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1

Harmonic maps as models for physical theories

Harmonic maps are an aesthetically appealing class of nonlinear field equations of which only a few nontrivial examples have as yet appeared in physical theories. These fields appear well suited for describing broken symmetries either in conjunction with or instead of the Yang-Mills equations. The harmonic mapping equation is quite similar in many respects to the Einstein equations for gravitation,

Charles Misner

1978-01-01

2

The harmonic oscillator and nuclear physics

NASA Technical Reports Server (NTRS)

The three-dimensional harmonic oscillator plays a central role in nuclear physics. It provides the underlying structure of the independent-particle shell model and gives rise to the dynamical group structures on which models of nuclear collective motion are based. It is shown that the three-dimensional harmonic oscillator features a rich variety of coherent states, including vibrations of the monopole, dipole, and quadrupole types, and rotations of the rigid flow, vortex flow, and irrotational flow types. Nuclear collective states exhibit all of these flows. It is also shown that the coherent state representations, which have their origins in applications to the dynamical groups of the simple harmonic oscillator, can be extended to vector coherent state representations with a much wider range of applicability. As a result, coherent state theory and vector coherent state theory become powerful tools in the application of algebraic methods in physics.

Rowe, D. J.

1993-01-01

3

Harmonic Analysis on Quantum Tori

NASA Astrophysics Data System (ADS)

This paper is devoted to the study of harmonic analysis on quantum tori. We consider several summation methods on these tori, including the square Fejér means, square and circular Poisson means, and Bochner-Riesz means. We first establish the maximal inequalities for these means, then obtain the corresponding pointwise convergence theorems. In particular, we prove the noncommutative analogue of the classical Stein theorem on Bochner-Riesz means. The second part of the paper deals with Fourier multipliers on quantum tori. We prove that the completely bounded L p Fourier multipliers on a quantum torus are exactly those on the classical torus of the same dimension. Finally, we present the Littlewood-Paley theory associated with the circular Poisson semigroup on quantum tori. We show that the Hardy spaces in this setting possess the usual properties of Hardy spaces, as one can expect. These include the quantum torus analogue of Fefferman's H1-BMO duality theorem and interpolation theorems. Our analysis is based on the recent developments of noncommutative martingale/ergodic inequalities and Littlewood-Paley-Stein theory.

Chen, Zeqian; Xu, Quanhua; Yin, Zhi

2013-09-01

4

Harmonic Analysis of the Output Voltage of a Third-Harmonic-Injected Inverter for LSM Drives

NASA Astrophysics Data System (ADS)

The superconducting magnetic levitation railway system (MAGLEV) under development in Japan uses a pulse-width-modulation (PWM) inverter for driving a linear synchronous motor (LSM). The inverter output voltage contains non-negligible harmonics which cause harmonic resonances in the LSM system, and therefore harmonics of the output voltage have been analyzed in order to control such harmonic resonances. This paper applies a third-harmonic injection method to the inverter for the purpose of enhancing the output voltage without changing the circuit configuration. It performs harmonic analysis of the output voltage of the inverter based on the third-harmonic injection. Validity of the harmonic analysis is verified by computer simulation.

Shigeeda, Hidenori; Okui, Akinobu; Akagi, Hirofumi

5

Harmonic analysis of industrial power systems

When large harmonic producing loads are added to an industrial plant power system it is good engineering practice to analyze the impact on the power system by performing harmonic modeling analysis of the system at the design stage. Such a study can identify any potentially harmful resonances or other harmonic levels that are predicted to be in excess of IEEE 519 recommended limits and suggest corrective measures (if necessary). This paper discusses the impact of the harmonic limits of IEEE 519-1992 on the industrial power consumer and addresses the differences between the 1992 and 1981 versions of the standard. Harmonics produced by variable frequency drives are discussed. The data required to conduct a harmonic study, the types of analyses that can be performed, and some of the mitigating measures that can be taken to alleviate a potential harmonic problem are detailed. A case study is presented based on a typical paper mill where a large variable frequency drive was added to the power system.

Ellis, R.G. [Allen-Bradley Canada Ltd., Cambridge, Ontario (Canada)] [Allen-Bradley Canada Ltd., Cambridge, Ontario (Canada)

1996-03-01

6

Reconstruction of local neutron physical functionals in surface harmonics method

Formulas for reconstruction of local neutron physical functionals for a three-stage calculation of a 2D VVER-1000 core using the surface harmonics method are obtained, implemented in the SUHAM code, and verified.

Boyarinov, V. F., E-mail: Boyarinov@dhtp.kiae.ru; Nevinitsa, V. A., E-mail: Neva@dhtp.kiae.ru [Russian Research Centre Kurchatov Institute (Russian Federation)

2010-12-15

7

Abstract Harmonic Analysis on Spacetime

In this paper, we consider the Poincare group (space time). In mathematics, the Poincar\\'e group of spacetime, named after Henri Poincar\\'e, is the group of isometries of Minkowski spacetime, introduced by Hermann Minkowski. It is a non-abelian Lie group with ten generators. Spacetime, in physical science, single concept that recognizes the union of space and time, posited by Albert Einstein in the theories of relativity. One of the interesting problems for Mathematicians and Physicists is. Can we do the Fourier analysis on space time. The purpose of this paper is to define the Fourier transform the Poincar\\'e group, and then we establish the Plancherel theorem for spacetime

Kahar El-Hussein

2014-04-06

8

Harmonic analysis of solar magnetic fields

The temporal variations of the global magnetic field in the Sun's photosphere have been investigated through a harmonic analysis of the zonal (m=0) as well as the non-axisymmetric (m!=0) modes. A 25 yr time series of magnetic maps, recorded at the Kitt Peak Observatory (Tucson, AZ) on a daily basis, was used to calculate the spherical coefficients of the radial

R. Knaack; J. O. Stenflo

2002-01-01

9

Harmonic analysis of spiking neuronal pairs

Abstract Harmonic analysis is applied to analyze the transmission of bandlimited signals via spike trains generated by a pair of leaky integrate-and-re,(LIF) model neurons organized in a push-pull, or ‘on\\/o’, conguration. It is found that lowpass signals can be transmitted with only moderate distortion utilizing mean spike rates with many,spikes per signal coherence time. The transmission of bandpass signals is

Charles H. Anderson; Qingfeng Huang; John W. Clark

2000-01-01

10

Spherical harmonic transit analysis with PAPER

NASA Astrophysics Data System (ADS)

We discuss the implementation of an all-sky spherical harmonic transit analysis in the context of observed data from the Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER). The technique (Shaw et al. 2014a,b), dubbed the m-mode formalism, circumvents the flat-sky approximation of traditional interferometric analysis and is presented as an option for more effective analysis for instruments investigating 21 cm cosmology. Using this framework, we apply PAPER data obtained from 32 dual-polarization antennas and show preliminary results for imaging. We explore these results and discuss further implications of this m-mode formalism towards data analysis of PAPER including other antenna array configurations and polarization sources.

Ling, Jason; Aryeh Kohn, Saul; Aguirre, James E.; Paper Collaboration

2015-01-01

11

Harmonic analysis of the AGS Booster imperfection

The harmonic content of magnetic field imperfections in the AGS Booster has been determined through careful measurements of the required field corrections of transverse resonances. An analysis of the required correction yielded amplitude and phase information which points to possible sources of imperfections. Dipole and quadrupole imperfections, which are proportional to the field of bending magnets (B), are mainly driven by any misalignment of the magnets. Quadrupole and sextupole imperfections, which are proportional to dB/dt, are driven by imperfections of the eddy-current correction system. The observations also suggest the presence of a remnant field.

Shoji, Y.; Gardner, C.

1993-12-31

12

Modular Approach to Physics: Simple Harmonic Motion - Weighted Spring

NSDL National Science Digital Library

This resource is a Java applet-based module relating to the simple harmonic motion produced by a block on a frictionless spring. It features a rich array of tools: motion graphs, energy graphs, vector components, reference circle, zoom toggle, and a data box that displays amplitude, angular frequency, displacement from equilibrium, phase angle, velocity, and acceleration of the oscillating block. Users control the spring constant, mass of the block, and amplitude of the oscillation. A comprehensive help section provides detailed directions and lesson ideas for instructors. This simulation is part of a larger collection of physics resources sponsored by the MAP project (Modular Approach to Physics).

2008-05-22

13

Enhancing tidal harmonic analysis: Robust (hybrid L1 ) solutions

Enhancing tidal harmonic analysis: Robust (hybrid L1 =L2 ) solutions Keith E. Leffler Ã?, David A 24 February 2008 Accepted 28 April 2008 Keywords: Tides Tidal analysis Harmonic analysis Robust is calculated from the power spectrum of the residual, a calculation that filters broad spectrum noise

Jay, David

14

NASA Technical Reports Server (NTRS)

An optimum truncation level, N, in a spherical-harmonic analysis of the geomagnetic main field at the core-mantle boundary is determined by harmonic-spline analysis. Specifically, that value of N is found at which the two analyses are closest in a well defined sense and, for that value of N, the 'closeness' of two models is determined. Depending slightly on the definition of closeness, optimum N is found to be either 10 or 11. For those values the two analyses give remarkably similar results, showing that the conveniences of spherical harmonics can be retained with little penalty.

Benton, E. R.; Kohl, Benjamin C.

1986-01-01

15

Platonic polyhedra tune the 3-sphere: Harmonic analysis on simplices

A spherical topological manifold of dimension n-1 forms a prototile on its cover, the (n-1)-sphere. The tiling is generated by the fixpoint-free action of the group of deck transformations. By a general theorem, this group is isomorphic to the first homotopy group. Multiplicity and selection rules appear in the form of reduction of group representations. A basis for the harmonic analysis on the (n-1)-sphere is given by the spherical harmonics which transform according to irreducible representations of the orthogonal group. The deck transformations form a subgroup, and so the representations of the orthogonal group can be reduced to those of this subgroup. Upon reducing to the identity representation of the subgroup, the reduced subset of spherical harmonics becomes periodic on the tiling and tunes the harmonic analysis on the (n-1)-sphere to the manifold. A particular class of spherical 3-manifolds arises from the Platonic polyhedra. The harmonic analysis on the Poincare dodecahedral 3-manifold was analyzed along these lines. For comparison we construct here the harmonic analysis on simplicial spherical manifolds of dimension n=1,2,3. Harmonic analysis applied to the cosmic microwave background by selection rules can provide evidence for multiply connected cosmic topologies.

Peter Kramer

2009-01-02

16

Aerodynamic Analysis of Cup Anemometers Performance: The Stationary Harmonic Response

The effect of cup anemometer shape parameters, such as the cups' shape, their size, and their center rotation radius, was experimentally analyzed. This analysis was based on both the calibration constants of the transfer function and the most important harmonic term of the rotor's movement, which due to the cup anemometer design is the third one. This harmonic analysis represents a new approach to study cup anemometer performances. The results clearly showed a good correlation between the average rotational speed of the anemometer's rotor and the mentioned third harmonic term of its movement. PMID:24381512

Pindado, Santiago; Cubas, Javier; Sanz-Andrés, Ángel

2013-01-01

17

NASA Technical Reports Server (NTRS)

This paper presents a spherical harmonic analysis of the plasma velocity distribution function using high-angular, energy, and time resolution Cluster data obtained from the PEACE spectrometer instrument to demonstrate how this analysis models the particle distribution function and its moments and anisotropies. The results show that spherical harmonic analysis produced a robust physical representation model of the velocity distribution function, resolving the main features of the measured distributions. From the spherical harmonic analysis, a minimum set of nine spectral coefficients was obtained from which the moment (up to the heat flux), anisotropy, and asymmetry calculations of the velocity distribution function were obtained. The spherical harmonic method provides a potentially effective "compression" technique that can be easily carried out onboard a spacecraft to determine the moments and anisotropies of the particle velocity distribution function for any species. These calculations were implemented using three different approaches, namely, the standard traditional integration, the spherical harmonic (SPH) spectral coefficients integration, and the singular value decomposition (SVD) on the spherical harmonic methods. A comparison among the various methods shows that both SPH and SVD approaches provide remarkable agreement with the standard moment integration method.

Gurgiolo, Chris; Vinas, Adolfo F.

2009-01-01

18

An electromagnetic time-harmonic analysis of shielded microstrip circuits

A Galerkin analysis of microstrip circuits of arbitrary planar geometry enclosed in a rectangular conducting box is described. The technique entails a time-harmonic electromagnetic analysis evaluating all fields and surface currents. This analysis is suitable for the accurate verification of microstrip designs prior to fabrication. A computer program implementing the analysis has been written in Pascal on a personal computer.

JAMES C. RAUTIO; Roger F. Harrington

1987-01-01

19

Review of Steven Krantz's A Panorama of Harmonic Analysis

Review of Steven Krantz's A Panorama of Harmonic Analysis by J. Marshall Ash Department of the University of Chicago's master of science exam in May 1963. But the analysis section went very well. No small part of the credit for this was due to Antoni Zygmund who had taught me real analysis I and II

Ash, J. Marshall

20

TOPICS IN HARMONIC ANALYSIS APPLICATIONS TO RADAR AND SONAR

TOPICS IN HARMONIC ANALYSIS WITH APPLICATIONS TO RADAR AND SONAR Willard Miller October 23, 2002 commutative and noncommutative, that are fundamental for the analysis of radar and sonar imaging. Several for the noncommutative groups which arise in radar-sonar. The insight and results obtained will are related directly

Weinberger, Hans

21

TOPICS IN HARMONIC ANALYSIS APPLICATIONS TO RADAR AND SONAR

TOPICS IN HARMONIC ANALYSIS WITH APPLICATIONS TO RADAR AND SONAR Willard Miller October 23, 2002, both commutative and noncommutative, that are fundamental for the analysis of radar and sonar imaging for the noncommutative groups which arise in radarÂsonar. The insight and results obtained will are related directly

Olver, Peter

22

HARMONIC COMPONENT DETECTION: OPTIMIZED SPECTRAL KURTOSIS FOR OPERATIONAL MODAL ANALYSIS

(resonance frequencies, damping ratio and mode shapes) of the structure, Ewins [1], Maia [2]. Modal1 HARMONIC COMPONENT DETECTION: OPTIMIZED SPECTRAL KURTOSIS FOR OPERATIONAL MODAL ANALYSIS J of Operational Modal Analysis to identify the modal parameters of mechanical structures using only measured

Boyer, Edmond

23

THE UNCERTAINTY PRINCIPLE IN HARMONIC ANALYSIS BLAINE TALBUT

THE UNCERTAINTY PRINCIPLE IN HARMONIC ANALYSIS BLAINE TALBUT Abstract. We present several uncertainty principle results from Fourier anal- ysis. The results we present are formally unrelated to one transform simultaneously. Contents 1. Introduction 1 2. Heisenberg's Uncertainty Principle 2 3. Complex

May, J. Peter

24

High-Speed Video Analysis of Damped Harmonic Motion

ERIC Educational Resources Information Center

In this paper, we acquire and analyse high-speed videos of a spring-mass system oscillating in glycerin at different temperatures. Three cases of damped harmonic oscillation are investigated and analysed by using high-speed video at a rate of 120 frames s[superscript -1] and Tracker Video Analysis (Tracker) software. We present empirical data for…

Poonyawatpornkul, J.; Wattanakasiwich, P.

2013-01-01

25

-okfl ^ ORNL/CON-172 Linear Harmonic Analysis of Free-

Stirling Engines N. C. J. Chen F. P. Griffin OPERATED BY MARTIN MARIETTA ENERGY SYSTEMS, INC. #12;ORNL/CON-172 Engineering Technology Division* LINEAR HARMONIC ANALYSIS OF FREE-PISTON STIRLING/dynamic problem that is associated with a free-piston Stirling engine (FPSE). The governing equations

Oak Ridge National Laboratory

26

Circular current loops, magnetic dipoles and spherical harmonic analysis.

Spherical harmonic analysis (SHA) is the most used method of describing the Earth's magnetic field, even though spherical harmonic coefficients (SHC) almost completely defy interpretation in terms of real sources. Some moderately successful efforts have been made to represent the field in terms of dipoles placed in the core in an effort to have the model come closer to representing real sources. Dipole sources are only a first approximation to the real sources which are thought to be a very complicated network of electrical currents in the core of the Earth. -Author

Alldredge, L.R.

1980-01-01

27

Harmonic analysis of precipitation climatology in Saudi Arabia

NASA Astrophysics Data System (ADS)

Annual rainfall records of 20 stations for 30 years are used in order to detect rainfall regimes and climatic features of Saudi Arabia using harmonic analysis techniques. In this study, the percentages of variance, amplitudes, and phase angles are calculated in order to depict the spatial and temporal characteristics of the country's rainfall. The first harmonic explains 42 % of rainfall variation in the western (W) region. This percentage increases toward east (E) and north (N) with 69 and 67 %, respectively. In the southwest (SW) region, the percentages explain 43 % of rainfall variation. The percentages of variance in W and SW are lower than in the E, NW, and central (C) regions. This implies significant contributions of the second harmonic in W and SW regions with 26 and 16 %, respectively. The high percentages of the second and third harmonics in W and SW regions suggest that these two regions are affected by different weather systems at different times. The SW region has the highest amplitudes of the first, second, and third harmonics. The amplitude of the first harmonic reaches to 21 mm in SW and 9 mm in both C and E regions. The time of maximum rainfall is calculated using phase angle; the result reflects that maximum rainfall is shifted forward on the time axis toward the spring season in SW and C regions, January in E and NW regions, and October and November in the W region. This reveals that the SW region is a completely different climatic region, though some of what affects this region also affects the central region. Conditions in the E and NW regions are mainly affected by Mediterranean weather systems, while the W region is affected by unstable conditions caused by the active Red Sea Trough (RST) in October and November.

Tarawneh, Qassem

2015-02-01

28

A note about Norbert Wiener and his contribution to Harmonic Analysis and Tauberian Theorems

NASA Astrophysics Data System (ADS)

In this note we explain the main motivations Norbert Wiener had for the creation of his Generalized Harmonic Analysis [13] and his Tauberian Theorems [14]. Although these papers belong to the most pure mathematical tradition, they were deeply based on some Engineering and Physics Problems and Wiener was able to use them for such diverse areas as Optics, Brownian motion, Filter Theory, Prediction Theory and Cybernetics.

Almira, J. M.; Romero, A. E.

2009-05-01

29

On the physical interpretation of some types of three-dimensional harmonic mappings

The development of the theory of three-dimensional harmonic mappings is considered. The new classes of mappings that generate three-dimensional harmonic functions are introduced. The physical interpretation of these mappings is applied to electrostatics problems. It is found that these mappings locally conserve electric charge of the equipotential surfaces. To confirm the correctness of the theory it is shown that by using the proposed mappings the electric field in two known electrostatic problems can be found.

Andrey Petrin

2011-12-19

30

A physical device for the measurement of weak harmonic distortions radiated from a piezoelectric rod

NASA Astrophysics Data System (ADS)

A physical device that promotes the acoustic radiation of the quadratic non-linear wave component from a piezoelectric element is designed, built and tested. The guiding model used to design the device, based on non-linear equivalent circuits for active and passive layers, is briefly recalled. Experimental signals where the second harmonic is the main component are shown. This work is expected to improve the accuracy of second harmonic component evaluation, in particular for NDE applications.

Haumesser, L.; Parenthoine, D.; Tran-Huu-Hue, L.-P.; Fortineau, J.; Vander Meulen, F.; Lethiecq, M.

2012-05-01

31

Harmonic Analysis and Qualitative Uncertainty Principle

This paper investigates the mathematical nature of qualitative uncertainty principle (QUP), which plays an important role in mathematics, physics and engineering fields. Consider a 3-tuple (K, H1, H2) that K: H1 -> H2 is an integral operator. Suppose a signal f in H1, {\\Omega}1 and {\\Omega}2 are domains on which f, Kf define respectively. Does this signal f vanish if |{\\Sigma}(f)|uncertainty principle, nonlinear method and sparse representation, are thus suggested. The notion of operator family is developed and is applied to understand remarkable performances of recent sparse representation.

Ji King

2010-08-09

32

We evaluate binomial series with harmonic number coefficients, providing recursion relations, integral representations, and several examples. The results are of interest to analytic number theory, the analysis of algorithms, and calculations of theoretical physics, as well as other applications.

Mark W. Coffey

2008-12-09

33

Probabilistic Harmonic Analysis of Wind Generators Based on Generalized Gamma Mixture Models

NASA Astrophysics Data System (ADS)

Grid-connected wind generators pose the power quality problems such as harmonic propagation and summation, and these problems are hard to solve by deterministic harmonic analysis due to the random harmonic current emissions. In this paper, probabilistic harmonic analysis is utilized to approximate harmonic currents of wind generators. Generalized gamma mixture models based on Gaussian mixture models, phasor clustering and generalized gamma models, are proposed to approximate the probability density functions of harmonic propagation and summation. And the simulation network built on PSCAD/EMTDC is utilized to verify the proposed models and method.

Xie, Guanglong; Zhang, Buhan

2013-01-01

34

Harmonic analysis of signed Ruelle transfer operators

Motivated by wavelet analysis, we prove that there is a one-to-one correspondence between the following data: (i)Solutions to R(h)=h where R is a certain non-positive Ruelle transfer operator;(ii)Operators that intertwine a certain class of representations of the C?-algebra AN on two unitary generators U, V subject to the relation UVU?1=VN. This correspondence enables us to give a criterion for the

Dorin Ervin Dutkay

2002-01-01

35

Optical Coherence Tomography imaging based on Non-Harmonic Analysis

A new processing technique called Non-Harmonic Analysis (NHA) is proposed for OCT imaging. Conventional Fourier-Domain OCT relies on the FFT calculation which depends on the window function and length. Axial resolution is counter proportional to the frame length of FFT that is limited by the swept range of the swept source in SS-OCT, or the pixel counts of CCD in

Xu Cao; Shigeki Hirobayashi; Changho Chong; Atsushi Morosawa; Koki Totsuka; Takuya Suzuki

2009-01-01

36

NASA Astrophysics Data System (ADS)

In this paper we present a new meshless method to solve well-known problems in physics and engineering with either constant or variable material properties in 2D space. Harmonic and bi-harmonic problems are considered in this paper. The method constructs a set of basis functions, called Equilibrated Basis Functions (EqBFs), through a weighted residual integration over a fictitious domain embedding the main one. The bases can satisfy the governing partial differential equations approximately. Chebyshev polynomials of the first kind are employed to construct the EqBFs and exponential functions are used as the weights in the integrals. The parameters of the solution are arranged so that all the integrals can be decomposed into much simpler 1D ones over a normalized intervals. This reduces the computational efforts significantly. Either the EqBFs or the results of the integration process may be stored for further use. The validity of the results is examined through an extended patch test. A set of physical sample problems with variable/non-variable material properties; as the potential flow over a cylinder, steady-state heat conduction problems in an anisotropic inhomogeneous functionally graded material, potential and stokes flow through a channel of finite width obstructed by periodic cylinders, and the bending of thin elastic plates having constant or variable thickness are solved to demonstrate the capabilities of the method. As a preliminary study, we show that the method may effectively be used in a domain decomposition approach.

Noormohammadi, N.; Boroomand, B.

2014-09-01

37

BAYESIAN ANALYSIS OF MULTIPLE HARMONIC OSCILLATIONS IN THE SOLAR CORONA

The detection of multiple mode harmonic kink oscillations in coronal loops enables us to obtain information on coronal density stratification and magnetic field expansion using seismology inversion techniques. The inference is based on the measurement of the period ratio between the fundamental mode and the first overtone and theoretical results for the period ratio under the hypotheses of coronal density stratification and magnetic field expansion of the wave guide. We present a Bayesian analysis of multiple mode harmonic oscillations for the inversion of the density scale height and magnetic flux tube expansion under each of the hypotheses. The two models are then compared using a Bayesian model comparison scheme to assess how plausible each one is given our current state of knowledge.

Arregui, I.; Asensio Ramos, A.; Diaz, A. J., E-mail: iarregui@iac.es [Instituto de Astrofisica de Canarias, Via Lactea s/n, E-38205 La Laguna, Tenerife (Spain)

2013-03-01

38

Projectively adapted pattern representation using noncommutative harmonic analysis

NASA Astrophysics Data System (ADS)

Projectively invariant classification of patterns is constructed in terms of orbits of the group SL(2,C) acting on an extended complex line (image plane with complex coordinates) by Mobius transformations. It provides projectively adapted noncommutative harmonic analysis for patterns by decomposing a pattern into irreducible representations of the unitary principal series of SL(2,C). It is the projective analog of the classical (Euclidean) Fourier decomposition, well suited for the analysis of projectively distorted images such as aerial images of the same scene when taken from different vantage points.

Turski, Jacek

1996-03-01

39

Semiclassical analysis of high harmonic generation in bulk crystals

NASA Astrophysics Data System (ADS)

High harmonic generation (HHG) in solids is investigated. We find that interband emission is dominant for the midinfrared laser driver frequencies, whereas intraband emission dominates the far-infrared range. Interband HHG is similar to atomic HHG and therewith opens the possibility to apply atomic attosecond technology to the condensed matter phase. Interband emission is investigated with a quasiclassical method, by which HHG can be modeled based on the classical trajectory analysis of electron-hole pairs. This analysis yields a simple approximate cutoff law for HHG in solids. Differences between HHG in atoms and solids are identified that are important for adapting atomic attosecond technology to make it applicable to condensed matter.

Vampa, G.; McDonald, C. R.; Orlando, G.; Corkum, P. B.; Brabec, T.

2015-02-01

40

RF physics of ICWC discharge at high cyclotron harmonics

Recent experiments on Ion Cyclotron Wall Conditioning (ICWC) performed in tokamaks TEXTOR and ASDEX Upgrade with standard ICRF antennas operated at fixed frequencies but variable toroidal magnetic field demonstrated rather contrasting parameters of ICWC discharge in scenarios with on-axis fundamental ion cyclotron resonance (ICR) for protons,?=?{sub H+}, and with its high cyclotron harmonics (HCH), ?=10?{sub cH+}? HCH scenario: very high antenna coupling to low density RF plasmas (P{sub pl}?0.9P{sub RF-G}) and low energy Maxwellian distribution of CX hydrogen atoms with temperature T{sub H}?350 eV. Fundamental ICR: lower antenna-plasma coupling efficiency (by factor of about 1.5 times) and generation of high energy non-Maxwellian CX hydrogen atoms (with local energy E{sub ?H} ?1.0 keV). In the present paper, we analyze the obtained experimental results numerically using (i) newly developed 0-D transport code describing the process of plasma production with electron and ion collisional ionization in helium-hydrogen gas mixture and (ii) earlier developed 1-D Dispersion Relation Solver accounting for finite temperature effects and collision absorption mechanisms for all plasma species in addition to conventionally examined Landau/TTPM damping for electrons and cyclotron absorption for ions. The numerical study of plasma production in helium with minor hydrogen content in low and high toroidal magnetic fields is presented. The investigation of the excitation, conversion and absorption of plasma waves as function of B{sub T}-field suggests that only fast waves (FW) may give a crucial impact on antenna coupling and characteristics of the ICWC discharge using standard poloidally polarized ICRF antennas designed to couple RF power mainly to FW. The collisional (non-resonant) absorption by electrons and ions and IC absorption by resonant ions of minor concentration in low T{sub e} plasmas is studied at fundamental ICR and its high harmonics.

Lyssoivan, A.; Van Eester, D.; Wauters, T.; Vervier, M.; Van Schoor, M. [Association Euratom-Belgian State, LPP-ERM-KMS, 1000 Brussels (Belgium); Bobkov, V.; Rohde, V.; Schneider, P. [Association Euratom-IPP, Max-Planck Institut für Plasmaphysik, 85748 Garching (Germany); Douai, D.; Kogut, D. [Association Euratom-CEA, CEA, IRFM, 13108 St Paul lez Durance (France); Kreter, A.; Möller, S.; Philipps, V.; Sergienko, G. [Association Euratom-IEK-4, Forschungszentrum Jülich, 52425 Jülich (Germany); Moiseenko, V. [Institute of Plasma Physics NSC KIPT, 61108 Kharkiv (Ukraine); Noterdaeme, J.-M. [Association Euratom-IPP, Max-Planck Institut für Plasmaphysik, 85748 Garching, Germany and Ghent University, 9000 Ghent (Belgium); Collaboration: TEXTOR Team; ASDEX Upgrade Team

2014-02-12

41

STATISTICAL PARSING FOR HARMONIC ANALYSIS OF JAZZ CHORD Mark Granroth-Wilding, Mark Steedman

STATISTICAL PARSING FOR HARMONIC ANALYSIS OF JAZZ CHORD SEQUENCES Mark Granroth-Wilding, Mark processing (NLP) to the problem of analysing harmonic progression. It uses a formal gram- mar of jazz chord space. Using supervised learning over a small corpus of jazz chord sequences annotated with harmonic

Steedman, Mark

42

Kinematic analysis of stellar radial velocities by the spherical harmonics

NASA Astrophysics Data System (ADS)

A method for a kinematic analysis of stellar radial velocities using spherical harmonics is proposed. This approach does not depend on the specific kinematic model and allows both low-frequency and high-frequency kinematic radial velocity components to be analyzed. The possible systematic variations of distances with coordinates on the celestial sphere that, in turn, are modeled by a linear combination of spherical harmonics are taken into account. Theoretical relations showing how the coefficients of the decomposition of distances affect the coefficients of the decomposition of the radial velocities themselves have been derived. It is shown that the larger the mean distance to the sample of stars being analyzed, the greater the shift in the solar apex coordinates, while the shifts in the Oort parameter A are determined mainly by the ratio of the second zonal harmonic coefficient to the mean distance to the stars, i.e., by the degree of flattening of the spatial distribution of stars toward the Galactic plane. The distances to the stars for which radial velocity estimates are available in the CRVAD-2 catalog have been decomposed into spherical harmonics, and the existing variations of distances with coordinates are shown to exert no noticeable influence on both the solar motion components and the estimates of the Oort parameter A, because the stars from this catalog are comparatively close to the Sun (no farther than 500 pc). In addition, a kinematic component that has no explanation in terms of the three-dimensional Ogorodnikov-Milne model is shown to be detected in the stellar radial velocities, as in the case of stellar proper motions.

Vityazev, V. V.; Tsvetkov, A. S.; Trofimov, D. A.

2014-11-01

43

NASA Astrophysics Data System (ADS)

VISPA is a development environment for high energy physics analyses which enables physicists to combine graphical and textual work. A physics analysis cycle consists of prototyping, performing, and verifying the analysis. The main feature of VISPA is a multipurpose window for visual steering of analysis steps, creation of analysis templates, and browsing physics event data at different steps of an analysis. VISPA follows an experiment-independent approach and incorporates various tools for steering and controlling required in a typical analysis. Connection to different frameworks of high energy physics experiments is achieved by using different types of interfaces. We present the look-and-feel for an example physics analysis at the LHC and explain the underlying software concepts of VISPA.

Actis, Oxana; Brodski, Michael; Erdmann, Martin; Fischer, Robert; Hinzmann, Andreas; Klimkovich, Tatsiana; Müller, Gero; Münzer, Thomas; Plum, Matthias; Steggemann, Jan; Winchen, Tobias

2010-04-01

44

PHYSICAL REVIEW A 81, 033412 (2010) Emission times in high-order harmonic generation

PHYSICAL REVIEW A 81, 033412 (2010) Emission times in high-order harmonic generation C. C. Chirila the classical simple man's model as well as against the more accurate quantum orbit model based on complex,1 I. Dreissigacker,1 E. V. van der Zwan,1,2 and M. Lein1 1 Centre for Quantum Engineering and Space-Time

Lein, Manfred

45

Fourier-Jacobi harmonic analysis and approximation of functions

NASA Astrophysics Data System (ADS)

We use the methods of Fourier-Jacobi harmonic analysis to study problems of the approximation of functions by algebraic polynomials in weighted function spaces on \\lbrack -1,1 \\rbrack . We prove analogues of Jackson's direct theorem for the moduli of smoothness of all orders constructed on the basis of Jacobi generalized translations. The moduli of smoothness are shown to be equivalent to K-functionals constructed from Sobolev-type spaces. We define Nikol'skii-Besov spaces for the Jacobi generalized translation and describe them in terms of best approximations. We also prove analogues of some inverse theorems of Stechkin.

Platonov, S. S.

2014-02-01

46

We describe a very simple physical model that allows the analysis of high-order harmonic generation in gases when the pumping laser beam has an intensity profile that is not Gaussian but truncated Bessel. This is the typical experimental condition when sub-10-fs pump-laser pulses, generated by the hollow fiber compression technique, are used. This model is based on the analysis of the phase-matching conditions for the harmonic generation process revisited in view of the new spatial mode of the fundamental beam. In particular, the role of the atomic dipole phase and the geometric phase terms are evidenced both for harmonics generated in the plateau and in the cutoff spectral regions. The influence of dispersion introduced by free electrons produced by laser ionization has also been discussed in some detail. Spatial patterns of far-field harmonics are then obtained by means of a simplified algorithm which allows one to avoid the numerical integration of the harmonic beam propagation equation. Experimental spatial distributions and divergence angles of high-order harmonics generated in Ne with 7-fs titanium-sapphire pulses are compared with numerical simulations in various experimental conditions. The agreement between measurements and calculated results is found to be very satisfactory.

Altucci, C. [Coherentia-INFM UdR di Napoli and Universita 'Federico II', Dipartimento di Scienze Fisiche-Complesso di Monte S. Angelo, via Cintia, 80126 Naples (Italy); Dipartimento di Chimica, Universita della Basilicata, Potenza, (Italy); Bruzzese, R.; De Lisio, C. [Coherentia-INFM UdR di Napoli and Universita 'Federico II', Dipartimento di Scienze Fisiche-Complesso di Monte S. Angelo, via Cintia, 80126 Naples (Italy); Nisoli, M.; Priori, E.; Stagira, S. [Ultras-INFM UdR di Milano, Dipartimento di Fisica, Politecnico di Milano, Milan (Italy); Pascolini, M.; Poletto, L.; Villoresi, P. [Laboratory for Ultraviolet and X-ray Optical Research-INFM DEI-Universita di Padova, Padova (Italy); Tosa, V. [Laser Technology Laboratory, RIKEN (Japan); National Institute for R and D in Isotopic and Molecular Technology, Cluj-Napoca (Romania); Midorikawa, K. [Laser Technology Laboratory, RIKEN (Japan)

2003-09-01

47

Physics of attosecond pulses produced via high harmonic generation

NASA Astrophysics Data System (ADS)

The physics of extreme ultraviolet attosecond pulse trains generated during the interaction between an intense laser pulse and a gas medium is presented, including a simple model based on the solution of the classical equations of motion of an electron in an oscillating laser field. The reconstruction of attosecond beating by the interference of a two-photon transition is described and used to determine the pulse duration of the emitted attosecond pulses. This application is the basis of a laboratory practical for a graduate atomic physics course.

Varjú, Katalin; Johnsson, Per; Mauritsson, Johan; L'Huillier, Anne; López-Martens, Rodrigo

2009-05-01

48

NASA Astrophysics Data System (ADS)

A model for the fifth-harmonic generation of pulsed IR lasers involving an external ring cavity resonating at the second harmonic has been developed. Numerical analysis is performed to show the relative effects of the pulse delay, input polarization, and orientation of the nonlinear crystals on the fifth harmonic power. The results are validated by published experimental results. The model is used to analyze and obtain the optimal combination of nonlinear optical crystals for the fifth-harmonic generation. Our calculation shows that the combination of LiB3O5 (LBO), CsLiB6O10 (CLBO), and CLBO crystals for the second-harmonic, fourth-harmonic, and fifth-harmonic generation steps respectively gives an approximate conversion of 30% from the fundamental to the fifth harmonic power, resulting in 2 W at 213 nm for an input of 7 W at 1064 nm.

Chang, Lien-Bee; Wang, S. C.; Kung, A. H.

2003-07-01

49

A full 3-D Analysis of super-radiant (bunched electron) free electron harmonic radiation is presented. A generalized form of the FEL pendulum equation was derived and numerically solved. Both spectral and phasor formulation were developed to treat the radiation in the time domain. In space the radiation field is expanded in terms of either a set of free space discrete modes or plane waves. The numerical solutions reveal some new distinctly 3-D effects to which we provide a physical explanation. 12 refs., 9 figs., 5 tabs.

Gover, A.; Friedman, A.; Luccio, A.

1986-09-01

50

A New Harmonic Analysis Method for AC\\/DC\\/AC Converters

A new direct harmonic analysis approach for AC\\/DC\\/AC conversion system is presented and discussed. It uses the characteristic of the vectors and their sequence characteristic to obtain the voltage and current transfer rules of the converters in conversion system, and then get the direct harmonic analysis method of the whole AC\\/DC\\/AC. The method can deduce the expression of AC harmonic

Zhaorui Lv; Li Xia; Zhengguo Wu

2008-01-01

51

Research of second harmonic generation images based on texture analysis

NASA Astrophysics Data System (ADS)

Texture analysis plays a crucial role in identifying objects or regions of interest in an image. It has been applied to a variety of medical image processing, ranging from the detection of disease and the segmentation of specific anatomical structures, to differentiation between healthy and pathological tissues. Second harmonic generation (SHG) microscopy as a potential noninvasive tool for imaging biological tissues has been widely used in medicine, with reduced phototoxicity and photobleaching. In this paper, we clarified the principles of texture analysis including statistical, transform, structural and model-based methods and gave examples of its applications, reviewing studies of the technique. Moreover, we tried to apply texture analysis to the SHG images for the differentiation of human skin scar tissues. Texture analysis method based on local binary pattern (LBP) and wavelet transform was used to extract texture features of SHG images from collagen in normal and abnormal scars, and then the scar SHG images were classified into normal or abnormal ones. Compared with other texture analysis methods with respect to the receiver operating characteristic analysis, LBP combined with wavelet transform was demonstrated to achieve higher accuracy. It can provide a new way for clinical diagnosis of scar types. At last, future development of texture analysis in SHG images were discussed.

Liu, Yao; Li, Yan; Gong, Haiming; Zhu, Xiaoqin; Huang, Zufang; Chen, Guannan

2014-09-01

52

Analysis of rotor vibratory loads using higher harmonic pitch control

NASA Technical Reports Server (NTRS)

Experimental studies of isolated rotors in forward flight have indicated that higher harmonic pitch control can reduce rotor noise. These tests also show that such pitch inputs can generate substantial vibratory loads. The modification is summarized of the RotorCRAFT (Computation of Rotor Aerodynamics in Forward flighT) analysis of isolated rotors to study the vibratory loading generated by high frequency pitch inputs. The original RotorCRAFT code was developed for use in the computation of such loading, and uses a highly refined rotor wake model to facilitate this task. The extended version of RotorCRAFT incorporates a variety of new features including: arbitrary periodic root pitch control; computation of blade stresses and hub loads; improved modeling of near wake unsteady effects; and preliminary implementation of a coupled prediction of rotor airloads and noise. Correlation studies are carried out with existing blade stress and vibratory hub load data to assess the performance of the extended code.

Quackenbush, Todd R.; Bliss, Donald B.; Boschitsch, Alexander H.; Wachspress, Daniel A.

1992-01-01

53

Regional GPS-based ionospheric TEC model over Australia using Spherical Cap Harmonic Analysis

This paper proposes an approach to regional Total Electron Content (TEC) representation using Spherical Cap Harmonic Analysis (SCHA) [Haines,1988] which, when applied to the whole sphere, is the usual method referred to as ordinary Spherical Harmonic Analysis (SHA). The model is based on longitudinal expansion in Fourier series and fractional Legendre colatitudinal functions over a spherical cap-like region including the

Zahra Bouya; Michael Terkildsen; Dave Neudegg

2010-01-01

54

Harmonic analysis of slip energy recovery induction motor drives

The impact of drives on the power system in terms of harmonic generation is becoming increasingly important. Slip energy recover induction motor drives (SERIMDs) have the rectifier and inverter connected to the rotor instead of the stator (the case in most conventional drives). The harmonic content of the SERIMD is thus quite different and arguably, less onerous than conventional drives. This paper examines the harmonic content of key waveforms of SERIMDs. Predicted results are supported by extensive experimental results.

Refoufi, L. (Inst. National D'Electricite, Boumerdes (Algeria)); Pillay, P. (Univ. of New Orleans, LA (United States). Dept. of Electrical Engineering)

1994-12-01

55

Analysis and Design of New Harmonic Mitigation Approaches

inverter APF (fsw =15 kHz). ................................................................................................. 124 xv FIGURE Page Fig. 101. Harmonic spectrum of dc capacitor current for dual...-Interleaved- inverter structure (fsw =15 kHz). ................................................................ 124 Fig. 102. Harmonic spectrum of dc capacitor current for Single inverter APF (fsw =4920Hz). Ic_rms=1 p...

Aeloiza Matus, Eddy 1972-

2012-11-01

56

Harmonic Analysis of a Three-Phase Diode Bridge Rectifier based on Sampled-Data Model

Harmonic Analysis of a Three-Phase Diode Bridge Rectifier based on Sampled-Data Model K. L. Lian is to incorporate it into a harmonic power flow program to yield improved accuracy. Index Terms-- Diode Bridge. INTRODUCTION THREE phase diode bridge rectifiers are often used in industry to provide the dc input voltage

Lehn, Peter W.

57

Crop identification using harmonic analysis of time-series AVHRR NDVI data

Harmonic analysis of a time series of National Oceanic and Atmospheric Administration (NOAA) advanced very high resolution radiometer normalized difference vegetation index (NDVI) data was used to develop an innovative technique for crop type identification based on temporal changes in NDVI values. Different crops (corn, soybeans, alfalfa) exhibit distinctive seasonal patterns of NDVI variation that have strong periodic characteristics. Harmonic

Mark E Jakubauskas; David R Legates; Jude H Kastens

2002-01-01

58

NUMERICAL ANALYSIS OF A FINITE ELEMENT SCHEME FOR THE APPROXIMATION OF HARMONIC MAPS INTO SURFACES

NUMERICAL ANALYSIS OF A FINITE ELEMENT SCHEME FOR THE APPROXIMATION OF HARMONIC MAPS INTO SURFACES submanifold N Rn without boundary. This excludes RP2 but still allows for a variety of interesting) and hence of harmonic maps into N follows with the direct method in the calculus of variations for non

Bartels, Soeren

59

Computers & Geosciences 32 (2006) 442451 Spherical harmonic analysis and synthesis using FFT

Computers & Geosciences 32 (2006) 442Â451 Spherical harmonic analysis and synthesis using FFT in revised form 2 July 2005; accepted 14 July 2005 Abstract FFT and complex algebra-based methods rights reserved. Keywords: FFT; Geoid; J2; Spherical harmonics; Temporal gravity 1. Introduction

Hwang, Cheinway

60

Optical coherence tomography imaging based on non-harmonic analysis

NASA Astrophysics Data System (ADS)

A new processing technique called Non-Harmonic Analysis (NHA) is proposed for OCT imaging. Conventional Fourier-Domain OCT relies on the FFT calculation which depends on the window function and length. Axial resolution is counter proportional to the frame length of FFT that is limited by the swept range of the swept source in SS-OCT, or the pixel counts of CCD in SD-OCT degraded in FD-OCT. However, NHA process is intrinsically free from this trade-offs; NHA can resolve high frequency without being influenced by window function or frame length of sampled data. In this study, NHA process is explained and applied to OCT imaging and compared with OCT images based on FFT. In order to validate the benefit of NHA in OCT, we carried out OCT imaging based on NHA with the three different sample of onion-skin,human-skin and pig-eye. The results show that NHA process can realize practical image resolution that is equivalent to 100nm swept range only with less than half-reduced wavelength range.

