density is derived from the no-core shell model (NCSM) one-body densities by generalizing the local density operator to a nonlocal form. The translational invariance is generated by exactly removing the spurious center of mass (COM) component of the harmonic oscillator wavefunctions. This enables the ab initio NCSM nuclear structure to be used in high energy nuclear reactions and density functional theory. The ground state local and nonlocal density of Helium-4, Helium-6, Helium-8, and Oxygen-16 are calculated to display the effects of COM removal on predicted nuclear structure. We show that amplified effects of the COM removal can be seen in related quantities like kinetic density, which is dependent on gradients of the nonlocal nuclear density. Additionally, we include nonlocal density in calculations of optical potentials - as opposed to using the local approximation - which produces more accurate theoretical predictions for the optical potentials of lighter nuclei. We present differential cross sections and analyzing powers for proton scattering on Helium-4, Helium-6, Helium-8, and Oxygen-16 at high energies using modern nucleon-nucleon and three-nucleon chiral interactions.

  7. ICECUBE NEUTRINOS AND LORENTZ INVARIANCE VIOLATION

    Energy Technology Data Exchange (ETDEWEB)

    Amelino-Camelia, Giovanni [Dipartimento di Fisica, Sapienza Università di Roma and INFN, Sez. Roma1, P.le A. Moro 2, I-00185 Roma (Italy); Guetta, D. [Osservatorio astronomico di Roma, v. Frascati 33, I-00040 Monte Porzio Catone (Italy); Piran, Tsvi [The Racah Institute for Physics, The Hebrew University of Jerusalem, Jerusalem 91904 (Israel)

    2015-06-20

    The IceCube neutrino telescope has found so far no evidence of gamma-ray burst (GRB) neutrinos. We here notice that these results assume the same travel times from source to telescope for neutrinos and photons, an assumption that is challenged by some much-studied pictures of spacetime quantization. We briefly review previous results suggesting that limits on quantum-spacetime effects obtained for photons might not be applicable to neutrinos, and we then observe that the outcome of GRB-neutrino searches could depend strongly on whether one allows for neutrinos to be affected by the minute effects of Lorentz invariance violation (LIV) predicted by some relevant quantum-spacetime models. We discuss some relevant issues using as an illustrative example three neutrinos that were detected by IceCube in good spatial coincidence with GRBs, but hours before the corresponding gamma rays. In general, this could happen if the earlier arrival reflects quantum-spacetime-induced LIV, but, as we stress, some consistency criteria must be enforced in order to properly test such a hypothesis. Our analysis sets the stage for future GRB-neutrino searches that could systematically test the possibility of quantum-spacetime-induced LIV.

  8. The Statistical Drake Equation

    Science.gov (United States)

    Maccone, Claudio

    2010-12-01

    We provide the statistical generalization of the Drake equation. From a simple product of seven positive numbers, the Drake equation is now turned into the product of seven positive random variables. We call this "the Statistical Drake Equation". The mathematical consequences of this transformation are then derived. The proof of our results is based on the Central Limit Theorem (CLT) of Statistics. In loose terms, the CLT states that the sum of any number of independent random variables, each of which may be ARBITRARILY distributed, approaches a Gaussian (i.e. normal) random variable. This is called the Lyapunov Form of the CLT, or the Lindeberg Form of the CLT, depending on the mathematical constraints assumed on the third moments of the various probability distributions. In conclusion, we show that: The new random variable N, yielding the number of communicating civilizations in the Galaxy, follows the LOGNORMAL distribution. Then, as a consequence, the mean value of this lognormal distribution is the ordinary N in the Drake equation. The standard deviation, mode, and all the moments of this lognormal N are also found. The seven factors in the ordinary Drake equation now become seven positive random variables. The probability distribution of each random variable may be ARBITRARY. The CLT in the so-called Lyapunov or Lindeberg forms (that both do not assume the factors to be identically distributed) allows for that. In other words, the CLT "translates" into our statistical Drake equation by allowing an arbitrary probability distribution for each factor. This is both physically realistic and practically very useful, of course. An application of our statistical Drake equation then follows. The (average) DISTANCE between any two neighboring and communicating civilizations in the Galaxy may be shown to be inversely proportional to the cubic root of N. Then, in our approach, this distance becomes a new random variable. We derive the relevant probability density

