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Sample records for average resonance parameters

  1. Average resonance parameters evaluation for actinides

    Energy Technology Data Exchange (ETDEWEB)

    Porodzinskij, Yu.V.; Sukhovitskij, E.Sh. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)

    1997-03-01

    New evaluated <{Gamma}{sub n}{sup 0}> and values for {sup 238}U, {sup 237}Np, {sup 243}Cm, {sup 245}Cm, {sup 246}Cm and {sup 241}Am nuclei in the resolved resonance region are presented. The applied method based on the idea that experimental resonance missing results in correlated changes of reduced neutron widths and level spacings distributions is discussed. (author)

  2. Average resonance parameters of zirconium and molybdenum nuclei

    International Nuclear Information System (INIS)

    Full sets of average resonance parameters S0, S1, R0', R1', S1,3/2 for zirconium and molybdenum nuclei with natural mixture of isotopes are determined by means of the method designed by authors. The determination is realized from analysis of the average experimental differential cross sections of neutron elastic scattering in the field of energy before 440 keV. Analysis of recommended parameters and some of the literary data had been performed also.

  3. Average resonance parameters of ruthenium and palladium nuclei

    International Nuclear Information System (INIS)

    Full sets of the average resonance parameters S0, S1, R0', R1', S1,3/2 for ruthenium and palladium nuclei with natural mixture of isotopes are determined by means of the method designed by authors. The determination is realized from analysis of the average experimental differential cross sections of neutron elastic scattering in the field of energy before 440 keV. The analysis of recommended parameters and of some of the literary data had been performed also.

  4. Average resonance parameters of germanium and selenium nuclei

    International Nuclear Information System (INIS)

    Full sets of average resonance parameters S0, S1, R0', R1', S1,3/2 for germanium and selenium nuclei with natural isotope content are determined. Parameters are received from the analysis of experimental neutron elastic scattering cross sections at energy region up to 440 keV with the help of the method developed by the authors. The analysis of recommended parameters and some literature data is fulfilled as well.

  5. Average resonance parameters of tellurium and neodymium nuclei

    International Nuclear Information System (INIS)

    Complete sets of average resonance parameters S0, S1, R''0, R''1, and S1,3/2 for tellurium and neodymium nuclei with natural isotope contents have been determined by analyzing the experimental differential cross-sections of neutron elastic scattering in the energy range lower than 440 keV. The data obtained, the recommended parameter values, and some literature data have been analyzed.

  6. Neutron resonance averaging

    International Nuclear Information System (INIS)

    The principles of resonance averaging as applied to neutron capture reactions are described. Several illustrations of resonance averaging to problems of nuclear structure and the distribution of radiative strength in nuclei are provided. 30 refs., 12 figs

  7. Neutron capture on (94)Zr: Resonance parameters and Maxwellian-averaged cross sections

    CERN Document Server

    Tagliente, G; Fujii, K; Abbondanno, U; Aerts, G; Alvarez, H; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Belloni, F; Berthoumieux, E; Bisterzo, S; Calvino, F; Calviani, M; Cano-Ott, D; Capote, R; Carrapico, C; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Embid-Segura, M; Ferrari, A; Ferreira-Marques, R; Furman, W; Gallino, R; Goncalves, I; Gonzalez-Romero, E; Gramegna, F; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Jericha, E; Kappeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Kossionides, E; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martinez, T; Massimi, C; Mastinu, P; Mengoni, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M.T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Savvidis, I; Stephan, C; Tain, J.L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vincente, M.C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wiescher, M; Wisshak, K

    2011-01-01

    The neutron capture cross sections of the Zr isotopes play an important role in nucleosynthesis studies. The s-process reaction flow between the Fe seed and the heavier isotopes passes through the neutron magic nucleus (90)Zr and through (91,92,93,94)Zr, but only part of the flow extends to (96)Zr because of the branching point at (95)Zr. Apart from their effect on the s-process flow, the comparably small isotopic (n, gamma) cross sections make Zr also an interesting structural material for nuclear reactors. The (94)Zr (n, gamma) cross section has been measured with high resolution at the spallation neutron source n_TOF at CERN and resonance parameters are reported up to 60 keV neutron energy.

  8. Evaluation of average neutron resonance parameters of actinides with the account of experimental resolution and discrimination threshold. Final report for the period 15 December 1996 - 14 December 1997

    International Nuclear Information System (INIS)

    New evaluation of average resonance parameters for 32 isotopes of the actinide region (229Th-252Cf) was completed. Obtained values of average level spacings produce a smooth systematics of the main level density parameter. The results were included into the Starter File of the Reference Input Parameter Library (segment Average Neutron Resonances) and officially released on 15 May 1998. The numerical results are available from the Internet (http://iaeand.iaea.or.at/ripl) and on CD-ROM. (author)

  9. Michel Parameters averages and interpretation

    International Nuclear Information System (INIS)

    The new measurements of Michel parameters in τ decays are combined to world averages. From these measurements model independent limits on non-standard model couplings are derived and interpretations in the framework of specific models are given. A lower limit of 2.5 tan β GeV on the mass of a charged Higgs boson in models with two Higgs doublets can be set and a 229 GeV limit on a right-handed W-boson in left-right symmetric models (95 % c.l.)

  10. Resonance averaged channel radiative neutron capture cross sections

    International Nuclear Information System (INIS)

    In order to apply Lane amd Lynn's channel capture model in calculations with a realistic optical model potential, we have derived an approximate wave function for the entrance channel in the neutron-nucleus reaction, based on the intermediate interaction model. It is valid in the exterior region as well as the region near the nuclear surface, ans is expressed in terms of the wave function and reactance matrix of the optical model and of the near-resonance parameters. With this formalism the averaged channel radiative neutron capture cross section in the resonance region is written as the sum of three terms. The first two terms correspond to contribution of the optical model real and imaginary parts respectively, and together can be regarded as the radiative capture of the shape elastic wave. The third term is a fluctuation term, corresponding to the radiative capture of the compound elastic wave in the exterior region. On applying this theory in the resonance region, we obtain an expression for the average valence radiative width similar to that of Lane and Mughabghab. We have investigated the magnitude and energy dependence of the three terms as a function of the neutron incident energy. Calculated results for 98Mo and 55Mn show that the averaged channel radiative capture cross section in the giant resonance region of the neutron strength function may account for a considerable fraction of the total (n, γ) cross section; at lower neutron energies a large part of this channel capture arises from the fluctuation term. We have also calculated the partial capture cross section in 98Mo and 55Mn at 2.4 keV and 24 keV, respectively, and compared the 98Mo results with the experimental data. (orig.)

  11. Comparison of near-identity averaging and multiple-scale expansions for sustained-resonance solutions

    Institute of Scientific and Technical Information of China (English)

    李怡平

    1995-01-01

    How the averaging near-identity transformations are equivalent to multiple-scale expansions to O(1) is shown in solving strictly nonlinear oscillatory systems with slowly varying parameters in sustained resonance.

  12. Simultaneous inference for model averaging of derived parameters

    DEFF Research Database (Denmark)

    Jensen, Signe Marie; Ritz, Christian

    2015-01-01

    Model averaging is a useful approach for capturing uncertainty due to model selection. Currently, this uncertainty is often quantified by means of approximations that do not easily extend to simultaneous inference. Moreover, in practice there is a need for both model averaging and simultaneous...... inference for derived parameters calculated in an after-fitting step. We propose a method for obtaining asymptotically correct standard errors for one or several model-averaged estimates of derived parameters and for obtaining simultaneous confidence intervals that asymptotically control the family...

  13. Neutron Resonance Parameters for Ra-226 (Radium)

    Science.gov (United States)

    Sukhoruchkin, S. I.; Soroko, Z. N.

    This document is part of the Supplement containing the complete sets of data of Volume 24 `Neutron Resonance Parameters' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides the neutron resonance parameters for the isotope Ra-226 (Radium).

  14. Average radiation widths and the giant dipole resonance width

    Energy Technology Data Exchange (ETDEWEB)

    Arnould, M.; Thielemann, F.K.

    1982-11-01

    The average E1 radiation width can be calculated in terms of the energy Esub(G) and width GAMMAsub(G) of the Giant Dipole Resonance (GDR). While various models can predict Esub(G) quite reliably, the theoretical situation regarding ..lambda..sub(G) is much less satisfactory. We propose a simple phenomenological model which is able to provide GAMMAsub(G) values in good agreement with experimental data for spherical or deformed intermediate and heavy nuclei. In particular, this model can account for shell effects in GAMMAsub(G), and can be used in conjunction with the droplet model. The GAMMAsub(G) values derived in such a way are used to compute average E1 radiation widths which are quite close to the experimental values. The method proposed for the calculation of GAMMAsub(G) also appears to be well suited when the GDR characteristics of extended sets of nuclei are required, as is namely the case in nuclear astrophysics.

  15. Evaluation of resonance parameters of U-233

    International Nuclear Information System (INIS)

    Compilation of nuclear data is in progress in Japan, and the second edition of Japanese Evaluated Nuclear Data Library (JENDL-2) will be published. The evaluation of the resonance parameters of U-233, which will be included in JENDL-2, has been made. The measured values of the resonance parameters after the publication of BNL-325 (second edition) were collected, and searched by using CINDA-78. The data by Blons, Kolar, Ryabov, and Bergen were used for the present evaluation. Complete set of the data was made for each measurement. Fission and capture areas integrated over energy intervals were obtained. The total, fission and capture cross-sections of U-233 were calculated from the various sets of complete resonance parameters, and shown in figures. The calculated values of total, fission and capture cross-sections based on the parameters by Blons were compared with the measured values. Correction of the resonance parameters with poor reproducibility was able to be made with the NDES system by Nakagawa. The final parameters which will be included in JENDL are shown in tables. (Kato, T.)

  16. Resolved resonance parameters for 236Np

    International Nuclear Information System (INIS)

    Multilevel Breit-Wigner parameters were obtained for fission cross-section representation in the 0.01-33 eV energy region from evaluation of a 236Np experimental fission cross-section in the resolved resonance region. (author)

  17. Measurement of the average lifetime of the beauty hadrons on the Z resonance

    International Nuclear Information System (INIS)

    From a fit to the impact parameter distribution of inclusive electron and muons from semileptonic b decay, the average lifetime of beauty hadrons produced in e+ e- collisions on the Z resonance was measured to be: TB=1.543+-0.016(est)+-0.024(sis)ps Combining this measurement with the earlier semileptonic braching ratio B gamma(B→y ν Χ) the Cabbibo-Kowayashi-Maskawa matrix element vertical barVcbvertical bar is determined to be: vertical barVcbvertical bar=(38.8+-0.8 (exp)+- ''3.02.6 (teor))x10-3

  18. Rho resonance parameters from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Dehua; Alexandru, Andrei; Molina, Raquel; Döring, Michael

    2016-08-01

    We perform a high-precision calculation of the phase shifts for $\\pi$-$\\pi$ scattering in the I = 1, J = 1 channel in the elastic region using elongated lattices with two mass-degenerate quark favors ($N_f = 2$). We extract the $\\rho$ resonance parameters using a Breit-Wigner fit at two different quark masses, corresponding to $m_{\\pi} = 226$MeV and $m_{\\pi} = 315$MeV, and perform an extrapolation to the physical point. The extrapolation is based on a unitarized chiral perturbation theory model that describes well the phase-shifts around the resonance for both quark masses. We find that the extrapolated value, $m_{\\rho} = 720(1)(15)$MeV, is significantly lower that the physical rho mass and we argue that this shift could be due to the absence of the strange quark in our calculation.

  19. Rho resonance parameters from lattice QCD

    Science.gov (United States)

    Guo, Dehua; Alexandru, Andrei; Molina, Raquel; Döring, Michael

    2016-08-01

    We perform a high-precision calculation of the phase shifts for π -π scattering in the I =1 , J =1 channel in the elastic region using elongated lattices with two mass-degenerate quark flavors (Nf=2 ). We extract the ρ resonance parameters using a Breit-Wigner fit at two different quark masses, corresponding to mπ=226 MeV and mπ=315 MeV , and perform an extrapolation to the physical point. The extrapolation is based on a unitarized chiral perturbation theory model that describes well the phase shifts around the resonance for both quark masses. We find that the extrapolated value, mρ=720 (1 )(15 ) MeV , is significantly lower that the physical rho mass and we argue that this shift could be due to the absence of the strange quark in our calculation.

  20. Partial Averaging and Resonance Trapping in a Restricted Three-Body System

    OpenAIRE

    Haghighipour, Nader

    2001-01-01

    Based on the value of the orbital eccentricity of a particle and also its proximity to the exact resonant orbit in a three-body system, the Pendulum Approximation (Dermott & Murray 1983) or the Second Fundamental Model of Resonance (Andoyer 1903; Henrard & Lemaitre 1983) are commonly used to study the motion of that particle near its resonance state. In this paper, we present the method of partial averaging as an analytical approach to study the dynamical evolution of a body near a resonance....

  1. Different approach to calculating average angular distributions of elastically scattered neutrons in the resonance region

    International Nuclear Information System (INIS)

    A relatively simple formalism for calculating the average neutron elastic angular distribution dσel/dΩ in the resonance region below several hundred keV is presented. The expression for dσel/dΩ depends mainly on the R-matrix parameters S0, R', S1, and R1∞. Comparisons between calculated and experimental angular distributions are presented for 103Rh, 139La, 232Th, and 238U. A fit to 238U data at 75 keV led to a value of the p-wave strength function of S1=1.81±0.35x10-4. Except for measuring a complete set of individual l=1 resonances, determining the p-wave strength function by fitting low-energy angular distributions is probably more reliable than, or competitive with, other techniques which are available. An analysis of elastic angular distributions as a function of neutron energy is also well suited to a search for intermediate structure in the s- or p-wave strength function. copyright 1997 The American Physical Society

  2. Quantum averaging and resonances: two-level atom in a one-mode classical laser field

    Directory of Open Access Journals (Sweden)

    M. Amniat-Talab

    2007-06-01

    Full Text Available   We use a nonperturbative method based on quantum averaging and an adapted from of resonant transformations to treat the resonances of the Hamiltonian of a two-level atom interacting with a one-mode classical field in Floquet formalism. We illustrate this method by extraction of effective Hamiltonians of the system in two regimes of weak and strong coupling. The results obtained in the strong-coupling regime, are valid in the whole range of the coupling constant for the one-photon zero-field resonance.

  3. Nuclear data adjustment methodology utilizing resonance parameter sensitivities and uncertainties

    International Nuclear Information System (INIS)

    This work presents the development and demonstration of a Nuclear Data Adjustment Method that allows inclusion of both energy and spatial self-shielding into the adjustment procedure. The resulting adjustments are for the basic parameters (i.e., resonance parameters) in the resonance regions and for the group cross sections elsewhere. The majority of this development effort concerns the production of resonance parameter sensitivity information which allows the linkage between the responses of interest and the basic parameters. The resonance parameter sensitivity methodology developed herein usually provides accurate results when compared to direct recalculations using existing and well-known cross section processing codes. However, it has been shown in several cases that self-shielded cross sections can be very non-linear functions of the basic parameters. For this reason caution must be used in any study which assumes that a linear relationship exists between a given self-shielded group cross section and its corresponding basic data parameters

  4. Partial Averaging and Resonance Trapping in a Restricted Three-Body System

    CERN Document Server

    Haghighipour, N

    2002-01-01

    Based on the value of the orbital eccentricity of a particle and also its proximity to the exact resonant orbit in a three-body system, the Pendulum Approximation (Dermott & Murray 1983) or the Second Fundamental Model of Resonance (Andoyer 1903; Henrard & Lemaitre 1983) are commonly used to study the motion of that particle near its resonance state. In this paper, we present the method of partial averaging as an analytical approach to study the dynamical evolution of a body near a resonance. To focus attention on the capabilities of this technique, a restricted, circular and planar three-body system is considered and the dynamics of its outer planet while captured in a resonance with the inner body is studied. It is shown that the first-order partially averaged system resembles a mathematical pendulum whose librational motion can be viewed as a geometrical interpretation of the resonance capture phenomenon. The driving force of this pendulum corresponds to the gravitational attraction of the inner bo...

  5. Time-Averaged Behaviour at the Critical Parameter Point of Transition to Spatiotemporal Chaos

    Institute of Scientific and Technical Information of China (English)

    贺凯芬

    2001-01-01

    A time-averaged behaviour is found to be important for investigating the critical behaviour in parameter space for the transition from temporal chaos to spatiotemporal chaos by using an energy representation. Considering any wave solution as a superposition of the steady wave with its perturbation wave, we find that when approaching the critical parameter point the averaged positive interaction energy for the k = 1 mode becomes competitive with the negative one, with the summation displaying a scaling behaviour of power law.

  6. Hafnium Resonance Parameter Analysis Using Neutron Capture and Transmission Experiments

    International Nuclear Information System (INIS)

    The focus of this work is to determine the resonance parameters for stable hafnium isotopes in the 0.005 - 200 eV region, with special emphasis on the overlapping 176Hf and 178Hf resonances near 8 eV. Accurate hafnium cross sections and resonance parameters are needed in order to quantify the effects of hafnium found in zirconium, a metal commonly used in reactors. The accuracy of the cross sections and the corresponding resonance parameters used in current nuclear analysis tools are rapidly becoming the limiting factor in reducing the overall uncertainty on reactor physics calculations. Experiments measuring neutron capture and transmission are routinely performed at the Rensselaer Polytechnic Institute (RPI) LINAC using the time-of flight technique. 6Li glass scintillation detectors were used for transmission experiments at flight path lengths of 15 and 25 m, respectively. Capture experiments were performed using a sixteen section NaI multiplicity detector at a flight path length of 25 m. These experiments utilized several thicknesses of metallic and isotope-enriched liquid Hf samples. The liquid Hf samples were designed to provide information on the 176Hf and 178Hf contributions to the 8 eV doublet without saturation. Data analyses were performed using the R-matrix Bayesian code SAMMY. A combined capture and transmission data analysis yielded resonance parameters for all hafnium isotopes from 0.005 - 200 eV. Additionally, resonance integrals were calculated, along with errors for each hafnium isotope, using the NJOY and INTER codes. The isotopic resonance integrals calculated were significantly different than previous values. The 176Hf resonance integral, based on this work, is approximately 73% higher than the ENDF/B-VI value. This is due primarily to the changes to resonance parameters in the 8 eV resonance, the neutron width presented in this work is more than twice that of the previous value. The calculated elemental hafnium resonance integral however

  7. Average H2 performance and maximal parameter pertubation radius for uncertain systems

    DEFF Research Database (Denmark)

    Zhao, K.-Y.; Grimble, M.J.; Stoustrup, Jakob

    1999-01-01

    In this paper methods are prsented for calculating the maximal parameter pertubation bounds under H2 performance constraints for a family of uncertain systems and for calculating the average H2 performance under such parameter variations. The uncertain systems are described by state space models...

  8. Single-level resonance parameters fit nuclear cross-sections

    Science.gov (United States)

    Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

    1970-01-01

    Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

  9. Vibrational resonance: a study with high-order word-series averaging

    CERN Document Server

    Murua, Ander

    2016-01-01

    We study a model problem describing vibrational resonance by means of a high-order averaging technique based on so-called word series. With the tech- nique applied here, the tasks of constructing the averaged system and the associ- ated change of variables are divided into two parts. It is first necessary to build recursively a set of so-called word basis functions and, after that, all the required manipulations involve only scalar coefficients that are computed by means of sim- ple recursions. As distinct from the situation with other approaches, with word- series, high-order averaged systems may be derived without having to compute the associated change of variables. In the system considered here, the construction of high-order averaged systems makes it possible to obtain very precise approxima- tions to the true dynamics.

  10. Averaged Solvent Embedding Potential Parameters for Multiscale Modeling of Molecular Properties.

    Science.gov (United States)

    Beerepoot, Maarten T P; Steindal, Arnfinn Hykkerud; List, Nanna Holmgaard; Kongsted, Jacob; Olsen, Jógvan Magnus Haugaard

    2016-04-12

    We derive and validate averaged solvent parameters for embedding potentials to be used in polarizable embedding quantum mechanics/molecular mechanics (QM/MM) molecular property calculations of solutes in organic solvents. The parameters are solvent-specific atom-centered partial charges and isotropic polarizabilities averaged over a large number of geometries of solvent molecules. The use of averaged parameters reduces the computational cost to obtain the embedding potential, which can otherwise be a rate-limiting step in calculations involving large environments. The parameters are evaluated by analyzing the quality of the resulting molecular electrostatic potentials with respect to full QM potentials. We show that a combination of geometry-specific parameters for solvent molecules close to the QM region and averaged parameters for solvent molecules further away allows for efficient polarizable embedding multiscale modeling without compromising the accuracy. The results are promising for the development of general embedding parameters for biomolecules, where the reduction in computational cost can be considerable. PMID:26938368

  11. Parameter-induced stochastic resonance with a periodic signal

    Institute of Scientific and Technical Information of China (English)

    Li Jian-Long; Xu Bo-Hou

    2006-01-01

    In this paper conventional stochastic resonance (CSR) is realized by adding the noise intensity. This demonstrates that tuning the system parameters with fixed noise can make the noise play a constructive role and realize parameterinduced stochastic resonance (PSR). PSR can be interpreted as changing the intrinsic characteristic of the dynamical system to yield the cooperative effect between the stochastic-subjected nonlinear system and the external periodic force. This can be realized at any noise intensity, which greatly differs from CSR that is realized under the condition of the initial noise intensity not greater than the resonance level. Moreover, it is proved that PSR is different from the optimization of system parameters.

  12. Averaged Solvent Embedding Potential Parameters for Multiscale Modeling of Molecular Properties

    DEFF Research Database (Denmark)

    Beerepoot, Maarten; Steindal, Arnfinn Hykkerud; List, Nanna Holmgaard;

    2016-01-01

    We derive and validate averaged solvent parameters for embedding potentials to be used in polarizable embedding quantum mechanics/molecular mechanics (QM/MM) molecular property calculations of solutes in organic solvents. The parameters are solvent-specific atom-centered partial charges...... by analyzing the quality of the resulting molecular electrostatic potentials with respect to full QM potentials. We show that a combination of geometry-specific parameters for solvent molecules close to the QM region and averaged parameters for solvent molecules further away allows for efficient polarizable...... embedding multiscale modeling without compromising the accuracy. The results are promising for the development of general embedding parameters for biomolecules, where the reduction in computational cost can be considerable....

  13. Recommended formulae and formats for a resonance parameter library

    International Nuclear Information System (INIS)

    It is proposed that a library of neutron resonance parameters be set up, on punched cards and magnetic tape, which will complement the cross section data in the present U.K. Nuclear Data Library. This report gives parametric formulae for the resolved resonance region, based on:- (i) the Breit-Wigner approximation, (ii) other approximations of R-matrix theory and (iii) the formulae of Adler and Adler. In addition, the statistical distributions of the parameters are given. The final section of the report contains the recommended formats for the parameters of the various formulae. (author)

  14. Sieve bootstrap t-tests on long-run average parameters

    OpenAIRE

    Fuertes, A.

    2008-01-01

    Panel estimators can provide consistent measures of a long-run average parameter even if the individual regressions are spurious. However, the t-test on this parameter is fraught with problems because the limit distribution of the test statistic is non-standard and rather complicated, particularly in panels with mixed (non-)stationary errors. A sieve bootstrap framework is suggested to approximate the distribution of the t-statistic. An extensive Monte Carlo study demonstrates that the bootst...

  15. Averaged resonant equations for non-gravitational effects without a spherical symmetry and their application for an interstellar gas flow

    CERN Document Server

    Pastor, P

    2013-01-01

    Within the framework of the circular restricted three body problem we investigate the motion of a dust particle captured into a mean motion resonance with a planet under the action of non-gravitational effects. From equations of motion in a near-canonical form averaged resonant equations are derived. The averaged resonant equations describe secular variations of the particle orbit in the mean motion resonance. The secular variations of the particle orbit caused by the non-gravitational effects can depend on the orientation of the orbit in space. The averaged resonant equations are derived with this dependence taken into account. We also present an alternative way how the averaged resonant equations can be derived. We applied derived theory for the case when non-gravitational effects are the Poynting-Robertson effect, radial stellar wind and interstellar wind. Obtained analytical and numerical results are in excellent agreement in the Solar system. We found that types of orbits correspond to libration centers ...

  16. Controlled degradation stochastic resonance in adaptive averaging cell-based architectures

    OpenAIRE

    Aymerich Capdevila, Nivard; Cotofana, Sorin; Rubio Sola, Jose Antonio

    2013-01-01

    In this paper, we first analyze the degradation stochastic resonance (DSR) effect in the context of adaptive averaging (AD-AVG) architectures. The AD-AVG is the adaptive version of the well-known AVG architecture . It is an optimized fault-tolerant design for future technologies with very high rates of failures and defects. With system degradation the AD-AVG reliability is diminishing, as expected, but at a certain moment in time it increases due to the DSR occurrence, which is counterintuiti...

  17. Effects of time-averaging climate parameters on predicted multicompartmental fate of pesticides and POPs.

    Science.gov (United States)

    Lammel, Gerhard

    2004-01-01

    With the aim to investigate the justification of time-averaging of climate parameters in multicompartment modelling the effects of various climate parameters and different modes of entry on the predicted substances' total environmental burdens and the compartmental fractions were studied. A simple, non-steady state zero-dimensional (box) mass-balance model of intercompartmental mass exchange which comprises four compartments was used for this purpose. Each two runs were performed, one temporally unresolved (time-averaged conditions) and a time-resolved (hourly or higher) control run. In many cases significant discrepancies are predicted, depending on the substance and on the parameter. We find discrepancies exceeding 10% relative to the control run and up to an order of magnitude for prediction of the total environmental burden from neglecting seasonalities of the soil and ocean temperatures and the hydroxyl radical concentration in the atmosphere and diurnalities of atmospheric mixing depth and the hydroxyl radical concentration in the atmosphere. Under some conditions it was indicated that substance sensitivity could be explained by the magnitude of the sink terms in the compartment(s) with parameters varying. In general, however, any key for understanding substance sensitivity seems not be linked in an easy manner to the properties of the substance, to the fractions of its burden or to the sink terms in either of the compartments with parameters varying. Averaging of diurnal variability was found to cause errors of total environmental residence time of different sign for different substances. The effects of time-averaging of several parameters are in general not additive but synergistic as well as compensatory effects occur. An implication of these findings is that the ranking of substances according to persistence is sensitive to time resolution on the scale of hours to months. As a conclusion it is recommended to use high temporal resolution in multi

  18. Determination of averaging period parameter and its effects analysis for eddy covariance measurements

    Institute of Scientific and Technical Information of China (English)

    SUN; Xiaomin; ZHU; Zhilin; XU; Jinping; YUAN; Guofu

    2005-01-01

    It is more and more popular to estimate the exchange of water vapor, heat and CO2fluxes between the land surface and the atmosphere using the eddy covariance technique. To get believable fluxes, it is necessary to correct the observations based on the different surface conditions and to determine relevant techinical parameters. The raw 10 Hz eddy covariance data observed in the Yucheng and Changbai Mountains stations were recalculated by various averaging periods (from 1 to 720 min) respectively, and the recalculated results were compared with the results calculated by the averaging period of 30 mins. Meanwhile, the distinctions of fluxes calculated by different averaging periods were analyzed. The continuous 15 days observations over wheat fields in the Yucheng station were mainly analyzed. The results are shown that: (i) In the Yucheng station, compared with the observations by 30 min, when the averaging period changes from 10 to 60 min, the variations of the eddy-covariance estimates of fluxes were less than 2%; when the averaging period changes less than 10 min, the estimate of fluxes reduced obviously with the reduction of the averaging period (the max relative error was -12%); and when the averaging period exceeds 120 min, the eddy covariance estimates of fluxes will be increased and become unsteady (the max relative error is over 10%); (ii) the eddy covariance estimates of fluxes over wheat field in the Yucheng station suggusted that it is much better to take 10 min as an averaging period in studying diurnal change of fluxes, and take 30min for a long-term flux observation; and (iii) normalized ratio was put forward to determine the range of averaging period of eddy covariance measurements. By comparing the observations over farmlands and those over forests, it is indicated that the increase of eddy covariance estimates over tall forest was more than that over short vegetation when the averaging period increased.

  19. Measuring the Dielectric Parameters of Frozen Sand in Microwave Resonators

    Science.gov (United States)

    Bordonsky, G. S.; Orlov, A. O.; Filippova, T. G.

    2004-04-01

    We measure the dielectric parameters of frozen sand by using a rectangular cavity resonator at frequencies 5.3-8.4 GHz. The transmission spectrum of the resonator completely filled with frozen sand shows supplementary resonances absent in the case where the resonator is filled with dry homogeneous sand. The difference of the resonance curves was observed for the cases of wetting the sand by ordinary (H2O) and heavy (D2O) water. It is supposed that the observed effects are related to percolation due to the existence and specific properties of the conducting liquid films of water on the surfaces of mineral particles. To verify this assumption, we performed measurements for the special medium consisting of a mixture of dry sand and small metal particles. This experiment showed that supplementary resonant peaks in the transmission spectrum of the resonator arise for a certain concentration of metal particles. The same effect is also observed in the case of incomplete filling of the resonator with dry sand. These anomalies can be explained by the appearance of negative dispersion of waves in the waveguide.

  20. Single-parameter adiabatic charge pumping in carbon nanotube resonators

    OpenAIRE

    Perroni, C. A.; Nocera, A.; Cataudella, V.

    2013-01-01

    Single-parameter adiabatic charge pumping, induced by a nearby radio-frequency antenna, is achieved in suspended carbon nanotubes close to the mechanical resonance. The charge pumping is due to an important dynamic adjustment of the oscillating motion to the antenna signal and it is different from the mechanism active in the two-parameter pumping. Finally, the second harmonic oscillator response shows an interesting relationship with the first harmonic that should be experimentally observed.

  1. Studying the $\\rho$ resonance parameters with staggered fermions

    CERN Document Server

    Fu, Ziwen

    2016-01-01

    We deliver a lattice study of $\\rho$ resonance parameters with p-wave $\\pi\\pi$ scattering phases, which are extracted by finite-size methods at one center-of-mass frame and four moving frames for six MILC lattice ensembles with pion masses ranging from $346$ to $ 176$ MeV. The effective range formula is applied to describe the scattering phases as a function of the energy covering the resonance region, this allows us to extract $\\rho$ resonance parameters and to investigate the quark-mass dependence. Lattice studies with three flavors of the Asqtad-improved staggered fermions enable us to use the moving-wall source technique on large lattice spatial dimensions ($L=64$) and small light $u/d$ quarks. Numerical computations are carried out at two lattice spacings, $a \\approx 0.12$ and $0.09$ fm.

  2. Measurement of the Z Resonance Parameters at LEP

    CERN Document Server

    Barate, R; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Merle, E; Minard, M N; Pietrzyk, B; Alemany, R; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Fernández, E; Fernández-Bosman, M; Garrido, L; Graugès-Pous, E; Juste, A; Martínez, M; Merino, G; Miquel, R; Mir, L M; Orteu, S; Pacheco, A; Park, I C; Perlas, J A; Riu, I; Sánchez, F; Colaleo, A; Creanza, D; De Palma, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Bazarko, A; Becker, U; Boix, G; Bird, F; Blucher, E; Bonvicini, G; Bright-Thomas, P G; Cattaneo, M; Cerutti, F; Ciulli, V; Dissertori, G; Drevermann, H; Forty, Roger W; Frank, M; Greening, T C; Hagelberg, R; Halley, A W; Hansen, J B; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Knobloch, J; Lazeyras, Pierre; Lehraus, Ivan; Maley, P; Mato, P; May, J; Moutoussi, A; Ranjard, F; Rolandi, Luigi; Schlatter, W D; Schmitt, M; Schneider, O; Spagnolo, P; Tejessy, W; Teubert, F; Tomalin, I R; Tournefier, E; Veenhof, R; Wiedenmann, W; Wright, A E; Ajaltouni, Ziad J; Badaud, F; Chazelle, G; Deschamps, O; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Bertelsen, H; Fernley, T; Hansen, F; Hansen, J D; Hansen, J R; Hansen, P H; Lindahl, A; Møllerud, R; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Blondel, A; Bonneaud, G R; Brient, J C; Rougé, A; Rumpf, M; Swynghedauw, M; Tanaka, R; Verderi, M; Videau, H L; Focardi, E; Parrini, G; Zachariadou, K; Cavanaugh, R J; Corden, M; Georgiopoulos, C H; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Picchi, P; Colrain, P; ten Have, I; Hughes, I S; Knowles, I G; Lynch, J G; Morton, W T; Raine, C; Reeves, P; O'Shea, V; Scarr, J M; Smith, K; Thompson, A S; Turnbull, R M; Buchmüller, O L; Dhamotharan, S; Geweniger, C; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Marinelli, N; Nash, J; Sciabà, A; Sedgbeer, J K; Thomson, E; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bowdery, C K; Buck, P G; Finch, A J; Foster, F; Hughes, G; Jones, R W L; Keemer, N R; Robertson, N A; Sloan, Terence; Snow, S W; Williams, M I; Bauerdick, L A T; Van Gemmeren, P; Giehl, I; Jakobs, K; Kasemann, M; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Schmelling, M; Wachsmuth, H W; Wanke, R; Zeitnitz, C; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Carr, J; Coyle, P; Etienne, F; Motsch, F; Payre, P; Rousseau, D; Talby, M; Thulasidas, M; Aleppo, M; Antonelli, M; Ragusa, F; Büscher, V; Dietl, H; Ganis, G; Hüttmann, K; Lütjens, G; Mannert, C; Männer, W; Moser, H G; Schael, S; Settles, Ronald; Seywerd, H C J; Stenzel, H; Wolf, G; Azzurri, P; Boucrot, J; Callot, O; Chen, S; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacholkowska, A; Le Diberder, F R; Lefrançois, J; Lutz, A M; Schune, M H; Veillet, J J; Videau, I; Zerwas, D; Bagliesi, G; Bettarini, S; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Fantechi, R; Ferrante, I; Fidecaro, F; Foà, L; Giassi, A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Rizzo, G; Sanguinetti, G; Sguazzoni, G; Steinberger, Jack; Tenchini, Roberto; Vannini, C; Venturi, A; Verdini, P G; Blair, G A; Cowan, G D; Green, M G; Medcalf, T; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Edwards, M; Haywood, S J; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Vallage, B; Black, S N; Dann, J H; Kim, H Y; Konstantinidis, N P; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S L; Combley, F; Lehto, M H; Thompson, L F; Affholderbach, K; Barberio, E; Böhrer, A; Brandt, S; Burkhardt, H; Feigl, E; Grupen, Claus; Hess, J; Lutters, G; Meinhard, H; Minguet-Rodríguez, J A; Mirabito, L; Misiejuk, A; Neugebauer, E; Prange, G; Rivera, F; Saraiva, P; Schäfer, U; Sieler, U; Smolik, L; Stephan, F; Trier, H; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Pitis, L; Kim, H; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Cinabro, D; Conway, J S; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y; González, S; Grahl, J; Harton, J L; Hayes, O J; Hu, H; Jin, S

    2000-01-01

    The properties of the Z resonance are measured from the analysis of 4.5 million Z decays into fermion pairs collected with the \\Aleph\\ detector at L EP. The data are consistent with lepton universality. The resonance parameters are measured to be $\\MZ=(91.1885 \\pm 0.0031)~\\Gevcc$, $\\GZ= (2.4951 \\pm 0.0043)~\\GeV$, $\\spol=(41.559 \\pm 0.058)$~nb and, combining the three lepton flavours $\\Rl= 20.725\\pm 0.039$. The corresponding number of light neutrino species is $N_{\

  3. Hafnium Resonance Parameter Analysis Using Neutron Capture and Transmission Experiments

    International Nuclear Information System (INIS)

    The focus of this work is to determine resonance parameters for stable hafnium isotopes in the 0.005-200 eV region, with special emphasis on the overlapping 176Hf and 178Hf resonances near 8 eV. The large neutron cross section of hafnium, combined with its corrosion resistance and excellent mechanical properties, make it a useful material for controlling nuclear reactions. Experiments measuring neutron capture and transmission were performed at the Rensselaer Polytechnic Institute (RPI) electron linear accelerator (LINAC) using the time of flight method. 6Li glass scintillation detectors were used for transmission experiments at flight path lengths of 15 and 25 m. Capture experiments were done using a sixteen section NaI(Tl) multiplicity detector at a flight path length of 25 m. These experiments utilized various thicknesses of metallic and isotopically-enriched liquid samples. The liquid samples were designed to provide information on the 176Hf and 178Hf contributions to the 8 eV doublet without saturation. Data analysis was done using the R-matrix Bayesian code SAMMY version M6 beta. SAMMY is able to account for experimental resolution effects for each of the experimental setups at the RPI LINAC, and also can correct for multiple scattering effects in neutron capture yield data. The combined capture and transmission data analysis yielded resonance parameters for all hafnium isotopes from 0.005-200 eV. Resonance integrals were calculated along with errors for each hafnium isotope using the NJOY [1] and INTER [2] codes. The isotopic resonance integrals calculated were significantly different than previously published values; however the calculated elemental hafnium resonance integral changed very little

  4. Robust nonlinear autoregressive moving average model parameter estimation using stochastic recurrent artificial neural networks

    DEFF Research Database (Denmark)

    Chon, K H; Hoyer, D; Armoundas, A A;

    1999-01-01

    In this study, we introduce a new approach for estimating linear and nonlinear stochastic autoregressive moving average (ARMA) model parameters, given a corrupt signal, using artificial recurrent neural networks. This new approach is a two-step approach in which the parameters of the deterministic...... part of the stochastic ARMA model are first estimated via a three-layer artificial neural network (deterministic estimation step) and then reestimated using the prediction error as one of the inputs to the artificial neural networks in an iterative algorithm (stochastic estimation step). The prediction...... error is obtained by subtracting the corrupt signal of the estimated ARMA model obtained via the deterministic estimation step from the system output response. We present computer simulation examples to show the efficacy of the proposed stochastic recurrent neural network approach in obtaining accurate...

  5. Resonances and anti-resonances in the material parameters of 2-D dielectric ENG, MNG, and DNG materials

    DEFF Research Database (Denmark)

    Wu, Yunqiu; Arslanagic, Samel

    The resonant/anti-resonant behavior of parameters extracted by the S-parameter method for two-dimensional epsilon-, mu- and double-negative (ENG, MNG, DNG) materials is investigated. The unit cells consist of infinite dielectric cylinders supporting electric dipole, magnetic dipole, or both....... It is shown that the extraction procedure yields one resonant material parameter, and one anti-resonant material parameter in MNG and ENG configurations. However, both parameters display an over-all resonant response in DNG configurations where electric and magnetic dipole modes are excited simultaneously....

  6. Describing the catchment-averaged precipitation as a stochastic process improves parameter and input estimation

    Science.gov (United States)

    Del Giudice, Dario; Albert, Carlo; Rieckermann, Jörg; Reichert, Peter

    2016-04-01

    Rainfall input uncertainty is one of the major concerns in hydrological modeling. Unfortunately, during inference, input errors are usually neglected, which can lead to biased parameters and implausible predictions. Rainfall multipliers can reduce this problem but still fail when the observed input (precipitation) has a different temporal pattern from the true one or if the true nonzero input is not detected. In this study, we propose an improved input error model which is able to overcome these challenges and to assess and reduce input uncertainty. We formulate the average precipitation over the watershed as a stochastic input process (SIP) and, together with a model of the hydrosystem, include it in the likelihood function. During statistical inference, we use "noisy" input (rainfall) and output (runoff) data to learn about the "true" rainfall, model parameters, and runoff. We test the methodology with the rainfall-discharge dynamics of a small urban catchment. To assess its advantages, we compare SIP with simpler methods of describing uncertainty within statistical inference: (i) standard least squares (LS), (ii) bias description (BD), and (iii) rainfall multipliers (RM). We also compare two scenarios: accurate versus inaccurate forcing data. Results show that when inferring the input with SIP and using inaccurate forcing data, the whole-catchment precipitation can still be realistically estimated and thus physical parameters can be "protected" from the corrupting impact of input errors. While correcting the output rather than the input, BD inferred similarly unbiased parameters. This is not the case with LS and RM. During validation, SIP also delivers realistic uncertainty intervals for both rainfall and runoff. Thus, the technique presented is a significant step toward better quantifying input uncertainty in hydrological inference. As a next step, SIP will have to be combined with a technique addressing model structure uncertainty.

  7. The total cross section and the fission cross section of 241Am in the resonance region. Resonance parameters

    International Nuclear Information System (INIS)

    The 241Am total and fission cross sections have been measured in the resonance region, using the 60MeV Saclay linac as a pulsed neutron source. The resonance parameters obtained by a single level shape analysis of the transmission data are given for 189 levels up to 150eV neutron energy. The mean level spacing, corrected for 18% of missed resonances in the 0 to 50eV energy range, is (0.55+-0.05)eV. The s-wave neutron strength function value, in the 0 to 150eV energy range, is equal to (0.94+-0.09)10-4. The average radiation width obtained from 43 resonances is (43.77+-0.72)MeV. Only preliminary results of the fission experiment are available now; 38 fission widths are given up to 32eV neutron energy, with the average value GAMMA(f) approximately equal to 0.23MeV; the statistical distribution of these fission widths corresponds to a X2 law with 4 degrees of freedom. An area analysis of the Los Alamos fission data has also been done, from which we obtain 36 GAMMA(f) values in the 20eV to 50eV energy range; the corresponding average value is: GAMMA(f) approximately equal to 0.52MeV; the statistical distribution obeys to a X2 law with 15 degrees of freedom, in desagreement with the Saclay results

  8. A method for the estimation of p-mode parameters from averaged solar oscillation power spectra

    CERN Document Server

    Reiter, J; Kosovichev, A G; Schou, J; Scherrer, P H; Larson, T P

    2015-01-01

    A new fitting methodology is presented which is equally well suited for the estimation of low-, medium-, and high-degree mode parameters from $m$-averaged solar oscillation power spectra of widely differing spectral resolution. This method, which we call the "Windowed, MuLTiple-Peak, averaged spectrum", or WMLTP Method, constructs a theoretical profile by convolving the weighted sum of the profiles of the modes appearing in the fitting box with the power spectrum of the window function of the observing run using weights from a leakage matrix that takes into account both observational and physical effects, such as the distortion of modes by solar latitudinal differential rotation. We demonstrate that the WMLTP Method makes substantial improvements in the inferences of the properties of the solar oscillations in comparison with a previous method that employed a single profile to represent each spectral peak. We also present an inversion for the internal solar structure which is based upon 6,366 modes that we ha...

  9. A Method for the Estimation of p-Mode Parameters from Averaged Solar Oscillation Power Spectra

    Science.gov (United States)

    Reiter, J.; Rhodes, E. J., Jr.; Kosovichev, A. G.; Schou, J.; Scherrer, P. H.; Larson, T. P.

    2015-04-01

    A new fitting methodology is presented that is equally well suited for the estimation of low-, medium-, and high-degree mode parameters from m-averaged solar oscillation power spectra of widely differing spectral resolution. This method, which we call the “Windowed, MuLTiple-Peak, averaged-spectrum” or WMLTP Method, constructs a theoretical profile by convolving the weighted sum of the profiles of the modes appearing in the fitting box with the power spectrum of the window function of the observing run, using weights from a leakage matrix that takes into account observational and physical effects, such as the distortion of modes by solar latitudinal differential rotation. We demonstrate that the WMLTP Method makes substantial improvements in the inferences of the properties of the solar oscillations in comparison with a previous method, which employed a single profile to represent each spectral peak. We also present an inversion for the internal solar structure, which is based upon 6366 modes that we computed using the WMLTP method on the 66 day 2010 Solar and Heliospheric Observatory/MDI Dynamics Run. To improve both the numerical stability and reliability of the inversion, we developed a new procedure for the identification and correction of outliers in a frequency dataset. We present evidence for a pronounced departure of the sound speed in the outer half of the solar convection zone and in the subsurface shear layer from the radial sound speed profile contained in Model S of Christensen-Dalsgaard and his collaborators that existed in the rising phase of Solar Cycle 24 during mid-2010.

  10. Large-scale solar wind streams: Average temporal evolution of parameters

    Science.gov (United States)

    Yermolaev, Yuri; Lodkina, Irina; Yermolaev, Michael; Nikolaeva, Nadezhda

    2016-07-01

    In the report we describe the average temporal profiles of plasma and field parameters in the disturbed large-scale types of solar wind (SW): corotating interaction regions (CIR), interplanetary coronal mass ejections (ICME) (both magnetic cloud (MC) and Ejecta), and Sheath as well as the interplanetary shock (IS) on the basis of OMNI database and our Catalog of large-scale solar wind phenomena during 1976-2000 (see website ftp://ftp.iki.rssi.ru/pub/omni/ and paper [Yermolaev et al., 2009]). To consider influence of both the surrounding undisturbed solar wind, and the interaction of the disturbed types of the solar wind on the parameters, we separately analyze the following sequences of the phenomena: (1) SW/CIR/SW, (2) SW/IS/CIR/SW, (3) SW/Ejecta/SW, (4) SW/Sheath/Ejecta/SW, (5) SW/IS/Sheath/Ejecta/SW, (6) SW/MC/SW, (7) SW/Sheath/MC/SW, and (8) SW/IS/Sheath/MC/SW. To take into account the different durations of SW types, we use the double superposed epoch analysis (DSEA) method: rescaling the duration of the interval for all types in such a manner that, respectively, beginning and end for all intervals of selected type coincide [Yermolaev et al., 2010; 2015]. Obtained data allow us to suggest that (1) the behavior of parameters in Sheath and in CIR is very similar not only qualitatively but also quantitatively, and (2) the speed angle phi in ICME changes from 2 to -2deg. while in CIR and Sheath it changes from -2 to 2 deg., i.e., the streams in CIR/Sheath and ICME deviate in the opposite side. The work was supported by the Russian Foundation for Basic Research, project 16-02-00125 and by Program of Presidium of the Russian Academy of Sciences. References: Yermolaev, Yu. I., N. S. Nikolaeva, I. G. Lodkina, and M. Yu. Yermolaev (2009), Catalog of Large-Scale Solar Wind Phenomena during 1976-2000, Cosmic Research, , Vol. 47, No. 2, pp. 81-94. Yermolaev, Y. I., N. S. Nikolaeva, I. G. Lodkina, and M. Y. Yermolaev (2010), Specific interplanetary conditions for CIR

  11. How can acoustic resonance reduce the average velocity in a falling body?

    OpenAIRE

    V. Torres-Zúñiga

    2011-01-01

    In this article, a simple experiment is described to overcome the misconception that acoustic pressure and levitation effects are difficult to observe in school laboratories. Analysis of the free fall velocity of a toy parachute inside a vertical tube, driven by sound in a range of frequencies around the resonant condition, exhibits the resonance frequency, the node pressure zones, and the optimal conditions to obtain acoustical levitation of a light body.

  12. Quantifying bone weathering stages using the average roughness parameter Ra measured from 3D data

    Science.gov (United States)

    Vietti, Laura A.

    2016-09-01

    Bone surface texture is known to degrade in a predictable fashion due to subaerial exposure, and can thus act as a relative proxy for estimating temporal information from modern and ancient bone assemblages. To date, the majority of bone weathering data is collected on a categorical scale based on descriptive terms. While this qualitative classification of weathering data is well established, textural analyses of bone surfaces may provide means to quantify weathering stages but have yet to be tested. Here, I examined the suitability of textural analyses for bone weathering studies by first establishing bone surface regions most appropriate for weathering analyses. I then measured and compared the roughness texture of weathered bones at different stages. To establish regions of bone most suitable for textural analyses, Ra was measured from 3D scans of dorsal ribs of four adult ungulate taxa. Results indicate that the rib-shafts from unweathered ungulate skeletons were similar and are likely good candidates because differences in surface texture will not be due to differences in initial bone texture. To test if textural measurements could reliably characterize weathering stages, the average roughness values (Ra) were measured from weathered ungulate rib-shafts assigned to four descriptive weathering stages. Results from analyses indicate that the Ra was statistically distinct for each weathering stage and that roughness positively correlates with the degree of weathering. As such, results suggest that textural analyses may provide the means for quantifying bone-weathering stages. Using Ra and other quantifiable texture parameters may enable more reliable and comparative taphonomic analyses by reducing inter-observer variations and by providing numerical data more compatible for multivariate statistics.

  13. Measuring Resonance Parameters of Heavy Higgs Bosons at TESLA

    CERN Document Server

    Meyer, N

    2003-01-01

    This study investigates the potential of the TESLA Linear Collider for measuring resonance parameters of Higgs bosons beyond the mass range studied so far. The analysis is based on the reconstruction of events from the Higgsstrahlung process e+e- -> HZ. It is shown that the total width, the mass and the event rate for Higgs production can be measured from the mass spectrum in a model independent fit. Also, the branching ratios to W- and Z-bosons can be measured, assuming these are the only relevant Higgs decay modes. The simulation includes realistic detector effects and all relevant Standard Model background processes. Results are given for mH=200-320 GeV assuming 500 fb^-1 integrated luminosity at collision energies of 500 GeV.

  14. Comments on extracting the resonance strength parameter from yield data

    Science.gov (United States)

    Croft, Stephen; Favalli, Andrea

    2015-10-01

    The F(α,n) reaction is the focus of on-going research in part because it is an important source of neutrons in the nuclear fuel cycle which can be exploited to assay nuclear materials, especially uranium in the form of UF6 [1,2]. At the present time there remains some considerable uncertainty (of the order of ±20%) in the thick target integrated over angle (α,n) yield from 19F (100% natural abundance) and its compounds as discussed in [3,4]. An important thin target cross-section measurement is that of Wrean and Kavanagh [5] who explore the region from below threshold (2.36 MeV) to approximately 3.1 MeV with fine energy resolution. Integration of their cross-section data over the slowing down history of a stopping α-particle allows the thick target yield to be calculated for incident energies up to 3.1 MeV. This trend can then be combined with data from other sources to obtain a thick target yield curve over the wider range of interest to the fuel cycle (roughly threshold to 10 MeV to include all relevant α-emitters). To estimate the thickness of the CaF2 target they used, Wrean and Kavanagh separately measured the integrated yield of the 6.129 MeV γ-rays from the resonance at 340.5 keV (laboratory α-particle kinetic energy) in the 19F(p,αγ) reaction. To interpret the data they adopted a resonance strength parameter of (22.3±0.8) eV based on a determination by Becker et al [6]. The value and its uncertainty directly affects the thickness estimate and the extracted (α,n) cross-section values. In their citation to Becker et al's work, Wrean and Kavanagh comment that they did not make use of an alternative value of (23.7±1.0) eV reported by Croft [7] because they were unable to reproduce the value from the data given in that paper. The value they calculated for the resonance strength from the thick target yield given by Croft was 21.4 eV. The purpose of this communication is to revisit the paper by Croft published in this journal and specifically to

  15. A quantitative analysis of the diurnal evolution of Ionospheric Alfvén resonator magnetic resonance features and calculation of changing IAR parameters

    Directory of Open Access Journals (Sweden)

    S. R. Hebden

    2005-07-01

    Full Text Available Resonance features of the Ionospheric Alfvén Resonator (IAR can be observed in pulsation magnetometer data from Sodankylä, Finland using dynamic spectra visualizations. IAR resonance features were identified on 13 of 30 days in October 1998, with resonance structures lasting for 3 or more hours over 10 intervals. The diurnal evolution of the harmonic features was quantified for these 10 intervals using a manual cursor-clicking technique. The resonance features displayed strong linear relationships between harmonic frequency and harmonic number for all of the time intervals studied, enabling a homogeneous cavity model for the IAR to be adopted to interpret the data. This enabled the diurnal variation of the effective size of the IAR to be obtained for each of the 10 time intervals. The average effective size was found to be 530 km, and to have an average variation of 32% over each time interval: small compared to the average variation in Alfvén velocity of 61%. Thus the diurnal variation of the harmonics is chiefly caused by the changing plasma density within the IAR due to changing insolation. This study confirms Odzimek (2004 that the dominating factor affecting the IAR eigenfrequencies is the variation in the Alfvén velocity at the F-layer ion-density peak, with the changing IAR size affecting the IAR eigenfrequencies to a smaller extent. Another IAR parameter was derived from the analysis of the IAR resonance features associated with the phase matching structure of the standing waves in the IAR. This parameter varied over the time intervals studied by 20% on average, possibly due to changing ionospheric conductivity.

    Keywords. Ionosphere (Auroral ionosphere;Wave propagation – Radio science (Electromagnetic noise and interference

  16. R-MATRIX RESONANCE ANALYSIS AND STATISTICAL PROPERTIES OF THE RESONANCE PARAMETERS OF 233U IN THE NEUTRON ENERGY RANGE FROM THERMAL TO 600 eV

    Energy Technology Data Exchange (ETDEWEB)

    Leal, L.C.

    2001-02-27

    The R-matrix resonance analysis of experimental neutron transmission and cross sections of {sup 233}U, with the Reich-Moore Bayesian code SAMMY, was extended up to the neutron energy of 600 eV by taking advantage of new high resolution neutron transmission and fission cross section measurements performed at the Oak Ridge Electron Linear Accelerator (ORELA). The experimental data base is described. In addition to the microscopic data (time-of-flight measurements of transmission and cross sections), some experimental and evaluated integral quantities were included in the data base. Tabulated and graphical comparisons between the experimental data and the SAMMY calculated cross sections are given. The ability of the calculated cross sections to reproduce the effective multiplication factors k{sub eff} for various thermal, intermediate, and fast systems was tested. The statistical properties of the resonance parameters were examined and recommended values of the average s-wave resonance parameters are given.

  17. Variations in environmental tritium doses due to meteorological data averaging and uncertainties in pathway model parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kock, A.

    1996-05-01

    The objectives of this research are: (1) to calculate and compare off site doses from atmospheric tritium releases at the Savannah River Site using monthly versus 5 year meteorological data and annual source terms, including additional seasonal and site specific parameters not included in present annual assessments; and (2) to calculate the range of the above dose estimates based on distributions in model parameters given by uncertainty estimates found in the literature. Consideration will be given to the sensitivity of parameters given in former studies.

  18. Variations in environmental tritium doses due to meteorological data averaging and uncertainties in pathway model parameters

    International Nuclear Information System (INIS)

    The objectives of this research are: (1) to calculate and compare off site doses from atmospheric tritium releases at the Savannah River Site using monthly versus 5 year meteorological data and annual source terms, including additional seasonal and site specific parameters not included in present annual assessments; and (2) to calculate the range of the above dose estimates based on distributions in model parameters given by uncertainty estimates found in the literature. Consideration will be given to the sensitivity of parameters given in former studies

  19. The Singer's Formant and Speaker's Ring Resonance: A Long-Term Average Spectrum Analysis

    OpenAIRE

    Lee, Sang-Hyuk; Kwon, Hee-Jun; Choi, Hyun-Jin; Lee, Nam-Hun; Lee, Sung-Jin; Jin, Sung-Min

    2008-01-01

    Objectives We previously showed that a trained tenor's voice has the conventional singer's formant at the region of 3 kHz and another energy peak at 8-9 kHz. Singers in other operatic voice ranges are assumed to have the same peak in their singing and speaking voice. However, to date, no specific measurement of this has been made. Methods Tenors, baritones, sopranos and mezzo sopranos were chosen to participate in this study of the singer's formant and the speaker's ring resonance. Untrained ...

  20. Compact and accurate linear and nonlinear autoregressive moving average model parameter estimation using laguerre functions

    DEFF Research Database (Denmark)

    Chon, K H; Cohen, R J; Holstein-Rathlou, N H

    1997-01-01

    A linear and nonlinear autoregressive moving average (ARMA) identification algorithm is developed for modeling time series data. The algorithm uses Laguerre expansion of kernals (LEK) to estimate Volterra-Wiener kernals. However, instead of estimating linear and nonlinear system dynamics via movi...