Cao, Xu; Hirobayashi, Shigeki; Chong, Changho; Morosawa, Atsushi; Totsuka, Koki; Suzuki, Takuya

2009-11-01

61

Non-Harmonic Analysis Applied to Optical Coherence Tomography Imaging

NASA Astrophysics Data System (ADS)

A new processing technique called non-harmonic analysis (NHA) is proposed for optical coherence tomography (OCT) imaging. Conventional Fourier-domain OCT employs the discrete Fourier transform (DFT), which depends on the window function and length. The axial resolution of the OCT image, calculated by using DFT, is inversely proportional to the full width at half maximum (FWHM) of the wavelength range. The FWHM of wavelength range is limited by the sweeping range of the source in swept-source OCT and it is limited by the number of CCD pixels in spectral-domain OCT. However, the NHA process does not have such constraints; NHA can resolve high frequencies irrespective of the window function and the frame length of the sampled data. In this study, the NHA process is described and it is applied to OCT imaging. It is compared with OCT images based on the DFT. To demonstrate the benefits of using NHA for OCT, we perform OCT imaging with NHA of an onion skin. The results reveal that NHA can achieve an image resolution equivalent that of a 100-nm sweep range using a significantly reduced wavelength range. They also reveal the potential of using this technique to achieve high-resolution imaging without using a broadband source. However, the long calculation times required for NHA must be addressed if it is to be used in clinical applications.

Cao, Xu; Uchida, Tetsuya; Hirobayashi, Shigeki; Chong, Changho; Morosawa, Atsushi; Totsuka, Koki; Suzuki, Takuya

2012-02-01

62

Analysis of cyclotron harmonic emissions at the outer planets

NASA Technical Reports Server (NTRS)

The flyby missions of Voyagers 1 and 2 at Jupiter, Saturn and Uranus revealed intense waves above the electron gyrofrequency. Observation of waves at the upper hybrid frequency is often accompanied by power at adjacent electron Bernstein harmonics, and the relative power in these modes depends both on the density and temperature ratios of the cold background electron population and the hot magnetospheric electrons which drive the instability. A model of electron distributions which is consistent with observations is used for analysis of the excited waves, their dependence upon plasma parameters, and the time scales of the saturation processes. It is shown that in the presence of two-temperature electron distributions the linear excitation is due to a fluidlike coupling of two eigenmodes for perpendicular propagation and to kinetic destalization of oblique modes. The dependence of linear growth rates on propagation angle is presented, along with results from particle simulations. A quasi-linear diffusion time for relaxing the hot electron loss cone is calculated and compared with simulation results. This time scale is faster than for local saturation by heating the cold population, and also the convective amplification time scale, suggesting that the waves saturate at quasi-linear levels, while being convectively localized to the equatorial regions of the outer planetary magnetospheres.

Roth, I.; Hudson, M. K.

1992-01-01

63

Platonic polyhedra tune the 3-sphere: II. Harmonic analysis on cubic spherical 3-manifolds

From the homotopy groups of two cubic spherical 3-manifolds we construct the isomorphic groups of deck transformations acting on the 3-sphere. These groups become the cyclic group of order eight and the quaternion group respectively. By reduction of representations from the orthogonal group to the identity representation of these subgroups we provide two subgroup-periodic bases for the harmonic analysis on the 3-manifolds. This harmonic analysis has applications to cosmic topology.

Peter Kramer

2009-03-01

64

Modelling and analysis of vertebra deformations with spherical harmonics.

In this paper we present an elaborate and precise geometrical model of the spine structure based on spherical harmonics. We first describe the application of spherical harmonics to the modelling of the vertebra surface, then we study the behaviour of the model under particular deformations. The first results of this study show that we can obtain a realistic model of each vertebra of the spine and that it is possible to estimate particular deformations with a good accuracy from the spherical harmonics coefficients of the deformed surface. Furthermore, this model constitutes an a priori geometrical knowledge for the diagnosis of the spine scoliosis in a three-dimensional approach (reconstruction from 2D images). PMID:15456024

Lefaix, Gildas; Haigron, Pascal; Rolland, Yan; Collorec, René

2002-01-01

65

Extracting tidal frequencies using multivariate harmonic analysis of sea level height time series

NASA Astrophysics Data System (ADS)

This contribution is seen as a first attempt to extract the tidal frequencies using a multivariate spectral analysis method applied to multiple time series of tide-gauge records. The existing methods are either physics-based in which the ephemeris of Moon, Sun and other planets are used, or are observation-based in which univariate analysis methods—Fourier and wavelet for instance—are applied to tidal observations. The existence of many long tide-gauge records around the world allows one to use tidal observations and extract the main tidal constituents for which efficient multivariate methods are to be developed. This contribution applies the multivariate least-squares harmonic estimation (LS-HE) to the tidal time series of the UK tide-gauge stations. The first 413 harmonics of the tidal constituents and their nonlinear components are provided using the multivariate LS-HE. A few observations of the research are highlighted: (1) the multivariate analysis takes information of multiple time series into account in an optimal least- squares sense, and thus the tidal frequencies have higher detection power compared to the univariate analysis. (2) Dominant tidal frequencies range from the long-term signals to the sixth-diurnal species interval. Higher frequencies have negligible effects. (3) The most important tidal constituents (the first 50 frequencies) ordered from their amplitudes range from 212 cm (M2) to 1 cm (OQ2) for the data set considered. There are signals in this list that are not available in the 145 main tidal frequencies of the literature. (4) Tide predictions using different lists of tidal frequencies on five different data sets around the world are compared. The prediction results using the first significant 50 constituents provided promising results on these locations of the world.

Amiri-Simkooei, A. R.; Zaminpardaz, S.; Sharifi, M. A.

2014-10-01

66

Physical Culture, Physical Education and Relational Analysis

This paper argues for the recovery of a notion of physical culture that can serve the purposes of relational analysis in social research. The recovery of the notion is undertaken through a brief etymology of the term, and through an historical overview of shifts in physical culture during the twentieth century. The recovered notion is described as one dimension of

David Kirk

1999-01-01

67

NASA Astrophysics Data System (ADS)

Transducers made of thin magnetostrictive patches and magnetic circuits have been recently developed as an effective means for non-destructive guided wave inspection of elastic structures. However, important characteristics of transducers, such as their wave radiation patterns, have been tested only by experiments or a first-order theoretical analysis. There have been some finite element analyses related to magnetostrictive actuators, but no numerical analysis has been performed to predict the wave radiation patterns of various magnetostrictive patch transducers. In this paper, we formulate a finite element procedure and implement it to predict the wave radiation pattern of a magnetostrictive patch transducer installed on a plate. In particular, a linearized model determining coupling matrix appearing in the magnetostrictive constitutive equation of a magnetostrictive patch in a transducer is developed. The developed model is then used to deal with the arbitrarily polarized static magnetic field induced in the transducers. For numerical efficiency, time-harmonic analysis is carried out and a technique to extract data corresponding to target guided wave modes is used. The validity of the developed finite element analysis is checked by comparing the simulated wave radiation patterns from the present analysis with experimental results. The reasons why certain radiation patterns are obtained for selected magnetic circuits are explained by physical reasoning and simulation results.

Oh, Joo Hwan; Sun, Kyung Ho; Kim, Yoon Young

2013-08-01

68

Analysis of higher harmonic contamination with a modified approach using a grating analyser

Soft x-ray spectra of the toroidal grating monochromator (TGM) at the reflectivity beamline of Indus-1 synchrotron source are analyzed for higher harmonic contribution. A diffraction grating of central line spacing 1200 l/mm is used to disperse the monochromatic beam received from TGM to quantify the harmonic contents in the 50–360 Å wavelength range. In order to calculate the harmonic contamination, conventionally the intensity of higher order peak is divided by first order peak intensity of the desired wavelength. This approach is found to give wrong estimate as first order peak itself is overlapped by higher order peaks. In the present study, a modified approach has been proposed to calculate harmonic contamination where the intensity contributions of overlapping orders have been removed from the first order diffraction peak of the desired wavelength. It is found that the order contamination in the TGM spectra is less than 15% in the wavelength range of 90–180 Å. The total harmonic contribution increases from 6%–60% in the wavelength range of 150–260 Å. The critical wavelength of Indus-1 is 61 Å hence the harmonic contamination below 90 Å is significantly low. The results obtained with modified approach match well with those obtained by quantitative analysis of multilayer reflectivity data. The obtained higher harmonics data are used to fit the transmission of aluminum edge filter in the 120–360 Å wavelength range.

Gupta, Rajkumar, E-mail: rkg@rract.gov.in; Modi, Mohammed H.; Lodha, G. S. [X-ray Optics Section, Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)] [X-ray Optics Section, Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Kumar, M.; Chakera, J. A. [Laser Plasma Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)] [Laser Plasma Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

2014-04-15

69

Harmonizing Physics & Cosmology With Everything Else in the Universe(s)

NASA Astrophysics Data System (ADS)

This paper postulates a theory of everything including our known finite physical universe within and as sub-set of an infinite virtual invisible universe occupying some of the same space and time. It attempts to harmonize astrophysics with everything else including life. It compares and contrasts properties, similarities, differences and relationships between the two universe(s). A particular attention is paid to the interface between the two and the challenges of building and/or traversing bridges between them. A number of inflection points between the two are identified. The paper also delineates their relationship to big bang, theory of evolution, gravity, dark matter, black holes, time travel, speed of light, theory of relativity and string theory just to name a few. Several new terms are introduced and defined to discuss proper relationship, transition and interface between the body, soul and spirit as well as their relationship to brain and mind. Physical bodies & beings are compared with virtual, meta and ultra bodies and beings and how the ``Virtual Inside'' relates to people, pets, plants and particles and their micro constituents as well as macro sets. The past, present, and potential of the concurrent universe(s) is compared and contrasted along with many myths and misconceptions of the meta physics as well as modern physics.

Asija, Pal

2006-03-01

70

Analysis of harmonic spline gravity models for Venus and Mars

NASA Technical Reports Server (NTRS)

Methodology utilizing harmonic splines for determining the true gravity field from Line-Of-Sight (LOS) acceleration data from planetary spacecraft missions was tested. As is well known, the LOS data incorporate errors in the zero reference level that appear to be inherent in the processing procedure used to obtain the LOS vectors. The proposed method offers a solution to this problem. The harmonic spline program was converted from the VAX 11/780 to the Ridge 32C computer. The problem with the matrix inversion routine that improved inversion of the data matrices used in the Optimum Estimate program for global Earth studies was solved. The problem of obtaining a successful matrix inversion for a single rev supplemented by data for the two adjacent revs still remains.

Bowin, Carl

1986-01-01

71

Development of Harmonic Excitation technique for Machine Tool stability analysis

The project described in this thesis was to establish the instrumentation and technique for analysing stability of machine-tools against chatter by harmonic excitation. To test out the technique, two sets of experiments were performed on centre lathes:\\u000a1) comparison of cutting stability with tour different types of boring bars, and\\u000a2) comparison of cutting stability of a tool oriented in

Michael King-Chun Lau

1973-01-01

72

Blind Analysis in Particle Physics

A review of the blind analysis technique, as used in particle physics measurements, is presented. The history of blind analyses in physics is briefly discussed. Next the dangers of "experimenter's bias" and the advantages of a blind analysis are described. Three distinct kinds of blind analysis in particle physics are presented in detail. Finally, the BABAR collaboration's experience with the blind analysis technique is discussed.

Aaron Roodman

2003-12-17

73

Data harmonization and federated analysis of population-based studies: the BioSHaRE project

Abstracts Background Individual-level data pooling of large population-based studies across research centres in international research projects faces many hurdles. The BioSHaRE (Biobank Standardisation and Harmonisation for Research Excellence in the European Union) project aims to address these issues by building a collaborative group of investigators and developing tools for data harmonization, database integration and federated data analyses. Methods Eight population-based studies in six European countries were recruited to participate in the BioSHaRE project. Through workshops, teleconferences and electronic communications, participating investigators identified a set of 96 variables targeted for harmonization to answer research questions of interest. Using each study’s questionnaires, standard operating procedures, and data dictionaries, harmonization potential was assessed. Whenever harmonization was deemed possible, processing algorithms were developed and implemented in an open-source software infrastructure to transform study-specific data into the target (i.e. harmonized) format. Harmonized datasets located on server in each research centres across Europe were interconnected through a federated database system to perform statistical analysis. Results Retrospective harmonization led to the generation of common format variables for 73% of matches considered (96 targeted variables across 8 studies). Authenticated investigators can now perform complex statistical analyses of harmonized datasets stored on distributed servers without actually sharing individual-level data using the DataSHIELD method. Conclusion New Internet-based networking technologies and database management systems are providing the means to support collaborative, multi-center research in an efficient and secure manner. The results from this pilot project show that, given a strong collaborative relationship between participating studies, it is possible to seamlessly co-analyse internationally harmonized research databases while allowing each study to retain full control over individual-level data. We encourage additional collaborative research networks in epidemiology, public health, and the social sciences to make use of the open source tools presented herein. PMID:24257327

2013-01-01

74

Comparison Among Three Harmonic Analysis Techniques on the Sphere and the Ellipsoid

NASA Astrophysics Data System (ADS)

The paper presents a comparison among three different techniques for harmonic analysis on the sphere and the ellipsoid. The EGM2008 global geopotential model has been used up to degree and order 360 in order to create gravity anomaly fields on both the sphere and the ellipsoid as the function fields of the current investigation. Harmonic analysis has then been carried out to compute the dimensionless potential coeficients using the created function fields. Three different harmonic analysis techniques have been applied: the least-squares technique, the Fast Fourier Transform (FFT) technique and the Gauss-Legendre numerical integration technique. The computed coeficients in spherical harmonics have then been compared with EGM2008 (in the frequency domain) and the computed fields on the sphere and the ellipsoid have been compared with fields created by EGM2008 up to degree and order 360 (in the space domain) in order to estimate the accuracy of the three different harmonic analysis techniques used within the current investigation. The results proved that the least-squares technique gives the best accuracy both in frequency and space domain. The FFT technique provides quite good results in a very short cpu time. The Gauss-Legendre technique gives the worst results among the presented techniques, but still the residuals in the space domain are negligibly small.

Abd-Elmotaal, Hussein; Abd-Elbaky, Mostafa; Seitz, Kurt; Heck, Bernhard

2014-04-01

75

Two methods for the harmonic analysis of periodic arbitrary signals based on digital sampling data were compared: an extension of Swerlein's algorithm to nonsinusoidal signals and a Bayesian spectrum analysis using approximations based on the normal distribution and the posterior mode.

G. A. Kyriazis

2010-01-01

76

NASA Astrophysics Data System (ADS)

Operational Modal Analysis (OMA) is used to extract modal parameters of a structure on the basis of their output response measured during operation. OMA, when applied to mechanical engineering structures is often faced with the problem of harmonics present in the output response. A complex structure may have many dominant frequency components in its response frequency spectrum. These may contain frequency components associated with resonant frequencies of the structure, which and the associated mode shapes and the damping factors represent the data of interest, but may also contain frequencies or harmonics associated with the excitation sources. Since in OMA the characteristics of the excitation sources are not known, one of the problems lies in separating the resonant frequencies from the harmonic excitation frequencies. Any error in this regard may lead to an error in modal identification with the consequence that a harmonic may be construed as a structural mode and vice versa. This issue is addressed in this paper and a method is presented for separating resonant frequencies from harmonic excitation frequencies using random decrement of the response. The principle of the method is presented using an analytical study on a single degree of freedom system. The effectiveness of the method is then demonstrated through numerical studies on a lumped parameter multi-degree of freedom system and a simulated plate structure. Detection of single and multiple harmonics in the response that are well separated as well as close to resonant frequencies are considered.

Modak, S. V.

2013-12-01

77

NASA Astrophysics Data System (ADS)

This paper describes a set of experiments aimed at overcoming some of the difficulties experienced by students learning about the topics of moments of inertia and simple harmonic motion, both of which are often perceived to be complex topics amongst students during their first-year university courses. By combining both subjects in a discussion about physical pendula, in which the oscillation time periods for the periodic motion of several objects (a tennis ball, a thin beam, a hoop and a solid disc) are measured and compared, students are able to understand both topics at a higher level and also experience the synergistic effect of combining two or more physics themes in order to accelerate their learning whilst simultaneously raising their motivation. Special attention is given to the ‘ball and stick’ pendulum in which a block of material (treated as a point mass) can be moved along a shaft to create a composite pendulum whose time period exhibits a minimum value at a certain separation between the block and the rotation axis.

Richardson, Tim H.; Brittle, Stuart A.

2012-09-01

78

Quantitative analysis of scanning force microscopy data using harmonic models

NASA Astrophysics Data System (ADS)

The separate identification of dissipative and elastic force contributions in Atomic Force Microscopy (AFM) is discussed. We show that within a harmonic approximation the interaction of the AFM tip with the sample surface can be described by average interaction parameters, namely an effective elastic tip-sample interaction kts and an effective dissipation ?ts, which can be extracted in a simple way from measured data. The method is applied to force spectroscopy curves on hard and soft polymeric model surfaces. The approach enables a thorough discussion of the influence of experimental parameters on the measured data. In imaging a clear identification of phases in systems with hard-soft contrast as for instance in semicrystalline polymers is made possible.

Henze, Thomas; Schroeter, Klaus; Petzold, Albrecht; Thurn-Albrecht, Thomas

2009-03-01

79

Automated cardiac sarcomere analysis from second harmonic generation images

NASA Astrophysics Data System (ADS)

Automatic quantification of cardiac muscle properties in tissue sections might provide important information related to different types of diseases. Second harmonic generation (SHG) imaging provides a stain-free microscopy approach to image cardiac fibers that, combined with our methodology of the automated measurement of the ultrastructure of muscle fibers, computes a reliable set of quantitative image features (sarcomere length, A-band length, thick-thin interaction length, and fiber orientation). We evaluated the performance of our methodology in computer-generated muscle fibers modeling some artifacts that are present during the image acquisition. Then, we also evaluated it by comparing it to manual measurements in SHG images from cardiac tissue of fetal and adult rabbits. The results showed a good performance of our methodology at high signal-to-noise ratio of 20 dB. We conclude that our automated measurements enable reliable characterization of cardiac fiber tissues to systematically study cardiac tissue in a wide range of conditions.

Garcia-Canadilla, Patricia; Gonzalez-Tendero, Anna; Iruretagoyena, Igor; Crispi, Fatima; Torre, Iratxe; Amat-Roldan, Ivan; Bijnens, Bart H.; Gratacos, Eduard

2014-05-01

80

Full vector spherical harmonic analysis of the Holocene geomagnetic field

NASA Astrophysics Data System (ADS)

High-quality time-series paleomagnetic measurements have been used to derive spherical harmonic models of Earth's magnetic field for the past 2,000 years. A newly-developed data compilation, PSVMOD2.0 consists of time-series directional and intensity records that significantly improve the data quality and global distribution used to develop previous spherical harmonic models. PSVMOD2.0 consists of 185 paleomagnetic time series records from 85 global sites, including 30 full-vector records (inclination, declination and intensity). It includes data from additional sites in the Southern Hemisphere and Arctic and includes globally distributed sediment relative paleointensity records, significantly improving global coverage over previous models. PSVMOD2.0 records have been assessed in a series of 7 regional intercomparison studies, four in the Northern Hemisphere and 3 in the southern hemisphere. Comparisons on a regional basis have improved the quality and chronology of the data and allowed investigation of spatial coherence and the scale length associated with paleomagnetic secular variation (PSV) features. We have developed a modeling methodology based on nonlinear inversion of the PSVMOD2.0 directional and intensity records. Models of the geomagnetic field in 100-year snapshots have been derived for the past 2,000 with the ultimate goal of developing models spanning the past 8,000 years. We validate the models and the methodology by comparing with the GUFM1 historical models during the 400-year period of overlap. We find that the spatial distribution of sites and quality of data are sufficient to derive models that agree with GUFM1 in the large-scale characteristics of the field. We use the the models derived in this study to downward continue the field to the core-mantle boundary and examine characteristics of the large-scale structure of the magnetic field at the source region. The derived models are temporally consistent from one epoch to the next and exhibit many of the expected characteristics of the field over time (high-latitude flux lobes, South Atlantic reverse flux patch, north pole reverse or null flux region).

Richardson, Marcia

81

Application of harmonic analysis in measuring the corrosion rate of rebar in concrete

The corrosion rate (CR) of rebar embedded in cement mortar, concrete and cement extract is determined using harmonic analysis technique (HA). Simultaneously using other electrochemical techniques such as impedance spectroscopy (EIS) and Tafel extrapolation (TET), the CR was determined and compared with the weight loss method. CR obtained from HA is comparable to that of EIS provided that the Stern–Geary

R. Vedalakshmi; S. P. Manoharan; Ha-Won Song; N. Palaniswamy

2009-01-01

82

Continuous-Time Operational Modal Analysis in the Presence of Harmonic Disturbances

Operational modal analysis (OMA) allows to identify the modal parameters from the measured response to unknown random perturbations of a mechanical structure in operation. However, in all applications with rotating components (e.g. helicopters, turbines, diesel motors, ...), the structural vibration in operation is a combination of the response to the random perturbation and the harmonic excitation due to the rotating

R. Pintelon; B. Peeters; P. Guillaume

2008-01-01

83

PROJET AURORA: COMPLEX AND HARMONIC ANALYSIS RELATED TO GENERATING SYSTEMS: PHASE SPACE LOCALIZATION PROPERTIES, SAMPLING AND APPLICATIONS The aim of the AURORA project CHARGE is to join the efforts holds: A f 2 | f, |2 B f . 1 #12;2 AURORA PROJECT CHARGE The first property is of essential

Saut, Olivier

84

Anisotropy analysis of third-harmonic generation in a germanium-doped silica optical fiber.

We performed an intermodal third-harmonic generation around 516 nm in a germanium-doped silica optical fiber. The analysis of the complex polarization behavior that was observed allowed us to determine the orientation symmetry group of the fiber and the relative values of the independent coefficients of the third-order electric susceptibility tensor. PMID:25768162

Borne, Adrien; Katsura, Tomotaka; Félix, Corinne; Doppagne, Benjamin; Segonds, Patricia; Bencheikh, Kamel; Levenson, Juan Ariel; Boulanger, Benoît

2015-03-15

85

Harmonic Analysis of a Short Stator Linear Induction Machine Using a Transformation Technique

An analysis method is introduced for the short stator linear induction machine with homogeneous conducting rotor. The method incorporates harmonic rotor currents and a coordinate transformation into a modified Lagrangian formulation of the equations of motion. These equations permit both excitation and ferromagnetic edge effects as well as skin effects to be accounted for.

G. G. North

1973-01-01

86

The algorithm of interpolating windowed FFT for harmonic analysis of electric power system

The fast Fourier transform (FFT) cannot be directly used in the harmonic analysis of an electric power system because of its higher errors, especially the phase error. This paper discusses the leakage phenomenon of FFT and presents a new amending algorithm, poly-item cosine window interpolation, which is based on the interpolating algorithm proposed by V. Jain and T Grandke. This

Fusheng Zhang; Zhongxing Geng; Wei Yuan

2001-01-01

87

The development and analysis of geopotential coefficient models to spherical harmonic degree 360

NASA Technical Reports Server (NTRS)

Two new geopotential coefficient models to spherical harmonic degree 360 are developed using recent advances made in theoretical modeling methods, satellite gravitational models, and expanded and improved terrestrial data. The new models are based on the combination of a satellite potential coefficient model (GEM-T2) to degree 50 with 30-arc mean gravity anomalies, yielding an adjusted set of coefficients and gravity anomalies, which were then harmonically analyzed to yield a set of potential coefficients to degree 360. The models were verified in several ways including satellite orbit residual analysis, demonstrating a substantial improvement over previous high-degree expansions.

Rapp, Richard H.; Pavlis, Nikolaos K.

1990-01-01

88

Polarization Analysis of Nonlinear Harmonic Radiation in a Crossed-Planar Undulator

There is growing interest in producing intense, coherent x-ray radiation with an adjustable and arbitrary polarization state. The crossed-planar undulator, which was first proposed by Kim, could achieve rapid polarization control in synchrotron radiation sources and free electron lasers (FELs) through the manipulation of a phase shifter. Recently, a statistical analysis shows that a polarization degree of over 80% is obtainable for a Self-Amplified Spontaneous Emission (SASE) FEL near saturation. In such a scheme, nonlinear harmonic radiation is also generated in each undulator and the polarization of the radiation is controllable in the same manner. In this paper, we study the degree of polarization achievable at the third harmonic in a crossed-planar undulator. We also propose a method for generating second harmonic radiation with arbitrary polarization.

Geng, H.; Ding, Y.; Huang, Z.; /SLAC

2009-06-23

89

Nonlinear constant evaluation in a piezoelectric rod from analysis of second harmonic generation.

The design of transducers requires a clear understanding of their electromechanical behavior. This involves precise linear modeling as well as characterization. With the development of novel techniques such as harmonic imaging as well as high-power applications, nonlinear aspects must also be taken into account. In this study, harmonic generation in the mechanical displacement of a piezoceramic rod under high sinusoidal electric fields was measured. Theoretically, the nonlinearity can come from various sources: dielectric, mechanical, and electromechanical. The nonlinearity coming from external sources being eliminated or taken into account, it is shown here that the analysis, over a wide frequency range, of 2 parameters related to the harmonic distortion enables the respective identification of these sources and, at the same time, the evaluation of third-order constants of the material. PMID:19213643

Parenthoine, Denis; Haumesser, Lionel; Vander Meulen, François; Lethiecq, Marc; Tran-Huu-Hue, Louis-Pascal

2009-01-01

90

NASA Astrophysics Data System (ADS)

In isogeometric analysis, parameterization of computational domain has great effects as mesh generation in finite element analysis. In this paper, based on the concept of harmonic mapping from the computational domain to parametric domain, a variational harmonic approach is proposed to construct analysis-suitable parameterization of computational domain from CAD boundary for 2D and 3D isogeometric applications. Different from the previous elliptic mesh generation method in finite element analysis, the proposed method focuses on isogeometric version, and converts the elliptic PDE into a nonlinear optimization problem, in which a regular term is integrated into the optimization formulation to achieve more uniform and orthogonal iso-parametric structure near convex (concave) parts of the boundary. Several examples are presented to show the efficiency of the proposed method in 2D and 3D isogeometric analysis.

Xu, Gang; Mourrain, Bernard; Duvigneau, Régis; Galligo, André

2013-11-01

91

Specialized hardware and software have been developed to facilitate harmonic error analysis measurements of one-meter-long Superconducting Super Collider (SSC) model dipole and quadrupole magnets. Cold bore measurements feature cryogenic search-coil arrays with high bucking ratios that also have sufficient sensitivity to make room-temperature measurements at the low magnet currents of approx.10 A. Three sets of search coils allow measurements of the center, either end, and/or the axially integrated field. Signals from the search coils are digitally integrated by means of a voltage-to-frequency converter feeding an up-down counter. The data are drift corrected, Fourier analyzed, converted to physical quantities, and printed and plotted. A cycle of measurements including data acquisition, processing, and the generation of tabular and graphic output requires 80 seconds. The vast amount of data generated (several hundred measurement cycles for each magnet) has led to the development of postprocessing programs and procedures. Spreadsheets allow easy manipulation and comparison of results within a test series and between magnets. 8 refs., 4 figs., 1 tab.

Green, M.I.; Barale, P.J.; Gilbert, W.S.; Hassenzahl, W.V.; Nelson, D.H.; Taylor, C.E.; Travis, N.J.; Van Dyke, D.A.

1987-09-01

92

To characterize primate arterial waveforms, we prospectively studied 38 bonnet macaques (Macaca radiata; 25 female, 13 ± 4 y). Brachial artery waveforms were recorded from these animals by applanation tonometry and were decomposed into harmonics by using Fourier analysis. The ratio of individual to total harmonic amplitude (H:T) was derived from frequency spectra. Left ventricular (LV) mass, ejection fraction, fractional shortening, septal wall thickness, posterior wall thickness, LV end-diastolic diameter, and LV end-systolic diameter were obtained by echocardiography in all 38 monkeys. Blood pressure was obtained by sphygmomanometry. The fundamental frequency was 2.76 cycles/s. Harmonics ranged from 5 to 14. Indexed LV mass was inversely correlated with third H:T and second H:T but not with systolic or diastolic blood pressure. In addition, the third H:T was inversely correlated with septal wall thickness, posterior wall thickness, and LV end-diastolic diameter, whereas second H:T was inversely correlated with LV end-diastolic diameter. Heart rate was inversely correlated with eighth H:T. On multivariate analysis adjusting for age, gender, weight, and length, only third H:T was an independent predictor of LV mass. Harmonic analysis of arterial waveforms may provide information pertaining to LV mass. Lower H:T ratios (second and third) are related to LV mass, whereas higher H:T (eighth) is related to heart rate. PMID:21333168

Olafiranye, Oladipupo; Salciccioli, Louis; Kamran, Haroon; Stewart, Mark; Carter, John; Lazar, Jason M

2011-01-01

93

Platonic polyhedra tune the 3-sphere: III. Harmonic analysis on octahedral spherical 3-manifolds

From the homotopy groups of three distinct octahedral spherical 3-manifolds we construct the isomorphic groups H of deck transformations acting on the 3-sphere. The H-invariant polynomials on the 3-sphere constructed by representation theory span the bases for the harmonic analysis on three spherical manifolds. Analysis of the Cosmic Microwave Background in terms of these new bases can reveal a non-simple topology of the space part of space-time.

Peter Kramer

2009-10-13

94

SPEECH ENHANCEMENT IN CAR NOISE ENVIRONMENT BASED ON AN ANALYSIS- SYNTHESIS APPROACH USING HARMONIC using harmonic noise model (HNM) in car noise environment. The major advantages of this method are effective suppression of car noise even in very low signal-to-noise ratio environments and mitigation

So, Hing-Cheung

95

Workshop on Harmonic Oscillators

NASA Technical Reports Server (NTRS)

Proceedings of a workshop on Harmonic Oscillators held at the College Park Campus of the University of Maryland on March 25 - 28, 1992 are presented. The harmonic oscillator formalism is playing an important role in many branches of physics. This is the simplest mathematical device which can connect the basic principle of physics with what is observed in the real world. The harmonic oscillator is the bridge between pure and applied physics.

Han, D. (editor); Kim, Y. S. (editor); Zachary, W. W. (editor)

1993-01-01

96

NASA Technical Reports Server (NTRS)

A finite difference method for solving the unsteady transonic flow about harmonically oscillating wings is investigated. The procedure is based on separating the velocity potential into steady and unsteady parts and linearizing the resulting unsteady differential equation for small disturbances. The differential equation for the unsteady velocity potential is linear with spatially varying coefficients and with the time variable eliminated by assuming harmonic motion. A study is presented of the shock motion associated with an oscillating airfoil and its representation by the harmonic procedure. The effects of the shock motion and the resulting pressure pulse are shown to be included in the harmonic pressure distributions and the corresponding generalized forces. Analytical and experimental pressure distributions for the NACA 64A010 airfoil are compared for Mach numbers of 0.75, 0.80 and 0.842. A typical section, two-degree-of-freedom flutter analysis of a NACA 64A010 airfoil is performed. The results show a sharp transonic bucket in one case and abrupt changes in instability modes.

Ehlers, F. E.; Weatherill, W. H.

1982-01-01

97

Enhancing tidal harmonic analysis: Robust (hybrid L1/L2) solutions

NASA Astrophysics Data System (ADS)

Traditional harmonic analysis of tides is highly sensitive to omnipresent environmental noise. Robust fitting is an extension of the ordinary least squares calculation of harmonic analysis that is more resistant to broad spectrum noise. Since the variance of the amplitude and phase is calculated from the power spectrum of the residual, a calculation that filters broad spectrum noise and reduces the residual variance will increase the confidence of the computed parameters, and also allows more low-amplitude constituents to be resolved from the background noise. Improvement in confidence and resolution of more constituents has obvious benefits to the resolution of both seasonal and long-term variation of amplitude and phase of tidal constituents. Using a 6 month calculation window, confidence intervals were systematically reduced by 30-85% over results calculated with standard methods, with an increase in resolved constituents of 20-75%. The analysis was carried out with Matlab, using the t-tide package [Pawlowicz, R., Beardsley, B., Lentz, S., 2002. Classical tidal harmonic analysis with errors in matlab using t-tide. Computers and Geosciences 28, 929-937], with modifications to accommodate Matlab's implementation of the Iteratively Reweighted Least Squares algorithm.

Leffler, Keith E.; Jay, David A.

2009-01-01

98

The simulation for accuracy validation of OCT based non-harmonic analysis

A new processing technique called non-harmonic analysis (NHA) is proposed for optical coherence tomography (OCT) imaging. Conventional Fourier-domain OCT employs the discrete Fourier transform (DFT), which depends on the window function and length. Its axial resolution is inversely proportional to the DFT frame length. The DFT frame length is limited by the sweeping range of the source in swept-source OCT

Tetsuya Uchida; Xu Cao; Shigeki Hirobayashi; Tadanobu Misawa; Toshio Yoshizawa; Changho Chong; Atsushi Morosawa; Takuya Suzuki

2011-01-01

99

Quasi-periodic signal analysis using harmonic transform with application to voiced speech processing

A new method for quasi-periodic signal analysis and modelling with application to speech processing is proposed in this paper. The model of quasi-periodic signal treats the signal as a composition the two components. Periodic component is modelled as a sum of harmonically related sinusoidal partials with slowly time-varying amplitudes and frequencies, aperiodic component is modulated white noise. Fundamental frequency, amplitudes

Piotr Zubrycki; Alexander A. Petrovsky

2010-01-01

100

NASA Technical Reports Server (NTRS)

In an earlier paper, Misner (2004, Class. Quant. Grav., 21, S243) presented a novel algorithm for computing the spherical harmonic components of data represented on a cubic grid. I extend Misner s original analysis by making detailed error estimates of the numerical errors accrued by the algorithm, by using symmetry arguments to suggest a more efficient implementation scheme, and by explaining how the algorithm can be applied efficiently on data with explicit reflection symmetries.

Fiske, David R.

2004-01-01

101

Fourier-series analysis (FSA) of time activity curves has been used to enhance the detection of regional abnormalities in function of the left ventricle (LV) on radionuclide ventriculograms (RVGs). Phase, or first harmonic analysis, does not permit separate determination of systolic and diastolic function. The retention of 2 harmonics (2-H) in the FSA allows definition of both systolic and diastolic parameters, including time to peak ejection rate (TPER) and time to peak filling rate (TPFR). The authors compared regional phase and 2-H analysis in 42 patients with normal LV function by conventional analysis of resting RVGs. All patients had ejection fraction greater than 50% and normal regional wall motion. Diagnoses, established by cardiac characterization, included coronary artery disease (CAD) and chest pain but normal coronary arteries (NCA). Normal homogeneity of LV function was established in 12 normal volunteers by computing the standard deviation of the distribution of LV pixels for TPER, TPFR and phase angle on the 35/sup 0/ LAO views. Thus, in patients with CAD but normal conventional analysis of RVGs, 2-H analysis detected abnormal diastolic filling in 70% whereas phase analysis was abnormal in only 15%. In patients with NCA, abnormalities by either phase or 2-H analysis were infrequent. These data suggest that 2-H analysis may be of value in the investigation of patients with chest pain but normal LV function.

Hurwitz, G.A.; Miller, T.R.; Biello, D.R.

1984-01-01

102

Harmonic Band Spectrum Analysis of Backscattered Ultrasound from Lesioned and Normal Tissue

NASA Astrophysics Data System (ADS)

HIFU dose curves (lesion size vs. exposure parameters) exhibit scatter because of local variations in the acoustic properties of tissue. Therefore, clinical applications of HIFU, such as cardiac and cancer ablation, will benefit from the ability to distinguish treated from normal tissue, which can provide the surgeon with lesion monitoring. However, HIFU lesions, especially protein-denaturing lesions (PDLs), may be difficult to visualize with conventional B-mode ultrasound. In this study, spectrum analysis of backscattered radiofrequency (RF) ultrasound was successful in imaging lesions. HIFU lesions were formed at 5 MHz for various intensities and durations in model tissues including degassed chicken breast in vitro, fresh rabbit liver ex vivo, and canine cardiac left ventricle in vivo. The tissues were scanned pre- and post-exposure using confocal array and single-element diagnostic probes incorporated into the HIFU transducer assembly. The diagnostic probes were excited with a monocycle pulse under conditions previously shown to generate a second harmonic comparable in amplitude to the fundamental, and RF echo-signal data were recorded. In an alternate set, the therapy and diagnostic transducers were operated pitch-catch, with the therapy transducer sending out a series of 0.4 ms pulses and the diagnostic transducer in passive receive mode. Spectrum analysis of the RF data was performed separately on first (fundamental) and second harmonic frequency bands. Linear regression fits to spectra computed for sliding regions-of-interest yielded 3 parameters: midband fit (integrated backscatter), y-intercept and slope; grayscale images were produced for each parameter. Differences among the B-mode and parameter images, and between the lesion site and adjacent untreated tissues, were characterized statistically. The results indicate that midband fit images of both the fundamental and harmonic offer improved contrast and lateral resolution compared to conventional images. PDLs and bubbly lesions that are not clearly visible in B-mode images can be imaged with harmonic band spectrum analysis.

Muratore, Robert; Lizzi, Frederic L.; Silverman, Ronald H.

2006-05-01

103

We present a time-dependent analysis of high-order harmonics generated by a self-guided femtosecond laser pulse propagating through a long gas jet. A three-dimensional model is used to calculate the harmonic fields generated by laser pulses, which only differ by the sign of their initial chirp. The time-frequency distributions of the single-atom dipole and harmonic field reveal the dynamics of harmonic generation in the cutoff. A time-dependent phase-matching calculation was performed, taking into account the self-phase modulation of the laser field. Good phase matching holds for only few optical cycles, being dependent on the electron trajectory. When the cutoff trajectory is phase matched, emitted harmonics are locked in phase and the emission intensity is maximized.

Tosa, V. [Department of Physics, KAIST, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); National Institute for R and D of Isotopic and Molecular Technologies, Cluj-Napoca (Romania); Kim, H.T.; Kim, I.J.; Nam, C.H. [Department of Physics, KAIST, Yuseong-gu, Daejeon, 305-701(Korea, Republic of)

2005-06-15

104

Harmonic Analysis of Sedimentary Cyclic Sequences in Kansas, Midcontinent, USA

Several stratigraphic sequences in the Upper Carboniferous (Pennsylvanian) in Kansas (Midcontinent, USA) were analyzed quantitatively for periodic repetitions. The sequences were coded by lithologic type into strings of datasets. The strings then were analyzed by an adaptation of a one-dimensional Fourier transform analysis and examined for evidence of periodicity. The method was tested using different states in coding to determine the robustness of the method and data. The most persistent response is in multiples of 8-10 ft (2.5-3.0 m) and probably is dependent on the depositional thickness of the original lithologic units. Other cyclicities occurred in multiples of the basic frequency of 8-10 with persistent ones at 22 and 30 feet (6.5-9.0 m) and large ones at 80 and 160 feet (25-50 m). These levels of thickness relate well to the basic cyclothem and megacyclothem as measured on outcrop. We propose that this approach is a suitable one for analyzing cyclic events in the stratigraphic record.

Merriam, D.F.; Robinson, J.E.

1997-01-01

105

The Influence of Spring Length on the Physical Parameters of Simple Harmonic Motion

ERIC Educational Resources Information Center

The aim of this work is to analyse the influence of spring length on the simple harmonic motion of a spring-mass system. In particular, we study the effect of changing the spring length on the elastic constant "[kappa]", the angular frequency "[omega]" and the damping factor "[gamma]" of the oscillations. To characterize the behaviour of these…

Triana, C. A.; Fajardo, F.

2012-01-01

106

ERIC Educational Resources Information Center

This paper describes a set of experiments aimed at overcoming some of the difficulties experienced by students learning about the topics of moments of inertia and simple harmonic motion, both of which are often perceived to be complex topics amongst students during their first-year university courses. By combining both subjects in a discussion…

Richardson, Tim H.; Brittle, Stuart A.

2012-01-01

107

NASA Astrophysics Data System (ADS)

The novel technique based on harmonic analysis of bioimpedance microvariations with original hard- and software complex incorporating a high-resolution impedance converter was used to assess the neural activity and circulation in human urinary bladder and penis in patients with pelvic pain, erectile dysfunction, and overactive bladder. The therapeutic effects of shock wave therapy and Botulinum toxin detrusor injections were evaluated quantitatively according to the spectral peaks at low 0.1 Hz frequency (M for Mayer wave), respiratory (R) and cardiac (C) rhythms with their harmonics. Enhanced baseline regional neural activity identified according to M and R peaks was found to be presumably sympathetic in pelvic pain patients, and parasympathetic - in patients with overactive bladder. Total pulsatile activity and pulsatile resonances found in the bladder as well as in the penile spectrum characterised regional circulation and vascular tone. The abnormal spectral parameters characteristic of the patients with genitourinary diseases shifted to the norm in the cases of efficient therapy. Bioimpedance harmonic analysis seems to be a potent tool to assess regional peculiarities of circulatory and autonomic nervous activity in the course of patient treatment.

Mudraya, I. S.; Revenko, S. V.; Khodyreva, L. A.; Markosyan, T. G.; Dudareva, A. A.; Ibragimov, A. R.; Romich, V. V.; Kirpatovsky, V. I.

2013-04-01

108

The space physics analysis network

The Space Physics Analysis Network, or SPAN, is emerging as a viable method for solving an immediate communication problem for space and Earth scientists and has been operational for nearly 7 years. SPAN and its extension into Europe, utilizes computer-to-computer communications allowing mail, binary and text file transfer, and remote logon capability to over 1000 space science computer systems. The

James L. Green

1988-01-01

109

Investigations of Low and Moderate Harmonic Fast Wave Physics on CDX-U

Third harmonic hydrogen cyclotron fast wave heating studies are planned in the near term on CDX-U to investigate the potential for bulk ion heating. In preparation for these studies, the available radio-frequency power in CDX-U has been increased to 0.5 MW. The operating frequency of the CDX-U radio-frequency transmitter was lowered to operate in the range of 8-10 MHz, providing access to the ion harmonic range 2* {approx} 4* in hydrogen. A similar regime is accessible for the 30 MHz radio-frequency system on the National Spherical Torus Experiment (NSTX), at 0.6 Tesla in hydrogen. Preliminary computational studies over the plasma regimes of interest for NSTX and CDX-U indicate the possibility of strong localized absorption on bulk ion species.

J. Spaleta; R. Majeski; C.K. Phillips; R.J. Dumont; R. Kaita; V. Soukhanovskii; L. Zakharov

2003-07-14

110

Experimental analysis of the high-order harmonic components generation in few-layer graphene

NASA Astrophysics Data System (ADS)

In this work, the nonlinear electromagnetic response of a few-layer graphene sheet is experimentally analyzed. The few-layer graphene sheet is obtained through mechanical exfoliation from highly ordered pyrolytic graphite and embedded in a rectangular waveguide structure which is used to guide the exciting and the output signals. The nonlinear electromagnetic response of the graphene sheet is exploited to implement a frequency multiplier in which the output signal, in the 330-500 GHz frequency band, will be obtained as a high-order harmonic component of the input signal, in the 26-40 GHz frequency band. Due to the particular selection of the input and output frequency ranges, the behavior of several harmonic components, from order 9 to 17, can be characterized. The analysis will be focused on the frequency response of the graphene sheet, the influence of the input power on the output signal and the differences between the even- and odd-order harmonic components. Finally, it will be shown that the developed assembly can be used as THz signal source based on high-order frequency multiplication.