  9. Statistical mechanics

    CERN Document Server

    Jana, Madhusudan

    2015-01-01

    Statistical mechanics is self sufficient, written in a lucid manner, keeping in mind the exam system of the universities. Need of study this subject and its relation to Thermodynamics is discussed in detail. Starting from Liouville theorem gradually, the Statistical Mechanics is developed thoroughly. All three types of Statistical distribution functions are derived separately with their periphery of applications and limitations. Non-interacting ideal Bose gas and Fermi gas are discussed thoroughly. Properties of Liquid He-II and the corresponding models have been depicted. White dwarfs and condensed matter physics, transport phenomenon - thermal and electrical conductivity, Hall effect, Magneto resistance, viscosity, diffusion, etc. are discussed. Basic understanding of Ising model is given to explain the phase transition. The book ends with a detailed coverage to the method of ensembles (namely Microcanonical, canonical and grand canonical) and their applications. Various numerical and conceptual problems ar...

  10. Statistical physics

    CERN Document Server

    Guénault, Tony

    2007-01-01

    In this revised and enlarged second edition of an established text Tony Guénault provides a clear and refreshingly readable introduction to statistical physics, an essential component of any first degree in physics. The treatment itself is self-contained and concentrates on an understanding of the physical ideas, without requiring a high level of mathematical sophistication. A straightforward quantum approach to statistical averaging is adopted from the outset (easier, the author believes, than the classical approach). The initial part of the book is geared towards explaining the equilibrium properties of a simple isolated assembly of particles. Thus, several important topics, for example an ideal spin-½ solid, can be discussed at an early stage. The treatment of gases gives full coverage to Maxwell-Boltzmann, Fermi-Dirac and Bose-Einstein statistics. Towards the end of the book the student is introduced to a wider viewpoint and new chapters are included on chemical thermodynamics, interactions in, for exam...

  11. Statistical mechanics

    CERN Document Server

    Schwabl, Franz

    2006-01-01

    The completely revised new edition of the classical book on Statistical Mechanics covers the basic concepts of equilibrium and non-equilibrium statistical physics. In addition to a deductive approach to equilibrium statistics and thermodynamics based on a single hypothesis - the form of the microcanonical density matrix - this book treats the most important elements of non-equilibrium phenomena. Intermediate calculations are presented in complete detail. Problems at the end of each chapter help students to consolidate their understanding of the material. Beyond the fundamentals, this text demonstrates the breadth of the field and its great variety of applications. Modern areas such as renormalization group theory, percolation, stochastic equations of motion and their applications to critical dynamics, kinetic theories, as well as fundamental considerations of irreversibility, are discussed. The text will be useful for advanced students of physics and other natural sciences; a basic knowledge of quantum mechan...

  12. Matrix elements from moments of correlation functions

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chia Cheng [SLAC National Accelerator Lab., Menlo Park, CA (United States); Bouchard, Chris [College of William and Mary, Williamsburg, VA (United States); Orginos, Konstantinos [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); College of William and Mary, Williamsburg, VA (United States); Richards, David G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-10-01

    Momentum-space derivatives of matrix elements can be related to their coordinate-space moments through the Fourier transform. We derive these expressions as a function of momentum transfer Q2 for asymptotic in/out states consisting of a single hadron. We calculate corrections to the finite volume moments by studying the spatial dependence of the lattice correlation functions. This method permits the computation of not only the values of matrix elements at momenta accessible on the lattice, but also the momentum-space derivatives, providing {\\it a priori} information about the Q2 dependence of form factors. As a specific application we use the method, at a single lattice spacing and with unphysically heavy quarks, to directly obtain the slope of the isovector form factor at various Q2, whence the isovector charge radius. The method has potential application in the calculation of any hadronic matrix element with momentum transfer, including those relevant to hadronic weak decays.