  1. Neutron resonance parameters of dysprosium isotopes using neutron capture yields

    Energy Technology Data Exchange (ETDEWEB)

    Shin, S. G.; Kye, Y. U.; Cho, M. H. [POSTECH, Pohang (Korea, Republic of); Namkung, W. [Pohang Accelerator Laboratory, Pohang (Korea, Republic of); Kim, G. N. [Kyungpook National University, Daegu (Korea, Republic of); Lee, M. W.; Kang, Y. R. [Dongnam Inst. Of Radiological and Medical Science, Busan (Korea, Republic of)

    2015-10-15

    Dysprosium is used in the field of nuclear reactor system because it has a very large thermal neutron absorption cross-section. The dysprosium alloyed with special stainless steels is attractive for control in nuclear reactor because of the ability to absorb neutrons readily without swelling or contracting over time and its high melting point. Dysprosium is also one of fission products from the thermal fission of {sup 234}U, {sup 233}U, and {sup 239}Pu. The fission products are accumulated in the reactor core by the burn-up of the nuclear fuel and the poison effect is increased. Therefore, it is required to understand how Dysprosium as both a poison and an absorbing material in the control rod has an effect on the neutron population in a nuclear reactor system over all energy regions. Neutron Capture experiments on Dy isotopes were performed at the electron linear accelerator (LINAC) facility of the Rensselear Polytechnic Institute (RPI) in the neutron energy region from 10 eV to 1 keV. Resonance parameters were extracted by fitting the neutron capture data using the SAMMY multilevel R-matrix Bayesian code.

  2. Set up of a method for the adjustment of resonance parameters on integral experiments

    International Nuclear Information System (INIS)

    Resonance parameters for actinides play a significant role in the neutronic characteristics of all reactor types. All the major integral parameters strongly depend on the nuclear data of the isotopes in the resonance-energy regions.The author sets up a method for the adjustment of resonance parameters taking into account the self-shielding effects and restricting the cross section deconvolution problem to a limited energy region. (N.T.)

  3. Giant dipole resonance in 88Mo from phonon damping model strength functions averaged over temperature and angular momentum distributions

    Science.gov (United States)

    Dinh Dang, N.; Ciemala, M.; Kmiecik, M.; Maj, A.

    2013-05-01

    The line shapes of giant dipole resonance (GDR) in the decay of the compound nucleus 88Mo, which is formed after the fusion-evaporation reaction 48Ti + 40Ca at various excitation energies E* from 58 to 308 MeV, are generated by averaging the GDR strength functions predicted within the phonon damping model (PDM) using the empirical probabilities for temperature and angular momentum. The average strength functions are compared with the PDM strength functions calculated at the mean temperature and mean angular momentum, which are obtained by averaging the values of temperature and angular momentum using the same temperature and angular momentum probability distributions, respectively. It is seen that these two ways of generating the GDR linear line shape yield very similar results. It is also shown that the GDR width approaches a saturation at angular momentum J≥ 50 ℏ at T=4 MeV and at J≥ 70 ℏ at any T.

  4. Giant dipole resonance in $^{88}$Mo from phonon damping model's strength functions averaged over temperature and angular momentum distributions

    CERN Document Server

    Dang, N Dinh; Kmiecik, M; Maj, A

    2013-01-01

    The line shapes of giant dipole resonance (GDR) in the decay of the compound nucleus $^{88}$Mo, which is formed after the fusion-evaporation reaction $^{48}$Ti + $^{40}$Ca at various excitation energies $E^{*}$ from 58 to 308 MeV, are generated by averaging the GDR strength functions predicted within the phonon damping model (PDM) using the empirical probabilities for temperature and angular momentum. The average strength functions are compared with the PDM strength functions calculated at the mean temperature and mean angular momentum, which are obtained by averaging the values of temperature and angular momentum using the same temperature and angular-momentum probability distributions, respectively. It is seen that these two ways of generating the GDR linear line shape yield very similar results. It is also shown that the GDR width approaches a saturation at angular momentum $J\\geq$ 50$\\hbar$ at $T=$ 4 MeV and at $J\\geq$ 70$\\hbar$ at any $T$.

  5. Optimized magnetic resonance sequences and parameters with operative assisted images for radical prostatectomy at 3 tesla-magnetic resonance image

    International Nuclear Information System (INIS)

    The objective of our study was to optimize magnetic resonance image (MRI) sequences and parameters using operative assisted images (three-dimensional images) for radical prostatectomy at 3 tesla (T) MRI. Five healthy volunteers underwent MRI on the 3.0 T scanner. Various sequences and parameters [Cube (echo time/repetition time (TE/TR)=18, 50, 90 ms/2000 ms), fast imaging employing steady state acquisition (FIESTA) (TE/TR/FA=2.4 ms/5 ms/40deg, 90deg), fast spoiled gradient recalled acquisition in the steady state (fSPGR) (TE/TR/FA=2.3 ms/11.2 ms/20deg), slice thickness=1.2 mm, matrix=192 x 160] were respectively compared. Several structures of the pelvis (the central zones and transition zones of the prostate, the peripheral zones of the prostate, seminal vesicles, rectum wall, bladder, muscle and fat) were determined. The signal intensities of these structures were measured on reformatted axial images and compared against several structures of the pelvis. Correlation with various sequences and parameters was based on the signal-to-noise ratio (SNR), the contrast ratio (CR) and the presence of artifacts. Student's t-test was used for statistical analysis. With Cube (TE/TR=50 ms/2000 ms), the average value of visual evaluation with artifacts was high, and SNR and CR were higher than for other sequence and parameters. Optimized MRI sequences and parameters were Cube (TE/TR=50 ms/2000 ms) which provides improved SNR and CR and the presence of artifacts with operative assisted images for radical prostatectomy. These operative assisted images obtained from Cube (TE/TR=50 ms/2000 ms) are likely to be useful for surgery. (author)

  6. The thermal neutron absorption cross-sections, resonance integrals and resonance parameters of silicon and its stable isotopes

    International Nuclear Information System (INIS)

    The data available up to the end of November 1968 on the thermal neutron absorption cross-sections, resonance absorption integrals, and resonance parameters of silicon and its stable isotopes are collected and discussed. Estimates are given of the mean spacing of the energy levels of the compound nuclei near the neutron binding energy. It is concluded that the thermal neutron absorption cross-section and resonance absorption integral of natural silicon are not well established. The data on these two parameters are somewhat correlated, and three different assessments of the resonance integral are presented which differ over-all by a factor of 230. Many resonances have been detected by charged particle reactions which have not yet been observed in neutron cross-section measurements. One of these resonances of Si28, at En = 4 ± 5 keV might account for the large resonance integral which is derived, very uncertainly, from integral data. The principal source of the measured resonance integral of Si30 has not yet been located. The thermal neutron absorption cross-section of Si28 appears to result mainly from a negative energy resonance, possibly the resonance at En = - 59 ± 5 keV detected by the Si28 (d,p) reaction. (author)

  7. Average arterial input function for quantitative dynamic contrast enhanced magnetic resonance imaging of neck nodal metastases

    OpenAIRE

    Shukla-Dave, Amita; Lee, Nancy; Stambuk, Hilda; Wang, YA; Huang, Wei; Howard T Thaler; Patel, Snehal G.; Shah, Jatin P.; Koutcher, Jason A

    2009-01-01

    Background The present study determines the feasibility of generating an average arterial input function (Avg-AIF) from a limited population of patients with neck nodal metastases to be used for pharmacokinetic modeling of dynamic contrast-enhanced MRI (DCE-MRI) data in clinical trials of larger populations. Methods Twenty patients (mean age 50 years [range 27–77 years]) with neck nodal metastases underwent pretreatment DCE-MRI studies with a temporal resolution of 3.75 to 7.5 sec on a 1.5T c...

  8. Calculation of resonant sound absorption parameters for performance evaluation of metal rubber material

    Institute of Scientific and Technical Information of China (English)

    E.A.IZZHEUROV

    2009-01-01

    The first resonant(anti-resonant)frequency and sound absorption coefficient of metal rubber(MR) material are theoretically studied with hard backed samples and with air layer.The equations of the first resonant and anti-resonant frequencies of MR are deduced from the undamped propagation characteristics of porous material.The first resonant and anti-resonance sound absorption coefficients are induced according to the theoretical formula for the acoustic characteristic parameters of MR,and the former is modified while the energy consumption at resonance is taken into consideration.The good agreement between the calculation results of these resonant sound absorption parameters and the experimental results verifies the effectiveness of this calculation method for the performance evaluation of MR as a sound absorption material.

  9. Calculation of resonant sound absorption parameters for performance evaluation of metal rubber material

    Institute of Scientific and Technical Information of China (English)

    WU GuoQi; AO HongRui; JIANG HongYuan; E.A.IZZHEUROV

    2009-01-01

    The first resonant(anti-resonant)frequency and sound absorption coefficient of metal rubber(MR)material are theoretically studied with hard backed samples and with air layer.The equations of the first resonant and anti-resonant frequencies of MR are deduced from the undamped propagation characteristics of porous material.The first resonant and anti-resonance sound absorption coefficients are induced according to the theoretical formula for the acoustic characteristic parameters of MR,and the former is modified while the energy consumption at resonance is taken into consideration.The good agreement between the calculation results of these resonant sound absorption parameters and the experimental results verifies the effectiveness of this calculation method for the performance evaluation of MR as a sound absorption material.

  10. Calculation of average molecular parameters, functional groups, and a surrogate molecule for heavy fuel oils using 1H and 13C NMR spectroscopy

    KAUST Repository

    Abdul Jameel, Abdul Gani

    2016-04-22

    Heavy fuel oil (HFO) is primarily used as fuel in marine engines and in boilers to generate electricity. Nuclear Magnetic Resonance (NMR) is a powerful analytical tool for structure elucidation and in this study, 1H NMR and 13C NMR spectroscopy were used for the structural characterization of 2 HFO samples. The NMR data was combined with elemental analysis and average molecular weight to quantify average molecular parameters (AMPs), such as the number of paraffinic carbons, naphthenic carbons, aromatic hydrogens, olefinic hydrogens, etc. in the HFO samples. Recent formulae published in the literature were used for calculating various derived AMPs like aromaticity factor 〖(f〗_a), C/H ratio, average paraffinic chain length (¯n), naphthenic ring number 〖(R〗_N), aromatic ring number〖 (R〗_A), total ring number〖 (R〗_T), aromatic condensation index (φ) and aromatic condensation degree (Ω). These derived AMPs help in understanding the overall structure of the fuel. A total of 19 functional groups were defined to represent the HFO samples, and their respective concentrations were calculated by formulating balance equations that equate the concentration of the functional groups with the concentration of the AMPs. Heteroatoms like sulfur, nitrogen, and oxygen were also included in the functional groups. Surrogate molecules were finally constructed to represent the average structure of the molecules present in the HFO samples. This surrogate molecule can be used for property estimation of the HFO samples and also serve as a surrogate to represent the molecular structure for use in kinetic studies.

  11. Determination of Scaling Parameter and Dynamical Resonances in Complex-Rotated Hamiltonian Ⅱ: Numerical Analysis

    Institute of Scientific and Technical Information of China (English)

    LIU Zong-Liang; ZHAO Fang; LI Shao-Hua; ZHAO Mei-Shan; CHEN Chang-Yong

    2008-01-01

    This paper is concerned with the determination of a unique scaling parameter in complex scaling analysis and with accurate calculation of dynamics resonances. In the preceding paper we have presented a theoretical analysis and provided a formalism for dynamical resonance calculations. In this paper we present accurate numerical results for two non-trivial dynamical processes, namely, models of diatomie molecular predissoeiation and of barrier potential scattering for resonances. The results presented in this paper confirm our theoretical analysis, remove a theoretical ambiguity on determination of the complex scaling parameter, and provide an improved understanding for dynamical resonance calculations in rigged Hilbert space.

  12. Ion beam sputter deposition of Ag films: Influence of process parameters on electrical and optical properties, and average grain sizes

    Energy Technology Data Exchange (ETDEWEB)

    Bundesmann, C., E-mail: carsten.bundesmann@iom-leipzig.de; Feder, R.; Gerlach, J.W.; Neumann, H.

    2014-01-31

    Ion beam sputter deposition is used to grow several sets of Ag films under systematic variation of ion beam parameters, such as ion species and ion energy, and geometrical parameters, such as ion incidence angle and polar emission angle. The films are characterized concerning their thickness by profilometry, their electrical properties by 4-point-probe-measurements, their optical properties by spectroscopic ellipsometry, and their average grain sizes by X-ray diffraction. Systematic influences of the growth parameters on film properties are revealed. The film thicknesses show a cosine-like angular distribution. The electrical resistivity increases for all sets with increasing emission angle and is found to be considerably smaller for Ag films grown by sputtering with Xe ions than for the Ag films grown by sputtering with Ar ions. Increasing the ion energy or the ion incidence angle also increases the electrical resistivity. The optical properties, which are the result of free charge carrier absorption, follow the same trends. The observed trends can be partly assigned to changes in the average grain size, which are tentatively attributed to different energetic and angular distributions of the sputtered and back-scattered particles. - Highlights: • Ion beam sputter deposition under systematic variation of process parameters. • Film characterization: thickness, electrical, optical and structural properties. • Electrical resistivity changes considerably with ion species and polar emission angle. • Electrical and optical data reveal a strong correlation with grain sizes. • Change of film properties related to changing properties of film-forming particles.

  13. On uncertainties and fluctuations of averaged neutron cross sections in unresolved resonance energy region for 235U, 238U, 239Pu

    International Nuclear Information System (INIS)

    This paper analyses the reasons for the differences which exist between group-averaged evaluated cross-section data from different evaluated data files for U235, U238 and Pu239 in the unresolved resonance energy region. (author)

  14. An in vivo three-dimensional magnetic resonance imaging-based averaged brain collection of the neonatal piglet (Sus scrofa.

    Directory of Open Access Journals (Sweden)

    Matthew S Conrad

    Full Text Available Due to the fact that morphology and perinatal growth of the piglet brain is similar to humans, use of the piglet as a translational animal model for neurodevelopmental studies is increasing. Magnetic resonance imaging (MRI can be a powerful tool to study neurodevelopment in piglets, but many of the MRI resources have been produced for adult humans. Here, we present an average in vivo MRI-based atlas specific for the 4-week-old piglet. In addition, we have developed probabilistic tissue classification maps. These tools can be used with brain mapping software packages (e.g. SPM and FSL to aid in voxel-based morphometry and image analysis techniques. The atlas enables efficient study of neurodevelopment in a highly tractable translational animal with brain growth and development similar to humans.

  15. An in vivo three-dimensional magnetic resonance imaging-based averaged brain collection of the neonatal piglet (Sus scrofa).

    Science.gov (United States)

    Conrad, Matthew S; Sutton, Bradley P; Dilger, Ryan N; Johnson, Rodney W

    2014-01-01

    Due to the fact that morphology and perinatal growth of the piglet brain is similar to humans, use of the piglet as a translational animal model for neurodevelopmental studies is increasing. Magnetic resonance imaging (MRI) can be a powerful tool to study neurodevelopment in piglets, but many of the MRI resources have been produced for adult humans. Here, we present an average in vivo MRI-based atlas specific for the 4-week-old piglet. In addition, we have developed probabilistic tissue classification maps. These tools can be used with brain mapping software packages (e.g. SPM and FSL) to aid in voxel-based morphometry and image analysis techniques. The atlas enables efficient study of neurodevelopment in a highly tractable translational animal with brain growth and development similar to humans.

  16. Estimation of the whole-body averaged SAR of grounded human models for plane wave exposure at respective resonance frequencies.

    Science.gov (United States)

    Hirata, Akimasa; Yanase, Kazuya; Laakso, Ilkka; Chan, Kwok Hung; Fujiwara, Osamu; Nagaoka, Tomoaki; Watanabe, Soichi; Conil, Emmanuelle; Wiart, Joe

    2012-12-21

    According to the international guidelines, the whole-body averaged specific absorption rate (WBA-SAR) is used as a metric of basic restriction for radio-frequency whole-body exposure. It is well known that the WBA-SAR largely depends on the frequency of the incident wave for a given incident power density. The frequency at which the WBA-SAR becomes maximal is called the 'resonance frequency'. Our previous study proposed a scheme for estimating the WBA-SAR at this resonance frequency based on an analogy between the power absorption characteristic of human models in free space and that of a dipole antenna. However, a scheme for estimating the WBA-SAR in a grounded human has not been discussed sufficiently, even though the WBA-SAR in a grounded human is larger than that in an ungrounded human. In this study, with the use of the finite-difference time-domain method, the grounded condition is confirmed to be the worst-case exposure for human body models in a standing posture. Then, WBA-SARs in grounded human models are calculated at their respective resonant frequencies. A formula for estimating the WBA-SAR of a human standing on the ground is proposed based on an analogy with a quarter-wavelength monopole antenna. First, homogenized human body models are shown to provide the conservative WBA-SAR as compared with anatomically based models. Based on the formula proposed here, the WBA-SARs in grounded human models are approximately 10% larger than those in free space. The variability of the WBA-SAR was shown to be ±30% even for humans of the same age, which is caused by the body shape. PMID:23202273

  17. Statistical inference of level densities from resolved resonance parameters

    International Nuclear Information System (INIS)

    Level densities are most directly obtained by counting the resonances observed in the resolved resonance range. Even in the measurements, however, weak levels are invariably missed so that one has to estimate their number and add it to the raw count. The main categories of missinglevel estimators are discussed in the present review, viz. (I) ladder methods including those based on the theory of Hamiltonian matrix ensembles (Dyson-Mehta statistics), (II) methods based on comparison with artificial cross section curves (Monte Carlo simulation, Garrison's autocorrelation method), (III) methods exploiting the observed neutron width distribution by means of Bayesian or more approximate procedures such as maximum-likelihood, least-squares or moment methods, with various recipes for the treatment of detection thresholds and resolution effects. The language of mathematical statistics is employed to clarify the basis of, and the relationship between, the various techniques. Recent progress in the treatment of resolution effects, detection thresholds and p-wave admixture is described. (orig.)

  18. Measurement of the Michel parameters and the average $\\tau$-neutrino helicity from $\\tau$ decays at LEP

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banerjee, Sw; Banicz, K; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Braccini, S; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Easo, S; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Extermann, Pierre; Fabre, M; Faccini, R; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Lacentre, P E; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lavorato, A; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Marchesini, P A; Marian, G; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; Mazumdar, K; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Migani, D; Mihul, A; Van Mil, A J W; Milcent, H; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Moulik, T; Mount, R; Muanza, G S; Muheim, F; Muijs, A J M; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Nowak, H; Oh, Yu D; Organtini, G; Ostonen, R; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pedace, M; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Produit, N; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Raja, N; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Rind, O; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Sakar, S; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F; Zilizi, G

    1998-01-01

    Four of the Michel parameters and the average tau-neutrino helicity have been measured by analysing tau decay spectra in 147 \\pb ~of data collected by the L3 detector. The decays \\tte, ~\\ttm, ~\\ttp, ~\\ttr ~and their charge conjugates were considered. The results: $\\rho = 0.762 \\pm 0.035$, $\\eta = 0.27 \\pm 0.14$, $\\xi = 0.70 \\pm 0.16$, $\\xi\\delta = 0.70 \\pm0.11$ and $\\xi_{h} = -1.032 \\pm 0.031$ are consistent with a V$-$A structure for the weak charged current and lepton universality.

  19. Aperiodic signals processing via parameter-tuning stochastic resonance in a photorefractive ring cavity

    Directory of Open Access Journals (Sweden)

    Xuefeng Li

    2014-04-01

    Full Text Available Based on solving numerically the generalized nonlinear Langevin equation describing the nonlinear dynamics of stochastic resonance by Fourth-order Runge-Kutta method, an aperiodic stochastic resonance based on an optical bistable system is numerically investigated. The numerical results show that a parameter-tuning stochastic resonance system can be realized by choosing the appropriate optical bistable parameters, which performs well in reconstructing aperiodic signals from a very high level of noise background. The influences of optical bistable parameters on the stochastic resonance effect are numerically analyzed via cross-correlation, and a maximum cross-correlation gain of 8 is obtained by optimizing optical bistable parameters. This provides a prospective method for reconstructing noise-hidden weak signals in all-optical signal processing systems.

  20. Aperiodic signals processing via parameter-tuning stochastic resonance in a photorefractive ring cavity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xuefeng, E-mail: lixfpost@163.com [School of Science, Xi' an University of Post and Telecommunications, Xi' an, 710121 (China); Cao, Guangzhan; Liu, Hongjun [Xi' an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an, 710119 (China)

    2014-04-15

    Based on solving numerically the generalized nonlinear Langevin equation describing the nonlinear dynamics of stochastic resonance by Fourth-order Runge-Kutta method, an aperiodic stochastic resonance based on an optical bistable system is numerically investigated. The numerical results show that a parameter-tuning stochastic resonance system can be realized by choosing the appropriate optical bistable parameters, which performs well in reconstructing aperiodic signals from a very high level of noise background. The influences of optical bistable parameters on the stochastic resonance effect are numerically analyzed via cross-correlation, and a maximum cross-correlation gain of 8 is obtained by optimizing optical bistable parameters. This provides a prospective method for reconstructing noise-hidden weak signals in all-optical signal processing systems.

  1. SAMDIST: A computer code for calculating statistical distributions for R-matrix resonance parameters

    Energy Technology Data Exchange (ETDEWEB)

    Leal, L.C.; Larson, N.M.

    1995-09-01

    The SAMDIST computer code has been developed to calculate distribution of resonance parameters of the Reich-Moore R-matrix type. The program assumes the parameters are in the format compatible with that of the multilevel R-matrix code SAMMY. SAMDIST calculates the energy-level spacing distribution, the resonance width distribution, and the long-range correlation of the energy levels. Results of these calculations are presented in both graphic and tabular forms.

  2. Resonance parameters of the {rho}-meson from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xu [DESY, Zeuthen (Germany). John von Neumann-Institut fuer Computing NIC; Muenster Univ. (Germany). Inst. fuer Theoretische Physik; Jansen, Karl; Renner, Dru B. [DESY, Zeuthen (Germany). John von Neumann-Institut fuer Computing NIC

    2010-12-15

    We perform a non-perturbative lattice calculation of the P-wave pion-pion scattering phase in the {rho}-meson decay channel using two flavors of maximally twisted mass fermions at pion masses ranging from 480 MeV to 290 MeV. Making use of finite-size methods, we evaluate the pion-pion scattering phase in the center-of-mass frame and two moving frames. Applying an effective range formula, we find a good description of our results for the scattering phase as a function of the energy covering the resonance region. This allows us to extract the {rho}-meson mass and decay width and to study their quark mass dependence. (orig.)

  3. Resonance Parameters of the Rho-Meson from Lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Xu Feng, Karl Jansen, Dru Renner

    2011-05-01

    We perform a non-perturbative lattice calculation of the P-wave pion-pion scattering phase in the rho-meson decay channel using two flavors of maximally twisted mass fermions at pion masses ranging from 480 MeV to 290 MeV. Making use of finite-size methods, we evaluate the pion-pion scattering phase in the center-of-mass frame and two moving frames. Applying an effective range formula, we find a good description of our results for the scattering phase as a function of the energy covering the resonance region. This allows us to extract the rho-meson mass and decay width and to study their quark mass dependence.

  4. Determination of Scaling Parameter and Dynamical Resonances in Complex-Rotated Hamiltonian Ⅰ: Theory

    Institute of Scientific and Technical Information of China (English)

    LI Heng-Mei; ZHAO Fang; YUAN Hong-Chun; ZHAO Mei-Shan

    2008-01-01

    In this paper we present a theoretical analysis on the determination of the scaling parameter in the complex-rotated Hamiltonian, which has served as a basis for successful applications of the rigged Hilbert space theory for resonances. Based on the complex energy eigenvalue, E(θ) = En(θ) - iF(θ)/2, as a function of the scaling parameter The condition dER(θR)/ dθ = 0 is merely a consequence of the Virial theorem and θⅠ = θR is not a necessary condition for a resonance state. We also provide a harmonic approximation formalism for resonances in scattering over a potential barrier.

  5. A coupling method of subgroup and wavelet expansion for the resonance parameter calculation

    International Nuclear Information System (INIS)

    Owing to their geometric flexibility, subgroup method and wavelet expansion method have become attractive approaches to obtain effective self-shielding microscopic cross sections within resonance energy groups for geometrically complex problems. However, the subgroup method is good in the dense resonance range, while the wavelet expansion method is good in the sparse resonance range. In order to get the resonance parameter in the whole resonance energy range more accurately and effectively, this paper developed a new coupling resonance calculation model based on subgroup method and wavelet expansion method. In this coupling model, the subgroup method is employed to handle the higher resonance energy groups, and the wavelet expansion method is employed to handle the lower resonance energy groups. At the coupling interface, they are coupled by transferring scattering source. In order to verify the coupling model, a series of benchmark problems are calculated in this paper. It is demonstrated that compared with subgroup method and wavelet expansion method respectively, this coupling resonance model has the ability to provide more exactly self-shielding microscopic cross sections in the whole resonance energy range while keeping enough efficiency. (author)

  6. Resonance parameters based analysis for metallic thickness optimization of a bimetallic plasmonic structure

    Science.gov (United States)

    Bera, Mahua; Banerjee, Jayeta; Ray, Mina

    2014-02-01

    Metallic film thickness optimization in mono- and bimetallic plasmonic structures has been carried out in order to determine the correct device parameters. Different resonance parameters, such as reflectivity, phase, field enhancement, and the complex amplitude reflectance Argand diagram (CARAD), have been investigated for the proposed optimization procedure. Comparison of mono- and bimetallic plasmonic structures has been carried out in the context of these resonance parameters with simultaneous angular and spectral interrogation. Differential phase analysis has also been performed and its application to sensing has been discussed along with a proposed interferometric set-up.

  7. Neutron Capture and Transmission Measurements and Resonance Parameter Analysis of Samarium

    International Nuclear Information System (INIS)

    The purpose of the present work is to accurately measure the neutron cross sections of samarium. The most significant isotope is 149Sm, which has a large neutron absorption cross section at thermal energies and is a 235U fission product with a 1% yield. Its cross sections are thus of concern to reactor neutronics. Neutron capture and transmission measurements were performed by the time-of-flight technique at the Rensselaer Polytechnic institute (RPI) LINAC facility using metallic and liquid Sm samples. The capture measurements were made at the 25 meter flight station with a multiplicity-type capture detector, and the transmission total cross-section measurements were performed at 15- and 25-meter flight stations with 6Li glass scintillation detectors. Resonance parameters were determined by a combined analysis of six experiments (three capture and three transmission) using the multi-level R-matrix Bayesian code SAMMY version M2. The significant features of this work are as follows. Dilute samples of samarium nitrate in deuterated water (D2O) were prepared to measure the strong resonances at 0.1 and 8 eV without saturation. Disk-shaped spectroscopic quartz cells were obtained with parallel inner surfaces to provide a uniform thickness of solution. The diluent feature of the SAMMY program was used to analyze these data. The SAMMY program also includes multiple scattering corrections to capture yield data and resolution functions specific to the RPI facility. Resonance parameters for all stable isotopes of samarium were deduced for all resonances up to 30 eV. Thermal capture cross-section and capture resonance integral calculations were made using the resultant resonance parameters and were compared to results obtained using resonance parameters from ENDF/B-VI updated through release 3. Extending the definition of the capture resonance integral to include the strong 0.1 eV resonance in 149Sm, present measurements agree within estimated uncertainties with En

  8. Short communication: Variation in production parameters among Canadian Holstein cows classified as high, average, and low immune responders.

    Science.gov (United States)

    Stoop, C L; Thompson-Crispi, K A; Cartwright, S L; Mallard, B A

    2016-06-01

    Dairy cattle evaluated for immune responses and identified as high responders are known to have a lower occurrence of economically important diseases, including mastitis, metritis, ketosis, and retained placenta. These high immune responders have also been shown to make more antibody following vaccination and to have improved milk and colostrum quality. Therefore, breeding for improved immune response is expected to have several benefits in the dairy industry. However, a concern of such an approach to improve animal health is the potential cost of lost production due to an allocation of host resources to mount a robust immune response. The objective of this study was to evaluate early- and late-lactation production parameters in cattle classified as having high, average, or low estimated breeding values (EBV) for cell-mediated (CMIR), antibody-mediated (AMIR), and overall immune responses. A total of 561 cows from 6 herds were phenotyped for immune response and ranked based on EBV for CMIR and AMIR. A linear animal model was used to evaluate differences in milk, fat, and protein yields among immune response groups, and a regression analysis was conducted based on immune response EBV. Overall, no difference in production parameters was found based on immune response rank; however, some positive relationships with immune response EBV were found, suggesting that breeding for enhanced immune responsiveness as a prophylactic approach to improve animal health would not come at the cost of lost production. PMID:27060821

  9. Process optimization in high-average-power ultrashort pulse laser microfabrication: how laser process parameters influence efficiency, throughput and quality

    Science.gov (United States)

    Schille, Joerg; Schneider, Lutz; Loeschner, Udo

    2015-09-01

    In this paper, laser processing of technical grade stainless steel and copper using high-average-power ultrashort pulse lasers is studied in order to gain deeper insight into material removal for microfabrication. A high-pulse repetition frequency picosecond and femtosecond laser is used in conjunction with high-performance galvanometer scanners and an in-house developed two-axis polygon scanner system. By varying the processing parameters such as wavelength, pulse length, fluence and repetition rate, cavities of standardized geometry are fabricated and analyzed. From the depths of the cavities produced, the ablation rate and removal efficiency are estimated. In addition, the quality of the cavities is evaluated by means of scanning electron microscope micrographs or rather surface roughness measurements. From the results obtained, the influence of the machining parameters on material removal and machining quality is discussed. In addition, it is shown that both material removal rate and quality increase by using femtosecond compared to picosecond laser pulses. On stainless steel, a maximum throughput of 6.81 mm3/min is achieved with 32 W femtosecond laser powers; if using 187 W picosecond laser powers, the maximum is 15.04 mm3/min, respectively. On copper, the maximum throughputs are 6.1 mm3/min and 21.4 mm3/min, obtained with 32 W femtosecond and 187 W picosecond laser powers. The findings indicate that ultrashort pulses in the mid-fluence regime yield most efficient material removal. In conclusion, from the results of this analysis, a range of optimum processing parameters are derived feasible to enhance machining efficiency, throughput and quality in high-rate micromachining. The work carried out here clearly opens the way to significant industrial applications.

  10. Effect of quantum resonance-percolation trajectories on the parameters of a Josephson vortex

    International Nuclear Information System (INIS)

    It is shown that, in the energy range of the tunneling resonances of a long superconductor-insulator-superconductor tunnel junction with a weak structural disorder (low impurity densities) in the insulator layer, the parameters of a Josephson vortex (flucson) are determined by the presence of quantum resonance-percolation trajectories that are randomly formed in the disordered insulator layer and connect the super-conducting banks of the junction

  11. Uncertainty of Doppler reactivity worth due to uncertainties of JENDL-3.2 resonance parameters

    Energy Technology Data Exchange (ETDEWEB)

    Zukeran, Atsushi [Hitachi Ltd., Hitachi, Ibaraki (Japan). Power and Industrial System R and D Div.; Hanaki, Hiroshi; Nakagawa, Tuneo; Shibata, Keiichi; Ishikawa, Makoto

    1998-03-01

    Analytical formula of Resonance Self-shielding Factor (f-factor) is derived from the resonance integral (J-function) based on NR approximation and the analytical expression for Doppler reactivity worth ({rho}) is also obtained by using the result. Uncertainties of the f-factor and Doppler reactivity worth are evaluated on the basis of sensitivity coefficients to the resonance parameters. The uncertainty of the Doppler reactivity worth at 487{sup 0}K is about 4 % for the PNC Large Fast Breeder Reactor. (author)

  12. Coupling Influence on Signal Readout of a Dual-Parameter LC Resonant System

    Directory of Open Access Journals (Sweden)

    Jijun Xiong

    2015-01-01

    Full Text Available Dual-parameter inductive-capacitive (LC resonant sensor is gradually becoming the measurement trend in complex harsh environments; however, the coupling between inductors greatly affects the readout signal, which becomes very difficult to resolve by means of simple mathematical tools. By changing the values of specific variables in a MATLAB code, the influence of coupling between coils on the readout signal is analyzed. Our preliminary conclusions underline that changing the coupling to antenna greatly affects the readout signal, but it simultaneously influences the other signal. When f01=f02, it is better to broaden the difference between the two coupling coefficients k1 and k2. On the other side, when f01 is smaller than f02, it is better to decrease the coupling between sensor inductors k12, in order to obtain two readout signals averaged in strength. Finally, a test system including a discrete capacitor soldered to a printed circuit board (PCB based planar spiral coil is built, and the readout signals under different relative inductors positions are analyzed. All experimental results are in good agreement with the results of the MATLAB simulation.

  13. [Effect of the evaluation parameter on sensitivity of resonance thrombography of thrombocytopenia in dogs].

    Science.gov (United States)

    Adamik, A; Mischke, R

    1998-11-01

    Based on 109 blood samples taken from 36 dogs suffering from thrombocytopenia resonance thrombography with the resonance thrombograph RTG 801 (von Hoerner und Sulger Electronic GmbH, Schwetzingen; manufacturer: Fresenius AG, Bad Homburg) was distinctly more sensitive and more closely correlated to the platelet count using an optimized parameter of the resonance thrombogramm (RTG) in comparison to usual parameters. Nevertheless, clinical requirements regarding samples with platelet counts > 25,000/microliter were not fulfilled. Out of 13 samples with reduced platelet count and simultanous extended capillary bleeding time, depending on the used parameter a maximum of 9 samples could be detected as pathological by the RTG. The normal RTG in part of the cases with clearly altered primary haemostasis contrasts to the exclusive use of RTG in the screening of thrombocytopenia in dogs. PMID:9857562

  14. Neutron Capture and Transmission Measurements and Resonance Parameter Analysis of Gadolinium

    International Nuclear Information System (INIS)

    Neutron capture and transmission measurements were performed by the time-of-flight technique at the Rensselaer Polytechnic Institute (RPI) linac facility using metallic and liquid Gd samples. The liquid samples were isotopically-enriched in either 155Gd or 157Gd. The capture measurements were made at the 25-m flight station with a multiplicity-type capture detector, and the transmission measurements were performed at 15- and 25-m flight stations with 6Li glass scintillation detectors. The multilevel R-matrix Bayesian code SAMMY was used to extract resonance parameters. Among the significant findings are the following. The neutron width of the largest resonance in Gd, at 0.032 eV in 157Gd, has been measured to be (9 ± 1)% smaller than that given in ENDF/B-VI updated through release 8. The thermal (2200 m/s) capture cross section of 157 Gd. has been measured to be 11% smaller than that calculated from ENDF. The other major thermal resonance, at 0.025 eV in 155Gd, did not display a significant deviation from the thermal capture cross section given by ENDF. In the epithermal region, 1-300 eV, the analysis, provided here represents the most extensive to date. Twenty eight new resonances are proposed and other resonances previously identified in the literature have been revisited. The assignment of resonances within regions of complicated structure incorporated the observations of other researchers, particularly on the six occasions where ENDF resonances are recommended to be removed. The poor match of the ENDF parameters to the current data is significant, and substantial improvement to the understanding of gadolinium cross sections is presented, particularly above 180 eV where the ENDF resolved region for 155Gd ends. In the epithermal energy range, natural metal samples were measured in capture and transmission. The data were analyzed with the Bayesian code SAMMY. Resonance parameters and resonance integrals have been calculated. The historical record was reviewed

  15. Two-parameter stochastic resonance in a model of electrochemical oxidation of formic acid on Pt

    Institute of Scientific and Technical Information of China (English)

    皮宗新; 辛厚文

    2002-01-01

    Stochastic resonance (SR) is shown in a two-parameter system, a model of electro-chemical oxidation of formic acid on Pt. The driving current and the saturation coverage for carbon monoxide are two control parameters in this model. Modulation of an excitable focal stable state close to a Hopf bifurcation by a weak periodic signal in one parameter and noise in the other parameter is found to give rise to SR. The results indicate that the noise can enlarge a weak peri-odic signal and lead the system to be ordered. The scenario and novel aspects of SR in this system are discussed.

  16. Two-parameter stochastic resonance in a model of electrochemical oxidation of formic acid on Pt

    Institute of Scientific and Technical Information of China (English)

    皮宗新; 辛厚文

    2002-01-01

    Stochastic resonance (SR) is shown in a two-parameter system, a model of electrochemical oxidation of formic acid on Pt. The driving current and the saturation coverage for carbon monoxide are two control parameters in this model. Modulation of an excitable focal stable state close to a Hopf bifurcation by a weak periodic signal in one parameter and noise in the other parameter is found to give rise to SR. The results indicate that the noise can enlarge a weak periodic signal and lead the system to be ordered. The scenario and novel aspects of SR in this system are discussed.

  17. Experiment and application of parameter-induced stochastic resonance in an over-damped random linear system

    Institute of Scientific and Technical Information of China (English)

    Jiang Shi-Qi; Hou Min-Jie; Jia Chun-Hua; He Ji-Rong; Gu Tian-Xiang

    2009-01-01

    This paper investigates the parameter-induced stochastic resonance using experimental methods in an over-damped random linear system with asymmetric dichotomous noise. Non-monotonic dependence of signal-to-noise ratio on the system parameter is observed. Several potential applications of parameter-induced stochastic resonance are given in circuits.

  18. Parametric Modeling of the Coupling Parameters of Planar Coupled-Resonator Microwave Filters

    OpenAIRE

    Caenepeel, Matthias; Seyfert, Fabien; Rolain, Yves; Olivi, Martine

    2015-01-01

    International audience —The design of planar coupled-resonator microwave filters is widely based on coupling matrix theory. In this framework a coupling matrix is first obtained during the synthesis step. Next this coupling matrix is physically implemented by correctly dimensioning the geometrical parameters of the filter. The implementation step is carried out using simplified empirical design curves relating the coupling coefficients and geometrical parameters. The curves typically only ...

  19. Cardiac magnetic resonance imaging parameters as surrogate endpoints in clinical trials of acute myocardial infarction

    OpenAIRE

    Gutberlet Matthias; Lurz Philipp; Fuernau Georg; de Waha Suzanne; Eitel Ingo; Desch Steffen; Schuler Gerhard; Thiele Holger

    2011-01-01

    Abstract Cardiac magnetic resonance (CMR) offers a variety of parameters potentially suited as surrogate endpoints in clinical trials of acute myocardial infarction such as infarct size, myocardial salvage, microvascular obstruction or left ventricular volumes and ejection fraction. The present article reviews each of these parameters with regard to the pathophysiological basis, practical aspects, validity, reliability and its relative value (strengths and limitations) as compared to competit...

  20. Design Considerations of Structural Parameters in Resonant Tunneling Diode by None-Equilibrium Green Function Method

    OpenAIRE

    M. Charmi; M.H. Yousefi

    2015-01-01

    This paper presents the effects of structural parameters like Quantum well width, barrier width, spacer width, contact width and contact doping, on performance of Resonant Tunneling Diode using full quantum simulation. The simulation is based on a self-consistent solution of the Poisson equation and Schrodinger equation with open boundary conditions, within the non-equilibrium Green’s function formalism. The effects of varying the structural parameters is investigated in terms of the output c...

  1. Rigorous conversion of Wigner-Eisenbud to Kapur-Peierls resonance parameters without level matrix inversion

    International Nuclear Information System (INIS)

    Kapur-Peierls resonance parameters are complex, energy-dependent in a quite indirectly specified way. In spite of these undesirable features they are needed whenever Doppler broadening of mutually interfering resonances is to be calculated by means of the Voigt profiles PSI and KHI commonly used in reactor physics. On the other hand most resonance parameters extracted from measured cross section data are of the Wigner-Eisenbud or Reich-Moore type, i.e. real and independent of energy. A practical method is presented to convert these to Kapur-Peierls parameters. The energy dependence of partial widths is fully taken into account so that the method works equally well for light and heavy nuclei, for s- and p- or d-wave channels. Large numbers of resonances are no special problem since no level matrix must be inverted. The number of particle channels should be small, however, which makes the method best suited for conversion of Reich-Moore parameters

  2. Determination of the a′-parameter of resonance lines in flames

    NARCIS (Netherlands)

    Trigt, C. van; Hollander, Tj.; Alkemade, C.T.J.

    1965-01-01

    A method is described for determining experimentally the a′-parameter of resonance lines of Na,K,Li,Cs,Ca and Sr by combining the so-called curves of growth† with duplication curves. Theoretical curves of growth and duplication curves for single lines and doublets (with 1 = 1/3 , 2 = 2/3 ) were calc

  3. Magnetic resonance imaging derived left ventricular global and region function parameters in healthy adults

    Institute of Scientific and Technical Information of China (English)

    穆莉莎

    2014-01-01

    Objective To establish cardiac magnetic resonance imaging(MRI)derived left ventricular(LV)global and region function parameters in normal adults.Methods Twenty normal adults were examined with fast imaging employing steady-state(Fiesta)acquisition sequence of cardiac MRI,LV global function and LV region function were measured at basal,middle,apical level and at 16

  4. Nonstationary weak signal detection based on normalization stochastic resonance with varying parameters

    Indian Academy of Sciences (India)

    HAIBIN ZHANG; WEI XIONG; SHANGBIN ZHANG; QINGBO HE; FANRANG KONG

    2016-06-01

    The nonlinear stochastic resonance system possesses the ability of taking advantage of background noise to enhance the weak signal. It provides a new approach to detect the weak signal embedded with heavy noise. This study proposes a new varying parameter stochastic resonance employing the fourth-order Runge–Kutta numerical method as well as the normalized transformation of a bistable stochastic resonance system. The model performs well in the detection of a time-varying signal with background noise for denoising and signal recovery. We take the fitness coefficient and cross-correlation coefficient as the criteria and analyze the influence of different parameters. The simulating results indicate its availability, validity and that it generates a betterperformance than the traditional stochastic resonance. The method develops the area of time-varying signal detection with stochastic resonance and presents new strategy for detection and denoising of a time-varying signal. It can be expected to be widely used in the areas of aperiodic signal processing, radar communication,etc

  5. Neutron Capture and Total Cross Section Measurements and Resonance Parameters of Gadolinium

    International Nuclear Information System (INIS)

    Neutron capture and transmission measurements were performed by the time-of-flight technique at the Rensselaer Polytechnic Institute (RPI) linac facility using metallic and liquid Gd samples. The liquid samples were isotopically-enriched in either 155Gd or 157Gd. The capture measurements were made at the 25-m flight station with a multiplicity-type capture detector, and the transmission measurements were performed at 15- and 25-m flight stations with 6Li glass scintillation detectors. The multilevel R-matrix Bayesian code SAMMY was used to extract resonance parameters. Among the significant findings are the following. The neutron width of the largest resonance in Gd, at 0.032 eV in 157Gd, has been measured to be (9 ± 1)% smaller than that given in ENDF/B-VI updated through release 8. The thermal (2200 m/s) capture cross section of 157Gd has been measured to be 11% smaller than that calculated from ENDF. The other major thermal resonance, at 0.025 eV in 155Gd, did not display a significant deviation from the thermal capture cross section given by ENDF. In the epithermal region, the analysis provided here represents the most extensive to date. Twenty eight new resonances are proposed and other resonances previously identified in the literature have been revisited. The assignment of resonances within regions of complicated structure incorporated the observations of other researchers, particularly on the six occasions where ENDF resonances are recommended to be removed. The poor match of the ENDF parameters to the current data is significant, and substantial improvement to the understanding of gadolinium cross sections is presented, particularly above 180 eV where the ENDF resolved region for 155Gd ends

  6. Evaluation of Silicon Neutron Resonance Parameters in the Energy Range Thermal to 1800 keV

    Energy Technology Data Exchange (ETDEWEB)

    Derrien, H.

    2002-09-30

    The evaluation of the neutron cross sections of the three stable isotopes of silicon in the energy range thermal to 20 MeV was performed by Hetrick et al. for ENDF/B-VI (Evaluated Nuclear Data File). Resonance parameters were obtained in the energy range thermal to 1500 keV from a SAMMY analysis of the Oak Ridge National Laboratory experimental neutron transmission data. A new measurement of the capture cross section of natural silicon in the energy range 1 to 700 keV has recently been performed at the Oak Ridge Electron Linear Accelerator. Results of this measurement were used in a SAMMY reevaluation of the resonance parameters, allowing determination of the capture width of a large number of resonances. The experimental data base is described; properties of the resonance parameters are given. For the first time the direct neutron capture component has been taken into account from the calculation by Rauscher et al. in the energy range from thermal to 1 MeV. Results of benchmark calculations are also given. The new evaluation is available in the ENDF/B-VI format.

  7. Calculation of Stark resonance parameters for valence orbitals of the water molecule

    CERN Document Server

    Laso, Susana Arias

    2016-01-01

    An exterior complex scaling technique is applied to compute Stark resonance parameters for two molecular orbitals ($1b_{1}$ and $1b_{2}$) represented in the field-free limit in a single-center expansion. For electric DC field configurations that guarantee azimuthal symmetry of the solution the calculation is carried out by solving a two-dimensional partial differential equation in spherical polar coordinates using a finite-element method. The resonance positions and widths as a function of electric field strengths are shown for field strengths starting in the tunnelling ionization regime, and extending well into the over-barrier ionization region.

  8. Neutron Capture and Transmission Measurements and Resonance Parameter Analysis of Niobium

    International Nuclear Information System (INIS)

    Epithermal neutron capture and transmission measurements were performed using the time-of-flight method at the RPI linac using metallic Nb samples. The capture measurements were made at the 25-meter flight station with a 16-section sodium iodide multiplicity detector and the transmission measurements at the 25-meter flight station with a Li-6 glass scintillation detector. Resonance parameters were determined for all resonances up to 500eV with a combined analysis of capture and transmission data using the multi-level R-matrix Bayesian code SAMMY. The present results are compared to those presented in ENDF/B-VI, updated through Release 3

  9. Determination of the $\\psi(3770)$, $\\psi(4040)$, $\\psi(4160)$ and $\\psi(4415)$ resonance parameters

    CERN Document Server

    Ablikim, M; Ban, Y; Cai, X; Chen, H F; Chen, H S; Chen, H X; Chen, J C; Chen, Jin; Chen, Y B; Chu, Y P; Dai, Y S; Diao, L Y; Deng, Z Y; Dong, Q F; Du, S X; Fang, J; Fang, S S; Fu, C D; Gao, C S; Gao, Y N; Gu, S D; Gu, Y T; Guo, Y N; Guo, Z J; Harris, F A; He, K L; He, M; Heng, Y K; Hou, J; Hu, H M; Hu, J H; Hu, T; Huang, G S; Huang, X T; Ji, X B; Jiang, X S; Jiang, X Y; Jiao, J B; Jin, D P; Jin, S; Lai, Y F; Li, G; Li, H B; Li, J; Li, R Y; Li, S M; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Liang, Y F; Liao, H B; Liu, B J; Liu, C X; Liu, F; Fang Liu; Liu, H H; Liu, H M; Liu, J; Liu, J B; Liu, J P; Liu, Jian; Liu, Q; Liu, R G; Liu, Z A; Lou, Y C; Lu, F; Lu, G R; Lu, J G; Luo, C L; Ma, F C; Ma, H L; Ma, L L; Ma, Q M; Mao, Z P; Mo, X H; Nie, J; Olsen, S L; Ping, R G; Qi, N D; Qin, H; Qiu, J F; Ren, Z Y; Rong, G; Ruan, X D; Shan, L Y; Shang, L; Shen, C P; Shen, D L; Shen, X Y; Sheng, H Y; Sun, H S; Sun, S S; Sun, Y Z; Sun, Z J; Tang, X; Tong, G L; Varner, G S; Wang, D Y; Wang, L; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, W F; Wang, Y F; Wang, Z; Wang, Z Y; Wang, Zheng; Wei, C L; Wei, D H; Weng, Y; Wu, N; Xia, X M; Xie, X X; Xu, G F; Xu, X P; Xu, Y; Yan, M L; Yang, H X; Yang, Y X; Ye, M H; Ye, Y X; Yu, G W; Yuan, C Z; Yuan, Y; Zang, S L; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C C; Zhang, D H; Zhang, H Q; Zhang, H Y; Zhang, J W; Zhang, J Y; Zhang, S H; Zhang, X Y; Zhang, Yiyun; Zhang, Z X; Zhang, Z P; Zhao, D X; Zhao, J W; Zhao, M G; Zhao, P P; Zhao, W R; Zhao, Z G; Zheng, H Q; Zheng, J P; Zheng, Z P; Zhou, L; Zhu, K J; Zhu, Q M; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, B A; Zhuang, X A; Zou, B S

    2008-01-01

    $R$ measurement data taken with the BESII detector at center-of-mass energies between 3.7 and 5.0 GeV is fitted to determine resonance parameters (mass, total width, electron width) of the high mass charmonium states, $\\psi(3770)$, $\\psi(4040)$, $\\psi(4160)$ and $\\psi(4415)$. Various effects, including the relative phases between the resonances, interferences, the energy-dependence of the full widths, and the initial state radiative correction, are examined. The results are compared to previous studies.

  10. Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from Major Evaluated Data Libraries

    OpenAIRE

    Pritychenko, B.; Mughabghab, S.F.

    2012-01-01

    We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-...

  11. Evidence of parameter-induced aperiodic stochastic resonance with fixed noise

    Institute of Scientific and Technical Information of China (English)

    Li Jian-Long

    2007-01-01

    Stochastic resonance (SR) is based on the cooperative effect between the stochastic dynamical system and the external forcing. As is well known, the cooperative effect is produced by adding noises. In this paper, we show the evidence that by changing the system parameters and the signal intensity, a nonlinear system in the presence of an input aperiodic signal can yield the cooperative effect, with the noise fixed. To quantify the nonlinear system output,we determine the theoretical bit error rate (BER). By numerical simulation, the validity of the theoretical derivation is checked. Besides, we show that parameter-induced SR is more realizable than SR via adding noises, especially when the noise intensity exceeds the resonance level, or when the characteristic of the noise is not known.

  12. Parameter-induced stochastic resonance based on spectral entropy and its application to weak signal detection.

    Science.gov (United States)

    Zhang, Jinjing; Zhang, Tao

    2015-02-01

    The parameter-induced stochastic resonance based on spectral entropy (PSRSE) method is introduced for the detection of a very weak signal in the presence of strong noise. The effect of stochastic resonance on the detection is optimized using parameters obtained in spectral entropy analysis. Upon processing employing the PSRSE method, the amplitude of the weak signal is enhanced and the noise power is reduced, so that the frequency of the signal can be estimated with greater precision through spectral analysis. While the improvement in the signal-to-noise ratio is similar to that obtained using the Duffing oscillator algorithm, the computational cost reduces from O(N(2)) to O(N). The PSRSE approach is applied to the frequency measurement of a weak signal made by a vortex flow meter. The results are compared with those obtained applying the Duffing oscillator algorithm.

  13. Atlas of giant dipole resonances. Parameters and graphs of photonuclear reaction cross sections

    International Nuclear Information System (INIS)

    Parameters of giant dipole resonances (GDR) observed in photonuclear reaction cross sections using various beams of incident photons are presented. Data, given for 200 stable isotopes from 2H to 243Am including their natural compositions, were collected from papers published over the years 1951-1996. GDR parameters, such as energy positions, amplitudes and widths, are included into the table and organized by element, isotope and reaction. Graphs of the majority of the photonuclear reaction cross sections, included in the international nuclear data library EXFOR by the end of 1998, are presented. The graphs are provided for 182 stable isotopes and natural compositions. (author)

  14. Spike-interval triggered averaging reveals a quasi-periodic spiking alternative for stochastic resonance in catfish electroreceptors.

    Directory of Open Access Journals (Sweden)

    Martin J M Lankheet

    Full Text Available Catfish detect and identify invisible prey by sensing their ultra-weak electric fields with electroreceptors. Any neuron that deals with small-amplitude input has to overcome sensitivity limitations arising from inherent threshold non-linearities in spike-generation mechanisms. Many sensory cells solve this issue with stochastic resonance, in which a moderate amount of intrinsic noise causes irregular spontaneous spiking activity with a probability that is modulated by the input signal. Here we show that catfish electroreceptors have adopted a fundamentally different strategy. Using a reverse correlation technique in which we take spike interval durations into account, we show that the electroreceptors generate a supra-threshold bias current that results in quasi-periodically produced spikes. In this regime stimuli modulate the interval between successive spikes rather than the instantaneous probability for a spike. This alternative for stochastic resonance combines threshold-free sensitivity for weak stimuli with similar sensitivity for excitations and inhibitions based on single interspike intervals.

  15. Analysis of critical current distribution of bent Bi2223 composite tapes by unifying parameter approach and its application to the description of average critical current-bending strain relation near the average irreversible strain

    Energy Technology Data Exchange (ETDEWEB)

    Ochiai, S; Okuda, H; Sugano, M; Hojo, M [Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501 (Japan); Osamura, K [Research Institute for Applied Sciences, Sakyo-ku, Kyoto 606-8202 (Japan); Kuroda, T; Itoh, K; Kitaguchi, H; Kumakura, H [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Wada, H, E-mail: shojiro.ochiai@materials.mbox.media.kyoto-u.ac.j [Graduate School of Frontier Sciences, University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan)

    2010-02-15

    When the critical current of bent Bi2223 composite tape is measured for many specimens, the critical current value is different from specimen to specimen, being distributed from low to high values. We need to characterize the distribution of critical current at various applied strains and also to predict the distribution of irreversible strain for reliability and safe design. The present work attempted to describe them from the statistical viewpoint. In the analysis, the unifying parameter approach proposed recently by the authors was employed, in which the difference in damage evolution and critical current among the specimens was correlated with the distribution of the unifying parameter that refers to the tensile damage strain of Bi2223 filaments in composite tapes. By application of this approach to the measured critical current values under various bending strains for three Bi2223 composite tapes from different suppliers (VAM1, VAM2 and VAM3 used as the common test samples in the round robin test of VAMAS/TWA16), the unifying parameters were estimated and were formulated by the Weibull distribution function. With the formulated distribution function of the unifying parameter, the distributions of the critical current at various strains, the distribution of the irreversible bending strain and the average critical current-bending strain relation near the average irreversible bending strain could be described satisfactorily.

  16. A method for extracting the resonance parameters from experimental cross-sections

    International Nuclear Information System (INIS)

    Within the proposed method, a set of experimental data points are fitted using a multi-channel S-matrix. Then the resonance parameters are located as its poles on an appropriate sheet of the Riemann surface of the energy. The main advantage of the method is that the S-matrix is constructed in such a way that it has proper analytic structure, i.e. for any number of two-body channels, the branching at all the channel thresholds is represented via exact analytic expressions in terms of the channel momenta. The way the S-matrix is constructed makes it possible not only to locate multi-channel resonances but also to extract their partial widths as well as to obtain the scattering cross-section in the channels for which no data are available. The efficiency of the method is demonstrated by two model examples of a single-channel and a two-channel problems, where known resonance parameters are rather accurately reproduced by fitting the pseudo-data artificially generated using the corresponding potentials. (author)

  17. A novel parameter-induced stochastic resonance phenomena in fractional Fourier domain

    Science.gov (United States)

    Lin, Lifeng; Wang, Huiqi; Lv, Wangyong; Zhong, Suchuan

    2016-08-01

    The parameter-induced stochastic resonance (SR) phenomenon in a novel self-adaptive dynamical system driven by linear frequency modulated (LFM) signal and additive noise is considered from the view of the signal-to-noise ratio (SNR). It is found that the dynamical system can be perfectly analyzed by equivalently transforming it into a traditional first-order linear dynamical system driven by periodic signal and additive noise in fractional Fourier transform (FrFT) domain with an optimal rotated angle, and the theoretical analysis and simulation results show that output SNR exhibits the SR behavior when it is plotted as a function of the system parameter. Furthermore, the optimal value of adjusted parameter is obtained, and the possible area of SNR gain is theoretically determined only by center-frequency and modulated frequency of the driving LFM signal.

  18. Design Considerations of Structural Parameters in Resonant Tunneling Diode by None-Equilibrium Green Function Method

    Directory of Open Access Journals (Sweden)

    M. Charmi

    2015-12-01

    Full Text Available This paper presents the effects of structural parameters like Quantum well width, barrier width, spacer width, contact width and contact doping, on performance of Resonant Tunneling Diode using full quantum simulation. The simulation is based on a self-consistent solution of the Poisson equation and Schrodinger equation with open boundary conditions, within the non-equilibrium Green’s function formalism. The effects of varying the structural parameters is investigated in terms of the output current, peak current, valley current, peak to valley current ratio and the voltage associated with the peak current. Simulation results illustrate that the device performance can be improved by proper selection of the structural parameters.