Hadarig, Andreea I.; Vázquez, Carlos; Fernández, Miguel; Ver Hoeye, Samuel; Hotopan, George R.; Camblor, René; Las Heras, Fernando

2015-01-01

111

Analysis of binning of normals for spherical harmonic cross-correlation

NASA Astrophysics Data System (ADS)

Spherical harmonic cross-correlation is a robust registration technique that uses the normals of two overlapping point clouds to bring them into coarse rotational alignment. This registration technique however has a high computational cost as spherical harmonics need to be calculated for every normal. By binning the normals, the computational efficiency is improved as the spherical harmonics can be pre-computed and cached at each bin location. In this paper we evaluate the efficiency and accuracy of the equiangle grid, icosahedron subdivision and the Fibonacci spiral, an approach we propose. It is found that the equiangle grid has the best efficiency as it can perform direct binning, followed by the Fibonacci spiral and then the icosahedron, all of which decrease the computational cost compared to no binning. The Fibonacci spiral produces the highest achieved accuracy of the three approaches while maintaining a low number of bins. The number of bins allowed by the equiangle grid and icosahedron are much more restrictive than the Fibonacci spiral. The performed analysis shows that the Fibonacci spiral can perform as well as the original cross-correlation algorithm without binning, while also providing a significant improvement in computational efficiency.

Larkins, Robert L.; Cree, Michael J.; Dorrington, Adrian A.

2012-03-01

112

Boston University Physics Easy Java Simulation: Uniform Circular Motion and Simple Harmonic Motion

NSDL National Science Digital Library

This interactive simulation offers a way for students to explore the connection between uniform circular motion and simple harmonic motion. The display shows two blocks on springs oscillating horizontally, and two balls traveling in uniform motion in a circular path. The user sets initial values for the blocks: amplitude, mass, and spring constant. The two balls are automatically set to the same values. Students are able to see that the circular motion of each ball corresponds to the motion of the blocks, thus promoting understanding of the basic equation for objects undergoing simple harmonic motion. To extend the learning, users can set values for the phase angles of each block. Also included by the author is a set of suggested activities to accompany the simulation. See Related Materials for an extensive online multimedia tutorial from PhysClips on the topic of simple harmonic motion. This applet was created with EJS, *Easy Java Simulations*, a modeling tool that allows users without formal programming experience to generate computer models and simulations.

2009-09-02

113

Harmonic Analysis and H2-Functions on Siegel Domains of Type II

It is known that the distinguished boundary of a Siegel domain of type II can be identified with a simply connected nilpotent Lie group of step two. The Plancherel formula for this group and the irreducible unitary representations which enter into that formula are determined. The H2-space of the domain and its Szegö kernel are characterized in terms of the harmonic analysis of the above group, in particular, the integral representations for H2-functions due to Gindikin and Korányi-Stein are shown to be instances of the Fourier inversion formula. PMID:16591961

Ogden, R. D.; Vági, S.

1972-01-01

114

Application of abstract harmonic analysis to the high-speed recognition of images

NASA Technical Reports Server (NTRS)

Methods are constructed for rapidly computing correlation functions using the theory of abstract harmonic analysis. The theory developed includes as a particular case the familiar Fourier transform method for a correlation function which makes it possible to find images which are independent of their translation in the plane. Two examples of the application of the general theory described are the search for images, independent of their rotation and scale, and the search for images which are independent of their translations and rotations in the plane.

Usikov, D. A.

1979-01-01

115

Multiple harmonic ULF waves in the plasma sheet boundary layer: Instability analysis

NASA Astrophysics Data System (ADS)

Multiple-harmonic electromagnetic waves in the ULF band have occasionally been observed in Earth's magnetosphere, both near the magnetic equator in the outer plasmasphere and in the plasma sheet boundary layer (PSBL) in Earth's magnetotail. Observations by the Cluster spacecraft of multiple-harmonic electromagnetic waves with fundamental frequency near the local proton cyclotron frequency, ?cp, were recently reported in the plasma sheet boundary layer by Broughton et al. (2008). A companion paper surveys the entire magnetotail passage of Cluster during 2003, and reports 35 such events, all in the PSBL, and all associated with elevated fluxes of counterstreaming ions and electrons. In this study we use observed pitch angle distributions of ions and electrons during a wave event observed by Cluster on 9 September 2003 to perform an instability analysis. We use a semiautomatic procedure for developing model distributions composed of bi-Maxwellian components that minimizes the difference between modeled and observed distribution functions. Analysis of wave instability using the WHAMP electromagnetic plasma wave dispersion code and these model distributions reveals an instability near ?cp and its harmonics. The observed and model ion distributions exhibit both beam-like and ring-like features which might lead to instability. Further instability analysis with simple beam-like and ring-like model distribution functions indicates that the instability is due to the ring-like feature. Our analysis indicates that this instability persists over an enormous range in the effective ion beta (based on a best fit for the observed distribution function using a single Maxwellian distribution), ?', but that the character of the instability changes with ?'. For ?' of order unity (for instance, the observed case with ?' ˜ 0.4), the instability is predominantly electromagnetic; the fluctuating magnetic field has components in both the perpendicular and parallel directions, but the perpendicular fluctuations are larger. If ?' is greatly decreased to about 5 × 10-4 (by increasing the magnetic field), the instability becomes electrostatic. On the other hand, if ?' is increased (by decreasing the magnetic field), the instability remains electromagnetic, but becomes predominantly compressional (magnetic fluctuations predominantly parallel) at ?' ˜ 2. The ?' dependence we observe here may connect various waves at harmonics of the proton gyrofrequency found in different regions of space.

Denton, R. E.; Engebretson, M. J.; Keiling, A.; Walsh, A. P.; Gary, S. P.; DéCréAu, P. M. E.; Cattell, C. A.; RèMe, H.

2010-12-01

116

Finite element method (FEM) is used for transient dynamic analysis of capacitive micromachined ultrasonic transducers (CMUT) and is particularly useful when the membranes are driven in the nonlinear regime. One major disadvantage of FEM is the excessive time required for simulation. Harmonic balance (HB) analysis, on the other hand, provides an accurate estimate of the steady-state response of nonlinear circuits very quickly. It is common to use Mason's equivalent circuit to model the mechanical section of CMUT. However, it is not appropriate to terminate Mason's mechanical LC section by a rigid piston's radiation impedance, especially for an immersed CMUT. We studied the membrane behavior using a transient FEM analysis and found out that for a wide range of harmonics around the series resonance, the membrane displacement can be modeled as a clamped radiator. We considered the root mean square of the velocity distribution on the membrane surface as the circuit variable rather than the average velocity. With this definition, the kinetic energy of the membrane mass is the same as that in the model. We derived the force and current equations for a clamped radiator and implemented them using a commercial HB simulator. We observed much better agreement between FEM and the proposed equivalent model, compared with the conventional model. PMID:20178910

Oguz, H Kagan; Olcum, Selim; Senlik, Muhammed N; Ta?, Vahdettin; Atalar, Abdullah; Köymen, Hayrettin

2010-01-01

117

Experiment Design and Analysis Guide - Neutronics & Physics

The purpose of this guide is to provide a consistent, standardized approach to performing neutronics/physics analysis for experiments inserted into the Advanced Test Reactor (ATR). This document provides neutronics/physics analysis guidance to support experiment design and analysis needs for experiments irradiated in the ATR. This guide addresses neutronics/physics analysis in support of experiment design, experiment safety, and experiment program objectives and goals. The intent of this guide is to provide a standardized approach for performing typical neutronics/physics analyses. Deviation from this guide is allowed provided that neutronics/physics analysis details are properly documented in an analysis report.

Misti A Lillo

2014-06-01

118

Texture analysis applied to second harmonic generation image data for ovarian cancer classification

NASA Astrophysics Data System (ADS)

Remodeling of the extracellular matrix has been implicated in ovarian cancer. To quantitate the remodeling, we implement a form of texture analysis to delineate the collagen fibrillar morphology observed in second harmonic generation microscopy images of human normal and high grade malignant ovarian tissues. In the learning stage, a dictionary of "textons"-frequently occurring texture features that are identified by measuring the image response to a filter bank of various shapes, sizes, and orientations-is created. By calculating a representative model based on the texton distribution for each tissue type using a training set of respective second harmonic generation images, we then perform classification between images of normal and high grade malignant ovarian tissues. By optimizing the number of textons and nearest neighbors, we achieved classification accuracy up to 97% based on the area under receiver operating characteristic curves (true positives versus false positives). The local analysis algorithm is a more general method to probe rapidly changing fibrillar morphologies than global analyses such as FFT. It is also more versatile than other texture approaches as the filter bank can be highly tailored to specific applications (e.g., different disease states) by creating customized libraries based on common image features.

Wen, Bruce L.; Brewer, Molly A.; Nadiarnykh, Oleg; Hocker, James; Singh, Vikas; Mackie, Thomas R.; Campagnola, Paul J.

2014-09-01

119

Three-dimensional analysis of harmonic generation in high-gain free-electron lasers

In a high-gain free-electron laser (FEL) employing a planar undulator, strong bunching at the fundamental wavelength can drive substantial bunching and power levels at the harmonic frequencies. In this paper we investigate the three-dimensional evolution of harmonic radiation based on the coupled Maxwell-Klimontovich equations that take into account nonlinear harmonic interactions. Each harmonic field is a sum of a linear amplification term and a term driven by nonlinear harmonic interactions. After a certain stage of exponential growth, the dominant nonlinear term is determined by interactions of the lower nonlinear harmonics and the fundamental radiation. As a result, the gain length, transverse profile, and temporal structure of the first few harmonics are eventually governed by those of the fundamental. Transversely coherent third-harmonic radiation power is found to approach 1% of the fundamental power level for current high-gain FEL projects. PMID:11102089

Huang; Kim

2000-11-01

120

Exact Analysis of the Adiabatic Invariants in Time-Dependent Harmonic Oscillator

The theory of adiabatic invariants has a long history and important applications in physics but is rarely rigorous. Here we treat exactly the general time-dependent 1-D harmonic oscillator, $\\ddot{q} + \\omega^2(t) q=0$ which cannot be solved in general. We follow the time-evolution of an initial ensemble of phase points with sharply defined energy $E_0$ and calculate rigorously the distribution of energy $E_1$ after time $T$, and all its moments, especially its average value $\\bar{E_1}$ and variance $\\mu^2$. Using our exact WKB-theory to all orders we get the exact result for the leading asymptotic behaviour of $\\mu^2$.

Marko Robnik; Valery G. Romanovski

2005-06-16

121

NASA Astrophysics Data System (ADS)

The homogeneous set of 80-year-long (1900-1979) International Latitude Service (ILS) polar motion data is analyzed using the autoregressive method (Chao and Gilbert, 1980) which resolves and produces estimates for the complex frequency (or frequency and Q) and complex amplitude (or amplitude and phase) of each harmonic component in the data. Principal conclusion of this analysis are that (1) the ILS data support the multiple-component hypothesis of the Chandler wobble (it is found that the Chandler wobble can be adequately modeled as a linear combination of four (coherent) harmonic components, each of which represents a steady, nearly circular, prograte motion, a behavior that is inconsistent with the hypothesis of a single Chandler period excited in a temporally and/or spatially random fashion). (2) the four-component Chandler wobble model ``explains'' the apparent phase reversal during 1920-1940 and the pre-1950 empirical period-amplitude relation, (3) the annual wobble is shown to be rather stationary over the years both in amplitude and in phase and no evidence is found to support the large variations reported by earlier investigations. (4) the Markowitz wobble is found to support the large variations reported by earlier investigations. (4) the Markowitz wobble is found to be marginally retrograde and appears to have a complicated behavior which cannot be resolved because of the shortness of the data set.

Fong Chao, B.

1983-12-01

122

NASA Astrophysics Data System (ADS)

Space manipulator is an important tool for spacecraft to complete a variety of tasks in space. Nowadays the harmonic drive is widely used as the reducer in the space manipulator, which may influence the dynamical properties of flexible space manipulator. The analysis of dynamic reliability and parameter sensitivity of space manipulator with harmonic drive is of significant importance for space manipulator designers in the early stage of design. The trajectory precision of the manipulator determines whether the mechanism performs normally. However, it is difficult to use the existing methods to resolve reliability apportionment issues because of the data insufficiency and the uncertainty of the relations among the components in the mechanical system. This paper establishes the dynamical models of space manipulator considering the harmonic hysteresis phenomenon derived from the harmonic reducer. A new method is proposed to analyze the dynamic reliability and parameter sensitivity of space manipulator with harmonic drive. The proposed method extends the previous response surface method (RSM) and focuses on the characteristics of the output dynamical property of the space manipulator. With the result of parameter sensitivity analysis, we can prolong the fine arm or shorten the main arm to improve the motion precision reliability of space manipulator. Therefore, our revised response surface method (RRSM) is suitable for reliability apportionment of the space manipulator when the design information has not been clearly identified, particularly in early design phrase.

Zhao, Jieliang; Yan, Shaoze; Wu, Jianing

2014-05-01

123

Advances in High-harmonic Fast Wave Physics in the National Spherical Torus Experiment

Improved core high-harmonic fast wave (HHFW) heating at longer wavelengths and during start-up and plasma current ramp-up, has now been obtained by lowering the edge density with lithium wall conditioning, thereby moving the critical density for perpendicular fast-wave propagation away from the vessel wall. Lithium conditioning allowed significant HHFW core electron heating of deuterium neutral beam injection (NBI) fuelled H-mode plasmas to be observed for the first time. Large edge localized modes were observed immediately after the termination of rf power. Visible and infrared camera images show that fast wave interactions can deposit considerable rf energy on the outboard divertor. HHFW-generated parametric decay instabilities were observed to heat ions in the plasma edge and may be the cause for a measured drag on edge toroidal rotation during HHFW heating. A significant enhancement in neutron rate and fast-ion profile were measured in NBI-fuelled plasmas when HHFW heating was applied. __________________________________________________

Taylor, G; Hosea, J C; LeBlanc, B P; Phillips, C K; Podesta, M; Valeo, E J; Wilson, J R; Ahn, J -W; Chen, G; Green, D L; Jaeger, E F; Maingi, R; Ryan, P M; Wilgen, J B; Heidbrink, W W; Liu, D; Bonoli, P T; Brecht, T; Choi, M

2009-12-01

124

Physics: A New Reactor Physics Analysis Toolkit

In the last year INL has internally pursued the development of a new reactor analysis tool: PHISICS. The software is built in a modular approach to simplify the independent development of modules by different teams and future maintenance. Most of the modules at the time of this summary are still under development (time dependent transport driver, depletion, cross section I/O and interpolation, generalized perturbation theory), while the transport solver INSTANT (Intelligent Nodal and Semi-structured Treatment for Advanced Neutron Transport) has already been widely used1, 2, 3, 4. For this reason we will focus mainly on the presentation of the transport solver INSTANT

C. Rabiti; Y. Wang; G. Palmiotti; H. Hiruta; J. Cogliati; A. Alfonsi

2011-06-01

125

Higher harmonic control analysis for vibration reduction of helicopter rotor systems

NASA Technical Reports Server (NTRS)

An advanced higher harmonic control (HHC) analysis has been developed and applied to investigate its effect on vibration reduction levels, blade and control system fatigue loads, rotor performance, and power requirements of servo-actuators. The analysis is based on a finite element method in space and time. A nonlinear time domain unsteady aerodynamic model, based on the indicial response formulation, is used to calculate the airloads. The rotor induced inflow is computed using a free wake model. The vehicle trim controls and blade steady responses are solved as one coupled solution using a modified Newton method. A linear frequency-domain quasi-steady transfer matrix is used to relate the harmonics of the vibratory hub loads to the harmonics of the HHC inputs. Optimal HHC is calculated from the minimization of the vibratory hub loads expressed in term of a quadratic performance index. Predicted vibratory hub shears are correlated with wind tunnel data. The fixed-gain HHC controller suppresses completely the vibratory hub shears for most of steady or quasi-steady flight conditions. HHC actuator amplitudes and power increase significantly at high forward speeds (above 100 knots). Due to the applied HHC, the blade torsional stresses and control loads are increased substantially. For flight conditions where the blades are stalled considerably, the HHC input-output model is quite nonlinear. For such cases, the adaptive-gain controller is effective in suppressing vibratory hub loads, even though HHC may actually increase stall areas on the rotor disk. The fixed-gain controller performs poorly for such flight conditions. Comparison study of different rotor systems indicates that a soft-inplane hingeless rotor requires less actuator power at high speeds (above 130 knots) than an articulated rotor, and a stiff-inplane hingeless rotor generally requires more actuator power than an articulated or a soft-inplane hingeless rotor. Parametric studies for a hingeless rotor operating in a transition flight regime and for an articulated rotor operating at the level-flight boundary (high speed and high thrust conditions) indicate that blade parameters including flap, lag, torsion stiffness distributions, linear pretwist, chordwise offset of center-of-mass from elastic axis and chordwise offset of elastic axis from aerodynamic center can be selected to minimize the actuator power requirements for HHC.

Nguyen, Khanh Q.

1994-01-01

126

NASA Astrophysics Data System (ADS)

In this paper a new electromagnetic (EM) interference analysis is proposed using the total harmonic distortion (THD) measurement of the audio signal by the 900MHz cordless telephones. The cordless telephone network in 900MHz was built up to be weak in EM interference. 400 and 800Hz of the sine-wave signal were used in transmitter (TX) system, and the receiver (RX) system was exposed to the EM interference. The THD value varies as the level of the exposed EM interference changes. The model of the cordless telephone also affects the THD value. By using fluctuation of the THD value depending on the amount of the exposure, the threshold value of the interference electric field strength was derived. Based on the derived threshold value of the electric field strength, validity of the regulation value for low power radio devices by CISPR 22 [CLASS B] and FCC is discussed.

Park, Jeung Geun; Kim, Che Young

127

Harmonic operation of STW filters

The physical mechanism causing the propagation loss of surface transverse wave (STW) devices during harmonic operation is modeled and analyzed. It is found that as the mode frequency is pushed beyond the fundamental, the dominant Bloch component of the STW solution passes through the higher spatial harmonics. In these frequency regions, the lower harmonic components which contribute (perhaps weakly) to

R. L. Baer; C. A. FLory

1988-01-01

128

Second harmonic generation microscopy for quantitative analysis of collagen fibrillar structure

Second-harmonic generation (SHG) microscopy has emerged as a powerful modality for imaging fibrillar collagen in a diverse range of tissues. Because of its underlying physical origin, it is highly sensitive to the collagen fibril/fiber structure, and, importantly, to changes that occur in diseases such as cancer, fibrosis and connective tissue disorders. We discuss how SHG can be used to obtain more structural information on the assembly of collagen in tissues than is possible by other microscopy techniques. We first provide an overview of the state of the art and the physical background of SHG microscopy, and then describe the optical modifications that need to be made to a laser-scanning microscope to enable the measurements. Crucial aspects for biomedical applications are the capabilities and limitations of the different experimental configurations. We estimate that the setup and calibration of the SHG instrument from its component parts will require 2–4 weeks, depending on the level of the user’s experience. PMID:22402635

Chen, Xiyi; Nadiarynkh, Oleg; Plotnikov, Sergey; Campagnola, Paul J

2013-01-01

129

Physics of Baseball Bats - An Analysis

An analysis of the physics of baseball bats is presented in this study. The analysis compares the performance of aluminum and wooden baseball bats. Novel experimental approaches to indirectly quantify the performance of these bats have been implemented. The analysis also considers various aspects of baseball including the physical dimensions of the baseball fields, ball exit speed ratio, moment of

N. M. Ravindra; Sushil K. Sikh; Ivan Padron

2009-01-01

130

We present a straightforward and robust algorithm for periodicity detection, working in the lag (autocorrelation) domain. When it is tested for periodic signals and for signals with additive noise or jitter, it proves to be several orders of magnitude more accurate than the methods commonly used for speech analysis. This makes our method capable of measuring harmonics-to-noise ratios in the

Paul Boersma

1993-01-01

131

The aim of the study was to reveal the mastication forces effect on the microstructure of mandible bone tissue of mini-pigs by Fouirier harmonic imaging analysis of bone sections images of back scattered electrons and assessment of calcium and phosphorous distribution maps obtained by roentgenofluorescence technique. The results showed that by higher functional loads not only the total content of mineral elements in the bone matrix increased but also the of the low-frequency harmonics in the image spectrum indicating structural heterogeneity decrease in bone mineralization. PMID:25588332

Guseva, I E; Zhitkov, M Iu; Loginova, N K; Mokhov, A V

2014-01-01

132

NASA Astrophysics Data System (ADS)

We have used a mobile phone acceleration sensor, and the Accelerometer Monitor application for Android, to collect data in physics experiments on free and damped oscillations. Results for the period, frequency, spring constant, and damping constant agree very well with measurements obtained by other methods. These widely available sensors are likely to find increased use in instructional laboratories.

Carlos Castro-Palacio, Juan; Velázquez-Abad, Luisberis; Giménez, Marcos H.; Monsoriu, Juan A.

2013-06-01

133

biologically rele- vant reactions, namely, L- to D-alanine amino acid inversion and alcohol acylation by amidesTHE JOURNAL OF CHEMICAL PHYSICS 139, 165104 (2013) Exploring chemical reaction mechanisms through Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology

2013-01-01

134

Teaching Harmonic Motion in Trigonometry: Inductive Inquiry Supported by Physics Simulations

ERIC Educational Resources Information Center

In this article, the authors present a lesson whose goal is to utilise a scientific environment to immerse a trigonometry student in the process of mathematical modelling. The scientific environment utilised during this activity is a physics simulation called "Wave on a String" created by the PhET Interactive Simulations Project at Colorado…

Sokolowski, Andrzej; Rackley, Robin

2011-01-01

135

Recent Developments in High-Harmonic Fast Wave Physics in NSTX

Understanding the interaction between ion cyclotron range of frequency (ICRF) fast waves and the fast-ions created by neutral beam injection (NBI) is critical for future devices such as ITER, which rely on a combination ICRF and NBI. Experiments in NSTX which use 30 MHz High-Harmonic Fast-Wave (HHFW) ICRF and NBI heating show a competition between electron heating via Landau damping and transit-time magnetic pumping, and radio-frequency wave acceleration of NBI generated fast ions. Understanding and mitigating some of the power loss mechanisms outside the last closed flux surface (LCFS) has resulted in improved HHFW heating inside the LCFS. Nevertheless a significant fraction of the HHFW power is diverted away from the enclosed plasma. Part of this power is observed locally on the divertor. Experimental observations point toward the radio-frequency (RF) excitation of surface waves, which disperse wave power outside the LCFS, as a leading loss mechanism. Lithium coatings lower the density at the antenna, thereby moving the critical density for perpendicular fast-wave propagation away from the antenna and surrounding material surfaces. Visible and infrared imaging reveal flows of RF power along open field lines into the divertor region. In L-mode -- low average NBI power -- conditions, the fast-ion D-alpha (FIDA) diagnostic measures a near doubling and broadening of the density profile of the upper energetic level of the fast ions concurrent with the presence of HHFW power launched with k// =-8m-1. We are able to heat NBI-induced H-mode plasmas with HHFW. The captured power is expected to be split between absorption by the electrons and absorption by the fast ions, based on TORIC calculation. In the case discussed here the Te increases over the whole profile when ~2MW of HHFW power with antenna k// =13m-1 is applied after the H-mode transition.. But somewhat unexpectedly fast-ion diagnostics do not observe a change between the HHFW heated NBI discharge and the reference NBI only plasma, although an increase in neutron production is measured. __________________________________________________

B.P. LeBlanc, R.E. Bell, P. Bonoli, R. Harvey, W.W. Heidbrink, J.C. Hosea, S.M. Kaye, D. Liu, R. Maingi, S.S. Medley, M. Ono, M. Podestà, C.K. Phillips, P.M. Ryan, A.L. Roquemore, G. Taylor, J.R. Wilson and the NSTX Team

2010-10-06

136

A harmonic analysis method was used to determine vertical hydraulic conductivities (Kv) in geologic media between vertically separated piezometers using water level measurements. In this method, each water level time series was filtered and then decomposed using harmonic analysis into a sum of trigonometric components. The phase and amplitude of each harmonic function were calculated. These data were used to estimate Kv values between vertically separated data sets assuming one-dimensional transient flow. The method was applied to water level data collected from nested piezometers at two thick clay-rich till aquitards in Saskatchewan, Canada. At one site, routine water levels were measured in 12 piezometers (installed between 1 and 29 m below ground surface) since installation (1995). At the other site, water levels were measured in seven piezometers (installed between 4 and 53 m below ground surface) since installation (1998-1999). The Kv calculated using harmonic analysis decreased with depth below the water table at both sites, approaching matrix estimates of hydraulic conductivity between 10 and 11 m and between 21 and 43 m below ground surface. These depths reflected the depth of extensive vertical fracturing at the sites and showed that the depth of fracturing may be site specific. PMID:12873014

Boldt-Leppin, Brigitte E J; Hendry, M Jim

2003-01-01

137

NASA Astrophysics Data System (ADS)

Osteoarthritis is one of the most prevalent joint diseases in the world. Although the cause of osteoarthritis is not exactly clear, the disease results in a degradation of the quality of the articular cartilage including collagen and other extracellular matrix components. We have investigated alterations in the structure of collagen fibers in the cartilage tissue of the human knee using mulitphoton microscopy. Due to inherent high nonlinear susceptibility, ordered collagen fibers present in the cartilage tissue matrix produces strong second harmonic generation (SHG) signals. Significant morphological differences are found in different Osteoarthritic grades of cartilage by SHG microscopy. Based on the polarization analysis of the SHG signal, we find that a few locations of hyaline cartilage (mainly type II collagen) is being replaced by fibrocartilage (mainly type I cartilage), in agreement with earlier literature. To locate the different types and quantify the alteration in the structure of collagen fiber, we employ polarization-SHG microscopic analysis, also referred to as _-tensor imaging. The image analysis of p-SHG image obtained by excitation polarization measurements would represent different tissue constituents with different numerical values at pixel level resolution.

Kumar, Rajesh; Grønhaug, Kirsten M.; Romijn, Elisabeth I.; Drogset, Jon O.; Lilledahl, Magnus B.

2014-05-01

138

On the use of windows for harmonic analysis with the discrete Fourier transform

This paper makes available a concise review of data windows and their affect on the detection of harmonic signals in the presence of broad-band noise, and in the presence of nearby strong harmonic interference. We also call attention to a number of common errors in the application of windows when used with the fast Fourier transform. This paper includes a

FREDRIC J. HARRIS

1978-01-01

139

Nonlinear constant evaluation in a piezoelectric rod from analysis of second harmonic generation

The design of transducers requires a clear understanding of their electromechanical behavior. This involves precise linear modeling as well as characterization. With the development of novel techniques such as harmonic imaging as well as high-power applications, nonlinear aspects must also be taken into account. In this study, harmonic generation in the mechanical displacement of a piezoceramic rod under high sinusoidal

D. Parenthoine; L. Haumesser; F. Meulen; M. Lethiecq; L.-P. Tran-Huu-Hue

2009-01-01

140

Analysis and control of harmonic radiation from active integrated oscillator antennas

Harmonic radiation from microstrip patch oscillators is examined experimentally and theoretically using both a single and dual parallel-tuned circuit Van der Pol oscillator model. Closed-form expressions are obtained for the fundamental and first harmonic voltage amplitudes, and results show reasonably good agreement with a commercial circuit simulator. Such expressions will be useful for designers of active integrated antennas, giving them

Martin J. Cryan; G. R. Buesnel; Peter S. Hall

2002-01-01

141

ERIC Educational Resources Information Center

The dynamical behaviour of simple harmonic motion can be found in numerous natural phenomena. Within the quantum realm of atomic, molecular and optical systems, two main features are associated with harmonic oscillations: a finite ground-state energy and equally spaced quantum energy levels. Here it is shown that there is in fact a one-to-one…

Andrews, David L.; Romero, Luciana C. Davila

2009-01-01

142

Spherical harmonic analysis of the sound radiation from omnidirectional loudspeaker arrays

NASA Astrophysics Data System (ADS)

Omnidirectional sound sources are widely used in room acoustics. These devices are made up of loudspeakers mounted on a spherical or polyhedral cabinet, where the dodecahedral shape prevails. Although such electroacoustic sources have been made readily available to acousticians by many manufacturers, an in-depth investigation of their vibroacoustic behavior has not been provided yet. In order to fulfill this lack, this paper presents a theoretical study of the sound radiation from omnidirectional loudspeaker arrays, which is carried out by using a mathematical model based on the spherical harmonic analysis. Eight different loudspeaker arrangements on the sphere are considered: the well-known five Platonic solid layouts and three extremal system layouts. The latter possess useful properties for spherical loudspeaker arrays used as directivity controlled sound sources, so that these layouts are included here in order to investigate whether or not they could be of interest as omnidirectional sources as well. It is shown through a comparative analysis that the dodecahedral array leads to the lowest error in producing an omnidirectional sound field and to the highest acoustic power, which corroborates the prevalence of such a layout. In addition, if a source with less than 12 loudspeakers is required, it is shown that tetrahedra or hexahedra can be used alternatively, whereas the extremal system layouts are not interesting choices for omnidirectional loudspeaker arrays.

Pasqual, A. M.

2014-09-01

143

Analysis of Second Harmonic Generation of a KDP crystal based on multi-scale topography simulation

NASA Astrophysics Data System (ADS)

The surface topography of the supporting frame of a KDP crystal is studied, as well as its influence on the deformation and stress of the KDP crystal, together with the Second Harmonic Generation (SHG). A comprehensive model incorporating principles of multi-scale surface analysis, mechanics, and optics is proposed, and it is applied to investigate the surface topography of the supporting frame, the deformation and stress of the KDP crystal, as well as the SHG efficiency. The surface topography is analyzed using fractural theory, and then classified according to its multi-scale specifics. Based on the surface analysis results, the mounting configuration of the KDP crystal is modeled and analyzed in global and local modes, respectively, using the Finite Element Method (FEM). Moreover, deformation and stress of the KDP crystal that is induced by the mechanical mounting is studied using the FEM, together with the effects of the surface topography on them. Furthermore, the change of the refractive index that induced by the deformation and stress are calculated, respectively, the results of which is applied to studied the phase mismatch, and the SHG efficiency considering the phase mismatch is eventually obtained. The numerical results demonstrate that the frame surface with multi-scale dimensions has diverse influences on the distortion and stress, as well as the SHG efficiency.

Liu, Hai Tao; Su, Rui Feng; Sun, Ya Zhou; Wang, He Ran

2015-04-01

144

Harmonic and anharmonic analysis of the IR and Raman spectrum of macrocyclic dioxopolyamine

NASA Astrophysics Data System (ADS)

A detailed analysis of the vibrational spectra of 8,8a,9,10,11,12,12a,13-octahydrodibenzo[b,h][1,4,7,10] dioxadiazacyclododecine-7,14 (6H,15H)-dione has been conducted in harmonic and anharmonic approximation. B3LYP and B3LYP-D3 functionals and 6-31G(d), 6-31+G(d,p) and TZVP basis set were employed. The calculated frequencies were compared with experimental fundamentals and the error distribution was analysis by Root Mean Square Deviation (RMSD). When a relatively large basis set (6-31+G(d,p)) is adopted, anharmonic approximation presents a overall advantage than empirical scaling factor method, when a medium basis set (6-31G(d)) is adopted, empirical scaling factor method provides a better accuracy than anharmonic approximation, except for ?(CH2) and ?(CH) mode. Anharmonic approximation cannot reduce the large errors of ?(Nsbnd H), ?(Nsbnd H) and ?(Cdbnd O) modes. The bimolecular model reveals that these errors mainly arise from intermolecular hydrogen bonds. Van der Waals correction on DFT makes a significant improvement on prediction of ?(CH2) and ?(CH) modes but a negligible change on the other modes.

Wang, Yujiao; Xie, Xiaomei; Lu, Huijuan; Chen, Feifei; Liu, Huihong; Li, Wei

2014-09-01

145

Harmonic analysis for the characterization and correction of geometric distortion in MRI

Purpose: Magnetic resonance imaging (MRI) is gaining widespread use in radiation therapy planning, patient setup verification, and real-time guidance of radiation delivery. Successful implementation of these technologies relies on the development of simple and efficient methods to characterize and monitor the geometric distortions arising due to system imperfections and gradient nonlinearities. To this end, the authors present the theory and validation of a novel harmonic approach to the quantification of system-related distortions in MRI. Methods: The theory of spatial encoding in MRI is applied to demonstrate that the 3D distortion vector field (DVF) is given by the solution of a second-order boundary value problem (BVP). This BVP is comprised of Laplace’s equation and a limited measurement of the distortion on the boundary of a specified region of interest (ROI). An analytical series expansion solving this BVP within a spherical ROI is obtained, and a statistical uncertainty analysis is performed to determine how random errors in the boundary measurements propagate to the ROI interior. This series expansion is then evaluated to obtain volumetric DVF mappings that are compared to reference data obtained on a 3 T full-body scanner. This validation is performed within two spheres of 20 cm diameter (one centered at the scanner origin and the other offset +3 cm along each of the transverse directions). Initially, a high-order mapping requiring measurements at 5810 boundary points is used. Then, after exploring the impact of the boundary sampling density and the effect of series truncation, a reduced-order mapping requiring measurements at 302 boundary points is evaluated. Results: The volumetric DVF mappings obtained from the harmonic analysis are in good agreement with the reference data. Following distortion correction using the high-order mapping, the authors estimate a reduction in the mean distortion magnitude from 0.86 to 0.42 mm and from 0.93 to 0.39 mm within the central and offset ROIs, respectively. In addition, the fraction of points with a distortion magnitude greater than 1 mm is reduced from 35.6% to 2.8% and from 40.4% to 1.5%, respectively. Similarly, following correction using the reduced-order mapping, the mean distortion magnitude reduces to 0.45–0.42 mm within the central and offset ROIs, and the fraction of points with a distortion magnitude greater than 1 mm is reduced to 2.8% and 1.5%, respectively. Conclusions: A novel harmonic approach to the characterization of system-related distortions in MRI is presented. This method permits a complete and accurate mapping of the DVF within a specified ROI using a limited measurement of the distortion on the ROI boundary. This technique eliminates the requirement to exhaustively sample the DVF at a dense 3D array of points, thereby permitting the design of simple, inexpensive phantoms that may incorporate additional modules for auxiliary quality assurance objectives.

Tadic, Tony, E-mail: ttadic@gmail.com; Stanescu, Teodor [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto M5S 3E2 (Canada); Jaffray, David A. [Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto M5G 2M9 (Canada); Department of Radiation Oncology, University of Toronto, Toronto M5S 3E2 (Canada); Department of Medical Biophysics, University of Toronto, Toronto M5G 1L7 (Canada)

2014-11-01

146

RUSHMAPS: Real-Time Uploadable Spherical Harmonic Moment Analysis for Particle Spectrometers

NASA Technical Reports Server (NTRS)

RUSHMAPS is a new onboard data reduction scheme that gives real-time access to key science parameters (e.g. moments) of a class of heliophysics science and/or solar system exploration investigation that includes plasma particle spectrometers (PPS), but requires moments reporting (density, bulk-velocity, temperature, pressure, etc.) of higher-level quality, and tolerates a lowpass (variable quality) spectral representation of the corresponding particle velocity distributions, such that telemetry use is minimized. The proposed methodology trades access to the full-resolution velocity distribution data, saving on telemetry, for real-time access to both the moments and an adjustable-quality (increasing quality increases volume) spectral representation of distribution functions. Traditional onboard data storage and downlink bandwidth constraints severely limit PPS system functionality and drive cost, which, as a consequence, drives a limited data collection and lower angular energy and time resolution. This prototypical system exploit, using high-performance processing technology at GSFC (Goddard Space Flight Center), uses a SpaceCube and/or Maestro-type platform for processing. These processing platforms are currently being used on the International Space Station as a technology demonstration, and work is currently ongoing in a new onboard computation system for the Earth Science missions, but they have never been implemented in heliospheric science or solar system exploration missions. Preliminary analysis confirms that the targeted processor platforms possess the processing resources required for realtime application of these algorithms to the spectrometer data. SpaceCube platforms demonstrate that the target architecture possesses the sort of compact, low-mass/power, radiation-tolerant characteristics needed for flight. These high-performing hybrid systems embed unprecedented amounts of onboard processing power in the CPU (central processing unit), FPGAs (field programmable gate arrays), and DSP (digital signal processing) elements. The fundamental computational algorithm de constructs 3D velocity distributions in terms of spherical harmonic spectral coefficients (which are analogous to a Fourier sine-cosine decomposition), but uses instead spherical harmonics Legendre polynomial orthogonal functions as a basis for the expansion, portraying each 2D angular distribution at every energy or, geometrically, spherical speed-shell swept by the particle spectrometer. Optionally, these spherical harmonic spectral coefficients may be telemetered to the ground. These will provide a smoothed description of the velocity distribution function whose quality will depend on the number of coefficients determined. Successfully implemented on the GSFC-developed processor, the capability to integrate the proposed methodology with both heritage and anticipated future plasma particle spectrometer designs is demonstrated (with sufficiently detailed design analysis to advance TRL) to show specific science relevancy with future HSD (Heliophysics Science Division) solar-interplanetary, planetary missions, sounding rockets and/or CubeSat missions.

Figueroa-Vinas, Adolfo

2013-01-01

147

Non-Characteristic Harmonics Analysis of the ITER Pulsed Power Supply

NASA Astrophysics Data System (ADS)

The ITER pulsed power supply system will be operated in non-ideal conditions including an asymmetric firing angle, an unbalanced AC supply and an unbalanced AC side impedance of the transformer. In this study the switching functions approach is used to calculate non-characteristic harmonics in ITER, possibly caused by an AC-DC convertor in non-ideal conditions. A PSCAD simulation model is set up to study the non-characteristic harmonics in those non-ideal conditions. It is found that the non-characteristic harmonic does appear and the simulation result is in accordance with the calculating strategy.

Yang, Wei; Xu, Liuwei; Fu, Peng; Lu, Huawei; Sheng, Zhicai

2009-08-01

148

Chronological skin aging is associated with flattening of the dermal-epidermal junction (DEJ), but to date no quantitative analysis focusing on the aging changes in the dermal papillae (DP) has been performed. The aim of the study is to determine the architectural changes and the collagen density related to chronological aging in the dermal papilla zone (DPZ) by in vivo harmonic generation microscopy (HGM) with a sub-femtoliter spatial resolution. We recruited 48 Asian subjects and obtained in vivo images on the sun-protected volar forearm. Six parameters were defined to quantify 3D morphological changes of the DPZ, which we analyzed both manually and computationally to study their correlation with age. The depth of DPZ, the average height of isolated DP, and the 3D interdigitation index decreased with age, while DP number density, DP volume, and the collagen density in DP remained constant over time. In vivo high-resolution HGM technology has uncovered chronological aging-related variations in DP, and sheds light on real-time quantitative skin fragility assessment and disease diagnostics based on collagen density and morphology. PMID:25401037

Liao, Yi-Hua; Kuo, Wei-Cheng; Chou, Sin-Yo; Tsai, Cheng-Shiun; Lin, Guan-Liang; Tsai, Ming-Rung; Shih, Yuan-Ta; Lee, Gwo-Giun; Sun, Chi-Kuang

2014-01-01

149

Chronological skin aging is associated with flattening of the dermal-epidermal junction (DEJ), but to date no quantitative analysis focusing on the aging changes in the dermal papillae (DP) has been performed. The aim of the study is to determine the architectural changes and the collagen density related to chronological aging in the dermal papilla zone (DPZ) by in vivo harmonic generation microscopy (HGM) with a sub-femtoliter spatial resolution. We recruited 48 Asian subjects and obtained in vivo images on the sun-protected volar forearm. Six parameters were defined to quantify 3D morphological changes of the DPZ, which we analyzed both manually and computationally to study their correlation with age. The depth of DPZ, the average height of isolated DP, and the 3D interdigitation index decreased with age, while DP number density, DP volume, and the collagen density in DP remained constant over time. In vivo high-resolution HGM technology has uncovered chronological aging-related variations in DP, and sheds light on real-time quantitative skin fragility assessment and disease diagnostics based on collagen density and morphology. PMID:25401037

Liao, Yi-Hua; Kuo, Wei-Cheng; Chou, Sin-Yo; Tsai, Cheng-Shiun; Lin, Guan-Liang; Tsai, Ming-Rung; Shih, Yuan-Ta; Lee, Gwo-Giun; Sun, Chi-Kuang

2014-09-01

150

NASA Astrophysics Data System (ADS)

Finding the consequences of symmetry for open-system quantum dynamics is a problem with broad applications, including describing thermal relaxation, deriving quantum limits on the performance of amplifiers, and exploring quantum metrology in the presence of noise. The symmetry of the dynamics may reflect a symmetry of the fundamental laws of nature or a symmetry of a low-energy effective theory, or it may describe a practical restriction such as the lack of a reference frame. In this paper, we apply some tools of harmonic analysis together with ideas from quantum information theory to this problem. The central idea is to study the decomposition of quantum operations—in particular, states, measurements, and channels—into different modes, which we call modes of asymmetry. Under symmetric processing, a given mode of the input is mapped to the corresponding mode of the output, implying that one can only generate a given output if the input contains all of the necessary modes. By defining monotones that quantify the asymmetry in a particular mode, we also derive quantitative constraints on the resources of asymmetry that are required to simulate a given asymmetric operation. We present applications of our results for deriving bounds on the probability of success in nondeterministic state transitions, such as quantum amplification, and a simplified formalism for studying the degradation of quantum reference frames.

Marvian, Iman; Spekkens, Robert W.

2014-12-01

151

This paper discusses the problems caused by zero sequence harmonic currents in neutral conductors of single phase circuits in commercial and industrial facilities. Common solutions to these problems are discussed for three distribution methods and shortcomings noted. A zero sequence harmonic filter, based on zig-zag grounding transformer principles, is described. Three case studies using zig-zag filter techniques are reviewed and cautions regarding their use are noted.

Newcombe, C.B. [Fluke Corp., Everett, WA (United States); Ferguson, G.N.C. [FES Power Systems, Inc., St. Petersburg, FL (United States)

1995-06-01

152

Formal journal article Experimental analysis of a piezoelectric energy harvesting system for harmonic, random, and sine on random vibration Abstract: Harvesting power with a piezoelectric vibration powered generator using a full-wave rectifier conditioning circuit is experimentally compared for varying sinusoidal, random and sine on random (SOR) input vibration scenarios. Additionally, the implications of source vibration characteristics on harvester design are discussed. Studies in vibration harvesting have yielded numerous alternatives for harvesting electrical energy from vibrations but piezoceramics arose as the most compact, energy dense means of energy transduction. The rise in popularity of harvesting energy from ambient vibrations has made piezoelectric generators commercially available. Much of the available literature focuses on maximizing harvested power through nonlinear processing circuits that require accurate knowledge of generator internal mechanical and electrical characteristics and idealization of the input vibration source, which cannot be assumed in general application. In this manuscript, variations in source vibration and load resistance are explored for a commercially available piezoelectric generator. We characterize the source vibration by its acceleration response for repeatability and transcription to general application. The results agree with numerical and theoretical predictions for in previous literature that load optimal resistance varies with transducer natural frequency and source type, and the findings demonstrate that significant gains are seen with lower tuned transducer natural frequencies for similar source amplitudes. Going beyond idealized steady state sinusoidal and simplified random vibration input, SOR testing allows for more accurate representation of real world ambient vibration. It is shown that characteristic interactions from more complex vibrational sources significantly alter power generation and power processing requirements by increasing harvested power, shifting optimal conditioning impedance, inducing significant voltage supply fluctuations and ultimately rendering idealized sinusoidal and random analyses insufficient.