  13. Sequence Classification Using Third-Order Moments

    DEFF Research Database (Denmark)

    Troelsgaard, Rasmus; Hansen, Lars Kai

    2017-01-01

    . The proposed method provides lower computational complexity at classification time than the usual likelihood-based methods. In order to demonstrate the properties of the proposed method, we perform classification of both simulated data and empirical data from a human activity recognition study.......Model-based classification of sequence data using a set of hidden Markov models is a well-known technique. The involved score function, which is often based on the class-conditional likelihood, can, however, be computationally demanding, especially for long data sequences. Inspired by recent...... theoretical advances in spectral learning of hidden Markov models, we propose a score function based on third-order moments. In particular, we propose to use the Kullback-Leibler divergence between theoretical and empirical third-order moments for classification of sequence data with discrete observations...

  14. Higher Mellin moments for charged current DIS

    Energy Technology Data Exchange (ETDEWEB)

    Rogal, M.; Moch, S.

    2007-06-15

    We report on our recent results for deep-inelastic neutrino({nu})-proton(P) scattering. We have computed the perturbative QCD corrections to three loops for the charged current structure functions F{sub 2}, F{sub L} and F{sub 3} for the combination {nu}P- anti {nu}P. In leading twist approximation we have calculated the first six odd-integer Mellin moments in the case of F{sub 2} and F{sub L} and the first six even-integer moments in the case of F{sub 3}. As a new result we have obtained the coefficient functions to O({alpha}{sup 3}{sub s}) and we have found the corresponding anomalous dimensions to agree with known results in the literature. (orig.)

  15. Stochastic development regression using method of moments

    DEFF Research Database (Denmark)

    Kühnel, Line; Sommer, Stefan Horst

    2017-01-01

    This paper considers the estimation problem arising when inferring parameters in the stochastic development regression model for manifold valued non-linear data. Stochastic development regression captures the relation between manifold-valued response and Euclidean covariate variables using...... the stochastic development construction. It is thereby able to incorporate several covariate variables and random effects. The model is intrinsically defined using the connection of the manifold, and the use of stochastic development avoids linearizing the geometry. We propose to infer parameters using...... the Method of Moments procedure that matches known constraints on moments of the observations conditional on the latent variables. The performance of the model is investigated in a simulation example using data on finite dimensional landmark manifolds....

  16. The Koszul complex of a moment map

    DEFF Research Database (Denmark)

    Herbig, Hans-Christian; Schwarz, Gerald W.

    2013-01-01

    Let $K\\to\\U(V)$ be a unitary representation of the compact Lie group $K$. Then there is a canonical moment mapping $\\rho\\colon V\\to\\liek^*$. We have the Koszul complex ${\\mathcal K}(\\rho,\\mathcal C^\\infty(V))$ of the component functions $\\rho_1,\\dots,\\rho_k$ of $\\rho$. Let $G=K_\\C$, the complexif......Let $K\\to\\U(V)$ be a unitary representation of the compact Lie group $K$. Then there is a canonical moment mapping $\\rho\\colon V\\to\\liek^*$. We have the Koszul complex ${\\mathcal K}(\\rho,\\mathcal C^\\infty(V))$ of the component functions $\\rho_1,\\dots,\\rho_k$ of $\\rho$. Let $G...

  17. Spectral properties of supersymmetric shape invariant potentials

    Indian Academy of Sciences (India)

    SIPs). Although the folded spectrum is completely random, unfolded spectrum shows that energy levels are highly correlated and absolutely rigid. All the SIPs exhibit harmonic oscillator-type spectral statistics in the unfolded spectrum.