  19. Dependence of the average spatial and energy characteristics of the hadron-lepton cascade on the strong interaction parameters at superhigh energies

    Science.gov (United States)

    Boyadjian, N. G.; Dallakyan, P. Y.; Garyaka, A. P.; Mamidjanian, E. A.

    1985-01-01

    A method for calculating the average spatial and energy characteristics of hadron-lepton cascades in the atmosphere is described. The results of calculations for various strong interaction models of primary protons and nuclei are presented. The sensitivity of the experimentally observed extensive air showers (EAS) characteristics to variations of the elementary act parameters is analyzed.

  20. Parameter allocation of parallel array bistable stochastic resonance and its application in communication systems

    Science.gov (United States)

    Liu, Jian; Wang, You-Guo; Zhai, Qi-Qing; Liu, Jin

    2016-10-01

    In this paper, we propose a parameter allocation scheme in a parallel array bistable stochastic resonance-based communication system (P-BSR-CS) to improve the performance of weak binary pulse amplitude modulated (BPAM) signal transmissions. The optimal parameter allocation policy of the P-BSR-CS is provided to minimize the bit error rate (BER) and maximize the channel capacity (CC) under the adiabatic approximation condition. On this basis, we further derive the best parameter selection theorem in realistic communication scenarios via variable transformation. Specifically, the P-BSR structure design not only brings the robustness of parameter selection optimization, where the optimal parameter pair is not fixed but variable in quite a wide range, but also produces outstanding system performance. Theoretical analysis and simulation results indicate that in the P-BSR-CS the proposed parameter allocation scheme yields considerable performance improvement, particularly in very low signal-to-noise ratio (SNR) environments. Project supported by the National Natural Science Foundation of China (Grant No. 61179027), the Qinglan Project of Jiangsu Province of China (Grant No. QL06212006), and the University Postgraduate Research and Innovation Project of Jiangsu Province (Grant Nos. KYLX15_0829, KYLX15_0831).

  1. Evaluation of resolved resonance parameters of fission product nuclides with atomic numbers Z=46-51 for JENDL-3.2

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Yutaka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1996-08-01

    Resolved resonance parameters of the following fission product nuclides with atomic numbers Z=46-51 have been evaluated for JENDL-3.2: {sup 102,104,105,106,107,108,110}Pd, {sup 107,109,110m}Ag, {sup 106,108,110,111,112,113,114,116}Cd, {sup 113,115I}n, {sup 121,123}Sb. Evaluation was made on the basis of JENDL-2 for most nuclides and of the data recommended by Mughabghab et al. for the nuclides whose data have not been contained in JENDL-2. Data measured after the JENDL-2 evaluation (1982) have been taken into account in the evaluation. Spin of the resonance state and angular momentum of the incident neutron have been given for all levels. When there exist no measured data, the spin has been given tentatively on the basis of a random sampling technique using their statistical properties, and the angular momentum was also tentatively given on the basis of the Bayes`s theorem on conditional probability using the s- and p-wave strength functions and average level spacings. The resonance parameters have been evaluated so as to reproduce measured capture area of individual resonance levels, thermal cross section and resonance integral. Evaluated results have been compiled into JENDL-3.2 in the formats of ENDF-5 and ENDF-6. (author)

  2. A small parameter in the 1/Nsub(c) expansion and narrowness of hadronic resonances

    International Nuclear Information System (INIS)

    The dynamical basis for the validity of the 1/Nsub(c) expansion is investigated in the context of QCD in 1+1 dimensions. This is carried out by studying the first non-leading corrections in 1/Nsub(c) to the mass operator in the space of physical states. The correction to the real part of the mass operator has a direct implication for the convergence of the 1/Nsub(c) expansion, since a small effective parameter is identified, where its smallness depends on the dynamical circumstances in a known way. The generated imaginary part of the mass operator provides us with an insight concerning the question of the narrowness of hadronic resonances. In order to have a more realistic contact with our world, we include also effects due to the flavor symmetry group SU(Nsub(f)). This allows us to understand better the validity and usefulness of the notions of resonance dominance and (smooth) Regge behavior. We also discuss the expansion with Nsub(f)/Nsub(c) fixed and compare the results with those obtained from Dual Resonance Model. It is remarked that a non-uniformity exists between the limits Nsub(c) → infinity, Nsub(f) = fixed and Nsub(c) → infinity Nsub(f)/Nsub(c) = fixed, which may affect physical quantities. (author)

  3. Sub-Harmonic Resonances of Periodic Parameter Excited Oscillators with Discontinuities

    Institute of Scientific and Technical Information of China (English)

    Jifeng Cui∗

    2015-01-01

    It is difficult to obtain analytic approximations of nonlinear problems such as parameter excited system with strong nonlinearity. An analytic approach based on the homotopy analysis method ( HAM ) is proposed to study the sub⁃harmonic resonances of highly nonlinear parameter excited oscillating systems with absolute value terms. The non⁃smoothness of absolute value terms is handled by means of an iteration approach with Fourier expansion. Two typical examples are employed to illustrate the validity and flexibility of this approach. The square residuals of the homotopy⁃approximations of the two examples decrease to 10-6 and 10-5 , respectively. Thus, the HAM combining with other methods gives hope to solve complex singular oscillating systems analytically.

  4. The effects of parameter estimation on minimizing the in-control average sample size for the double sampling X bar chart

    Directory of Open Access Journals (Sweden)

    Michael B.C. Khoo

    2013-11-01

    Full Text Available The double sampling (DS X bar chart, one of the most widely-used charting methods, is superior for detecting small and moderate shifts in the process mean. In a right skewed run length distribution, the median run length (MRL provides a more credible representation of the central tendency than the average run length (ARL, as the mean is greater than the median. In this paper, therefore, MRL is used as the performance criterion instead of the traditional ARL. Generally, the performance of the DS X bar chart is investigated under the assumption of known process parameters. In practice, these parameters are usually estimated from an in-control reference Phase-I dataset. Since the performance of the DS X bar chart is significantly affected by estimation errors, we study the effects of parameter estimation on the MRL-based DS X bar chart when the in-control average sample size is minimised. This study reveals that more than 80 samples are required for the MRL-based DS X bar chart with estimated parameters to perform more favourably than the corresponding chart with known parameters.

  5. Two-Parameter Stochastic Resonance in a Model of Electrodissolution of Fe in H2SO4

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Stochastic resonance (SR) is shown in a two-parameter system, a model of electrodissolution of Fe in H2SO4. Modulation of two different parameters by a periodic signal in one parameter and noise in the other parameter is found to give rise to SR. The result indicates that the noise can enlarge a weak periodic signal and lead the system to order. The scenario and novel aspects of SR in this system are discussed.

  6. The Effect of System and Amplifier Parameters on the Performance of Average Soliton Transmission System Using PSA as In-Line Amplifier

    Institute of Scientific and Technical Information of China (English)

    LIN Hong-rong; YANG Ai-xia; QIAN Sheng; LI Yue-hui

    2004-01-01

    In this paper, the effect of system and amplifier parameters on the performance of soliton transmission system using Phase Sensitive Amplifier (PSA) as in-line amplifier has been researched theoretically by computer simulation.Since in PSA soliton system the performance of average soliton regime is much better than that of dynamic soliton regime,in our simulation we only considered average soliton regime. Our simulation results show that although using PSA as inline amplifiers in soliton system can not only overcome Gordon-Haus restriction but also suppress solitons interaction,lengthen soliton stable transmission distance significantly, the system and amplifier parameters have to be chosen carefully in order to get a better system performance.

  7. Study and Optimization of CPT Resonance Parameters in 87 Rb/Ar/Ne Microcells Aimed for Application in Metrology

    Science.gov (United States)

    Masian, Y.; Sivak, A.; Sevostianov, D.; Vassiliev, V.; Velichansky, V.

    The paper shows the presents results of studies of small-size rubidium cells with argon and neon buffer gases, produced by a patent pended technique of laser welding [Fishman et al. (2014)]. Cells were designed for miniature frequency standard. Temperature dependence of the frequency of the coherent population trapping (CPT) resonance was measured and used to optimize the ratio of partial pressures of buffer gases. The influence of duration and regime of annealing on the CPT-resonance frequency drift was investigated. The parameters of the FM modulation of laser current for two cases which correspond to the highest amplitude of CPT resonance and to the smallest light shifts of the resonance frequency were determined. The temperature dependences of the CPT resonance frequency were found to be surprisingly different in the two cases. A non-linear dependence of CPT resonance frequency on the temperature of the cell with the two extremes was revealed for one of these cases.

  8. Neutron total cross-sections and resonance parameters of Mo and Ta

    Indian Academy of Sciences (India)

    A K M Moinul Haque Meaze; K Devan; Y S Lee; Y D Oh; G N Kim; D Son

    2007-02-01

    Experimental results of transmissions for the samples of natural molybdenum with thickness 0.0192 atoms/barn and for the four samples of natural tantalum with thickness 0.0222, 0.0111, 0.0055 and 0.0025 atoms/barn are presented in this work. Measurements were carried out at the Pohang Neutron Facility which consists of a 100 MeV Linac, water-cooled tantalum target, and 12 m flight path length. Effective total cross-sections were extracted from the transmission data, and resonance parameters were obtained by using the code SAMMY. The present measurements were compared with other measurements and with the evaluated nuclear data file ENDF/B-VI.8.

  9. Determination of molecular spectroscopic parameters and energy-transfer rates by double-resonance spectroscopy

    Science.gov (United States)

    Steinfeld, J. I.; Foy, B.; Hetzler, J.; Flannery, C.; Klaassen, J.; Mizugai, Y.; Coy, S.

    1990-01-01

    The spectroscopy of small to medium-size polyatomic molecules can be extremely complex, especially in higher-lying overtone and combination vibrational levels. The high density of levels also complicates the understanding of inelastic collision processes, which is required to model energy transfer and collision broadening of spectral lines. Both of these problems can be addressed by double-resonance spectroscopy, i.e., time-resolved pump-probe measurements using microwave, infrared, near-infrared, and visible-wavelength sources. Information on excited-state spectroscopy, transition moments, inelastic energy transfer rates and propensity rules, and pressure-broadening parameters may be obtained from such experiments. Examples are given for several species of importance in planetary atmospheres, including ozone, silane, ethane, and ammonia.

  10. Distinguishing black-hole spin-orbit resonances by their gravitational wave signatures. II: Full parameter estimation

    CERN Document Server

    Trifirò, Daniele; Gerosa, Davide; Berti, Emanuele; Kesden, Michael; Littenberg, Tyson; Sperhake, Ulrich

    2015-01-01

    Gravitational waves from coalescing binary black holes encode the evolution of their spins prior to merger. In the post-Newtonian regime and on the precession timescale, this evolution has one of three morphologies, with the spins either librating around one of two fixed points ("resonances") or circulating freely. In this work we perform full parameter estimation on resonant binaries with fixed masses and spin magnitudes, changing three parameters: a conserved "projected effective spin" $\\xi$ and resonant family $\\Delta\\Phi=0,\\pi$ (which uniquely label the source); the inclination $\\theta_{JN}$ of the binary's total angular momentum with respect to the line of sight (which determines the strength of precessional effects in the waveform); and the signal amplitude. We demonstrate that resonances can be distinguished for a wide range of binaries, except for highly symmetric configurations where precessional effects are suppressed. Motivated by new insight into double-spin evolution, we introduce new variables t...

  11. Discrete ambiguity resolution and baryon-resonance parameter determination. [1400 to 2200 MeV, causality, unitarity

    Energy Technology Data Exchange (ETDEWEB)

    Chew, D.M; Urban, M.

    1978-04-01

    A partial-wave analysis was performed on elastic ..pi../sup +/p data between 1400 and 2200 MeV, using principles of analyticity (to select and amalgamate data), causality and unitarity together with Barrelet zeros are the resonating waves between 1500 and 1800 MeV examined in detail, and it is shown how a new resolution of the discrete ambiguity gives, for the S31 and D33 resonances, different parameters than found in an earlier resolution using less accurate information. In either case, mass degeneracy of these resonances is observed in agreement with general considerations regarding smooth zero trajectories. 18 references.

  12. Achieving high bit rate logical stochastic resonance in a bistable system by adjusting parameters

    Science.gov (United States)

    Yang, Ding-Xin; Gu, Feng-Shou; Feng, Guo-Jin; Yang, Yong-Min; Ball, Andrew

    2015-11-01

    The phenomenon of logical stochastic resonance (LSR) in a nonlinear bistable system is demonstrated by numerical simulations and experiments. However, the bit rates of the logical signals are relatively low and not suitable for practical applications. First, we examine the responses of the bistable system with fixed parameters to different bit rate logic input signals, showing that an arbitrary high bit rate LSR in a bistable system cannot be achieved. Then, a normalized transform of the LSR bistable system is introduced through a kind of variable substitution. Based on the transform, it is found that LSR for arbitrary high bit rate logic signals in a bistable system can be achieved by adjusting the parameters of the system, setting bias value and amplifying the amplitudes of logic input signals and noise properly. Finally, the desired OR and AND logic outputs to high bit rate logic inputs in a bistable system are obtained by numerical simulations. The study might provide higher feasibility of LSR in practical engineering applications. Project supported by the National Natural Science Foundation of China (Grant No. 51379526).

  13. Achieving high bit rate logical stochastic resonance in a bistable system by adjusting parameters

    Institute of Scientific and Technical Information of China (English)

    杨定新; 谷丰收; 冯国金; 杨拥民

    2015-01-01

    The phenomenon of logical stochastic resonance (LSR) in a nonlinear bistable system is demonstrated by numerical simulations and experiments. However, the bit rates of the logical signals are relatively low and not suitable for practical applications. First, we examine the responses of the bistable system with fixed parameters to different bit rate logic input signals, showing that an arbitrary high bit rate LSR in a bistable system cannot be achieved. Then, a normalized transform of the LSR bistable system is introduced through a kind of variable substitution. Based on the transform, it is found that LSR for arbitrary high bit rate logic signals in a bistable system can be achieved by adjusting the parameters of the system, setting bias value and amplifying the amplitudes of logic input signals and noise properly. Finally, the desired OR and AND logic outputs to high bit rate logic inputs in a bistable system are obtained by numerical simulations. The study might provide higher feasibility of LSR in practical engineering applications.

  14. Extracting the resonance parameters from experimental data on scattering of charged particles

    CERN Document Server

    Vaandrager, P

    2016-01-01

    A new parametrization of the multi-channel S-matrix is used to fit scattering data and then to locate the resonances as its poles. The S-matrix is written in terms of the corresponding "in" and "out" Jost matrices which are expanded in the Taylor series of the collision energy E around an appropriately chosen energy E0. In order to do this, the Jost matrices are written in a semi-analytic form where all the factors (involving the channel momenta and Sommerfeld parameters) responsible for their "bad behaviour" (i.e. responsible for the multi-valuedness of the Jost matrices and for branching of the Riemann surface of the energy) are given explicitly. The remaining unknown factors in the Jost matrices are analytic and single-valued functions of the variable E and are defined on a simple energy plane. The expansion is done for these analytic functions and the expansion coefficients are used as the fitting parameters. The method is tested on a two-channel model, using a set of artificially generated data points wi...

  15. A measurement of the resonance parameters of the neutral intermediate vector boson

    International Nuclear Information System (INIS)

    This thesis presents a measurement of the Z0 Boson resonance parameters. The measurement was performed at the Stanford Linear Collider using the Mark II detector. Based on a sample of 480 Hadronic and Leptonic decays, the mass is found to be 91.14 ± 0.12 GeV/c2, the total width is 2.42 -0.35+0.45 GeV, and the peak cross section for all Hadronic events, and for Muon and Tau events with cosθThrust < 0. 65 is 45 ± 4 nb. By constraining the visible width to the Standard Model value for 5 quarks and 3 charged leptons, and allowing the invisible width to be a parameter, the width to invisible decay modes is found to be 0.46 ± 0.10 GeV. Assuming this width comes from massless neutrinos, this measurement corresponds to 2.8 ± 0.6 neutrino species. This measurement sets an upper limit of 3.9 neutrino generations at the 95% confidence level, ruling out a fourth generation of Standard Model neutrinos at this level. 54 refs., 65 figs., 11 tabs

  16. Role of Quantitative Magnetic Resonance Imaging Parameters in the Evaluation of Treatment Response in Malignant Tumors

    Institute of Scientific and Technical Information of China (English)

    Qing-Gang Xu; Jun-Fang Xian

    2015-01-01

    Objective:To elaborate the role of quantitative magnetic resonance imaging (MRI) parameters in the evaluation of treatment response in malignant tumors.Data Sources:Data cited in this review were obtained mainly from PubMed in English from 1999 to 2014,with keywords "dynamic contrast-enhanced (DCE)-MRI," "diffusion-weighted imaging (DWI)," "microcirculation," "apparent diffusion coefficient (ADC)," "treatment response" and "oncology."Study Selection:Articles regarding principles of DCE-MRI,principles of DWI,clinical applications as well as opportunity and aspiration were identified,retrieved and reviewed.Results:A significant correlation between ADC values and treatment response was reported in most DWI studies.Most quantitative DCE-MRI studies showed a significant correlation between K~s values and treatment response.However,in different tumors and studies,both high and low pretreatment ADC or K~s values were found to be associated with response rate.Both DCE-MRI and DWI demonstrated changes in their parameters hours to days after treatment,showing a decrease in K~ns or an increase in ADC associated with response in most cases.Conclusions:Combinations of quantitative MRI play an important role in the evaluation of treatment response of malignant tumors and hold promise for use as a cancer treatment response biomarker.However,validation is hampered by the lack of reproducibility and standardization.MRI acquisition protocols and quantitative image analysis approaches should be properly addressed prior to further testing the clinical use of quantitative MRI parameters in the assessment of treatments.

  17. Features of the effect of the parameters of resonance systems with different configurations on the current-voltage characteristics of resonant-tunneling nanostructures in a subterahertz frequency range

    International Nuclear Information System (INIS)

    Features of the effect of a subterahertz microwave field on the current characteristics of a resonant-tunneling diode in resonance systems with different configurations have been studied. Changes in the current characteristics of the resonant-tunneling diode under variation of the electrophysical parameters of dielectric and microstrip resonators, in particular high-Q-factor superconducting microstrip resonators, have been experimentally studied and analyzed

  18. Coagulation and fibrinolytic parameters as predictors for small-vessel disease revealed by magnetic resonance imaging of the brain

    International Nuclear Information System (INIS)

    We correlated coagulation and fibrinolytic parameters with small-vessel disease revealed by magnetic resonance imaging (MRI) of the brain. One hundred and eleven patients with asymptomatic or symptomatic cerebral infarction were randomly selected for the study; 57 males and 54 females with an average age of 66.6±9.6, age range 40 to 85, years old. Among them, 76 patients had a history of symptomatic cerebral infarction; 38 patients hypertension; and 24 patients diabetes mellitus. Patients with large cortical infarction, cerebral hemorrhage, demyelinating disease or mass lesions were excluded from the present study. The MRI scans were reviewed for areas with increased signal intensity on T2-weighted images. The small infarction was defined as a lesion less than 10 mm in diameter. The activity of von Willebrand factor (vWF) correlated significantly with the grade of caps at the anterior and posterior horns of the lateral ventricle, and the number of small infarctions in the subcortical white matter and basal ganglia, suggesting vWF could be a predictor for these small-vessel disease. The grade of caps at posterior horn of the lateral ventricle and the number of small infarctions in the subcortical white matter were associated significantly with the concentration of plasma fibrinogen and reversely with the activity of antithrombin III, an inhibitory factor in coagulation system. These results indicate that hypercoagulable state may causatively relate with small-vessel disease in the territory of medullary artery branching from cortical artery. On the contrary, these coagulation parameters did not correlate significantly with small ischemic lesions in the territory of perforating artery. No correlation was observed between the level of marker proteins for platelet activation and the degree of small-vessel disease, indicating the activation of platelet could not associate with the etiology of small-vessel disease. (author)

  19. Lumped parameter model for resonant frequency estimation of a thermoacoustic engine with gas-liquid coupling oscillation

    Institute of Scientific and Technical Information of China (English)

    Ke TANG; Tian LEI; Xiao-gang LIN; Tao JIN; Yu ZHANG

    2011-01-01

    Gas-liquid coupling oscillation is a novel approach to reducing the resonant frequency and to elevating the pressure amplitude of a thermoacoustic engine. If a thermoacoustic engine is used to drive low-frequency pulse tube refrigerators, the frequency matching between the thermoacoustic engine and the refrigerator plays an important role. Based on an acoustic-electric analogy, a lumped parameter model is proposed to estimate the resonant frequency of a standing-wave thermoacoustic engine with gas-liquid coupling oscillation. Furthermore, a simplified lumped parameter model is also developed to reduce the computation complexity. The resonant frequency dependence on the mean pressure, the gas space volume, and the water column length is computed and analyzed. The impact of different working gases on the resonant frequency is also discussed. The effectiveness of the models is validated by comparing the computed results with the experimental data of the gas-liquid coupling oscillation system. An increase in the mean working pressure can lead to a rise in the resonant frequency, and a lower resonant frequency can be achieved by elongating the liquid column. In comparison with nitrogen and argon, carbon dioxide can realize a lower frequency due to a smaller specific heat ratio.

  20. Development of 239Pu total cross section multilevel parameters determination technique by analysing experiments on neutron transmission in resolved resonance region

    International Nuclear Information System (INIS)

    The aim of this work is development of S-matrix multilevel resonance parameters determination technique with neutron transmission data used in resolved resonance region. Experimental transmission data values were obtained for the Pu-239 thickness range 0.00217-0.1234 nucl/barns on the time-of-flight spectrometer with 70 ns/m resolution. S-matrix Adler's formalism with least square method fit were used for experimental data description. The method developed enables to justify the resonance-resonance interference parameters H. Its possibilities are demonstrated by determination of these parameters for four resonances of the Pu-239 total cross section

  1. Treatment time reduction through parameter optimization in magnetic resonance guided high intensity focused ultrasound treatments

    Science.gov (United States)

    Coon, Joshua

    Magnetic Resonance guided High Intensity Focused Ultrasound (MRgHIFU) treatments are a promising modality for cancer treatments in which a focused beam of ultrasound energy is used to kill tumor tissue. However, obstacles still exist to its widespread clinical implementation, including long treatment times. This research demonstrates reductions in treatment times through intelligent selection of the user-controllable parameters, including: the focal zone treatment path, focal zone size, focal zone spacing, and whether to treat one or several focal zone locations at any given time. Several treatments using various combinations of these parameters were simulated using a finite difference method to solve the Pennes bio-heat transfer equation for an ultrasonically heated tissue region with a wide range of acoustic, thermal, geometric, and tumor properties. The total treatment time was iteratively optimized using either a heuristic method or routines included in the Matlab software package, with constraints imposed for patient safety and treatment efficacy. The results demonstrate that large reductions in treatment time are possible through the intelligent selection of user-controllable treatment parameters. For the treatment path, treatment times are reduced by as much as an order of magnitude if the focal zones are arranged into stacks along the axial direction and a middle-front-back ordering is followed. For situations where normal tissue heating constraints are less stringent, these focal zones should have high levels of adjacency to further decrease treatment times; however, adjacency should be reduced in some cases where normal tissue constraints are more stringent. Also, the use of smaller, more concentrated focal zones produces shorter treatment times than larger, more diluted focal zones, a result verified in an agar phantom model. Further, focal zones should be packed using only a small amount of overlap in the axial direction and with a small gap in the

  2. Set up of a method for the adjustment of resonance parameters on integral experiments; Mise au point d`une methode d`ajustement des parametres de resonance sur des experiences integrales

    Energy Technology Data Exchange (ETDEWEB)

    Blaise, P.

    1996-12-18

    Resonance parameters for actinides play a significant role in the neutronic characteristics of all reactor types. All the major integral parameters strongly depend on the nuclear data of the isotopes in the resonance-energy regions.The author sets up a method for the adjustment of resonance parameters taking into account the self-shielding effects and restricting the cross section deconvolution problem to a limited energy region. (N.T.).

  3. Methodological aspects in the calculation of parity-violating effects in nuclear magnetic resonance parameters.

    Science.gov (United States)

    Weijo, Ville; Bast, Radovan; Manninen, Pekka; Saue, Trond; Vaara, Juha

    2007-02-21

    We examine the quantum chemical calculation of parity-violating (PV) electroweak contributions to the spectral parameters of nuclear magnetic resonance (NMR) from a methodological point of view. Nuclear magnetic shielding and indirect spin-spin coupling constants are considered and evaluated for three chiral molecules, H2O2, H2S2, and H2Se2. The effects of the choice of a one-particle basis set and the treatment of electron correlation, as well as the effects of special relativity, are studied. All of them are found to be relevant. The basis-set dependence is very pronounced, especially at the electron correlated ab initio levels of theory. Coupled-cluster and density-functional theory (DFT) results for PV contributions differ significantly from the Hartree-Fock data. DFT overestimates the PV effects, particularly with nonhybrid exchange-correlation functionals. Beginning from third-row elements, special relativity is of importance for the PV NMR properties, shown here by comparing perturbational one-component and various four-component calculations. In contrast to what is found for nuclear magnetic shielding, the choice of the model for nuclear charge distribution--point charge or extended (Gaussian)--has a significant impact on the PV contribution to the spin-spin coupling constants. PMID:17328593

  4. Measurement of resonance parameters of orbitally excited narrow B0 mesons.

    Science.gov (United States)

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; González, B Alvarez; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzurri, P; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beringer, J; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burke, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Chwalek, T; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cordelli, M; Cortiana, G; Cox, C A; Cox, D J; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Derwent, P F; di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Elagin, A; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; da Costa, J Guimaraes; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hays, C; Heck, M; Heijboer, A; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhr, T; Kulkarni, N P; Kurata, M; Kusakabe, Y; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, E; Lee, H S; Lee, S W; Leone, S; Lewis, J D; Lin, C-S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lucchesi, D; Luci, C; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Merkel, P; Mesropian, C; Miao, T; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moggi, N; Moon, C S; Moore, R; Morello, M J; Morlok, J; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Nett, J; Neu, C; Neubauer, M S; Neubauer, S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Griso, S Pagan; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J

    2009-03-13

    We report a measurement of resonance parameters of the orbitally excited (L=1) narrow B0 mesons in decays to B;{(*)+}pi;{-} using 1.7 fb;{-1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B_{2};{*0} state are measured to be m(B_{2};{*0})=5740.2_{-1.8};{+1.7}(stat)-0.8+0.9(syst) MeV/c;{2} and Gamma(B_{2};{*0})=22.7_{-3.2};{+3.8}(stat)-10.2+3.2(syst) MeV/c;{2}. The mass difference between the B_{2};{*0} and B10 states is measured to be 14.9_{-2.5};{+2.2}(stat)-1.4+1.2(syst) MeV/c;{2}, resulting in a B10 mass of 5725.3_{-2.2};{+1.6}(stat)-1.5+1.4(syst) MeV/c;{2}. This is currently the most precise measurement of the masses of these states and the first measurement of the B_{2};{*0} width. PMID:19392106

  5. Electron paramagnetic resonance parameters and local structure for Gd3+ in KY3F10

    Indian Academy of Sciences (India)

    Shao-Yi Wu; Hua-Ming Zhang; Guang-Duo Lu; Zhi-Hong Zhang

    2007-09-01

    The electron paramagnetic resonance parameters, zero-field splittings (ZFSs) b$_{2}^{0}$, b$_{4}^{0}$, b$_{4}^{4}$, b$_{6}^{0}$, b$_{6}^{4}$ and the factors for Gd3+ on the tetragonal Y3+ site in KY3F10 are theoretically studied from the superposition model for the ZFSs and the approximation formula for the factor containing the admixture of the ground 8S7/2 and the excited 6L7/2 (L=P, D, F, G) states via the spin–orbit coupling interactions, respectively. By analysing the above ZFSs, the local structure information for the impurity Gd3+ is obtained, i.e., the impurity–ligand bonding angles related to the four-fold (C4) axis for the impurity Gd3+ center are found to be about 0.6° larger than those for the host Y3+ site in KY3F10. The calculated ZFSs based on the above angular distortion as well as the factors are in reasonable agreement with the observed values. The present studies on the ZFSs and the local structure would be helpful to understand the optical and magnetic properties of this material with Gd dopants.

  6. Measurement of Resonance Parameters of Orbitally Excited Narrow B^0 Mesons

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, : T.

    2008-09-01

    The authors report a measurement of resonance parameters of the orbitally excited (L = 1) narrow B{sup 0} mesons in decays to B{sup (*)+}{pi}{sup -} using 1.7 fb{sup -1} of data collected by the CDF II detector at the Fermilab Tevatron. The mass and width of the B*{sub 2}{sup 0} state are measured to be m(B*{sub 2}{sup 0}) = 5740.2{sub -1.8}{sup +1.7}(stat.){sub -0.8}{sup +0.9}(syst.) MeV/c{sup 2} and {Lambda}(B*{sub 2}{sup 0}) = 22.7{sub -3.2}{sup +3.8}(stat.){sub -10.2}{sup +3.2}(syst.) MeV/c{sub 2}. The mass difference between the B*{sub 2}{sup 0} and B{sub 1}{sup 0} states is measured to be 14.9{sub -2.5}{sup +2.2}(stat.){sub -1.4}{sup +1.2}(syst.) MeV/c{sup 2}, resulting in a B{sub 1}{sup 0} mass of 5725.3{sub -2.2}{sup +1.6}(stat.){sub -1.5}{sup +1.4}(syst.) MeV/c{sup 2}. This is currently the most precise measurement of the masses of these states and the first measurement of the B*{sub 2}{sup 0} width.

  7. The limits on the strong Higgs sector parameters in the presence of new vector resonances

    CERN Document Server

    Gintner, Mikulas

    2016-01-01

    In this paper, we investigate how the LHC data limit the Higgs related couplings in the effective description of a strongly interacting extension of the Standard model. The Higgs boson is introduced as a scalar composite state and it is followed in the mass hierarchy by an $SU(2)$ triplet of vector composites. The limits are calculated from the constraints on the parameters of the interim kappa framework obtained in the recent ATLAS+CMS combined analysis of the data from 2011 and 2012. In our work, we find that the data prefer the scenario where the Higgs couplings to the electroweak gauge bosons differ from its couplings to the vector triplet. We calculate the experimentally preferred values for these couplings along with the preferred value for the Higgs coupling to the top quark. We also investigate the unitarity limits of the studied effective model for these experimentally preferred values. We find from the $\\pi\\pi\\rightarrow\\pi\\pi$ scattering amplitudes that for the vector resonance masses between one a...

  8. Blade resonance parameter identification based on tip-timing method without the once-per revolution sensor

    Science.gov (United States)

    Guo, Haotian; Duan, Fajie; Zhang, Jilong

    2016-01-01

    Blade tip-timing is the most effective method for blade vibration online measurement of turbomachinery. In this article a synchronous resonance vibration measurement method of blade based on tip-timing is presented. This method requires no once-per revolution sensor which makes it more generally applicable in the condition where this sensor is difficult to install, especially for the high-pressure rotors of dual-rotor engines. Only three casing mounted probes are required to identify the engine order, amplitude, natural frequency and the damping coefficient of the blade. A method is developed to identify the blade which a tip-timing data belongs to without once-per revolution sensor. Theoretical analyses of resonance parameter measurement are presented. Theoretic error of the method is investigated and corrected. Experiments are conducted and the results indicate that blade resonance parameter identification is achieved without once-per revolution sensor.

  9. State Averages

    Data.gov (United States)

    U.S. Department of Health & Human Services — A list of a variety of averages for each state or territory as well as the national average, including each quality measure, staffing, fine amount and number of...

  10. Autoregressive moving average (ARMA) model applied to quantification of cerebral blood flow using dynamic susceptibility contrast-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the feasibility of the autoregressive moving average (ARMA) model for quantification of cerebral blood flow (CBF) with dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSC-MRI) in comparison with deconvolution analysis based on singular value decomposition (DA-SVD). Using computer simulations, we generated a time-dependent concentration of the contrast agent in the volume of interest (VOI) from the arterial input function (AIF) modeled as a gamma-variate function under various CBFs, cerebral blood volumes and signal-to-noise ratios (SNRs) for three different types of residue function (exponential, triangular, and box-shaped). We also considered the effects of delay and dispersion in AIF. The ARMA model and DA-SVD were used to estimate CBF values from the simulated concentration-time curves in the VOI and AIFs, and the estimated values were compared with the assumed values. We found that the CBF value estimated by the ARMA model was more sensitive to the SNR and the delay in AIF than that obtained by DA-SVD. Although the ARMA model considerably overestimated CBF at low SNRs, it estimated the CBF more accurately than did DA-SVD at high SNRs for the exponential or triangular residue function. We believe this study will contribute to an understanding of the usefulness and limitations of the ARMA model when applied to quantification of CBF with DSC-MRI. (author)

  11. Comparison of two non-convex mixed-integer nonlinear programming algorithms applied to autoregressive moving average model structure and parameter estimation

    Science.gov (United States)

    Uilhoorn, F. E.

    2016-10-01

    In this article, the stochastic modelling approach proposed by Box and Jenkins is treated as a mixed-integer nonlinear programming (MINLP) problem solved with a mesh adaptive direct search and a real-coded genetic class of algorithms. The aim is to estimate the real-valued parameters and non-negative integer, correlated structure of stationary autoregressive moving average (ARMA) processes. The maximum likelihood function of the stationary ARMA process is embedded in Akaike's information criterion and the Bayesian information criterion, whereas the estimation procedure is based on Kalman filter recursions. The constraints imposed on the objective function enforce stability and invertibility. The best ARMA model is regarded as the global minimum of the non-convex MINLP problem. The robustness and computational performance of the MINLP solvers are compared with brute-force enumeration. Numerical experiments are done for existing time series and one new data set.

  12. The management-retrieval code system of giant dipole resonance parameter sub-library (CENPL.GDP-1)

    International Nuclear Information System (INIS)

    The giant dipole resonance parameter library, a sub-library of Chinese Evaluated Nuclear Parameter Library (CENPL), consists of two parts: the data file and management-retrieval code system. The former stores the giant dipole resonance parameters (GDRP) of Lorentz curves fitted the total photoneutron cross section data for 102 nuclides from 51V to 239Pu. The latter is used for retrieving GDRP. Since there are no GDRP for most nuclides, a treatment method, which could supplement the GDRP for lack of ones in the data file by using the code system, is presented. It contains the direct retrieval, replacement, interpolation and systematic calculation. The function, feature and operation instruction of the code system are described briefly

  13. Nuclear magnetic resonance parameters of atomic xenon dissolved in Gay-Berne model liquid crystal.

    Science.gov (United States)

    Lintuvuori, Juho; Straka, Michal; Vaara, Juha

    2007-03-01

    We present constant-pressure Monte Carlo simulations of nuclear magnetic resonance (NMR) spectral parameters, nuclear magnetic shielding relative to the free atom as well as nuclear quadrupole coupling, for atomic xenon dissolved in a model thermotropic liquid crystal. The solvent is described by Gay-Berne (GB) molecules with parametrization kappa=4.4, kappa{'}=20.0 , and mu=nu=1 . The reduced pressure of P{*}=2.0 is used. Previous simulations of a pure GB system with this parametrization have shown that upon lowering the temperature, the model exhibits isotropic, nematic, smectic- A , and smectic- B /molecular crystal phases. We introduce spherical xenon solutes and adjust the energy and length scales of the GB-Xe interaction to those of the GB-GB interaction. This is done through first principles quantum chemical calculations carried out for a dimer of model mesogens as well as the mesogen-xenon complex. We preparametrize quantum chemically the Xe nuclear shielding and quadrupole coupling tensors when interacting with the model mesogen, and use the parametrization in a pairwise additive fashion in the analysis of the simulation. We present the temperature evolution of {129/131}Xe shielding and 131Xe quadrupole coupling in the different phases of the GB model. From the simulations, separate isotropic and anisotropic contributions to the experimentally available total shielding can be obtained. At the experimentally relevant concentration, the presence of the xenon atoms does not significantly affect the phase behavior as compared to the pure GB model. The simulations reproduce many of the characteristic experimental features of Xe NMR in real thermotropic LCs: Discontinuity in the value or trends of the shielding and quadrupole coupling at the nematic-isotropic and smectic-A-nematic phase transitions, nonlinear shift evolution in the nematic phase reflecting the behavior of the orientational order parameter, and decreasing shift in the smectic-A phase. The last

  14. Neutron Resonance Parameters of 238U and the Calculated Cross Sections from the Reich-Moore Analysis of Experimental Data in the Neutron Energy Range from 0 keV to 20 keV

    Energy Technology Data Exchange (ETDEWEB)

    Derrien, H

    2005-12-05

    The neutron resonance parameters of {sup 238}U were obtained from a SAMMY analysis of high-resolution neutron transmission measurements and high-resolution capture cross section measurements performed at the Oak Ridge Electron Linear Accelerator (ORELA) in the years 1970-1990, and from more recent transmission and capture cross section measurements performed at the Geel Linear Accelerator (GELINA). Compared with previous evaluations, the energy range for this resonance analysis was extended from 10 to 20 keV, taking advantage of the high resolution of the most recent ORELA transmission measurements. The experimental database and the method of analysis are described in this report. The neutron transmissions and the capture cross sections calculated with the resonance parameters are compared with the experimental data. A description is given of the statistical properties of the resonance parameters and of the recommended values of the average parameters. The new evaluation results in a slight decrease of the effective capture resonance integral and improves the prediction of integral thermal benchmarks by 70 pcm to 200 pcm.

  15. Quaternion Averaging

    Science.gov (United States)

    Markley, F. Landis; Cheng, Yang; Crassidis, John L.; Oshman, Yaakov

    2007-01-01

    Many applications require an algorithm that averages quaternions in an optimal manner. For example, when combining the quaternion outputs of multiple star trackers having this output capability, it is desirable to properly average the quaternions without recomputing the attitude from the the raw star tracker data. Other applications requiring some sort of optimal quaternion averaging include particle filtering and multiple-model adaptive estimation, where weighted quaternions are used to determine the quaternion estimate. For spacecraft attitude estimation applications, derives an optimal averaging scheme to compute the average of a set of weighted attitude matrices using the singular value decomposition method. Focusing on a 4-dimensional quaternion Gaussian distribution on the unit hypersphere, provides an approach to computing the average quaternion by minimizing a quaternion cost function that is equivalent to the attitude matrix cost function Motivated by and extending its results, this Note derives an algorithm that deterniines an optimal average quaternion from a set of scalar- or matrix-weighted quaternions. Rirthermore, a sufficient condition for the uniqueness of the average quaternion, and the equivalence of the mininiization problem, stated herein, to maximum likelihood estimation, are shown.

  16. Arrange and average algorithm for the retrieval of aerosol microphysical parameters from HSRL-2. Comparison with in-situ measurements during DISCOVER-AQ California and Texas (2013)

    Science.gov (United States)

    Chemyakin, E.; Sawamura, P.; Mueller, D.; Burton, S. P.; Ferrare, R. A.; Hostetler, C. A.; Scarino, A. J.; Hair, J. W.; Berkoff, T.; Cook, A. L.; Harper, D. B.; Seaman, S. T.

    2015-12-01

    Although aerosols are only a fairly minor constituent of Earth's atmosphere they are able to affect its radiative energy balance significantly. Light detection and ranging (lidar) instruments have the potential to play a crucial role in atmospheric research as only these instruments provide information about aerosol properties at a high vertical resolution. We are exploring different algorithmic approaches to retrieve microphysical properties of aerosols using lidar. Almost two decades ago we started with inversion techniques based on Tikhonov's regularization that became a reference point for the improvement of retrieval capabilities of inversion algorithms. Recently we began examining the potential of the "arrange and average" scheme, which relies on a look-up table of optical and microphysical aerosol properties. The future combination of these two different inversion schemes may help us to improve the accuracy of the microphysical data products.The novel arrange and average algorithm was applied to retrieve aerosol optical and microphysical parameters using NASA Langley Research Center (LaRC) High Spectral Resolution Lidar (HSRL-2) data. HSRL-2 is the first airborne HSRL system that is able to provide advanced datasets consisting of backscatter coefficients at 355, 532, and 1064 nm, and extinction coefficients at 355 and 532 nm as input information for aerosol microphysical retrievals. HSRL-2 was deployed on-board NASA LaRC's King Air aircraft during the Deriving Information on Surface Conditions from Column and VERtically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) field campaigns over the California Central Valley and Houston. Vertical profiles of aerosol optical properties and size distributions were obtained from in-situ instruments on-board the NASA's P-3B aircraft. As HSRL-2 flew along the same flight track of the P-3B, synergistic measurements and retrievals were obtained by these two independent platforms. We will present an

  17. Averaging kernel prediction from atmospheric and surface state parameters based on multiple regression for nadir-viewing satellite measurements of carbon monoxide and ozone

    Directory of Open Access Journals (Sweden)

    H. M. Worden

    2013-07-01

    Full Text Available A current obstacle to the observation system simulation experiments (OSSEs used to quantify the potential performance of future atmospheric composition remote sensing systems is a computationally efficient method to define the scene-dependent vertical sensitivity of measurements as expressed by the retrieval averaging kernels (AKs. We present a method for the efficient prediction of AKs for multispectral retrievals of carbon monoxide (CO and ozone (O3 based on actual retrievals from MOPITT (Measurements Of Pollution In The Troposphere on the Earth Observing System (EOS-Terra satellite and TES (Tropospheric Emission Spectrometer and OMI (Ozone Monitoring Instrument on EOS-Aura, respectively. This employs a multiple regression approach for deriving scene-dependent AKs using predictors based on state parameters such as the thermal contrast between the surface and lower atmospheric layers, trace gas volume mixing ratios (VMRs, solar zenith angle, water vapor amount, etc. We first compute the singular value decomposition (SVD for individual cloud-free AKs and retain the first three ranked singular vectors in order to fit the most significant orthogonal components of the AK in the subsequent multiple regression on a training set of retrieval cases. The resulting fit coefficients are applied to the predictors from a different test set of test retrievals cased to reconstruct predicted AKs, which can then be evaluated against the true retrieval AKs from the test set. By comparing the VMR profile adjustment resulting from the use of the predicted vs. true AKs, we quantify the CO and O3 VMR profile errors associated with the use of the predicted AKs compared to the true AKs that might be obtained from a computationally expensive full retrieval calculation as part of an OSSE. Similarly, we estimate the errors in CO and O3 VMRs from using a single regional average AK to represent all retrievals, which has been a common approximation in chemical OSSEs

  18. Parameter Diversity Induced Multiple Spatial Coherence Resonances and Spiral Waves in Neuronal Network with and Without Noise

    Institute of Scientific and Technical Information of China (English)

    李玉叶; 贾冰; 古华光; 安书成

    2012-01-01

    Diversity in the neurons and noise are inevitable in the real neuronal network.In this paper,parameter diversity induced spiral waves and multiple spatial coherence resonances in a two-dimensional neuronal network without or with noise are simulated.The relationship between the multiple resonances and the multiple transitions between patterns of spiral waves are identified.The coherence degrees induced by the diversity are suppressed when noise is introduced and noise density is increased.The results suggest that natural nervous system might profit from both parameter diversity and noise,provided a possible approach to control formation and transition of spiral wave by the cooperation between the diversity and noise.

  19. Quantifying Uranium Isotope Ratios Using Resonance Ionization Mass Spectrometry: The Influence of Laser Parameters on Relative Ionization Probability

    OpenAIRE

    Isselhardt, Brett Hallen

    2011-01-01

    Resonance Ionization Mass Spectrometry (RIMS) has been developed as a method to measure relative uranium isotope abundances. In this approach, RIMS is used as an element-selective ionization process to provide a distinction between uranium atoms and potential isobars without the aid of chemical purification and separation. We explore the laser parameters critical to the ionization process and their effects on the measured isotope ratio. Specifically, the use of broad bandwidth lasers with aut...

  20. Dependence of nuclear quadrupole resonance transitions on the electric field gradient asymmetry parameter for nuclides with half-integer spins

    Science.gov (United States)

    Cho, Herman

    2016-09-01

    Allowed transition energies and eigenstate expansions have been calculated and tabulated in numerical form as functions of the electric field gradient asymmetry parameter for the zero field Hamiltonian of quadrupolar nuclides with I = 3 / 2 , 5 / 2 , 7 / 2, and 9 / 2. These results are essential to interpret nuclear quadrupole resonance (NQR) spectra and extract accurate values of the electric field gradient tensors. Applications of NQR methods to studies of electronic structure in heavy element systems are proposed.

  1. Determination of neutron resonance parameters of Neptunium 237 between 0 and 500 eV. The covariance matrices of statistical and of systematic origin, relating the resonance parameters, are also given; Determination des parametres des resonances neutroniques du neptunium 237, en dessous de 500eV, et obtention des matrices de covariances statistiques et systematiques entre les parametres de ces resonances

    Energy Technology Data Exchange (ETDEWEB)

    Lepretre, A.; Herault, N. [CEA Saclay, Dept. d' Astrophysique de Physique des Particules, de Physique Nucleaire et de l' Instrumentation Associee, 91- Gif sur Yvette (France); Brusegan, A.; Noguere, G.; Siegler, P. [Institut des Materiaux et des Metrologies - IRMM, Joint Research Centre, Gell (Belgium)

    2002-12-01

    This report is a follow up of the report CEA DAPNIA/SPHN-99-04T of Vincent Gressier. In the frame of a collaboration between the 'Commissariat a l'Energie Atomique (CEA)' and the Institute for Reference Materials and Measurement (IRMM, Geel, Belgique), the resonance parameters of neptunium 237 have been determined in the energy interval between 0 and 500 eV. These parameters have been obtained by using the Refit code in analysing simultaneously three transmission experiments. The covariance matrix of statistical origin is provided. A new method, based on various sensitivity studies is proposed for determining also the covariance matrix of systematic origin, relating the resonance parameters. From an experimental viewpoint, the study indicated that, with a large probability, the background spectrum has structure. A two dimensional profiler for the neutron density has been proved feasible. Such a profiler could, among others, demonstrate the existence of the structured background. (authors)

  2. Arrange and average algorithm for the retrieval of aerosol parameters from multiwavelength high-spectral-resolution lidar/Raman lidar data.

    Science.gov (United States)

    Chemyakin, Eduard; Müller, Detlef; Burton, Sharon; Kolgotin, Alexei; Hostetler, Chris; Ferrare, Richard

    2014-11-01

    We present the results of a feasibility study in which a simple, automated, and unsupervised algorithm, which we call the arrange and average algorithm, is used to infer microphysical parameters (complex refractive index, effective radius, total number, surface area, and volume concentrations) of atmospheric aerosol particles. The algorithm uses backscatter coefficients at 355, 532, and 1064 nm and extinction coefficients at 355 and 532 nm as input information. Testing of the algorithm is based on synthetic optical data that are computed from prescribed monomodal particle size distributions and complex refractive indices that describe spherical, primarily fine mode pollution particles. We tested the performance of the algorithm for the "3 backscatter (β)+2 extinction (α)" configuration of a multiwavelength aerosol high-spectral-resolution lidar (HSRL) or Raman lidar. We investigated the degree to which the microphysical results retrieved by this algorithm depends on the number of input backscatter and extinction coefficients. For example, we tested "3β+1α," "2β+1α," and "3β" lidar configurations. This arrange and average algorithm can be used in two ways. First, it can be applied for quick data processing of experimental data acquired with lidar. Fast automated retrievals of microphysical particle properties are needed in view of the enormous amount of data that can be acquired by the NASA Langley Research Center's airborne "3β+2α" High-Spectral-Resolution Lidar (HSRL-2). It would prove useful for the growing number of ground-based multiwavelength lidar networks, and it would provide an option for analyzing the vast amount of optical data acquired with a future spaceborne multiwavelength lidar. The second potential application is to improve the microphysical particle characterization with our existing inversion algorithm that uses Tikhonov's inversion with regularization. This advanced algorithm has recently undergone development to allow automated and

  3. Experimental verification of a one-parameter scaling law for the quantum and "classical" resonances of the atom-optics kicked rotor

    CERN Document Server

    Wimberger, S M; Parkins, S; Leonhardt, R; Wimberger, Sandro; Sadgrove, Mark; Parkins, Scott; Leonhardt, Rainer

    2005-01-01

    We present experimental measurements of the mean energy in the vicinity of the first and second quantum resonances of the atom optics kicked rotor for a number of different experimental parameters. Our data is rescaled and compared with the one parameter epsilon--classical scaling function developed to describe the quantum resonance peaks. Additionally, experimental data is presented for the ``classical'' resonance which occurs in the limit as the kicking period goes to zero. This resonance is found to be analogous to the quantum resonances, and a similar one-parameter classical scaling function is derived, and found to match our experimental results. The width of the quantum and classical resonance peaks is compared, and their Sub-Fourier nature examined.

  4. New experimental determination of the neutron resonance parameters of 99Tc

    International Nuclear Information System (INIS)

    In order to improve nuclear data for nuclear waste transmutation cross-sections of Tc99 in the resonance energy region have been performed using the time-of-flight method at the pulsed white neutron source GELINA of the Institute for Reference Materials and Measurements, Geel, Belgium. The energy range studied spreads from 3 eV to 100 KeV. 2 kinds of measurements have been performed: capture and transmission measurements. In the energy range between 0 and 2 KeV, more than 220 resonances have been analyzed. About 130 resonances which had stayed previously undiscovered, have been detected and analyzed. Because of instability problems concerning the process of measuring itself, the systematic error is not yet determined. The accuracy which takes into account statistical and systematic errors is expected to be between 4 and 5%

  5. Comprehensive Population-Averaged Arterial Input Function for Dynamic Contrast–Enhanced vMagnetic Resonance Imaging of Head and Neck Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Onxley, Jennifer D.; Yoo, David S. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Muradyan, Naira [iCAD Inc., Nashua, New Hampshire (United States); MacFall, James R. [Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Brizel, David M. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Department of Surgery, Duke University Medical Center, Durham, North Carolina (United States); Craciunescu, Oana I., E-mail: Oana.Craciunescu@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)

    2014-07-01

    Purpose: To generate a population-averaged arterial input function (PA-AIF) for quantitative analysis of dynamic contrast-enhanced MRI data in head and neck cancer patients. Methods and Materials: Twenty patients underwent dynamic contrast-enhanced MRI during concurrent chemoradiation therapy. Imaging consisted of 2 baseline scans 1 week apart (B1/B2) and 1 scan after 1 week of chemoradiation therapy (Wk1). Regions of interest (ROIs) in the right and left carotid arteries were drawn on coronal images. Plasma concentration curves of all ROIs were averaged and fit to a biexponential decay function to obtain the final PA-AIF (AvgAll). Right-sided and left-sided ROI plasma concentration curves were averaged separately to obtain side-specific AIFs (AvgRight/AvgLeft). Regions of interest were divided by time point to obtain time-point-specific AIFs (AvgB1/AvgB2/AvgWk1). The vascular transfer constant (K{sub trans}) and the fractional extravascular, extracellular space volume (V{sub e}) for primaries and nodes were calculated using the AvgAll AIF, the appropriate side-specific AIF, and the appropriate time-point-specific AIF. Median K{sub trans} and V{sub e} values derived from AvgAll were compared with those obtained from the side-specific and time-point-specific AIFs. The effect of using individual AIFs was also investigated. Results: The plasma parameters for AvgAll were a{sub 1,2} = 27.11/17.65 kg/L, m{sub 1,2} = 11.75/0.21 min{sup −1}. The coefficients of repeatability (CRs) for AvgAll versus AvgLeft were 0.04 min{sup −1} for K{sub trans} and 0.02 for V{sub e}. For AvgAll versus AvgRight, the CRs were 0.08 min{sup −1} for K{sub trans} and 0.02 for V{sub e}. When AvgAll was compared with AvgB1/AvgB2/AvgWk1, the CRs were slightly higher: 0.32/0.19/0.78 min{sup −1}, respectively, for K{sub trans}; and 0.07/0.08/0.09 for V{sub e}. Use of a PA-AIF was not significantly different from use of individual AIFs. Conclusion: A PA-AIF for head and neck cancer

  6. The precision of pharmacokinetic parameters in dynamic contrast-enhanced magnetic resonance imaging: the effect of sampling frequency and duration

    Energy Technology Data Exchange (ETDEWEB)

    Aerts, Hugo J W L [Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University, Maastricht (Netherlands); Jaspers, K; Backes, Walter H, E-mail: w.backes@mumc.nl [Department of Radiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center (MUMC), Maastricht (Netherlands)

    2011-09-07

    Dynamic contrast-enhanced magnetic resonance imaging is increasingly applied for tumour diagnosis and early evaluation of therapeutic responses over time. However, the reliability of pharmacokinetic parameters derived from DCE-MRI is highly dependent on the experimental settings. In this study, the effect of sampling frequency (f{sub s}) and duration on the precision of pharmacokinetic parameters was evaluated based on system identification theory and computer simulations. Both theoretical analysis and simulations showed that a higher value of the pharmacokinetic parameter K{sup trans} required an increasing sampling frequency. For instance, for similar results, a relatively low f{sub s} of 0.2 Hz was sufficient for a low K{sup trans} of 0.1 min{sup -1}, compared to a high f{sub s} of 3 Hz for a high K{sup trans} of 0.5 min{sup -1}. For the parameter v{sub e}, a decreasing value required a higher sampling frequency. A sampling frequency below 0.1 Hz systematically resulted in imprecise estimates for all parameters. For the K{sup trans} and v{sub e} parameters, the sampling duration should be above 2 min, but durations of more than 7 min do not further improve parameter estimates.

  7. The precision of pharmacokinetic parameters in dynamic contrast-enhanced magnetic resonance imaging: the effect of sampling frequency and duration

    Science.gov (United States)

    Aerts, Hugo J. W. L.; Jaspers, K.; Backes, Walter H.

    2011-09-01

    Dynamic contrast-enhanced magnetic resonance imaging is increasingly applied for tumour diagnosis and early evaluation of therapeutic responses over time. However, the reliability of pharmacokinetic parameters derived from DCE-MRI is highly dependent on the experimental settings. In this study, the effect of sampling frequency (fs) and duration on the precision of pharmacokinetic parameters was evaluated based on system identification theory and computer simulations. Both theoretical analysis and simulations showed that a higher value of the pharmacokinetic parameter Ktrans required an increasing sampling frequency. For instance, for similar results, a relatively low fs of 0.2 Hz was sufficient for a low Ktrans of 0.1 min-1, compared to a high fs of 3 Hz for a high Ktrans of 0.5 min-1. For the parameter ve, a decreasing value required a higher sampling frequency. A sampling frequency below 0.1 Hz systematically resulted in imprecise estimates for all parameters. For the Ktrans and ve parameters, the sampling duration should be above 2 min, but durations of more than 7 min do not further improve parameter estimates.

  8. Generalized Parameter-Adjusted Stochastic Resonance of Duffing Oscillator and Its Application to Weak-Signal Detection.

    Science.gov (United States)

    Lai, Zhi-Hui; Leng, Yong-Gang

    2015-08-28

    A two-dimensional Duffing oscillator which can produce stochastic resonance (SR) is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR) model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application.

  9. Generalized Parameter-Adjusted Stochastic Resonance of Duffing Oscillator and Its Application to Weak-Signal Detection

    Directory of Open Access Journals (Sweden)

    Zhi-Hui Lai

    2015-08-01

    Full Text Available A two-dimensional Duffing oscillator which can produce stochastic resonance (SR is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application.

  10. Electrostatic Generation of Bulk Acoustic Waves and Electrical Parameters of Si-MEMS Resonators.

    Science.gov (United States)

    Dulmet, Bernard; Ivan, Mihaela Eugenia; Ballandras, Sylvain

    2016-02-01

    This paper proposes an analytical approach to model the generation of bulk acoustic waves in an electrostatically excited silicon MEMS structure, as well as its electromechanical response in terms of static and dynamic displacements, electromechanical coupling, and motional current. The analysis pertains to the single-port electrostatic drive of trapped-energy thickness-extensional (TE) modes in thin plates. Both asymmetric single-side and symmetric double-side electrostatic gap configurations are modeled. Green's function is used to describe the characteristic of the static displacement of the driven surface of the structure versus the dc bias voltage, which allows us to determine the electrical response of the resonator. Optical and electrical characterizations have been performed on resonator samples operating at 10.3 MHz on the fundamental of TE mode under single-side electrostatic excitation. The various figures of merit depend on the dc bias voltage. Typical values of 9000 for the Q-factor, and of 10(-5) for the electromechanical coupling factor k(2) have been obtained with [Formula: see text] for [Formula: see text]-thick gaps. Here-considered modes have a typical temperature coefficients of frequency (TCF) close to -30 ppm/(°)C. We conclude that the practical usability of such electrostatically excited bulk acoustic waves (BAW) resonators essentially depends on the efficiency of the compensation of feed-through capacitance.