Cryns, Jackson W.; Hatchell, Brian K.; Santiago-Rojas, Emiliano; Silvers, Kurt L.

2013-07-01

153

Advanced Analysis Methods in High Energy Physics

During the coming decade, high energy physics experiments at the Fermilab Tevatron and around the globe will use very sophisticated equipment to record unprecedented amounts of data in the hope of making major discoveries that may unravel some of Nature's deepest mysteries. The discovery of the Higgs boson and signals of new physics may be around the corner. The use of advanced analysis techniques will be crucial in achieving these goals. The author discusses some of the novel methods of analysis that could prove to be particularly valuable for finding evidence of any new physics, for improving precision measurements and for exploring parameter spaces of theoretical models.

Pushpalatha C. Bhat

2001-10-03

154

The dynamics of wind turbine planetary gears with gravity effects are investigated using an extended harmonic balance method that extends established harmonic balance formulations to include simultaneous internal and external excitations. The extended harmonic balance method with arc-length continuation and Floquet theory is applied to a lumped-parameter planetary gear model including gravity, fluctuating mesh stiffness, bearing clearance, and nonlinear tooth contact to obtain the planetary gear dynamic response. The calculated responses compare well with time domain integrated mathematical models and experimental results. Gravity is a fundamental vibration source in wind turbine planetary gears and plays an important role in system dynamics, causing hardening effects induced by tooth wedging and bearing-raceway contacts. Bearing clearance significantly reduces the lowest resonant frequencies of translational modes. Gravity and bearing clearance together lowers the speed at which tooth wedging occurs lower than the resonant frequency.

Guo, Y.; Keller, J.; Parker, R. G.

2012-06-01

155

Multielectron Correlation in High-Harmonic Generation: A 2D Model Analysis

We analyze the role of multielectron dynamics in high-harmonic generation spectroscopy, using an example of a two-electron system. We identify and systematically quantify the importance of correlation and exchange effects. One of the main sources for correlation is identified to be the polarization of the ion by the recombining continuum electron. This effect, which plays an important qualitative and quantitative role, seriously undermines the validity of the standard approaches to high-harmonic generation, which ignore the contribution of excited ionic states to the radiative recombination of the continuum electron.

Sukiasyan, Suren [Physics Department and Center for Research in Photonics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5 (Canada); National Research Council, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); McDonald, Chris; Destefani, Carlos; Brabec, Thomas [Physics Department and Center for Research in Photonics, University of Ottawa, 150 Louis Pasteur, Ottawa, Ontario K1N 6N5 (Canada); Ivanov, Misha Yu. [National Research Council, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada)

2009-06-05

156

Cosmic physics data analysis program

NASA Technical Reports Server (NTRS)

A data analysis program was carried out to investigate the intensity, propagation, and origin of primary Cosmic Ray Galactic electrons. Scanning was carried out on two new balloon flight experiments as well as the border area of previous experiments. The identification and evaluation of the energies of the primary electrons were carried out. A new analysis of these data were incorporated into an overall evaluation of the roll of electrons in the problem of the origin of cosmic rays. Recent measurements indicate that the earth may be within the expanding Geminga supernova shock wave which is expected to have a major effect upon the propagation and the energy spectrum of galactic electrons. Calculations with the Geminga model indicate that the cut-off energy may be very close to the observed highest energy electrons in our analysis.

Wilkes, R. Jeffrey

1993-01-01

157

Digital Movement Analysis in Physical Education

ERIC Educational Resources Information Center

Mobile devices such as smartphones and tablets offer applications (apps) that make digital movement analysis simple and efficient in physical education. Highly sophisticated movement analysis software has been available for many years but has mainly appealed to coaches of elite athletes and biomechanists. Apps on mobile devices are less expensive…

Trout, Josh

2013-01-01

158

Physical basis of critical analysis

NASA Astrophysics Data System (ADS)

A new approach to provide a fruitful analysis of signal amplitude is proposed. It is this method that has made it possible to eliminate some observed artificial events from the list of candidates for decays of superheavy nuclei. Examples of estimates of measured amplitudes of evaporation residues (EVR) are presented. Some attention is paid to a new "hard" statistical criterion for detecting rare events.

Tsyganov, Yu. S.

2014-11-01

159

IEEE TRANSACTIONS ON AUDIO, SPEECH, AND LANGUAGE PROCESSING 1 Harmonic Adaptive Latent Component of automatic music transcription. However those tech- niques are not necessarily suitable for notes having converging towards a meaningful solution. We applied this model for automatic music transcription: the onset

Richard, Gaël

160

IEEE TRANSACTIONS ON AUDIO, SPEECH, AND LANGUAGE PROCESSING 1 Harmonic Adaptive Latent Component the problem of automatic music transcription. However those tech- niques are not necessarily suitable algorithm converging towards a meaningful solution. We applied this model for automatic music transcription

Badeau, Roland

161

Theoretical analysis on the penetration of power line harmonic radiation into the ionosphere

Radiation at the fundamental and higher harmonic frequencies from power lines affects the environment of Earth's ionosphere and magnetosphere, because such radiation may lead to the enhanced electron precipitation into the ionosphere due to wave-particle interactions in the magnetosphere. In this paper we analyze theoretically the penetration of power line radiation, taking into account the presence of the anisotropic, homogeneous

Yoshiaki Ando; Masashi Hayakawa; Oleg A. Molchanov

2002-01-01

162

A high efficiency harmonic engine based on a resonantly reciprocating piston expander that extracts work from heat and pressurizes working fluid in a reciprocating piston compressor. The engine preferably includes harmonic oscillator valves capable of oscillating at a resonant frequency for controlling the flow of working fluid into and out of the expander, and also preferably includes a shunt line

Charles L

2009-01-01

163

, an atom, a molecule, a biological object such as a receptor cluster, a cell, or even an animal and photosynthesis. Funneling phenomena attract excitations in photosynthetic antennae and molecular crystals and aggre- gates. Particle diffusion in a harmonic field occurs also in biophysical studies on DNA

Kenkre, V.M.

2013-01-01

164

NASA Astrophysics Data System (ADS)

Periodical loads, such as waves and rotating machinery, form a problem for operational modal analysis (OMA). In OMA only the vibrations of a structure of interest are measured and little to nothing is known about the loads causing these vibrations. Therefore, it is often assumed that all dynamics in the measured data are linked to the system of interest. Periodical loads defy this assumption as their periodical behavior is often visible within the measured vibrations. As a consequence most OMA techniques falsely associate the dynamics of the periodical load with the system of interest. Without additional information about the load, one is not able to correctly differentiate between structural dynamics and the dynamics of the load. In several applications, e.g. turbines and helicopters, it was observed that because of periodical loads one was unable to correctly identify one or multiple modes. Transmissibility based OMA (TOMA) is a completely different approach to OMA. By using transmissibility functions to estimate the structural dynamics of the system of interest, all influence of the load-spectrum can be eliminated. TOMA therefore allows to identify the modal parameters without being influenced by the presence of periodical loads, such as harmonics. One of the difficulties of TOMA is that the analyst is required to find two independent datasets, each associated with a different loading condition of the system of interest. This poses a dilemma for TOMA; how can an analyst identify two different loading conditions when little is known about the loads on the system? This paper tackles that problem by assuming that the loading conditions vary continuously over time, e.g. the changing wind directions. From this assumption TOMA is developed into a time-varying framework. This development allows TOMA to not only cope with the continuously changing loading conditions. The time-varying framework also enables the identification of the modal parameters from a single dataset. Moreover, the time-varying TOMA approach can be implemented in such a way that the analyst no longer has to identify different loading conditions. For these combined reasons the time-varying TOMA is less dependent on the user and requires less testing time than the earlier TOMA-technique.

Weijtjens, Wout; Lataire, John; Devriendt, Christof; Guillaume, Patrick

2014-12-01

165

NASA Astrophysics Data System (ADS)

Simultaneous tones that are harmonically related tend to be grouped perceptually to form a unitary auditory image. A partial that is mistuned stands out from the other tones, and harmonic complexes with different fundamental frequencies can readily be perceived as separate auditory objects. These phenomena are evidence for the strong role of harmonicity in perceptual grouping and segregation of sounds. This study measured the discriminability of harmonicity directly. In a two interval, two alternative forced-choice (2I2AFC) paradigm, the listener chose which of two sounds, signal or foil, was composed of tones that more closely matched an exact harmonic relationship. In one experiment, the signal was varied from perfectly harmonic to highly inharmonic by adding frequency perturbation to each component. The foil always had 100% perturbation. Group mean performance decreased from greater than 90% correct for 0% signal perturbation to near chance for 80% signal perturbation. In the second experiment, adding a masker presented simultaneously with the signals and foils disrupted harmonicity. Both monaural and dichotic conditions were tested. Signal level was varied relative to masker level to obtain psychometric functions from which slopes and midpoints were estimated. Dichotic presentation of these audible stimuli improved performance by 3-10 dB, due primarily to a release from ``informational masking'' by the perceptual segregation of the signal from the masker.

Kidd, Gerald; Mason, Christine R.; Brughera, Andrew; Chiu, Chung-Yiu Peter

2003-08-01

166

, or focusing a low power laser tightly to reach sufficient intensity for efficient conversion. However, tight operating lifetime that is suitable for use with commercially-available mid- to low-power diode-pumped solid-harmonic waves to build up the intracavity intensity of the SHG. Consequently the conver- sion to the fourth

Kung, Andy

167

An electron-hole transport model for the analysis of the photorefractive harmonic gratings

The steady-state exact solution for the higher har- monic gratings that synthesize the space-charge field is derived without restrictions within an electron-hole transport model which allows the behavior of these harmonic gratings to be determined rigorously in terms of the main photorefractive parameters. The model predicts the independence of the fundamental and har- monic amplitudes on the average excitation intensity.

P. Vaveliuk; B. Ruiz; O. M. Matos; G. A. Torchia; N. Bolognini

2001-01-01

168

NASA Astrophysics Data System (ADS)

One of the main advantages of nonlinear microscopy is that it provides 3D imaging capability. Second harmonic generation is widely used to image the 3D structure of collagen fibers, and several works have highlighted the modification of the collagen fiber fabric in important diseases. By using an ellipsoidal specific fitting technique on the Fourier transformed image, we show, using both synthetic images and SHG images from cartilage, that the 3D direction of the collagen fibers can be robustly determined.

Romijn, Elisabeth I.; Lilledahl, Magnus B.

2013-02-01

169

Harmonic analysis of tides and tidal currents in South San Francisco Bay, California

Water level observations from tide stations and current observations from current-meter moorings in South San Francisco Bay (South Bay), California have been harmonically analysed. At each tide station, 13 harmonic constituents have been computed by a least-squares regression without inference. Tides in South Bay are typically mixed; there is a phase lag of approximately 1 h and an amplification of 1??5 from north to south for a mean semi-diurnal tide. Because most of the current-meter records are between 14 and 29 days, only the five most important harmonics have been solved for east-west and north-south velocity components. The eccentricity of tidal-current ellipse is generally very small, which indicates that the tidal current in South Bay is strongly bidirectional. The analyses further show that the principal direction and the magnitude of tidal current are well correlated with the basin bathymetry. Patterns of Eulerian residual circulation deduced from the current-meter data show an anticlockwise gyre to the west and a clockwise gyre to the east of the main channel in the summer months due to the prevailing westerly wind. Opposite trends have been observed during winter when the wind was variable. ?? 1985.

Cheng, R.T.; Gartner, J.W.

1985-01-01

170

Operational modal analysis of a ship model in the presence of harmonic excitation

NASA Astrophysics Data System (ADS)

A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic responses. In order to reduce structural vibration, it is important to obtain the modal parameters information of a ship. However, the traditional modal parameter identification methods are not suitable since the excitation information is difficult to obtain. Natural excitation technique-eigensystem realization algorithm (NExT-ERA) is an operational modal identification method which abstracts modal parameters only from the response signals, and it is based on the assumption that the input to the structure is pure white noise. Hence, it is necessary to study the influence of harmonic excitations while applying the NExT-ERA method to a ship structure. The results of this research paper indicate the practical experiences under ambient excitation, ship model experiments were successfully done in the modal parameters identification only when the harmonic frequencies were not too close to the modal frequencies.

Xu, Junchen; Hong, Ming; Liu, Xiaobing

2013-03-01

171

Symbolic Vector Analysis in Plasma Physics

Many problems in plasma physics involve substantial amounts of analytical vector calculation. The complexity usually originates from both the vector operations themselves and the choice of underlying coordinate system. A computer algebra package for symbolic vector analysis in general coordinate systems, General Vector Analysis (GVA), is developed using Mathematica. The modern viewpoint for 3D vector calculus, differential forms on 3-manifolds, is adopted to unify and systematize the vector calculus operations in general coordinate systems. This package will benefit physicists and applied mathematicians in their research where complicated vector analysis is required. It will not only save a huge amount of human brain-power and dramatically improve accuracy, but this package will also be an intelligent tool to assist researchers in finding the right approaches to their problems. Several applications of this symbolic vector analysis package to plasma physics are also given.

Qin, H.; Tang, W.M.; Rewoldt, G.

1997-10-09

172

Physics and Astronomy Seminar Broadband Spectrum Analysis

Physics and Astronomy Seminar Broadband Spectrum Analysis and Signal Processing based will be presented on 1) a 20 GHz bandwidth high performance spectrum monitoring system with sub-MHz resolution) broadband spread spectrum communication over 30dB below the noise floor. Friday, November 21, 2014 CHCB 231

Chu, Xi

173

Strong-Field Many-Body Physics and the Giant Enhancement in the High-Harmonic Spectrum of Xenon

We resolve an open question about the origin of the giant enhancement in the high-harmonic generation (HHG) spectrum of atomic xenon around 100 eV. By solving the many-body time-dependent Schr\\"odinger equation with all orbitals in the 4d, 5s, and 5p shells active, we demonstrate the enhancement results truly from collective many-body excitation induced by the returning photoelectron via two-body interchannel interactions. Without the many-body interactions, which promote a 4d electron into the 5p vacancy created by strong-field ionization, no collective excitation and no enhancement in the HHG spectrum exist.

Pabst, Stefan

2013-01-01

174

Optimal analysis on the performance of an irreversible harmonic quantum Brayton refrigeration cycle.

An irreversible model of a quantum refrigeration cycle working with many noninteracting harmonic oscillators is established. The refrigeration cycle consists of two adiabatic and two constant-frequency processes. The general performance characteristics of the cycle are investigated, based on the quantum master equation and the semigroup approach. The expressions for several important performance parameters such as the coefficient of performance, cooling rate, power input, and rate of entropy production are derived. By using numerical solutions, the cooling rate of the refrigeration cycle subject to finite cycle duration is optimized. The maximum cooling rate and the corresponding parameters are calculated numerically. The optimal region of the coefficient of performance and the optimal ranges of temperatures of the working substance and times spent on the two constant-frequency processes are determined. Moreover, the optimal performance of the cycle in the high-temperature limit is compared with that of a classical Brayton refrigerator working with an ideal gas. The results obtained here show that in the high-temperature limit a harmonic quantum Brayton cycle may be equivalent to a classical Brayton cycle. PMID:14682856

Lin, Bihong; Chen, Jincan

2003-11-01

175

Photonic band structure in one-dimensional nonlinear crystal: Analysis of harmonic stability

NASA Astrophysics Data System (ADS)

We consider a one-dimensional nonlinear photonic crystal consisting of an infinite set of concentrated equidistant scatterers inserted in a linear dielectric medium. Each of the scatterers is made by a very thin layer of a nonlinear medium with high refractive index that we model by a delta function. We show that the nonlinear optical exact solutions of this system form an intensity dependent band structure. To analyze the stability of these solutions we consider a modulation harmonic perturbation of these solutions whose amplitudes are slightly above the instability threshold. We demonstrate that the nonlinearity gives rise to an oscillatory instability of the solutions, which is a localized version of the well-known modulational instability of the nonlinear Schrodinger equation. We show that the linear harmonic perturbation forms as well a band structure whose allowed bands coincide for some intervals with those of the nonlinear band structure of the solutions for which case the structures are unstable whereas in the region where both the linear and nonlinear bands do not coincide, the nonlinear waves are indeed stable so that they conform spatial solitons.

Avendaño, Carlos G.; Reyes, J. Adrián

2015-01-01

176

NASA Technical Reports Server (NTRS)

The homogeneous set of 80-year-long (1900-1979) International Latitude Service (ILS) polar motion data is analyzed using the autoregressive method (Chao and Gilbert, 1980), which resolves and produces estimates for the complex frequency (or frequency and Q) and complex amplitude (or amplitude and phase) of each harmonic component in the data. The ILS data support the multiple-component hypothesis of the Chandler wobble. It is found that the Chandler wobble can be adequately modeled as a linear combination of four (coherent) harmonic components, each of which represents a steady, nearly circular, prograde motion. The four-component Chandler wobble model 'explains' the apparent phase reversal during 1920-1940 and the pre-1950 empirical period-amplitude relation. The annual wobble is shown to be rather stationary over the years both in amplitude and in phase, and no evidence is found to support the large variations reported by earlier investigations. The Markowitz wobble is found to be marginally retrograde and appears to have a complicated behavior which cannot be resolved because of the shortness of the data set.

Chao, B. F.

1983-01-01

177

NASA Astrophysics Data System (ADS)

The homogeneous set of 80-year-long (1900-1979) International Latitude Service (ILS) polar motion data is analyzed using the autoregressive method (Chao and Gilbert, 1980), which resolves and produces estimates for the complex frequency (or frequency and Q) and complex amplitude (or amplitude and phase) of each harmonic component in the data. The ILS data support the multiple-component hypothesis of the Chandler wobble. It is found that the Chandler wobble can be adequately modeled as a linear combination of four (coherent) harmonic components, each of which represents a steady, nearly circular, prograde motion. The four-component Chandler wobble model 'explains' the apparent phase reversal during 1920-1940 and the pre-1950 empirical period-amplitude relation. The annual wobble is shown to be rather stationary over the years both in amplitude and in phase, and no evidence is found to support the large variations reported by earlier investigations. The Markowitz wobble is found to be marginally retrograde and appears to have a complicated behavior which cannot be resolved because of the shortness of the data set.

Chao, B. F.

1983-12-01

178

Stability Analysis of a Second Harmonic Coaxial-Waveguide Gyrotron Backward-Wave Oscillator

NASA Astrophysics Data System (ADS)

This study analyzes the stability of a Ka-band second harmonic gyrotron backward-wave oscillator (gyro-BWO) with a coaxial interaction waveguide. All of the possible competing modes in the frequency tuning range are considered. To suppress various competing modes, the downstream part of the coaxial interaction waveguide is loaded with distributed losses. Although the competing modes have different kinds of transverse field distributions, simulation results show that the losses of the outer cylinder and those of the inner cylinder serve as complementary means of suppressing the competing modes. The losses can stabilize the competing modes while having minor effects on the start-oscillation current of the operating mode. Detailed investigations were performed involving the dependence of the start-oscillation currents on the parameters of the lossy inner cylinder and the lossy outer cylinder, including the resistivity and the length of the lossy section. Moreover, under stable operating conditions, the performances of the second harmonic coaxial gyro-BWO with different sets of circuit parameters are predicted and compared.

Hung, C. L.; Hong, J. H.

2012-12-01

179

Global QCD Analysis and Hadron Collider Physics

The role of global QCD analysis of parton distribution functions (PDFs) in collider physics at the Tevatron and LHC is surveyed. Current status of PDF analyses are reviewed, emphasizing the uncertainties and the open issues. The stability of NLO QCD global analysis and its prediction on 'standard candle' W/Z cross sections at hadron colliders are discussed. The importance of the precise measurement of various W/Z cross sections at the Tevatron in advancing our knowledge of PDFs, hence in enhancing the capabilities of making significant progress in W mass and top quark parameter measurements, as well as the discovery potentials of Higgs and New Physics at the Tevatron and LHC, is emphasized.

Tung, W.-K. [Michigan State University, E. Lansing, MI (United States)

2005-03-22

180

NASA Astrophysics Data System (ADS)

A comparison between two methods of timing jitter calculation is presented. The integral method utilizes spectral area of the single side-band (SSB) phase noise spectrum to calculate root mean square (rms) timing jitter. In contrast the harmonic analysis exploits the uppermost noise power in high harmonics to retrieve timing fluctuation. The results obtained show that a consistent timing jitter of 1.2 ps is found by the integral method and harmonic analysis in gain-switched laser diodes with an external cavity scheme. A comparison of the two approaches in noise measurement of a diode-pumped Yb:KY(WO4)2 passively mode-locked laser is also shown in which both techniques give 2 ps rms timing jitter.

Metzger, N. K.; Su, C.-R.; Edwards, T. J.; Brown, C. T. A.

2015-04-01

181

NASA Astrophysics Data System (ADS)

We report on measurements and characterization of polarization properties of Second Harmonic (SH) signals using a four-channel photon counting based Stokes polarimeter from type I collagen and starch granules. In this way, the critical polarization parameters including the degree of polarization (DOP), the degree of linear polarization (DOLP), and the degree of circular polarization (DOCP), are extracted from the reconstructed Stokes vector based SH images in a pixel-by-pixel manner. The measurements are further extended to determine the molecular structure and orientation of the samples by varying the polarization states of the incident light and recording the resulting Stokes parameters of the SH signal. The combination of SHG microscopy and Stokes polarimeter hence makes a powerful tool to investigate the structural order of starch granules under water and heating environment.

Mazumder, Nirmal; Xiang, Lu Yun; Qiu, Jianjun; Kao, Fu-Jen

2014-02-01

182

Analysis and projections of physics in Chile

NASA Astrophysics Data System (ADS)

In the present work, an assessment of the Physics research capacity in Chile is presented. For this, the period between 2000 and June 2005 has been studied. In this period almost 200 physicists have contributed to scientific production in terms of ISI publications. Amongst these 200, ~160 correspond to theoretical physicists and only ~40 to experimental physicists; ~178 are men and only ~22 are women. A more detailed analysis shows that ~160 physicists have at least one appearance in ISI publications per year considering the last 3 years. Ten years ago, a similar criteria (at least one appearance per year in ISI articles, considering mobile three-year periods), the number of active physicists in the Chilean community was estimated at 70. Therefore, the Chilean active physicists' community has doubled in 10 years. There exist 20 centres in which scientific research is developed: 18 university centres, a government institute and a private institute. As regards scientific productivity, both as related to disciplines or research areas, and well as in relation to research centres, it is found that, generally, scientific production, in a particular area in Physics or in a research centre, is directly related to the number of corresponding researchers; that is to say, the percentage of the national productivity in an area or research centre corresponds to its share in the total number of physicists in the country. A geographical analysis shows that 50% of the productivity corresponds to Santiago and 50% to the rest of the country. The impact of the different funds for research is assessed, also: FONDECYT, Presidential Chairs and large projects and centres of excellence. According to Physics researchers opinion, Fondo Nacional de Ciencia y Tecnología (FONDECYT, National Fund fro Science and Technology) has become the best instrument to support researchi activities in Chile. However, the amount of projects awarded has practically not been increased, which is insufficient for a community that has doubled. Likewise, even 50% of the productivity corresponds to regional centres, only 35% of projects coming from FONDECYT are awarded to the regions (away from the metropolitan region). Regarding experimental Physics, this represents 20% of the community in both, researchers and productivity of the community. However, in the regular FONDECYT contest in 2005, only 2 projects (10%) were awarded in experimental Physics, which is undoubtedly insufficient. The study also includes a brief analysis according to social appraisal of Physics, dissemination activities to other areas of national living, and relation of Physics with the productive sector. Finally, some recommendations are made: - To create a special fund for experimental Physics in the regular FONDECYT contest. Complementarily, experimental Physics should be one of the priority areas for the technological and scientific development of the country. - To duplicate the amount assigned to Physics in the regular FONDECYT contest. - To create a system that allows increasing the salaries of the researchers in Physics so they could be assimilated to other professional salaries in our country or at an international level. Not only demands must be globalized but also the benefits.

Soto, Leopoldo; Zambra, Marcelo; Loewe, Marcelo; Gutiérrez, Gonzalo; Molina, Mario; Barra, Felipe; Lund, Fernando; Saavedra, Carlos; Haberle, Patricio

2008-11-01

183

BESIU Physical Analysis on Hadoop Platform

NASA Astrophysics Data System (ADS)

In the past 20 years, computing cluster has been widely used for High Energy Physics data processing. The jobs running on the traditional cluster with a Data-to-Computing structure, have to read large volumes of data via the network to the computing nodes for analysis, thereby making the I/O latency become a bottleneck of the whole system. The new distributed computing technology based on the MapReduce programming model has many advantages, such as high concurrency, high scalability and high fault tolerance, and it can benefit us in dealing with Big Data. This paper brings the idea of using MapReduce model to do BESIII physical analysis, and presents a new data analysis system structure based on Hadoop platform, which not only greatly improve the efficiency of data analysis, but also reduces the cost of system building. Moreover, this paper establishes an event pre-selection system based on the event level metadata(TAGs) database to optimize the data analyzing procedure.

Huo, Jing; Zang, Dongsong; Lei, Xiaofeng; Li, Qiang; Sun, Gongxing

2014-06-01

184

NASA Astrophysics Data System (ADS)

An amplitude-frequency analysis of the rotary-oscillatory Earth motion under the action of gravitational-tidal perturbing torques from the Sun and the Moon is carried out using the classical mechanics' methods. The simulation results of the oscillatory process in the motion of the Earth pole and the variations of the second zonal harmonic ¥delta c_20 of the geopotential are studied. Based on the dynamic Euler-Liouville equations expressions for amplitude and phase of the Earth pole oscillations are obtained. A comparison of the spectral power densities of the time series between the Earth pole coordinates and the delta c_20 variations of the geopotential is carried out. A functional dependence of the aforementioned component of the geopotential from the amplitude and phase of the Earth's pole oscillatory process is shown.

Bondarenko, V. V.; Filippova, A. S.; Markov, Yu. G.; Perepelkin, V.

2014-12-01

185

A cryogenic search-coil array has been fabricated at LBL for harmonic error analysis of SSC model quadrupoles. It consists of three triplets of coils; the center-coil triplet is 10 cm long, and the end coil triplets are 70 cm long. Design objectives are a high bucking ratio for the dipole and quadrupole signals and utility at cryogenic operating currents (approx.6 kA) with sufficient sensitivity for use at room-temperature currents (approx.10 A). the design and fabrication are described. Individual coils are mechanically measured to +-5 ..mu..m, and their magnetic areas measured to 0.05%. A computer program has been developed to predict the quadrupole and dipole bucking ratios from the mechanical and magnetic measurements. The calibration procedure and accuracy of the array are specified. Results of measurements of SSC model quadrupoles are presented. 1 ref., 4 figs.

Green, M.I.; Barale, P.J.; Hassenzahl, W.V.; Nelson, D.H.; O'Neill, J.W.; Schafer, R.V.; Taylor, C.E.

1987-09-01

186

Harmonic analysis approach to the 'TunneLadder' - A modified Karp circuit for millimeter-wave TWTA's

NASA Technical Reports Server (NTRS)

A field approach to the summed harmonic analysis of the TunneLadder structure, or modified forward-wave Karp circuit, is developed by combining TM(01) and TE(11) modes. Results suggest the suitability of this structure as a high-impedance, about 1-% bandwidth circuit, millimeter-wave forward-wave-type amplifier that is voltage tunable over about a 5-% frequency range and has excellent power handling ability. Theory gives good agreement with experimental results obtained by Karp in omega-beta dispersion and predicts qualitatively the appearances of the antisymmetric mode discussed and of the so called Hightron mode that was discussed earlier in White, Enderby and Birdsall (1964), and Enderby (1964), in addition to the desired symmetric mode.

Kosmahl, H. G.; Palmer, R. W.

1982-01-01

187

Harmonic analysis approach to the 'TunneLadder' - A modified Karp circuit for millimeter-wave TWTA's

NASA Astrophysics Data System (ADS)

A field approach to the summed harmonic analysis of the TunneLadder structure, or modified forward-wave Karp circuit, is developed by combining TM(01) and TE(11) modes. Results suggest the suitability of this structure as a high-impedance, about 1-% bandwidth circuit, millimeter-wave forward-wave-type amplifier that is voltage tunable over about a 5-% frequency range and has excellent power handling ability. Theory gives good agreement with experimental results obtained by Karp in omega-beta dispersion and predicts qualitatively the appearances of the antisymmetric mode discussed and of the so called Hightron mode that was discussed earlier in White, Enderby and Birdsall (1964), and Enderby (1964), in addition to the desired symmetric mode.

Kosmahl, H. G.; Palmer, R. W.

1982-05-01

188

mixing process 1 + 2 = 3 is defined through the wave vector difference k = k3 - k1 - k2 of the three, the anisotropy of the common nonlinear crystals can be utilized to obtain phase matching between waves and Yuri S. Kivshar1 1 Nonlinear Physics Center, Research School of Physics and Engineering, The Australian

2010-01-01

189

NASA Astrophysics Data System (ADS)

We study a functional, whose critical points couple Dirac-harmonic maps from surfaces with a two form. The critical points can be interpreted as coupling the prescribed mean curvature equation to spinor fields. On the other hand, this functional also arises as part of the supersymmetric sigma model in theoretical physics. In two dimensions it is conformally invariant. We call critical points of this functional magnetic Dirac-harmonic maps. We study geometric and analytic properties of magnetic Dirac-harmonic maps including their regularity and the removal of isolated singularities.

Branding, Volker

2015-03-01

190

Numerical and experimental analysis of harmonic distortion in a moving-coil loudspeaker

NASA Astrophysics Data System (ADS)

The nonlinear effect of a moving-coil loudspeaker, originating from its magnetic coupling factor and the system's stiffness, presents a significant impact on the sound quality. For improving the sound quality, this article proposes an approach to reduce the total harmonic distortion (THD) by adjusting the initial position of its voice-coil. First, a mathematical model involving the nonlinearities of force factor, mechanical stiffness, and inductance of voice coil is constructed and then solved using a novel algorithm called the parameter spline difference method (PSD). In the course of pursuing reduction of the corresponding THD of a typical moving-coil loudspeaker, the model was used to analyze the nonlinearity of the THD, revealing itself as a nonlinear function of force factor, the system's stiffness and inductance of voice coil. For various initial positions of the voice-coil, the coupled nonlinear differential equations were solved using the PSD to yield corresponding sound pressure level and THD. To our satisfaction, the loudspeaker driver with its voice-coil optimally tuned for the initial position turns out to have a THD reduction of 10%, which is also consistent with our experimental observations.

Chang, Chun; Wang, Chi-Chang; Shiah, Y. C.; Huang, Jin H.

2013-07-01

191

Analysis of second-harmonic-generation microscopy in a mouse model of ovarian carcinoma.

Second-harmonic-generation (SHG) imaging of mouse ovaries ex vivo was used to detect collagen structure changes accompanying ovarian cancer development. Dosing with 4-vinylcyclohexene diepoxide and 7,12-dimethylbenz[a]anthracene resulted in histologically confirmed cases of normal, benign abnormality, dysplasia, and carcinoma. Parameters for each SHG image were calculated using the Fourier transform matrix and gray-level co-occurrence matrix (GLCM). Cancer versus normal and cancer versus all other diagnoses showed the greatest separation using the parameters derived from power in the highest-frequency region and GLCM energy. Mixed effects models showed that these parameters were significantly different between cancer and normal (P<0.008). Images were classified with a support vector machine, using 25% of the data for training and 75% for testing. Utilizing all images with signal greater than the noise level, cancer versus not-cancer specimens were classified with 81.2% sensitivity and 80.0% specificity, and cancer versus normal specimens were classified with 77.8% sensitivity and 79.3% specificity. Utilizing only images with greater than of 75% of the field of view containing signal improved sensitivity and specificity for cancer versus normal to 81.5% and 81.1%. These results suggest that using SHG to visualize collagen structure in ovaries could help with early cancer detection. PMID:22894485

Watson, Jennifer M; Rice, Photini F; Marion, Samuel L; Brewer, Molly A; Davis, John R; Rodriguez, Jeffrey J; Utzinger, Urs; Hoyer, Patricia B; Barton, Jennifer K

2012-07-01

192

Analysis of second-harmonic-generation microscopy in a mouse model of ovarian carcinoma

NASA Astrophysics Data System (ADS)

Second-harmonic-generation (SHG) imaging of mouse ovaries ex vivo was used to detect collagen structure changes accompanying ovarian cancer development. Dosing with 4-vinylcyclohexene diepoxide and 7,12-dimethylbenz[a]anthracene resulted in histologically confirmed cases of normal, benign abnormality, dysplasia, and carcinoma. Parameters for each SHG image were calculated using the Fourier transform matrix and gray-level co-occurrence matrix (GLCM). Cancer versus normal and cancer versus all other diagnoses showed the greatest separation using the parameters derived from power in the highest-frequency region and GLCM energy. Mixed effects models showed that these parameters were significantly different between cancer and normal (P<0.008). Images were classified with a support vector machine, using 25% of the data for training and 75% for testing. Utilizing all images with signal greater than the noise level, cancer versus not-cancer specimens were classified with 81.2% sensitivity and 80.0% specificity, and cancer versus normal specimens were classified with 77.8% sensitivity and 79.3% specificity. Utilizing only images with greater than of 75% of the field of view containing signal improved sensitivity and specificity for cancer versus normal to 81.5% and 81.1%. These results suggest that using SHG to visualize collagen structure in ovaries could help with early cancer detection.

Watson, Jennifer M.; Rice, Photini F.; Marion, Samuel L.; Brewer, Molly A.; Davis, John R.; Rodriguez, Jeffrey J.; Utzinger, Urs; Hoyer, Patricia B.; Barton, Jennifer K.

2012-07-01

193

NASA Astrophysics Data System (ADS)

In this work, we report harmonic vibrational frequencies, molecular structure, NBO and HOMO, LUMO analysis of Umbelliferone also known as 7-hydroxycoumarin (7HC). The optimized geometric bond lengths and bond angles obtained by computation (monomer and dimmer) shows good agreement with experimental XRD data. Harmonic frequencies of 7HC were determined and analyzed by DFT utilizing 6-311+G(d,p) as basis set. The assignments of the vibrational spectra have been carried out with the help of Normal Coordinate Analysis (NCA) following the Scaled Quantum Mechanical Force Field Methodology (SQMFF). The change in electron density (ED) in the ?* and ?* antibonding orbitals and stabilization energies E(2) have been calculated by Natural Bond Orbital (NBO) analysis to give clear evidence of stabilization originating in the hyperconjugation of hydrogen-bonded interaction. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) complements with the experimental findings. The simulated spectra satisfactorily coincides with the experimental spectra. Microbial activity of studied compounds was tested against Staphylococcus aureus, Streptococcus pyogenes, Bacillus subtilis, Escherichia coli, Psuedomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Shigella flexneri, Salmonella typhi and Enterococcus faecalis.

Sebastian, S.; Sylvestre, S.; Jayarajan, D.; Amalanathan, M.; Oudayakumar, K.; Gnanapoongothai, T.; Jayavarthanan, T.

2013-01-01

194

Theory of high-harmonic generation in solids

NASA Astrophysics Data System (ADS)

High-harmonic generation (HHG) in bulk crystals exposed to intense mid-infrared lasers with photon energies below the bandgap is investigated theoretically. A three dimensional, two-band model that considers both interband and intraband currents is used. It is shown that the interband current is the dominant mechanism for HHG in solids. A physical interpretation of interband HHG – similar to atomic HHG – is provided by saddle point analysis. The effects of dephasing time and driving field wavelength on the harmonic specrum are investigated.

McDonald, C. R.; Vampa, G.; Orlando, G.; Corkum, P. B.; Brabec, T.

2015-03-01

195

A high efficiency harmonic engine based on a resonantly reciprocating piston expander that extracts work from heat and pressurizes working fluid in a reciprocating piston compressor. The engine preferably includes harmonic oscillator valves capable of oscillating at a resonant frequency for controlling the flow of working fluid into and out of the expander, and also preferably includes a shunt line connecting an expansion chamber of the expander to a buffer chamber of the expander for minimizing pressure variations in the fluidic circuit of the engine. The engine is especially designed to operate with very high temperature input to the expander and very low temperature input to the compressor, to produce very high thermal conversion efficiency.

Bennett, Charles L. (Livermore, CA)

2009-10-20

196

Spatial Harmonic Decomposition as a tool for unsteady flow phenomena analysis

NASA Astrophysics Data System (ADS)

Hydropower is already the largest single renewable electricity source today but its further development will face new deployment constraints such as large-scale projects in emerging economies and the growth of intermittent renewable energy technologies. The potential role of hydropower as a grid stabilizer leads to operating hydro power plants in "off-design" zones. As a result, new methods of analyzing associated unsteady phenomena are needed to improve the design of hydraulic turbines. The key idea of the development is to compute a spatial description of a phenomenon by using a combination from several sensor signals. The spatial harmonic decomposition (SHD) extends the concept of so-called synchronous and asynchronous pulsations by projecting sensor signals on a linearly independent set of a modal scheme. This mathematical approach is very generic as it can be applied on any linear distribution of a scalar quantity defined on a closed curve. After a mathematical description of SHD, this paper will discuss the impact of instrumentation and provide tools to understand SHD signals. Then, as an example of a practical application, SHD is applied on a model test measurement in order to capture and describe dynamic pressure fields. Particularly, the spatial description of the phenomena provides new tools to separate the part of pressure fluctuations that contribute to output power instability or mechanical stresses. The study of the machine stability in partial load operating range in turbine mode or the comparison between the gap pressure field and radial thrust behavior during turbine brake operation are both relevant illustrations of SHD contribution.

Duparchy, A.; Guillozet, J.; De Colombel, T.; Bornard, L.

2014-12-01

197

NASA Technical Reports Server (NTRS)

Progress in the harmonic analysis of MAGSAT data is reported. Single-day data sets were subdivided into information on the sunrise side of the Earth and information on the sunset side of the Earth. Data for the main and external fields each demonstrate a clear and consistent systematic difference between the sets of data which was determined to be, due to ionospheric currents which differ from the sunset to the sunrise terminator. A toroidal field was analyzed for and determined to be an apparent toroidal field resulting from electric currents concentrated in the two terminators. Progressive elimination of auroral zone data demonstrates that the information presented does not arise from complications due to Birkeland currents.

Barraclough, D. R.; Hide, R.; Leaton, B. R.; Lowes, F. J.; Malin, S. R. C.; Wilson, R. L. (principal investigators)

1982-01-01

198

With the advancements in semiconductor technology, high power medium voltage (MV) Drives are extensively used in numerous industrial applications. Challenging technical requirements of MV Drives is to control multilevel inverter (MLI) with less Total harmonic distortion (%THD) which satisfies IEEE standard 519-1992 harmonic guidelines and less switching losses. Among all modulation control strategies for MLI, Selective harmonic elimination (SHE) technique is one of the traditionally preferred modulation control technique at fundamental switching frequency with better harmonic profile. On the other hand, the equations which are formed by SHE technique are highly non-linear in nature, may exist multiple, single or even no solution at particular modulation index (MI). However, in some MV Drive applications, it is required to operate over a range of MI. Providing analytical solutions for SHE equations during the whole range of MI from 0 to 1, has been a challenging task for researchers. In this paper, an attempt is made to solve SHE equations by using deterministic and stochastic optimization methods and comparative harmonic analysis has been carried out. An effective algorithm which minimizes %THD with less computational effort among all optimization algorithms has been presented. To validate the effectiveness of proposed MPSO technique, an experiment is carried out on a low power proto type of three phase CHB 11- level Inverter using FPGA based Xilinx's Spartan -3A DSP Controller. The experimental results proved that MPSO technique has successfully solved SHE equations over all range of MI from 0 to 1, the %THD obtained over major range of MI also satisfies IEEE 519-1992 harmonic guidelines too. PMID:24010030

Vesapogu, Joshi Manohar; Peddakotla, Sujatha; Kuppa, Seetha Rama Anjaneyulu

2013-01-01

199

Classical tidal harmonic analysis including error estimates in MATLAB using T_TIDE

A standard part of any oceanic pressure gauge or current meter analysis is the separation of tidal from non-tidal components of the signal. The tidal signal can either be discarded, or its characteristics described in some fashion useful for further analysis. Although tidal signals can be removed by standard high or bandpass filtering techniques, their relatively deterministic character and large

Rich Pawlowicz; Bob Beardsley; Steve Lentz

2002-01-01

200

NASA Astrophysics Data System (ADS)

A theoretical three-dimensional transverse magnetic (TM) mode analysis to describe the presence of interactions between surface plasma waves of carriers in a two-dimensional electron gas (2DEG) at AlGaAs/GaAs heterostructure and electromagnetic space harmonics slow waves using the so-called interdigital-gated high-electron-mobility-transistor (HEMT) plasma wave devices is presented. First, the device structure and the outline of theoretical formulation to determine the admittance of the interdigital structure are described. Then, the analysis of the space harmonics propagating through the interdigital slow-wave structures is performed. Next, the numerical procedures to solve the integral equations which are used in determining the admittance are explained. Finally, we point out and discuss the main results of the theoretical analysis where an appearance of negative conductance is obtained.

Hashim, Abdul Manaf; Ahir, Zon Fazlila Mohd; Kasai, Seiya; Hashizume, Tamotsu; Hasegawa, Hideki

2009-07-01

201

A theoretical three-dimensional transverse magnetic (TM) mode analysis to describe the presence of interactions between surface plasma waves of carriers in a two-dimensional electron gas (2DEG) at AlGaAs/GaAs heterostructure and electromagnetic space harmonics slow waves using the so-called interdigital-gated high-electron-mobility-transistor (HEMT) plasma wave devices is presented. First, the device structure and the outline of theoretical formulation to determine the admittance of the interdigital structure are described. Then, the analysis of the space harmonics propagating through the interdigital slow-wave structures is performed. Next, the numerical procedures to solve the integral equations which are used in determining the admittance are explained. Finally, we point out and discuss the main results of the theoretical analysis where an appearance of negative conductance is obtained.

Hashim, Abdul Manaf [Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Ahir, Zon Fazlila Mohd [Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Kasai, Seiya; Hashizume, Tamotsu; Hasegawa, Hideki [Research Center for Integrated Quantum Electronics, Hokkaido University North 12 West 8, Sapporo 060-8628 (Japan)

2009-07-07

202

Analysis of physical activities in Taekwondo Pumsae.