  18. Statistical mechanics

    CERN Document Server

    Davidson, Norman

    2003-01-01

    Clear and readable, this fine text assists students in achieving a grasp of the techniques and limitations of statistical mechanics. The treatment follows a logical progression from elementary to advanced theories, with careful attention to detail and mathematical development, and is sufficiently rigorous for introductory or intermediate graduate courses.Beginning with a study of the statistical mechanics of ideal gases and other systems of non-interacting particles, the text develops the theory in detail and applies it to the study of chemical equilibrium and the calculation of the thermody

  19. AP statistics

    CERN Document Server

    Levine-Wissing, Robin

    2012-01-01

    All Access for the AP® Statistics Exam Book + Web + Mobile Everything you need to prepare for the Advanced Placement® exam, in a study system built around you! There are many different ways to prepare for an Advanced Placement® exam. What's best for you depends on how much time you have to study and how comfortable you are with the subject matter. To score your highest, you need a system that can be customized to fit you: your schedule, your learning style, and your current level of knowledge. This book, and the online tools that come with it, will help you personalize your AP® Statistics prep

  20. Statistical inference

    CERN Document Server

    Rohatgi, Vijay K

    2003-01-01

    Unified treatment of probability and statistics examines and analyzes the relationship between the two fields, exploring inferential issues. Numerous problems, examples, and diagrams--some with solutions--plus clear-cut, highlighted summaries of results. Advanced undergraduate to graduate level. Contents: 1. Introduction. 2. Probability Model. 3. Probability Distributions. 4. Introduction to Statistical Inference. 5. More on Mathematical Expectation. 6. Some Discrete Models. 7. Some Continuous Models. 8. Functions of Random Variables and Random Vectors. 9. Large-Sample Theory. 10. General Meth

  1. New discrete orthogonal moments for signal analysis

    Czech Academy of Sciences Publication Activity Database

    Honarvar Shakibaei Asli, Barmak; Flusser, Jan

    2017-01-01

    Roč. 141, č. 1 (2017), s. 57-73 ISSN 0165-1684 R&D Projects: GA ČR GA15-16928S Institutional support: RVO:67985556 Keywords : Orthogonal polynomials * Moment functions * Z-transform * Rodrigues formula * Hypergeometric form Subject RIV: JD - Computer Applications, Robotics Impact factor: 3.110, year: 2016 http:// library .utia.cas.cz/separaty/2017/ZOI/flusser-0475248.pdf

  2. Some special moments from last month

    CERN Multimedia

    Claudia Marcelloni de Oliveira

    Integration of the three shells into the ATLAS pixel barrel last month. Lowering of the first sector of the MDT Muon Big Wheel on side C in the ATLAS cavern in December 2006. Some intense moment during the first ATLAS integration run from the main ATLAS control room. Muriel was one of the 20000 ATLAS cavern visitors in 2006 to enjoy herself during her visit.

  3. Analytic Moment-based Gaussian Process Filtering

    OpenAIRE

    Deisenroth, MP; Huber, MF; Hanebeck, UD

    2009-01-01

    04.07.13 KB. Ok to add accepted version to Spiral, authors retain copyright. We propose an analytic moment-based filter for nonlinear stochastic dynamic systems modeled by Gaussian processes. Exact expressions for the expected value and the covariance matrix are provided for both the prediction step and the filter step, where an additional Gaussian assumption is exploited in the latter case. Our filter does not require further approximations. In particular, it avoids finite-sample approxi...

  4. A big measurement of a small moment

    Science.gov (United States)

    E Sauer, B.; Devlin, J. A.; Rabey, I. M.

    2017-07-01

    A beam of ThO molecules has been used to make the most precise measurement of the electron’s electric dipole moment (EDM) to date. In their recent paper, the ACME collaboration set out in detail their experimental and data analysis techniques. In a tour-de-force, they explain the many ways in which their apparatus can produce a signal which mimics the EDM and show how these systematic effects are measured and controlled.