  11. Application of Optimized Neural Network Models for Prediction of Nuclear Magnetic Resonance Parameters in Carbonate Reservoir Rocks

    Directory of Open Access Journals (Sweden)

    Javad Ghiasi-Freez

    2015-05-01

    Full Text Available Neural network models are powerful tools for extracting the underlying dependency of a set of input/output data. However, the mentioned tools are in danger of sticking in local minima. The present study went to step forward by optimizing neural network models using three intelligent optimization algorithms, including genetic algorithm (GA, particle swarm optimization (PSO, and ant colony (AC, to eliminate the risk of being exposed to local minima. This strategy was capable of significantly improving the accuracy of a neural network by optimizing network parameters such as weights and biases. Nuclear magnetic resonance (NMR log measures some of the most useful characteristics of reservoir rock; the capabilities of the optimized models were used for prediction of nuclear magnetic resonance (NMR log parameters in a carbonate reservoir rock of Iran. Conventional porosity logs, which are the easily accessible tools compared to NMR log’s parameters, were introduced to the models as inputs while free fluid porosity and permeability, which were measured by NMR log, are desire outputs. The performance of three optimized models was verified by some unseen test data. The results show that PSO-based network and ACO-based network is the best and poorest method, respectively, in terms of accuracy; however, the convergence time of GA-based model is considerably smaller than PSO-based and GA-based models.

  12. Neutron Transmission and Capture Measurements and Resonance Parameter Analysis of Neodymium from 1eV to 500 eV

    International Nuclear Information System (INIS)

    Neodymium is a 235U fission product and is important for reactor neutronic calculations. The aim of the present work is to improve upon the existing neutron cross section data of neodymium. Neutron capture and transmission measurements were performed by the time-off-light technique at the Rensselaer Polytechnic Institute LINAC laboratory using metallic neodymium samples. The capture measurements were made at the 25-m flight station with a 16-segment NaI multiplicity detector, and the transmission measurements were performed at 15-m and 25-m flight stations, respectively, with 6Li glass scintillation detectors. After the data were collected and reduced, resonance parameters were determined by combined fitting of the transmission and capture data with the multilevel R-matrix Bayesian code SAMMY. The resonance parameters for all naturally occurring neodymium isotopes were deduced within the energy range of 1 eV to 500 eV. The resulting resonance parameters were used to calculate the capture resonance integrals from this energy. The RPI parameters gave a resonance integral value of 32 ± 1 barns that is approximately 7% lower than that obtained with the ENDF-B/VI parameters. The current measurements significantly reduce the uncertainties on the resonance parameters when compared with previously published parameters

  13. Dependence of nuclear quadrupole resonance transitions on the electric field gradient asymmetry parameter for nuclides with half-integer spins

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Herman

    2016-09-01

    Allowed transition energies and eigenstate expansions have been calculated and tabulated in numerical form as functions of the electric field gradient asymmetry parameter for the zero field Hamiltonian of quadrupolar nuclides with I = 3/2, 5/2, 7/2, and 9/2. These results may be used to interpret nuclear quadrupole resonance (NQR) spectra and extract accurate values of the electric field gradient tensors. Applications of NQR methods to studies of electronic structure in heavy element systems are proposed. This material is based upon work supported by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences, Heavy Element Chemistry program.

  14. Relativistic effects in the intermolecular interaction-induced nuclear magnetic resonance parameters of xenon dimer

    DEFF Research Database (Denmark)

    Hanni, Matti; Lantto, Perttu; Ilias, Miroslav;

    2007-01-01

    Relativistic effects on the 129Xe nuclear magnetic resonance shielding and 131Xe nuclear quadrupole coupling (NQC) tensors are examined in the weakly bound Xe2 system at different levels of theory including the relativistic four-component Dirac-Hartree-Fock (DHF) method. The intermolecular...... hand, for the BPPT-based cross coupling of relativity and correlation. For ?ll, the fully relativistic DMP2 results obtain a correction for NR correlation effects beyond MP2. The computed temperature dependence of the second virial coefficient of the 129Xe nuclear shielding is compared to experiment...... interaction-induced binary chemical shift d, the anisotropy of the shielding tensor ?s, and the NQC constant along the internuclear axis ?ll are calculated as a function of the internuclear distance. DHF shielding calculations are carried out using gauge-including atomic orbitals. For comparison, the full...

  15. Equivariant singularity theory with distinguished parameters : Two case studies of resonant Hamiltonian systems

    NARCIS (Netherlands)

    Broer, H.W.; Lunter, G.A.; Vegter, G.

    1998-01-01

    We consider Hamiltonian systems near equilibrium that can be (formally) reduced to one degree of freedom. Spatiotemporal symmetries play a key role. The planar reduction is studied by equivariant singularity theory with distinguished parameters. The method is illustrated on the conservative spring-p

  16. Method for determination of the average parameters of the dispersion optical potential for p+A in the range of 40 ≤ A ≤ 208 and -60 ≤ E ≤ 65 MeV

    International Nuclear Information System (INIS)

    The method for determination of the average parameters of the proton dispersion optical potential, applicable in the area of the nuclei mass numbers 40 ≤ A ≤ 208 and within the energy range of -60 ≤ E ≤+65 MeV is proposed. Application of the average parameters makes it possible to reliable forecast the differential cross sections of elastic scattering and polarization, complete cross sections of reactions, characteristics of the single-particle proton stets in the A-1 and A+1 nuclei

  17. Determination of GLUT1 Oligomerization Parameters using Bioluminescent Förster Resonance Energy Transfer

    Science.gov (United States)

    Looyenga, Brendan; VanOpstall, Calvin; Lee, Zion; Bell, Jed; Lodge, Evans; Wrobel, Katherine; Arnoys, Eric; Louters, Larry

    2016-01-01

    The facilitated glucose transporter GLUT1 (SLC2A1) is an important mediator of glucose homeostasis in humans. Though it is found in most cell types to some extent, the level of GLUT1 expression across different cell types can vary dramatically. Prior studies in erythrocytes—which express particularly high levels of GLUT1—have suggested that GLUT1 is able to form tetrameric complexes with enhanced transport activity. Whether dynamic aggregation of GLUT1 also occurs in cell types with more modest expression of GLUT1, however, is unclear. To address this question, we developed a genetically encoded bioluminescent Förster resonance energy transfer (BRET) assay using the luminescent donor Nanoluciferase and fluorescent acceptor mCherry. By tethering these proteins to the N-terminus of GLUT1 and performing saturation BRET analysis, we were able to demonstrate the formation of multimeric complexes in live cells. Parallel use of flow cytometry and immunoblotting further enabled us to estimate the density of GLUT1 proteins required for spontaneous oligomerization. These data provide new insights into the physiological relevance of GLUT1 multimerization as well as a new variant of BRET assay that is useful for measuring the interactions among other cell membrane proteins in live cells. PMID:27357903

  18. Cyclotron resonant scattering feature simulations. I. Thermally averaged cyclotron scattering cross sections, mean free photon-path tables, and electron momentum sampling

    CERN Document Server

    Schwarm, F -W; Falkner, S; Pottschmidt, K; Wolff, M T; Becker, P A; Sokolova-Lapa, E; Klochkov, D; Ferrigno, C; Fuerst, F; Hemphill, P B; Marcu-Cheatham, D M; Dauser, T; Wilms, J

    2016-01-01

    Electron cyclotron resonant scattering features (CRSFs) are observed as absorption-like lines in the spectra of X-ray pulsars. A significant fraction of the computing time for Monte Carlo simulations of these quantum mechanical features is spent on the calculation of the mean free path for each individual photon before scattering, since it involves a complex numerical integration over the scattering cross section and the (thermal) velocity distribution of the scattering electrons. We aim to numerically calculate interpolation tables which can be used in CRSF simulations to sample the mean free path of the scattering photon and the momentum of the scattering electron. The tables also contain all the information required for sampling the scattering electron's final spin. The tables were calculated using an adaptive Simpson integration scheme. The energy and angle grids were refined until a prescribed accuracy is reached. The tables are used by our simulation code to produce artificial CRSF spectra. The electron...

  19. Stack Parameters Effect on the Performance of Anharmonic Resonator Thermoacoustic Heat Engine

    KAUST Repository

    Nouh, Mostafa A.

    2014-01-01

    A thermoacoustic heat engine (TAHE) converts heat into acoustic power with no moving parts. It exhibits several advantages over traditional engines, such as simple design, stable functionality, and environment-friendly working gas. In order to further improve the performance of TAHE, stack parameters need to be optimized. Stack\\'s position, length and plate spacing are the three main parameters that have been investigated in this study. Stack\\'s position dictates both the efficiency and the maximum produced acoustic power of the heat engine. Positioning the stack closer to the pressure anti-node might ensure high efficiency on the expense of the maximum produced acoustic power. It is noticed that the TAHE efficiency can further be improved by spacing the plates of the stack at a value of 2.4 of the thermal penetration depth, δk . Changes in the stack length will not affect the efficiency much as long as the temperature gradient across the stack, as a ratio of the critical temperature gradient ψ is more than 1. Upon interpreting the effect of these variations, attempts are made towards reaching the engine\\'s most powerful operating point.

  20. Brain magnetic resonance imaging, aerobic power, and metabolic parameters among 30 asymptomatic scuba divers.

    Science.gov (United States)

    Tripodi, D; Dupas, B; Potiron, M; Louvet, S; Geraut, C

    2004-11-01

    The aim of the study was to evaluate the presence of cerebral lesions in asymptomatic scuba divers and explain the causes of them: potential risk factors associating cardiovascular risk factors, low aerobic capacity, or characteristics of diving (maximum depth, ascent rate). Experienced scuba divers, over 40 years of age, without any decompression sickness (DCS) history were included. We studied 30 scuba divers (instructors) without any clinical symptoms. For all of them, we carried out a clinical examination with fatty body mass determination and we questioned them about their diving habits. A brain Magnetic Resonance imaging (MRI), an assessment of maximal oxygen uptake, glycemia, triglyceridemia, and cholesterolemia were systematically carried out. Cerebral spots of high intensity were found at 33 % in the scuba diving group and 30 % in the control group. In the diving group, abnormalities were related to unsafe scuba-diving or metabolic abnormalities. In our study, we did not find a significant relationship between the lesions of the central nervous system, and the age, depth of the dives, number of dives, and ergometric performances (maximal oxygen uptake, V.O (2max), serum level of blood lactate). Nevertheless, we found a significant relationship between the lesions of the central nervous system and ascent rate faster than 10 meters per minute (r = 0.57; p = 0.003) or presence of high level of cholesterolemia (r = 0.6; p = 0.001). We found concordant results using the Cochran's Test: meaningful link between the number of brain lesions and the speed of decompression (Uexp = 14 < Utable = 43; alpha = 0.05, p < 0.01). We concluded that hyperintensities can be explained by preformed nitrogen gas microbubbles and particularly in presence of cholesterol, when the ascent rate is up to 10 meters per minute. So, it was remarkable to note that asymptomatic patients practicing scuba diving either professionally or recreationally, presented lesions of the central nervous

  1. Method of averaged energy differences of coupled states and other approaches for calculation line broadening parameters of HD16O transitions

    Science.gov (United States)

    Dudaryonok, A. S.; Voronin, B. A.; Lavrentieva, N. N.; Lugovskoy, A. A.; Starikov, V. I.

    2012-11-01

    Air-broadening coefficients of the water isotopologue HD16O up to J = 50 for P, Q and R branches calculated using different methods are presented. For partially labeled lines ("good" quantum numbers: J, symmetry and level number) we combined three methods for calculating half-widths: J-dependence and JJ'-dependence up to J=15 and averaging coefficients calculated using a previously developed semi-empirical method for high J (15-50). For lines with full assignments based on normal modes v1, v2, v3, Ka, Kc we used: (a) an analytical model (approximation) which depends on use of rotational quantum numbers J and Ka for both the upper and lower levels; and (b) a method based on the estimate of the averaged energy differences between coupled states. The comparison of calculated data with broadening coefficients from HITRAN-2008 and available experimental data is presented. The resulting broadening coefficients can be used to calculate spectra of water vapor with hundreds millions of weak lines with reasonable accuracy. The line list VTT [Voronin, Tennyson, Tolchenov, MNRAS, 2010], supporting programs, files for calculations of spectra HD16O and estimation of broadening coefficient are made freely available also in electronic form via http://www.exomol.com.

  2. Low-Field Magnetic Resonance Imaging of the Lumbar Spine: Reliability of Qualitative Evaluation of Disc and Muscle Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Solgaard Sorensen, J.; Kjaer, P.; Jensen, S.T.; Andersen, P. [Univ. of Southern Denmark, Ringe (Denmark). Clinical Locomotion Science

    2006-11-15

    Purpose: To determine the intra- and interobserver reliability in grading disc and muscle parameters using low-field magnetic resonance imaging (MRI). Material and Methods: MRI scans of 100 subjects representative of the general population were evaluated blindly by two radiologists. Criteria for grading lumbar discs were based on the spinal nomenclature of the Combined Task Force and the literature. Consensus in rating was achieved by evaluating 50 MRI examinations in tandem. The remaining 50 examinations were evaluated independently by the observers to determine interobserver agreement and re-evaluated by one of the observers to determine intra-observer agreement. Results: Intra- and interobserver agreement was substantial when grading changes in the lumbar discs. Interobserver agreement was fair to moderate in grading the lumbar muscles, whereas intra-observer agreement was almost perfect. Conclusion: Convincing reliability was found in the evaluation of disc- and muscle-related MRI variables.

  3. Relativistic theory of nuclear magnetic resonance parameters in a Gaussian basis representation

    International Nuclear Information System (INIS)

    The calculation of NMR parameters from relativistic quantum theory in a Gaussian basis expansion requires some care. While in the absence of a magnetic field the expansion in a kinetically balanced basis converges for the wave function in the mean and for the energy with any desired accuracy, this is not necessarily the case for magnetic properties. The results for the magnetizability or the nuclear magnetic shielding are not even correct in the nonrelativistic limit (nrl) if one expands the original Dirac equation in a kinetically balanced Gaussian basis. This defect disappears if one starts from the unitary transformed Dirac equation as suggested by Kutzelnigg [Phys. Rev. A 67, 032109 (2003)]. However, a new difficulty can arise instead if one applies the transformation in the presence of the magnetic field of a point nucleus. If one decomposes certain contributions, the individual terms may diverge, although their sum is regular. A controlled cancellation may become difficult and numerical instabilities can arise. Various ways exist to avoid these singularities and at the same time get the correct nrl. There are essentially three approaches intermediate between the transformed and the untransformed formulation, namely, the bispinor decomposition, the decomposition of the lower component, and the hybrid unitary transformation partially at operator and partially at matrix level. All three possibilities were first considered by Xiao et al. [J. Chem. Phys. 126, 214101 (2007)] in a different context and in a different nomenclature. Their analysis and classification in a more general context are given here for the first time. Use of an extended balanced basis has no advantages and has other drawbacks and is not competitive, while the use of a restricted magnetic balance basis can be justified.

  4. Resonance parameters of the reaction {sup 12}C(d,pγ){sup 13}C in the vicinity of 1450 keV for accelerator energy calibration

    Energy Technology Data Exchange (ETDEWEB)

    Csedreki, L., E-mail: csedreki@atomki.mta.hu [Institute for Nuclear Research, Hungarian Academy of Sciences, MTA Atomki, H-4001 Debrecen, P.O. Box 51 (Hungary); Szíki, G.Á. [University of Debrecen, Faculty of Engineering, Department of Basic Technical Studies, H-4028 Debrecen, Ótemető u. 2-4 (Hungary); Szikszai, Z. [Institute for Nuclear Research, Hungarian Academy of Sciences, MTA Atomki, H-4001 Debrecen, P.O. Box 51 (Hungary); Kocsis, I. [University of Debrecen, Faculty of Engineering, Department of Basic Technical Studies, H-4028 Debrecen, Ótemető u. 2-4 (Hungary)

    2015-01-01

    The observed resonance parameters of the {sup 12}C(d,pγ){sup 13}C reaction in the vicinity of 1450 keV deuteron energy have been determined in a thorough procedure, fitting our recent experimental excitation curve, as well as earlier literature data with the Root Software Package. The resulting energy and width (FWHM) of resonance are 1445.8 ± 0.2 keV and 5.3 ± 0.4 keV, respectively. We propose the application of this resonance as a precise and simple method for accelerator energy calibration when performing DIGE analysis.

  5. Quantifying Uranium Isotope Ratios Using Resonance Ionization Mass Spectrometry: The Influence of Laser Parameters on Relative Ionization Probability

    Energy Technology Data Exchange (ETDEWEB)

    Isselhardt, Brett H. [Univ. of California, Berkeley, CA (United States)

    2011-09-01

    Resonance Ionization Mass Spectrometry (RIMS) has been developed as a method to measure relative uranium isotope abundances. In this approach, RIMS is used as an element-selective ionization process to provide a distinction between uranium atoms and potential isobars without the aid of chemical purification and separation. We explore the laser parameters critical to the ionization process and their effects on the measured isotope ratio. Specifically, the use of broad bandwidth lasers with automated feedback control of wavelength was applied to the measurement of 235U/238U ratios to decrease laser-induced isotopic fractionation. By broadening the bandwidth of the first laser in a 3-color, 3-photon ionization process from a bandwidth of 1.8 GHz to about 10 GHz, the variation in sequential relative isotope abundance measurements decreased from >10% to less than 0.5%. This procedure was demonstrated for the direct interrogation of uranium oxide targets with essentially no sample preparation. A rate equation model for predicting the relative ionization probability has been developed to study the effect of variation in laser parameters on the measured isotope ratio. This work demonstrates that RIMS can be used for the robust measurement of uranium isotope ratios.

  6. A laboratory study to estimate pore geometric parameters of sandstones using complex conductivity and nuclear magnetic resonance for permeability prediction

    Science.gov (United States)

    Osterman, Gordon; Keating, Kristina; Binley, Andrew; Slater, Lee

    2016-06-01

    We estimate parameters from the Katz and Thompson permeability model using laboratory complex electrical conductivity (CC) and nuclear magnetic resonance (NMR) data to build permeability models parameterized with geophysical measurements. We use the Katz and Thompson model based on the characteristic hydraulic length scale, determined from mercury injection capillary pressure estimates of pore throat size, and the intrinsic formation factor, determined from multisalinity conductivity measurements, for this purpose. Two new permeability models are tested, one based on CC data and another that incorporates CC and NMR data. From measurements made on forty-five sandstone cores collected from fifteen different formations, we evaluate how well the CC relaxation time and the NMR transverse relaxation times compare to the characteristic hydraulic length scale and how well the formation factor estimated from CC parameters compares to the intrinsic formation factor. We find: (1) the NMR transverse relaxation time models the characteristic hydraulic length scale more accurately than the CC relaxation time (R2 of 0.69 and 0.33 and normalized root mean square errors (NRMSE) of 0.16 and 0.21, respectively); (2) the CC estimated formation factor is well correlated with the intrinsic formation factor (NRMSE=0.23). We demonstrate that that permeability estimates from the joint-NMR-CC model (NRMSE=0.13) compare favorably to estimates from the Katz and Thompson model (NRMSE=0.074). This model advances the capability of the Katz and Thompson model by employing parameters measureable in the field giving it the potential to more accurately estimate permeability using geophysical measurements than are currently possible.

  7. Physical training is associated with changes in Nuclear magnetic resonance and morphometrical parameters of the skeletal muscle in senescent mice

    Directory of Open Access Journals (Sweden)

    C Zancanaro

    2009-08-01

    Full Text Available The effect of a three-month training period on T2 relaxation time as well as on myofibre size and type was investigated in the lower limbs of senescent mice. After training, T2 (which is a magnetic resonance imaging parameter known to increase during acute exercise was significantly higher in trained mice (36.37±1.27 vs 37.76±2.06 ms, p=0.003, n=8, whereas no change was found in non-trained animals (36.35±1.02 vs 36.24±1.15 ms, p=0.278, n=8. The percentage of muscle limb area evaluated in vivo on magnetic resonance images before and after the experimental period was unchanged in trained mice (69.84±2.50 vs 70.29±2.29, p=0.896, n=3 and decreased in non-trained animals (72.98±1.68 vs 64.62±2.34, p=0.006, n=3. Cross-sectional area of fast and slow myofibres, evaluated on paraffin-embedded samples after immunolabelling for skeletal fast fibre myosin, was lower in non-trained than in trained mice in both gastrocnemius and quadriceps muscle, but no change in slow/fast fibre ratio nor in apoptotic rate was found. These data show that training can prevent sarcopenia in senescent mice by affecting muscle status and inducing myofibre hypertrophy in the absence of significant muscle damage.

  8. Note: Modified π-type Butterworth-Van Dyke model for dual-mode Lamb-wave resonator with precise two-port Y-parameter characterizations

    Science.gov (United States)

    Wang, Yong; Hong, Yan; Goh, Wang Ling; Mu, Xiaojing

    2016-10-01

    Dual-mode Lamb-wave resonator has become a powerful component for clock reference and sensing applications, enabling efficient compensations of temperature effects, concurrent measurements of multiple environmental parameters, etc. An equivalent circuit model for the dual-mode Lamb-wave resonator is indispensable as it provides a means as well as being an effective tool for evaluating device characteristics and to aid the designing of circuitry for the resonators. This could be the first time ever that an efficient equivalent-circuit model, i.e., modified π-type Butterworth-Van Dyke model for dual-mode Lamb-wave resonators is reported. Evaluated by experiments, this model attains noteworthy agreements on both the magnitudes and phases of Y11 and Y21 of the measurement results. Compared to literature, the proposed model is capable of modeling the dual resonances efficiently. Moreover, this work also proves more accurate when viewing the Y-parameters across a wide frequency range. The gained features of this model are most beneficial for the analysis of the dual-mode Lamb-wave resonator and also for the designing of circuits.

  9. Ferro-resonance in medium and high-voltage grids - Part 3: ferro-resonance parameters and investigation methods; Ferroresonanzschwingungen in Hoch- und Mittelspannungsnetzen. Teil 3: Parameter von Ferroresonanzkreisen und Methoden zur Untersuchung

    Energy Technology Data Exchange (ETDEWEB)

    Braeunlich, R. [Fachkommission fuer Hochspannungsfragen, Zuerich (Switzerland); Daeumling, H. [Ritz Messwandler GmbH, Hamburg (Germany); Hofstetter, M. [Elektrizitaetswerk der Stadt Zuerich (EWZ), Zuerich (Switzerland); Prucker, U.; Schmid, J.; Minkner, R. [Trench-Germany GmbH, Bamberg (Germany); Schlierf, H.-W. [RWE Transportnetz Strom GmbH, Dortmund (Germany)

    2008-07-01

    This illustrated article is part of a series of four articles that examine ferro-resonance oscillations that can occur under certain operational conditions that involve inductive and capacitive elements. The authors take a look at the criteria involved with reference to the dangers posed by ferro-resonance oscillations and describe how the presence of such oscillations can be detected. Installations that can be endangered by ferro-resonance are described and the components of the installations that are involved are examined. Single-phase and three-phase resonance are examined and the detection of resonance in the electricity mains is discussed. Modeling and simulation of ferro-resonance oscillations are examined. Magnetization characteristics and circuit losses are discussed and the results of simulations are presented and discussed.

  10. Determination of the neutron resonance parameters for 206Pb and of the thermal neutron capture cross section for 206Pb and 209Bi

    International Nuclear Information System (INIS)

    Chapter 1 describes the motivation of the measurements (accelerator driven systems, stellar nucleosynthesis, neutron induced reactions on 206Pb), the present status of the neutron capture data for 206Pb and 209Bi and the structure of this work. In Chapter 2 the basic reaction theory underlying this work is described. The neutron induced reaction mechanism and formalism are explained. The parameterisation of the cross section in terms of R-matrix theory is discussed and we put particular emphasis on the statistical behaviour of the resonance parameters and the impact of the angular distribution of gamma rays following neutron capture. The relation between experimental observables and the resonance parameters is discussed together with general comments related to resonance shape analysis. Chapter 3 is focused on the determination of resonance parameters for 206Pb. We performed high-resolution transmission and capture measurements at the Time-Of-Flight (TOF) facility GELINA of the IRMM at Geel (B) and determined the resonance parameters. For nuclei like 206Pb, where the total width is dominated by Γn, the capture area allows to determine G. Transmission measurements were carried out to determine Γn, and the statistical factor g of resonances. Before performing a Resonance Shape Analysis (RSA) on the transmission and capture data, we verified the neutron flux and resolution at GELINA. We also compared the characteristics of GELINA with those of the n-TOF facility at CERN. A special emphasis is placed on the total energy detection technique using C6D6 detectors. This technique was applied for the determination of the capture cross section. To reduce systematic bias effects on the capture cross section, the response of the detectors was determined by Monte Carlo simulations, which has been validated by experiments. Using these response functions the partial capture cross sections for individual resonances of 206Pb have been deduced, by unfolding the response of the C6D

  11. Magnetic resonance imaging in assessment of stress urinary incontinence in women: Parameters differentiating urethral hypermobility and intrinsic sphincter deficiency

    Institute of Scientific and Technical Information of China (English)

    Katarzyna; Jadwiga; Macura; Richard; Eugene; Thompson; David; Alan; Bluemke; Rene; Genadry

    2015-01-01

    AIM: To define the magnetic resonance imaging(MRI) parameters differentiating urethral hypermobility(UH) and intrinsic sphincter deficiency(ISD) in women with stress urinary incontinence(SUI).METHODS: The static and dynamic MR images of 21 patients with SUI were correlated to urodynamic(UD) findings and compared to those of 10 continent controls. For the assessment of the urethra and integrity of the urethral support structures, we applied the highresolution endocavitary MRI, such as intraurethral MRI, endovaginal or endorectal MRI. For the functional imaging of the urethral support, we performed dynamic MRI with the pelvic phased array coil. We assessed the following MRI parameters in both the patient and thevolunteer groups:(1) urethral angle;(2) bladder neck descent;(3) status of the periurethral ligaments,(4) vaginal shape;(5) urethral sphincter integrity, length and muscle thickness at mid urethra;(6) bladder neck funneling;(7) status of the puborectalis muscle;(8) pubo-vaginal distance. UDs parameters were assessed in the patient study group as follows:(1) urethral mobility angle on Q-tip test;(2) Valsalva leak point pressure(VLPP) measured at 250 cc bladder volume; and(3) maximum urethral closure pressure(MUCP). The UH type of SUI was defined with the Q-tip test angle over 30 degrees, and VLPP pressure over 60 cm H2 O. The ISD incontinence was defined with MUCP pressure below 20 cm H2 O, and VLPP pressure less or equal to 60 cm H2 O. We considered the associations between the MRI and clinical data and UDs using a variety of statistical tools to include linear regression, multivariate logistic regression and receiver operating characteristic(ROC) analysis. All statistical analyses were performed using STATA version 9.0(Stata Corp LP, College Station, TX).RESULTS: In the incontinent group, 52% have history of vaginal delivery trauma as compared to none in control group(P < 0.001). There was no difference between the continent volunteers and incontinent

  12. Phase diagram distortion from traffic parameter averaging.

    NARCIS (Netherlands)

    Stipdonk, H. Toorenburg, J. van & Postema, M.

    2010-01-01

    Motorway traffic congestion is a major bottleneck for economic growth. Therefore, research of traffic behaviour is carried out in many countries. Although well describing the undersaturated free flow phase as an almost straight line in a (k,q)-phase diagram, congested traffic observations and theori

  13. New experimental determination of the neutronic resonance parameters of {sup 237}Np below 500 eV; Nouvelle determination experimentale des parametres de resonances neutroniques de {sup 237}Np en dessous de 500 eV

    Energy Technology Data Exchange (ETDEWEB)

    Gressier, V

    1999-10-01

    For studies of future nuclear reactors dedicated to nuclear waste transmutation, an improvement of the accuracy of the neutron radiative capture cross section of {sup 237}Np appears necessary. In the framework of a collaboration between the Commissariat a l'Energie atomique (CEA) and Institute for Reference Materials and Measurement (IRMM, Geel, Bergium), a new determination of the resonance parameters of {sup 237}Np has been performed. Two types of experiments are carried out at GELINA, the IRMM pulsed neutron source, using the time of flight method: a transmission experiment which is related to the neutron total cross section and a capture experiment which gives the neutron radiative capture cross section. The resonance parameters presented in this work are extracted from the transmission data between 0 and 500 eV with the least square code REFIT, using the Reich-Moore formalism. In parallel, the Doppler effect is investigated. The commonly used free gas model appears inadequate below 20 eV for neptunium dioxide at room temperature. By the use of the program DOPUSH, which calculates the Doppler broadening with a harmonic crystal model according to Lamb's theory, we are able to produce abetter fit of the experimental data for the resonances of {sup 237}Np in NpO{sub 2} at low energy or temperatures. In addition to the resonance parameters, a study of their mean value and distribution is included in this work. (authors)

  14. The Application of Multiobjective Genetic Algorithm to the Parameter Optimization of Single-Well Potential Stochastic Resonance Algorithm Aimed at Simultaneous Determination of Multiple Weak Chromatographic Peaks

    Directory of Open Access Journals (Sweden)

    Haishan Deng

    2014-01-01

    Full Text Available Simultaneous determination of multiple weak chromatographic peaks via stochastic resonance algorithm attracts much attention in recent years. However, the optimization of the parameters is complicated and time consuming, although the single-well potential stochastic resonance algorithm (SSRA has already reduced the number of parameters to only one and simplified the process significantly. Even worse, it is often difficult to keep amplified peaks with beautiful peak shape. Therefore, multiobjective genetic algorithm was employed to optimize the parameter of SSRA for multiple optimization objectives (i.e., S/N and peak shape and multiple chromatographic peaks. The applicability of the proposed method was evaluated with an experimental data set of Sudan dyes, and the results showed an excellent quantitative relationship between different concentrations and responses.

  15. Inter- and intra-rater reproducibility of semiautomatic determination of volume parameters in cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Trieb, Thomas [Department of Radiology, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck (Austria)], E-mail: thomas.trieb@i-med.ac.at; Glodny, Bernhard; Scheiblhofer, Martin; Wolf, Christian [Department of Radiology, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck (Austria); Metzler, Bernhard; Pachinger, Otmar [Division of Cardiology, Department of Internal Medicine, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck (Austria); Jaschke, Werner R.; Schocke, Michael F.H. [Department of Radiology, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck (Austria)

    2008-12-15

    Purpose: The purpose of this study was to evaluate inter- and intra-rater reproducibility in volume assessment using cardiac magnetic resonance imaging (CMRI). Methods: Twenty-five healthy volunteers and 106 patients were included into this retrospective study and received CMRI. The patients were divided in three groups (group I, 80 patients with arrhythmia; group II, 20 patients with cardiomyopathy; group III, 6 patients after correction of septum defects). Therefore, the images were semiautomatically segmented by an experienced and an unexperienced radiologists. The analysis of end-diastolic volume (EDV), end-systolic volume (ESV) and stroke volume (SV) as well as ejection fraction (EF) and myocardial mass (MM) were performed twice by an experienced and an unexperienced radiologists. The intra-class correlation coefficients (ICC) were determined for the evaluation of inter- and intra-rater variance. Results: The intra-rater reproducibility for determination of EF, ESV, EDV and MM was excellent with ICCs ranging from 0.88 to 0.99 (all p < 0.001). The inter-observer reproducibility for these parameters was also excellent with ICCs ranging from 0.91 to 0.98 (all p < 0.001). The assessment of the SV showed an excellent intra-rater agreement with ICCs of 0.96 and 0.92 (both p < 0.001), but only a moderate ICC for the inter-rater reproducibility (0.54, p < 0.001). Conclusions: Our study shows that assessment of cardiac volumes can be performed on CMRIs with an excellent reproducibility by both experienced and unexperienced investigators.

  16. Applied neutron resonance theory

    International Nuclear Information System (INIS)

    Utilisation of resonance theory in basic and applications-oriented neutron cross section work is reviewed. The technically important resonance formalisms, principal concepts and methods as well as representative computer programs for resonance parameter extraction from measured data, evaluation of resonance data, calculation of Doppler-broadened cross sections and estimation of level-statistical quantities from resonance parameters are described. (orig.)

  17. Theoretical study of the electron paramagnetic resonance parameters and local structure for the tetragonal Ir2+ centre in NaCl

    Indian Academy of Sciences (India)

    Y-X Hu; S-Y Wu; X-F Wang; P Xu

    2010-04-01

    The electron paramagnetic resonance (EPR) parameters (the factors, hyperfine structure constants and the superhyperfine parameters) for the tetragonal Ir2+ centre in NaCl are theoretically investigated from the perturbation formulas of these parameters for a 5d7 ion in tetragonally elongated octahedra. This impurity centre is attributed to the substitutional [IrCl6]4- cluster on host Na+ site, associated with the 4% relative elongation along the 4-axis due to the Jahn–Teller effect. Despite the ionicity of host NaCl, the [IrCl6]4- cluster still exhibits moderate covalency and then the ligand orbital and spin-orbit coupling contributions should be taken into account. In addition, the theoretical EPR parameters based on the Jahn–Teller elongation show good agreement with the observed values.

  18. Measurement of the parity-violation parameters Ab and Ac from the left-right forward-backward asymmetry of leptons in hadronic events at the Z0 resonance

    International Nuclear Information System (INIS)

    The parity-violating parameters Ab and Ac are directly measured by the SLD experiment at the SLAC Linear Collider in e+e- collisions with polarized electrons at the Z0 resonance. Leptons with distinctive total and transverse momenta are used to select and analyze Z0→bcbar events. Ab and Ac are extracted by forming the left-right forward-backward asymmetry in electron beam polarization and quark polar angle. From our 1993 sample of 1.8 pb--1 of Z0 decay data with an average electron beam polarization of 63% we find Ab=0.91±0.14 (stat) ±0.07 (syst) and Ac=0.37±0.23 (stat) ±0.21 (syst)

  19. Experimental investigation of resonance self-shielding and the Doppler effect in uranium and tantalum

    Science.gov (United States)

    Byoun, T. Y.; Block, R. C.; Semler, T. T.

    1972-01-01

    A series of average transmission and average self-indication ratio measurements were performed in order to investigate the temperature dependence of the resonance self-shielding effect in the unresolved resonance region of depleted uranium and tantalum. The measurements were carried out at 77 K, 295 K and approximately 1000 K with sample thicknesses varying from approximately 0.1 to 1.0 mean free path. The average resonance parameters as well as the temperature dependence were determined by using an analytical model which directly integrates over the resonance parameter distribution functions.

  20. Multilevel analysis of the 233U and 235U capture and fission cross-sections and statistical properties of the Kapur-Peierls-type resonance parameters for the S-wave cross-sections of the fissile isotopes

    International Nuclear Information System (INIS)

    At the 1966 Conference on Nuclear Data for Reactors, simultaneous measurements of the capture and fission cross-sections of 233U and 235U were presented. Those measurements have now been analysed with the multilevel formalism developed by Adler and Adler. To obtain consistent sets of resonance parameters the capture and fission data were least-square fitted simultaneously. This analysis was carried out to 60 eV for 233U and to 100 eV for 235U. The main purpose of this analysis was to provide a simple and precise analytical description of the very complex structure of the fission and capture cross-sections of 233U and 235U at low energy. Such an analytical description should be useful to calculate reaction rates in nuclear reactors and to compare experimental data taken with different energy resolutions or at different sample temperatures. For the low-energy resonances of 233U and 235U, the neutron width is always smaller, by at least two orders of magnitude, than the total width. Thus, the total cross-section, for those isotopes, can be approximated as the sum of the absorption cross-section and the potential scattering cross-section. Hence it is possible to compute the total cross-section from the resonance parameters obtained by fitting the fission and capture cross-sections. The total cross-section of 235U computed by this method is compared to the data from a transmission measurement done at Saclay, with the sample at 77 deg. K. The computed total cross-section of 233U is compared with transmission data obtained at Oak Ridge National Laboratory and at the Material Testing Reactor. Such comparisons between data obtained by different experimental techniques illustrate the internal consistency of the low-energy cross-sections of the two main uranium fissile isotopes. The physical interpretation of the resonance parameters is somewhat ambiguous, because such multilevel fits are by no means unique. This is particularly true for 233U since, for this nucleus, the

  1. Theoretical explanation of electron paramagnetic resonance and optical parameters for Cu2+ ion in LiNbO3 crystal

    Indian Academy of Sciences (India)

    S Ravi; P Subramanian

    2007-08-01

    The EPR parameters, anisotropic -factors , and for Cu2+ ion and hyperfine structure constants , and for Cu2+ in LiNbO3 crystal are calculated by the method of diagonalizing the full Hamiltonian matrix. The crystal-field parameters contact with the crystal structure by the aid of the superposition model. The optical transition parameters are calculated using Zhao crystal-field model. The calculated results are in good agreement with the observed values. The results are discussed.

  2. Impact of the mass and other parameters of charged particles on the results of laser resonance acceleration

    Directory of Open Access Journals (Sweden)

    Adam Dubik

    2014-03-01

    Full Text Available Theoretical and numerical analyses are presented concerning the conditions at which the charged particles of different masses can be accelerated to significant kinetic energy in the circularly polarized laser or maser beams and a static magnetic field. The studies are carried out using the analytical derivations of the particles dynamics and theirs kinetic energy. The presented illustrations enabled interpretation of the complex motion of particles and the possibilities of their acceleration. At the examples of an electron, proton and deuteron, the velocity, kinetic energy and trajectory as a function of the acceleration time at the resonance condition are illustrated in the appropriate graphs. The particles with larger masses require the application of enhanced magnetic field intensity at the resonance condition. However, this field intensity can be significantly reduced if the particles are preaccelerated. [b]Keywords[/b]: optoelectronics, acceleration of charged particles, laser, maser, relativistic dynamics, kinetic energy of a particle, electron, proton, deuteron

  3. 半桥LLC谐振变换器参数优化设计%Optimal design of parameters of half-bridge LLC resonant converter

    Institute of Scientific and Technical Information of China (English)

    钟运平; 程小华; 张勇; 程声烽

    2014-01-01

    To solve those problems such as difficulty in analyzing working principle of half-bridge LLC resonant converter,unintuitivity of parameter design, analysis of the working principle of the resonant converter was simplified based on the relationship between resonance and excitation current. Voltage gain and impedance characteristics was analyzed according to equivalent model, and the mutual relationship between the parameters was analyzed from curves of voltage gain and impedance characteristics. Parameter optimization design procedure was given. Finally a 180W/24V drive power was designed and desired simulation and experimental results were obtained.%针对半桥LLC谐振变换器工作原理分析复杂、参数设计直观性较差等问题,根据谐振电流、励磁电流的变化关系,简化了半桥LLC谐振变换器工作原理的分析。由变换器的等效电路模型分析了其电压增益、阻抗特性,并通过相应的电压增益曲线、阻抗特性曲线直观地分析了各参数间相互关系,给出了参数的优化设计步骤。最后设计了180W/24V驱动电源,仿真及实验结果均达到预期效果。

  4. Tests of the 238U+n evaluation for JEF-2 in the unresolved resonance region

    International Nuclear Information System (INIS)

    During the JEF-2 test phase the new evaluation for 238U+n in the unresolved resonance region (adopted for JEF-2 up to 200 keV, for ENDF/B-VI up to 149 keV) has been checked against recent capture cross section measurements and against thick-sample transmission data and capture self-indication ratios. Effects of the unresolved resonance structure on self-shielding and multiple scattering were treated by Monte Carlo techniques based on resonance statistics and average resonance parameters. It was found that the average cross sections and the average resonance parameters given in the new evaluation permit very satisfactory reproduction of all the test data. The resonance-averaged capture cross sections below 200 keV appear now to be known with roughly 2% uncertainty. (orig.)

  5. Challenges and solutions for random sampling of parameters with extremely large uncertainties and analysis of the 232Th resonance covariances

    International Nuclear Information System (INIS)

    Covariance data in the existing evaluated nuclear data libraries often include large relative uncertainties and mathematical inconsistencies, which arise especially in combination with random sampling. The 232Th evaluation from the ENDF/B-VII.1 library has been taken as an example. Possible solutions for mathematically impossible correlation matrices with negative eigenvalues and too low correlation coefficients between inherently positive parameters with large relative uncertainties are proposed. Convergence of the random sampling for lognormal distribution with extremely high relative standard deviations is slow by nature. Using weighted sampling, single parameters or a limited number of correlated parameters with large uncertainties can be sampled. Efficient sampling of a large number of correlated parameters with extremely large relative uncertainties remains unsolved

  6. Dependence of gain and phase-shift on crystal parameters and pump intensity in unidirectional photorefractive ring resonators

    Indian Academy of Sciences (India)

    M K Maurya; T K Yadav; R A Yadav

    2009-04-01

    The steady-state amplification of light beam during two-wave mixing in photorefractive materials has been analysed in the strong nonlinear regime. The oscillation conditions for unidirectional ring resonator have been studied. The signal beam can be amplified in the presence of material absorption, provided the gain due to the beam coupling is large enough to overcome the cavity losses. Such amplification is responsible for the oscillations. The gain bandwidth is only a few Hz. In spite of such an extremely narrow bandwidth, unidirectional oscillation can be observed easily at any cavity length in ring resonators by using photorefractive crystals as the medium and this can be explained in terms of the photorefractive phase-shift. The presence of such a phase-shift allows the possibility of the non-reciprocal steady-state transfer of energy between the two light beams. Dependence of gain bandwidth on coupling constant, absorption coefficient of the material's cavity length (crystal length) and modulation ratio have also been studied.

  7. Initial experience of correlating parameters of intravoxel incoherent motion and dynamic contrast-enhanced magnetic resonance imaging at 3.0 T in nasopharyngeal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Qian-Jun; Zhang, Shui-Xing; Chen, Wen-Bo; Liang, Long; Zhou, Zheng-Gen; Liu, Zai-Yi; Zeng, Qiong-Xin; Liang, Chang-Hong [Guangdong General Hospital/Guangdong Academy of Medical Sciences, Department of Radiology, Guangzhou, Guangdong Province (China); Qiu, Qian-Hui [Guangdong General Hospital/Guangdong Academy of Medical Sciences, Department of Otolaryngology, Guangzhou, Guangdong Province (China)

    2014-12-15

    To determine the correlation between intravoxel incoherent motion (IVIM) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters. Thirty-eight newly diagnosed NPC patients were prospectively enrolled. Diffusion-weighted images (DWI) at 13 b-values were acquired using a 3.0-T MRI system. IVIM parameters including the pure molecular diffusion (D), perfusion-related diffusion (D*), perfusion fraction (f), DCE-MRI parameters including maximum slope of increase (MSI), enhancement amplitude (EA) and enhancement ratio (ER) were calculated by two investigators independently. Intra- and interobserver agreement were evaluated using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. Relationships between IVIM and DCE-MRI parameters were evaluated by calculation of Spearman's correlation coefficient. Intra- and interobserver reproducibility were excellent to relatively good (ICC = 0.887-0.997; narrow width of 95 % limits of agreement). The highest correlation was observed between f and EA (r = 0.633, P < 0.001), with a strong correlation between f and MSI (r = 0.598, P = 0.001). No correlation was observed between f and ER (r = -0.162; P = 0.421) or D* and DCE parameters (r = 0.125-0.307; P > 0.119). This study suggests IVIM perfusion imaging using 3.0-T MRI is feasible in NPC, and f correlates significantly with EA and MSI. (orig.)

  8. Multivariate modelling of prostate cancer combining magnetic resonance derived T2, diffusion, dynamic contrast-enhanced and spectroscopic parameters

    Energy Technology Data Exchange (ETDEWEB)

    Riches, S.F.; Payne, G.S.; Morgan, V.A.; DeSouza, N.M. [Royal Marsden NHS Foundation Trust and Institute of Cancer Research, CRUK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Dearnaley, D. [Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Department of Urology and Department of Academic Radiotherapy, Sutton, Surrey (United Kingdom); Morgan, S. [The Ottawa Hospital Cancer Centre and the University of Ottawa, Division of Radiation Oncology, Ottawa, Ontario (Canada); Partridge, M. [The Institute of Cancer Research, Section of Radiotherapy and Imaging, Sutton, Surrey (United Kingdom); University of Oxford, The Gray Institute for Radiation Oncology and Biology, Oxford (United Kingdom); Livni, N. [Royal Marsden NHS Foundation Trust Chelsea, Department of Histopathology, London (United Kingdom); Ogden, C. [Royal Marsden NHS Foundation Trust Chelsea, Department of Urology, London (United Kingdom)

    2015-05-01

    The objectives are determine the optimal combination of MR parameters for discriminating tumour within the prostate using linear discriminant analysis (LDA) and to compare model accuracy with that of an experienced radiologist. Multiparameter MRIs in 24 patients before prostatectomy were acquired. Tumour outlines from whole-mount histology, T{sub 2}-defined peripheral zone (PZ), and central gland (CG) were superimposed onto slice-matched parametric maps. T{sub 2,} Apparent Diffusion Coefficient, initial area under the gadolinium curve, vascular parameters (K{sup trans},K{sub ep},V{sub e}), and (choline+polyamines+creatine)/citrate were compared between tumour and non-tumour tissues. Receiver operating characteristic (ROC) curves determined sensitivity and specificity at spectroscopic voxel resolution and per lesion, and LDA determined the optimal multiparametric model for identifying tumours. Accuracy was compared with an expert observer. Tumours were significantly different from PZ and CG for all parameters (all p < 0.001). Area under the ROC curve for discriminating tumour from non-tumour was significantly greater (p < 0.001) for the multiparametric model than for individual parameters; at 90 % specificity, sensitivity was 41 % (MRSI voxel resolution) and 59 % per lesion. At this specificity, an expert observer achieved 28 % and 49 % sensitivity, respectively. The model was more accurate when parameters from all techniques were included and performed better than an expert observer evaluating these data. (orig.)

  9. Initial experience of correlating parameters of intravoxel incoherent motion and dynamic contrast-enhanced magnetic resonance imaging at 3.0 T in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    To determine the correlation between intravoxel incoherent motion (IVIM) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters. Thirty-eight newly diagnosed NPC patients were prospectively enrolled. Diffusion-weighted images (DWI) at 13 b-values were acquired using a 3.0-T MRI system. IVIM parameters including the pure molecular diffusion (D), perfusion-related diffusion (D*), perfusion fraction (f), DCE-MRI parameters including maximum slope of increase (MSI), enhancement amplitude (EA) and enhancement ratio (ER) were calculated by two investigators independently. Intra- and interobserver agreement were evaluated using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. Relationships between IVIM and DCE-MRI parameters were evaluated by calculation of Spearman's correlation coefficient. Intra- and interobserver reproducibility were excellent to relatively good (ICC = 0.887-0.997; narrow width of 95 % limits of agreement). The highest correlation was observed between f and EA (r = 0.633, P 0.119). This study suggests IVIM perfusion imaging using 3.0-T MRI is feasible in NPC, and f correlates significantly with EA and MSI. (orig.)

  10. Multi-Group Formulation of the Temperature-Dependent Resonance Scattering Model and its Impact on Reactor Core Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Ghrayeb, Shadi Z. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering; Ougouag, Abderrafi M. [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Ouisloumen, Mohamed [Westinghouse Electric Company, Cranberry Township, PA (United States); Ivanov, Kostadin N. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical and Nuclear Engineering

    2014-01-01

    A multi-group formulation for the exact neutron elastic scattering kernel is developed. It incorporates the neutron up-scattering effects, stemming from lattice atoms thermal motion and accounts for it within the resulting effective nuclear cross-section data. The effects pertain essentially to resonant scattering off of heavy nuclei. The formulation, implemented into a standalone code, produces effective nuclear scattering data that are then supplied directly into the DRAGON lattice physics code where the effects on Doppler Reactivity and neutron flux are demonstrated. The correct accounting for the crystal lattice effects influences the estimated values for the probability of neutron absorption and scattering, which in turn affect the estimation of core reactivity and burnup characteristics. The results show an increase in values of Doppler temperature feedback coefficients up to -10% for UOX and MOX LWR fuels compared to the corresponding values derived using the traditional asymptotic elastic scattering kernel. This paper also summarizes the results done on this topic to date.

  11. Investigation of some parameters influencing the sensitivity of human tooth enamel to gamma radiation using electron paramagnetic resonance

    International Nuclear Information System (INIS)

    Electron paramagnetic resonance (EPR) has been successfully used as a physical technique for gamma radiation dose reconstruction using calcified tissues. To minimize potential discrepancies between EPR readings in future studies, the effects of cavity response factor, tooth position and donor gender on the estimated gamma radiation dose were studied. It was found that the EPR response per sample mass used for assessment of doses in teeth outside of the 70-100 mg range should be corrected by a factor which is a function of the sample mass. In the EPR measurements, the difference in sensitivity of different tooth positions to γ-radiation was taken into consideration. It was determined that among all the premolars and molars tooth positions, the relative standard deviation of sensitivity was 6.5%, with the wisdom teeth and the first molars having the highest and lowest sensitivity to γ-radiation, respectively. The current results reveal no effect of the donor gender on the sensitivity to γ-radiation. (author)

  12. Evaluation of nuclear data for 242Pu in the region of resolved and unresolved resonances (10-5 eV-200 keV)

    International Nuclear Information System (INIS)

    Neutron data for 242Pu are evaluated in the resolved and unresolved resonance regions. In the 10-5-1 keV region, the evaluation is based on the Breit-Wigner resonance parameters. In the unresolved resonance region, all types of average cross-section and width are calculated. The authors quote average parameters and cross-sections in the 1-200 keV region and analyse the errors in the evaluated data. (author)

  13. Averaging anisotropic cosmologies

    International Nuclear Information System (INIS)

    We examine the effects of spatial inhomogeneities on irrotational anisotropic cosmologies by looking at the average properties of anisotropic pressure-free models. Adopting the Buchert scheme, we recast the averaged scalar equations in Bianchi-type form and close the standard system by introducing a propagation formula for the average shear magnitude. We then investigate the evolution of anisotropic average vacuum models and those filled with pressureless matter. In the latter case we show that the backreaction effects can modify the familiar Kasner-like singularity and potentially remove Mixmaster-type oscillations. The presence of nonzero average shear in our equations also allows us to examine the constraints that a phase of backreaction-driven accelerated expansion might put on the anisotropy of the averaged domain. We close by assessing the status of these and other attempts to define and calculate 'average' spacetime behaviour in general relativity

  14. LLC半桥式谐振变换器参数模型与设计%Parameter Model and Design for LLC Resonant Half-bridge Converter

    Institute of Scientific and Technical Information of China (English)

    王镇道; 赵亚魁; 章兢; 吴旭; 易峰

    2012-01-01

    According to working principle of LLC topology,a mathematical model for LLC resonant half-bridge converter is presented in this paper.On the basis of conversion relations between the best conversion efficiency and wide scope of load changes,leakage inductance,magnetic inductance and resonant capacitance are confirmed according to the proposed model.Also a LLC resonant half-bridge converter is designed.By improving switch frequency to MHz-level,its converter efficiency can reach to 94% either in full or light loader.At the same time,the power density can reach to 500W/in3.Experiment results ultimately verify the correctness of the model and parameter deduction.%根据LLC拓扑结构工作原理,建立了LLC半桥式谐振变换器的数学模型。基于最优转换效率和宽负载变化范围的转换关系,根据模型确定了漏感、励磁电感和谐振电容,并设计了一款LLC半桥式谐振变换器,开关频率提高到兆赫兹级,在轻载和满载时效率均达到94%,功率密度达到500W/in3,实验结果表明了模型和参数设计的正确性。

  15. Mass- and field-shift isotope parameters for the $2s - 2p$ resonance doublet of lithium-like ions

    CERN Document Server

    Li, Jiguang; Godefroid, Michel; Fritzsche, Stephan; Gaigalas, Gediminas; Indelicato, Paul; Jönsson, Per

    2012-01-01

    It was recently shown that dielectronic recombination measurements can be used for accurately inferring changes in the nuclear mean-square charge radii of highly-charged lithium-like neodymium [Brandau et al., Phys. Rev. Lett. 100 073201 (2008)]. To make use of this method to derive information about the nuclear charge distribution for other elements and isotopes, accurate electronic isotope shift parameters are required. In this work, we calculate and discuss the relativistic mass- and field-shift factors for the two $2s ^{2}S_{1/2} - 2p ^{2}P^{o}_{1/2,3/2}$ transitions along the lithium isoelectronic sequence. Based on the multiconfiguration Dirac-Hartree-Fock method, the electron correlation and the Breit interaction are taken into account systematically. The analysis of the isotope shifts for these two transitions along the isoelectronic sequence demonstrates the importance and competition between the mass shifts and the field shifts.

  16. Relationship between myocardial T2* values and cardiac volumetric and functional parameters in β-thalassemia patients evaluated by cardiac magnetic resonance in association with serum ferritin levels

    International Nuclear Information System (INIS)

    Purpose: Myocardial T2* cardiovascular magnetic resonance provides a rapid and reproducible assessment of cardiac iron load in thalassemia patients. Although cardiac involvement is mainly characterized by left ventricular dysfunction caused by iron overload, little is known about right ventricular function. The aim of this study was to assess the relationship between T2* value in myocardium and left–right ventricular volumetric and functional parameters and to evaluate the existing associations between left–right ventricles volumetric and functional parameter, myocardial T2* values and blood ferritin levels. Materials and methods: A retrospective analysis of 208 patients with β-thalassemia major and thalassemia intermedia was performed (109 males and 99 females; mean age 37.7 ± 13 years; 143 thalassemia major, 65 thalassemia intermedia). Myocardial iron load was assessed by T2* measurements, and volumetric functions were analyzed using the steady state free precession sequence. Results: A significant correlation was observed between EFLV and T2* (p = 0.0001), EFRV and T2* (p = 0.0279). An inverse correlation was present between DVLV and T2* (p = 0.0468), SVLV and T2* (p = 0.0003), SVRV and T2* (p = 0.0001). There was no significant correlation between cardiac T2* and LV–RV mass indices. A significant correlation was observed between T2* and serum ferritin levels (p < 0.001) and between EFLV and serum ferritin (p < 0.05). Conclusion: Myocardial iron load assessed by T2* cardiac magnetic resonance is associated with deterioration in left–right ventricular function; this is more evident when T2* values fall below 14 ms. CMR appears to be a promising approach for cardiac risk evaluation in TM patients

  17. Relationship between myocardial T2* values and cardiac volumetric and functional parameters in β-thalassemia patients evaluated by cardiac magnetic resonance in association with serum ferritin levels

    Energy Technology Data Exchange (ETDEWEB)

    Liguori, Carlo, E-mail: c.liguori@unicampus.it [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Pitocco, Francesca, E-mail: f.pitocco@unicampus.it [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Di Giampietro, Ilenia, E-mail: i.digiampietro@unicampus.it [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Vivo, Aldo Eros de, E-mail: devivoeros@gmail.com [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Schena, Emiliano, E-mail: e.schena@unicampus.it [Unit of Measurements and Biomedical Instrumentation, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Cianciulli, Paolo, E-mail: CIANCIULLI.PAOLO@aslrmc.it [Thalassemia Unit, Ospedale Sant Eugenio, Piazzale dell’Umanesimo 10, 00143 Rome (Italy); Zobel, Bruno Beomonte, E-mail: b.zobel@unicampus.it [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy)

    2013-09-15

    Purpose: Myocardial T2* cardiovascular magnetic resonance provides a rapid and reproducible assessment of cardiac iron load in thalassemia patients. Although cardiac involvement is mainly characterized by left ventricular dysfunction caused by iron overload, little is known about right ventricular function. The aim of this study was to assess the relationship between T2* value in myocardium and left–right ventricular volumetric and functional parameters and to evaluate the existing associations between left–right ventricles volumetric and functional parameter, myocardial T2* values and blood ferritin levels. Materials and methods: A retrospective analysis of 208 patients with β-thalassemia major and thalassemia intermedia was performed (109 males and 99 females; mean age 37.7 ± 13 years; 143 thalassemia major, 65 thalassemia intermedia). Myocardial iron load was assessed by T2* measurements, and volumetric functions were analyzed using the steady state free precession sequence. Results: A significant correlation was observed between EFLV and T2* (p = 0.0001), EFRV and T2* (p = 0.0279). An inverse correlation was present between DVLV and T2* (p = 0.0468), SVLV and T2* (p = 0.0003), SVRV and T2* (p = 0.0001). There was no significant correlation between cardiac T2* and LV–RV mass indices. A significant correlation was observed between T2* and serum ferritin levels (p < 0.001) and between EFLV and serum ferritin (p < 0.05). Conclusion: Myocardial iron load assessed by T2* cardiac magnetic resonance is associated with deterioration in left–right ventricular function; this is more evident when T2* values fall below 14 ms. CMR appears to be a promising approach for cardiac risk evaluation in TM patients.