Exercise is very important element for successful aging. Among many sports events, Korea is the suzerain of Taekwondo. When competing (Taekwondo Free Fighting) after learning Poomse as basic movements and inuring them, people compete with movements depending on situation. Among Poomses of Taekwondo, Taegeuk Poomse consists of very basic movements from 1 Jang to 8 Jang and they are for inuring to body. In order to prescribe Taegeuk Jang, which is the basic movement of Taekwondo that Korea is the suzerain, as an exercise for successful aging, it is necessary to analyze physical activity level of each Taegeuk Jang (From 1 Jang through 8 Jang) and suggest the same. Therefore, in this study, I analyzed physical activity level of each Jang of Taegeuk Poomse by attaching Armband made by Body Media Company on brachia and legs below knee of Taekwondo trainees. The result of the analysis of the whole momentum from Taegeuk 1 Jang to 8 Jang is as follows: First, the average absolute value of acceleration variation of vertical direction signal (L-MAD): 5.15. Second, the average absolute value of acceleration variation of horizontal direction signal (T-MAD): 3.44. Finally, the average of calorie consumption per minute (AEE/Min): 5.06 Cal. The obtained result corresponds to proper exercise condition for successful aging and it can be utilized as data for exercise prescription for the young and the old. PMID:19163880

Lee, Sang-Bock; Cha, Eun-Jong; Lee, Tae-Soo

2008-01-01

203

Random harmonic analysis program, L221 (TEV156). Volume 1: Engineering and usage

NASA Technical Reports Server (NTRS)

A digital computer program capable of calculating steady state solutions for linear second order differential equations due to sinusoidal forcing functions is described. The field of application of the program, the analysis of airplane response and loads due to continuous random air turbulence, is discussed. Optional capabilities including frequency dependent input matrices, feedback damping, gradual gust penetration, multiple excitation forcing functions, and a static elastic solution are described. Program usage and a description of the analysis used are presented.

Miller, R. D.; Graham, M. L.

1979-01-01

204

NASA Astrophysics Data System (ADS)

Although second harmonic generation is intrinsically sensitive for probing interfaces, interpreting experimental observations for the determination of interfacial properties of colloidal particles requires rigorous theoretical treatment. A generally applicable nonlinear Mie theory is expanded into higher multipolar terms for describing second harmonic scattering from the surface of spherical particles. From a nonlinear least-square fitting of the scattering angular distribution of second harmonic light from molecules adsorbed on the surface, we demonstrate the determination of molecular hyperpolarizability and adsorption geometry on the surface of nanometer- to micrometer-sized spherical particles.

Gonella, Grazia; Dai, Hai-Lung

2011-09-01

205

We perform a comparative study for the harmonic versus arithmetic averaging of the heat conduction coefficient when solving non-linear heat transfer problems. In literature, the harmonic average is the method of choice, because it is widely believed that the harmonic average is more accurate model. However, our analysis reveals that this is not necessarily true. For instance, we show a case in which the harmonic average is less accurate when a coarser mesh is used. More importantly, we demonstrated that if the boundary layers are finely resolved, then the harmonic and arithmetic averaging techniques are identical in the truncation error sense. Our analysis further reveals that the accuracy of these two techniques depends on how the physical problem is modeled.

Samet Y. Kadioglu; Robert R. Nourgaliev; Vincent A. Mousseau

2008-03-01

206

Killing vector fields and harmonic superfield theories

NASA Astrophysics Data System (ADS)

The harmonic action functional allows a natural generalisation to semi-Riemannian supergeometry, also referred to as harmonic, which resembles the supersymmetric sigma models studied in high energy physics. We show that Killing vector fields are infinitesimal supersymmetries of this harmonic action and prove three different Noether theorems in this context. En passant, we provide a homogeneous treatment of five characterisations of Killing vector fields on semi-Riemannian supermanifolds, thus filling a gap in the literature.

Groeger, Josua

2014-09-01

207

Learning from physical sequence data Fermat Component Analysis

Learning from physical sequence data Fermat Component Analysis Efficient high-dimensional inference Fermat Components Analysis Paul Vernaza Daniel D. Lee GRASP Lab University of Pennsylvania May 25, 2010 Paul Vernaza, Daniel D. Lee #12;Learning from physical sequence data Fermat Component Analysis

Vernaza, Paul

208

An engine based on a reciprocating piston engine that extracts work from pressurized working fluid. The engine includes a harmonic oscillator inlet valve capable of oscillating at a resonant frequency for controlling the flow of working fluid into of the engine. In particular, the inlet valve includes an inlet valve head and a spring arranged together as a harmonic oscillator so that the inlet valve head is moveable from an unbiased equilibrium position to a biased closed position occluding an inlet. Upon releasing the inlet valve the inlet valve head undergoes a single oscillation past the equilibrium positio to a maximum open position and returns to a biased return position close to the closed position to choke the flow and produce a pressure drop across the inlet valve causing the inlet valve to close. Protrusions carried either by the inlet valve head or piston head are used to bump open the inlet valve from the closed position and initiate the single oscillation of the inlet valve head, and protrusions carried either by the outlet valve head or piston head are used to close the outlet valve ahead of the bump opening of the inlet valve.

Bennett, Charles L.; Sewall, Noel; Boroa, Carl

2014-08-19

209

The 2dF Galaxy Redshift Survey: Spherical Harmonics analysis of fluctuations in the final catalogue

We present the result of a decomposition of the 2dFGRS galaxy overdensity field into an orthonormal basis of spherical harmonics and spherical Bessel functions. Galaxies are expected to directly follow the bulk motion of the density field on large scales, so the absolute amplitude of the observed large-scale redshift-space distortions caused by this motion is expected to be independent of galaxy properties. By splitting the overdensity field into radial and angular components, we linearly model the observed distortion and obtain the cosmological constraint Omega_m^{0.6} sigma_8=0.46+/-0.06. The amplitude of the linear redshift-space distortions relative to the galaxy overdensity field is dependent on galaxy properties and, for L_* galaxies at redshift z=0, we measure beta(L_*,0)=0.58+/-0.08, and the amplitude of the overdensity fluctuations b(L_*,0) sigma_8=0.79+/-0.03, marginalising over the power spectrum shape parameters. Assuming a fixed power spectrum shape consistent with the full Fourier analysis produces very similar parameter constraints.

Will J. Percival; Daniel Burkey; Alan Heavens; Andy Taylor; Shaun Cole; John A. Peacock; Carlton M. Baugh; Joss Bland-Hawthorn; Terry Bridges; Russell Cannon; Matthew Colless; Chris Collins; Warrick Couch; Gavin Dalton; Roberto De Propris; Simon P. Driver; George Efstathiou; Richard S. Ellis; Carlos S. Frenk; Karl Glazebrook; Carole Jackson; Ofer Lahav; Ian Lewis; Stuart Lumsden; Steve Maddox; Peder Norberg; Bruce A. Peterson; Will Sutherland; Keith Taylor

2004-06-23

210

Methodological considerations for the harmonization of non-cholesterol sterol bio-analysis.

Non-cholesterol sterols (NCS) are used as surrogate markers of cholesterol metabolism which can be measured from a single blood sample. Cholesterol precursors are used as markers of endogenous cholesterol synthesis and plant sterols are used as markers of cholesterol absorption. However, most aspects of NCS analysis show wide variability among researchers within the area of biomedical research. This variability in methodology is a significant contributor to variation between reported NCS values and hampers the confidence in comparing NCS values across different research groups, as well as the ability to conduct meta-analyses. This paper summarizes the considerations and conclusions of a workshop where academic and industrial experts met to discuss NCS measurement. Highlighted is why each step in the analysis of NCS merits critical consideration, with the hopes of moving toward more standardized and comparable NCS analysis methodologies. Alkaline hydrolysis and liquid-liquid extraction of NCS followed by parallel detection on GC-FID and GC-MS is proposed as an ideal methodology for the bio-analysis of NCS. Furthermore the importance of cross-comparison or round robin testing between various groups who measure NCS is critical to the standardization of NCS measurement. PMID:24674990

Mackay, Dylan S; Jones, Peter J H; Myrie, Semone B; Plat, Jogchum; Lütjohann, Dieter

2014-04-15

211

Constructing analysis-suitable parameterization of computational domain from CAD boundary-suitable parameterization of computational domain from CAD boundary for 2D and 3D isogeometric applications. Different from that offers the possibility of seamless integration between CAD and CAE. The method uses the same type

Paris-Sud XI, UniversitÃ© de

212

Constructing analysis-suitable parameterization of computational domain from CAD boundary-suitable parameterization of computational domain from CAD boundary for 2D and 3D isogeometric applications. Different from computational approach that offers the possibility of seamless integration between CAD and CAE. The method uses

Paris-Sud XI, UniversitÃ© de

213

ANALYSIS AND RESYNTHESIS OF QUASI-HARMONIC SOUNDS: AN ITERATIVE FILTERBANK APPROACH

We employ a hybrid state-space sinusoidal model for general use in analysis-synthesis based audio transformations. This model, which has appeared previously in altered forms (e.g. (5), (8), perhaps others) combines the advantages of a source-filter model with the flexible, time-frequency based transformations of the si- nusoidal model. For this paper, we specialize the parameter iden- tification task to a class

Harvey D. Thornburg; Randal J. Leistikow

2003-01-01

214

Simulation and analysis of physical mapping

The current talk involves objects smaller than those that are macro-restriction mapped but larger than the bases that are sequenced. Specifically, we describe simulations of the alignment of recombinant lambdoid and cosmid clones by fingerprinting methods. The purpose of the simulation is to compare methods, as realistically as desired, while preparing for the analysis of actual physical mapping data. Furthermore, we will eventually begin to ''submit'' data to the Human Genome Information Resource (HGIR) to exercise its database. A simulation has advantages over a formal mathematical analysis. Not only can a simulation be as realistic as desired (for example by using actual sequences from GenBank/trademark/) but if desired properly, when finished much of the code could be used on actual data. Furthermore, a simulation can be designed to utilize any degree of parameterization, while analyses usually must make simplifying assumptions to minimize the number of parameters. For example, the way this simulation is designed one could, by simply adding a short module, mimic rearrangements that might occur during cloning in order to discover the effect that they would have on the contig generating algorithms and to learn how to recognize and deal with such rearrangements. This talk describes the structure and announces the availability of the code for the simulation modules. We tested the method for aligning clones based upon oligonucleotide hybridizing sites comparing its efficacy on actual human DNA sequences from GenBank to its efficacy on random, completely uncorrelated sequence. Surprisingly, its performance was about the same on both sequences.

Sirotkin, K.; Loehr, J.J.

1988-01-01

215

Cost and performance analysis of physical security systems

Analysis of cost and performance of physical security systems can be a complex, multi-dimensional problem. There are a number of point tools that address various aspects of cost and performance analysis. Increased interest in cost tradeoffs of physical security alternatives has motivated development of an architecture called Cost and Performance Analysis (CPA), which takes a top-down approach to aligning cost and performance metrics. CPA incorporates results generated by existing physical security system performance analysis tools, and utilizes an existing cost analysis tool. The objective of this architecture is to offer comprehensive visualization of complex data to security analysts and decision-makers.

Hicks, M.J. [Sandia National Labs., Albuquerque, NM (United States); Yates, D.; Jago, W.H.; Phillips, A.W. [Tecolote Research, Inc., Santa Barbara, CA (United States)

1998-04-01

216

Mean squared displacement analysis of an-harmonic behaviour in lyophilised proteins

NASA Astrophysics Data System (ADS)

The temperature dependence of the mean squared displacement (msd),

Telling, Mark T. F.; Howells, Spencer; Combet, Jérôme; Clifton, Luke A.; García Sakai, Victoria

2013-10-01

217

Analysis of Percussion Grip for Physically Based Character Animation

about physically-based character animation using motion capture data, style- based computer animationAnalysis of Percussion Grip for Physically Based Character Animation Alexandre Bou¨enard* Marcelo character simulation. Physically-based charac- ter animation techniques provide a solution to the lim- ited

Paris-Sud XI, Université de

218

Descriptive Analysis of Physical Activity Conversations on Twitter

Descriptive Analysis of Physical Activity Conversations on Twitter Abstract This paper explores how activities. The content analysis describes how people are using Twitter to post about their health behaviors, such as physical activity, that are known to reduce the risk of a range of health conditions

Pratt, Wanda

219

An SQL-based approach to physics analysis

NASA Astrophysics Data System (ADS)

As part of the CERN openlab collaboration a study was made into the possibility of performing analysis of the data collected by the experiments at the Large Hadron Collider (LHC) through SQL-queries on data stored in a relational database. Currently LHC physics analysis is done using data stored in centrally produced "ROOT-ntuple" files that are distributed through the LHC computing grid. The SQL-based approach to LHC physics analysis presented in this paper allows calculations in the analysis to be done at the database and can make use of the database's in-built parallelism features. Using this approach it was possible to reproduce results for several physics analysis benchmarks. The study shows the capability of the database to handle complex analysis tasks but also illustrates the limits of using row-based storage for storing physics analysis data, as performance was limited by the I/O read speed of the system.

Limper, Maaike, Dr

2014-06-01

220

Dimensional analysis as the other language of physics

NASA Astrophysics Data System (ADS)

We review the use of dimensional analysis as a tool for the systematic study and analysis of physical concepts and phenomena at multiple levels in the physics curriculum. After reviewing the methodology of its use and citing examples from classical physics, we illustrate how it can be applied to problems in quantum mechanics, including research-level problems, noting both its power and its limitations.

Robinett, R. W.

2015-04-01

221

In searching for novel objective methods to diagnosticate pelvic pain and assess efficiency of analgesic therapy, 37 male patients were examined prior to and after the course of extracorporeal shock wave therapy (5-10 sessions) with the waves directed to projections of prostate and/or crura and shaft of the penis. The repetition rate of mechanical pulses was 3-5 Hz. The range of energy pulse density was 0.09-0.45 mJ/mm(2). The overall number of pulses in a session was 1500-3000 in any treated zone with total energy smaller than 60 J. The applicator was relocated every other series of 300-500 pulses. Effect of the shock wave therapy was assessed according to subjective symptomatic scales: International Prostate Symptom Score, International Index of Erectile Function, Quality of Life, and nociceptive Visual Analog Scale. The objective assessment of shock wave therapy was performed with harmonic analysis of penile bioimpedance variability, which quantitatively evaluated the low-frequency rhythmic and asynchronous activities at rest as well as the total pulsatile activity of the penis. The magnitude of spectrum components of bioimpedance variations was assessed with a novel parameter, the effective impedance. The spectral parameters were measured in 16 patients prior to and after the treatment course. The corresponding control values were measured in the group of healthy patients. Prior to the shock wave therapy course, all spectrum parameters of penile bioimpedance significantly differed from the control (p<0.05). After this course, low-frequency rhythmic and the total pulsatile activity decreased to normal, while asynchronous activity remained significantly different from the normal. The novel objective physiological criteria of pelvic pain diagnostics and efficiency of its treatment reflecting the regional features of circulation and neural activity corresponded to the clinical symptom scaling prior to and after the shock wave course, and on the whole, these criteria corroborated improvement of the patient state after this therapy. PMID:24131011

Khodyreva, L A; Dudareva, A A; Mudraya, I S; Markosyan, T G; Revenko, S V; Kumachev, K V; Logvinov, L A

2013-06-01

222

NASA Astrophysics Data System (ADS)

A spherical cap harmonic analysis (SCHA) technique is introduced for mapping the 2-D high-latitude ionospheric convection pattern based on Super Dual Auroral Radar Network (SuperDARN) velocity measurements. The current method for generating such maps is the FIT technique which generates global-scale maps over the entire convection region. This is accomplished by combining observations with a statistical model to prevent unphysical solutions in areas away from the observation points and by forcing the plasma flow to zero at the low-latitude boundary of the convection zone. Both constraints distort the mapped convection and require a preconception of where the plasma flow lines should close. By focusing on mapping the convection over a region well covered by velocity observations, the SCHA technique is freed of these constraints and more accurately reproduces local convection. We generate large-scale convection maps from SuperDARN data for various interplanetary magnetic field (IMF) conditions during periods of widespread radar coverage to show the patterns are consistent with expectations for various IMF configurations. We validate the SCHA maps by comparing them with the 2-D ion drifts measured by the DMSP satellites and with the 2-D convection vectors obtained by merging SuperDARN measurements at beam crossings. The SCHA technique is shown to perform comparably to the FIT technique over regions of good data coverage. For limited data coverage and over regions of highly variable flow, particularly near the equatorward edge of the mapping region, the SCHA technique provides a better solution for mapping ionospheric convection based on SuperDARN radar observations.

Fiori, R. A. D.; Boteler, D. H.; Koustov, A. V.; Haines, G. V.; Ruohoniemi, J. M.

2010-07-01

223

Standing Waves: Harmonics and Patterns

NSDL National Science Digital Library

This high school physics tutorial provides an introduction to standing waves. The site contains a description of such waves and related features such as nodes, antinodes, and interference. The site presents several simulations that demonstrate harmonics and their associated wave patterns.

Henderson, Tom

224

NASA Technical Reports Server (NTRS)

Half-daily global wind speeds in the east-west (u) and north-south (v) directions at the 10-meter height level were obtained from the European Centre for Medium Range Weather Forecasts (ECMWF) data set of global analyses. The data set covered the period 1985 January to 1995 January. A spherical harmonic expansion to degree and order 50 was used to perform harmonic analysis of the east-west (u) and north-south (v) velocity field components. The resulting wind field is displayed, as well as the residual of the fit, at a particular time. The contribution of particular coefficients is shown. The time variability of the coefficients up to degree and order 3 is presented. Corresponding power spectrum plots are given. Time series analyses were applied also to the power associated with degrees 0-10; the results are included.

Sanchez, Braulio V.; Nishihama, Masahiro

1997-01-01

225

Can recent innovations in harmonic analysis 'explain' key findings in natural image statistics?

Recently, applied mathematicians have been pursuing the goal of sparse coding of certain mathematical models of images with edges. They have found by mathematical analysis that, instead of wavelets and Fourier methods, sparse coding leads towards new systems: ridgelets and curvelets. These new systems have elements distributed across a range of scales and locations, but also orientations. In fact they have highly direction-specific elements and exhibit increasing numbers of distinct directions as we go to successively finer scales. Meanwhile, researchers in natural scene statistics (NSS) have been attempting to find sparse codes for natural images. The new systems they have found by computational optimization have elements distributed across a range of scales and locations, but also orientations. The new systems are certainly unlike wavelet and Gabor systems, on the one hand because of the multi-orientation and on the other hand because of the multi-scale nature. There is a certain degree of visual resemblance between the findings in the two fields, which suggests the hypothesis that certain important findings in the NSS literature might possibly be explained by the slogan: edges are the dominant features in images, and curvelets are the right tool for representing edges. We consider here certain empirical consequences of this hypothesis, looking at key findings of the NSS literature and conducting studies of curvelet and ridgelet transforms on synthetic and real images, to see if the results are consistent with predictions from this slogan. Our first experiment measures the nonGaussianity of Fourier, wavelet, ridgelet and curvelet coefficients over a database of synthetic and photographic images. Empirically the curvelet coefficients exhibit noticeably higher kurtosis than wavelet, ridgelet, or Fourier coefficients. This is consistent with the hypothesis. Our second experiment studies the inter-scale correlation of wavelet coefficient energies at the same location. We describe a simple experiment showing that presence of edges explains these correlations. We also develop a crude nonlinear 'partial correlation' by considering the correlation between wavelet parents and children after a few curvelet coefficients are removed. When we kill the few biggest coefficients of the curvelet transform, much of the correlation between wavelet subbands disappears--consistent with the hypothesis. We suggest implications for future discussions about NSS. PMID:11563535

Donoho, D L; Flesia, A G

2001-08-01

226

Transmission characteristics of cyclotron harmonic waves in plasma

In recent years the importance of cyclotron harmonic waves has become apparent in many branches of plasma physics. For example, it has been demonstrated that they are involved in the anomalously high noise radiation near the electron cyclotron harmonic frequencies that has been observed from thermonuclear fusion study devices, and that they can explain the cyclotron harmonic resonances observed in

F. W. Crawford; H. H. Weiss

1966-01-01

227

Chemistry 160: Physical Measurements and Analysis

NSDL National Science Digital Library

This site contains lab experiments for both analytical and physical chemical measurements. There are 6 analytical experiments: data acquisition, AAS, voltammetry, ASV, GC-MS, stop-flow kinetics and HPLC. Experiments use real samples and are ready for implementation.

Steinmetz, Wayne E.

228

. They constitute the input conversion stage for power supplies of many electronic appliances such as TV sets%. The harmonics injected into the power network can have an adverse impact on the power systems. It is therefore], [6], [7] where the dc load is modeled as an equivalent resistance, Req, R L idi VS LD1I LD4 LD3 C Req

Lehn, Peter W.

229

The ability to attend to a particular sound in a noisy environment is an essential aspect of hearing. To accomplish this feat, the auditory system must segregate sounds that overlap in frequency and time. Many natural sounds, such as human voices, consist of harmonics of a common fundamental frequency (F0). Such harmonic complex tones (HCTs) evoke a pitch corresponding to their F0. A difference in pitch between simultaneous HCTs provides a powerful cue for their segregation. The neural mechanisms underlying concurrent sound segregation based on pitch differences are poorly understood. Here, we examined neural responses in monkey primary auditory cortex (A1) to two concurrent HCTs that differed in F0 such that they are heard as two separate “auditory objects” with distinct pitches. We found that A1 can resolve, via a rate-place code, the lower harmonics of both HCTs, a prerequisite for deriving their pitches and for their perceptual segregation. Onset asynchrony between the HCTs enhanced the neural representation of their harmonics, paralleling their improved perceptual segregation in humans. Pitches of the concurrent HCTs could also be temporally represented by neuronal phase-locking at their respective F0s. Furthermore, a model of A1 responses using harmonic templates could qualitatively reproduce psychophysical data on concurrent sound segregation in humans. Finally, we identified a possible intracortical homolog of the “object-related negativity” recorded noninvasively in humans, which correlates with the perceptual segregation of concurrent sounds. Findings indicate that A1 contains sufficient spectral and temporal information for segregating concurrent sounds based on differences in pitch. PMID:25209282

Steinschneider, Mitchell; Micheyl, Christophe

2014-01-01

230

Physics and Analysis at a Hadron Collider - Searching for New Physics (2/3)

This is the second lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This second lecture discusses techniques important for analyses searching for new physics using the CDF B_s --> mu+ mu- search as a specific example. The lectures are aimed at graduate students.

None

2010-01-20

231

ERIC Educational Resources Information Center

This paper provides an analysis of the discourses associated with physical education in Scotland's "Curriculum for Excellence". We implement a poststructural perspective in order to identify the discourses that underpin the physical education sections of the "Curriculum for Excellence" "health and well-being"…

McEvilly, Nollaig; Verheul, Martine; Atencio, Matthew; Jess, Mike

2014-01-01

232

The backscatter cross-sections of dihedral corner reflectors in the azimuthal plane are presently determined by both physical optics (PO) and the physical theory of diffraction (PTD), yielding results for the vertical and horizontal polarizations. In the first analysis method used, geometrical optics is used in place of PO at initial reflections in order to maintain the planar character of the

Timothy Griesser; Constantine A. Balanis

1987-01-01

233

Physics and Analysis at a Hadron Collider - Searching for New Physics (2/3)

This is the second lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This second lecture discusses techniques important for analyses searching for new physics using the CDF B_s --> mu+ mu- search as a specific example. The lectures are aimed at graduate students.

None

2011-10-06

234

Benchmarking patient improvement in physical therapy with data envelopment analysis

Purpose – The purpose of this article is to present a case study that documents how management science techniques (in particular data envelopment analysis) can be applied to performance improvement initiatives in an inpatient physical therapy setting. Design\\/methodology\\/approach – The data used in this study consist of patients referred for inpatient physical therapy following total knee replacement surgery (at a

Daniel Friesner; Donna Neufelder; Janet Raisor; Mohammed Khayum

2005-01-01

235

Interactive ergonomic analysis of a physically disabled person's workplace

Interactive ergonomic analysis of a physically disabled person's workplace Matthieu Aubry1 , Fr approach for in- teractive ergonomics evaluation, and especially adaptation of physically disabled people's workplaces. After a general survey of existing tools, we describe the requirements to perform ergonomic

Paris-Sud XI, UniversitÃ© de

236

Exploratory versus Confirmatory Factor Analysis of Collegiate Physical Fitness.

ERIC Educational Resources Information Center

Twenty-one variables believed to be important indicators of health related physical fitness were measured on male and female college students between 1991 and 1993 (n=433). Exploratory and confirmatory factor analytic techniques were used in an attempt to derive important components of physical fitness. The exploratory factor analysis identified…

Mead, Tim P.; Legg, David L.

237

Dimensional Analysis in Physics and the Buckingham Theorem

ERIC Educational Resources Information Center

Dimensional analysis is a simple, clear and intuitive method for determining the functional dependence of physical quantities that are of importance to a certain process. However, in physics textbooks, very little space is usually given to this approach and it is often presented only as a diagnostic tool used to determine the validity of…

Misic, Tatjana; Najdanovic-Lukic, Marina; Nesic, Ljubisa

2010-01-01

238

A comparative analysis of physical-layer rateless coding architectures

An analysis of rateless codes implemented at the physical layer is developed. Our model takes into account two aspects of practical communication system design that are abstracted away in many existing works on the subject. ...

Romero, David Luis

2014-01-01

239

Exhaled breath analysis: physical methods, instruments, and medical diagnostics

NASA Astrophysics Data System (ADS)

This paper reviews the analysis of exhaled breath, a rapidly growing field in noninvasive medical diagnostics that lies at the intersection of physics, chemistry, and medicine. Current data are presented on gas markers in human breath and their relation to human diseases. Various physical methods for breath analysis are described. It is shown how measurement precision and data volume requirements have stimulated technological developments and identified the problems that have to be solved to put this method into clinical practice.

Vaks, V. L.; Domracheva, E. G.; Sobakinskaya, E. A.; Chernyaeva, M. B.

2014-07-01

240

We consider hollow-core fibres with a microstructure photonic-crystal cladding, which open a unique opportunity of implementing nonlinear-optical interactions of waveguide modes with transverse sizes on the order of several microns in the gas phase. Phase-matching conditions for optical harmonic generation can be improved in higher waveguide modes of hollow-core photonic-crystal fibres by optimising parameters of the gas medium filling the fibre and characteristics of the fibre. (optical fibres)

Naumov, A N; Zheltikov, Aleksei M [Department of Physics, M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

2002-02-28

241

NASA Astrophysics Data System (ADS)

The atomistic finite element method (AFEM) is a multiscale technique where a sequential mode is used to transfer information between two length scales to model and simulate nanostructures at the continuum level. This method is used in this paper to investigate the nonlinear frequency response of a single-layered graphene sheet (SLGS) for impulse and harmonic excitation. The multi-body interatomic Tersoff–Brenner (TB) potential is used to represent the energy between two adjacent carbon atoms. Based on the TB potential, the equivalent geometric and elastic properties of carbon–carbon bonds are derived which are consistent with the material constitutive relations. These properties are used further to derive the nonlinear material model (stress–strain curve) of carbon–carbon bonds based on the force–deflection curve using the multi-body interatomic Tersoff–Brenner potential. A square SLGS is considered and its nonlinear vibration characteristics under an impulse and harmonic excitation for bridged, cantilever and clamped boundary conditions are investigated using the derived nonlinear material model (NMM). Before using the proposed nonlinear material model, the derived equivalent geometric and elastic properties of carbon–carbon bond are validated using molecular dynamics simulation results. The geometric (large deformation) and material nonlinearities are included in the nonlinear frequency response analysis. The investigated results of the nonlinear frequency response analysis are compared with those of the linear frequency response analysis, and the effect of the nonlinear behavior of carbon–carbon bonds on the frequency response of SLGS is studied.

Gajbhiye, Sachin O.; Singh, S. P.

2015-04-01

242

Atmospheric cloud physics thermal systems analysis

NASA Technical Reports Server (NTRS)

Engineering analyses performed on the Atmospheric Cloud Physics (ACPL) Science Simulator expansion chamber and associated thermal control/conditioning system are reported. Analyses were made to develop a verified thermal model and to perform parametric thermal investigations to evaluate systems performance characteristics. Thermal network representations of solid components and the complete fluid conditioning system were solved simultaneously using the Systems Improved Numerical Differencing Analyzer (SINDA) computer program.

1977-01-01

243

Analytic signals and harmonic measures

NASA Astrophysics Data System (ADS)

We prove that a sufficient and necessary condition for Hei[Theta](s)=-iei[Theta](s), where H is Hilbert transformation, [Theta] is a continuous and strictly increasing function with [Theta](R)=2[pi], is that d[Theta](s) is a harmonic measure on the line. The counterpart result for the periodic case is also established. The study is motivated by, and has significant impact to time-frequency analysis, especially to aspects of analytic signals inducing instantaneous amplitude and frequency. As a by-product we introduce the theory of Hardy-space-preserving weighted trigonometric series and Fourier transformations induced by harmonic measures in the respective contexts.

Qian, Tao

2006-02-01

244

Harmonization of Biodiesel Specifications

Worldwide biodiesel production has grown dramatically over the last several years. Biodiesel standards vary across countries and regions, and there is a call for harmonization. For harmonization to become a reality, standards have to be adapted to cover all feedstocks. Additionally, all feedstocks cannot meet all specifications, so harmonization will require standards to either tighten or relax. For harmonization to succeed, the biodiesel market must be expanded with the alignment of test methods and specification limits, not contracted.

Alleman, T. L.

2008-02-01

245

Harmonic nanoparticles for regenerative research.

In this visualized experiment, protocol details are provided for in vitro labeling of human embryonic stem cells (hESC) with second harmonic generation nanoparticles (HNPs). The latter are a new family of probes recently introduced for labeling biological samples for multi-photon imaging. HNPs are capable of doubling the frequency of excitation light by the nonlinear optical process of second harmonic generation with no restriction on the excitation wavelength. Multi-photon based methodologies for hESC differentiation into cardiac clusters (maintained as long term air-liquid cultures) are presented in detail. In particular, evidence on how to maximize the intense second harmonic (SH) emission of isolated HNPs during 3D monitoring of beating cardiac tissue in 3D is shown. The analysis of the resulting images to retrieve 3D displacement patterns is also detailed. PMID:24836220

Ronzoni, Flavio; Magouroux, Thibaud; Vernet, Remi; Extermann, Jérôme; Crotty, Darragh; Prina-Mello, Adriele; Ciepielewski, Daniel; Volkov, Yuri; Bonacina, Luigi; Wolf, Jean-Pierre; Jaconi, Marisa

2014-01-01

246

High-Speed Video Analysis in a Conceptual Physics Class

ERIC Educational Resources Information Center

The use of probe ware and computers has become quite common in introductory physics classrooms. Video analysis is also becoming more popular and is available to a wide range of students through commercially available and/or free software. Video analysis allows for the study of motions that cannot be easily measured in the traditional lab setting…

Desbien, Dwain M.

2011-01-01

247

Physics-Based Simulator for NEO Exploration Analysis & Modeling

Physics-Based Simulator for NEO Exploration Analysis & Modeling J. (Bob) Balaram , J. Cameron , A (NEOs). The simulator is under development at JPL and can be used to provide detailed analysis of various surface and near-surface NEO robotic and human exploration concepts. In this paper we describe

248

Root Cause Analysis to Identify Physical Causes G. Medina Olivaa

Why Analysis, Ishikawa Diagram, HAZOP, among others) and quantitative (Bayesian Inference, Pareto that they can avoid the chronic failure and returning to a specified plan of action. The flow chart belowRoot Cause Analysis to Identify Physical Causes G. Medina Olivaa , B. Iunga , L. BarberÃ¡b , P

Boyer, Edmond

249

Accelerator physics analysis with interactive tools

Work is in progress on interactive tools for linear and nonlinear accelerator design, analysis, and simulation using X-based graphics. The BEAMLINE and MXYZPTLK class libraries, were used with an X Windows graphics library to build a program for interactively editing lattices and studying their properties.

Holt, J.A.; Michelotti, L.

1993-05-01

250

Gesture Analysis for Physics Education Researchers

ERIC Educational Resources Information Center

Systematic observations of student gestures can not only fill in gaps in students' verbal expressions, but can also offer valuable information about student ideas, including their source, their novelty to the speaker, and their construction in real time. This paper provides a review of the research in gesture analysis that is most relevant to…

Scherr, Rachel E.

2008-01-01

251

Analysis of ANS LWR physics benchmark problems.

Various Monte Carlo and deterministic solutions to the three PWR Lattice Benchmark Problems recently defined by the ANS Ad Hoc Committee on Reactor Physics Benchmarks are presented. These solutions were obtained using the VIM continuous-energy Monte Carlo code and the DIF3D/WIMS-D4M code package implemented at the Argonne National Laboratory. The code results for the K{sub eff} and relative pin power distribution are compared to measured values. Additionally, code results for the three benchmark-prescribed infinite lattice configurations are also intercompared. The results demonstrate that the codes produce very good estimates of both the K{sub eff} and power distribution for the critical core and the lattice parameters of the infinite lattice configuration.

Taiwo, T. A.

1998-07-29

252

Cardiac Image Analysis Corresponding To Physical Parameters

NASA Astrophysics Data System (ADS)

A practical analyzing procedure has been developed to evaluate dynamic images with reference to time series data from the same object. A special recording and analyzing system has been contructed, and its validity and an analyzing procedure are demonstrated using actual dynamical cardiac images. Echocardiogram and X-ray TV images were recorded on the video tape simultaneously with physical parameters. These data were fed into the computer and analyzed in reference to each other. Actual experiments were then executed to analyze myocardial ultrasound and X-ray images quantitatively, using subtraction and densitometry techniques. In both images, abnormalities of myocardial perfusion were clearly described by the subtraction image with reference to the ECG signal and the M-mode image, in the case of the echocardiogram. The temporal change of myocardial images was also represented by subtraction, and the details were described by densitometry. These image processing techniques can be a useful tool in evaluating cardiac dynamics in daily practice.

Akatsuka, Takao; Matsuda, Mitsuo; Takeda, Tohoru; Kuwako, Kenji; Sugishita, Yasuro; Akisada, Masayoshi

1984-08-01

253

NASA Astrophysics Data System (ADS)

The superconducting properties of mm-sized Fe1.02Se crystals grown by a flux method are investigated. The structural and morphological features are studied by x-ray diffraction (XRD) and by scanning electron microscopy-energy dispersive x-ray spectroscopy SEM-EDX analysis, which identified a co-growth of a dominant superconducting tetragonal phase, with the minority of a non-superconducting hexagonal phase. The ac magnetic response is analyzed using a combined method of the fundamental and the 3rd harmonic ac magnetic susceptibility as a function of the temperature at different ac magnetic field amplitudes and frequencies and with various superimposed dc fields. The variation of the ac magnetic field and frequency in different ranges especially affects the 3rd harmonic components, which are more sensitive to the changes in the flux dynamic regimes. This allows a fine observation of the evolution of the different linear and non-linear processes responsible for the ac magnetic response of the Fe1.02Se crystals. At low enough ac amplitudes and frequencies, and even in high imposed dc magnetic fields, the Fe1.02Se crystals show a typical critical state behavior, marking a high stability of the pinning, with very small influence of the vortex dynamical processes. With the change of ac field amplitude and frequency a gradual crossover is observed from the initial stable pinning state through the domination of the intermediate regimes as flux creep and finally to the complete dominance of flux flow. The ac magnetic response is also influenced by geometric edge barrier effects arising from the plate-like geometry of the Fe1.02Se crystals. The changes of the dominant irreversible (non-linear) mechanism from surface pinning to bulk pinning or to prevailing dynamical regimes is also identified by analyzing the behavior of the 3rd harmonic components.

Buchkov, K.; Polichetti, M.; Nenkov, K.; Nazarova, E.; Mancusi, D.; Balchev, N.; Kovacheva, D.; Zahariev, A.; Pace, S.

2015-03-01

254

HEPDOOP: High-Energy Physics Analysis using Hadoop

NASA Astrophysics Data System (ADS)

We perform a LHC data analysis workflow using tools and data formats that are commonly used in the "Big Data" community outside High Energy Physics (HEP). These include Apache Avro for serialisation to binary files, Pig and Hadoop for mass data processing and Python Scikit-Learn for multi-variate analysis. Comparison is made with the same analysis performed with current HEP tools in ROOT.

Bhimji, W.; Bristow, T.; Washbrook, A.

2014-06-01

255

34 GHz second-harmonic peniotron oscillator

NASA Astrophysics Data System (ADS)

Harmonic operation of gyro-devices has been proposed as a way to lower the magnetic field required to a level feasible with normal (i.e., non-superconducting) magnets. The problem is, however, that gyrotron efficiency drops dramatically at harmonics greater than two, making development of such a device of limited utility. A promising solution to this quandary is the development of a related device, the peniotron, which is believed capable of achieving both high efficiency and harmonic operation resulting in a reduction of the required axial magnetic field. Although the physics of the peniotron interaction, including its high electronic conversion efficiency, has been understood and experimentally verified, demonstration of characteristics consistent with a practical device has been more elusive. This is the goal of this effort---specifically, to demonstrate high device efficiency (defined as the actual power output as a fraction of the electron beam power) with an electron beam generated by a compact cusp electron gun consistent in size and performance with other microwave vacuum electron devices. The cavity design process revealed that the pi/2 mode couples easily to the output circular waveguide. In fact, the transition to circular waveguide produced such a low reflection coefficient that an iris was needed at the cavity output to achieve the desired Q. Integral couplers were also designed to couple directly into the slotted cavity for diagnostic purposes for simplicity in this proof-of-principle physics experiment. This eliminated the need for a high-power circular vacuum window and allowed the diagnostic coupling to be made in standard WR-28 rectangular waveguide. Although mode competition did prevent the second-harmonic peniotron mode from being tuned over its entire range of magnetic field, the peniotron mode was stable over a range sufficient to allow useful experimental data to be obtained. However, another unexpected problem which occurred during execution of the experiment was persistent arcing along the cusp gun high-voltage ceramic which prevented the gun from being operated at its full design voltage of 70 kV. The measured output power and efficiency was then reduced to about a third of that originally predicted. That is, a maximum peak power of approximately 35 kW and maximum efficiency of 18% was achieved. Significant post-test analysis revealed that the reduced operating voltage of the cusp gun degraded the operation of the device in several inter-related ways. First, the lower voltage shifted the desired peniotron interaction to a lower interaction magnetic field such that the maximum power which could have been achieved was right at the point of greatest interference from the competing mode. Secondly, the lower gun voltage resulted in a correspondingly lower beam power to drive the interaction. Finally, the beam optics of the cusp gun was designed for operation at 70 kV such that reduced beam voltage resulted in degradation of the beam quality. Nonetheless, the viability of the device was proven as the measured output power and device efficiency still represent unprecedented performance for a harmonic peniotron. Finally, analysis of the cavity design and competing mode characteristics indicate that a simple re-design of the cavity will result in a comparable design in which the competing fourth-harmonic gyrotron mode is removed. This design entails a slight change to the slot depth and vane angle of the four-vane cavity. Other parameters would not necessarily need to be changed and the modified device should achieve virtually the same results (power and efficiency) as originally predicted. Furthermore, with the competing mode removed (and assuming the gun arcing can be suppressed), the higher current available from the cusp gun could be exploited to achieve even higher output power than originally predicted. (Abstract shortened by UMI.)

Dressman, Lawrence Jude

256

Accelerator physics analysis with an integrated toolkit

Work is in progress on an integrated software toolkit for linear and nonlinear accelerator design, analysis, and simulation. As a first application, ``beamline`` and ``MXYZPTLK`` (differential algebra) class libraries, were used with an X Windows graphics library to build an user-friendly, interactive phase space tracker which, additionally, finds periodic orbits. This program was used to analyse a theoretical lattice which contains octupoles and decapoles to find the 20th order, stable and unstable periodic orbits and to explore the local phase space structure.

Holt, J.A.; Michelotti, L.; Satogata, T.

1992-08-01

257

Plasma physics analysis of SERT-2 operation

NASA Technical Reports Server (NTRS)

An analysis of the major plasma processes involved in the SERT 2 spacecraft experiments was conducted to aid in the interpretation of recent data. A plume penetration model was developed for neutralization electron conduction to the ion beam and showed qualitative agreement with flight data. In the SERT 2 configuration conduction of neutralization electrons between thrusters was experimentally demonstrated in space. The analysis of this configuration suggests that the relative orientation of the two magnetic fields was an important factor in the observed results. Specifically, the opposed field orientation appeared to provide a high conductivity channel between thrusters and a barrier to the ambient low energy electrons in space. The SERT 2 neutralizer currents with negative neutralizer biases were up to about twice the theoretical prediction for electron collection by the ground screen. An explanation for the higher experimental values was a possible conductive path from the neutralizer plume to a nearby part of the ground screen. Plasma probe measurements of SERT 2 gave the clearest indication of plasma electron temperature, with normal operation being near 5 eV and discharge only operation near 2 eV.

Kaufman, H. R.

1980-01-01

258

High order harmonic generation in rare gases

The process of high order harmonic generation in atomic gases has shown great promise as a method of generating extremely short wavelength radiation, extending far into the extreme ultraviolet (XUV). The process is conceptually simple. A very intense laser pulse (I {approximately}10{sup 13}-10{sup 14} W/cm{sup 2}) is focused into a dense ({approximately}10{sup l7} particles/cm{sup 3}) atomic medium, causing the atoms to become polarized. These atomic dipoles are then coherently driven by the laser field and begin to radiate at odd harmonics of the laser field. This dissertation is a study of both the physical mechanism of harmonic generation as well as its development as a source of coherent XUV radiation. Recently, a semiclassical theory has been proposed which provides a simple, intuitive description of harmonic generation. In this picture the process is treated in two steps. The atom ionizes via tunneling after which its classical motion in the laser field is studied. Electron trajectories which return to the vicinity of the nucleus may recombine and emit a harmonic photon, while those which do not return will ionize. An experiment was performed to test the validity of this model wherein the trajectory of the electron as it orbits the nucleus or ion core is perturbed by driving the process with elliptically, rather than linearly, polarized laser radiation. The semiclassical theory predicts a rapid turn-off of harmonic production as the ellipticity of the driving field is increased. This decrease in harmonic production is observed experimentally and a simple quantum mechanical theory is used to model the data. The second major focus of this work was on development of the harmonic {open_quotes}source{close_quotes}. A series of experiments were performed examining the spatial profiles of the harmonics. The quality of the spatial profile is crucial if the harmonics are to be used as the source for experiments, particularly if they must be refocused.

Budil, K.S.

1994-05-01

259

Synchronous Discrete Harmonic Oscillator

We introduce the synchronous discrete harmonic oscillator, and present an analytical, numerical and graphical study of its characteristics. The oscillator is synchronous when the time T for one revolution covering an angle of 2{pi} in phase space, is an integral multiple N of the discrete time step {delta}t. It is fully synchronous when N is even. It is pseudo-synchronous when T/{delta}t is rational. In the energy conserving hyperincursive representation, the phase space trajectories are perfectly stable at all time scales, and in both synchronous and pseudo-synchronous modes they cycle through a finite number of phase space points. Consequently, both the synchronous and the pseudo-synchronous hyperincursive modes of time-discretization provide a physically realistic and mathematically coherent, procedure for dynamic, background independent, discretization of spacetime. The procedure is applicable to any stable periodic dynamical system, and provokes an intrinsic correlation between space and time, whereby space-discretization is a direct consequence of background-independent time-discretization. Hence, synchronous discretization moves the formalism of classical mechanics towards that of special relativity. The frequency of the hyperincursive discrete harmonic oscillator is ''blue shifted'' relative to its continuum counterpart. The frequency shift has the precise value needed to make the speed of the system point in phase space independent of the discretizing time interval {delta}t. That is the speed of the system point is the same on the polygonal (in the discrete case) and the circular (in the continuum case) phase space trajectories.