  5. Kairos time at the moment of birth.

    Science.gov (United States)

    Crowther, Susan; Smythe, Elizabeth; Spence, Deb

    2015-04-01

    there is something extraordinary in the lived experience of being there at the time of birth. Yet the meaning and significance of this special time, named Kairos time in this paper, have received little attention. to describe the lived-experience of Kairos time at birth and surface its meaning. this is an interpretive hermeneutic phenomenology study informed by the writings of Heidegger and Gadamer. 14 in-depth interviews with mothers, birth partners, midwives and obstetricians were transcribed and stories from the data were hermeneutically analysed. there is a time, like no other, at the moment of birth that is widely known and valued. This paper reveals and names this phenomenon Kairos time. This is a felt-time that is lineal, process and cyclic time and more. Kairos time describes an existential temporal experience that is rich in significant sacred meaning; a time of emergent insight rarely spoken about in practice yet touches everyone present. The notion of Kairos time in relation to the moment of birth is introduced as a reminder of something significant that matters. Kairos time is revealed as a moment in and beyond time. It has a temporal enigmatic mystery involving spiritual connectedness. Kairos time is a time of knowing and remembrance of our shared natality. In this time life is disclosed as extraordinary and beyond everyday personal and professional concerns. It is all this and more. Kairos time at birth is precious and powerful yet vulnerable. It needs to be safeguarded to ensure its presence continues to emerge. This means maternity care providers and others at birth need to shelter and protect Kairos time from the sometimes harsh realities of birth and the potentially insensitive ways of being there at the moments of birth. Those who find themselves at birth need to pause and allow the profundity of its meaning to surface and inspire their actions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Monte Carlo Volcano Seismic Moment Tensors

    Science.gov (United States)

    Waite, G. P.; Brill, K. A.; Lanza, F.

    2015-12-01

    Inverse modeling of volcano seismic sources can provide insight into the geometry and dynamics of volcanic conduits. But given the logistical challenges of working on an active volcano, seismic networks are typically deficient in spatial and temporal coverage; this potentially leads to large errors in source models. In addition, uncertainties in the centroid location and moment-tensor components, including volumetric components, are difficult to constrain from the linear inversion results, which leads to a poor understanding of the model space. In this study, we employ a nonlinear inversion using a Monte Carlo scheme with the objective of defining robustly resolved elements of model space. The model space is randomized by centroid location and moment tensor eigenvectors. Point sources densely sample the summit area and moment tensors are constrained to a randomly chosen geometry within the inversion; Green's functions for the random moment tensors are all calculated from modeled single forces, making the nonlinear inversion computationally reasonable. We apply this method to very-long-period (VLP) seismic events that accompany minor eruptions at Fuego volcano, Guatemala. The library of single force Green's functions is computed with a 3D finite-difference modeling algorithm through a homogeneous velocity-density model that includes topography, for a 3D grid of nodes, spaced 40 m apart, within the summit region. The homogenous velocity and density model is justified by long wavelength of VLP data. The nonlinear inversion reveals well resolved model features and informs the interpretation through a better understanding of the possible models. This approach can also be used to evaluate possible station geometries in order to optimize networks prior to deployment.

  7. Non-Hamiltonian equilibrium statistical mechanics.

    Science.gov (United States)

    Sergi, Alessandro

    2003-02-01

    In this paper the equilibrium statistical mechanics of non-Hamiltonian systems is formulated introducing an algebraic bracket. The latter defines non-Hamiltonian equations of motion in classical phase space according to the approach introduced in Phys. Rev. E 64, 056125 (2001). The Jacobi identity is no longer satisfied by the generalized bracket and as a result the algebra of phase space functions is not time translation invariant. The presence of a nonzero phase space compressibility spoils also the time-reversal invariance of the dynamics. The general Liouville equation is rederived and the properties of statistical averages are accounted for. The features of time correlation functions and linear response theory are also discussed.