  18. Spectral averaging techniques for Jacobi matrices

    CERN Document Server

    del Rio, Rafael; Schulz-Baldes, Hermann

    2008-01-01

    Spectral averaging techniques for one-dimensional discrete Schroedinger operators are revisited and extended. In particular, simultaneous averaging over several parameters is discussed. Special focus is put on proving lower bounds on the density of the averaged spectral measures. These Wegner type estimates are used to analyze stability properties for the spectral types of Jacobi matrices under local perturbations.

  19. Measurements of Cross Sections and Forward-Backward Asymmetries at the Z Resonance and Determination of Electroweak Parameters

    CERN Document Server

    Acciarri, M; Adriani, O; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Balandras, A; Ball, R C; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brigljevic, V; Brochu, F; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Button, A M; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; Cozzoni, B; de la Cruz, B; Csilling, Akos; Cucciarelli, S; Dai, T S; van Dalen, J A; D'Alessandro, R; De Asmundis, R; Déglon, P L; Degré, A; Deiters, K; Della Volpe, D; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Dufournaud, D; Duinker, P; Durán, I; Dutta, S; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Extermann, Pierre; Fabre, M; Faccini, R; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Hofer, H; Holzner, G; Hoorani, H; Hou, S R; Iashvili, I; Innocente, Vincenzo; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Khan, R A; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Koffeman, E; Kopp, A; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kuijten, H; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lassila-Perini, K M; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lu, W; Lübelsmeyer, K; Luci, C; Luckey, D; Lugnier, L; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Marchesini, P A; Marian, G; Martin, J P; Marzano, F; Massaro, G G G; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Merk, M; Meschini, M; Metzger, W J; Von der Mey, M; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Molnár, P; Monteleoni, B; Moulik, T; Muanza, G S; Muheim, F; Muijs, A J M; Musy, M; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Organtini, G; Oulianov, A; Palomares, C; Pandoulas, D; Paoletti, S; Paoloni, A; Paolucci, P; Paramatti, R; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Produit, N; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Raspereza, A V; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Sciarrino, D; Seganti, A; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stone, H; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Suter, H; Swain, J D; Szillási, Z; Sztaricskai, T; Tang, X W; Tauscher, Ludwig; Taylor, L; Tellili, B; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, M; Wang, X L; Wang, Z M; Weber, A; Weber, M; Wienemann, P; Wilkens, H; Wu, S X; Wynhoff, S; Xia, L; Xu, Z Z; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zhang, Z P; Zhu, G Y; Zhu, R Y; Zichichi, A; Zilizi, G; Zöller, M

    2000-01-01

    We report on measurements of hadronic and leptonic cross sections and leptonic forward-backward asymmetries performed with the L3 detector in the years $1993-95$.A total luminosity of 103 pb$^{-1}$ was collected at centre-of-mass energies $\\sqrt{s} \\approx m_\\mathrm{Z}$ and $\\sqrt{s} \\approx m_\\mathrm{Z} \\pm 1.8$ GeVwhich corresponds to 2.5 million hadronic and 245 thousand leptonic events selected.These data lead to a significantly improved determination of Z parameters.From the total cross sections, combined with our measurements in $1990-92$,we obtain the final results:%%%\\begin{eqnarr ay*} m_\\mathrm{Z} = 91189.8 \\pm 3.1\\ \\mathrm{MeV} \\, , & & \\Gamma_\\mathrm{Z} = 2502.4 \\pm 4.2\\ \\mathrm{MeV} \\, , \\\\ \\Gamma_\\mathrm{had} = 1741.1 \\pm 3.8\\ \\mathrm{MeV} \\, , & & \\Gamma_\\ell = 84.14 \\pm 0.17\\ \\mathrm{MeV} \\,. \\label{eq:Zpara_abstract}\\end{eqnarray*}%%%An invisible width of $\\Gamma_\\mathrm{inv} = 499.1 \\pm 2.9$ MeV is derived which in the Standard Model yields for the numberof light neutrino spec...

  20. Incorporating doubly resonant $W^\\pm$ data in a global fit of SMEFT parameters to lift flat directions

    CERN Document Server

    Berthier, Laure; Trott, Michael

    2016-01-01

    We calculate the double pole contribution to two to four fermion scattering through $W^{\\pm}$ currents at tree level in the Standard Model Effective Field Theory (SMEFT). We assume all fermions to be massless, $\\rm U(3)^5$ flavour and $\\rm CP$ symmetry. Using this result, we update the global constraint picture on SMEFT parameters including LEPII data on these charged current processes, and also include modifications to our fit procedure motivated by a companion paper focused on $W^{\\pm}$ mass extractions. The fit reported is now to 177 observables and emphasises the need for a consistent inclusion of theoretical errors, and a consistent treatment of observables. Including charged current data lifts the two-fold degeneracy previously encountered in LEP (and lower energy) data, and allows us to set simultaneous constraints on 20 of 53 Wilson coefficients in the SMEFT, consistent with our assumptions. This allows the model independent inclusion of LEP data in SMEFT studies at LHC, which are projected into the S...

  1. Modifications in Dynamic Contrast-Enhanced Magnetic Resonance Imaging Parameters After α-Particle-Emitting {sup 227}Th-trastuzumab Therapy of HER2-Expressing Ovarian Cancer Xenografts

    Energy Technology Data Exchange (ETDEWEB)

    Heyerdahl, Helen, E-mail: Helen.Heyerdahl@rr-research.no [Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital - The Norwegian Radium Hospital, Oslo (Norway); Røe, Kathrine [Department of Oncology, Division of Medicine, Akershus University Hospital, Lørenskog (Norway); Brevik, Ellen Mengshoel [Department of Research and Development, Algeta ASA, Oslo (Norway); Dahle, Jostein [Nordic Nanovector AS, Oslo (Norway)

    2013-09-01

    Purpose: The purpose of this study was to investigate the effect of α-particle-emitting {sup 227}Th-trastuzumab radioimmunotherapy on tumor vasculature to increase the knowledge about the mechanisms of action of {sup 227}Th-trastuzumab. Methods and Materials: Human HER2-expressing SKOV-3 ovarian cancer xenografts were grown bilaterally in athymic nude mice. Mice with tumor volumes 253 ± 36 mm{sup 3} (mean ± SEM) were treated with a single injection of either {sup 227}Th-trastuzumab at a dose of 1000 kBq/kg body weight (treated group, n=14 tumors) or 0.9% NaCl (control group, n=10 tumors). Dynamic T1-weighted contrast-enhanced magnetic resonance imaging (DCEMRI) was used to study the effect of {sup 227}Th-trastuzumab on tumor vasculature. DCEMRI was performed before treatment and 1, 2, and 3 weeks after therapy. Tumor contrast-enhancement curves were extracted voxel by voxel and fitted to the Brix pharmacokinetic model. Pharmacokinetic parameters for the tumors that underwent radioimmunotherapy were compared with the corresponding parameters of control tumors. Results: Significant increases of k{sub ep}, the rate constant of diffusion from the extravascular extracellular space to the plasma (P<.05), and k{sub el,} the rate of clearance of contrast agent from the plasma (P<.01), were seen in the radioimmunotherapy group 2 and 3 weeks after injection, compared with the control group. The product of k{sub ep} and the amplitude parameter A, associated with increased vessel permeability and perfusion, was also significantly increased in the radioimmunotherapy group 2 and 3 weeks after injection (P<.01). Conclusions: Pharmacokinetic modeling of MRI contrast-enhancement curves evidenced significant alterations in parameters associated with increased tumor vessel permeability and tumor perfusion after {sup 227}Th-trastuzumab treatment of HER2-expressing ovarian cancer xenografts.

  2. Stochastic averaging of quasi-Hamiltonian systems

    Institute of Scientific and Technical Information of China (English)

    朱位秋

    1996-01-01

    A stochastic averaging method is proposed for quasi-Hamiltonian systems (Hamiltonian systems with light dampings subject to weakly stochastic excitations). Various versions of the method, depending on whether the associated Hamiltonian systems are integrable or nonintegrable, resonant or nonresonant, are discussed. It is pointed out that the standard stochastic averaging method and the stochastic averaging method of energy envelope are special cases of the stochastic averaging method of quasi-Hamiltonian systems and that the results obtained by this method for several examples prove its effectiveness.

  3. An analytical method for estimating the 14N nuclear quadrupole resonance parameters of organic compounds with complex free induction decays for radiation effects studies

    International Nuclear Information System (INIS)

    The use of 14N nuclear quadrupole resonance (NQR) as a radiation dosimetry tool has only recently been explored. An analytical method for analyzing 14N NQR complex free induction decays is presented with the background necessary to conduct pulsed NQR experiments. The 14N NQR energy levels and possible transitions are derived in step-by-step detail. The components of a pulsed NQR spectrometer are discussed along with the experimental techniques for conducting radiation effects experiments using the spectrometer. Three data analysis techniques -- the power spectral density Fourier transform, state space singular value decomposition (HSVD), and nonlinear curve fitting (using the downhill simplex method of global optimization and the Levenberg-Marquart method) -- are explained. These three techniques are integrated into an analytical method which uses these numerical techniques in this order to determine the physical NQR parameters. Sample data sets of urea and guanidine sulfate data are used to demonstrate how these methods can be employed to analyze both simple and complex free induction decays. By determining baseline values for biologically significant organics, radiation effects on the NQR parameters can be studied to provide a link between current radiation dosimetry techniques and the biological effects of radiation

  4. An analytical method for estimating the {sup 14}N nuclear quadrupole resonance parameters of organic compounds with complex free induction decays for radiation effects studies

    Energy Technology Data Exchange (ETDEWEB)

    Iselin, L.H.

    1992-12-31

    The use of {sup 14}N nuclear quadrupole resonance (NQR) as a radiation dosimetry tool has only recently been explored. An analytical method for analyzing {sup 14}N NQR complex free induction decays is presented with the background necessary to conduct pulsed NQR experiments. The {sup 14}N NQR energy levels and possible transitions are derived in step-by-step detail. The components of a pulsed NQR spectrometer are discussed along with the experimental techniques for conducting radiation effects experiments using the spectrometer. Three data analysis techniques -- the power spectral density Fourier transform, state space singular value decomposition (HSVD), and nonlinear curve fitting (using the downhill simplex method of global optimization and the Levenberg-Marquart method) -- are explained. These three techniques are integrated into an analytical method which uses these numerical techniques in this order to determine the physical NQR parameters. Sample data sets of urea and guanidine sulfate data are used to demonstrate how these methods can be employed to analyze both simple and complex free induction decays. By determining baseline values for biologically significant organics, radiation effects on the NQR parameters can be studied to provide a link between current radiation dosimetry techniques and the biological effects of radiation.

  5. Average-energy games

    OpenAIRE

    Bouyer, Patricia; Markey, Nicolas; Randour, Mickael; Larsen, Kim G.; Laursen, Simon

    2015-01-01

    Two-player quantitative zero-sum games provide a natural framework to synthesize controllers with performance guarantees for reactive systems within an uncontrollable environment. Classical settings include mean-payoff games, where the objective is to optimize the long-run average gain per action, and energy games, where the system has to avoid running out of energy. We study average-energy games, where the goal is to optimize the long-run average of the accumulated energy. We show that this ...

  6. Averaged extreme regression quantile

    OpenAIRE

    Jureckova, Jana

    2015-01-01

    Various events in the nature, economics and in other areas force us to combine the study of extremes with regression and other methods. A useful tool for reducing the role of nuisance regression, while we are interested in the shape or tails of the basic distribution, is provided by the averaged regression quantile and namely by the average extreme regression quantile. Both are weighted means of regression quantile components, with weights depending on the regressors. Our primary interest is ...

  7. On the Averaging Principle

    OpenAIRE

    Fibich, Gadi; Gavious, Arieh; Solan, Eilon

    2012-01-01

    Typically, models with a heterogeneous property are considerably harder to analyze than the corresponding homogeneous models, in which the heterogeneous property is replaced with its average value. In this study we show that any outcome of a heterogeneous model that satisfies the two properties of differentiability and interchangibility is O(\\epsilon^2) equivalent to the outcome of the corresponding homogeneous model, where \\epsilon is the level of heterogeneity. We then use this averaging pr...

  8. Average Angular Velocity

    OpenAIRE

    Van Essen, H.

    2004-01-01

    This paper addresses the problem of the separation of rotational and internal motion. It introduces the concept of average angular velocity as the moment of inertia weighted average of particle angular velocities. It extends and elucidates the concept of Jellinek and Li (1989) of separation of the energy of overall rotation in an arbitrary (non-linear) $N$-particle system. It generalizes the so called Koenig's theorem on the two parts of the kinetic energy (center of mass plus internal) to th...

  9. On Averaging Rotations

    DEFF Research Database (Denmark)

    Gramkow, Claus

    1999-01-01

    In this article two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very offten the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...... approximations to the Riemannian metric, and that the subsequent corrections are inherient in the least squares estimation. Keywords: averaging rotations, Riemannian metric, matrix, quaternion...

  10. Averaging anisotropic cosmologies

    CERN Document Server

    Barrow, J D; Barrow, John D.; Tsagas, Christos G.

    2006-01-01

    We examine the effects of spatial inhomogeneities on irrotational anisotropic cosmologies by looking at the average properties of pressure-free Bianchi-type models. Adopting the Buchert averaging scheme, we identify the kinematic backreaction effects by focussing on spacetimes with zero or isotropic spatial curvature. This allows us to close the system of the standard scalar formulae with a propagation equation for the shear magnitude. We find no change in the already known conditions for accelerated expansion. The backreaction terms are expressed as algebraic relations between the mean-square fluctuations of the models' irreducible kinematical variables. Based on these we investigate the early evolution of averaged vacuum Bianchi type $I$ universes and those filled with pressureless matter. In the latter case we show that the backreaction effects can modify the familiar Kasner-like singularity and potentially remove Mixmaster-type oscillations. We also discuss the possibility of accelerated expansion due to ...

  11. Average Angular Velocity

    CERN Document Server

    Essén, H

    2003-01-01

    This paper addresses the problem of the separation of rotational and internal motion. It introduces the concept of average angular velocity as the moment of inertia weighted average of particle angular velocities. It extends and elucidates the concept of Jellinek and Li (1989) of separation of the energy of overall rotation in an arbitrary (non-linear) $N$-particle system. It generalizes the so called Koenig's theorem on the two parts of the kinetic energy (center of mass plus internal) to three parts: center of mass, rotational, plus the remaining internal energy relative to an optimally translating and rotating frame.

  12. On sparsity averaging

    CERN Document Server

    Carrillo, Rafael E; Wiaux, Yves

    2013-01-01

    Recent developments in Carrillo et al. (2012) and Carrillo et al. (2013) introduced a novel regularization method for compressive imaging in the context of compressed sensing with coherent redundant dictionaries. The approach relies on the observation that natural images exhibit strong average sparsity over multiple coherent frames. The associated reconstruction algorithm, based on an analysis prior and a reweighted $\\ell_1$ scheme, is dubbed Sparsity Averaging Reweighted Analysis (SARA). We review these advances and extend associated simulations establishing the superiority of SARA to regularization methods based on sparsity in a single frame, for a generic spread spectrum acquisition and for a Fourier acquisition of particular interest in radio astronomy.

  13. Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from the ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0, ROSFOND-2010, CENDL-3.1 and EAF-2010 Evaluated Data Libraries

    Science.gov (United States)

    Pritychenko, B.; Mughabghab, S. F.

    2012-12-01

    We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellian-averaged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data. Nuclear reaction calculations are discussed and new results are presented. Due to space limitations, the present paper contains only calculated Maxwellian-averaged cross sections and their uncertainties. The complete data sets for all results are published in the Brookhaven National Laboratory report.

  14. Theoretical studies of the local structure and electron paramagnetic resonance parameters for tetragonal VO{sup 2+} in C{sub 6}H{sub 7}KO{sub 7}

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ping [Chongqing Jiaotong Univ. (China). School of Science; Li, Ling [Sichuan University of Arts and Science, Dazhou (China). Dept. of Maths and Finance-Economics

    2015-07-01

    The optical spectra, electron paramagnetic resonance parameters (i.e., the spin Hamiltonian parameters, including paramagnetic g factors and the hyperfine structure constants A{sub i}) and the local distortion structure for the tetragonal VO{sup 2+} in C{sub 6}H{sub 7}KO{sub 7} are theoretically studied based on the crystal-field theory and three-order perturbation formulas of a 3d{sup 1} centre in tetragonal site. The magnitude of orbital reduction factor, core polarisation constant κ, and local structure parameters are obtained by fitting the calculated optical spectra and electron paramagnetic resonance parameters to the experimental values. The theoretical results are in reasonable agreement with the experimental values.

  15. On Averaging Rotations

    DEFF Research Database (Denmark)

    Gramkow, Claus

    2001-01-01

    In this paper two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very often the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...

  16. Resonant spin-flavor precession constraints on the neutrino parameters and the twisting structure of the solar magnetic fields from the solar neutrino data

    Indian Academy of Sciences (India)

    S Dev; Jyoti Dhar Sharma; U C Pandey; S P Sud; B C Chauhan

    2003-07-01

    Resonant spin-flavor precession (RSFP) scenario with twisting solar magnetic fields has been confronted with the solar neutrino data from various ongoing experiments. The anticorrelation apparent in the Homestake solar neutrino data has been taken seriously to constrain ( 2,') parameter space and the twisting profiles of the magnetic field in the convective zone of the Sun. The twisting profiles, thus derived, have been used to calculate the variation of the neutrino detection rates with the solar magnetic activity for the Homestake, Super-Kamiokande and the gallium experiments. It is found that the presence of twisting reduces the degree of anticorrelation in all the solar neutrino experiments. However, the anticorrelation in the Homestake experiment is expected to be more pronounced in this scenario. Moreover, the anticorrelation of the solar neutrino flux emerging from the southern solar hemisphere is expected to be stronger than that for the neutrinos emerging from the northern solar hemispheres.

  17. Updated Chinese Evaluated Nuclear Parameter Library (CENPL - 2)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In nuclear model calculations, besides the need of advanced theoretical models, a large volume ofprecise nuclear basic data and reliable nuclear model parameters are also very important. Therefore theChinese Evaluated Nuclear Parameter Library (CENPL) for the model calculations of nuclear reactionswas developed in the past ten years. The CENPL include (1) atomic masses and deformations (AMD);(2)discrete level schemes (DLS); (3) average neutron resonance parameters (ARP); (4) level density

  18. The averaging principle

    OpenAIRE

    Fibich, Gadi; Gavious, Arieh; Solan, Eilon

    2012-01-01

    Typically, models with a heterogeneous property are considerably harder to analyze than the corresponding homogeneous models, in which the heterogeneous property is replaced with its average value. In this study we show that any outcome of a heterogeneous model that satisfies the two properties of \\emph{differentiability} and \\emph{interchangibility}, is $O(\\epsilon^2)$ equivalent to the outcome of the corresponding homogeneous model, where $\\epsilon$ is the level of heterogeneity. We then us...

  19. Progress on the 140 KV, 10 Megawatt Peak, 1 Megawatt Average Polyphase Quasi-Resonant Bridge, Boost Converter/Modulator for the Spallation Neutron Source (SNS) Klystron Power System

    CERN Document Server

    Reass, W A; Gribble, R F; Lynch, M T; Tallerico, P J; Reass, William A.; Doss, James D.; Gribble, Robert F.; Lynch, Michael T.; Tallerico, Paul J.

    2000-01-01

    This paper describes electrical design and operational characteristics of a zero-voltage-switching 20 kHz polyphase bridge, boost converter/modulator for klystron pulse application. The DC-DC converter derives the buss voltages from a standard 13.8 kV to 2300 Y substation cast-core transformer. Energy storage and filtering is provided by self-clearing metallized hazy polypropylene traction capacitors. Three "H-Bridge" IGBT switching networks are used to generate the polyphase 20 kHz transformers primary drive waveforms. The 20 kHz drive waveforms are chirped the appropriate duration to generate the desired klystron pulse width. PWM (pulse width modulation) of the individual 20 kHz pulses is utilized to provide regulated output waveforms with adaptive feedforward and feedback techniques. The boost transformer design utilizes amorphous nanocrystalline material that provides the required low core loss at design flux levels and switching frequencies. Resonant shunt peaking is used on the transformer secondary to ...

  20. Evaluation of Cm-247 neutron cross sections in the resonance region

    International Nuclear Information System (INIS)

    The neutron cross sections of Cm-247 are evaluated in the resonance (resolved and unresolved) region up to 10 keV. Average resonance parameters (i.e. spacing D, fission and radiative widths, neutron strength functions) are determined for unresolved region calculations. Moreover for a better comparison with the experimental data, fission cross section is calculated up to 10 MeV. In addition, the average number of neutrons emitted per fission as a function of energy is estimated

  1. Parasitic analysis and π-type Butterworth-Van Dyke model for complementary-metal-oxide-semiconductor Lamb wave resonator with accurate two-port Y-parameter characterizations

    Science.gov (United States)

    Wang, Yong; Goh, Wang Ling; Chai, Kevin T.-C.; Mu, Xiaojing; Hong, Yan; Kropelnicki, Piotr; Je, Minkyu

    2016-04-01

    The parasitic effects from electromechanical resonance, coupling, and substrate losses were collected to derive a new two-port equivalent-circuit model for Lamb wave resonators, especially for those fabricated on silicon technology. The proposed model is a hybrid π-type Butterworth-Van Dyke (PiBVD) model that accounts for the above mentioned parasitic effects which are commonly observed in Lamb-wave resonators. It is a combination of interdigital capacitor of both plate capacitance and fringe capacitance, interdigital resistance, Ohmic losses in substrate, and the acoustic motional behavior of typical Modified Butterworth-Van Dyke (MBVD) model. In the case studies presented in this paper using two-port Y-parameters, the PiBVD model fitted significantly better than the typical MBVD model, strengthening the capability on characterizing both magnitude and phase of either Y11 or Y21. The accurate modelling on two-port Y-parameters makes the PiBVD model beneficial in the characterization of Lamb-wave resonators, providing accurate simulation to Lamb-wave resonators and oscillators.

  2. Group cross-sections and resonance self-shielding factors for 239Pu in the unresolved resonance region

    International Nuclear Information System (INIS)

    The authors analyse experimental data on the transmission and fission self-indication functions for 239Pu in the unresolved resonance region. Use is made of the method of generating a cross-section structure based on the multi-level R-matrix formalism (stochastic K-matrix method). Evaluations of the average resonance parameters and group constants for 239Pu are made. (author)

  3. Negative Average Preference Utilitarianism

    Directory of Open Access Journals (Sweden)

    Roger Chao

    2012-03-01

    Full Text Available For many philosophers working in the area of Population Ethics, it seems that either they have to confront the Repugnant Conclusion (where they are forced to the conclusion of creating massive amounts of lives barely worth living, or they have to confront the Non-Identity Problem (where no one is seemingly harmed as their existence is dependent on the “harmful” event that took place. To them it seems there is no escape, they either have to face one problem or the other. However, there is a way around this, allowing us to escape the Repugnant Conclusion, by using what I will call Negative Average Preference Utilitarianism (NAPU – which though similar to anti-frustrationism, has some important differences in practice. Current “positive” forms of utilitarianism have struggled to deal with the Repugnant Conclusion, as their theory actually entails this conclusion; however, it seems that a form of Negative Average Preference Utilitarianism (NAPU easily escapes this dilemma (it never even arises within it.

  4. Resonant interactions of perturbations in MHD flows

    Energy Technology Data Exchange (ETDEWEB)

    Sagalakov, A.M.; Shtern, V.N.

    1977-01-17

    The nonlinear theory of hydrodynamic stability differentiates three types of interactions: deformation of the initial velocity profile by Reynolds stress pulsations, multiplication of harmonics, and the resonant interaction of harmonics with dissimilar wave numbers and frequencies. This article analyzes an approach considering the first and third of these non-linear mechanisms, producing an acceptable approximation of the averaged characteristics of a developing pulsation movement, particularly the averaged turbulent velocity profile. The approach consists in analysis of triharmonic oscillations, the parameters of which satisfy the resonant relationships. A model of a triharmonic pulsation mode is studied which is applicable to MHD flows. It is shown in particular how a magnetic field transverse to the flow plane suppresses the resonant interaction of three-dimensional perturbations. This agrees with experimental studies on two-dimensional turbulence conducted earlier. 11 references, 3 figures.

  5. Controlling Parametric Resonance

    DEFF Research Database (Denmark)

    Galeazzi, Roberto; Pettersen, Kristin Ytterstad

    2012-01-01

    Parametric resonance is a resonant phenomenon which takes place in systems characterized by periodic variations of some parameters. While seen as a threatening condition, whose onset can drive a system into instability, this chapter advocates that parametric resonance may become an advantage if t...

  6. Treatment of Locally Advanced Vaginal Cancer With Radiochemotherapy and Magnetic Resonance Image-Guided Adaptive Brachytherapy: Dose–Volume Parameters and First Clinical Results

    International Nuclear Information System (INIS)

    Purpose: To investigate the clinical feasibility of magnetic resonance image-guided adaptive brachytherapy (IGABT) for patients with locally advanced vaginal cancer and to report treatment outcomes. Methods and Materials: Thirteen patients with vaginal cancer were treated with external beam radiotherapy (45–50.4 Gy) plus IGABT with or without chemotherapy. Distribution of International Federation of Gynecology and Obstetrics stages among patients were as follows: 4 patients had Stage II cancer, 5 patients had Stage III cancer, and 4 patients had Stage IV cancer. The concept of IGABT as developed for cervix cancer was transferred and adapted for vaginal cancer, with corresponding treatment planning and reporting. Doses were converted to the equivalent dose in 2 Gy, applying the linear quadratic model (α/β = 10 Gy for tumor; α/β = 3 for organs at risk). Endpoints studied were gross tumor volume (GTV), dose-volume parameters for high-risk clinical target volume (HRCTV), and organs at risk, local control (LC), adverse side effects, and survival. Results: The mean GTV (± 1 standard deviation) at diagnosis was 45.3 (±30) cm3, and the mean GTV at brachytherapy was 10 (±14) cm3. The mean D90 for the HRCTV was 86 (±13) Gy. The mean D2cc for bladder, urethra, rectum, and sigmoid colon were 80 (±20) Gy, 76 (±16) Gy, 70 (±9) Gy, and 60 (±9) Gy, respectively. After a median follow-up of 43 months (range, 19–87 months), one local recurrence and two distant metastases cases were observed. Actuarial LC and overall survival rates at 3 years were 92% and 85%. One patient with Stage IVA and 1 patient with Stage III disease experienced fistulas (one vesicovaginal, one rectovaginal), and 1 patient developed periurethral necrosis. Conclusions: The concept of IGABT, originally developed for treating cervix cancer, appears to be applicable to vaginal cancer treatment with only minor adaptations. Dose-volume parameters for HRCTV and organs at risk are in a comparable range

  7. Treatment of Locally Advanced Vaginal Cancer With Radiochemotherapy and Magnetic Resonance Image-Guided Adaptive Brachytherapy: Dose-Volume Parameters and First Clinical Results

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, Johannes C.A. [Department of Radiation Oncology, Metropolitan Hospital, Athens (Greece); Schmid, Maximilian P., E-mail: maximilian.schmid@akhwien.at [Department of Radiotherapy, Medical University of Vienna, Vienna (Austria); Fidarova, Elena; Berger, Daniel; Kirisits, Christian; Poetter, Richard [Department of Radiotherapy, Medical University of Vienna, Vienna (Austria)

    2012-04-01

    Purpose: To investigate the clinical feasibility of magnetic resonance image-guided adaptive brachytherapy (IGABT) for patients with locally advanced vaginal cancer and to report treatment outcomes. Methods and Materials: Thirteen patients with vaginal cancer were treated with external beam radiotherapy (45-50.4 Gy) plus IGABT with or without chemotherapy. Distribution of International Federation of Gynecology and Obstetrics stages among patients were as follows: 4 patients had Stage II cancer, 5 patients had Stage III cancer, and 4 patients had Stage IV cancer. The concept of IGABT as developed for cervix cancer was transferred and adapted for vaginal cancer, with corresponding treatment planning and reporting. Doses were converted to the equivalent dose in 2 Gy, applying the linear quadratic model ({alpha}/{beta} = 10 Gy for tumor; {alpha}/{beta} = 3 for organs at risk). Endpoints studied were gross tumor volume (GTV), dose-volume parameters for high-risk clinical target volume (HRCTV), and organs at risk, local control (LC), adverse side effects, and survival. Results: The mean GTV ({+-} 1 standard deviation) at diagnosis was 45.3 ({+-}30) cm{sup 3}, and the mean GTV at brachytherapy was 10 ({+-}14) cm{sup 3}. The mean D90 for the HRCTV was 86 ({+-}13) Gy. The mean D2cc for bladder, urethra, rectum, and sigmoid colon were 80 ({+-}20) Gy, 76 ({+-}16) Gy, 70 ({+-}9) Gy, and 60 ({+-}9) Gy, respectively. After a median follow-up of 43 months (range, 19-87 months), one local recurrence and two distant metastases cases were observed. Actuarial LC and overall survival rates at 3 years were 92% and 85%. One patient with Stage IVA and 1 patient with Stage III disease experienced fistulas (one vesicovaginal, one rectovaginal), and 1 patient developed periurethral necrosis. Conclusions: The concept of IGABT, originally developed for treating cervix cancer, appears to be applicable to vaginal cancer treatment with only minor adaptations. Dose-volume parameters for HRCTV and

  8. Averaged Lema\\^itre-Tolman-Bondi dynamics

    CERN Document Server

    Isidro, Eddy G Chirinos; Piattella, Oliver F; Zimdahl, Winfried

    2016-01-01

    We consider cosmological backreaction effects in Buchert's averaging formalism on the basis of an explicit solution of the Lema\\^itre-Tolman-Bondi (LTB) dynamics which is linear in the LTB curvature parameter and has an inhomogeneous bang time. The volume Hubble rate is found in terms of the volume scale factor which represents a derivation of the simplest phenomenological solution of Buchert's equations in which the fractional densities corresponding to average curvature and kinematic backreaction are explicitly determined by the parameters of the underlying LTB solution at the boundary of the averaging volume. This configuration represents an exactly solvable toy model but it does not adequately describe our "real" Universe.

  9. Average Neutron Total Cross Sections in the Unresolved Energy Range From ORELA High Resolutio Transmission Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Derrien, H

    2004-05-27

    Average values of the neutron total cross sections of {sup 233}U, {sup 235}U, {sup 238}U, and {sup 239}Pu have been obtained in the unresolved resonance energy range from high-resolution transmission measurements performed at ORELA in the past two decades. The cross sections were generated by correcting the effective total cross sections for the self-shielding effects due to the resonance structure of the data. The self-shielding factors were found by calculating the effective and true cross sections with the computer code SAMMY for the same Doppler and resolution conditions as for the transmission measurements, using an appropriate set of resonance parameters. Our results are compared to results of previous measurements and to the current ENDF/B-VI data.

  10. Average-cost based robust structural control

    Science.gov (United States)

    Hagood, Nesbitt W.

    1993-01-01

    A method is presented for the synthesis of robust controllers for linear time invariant structural systems with parameterized uncertainty. The method involves minimizing quantities related to the quadratic cost (H2-norm) averaged over a set of systems described by real parameters such as natural frequencies and modal residues. Bounded average cost is shown to imply stability over the set of systems. Approximations for the exact average are derived and proposed as cost functionals. The properties of these approximate average cost functionals are established. The exact average and approximate average cost functionals are used to derive dynamic controllers which can provide stability robustness. The robustness properties of these controllers are demonstrated in illustrative numerical examples and tested in a simple SISO experiment on the MIT multi-point alignment testbed.

  11. Main resonance analysis for a MR suspension system with slowly varying parameters%参数慢变磁流变非线性悬架系统主共振研究

    Institute of Scientific and Technical Information of China (English)

    董小闵; 王小龙; 古晓科

    2014-01-01

    The output damping force of a magneto-rheological (MR)damper is reduced with increase in working temperature.As a result,the performance of a MR suspension system is degraded.On the basis of the theory of heat transfer and nonlinear vibration,the main resonance of a MR suspension dynamic system with slowly varying parameters was analyzed here.The energy differential equations at the working area of the MR damper were established and solved with the numerical method.The modified Bingham model was applied to calculate the output damping force of the MR damper.The nonlinear dynamic equation of the MR suspension system with slowly varying parameters was formulated.The steady amplitude response of the MR suspension system under the excitation of main resonance was solved with the averaging method.The calculated results showed that the working temperature rises with increase in running time of the MR damper,consequently,the output damping force of the MR damper decreases significantly and the vibration amplitude variation of the suspension system increases,the performance of the MR suspension system is degraded.%针对磁流变阻尼器随工作温度变化导致阻尼力发生改变,进而降低磁流变悬架系统性能的问题,基于传热学方程和参数慢变非线性振动理论研究温度变化对磁流变非线性悬架系统的主共振动力学行为的影响。根据传热学理论建立磁流变阻尼器工作区域能量微分方程,用数值方法求出温度变化规律,用改进的Bingham模型计算磁流变阻尼力;建立慢变参数磁流变非线性悬架系统动力学方程,利用平均法求解主共振激励下的悬架动行程的稳态幅值响应。研究表明:随着运行时间增加,磁流变阻尼器的温度逐渐升高,导致磁流变阻尼力大幅降低,悬架动行程稳态振幅及其变化量越大,从而使得悬架系统的性能偏离设计目标。

  12. LLC半桥谐振变换器参数设计法的比较与优化%Comparison and Optimization for LLC Half-bridge Resonant Converter Parameter Design

    Institute of Scientific and Technical Information of China (English)

    江雪; 龚春英

    2009-01-01

    LLC half-bridge resonant converter has been widely studied due to advantages of high efficiency and high power density.The accurate parameters can create a precondition for LLC resonant converter to achieve high efficiency and satis-factory soft switching.A parameter design strategy based on frequency domain is described,a more accurate design strategy is introduced based on frequency and time domains in order to optimize the parameter.A I,LC resonant converter prototype which employ the latter strategy is designed and the results verify the feasibility of the strategy.%LLC半桥谐振变换器以其高效率、高功率密度等优点成为研究的热门拓扑.合理选择其参数的是实现变换器高工作效率.优良软开关特性的前提和保证.介绍了一种皋丁频域分析的参数设计方法,在总结其优缺点的基础上给出一种更为精确的频域、时域相结合的方法.通过优化参数设计,并根据该设计策略制作了一台LLC半桥谐振变换器样机,以验证所述方法的可行性.

  13. Evaluation of parameters of the HDV (V20 and dose average) in radiotherapy of lung cancer with lung volumes design adapted compounds (ITV); Evaluacion de parametros del HDV (V20 Y Dmed) en radioterapia adaptada de cancer de pulmon con diseno de volumenes pulmonares compuestos (ITV)

    Energy Technology Data Exchange (ETDEWEB)

    Monroy Anton, J. L.; Solar Tortosa, M.; Lopez Munoz, M.; Navarro Bergada, A.; Estornell Gualde, M. A.; Melchor Iniguez, M.

    2013-07-01

    Our objective was to evaluate the V20 parameters and dose average compared to a single lung volume designed with a CT study in normal breathing of the patient and the corresponding to a lung volume composed, designed from three studies of CT in different phases of the respiratory cycle. Check if there are important differences in these cases that determine the necessity of creating a composite lung volume to evaluate dose volume histogram. (Author)

  14. Change in resonance parameters of a linear molecule as it bends: Evidence in electron-impact vibrational transitions of hot COS and CO2 molecules*

    Science.gov (United States)

    Hoshino, Masamitsu; Ishijima, Yohei; Kato, Hidetoshi; Mogi, Daisuke; Takahashi, Yoshinao; Fukae, Katsuya; Limão-Vieira, Paulo; Tanaka, Hiroshi; Shimamura, Isao

    2016-04-01

    Inelastic and superelastic electron-impact vibrational excitation functions of hot carbonyl sulphide COS (and hot CO2) are measured for electron energies from 0.5 to 3.0 eV (1.5 to 6.0 eV) and at a scattering angle of 90°. Based on the vibrational populations and the principle of detailed balance, these excitation functions are decomposed into contributions from state-to-state vibrational transitions involving up to the second bending overtone (030) in the electronically ground state. Both the 2Π resonance for COS around 1.2 eV and the 2Πu resonance for CO2 around 3.8 eV are shifted to lower energies as the initial vibrational state is excited in the bending mode. The width of the resonance hump for COS changes only little as the molecule bends, whereas that of the overall boomerang resonance for CO2 becomes narrower. The angular distribution of the electrons resonantly scattered by hot COS and hot CO2 is also measured. The different shapes depending on the vibrational transitions and gas temperatures are discussed in terms of the symmetry of the vibrational wave functions. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

  15. Dissociating Averageness and Attractiveness: Attractive Faces Are Not Always Average

    Science.gov (United States)

    DeBruine, Lisa M.; Jones, Benedict C.; Unger, Layla; Little, Anthony C.; Feinberg, David R.

    2007-01-01

    Although the averageness hypothesis of facial attractiveness proposes that the attractiveness of faces is mostly a consequence of their averageness, 1 study has shown that caricaturing highly attractive faces makes them mathematically less average but more attractive. Here the authors systematically test the averageness hypothesis in 5 experiments…

  16. Averaging procedure in variable-G cosmologies

    CERN Document Server

    Cardone, Vincenzo F

    2008-01-01

    Previous work in the literature had built a formalism for spatially averaged equations for the scale factor, giving rise to an averaged Raychaudhuri equation and averaged Hamiltonian constraint, which involve a backreaction source term. The present paper extends these equations to include models with variable Newton parameter and variable cosmological term, motivated by the non-perturbative renormalization program for quantum gravity based upon the Einstein--Hilbert action. The coupling between backreaction and spatially averaged three-dimensional scalar curvature is found to survive, and all equations involving contributions of a variable Newton parameter are worked out in detail. Interestingly, under suitable assumptions, an approximate solution can be found where the universe tends to a FLRW model, while keeping track of the original inhomogeneities through two effective fluids.

  17. Virtual Averaging Making Nonframe-Averaged Optical Coherence Tomography Images Comparable to Frame-Averaged Images

    OpenAIRE

    Chen, Chieh-Li; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A.; Kagemann, Larry; Schuman, Joel S.

    2016-01-01

    Purpose Developing a novel image enhancement method so that nonframe-averaged optical coherence tomography (OCT) images become comparable to active eye-tracking frame-averaged OCT images. Methods Twenty-one eyes of 21 healthy volunteers were scanned with noneye-tracking nonframe-averaged OCT device and active eye-tracking frame-averaged OCT device. Virtual averaging was applied to nonframe-averaged images with voxel resampling and adding amplitude deviation with 15-time repetitions. Signal-to...

  18. Formalism for neutron cross section covariances in the resonance region using kernel approximation

    Energy Technology Data Exchange (ETDEWEB)

    Oblozinsky, P.; Cho,Y-S.; Matoon,C.M.; Mughabghab,S.F.

    2010-04-09

    We describe analytical formalism for estimating neutron radiative capture and elastic scattering cross section covariances in the resolved resonance region. We use capture and scattering kernels as the starting point and show how to get average cross sections in broader energy bins, derive analytical expressions for cross section sensitivities, and deduce cross section covariances from the resonance parameter uncertainties in the recently published Atlas of Neutron Resonances. The formalism elucidates the role of resonance parameter correlations which become important if several strong resonances are located in one energy group. Importance of potential scattering uncertainty as well as correlation between potential scattering and resonance scattering is also examined. Practical application of the formalism is illustrated on {sup 55}Mn(n,{gamma}) and {sup 55}Mn(n,el).

  19. Resonance and Fractal Geometry

    OpenAIRE

    Broer, Henk W.

    2012-01-01

    The phenomenon of resonance will be dealt with from the viewpoint of dynamical systems depending on parameters and their bifurcations. Resonance phenomena are associated to open subsets in the parameter space, while their complement corresponds to quasi-periodicity and chaos. The latter phenomena occur for parameter values in fractal sets of positive measure. We describe a universal phenomenon that plays an important role in modelling. This paper gives a summary of the background theory, vein...

  20. Time-dependent angularly averaged inverse transport

    OpenAIRE

    Bal, Guillaume; Jollivet, Alexandre

    2009-01-01

    This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from knowledge of angularly averaged measurements performed at the boundary of a domain of interest. We show that the absorption coefficient and the spatial component of the scattering coefficient are uniquely determined by such measurements. We obtain stability results on the reconstruction of the absorption and scattering parameters with respect to the measured al...

  1. Improving existing computer codes by interactive computer graphics: HAREA: an interactive program to derive resonance parameters by area analysis of neutron transmission data

    International Nuclear Information System (INIS)

    An arrangement of programs is described providing interactive computer graphics assistance to improve the operation of an existing fitting program. The particular example is the well-known 'Atta-Harvey' code used in resonance area analysis of neutron transmission data. This report is intended both as a manual for running the area analysis programs and as a practical example of program improvement by interactive programming methods. (U.K.)

  2. Bayesian Averaging is Well-Temperated

    DEFF Research Database (Denmark)

    Hansen, Lars Kai

    2000-01-01

    Bayesian predictions are stochastic just like predictions of any other inference scheme that generalize from a finite sample. While a simple variational argument shows that Bayes averaging is generalization optimal given that the prior matches the teacher parameter distribution the situation...

  3. Resolving resonances in R-matrix calculations

    International Nuclear Information System (INIS)

    We present a technique to obtain detailed resonance structures from R-matrix calculations of atomic cross sections for both collisional and radiative processes. The resolving resonances (RR) method relies on the QB method of Quigley-Berrington (Quigley L, Berrington K A and Pelan J 1998 Comput. Phys. Commun. 114 225) to find the position and width of resonances directly from the reactance matrix. Then one determines the symmetry parameters of these features and generates an energy mesh whereby fully resolved cross sections are calculated with minimum computational cost. The RR method is illustrated with the calculation of the photoionization cross sections and the unified recombination rate coefficients of Fe XXIV, O VI, and Fe XVII. The RR method reduces numerical errors arising from unresolved R-matrix cross sections in the computation of synthetic bound-free opacities, thermally averaged collision strengths and recombination rate coefficients. (author)

  4. Average Convexity in Communication Situations

    NARCIS (Netherlands)

    Slikker, M.

    1998-01-01

    In this paper we study inheritance properties of average convexity in communication situations. We show that the underlying graph ensures that the graphrestricted game originating from an average convex game is average convex if and only if every subgraph associated with a component of the underlyin

  5. Control of average spacing of OMCVD grown gold nanoparticles

    Science.gov (United States)

    Rezaee, Asad

    Metallic nanostructures and their applications is a rapidly expanding field. Nobel metals such as silver and gold have historically been used to demonstrate plasmon effects due to their strong resonances, which occur in the visible part of the electromagnetic spectrum. Localized surface plasmon resonance (LSPR) produces an enhanced electromagnetic field at the interface between a gold nanoparticle (Au NP) and the surrounding dielectric. This enhanced field can be used for metal-dielectric interfacesensitive optical interactions that form a powerful basis for optical sensing. In addition to the surrounding material, the LSPR spectral position and width depend on the size, shape, and average spacing between these particles. Au NP LSPR based sensors depict their highest sensitivity with optimized parameters and usually operate by investigating absorption peak: shifts. The absorption peak: of randomly deposited Au NPs on surfaces is mostly broad. As a result, the absorption peak: shifts, upon binding of a material onto Au NPs might not be very clear for further analysis. Therefore, novel methods based on three well-known techniques, self-assembly, ion irradiation, and organo-meta1lic chemical vapour deposition (OMCVD) are introduced to control the average-spacing between Au NPs. In addition to covalently binding and other advantages of OMCVD grown Au NPs, interesting optical features due to their non-spherical shapes are presented. The first step towards the average-spacing control is to uniformly form self-assembled monolayers (SAMs) of octadecyltrichlorosilane (OTS) as resists for OMCVD Au NPs. The formation and optimization of the OTS SAMs are extensively studied. The optimized resist SAMs are ion-irradiated by a focused ion beam (Fill) and ions generated by a Tandem accelerator. The irradiated areas are refilled with 3-mercaptopropyl-trimethoxysilane (MPTS) to provide nucleation sites for the OMCVD Au NP growth. Each step during sample preparation is monitored by

  6. The difference between alternative averages

    Directory of Open Access Journals (Sweden)

    James Vaupel

    2012-09-01

    Full Text Available BACKGROUND Demographers have long been interested in how compositional change, e.g., change in age structure, affects population averages. OBJECTIVE We want to deepen understanding of how compositional change affects population averages. RESULTS The difference between two averages of a variable, calculated using alternative weighting functions, equals the covariance between the variable and the ratio of the weighting functions, divided by the average of the ratio. We compare weighted and unweighted averages and also provide examples of use of the relationship in analyses of fertility and mortality. COMMENTS Other uses of covariances in formal demography are worth exploring.

  7. LLC半桥谐振变换器参数优化设计与实现%Design and Implementation of LLC Half-bridge Resonant Converter Parameter Optimization

    Institute of Scientific and Technical Information of China (English)

    叶湖; 周唯逸; 贾文超; 姜明伟

    2016-01-01

    Half-bridge LLC resonant converter of high efficiency and high power density is widely used to drive the LED light source. Through the analysis of its principle, characterization and the resonant network transmission efficiency, we summed up a simple parameter design method. This method designs the LLC half-bridge resonant circuit of 100kHz and 120W with 90% conversion efficiency. The results of experiment confirm the feasibility of the design method.%LLC半桥谐振变换器的高效率、高功率密度使其广泛应用于LED光源驱动器。通过对其工作原理、特性及谐振网络传输效率的分析,归纳出一种简易的参数设计方法。最后,用该方法设计了具有90%变换效率的100kHz、120W的LLC半桥谐振电路,实验结果证实了此设计方法的可行性。

  8. Physical Theories with Average Symmetry

    CERN Document Server

    Alamino, Roberto C

    2013-01-01

    This Letter probes the existence of physical laws invariant only in average when subjected to some transformation. The concept of a symmetry transformation is broadened to include corruption by random noise and average symmetry is introduced by considering functions which are invariant only in average under these transformations. It is then shown that actions with average symmetry obey a modified version of Noether's Theorem with dissipative currents. The relation of this with possible violations of physical symmetries, as for instance Lorentz invariance in some quantum gravity theories, is briefly commented.

  9. Electron paramagnetic resonance parameters of Mn4+ ion in h-BaTiO3 crystal from a two-mechanism model

    Indian Academy of Sciences (India)

    Wu Xiao-Xuan; Fang Wang; Feng Wen-Lin; Zheng Wen-Chen

    2009-03-01

    The EPR parameters ( factors ∥, ⊥ and zero-field splitting ) of Mn4+ ion in h-BaTiO3 crystal are calculated from the complete high-order perturbation formulas based on a two-mechanism model for the EPR parameters of 33 ions in trigonal symmetry. In the model, not only the widely used crystal-field mechanism, but also the charge-transfer mechanism (which is not considered in crystal-field theory) are included. The calculated results are in reasonable agreement with the experimental values. The relative importance of charge-transfer mechanism to EPR parameters and the defect structure of Mn4+ centre in h-BaTiO3 crystal obtained from the calculations are discussed.

  10. The ratio of the kinetic inductance to the geometric inductance: a key parameter for the frequency tuning of the THz semiconductor split-ring resonator.

    Science.gov (United States)

    Cong, Jiawei; Yun, Binfeng; Cui, Yiping

    2013-08-26

    By introducing the frequency tuning sensitivity, an analytical model based on equivalent LC circuit is developed for the relative frequency tuning range of THz semiconductor split-ring resonator (SRR). And the model reveals that the relative tuning range is determined by the ratio of the kinetic inductance to the geometric inductance (RKG). The results show that under the same carrier density variation, a larger RKG results in a larger relative tuning range. Based on this model, a stacked SRR-dimer structure with larger RKG compared to the single SRR due to the inductive coupling is proposed, which improves the relative tuning range effectively. And the results obtained by the simple analytical model agree well with the numerical FDTD results. The presented analytical model is robust and can be used to analyze the relative frequency tuning of other tunable THz devices.

  11. Measurements of the braching fractions for psi(3770)--> D0D0-bar,D+D-,DD-bar$ and the resonance parameters of psi(3770) and psi(2S)

    CERN Document Server

    Ablikim, M

    2006-01-01

    We report measurements of the branching fractions for $\\psi(3770)\\to D^0 \\bar D^0, D^+D^-, D\\bar D$ and resonance parameters of $\\psi(3770)$ and $\\psi(2S)$. By analyzing the line-shapes of the cross sections for inclusive hadron, $D^0 \\bar D^0$ and $D^+D^-$ event production in the range from 3.660 GeV to 3.872 GeV covering both $\\psi(2S)$ and $\\psi(3770)$ resonances, we extract the branching fractions for $\\psi(3770)$ decay into $D^0\\bar D^0 {\\rm and} D^+D^-$ respectively to be $B(\\psi(3770)\\to D^0 \\bar D^0)=(46.7 \\pm 4.7 \\pm 2.3)%$ and $B(\\psi(3770)\\to D^+ D^-)=(36.9 \\pm 3.7 \\pm 2.8)%$, which give $B(\\psi(3770)\\to D \\bar D)=(83.6 \\pm 7.3 \\pm 4.2)%$ and non-$D\\bar D$ branching fraction of $\\psi(3770)$ to be $B(\\psi(3770)\\to non-D \\bar D)=(16.4 \\pm 7.3 \\pm 4.2)%$. We meanwhile obtain the resonance parameters of $\\psi(3770)$ and $\\psi(2S)$ to be $M_{\\psi(3770)}=3772.2 \\pm 0.7 \\pm 0.3$ MeV, $\\Gamma^{\\rm tot}_{\\psi(3770)}=26.9 \\pm 2.4 \\pm 0.3$ MeV and $\\Gamma^{ee}_{\\psi(3770)}=251 \\pm 26 \\pm 11$ eV; $M_{\\psi(2S)}...

  12. 238U self-indication ratio measurement in the resonance region

    International Nuclear Information System (INIS)

    An accurate representation of the 238U cross-section structures in the resonance region is required to compute the resonance self-shielded effective cross sections used in the calculation of thermal and fast-reactor performance parameters. Several authors have demonstrated the usefulness of self-indication and average transmission measurements to investigate the resonance structure of the 238U cross sections. This paper compares measured self-indication ratios with calculations based on ENDF/B-V, in the resolved energy range from 100 eV to 4 keV. In that energy range the ENDF/B-V evaluation is chiefly based on high resolution transmission measurements. The immediate purpose of the comparison presented is not to generate a new set of improved resonance parameters but to provide an additional test of the adequacy of the ENDF/B-V representation for the calculation of resonance self-shielding

  13. Evaluation of the average ion approximation for a tokamak plasma

    International Nuclear Information System (INIS)

    The average ion approximation, sometimes used to calculated atomic processes in plasmas, is assessed by computing deviations in various rates over a set of conditions representative of tokamak edge plasmas. Conditions are identified under which the rates are primarily a function of the average ion charge and plasma parameters, as assumed in the average ion approximation. (Author) 19 refs., tab., 5 figs

  14. Centrality dependence of chemical freeze-out parameters from net-proton and net-charge fluctuations using hadron resonance gas model

    CERN Document Server

    Adak, Rama Prasad; Ghosh, Sanjay K; Ray, Rajarshi; Samanta, Subhasis

    2016-01-01

    We extract chemical freeze-out parameters in HRG and EVHRG model, analysing the experimental information of net-proton and net-charge fluctuations measured in Au + Au collisions by the STAR collaboration at RHIC. We observe that chemical freeze-out parameters extracted from lower and higher order fluctuations are though almost same for $\\sqrt{s_{NN}} > 27$ GeV, they tend to deviate from each other at lower $\\sqrt{s_{NN}}$. Moreover, these separations increase with decrease of $\\sqrt{s_{NN}}$ and for a fixed $\\sqrt{s_{NN}}$ increase towards central collisions. This may be an indication of approach of critical region at lower $\\sqrt{s_{NN}}$. Furthermore, we observe an approximate scaling behaviour of $(\\mu_B/T)/(\\mu_B/T)_{central}$ with $(N_{part})/(N_{part})_{central}$ for the parameters extracted from lower order fluctuations for 11.5 GeV $\\le \\sqrt{s_{NN}} \\le$ 200 GeV. Scaling is violated for the parameters extracted from higher order fluctuations for $\\sqrt{s_{NN}}= 11.5$ and 19.6 GeV. It is observed that...

  15. "Pricing Average Options on Commodities"

    OpenAIRE

    Kenichiro Shiraya; Akihiko Takahashi

    2010-01-01

    This paper proposes a new approximation formula for pricing average options on commodities under a stochastic volatility environment. In particular, it derives an option pricing formula under Heston and an extended lambda-SABR stochastic volatility models (which includes an extended SABR model as a special case). Moreover, numerical examples support the accuracy of the proposed average option pricing formula.

  16. Quantized average consensus with delay

    NARCIS (Netherlands)

    Jafarian, Matin; De Persis, Claudio

    2012-01-01

    Average consensus problem is a special case of cooperative control in which the agents of the network asymptotically converge to the average state (i.e., position) of the network by transferring information via a communication topology. One of the issues of the large scale networks is the cost of co

  17. Time-dependent angularly averaged inverse transport

    International Nuclear Information System (INIS)

    This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from knowledge of angularly averaged measurements performed at the boundary of a domain of interest. Such measurement settings find applications in medical and geophysical imaging. We show that the absorption coefficient and the spatial component of the scattering coefficient are uniquely determined by such measurements. We obtain stability results on the reconstruction of the absorption and scattering parameters with respect to the measured albedo operator. The stability results are obtained by a precise decomposition of the measurements into components with different singular behavior in the time domain

  18. Time-dependent angularly averaged inverse transport

    CERN Document Server

    Bal, Guillaume

    2009-01-01

    This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from knowledge of angularly averaged measurements performed at the boundary of a domain of interest. We show that the absorption coefficient and the spatial component of the scattering coefficient are uniquely determined by such measurements. We obtain stability results on the reconstruction of the absorption and scattering parameters with respect to the measured albedo operator. The stability results are obtained by a precise decomposition of the measurements into components with different singular behavior in the time domain.

  19. Nanofibrous Resonant Membrane for Acoustic Applications

    Directory of Open Access Journals (Sweden)

    K. Kalinová

    2011-01-01

    Full Text Available Because the absorption of lower-frequency sound is problematic with fibrous material made up of coarser fibers, highly efficient sound absorption materials must be developed. The focus of this paper is on the development of a new material with high acoustic absorption characteristics. For low-frequency absorption, structures based upon the resonance principle of nanofibrous layers are employed in which the resonance of some elements allows acoustic energy to be converted into thermal energy. A nanofibrous membrane was produced by an electrostatic spinning process from an aqueous solution of polyvinyl alcohol and the acoustic characteristics of the material measured. The resonant frequency prediction for the nanofibrous membrane is based on research into its production parameters. The distance between electrodes during the electrostatic spinning process determines the average diameter of the nanofibers, and the outlet velocity of the material determines its area density. The average diameter of nanofibers was measured using the Lucia software package directly from an electron microscope image. The resonant frequency of nanofibrous membranes was determined from the sound absorption coefficient and transmission loss measurement.