Antippa, Adel F. [Departement de Physique Universite du Quebec a Trois-Rivieres Trois-Rivieres, Quebec, G9A 5H7 (Canada); Dubois, Daniel M. [Centre for Hyperincursion and Anticipation in Ordered Systems, CHAOS asbl, Institute of Mathematics, B37, University of Liege Grande Traverse 12, B-4000 LIEGE 1 (Belgium)

2008-10-17

260

NASA Astrophysics Data System (ADS)

In this paper we analytically study and evaluate the performance of a Spectral-Phase-Encoded Optical CDMA system for different parameters such as the user's code length and the number of users in the network. In this system an advanced receiver structure in which the Second Harmonic Generation effect imposed in a thick crystal is employed as the nonlinear pre-processor prior to the conventional low speed photodetector. We consider ASE noise of the optical amplifiers, effective in low power conditions, besides the multiple access interference (MAI) noise which is the dominant source of noise in any OCDMA communications system. We use the results of the previous work which we analyzed the statistical behavior of the thick crystals in an optically amplified digital lightwave communication system to evaluate the performance of the SPE-OCDMA system with thick crystals receiver structure. The error probability is evaluated using Saddle-Point approximation and the approximation is verified by Monte-Carlo simulation.

Matinfar, Mehdi D.; Salehi, Jawad A.

2009-11-01

261

formed in TeO2-based glasses is a key factor for fabrication of glass-ceramic with SHG. In this study, we of the 10K2O-4Na2O-14Nb2O5-72TeO2 glass-ceramic with second harmonic generation were studied by using an energy dispersive method in X-ray spectroscopy and XRD. The Bravais lattice of 10K2O-4Na2O-14Nb2O5-72TeO2

Pak, Hyuk Kyu

262

Tabletop coherent extreme ultraviolet and soft X-ray sources based on high harmonic generation

High harmonic generation (HHG) is a fascinating strong-field physics phenomenon that occurs when a laser pulse with a moderate intensity interacts with atoms and partially ionizes the atoms. A series of harmonics are ...

Lai, Chien-Jen, Ph. D. Massachusetts Institute of Technology

2014-01-01

263

Physics-based deformable organisms for medical image analysis

NASA Astrophysics Data System (ADS)

Previously, "Deformable organisms" were introduced as a novel paradigm for medical image analysis that uses artificial life modelling concepts. Deformable organisms were designed to complement the classical bottom-up deformable models methodologies (geometrical and physical layers), with top-down intelligent deformation control mechanisms (behavioral and cognitive layers). However, a true physical layer was absent and in order to complete medical image segmentation tasks, deformable organisms relied on pure geometry-based shape deformations guided by sensory data, prior structural knowledge, and expert-generated schedules of behaviors. In this paper we introduce the use of physics-based shape deformations within the deformable organisms framework yielding additional robustness by allowing intuitive real-time user guidance and interaction when necessary. We present the results of applying our physics-based deformable organisms, with an underlying dynamic spring-mass mesh model, to segmenting and labelling the corpus callosum in 2D midsagittal magnetic resonance images.

Hamarneh, Ghassan; McIntosh, Chris

2005-04-01

264

Disability in Physical Education Textbooks: An Analysis of Image Content

ERIC Educational Resources Information Center

The aim of this paper is to show how images of disability are portrayed in physical education textbooks for secondary schools in Spain. The sample was composed of 3,316 images published in 36 textbooks by 10 publishing houses. A content analysis was carried out using a coding scheme based on categories employed in other similar studies and adapted…

Taboas-Pais, Maria Ines; Rey-Cao, Ana

2012-01-01

265

NASA Astrophysics Data System (ADS)

Harmon Craig, one of the great pioneers of isotope geochemistry died on 14 March after suffering a massive heart attack at his home in La Jolla, California. He was one day shy of his 77th birthday. Through an academic career of more than fifty years, Craig—or simply “Harmon,” as he was known throughout the world of geochemistry—made a remarkable number of fundamental and far-reaching contributions in a wide range of important areas concerned with the chemical and physical processes by which the solid Earth, the oceans, the atmosphere, and the solar system interact. While his research was broad in scope, it was also characterized by a strong emphasis on meticulous field and laboratory work, and on original and insightful interpretations of the resulting observations.

Weiss, Ray

266

Operation of a free-electron laser at harmonics of the fundamental frequency is explored with the numerical simulation code HELEX. This code includes coupling to the harmonics caused by misalignment of the electrons with the optical beam and coupling due to transverse gradients. Albeit weak, the transverse gradients produce the dominant coupling of the electrons to the even-harmonic light. Even-harmonic lasing occurs in a TEM{sub 0,2m+1}-like mode where the field on axis is zero. As bunching of the electron beam progresses, radiation at the higher odd harmonics is suppressed owing to the absence of higher-order odd-harmonic Fourier components in the bunch. Growth of the even-harmonic power from small signal requires suppression of competing harmonics (including the fundamental) that have higher gain. Lasing at an even harmonic has yet to be experimentally demonstrated in an open resonator (i.e. optical cavity). Strategies to make such an experiment possible are discussed. 9 refs., 5 figs., 1 tab.

Schmitt, M.J.

1991-01-01

267

Background The purpose of this study was to develop a multi-harmonic phase analysis method to measure diastolic dyssynchrony from conventional gated SPECT myocardial perfusion imaging(MPI) data and to compare it with systolic dyssynchrony in normal subjects and in patients with end-stage renal disease (ESRD) and normal left-ventricular ejection fraction (LVEF). Methods 121 consecutive patients with ESRD and normal LVEF and 30 consecutive normal controls were enrolled. Diastolic dyssynchrony parameters were calculated using 3-harmonic phase analysis. Systolic dyssynchrony parameters were calculated using the established 1-harmonic phase analysis. Results The systolic and diastolic dyssynchrony parameters were correlated, but significantly different in both control and ESRD groups, indicating they were physiologically related but measured different LV mechanisms. The systolic and diastolic dyssynchrony parameters were each significantly different between the control and the ESRD groups. Significant systolic and diastolic dyssynchrony were found in 47% and 65% of the entire ESRD group. Conclusion Multi-harmonic phase analysis has been developed to assess diastolic dyssynchrony, which measured a new LV mechanism of regional function from gated SPECT MPI and showed a significantly higher prevalence rate than systolic dyssynchrony in patients with ESRD and normal LVEF. PMID:21229401

Chen, Ji; Kalogeropoulos, Andreas P.; Verdes, Liudmila; Butler, Javed; Garcia, Ernest V.

2011-01-01

268

Game theoretic analysis of physical protection system design

The physical protection system (PPS) of a fictional small modular reactor (SMR) facility have been modeled as a platform for a game theoretic approach to security decision analysis. To demonstrate the game theoretic approach, a rational adversary with complete knowledge of the facility has been modeled attempting a sabotage attack. The adversary adjusts his decisions in response to investments made by the defender to enhance the security measures. This can lead to a conservative physical protection system design. Since defender upgrades were limited by a budget, cost benefit analysis may be conducted upon security upgrades. One approach to cost benefit analysis is the efficient frontier, which depicts the reduction in expected consequence per incremental increase in the security budget.

Canion, B.; Schneider, E. [Nuclear and Radiation Engineering Program, University of Texas, 204 E. Dean Keeton Street, Stop C2200, Austin, TX 78712 (United States); Bickel, E.; Hadlock, C.; Morton, D. [Operations Research Program, University of Texas, 204 E. Dean Keeton Street, Stop C2200, Austin, TX 78712 (United States)

2013-07-01

269

Data management, archiving, visualization and analysis of space physics data

NASA Technical Reports Server (NTRS)

A series of programs for the visualization and analysis of space physics data has been developed at UCLA. In the course of those developments, a number of lessons have been learned regarding data management and data archiving, as well as data analysis. The issues now facing those wishing to develop such software, as well as the lessons learned, are reviewed. Modern media have eased many of the earlier problems of the physical volume required to store data, the speed of access, and the permanence of the records. However, the ultimate longevity of these media is still a question of debate. Finally, while software development has become easier, cost is still a limiting factor in developing visualization and analysis software.

Russell, C. T.

1995-01-01

270

Covariant harmonic oscillators and coupled harmonic oscillators

NASA Technical Reports Server (NTRS)

It is shown that the system of two coupled harmonic oscillators shares the basic symmetry properties with the covariant harmonic oscillator formalism which provides a concise description of the basic features of relativistic hadronic features observed in high-energy laboratories. It is shown also that the coupled oscillator system has the SL(4,r) symmetry in classical mechanics, while the present formulation of quantum mechanics can accommodate only the Sp(4,r) portion of the SL(4,r) symmetry. The possible role of the SL(4,r) symmetry in quantum mechanics is discussed.

Han, Daesoo; Kim, Young S.; Noz, Marilyn E.

1995-01-01

271

A Global Sensitivity Analysis Methodology for Multi-physics Applications

Experiments are conducted to draw inferences about an entire ensemble based on a selected number of observations. This applies to both physical experiments as well as computer experiments, the latter of which are performed by running the simulation models at different input configurations and analyzing the output responses. Computer experiments are instrumental in enabling model analyses such as uncertainty quantification and sensitivity analysis. This report focuses on a global sensitivity analysis methodology that relies on a divide-and-conquer strategy and uses intelligent computer experiments. The objective is to assess qualitatively and/or quantitatively how the variabilities of simulation output responses can be accounted for by input variabilities. We address global sensitivity analysis in three aspects: methodology, sampling/analysis strategies, and an implementation framework. The methodology consists of three major steps: (1) construct credible input ranges; (2) perform a parameter screening study; and (3) perform a quantitative sensitivity analysis on a reduced set of parameters. Once identified, research effort should be directed to the most sensitive parameters to reduce their uncertainty bounds. This process is repeated with tightened uncertainty bounds for the sensitive parameters until the output uncertainties become acceptable. To accommodate the needs of multi-physics application, this methodology should be recursively applied to individual physics modules. The methodology is also distinguished by an efficient technique for computing parameter interactions. Details for each step will be given using simple examples. Numerical results on large scale multi-physics applications will be available in another report. Computational techniques targeted for this methodology have been implemented in a software package called PSUADE.

Tong, C H; Graziani, F R

2007-02-02

272

Relativistic harmonic oscillator revisited

The familiar Fock space commonly used to describe the relativistic harmonic oscillator, for example, as part of string theory, is insufficient to describe all the states of the relativistic oscillator. We find that there are three different vacua leading to three disconnected Fock sectors, all constructed with the same creation-annihilation operators. These have different spacetime geometric properties as well as different algebraic symmetry properties or different quantum numbers. Two of these Fock spaces include negative norm ghosts (as in string theory), while the third one is completely free of ghosts. We discuss a gauge symmetry in a worldline theory approach that supplies appropriate constraints to remove all the ghosts from all Fock sectors of the single oscillator. The resulting ghost-free quantum spectrum in d+1 dimensions is then classified in unitary representations of the Lorentz group SO(d,1). Moreover, all states of the single oscillator put together make up a single infinite dimensional unitary representation of a hidden global symmetry SU(d,1), whose Casimir eigenvalues are computed. Possible applications of these new results in string theory and other areas of physics and mathematics are briefly mentioned.

Bars, Itzhak [Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-2535 (United States)

2009-02-15

273

Reactor Physics Methods and Analysis Capabilities in SCALE

The TRITON sequence of the SCALE code system provides a powerful, robust, and rigorous approach for performing reactor physics analysis. This paper presents a detailed description of TRITON in terms of its key components used in reactor calculations. The ability to accurately predict the nuclide composition of depleted reactor fuel is important in a wide variety of applications. These applications include, but are not limited to, the design, licensing, and operation of commercial/research reactors and spent-fuel transport/storage systems. New complex design projects such as next-generation power reactors and space reactors require new high-fidelity physics methods, such as those available in SCALE/TRITON, that accurately represent the physics associated with both evolutionary and revolutionary reactor concepts as they depart from traditional and well-understood light water reactor designs.

DeHart, Mark D [ORNL; Bowman, Stephen M [ORNL

2011-01-01

274

Physically based groundwater vulnerability assessment using sensitivity analysis methods.

A general physically based method is presented to assess the vulnerability of groundwater to external pressures by numerical simulation of groundwater flow. The concept of groundwater vulnerability assessment considered here is based on the calculation of sensitivity coefficients for a user-defined groundwater state for which we propose several physically based indicators. Two sensitivity analysis methods are presented: the sensitivity equation method and the adjoint operator method. We show how careful selection of a method can significantly minimize the computational effort. An illustration of the general methodology is presented for the Herten aquifer analog (Germany). This application to a simple, yet insightful, case demonstrates the potential use of this general and physically based vulnerability assessment method to complex aquifers. PMID:24236887

Beaujean, Jean; Lemieux, Jean-Michel; Dassargues, Alain; Therrien, René; Brouyère, Serge

2014-01-01

275

Reactor Physics Methods and Analysis Capabilities in SCALE

The TRITON sequence of the SCALE code system provides a powerful, robust, and rigorous approach for performing reactor physics analysis. This paper presents a detailed description of TRITON in terms of its key components used in reactor calculations. The ability to accurately predict the nuclide composition of depleted reactor fuel is important in a wide variety of applications. These applications include, but are not limited to, the design, licensing, and operation of commercial/research reactors and spent-fuel transport/storage systems. New complex design projects such as next-generation power reactors and space reactors require new high-fidelity physics methods, such as those available in SCALE/TRITON, that accurately represent the physics associated with both evolutionary and revolutionary reactor concepts as they depart from traditional and well-understood light water reactor designs.

Mark D. DeHart; Stephen M. Bowman

2011-05-01

276

Optical High Harmonic Generation in C60

NASA Astrophysics Data System (ADS)

C60 et al. Physical Review Letters Physical Review B High harmonic generation (HHG) requires a strong laser field, but in a relatively weak laser field is sufficient. Numerical results presented here show while its low order harmonics result from the laser field, its high order ones are mainly from the multiple excitations. Since high order harmonics directly correlate electronic transitions, the HHG spectrum accurately measures transition energies. Therefore, is not only a promising material for HHG, but may also present an opportunity to develop HHG into an electronic structure probing tool. References: G. P. Zhang, 91, 176801 (2003); G. P. Zhang and T. F. George, 68, 165410 (2003); P. B. Corkum, 71, 1994 (1993); G. P. Zhang and Thomas F. George, 93, 147401 (2004); H. Niikura ,ature 417, 917 (2002); ibid. 421, 826 (2003); Y. Mairesse ,cience 302, 1540 (2003); A. Baltuska ,ature 421, 611 (2003).

Zhang, Guoping

2005-03-01

277

Second International Workshop on Harmonic Oscillators

NASA Technical Reports Server (NTRS)

The Second International Workshop on Harmonic Oscillators was held at the Hotel Hacienda Cocoyoc from March 23 to 25, 1994. The Workshop gathered 67 participants; there were 10 invited lecturers, 30 plenary oral presentations, 15 posters, and plenty of discussion divided into the five sessions of this volume. The Organizing Committee was asked by the chairman of several Mexican funding agencies what exactly was meant by harmonic oscillators, and for what purpose the new research could be useful. Harmonic oscillators - as we explained - is a code name for a family of mathematical models based on the theory of Lie algebras and groups, with applications in a growing range of physical theories and technologies: molecular, atomic, nuclear and particle physics; quantum optics and communication theory.

Han, Daesoo (editor); Wolf, Kurt Bernardo (editor)

1995-01-01

278

QA/QC requirements for physical properties sampling and analysis

This report presents results of an assessment of the available information concerning US Environmental Protection Agency (EPA) quality assurance/quality control (QA/QC) requirements and guidance applicable to sampling, handling, and analyzing physical parameter samples at Comprehensive Environmental Restoration, Compensation, and Liability Act (CERCLA) investigation sites. Geotechnical testing laboratories measure the following physical properties of soil and sediment samples collected during CERCLA remedial investigations (RI) at the Hanford Site: moisture content, grain size by sieve, grain size by hydrometer, specific gravity, bulk density/porosity, saturated hydraulic conductivity, moisture retention, unsaturated hydraulic conductivity, and permeability of rocks by flowing air. Geotechnical testing laboratories also measure the following chemical parameters of soil and sediment samples collected during Hanford Site CERCLA RI: calcium carbonate and saturated column leach testing. Physical parameter data are used for (1) characterization of vadose and saturated zone geology and hydrogeology, (2) selection of monitoring well screen sizes, (3) to support modeling and analysis of the vadose and saturated zones, and (4) for engineering design. The objectives of this report are to determine the QA/QC levels accepted in the EPA Region 10 for the sampling, handling, and analysis of soil samples for physical parameters during CERCLA RI.

Innis, B.E.

1993-07-21

279

High-Speed Video Analysis in a Conceptual Physics Class

NASA Astrophysics Data System (ADS)

The use of probe ware and computers has become quite common in introductory physics classrooms. Video analysis is also becoming more popular and is available to a wide range of students through commercially available and/or free software.2,3 Video analysis allows for the study of motions that cannot be easily measured in the traditional lab setting and also allows real-world situations to be analyzed. Many motions are too fast to easily be captured at the standard video frame rate of 30 frames per second (fps) employed by most video cameras. This paper will discuss using a consumer camera that can record high-frame-rate video in a college-level conceptual physics class. In particular this will involve the use of model rockets to determine the acceleration during the boost period right at launch and compare it to a simple model of the expected acceleration.

Desbien, Dwain M.

2011-09-01

280

Density functional theory (DFT) computations have become an efficient tool in the prediction of molecular structure, harmonic force fields, vibrational wave numbers as well as the IR and Raman intensities of pharmaceutically important molecule. In this work, we report harmonic vibrational frequencies, molecular structure, NBO and HOMO, LUMO analysis and detonation properties of (S)-2-(2-oxopyrrolidin-1-yl) butanamide. The solid phase FT-IR and FT-Raman spectra of (S)-2-(2-oxopyrrolidin-1-yl) butanamide were recorded in the region 4000-450 cm(-1) and 4000-50 cm(-1) respectively. Harmonic frequencies of this compound were determined and analyzed by DFT utilizing 6-31G(d,p), 6-31+G(d,p) basis sets. The assignments of the vibrational spectra have been carried out with the help of Normal Coordinate Analysis (NCA) following the Scaled Quantum Mechanical Force Field Methodology (SQMFF). The calculated infrared and Raman spectra of the title compounds were also stimulated utilizing the scaled force fields and the computed dipole derivatives for IR intensities and polarizability derivatives for Raman intensities. The change in electron density (ED) in the ?(*) and ?(*) antibonding orbital's and stabilization energies E(2) have been calculated by Natural Bond Orbital (NBO) analysis to give clear evidence of stabilization originating in the hyperconjugation of hydrogen-bonded interaction. Heat of formation (HOF) and calculated density were estimated to evaluate detonation properties using Kamlet-Jacobs equations. The linear polarizability (?) and the first order hyperpolarizability (?) values of the investigated molecule have been computed using DFT calculations. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The observed and calculated wave numbers are found to be in good agreement. On the basis of vibrational analyses, the thermodynamic properties of title compound at different temperatures have been calculated. PMID:24096066

Renuga, S; Muthu, S

2014-01-24

281

PHYSICS AND SAFETY ANALYSIS FOR THE NIST RESEARCH REACTOR

Detailed reactor physics and safety analyses have been performed for the 20 MW DO moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The analyses provide an update to the Final Safety Analysis Report (FSAR) and employ state-of-the-art calculational methods. Three-dimensional MCNP Monte Carlo neutron and photon transport calculations were performed to determine the safety parameters

J. CHENG; L. HANSON; J. RORER; D. DIAMOND

2003-01-01

282

PHYSICS AND SAFETY ANALYSIS FOR THE NIST RESEARCH REACTOR

Detailed reactor physics and safety analyses have been performed for the 20 MW DO moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The analyses provide an update to the Final Safety Analysis Report (FSAR) and employ state-of-the-art calculational methods. Three-dimensional Monte Carlo neutron and photon transport calculations were performed with the MCNP code to determine

L. HANSON; A. DIAMOND; D. XU; J. CAREW; J. RORER

2004-01-01

283

Physics analysis of the gang partial rod drive event

During the routine positioning of partial-length control rods in Gang 3 on the afternoon of Monday, July 27, 1992, the partial-length rods continued to drive into the reactor even after the operator released the controlling toggle switch. In response to this occurrence, the Safety Analysis and Engineering Services Group (SAEG) requested that the Applied Physics Group (APG) analyze the gang partial rod drive event. Although similar accident scenarios were considered in analysis for Chapter 15 of the Safety Analysis Report (SAR), APG and SAEG conferred and agreed that this particular type of gang partial-length rod motion event was not included in the SAR. This report details this analysis.

Boman, C.; Frost, R.L.

1992-08-01

284

The human body's response to glucose and three physical models

NASA Astrophysics Data System (ADS)

Three physical models of the human body's response to a glucose challenge are presented from the medical literature. Glucose tolerance is evaluated using kinematical techniques, an exponential-decay analysis, and a damped harmonic-oscillator model. Each treatment contains material suitable as supplementary topics in physics courses, both introductory and intermediate.

Ruiz, Michael J.

1987-07-01

285

The Local Stellar Velocity Field via Vector Spherical Harmonics

NASA Technical Reports Server (NTRS)

We analyze the local field of stellar tangential velocities for a sample of 42,339 nonbinary Hipparcos stars with accurate parallaxes, using a vector spherical harmonic formalism. We derive simple relations between the parameters of the classical linear model (Ogorodnikov-Milne) of the local systemic field and low-degree terms of the general vector harmonic decomposition. Taking advantage of these relationships, we determine the solar velocity with respect to the local stars of (V(sub X), V(sub Y), V(sub Z)) (10.5, 18.5, 7.3) +/- 0.1 km s(exp -1) not corrected for the asymmetric drift with respect to the local standard of rest. If only stars more distant than 100 pc are considered, the peculiar solar motion is (V(sub X), V(sub Y), V(sub Z)) (9.9, 15.6, 6.9) +/- 0.2 km s(exp -1). The adverse effects of harmonic leakage, which occurs between the reflex solar motion represented by the three electric vector harmonics in the velocity space and higher degree harmonics in the proper-motion space, are eliminated in our analysis by direct subtraction of the reflex solar velocity in its tangential components for each star. The Oort parameters determined by a straightforward least-squares adjustment in vector spherical harmonics are A=14.0 +/- 1.4, B=13.1 +/- 1.2, K=1.1 +/- 1.8, and C=2.9 +/- 1.4 km s(exp -1) kpc(exp -1). The physical meaning and the implications of these parameters are discussed in the framework of a general linear model of the velocity field. We find a few statistically significant higher degree harmonic terms that do not correspond to any parameters in the classical linear model. One of them, a third-degree electric harmonic, is tentatively explained as the response to a negative linear gradient of rotation velocity with distance from the Galactic plane, which we estimate at approximately -20 km s(exp -1) kpc(exp -1). A similar vertical gradient of rotation velocity has been detected for more distant stars representing the thick disk (z greater than 1 kpc), but here we surmise its existence in the thin disk at z less than 200 pc. The most unexpected and unexplained term within the Ogorodnikov-Milne model is the first-degree magnetic harmonic, representing a rigid rotation of the stellar field about the axis -Y pointing opposite to the direction of rotation. This harmonic comes out with a statistically robust coefficient of 6.2 +/- 0.9 km s(exp -1) kpc(exp -1) and is also present in the velocity field of more distant stars. The ensuing upward vertical motion of stars in the general direction of the Galactic center and the downward motion in the anticenter direction are opposite to the vector field expected from the stationary Galactic warp model.

Markarov, V. V.; Murphy, D. W.

2007-01-01

286

NASA Astrophysics Data System (ADS)

Quantitative methods for noninvasive diagnosis of scars are a challenging issue in medicine. This work aims to implement a texture analysis method for quantitatively discriminating abnormal scars from normal scars based on second-harmonic generation (SHG) images. A local difference local binary pattern (LD-LBP) operator combined with a wavelet transform was explored to extract diagnosis features from scar SHG images that were related to the alteration in collagen morphology. Based on the quantitative parameters including the homogeneity, directional and coarse features in SHG images, the scar collagen SHG images were classified into normal or abnormal scars by a support vector machine classifier in a leave-one-out cross-validation procedure. Our experiments and data analyses demonstrated apparent differences between normal and abnormal scars in terms of their morphological structure of collagen. By comparing with gray level co-occurrence matrix, wavelet transform, and combined basic local binary pattern and wavelet transform with respect to the accuracy and receiver operating characteristic analysis, the method proposed herein was demonstrated to achieve higher accuracy and more reliable classification of SHG images. This result indicated that the extracted texture features with the proposed method were effective in the classification of scars. It could provide assistance for physicians in the diagnostic process.

Liu, Yao; Zhu, Xiaoqin; Huang, Zufang; Cai, Jianyong; Chen, Rong; Xiong, Shuyuan; Chen, Guannan; Zeng, Haishan

2015-01-01

287

Quantitative methods for noninvasive diagnosis of scars are a challenging issue in medicine. This work aims to implement a texture analysis method for quantitatively discriminating abnormal scars from normal scars based on second-harmonic generation (SHG) images. A local difference local binary pattern (LD-LBP) operator combined with a wavelet transform was explored to extract diagnosis features from scar SHG images that were related to the alteration in collagen morphology. Based on the quantitative parameters including the homogeneity, directional and coarse features in SHG images, the scar collagen SHG images were classified into normal or abnormal scars by a support vector machine classifier in a leave-one-out cross-validation procedure. Our experiments and data analyses demonstrated apparent differences between normal and abnormal scars in terms of their morphological structure of collagen. By comparing with gray level co-occurrence matrix, wavelet transform, and combined basic local binary pattern and wavelet transform with respect to the accuracy and receiver operating characteristic analysis, the method proposed herein was demonstrated to achieve higher accuracy and more reliable classification of SHG images. This result indicated that the extracted texture features with the proposed method were effective in the classification of scars. It could provide assistance for physicians in the diagnostic process. PMID:25611867

Liu, Yao; Zhu, Xiaoqin; Huang, Zufang; Cai, Jianyong; Chen, Rong; Xiong, Shuyuan; Chen, Guannan; Zeng, Haishan

2015-01-01

288

Meta-Analysis of Workplace Physical Activity Interventions

Context Most adults do not achieve adequate physical activity. Despite the potential benefits of worksite health promotion, no previous comprehensive meta-analysis has summarized health and physical activity behavior outcomes from these programs. This comprehensive meta-analysis integrated the extant wide range of worksite physical activity intervention research. Evidence acquisition Extensive searching located published and unpublished intervention studies reported from 1969 through 2007. Results were coded from primary studies. Random-effects meta-analytic procedures, including moderator analyses, were completed in 2008. Evidence synthesis Effects on most variables were substantially heterogeneous because diverse studies were included. Standardized mean difference (d) effect sizes were synthesized across approximately 38,231 subjects. Significantly positive effects were observed for physical activity behavior (0.21), fitness (0.57), lipids (0.13), anthropometric measures (0.08), work attendance (0.19), and job stress (0.33). The significant effect size for diabetes risk (0.98) is more tentative given small sample sizes. Significant heterogeneity documents intervention effects varied across studies. The mean effect size for fitness corresponds to a difference between treatment minus control subjects' means on V02max of 3.5 mL/kg/min; for lipids, ?0.2 on total cholesterol:HDL; and for diabetes risk, ?12.6 mg/dL on fasting glucose. Conclusions These findings document that some workplace physical activity interventions can improve both health and important worksite outcomes. Effects were variable for most outcomes, reflecting the diversity of primary studies. Future primary research should compare interventions to confirm causal relationships and further explore heterogeneity. PMID:19765506

Conn, Vicki S.; Hafdahl, Adam R.; Cooper, Pamela S.; Brown, Lori M.; Lusk, Sally L.

2009-01-01

289

Symbolic Vector Analysis in Plasma Physics H. Qin, W. M. Tang, and G. Rewoldt

Symbolic Vector Analysis in Plasma Physics H. Qin, W. M. Tang, and G. Rewoldt Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ, 08543451 Many problems in plasma physics involve to their problems. Several applications of this symbolic vector analysis package to plasma physics are also given

290

Search for Harmonic tremor in the Galapagos Jonathan M. Lees, University of North Carolina, Chapel Hill Harmonic volcano tremor can provide details of conduit physics during magma flow and volcano.71.2 Hz. Harmonic tremor has not been reported on Galapagos volcanoes, possibly because seismic

Geist, Dennis

291

Introduction to the Space Physics Analysis Network (SPAN)

NASA Technical Reports Server (NTRS)

The Space Physics Analysis Network or SPAN is emerging as a viable method for solving an immediate communication problem for the space scientist. SPAN provides low-rate communication capability with co-investigators and colleagues, and access to space science data bases and computational facilities. The SPAN utilizes up-to-date hardware and software for computer-to-computer communications allowing binary file transfer and remote log-on capability to over 25 nationwide space science computer systems. SPAN is not discipline or mission dependent with participation from scientists in such fields as magnetospheric, ionospheric, planetary, and solar physics. Basic information on the network and its use are provided. It is anticipated that SPAN will grow rapidly over the next few years, not only from the standpoint of more network nodes, but as scientists become more proficient in the use of telescience, more capability will be needed to satisfy the demands.

Green, J. L. (editor); Peters, D. J. (editor)

1985-01-01

292

Positioning Ideas: Creating and Relating Physics Identities Through Video Analysis

NASA Astrophysics Data System (ADS)

Prior research has documented that analyzing video of children learning science aids pre-service teachers in developing physics knowledge and deepens their understanding of the learning process. Research on video analysis in teacher education suggests that the primary value of such tasks comes not from watching the video, but from the subsequent discussions. We questioned whether similar advantages would be evident when participants watched and analyzed video clips via online threaded discussions. We found that participants used the video clips as a mediating tool to position their own current ideas about physics topics with respect to their prior understandings as well as to ideas articulated by the students in the video clips. We discuss the study findings and affordances and limitations of online discussion formats.

Harlow, Danielle Boyd; Swanson, Lauren H.

2009-11-01

293

Disability in physical education textbooks: an analysis of image content.

The aim of this paper is to show how images of disability are portrayed in physical education textbooks for secondary schools in Spain. The sample was composed of 3,316 images published in 36 textbooks by 10 publishing houses. A content analysis was carried out using a coding scheme based on categories employed in other similar studies and adapted to the requirements of this study with additional categories. The variables were camera angle, gender, type of physical activity, field of practice, space, and level. Univariate and bivariate descriptive analyses were also carried out. The Pearson chi-square statistic was used to identify associations between the variables. Results showed a noticeable imbalance between people with disabilities and people without disabilities, and women with disabilities were less frequently represented than men with disabilities. People with disabilities were depicted as participating in a very limited variety of segregated, competitive, and elite sports activities. PMID:23027145

Táboas-Pais, María Inés; Rey-Cao, Ana

2012-10-01

294

Toward the automated analysis of plasma physics problems

A program (CALC) is described, which carries out nontrivial plasma physics calculations, in a manner intended to emulate the approach of a human theorist. This includes the initial process of gathering the relevant equations from a plasma knowledge base, and then determining how to solve them. Solution of the sets of equations governing physics problems, which in general have a nonuniform,irregular structure, not amenable to solution by standardized algorithmic procedures, is facilitated by an analysis of the structure of the equations and the relations among them. This often permits decompositions of the full problem into subproblems, and other simplifications in form, which renders the resultant subsystems soluble by more standardized tools. CALC's operation is illustrated by a detailed description of its treatment of a sample plasma calculation. 5 refs., 3 figs.

Mynick, H.E.

1989-04-01

295

Collagen is the most prominent protein in the human body, making up 30% of the total protein content. Quantitative studies have shown structural differences between collagen fibers of the normal and diseased tissues, due to the remodeling of the extracellular matrix during the pathological process. The dominant orientation, which is an important characteristic of collagen fibers, has not been taken into consideration for quantitative collagen analysis. Based on the conventional gray level co-occurrence matrix (GLCM) method, the authors proposed the orientation-dependent GLCM (OD-GLCM) method by estimating the dominant orientation of collagen fibers. The authors validated the utility of the OD-GLCM method on second harmonic generation (SHG) microscopic images of tendons from rats with different ages. Compared with conventional GLCM method, the authors' method has not only improved the discrimination between different tissues but also provided additional texture information of the orderliness of collagen fibers and the fiber size. The OD-GLCM method was further applied to the differentiation of the preliminary SHG images of normal and cancerous human pancreatic tissues. The combination of SHG microscopy and the OD-GLCM method might be helpful for the evaluation of diseases marked with abnormal collagen morphology. PMID:22463039

Hu, Wenyan; Li, Hui; Wang, Chunyou; Gou, Shanmiao; Fu, Ling

2012-02-01

296

NASA Astrophysics Data System (ADS)

Collagen is the most prominent protein in the human body, making up 30% of the total protein content. Quantitative studies have shown structural differences between collagen fibers of the normal and diseased tissues, due to the remodeling of the extracellular matrix during the pathological process. The dominant orientation, which is an important characteristic of collagen fibers, has not been taken into consideration for quantitative collagen analysis. Based on the conventional gray level co-occurrence matrix (GLCM) method, the authors proposed the orientation-dependent GLCM (OD-GLCM) method by estimating the dominant orientation of collagen fibers. The authors validated the utility of the OD-GLCM method on second harmonic generation (SHG) microscopic images of tendons from rats with different ages. Compared with conventional GLCM method, the authors' method has not only improved the discrimination between different tissues but also provided additional texture information of the orderliness of collagen fibers and the fiber size. The OD-GLCM method was further applied to the differentiation of the preliminary SHG images of normal and cancerous human pancreatic tissues. The combination of SHG microscopy and the OD-GLCM method might be helpful for the evaluation of diseases marked with abnormal collagen morphology.

Hu, Wenyan; Li, Hui; Wang, Chunyou; Gou, Shanmiao; Fu, Ling

2012-02-01

297

Management of the Space Physics Analysis Network (SPAN)

NASA Technical Reports Server (NTRS)

Here, the purpose is to define the operational management structure and to delineate the responsibilities of key Space Physics Analysis Network (SPAN) individuals. The management structure must take into account the large NASA and ESA science research community by giving them a major voice in the operation of the system. Appropriate NASA and ESA interfaces must be provided so that there will be adequate communications facilities available when needed. Responsibilities are delineated for the Advisory Committee, the Steering Committee, the Project Scientist, the Project Manager, the SPAN Security Manager, the Internetwork Manager, the Network Operations Manager, the Remote Site Manager, and others.

Green, James L.; Thomas, Valerie L.; Butler, Todd F.; Peters, David J.; Sisson, Patricia L.

1990-01-01

298

Multi-Physics Analysis of the Fermilab Booster RF Cavity

After about 40 years of operation the RF accelerating cavities in Fermilab Booster need an upgrade to improve their reliability and to increase the repetition rate in order to support a future experimental program. An increase in the repetition rate from 7 to 15 Hz entails increasing the power dissipation in the RF cavities, their ferrite loaded tuners, and HOM dampers. The increased duty factor requires careful modelling for the RF heating effects in the cavity. A multi-physic analysis investigating both the RF and thermal properties of Booster cavity under various operating conditions is presented in this paper.

Awida, M.; Reid, J.; Yakovlev, V.; Lebedev, V.; Khabiboulline, T.; Champion, M.; /Fermilab

2012-05-14

299

Fault detection and diagnostics for non-intrusive monitoring using motor harmonics

Harmonic analysis of motor current has been used to track the speed of motors for sensorless control. Algorithms exist that track the speed of a motor given a dedicated stator current measurement, for example. Harmonic analysis has also been applied for diagnostic detection of electro-mechanical faults such as damaged bearings and rotor eccentricity. This paper demonstrates the utility of harmonic

Uzoma A. Orji; Z. Remscrim; C. Laughman; S. B. Leeb; W. Wichakool; C. Schantz; R. Cox; J. L. Kirtley; L. K. Norford

2010-01-01

300

Fault Detection and Diagnostics for Non-Intrusive Monitoring Using Motor Harmonics

Harmonic analysis of motor current has been used to track the speed of motors for sensorless control. Algorithms exist that track the speed of a motor given a dedicated stator current measurement, for example. Harmonic ...

Orji, Uzoma A.

301

Simulated, Emulated, and Physical Investigative Analysis (SEPIA) of networked systems.

This report describes recent progress made in developing and utilizing hybrid Simulated, Emulated, and Physical Investigative Analysis (SEPIA) environments. Many organizations require advanced tools to analyze their information system's security, reliability, and resilience against cyber attack. Today's security analysis utilize real systems such as computers, network routers and other network equipment, computer emulations (e.g., virtual machines) and simulation models separately to analyze interplay between threats and safeguards. In contrast, this work developed new methods to combine these three approaches to provide integrated hybrid SEPIA environments. Our SEPIA environments enable an analyst to rapidly configure hybrid environments to pass network traffic and perform, from the outside, like real networks. This provides higher fidelity representations of key network nodes while still leveraging the scalability and cost advantages of simulation tools. The result is to rapidly produce large yet relatively low-cost multi-fidelity SEPIA networks of computers and routers that let analysts quickly investigate threats and test protection approaches.

Burton, David P.; Van Leeuwen, Brian P.; McDonald, Michael James; Onunkwo, Uzoma A.; Tarman, Thomas David; Urias, Vincent E.

2009-09-01

302

Omics integrating physical techniques: aged Piedmontese meat analysis.

Piedmontese meat tenderness becomes higher by extending the ageing period after slaughter up to 44 days. Classical physical analysis only partially explain this evidence, so in order to discover the reason of the potential beneficial effects of prolonged ageing, we performed omic analysis in the Longissimus thoracis muscle by examining main biochemical changes through mass spectrometry-based metabolomics and proteomics. We observed a progressive decline in myofibrillar structural integrity (underpinning meat tenderness) and impaired energy metabolism. Markers of autophagic responses (e.g. serine and glutathione metabolism) and nitrogen metabolism (urea cycle intermediates) accumulated until the end of the assayed period. Key metabolites such as glutamate, a mediator of the appreciated umami taste of the meat, were found to constantly accumulate until day 44. Finally, statistical analyses revealed that glutamate, serine and arginine could serve as good predictors of ultimate meat quality parameters, even though further studies are mandatory. PMID:25442615

Lana, Alessandro; Longo, Valentina; Dalmasso, Alessandra; D'Alessandro, Angelo; Bottero, Maria Teresa; Zolla, Lello

2015-04-01

303

Application of higher harmonic blade feathering for helicopter vibration reduction

NASA Technical Reports Server (NTRS)

Higher harmonic blade feathering for helicopter vibration reduction is considered. Recent wind tunnel tests confirmed the effectiveness of higher harmonic control in reducing articulated rotor vibratory hub loads. Several predictive analyses developed in support of the NASA program were shown to be capable of calculating single harmonic control inputs required to minimize a single 4P hub response. In addition, a multiple-input, multiple-output harmonic control predictive analysis was developed. All techniques developed thus far obtain a solution by extracting empirical transfer functions from sampled data. Algorithm data sampling and processing requirements are minimal to encourage adaptive control system application of such techniques in a flight environment.

Powers, R. W.

1978-01-01

304

Nondeducibility-Based Analysis of Cyber-Physical Systems

NASA Astrophysics Data System (ADS)

Controlling information flow in a cyber-physical system (CPS) is challenging because cyber domain decisions and actions manifest themselves as visible changes in the physical domain. This paper presents a nondeducibility-based observability analysis for CPSs. In many CPSs, the capacity of a low-level (LL) observer to deduce high-level (HL) actions ranges from limited to none. However, a collaborative set of observers strategically located in a network may be able to deduce all the HL actions. This paper models a distributed power electronics control device network using a simple DC circuit in order to understand the effect of multiple observers in a CPS. The analysis reveals that the number of observers required to deduce all the HL actions in a system increases linearly with the number of configurable units. A simple definition of nondeducibility based on the uniqueness of low-level projections is also presented. This definition is used to show that a system with two security domain levels could be considered “nondeducibility secure” if no unique LL projections exist.

Gamage, Thoshitha; McMillin, Bruce

305

A pair of uniaxial birefringent crystal elements are fixed together to form a serially arranged, integral assembly which, alternatively, provides either a linearly or elliptically polarized second-harmonic output wave or a linearly polarized third-harmonic output wave. The extraordinary or e directions of the crystal elements are oriented in the integral assembly to be in quadrature (90/sup 0/). For a second-harmonic generation in the Type-II-Type-II angle tuned case, the input fundamental wave has equal amplitude o and e components. For a third-harmonic generation, the input fundamental wave has o and e components whose amplitudes are in a ratio of 2:1 (o:e reference first crystal). In the typical case of a linearly polarized input fundamental wave this can be accomplished by simply rotating the crystal assembly about the input beam direction by 10/sup 0/. For both second and third harmonic generation input precise phase-matching is achieved by tilting the crystal assembly about its two sensitive axeses (o).

Summers, M.A.; Eimerl, D.; Boyd, R.D.

1982-06-10

306

A pair of uniaxial birefringent crystal elements are fixed together to form a serially arranged, integral assembly which, alternatively, provides either a linearly or elliptically polarized second-harmonic output wave or a linearly polarized third-harmonic output wave. The "extraordinary" or "e" directions of the crystal elements are oriented in the integral assembly to be in quadrature (90.degree.). For a second-harmonic generation in the Type-II-Type-II angle tuned case, the input fundamental wave has equal amplitude "o" and "e" components. For a third-harmonic generation, the input fundamental wave has "o" and "e" components whose amplitudes are in a ratio of 2:1 ("o":"e" reference first crystal). In the typical case of a linearly polarized input fundamental wave this can be accomplished by simply rotating the crystal assembly about the input beam direction by 10.degree.. For both second and third harmonic generation input precise phase-matching is achieved by tilting the crystal assembly about its two sensitive axes ("o").