  8. Facades structure detection by geometric moment

    Science.gov (United States)

    Jiang, Diqiong; Chen, Hui; Song, Rui; Meng, Lei

    2017-06-01

    This paper proposes a novel method for extracting facades structure from real-world pictures by using local geometric moment. Compared with existing methods, the proposed method has advantages of easy-to-implement, low computational cost, and robustness to noises, such as uneven illumination, shadow, and shade from other objects. Besides, our method is faster and has a lower space complexity, making it feasible for mobile devices and the situation where real-time data processing is required. Specifically, a facades structure modal is first proposed to support the use of our special noise reduction method, which is based on a self-adapt local threshold with Gaussian weighted average for image binarization processing and the feature of the facades structure. Next, we divide the picture of the building into many individual areas, each of which represents a door or a window in the picture. Subsequently we calculate the geometric moment and centroid for each individual area, for identifying those collinear ones based on the feature vectors, each of which is thereafter replaced with a line. Finally, we comprehensively analyze all the geometric moment and centroid to find out the facades structure of the building. We compare our result with other methods and especially report the result from the pictures taken in bad environmental conditions. Our system is designed for two application, i.e, the reconstruction of facades based on higher resolution ground-based on imagery, and the positional system based on recognize the urban building.

  9. Nuclear moments of /sup 9/Li

    Energy Technology Data Exchange (ETDEWEB)

    Correll, F.D.; Madansky, L.; Hardekopf, R.A.; Sunier, J.W.

    1983-08-01

    The ground-state magnetic dipole and electric quadrupole moments of the ..beta.. emitter /sup 9/Li (J/sup ..pi../ = (3/2)/sup -/, T/sub 1/2/ = 0.176 s) have been measured for the first time. Polarized /sup 9/Li nuclei were produced in the /sup 7/Li(t,p) reaction, using 5--6 MeV polarized tritons. The recoiling /sup 9/Li nuclei were stopped either in Au foils or in LiNbO/sub 3/ single crystals, and their polarization was detected by measuring the ..beta..-decay asymmetry. Nuclear magnetic resonance techniques were used to depolarize the nuclei, and the resonant frequencies were deduced from changes in the asymmetry. The /sup 9/Li dipole moment was deduced from the measured Larmor frequency in Au; the result, including corrections for diamagnetic shielding and the Knight shift, is Vertical Bar..mu..Vertical Bar = 3.4391(6) ..mu../sub N/. The ratio of the /sup 9/Li quadrupole moment to that of /sup 7/Li was derived from their respective quadrupole couplings in LiNbO/sub 3/; the value is Vertical BarQ( /sup 9/Li)/Q( /sup 7/Li)Vertical Bar = 0. 88 +- 0.18. Both results are in agreement with shell model predictions.

  10. Learning moment-based fast local binary descriptor

    Science.gov (United States)

    Bellarbi, Abdelkader; Zenati, Nadia; Otmane, Samir; Belghit, Hayet

    2017-03-01

    Recently, binary descriptors have attracted significant attention due to their speed and low memory consumption; however, using intensity differences to calculate the binary descriptive vector is not efficient enough. We propose an approach to binary description called POLAR_MOBIL, in which we perform binary tests between geometrical and statistical information using moments in the patch instead of the classical intensity binary test. In addition, we introduce a learning technique used to select an optimized set of binary tests with low correlation and high variance. This approach offers high distinctiveness against affine transformations and appearance changes. An extensive evaluation on well-known benchmark datasets reveals the robustness and the effectiveness of the proposed descriptor, as well as its good performance in terms of low computation complexity when compared with state-of-the-art real-time local descriptors.

  11. Evolution of Brain Tumor and Stability of Geometric Invariants

    Directory of Open Access Journals (Sweden)

    K. Tawbe

    2008-01-01

    Full Text Available This paper presents a method to reconstruct and to calculate geometric invariants on brain tumors. The geometric invariants considered in the paper are the volume, the area, the discrete Gauss curvature, and the discrete mean curvature. The volume of a tumor is an important aspect that helps doctors to make a medical diagnosis. And as doctors seek a stable calculation, we propose to prove the stability of some invariants. Finally, we study the evolution of brain tumor as a function of time in two or three years depending on patients with MR images every three or six months.