  20. Average Cross Section Evaluation - Room for Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Frohner, G.H. [Forschungszentrum Karlsruhe Institut fur Kern- und Energietechnik, Karlsruhe (Germany)

    2006-07-01

    Full text of publication follows: Techniques for evaluation of average nuclear cross sections are well established. Nevertheless there seems room for improvement. Heuristic expressions for average partial cross sections of the Hauser-Feshbach type with width fluctuation corrections could be replaced by the correct GOE triple integral. Transmission coefficients derived from macroscopic models (optical, single and double hump fission barrier, etc) lead to better descriptions of cross section behaviour over wide energy ranges. At higher energies (n,{gamma}n') reactions compete with radiative capture (Moldauer effect). In all cross section modeling one must distinguish properly between average S- and R-matrix parameters. The exact relationship between them is given, as well as the connection to Endf format rules. Fitting codes (e.g. FITACS) should be able to digest observed data directly, instead of only reduced data corrected already for self shielding and multiple scattering (e.g. with SESH). (author)

  1. Model averaging and muddled multimodel inferences.

    Science.gov (United States)

    Cade, Brian S

    2015-09-01

    Three flawed practices associated with model averaging coefficients for predictor variables in regression models commonly occur when making multimodel inferences in analyses of ecological data. Model-averaged regression coefficients based on Akaike information criterion (AIC) weights have been recommended for addressing model uncertainty but they are not valid, interpretable estimates of partial effects for individual predictors when there is multicollinearity among the predictor variables. Multicollinearity implies that the scaling of units in the denominators of the regression coefficients may change across models such that neither the parameters nor their estimates have common scales, therefore averaging them makes no sense. The associated sums of AIC model weights recommended to assess relative importance of individual predictors are really a measure of relative importance of models, with little information about contributions by individual predictors compared to other measures of relative importance based on effects size or variance reduction. Sometimes the model-averaged regression coefficients for predictor variables are incorrectly used to make model-averaged predictions of the response variable when the models are not linear in the parameters. I demonstrate the issues with the first two practices using the college grade point average example extensively analyzed by Burnham and Anderson. I show how partial standard deviations of the predictor variables can be used to detect changing scales of their estimates with multicollinearity. Standardizing estimates based on partial standard deviations for their variables can be used to make the scaling of the estimates commensurate across models, a necessary but not sufficient condition for model averaging of the estimates to be sensible. A unimodal distribution of estimates and valid interpretation of individual parameters are additional requisite conditions. The standardized estimates or equivalently the t

  2. Contribution to the study of the unresolved resonance range of the neutrons cross sections

    International Nuclear Information System (INIS)

    This document presents the statistical description of neutron cross sections in the unresolved resonance range. The modeling of the total cross section and of the 'shape - elastic' cross section is based on the 'average R-Matrix' formalism. The partial cross sections describing the radiative capture, elastic scattering, inelastic scattering and fission process are calculated using the Hauser-Feshbach formalism with width fluctuation corrections. In the unresolved resonance range, these models depend on the average resonance parameters (neutron strength function Sc, mean level spacing Dc, average partial reaction widths Γc, channel radius ac, effective radius R' and distant level parameter R-barc∞). The codes (NJOY, CALENDF...) dedicated to the processing of nuclear data libraries (JEFF, ENDF/B, JENDL, CENDL, BROND... ) use the average parameters to take into account the self-shielding phenomenon for the simulation of the neutron transport in Monte-Carlo (MCNP, TRIPOLI... ) and deterministic (APOLLO, ERANOS...) codes. The evaluation work consists in establishing a consistent set of average parameters as a function of the total angular momentum J of the system and of the orbital moment of the incident neutron l. The work presented in this paper aims to describe the links between the S-Matrix and the 'average R-Matrix' formalism for the calculation of Sc, R-barc∞, ac and R'. (author)

  3. Theoretical evaluation of the electron paramagnetic resonance spin Hamiltonian parameters for the impurity displacements for Fe3+ and Ru3+ in corundum

    Indian Academy of Sciences (India)

    Q Fu; S Y Wu; J Z Lin; J S Yao

    2007-03-01

    The impurity displacements for Fe3+ and Ru3+ in corundum (Al2O3) are theoretically studied using the perturbation formulas of the spin Hamiltonian parameters (zero-field splitting and anisotropic factors) for a 3d5 (with high spin = 5/2) and a 4d5 (with low spin = 1/2) ion in trigonal symmetry, respectively. According to the investigations, the nd5 ( = 3 and 4) impurity ions may not locate at the ideal Al3+ site but undergo axial displacements by about 0.132 Å and 0.170 Å for Fe3+ and Ru3+, respectively, away from the center of the ligand octahedron along the C3 axis. The calculated spin Hamiltonian parameters based on the above axial displacements show good agreement with the observed values. The validity of the results is discussed.

  4. Gaussian moving averages and semimartingales

    DEFF Research Database (Denmark)

    Basse-O'Connor, Andreas

    2008-01-01

    In the present paper we study moving averages (also known as stochastic convolutions) driven by a Wiener process and with a deterministic kernel. Necessary and sufficient conditions on the kernel are provided for the moving average to be a semimartingale in its natural filtration. Our results...... are constructive - meaning that they provide a simple method to obtain kernels for which the moving average is a semimartingale or a Wiener process. Several examples are considered. In the last part of the paper we study general Gaussian processes with stationary increments. We provide necessary and sufficient...

  5. Band Structure Parameters and Fermi Resonances of Exciton-Polaritons in CsI and CsBr under Hydrostatic Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Lipp, M J; Yoo, C H; Strachan, D; Daniels, W B

    2005-11-29

    Most alkali halides crystallize in the fcc sodium chloride structure. In contrast, with the exception of CsF, the Cs-halides form the simple cubic cesium chloride (CsCl) structure at ambient conditions and they have a substantially different electronic structure than other alkali halides; in particular, they have several nearly degenerate electronic levels near the Brillouin zone center. Highly resolved Three-Photon Spectroscopy (TPS) measurements allow direct observation of the near band edge structure and, in the case of CsI, probe more states than one-photon techniques. A number of interesting phenomena, among them level repulsion (Fermi resonance), occur as these levels are tuned through one another by application of hydrostatic pressure. To the best of our knowledge, this has been observed for CsBr for the first time. Doubling the photon energy range compared to a previous publication [see Yoo et al. PRL 84, 3875 (2000)] allows direct observation of the n=1, 2 and 3 exciton-polariton members of the {Lambda}{sub 8}{sup -}-{Lambda}{sub 6}{sup +} transition in CsI and lets us establish unambiguous values for the bandgap (6.139 eV), binding energy (0.265 eV) and their pressure dependence up to 7 kbar. Similarly to CsI, the CsBr linewidth of the lowest {Lambda}{sub 4}{sup -} polariton (A) decreases upon compression.

  6. Validation of the GROMOS force-field parameter set 45A3 against nuclear magnetic resonance data of hen egg lysozyme

    Energy Technology Data Exchange (ETDEWEB)

    Soares, T. A. [ETH Hoenggerberg Zuerich, Laboratory of Physical Chemistry (Switzerland); Daura, X. [Universitat Autonoma de Barcelona, InstitucioCatalana de Recerca i Estudis Avancats and Institut de Biotecnologia i Biomedicina (Spain); Oostenbrink, C. [ETH Hoenggerberg Zuerich, Laboratory of Physical Chemistry (Switzerland); Smith, L. J. [University of Oxford, Oxford Centre for Molecular Sciences, Central Chemistry Laboratory (United Kingdom); Gunsteren, W. F. van [ETH Hoenggerberg Zuerich, Laboratory of Physical Chemistry (Switzerland)], E-mail: wfvgn@igc.phys.chem.ethz.ch

    2004-12-15

    The quality of molecular dynamics (MD) simulations of proteins depends critically on the biomolecular force field that is used. Such force fields are defined by force-field parameter sets, which are generally determined and improved through calibration of properties of small molecules against experimental or theoretical data. By application to large molecules such as proteins, a new force-field parameter set can be validated. We report two 3.5 ns molecular dynamics simulations of hen egg white lysozyme in water applying the widely used GROMOS force-field parameter set 43A1 and a new set 45A3. The two MD ensembles are evaluated against NMR spectroscopic data NOE atom-atom distance bounds, {sup 3}J{sub NH{alpha}} and {sup 3}J{sub {alpha}}{sub {beta}} coupling constants, and {sup 1}5N relaxation data. It is shown that the two sets reproduce structural properties about equally well. The 45A3 ensemble fulfills the atom-atom distance bounds derived from NMR spectroscopy slightly less well than the 43A1 ensemble, with most of the NOE distance violations in both ensembles involving residues located in loops or flexible regions of the protein. Convergence patterns are very similar in both simulations atom-positional root-mean-square differences (RMSD) with respect to the X-ray and NMR model structures and NOE inter-proton distances converge within 1.0-1.5 ns while backbone {sup 3}J{sub HN{alpha}}-coupling constants and {sup 1}H- {sup 1}5N order parameters take slightly longer, 1.0-2.0 ns. As expected, side-chain {sup 3}J{sub {alpha}}{sub {beta}}-coupling constants and {sup 1}H- {sup 1}5N order parameters do not reach full convergence for all residues in the time period simulated. This is particularly noticeable for side chains which display rare structural transitions. When comparing each simulation trajectory with an older and a newer set of experimental NOE data on lysozyme, it is found that the newer, larger, set of experimental data agrees as well with each of the

  7. Power convergence of Abel averages

    OpenAIRE

    Kozitsky, Yuri; Shoikhet, David; Zemanek, Jaroslav

    2012-01-01

    Necessary and sufficient conditions are presented for the Abel averages of discrete and strongly continuous semigroups, $T^k$ and $T_t$, to be power convergent in the operator norm in a complex Banach space. These results cover also the case where $T$ is unbounded and the corresponding Abel average is defined by means of the resolvent of $T$. They complement the classical results by Michael Lin establishing sufficient conditions for the corresponding convergence for a bounded $T$.

  8. T2-weighted hypointense lesions within prostate gland: Differential diagnosis using wash-in rate parameter on the basis of dynamic contrast-enhanced magnetic resonance imaging-Hystopatology correlations

    Energy Technology Data Exchange (ETDEWEB)

    Valentini, Anna Lia, E-mail: alvalentini@rm.unicatt.it [Department of Bioimaging and Radiological Sciences, Institute of Radiology, Catholic University of Rome, Policlinico A Gemelli, Lgo A Gemelli n 8, 00168 Rome (Italy); Gui, Benedetta, E-mail: bgui@rm.unicatt.it [Department of Bioimaging and Radiological Sciences, Institute of Radiology, Catholic University of Rome, Policlinico A Gemelli, Lgo A Gemelli n 8, 00168 Rome (Italy); Cina, Alessandro, E-mail: acina@sirm.org [Department of Bioimaging and Radiological Sciences, Institute of Radiology, Catholic University of Rome, Policlinico A Gemelli, Lgo A Gemelli n 8, 00168 Rome (Italy); Pinto, Francesco, E-mail: francesco.pinto@libero.it [Department of Surgical Sciences, Institute of Urology, Catholic University of Rome, Policlinico A Gemelli, Lgo A Gemelli n 8, 00168 Rome (Italy); Totaro, Angelo, E-mail: dr.atotaro@gmail.com [Department of Surgical Sciences, Institute of Urology, Catholic University of Rome, Policlinico A Gemelli, Lgo A Gemelli n 8, 00168 Rome (Italy); Pierconti, Francesco, E-mail: francescopierconti@rm.unicatt.it [Department of Pathology, Catholic University of Rome, Policlinico A Gemelli, Lgo A Gemelli n 8, 00168 Rome (Italy); Bassi, Pier Francesco, E-mail: bassipf@gmail.com [Department of Surgical Sciences, Institute of Urology, Catholic University of Rome, Policlinico A Gemelli, Lgo A Gemelli n 8, 00168 Rome (Italy); Bonomo, Lorenzo, E-mail: lbonomo@rm.unicatt.it [Department of Bioimaging and Radiological Sciences, Institute of Radiology, Catholic University of Rome, Policlinico A Gemelli, Lgo A Gemelli n 8, 00168 Rome (Italy)

    2012-11-15

    Background and aims: Dynamic contrast enhanced magnetic resonance improves prostate cancer detection. The aims of this paper are to verify whether wash-in-rate parameter (speed of contrast uptake in dynamic contrast enhanced magnetic resonance) can help to differentiate prostate cancer from non-neoplastic T2-weighted hypointense lesions within prostate gland and to assess a cut-off for prostate cancer diagnosis. Methods: Prospective, monocentric, multi-departmental study. Thirty consecutive patients underwent T2-weighted and dynamic contrast enhanced magnetic resonance, and re-biopsy. T2-weighted hypointense lesions, >5 mm in size, were noted. Lesions were assessed as cancerous (showing mass effect, or no defined margin within transitional zone) and non cancerous (no mass effect) and were compared with histopathology by 2 Multiplication-Sign 2 tables. Wash-in-rate of each lesion was calculated and was correlated with histopathology. Student's t-test was adopted to assess significant differences. Receiver operating characteristic (ROC) analysis was employed to identify the best cut-off for wash-in-rate in detecting prostate cancer. Results: At re-biopsy, cancer was proven in 43% of patients. On T2-weighted MRI, 111 hypointense lesions {>=}5 mm in size were found. Sensitivity, specificity and accuracy of T2-weighted MRI were 80% ({+-}12.4 CI 95%), 74.6% ({+-}10.1 CI 95%), and 76.5% ({+-}7.9 CI 95%), respectively. Mean WR was 5.8 {+-} 1.9/s for PCa zones and 2.96 {+-} 1.44/s for non-PCa zones (p < 0.00000001). At ROC analysis, the best area under curve (AUC) for wash-in-rate parameter was associated to 4.2/s threshold with 82.5% sensitivity (CI {+-} 7.07), 97.2% specificity (CI {+-} 4.99) and 91.2% accuracy (CI {+-} 5.27). Eighteen false positive lesions on T2-weighted MRI showed low wash-in-rate values suggesting non-cancer lesions, while in 5/8 false negative cases high wash-in-rate values correctly suggested prostate cancer. Nine lesions with surgically proven

  9. T2-weighted hypointense lesions within prostate gland: Differential diagnosis using wash-in rate parameter on the basis of dynamic contrast-enhanced magnetic resonance imaging—Hystopatology correlations

    International Nuclear Information System (INIS)

    Background and aims: Dynamic contrast enhanced magnetic resonance improves prostate cancer detection. The aims of this paper are to verify whether wash-in-rate parameter (speed of contrast uptake in dynamic contrast enhanced magnetic resonance) can help to differentiate prostate cancer from non-neoplastic T2-weighted hypointense lesions within prostate gland and to assess a cut-off for prostate cancer diagnosis. Methods: Prospective, monocentric, multi-departmental study. Thirty consecutive patients underwent T2-weighted and dynamic contrast enhanced magnetic resonance, and re-biopsy. T2-weighted hypointense lesions, >5 mm in size, were noted. Lesions were assessed as cancerous (showing mass effect, or no defined margin within transitional zone) and non cancerous (no mass effect) and were compared with histopathology by 2 × 2 tables. Wash-in-rate of each lesion was calculated and was correlated with histopathology. Student's t-test was adopted to assess significant differences. Receiver operating characteristic (ROC) analysis was employed to identify the best cut-off for wash-in-rate in detecting prostate cancer. Results: At re-biopsy, cancer was proven in 43% of patients. On T2-weighted MRI, 111 hypointense lesions ≥5 mm in size were found. Sensitivity, specificity and accuracy of T2-weighted MRI were 80% (±12.4 CI 95%), 74.6% (±10.1 CI 95%), and 76.5% (±7.9 CI 95%), respectively. Mean WR was 5.8 ± 1.9/s for PCa zones and 2.96 ± 1.44/s for non-PCa zones (p < 0.00000001). At ROC analysis, the best area under curve (AUC) for wash-in-rate parameter was associated to 4.2/s threshold with 82.5% sensitivity (CI ± 7.07), 97.2% specificity (CI ± 4.99) and 91.2% accuracy (CI ± 5.27). Eighteen false positive lesions on T2-weighted MRI showed low wash-in-rate values suggesting non-cancer lesions, while in 5/8 false negative cases high wash-in-rate values correctly suggested prostate cancer. Nine lesions with surgically proven cancer were not included in the

  10. Average life of oxygen vacancies of quartz in sediments

    Institute of Scientific and Technical Information of China (English)

    刁少波; 业渝光

    2002-01-01

    Average life of oxygen vacancies of quartz in sediments is estimated by using the ESR (electron spin resonance) signals of E( centers from the thermal activation technique. The experimental results show that the second-order kinetics equation is more applicable to the life estimation compared with the first order equation. The average life of oxygen vacancies of quartz from 4895 to 4908 deep sediments in the Tarim Basin is about 1018 a at 27℃.

  11. Vocal attractiveness increases by averaging.

    Science.gov (United States)

    Bruckert, Laetitia; Bestelmeyer, Patricia; Latinus, Marianne; Rouger, Julien; Charest, Ian; Rousselet, Guillaume A; Kawahara, Hideki; Belin, Pascal

    2010-01-26

    Vocal attractiveness has a profound influence on listeners-a bias known as the "what sounds beautiful is good" vocal attractiveness stereotype [1]-with tangible impact on a voice owner's success at mating, job applications, and/or elections. The prevailing view holds that attractive voices are those that signal desirable attributes in a potential mate [2-4]-e.g., lower pitch in male voices. However, this account does not explain our preferences in more general social contexts in which voices of both genders are evaluated. Here we show that averaging voices via auditory morphing [5] results in more attractive voices, irrespective of the speaker's or listener's gender. Moreover, we show that this phenomenon is largely explained by two independent by-products of averaging: a smoother voice texture (reduced aperiodicities) and a greater similarity in pitch and timbre with the average of all voices (reduced "distance to mean"). These results provide the first evidence for a phenomenon of vocal attractiveness increases by averaging, analogous to a well-established effect of facial averaging [6, 7]. They highlight prototype-based coding [8] as a central feature of voice perception, emphasizing the similarity in the mechanisms of face and voice perception.

  12. Vocal attractiveness increases by averaging.

    Science.gov (United States)

    Bruckert, Laetitia; Bestelmeyer, Patricia; Latinus, Marianne; Rouger, Julien; Charest, Ian; Rousselet, Guillaume A; Kawahara, Hideki; Belin, Pascal

    2010-01-26

    Vocal attractiveness has a profound influence on listeners-a bias known as the "what sounds beautiful is good" vocal attractiveness stereotype [1]-with tangible impact on a voice owner's success at mating, job applications, and/or elections. The prevailing view holds that attractive voices are those that signal desirable attributes in a potential mate [2-4]-e.g., lower pitch in male voices. However, this account does not explain our preferences in more general social contexts in which voices of both genders are evaluated. Here we show that averaging voices via auditory morphing [5] results in more attractive voices, irrespective of the speaker's or listener's gender. Moreover, we show that this phenomenon is largely explained by two independent by-products of averaging: a smoother voice texture (reduced aperiodicities) and a greater similarity in pitch and timbre with the average of all voices (reduced "distance to mean"). These results provide the first evidence for a phenomenon of vocal attractiveness increases by averaging, analogous to a well-established effect of facial averaging [6, 7]. They highlight prototype-based coding [8] as a central feature of voice perception, emphasizing the similarity in the mechanisms of face and voice perception. PMID:20129047

  13. Sparsity Averaging for Compressive Imaging

    CERN Document Server

    Carrillo, Rafael E; Van De Ville, Dimitri; Thiran, Jean-Philippe; Wiaux, Yves

    2012-01-01

    We propose a novel regularization method for sparse image reconstruction from compressive measurements. The approach relies on the conjecture that natural images exhibit strong average sparsity over multiple coherent frames. The associated reconstruction algorithm, based on an analysis prior and a reweighted $\\ell_1$ scheme, is dubbed Sparsity Averaging Reweighted Analysis (SARA). We test our prior and the associated algorithm through extensive numerical simulations for spread spectrum and Gaussian acquisition schemes suggested by the recent theory of compressed sensing with coherent and redundant dictionaries. Our results show that average sparsity outperforms state-of-the-art priors that promote sparsity in a single orthonormal basis or redundant frame, or that promote gradient sparsity. We also illustrate the performance of SARA in the context of Fourier imaging, for particular applications in astronomy and medicine.

  14. Normal ranges and test-retest reproducibility of flow and velocity parameters in intracranial arteries measured with phase-contrast magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Correia de Verdier, Maria; Wikstroem, Johan [Uppsala University Hospital, Department of Radiology, Uppsala University, Uppsala (Sweden)

    2016-05-15

    The purpose of the present study was to investigate normal ranges and test-retest reproducibility of phase-contrast MRI (PC-MRI)-measured flow and velocity parameters in intracranial arteries. Highest flow (HF), lowest flow (LF), peak systolic velocity (PSV), and end diastolic velocity (EDV) were measured at two dates in the anterior (ACA), middle (MCA), and posterior (PCA) cerebral arteries of 30 healthy volunteers using two-dimensional PC-MRI at 3 T. Least detectable difference (LDD) was calculated. In the left ACA, HF was (mean (range, LDD)) 126 ml/min (36-312, 59 %), LF 61 ml/min (0-156, 101 %), PSV 64 cm/s (32-141, 67 %), and EDV 35 cm/s (18-55, 42 %); in the right ACA, HF was 154 ml/min (42-246, 49 %), LF 77 ml/min (0-156, 131 %), PSV 75 cm/s (26-161, 82 %), and EDV 39 cm/s (7-59, 67 %). In the left MCA, HF was 235 ml/min (126-372, 35 %), LF 116 ml/min (42-186, 48 %), PSV 90 cm/s (55-183, 39 %), and EDV 46 cm/s (20-66, 28 %); in the right MCA, HF was 238 ml/min (162-342, 44 %), LF 120 ml/min (72-216, 48 %), PSV 88 cm/s (55-141, 35 %), and EDV 45 cm/s (26-67, 23 %). In the left PCA, HF was 108 ml/min (42-168, 54 %), LF 53 ml/min (18-108, 64 %), PSV 50 cm/s (24-77, 63 %), and EDV 28 cm/s (14-40, 45 %); in the right PCA, HF was 98 ml/min (30-162, 49 %), LF 49 ml/min (12-84, 55 %), PSV 47 cm/s (27-88, 59 %), and EDV 27 cm/s (16-41, 45 %). PC-MRI-measured flow and velocity parameters in the main intracranial arteries have large normal ranges. Reproducibility is highest in MCA. (orig.)

  15. Motional averaging in a superconducting qubit.

    Science.gov (United States)

    Li, Jian; Silveri, M P; Kumar, K S; Pirkkalainen, J-M; Vepsäläinen, A; Chien, W C; Tuorila, J; Sillanpää, M A; Hakonen, P J; Thuneberg, E V; Paraoanu, G S

    2013-01-01

    Superconducting circuits with Josephson junctions are promising candidates for developing future quantum technologies. Of particular interest is to use these circuits to study effects that typically occur in complex condensed-matter systems. Here we employ a superconducting quantum bit--a transmon--to perform an analogue simulation of motional averaging, a phenomenon initially observed in nuclear magnetic resonance spectroscopy. By modulating the flux bias of a transmon with controllable pseudo-random telegraph noise we create a stochastic jump of its energy level separation between two discrete values. When the jumping is faster than a dynamical threshold set by the frequency displacement of the levels, the initially separate spectral lines merge into a single, narrow, motional-averaged line. With sinusoidal modulation a complex pattern of additional sidebands is observed. We show that the modulated system remains quantum coherent, with modified transition frequencies, Rabi couplings, and dephasing rates. These results represent the first steps towards more advanced quantum simulations using artificial atoms. PMID:23361011

  16. Phase-averaged transport for quasiperiodic Hamiltonians

    CERN Document Server

    Bellissard, J; Schulz-Baldes, H

    2002-01-01

    For a class of discrete quasi-periodic Schroedinger operators defined by covariant re- presentations of the rotation algebra, a lower bound on phase-averaged transport in terms of the multifractal dimensions of the density of states is proven. This result is established under a Diophantine condition on the incommensuration parameter. The relevant class of operators is distinguished by invariance with respect to symmetry automorphisms of the rotation algebra. It includes the critical Harper (almost-Mathieu) operator. As a by-product, a new solution of the frame problem associated with Weyl-Heisenberg-Gabor lattices of coherent states is given.

  17. Dependability in Aggregation by Averaging

    CERN Document Server

    Jesus, Paulo; Almeida, Paulo Sérgio

    2010-01-01

    Aggregation is an important building block of modern distributed applications, allowing the determination of meaningful properties (e.g. network size, total storage capacity, average load, majorities, etc.) that are used to direct the execution of the system. However, the majority of the existing aggregation algorithms exhibit relevant dependability issues, when prospecting their use in real application environments. In this paper, we reveal some dependability issues of aggregation algorithms based on iterative averaging techniques, giving some directions to solve them. This class of algorithms is considered robust (when compared to common tree-based approaches), being independent from the used routing topology and providing an aggregation result at all nodes. However, their robustness is strongly challenged and their correctness often compromised, when changing the assumptions of their working environment to more realistic ones. The correctness of this class of algorithms relies on the maintenance of a funda...

  18. Stochastic Approximation with Averaging Innovation

    CERN Document Server

    Laruelle, Sophie

    2010-01-01

    The aim of the paper is to establish a convergence theorem for multi-dimensional stochastic approximation in a setting with innovations satisfying some averaging properties and to study some applications. The averaging assumptions allow us to unify the framework where the innovations are generated (to solve problems from Numerical Probability) and the one with exogenous innovations (market data, output of "device" $e.g.$ an Euler scheme) with stationary or ergodic properties. We propose several fields of applications with random innovations or quasi-random numbers. In particular we provide in both setting a rule to tune the step of the algorithm. At last we illustrate our results on five examples notably in Finance.

  19. High average power supercontinuum sources

    Indian Academy of Sciences (India)

    J C Travers

    2010-11-01

    The physical mechanisms and basic experimental techniques for the creation of high average spectral power supercontinuum sources is briefly reviewed. We focus on the use of high-power ytterbium-doped fibre lasers as pump sources, and the use of highly nonlinear photonic crystal fibres as the nonlinear medium. The most common experimental arrangements are described, including both continuous wave fibre laser systems with over 100 W pump power, and picosecond mode-locked, master oscillator power fibre amplifier systems, with over 10 kW peak pump power. These systems can produce broadband supercontinua with over 50 and 1 mW/nm average spectral power, respectively. Techniques for numerical modelling of the supercontinuum sources are presented and used to illustrate some supercontinuum dynamics. Some recent experimental results are presented.

  20. Predicting vibration-induced displacement for a resonant friction slider

    DEFF Research Database (Denmark)

    Fidlin, A.; Thomsen, Jon Juel

    2001-01-01

    A mathematical model is set up to quantify vibration-induced motions of a slider, sandwiched between friction layers with different coefficients of friction, and equipped with an imbedded resonator that oscillates at high frequency and small amplitude. This model is highly nonlinear, involving non......-smooth functions with strong harmonic excitation terms. The method of averaging is extended to hold for systems of this class, and used to derive approximate expressions for predicting average velocities of the slider. These expressions are shown to produce results that agree very well with numerical integration...... of the full equations of motion. The expressions are used to estimate and explain the influence of system parameters....

  1. United States Average Annual Precipitation, 1990-2009 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows polygons of average annual precipitation in the contiguous United States, for the climatological period 1990-2009. Parameter-elevation...

  2. United States Average Annual Precipitation, 1961-1990 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows polygons of average annual precipitation in the contiguous United States, for the climatological period 1961-1990. Parameter-elevation...

  3. United States Average Annual Precipitation, 1995-1999 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows polygons of average annual precipitation in the contiguous United States, for the climatological period 1995-1999. Parameter-elevation...

  4. United States Average Annual Precipitation, 2005-2009 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows polygons of average annual precipitation in the contiguous United States, for the climatological period 2005-2009. Parameter-elevation...

  5. United States Average Annual Precipitation, 2000-2004 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows polygons of average annual precipitation in the contiguous United States, for the climatological period 2000-2004. Parameter-elevation...

  6. United States Average Annual Precipitation, 1990-1994 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows polygons of average annual precipitation in the contiguous United States, for the climatological period 1990-1994. Parameter-elevation...

  7. On Dupree's resonance function

    International Nuclear Information System (INIS)

    It is shown that Dupree's resonance function has a negative real asymptotic tail, so that the dispersion relation of the renormalized weak turbulence theory leads to unstable high phase velocity waves, even when the average distribution is a Gaussian. A possible explanation of this paradox is proposed

  8. Split ring resonator resonance assisted terahertz antennas

    CERN Document Server

    Galal, Hossam; Vitiello, Miriam S

    2016-01-01

    We report on the computational development of novel architectures of low impedance broadband antennas, for efficient detection of Terahertz (THz) frequency beams. The conceived Split Ring Resonator Resonance Assisted (SRR RA) antennas are based on both a capacitive and inductive scheme, exploiting a 200 Ohm and 400 Ohm impedance, respectively. Moreover, the impedance is tunable by varying the coupling parameters in the exploited geometry, allowing for better matching with the detector circuit for maximum power extraction. Our simulation results have been obtained by assuming a 1.5 THz operation frequency.

  9. Average Description of Dipole Gamma Transitions in Hot Atomic Nuclei

    Science.gov (United States)

    Plujko, V. A.; Gorbachenko, O. M.; Rovenskykh, E. P.; Zheltonozhskii, V. A.

    2014-04-01

    A new version of the modified Lorentzian approach for radiative strength function is proposed. It is based on renewed systematics for giant dipole resonance (GDR) parameters. The gamma-decay strength functions are calculated using new GDR parameters and compared with experimental data. It is demonstrated that closed-form approaches with energy-dependent width of the gamma strength, as a rule, provide a reliable simple method for description of gamma-decay processes.

  10. Geomagnetic effects on the average surface temperature

    Science.gov (United States)

    Ballatore, P.

    Several results have previously shown as the solar activity can be related to the cloudiness and the surface solar radiation intensity (Svensmark and Friis-Christensen, J. Atmos. Sol. Terr. Phys., 59, 1225, 1997; Veretenenkoand Pudovkin, J. Atmos. Sol. Terr. Phys., 61, 521, 1999). Here, the possible relationships between the averaged surface temperature and the solar wind parameters or geomagnetic activity indices are investigated. The temperature data used are the monthly SST maps (generated at RAL and available from the related ESRIN/ESA database) that represent the averaged surface temperature with a spatial resolution of 0.5°x0.5° and cover the entire globe. The interplanetary data and the geomagnetic data are from the USA National Space Science Data Center. The time interval considered is 1995-2000. Specifically, possible associations and/or correlations of the average temperature with the interplanetary magnetic field Bz component and with the Kp index are considered and differentiated taking into account separate geographic and geomagnetic planetary regions.

  11. On Backus average for generally anisotropic layers

    CERN Document Server

    Bos, Len; Slawinski, Michael A; Stanoev, Theodore

    2016-01-01

    In this paper, following the Backus (1962) approach, we examine expressions for elasticity parameters of a homogeneous generally anisotropic medium that is long-wave-equivalent to a stack of thin generally anisotropic layers. These expressions reduce to the results of Backus (1962) for the case of isotropic and transversely isotropic layers. In over half-a-century since the publications of Backus (1962) there have been numerous publications applying and extending that formulation. However, neither George Backus nor the authors of the present paper are aware of further examinations of mathematical underpinnings of the original formulation; hence, this paper. We prove that---within the long-wave approximation---if the thin layers obey stability conditions then so does the equivalent medium. We examine---within the Backus-average context---the approximation of the average of a product as the product of averages, and express it as a proposition in terms of an upper bound. In the presented examination we use the e...

  12. Switching Characteristics and Analysis of Resonant Tunneling Diodes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Resonant tunneling diode (RTD) of AlAs/InGaAs/AlAs double barrier-single well structure was designed and fabricated. The devices showed current-voltage characteristics with peak-valley current ratio of 4: 1 at room temperature. The scattering parameter of RTD was measured by using an HP8510(C) network analyzer. Equivalent circuit parameters were obtained by curve fitting and optimized. The RTD switching time was estimated using the measured capacitance and average negative differential resistance. The minimum rise time of the sample was estimated to be 21 ps.

  13. Resonant frequencies of whispering gallery modes of dielectric resonator

    OpenAIRE

    S.L. Badnilcar; N.Shanmugam; V. R. K. Murthy

    2001-01-01

    The modal spectrum of the whispering gallery modes of dielectric resonator depends mainly on its physical dimensions, dielectric constant, and to a lesser extent, on the environment. This paper carries investigation of the resonant frequencies in dielectric disc utilising the ring resonator model. Results of the structural design parameters are used to generate a nume!ical expression for describing the operational frequencies useful for computer-aided design applications. Theoretical ...

  14. Calculating High Speed Centrifugal Compressor Performance from Averaged Measurements

    Science.gov (United States)

    Lou, Fangyuan; Fleming, Ryan; Key, Nicole L.

    2012-12-01

    To improve the understanding of high performance centrifugal compressors found in modern aircraft engines, the aerodynamics through these machines must be experimentally studied. To accurately capture the complex flow phenomena through these devices, research facilities that can accurately simulate these flows are necessary. One such facility has been recently developed, and it is used in this paper to explore the effects of averaging total pressure and total temperature measurements to calculate compressor performance. Different averaging techniques (including area averaging, mass averaging, and work averaging) have been applied to the data. Results show that there is a negligible difference in both the calculated total pressure ratio and efficiency for the different techniques employed. However, the uncertainty in the performance parameters calculated with the different averaging techniques is significantly different, with area averaging providing the least uncertainty.

  15. Flexible time domain averaging technique

    Science.gov (United States)

    Zhao, Ming; Lin, Jing; Lei, Yaguo; Wang, Xiufeng

    2013-09-01

    Time domain averaging(TDA) is essentially a comb filter, it cannot extract the specified harmonics which may be caused by some faults, such as gear eccentric. Meanwhile, TDA always suffers from period cutting error(PCE) to different extent. Several improved TDA methods have been proposed, however they cannot completely eliminate the waveform reconstruction error caused by PCE. In order to overcome the shortcomings of conventional methods, a flexible time domain averaging(FTDA) technique is established, which adapts to the analyzed signal through adjusting each harmonic of the comb filter. In this technique, the explicit form of FTDA is first constructed by frequency domain sampling. Subsequently, chirp Z-transform(CZT) is employed in the algorithm of FTDA, which can improve the calculating efficiency significantly. Since the signal is reconstructed in the continuous time domain, there is no PCE in the FTDA. To validate the effectiveness of FTDA in the signal de-noising, interpolation and harmonic reconstruction, a simulated multi-components periodic signal that corrupted by noise is processed by FTDA. The simulation results show that the FTDA is capable of recovering the periodic components from the background noise effectively. Moreover, it can improve the signal-to-noise ratio by 7.9 dB compared with conventional ones. Experiments are also carried out on gearbox test rigs with chipped tooth and eccentricity gear, respectively. It is shown that the FTDA can identify the direction and severity of the eccentricity gear, and further enhances the amplitudes of impulses by 35%. The proposed technique not only solves the problem of PCE, but also provides a useful tool for the fault symptom extraction of rotating machinery.

  16. Lattices of dielectric resonators

    CERN Document Server

    Trubin, Alexander

    2016-01-01

    This book provides the analytical theory of complex systems composed of a large number of high-Q dielectric resonators. Spherical and cylindrical dielectric resonators with inferior and also whispering gallery oscillations allocated in various lattices are considered. A new approach to S-matrix parameter calculations based on perturbation theory of Maxwell equations, developed for a number of high-Q dielectric bodies, is introduced. All physical relationships are obtained in analytical form and are suitable for further computations. Essential attention is given to a new unified formalism of the description of scattering processes. The general scattering task for coupled eigen oscillations of the whole system of dielectric resonators is described. The equations for the  expansion coefficients are explained in an applicable way. The temporal Green functions for the dielectric resonator are presented. The scattering process of short pulses in dielectric filter structures, dielectric antennas  and lattices of d...

  17. Three-pion resonances

    Science.gov (United States)

    Garcilazo, H.; Mathelitsch, L.

    1994-03-01

    We investigate the continuum three-pion problem within a relativistic three-body model that takes into account the ππ S and P waves. The dynamical input of the two-body subsystem is given by separable potentials, which yield a good fit to the ππ scattering data and resonance parameters up to a two-body invariant mass of 900MeV. We introduce a parameter ν expressing the ambiguity in the reduction of a fully relativistic theory to a three-dimensional one. The masses and widths of the ω, a 1(1260), and π(1300) mesons, which decay predominantly into three pions, are reasonably well described by our model. The h 1(1170) meson, however, which also decays into three pions, cannot be explained as a three-pion resonance. Some πρ Argand diagrams are shown in those channels where resonances exist.

  18. The stability of a zonally averaged thermohaline circulation model

    CERN Document Server

    Schmidt, G A

    1995-01-01

    A combination of analytical and numerical techniques are used to efficiently determine the qualitative and quantitative behaviour of a one-basin zonally averaged thermohaline circulation ocean model. In contrast to earlier studies which use time stepping to find the steady solutions, the steady state equations are first solved directly to obtain the multiple equilibria under identical mixed boundary conditions. This approach is based on the differentiability of the governing equations and especially the convection scheme. A linear stability analysis is then performed, in which the normal modes and corresponding eigenvalues are found for the various equilibrium states. Resonant periodic solutions superimposed on these states are predicted for various types of forcing. The results are used to gain insight into the solutions obtained by Mysak, Stocker and Huang in a previous numerical study in which the eddy diffusivities were varied in a randomly forced one-basin zonally averaged model. Resonant stable oscillat...

  19. PAPIN: A Fortran-IV program to calculate cross section probability tables, Bondarenko and transmission self-shielding factors for fertile isotopes in the unresolved resonance region

    Energy Technology Data Exchange (ETDEWEB)

    Munoz-Cobos, J.G.

    1981-08-01

    The Fortran IV code PAPIN has been developed to calculate cross section probability tables, Bondarenko self-shielding factors and average self-indication ratios for non-fissile isotopes, below the inelastic threshold, on the basis of the ENDF/B prescriptions for the unresolved resonance region. Monte-Carlo methods are utilized to generate ladders of resonance parameters in the unresolved resonance region, from average resonance parameters and their appropriate distribution functions. The neutron cross-sections are calculated by the single level Breit-Wigner (SLBW) formalism, with s, p and d-wave contributions. The cross section probability tables are constructed by sampling the Doppler-broadened cross sections. The various self-shielded factors are computed numerically as Lebesgue integrals over the cross section probability tables. The program PAPIN has been validated through extensive comparisons with several deterministic codes.

  20. Hedge algorithm and Dual Averaging schemes

    CERN Document Server

    Baes, Michel

    2011-01-01

    We show that the Hedge algorithm, a method that is widely used in Machine Learning, can be interpreted as a particular instance of Dual Averaging schemes, which have recently been introduced by Nesterov for regret minimization. Based on this interpretation, we establish three alternative methods of the Hedge algorithm: one in the form of the original method, but with optimal parameters, one that requires less a priori information, and one that is better adapted to the context of the Hedge algorithm. All our modified methods have convergence results that are better or at least as good as the performance guarantees of the vanilla method. In numerical experiments, our methods significantly outperform the original scheme.

  1. Orbital resonances around black holes.

    Science.gov (United States)

    Brink, Jeandrew; Geyer, Marisa; Hinderer, Tanja

    2015-02-27

    We compute the length and time scales associated with resonant orbits around Kerr black holes for all orbital and spin parameters. Resonance-induced effects are potentially observable when the Event Horizon Telescope resolves the inner structure of Sgr A*, when space-based gravitational wave detectors record phase shifts in the waveform during the resonant passage of a compact object spiraling into the black hole, or in the frequencies of quasiperiodic oscillations for accreting black holes. The onset of geodesic chaos for non-Kerr spacetimes should occur at the resonance locations quantified here. PMID:25768747

  2. Orbital resonances around black holes.

    Science.gov (United States)

    Brink, Jeandrew; Geyer, Marisa; Hinderer, Tanja

    2015-02-27

    We compute the length and time scales associated with resonant orbits around Kerr black holes for all orbital and spin parameters. Resonance-induced effects are potentially observable when the Event Horizon Telescope resolves the inner structure of Sgr A*, when space-based gravitational wave detectors record phase shifts in the waveform during the resonant passage of a compact object spiraling into the black hole, or in the frequencies of quasiperiodic oscillations for accreting black holes. The onset of geodesic chaos for non-Kerr spacetimes should occur at the resonance locations quantified here.

  3. The monthly-averaged and yearly-averaged cosine effect factor of a heliostat field

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rabghi, O.M.; Elsayed, M.M. (King Abdulaziz Univ., Jeddah (Saudi Arabia). Dept. of Thermal Engineering)

    1992-01-01

    Calculations are carried out to determine the dependence of the monthly-averaged and the yearly-averaged daily cosine effect factor on the pertinent parameters. The results are plotted on charts for each month and for the full year. These results cover latitude angles between 0 and 45[sup o]N, for fields with radii up to 50 tower height. In addition, the results are expressed in mathematical correlations to facilitate using them in computer applications. A procedure is outlined to use the present results to preliminary layout the heliostat field, and to predict the rated MW[sub th] reflected by the heliostat field during a period of a month, several months, or a year. (author)

  4. Hand-held resonance sensor for tissue stiffness measurements—a theoretical and experimental analysis

    International Nuclear Information System (INIS)

    A piezoelectric transducer in a feedback circuit operating in a resonance state is the basis of a resonance sensor. Upon contact with a soft object a change in the resonance frequency reflects the acoustic impedance. Together with force measurement it is possible to obtain the elastic stiffness of the object. The aim of this study was to evaluate the concept of a hand-held resonance sensor for tissue stiffness measurement. A time derivative analysis of the force and the frequency change showed that a stiffness-sensitive parameter was independent of the impression speed. Soft tissue phantoms of gelatin were used in an experimental validation of the theory. A force indentation method was used as a reference method for assessing the gelatin's elastic stiffness. Results from the hand-held measurements showed that the stiffness parameter accurately measured the elastic stiffness of the gelatin (R2 = 0.94, p 2 = 0.15) and non-significantly (p > 0.05, 14 out of 17) dependent on an impression speed parameter. On average, a small amount of the total variance was explained by the impression speed. In conclusion, soft tissue stiffness can be objectively measured with free-hand measurement with a resonance sensor. This study contributes a theoretical analysis and an experimental demonstration of the concept of a hand-held resonance sensor for stiffness measurements

  5. Equivalent Circuit Model for Thick Split Ring Resonators and Thick Spiral Resonators

    CERN Document Server

    Mancera, Laura Maria Pulido

    2014-01-01

    A simple theoretical model which provides circuit parameters and resonance frequency of metallic thick resonators is presented. Two different topologies were studied: the original Pendry's SRR and spiral resonators of two and three turns. Theoretical computations of resonant frequencies are in good agreement with values obtained with a commercial electromagnetic solver. The model could be helpful for designing thick frequency selective surfaces (FSS) based on this types of resonators, so called metasurfaces.

  6. Nonlinear resonances

    CERN Document Server

    Rajasekar, Shanmuganathan

    2016-01-01

    This introductory text presents the basic aspects and most important features of various types of resonances and anti-resonances in dynamical systems. In particular, for each resonance, it covers the theoretical concepts, illustrates them with case studies, and reviews the available information on mechanisms, characterization, numerical simulations, experimental realizations, possible quantum analogues, applications and significant advances made over the years. Resonances are one of the most fundamental phenomena exhibited by nonlinear systems and refer to specific realizations of maximum response of a system due to the ability of that system to store and transfer energy received from an external forcing source. Resonances are of particular importance in physical, engineering and biological systems - they can prove to be advantageous in many applications, while leading to instability and even disasters in others. The book is self-contained, providing the details of mathematical derivations and techniques invo...

  7. A precise measurement of the average b hadron lifetime

    CERN Document Server

    Buskulic, Damir; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Ariztizabal, F; Chmeissani, M; Crespo, J M; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Gaitan, V; Garrido, L; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Palla, Fabrizio; Pascual, A; Perlas, J A; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Farilla, A; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Natali, S; Nuzzo, S; Ranieri, A; Raso, G; Romano, F; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Engelhardt, A; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Knobloch, J; Lehraus, Ivan; Markou, C; Martin, E B; Mato, P; Meinhard, H; Minten, Adolf G; Miquel, R; Oest, T; Palazzi, P; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wiedenmann, W; Wildish, T; Witzeling, W; Wotschack, J; Ajaltouni, Ziad J; Bardadin-Otwinowska, Maria; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Saadi, F; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Kyriakis, A; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Passalacqua, L; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Delfino, M C; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Pepé-Altarelli, M; Dorris, S J; Halley, A W; ten Have, I; Knowles, I G; Lynch, J G; Morton, W T; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Smith, M G; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Braun, O; Geweniger, C; Graefe, G; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Colling, D J; Dornan, Peter J; Konstantinidis, N P; Moneta, L; Moutoussi, A; Nash, J; San Martin, G; Sedgbeer, J K; Stacey, A M; Dissertori, G; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bowdery, C K; Brodbeck, T J; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Whelan, E P; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Raab, J; Renk, B; Sander, H G; Wanke, R; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Thulasidas, M; Nicod, D; Payre, P; Rousseau, D; Talby, M; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Brown, D; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Stierlin, U; Saint-Denis, R; Wolf, G; Alemany, R; Boucrot, J; Callot, O; Cordier, A; Courault, F; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Musolino, G; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Abbaneo, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Triggiani, G; Vannini, C; Verdini, P G; Walsh, J; Betteridge, A P; Blair, G A; Bryant, L M; Cerutti, F; Gao, Y; Green, M G; Johnson, D L; Medcalf, T; Mir, L M; Perrodo, P; Strong, J A; Bertin, V; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Edwards, M; Maley, P; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Duarte, H; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Rosowsky, A; Roussarie, A; Schuller, J P; Schwindling, J; Si Mohand, D; Trabelsi, A; Vallage, B; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Cartwright, S L; Combley, F; Dawson, I; Köksal, A; Letho, M; Newton, W M; Rankin, C; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Feigl, E; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Ragusa, F; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, P; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Turk, J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

    1996-01-01

    An improved measurement of the average b hadron lifetime is performed using a sample of 1.5 million hadronic Z decays, collected during the 1991-1993 runs of ALEPH, with the silicon vertex detector fully operational. This uses the three-dimensional impact parameter distribution of lepton tracks coming from semileptonic b decays and yields an average b hadron lifetime of 1.533 \\pm 0.013 \\pm 0.022 ps.

  8. Neutron capture cross section measurements for 238U in the resonance region at GELINA

    Science.gov (United States)

    Kim, H. I.; Paradela, C.; Sirakov, I.; Becker, B.; Capote, R.; Gunsing, F.; Kim, G. N.; Kopecky, S.; Lampoudis, C.; Lee, Y.-O.; Massarczyk, R.; Moens, A.; Moxon, M.; Pronyaev, V. G.; Schillebeeckx, P.; Wynants, R.

    2016-06-01

    Measurements were performed at the time-of-flight facility GELINA to determine the 238U(n, γ) cross section in the resonance region. Experiments were carried out at a 12.5 and 60m measurement station. The total energy detection principle in combination with the pulse height weighting technique was applied using C6D6 liquid scintillators as prompt γ-ray detectors. The energy dependence of the neutron flux was measured with ionisation chambers based on the 10B(n, α) reaction. The data were normalised to the isolated and saturated 238U resonance at 6.67 eV. Special procedures were applied to reduce bias effects due to the weighting function, normalization, dead time and background corrections, and corrections related to the sample properties. The total uncertainty due to the weighting function, normalization, neutron flux and sample characteristics is about 1.5%. Resonance parameters were derived from a simultaneous resonance shape analysis of the GELINA capture data and transmission data obtained previously at a 42m and 150m station of ORELA. The parameters of resonances below 500 eV are in good agreement with those resulting from an evaluation that was adopted in the main data libraries. Between 500 eV and 1200 eV a systematic difference in the neutron width is observed. Average capture cross section data were derived from the experimental capture yield in the energy region between 3.5 keV and 90 keV. The results are in good agreement with an evaluated cross section resulting from a least squares fit to experimental data available in the literature prior to this work. The average cross section data derived in this work were parameterised in terms of average resonance parameters and included in a least squares analysis together with other experimental data reported in the literature.

  9. Theoretical and experimental investigation of microstrip rhombic resonators

    Science.gov (United States)

    Al-Charchafchi, S. H.; Boulkos, J.

    1990-06-01

    The resonant behavior of a novel microstrip rhombic resonator is investigated by analyzing an equivalent circuit based on transmission line modeling. Design curves showing the dependence of resonator performance on its parameters, as well as the substrate parameters, are presented. Experiments carried out showed a significant reduction in insertion loss when the rhombic resonator is dielectrically shielded. The resonator could be used as a microwave bandpass filter or a stabilization circuit for microwave oscillators in both hybrid and monolithic integrated circuits.

  10. 7 CFR 1209.12 - On average.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false On average. 1209.12 Section 1209.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS....12 On average. On average means a rolling average of production or imports during the last two...

  11. On the extremal properties of the average eccentricity

    CERN Document Server

    Ilic, Aleksandar

    2011-01-01

    The eccentricity of a vertex is the maximum distance from it to another vertex and the average eccentricity $ecc (G)$ of a graph $G$ is the mean value of eccentricities of all vertices of $G$. The average eccentricity is deeply connected with a topological descriptor called the eccentric connectivity index, defined as a sum of products of vertex degrees and eccentricities. In this paper we analyze extremal properties of the average eccentricity, introducing two graph transformations that increase or decrease $ecc (G)$. Furthermore, we resolve four conjectures, obtained by the system AutoGraphiX, about the average eccentricity and other graph parameters (the clique number, the Randi\\' c index and the independence number), refute one AutoGraphiX conjecture about the average eccentricity and the minimum vertex degree and correct one AutoGraphiX conjecture about the domination number.

  12. Gaussian-Beam Laser-Resonator Program

    Science.gov (United States)

    Cross, Patricia L.; Bair, Clayton H.; Barnes, Norman

    1989-01-01

    Gaussian Beam Laser Resonator Program models laser resonators by use of Gaussian-beam-propagation techniques. Used to determine radii of beams as functions of position in laser resonators. Algorithm used in program has three major components. First, ray-transfer matrix for laser resonator must be calculated. Next, initial parameters of beam calculated. Finally, propagation of beam through optical elements computed. Written in Microsoft FORTRAN (Version 4.01).

  13. D Pi scattering and D meson resonances from lattice QCD

    CERN Document Server

    Mohler, Daniel; Woloshyn, R M

    2012-01-01

    The masses and widths of the broad scalar D_0^*(2400) and the axial D_1(2430) charmed-light resonances are extracted by simulating the corresponding D Pi and D* Pi scattering on the lattice. The resonance parameters are obtained using a Breit-Wigner fit of the elastic phase shifts. The resulting D_0^*(2400) mass is 351+/-21 MeV above the spin-average 1/4(m_D+3m_{D*}), in agreement with the experimental value of 347+/-29 MeV above. The resulting D_0^* to D Pi coupling g^{lat}=2.55+/-0.21 GeV is close to the experimental value g^{exp}<=1.92+/-0.14 GeV, where g parametrizes the width $\\Gamma\\equiv g^2p^*/s$. The resonance parameters for the broad D_1(2430) are also found close to the experimental values; these are obtained by appealing to the heavy quark limit, where the neighboring resonance D_1(2420) is narrow. The calculated I=1/2 scattering lengths are a_0=0.81+/-0.14 fm for D Pi and a_0=0.81+/-0.17 fm for D* Pi scattering. The simulation of the scattering in these channels incorporates quark-antiquark as...

  14. A modified Eddington-Barbier relation in highly coherent resonance-line wings

    Science.gov (United States)

    Gayley, K. G.

    1992-01-01

    It is shown that resonance-line wings are just as useful in inferring plane-parallel stellar chromospheric S sub L distributions as complete redistribution (CRD) profiles. Although coherent scattering effects at a given frequency tend to average depth-dependent parameters over a larger volume than in CRD, this effect can be offset by simply looking closer to line center, where the same depth-dependent information exists as in CRD, albeit somewhat more compressed in frequency space. For resonance lines with high excitation energies such as Ly-alpha, steep Planck function gradients can invalidate the modified Eddington-Barbier approach given, but this problem also exists in CRD.

  15. Effect of slice thickness on brain magnetic resonance image texture analysis

    OpenAIRE

    Heinonen Tomi; Luukkaala Tiina; Harrison Lara CV; Savio Sami J; Dastidar Prasun; Soimakallio Seppo; Eskola Hannu J

    2010-01-01

    Abstract Background The accuracy of texture analysis in clinical evaluation of magnetic resonance images depends considerably on imaging arrangements and various image quality parameters. In this paper, we study the effect of slice thickness on brain tissue texture analysis using a statistical approach and classification of T1-weighted images of clinically confirmed multiple sclerosis patients. Methods We averaged the intensities of three consecutive 1-mm slices to simulate 3-mm slices. Two h...

  16. Universal formalism of Fano resonance

    International Nuclear Information System (INIS)

    The phenomenon of Fano resonance is ubiquitous in a large variety of wave scattering systems, where the resonance profile is typically asymmetric. Whether the parameter characterizing the asymmetry should be complex or real is an issue of great experimental interest. Using coherent quantum transport as a paradigm and taking into account of the collective contribution from all available scattering channels, we derive a universal formula for the Fano-resonance profile. We show that our formula bridges naturally the traditional Fano formulas with complex and real asymmetry parameters, indicating that the two types of formulas are fundamentally equivalent (except for an offset). The connection also reveals a clear footprint for the conductance resonance during a dephasing process. Therefore, the emergence of complex asymmetric parameter when fitting with experimental data needs to be properly interpreted. Furthermore, we have provided a theory for the width of the resonance, which relates explicitly the width to the degree of localization of the close-by eigenstates and the corresponding coupling matrices or the self-energies caused by the leads. Our work not only resolves the issue about the nature of the asymmetry parameter, but also provides deeper physical insights into the origin of Fano resonance. Since the only assumption in our treatment is that the transport can be described by the Green’s function formalism, our results are also valid for broad disciplines including scattering problems of electromagnetic waves, acoustics, and seismology

  17. Damping of nanomechanical resonators.

    Science.gov (United States)

    Unterreithmeier, Quirin P; Faust, Thomas; Kotthaus, Jörg P

    2010-07-01

    We study the transverse oscillatory modes of nanomechanical silicon nitride strings under high tensile stress as a function of geometry and mode index m≤9. Reproducing all observed resonance frequencies with classical elastic theory we extract the relevant elastic constants. Based on the oscillatory local strain we successfully predict the observed mode-dependent damping with a single frequency-independent fit parameter. Our model clarifies the role of tensile stress on damping and hints at the underlying microscopic mechanisms. PMID:20867737

  18. A Small Signal Equivalent Circuit Model for Resonant Tunnelling Diode

    Institute of Scientific and Technical Information of China (English)

    MA Long; HUANG Ying-Long; ZHANG Yang; WANG Liang-Chen; YANG Fu-Hua; ZENG Yi-Ping

    2006-01-01

    @@ We report a resonant tunnelling diode (RTD) small signal equiwlent circuit model consisting of quantum capacitance and quantum inductance. The model is verified through the actual InAs/In0.53Ga0.47As/AlAs RTD fabricated on an InP substrate. Model parameters are extracted by fitting the equivalent circuit model with ac measurement data in three different regions of RTD current-voltage (Ⅰ-Ⅴ) characteristics. The electron lifetime,representing the average time that the carriers remain in the quasibound states during the tunnelling process, is also calculated to be 2.09ps.

  19. Averages of $b$-hadron, $c$-hadron, and $\\tau$-lepton properties as of summer 2014

    CERN Document Server

    Amhis, Y; Ben-Haim, E; Blyth, S; Bozek, A; Bozzi, C; Carbone, A; Chistov, R; Chrząszcz, M; Cibinetto, G; Dingfelder, J; Gelb, M; Gersabeck, M; Gershon, T; Gibbons, L; Golob, B; Harr, R; Hayasaka, K; Hayashii, H; Kuhr, T; Leroy, O; Lusiani, A; Miyabayashi, K; Naik, P; Nishida, S; Campos, A Oyanguren; Patel, M; Pedrini, D; Petrič, M; Rama, M; Roney, M; Rotondo, M; Schneider, O; Schwanda, C; Schwartz, A J; Shwartz, B; Smith, J G; Tesarek, R; Trabelsi, K; Urquijo, P; Van Kooten, R; Zupanc, A

    2014-01-01

    This article reports world averages of measurements of $b$-hadron, $c$-hadron, and $\\tau$-lepton properties obtained by the Heavy Flavor Averaging Group (HFAG) using results available through summer 2014. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, $CP$ violation parameters, parameters of semileptonic decays and CKM matrix elements.