Summers, Mark A. (Livermore, CA); Eimerl, David (Pleasanton, CA); Boyd, Robert D. (Livermore, CA)

1985-01-01

307

On the validity of harmonic source detection methods and indices

In this paper, the validity of the single-point measurements methods and indices, which were proposed for harmonic source detection and sharing harmonic responsibility between utility and consumer, are investigated in a typical distribution system which consists of several critical load cases. A parametrical analysis by means of the variation of the utility side impedance's X\\/R ratio is also undertaken. The

M. Erhan Balci

2010-01-01

308

IM and harmonic interference on DCS1800 band

Intermodulation and harmonic interference occur because of nonlinear processes, such as the amplifier discussed in this article. It presents a serious problem between the transmitter and receiver of different cellular providers. We discuss the IM and harmonic interference on the DCS-1800 band. A simulator was also developed to do the analysis. The worst scenario and possible prevention method for IM

D. Lee; C. Xu; U. Mayekar; M. Mohile

1997-01-01

309

A generative grammar approach to diatonic harmonic structure

. This approach covers cases of modulation, tonicisation and some aspects of large-scale harmonic form, and may and corpus analysis, as well as in the music psychological investigation of tonal cognition.1 I. INTRODUCTION explained by linear approaches. In compositional practice, harmonic progressions explore a large set

Kouroupetroglou, Georgios

310

Animal models suggest growth restriction in utero leads to lower levels of motor activity. Furthermore, individuals with very low birth weight report lower levels of physical activity as adults. The aim of this study was to examine whether birth weight acts as a biological determinant of physical activity and sedentary time. This study uses combined analysis of three European cohorts

Charlotte L. Ridgway; Søren Brage; Stephen J. Sharp; Kirsten Corder; Kate L. Westgate; Esther M. van Sluijs; Ian M. Goodyer; Pedro C. Hallal; Sigmund A. Anderssen; Luis B. Sardinha; Lars Bo Andersen; Ulf Ekelund; Jacqueline Ho

2011-01-01

311

NASA Astrophysics Data System (ADS)

The modal truncation problem is frequently encountered in nonviscously (viscoelastically) damped systems since only the modes of interest are usually considered in the dynamic analysis of engineering problems. This study aims at accurately calculating the steady-state responses of nonviscously damped systems by only considering the modes of interest. Based on the Neumann expansion theorem and the frequency shifting technique, a property obtained from the first-order terms of the Neumann expansion of the frequency response function (FRF) matrix of nonviscously damped systems is given. However, this procedure cannot be extended to consider the further higher-order terms. It means a truncation expansion problem exists for nonviscously damped systems. By considering the first-order terms of the Neumann expansion, a generalized mode acceleration method (GMAM) is presented to handle the modal truncation problem. The GMAM can overcome the singular problem of the stiffness matrix. The modal truncation augmentation method (MTAM) is also presented to handle the modal truncation problem by making the equilibrium equations into a subspace equation spanned in terms of the columns of a projection basis given in the GMAM. Several conclusions concerning the implementation of the presented methods are formulated on the basis of the results of three examples.

Li, Li; Hu, Yujin

2015-02-01

312

NASA Astrophysics Data System (ADS)

Western Kentucky University is undertaking the development of a thermoacoustically powered acoustic agglomerator as a means of pretreating exhaust from coal generators before entering standard industrial electrostatic precipitators. In order to fulfill the design requirement of maintaining a clean, isolated environment for the thermoacoustic components, it will be necessary to operate a thermoacoustic prime mover in a harmonic mode, which normally is not a desirable feature in typical devices. Details of a harmonic-mode prime mover will be presented. [Work supported by KY EPSCoR and the Western Kentucky Office of Sponsored Programs.

Rice, Ian; Smith, Gordon

2005-09-01

313

A Proposed Cost-benefit Analysis Model for Physical Form Analysis for a Futuristic Submarine for Physical Form Analysis for a Futuristic Submarine Decision Support System by Dhiman Bhattacharjee Submitted for submarine commanders managing multiple unmanned underwater vehicles, follows an integrated systems

Cummings, Mary "Missy"

314

Higher order harmonic detection for exploring nonlinear interactions with nanoscale resolution

Nonlinear dynamics underpin a vast array of physical phenomena ranging from interfacial motion to jamming transitions. In many cases, insight into the nonlinear behavior can be gleaned through exploration of higher order harmonics. Here, a method using band excitation scanning probe microscopy (SPM) to investigate higher order harmonics of the electromechanical response, with nanometer scale spatial resolution is presented. The technique is demonstrated by probing the first three harmonics of strain for a Pb(Zr1-xTix)O3 (PZT) ferroelectric capacitor. It is shown that the second order harmonic response is correlated with the first harmonic response, whereas the third harmonic is not. Additionally, measurements of the second harmonic reveal significant deviations from Rayleigh-type models in the form of a much more complicated field dependence than is observed in the spatially averaged data. These results illustrate the versatility of nth order harmonic SPM detection methods in exploring nonlinear phenomena in nanoscale materials. PMID:24045269

Vasudevan, R. K.; Okatan, M. Baris; Rajapaksa, I.; Kim, Y.; Marincel, D.; Trolier-McKinstry, S.; Jesse, S.; Valanoor, N.; Kalinin, S. V.

2013-01-01

315

From general equations which describe the transient electromechanical behavior of the asynchronous squirrel-cage motor, and which include the influence of space harmonics and mutual slotting, simplified models are derived and compared. The models derived are demonstrated in examples where special attention is paid to the influence of the place of the harmonics in the mutual inductance matrix and the influence of mutual slotting. Further, the steady-state equations are derived and the back-transformation for the stator and rotor currents is given. One example is compared with the result of measurements.

Paap, G.C. (Power Systems Laboratory, Delft Univ. of Technology, P.O. Box 5031, 2600 CD Delft (NL))

1991-03-01

316

NSDL National Science Digital Library

SphericalHarmonic returns the value of P(theta,phi) where theta and phi are defined in terms of a standard spherical coordinate system (phi measures angle (x,y,z) makes with z axis.) The algorithm is taken from Messiah's Quantum Mechanics, but readers should note that Messiah defines theta and phi in opposite order from this implementation.

David Joiner

317

NASA Astrophysics Data System (ADS)

1. Elementary theory of harmonic motion; 2. Experimental work in harmonic motion; Experiment 1. Determination of g by a simple pendulum; Experiment 2. Harmonic motion of a body suspended by a spring; Experiment 3. Harmonic motion of a rigid body suspended by a torsion wire; Experiment 4. Study of a system with variable moment of inertia; Experiment 5. Dynamical determination of ratio of couple to twist for a torsion wire; Experiment 6. Comparison of the moments of inertia of two bodies; Experiment 7. Experiment with a pair of inertia bars; Experiment 8. Determination of the moment of inertia of a rigid pendulum; Experiment 9. Experiment on a pendulum with variable moment of inertia; Experiment 10. Determination of g by a rigid pendulum; Experiment 11. Pendulum on a yielding support; Experiment 12. Determination of the radius of curvature of a concave mirror by the oscillations of a sphere rolling in it; Experiment 13. Determination of g by the oscillations of a rod rolling on a cylinder; Experiment 14. Study of a vibrating system with two degrees of freedom; Note 1. On the vibration of a body suspended from a light spring; Note 2. Periodic time of a pendulum vibrating through a finite arc; Note 3. Periodic time for finite motion; Note 4. Periodic times of a pendulum with two degrees of freedom.

Searle, G. F. C.

2014-05-01

318

Harmonically excited orbital variations

Rephrasing the equations of motion for orbital maneuvers in terms of Lagrangian generalized coordinates instead of Newtonian rectangular cartesian coordinates can make certain harmonic terms in the orbital angular momentum vector more readily apparent. In this formulation the equations of motion adopt the form of a damped harmonic oscillator when torques are applied to the orbit in a variationally prescribed manner. The frequencies of the oscillator equation are in some ways unexpected but can nonetheless be exploited through resonant forcing functions to achieve large secular variations in the orbital elements. Two cases are discussed using a circular orbit as the control case: (1) large changes in orbital inclination achieved by harmonic excitation rather than one impulsive velocity change, and (2) periodic and secular changes to the longitude of the ascending node using both stable and unstable excitation strategies. The implications of these equations are also discussed for both artificial satellites and natural satellites. For the former, two utilitarian orbits are suggested, each exploiting a form of harmonic excitation. 5 refs.

Morgan, T.

1985-08-06

319

ERIC Educational Resources Information Center

We present a unit comprising theory, simulation and experiment for a body oscillating on a vertical spring, in which the simultaneous use of a force probe and an ultrasonic range finder enables one to explore quantitatively and understand many aspects of simple and damped harmonic motions. (Contains 14 figures.)

Gluck, P.; Krakower, Zeev

2010-01-01

320

Echo-enabled harmonic generation free electron lasers hold great promise for the generation of fully coherent radiation in x-ray wavelengths. Here we report the first evidence of high harmonics from the echo-enabled harmonic generation technique in the realistic scenario where the laser energy modulation is comparable to the beam slice energy spread. In this experiment, coherent radiation at the seventh harmonic of the second seed laser is generated when the energy modulation amplitude is about 2-3 times the slice energy spread. The experiment confirms the underlying physics of echo-enabled harmonic generation and may have a strong impact on emerging seeded x-ray free electron lasers that are capable of generating laserlike x rays which will advance many areas of science.

Xiang, D.; Colby, E.; Dunning, M.; Gilevich, S.; Hast, C.; Jobe, K.; McCormick, D.; Nelson, J.; Raubenheimer, T.O.; Soong, K.; Stupakov, G.; Szalata, Z.; Walz, D.; Weathersby, S.; Woodle, M.; /SLAC; ,

2012-02-15

321

Echo-enabled harmonic generation free electron lasers hold great promise for the generation of fully coherent radiation in x-ray wavelengths. Here we report the first evidence of high harmonics from the echo-enabled harmonic generation technique in the realistic scenario where the laser energy modulation is comparable to the beam slice energy spread. In this experiment, coherent radiation at the seventh harmonic of the second seed laser is generated when the energy modulation amplitude is about 2-3 times the slice energy spread. The experiment confirms the underlying physics of echo-enabled harmonic generation and may have a strong impact on emerging seeded x-ray free electron lasers that are capable of generating laserlike x rays which will advance many areas of science. PMID:22324690

Xiang, D; Colby, E; Dunning, M; Gilevich, S; Hast, C; Jobe, K; McCormick, D; Nelson, J; Raubenheimer, T O; Soong, K; Stupakov, G; Szalata, Z; Walz, D; Weathersby, S; Woodley, M

2012-01-13

322

Quantum Mechanical Search and Harmonic Perturbation

Perturbation theory in quantum mechanics studies how quantum systems interact with their environmental perturbations. Harmonic perturbation is a rare special case of time-dependent perturbations in which exact analysis exists. Some important technology advances, such as masers, lasers, nuclear magnetic resonance, etc., originated from it. Here we add quantum computation to this list with a theoretical demonstration. Based on harmonic perturbation, a quantum mechanical algorithm is devised to search the ground state of a given Hamiltonian. The intrinsic complexity of the algorithm is continuous and parametric in both time T and energy E. More precisely, the probability of locating a search target of a Hamiltonian in N-dimensional vector space is shown to be 1/(1+ c N E^{-2} T^{-2}) for some constant c. This result is optimal. As harmonic perturbation provides a different computation mechanism, the algorithm may suggest new directions in realizing quantum computers.

Jie-Hong R. Jiang; Dah-Wei Chiou; Cheng-En Wu

2007-09-14

323

Physical and Chemical Analytical Analysis: A key component of Bioforensics

The anthrax letters event of 2001 has raised our awareness of the potential importance of non-biological measurements on samples of biological agents used in a terrorism incident. Such measurements include a variety of mass spectral, spectroscopic, and other instrumental techniques that are part of the current armamentarium of the modern materials analysis or analytical chemistry laboratory. They can provide morphological, trace element, isotopic, and other molecular ''fingerprints'' of the agent that may be key pieces of evidence, supplementing that obtained from genetic analysis or other biological properties. The generation and interpretation of such data represents a new domain of forensic science, closely aligned with other areas of ''microbial forensics''. This paper describes some major elements of the R&D agenda that will define this sub-field in the immediate future and provide the foundations for a coherent national capability. Data from chemical and physical analysis of BW materials can be useful to an investigation of a bio-terror event in two ways. First, it can be used to compare evidence samples collected at different locations where such incidents have occurred (e.g. between the powders in the New York and Washington letters in the Amerithrax investigation) or between the attack samples and those seized during the investigation of sites where it is suspected the material was manufactured (if such samples exist). Matching of sample properties can help establish the relatedness of disparate incidents, and mis-matches might exclude certain scenarios, or signify a more complex etiology of the events under investigation. Chemical and morphological analysis for sample matching has a long history in forensics, and is likely to be acceptable in principle in court, assuming that match criteria are well defined and derived from known limits of precision of the measurement techniques in question. Thus, apart from certain operational issues (such as how to prioritize such measurements in the face of limited sample availability, or how to render samples safe for handling in the analytical laboratory,) instrumental analysis of biological agents for purposes of sample matching alone is unlikely to present fundamental problems that require extensive research and development investments. The second way that the data generated by instrumental analysis can be useful to an investigation is through inferences that can be drawn regarding the processes used to grow and ''weaponize'' the agent. In contrast to the case of sample matching, there are significant R&D challenges associated with developing a robust capability that will reliably permit such inferential uses of instrumental data. Elaborating these challenges occupies the major portion of this paper.

Velsko, S P

2005-02-15

324

Higher order harmonic detection for exploring nonlinear interactions

Nonlinear dynamics underpin a vast array of physical phenomena ranging from interfacial motion to jamming transitions. In many cases, decoupling the contributions of competing or co-existing mechanisms to the system response can be achieved through investigation of higher order harmonics. Here, a method using band excitation scanning probe microscopy to investigate higher order harmonics of the electromechanical response, with nanometer scale spatial resolution is presented. The utility of the technique is demonstrated by probing the first three harmonics of strain for a well-known system, a model Pb(Zr1-xTix)O3 ferroelectric capacitor. It is shown that the second order harmonic response is correlated with the first harmonic response, whereas the third harmonic is not. Additionally, nanoscale measurements of the second harmonic response with field reveal significant deviations from Rayleigh-type models in the form of a much more complicated field dependence than is observed in the spatially averaged data. These results illustrate the versatility of combining proximal probe techniques with nth harmonic detection methods in exploring and decoupling nonlinear dynamics in a wide variety of nanoscale materials.

Vasudevan, Rama K [ORNL; Okatan, M. B. [University of New South Wales; Rajapaksa, Indrajit [Oak Ridge National Laboratory (ORNL); Kim, Yunseok [ORNL; Marincel, Dan [Materials Science and Engineering, Pennsylvania State University; Trolier-McKinstry, Susan [Pennsylvania State University; Jesse, Stephen [ORNL; Nagarajan, Valanoor [University of New South Wales; Kalinin, Sergei V [ORNL

2013-01-01

325

Data intensive high energy physics analysis in a distributed cloud

NASA Astrophysics Data System (ADS)

We show that distributed Infrastructure-as-a-Service (IaaS) compute clouds can be effectively used for the analysis of high energy physics data. We have designed a distributed cloud system that works with any application using large input data sets requiring a high throughput computing environment. The system uses IaaS-enabled science and commercial clusters in Canada and the United States. We describe the process in which a user prepares an analysis virtual machine (VM) and submits batch jobs to a central scheduler. The system boots the user-specific VM on one of the IaaS clouds, runs the jobs and returns the output to the user. The user application accesses a central database for calibration data during the execution of the application. Similarly, the data is located in a central location and streamed by the running application. The system can easily run one hundred simultaneous jobs in an efficient manner and should scale to many hundreds and possibly thousands of user jobs.

Charbonneau, A.; Agarwal, A.; Anderson, M.; Armstrong, P.; Fransham, K.; Gable, I.; Harris, D.; Impey, R.; Leavett-Brown, C.; Paterson, M.; Podaima, W.; Sobie, R. J.; Vliet, M.

2012-02-01

326

Preliminary Rock Physics Analysis on Lodgepole Formation in Manitoba, Canada

NASA Astrophysics Data System (ADS)

We present rock physics analysis results of Lodgepole Formation, a carbonate reservoir in Daly Field, Manitoba, Canada. We confirmed that the Lodgepole Formation can be divided into six units in the study area: Basal Limestone, Cromer Shale, Cruickshank Crinoidal, Cruickshank Shale, Daly member and Flossie Lake member from the bottom, using eight well log data and previous works. We then performed rock physics analyses on four carbonate units (Basal Limestone, Cruickshank Crinoidal, Daly and Flossie Lake), such as Vp-porosity, AI-porosity, DEM (differential effective medium) modeling, and fluid substitution analysis. In Vp-porosity domain, the top unit, Flossie Lake member has lower porosity and higher velocity, while the other units show similar porosity and velocity. We think that this results from the diagenesis of Flossie Lake member since it bounds with unconformity. However, the four units show very similar trend in Vp-porosity domain, and we can report one Vp-porosity relation for all carbonate units of the Lodgepole formation. We also found that the acoustic impedance varies more than 10% from low porosity zone (3-6%) to high porosity zone (9-12%) from AI-porosity analysis. Thus one can delineate high porosity zone from seismic impedance data. DEM modeling showed that Flossie Lake would have relatively low aspect ratio of pores than the others, which implies that the top unit has been influenced by diagenesis. To determine fluid sensitivity of carbonate units, we conducted fluid substitution on four units from 100% water to 100% oil. The top unit, Flossie Lake, showed slight increase of Vp, which seems to be density effect. The others showed small decrease of Vp, but not significant. If we observe Vp/Vs rather than Vp, the sensitivity increases. However, fluid discrimination would be difficult because of high stiffness of rock frame. In summary, three lower carbonate units of Lodgepole Formation would be prospective and high porosity zone can be delineated from seismic impedance data. However, we think that finding pay zones from seismic data would be difficult. Acknowledgement:This work was supported by the Energy Resources R&D program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 2009201030001A).

Kim, N.; Keehm, Y.

2012-12-01

327

Point-based manifold harmonics.

This paper proposes an algorithm to build a set of orthogonal Point-Based Manifold Harmonic Bases (PB-MHB) for spectral analysis over point-sampled manifold surfaces. To ensure that PB-MHB are orthogonal to each other, it is necessary to have symmetrizable discrete Laplace-Beltrami Operator (LBO) over the surfaces. Existing converging discrete LBO for point clouds, as proposed by Belkin et al., is not guaranteed to be symmetrizable. We build a new point-wisely discrete LBO over the point-sampled surface that is guaranteed to be symmetrizable, and prove its convergence. By solving the eigen problem related to the new operator, we define a set of orthogonal bases over the point cloud. Experiments show that the new operator is converging better than other symmetrizable discrete Laplacian operators (such as graph Laplacian) defined on point-sampled surfaces, and can provide orthogonal bases for further spectral geometric analysis and processing tasks. PMID:22879345

Liu, Yang; Prabhakaran, Balakrishnan; Guo, Xiaohu

2012-10-01

328

Interference effects in two-color high-order harmonic generation

We study high-order harmonic generation in argon driven by an intense 800 nm laser field and a small fraction of its second harmonic. The intensity and divergence of the emitted even and odd harmonics are strongly modulated as a function of the relative delay between the two fields. We provide a detailed analysis of the underlying interference effects. The interference changes drastically when approaching the cutoff region due to a switch of the dominant trajectory responsible for harmonic generation.

He, X.; Dahlstroem, J. M.; Rakowski, R.; Persson, A.; Mauritsson, J.; L'Huillier, A. [Department of Physics, Lund University, P. O. Box 118, SE-221 00 Lund (Sweden); Heyl, C. M. [Department of Physics, Lund University, P. O. Box 118, SE-221 00 Lund (Sweden); Department of Physics, University of Marburg, Marburg (Germany)

2010-09-15

329

Enhancement of third harmonic generation in air filamentation using obstacles

NASA Astrophysics Data System (ADS)

The intensity of third harmonic emission in air filamentation disturbed by copper fibers and alcohol droplets has been investigated experimentally. Enhancement of the third harmonic emission up to more than one order of magnitude has been observed. The physical mechanism of third harmonic enhancement is attributed to suppression of the destructive interference by comparison of the experimental results and it is closely related to the type, size, and relative position of the obstacles. Project supported by the National Key Technology R&D Program of the Ministry of Science and Technology, China (Grant No. 2012BAC23B00) and the National Natural Science Foundation of China (Grants No. 11404335).

Liu, Xiao-Long; Lu, Xin; Du, Zhi-Gui; Ma, Jing-Long; Li, Yu-Tong; Zhang, Jie

2015-03-01

330

BACKGROUND: Cardiovascular risk factors are associated with physical fitness and, to a lesser extent, physical activity. Lifestyle interventions directed at enhancing physical fitness in order to decrease the risk of cardiovascular diseases should be extended. To enable the development of effective lifestyle interventions for people with cardiovascular risk factors, we investigated motivational, social-cognitive determinants derived from the Theory of Planned

Barbara Sassen; Gerjo Kok; Herman Schaalma; Henri Kiers; Luc Vanhees

2010-01-01

331

Physical Disability on Children's Television Programming: A Content Analysis

ERIC Educational Resources Information Center

Research Findings: Media representations of physical disability can influence the attitudes of child audiences. In the current study, the depiction of physical disability was analyzed in more than 400 episodes of children's television programming to better understand how media depict physical disability to children and, in turn, how exposure may…

Bond, Bradley J.

2013-01-01

332

Harmonic Balance, Melnikov Method and Nonlinear Oscillators Under Resonant Perturbation

Harmonic Balance, Melnikov Method and Nonlinear Oscillators Under Resonant Perturbation Michele tool for the analysis of subharmonic orbits in weakly perturbed nonlinear oscillators, but its that bifurcations of subharmonic orbits in perturbed systems can be easily detected computing the Melnikov

Bonnin, Michele

333

Three-dimensional simulations of harmonic radiation and harmonic lasing

Characteristics of the harmonic emission from free-electron lasers (FELs) are examined in the spontaneous, coherent-spontaneous and stimulated emission regimes. The radiation at both odd and even harmonic frequencies is treated for electron beams with finite emittance and energy spread. In the spontaneous emission regime, the transverse radiation patterns including the transverse frequency dependences, are given. How this expression is modified to include energy spread and emittance is described. In the coherent-spontaneous emission and stimulated emission regimes, the interaction of the radiation fields with the electrons must be treated self-consistently. Here, a single-frequency distributed transverse source function for each electron is used in the harmonic version of the 3-D code FELEX to model the harmonic radiation. The code has recently been modified to simultaneously model the fundamental and harmonic interactions for multiple-pass oscillator simulations. These modifications facilitate the examination of FELs under various operating conditions. When the FEL is lasing at the fundamental, the evolution of the harmonic fields can be examined. This evolution is unique in the sense that the electron beam radiates at the harmonic frequencies in the presence of the harmonic radiation circulating in the cavity. As a result, enhancements of the harmonic emission can be observed. Finally, harmonic lasing can occur in cases where there is sufficient gain to overcome cavity losses and lasing at the fundamental can be suppressed. The characteristics and efficiency of these interactions are explored. 11 refs., 9 figs.

Schmitt, M.J.; McVey, B.D.

1990-01-01

334

Anxiety Outcomes after Physical Activity Interventions: Meta-Analysis Findings

Background Although numerous primary studies have documented the mental health benefits of physical activity (PA), no previous quantitative synthesis has examined anxiety outcomes of interventions to increase PA. Objectives This meta-analysis integrates extant research about anxiety outcomes from interventions to increase PA among healthy adults. Method Extensive literature searching located published and unpublished PA intervention studies with anxiety outcomes. Eligible studies reported findings from interventions designed to increase PA delivered to healthy adults without anxiety disorders. Data were coded from primary studies. Random-effects meta-analytic procedures were completed. Exploratory moderator analyses using meta-analysis ANOVA and regression analogues were conducted to determine if report, methods, sample, or intervention characteristics were associated with differences in anxiety outcomes. Results Data were synthesized across 3,289 subjects from 19 eligible reports. The overall mean anxiety effect size (d-index) for two-group comparisons was 0.22 with significant heterogeneity (Q = 32.15). Exploratory moderator analyses found larger anxiety improvement effect sizes among studies that included larger samples, used random allocation of subjects to treatment and control conditions, targeted only PA behavior instead of multiple health behaviors, included supervised exercise (vs. home-based PA), used moderate or high-intensity instead of low-intensity PA, and suggested subjects exercise at a fitness facility (vs. home) following interventions. Discussion These findings document that some interventions can decrease anxiety symptoms among healthy adults. Exploratory moderator analyses suggest possible directions for future primary research to compare interventions in randomized trials to confirm causal relationships. PMID:20410849

Conn, Vicki S.

2011-01-01

335

Structural, Physical, and Compositional Analysis of Lunar Simulants and Regolith

NASA Technical Reports Server (NTRS)

Relative to the prior manned Apollo and unmanned robotic missions, planned Lunar initiatives are comparatively complex and longer in duration. Individual crew rotations are envisioned to span several months, and various surface systems must function in the Lunar environment for periods of years. As a consequence, an increased understanding of the surface environment is required to engineer and test the associated materials, components, and systems necessary to sustain human habitation and surface operations. The effort described here concerns the analysis of existing simulant materials, with application to Lunar return samples. The interplay between these analyses fulfills the objective of ascertaining the critical properties of regolith itself, and the parallel objective of developing suitable stimulant materials for a variety of engineering applications. Presented here are measurements of the basic physical attributes, i.e. particle size distributions and general shape factors. Also discussed are structural and chemical properties, as determined through a variety of techniques, such as optical microscopy, SEM and TEM microscopy, Mossbauer Spectroscopy, X-ray diffraction, Raman microspectroscopy, inductively coupled argon plasma emission spectroscopy and energy dispersive X-ray fluorescence mapping. A comparative description of currently available stimulant materials is discussed, with implications for more detailed analyses, as well as the requirements for continued refinement of methods for simulant production.

Greenberg, Paul; Street, Kenneth W.; Gaier, James

2008-01-01

336

This paper presents a method and cantilever design for improving the mechanical measurement sensitivity in the atomic force microscopy (AFM) tapping mode. The method uses two harmonics in the drive signal to generate a bi-harmonic tapping trajectory. Mathematical analysis demonstrates that the wide-valley bi-harmonic tapping trajectory is as much as 70% more sensitive to changes in the sample topography than the standard single-harmonic trajectory typically used. Although standard AFM cantilevers can be driven in the bi-harmonic tapping trajectory, they require large forcing at the second harmonic. A design is presented for a bi-harmonic cantilever that has a second resonant mode at twice its first resonant mode, thereby capable of generating bi-harmonic trajectories with small forcing signals. Bi-harmonic cantilevers are fabricated by milling a small cantilever on the interior of a standard cantilever probe using a focused ion beam. Bi-harmonic drive signals are derived for standard cantilevers and bi-harmonic cantilevers. Experimental results demonstrate better than 30% improvement in measurement sensitivity using the bi-harmonic cantilever. Images obtained through bi-harmonic tapping exhibit improved sharpness and surface tracking, especially at high scan speeds and low force fields.

Loganathan, Muthukumaran; Bristow, Douglas A., E-mail: dbristow@mst.edu [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, Missouri 65401 (United States)

2014-04-15

337

PHYSICS AND SAFETY ANALYSIS FOR THE NIST RESEARCH REACTOR.

Detailed reactor physics and safety analyses have been performed for the 20 MW D{sub 2}O moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The analyses provide an update to the Final Safety Analysis Report (FSAR) and employ state-of-the-art calculational methods. Three-dimensional Monte Carlo neutron and photon transport calculations were performed with the MCNP code to determine the safety parameters for the NBSR. The core depletion and determination of the fuel compositions were performed with MONTEBURNS. MCNP calculations were performed to determine the beginning, middle, and end-of-cycle power distributions, moderator temperature coefficient, and shim safety arm, beam tube and void reactivity worths. The calculational model included a plate-by-plate description of each fuel assembly, axial mid-plane water gap, beam tubes and the tubular geometry of the shim safety arms. The time-dependent analysis of the primary loop was determined with a RELAP5 transient analysis model that includes the pump, heat exchanger, fuel element geometry, and flow channels for both the six inner and twenty-four outer fuel elements. The statistical analysis used to assure protection from critical heat flux (CHF) was performed using a Monte Carlo simulation of the uncertainties contributing to the CHF calculation. The power distributions used to determine the local fuel conditions and margin to CHF were determined with MCNP. Evaluations were performed for the following accidents: (1) the control rod withdrawal startup accident, (2) the maximum reactivity insertion accident, (3) loss-of-flow resulting from loss of electrical power, (4) loss-of-flow resulting from a primary pump seizure, (5) loss-of-flow resulting from inadvertent throttling of a flow control valve, (6) loss-of-flow resulting from failure of both shutdown cooling pumps and (7) misloading of a fuel element. In both the startup and maximum reactivity insertion accidents, the core power transient is terminated by a reactor trip at 26 MW. The calculations show that both the peak reactor power and the excursion energy depend on the negative reactivity insertion from reactor trip. In one of the loss-of-flow accidents offsite electrical power is assumed lost to the three operating primary pumps. A slightly delayed reactor scram is initiated as a result of primary flow coast down. The RELAP5 results indicate that there is adequate margin to CHF and no damage to the fuel will occur, because of the momentum of the coolant flowing through the fuel channels and the negative scram reactivity insertion. For both the primary pump seizure and inadvertent throttling of a flow control valve, the RELAP5 analyses indicate that the reduction in power following the trip is sufficient to ensure that there is adequate margin to CHF and that the fuel cladding does not fail. The analysis of the loss-of-flow accident in the extremely unlikely case where both shutdown pumps fail, shows that the cooling provided by the D{sub 2}O is sufficient to ensure the cladding does not fail. The power distributions were examined for a set of fuel misloadings in which a fresh fuel element is moved from a peripheral low-reactivity location to a central high-reactivity location. The calculations show that there is adequate margin to CHF and the cladding does not fail. An additional analysis was performed to simulate the operation at low power (500 kW) without forced flow cooling. The result indicates that natural convection cooling is adequate for operation of the NBSR at a power level of 500 kW.

CHENG,L.HANSON,A.DIAMOND,D.XU,J.CAREW,J.RORER,D.

2004-03-31

338

LC-TOOL-2003-015 1 Java Physics Generator and Analysis Modules

LC-TOOL-2003-015 1 Java Physics Generator and Analysis Modules Michael T. Ronan LBNL, Berkeley, CA) physics event generators are used in de#12;ning a common generator interface package. Portable libraries provide high-level OO study tools. Complete physics generation, parallel detector simulations

339

Effectiveness of Physical Activity Interventions for Preschoolers: A Meta-Analysis

ERIC Educational Resources Information Center

Purpose: The purpose of the meta-analysis was to examine the effectiveness of physical activity interventions on physical activity participation among preschoolers. A secondary purpose was to investigate the influence of several possible moderator variables (e.g., intervention length, location, leadership, type) on moderate-to-vigorous physical…

Gordon, Elliott S.; Tucker, Patricia; Burke, Shauna M.; Carron, Albert V.

2013-01-01

340

Effects of Physical Exercise on Autism Spectrum Disorders: A Meta-Analysis

ERIC Educational Resources Information Center

It is generally agreed that regular physical exercise promotes physical and mental health, but what are the benefits in people with Autism Spectrum Disorders (ASD)? This meta-analysis evaluates 16 behavioural studies reporting on a total of 133 children and adults with various variants of the syndrome who were offered structured physical…

Sowa, Michelle; Meulenbroek, Ruud

2012-01-01

341

We report theoretical calculations of the effect of the multiple-orbital contribution in high-order harmonic generation (HHG) of aligned CO{sub 2} with the inclusion of macroscopic propagation of harmonic fields in the medium. Our results show very good agreement with recent experiments for the dynamics of the minimum in HHG spectra as laser intensity or alignment angle changes. Calculations are carried out to check how the position of the minimum in HHG spectra depends on the degrees of molecular alignment, laser-focusing conditions, and the effects of alignment-dependent ionization rates of the different molecular orbitals. These analyses help to explain why the minima observed in different experiments may vary.

Jin, Cheng; Le, Anh-Thu; Lin, C. D. [J. R. Macdonald Laboratory, Physics Department, Kansas State University, Manhattan, Kansas 66506-2604 (United States)

2011-05-15

342

INTRODUCTION 1. 1 Introduction 1. 2 Three Phase Rectifier Interface. 1. 3 Rectifier Interface without DC-link Inductor. . . . . 1. 4 Review of Harmonic Current Cancellation Methods . 1. 5 Research Objective . 1. 6 Scope of Thesis DESIGN CONSIDERATIONS... specificaiions II Designed values for circuit model simulanon 63 LIST OF FIGURES FIGURE Page 1 Typical circuit diagram in an AC motor drive system 2 Line to neutral voltage V and line current I?without smoothing inductor 5 3 Frequency specmim of the line...

Rendusara, Dudi Abdullah

1995-01-01

343

Electron cyclotron harmonic wave acceleration

NASA Technical Reports Server (NTRS)

A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts.

Karimabadi, H.; Menyuk, C. R.; Sprangle, P.; Vlahos, L.

1987-01-01

344

PHYSICS AND SAFETY ANALYSIS FOR THE NIST RESEARCH REACTOR.

Detailed reactor physics and safety analyses have been performed for the 20 MW D{sub 2}O moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The analyses provide an update to the Final Safety Analysis Report (FSAR) and employ state-of-the-art calculational methods. Three-dimensional MCNP Monte Carlo neutron and photon transport calculations were performed to determine the safety parameters for the NBSR. The core depletion and determination of the fuel compositions were performed with MONTEBURNS. MCNP calculations were performed to determine the beginning, middle, and end-of-cycle power distributions, moderator temperature coefficient, and shim arm, beam tube and void reactivity worths. The calculational model included a plate-by-plate description of each fuel assembly, axial mid-plane water gap, beam tubes and the tubular geometry of the shim arms. The time-dependent analysis of the primary loop was determined with a RELAP5 transient analysis model including the pump, heat exchanger, fuel element geometry, and flow channels for both the six inner and twenty-four outer fuel elements. The statistical analysis used to assure protection from critical heat flux (CHF) was performed using a Monte Carlo simulation of the uncertainties contributing to the CHF calculation. The power distributions used to determine the local fuel conditions and margin to CHF were determined with MCNP. Evaluations were performed for the following accidents: (1) the control rod withdrawal startup accident, (2) the maximum reactivity insertion accident, (3) loss-of-flow resulting from loss of electrical power, (4) loss-of-flow resulting from a primary pump seizure, (5) loss-of-flow resulting from inadvertent throttling of a flow control valve, (6) loss-of-flow resulting from failure of both shutdown cooling pumps and (7) misloading of a fuel element. In both the startup and maximum reactivity insertion accidents, the core power transient is terminated by a reactor trip at 30 MW. The calculations show that both the peak reactor power and the excursion energy depend on the negative reactivity insertion from reactor trip. Two cases were considered for loss of electrical power. In the first case offsite power is lost, resulting in an immediate scram caused by loss of power to the control rod system. In the second case power is lost to only the three operating primary pumps, resulting in a slightly delayed scram when loss-of-flow is detected as the pumps coast down. In both instances, RELAP5 results indicate that there is adequate margin to CHF and no damage to the fuel will occur, because of the momentum of the coolant flowing through the fuel channels and the negative scram reactivity insertion. For both the primary pump seizure and inadvertent throttling of a flow control valve, the RELAP5 analyses indicate that the reduction in power following the trip is sufficient to ensure that there is adequate margin to CHF and the fuel cladding does not fail. The analysis of the loss-of-flow accident in the extremely unlikely case where both shutdown pumps fail shows that the cooling provided by the D{sub 2}O is sufficient to ensure the cladding does not fail. The power distributions were examined for a set of fuel misloadings in which a fresh fuel element is moved from a peripheral low-reactivity location to a central high-reactivity location. The calculations show that there is adequate margin to CHF and the cladding does not fail.

CAREW,J.CHENG,L.HANSON,AXU,J.RORER,D.DIAMOND,D.

2003-08-26

345

Physics and Analysis at a Hadron Collider - An Introduction (1/3)

This is the first lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This first lecture provides a brief introduction to hadron collider physics and collider detector experiments as well as offers some analysis guidelines. The lectures are aimed at graduate students.

None

2010-01-20

346

Physics and Analysis at a Hadron Collider - An Introduction (1/3)

This is the first lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This first lecture provides a brief introduction to hadron collider physics and collider detector experiments as well as offers some analysis guidelines. The lectures are aimed at graduate students.

None

2011-10-06

347

An Analysis of Middle School Students Physical Education Physical Activity Preferences

ERIC Educational Resources Information Center

The idea of providing student's choice over curricular offerings in physical education has gained a considerable amount of attention in recent years. The purpose of this study was to determine which physical education activities middle school students would like to have included in the yearly curriculum and if there were differences in responses…

Hill, Grant; Hannon, James C.

2008-01-01

348

A Meta-Analysis of College Students' Physical Activity Behaviors

The authors reviewed studies on college students' physical activity (PA) behaviors and found that previous research on this topic focused on describing college students' PA patterns and their determinants. Researchers reported that about 40% to 50% of college students are physically inactive. More important, health and PA professionals in higher education have not been able to effectively increase students' PA

Xiaofen Deng Keating; Jianmin Guan; José Castro Piñero; Dwan Marie Bridges

2005-01-01

349

Information-Theoretic Security Analysis of Physical Uncloneable Functions

We propose a general theoretical framework to analyze the security of Physical Uncloneable Functions (PUFs). We apply the frame- work to optical PUFs. In particular we present a derivation, based on the physics governing multiple scattering processes, of the number of in- dependent challenge-response pairs supported by a PUF. We flnd that the number of independent challenge-response pairs is proportional

Pim Tuyls; Boris Skoric; S. Stallinga; Anton H. M. Akkermans; W. Ophey

2005-01-01

350

Recapturing physics in the 1920s through citation analysis

Data on highly cited papers from a recently compiled citation index for physics in the 1920 s are explored in relation to the revolutionary developments that are widely regarded as constituting a golden age in physics. It is found that most of the \\

H. Small

1986-01-01

351

Developing Skill-Analysis Competency in Physical Education Teachers

ERIC Educational Resources Information Center

Given the known relationship between physical inactivity and chronic disease (US Dept. of Health and Human Services [USDHHS], 2000, 2001), learning more about antecedents for physical activity engagement is an important research priority. In this vein, a number of studies have found a relationship between perceived and actual motor skill…

Lounsbery, Monica; Coker, Cheryl

2008-01-01

352

Characterization and nultivariate analysis of physical properties of processing peaches

Technology Transfer Automated Retrieval System (TEKTRAN)

Characterization of physical properties of fruits represents the first vital step to ensure optimal performance of fruit processing operations and is also a prerequisite in the development of new processing equipment. In this study, physical properties of engineering significance to processing of th...

353

Applying Cluster Analysis to Physics Education Research Data

ERIC Educational Resources Information Center

One major thrust of Physics Education Research (PER) is the identification of student ideas about specific physics concepts, both correct ideas and those that differ from the expert consensus. Typically the research process of eliciting the spectrum of student ideas involves the administration of specially designed questions to students. One major…

Springuel, R. Padraic

2010-01-01

354

Investigation of Student Reasoning about Harmonic Motions

NASA Astrophysics Data System (ADS)

This study aimed to investigate student reasoning about harmonic oscillations. We conducted a semi-structured interview based on three situations of harmonic motions—(1) a mass attaching to spring and horizontally oscillating without damping, (2) the same situation but vertically oscillating and (3) a mass attaching to spring and oscillating in viscous liquid. Forty-five second-year students taking a vibrations and wave course at Chiang Mai University, Thailand participated in a fifteen-minute interview, which was video-recorded. The videos were transcribed and analyzed by three physics instructors. As results, we found that most students had misconceptions about angular frequency and energy mostly in the second and third situations.

Tongnopparat, N.; Poonyawatpornkul, J.; Wattanakasiwich, P.

355

NASA Astrophysics Data System (ADS)

A complete variational treatment is provided for a family of spiked-harmonic oscillator Hamiltonians H=-d2/dx2+Bx2+?/x?(B>0,?>0), for arbitrary ?>0. A compact topological proof is presented that the set S={?n} of known exact solutions for ?=2 constitutes an orthonormal basis of the Hilbert space L2(0,?). Closed-form expressions are derived for the matrix elements of H with respect to S. These analytical results, and the inclusion of a further free parameter, facilitate optimized variational estimation of the eigenvalues of H to high accuracy.

Hall, Richard L.; Saad, Nasser; von Keviczky, Attila B.

2002-01-01

356

Nonlinear harmonic generation in free-electron lasers with helical wigglers.

It is widely believed that harmonics are suppressed in helical wigglers. However, linear harmonic generation (LHG) occurs by an azimuthal resonance that excites circularly polarized, off-axis waves, where the hth harmonic varies as exp((ihtheta). Nonlinear harmonic generation (NHG) is driven by bunching at the fundamental and has different properites from LHG. While NHG has been studied in planar wigglers, there has been no analysis of NHG in helical wigglers. The 3D simulation code medusa has been modified for this purpose, and it is shown that NHG is substantial in helical wigglers and that the even and odd harmonics have comparable intensities. PMID:15783822

Freund, H P; O'Shea, P G; Biedron, S G

2005-02-25

357

Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac filter design for HVDC systems and a survey of literature related to filter design have been performed. Two methods for calculating system harmonic impedances have been investigated. In the measurement method, an instrumentation system for measuring system voltage and current has been assembled. Different schemes of using the measurements to calculate system harmonic impedances have been studied. In the analytical method, a procedure to include various operating conditions has been proposed. Computer programs for both methods have been prepared, and the results of the measurement and analytical methods analyzed. A conclusion of the project is that the measurement and analytical methods both provided reasonable results. There are correlations between the measured and analytical results for most harmonics, although there are discrepancies between the assumptions used in the two methods. A sensitivity approach has been proposed to further correlate the results. From the results of the analysis, it is recommended that both methods should be tested further. For the measurement method, more testing should be done to cover different system operating conditions. In the analytical method, more detailed models for representing system components should be studied. In addition, alternative statistical and sensitivity approaches should be attempted.

Breuer, G D; Chow, J H; Lindh, C B; Miller, N W; Numrich, F H; Price, W W; Turner, A E; Whitney, R R

1982-09-01

358

The purpose of this study was to examine three frameworks, (a) process-product, (b) student mediation, and (c) classroom ecology, to understand physical activity (PA) behavior of adolescents with and without disabilities in middle school inclusive physical education (PE). A total of 13 physical educators teaching inclusive PE and their 503 students, including 22 students with different disabilities, participated in this study. A series of multilevel regression analyses indicated that physical educators' teaching behavior and students' implementation intentions play important roles in promoting the students' PA in middle school inclusive PE settings when gender, disability, lesson content, instructional model, and class location are considered simultaneously. The findings suggest that the ecological framework should be considered to effectively promote PA of adolescents with and without disabilities in middle school PE classes. PMID:23860507

Jin, Jooyeon; Yun, Joonkoo

2013-07-01

359

Physics Analysis and Design for the Sustained Speromak Physics Experiment, SSPX.

NASA Astrophysics Data System (ADS)

SSPX is designed to provide a flexible facility to study critical spheromak physics issues, especially energy and current transport during a sustained discharge. Central to this study are the stability of MHD (ideal and resistive) modes and islands, the extent of island overlap and magnetic turbulence, etc. The experimental design is planned to achieve sustained operation at a few hundred eV in a configuration including the possibility of a bias magnetic flux with magnetic fieldlines which conform to the flux conserver shape. The physics will be studied for times (ms) short compared with the soak-through time of the flux conserver. A divertor is planned to control density and impurities. Physics design will be presented based on modeling MHD, stability, transport, vacuum, etc. The results are implemented in the detailed design of the flux conserver, helicity injector, and power systems. Critical diagnostics to carry out the physics program will be described.

Hooper, E. B.; Wood, R. D.; Bulmer, R. H.; Cohen, B. I.; Pearlstein, L. D.; Thomassen, K. I.; Hua, D.; Gatto, R.; Domier, C. W.; Jarboe, T. R.

1997-11-01

360

Harmonic oscillators and resonance series generated by a periodic unstable classical orbit

NASA Technical Reports Server (NTRS)

The presence of an unstable periodic classical orbit allows one to introduce the decay time as a purely classical magnitude: inverse of the Lyapunov index which characterizes the orbit instability. The Uncertainty Relation gives the corresponding resonance width which is proportional to the Planck constant. The more elaborate analysis is based on the parabolic equation method where the problem is effectively reduced to the multidimensional harmonic oscillator with the time-dependent frequency. The resonances form series in the complex energy plane which is equidistant in the direction perpendicular to the real axis. The applications of the general approach to various problems in atomic physics are briefly exposed.