  12. Gauge invariance properties and singularity cancellations in a modified PQCD

    CERN Document Server

    Cabo-Montes de Oca, Alejandro; Cabo, Alejandro; Rigol, Marcos

    2006-01-01

    The gauge-invariance properties and singularity elimination of the modified perturbation theory for QCD introduced in previous works, are investigated. The construction of the modified free propagators is generalized to include the dependence on the gauge parameter $\\alpha $. Further, a functional proof of the independence of the theory under the changes of the quantum and classical gauges is given. The singularities appearing in the perturbative expansion are eliminated by properly combining dimensional regularization with the Nakanishi infrared regularization for the invariant functions in the operator quantization of the $\\alpha$-dependent gauge theory. First-order evaluations of various quantities are presented, illustrating the gauge invariance-properties.

  13. Conformal invariant cosmological perturbations via the covariant approach

    CERN Document Server

    Li, Mingzhe

    2015-01-01

    It is known that some cosmological perturbations are conformal invariant. This facilitates the studies of perturbations within some gravitational theories alternative to general relativity, for example the scalar-tensor theory, because it is possible to do equivalent analysis in a certain frame in which the perturbation equations are simpler. In this paper we revisit the problem of conformal invariances of cosmological perturbations in terms of the covariant approach in which the perturbation variables have clear geometric and physical meanings. We show that with this approach the conformal invariant perturbations are easily identified.

  14. Tuning the cosmological constant, broken scale invariance, unitarity

    Energy Technology Data Exchange (ETDEWEB)

    Förste, Stefan; Manz, Paul [Bethe Center for Theoretical Physics,Nussallee 12, 53115 Bonn (Germany); Physikalisches Institut der Universität Bonn,Nussallee 12, 53115 Bonn (Germany)

    2016-06-10

    We study gravity coupled to a cosmological constant and a scale but not conformally invariant sector. In Minkowski vacuum, scale invariance is spontaneously broken. We consider small fluctuations around the Minkowski vacuum. At the linearised level we find that the trace of metric perturbations receives a positive or negative mass squared contribution. However, only for the Fierz-Pauli combination the theory is free of ghosts. The mass term for the trace of metric perturbations can be cancelled by explicitly breaking scale invariance. This reintroduces fine-tuning. Models based on four form field strength show similarities with explicit scale symmetry breaking due to quantisation conditions.

  15. Invariants for minimal conformal supergravity in six dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Butter, Daniel [Nikhef Theory Group,Science Park 105, 1098 XG Amsterdam (Netherlands); Kuzenko, Sergei M. [School of Physics M013, The University of Western Australia,35 Stirling Highway, Crawley W.A. 6009 (Australia); Novak, Joseph; Theisen, Stefan [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut,Am Mühlenberg 1, D-14476 Golm (Germany)

    2016-12-15

    We develop a new off-shell formulation for six-dimensional conformal supergravity obtained by gauging the 6D N=(1,0) superconformal algebra in superspace. This formulation is employed to construct two invariants for 6D N=(1,0) conformal supergravity, which contain C{sup 3} and C◻C terms at the component level. Using a conformal supercurrent analysis, we prove that these exhaust all such invariants in minimal conformal supergravity. Finally, we show how to construct the supersymmetric F◻F invariant in curved superspace.

  16. Statistical Mechancis

    CERN Document Server

    Gallavotti, Giovanni

    2011-01-01

    C. Cercignani: A sketch of the theory of the Boltzmann equation.- O.E. Lanford: Qualitative and statistical theory of dissipative systems.- E.H. Lieb: many particle Coulomb systems.- B. Tirozzi: Report on renormalization group.- A. Wehrl: Basic properties of entropy in quantum mechanics.