  20. Genuine non-self-averaging and ultraslow convergence in gelation.

    Science.gov (United States)

    Cho, Y S; Mazza, M G; Kahng, B; Nagler, J

    2016-08-01

    In irreversible aggregation processes droplets or polymers of microscopic size successively coalesce until a large cluster of macroscopic scale forms. This gelation transition is widely believed to be self-averaging, meaning that the order parameter (the relative size of the largest connected cluster) attains well-defined values upon ensemble averaging with no sample-to-sample fluctuations in the thermodynamic limit. Here, we report on anomalous gelation transition types. Depending on the growth rate of the largest clusters, the gelation transition can show very diverse patterns as a function of the control parameter, which includes multiple stochastic discontinuous transitions, genuine non-self-averaging and ultraslow convergence of the transition point. Our framework may be helpful in understanding and controlling gelation. PMID:27627355

  1. Time-averaged photon-counting digital holography.

    Science.gov (United States)

    Demoli, Nazif; Skenderović, Hrvoje; Stipčević, Mario

    2015-09-15

    Time-averaged holography has been using photo-emulsions (early stage) and digital photo-sensitive arrays (later) to record holograms. We extend the recording possibilities by utilizing a photon-counting camera, and we further investigate the possibility of obtaining accurate hologram reconstructions in rather severe experimental conditions. To achieve this, we derived an expression for fringe function comprising the main parameters affecting the hologram recording. Influence of the main parameters, namely the exposure time and the number of averaged holograms, is analyzed by simulations and experiments. It is demonstrated that taking long exposure times can be avoided by averaging over many holograms with the exposure times much shorter than the vibration cycle. Conditions in which signal-to-noise ratio in reconstructed holograms can be substantially increased are provided. PMID:26371907

  2. Averages of Values of L-Series

    OpenAIRE

    Alkan, Emre; Ono, Ken

    2013-01-01

    We obtain an exact formula for the average of values of L-series over two independent odd characters. The average of any positive moment of values at s = 1 is then expressed in terms of finite cotangent sums subject to congruence conditions. As consequences, bounds on such cotangent sums, limit points for the average of first moment of L-series at s = 1 and the average size of positive moments of character sums related to the class number are deduced.

  3. Resonating Statements

    DEFF Research Database (Denmark)

    Hjelholt, Morten; Jensen, Tina Blegind

    2015-01-01

    IT projects are often complex arrangements of technological components, social actions, and organizational transformation that are difficult to manage in practice. This paper takes an analytical discourse perspective to explore the process of legitimizing IT projects. We introduce the concept...... of resonating statements to highlight how central actors navigate in various discourses over time. Particularly, the statements and actions of an IT project manager are portrayed to show how individuals can legitimize actions by connecting statements to historically produced discourses. The case study...... of an IT project in a Danish local government spans a two-year time period and demonstrates a double-loop legitimization process. First, resonating statements are produced to localize a national IT initiative to support the specificity of a local government discourse. Second, the resonating statements are used...

  4. Probing the charge of a quantum dot with a nanomechanical resonator

    Science.gov (United States)

    Meerwaldt, H. B.; Labadze, G.; Schneider, B. H.; Taspinar, A.; Blanter, Ya. M.; van der Zant, H. S. J.; Steele, G. A.

    2012-09-01

    We have used the mechanical motion of a carbon nanotube (CNT) as a probe of the average charge on a quantum dot. Variations of the resonance frequency and the quality factor are determined by the change in average charge on the quantum dot during a mechanical oscillation. The average charge, in turn, is influenced by the gate voltage, the bias voltage, and the tunnel rates of the barriers to the leads. At bias voltages that exceed the broadening due to tunnel coupling, the resonance frequency and quality factor show a double dip as a function of gate voltage. We find that increasing the current flowing through the CNT at the Coulomb peak does not increase the damping, but in fact decreases damping. Using a model with energy-dependent tunnel rates, we obtain quantitative agreement between the experimental observations and the model. We theoretically compare different contributions to the single-electron induced nonlinearity, and show that only one term is significant for both the Duffing parameter and the mode coupling parameter. We also present additional measurements which support the model we develop: Tuning the tunnel barriers of the quantum dot to the leads gives a 200-fold decrease of the quality factor. Single-electron tunneling through an excited state of the CNT quantum dot also changes the average charge on the quantum dot, bringing about a decrease in the resonance frequency. In the Fabry-Pérot regime, the absence of charge quantization results in a spring behavior without resonance frequency dips, which could be used, for example, to probe the transition from quantized to continuous charge with a nanomechanical resonator.

  5. Preheating and locked inflation: an analytic approach towards parametric resonance

    CERN Document Server

    Wang, Lingfei

    2011-01-01

    We take an analytic approach towards the framework of parametric resonance and apply it on preheating and locked inflation. A two-scalar toy model is analytically solved for the \\lambda\\phi^2\\chi^2 coupling for the homogenous modes. The effects of dynamic universe background and backreaction are taken into account. We show the average effect of parametric resonance to be that \\chi's amplitude doubles for each cycle of \\phi. Our framework partly solves the preheating scenario, showing two distinct stages of preheating and making the parameters of preheating analytically calculable. It is demonstrated for slowroll inflation models, preheating is terminated, if by backreaction, typically in the 5th e-fold. Under our framework, a possible inhomogeneity amplification effect is also found during preheating, which both may pose strong constraints on some inflationary models and may amplify tiny existing inhomogeneities to the desired scale. For demonstration, we show it rules out the backreaction end of preheating o...

  6. Resonance conditions

    CERN Document Server

    Rebusco, P

    2005-01-01

    Non-linear parametric resonances occur frequently in nature. Here we summarize how they can be studied by means of perturbative methods. We show in particular how resonances can affect the motion of a test particle orbiting in the vicinity of a compact object. These mathematical toy-models find application in explaining the structure of the observed kHz Quasi-Periodic Oscillations: we discuss which aspects of the reality naturally enter in the theory, and which one still remain a puzzle.

  7. Resonance conditions

    Science.gov (United States)

    Rebusco, P.

    2005-11-01

    Non-linear parametric resonances occur frequently in nature. Here we summarize how they can be studied by means of perturbative methods. We show in particular how resonances can affect the motion of a test particle orbiting in the vicinity of a compact object. These mathematical toy-models find application in explaining the structure of the observed kHz Quasi-Periodic Oscillations: we show which aspects of the reality naturally enter in the theory, and which one still remain a puzzle.

  8. Baryon Resonances

    CERN Document Server

    Oset, E; Sun, Bao Xi; Vacas, M J Vicente; Ramos, A; Gonzalez, P; Vijande, J; Torres, A Martinez; Khemchandani, K

    2009-01-01

    In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the $\\Lambda(1405)$ resonance, as well as the prediction of one $1/2^+$ baryon state around 1920 MeV which might have been seen in the $\\gamma p \\to K^+ \\Lambda$ reaction.

  9. Baryon Resonances

    Energy Technology Data Exchange (ETDEWEB)

    Oset, E. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Sarkar, S. [Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064 (India); Sun Baoxi [Institute of Theoretical Physics, College of Applied Sciences, Beijing University of Technology, Beijing 100124 (China); Vicente Vacas, M.J. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Ramos, A. [Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, 08028 Barcelona (Spain); Gonzalez, P. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Vijande, J. [Departamento de Fisica Atomica Molecular y Nuclear and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Martinez Torres, A. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Khemchandani, K. [Centro de Fisica Computacional, Departamento de Fisica, Universidade de Coimbra, P-3004-516 Coimbra (Portugal)

    2010-04-01

    In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the {lambda}(1405) resonance, as well as the prediction of one 1/2{sup +} baryon state around 1920 MeV which might have been seen in the {gamma}p{yields}K{sup +}{lambda} reaction.

  10. Neuroaesthetic Resonance

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2013-01-01

    tailored channeling of sensory stimulus aligned as ‘art-making’ and ‘game playing’ core experiences. Thus, affecting brain plasticity and human motoric-performance via the adaptability (plasticity) of digital medias result in closure of the human afferent-efferent neural feedback loop closure through...... the unencumbered motion-to-computer-generated activities - ‘Music Making’, ‘Painting’, ‘Robotic’ and ‘Video Game’ control. A focus of this position paper is to highlight how Aesthetic Resonance, in this context, relates to the growing body of research on Neuroaesthetics to evolve Neuroaesthetic Resonance....

  11. Determination of the Orientation and Dynamics of Ergosterol in Model Membranes Using Uniform 13C Labeling and Dynamically Averaged 13C Chemical Shift Anisotropies as Experimental Restraints

    Science.gov (United States)

    Soubias, O.; Jolibois, F.; Massou, S.; Milon, A.; Réat, V.

    2005-01-01

    A new strategy was established to determine the average orientation and dynamics of ergosterol in dimyristoylphosphatidylcholine model membranes. It is based on the analysis of chemical shift anisotropies (CSAs) averaged by the molecular dynamics. Static 13C CSA tensors were computed by quantum chemistry, using the gauge-including atomic-orbital approach within Hartree-Fock theory. Uniformly 13C-labeled ergosterol was purified from Pichia pastoris cells grown on labeled methanol. After reconstitution into dimyristoylphosphatidylcholine lipids, the complete 1H and 13C assignment of ergosterol's resonances was performed using a combination of magic-angle spinning two-dimensional experiments. Dynamically averaged CSAs were determined by standard side-band intensity analysis for isolated 13C resonances (C3 and ethylenic carbons) and by off-magic-angle spinning experiments for other carbons. A set of 18 constraints was thus obtained, from which the sterol's molecular order parameter and average orientation could be precisely defined. The validity of using computed CSAs in this strategy was verified on cholesterol model systems. This new method allowed us to quantify ergosterol's dynamics at three molar ratios: 16 mol % (Ld phase), 30 mol % (Lo phase), and 23 mol % (mixed phases). Contrary to cholesterol, ergosterol's molecular diffusion axis makes an important angle (14°) with the inertial axis of the rigid four-ring system. PMID:15923221

  12. Interpreting Sky-Averaged 21-cm Measurements

    Science.gov (United States)

    Mirocha, Jordan

    2015-01-01

    Within the first ~billion years after the Big Bang, the intergalactic medium (IGM) underwent a remarkable transformation, from a uniform sea of cold neutral hydrogen gas to a fully ionized, metal-enriched plasma. Three milestones during this epoch of reionization -- the emergence of the first stars, black holes (BHs), and full-fledged galaxies -- are expected to manifest themselves as extrema in sky-averaged ("global") measurements of the redshifted 21-cm background. However, interpreting these measurements will be complicated by the presence of strong foregrounds and non-trivialities in the radiative transfer (RT) modeling required to make robust predictions.I have developed numerical models that efficiently solve the frequency-dependent radiative transfer equation, which has led to two advances in studies of the global 21-cm signal. First, frequency-dependent solutions facilitate studies of how the global 21-cm signal may be used to constrain the detailed spectral properties of the first stars, BHs, and galaxies, rather than just the timing of their formation. And second, the speed of these calculations allows one to search vast expanses of a currently unconstrained parameter space, while simultaneously characterizing the degeneracies between parameters of interest. I find principally that (1) physical properties of the IGM, such as its temperature and ionization state, can be constrained robustly from observations of the global 21-cm signal without invoking models for the astrophysical sources themselves, (2) translating IGM properties to galaxy properties is challenging, in large part due to frequency-dependent effects. For instance, evolution in the characteristic spectrum of accreting BHs can modify the 21-cm absorption signal at levels accessible to first generation instruments, but could easily be confused with evolution in the X-ray luminosity star-formation rate relation. Finally, (3) the independent constraints most likely to aide in the interpretation

  13. Simple classical approach to spin resonance phenomena

    DEFF Research Database (Denmark)

    Gordon, R A

    1977-01-01

    A simple classical method of describing spin resonance in terms of the average power absorbed by a spin system is discussed. The method has several advantages over more conventional treatments, and a number of important spin resonance phenomena, not normally considered at the introductory level...

  14. Note: On-line weak signal detection via adaptive stochastic resonance.

    Science.gov (United States)

    Lu, Siliang; He, Qingbo; Kong, Fanrang

    2014-06-01

    We design an instrument with a novel embedded adaptive stochastic resonance (SR) algorithm that consists of a SR module and a digital zero crossing detection module for on-line weak signal detection in digital signal processing applications. The two modules are responsible for noise filtering and adaptive parameter configuration, respectively. The on-line weak signal detection can be stably achieved in seconds. The prototype instrument exhibits an advance of 20 dB averaged signal-to-noise ratio and 5 times averaged adjust R-square as compared to the input noisy signal, in considering different driving frequencies and noise levels.

  15. Parameter Estimation

    DEFF Research Database (Denmark)

    Sales-Cruz, Mauricio; Heitzig, Martina; Cameron, Ian;

    2011-01-01

    In this chapter the importance of parameter estimation in model development is illustrated through various applications related to reaction systems. In particular, rate constants in a reaction system are obtained through parameter estimation methods. These approaches often require the application...... of optimisation techniques coupled with dynamic solution of the underlying model. Linear and nonlinear approaches to parameter estimation are investigated. There is also the application of maximum likelihood principles in the estimation of parameters, as well as the use of orthogonal collocation to...... generate a set of algebraic equations as the basis for parameter estimation.These approaches are illustrated using estimations of kinetic constants from reaction system models....

  16. The characteristics of plasma-sheath resonances in a non-uniform radio-frequency plasma

    International Nuclear Information System (INIS)

    Plasma-sheath resonances in the resonance-probe were first reported by Takayama et al. in 1960. At that time the resonance was thought to occur at the plasma frequency; later work, however, showed that a plasma-sheath resonance was taking place. In this paper the authors plotted the ratio of RF field in the probe sheath to the RF probe voltage versus ω/ωep, and found that the ratio passed through a maximum when the probe was at resonance. The maximum corresponded to a ratio ω/ωep less than 1, the resonance frequency was confirmed to be below the plasma frequency and the open-quotes series resonance modelclose quotes was verified. After this definitive paper on the subject the interest of resonance probe moved into more practical applications. These include: determining the collision frequency between the electrons and neutrals in a low density plasma; measuring the electron density in the ionosphere; measuring the averaged densities of the charged particles as well as their temperature in a bounded plasma with an external magnetic field; studying antenna signals in space plasmas, etc. It is apparent that the harmonics developing in the plasma may weaken the conventional open-quotes drivenclose quotes Langmuir probe technique which is widely used in plasma research. There have been many attempts to resolve this problem, for example, driving, actively, the first two RF harmonics that appear across the probe sheath to achieve more precise plasma parameters. Nevertheless, it has been recently found that the natural frequency of the plasma-sheath system can be much more influential than the contributions from the external circuitry at certain fairly low pressures. This in particular when the plasma-sheath resonance coincides with one of the harmonics of the fundamental frequency. In this contribution we present some theoretical and experimental aspects of the plasma-sheath resonance in a parallel-plate RF plasma reactor

  17. Progress report on research project [Parameters for calculation of nuclear reactions of relevance to non-energy nuclear applications (Reference Input Parameter Library: Phase III)

    International Nuclear Information System (INIS)

    Full text: Uncertainties of the KD03 global optical model parameters. An estimate of the uncertainties of the parameters of the KD03 global optical model potential has been given. A Monte Carlo method for generating uncertainties of the final cross sections and angular distributions is used. The approach is pragmatic: The parameter uncertainties are adjusted such that the resulting calculated uncertainties account for the difference between the global prediction and the experimental data. At this stage, no OMP parameter correlations have been taken into account. We think however that the present results (summarized in a table), allow for adjustment of OMP parameters for data evaluation purposes. The presented uncertainties give a measure of the allowed deviation from the average parameters. Phenomenological level density parameters A computational set up for a consistent parameterization of three level density models has been built. This includes the Back-shifted Fermi gas Model, the Constant Temperature Model and the Generalized Superfluid Model, each without and with explicit collective enhancement. The resulting level densities should be applicable over a large energy range, taking into account experimental information from both discrete levels and mean resonance spacing. For each of the three models, we have produced local level density parameters, i.e. parameters that are adjusted per nucleus, which give the best average description of all observables (discrete levels, mean resonance spacing) for that nucleus. We have also produced a global level density parameterization for all models, i.e. formulae for the global expressions that enter the level density formula, to be used for any nucleus. A few remaining deficiencies in the procedure need to be removed before the parameter collection can be delivered to RIPL-3)

  18. Autostereogram resonators

    Science.gov (United States)

    Leavey, Sean; Rae, Katherine; Murray, Adam; Courtial, Johannes

    2012-09-01

    Autostereograms, or "Magic Eye" pictures, are repeating patterns designed to give the illusion of depth. Here we discuss optical resonators that create light patterns which, when viewed from a suitable position by a monocular observer, are autostereograms of the three-dimensional shape of one of the mirror surfaces.

  19. Mechanical and vibrational responses of gate-tunable graphene resonator

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Yuqing; Sun, Jiangping; Gong, Xionghui, E-mail: sensorman@163.com

    2015-03-15

    The vibrational mechanical properties of gate-tunable graphene resonator were investigated in detail using finite element analysis (FEA) and simulation. Treating the graphene resonator as a two-dimensional (2D) thin plate, the relationship between resonance frequency and driving force was explored. The effects of built-in tension, adsorbates and graphene size on the performance of resonator including resonance frequency and tunability were also studied. It was shown that resonance frequency could be tuned by the electrostatically induced average tension due to driving force, and exponentially increased with increasing driving force. When the single-layer graphene resonator without any adsorbates had no or very small built-in tension, the tunability of resonator was greater. However, for a high-frequency-range resonator, the resonator with high built-in tension should be used. The simulation results suggested potential applications of graphene resonators tuned by a driving force, such as widely tunable or ultrahigh frequency nanoelectromechanical systems (NEMS) devices.

  20. MEASUREMENT AND MODELLING AVERAGE PHOTOSYNTHESIS OF MAIZE

    OpenAIRE

    ZS LÕKE

    2005-01-01

    The photosynthesis of fully developed maize was investigated in the Agrometeorological Research Station Keszthely, in 2000. We used LI-6400 type measurement equipment to locate measurement points where the intensity of photosynthesis mostly nears the average. So later we could obtain average photosynthetic activities featuring the crop, with only one measurement. To check average photosynthesis of maize we used Goudriaan’s simulation model (CMSM) as well to calculate values on cloudless sampl...

  1. WIDTHS AND AVERAGE WIDTHS OF SOBOLEV CLASSES

    Institute of Scientific and Technical Information of China (English)

    刘永平; 许贵桥

    2003-01-01

    This paper concerns the problem of the Kolmogorov n-width, the linear n-width, the Gel'fand n-width and the Bernstein n-width of Sobolev classes of the periodicmultivariate functions in the space Lp(Td) and the average Bernstein σ-width, averageKolmogorov σ-widths, the average linear σ-widths of Sobolev classes of the multivariatequantities.

  2. Quantum state discrimination using the minimum average number of copies

    CERN Document Server

    Slussarenko, Sergei; Li, Jun-Gang; Campbell, Nicholas; Wiseman, Howard M; Pryde, Geoff J

    2016-01-01

    In the task of discriminating between nonorthogonal quantum states from multiple copies, the key parameters are the error probability and the resources (number of copies) used. Previous studies have considered the task of minimizing the average error probability for fixed resources. Here we consider minimizing the average resources for a fixed admissible error probability. We derive a detection scheme optimized for the latter task, and experimentally test it, along with schemes previously considered for the former task. We show that, for our new task, our new scheme outperforms all previously considered schemes.

  3. Cranial magnetic resonance imaging

    International Nuclear Information System (INIS)

    Cranial Magnetic Resonance Imaging is comprehensive, well structured, and well written. The material is current and well referenced. The illustrations are good and complement the text well. The overall quality of publication is above average. The greatest attribute of the book is its readability. The author demonstrates ample skill in making complex subjects, such as MR physics and imaging of cerebral hemorrhage, easy to understand. The book closes with a detailed atlas on the anatomic appearance of the brain on MR images in the axial, coronal, and sagittal planes

  4. Engineering a resonant nanocoating for an optical refractive index sensor

    Science.gov (United States)

    Bialiayeu, A.; Ianoul, A.; Albert, J.

    2014-03-01

    We proposing to boost the performance of refractive index sensors based on the tilted fiber Bragg grating (TFBG) structure by resonant coupling of small spherical nanoparticles to the TFBG resonances. The optimal choice of nanoparticle parameters is discussed.

  5. NOAA Average Annual Salinity (3-Zone)

    Data.gov (United States)

    California Department of Resources — The 3-Zone Average Annual Salinity Digital Geography is a digital spatial framework developed using geographic information system (GIS) technology. These salinity...

  6. Reconstruction of ionization probabilities from spatially averaged data in N-dimensions

    CERN Document Server

    Strohaber, J; Schuessler, H A

    2010-01-01

    We present an analytical inversion technique which can be used to recover ionization probabilities from spatially averaged data in an N-dimensional detection scheme. The solution is given as a power series in intensity. For this reason, we call this technique a multiphoton expansion (MPE). The MPE formalism was verified with an exactly solvable inversion problem in 2D, and probabilities in the postsaturation region, where the intensity-selective scanning approach breaks down, were recovered. In 3D, ionization probabilities of Xe were successfully recovered with MPE from simulated (using the ADK tunneling theory) ion yields. Finally, we tested our approach with intensity-resolved benzene ion yields showing a resonant multiphoton ionization process. By applying MPE to this data (which was artificially averaged) the resonant structure was recovered-suggesting that the resonance in benzene may have been observable in spatially averaged data taken elsewhere.

  7. Subharmonic Resonance of Van Der Pol Oscillator with Fractional-Order Derivative

    Directory of Open Access Journals (Sweden)

    Yongjun Shen

    2014-01-01

    Full Text Available The subharmonic resonance of van der Pol (VDP oscillator with fractional-order derivative is studied by the averaging method. At first, the first-order approximate solutions are obtained by the averaging method. Then the definitions of equivalent linear damping coefficient (ELDC and equivalent linear stiffness coefficient (ELSC for subharmonic resonance are established, and the effects of the fractional-order parameters on the ELDC, the ELSC, and the dynamical characteristics of system are also analysed. Moreover, the amplitude-frequency equation and phase-frequency equation of steady-state solution for subharmonic resonance are established. The corresponding stability condition is presented based on Lyapunov theory, and the existence condition for subharmonic resonance (ECSR is also obtained. At last, the comparisons of the fractional-order and the traditional integer-order VDP oscillator are fulfilled by the numerical simulation. The effects of the parameters in fractional-order derivative on the steady-state amplitude, the amplitude-frequency curves, and the system stability are also studied.

  8. Preheating and locked inflation: an analytic approach towards parametric resonance

    International Nuclear Information System (INIS)

    We take an analytic approach towards the framework of parametric resonance and apply it on preheating and locked inflation. A two-scalar toy model is analytically solved for the λφ2χ2 coupling for the homogenous modes. The effects of dynamic universe background and backreaction are taken into account. We show the average effect of parametric resonance to be that χ's amplitude doubles for each cycle of φ. Our framework partly solves the broad resonance for preheating scenario, showing two distinct stages of preheating and making the parameters of preheating analytically calculable. It is demonstrated for slowroll inflation models, preheating is terminated, if by backreaction, typically in the 5th e-fold. Under our framework, a possible inhomogeneity amplification effect is also found during preheating, which both may pose strong constraints on some inflationary models and may amplify tiny existing inhomogeneities to the desired scale. For demonstration, we show it rules out the backreaction end of preheating of the quadratic slowroll inflation model with mass m ∼ 10−6. For locked inflation, parametric resonance is found to be inhibited if φ has more than one real component

  9. Magnetic resonance imaging derived left ventricular global and region function parameters in healthy adults%健康成年人左心室整体及局部功能参数的磁共振研究

    Institute of Scientific and Technical Information of China (English)

    穆莉莎; 蒲艳军; 孙凯; 朱力; 李文玲; 田兴仓

    2014-01-01

    Objective To establish cardiac magnetic resonance imaging (MRI) derived left ventricular (LV) global and region function parameters in normal adults.Methods Twenty normal adults were examined with fast imaging employing steady-state (Fiesta) acquisition sequence of cardiac MRI,LV global function and LV region function were measured at basal,middle,apical level and at 16 LV segments.The regional function parameters among different levels and different segments of the same level were analyzed.Results (1) LV global function: end-diastolic volume (109.17 ± 19.52) ml ; end-systolic volume (37.76 ± 14.16) ml ; ejection fraction (65.93 ± 7.79) % ; wall thickening (83.24 ± 40.82) % ; longitudinal shortening (15.51 ± 3.78)% ; fractional shortening (31.78 ± 9.55)% ; end-diastolic mass (95.20 ± 19.95) g.(2) LV regional function: In each LV level,there was no significant difference in end-systolic wall thickness (P > 0.05).End-diastolic wall thickness and wall thickening were similar between the middle and apical levels,but there were significant differences between middle and apical levels with the basal level (both P <0.05).End-systolic wall thickness of the middle and the apical level was similar,but there were significant differences between middle and apical levels with the basal level (both P < 0.05).At the segments of the same level,end-diastolic wall thickness and the relevant regional function parameters between the segments of anteroseptal and inferoseptal at base and middle level were similar (P > 0.05) ; the end-diastolic wall thickness was the largest and the WT was the minimal at the septal segments of three levels,and the difference were significant between the septal and other segments in the same level (P <0.05).Conclusions Fractional shortening and longitudinal shortening provide new indicators for assessing LV global function by cardiac MRI.There is obvious heterogeneity on LV regional function in normal adults,systolic function is

  10. Average Transmission Probability of a Random Stack

    Science.gov (United States)

    Lu, Yin; Miniatura, Christian; Englert, Berthold-Georg

    2010-01-01

    The transmission through a stack of identical slabs that are separated by gaps with random widths is usually treated by calculating the average of the logarithm of the transmission probability. We show how to calculate the average of the transmission probability itself with the aid of a recurrence relation and derive analytical upper and lower…

  11. Average sampling theorems for shift invariant subspaces

    Institute of Scientific and Technical Information of China (English)

    孙文昌; 周性伟

    2000-01-01

    The sampling theorem is one of the most powerful results in signal analysis. In this paper, we study the average sampling on shift invariant subspaces, e.g. wavelet subspaces. We show that if a subspace satisfies certain conditions, then every function in the subspace is uniquely determined and can be reconstructed by its local averages near certain sampling points. Examples are given.

  12. Average excitation potentials of air and aluminium

    NARCIS (Netherlands)

    Bogaardt, M.; Koudijs, B.

    1951-01-01

    By means of a graphical method the average excitation potential I may be derived from experimental data. Average values for Iair and IAl have been obtained. It is shown that in representing range/energy relations by means of Bethe's well known formula, I has to be taken as a continuously changing fu

  13. New results on averaging theory and applications

    Science.gov (United States)

    Cândido, Murilo R.; Llibre, Jaume

    2016-08-01

    The usual averaging theory reduces the computation of some periodic solutions of a system of ordinary differential equations, to find the simple zeros of an associated averaged function. When one of these zeros is not simple, i.e., the Jacobian of the averaged function in it is zero, the classical averaging theory does not provide information about the periodic solution associated to a non-simple zero. Here we provide sufficient conditions in order that the averaging theory can be applied also to non-simple zeros for studying their associated periodic solutions. Additionally, we do two applications of this new result for studying the zero-Hopf bifurcation in the Lorenz system and in the Fitzhugh-Nagumo system.

  14. Overview of the 100 mA average-current RF photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, D.C. E-mail: dcnguyen@lanl.gov; Colestock, P.L.; Kurennoy, S.S.; Rees, D.E.; Regan, A.H.; Russell, S.; Schrage, D.L.; Wood, R.L.; Young, L.M.; Schultheiss, T.; Christina, V.; Cole, M.; Rathke, J.; Shaw, J.; Eddy, C.; Holm, R.; Henry, R.; Yater, J

    2004-08-01

    High-average-power FELs require high-current, low-emittance and low-energy-spread electron beams. These qualities have been achieved with RF photoinjectors operating at low-duty factors. To date, a high-average-current RF photoinjector operating continuously at 100% duty factor is yet to be demonstrated. The principal challenges of a high-duty-factor normal-conducting RF photoinjector are related to applying a high accelerating gradient continuously, thus generating large ohmic losses in the cavity walls, cooling the injector cavity walls and the high-power RF couplers, and finding a photocathode with reasonable Q.E. that can survive the poor vacuum of the RF photoinjector. We present the preliminary design of a normal-conducting 700 MHz photoinjector with solenoid magnetic fields for emittance compensation. The photoinjector is designed to produce 2.7 MeV electron beams at 3 nC bunch charge and 35 MHz repetition rate (100 mA average current). The photoinjector consists of a 2((1)/(2))-cell, {pi}-mode, RF cavity with on-axis electric coupling, and a non-resonant vacuum plenum. Heat removal in the resonant cells is achieved via dense arrays of internal cooling passages capable of handling high-velocity water flows. Megawatt RF power is coupled into the injector through two tapered ridge-loaded waveguides. PARMELA simulations show that the 2((1)/(2))-cell injector can produce a 7 {mu}m emittance directly. Transverse plasma oscillations necessitate additional acceleration and a second solenoid to realign the phase space envelopes of different axial slices at higher energy, resulting in a normalized rms emittance of 6.5 {mu}m and 34 keV rms energy spread. We are developing a novel cesiated p-type GaN photocathode with 7% quantum efficiency at 350 nm and a cesium dispenser to replenish the cathode with cesium through a porous silicon carbide substrate. These performance parameters will be necessary for the design of the 100 kW FEL.

  15. Overview of the 100 mA average-current RF photoinjector

    Science.gov (United States)

    Nguyen, D. C.; Colestock, P. L.; Kurennoy, S. S.; Rees, D. E.; Regan, A. H.; Russell, S.; Schrage, D. L.; Wood, R. L.; Young, L. M.; Schultheiss, T.; Christina, V.; Cole, M.; Rathke, J.; Shaw, J.; Eddy, C.; Holm, R.; Henry, R.; Yater, J.

    2004-08-01

    High-average-power FELs require high-current, low-emittance and low-energy-spread electron beams. These qualities have been achieved with RF photoinjectors operating at low-duty factors. To date, a high-average-current RF photoinjector operating continuously at 100% duty factor is yet to be demonstrated. The principal challenges of a high-duty-factor normal-conducting RF photoinjector are related to applying a high accelerating gradient continuously, thus generating large ohmic losses in the cavity walls, cooling the injector cavity walls and the high-power RF couplers, and finding a photocathode with reasonable Q.E. that can survive the poor vacuum of the RF photoinjector. We present the preliminary design of a normal-conducting 700 MHz photoinjector with solenoid magnetic fields for emittance compensation. The photoinjector is designed to produce 2.7 MeV electron beams at 3 nC bunch charge and 35 MHz repetition rate (100 mA average current). The photoinjector consists of a 2 {1}/{2}-cell, π-mode, RF cavity with on-axis electric coupling, and a non-resonant vacuum plenum. Heat removal in the resonant cells is achieved via dense arrays of internal cooling passages capable of handling high-velocity water flows. Megawatt RF power is coupled into the injector through two tapered ridge-loaded waveguides. PARMELA simulations show that the 2 {1}/{2}-cell injector can produce a 7 μm emittance directly. Transverse plasma oscillations necessitate additional acceleration and a second solenoid to realign the phase space envelopes of different axial slices at higher energy, resulting in a normalized rms emittance of 6.5 μm and 34 keV rms energy spread. We are developing a novel cesiated p-type GaN photocathode with 7% quantum efficiency at 350 nm and a cesium dispenser to replenish the cathode with cesium through a porous silicon carbide substrate. These performance parameters will be necessary for the design of the 100 kW FEL.

  16. Planar undulator motion excited by a fixed traveling wave. Quasiperiodic averaging normal forms and the FEL pendulum

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, James A.; Heinemann, Klaus [New Mexico Univ., Albuquerque, NM (United States). Dept. of Mathematics and Statistics; Vogt, Mathias [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Gooden, Matthew [North Carolina State Univ., Raleigh, NC (United States). Dept. of Physics

    2013-03-15

    We present a mathematical analysis of planar motion of energetic electrons moving through a planar dipole undulator, excited by a fixed planar polarized plane wave Maxwell field in the X-Ray FEL regime. Our starting point is the 6D Lorentz system, which allows planar motions, and we examine this dynamical system as the wave length {lambda} of the traveling wave varies. By scalings and transformations the 6D system is reduced, without approximation, to a 2D system in a form for a rigorous asymptotic analysis using the Method of Averaging (MoA), a long time perturbation theory. The two dependent variables are a scaled energy deviation and a generalization of the so- called ponderomotive phase. As {lambda} varies the system passes through resonant and nonresonant (NR) zones and we develop NR and near-to-resonant (NtoR) MoA normal form approximations. The NtoR normal forms contain a parameter which measures the distance from a resonance. For a special initial condition, for the planar motion and on resonance, the NtoR normal form reduces to the well known FEL pendulum system. We then state and prove NR and NtoR first-order averaging theorems which give explicit error bounds for the normal form approximations. We prove the theorems in great detail, giving the interested reader a tutorial on mathematically rigorous perturbation theory in a context where the proofs are easily understood. The proofs are novel in that they do not use a near identity transformation and they use a system of differential inequalities. The NR case is an example of quasiperiodic averaging where the small divisor problem enters in the simplest possible way. To our knowledge the planar prob- lem has not been analyzed with the generality we aspire to here nor has the standard FEL pendulum system been derived with associated error bounds as we do here. We briefly discuss the low gain theory in light of our NtoR normal form. Our mathematical treatment of the noncollective FEL beam dynamics problem in

  17. Short-Term Auditory Memory of Above-Average and Below-Average Grade Three Readers.

    Science.gov (United States)

    Caruk, Joan Marie

    To determine if performance on short term auditory memory tasks is influenced by reading ability or sex differences, 62 third grade reading students (16 above average boys, 16 above average girls, 16 below average boys, and 14 below average girls) were administered four memory tests--memory for consonant names, memory for words, memory for…

  18. Clarifying the Relationship between Average Excesses and Average Effects of Allele Substitutions.

    Science.gov (United States)

    Alvarez-Castro, José M; Yang, Rong-Cai

    2012-01-01

    Fisher's concepts of average effects and average excesses are at the core of the quantitative genetics theory. Their meaning and relationship have regularly been discussed and clarified. Here we develop a generalized set of one locus two-allele orthogonal contrasts for average excesses and average effects, based on the concept of the effective gene content of alleles. Our developments help understand the average excesses of alleles for the biallelic case. We dissect how average excesses relate to the average effects and to the decomposition of the genetic variance. PMID:22509178

  19. Clarifying the relationship between average excesses and average effects of allele substitutions

    Directory of Open Access Journals (Sweden)

    Jose M eÁlvarez-Castro

    2012-03-01

    Full Text Available Fisher’s concepts of average effects and average excesses are at the core of the quantitative genetics theory. Their meaning and relationship have regularly been discussed and clarified. Here we develop a generalized set of one-locus two-allele orthogonal contrasts for average excesses and average effects, based on the concept of the effective gene content of alleles. Our developments help understand the average excesses of alleles for the biallelic case. We dissect how average excesses relate to the average effects and to the decomposition of the genetic variance.

  20. Photo detection process and power spectrum estimation of optical radiation by the multichannel resonant spectrum analyzer

    Science.gov (United States)

    Moskaletz, O. D.; Paraskun, A. S.; Vaganov, M. A.

    2016-08-01

    The problem of receiving of an energy spectrum estimation of optical radiations in the new analyzer of optical signals is considered. It is the parallel resonant optical spectrum analyzer (SPECTRUM ANALYZER). Its resolving system is a set of narrow-band optical resonators in the form of interference filters. Each optical resonator is equivalent to a system with lumped parameters. This allows us to consider only oscillations of an optical field in the form of a scalar functions and adopt as a model of analyzed signal harmonized scalar random process. The photodetector operation and average of photocurrent using an integrator and integrating circuit is considered too. On the basis of the application prolate entire spheroidal wave function theory energy spectrum estimation by the integral of photocurrent is obtained. This energy spectrum estimation is consistent and asymptotically unbiased.

  1. Small scale magnetic flux-averaged magnetohydrodynamics

    International Nuclear Information System (INIS)

    By relaxing exact magnetic flux conservation below a scale λ a system of flux-averaged magnetohydrodynamic equations are derived from Hamilton's principle with modified constraints. An energy principle can be derived from the linearized averaged system because the total system energy is conserved. This energy principle is employed to treat the resistive tearing instability and the exact growth rate is recovered when λ is identified with the resistive skin depth. A necessary and sufficient stability criteria of the tearing instability with line tying at the ends for solar coronal loops is also obtained. The method is extended to both spatial and temporal averaging in Hamilton's principle. The resulting system of equations not only allows flux reconnection but introduces irreversibility for appropriate choice of the averaging function. Except for boundary contributions which are modified by the time averaging process total energy and momentum are conserved over times much longer than the averaging time τ but not for less than τ. These modified boundary contributions correspond to the existence, also, of damped waves and shock waves in this theory. Time and space averaging is applied to electron magnetohydrodynamics and in one-dimensional geometry predicts solitons and shocks in different limits

  2. Microwave power coupling with electron cyclotron resonance plasma using Langmuir probe

    Indian Academy of Sciences (India)

    S K Jain; V K Senecha; P A Naik; P R Hannurkar; S C Joshi

    2013-07-01

    Electron cyclotron resonance (ECR) plasma was produced at 2.45 GHz using 200 – 750 W microwave power. The plasma was produced from argon gas at a pressure of 2 × 10−4 mbar. Three water-cooled solenoid coils were used to satisfy the ECR resonant conditions inside the plasma chamber. The basic parameters of plasma, such as electron density, electron temperature, floating potential, and plasma potential, were evaluated using the current–voltage curve using a Langmuir probe. The effect of microwave power coupling to the plasma was studied by varying the microwave power. It was observed that the optimum coupling to the plasma was obtained for ∼ 600 W microwave power with an average electron density of ∼ 6 × 1011 cm−3 and average electron temperature of ∼ 9 eV.

  3. Average-passage flow model development

    Science.gov (United States)

    Adamczyk, John J.; Celestina, Mark L.; Beach, Tim A.; Kirtley, Kevin; Barnett, Mark

    1989-01-01

    A 3-D model was developed for simulating multistage turbomachinery flows using supercomputers. This average passage flow model described the time averaged flow field within a typical passage of a bladed wheel within a multistage configuration. To date, a number of inviscid simulations were executed to assess the resolution capabilities of the model. Recently, the viscous terms associated with the average passage model were incorporated into the inviscid computer code along with an algebraic turbulence model. A simulation of a stage-and-one-half, low speed turbine was executed. The results of this simulation, including a comparison with experimental data, is discussed.

  4. Average Shape of Transport-Limited Aggregates

    Science.gov (United States)

    Davidovitch, Benny; Choi, Jaehyuk; Bazant, Martin Z.

    2005-08-01

    We study the relation between stochastic and continuous transport-limited growth models. We derive a nonlinear integro-differential equation for the average shape of stochastic aggregates, whose mean-field approximation is the corresponding continuous equation. Focusing on the advection-diffusion-limited aggregation (ADLA) model, we show that the average shape of the stochastic growth is similar, but not identical, to the corresponding continuous dynamics. Similar results should apply to DLA, thus explaining the known discrepancies between average DLA shapes and viscous fingers in a channel geometry.

  5. Averaging of Backscatter Intensities in Compounds

    Science.gov (United States)

    Donovan, John J.; Pingitore, Nicholas E.; Westphal, Andrew J.

    2002-01-01

    Low uncertainty measurements on pure element stable isotope pairs demonstrate that mass has no influence on the backscattering of electrons at typical electron microprobe energies. The traditional prediction of average backscatter intensities in compounds using elemental mass fractions is improperly grounded in mass and thus has no physical basis. We propose an alternative model to mass fraction averaging, based of the number of electrons or protons, termed “electron fraction,” which predicts backscatter yield better than mass fraction averaging. PMID:27446752

  6. Experimental Demonstration of Squeezed State Quantum Averaging

    CERN Document Server

    Lassen, Mikael; Sabuncu, Metin; Filip, Radim; Andersen, Ulrik L

    2010-01-01

    We propose and experimentally demonstrate a universal quantum averaging process implementing the harmonic mean of quadrature variances. The harmonic mean protocol can be used to efficiently stabilize a set of fragile squeezed light sources with statistically fluctuating noise levels. The averaged variances are prepared probabilistically by means of linear optical interference and measurement induced conditioning. We verify that the implemented harmonic mean outperforms the standard arithmetic mean strategy. The effect of quantum averaging is experimentally tested both for uncorrelated and partially correlated noise sources with sub-Poissonian shot noise or super-Poissonian shot noise characteristics.

  7. Self-averaging characteristics of spectral fluctuations

    OpenAIRE

    Braun, Petr; Haake, Fritz

    2014-01-01

    The spectral form factor as well as the two-point correlator of the density of (quasi-)energy levels of individual quantum dynamics are not self-averaging. Only suitable smoothing turns them into useful characteristics of spectra. We present numerical data for a fully chaotic kicked top, employing two types of smoothing: one involves primitives of the spectral correlator, the second a small imaginary part of the quasi-energy. Self-averaging universal (like the CUE average) behavior is found f...

  8. Changing mortality and average cohort life expectancy

    DEFF Research Database (Denmark)

    Schoen, Robert; Canudas-Romo, Vladimir

    2005-01-01

    of survivorship. An alternative aggregate measure of period mortality which has been seen as less sensitive to period changes, the cross-sectional average length of life (CAL) has been proposed as an alternative, but has received only limited empirical or analytical examination. Here, we introduce a new measure......, the average cohort life expectancy (ACLE), to provide a precise measure of the average length of life of cohorts alive at a given time. To compare the performance of ACLE with CAL and with period and cohort life expectancy, we first use population models with changing mortality. Then the four aggregate...

  9. Effect of slice thickness on brain magnetic resonance image texture analysis

    Directory of Open Access Journals (Sweden)

    Heinonen Tomi

    2010-10-01

    Full Text Available Abstract Background The accuracy of texture analysis in clinical evaluation of magnetic resonance images depends considerably on imaging arrangements and various image quality parameters. In this paper, we study the effect of slice thickness on brain tissue texture analysis using a statistical approach and classification of T1-weighted images of clinically confirmed multiple sclerosis patients. Methods We averaged the intensities of three consecutive 1-mm slices to simulate 3-mm slices. Two hundred sixty-four texture parameters were calculated for both the original and the averaged slices. Wilcoxon's signed ranks test was used to find differences between the regions of interest representing white matter and multiple sclerosis plaques. Linear and nonlinear discriminant analyses were applied with several separate training and test sets to determine the actual classification accuracy. Results Only moderate differences in distributions of the texture parameter value for 1-mm and simulated 3-mm-thick slices were found. Our study also showed that white matter areas are well separable from multiple sclerosis plaques even if the slice thickness differs between training and test sets. Conclusions Three-millimeter-thick magnetic resonance image slices acquired with a 1.5 T clinical magnetic resonance scanner seem to be sufficient for texture analysis of multiple sclerosis plaques and white matter tissue.

  10. Nested trampoline resonators for optomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, M. J., E-mail: mweaver@physics.ucsb.edu; Pepper, B.; Luna, F.; Perock, B. [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Buters, F. M.; Eerkens, H. J.; Welker, G.; Heeck, K.; Man, S. de [Huygens-Kamerlingh Onnes Laboratorium, Universiteit Leiden, 2333 CA Leiden (Netherlands); Bouwmeester, D. [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Huygens-Kamerlingh Onnes Laboratorium, Universiteit Leiden, 2333 CA Leiden (Netherlands)

    2016-01-18

    Two major challenges in the development of optomechanical devices are achieving a low mechanical and optical loss rate and vibration isolation from the environment. We address both issues by fabricating trampoline resonators made from low pressure chemical vapor deposition Si{sub 3}N{sub 4} with a distributed Bragg reflector mirror. We design a nested double resonator structure with 80 dB of mechanical isolation from the mounting surface at the inner resonator frequency, and we demonstrate up to 45 dB of isolation at lower frequencies in agreement with the design. We reliably fabricate devices with mechanical quality factors of around 400 000 at room temperature. In addition, these devices were used to form optical cavities with finesse up to 181 000 ± 1000. These promising parameters will enable experiments in the quantum regime with macroscopic mechanical resonators.

  11. Nested Trampoline Resonators for Optomechanics

    CERN Document Server

    Weaver, Matthew J; Luna, Fernando; Buters, Frank M; Eerkens, Hedwig J; Welker, Gesa; Perock, Blaise; Heeck, Kier; de Man, Sven; Bouwmeester, Dirk

    2015-01-01

    Two major challenges in the development of optomechanical devices are achieving a low mechanical and optical loss rate and vibration isolation from the environment. We address both issues by fabricating novel trampoline resonators made from low pressure chemical vapor deposition (LPCVD) Si$_3$N$_4$ with a distributed bragg reflector (DBR) mirror. We construct a nested double resonator structure that generates approximately 80 dB of mechanical isolation from the mounting surface, eliminating the strong mounting dependence of the quality factor observed with single resonators. With the consistency provided by this isolation scheme we reliably fabricate devices with mechanical quality factors of around 400,000 at room temperature. In addition these devices were used to form optical cavities with finesse up to 181,000 $\\pm$ 1,000. These promising parameters will enable experiments in the quantum regime with macroscopic mechanical resonators.

  12. Nested trampoline resonators for optomechanics

    International Nuclear Information System (INIS)

    Two major challenges in the development of optomechanical devices are achieving a low mechanical and optical loss rate and vibration isolation from the environment. We address both issues by fabricating trampoline resonators made from low pressure chemical vapor deposition Si3N4 with a distributed Bragg reflector mirror. We design a nested double resonator structure with 80 dB of mechanical isolation from the mounting surface at the inner resonator frequency, and we demonstrate up to 45 dB of isolation at lower frequencies in agreement with the design. We reliably fabricate devices with mechanical quality factors of around 400 000 at room temperature. In addition, these devices were used to form optical cavities with finesse up to 181 000 ± 1000. These promising parameters will enable experiments in the quantum regime with macroscopic mechanical resonators

  13. Stochastic charging of dust grains in planetary rings: Diffusion rates and their effects on Lorentz resonances

    Science.gov (United States)

    Schaffer, L.; Burns, J. A.

    1995-01-01

    Dust grains in planetary rings acquire stochastically fluctuating electric charges as they orbit through any corotating magnetospheric plasma. Here we investigate the nature of this stochastic charging and calculate its effect on the Lorentz resonance (LR). First we model grain charging as a Markov process, where the transition probabilities are identified as the ensemble-averaged charging fluxes due to plasma pickup and photoemission. We determine the distribution function P(t;N), giving the probability that a grain has N excess charges at time t. The autocorrelation function tau(sub q) for the strochastic charge process can be approximated by a Fokker-Planck treatment of the evolution equations for P(t; N). We calculate the mean square response to the stochastic fluctuations in the Lorentz force. We find that transport in phase space is very small compared to the resonant increase in amplitudes due to the mean charge, over the timescale that the oscillator is resonantly pumped up. Therefore the stochastic charge variations cannot break the resonant interaction; locally, the Lorentz resonance is a robust mechanism for the shaping of etheral dust ring systems. Slightly stronger bounds on plasma parameters are required when we consider the longer transit times between Lorentz resonances.

  14. Dual wavelength demultiplexer based on metal–insulator–metal plasmonic circular ring resonators

    Science.gov (United States)

    Rakhshani, Mohammad Reza; Mansouri-Birjandi, Mohammad Ali

    2016-06-01

    In this paper, we investigated a plasmonic demultiplexer structure based on Metal-Insulator-Metal (MIM) waveguides and circular ring resonators. In order to achieve the structure of demultiplexer, two improved ring resonators have been used, which input and outputs MIM waveguides coupled by the ring resonators. To improve the transmission efficiency, a reflector was introduced at the right end of the input and output waveguides. By substituting the ring core with dielectric, the possibility of tuning the resonance wavelength of the proposed structure is illustrated, and the effect of various parameters such as radius and refractive index in transmission efficiency is studied in detail. This is useful for the design of integrated circuits in which it is not possible to extend the dimension of the ring resonator to attain a longer resonance wavelength. Transmission efficiency and quality factor of the single ring are 84% and 110, respectively. The simulation results using finite difference time domain method shows that in the proposed demultiplexer, which is composed of two rings with different core refractive indexes, the average power efficiency, bandwidth for each output channel, and the mean value of crosstalk are estimated 80%, 17 nm, and -26.95 dB, respectively. It is revealed that the significant features of the device are high transmission efficiency, low crosstalk, high-quality factor, and tunability for desired wavelengths. Therefore, the proposed structure has the potential to be applied in plasmonic integrated circuits.

  15. Average Vegetation Growth 1992 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1992 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  16. Average Vegetation Growth 1994 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1994 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  17. Average Vegetation Growth 1991 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1991 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  18. Average Vegetation Growth 1993 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1993 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  19. Average Vegetation Growth 1998 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1998 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  20. Average Vegetation Growth 1999 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1999 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  1. Average Vegetation Growth 1990 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1990 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  2. Average Vegetation Growth 2003 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2003 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  3. Sea Surface Temperature Average_SST_Master

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sea surface temperature collected via satellite imagery from http://www.esrl.noaa.gov/psd/data/gridded/data.noaa.ersst.html and averaged for each region using...

  4. MN Temperature Average (1961-1990) - Polygon

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data set depicts 30-year averages (1961-1990) of monthly and annual temperatures for Minnesota. Isolines and regions were created using kriging and...

  5. Average Vegetation Growth 2002 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2002 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  6. Average Vegetation Growth 1997 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1997 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  7. Spacetime Average Density (SAD) Cosmological Measures

    CERN Document Server

    Page, Don N

    2014-01-01

    The measure problem of cosmology is how to obtain normalized probabilities of observations from the quantum state of the universe. This is particularly a problem when eternal inflation leads to a universe of unbounded size so that there are apparently infinitely many realizations or occurrences of observations of each of many different kinds or types, making the ratios ambiguous. There is also the danger of domination by Boltzmann Brains. Here two new Spacetime Average Density (SAD) measures are proposed, Maximal Average Density (MAD) and Biased Average Density (BAD), for getting a finite number of observation occurrences by using properties of the Spacetime Average Density (SAD) of observation occurrences to restrict to finite regions of spacetimes that have a preferred beginning or bounce hypersurface. These measures avoid Boltzmann brain domination and appear to give results consistent with other observations that are problematic for other widely used measures, such as the observation of a positive cosmolo...

  8. A practical guide to averaging functions

    CERN Document Server

    Beliakov, Gleb; Calvo Sánchez, Tomasa

    2016-01-01

    This book offers an easy-to-use and practice-oriented reference guide to mathematical averages. It presents different ways of aggregating input values given on a numerical scale, and of choosing and/or constructing aggregating functions for specific applications. Building on a previous monograph by Beliakov et al. published by Springer in 2007, it outlines new aggregation methods developed in the interim, with a special focus on the topic of averaging aggregation functions. It examines recent advances in the field, such as aggregation on lattices, penalty-based aggregation and weakly monotone averaging, and extends many of the already existing methods, such as: ordered weighted averaging (OWA), fuzzy integrals and mixture functions. A substantial mathematical background is not called for, as all the relevant mathematical notions are explained here and reported on together with a wealth of graphical illustrations of distinct families of aggregation functions. The authors mainly focus on practical applications ...

  9. MN Temperature Average (1961-1990) - Line

    Data.gov (United States)

    Minnesota Department of Natural Resources — This data set depicts 30-year averages (1961-1990) of monthly and annual temperatures for Minnesota. Isolines and regions were created using kriging and...

  10. Average Vegetation Growth 2001 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2001 average vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the...

  11. Monthly snow/ice averages (ISCCP)

    Data.gov (United States)

    National Aeronautics and Space Administration — September Arctic sea ice is now declining at a rate of 11.5 percent per decade, relative to the 1979 to 2000 average. Data from NASA show that the land ice sheets...

  12. Modeling and Instability of Average Current Control

    OpenAIRE

    Fang, Chung-Chieh

    2012-01-01

    Dynamics and stability of average current control of DC-DC converters are analyzed by sampled-data modeling. Orbital stability is studied and it is found unrelated to the ripple size of the orbit. Compared with the averaged modeling, the sampled-data modeling is more accurate and systematic. An unstable range of compensator pole is found by simulations, and is predicted by sampled-data modeling and harmonic balance modeling.

  13. Nonequilibrium statistical averages and thermo field dynamics

    International Nuclear Information System (INIS)

    An extension of thermo field dynamics is proposed, which permits the computation of nonequilibrium statistical averages. The Brownian motion of a quantum oscillator is treated as an example. In conclusion it is pointed out that the procedure proposed to computation of time-dependent statistical average gives the correct two-point Green function for the damped oscillator. A simple extension can be used to compute two-point Green functions of free particles

  14. Average Bandwidth Allocation Model of WFQ

    Directory of Open Access Journals (Sweden)

    Tomáš Balogh

    2012-01-01

    Full Text Available We present a new iterative method for the calculation of average bandwidth assignment to traffic flows using a WFQ scheduler in IP based NGN networks. The bandwidth assignment calculation is based on the link speed, assigned weights, arrival rate, and average packet length or input rate of the traffic flows. We prove the model outcome with examples and simulation results using NS2 simulator.

  15. Disk-averaged synthetic spectra of Mars

    OpenAIRE

    Tinetti, Giovanna; Meadows, Victoria S.; Crisp, David; Fong, William; Velusamy, Thangasamy; Snively, Heather

    2004-01-01

    The principal goal of the NASA Terrestrial Planet Finder (TPF) and ESA Darwin mission concepts is to directly detect and characterize extrasolar terrestrial (Earth-sized) planets. This first generation of instruments is expected to provide disk-averaged spectra with modest spectral resolution and signal-to-noise. Here we use a spatially and spectrally resolved model of the planet Mars to study the detectability of a planet's surface and atmospheric properties from disk-averaged spectra as a f...

  16. Application of Stochastic Resonance Signal Recovery

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying; WANG Taiyong; LENG Yonggang; DENG Hui

    2009-01-01

    Stochastic resonance(SR) enhances the nonlinear system behavior with the assistance of noise, including the sensitivity and selectivity of the response to the exterior stimulus. The energy-transfer mechanism makes the weak information revealed in the output spectrum, while the time-waveform is distorted. The distortion analysis was made both from the particle's dynamics and signal processing. The factors causing the deviation in the output are presented and the function of the recovery system is proposed. By the investigation of the particle's motion track in the bistable system and the suggested recovery system, the influences of noise and system parameters on the recovery course were discussed. Moreover, the pulse distortion appearing the recovery waveform caused by the particle's transitions at the bistable potential' inflexions was explained. Due to different characteristics, cascaded-bistable SR or mono-stable SR was introduced to process different types of signals. The final recovery signal is just the suggested recovery system's response to the SR output. Meanwhile, the recovery system is optional, as parameter-tuned or parameter-fixed. Since the method requires no average processing, it is applicable to a single sample with limited length. The numerical simulations reveal that the SR recovery method can recover the waveform containing weak information submerged in noise effectively. The engineering application to the vibration analysis of metal cutting chose the combination of mono-stable SR and the parameter-fixed recovery system. Because the optimal SR state is not required strongly, the system parameters are tuned in a wider range than the traditional SR processing methods.

  17. Optimal VLF Parameters for Pitch Angle Scattering of Trapped Electrons

    Science.gov (United States)

    Albert, J. M.; Inan, U. S.

    2001-12-01

    VLF waves are known to determine the lifetimes of energetic radiation belt electrons in the inner radiation belt and slot regions. Artificial injection of such waves from ground- or space-based transmitters may thus be used to affect the trapped electron population. In this paper, we seek to determine the optimal parameters (frequency and wave normal angle) of a quasi-monochromatic VLF wave using bounce-averaged quasi-linear theory. We consider the cumulative effects of all harmonic resonances and determine the diffusion rates of particles with selected energies on particular L-shells. We also compare the effects of the VLF wave to diffusion driven by other whistler-mode waves (plasmaspheric hiss, lightning, and VLF transmitters). With appropriate choice of the wave parameters, it may be possible to substantially reduce the lifetime of selected classes of particles.