  17. Statistical Computing

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 10. Statistical Computing - Understanding Randomness and Random Numbers. Sudhakar Kunte. Series Article Volume 4 Issue 10 October 1999 pp 16-21. Fulltext. Click here to view fulltext PDF. Permanent link:

  18. Improved moment scaling estimation for multifractal signals

    Directory of Open Access Journals (Sweden)

    D. Veneziano

    2009-11-01

    Full Text Available A fundamental problem in the analysis of multifractal processes is to estimate the scaling exponent K(q of moments of different order q from data. Conventional estimators use the empirical moments μ^rq=⟨ | εr(τ|q of wavelet coefficients εr(τ, where τ is location and r is resolution. For stationary measures one usually considers "wavelets of order 0" (averages, whereas for functions with multifractal increments one must use wavelets of order at least 1. One obtains K^(q as the slope of log( μ^rq against log(r over a range of r. Negative moments are sensitive to measurement noise and quantization. For them, one typically uses only the local maxima of | εr(τ| (modulus maxima methods. For the positive moments, we modify the standard estimator K^(q to significantly reduce its variance at the expense of a modest increase in the bias. This is done by separately estimating K(q from sub-records and averaging the results. For the negative moments, we show that the standard modulus maxima estimator is biased and, in the case of additive noise or quantization, is not applicable with wavelets of order 1 or higher. For these cases we propose alternative estimators. We also consider the fitting of parametric models of K(q and show how, by splitting the record into sub-records as indicated above, the accuracy of standard methods can be significantly improved.

  19. Network connectivity modulates power spectrum scale invariance.

    Science.gov (United States)

    Rădulescu, Anca; Mujica-Parodi, Lilianne R

    2014-04-15

    Measures of complexity are sensitive in detecting disease, which has made them attractive candidates for diagnostic biomarkers; one complexity measure that has shown promise in fMRI is power spectrum scale invariance (PSSI). Even if scale-free features of neuroimaging turn out to be diagnostically useful, however, their underlying neurobiological basis is poorly understood. Using modeling and simulations of a schematic prefrontal-limbic meso-circuit, with excitatory and inhibitory networks of nodes, we present here a framework for how network density within a control system can affect the complexity of signal outputs. Our model demonstrates that scale-free behavior, similar to that observed in fMRI PSSI data, can be obtained for sufficiently large networks in a context as simple as a linear stochastic system of differential equations, although the scale-free range improves when introducing more realistic, nonlinear behavior in the system. PSSI values (reflective of complexity) vary as a function of both input type (excitatory, inhibitory) and input density (mean number of long-range connections, or strength), independent of their node-specific geometric distribution. Signals show pink noise (1/f) behavior when excitatory and inhibitory influences are balanced. As excitatory inputs are increased and decreased, signals shift towards white and brown noise, respectively. As inhibitory inputs are increased and decreased, signals shift towards brown and white noise, respectively. The results hold qualitatively at the hemodynamic scale, which we modeled by introducing a neurovascular component. Comparing hemodynamic simulation results to fMRI PSSI results from 96 individuals across a wide spectrum of anxiety-levels, we show how our model can generate concrete and testable hypotheses for understanding how connectivity affects regulation of meso-circuits in the brain. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Constraints on T-Odd, P-Even Interactions from Electric Dipole Moments

    Energy Technology Data Exchange (ETDEWEB)

    A. Kurylov; G. C. McLaughlin; M.J. Ramsey-Musolf

    2001-03-01

    We construct the relationship between nonrenormalizable,effective, time-reversal violating (TV) parity-conserving (PC) interactions of quarks and gauge bosons and various low-energy TVPC and TV parity-violating (PV) observables. Using effective field theory methods, we delineate the scenarios under which experimental limits on permanent electric dipole moments (EDM's) of the electron, neutron, and neutral atoms as well as limits on TVPC observables provide the most stringent bounds on new TVPC interactions. Under scenarios in which parity invariance is restored at short distances, the one-loop EDM of elementary fermions generate the most severe constraints. The limits derived from the atomic EDM of {sup 199}Hg are considerably weaker. When parity symmetry remains broken at short distances, direct TVPC search limits provide the least ambiguous bounds. The direct limits follow from TVPC interactions between two quarks.