  18. Averaged universe confronted to cosmological observations: a fully covariant approach

    CERN Document Server

    Wijenayake, Tharake; Ishak, Mustapha

    2016-01-01

    One of the outstanding problems in general relativistic cosmology is that of the averaging. That is, how the lumpy universe that we observe at small scales averages out to a smooth Friedmann-Lemaitre-Robertson-Walker (FLRW) model. The root of the problem is that averaging does not commute with the Einstein equations that govern the dynamics of the model. This leads to the well-know question of backreaction in cosmology. In this work, we approach the problem using the covariant framework of Macroscopic Gravity (MG). We use its cosmological solution with a flat FLRW macroscopic background where the result of averaging cosmic inhomogeneities has been encapsulated into a backreaction density parameter denoted $\\Omega_\\mathcal{A}$. We constrain this averaged universe using available cosmological data sets of expansion and growth including, for the first time, a full CMB analysis from Planck temperature anisotropy and polarization data, the supernovae data from Union 2.1, the galaxy power spectrum from WiggleZ, the...

  19. Average Soil Water Retention Curves Measured by Neutron Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Chu-Lin [ORNL; Perfect, Edmund [University of Tennessee, Knoxville (UTK); Kang, Misun [ORNL; Voisin, Sophie [ORNL; Bilheux, Hassina Z [ORNL; Horita, Juske [Texas Tech University (TTU); Hussey, Dan [NIST Center for Neutron Research (NCRN), Gaithersburg, MD

    2011-01-01

    Water retention curves are essential for understanding the hydrologic behavior of partially-saturated porous media and modeling flow transport processes within the vadose zone. In this paper we report direct measurements of the main drying and wetting branches of the average water retention function obtained using 2-dimensional neutron radiography. Flint sand columns were saturated with water and then drained under quasi-equilibrium conditions using a hanging water column setup. Digital images (2048 x 2048 pixels) of the transmitted flux of neutrons were acquired at each imposed matric potential (~10-15 matric potential values per experiment) at the NCNR BT-2 neutron imaging beam line. Volumetric water contents were calculated on a pixel by pixel basis using Beer-Lambert s law after taking into account beam hardening and geometric corrections. To remove scattering effects at high water contents the volumetric water contents were normalized (to give relative saturations) by dividing the drying and wetting sequences of images by the images obtained at saturation and satiation, respectively. The resulting pixel values were then averaged and combined with information on the imposed basal matric potentials to give average water retention curves. The average relative saturations obtained by neutron radiography showed an approximate one-to-one relationship with the average values measured volumetrically using the hanging water column setup. There were no significant differences (at p < 0.05) between the parameters of the van Genuchten equation fitted to the average neutron radiography data and those estimated from replicated hanging water column data. Our results indicate that neutron imaging is a very effective tool for quantifying the average water retention curve.

  20. Neutron capture cross section of $^{232}Th$ measured at the nTOF facility at CERN in the unresolved resonance region up to 1 MeV

    CERN Document Server

    Aerts, G; Alvarez, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, P A; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carillo de Albornoz, A; Cennini, P; Chepel, V Yu; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Durán, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Kölbl, H; Fujii, K; Furman, W; Gonçalves, I; González-Romero, E M; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Isaev, S; Jericha, E; Käppeler, F K; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Ketlerov, V; Köhler, P; Konovalov, V; Kossionides, E; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Mastinu, P; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, Heinz; O'Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Taliente, G; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2006-01-01

    We have measured the neutron capture reaction yield of /sup 232energy range from 1 eV to 1 MeV. The average capture cross section has been extracted in the energy range from 4 keV up to 1 MeV with an overall accuracy better than 4%. An independent IAEA evaluation shows good agreement with the data. The average cross section has been expressed in terms of average resonance parameters using the partial waves script l=0,1, and 2.

  1. Resonance, Multi-resonance, and Reverse-resonance Induced by Multiplicative Dichotomous Noise

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A constant-potential system driven by multiplicative dichotomous noise and subject to an input oscillatory signal is investigated. Two phenomena of stochastic resonance are observed. One is the response as a function of the noise's parameters; the other is that as a function of the input signal frequency. A phenomenon of multi-resonance (there are three or four peaks) is found for the response as a function of a parameter of the noise. A phenomenon of reverse-resonance is found, for which the response of the system to the signal can be weakened by the presence of the noise (there is an optimal minimum). These results help in studies of the systems with multiplicative dichotomous noise, such as the semiconductor, the proteins motor, the chemical reaction, and so on.

  2. Developing accelerometer based on graphene nanoribbon resonators

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jeong Won, E-mail: jwkang@ut.ac.kr [Department of Computer Engineering, Korea National University of Transportation, Chungju 380-702 (Korea, Republic of); Lee, Jun Ha, E-mail: junha@smu.ac.kr [Department of Computer System Engineering, Sangmyung University, Chonan 330-720 (Korea, Republic of); Hwang, Ho Jung, E-mail: hjhwang@cau.ac.kr [School of Electrical and Electronic Engineering, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Kim, Ki-Sub, E-mail: kks1114@ut.ac.kr [Department of Chemical and Biological Engineering, Korea National University of Transportation, Chungju 380-702 (Korea, Republic of)

    2012-10-01

    We investigated an ultrahigh sensitive accelerometer based on graphene nanoribbon resonators. Sensing acceleration can be made by their resonance frequency shift and/or their capacitance change. Schematics and the static properties were introduced and the dynamic properties were investigated via classical molecular dynamics simulation. As the acceleration increased, the oscillations of the deflections were going dramatically faster and the mean deflections increased, then the capacitance continually varied with large amplitudes and the resonance frequencies linearly increased in a log–log scale by power regression. The energy loss decreased with increasing time, and the average quality factors were dramatically reduced with increasing acceleration. -- Highlights: ► Ultrahigh sensitive accelerometer based on graphene nanoribbon resonators. ► Sensing acceleration by resonance frequency shift and/or capacitance change. ► Resonance frequencies linearly increased with increasing acceleration in a log–log scale. ► Quality factors were dramatically reduced with increasing acceleration.

  3. Comparison of Mouse Brain DTI Maps Using K-space Average, Image-space Average, or No Average Approach

    OpenAIRE

    Sun, Shu-Wei; Mei, Jennifer; Tuel, Keelan

    2013-01-01

    Diffusion tensor imaging (DTI) is achieved by collecting a series of diffusion-weighted images (DWIs). Signal averaging of multiple repetitions can be performed in the k-space (k-avg) or in the image space (m-avg) to improve the image quality. Alternatively, one can treat each acquisition as an independent image and use all of the data to reconstruct the DTI without doing any signal averaging (no-avg). To compare these three approaches, in this study, in vivo DTI data was collected from five ...

  4. Low-Loss Polymer-Based Ring Resonator for Resonant Integrated Optical Gyroscopes

    Directory of Open Access Journals (Sweden)

    Guang Qian

    2014-01-01

    Full Text Available Waveguide ring resonator is the sensing element of resonant integrated optical gyroscope (RIOG. This paper reports a polymer-based ring resonator with a low propagation loss of about 0.476 dB/cm for RIOG. The geometrical parameters of the waveguide and the coupler of the resonator were optimally designed. We also discussed the optical properties and gyroscope performance of the polymer resonator which shows a high quality factor of about 105. The polymer-based RIOG exhibits a limited sensitivity of less than 20 deg/h for the low and medium resolution navigation systems.

  5. Orientation-averaged optical properties of natural aerosol aggregates

    International Nuclear Information System (INIS)

    Orientation-averaged optical properties of natural aerosol aggregates were analyzed by using discrete dipole approximation (DDA) for the effective radius in the range of 0.01 to 2 μm with the corresponding size parameter from 0.1 to 23 for the wavelength of 0.55 μm. Effects of the composition and morphology on the optical properties were also investigated. The composition show small influence on the extinction-efficiency factor in Mie scattering region, scattering- and backscattering-efficiency factors. The extinction-efficiency factor with the size parameter from 9 to 23 and asymmetry factor with the size parameter below 2.3 are almost independent of the natural aerosol composition. The extinction-, absorption, scattering-, and backscattering-efficiency factors with the size parameter below 0.7 are irrespective of the aggregate morphology. The intrinsic symmetry and discontinuity of the normal direction of the particle surface have obvious effects on the scattering properties for the size parameter above 4.6. Furthermore, the scattering phase functions of natural aerosol aggregates are enhanced at the backscattering direction (opposition effect) for large size parameters in the range of Mie scattering. (authors)

  6. Basics of averaging of the Maxwell equations

    CERN Document Server

    Chipouline, A; Tretyakov, S

    2011-01-01

    Volume or statistical averaging of the microscopic Maxwell equations (MEs), i.e. transition from microscopic MEs to their macroscopic counterparts, is one of the main steps in electrodynamics of materials. In spite of the fundamental importance of the averaging procedure, it is quite rarely properly discussed in university courses and respective books; up to now there is no established consensus about how the averaging procedure has to be performed. In this paper we show that there are some basic principles for the averaging procedure (irrespective to what type of material is studied) which have to be satisfied. Any homogenization model has to be consistent with the basic principles. In case of absence of this correlation of a particular model with the basic principles the model could not be accepted as a credible one. Another goal of this paper is to establish the averaging procedure for metamaterials, which is rather close to the case of compound materials but should include magnetic response of the inclusi...

  7. Electron-ion collisions in the average-configuration distorted-wave approximation

    International Nuclear Information System (INIS)

    Explicit expressions for the electron-impact excitation, ionization, and resonant-recombination cross sections are derived in the average-configuration distorted-wave approximation. Calculations using these expressions are applied to several types of phenomena in electron-ion scattering where comparison with other theoretical methods and experimental measurements can be made. 24 refs., 5 figs

  8. Averaging and Benjamin-Feir instabilities in a parametrically forced nonlinear Schroedinger equation

    Energy Technology Data Exchange (ETDEWEB)

    Panayotaros, Panayotis

    2004-03-29

    We study small amplitude solutions of a parametrically forced nonlinear Schroedinger equation, and give exact expressions for the quartic resonant mode interactions by analyzing the corresponding Diophantine equations. We use this information to find some classes of periodic orbits of the averaged equation and characterize the linearly unstable directions of Stokes wave solutions.

  9. Books average previous decade of economic misery.

    Science.gov (United States)

    Bentley, R Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios

    2014-01-01

    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade. PMID:24416159

  10. Cosmic structure, averaging and dark energy

    CERN Document Server

    Wiltshire, David L

    2013-01-01

    These lecture notes review the theoretical problems associated with coarse-graining the observed inhomogeneous structure of the universe at late epochs, of describing average cosmic evolution in the presence of growing inhomogeneity, and of relating average quantities to physical observables. In particular, a detailed discussion of the timescape scenario is presented. In this scenario, dark energy is realized as a misidentification of gravitational energy gradients which result from gradients in the kinetic energy of expansion of space, in the presence of density and spatial curvature gradients that grow large with the growth of structure. The phenomenology and observational tests of the timescape model are discussed in detail, with updated constraints from Planck satellite data. In addition, recent results on the variation of the Hubble expansion on < 100/h Mpc scales are discussed. The spherically averaged Hubble law is significantly more uniform in the rest frame of the Local Group of galaxies than in t...

  11. Books average previous decade of economic misery.

    Directory of Open Access Journals (Sweden)

    R Alexander Bentley

    Full Text Available For the 20(th century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.

  12. Books average previous decade of economic misery.

    Science.gov (United States)

    Bentley, R Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios

    2014-01-01

    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.

  13. Matrix averages relating to Ginibre ensembles

    Energy Technology Data Exchange (ETDEWEB)

    Forrester, Peter J [Department of Mathematics and Statistics, University of Melbourne, Victoria 3010 (Australia); Rains, Eric M [Department of Mathematics, California Institute of Technology, Pasadena, CA 91125 (United States)], E-mail: p.forrester@ms.unimelb.edu.au

    2009-09-25

    The theory of zonal polynomials is used to compute the average of a Schur polynomial of argument AX, where A is a fixed matrix and X is from the real Ginibre ensemble. This generalizes a recent result of Sommers and Khoruzhenko (2009 J. Phys. A: Math. Theor. 42 222002), and furthermore allows analogous results to be obtained for the complex and real quaternion Ginibre ensembles. As applications, the positive integer moments of the general variance Ginibre ensembles are computed in terms of generalized hypergeometric functions; these are written in terms of averages over matrices of the same size as the moment to give duality formulas, and the averages of the power sums of the eigenvalues are expressed as finite sums of zonal polynomials.

  14. Stochastic Averaging and Stochastic Extremum Seeking

    CERN Document Server

    Liu, Shu-Jun

    2012-01-01

    Stochastic Averaging and Stochastic Extremum Seeking develops methods of mathematical analysis inspired by the interest in reverse engineering  and analysis of bacterial  convergence by chemotaxis and to apply similar stochastic optimization techniques in other environments. The first half of the text presents significant advances in stochastic averaging theory, necessitated by the fact that existing theorems are restricted to systems with linear growth, globally exponentially stable average models, vanishing stochastic perturbations, and prevent analysis over infinite time horizon. The second half of the text introduces stochastic extremum seeking algorithms for model-free optimization of systems in real time using stochastic perturbations for estimation of their gradients. Both gradient- and Newton-based algorithms are presented, offering the user the choice between the simplicity of implementation (gradient) and the ability to achieve a known, arbitrary convergence rate (Newton). The design of algorithms...

  15. Average Cycle Period in Asymmetrical Flashing Ratchet

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-Yan; HE Hou-Sheng; BAO Jing-Dong

    2005-01-01

    The directed motion of a Brownian particle in a flashing potential with various transition probabilities and waiting times in one of two states is studied. An expression for the average cycle period is proposed and the steady current J of the particle is calculated via Langevin simulation. The results show that the optimal cycle period rm,which takes the maximum of J, is shifted to a small value when the transition probability λ from the potential on to the potential off decreases, the maximalcurrent appears in the case of the average waiting time in the potential on being longer than in the potential off, and the direction of current depends on the ratio of the average times waiting in two states.

  16. Resonance self-indication as a method for estimating fissile elements in spent nuclear assemblies

    International Nuclear Information System (INIS)

    The integral version of the neutron resonance transmission analysis (NRTA) has been developed in order to solve the problem of estimating fissile elements in spent nuclear fuel. Two variants of the integral neutron resonance transmission analysis (the resonance self-indication (the average transmission by fission) and the average full transmission) have been described

  17. Scalar-Pseudoscalar scattering and pseudoscalar resonances

    CERN Document Server

    Albaladejo, M

    2010-01-01

    The interactions between the f_0(980) and a_0(980) scalar resonances and the lightest pseudoscalar mesons are studied. We first obtain the interacting kernels, without including any ad hoc free parameter, because the lightest scalar resonances are dynamically generated. These kernels are unitarized, giving the final amplitudes, which generate pseudoscalar resonances, associated with the K(1460), \\pi(1300), \\pi(1800), \\eta(1475) and X(1835). We also consider the exotic channels with I=3/2 and I^G=1^+ quantum numbers. The former could be also resonant in agreement with a previous prediction.

  18. Composite spin-1 resonances at the LHC

    CERN Document Server

    Low, Matthew; Wang, Lian-Tao

    2015-01-01

    In this paper, we discuss the signal of composite spin-1 resonances at the LHC. Motivated by the possible observation of a diboson resonance in the 8 TeV LHC data, we demonstrate that vector resonances from composite Higgs models are able to describe the data. We pay particular attention to the role played by fermion partial compositeness, which is a common feature in composite Higgs models. The parameter space that is both able to account for the diboson excess and passes electroweak precision and flavor tests is explored. Finally, we make projections for signals of such resonances at the 13 TeV run of the LHC.

  19. Books Average Previous Decade of Economic Misery

    OpenAIRE

    R Alexander Bentley; Alberto Acerbi; Paul Ormerod; Vasileios Lampos

    2014-01-01

    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is signific...

  20. An improved moving average technical trading rule

    Science.gov (United States)

    Papailias, Fotis; Thomakos, Dimitrios D.

    2015-06-01

    This paper proposes a modified version of the widely used price and moving average cross-over trading strategies. The suggested approach (presented in its 'long only' version) is a combination of cross-over 'buy' signals and a dynamic threshold value which acts as a dynamic trailing stop. The trading behaviour and performance from this modified strategy are different from the standard approach with results showing that, on average, the proposed modification increases the cumulative return and the Sharpe ratio of the investor while exhibiting smaller maximum drawdown and smaller drawdown duration than the standard strategy.

  1. A singularity theorem based on spatial averages

    Indian Academy of Sciences (India)

    J M M Senovilla

    2007-07-01

    Inspired by Raychaudhuri's work, and using the equation named after him as a basic ingredient, a new singularity theorem is proved. Open non-rotating Universes, expanding everywhere with a non-vanishing spatial average of the matter variables, show severe geodesic incompletness in the past. Another way of stating the result is that, under the same conditions, any singularity-free model must have a vanishing spatial average of the energy density (and other physical variables). This is very satisfactory and provides a clear decisive difference between singular and non-singular cosmologies.

  2. Average-case analysis of numerical problems

    CERN Document Server

    2000-01-01

    The average-case analysis of numerical problems is the counterpart of the more traditional worst-case approach. The analysis of average error and cost leads to new insight on numerical problems as well as to new algorithms. The book provides a survey of results that were mainly obtained during the last 10 years and also contains new results. The problems under consideration include approximation/optimal recovery and numerical integration of univariate and multivariate functions as well as zero-finding and global optimization. Background material, e.g. on reproducing kernel Hilbert spaces and random fields, is provided.

  3. Resonant Nucleation

    CERN Document Server

    Gleiser, M; Gleiser, Marcelo; Howell, Rafael

    2004-01-01

    We investigate the role played by fast quenching on the decay of metastable (or false vacuum) states. Instead of the exponentially-slow decay rate per unit volume, $\\Gamma_{\\rm HN} \\sim \\exp[-E_b/k_BT]$ ($E_b$ is the free energy of the critical bubble), predicted by Homogeneous Nucleation theory, we show that under fast enough quenching the decay rate is, in fact, a power law $\\Gamma_{\\rm RN} \\sim [E_b/k_BT]^{-B}$, where $B$ is weakly sensitive to the temperature. We argue that the fast quench generates large-amplitude fluctuations about the metastable state which promote its rapid decay via parametric resonance. Possible decay mechanisms and their dependence on $E_b$ are proposed and illustrated in a (2+1)-dimensional scalar field model with an asymmetric double-well potential.

  4. Averaged electron collision cross sections for thermal mixtures of $\\alpha$-Alanine conformers in the gas phase

    CERN Document Server

    Fujimoto, Milton M; Tennyson, Jonathan

    2016-01-01

    A theoretical study of elastic electron collisions with 9 conformers of the gas-phase amino acid $\\alpha$-alanine (CH$_3$CH(NH$_2$)COOH) is performed. The eigenphase sums, resonance features, differential and integral cross sections are computed for each individual conformer. Resonance positions for the low-energy $\\pi^*$ shape resonance are found to vary from 2.6 eV to 3.1 eV and the resonance widths from 0.3 eV to 0.5 eV. Averaged cross sections for thermal mixtures of the 9 conformers are presented. Both theoretical and experimental population ratios are considered. Thermally-averaged cross sections obtained using the best theoretical estimates give reasonable agreement with the observed thermal cross sections. Excited conformers IIA and IIB make a large contribution to this average due to their large permanent dipole moments.

  5. Micro-machined resonator oscillator

    Science.gov (United States)

    Koehler, Dale R.; Sniegowski, Jeffry J.; Bivens, Hugh M.; Wessendorf, Kurt O.

    1994-01-01

    A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a "telemetered sensor beacon" that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20-100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available.

  6. Multimode Resonant Coupling in Pulsating Stars

    CERN Document Server

    Nowakowski, R M

    2005-01-01

    We consider evolution of an unstable acoustic mode interacting with an ensemble of stable g-modes. We show that the static multimode solution does not exist. We then find the condition for the stability of the statistical equilibrium. Performing numerical integration of amplitude equations for a simplified system we find that the acoustic mode amplitude exhibits a large irregular variability on the timescale given by the inverse of the growth rate. The g-mode pairs are excited in significantly wider range of detuning parameters than it is implied by the parametric instability criterion applied to the average amplitude. However, the number of interacting g-mode pairs is reduced because the pairs differing in the detuning parameter by less than their damping rates are synchronized and effectively act as a single pair. We apply the multimode resonant coupling theory to a realistic stellar model. We choose a seismic model of the Delta Scuti star XX Pyxidis. Although for some l=2 modes we find amplitudes of the or...

  7. HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS

    International Nuclear Information System (INIS)

    Historically, the first demonstration of the optical FEL was in an amplifier configuration at Stanford University [l]. There were other notable instances of amplifying a seed laser, such as the LLNL PALADIN amplifier [2] and the BNL ATF High-Gain Harmonic Generation FEL [3]. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance FEL's with average power of 100 kW or more. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting Energy Recovery Linacs (ERL) combine well with the high-gain FEL amplifier to produce unprecedented average power FELs. This combination has a number of advantages. In particular, we show that for a given FEL power, an FEL amplifier can introduce lower energy spread in the beam as compared to a traditional oscillator. This properly gives the ERL based FEL amplifier a great wall-plug to optical power efficiency advantage. The optics for an amplifier is simple and compact. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Linac which is under construction at Brookhaven National Laboratory's Collider-Accelerator Department

  8. Average beta measurement in EXTRAP T1

    International Nuclear Information System (INIS)

    Beginning with the ideal MHD pressure balance equation, an expression for the average poloidal beta, ΒΘ, is derived. A method for unobtrusively measuring the quantities used to evaluate ΒΘ in Extrap T1 is described. The results if a series of measurements yielding ΒΘ as a function of externally applied toroidal field are presented. (author)

  9. Quantum Averaging of Squeezed States of Light

    DEFF Research Database (Denmark)

    Squeezing has been recognized as the main resource for quantum information processing and an important resource for beating classical detection strategies. It is therefore of high importance to reliably generate stable squeezing over longer periods of time. The averaging procedure for a single qu...

  10. An approximate analytical approach to resampling averages

    DEFF Research Database (Denmark)

    Malzahn, Dorthe; Opper, M.

    2004-01-01

    Using a novel reformulation, we develop a framework to compute approximate resampling data averages analytically. The method avoids multiple retraining of statistical models on the samples. Our approach uses a combination of the replica "trick" of statistical physics and the TAP approach for appr...

  11. Discontinuities and hysteresis in quantized average consensus

    NARCIS (Netherlands)

    Ceragioli, Francesca; Persis, Claudio De; Frasca, Paolo

    2011-01-01

    We consider continuous-time average consensus dynamics in which the agents’ states are communicated through uniform quantizers. Solutions to the resulting system are defined in the Krasowskii sense and are proven to converge to conditions of ‘‘practical consensus’’. To cope with undesired chattering

  12. Error estimates on averages of correlated data

    International Nuclear Information System (INIS)

    We describe how the true statistical error on an average of correlated data can be obtained with ease and efficiency by a renormalization group method. The method is illustrated with numerical and analytical examples, having finite as well as infinite range correlations. (orig.)

  13. Average utility maximization: A preference foundation

    NARCIS (Netherlands)

    A.V. Kothiyal (Amit); V. Spinu (Vitalie); P.P. Wakker (Peter)

    2014-01-01

    textabstractThis paper provides necessary and sufficient preference conditions for average utility maximization over sequences of variable length. We obtain full generality by using a new algebraic technique that exploits the richness structure naturally provided by the variable length of the sequen

  14. High average-power induction linacs

    Energy Technology Data Exchange (ETDEWEB)

    Prono, D.S.; Barrett, D.; Bowles, E.; Caporaso, G.J.; Chen, Yu-Jiuan; Clark, J.C.; Coffield, F.; Newton, M.A.; Nexsen, W.; Ravenscroft, D.

    1989-03-15

    Induction linear accelerators (LIAs) are inherently capable of accelerating several thousand amperes of /approximately/ 50-ns duration pulses to > 100 MeV. In this paper we report progress and status in the areas of duty factor and stray power management. These technologies are vital if LIAs are to attain high average power operation. 13 figs.

  15. Bayesian Model Averaging for Propensity Score Analysis

    Science.gov (United States)

    Kaplan, David; Chen, Jianshen

    2013-01-01

    The purpose of this study is to explore Bayesian model averaging in the propensity score context. Previous research on Bayesian propensity score analysis does not take into account model uncertainty. In this regard, an internally consistent Bayesian framework for model building and estimation must also account for model uncertainty. The…

  16. Generalized Jackknife Estimators of Weighted Average Derivatives

    DEFF Research Database (Denmark)

    Cattaneo, Matias D.; Crump, Richard K.; Jansson, Michael

    With the aim of improving the quality of asymptotic distributional approximations for nonlinear functionals of nonparametric estimators, this paper revisits the large-sample properties of an important member of that class, namely a kernel-based weighted average derivative estimator. Asymptotic...

  17. Independence, Odd Girth, and Average Degree

    DEFF Research Database (Denmark)

    Löwenstein, Christian; Pedersen, Anders Sune; Rautenbach, Dieter;

    2011-01-01

      We prove several tight lower bounds in terms of the order and the average degree for the independence number of graphs that are connected and/or satisfy some odd girth condition. Our main result is the extension of a lower bound for the independence number of triangle-free graphs of maximum...

  18. Bootstrapping Density-Weighted Average Derivatives

    DEFF Research Database (Denmark)

    Cattaneo, Matias D.; Crump, Richard K.; Jansson, Michael

    Employing the "small bandwidth" asymptotic framework of Cattaneo, Crump, and Jansson (2009), this paper studies the properties of a variety of bootstrap-based inference procedures associated with the kernel-based density-weighted averaged derivative estimator proposed by Powell, Stock, and Stoker...

  19. A dynamic analysis of moving average rules

    NARCIS (Netherlands)

    C. Chiarella; X.Z. He; C.H. Hommes

    2006-01-01

    The use of various moving average (MA) rules remains popular with financial market practitioners. These rules have recently become the focus of a number empirical studies, but there have been very few studies of financial market models where some agents employ technical trading rules of the type use

  20. Some applications of stochastic averaging method for quasi Hamiltonian systems in physics

    Institute of Scientific and Technical Information of China (English)

    DENG MaoLin; ZHU WeiQiu

    2009-01-01

    Many physical systems can be modeled as quasi-Hamiltonian systems and the stochastic averaging method for uasi-Hamiltonian systems can be applied to yield reasonable approximate response sta-tistics. In the present paper, the basic idea and procedure of the stochastic averaging method for quasi Hamiltonian systems are briefly introduced. The applications of the stochastic averaging method in studying the dynamics of active Brownian particles, the reaction rate theory, the dynamics of breathing and denaturation of DNA, and the Fermi resonance and its effect on the mean transition time are re-viewed.

  1. Some applications of stochastic averaging method for quasi Hamiltonian systems in physics

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Many physical systems can be modeled as quasi-Hamiltonian systems and the stochastic averaging method for quasi-Hamiltonian systems can be applied to yield reasonable approximate response sta-tistics.In the present paper,the basic idea and procedure of the stochastic averaging method for quasi Hamiltonian systems are briefly introduced.The applications of the stochastic averaging method in studying the dynamics of active Brownian particles,the reaction rate theory,the dynamics of breathing and denaturation of DNA,and the Fermi resonance and its effect on the mean transition time are reviewed.

  2. Coupled-resonator optical waveguides

    DEFF Research Database (Denmark)

    Raza, Søren; Grgic, Jure; Pedersen, Jesper Goor;

    2010-01-01

    Coupled-resonator optical waveguides hold potential for slow-light propagation of optical pulses. The dispersion properties may adequately be analyzed within the framework of coupled-mode theory. We extend the standard coupled-mode theory for such structures to also include complex-valued paramet......Coupled-resonator optical waveguides hold potential for slow-light propagation of optical pulses. The dispersion properties may adequately be analyzed within the framework of coupled-mode theory. We extend the standard coupled-mode theory for such structures to also include complex...

  3. Pulsar average waveforms and hollow cone beam models

    Science.gov (United States)

    Backer, D. C.

    1975-01-01

    An analysis of pulsar average waveforms at radio frequencies from 40 MHz to 15 GHz is presented. The analysis is based on the hypothesis that the observer sees one cut of a hollow-cone beam pattern and that stationary properties of the emission vary over the cone. The distributions of apparent cone widths for different observed forms of the average pulse profiles (single, double/unresolved, double/resolved, triple and multiple) are in modest agreement with a model of a circular hollow-cone beam with random observer-spin axis orientation, a random cone axis-spin axis alignment, and a small range of physical hollow-cone parameters for all objects.

  4. RIPL - Reference Input Parameter Library for Calculation of Nuclear Reactions and Nuclear Data Evaluations

    Science.gov (United States)

    Capote, R.; Herman, M.; Obložinský, P.; Young, P. G.; Goriely, S.; Belgya, T.; Ignatyuk, A. V.; Koning, A. J.; Hilaire, S.; Plujko, V. A.; Avrigeanu, M.; Bersillon, O.; Chadwick, M. B.; Fukahori, T.; Ge, Zhigang; Han, Yinlu; Kailas, S.; Kopecky, J.; Maslov, V. M.; Reffo, G.; Sin, M.; Soukhovitskii, E. Sh.; Talou, P.

    2009-12-01

    We describe the physics and data included in the Reference Input Parameter Library, which is devoted to input parameters needed in calculations of nuclear reactions and nuclear data evaluations. Advanced modelling codes require substantial numerical input, therefore the International Atomic Energy Agency (IAEA) has worked extensively since 1993 on a library of validated nuclear-model input parameters, referred to as the Reference Input Parameter Library (RIPL). A final RIPL coordinated research project (RIPL-3) was brought to a successful conclusion in December 2008, after 15 years of challenging work carried out through three consecutive IAEA projects. The RIPL-3 library was released in January 2009, and is available on the Web through http://www-nds.iaea.org/RIPL-3/. This work and the resulting database are extremely important to theoreticians involved in the development and use of nuclear reaction modelling (ALICE, EMPIRE, GNASH, UNF, TALYS) both for theoretical research and nuclear data evaluations. The numerical data and computer codes included in RIPL-3 are arranged in seven segments: MASSES contains ground-state properties of nuclei for about 9000 nuclei, including three theoretical predictions of masses and the evaluated experimental masses of Audi et al. (2003). DISCRETE LEVELS contains 117 datasets (one for each element) with all known level schemes, electromagnetic and γ-ray decay probabilities available from ENSDF in October 2007. NEUTRON RESONANCES contains average resonance parameters prepared on the basis of the evaluations performed by Ignatyuk and Mughabghab. OPTICAL MODEL contains 495 sets of phenomenological optical model parameters defined in a wide energy range. When there are insufficient experimental data, the evaluator has to resort to either global parameterizations or microscopic approaches. Radial density distributions to be used as input for microscopic calculations are stored in the MASSES segment. LEVEL DENSITIES contains

  5. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

    ... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options ... 8 MB) Also available in Other Language versions . Magnetic Resonance Imaging (MRI) is a medical imaging procedure for making ...

  6. Probing Resonances of the Dirac Equation with Complex Momentum Representation

    Science.gov (United States)

    Li, Niu; Shi, Min; Guo, Jian-You; Niu, Zhong-Ming; Liang, Haozhao

    2016-08-01

    Resonance plays critical roles in the formation of many physical phenomena, and several methods have been developed for the exploration of resonance. In this work, we propose a new scheme for resonance by solving the Dirac equation in the complex momentum representation, in which the resonant states are exposed clearly in the complex momentum plane and the resonance parameters can be determined precisely without imposing unphysical parameters. Combined with the relativistic mean-field theory, this method is applied to probe the resonances in 120120 with the energies, widths, and wave functions being obtained. Compared to other methods, this method is not only very effective for narrow resonances, but also can be reliably applied to broad resonances.

  7. Probing Resonances of the Dirac Equation with Complex Momentum Representation.

    Science.gov (United States)

    Li, Niu; Shi, Min; Guo, Jian-You; Niu, Zhong-Ming; Liang, Haozhao

    2016-08-01

    Resonance plays critical roles in the formation of many physical phenomena, and several methods have been developed for the exploration of resonance. In this work, we propose a new scheme for resonance by solving the Dirac equation in the complex momentum representation, in which the resonant states are exposed clearly in the complex momentum plane and the resonance parameters can be determined precisely without imposing unphysical parameters. Combined with the relativistic mean-field theory, this method is applied to probe the resonances in ^{120}Sn with the energies, widths, and wave functions being obtained. Compared to other methods, this method is not only very effective for narrow resonances, but also can be reliably applied to broad resonances. PMID:27541464

  8. Capture cross section measurements of {sup 186,187,188}Os at n-TOF: the resolved resonance region

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, K.; Mosconi, M.; Milazzo, P.M.; Domingo-Pardo, C.; Kappeler, F.; Mengoni, A.; Abbondanno, U.; Aerts, G.; Alvarez, H.; A lvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Becvar, F.; Berthoumieux, E.; Calvino, F.; Calviani, M.; Cano-Ott, D.; Capote, R.; Carrapic, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Furman, W.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Koehler, P.; Kossionides, E.; Krticka, M.; Lampoudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, H.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Moreau, C.; Neves, F.; Oberhummer, H.; O' Brien, S.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M.T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J.L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M.C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wiescher, M.; Wisshak, K

    2008-07-01

    The neutron capture cross sections of {sup 186,187,188}Os have been measured at the CERN neutron time-of-flight facility, n-TOF, in the neutron energy range from 1 eV up to 1 MeV. In this contribution, we report the results of the analysis of the resolved resonance region (RRR). Resonance parameters have been extracted from a full R-matrix fit of the capture yields with the SAMMY code. A statistical analysis has been performed and the related average resonance parameters are derived. This information is crucial for a complete understanding and modeling in terms of the Hauser-Feshbach statistical model of the capture and inelastic reaction channels, required for the evaluation of the stellar reaction rates of these isotopes. Maxwellian average cross sections for the range of temperatures relevant for s-process nucleosynthesis have been derived from the combined information of the experimental data in the resolved and unresolved resonance regions. A brief account of the implications of this analysis in the estimation of the s-process component of the {sup 187}Os abundance and the related impact on the estimates of the time-duration of the galactic nucleosynthesis through the Re/Os clock is given. (authors)

  9. Regenerative feedback resonant circuit

    Science.gov (United States)

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  10. RELATIONSHIP BETWEEN J-INTEGRAL AND FRACTURE SURFACE AVERAGE PROFILE

    Institute of Scientific and Technical Information of China (English)

    Y.G. Cao; S.F. Xue; K.Tanaka

    2007-01-01

    To investigate the causes that led to the formation of cracks in materials, a novel method that only considered the fracture surfaces for determining the fracture toughness parameters of J-integral for plain strain was proposed. The principle of the fracture-surface topography analysis (FRASTA) was used. In FRASTA, the fracture surfaces were scanned by laser microscope and the elevation data was recorded for analysis. The relationship between J-integral and fracture surface average profile for plain strain was deduced. It was also verified that the J-integral determined by the novel method and by the compliance method matches each other well.

  11. MAXIMUM LIKELIHOOD ESTIMATION FOR PERIODIC AUTOREGRESSIVE MOVING AVERAGE MODELS.

    Science.gov (United States)

    Vecchia, A.V.

    1985-01-01

    A useful class of models for seasonal time series that cannot be filtered or standardized to achieve second-order stationarity is that of periodic autoregressive moving average (PARMA) models, which are extensions of ARMA models that allow periodic (seasonal) parameters. An approximation to the exact likelihood for Gaussian PARMA processes is developed, and a straightforward algorithm for its maximization is presented. The algorithm is tested on several periodic ARMA(1, 1) models through simulation studies and is compared to moment estimation via the seasonal Yule-Walker equations. Applicability of the technique is demonstrated through an analysis of a seasonal stream-flow series from the Rio Caroni River in Venezuela.

  12. Using Averaged Modeling for Capacitors Voltages Observer in NPC Inverter

    Directory of Open Access Journals (Sweden)

    Bassem Omri

    2012-01-01

    Full Text Available This paper developed an adaptive observer to estimate capacitors voltages of a three-level neutral-point-clamped (NPC inverter. A robust estimated method using one parameter is proposed, which eliminates the voltages sensors. An averaged modeling of the inverter was used to develop the observer. This kind of modeling allows a good trade-off between simulation cost and precision. Circuit model of the inverter (implemented in Simpower Matlab simulator associated to the observer algorithm was used to validate the proposed algorithm.

  13. Model averaging for semiparametric additive partial linear models

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    To improve the prediction accuracy of semiparametric additive partial linear models(APLM) and the coverage probability of confidence intervals of the parameters of interest,we explore a focused information criterion for model selection among ALPM after we estimate the nonparametric functions by the polynomial spline smoothing,and introduce a general model average estimator.The major advantage of the proposed procedures is that iterative backfitting implementation is avoided,which thus results in gains in computational simplicity.The resulting estimators are shown to be asymptotically normal.A simulation study and a real data analysis are presented for illustrations.

  14. Glial fibrillary acidic protein (GFAP) immunoreactivity correlates with cortical perfusion parameters determined by bolus tracking arterial spin labelling (bt-ASL) magnetic resonance (MR) imaging in the Wistar Kyoto rat.

    Science.gov (United States)

    Gormley, Shane; Rouine, Jennifer; McIntosh, Allison; Kerskens, Christian; Harkin, Andrew

    2016-06-01

    Alterations in astrocyte number and function have been implicated in the pathophysiology of a number of psychiatric disorders. The development of magnetic resonance imaging (MRI) as a tool in the animal laboratory has enabled an investigation of the relationship between pathological and neuroimaging markers in animal models. However the physiological processes which underlie these markers and their role in mediating behavioural deficits is still poorly understood. Rodent models have provided us with important insights into physiological and cellular mechanisms which may mediate anxiety and depression-related behaviours. The Wistar-Kyoto (WKY) rat is a strain which endogenously expresses highly anxious and depressive-like behaviours and has previously been reported to exhibit alterations in immunoreactivity for the astrocytic marker glial fibrillary acidic protein (GFAP) in brain sub-regions relative to more stress resilient out-bred strains. Here we report that the depressive and anxiety-like behaviours exhibited by the WKY rat strain are associated with alterations in brain morphology including a decrease in hippocampal volume, coupled with reduced resting state frontal cortical perfusion as assessed by MR bolus tracking arterial spin labelling (bt-ASL) relative to the out-bred Wistar strain. Pre-limbic cortical GFAP immunoreactivity and astrocyte cell number were positively correlated with cortical blood perfusion in the WKY strain. These experiments provide a link between pathological and neuroimaging markers of aberrant astrocytic function and add validity to the WKY rat as a model for co-morbid anxiety and depression. PMID:27068181

  15. Averaged Extended Tree Augmented Naive Classifier

    Directory of Open Access Journals (Sweden)

    Aaron Meehan

    2015-07-01

    Full Text Available This work presents a new general purpose classifier named Averaged Extended Tree Augmented Naive Bayes (AETAN, which is based on combining the advantageous characteristics of Extended Tree Augmented Naive Bayes (ETAN and Averaged One-Dependence Estimator (AODE classifiers. We describe the main properties of the approach and algorithms for learning it, along with an analysis of its computational time complexity. Empirical results with numerous data sets indicate that the new approach is superior to ETAN and AODE in terms of both zero-one classification accuracy and log loss. It also compares favourably against weighted AODE and hidden Naive Bayes. The learning phase of the new approach is slower than that of its competitors, while the time complexity for the testing phase is similar. Such characteristics suggest that the new classifier is ideal in scenarios where online learning is not required.

  16. Grassmann Averages for Scalable Robust PCA

    DEFF Research Database (Denmark)

    Hauberg, Søren; Feragen, Aasa; Black, Michael J.

    2014-01-01

    As the collection of large datasets becomes increasingly automated, the occurrence of outliers will increase—“big data” implies “big outliers”. While principal component analysis (PCA) is often used to reduce the size of data, and scalable solutions exist, it is well-known that outliers can...... can be efficiently computed, we immediately gain scalability. GA is inherently more robust than PCA, but we show that they coincide for Gaussian data. We exploit that averages can be made robust to formulate the Robust Grassmann Average (RGA) as a form of robust PCA. Robustness can be with respect......, making it scalable to “big noisy data.” We demonstrate TGA for background modeling, video restoration, and shadow removal. We show scalability by performing robust PCA on the entire Star Wars IV movie....

  17. ANALYSIS OF THE FACTORS AFFECTING THE AVERAGE

    Directory of Open Access Journals (Sweden)

    Carmen BOGHEAN

    2013-12-01

    Full Text Available Productivity in agriculture most relevantly and concisely expresses the economic efficiency of using the factors of production. Labour productivity is affected by a considerable number of variables (including the relationship system and interdependence between factors, which differ in each economic sector and influence it, giving rise to a series of technical, economic and organizational idiosyncrasies. The purpose of this paper is to analyse the underlying factors of the average work productivity in agriculture, forestry and fishing. The analysis will take into account the data concerning the economically active population and the gross added value in agriculture, forestry and fishing in Romania during 2008-2011. The distribution of the average work productivity per factors affecting it is conducted by means of the u-substitution method.

  18. Trajectory averaging for stochastic approximation MCMC algorithms

    CERN Document Server

    Liang, Faming

    2010-01-01

    The subject of stochastic approximation was founded by Robbins and Monro [Ann. Math. Statist. 22 (1951) 400--407]. After five decades of continual development, it has developed into an important area in systems control and optimization, and it has also served as a prototype for the development of adaptive algorithms for on-line estimation and control of stochastic systems. Recently, it has been used in statistics with Markov chain Monte Carlo for solving maximum likelihood estimation problems and for general simulation and optimizations. In this paper, we first show that the trajectory averaging estimator is asymptotically efficient for the stochastic approximation MCMC (SAMCMC) algorithm under mild conditions, and then apply this result to the stochastic approximation Monte Carlo algorithm [Liang, Liu and Carroll J. Amer. Statist. Assoc. 102 (2007) 305--320]. The application of the trajectory averaging estimator to other stochastic approximation MCMC algorithms, for example, a stochastic approximation MLE al...

  19. Resonances, resonance functions and spectral deformations

    International Nuclear Information System (INIS)

    The present paper is aimed at an analysis of resonances and resonance states from a mathematical point of view. Resonances are characterized as singular points of the analytically continued Lippman-Schwinger equation, as complex eigenvalues of the Hamiltonian with a purely outgoing, exponentially growing eigenfunction, and as poles of the S-matrix. (orig./HSI)

  20. Average Regression-Adjusted Controlled Regenerative Estimates

    OpenAIRE

    Lewis, Peter A.W.; Ressler, Richard

    1991-01-01

    Proceedings of the 1991 Winter Simulation Conference Barry L. Nelson, W. David Kelton, Gordon M. Clark (eds.) One often uses computer simulations of queueing systems to generate estimates of system characteristics along with estimates of their precision. Obtaining precise estimates, espescially for high traffic intensities, can require large amounts of computer time. Average regression-adjusted controlled regenerative estimates result from combining the two techniques ...

  1. Endogenous average cost based access pricing

    OpenAIRE

    Fjell, Kenneth; Foros, Øystein; Pal, Debashis

    2006-01-01

    We consider an industry where a downstream competitor requires access to an upstream facility controlled by a vertically integrated and regulated incumbent. The literature on access pricing assumes the access price to be exogenously fixed ex-ante. We analyze an endogenous average cost based access pricing rule, where both firms realize the interdependence among their quantities and the regulated access price. Endogenous access pricing neutralizes the artificial cost advantag...

  2. Average Drift Analysis and Population Scalability

    OpenAIRE

    He, Jun; Yao, Xin

    2013-01-01

    This paper aims to study how the population size affects the computation time of evolutionary algorithms in a rigorous way. The computation time of an evolutionary algorithm can be measured by either the expected number of generations (hitting time) or the expected number of fitness evaluations (running time) to find an optimal solution. Population scalability is the ratio of the expected hitting time between a benchmark algorithm and an algorithm using a larger population size. Average drift...

  3. On Heroes and Average Moral Human Beings

    OpenAIRE

    Kirchgässner, Gebhard

    2001-01-01

    After discussing various approaches about heroic behaviour in the literature, we first give a definition and classification of moral behaviour, in distinction to intrinsically motivated and ‘prudent' behaviour. Then, we present some arguments on the function of moral behaviour according to ‘minimal' standards of the average individual in a modern democratic society, before we turn to heroic behaviour. We conclude with some remarks on methodological as well as social problems which arise or ma...

  4. A Visibility Graph Averaging Aggregation Operator

    OpenAIRE

    Chen, Shiyu; Hu, Yong; Mahadevan, Sankaran; Deng, Yong

    2013-01-01

    The problem of aggregation is considerable importance in many disciplines. In this paper, a new type of operator called visibility graph averaging (VGA) aggregation operator is proposed. This proposed operator is based on the visibility graph which can convert a time series into a graph. The weights are obtained according to the importance of the data in the visibility graph. Finally, the VGA operator is used in the analysis of the TAIEX database to illustrate that it is practical and compare...

  5. Dollar-Cost Averaging: An Investigation

    OpenAIRE

    Fang, Wei

    2007-01-01

    Dollar-cost Averaging (DCA) is a common and useful systematic investment strategy for mutual fund managers, private investors, financial analysts and retirement planners. The issue of performance effectiveness of DCA is greatly controversial among academics and professionals. As a popularly recommended investment strategy, DCA is recognized as a risk reduction strategy; however, the advantage was claimed as the expense of generating higher returns. The dissertation is to intensively inves...

  6. Average Annual Rainfall over the Globe

    Science.gov (United States)

    Agrawal, D. C.

    2013-01-01

    The atmospheric recycling of water is a very important phenomenon on the globe because it not only refreshes the water but it also redistributes it over land and oceans/rivers/lakes throughout the globe. This is made possible by the solar energy intercepted by the Earth. The half of the globe facing the Sun, on the average, intercepts 1.74 ×…

  7. Averages of B-Hadron, C-Hadron, and tau-lepton properties as of early 2012

    Energy Technology Data Exchange (ETDEWEB)

    Amhis, Y.; et al.

    2012-07-01

    This article reports world averages of measurements of b-hadron, c-hadron, and tau-lepton properties obtained by the Heavy Flavor Averaging Group (HFAG) using results available through the end of 2011. In some cases results available in the early part of 2012 are included. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CP violation parameters, parameters of semileptonic decays and CKM matrix elements.

  8. Magnetic resonance angiography

    Science.gov (United States)

    MRA; Angiography - magnetic resonance ... Kwong RY. Cardiovascular Magnetic Resonance Imaging. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine . ...

  9. Spatial averaging infiltration model for layered soil

    Institute of Scientific and Technical Information of China (English)

    HU HePing; YANG ZhiYong; TIAN FuQiang

    2009-01-01

    To quantify the influences of soil heterogeneity on infiltration, a spatial averaging infiltration model for layered soil (SAI model) is developed by coupling the spatial averaging approach proposed by Chen et al. and the Generalized Green-Ampt model proposed by Jia et al. In the SAI model, the spatial heterogeneity along the horizontal direction is described by a probability distribution function, while that along the vertical direction is represented by the layered soils. The SAI model is tested on a typical soil using Monte Carlo simulations as the base model. The results show that the SAI model can directly incorporate the influence of spatial heterogeneity on infiltration on the macro scale. It is also found that the homogeneous assumption of soil hydraulic conductivity along the horizontal direction will overestimate the infiltration rate, while that along the vertical direction will underestimate the infiltration rate significantly during rainstorm periods. The SAI model is adopted in the spatial averaging hydrological model developed by the authors, and the results prove that it can be applied in the macro-scale hydrological and land surface process modeling in a promising way.

  10. Spatial averaging infiltration model for layered soil

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    To quantify the influences of soil heterogeneity on infiltration, a spatial averaging infiltration model for layered soil (SAI model) is developed by coupling the spatial averaging approach proposed by Chen et al. and the Generalized Green-Ampt model proposed by Jia et al. In the SAI model, the spatial hetero- geneity along the horizontal direction is described by a probability distribution function, while that along the vertical direction is represented by the layered soils. The SAI model is tested on a typical soil using Monte Carlo simulations as the base model. The results show that the SAI model can directly incorporate the influence of spatial heterogeneity on infiltration on the macro scale. It is also found that the homogeneous assumption of soil hydraulic conductivity along the horizontal direction will overes- timate the infiltration rate, while that along the vertical direction will underestimate the infiltration rate significantly during rainstorm periods. The SAI model is adopted in the spatial averaging hydrological model developed by the authors, and the results prove that it can be applied in the macro-scale hy- drological and land surface process modeling in a promising way.

  11. Unscrambling The "Average User" Of Habbo Hotel

    Directory of Open Access Journals (Sweden)

    Mikael Johnson

    2007-01-01

    Full Text Available The “user” is an ambiguous concept in human-computer interaction and information systems. Analyses of users as social actors, participants, or configured users delineate approaches to studying design-use relationships. Here, a developer’s reference to a figure of speech, termed the “average user,” is contrasted with design guidelines. The aim is to create an understanding about categorization practices in design through a case study about the virtual community, Habbo Hotel. A qualitative analysis highlighted not only the meaning of the “average user,” but also the work that both the developer and the category contribute to this meaning. The average user a represents the unknown, b influences the boundaries of the target user groups, c legitimizes the designer to disregard marginal user feedback, and d keeps the design space open, thus allowing for creativity. The analysis shows how design and use are intertwined and highlights the developers’ role in governing different users’ interests.

  12. Disk-averaged synthetic spectra of Mars

    CERN Document Server

    Tinetti, G; Fong, W; Meadows, V S; Snively, H; Velusamy, T; Crisp, David; Fong, William; Meadows, Victoria S.; Snively, Heather; Tinetti, Giovanna; Velusamy, Thangasamy

    2004-01-01

    The principal goal of the NASA Terrestrial Planet Finder (TPF) and ESA Darwin mission concepts is to directly detect and characterize extrasolar terrestrial (Earth-sized) planets. This first generation of instruments is expected to provide disk-averaged spectra with modest spectral resolution and signal-to-noise. Here we use a spatially and spectrally resolved model of the planet Mars to study the detectability of a planet's surface and atmospheric properties from disk-averaged spectra as a function of spectral resolution and wavelength range, for both the proposed visible coronograph (TPF-C) and mid-infrared interferometer (TPF-I/Darwin) architectures. At the core of our model is a spectrum-resolving (line-by-line) atmospheric/surface radiative transfer model which uses observational data as input to generate a database of spatially-resolved synthetic spectra for a range of illumination conditions (phase angles) and viewing geometries. Results presented here include disk averaged synthetic spectra, light-cur...

  13. Data Point Averaging for Computational Fluid Dynamics Data

    Science.gov (United States)

    Norman, Jr., David (Inventor)

    2016-01-01

    A system and method for generating fluid flow parameter data for use in aerodynamic heating analysis. Computational fluid dynamics data is generated for a number of points in an area on a surface to be analyzed. Sub-areas corresponding to areas of the surface for which an aerodynamic heating analysis is to be performed are identified. A computer system automatically determines a sub-set of the number of points corresponding to each of the number of sub-areas and determines a value for each of the number of sub-areas using the data for the sub-set of points corresponding to each of the number of sub-areas. The value is determined as an average of the data for the sub-set of points corresponding to each of the number of sub-areas. The resulting parameter values then may be used to perform an aerodynamic heating analysis.

  14. Preparation of high viscosity average molecular mass poly-L-lactide

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhi-hua; RUAN Jian-ming; ZOU Jian-peng; ZHOU Zhong-cheng; SHEN Xiong-jun

    2006-01-01

    Poly-L-lactide(PLLA) was synthesized by ring-opening polymerization from high purity L-lactide with tin octoate as initiator, and characterized by means of infrared, and 1H-nuclear magnetic resonance. The influences of initiator concentration,polymerization temperature and polymerization time on the viscosity average molecular mass of PLLA were investigated. The effects of different purification methods on the concentration of initiator and viscosity average molecular mass were also studied. PLLA with a viscosity average molecular mass of about 50.5×104 was obtained when polymerization was conducted for 24 h at 140 ℃ with the molar ratio of monomer to purification initator being 12 000. After purification, the concentration of tin octoate decreases; however,the effect of different purification methods on the viscosity average molecular mass of PLLA is different, and the obtained PLLA is a typical amorphous polymeric material. The crystallinity of PLLA decreases with the increase of viscosity average molecular mass.

  15. Resonance in Defect Turbulence under Periodic External Force

    Institute of Scientific and Technical Information of China (English)

    QIAO Chun; FENG Xiao-Bo; WANG Hong-Li; OUYANG Qi

    2007-01-01

    The periodically forced spatially extended Brusselator is investigated in the chaotic regime. We explore resonant or non-resonant patterns generated under various forcing frequencies and forcing amplitudes. Resonant spatially uniform oscillation and irregular structures are found. Furthermore two types of regular spatial patterns are generated under appropriate parameters. Our results of numerical simulations demonstrate that periodic force can give rise to resonant patterns in forced systems of spatiotemporal chaos similar to the situation of forced systems of regular oscillations.

  16. Interference scattering effects on intermediate resonance absorption at operating temperatures

    International Nuclear Information System (INIS)

    Resonance integrals may be accurately calculated using the intermediate resonance (IR) approximation. Results are summarized for the case of an absorber with given potential scattering cross sections and interference scattering parameter admixed with a non absorbing moderator of given cross section and located in a narrow resonance moderating medium. From the form of the IR solutions, it is possible to make some general observations about effects of interference scattering on resonance absorption. 2 figures

  17. Unstable optical resonator loss calculations using the prony method.

    Science.gov (United States)

    Siegman, A E; Miller, H Y

    1970-12-01

    The eigenvalues for all the significant low-order resonant modes of an unstable optical resonator with circular mirrors are computed using an eigenvalue method called the Prony method. A general equivalence relation is also given, by means of which one can obtain the design parameters for a single-ended unstable resonator of the type usually employed in practical lasers, from the calculated or tabulated values for an equivalent symmetric or double-ended unstable resonator.

  18. How do partly omitted control variables influence the averages used in meta-analysis in economics?

    DEFF Research Database (Denmark)

    Paldam, Martin

    of the primary studies. They are the POCs, partly omitted controls, of the meta-study. Some POCs are ceteris paribus controls chosen to make results from different data samples comparable. They should differ. Others are model variables. They may be true and should always be included, while others are false......Meta regression analysis is used to extract the best average from a set of N primary studies of one economic parameter. Three averages of the N-set are discussed: The mean, the PET meta-average and the augmented meta-average. They are affected by control variables that are used in some...... and should always be excluded, if only we knew. If POCs are systematically included for their effect on the estimate of the parameter, it gives publication bias. It is corrected by the meta-average. If a POC is randomly included, it gives a bias, which is corrected by the augmented meta-average. With many...

  19. Experimental investigation of quantum effects in time-resolved resonance Rayleigh scattering from quantum well excitons

    DEFF Research Database (Denmark)

    Birkedal, Dan; Shah, Jagdeep; Shchegrov, Andrei V.;

    2000-01-01

    Resonant Rayleigh scattering from quantum well excitons is investigated using ultrafast spectral interferometry. We isolate the coherent Rayleigh scattering from incoherent luminescence in a single speckle. Averaging the resonant Rayleigh intensity over several speckles allows us to identify...

  20. Resonances of a nonlinear SDOF system with time-delay in linear feedback control

    Energy Technology Data Exchange (ETDEWEB)

    El-Bassiouny, A F [Mathematics Department, Faculty of Science, Benha University, Benha 13518 (Egypt); El-kholy, S [Department of Mathematics, Faculty of Science, Menoufia University, Shebin El-kom (Egypt)], E-mail: atef_elbassiouny@yahoo.com

    2010-01-15

    The primary and subharmonic resonances of a nonlinear single-degree-of-freedom (SDOF) system under feedback control with a time delay have been studied by means of an asymptotic perturbation technique. Both external (forcing) and parametric excitations have been included. By means of the averaging method and multiple scales method, two slow-flow equations for the amplitude and phase of the primary and subharmonic resonances and all other parameters are obtained, respectively. The steady state solutions (fixed points) for the original system are investigated. The stability of the fixed points is examined by using the variational method. The effect of the feedback gains, time-delay, the coefficient of cubic term, the coefficients of external and parametric excitations on the steady state responses are investigated and the results are presented as plots of the steady state response amplitude versus the detuning parameter. The results obtained by the two methods are in excellent agreement. There exist saddle node bifurcations for the case of primary resonance and the solutions lose stability for the case of resonance subharmonic.