Kazansky, A. K.; Ostrovsky, Valentin N.

1995-01-01

361

Harmonic generation at high intensities

Atomic electrons subject to intense laser fields can absorb many photons, leading either to multiphoton ionization or the emission of a single, energetic photon which can be a high multiple of the laser frequency. The latter process, high-order harmonic generation, has been observed experimentally using a range of laser wavelengths and intensities over the past several years. Harmonic generation spectra have a generic form: a steep decline for the low order harmonics, followed by a plateau extending to high harmonic order, and finally an abrupt cutoff beyond which no harmonics are discernible. During the plateau the harmonic production is a very weak function of the process order. Harmonic generation is a promising source of coherent, tunable radiation in the XUV to soft X-ray range which could have a variety of scientific and possibly technological applications. Its conversion from an interesting multiphoton phenomenon to a useful laboratory radiation source requires a complete understanding of both its microscopic and macroscopic aspects. We present some recent results on the response of single atoms at intensities relevant to the short pulse experiments. The calculations employ time-dependent methods, which we briefly review in the next section. Following that we discuss the behavior of the harmonics as a function of laser intensity. Two features are notable: the slow scaling of the harmonic intensities with laser intensity, and the rapid variation in the phase of the individual harmonics with respect to harmonic order. We then give a simple empirical formula that predicts the extent of the plateau for a given ionization potential, wavelength and intensity.

Schafer, K.J.; Krause, J.L.; Kulander, K.C.

1993-06-01

362

Analysis of Free Will and Determinism in Physics

It is considered the study of determinism in the theories of physics. Based on fundamental postulates of physics, it is proved that the evolution of the universe is univocally determined, proving ultimately that free will does not exist. In addition, it is presented some contradictions and weaknesses of quantum mechanics, suggesting paradoxes in the theory. It is also analyzed some consequences of the postulates in justice and ethics.

Edgar Jose Candales Dugarte

2014-06-27

363

This thesis proposes a model for cost-benefit analysis for physical form selection of a decision support tool, primarily to support system acquisition decisions that need to be made early in the system life cycle. By ...

Bhattacharjee, Dhiman

2007-01-01

364

Harmonic Series Meets Fibonacci Sequence

ERIC Educational Resources Information Center

The terms of a conditionally convergent series may be rearranged to converge to any prescribed real value. What if the harmonic series is grouped into Fibonacci length blocks? Or the harmonic series is arranged in alternating Fibonacci length blocks? Or rearranged and alternated into separate blocks of even and odd terms of Fibonacci length?

Chen, Hongwei; Kennedy, Chris

2012-01-01

365

MODEL HARMONIZATION POTENTIAL AND BENEFITS

The IPCS Harmonization Project, which is currently ongoing under the auspices of the WHO, in the context of chemical risk assessment or exposure modeling, does not imply global standardization. Instead, harmonization is thought of as an effort to strive for consistency among appr...

366

Luke J. Harmon Curriculum Vitae

, Chelsea Specht, Curtis Lisle, and Jorge Soberon; total $4,000,000, Harmon lab budget $921,602; Start date in action examined over a phylogeny" (co-PI Joe Felsenstein; total $132,794, Harmon lab budget $65,306) 2009

Harmon, Luke

367

The technical analysis of the stock exchange and physics: Japanese candlesticks for solar activity

NASA Astrophysics Data System (ADS)

In this article, we use the Japanese candlesticks, a method popular in the technical analysis of the Stock/Forex markets and apply it to a variable in physics-the solar activity. This method is invented and used exclusively for economic analysis and its application to a physical problem produced unexpected results. We found that the Japanese candlesticks are convenient tool in the analysis of the variables in the physics of the Sun. Based on our observations, we differentiated a new cycle in the solar activity.

Dineva, C.; Atanasov, V.

2013-09-01

368

Harmonization of laboratory testing - Current achievements and future strategies.

Harmonization in laboratory testing is more far-reaching than merely analytical harmonization. It includes all aspects of the total testing process from the "pre-pre-analytical" phase through analysis to the "post-post-analytical" phase. Harmonizing the pre-analytical phase requires use of standardized operating procedures for correct test selection, sample collection and handling, while standardized test terminology, and units and traceability to ISO standard 17511 are required to ensure equivalency of measurement results. Use of harmonized reference intervals and decision limits for analytes where platforms share allowable bias requirements will reduce inaccurate clinical interpretation and unnecessary laboratory testing. In the post-analytical phase, harmonized procedures for the management of critical laboratory test results are required to improve service quality and ensure patient safety. Monitoring of the outcomes of harmonization activities is through surveillance by external quality assessment schemes that use commutable materials and auditing of the "pre-pre-analytical" and "post-post-analytical" phases. Successful implementation of harmonization in laboratory testing requires input by all stakeholders, including the clinical laboratory community, diagnostics industry, clinicians, professional societies, IT providers, consumer advocate groups and governmental bodies. PMID:24001695

Tate, Jillian R; Johnson, Roger; Barth, Julian; Panteghini, Mauro

2014-05-15

369

The generation of harmonics of a high-power-laser-pulse field in a gas during impact ionisation of atoms by oscillating electrons is studied theoretically. Fields are considered under conditions when the oscillation energy of electrons in the radiation field, remaining nonrelativistic, considerably exceeds the ionisation potential of an atom. In addition, the radiation field was assumed weak compared to the atomic field

M. V. Kuzelev; A. A. Rukhadze

2007-01-01

370

Learning physics: A comparative analysis between instructional design methods

NASA Astrophysics Data System (ADS)

The purpose of this research was to determine if there were differences in academic performance between students who participated in traditional versus collaborative problem-based learning (PBL) instructional design approaches to physics curricula. This study utilized a quantitative quasi-experimental design methodology to determine the significance of differences in pre- and posttest introductory physics exam performance between students who participated in traditional (i.e., control group) versus collaborative problem solving (PBL) instructional design (i.e., experimental group) approaches to physics curricula over a college semester in 2008. There were 42 student participants (N = 42) enrolled in an introductory physics course at the research site in the Spring 2008 semester who agreed to participate in this study after reading and signing informed consent documents. A total of 22 participants were assigned to the experimental group (n = 22) who participated in a PBL based teaching methodology along with traditional lecture methods. The other 20 students were assigned to the control group (n = 20) who participated in the traditional lecture teaching methodology. Both the courses were taught by experienced professors who have qualifications at the doctoral level. The results indicated statistically significant differences (p < .01) in academic performance between students who participated in traditional (i.e., lower physics posttest scores and lower differences between pre- and posttest scores) versus collaborative (i.e., higher physics posttest scores, and higher differences between pre- and posttest scores) instructional design approaches to physics curricula. Despite some slight differences in control group and experimental group demographic characteristics (gender, ethnicity, and age) there were statistically significant (p = .04) differences between female average academic improvement which was much higher than male average academic improvement (˜63%) in the control group which may indicate that traditional teaching methods are more effective in females, whereas there was no significant difference noted in the experimental group between male and female participants. There was a statistically significant and negative relationship (r = -.61, p = .01) between age and physics pretest scores in the control group. No statistical analyses yielded significantly different average academic performance values in either group as delineated by ethnicity.

Mathew, Easow

371

Analysis of physical human-robot interaction for motor learning with physical help

In this paper we investigate physical human-robot interaction (PHRI) as an important extension of traditional HRI research. The aim of this research is to develop a humanoid robot that can work in the same spaces as humans. We first propose a new control system that takes advantage of inherent joint flexibility. The control system is applied on a new humanoid

Shuhei Ikemoto; Takashi Minato; Hiroshi Ishiguro

2008-01-01

372

Physics Analysis and Design for the Sustained Speromak Physics Experiment, SSPX

SSPX is designed to provide a flexible facility to study critical spheromak physics issues, especially energy and current transport during a sustained discharge. Central to this study are the stability of MHD (ideal and resistive) modes and islands, the extent of island overlap and magnetic turbulence, etc. The experimental design is planned to achieve sustained operation at a few hundred

E. B. Hooper; R. D. Wood; R. H. Bulmer; B. I. Cohen; L. D. Pearlstein; K. I. Thomassen; D. Hua; R. Gatto; C. W. Domier; T. R. Jarboe

1997-01-01

373

ChroMirror: A Real-Time Interactive Mirror for Chromatic and Color-Harmonic Dressing

and color-harmonic clothes. Keywords Ubiquitous computing, home computing, interactive design, color appropriate clothing color combinations. By digitally rendering a mirror image of the user wearing clothing variety of chromatic and color-harmonic clothing combinations (i.e., without having to physically change

Ouhyoung, Ming

374

Hydrogen Generation from Water Disassociation Using Small Currents and Harmonics Trien N. Nguyen1

Hydrogen Generation from Water Disassociation Using Small Currents and Harmonics Trien N. Nguyen1 1 Department of Physics, Purdue School of Science Hydrogen can be produced cheaply and efficiently from water sources using a combination of harmonics and small currents. Hydrogen is a clean and virtually

Zhou, Yaoqi

375

Harmonic Map Formulation of Colliding Electrovac Plane Waves

The formulation of the Einstein field equations admitting two Killing vectors in terms of harmonic mappings of Riemannian manifolds is a subject in which Charlie Misner has played a pioneering role. We shall consider the hyperbolic case of the Einstein-Maxwell equations admitting two hypersurface orthogonal Killing vectors which physically describes the interaction of two electrovac plane waves. Following Penrose's discussion of the Cauchy problem we shall present the initial data appropriate to this collision problem. We shall also present three different ways in which the Einstein-Maxwell equations for colliding plane wave spacetimes can be recognized as a harmonic map. The goal is to cast the Einstein-Maxwell equations into a form adopted to the initial data for colliding impulsive gravitational and electromagnetic shock waves in such a way that a simple harmonic map will directly yield the metric and the Maxwell potential 1-form of physical interest. For Charles W. Misner on his 60th birthday

Y. Nutku

1998-12-10

376

Physical properties analysis of nano-filled microcomposite epoxy materials

The physical properties of the insulating materials are sensitive to the constraints that they undergo. Indeed, the process of manufacturing is the first to act on these properties. Then, follow the constraints undergone by the material, which appear with the nominal conditions of use or in accelerated ones. Therefore, these properties are features of the performances of these materials. Thus,

J. Castellon; S. Agnel; A. Toureille; M. Frechette; G. Platbrood; K. C. Cole; D. Desgagnes

2007-01-01

377

Instrumental physical analysis of microwaved glycerol citrate foams

Technology Transfer Automated Retrieval System (TEKTRAN)

Solid polyester glyceride polymers generated by microwave cooking were further cured in a conventional oven at 100 oC for 0, 6, 24, 48, or 72 hr and their physical properties were tested. Curing polyester glycerides resulted in decreased moisture content (MC), altered color, increased hydrated polym...

378

Analysis of repeated measurements in physical therapy research

In this paper, I attempt to introduce physical therapists to the most common statistical tests for analysing differences between repeated measurements over time. Using the example of ‘whole-body flexibility’ recorded at six different times of day and the Statistical Package for the Social Sciences (SPSS), I discuss the advantages and disadvantages of the various approaches for analysing a simple one-factor

Greg Atkinson

2001-01-01

379

24 CFR 401.451 - PAE Physical Condition Analysis (PCA).

Code of Federal Regulations, 2010 CFR

(1) The PAE must independently evaluate the physical condition of the project by means of a PCA. If the PAE finds any immediate threats to health and safety, the owner must complete those work items immediately, or the PAE must evaluate the project's eligibility in accordance with §...

2010-04-01

380

Physical interpretation and sensitivity analysis of the TOPMODEL

The TOPMODEL is a variable contributing area conceptual model in which the predominant factors determining the formation of runoff are represented by the topography of the basin and a negative exponential law linking the transmissivity of the soil with the distance to the saturated zone below the ground level. Although conceptual, this model is frequently described as a ‘physically based

Marco Franchini; Jacques Wendling; Charles Obled; Ezio Todini

1996-01-01

381

The Use of Cluster Analysis in Physical Data Base Design

The physical structure and relative placement of information elements within a data base is critical for the efficient design of a computerized information system which is shared by a community of users. Traditionally the selection among alternative structural designs has been handled largely via heuristics. Recent research has shown that a number of significant design problems can be stated mathematically

Jeffrey A. Hoffer; Dennis G. Severance

1975-01-01

382

In this paper, an improved approach to reduce harmonics in the utility interface of wind, photovoltaic and fuel cells power systems is presented. The approach is based on circulating third harmonic current injection to reduce utility line current harmonics in SCR converters. In this paper, a new injected current shape is computed from analysis to achieve sinusoidal utility line currents.

Ali M. El-Tamaly; P. N. Enjeti; H. H. El-Tamaly

2000-01-01

383

A theoretical analysis of FGM thin plates based on physical neutral surface

This paper presents a theoretical analysis to the FGM (functionally graded materials) thin plates based on the physical neutral surface. Under the assumption of changeable parameters such as the Young’s modulus E and the mass density ? along the thickness of the plate, the physical neutral surface of a FGM plate is determined by the theory of thin plate when

Da-Guang Zhang; You-He Zhou

2008-01-01

384

ERIC Educational Resources Information Center

This study proposes a multi-dimensional approach to investigate, represent, and categorize students' in-depth understanding of complex physics concepts. Clinical interviews were conducted with 30 undergraduate physics students to probe their understanding of heat conduction. Based on the data analysis, six aspects of the participants' responses…

Chiou, Guo-Li; Anderson, O. Roger

2010-01-01

385

Important physical properties of petroleum reservoirs are, usually, obtained by applying standard experimental tests on rock samples collected along selected depths of the petroleum well. This is, presently, a laborious and high cost procedure. Present paper describes Imago, which is a new petrographic analysis software, developed for predicting the physical properties of reservoir rocks, starting from petrographic thin sections routinely

M. C. Damiani; A. D. Bueno; L. O. E. Santos; J. A. B. da Cunha; P. C. Philippi

386

, a thin shell animation, which focuses on visualization, experimentation, and control. Through the useInteractive Thin Shells Â A Model Interface for the Analysis of Physically-based Animation James, and sensitive to changes in experimental parameters. We present an interface to a physically-based algorithm

Wood, ZoÃ« J.

387

A Functional Analysis of Moderate-to-Vigorous Physical Activity in Young Children

ERIC Educational Resources Information Center

Inadequate physical activity increases the risks related to a number of health problems in children, most notably obesity and the corresponding range of associated health problems. The purpose of the current study was to conduct a functional analysis to investigate the effects of several consequent variables on moderate-to-vigorous physical…

Larson, Tracy A.; Normand, Matthew P.; Morley, Allison J.; Miller, Bryon G.

2013-01-01

388

Mapping university students' epistemic framing of computational physics using network analysis

NASA Astrophysics Data System (ADS)

Solving physics problem in university physics education using a computational approach requires knowledge and skills in several domains, for example, physics, mathematics, programming, and modeling. These competences are in turn related to students’ beliefs about the domains as well as about learning. These knowledge and beliefs components are referred to here as epistemic elements, which together represent the students’ epistemic framing of the situation. The purpose of this study was to investigate university physics students’ epistemic framing when solving and visualizing a physics problem using a particle-spring model system. Students’ epistemic framings are analyzed before and after the task using a network analysis approach on interview transcripts, producing visual representations as epistemic networks. The results show that students change their epistemic framing from a modeling task, with expectancies about learning programming, to a physics task, in which they are challenged to use physics principles and conservation laws in order to troubleshoot and understand their simulations. This implies that the task, even though it is not introducing any new physics, helps the students to develop a more coherent view of the importance of using physics principles in problem solving. The network analysis method used in this study is shown to give intelligible representations of the students’ epistemic framing and is proposed as a useful method of analysis of textual data.

Bodin, Madelen

2012-06-01

389

Methods for Examining Small Literatures: Explication, Physical Analysis, and Citation Patterns.

ERIC Educational Resources Information Center

Analyzes literature on information overload research in library studies using explication, physical analysis, and citation patterns. Makes cross-discipline comparisons with consumer science and psychology/psychiatry. Contains 93 references. (PEN)

Akin, Lynn

1998-01-01

390

Volumetric Colon Wall Unfolding Using Harmonic Differentials

Volumetric colon wall unfolding is a novel method for virtual colon analysis and visualization with valuable applications in virtual colonoscopy (VC) and computer-aided detection (CAD) systems. A volumetrically unfolded colon enables doctors to visualize the entire colon structure without occlusions due to haustral folds, and is critical for performing efficient and accurate texture analysis on the volumetric colon wall. Though conventional colon surface flattening has been employed for these uses, volumetric colon unfolding offers the advantages of providing the needed quantities of information with needed accuracy. This work presents an efficient and effective volumetric colon unfolding method based on harmonic differentials. The colon volumes are reconstructed from CT images and are represented as tetrahedral meshes. Three harmonic 1-forms, which are linearly independent everywhere, are computed on the tetrahedral mesh. Through integration of the harmonic 1-forms, the colon volume is mapped periodically to a canonical cuboid. The method presented is automatic, simple, and practical. Experimental results are reported to show the performance of the algorithm on real medical datasets. Though applied here specifically to the colon, the method is general and can be generalized for other volumes. PMID:21765563

Zeng, Wei; Marino, Joseph; Kaufman, Arie; Gu, Xianfeng David

2011-01-01

391

High-order harmonic generation in alkanes

We have investigated the process of high-order harmonic generation in light alkanes by using femtosecond laser pulses. We show the experimental results cannot be matched by a model that assumes a single active electron only in a hydrogenic s orbital. Clear evidences are shown of the important role played by the p-like character originating from the covalent C-H bond. By constructing a suitable mixture of s-type and p-type atomic wave functions, an excellent agreement between measurements in methane and simulations is found, thus confirming the validity of the developed method as a general tool for the analysis of high-order harmonic generation in complex molecules.

Altucci, C.; Velotta, R.; Heesel, E.; Springate, E.; Marangos, J. P.; Vozzi, C.; Benedetti, E.; Calegari, F.; Sansone, G.; Stagira, S.; Nisoli, M.; Tosa, V. [CNISM-Dipartimento di Scienze Fisiche, Universita di Napoli 'Federico II', Naples (Italy); Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); National Laboratory for Ultrafast and Ultraintense Optical Science, CNR, INFM, Department of Physics, Politecnico, Milan (Italy); NIRDINT, Donath Street 71-103, 400293 Cluj-Napoca (Romania)

2006-04-15

392

NASA Astrophysics Data System (ADS)

Nuclear, plasma, elementary particle, and atomic and molecular physics are surveyed along with the physics of condensed matter and relativistic astrophysics. Attention is given to the discovery of quarks, psi particles, bosons and nuclear quantum states, the role of group theory and the search for a unified field theory. Also considered are magnetic and inertial confinement regarding fusion power, and the use of tunable lasers and microwave spectroscopy to study Rydberg states. In addition, surface physics, amorphous solids, superfluidity and gravitational collapse are discussed.

Bromley, D. A.

1980-07-01

393

Analysis of self-directed mastery learning of honors physics

NASA Astrophysics Data System (ADS)

Self-directed learning (SDL) is an important life skill in a knowledge-based society and prepares students to persist, manage their time and resources, use logic to construct their knowledge, argue their views, and collaborate. The purpose of this study was to facilitate mastery of physics concepts through self-directedness in formative testing with feedback, a choice of learning activities, and multiple forms of support. This study was conducted within two sections of honors physics at a private high school (N=24). Students' learning activity choices, time investments, and perceptions (assessed through a post survey) were tracked and analyzed. SDL readiness was linked to success in mastering physics concepts. The three research questions pursued in this study were: What SDL activities did honors physics students choose in their self-directed mastery learning environment? How many students achieved concept mastery and how did they spend their time? Did successful and unsuccessful students perceive the self-directed mastery learning environment differently? Only seven of 24 students were successful in passing the similar concept-based unit tests within four tries, and these seven students were separated into a "successful" group and the other 17 into an "unsuccessful" group. Differences between the two groups were analyzed. A profile of a self-directed secondary honors physics student emerged. A successful self-directed student invested more time learning from activities rather than simply completing them, focused on learning concepts more than rote operations, intentionally selected activities to fill in gaps of knowledge and practice concepts, actively constructed knowledge into a cognitive framework, engaged in academic discourse with instructor and peers as they made repeated attempts to master content and pass the test given constructive feedback, used a wide variety of learning resources, and managed their workload to meet deadlines. This capstone study found that parallel instruction in content and SDL skills could be important for improving learning outcomes and better equipping secondary honors physics students for college and life in general. Mastery learning principles coupled with modeling in self-direction appear mutually reinforcing and, when more explicitly approached, should yield dual benefits in concept mastery as well as self-efficacy.

Athens, Wendy

394

Investigation of plasma diagnostics using a dual frequency harmonic technique

Plasma diagnostic methods using harmonic currents analysis of electrostatic probes were experimentally investigated to understand the differences in their measurement of the plasma parameters. When dual frequency voltage (?{sub 1},?{sub 2}) was applied to a probe, various harmonic currents (?{sub 1},?2?{sub 1},?{sub 2},?2?{sub 2},?{sub 2}±?{sub 1},?{sub 2}±2?{sub 1}) were generated due to the non-linearity of the probe sheath. The electron temperature can be obtained from the ratio of the two harmonics of the probe currents. According to the combinations of the two harmonics, the sensitivities in the measurement of the electron temperature differed, and this results in a difference of the electron temperature. From experiments and simulation, it is shown that this difference is caused by the systematic and random noise.

Kim, Dong-Hwan [Department of Nanoscale Semiconductor Engineering, Hanyang University, Seoul (Korea, Republic of); Kim, Young-Do; Cho, Sung-Won; Kim, Yu-Sin; Chung, Chin-Wook, E-mail: joykang@hanyang.ac.kr [Department of Electrical Engineering, Hanyang University, Seoul (Korea, Republic of)

2014-09-07

395

NSDL National Science Digital Library

Physics is the scientific study of the basic principles of the universe, including matter, energy, motion and force, and their interactions. Major topics include classical mechanics, thermodynamics, light and optics, electromagnetism and relativity.

K-12 Outreach,

396

Application of logistic analysis to the history of physics.

Recently, two analyses have tried to put technological progress in a larger context. One interpretation hypothesizes that technological progress is likely to continue at increasingly higher rates of change. Another interpretation, which includes data from the beginning of the universe to the present, suggests that the universe is approaching a transition point in a logistic development of complexity. This logistic development is similar to the way ideas or products diffuse in a population, i.e., the rate of discovery in a field of knowledge is proportional to the amount discovered and the amount to be discovered. To test a part of this hypothesis, a leading indicator field (fundamental physics) was identified and the events in the history of this field were analyzed. Twelve subfields were identified and grouped into six stages. Each stage seemed to demonstrate a logistic-like development. By analyzing both the median time of development and the characteristic time of development of these stages, the overall development of this one field was found to suggest logistic development. These data seem to indicate that development in fundamental physics is slowing down, with at least one subfield beyond string physics yet to be developed. The data tend to support the hypothesis that a knowledge field can develop logistically.

LePoire, D. J.; Environmental Assessment

2005-05-01

397

Courses: Physics (PHYS) Page 363Sonoma State University 2012-2013 Catalog Physics (PHYS)

programs. Fundamentals of kinematics, Newton's laws, work, momentum, harmonic motion, and an introduction mechanics; simple harmonic motion; thermodynam- ics and kinetics. Satisfies GE, category B1 or B3 (Physical DeScriPtive PHYSicS (3) Lecture, 3 hours. A descriptive survey of the important principles of physics

Ravikumar, B.

398

Polarization attractors in harmonic mode-locked fiber laser.

We report on a polarimetry of harmonic mode-locked erbium-doped fiber laser with carbon nanotubes saturable absorber. We find new types of vector solitons with locked, switching and precessing states of polarization. The underlying physics presents interplay between birefringence of a laser cavity created by polarization controller along with light induced anisotropy caused by polarization hole burning. PMID:24977612

Habruseva, Tatiana; Mou, Chengbo; Rozhin, Alex; Sergeyev, Sergey V

2014-06-16

399

A Simple Mechanical Model for the Isotropic Harmonic Oscillator

ERIC Educational Resources Information Center

A constrained elastic pendulum is proposed as a simple mechanical model for the isotropic harmonic oscillator. The conceptual and mathematical simplicity of this model recommends it as an effective pedagogical tool in teaching basic physics concepts at advanced high school and introductory undergraduate course levels. (Contains 2 figures.)

Nita, Gelu M.

2010-01-01

400

Engaging Students in a Physics Course through Use of Digital Video Capture and Analysis

NASA Astrophysics Data System (ADS)

Use of digital video motion analysis as a teaching tool in an introductory physics course is presented. The focus of the presentation is the application of digital video technology in a Physics for Movement Science course geared towards Physical Education, Athletic Training and Exercise Science majors. The Dickinson movie set was found to be the most applicable for in-class activities, homework assignments, and projects. Some of the movie clips chosen for analysis are focused on human motion and sports. Additionally, students are starting to capture and analyze their own movie clips.

Lojewska, Zenobia

2007-10-01

401

Physical activity and risk of pancreatic cancer: a systematic review and meta-analysis.

Physical activity may prevent pancreatic cancer by regulating body weight and decreasing insulin resistance, DNA damage, and chronic inflammation. Previous meta-analyses found inconsistent evidence for a protective effect of physical activity on pancreatic cancer but those studies did not investigate whether the association between physical activity and pancreatic cancer varies by smoking status, body mass index (BMI), or level of consistency of physical activity over time. To address these issues, we conducted an updated meta-analysis following the PRISMA guidelines among 30 distinct studies with a total of 10,501 pancreatic cancer cases. Random effects meta-analysis of cohort studies revealed a weak, statistically significant reduction in pancreatic cancer risk for high versus low levels of physical activity (relative risk (RR) 0.93, 95 % confidence interval (CI) 0.88-0.98). By comparison, case-control studies yielded a stronger, statistically significant risk reduction (RR 0.78, 95 % CI 0.66-0.94; p-difference by study design = 0.07). When focusing on cohort studies, physical activity summary risk estimates appeared to be more pronounced for consistent physical activity over time (RR 0.86, 95 % CI 0.76-0.97) than for recent past physical activity (RR 0.95, 95 % CI 0.90-1.01) or distant past physical activity (RR 0.95, 95 % CI 0.79-1.15, p-difference by timing in life of physical activity = 0.36). Physical activity summary risk estimates did not differ by smoking status or BMI. In conclusion, physical activity is not strongly associated with pancreatic cancer risk, and the relation is not modified by smoking status or BMI level. While overall findings were weak, we did find some suggestion of potential pancreatic cancer risk reduction with consistent physical activity over time. PMID:25773752

Behrens, Gundula; Jochem, Carmen; Schmid, Daniela; Keimling, Marlen; Ricci, Cristian; Leitzmann, Michael F

2015-04-01

402

SunPy: Python for Solar Physics Data Analysis

NASA Astrophysics Data System (ADS)

In recent years, Python, a free cross platform general purpose high-level programming language, has seen widespread adoption among the scientific community resulting in the availability of wide range of software, from numerical computation and machine learning to spectral analysis and visualization. SunPy is a software suite specializing in providing the tools necessary to analyze solar and heliospheric datasets in Python. It provides a free and open-source alternative to the IDL-based SolarSoft (SSW) solar data analysis environment. We present the current capabilities of SunPy which include WCS-aware map objects that allow simple overplotting of data from multiple image FITS files; time-series objects that allow overplotting of multiple lightcurves, and integration with online services such as The Virtual Solar Observatory (VSO) and The Heliophysics Event Knowledgebase (HEK). SunPy also provides functionality that is not currently available in SSW such as advanced time series manipulation routines and support for working with solar data stored using JPEG 2000. We present examples of solar data analysis in SunPy, and show how Python-based solar data-analysis can leverage the many existing data analysis tools currently available in Python. We discuss the future goals of the project and encourage interested users to become involved in the planning and development of SunPy.

Hughitt, V. Keith; Christe, S.; Ireland, J.; Shih, A.; Mayer, F.; Earnshaw, M. D.; Young, C.; Perez-Suarez, D.; Schwartz, R.

2012-05-01

403

Azimuthal anisotropy: The higher harmonics

We report the first observations of the fourth harmonic (v{sub 4}) in the azimuthal distribution of particles at RHIC. The measurement was done taking advantage of the large elliptic flow generated at RHIC. The integrated v{sub 4} is about a factor of 10 smaller than v{sub 2}. For the sixth (v{sub 6}) and eighth (v{sub 8}) harmonics upper limits on the magnitudes are reported.

Poskanzer, Arthur M.; STAR Collaboration

2004-03-12

404

Echo-Enabled Harmonic Generation

A recently proposed concept of the Echo-Enabled Harmonic Generation (EEHG) FEL uses two laser modulators in combination with two dispersion sections to generate a high-harmonic density modulation in a relativistic beam. This seeding technique holds promise of a one-stage soft x-ray FEL that radiates not only transversely but also longitudinally coherent pulses. Currently, an experimental verification of the concept is being conducted at the SLAC National Accelerator Laboratory aimed at the demonstration of the EEHG.

Stupakov, Gennady

2010-08-25

405

Echo-Enabled Harmonic Generation

A recently proposed concept of the Echo-Enabled Harmonic Generation (EEHG) FEL uses two laser modulators in combination with two dispersion sections to generate a high-harmonic density modulation in a relativistic beam. This seeding technique holds promise of a one-stage soft x-ray FEL that radiates not only transversely but also longitudinally coherent pulses. Currently, an experimental verification of the concept is being conducted at the SLAC National Accelerator Laboratory aimed at the demonstration of the EEHG.

Stupakov, Gennady; /SLAC

2012-06-28

406

Mathematical basis of computational statistical physics and quantum analysis

NASA Astrophysics Data System (ADS)

A mathematical basis of quantum Mote Carlo methods is discussed using the exponential product formulas (Suzuki, 1966; Trotter, 1959) which have been generalized by the present author to infinite order (Suzuki, 1990). The investigation of this scheme has inspired the author to construct a new mathematical framework of quantum analysis (Suzuki, 1990; 1991; 1992), namely a noncommutative derivative of f(A) for an operator with respect to the operator A itself. Applications of this quantum analysis to statistical mechanics are discussed briefly (Suzuki, 1991; 1992).

Suzuki, Masuo

2000-05-01

407

Generalized hydraulic geometry: Insights based on fluvial instability analysis and a physical model

Generalized hydraulic geometry: Insights based on fluvial instability analysis and a physical model asymmetry over reaches of increasing scale. To test this hypothesis, we employ both a direct analysis multiscaling model. INDEX TERMS: 1824 Hydrology: Geomorphology (1625); 1860 Hydrology: Runoff and streamflow

Foufoula-Georgiou, Efi

408

Characterizing Students' Use of Graphs in Introductory Physics with a Graphical Analysis Epistemic). The e-game discussed by Collins & Ferguson most relevant to the use of graphs in science is the Trend data. In this Trend Analysis e-game, the moves of the game have a natural progressive order

Zollman, Dean

409

Relation of squeezed states between damped harmonic and simple harmonic oscillators

NASA Technical Reports Server (NTRS)

The minimum uncertainty and other relations are evaluated in the framework of the coherent states of the damped harmonic oscillator. It is shown that the coherent states of the damped harmonic oscillator are the squeezed coherent states of the simple harmonic oscillator. The unitary operator is also constructed, and this connects coherent states with damped harmonic and simple harmonic oscillators.

Um, Chung-In; Yeon, Kyu-Hwang; George, Thomas F.; Pandey, Lakshmi N.

1993-01-01

410

An iterative filterbank approach for extracting sinusoidal parameters from quasi-harmonic sounds

We propose an iterative filterbank method for tracking the parameters of exponentially damped sinusoidal components of quasi-harmonic sounds. The quasi-harmonic criteria specialize our analysis to a wide variety of acoustic instrument recordings while allowing for inharmonicity. The filterbank splits the recorded signal into subbands, one per harmonic, in which time-varying parameters of multiple closely-spaced sinusoids are estimated using a Steiglitz-McBride\\/Kalman

Harvey D. Thornburg; Randal J. Leistikow

2003-01-01

411

, moments and equilibrium Dynamics Â Newton's laws; rectilinear and circular motion; simple harmonic motion MODULE CONVENER Andy Robertson DURATION TERM 1 2 3 Number Students Taking Module (anticipated) 20 WEEKS of physical science 2 apply basic concepts in the analysis of mechanical, electrical and thermal problems 3

Mumby, Peter J.

412

The California Current system: The seasonal variability of its physical characteristics

The seasonal variation of the physical characteristics and of large-scale current patterns of the California Current system is examined using harmonic analysis applied to the 23 years of California cooperative Oceanic Fisheries Investigations data collected between 1950 and 1978. The amplitude and phasing of seasonal variation in dynamic height and the overall standard deviation of dynamic height define three domains:

Ronald J. Lynn; James J. Simpson

1987-01-01

413

Physical Analysis of the Jovian Synchrotron Radio Emission

We present results of our recent investigation of the Jovian synchrotron emission based on a particle transport code. The features of the two-dimensional brightness distributions, radio spectra and beaming curves are correlated to the different phenomena driven the dynamics of the electron radiation belts. The adiabatic invariant theory was used for performing this analysis work. The theoretical approach first enabled

D. Santos-Costa; S. J. Bolton; S. M. Levin; R. M. Thorne

2006-01-01

414

Global and Local Sensitivity Analysis Methods for a Physical System

ERIC Educational Resources Information Center

Sensitivity analysis is the study of how the different input variations of a mathematical model influence the variability of its output. In this paper, we review the principle of global and local sensitivity analyses of a complex black-box system. A simulated case of application is given at the end of this paper to compare both approaches.…

Morio, Jerome

2011-01-01

415

A parametric study of harmonic rotor hub loads

NASA Technical Reports Server (NTRS)

A parametric study of vibratory rotor hub loads in a nonrotating system is presented. The study is based on a CAMRAD/JA model constructed for the GBH (Growth Version of Blackhawk Helicopter) Mach-scaled wind tunnel rotor model with high blade twist (-16 deg). The theoretical hub load predictions are validated by correlation with available measured data. Effects of various blade aeroelastic design changes on the harmonic nonrotating frame hub loads at both low and high forward flight speeds are investigated. The study aims to illustrate some of the physical mechanisms for change in the harmonic rotor hub loads due to blade design variations.

He, Chengjian

1993-01-01

416

Geometry Description Markup Language for Physics Simulation And Analysis Applications.

The Geometry Description Markup Language (GDML) is a specialized XML-based language designed as an application-independent persistent format for describing the geometries of detectors associated with physics measurements. It serves to implement ''geometry trees'' which correspond to the hierarchy of volumes a detector geometry can be composed of, and to allow to identify the position of individual solids, as well as to describe the materials they are made of. Being pure XML, GDML can be universally used, and in particular it can be considered as the format for interchanging geometries among different applications. In this paper we will present the current status of the development of GDML. After having discussed the contents of the latest GDML schema, which is the basic definition of the format, we will concentrate on the GDML processors. We will present the latest implementation of the GDML ''writers'' as well as ''readers'' for either Geant4 [2], [3] or ROOT [4], [10].

Chytracek, R.; /CERN; McCormick, J.; /SLAC; Pokorski, W.; /CERN; Santin, G.; /European Space Agency

2007-01-23

417

Survival Analysis in Amputees Based on Physical Independence Grade Achievement

Backgound Survival implications of achieving different grades of physical independence after lower extremity amputation are unknown. Objectives To identify thresholds of physical independence achievement associated with improved 6-month survival and to identify and compare other risk factors after removing the influence of the grade achieved. Design Data were combined from 8 administrative databases. Grade was measured on the basis of 13 individual self-care and mobility activities measured at inpatient rehabilitation discharge. Setting Ninety-nine US Department of Veterans Affairs Medical Centers. Patients Retrospective longitudinal cohort study of 2616 veterans who underwent lower extremity amputation and subsequent inpatient rehabilitation between October 1, 2002, and September 30, 2004. Main Outcome Measure Cumulative 6-month survival after rehabilitation discharge. Results The 6-month survival rate (95% confidence interval [CI]) for those at grade 1 (total assistance) was 73.5% (70.5%-76.2%). The achievement of grade 2 (maximal assistance) led to the largest incremental improvement in prognosis with survival increasing to 91.1% (95% CI, 85.6%-94.5%). In amputees who remained at grade 1, the 30-day hazards ratio for survival compared with grade 6 (independent) was 43.9 (95% CI, 10.8-278.2), sharply decreasing with time. Whereas metastatic cancer and hemodialysis remained significantly associated with reduced survival (both P ? .001), anatomical amputation level was not significant when rehabilitation discharge grade and other diagnostic conditions were considered. Conclusions Even a small improvement to grade 2 in the most severely impaired amputees resulted in better 6-month survival. Health care systems must plan appropriate interdisciplinary treatment strategies for both medical and functional issues after amputation. PMID:19528388

Stineman, Margaret G.; Kurichi, Jibby E.; Kwong, Pui L.; Maislin, Greg; Reker, Dean M.; Bruce Vogel, W.; Prvu-Bettger, Janet A.; Bidelspach, Douglas E.; Bates, Barbara E.

2010-01-01

418

By using displacement current measurement (DCM) and electric-field-induced optical second-harmonic generation (EFISHG) measurement, we studied the carrier behavior in the indium-tin oxide (ITO)/Poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE))/C60/Au(or Al) capacitors. Two DCM peaks appeared asymmetrically at around ?35.5?V and +30.0?V in the dark. Correspondingly, the EFISHG response from the C60 layer was observed, but the peak positions were different with respect to DCM ones. The results show that the spontaneous polarization of the ferroelectric P(VDF-TrFE) polymeric layer directly affects the electric field in the C60 layer, and thus governs the carrier motion in this layer. As a result, the C60 layer serves like an insulator in the dark, while electrons and holes are captured and released at the interface in response to the turn-over of spontaneous polarization of ferroelectric layer. On the other hand, under white light illumination, C60 layer serves like a conductor due to the increase of photogenerated mobile carriers, and these carriers dominate the carrier motions therein. Our findings here will be helpful for analyzing carrier behaviors in organic electronic devices using ferroelectric polymers.

Cui, Xiaojin [Department of Physical Electronics, Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan); State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

2013-12-21

419

NASA Astrophysics Data System (ADS)

In this work we have investigated some properties of classical phase-space with symplectic structures consistent, at the classical level, with two noncommutative (NC) algebras: the Doplicher-Fredenhagen-Roberts algebraic relations and the NC approach which uses an extended Hilbert space with rotational symmetry. This extended Hilbert space includes the operators ? ij and their conjugate momentum ? ij operators. In this scenario, the equations of motion for all extended phase-space coordinates with their corresponding solutions were determined and a rotational invariant NC Newton's second law was written. As an application, we treated a NC harmonic oscillator constructed in this extended Hilbert space. We have showed precisely that its solution is still periodic if and only if the ratio between the frequencies of oscillation is a rational number. We investigated, analytically and numerically, the solutions of this NC oscillator in a two-dimensional phase-space. The result led us to conclude that noncommutativity induces a stable perturbation into the commutative standard oscillator and that the rotational symmetry is not broken. Besides, we have demonstrated through the equations of motion that a zero momentum ? ij originated a constant NC parameter, namely, ? ij = const., which changes the original variable characteristic of ? ij and reduces the phase-space of the system. This result shows that the momentum ? ij is relevant and cannot be neglected when we have that ? ij is a coordinate of the system.

Abreu, Everton M. C.; Marcial, Mateus V.; Mendes, Albert C. R.; Oliveira, Wilson

2013-11-01

420

NASA Astrophysics Data System (ADS)

The effect of ferroelectric polymer on carrier behaviors in indium-tin oxide (ITO)/poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)]/N,N?-di-[(1-naphthyl)-N,N?-diphenyl]-(1,1?-biphenyl)-4,4?-diamine (?-NPD)/Au structure was investigated. The internal electric field in ?-NPD introduced by the dipole moments from ferroelectric P(VDF-TrFE) together with the ?-NPD/P(VDF-TrFE) interface accumulated charges plays an important role in the carrier motion in ?-NPD. In displacement current measurement (DCM), two asymmetric peaks and reduced polarization resulting from a large injection barrier from Au electrode to ?-NPD layer were observed. Coupled with the electric-field-induced optical second-harmonic generation (EFISHG) measurement, the electric field in ?-NPD layer was directly probed and gave a support that only part of the dipoles in P(VDF-TrFE) was polarized. We proposed that the formation of an amorphous insulating layer between amorphous ?-NPD layer and partially crystallized P(VDF-TrFE) layer markedly decreased the voltage directly applied on the P(VDF-TrFE) film and caused a reduced polarization. Our findings here will be helpful in analyzing the carrier behavior in organic electronic devices using ferroelectric layers.

Cui, Xiaojin; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

2014-02-01

421

NASA Astrophysics Data System (ADS)

By using displacement current measurement (DCM) and electric-field-induced optical second-harmonic generation (EFISHG) measurement, we studied the carrier behavior in the indium-tin oxide (ITO)/Poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE))/C60/Au(or Al) capacitors. Two DCM peaks appeared asymmetrically at around -35.5 V and +30.0 V in the dark. Correspondingly, the EFISHG response from the C60 layer was observed, but the peak positions were different with respect to DCM ones. The results show that the spontaneous polarization of the ferroelectric P(VDF-TrFE) polymeric layer directly affects the electric field in the C60 layer, and thus governs the carrier motion in this layer. As a result, the C60 layer serves like an insulator in the dark, while electrons and holes are captured and released at the interface in response to the turn-over of spontaneous polarization of ferroelectric layer. On the other hand, under white light illumination, C60 layer serves like a conductor due to the increase of photogenerated mobile carriers, and these carriers dominate the carrier motions therein. Our findings here will be helpful for analyzing carrier behaviors in organic electronic devices using ferroelectric polymers.

Cui, Xiaojin; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

2013-12-01

422

Aircraft Conceptual Design and Risk Analysis Using Physics-Based Noise Prediction

NASA Technical Reports Server (NTRS)

An approach was developed which allows for design studies of commercial aircraft using physics-based noise analysis methods while retaining the ability to perform the rapid trade-off and risk analysis studies needed at the conceptual design stage. A prototype integrated analysis process was created for computing the total aircraft EPNL at the Federal Aviation Regulations Part 36 certification measurement locations using physics-based methods for fan rotor-stator interaction tones and jet mixing noise. The methodology was then used in combination with design of experiments to create response surface equations (RSEs) for the engine and aircraft performance metrics, geometric constraints and take-off and landing noise levels. In addition, Monte Carlo analysis was used to assess the expected variability of the metrics under the influence of uncertainty, and to determine how the variability is affected by the choice of engine cycle. Finally, the RSEs were used to conduct a series of proof-of-concept conceptual-level design studies demonstrating the utility of the approach. The study found that a key advantage to using physics-based analysis during conceptual design lies in the ability to assess the benefits of new technologies as a function of the design to which they are applied. The greatest difficulty in implementing physics-based analysis proved to be the generation of design geometry at a sufficient level of detail for high-fidelity analysis.

Olson, Erik D.; Mavris, Dimitri N.

2006-01-01

423

Toward a Cost/Benefit Analysis of Physical Fitness

This article, which is based, in part, on a paper presented to the Canadian Association of Sport Sciences, Quebec City, in November 1985, evaluates the principles of cost/benefit and cost-effectiveness analysis in the specific context of fitness programming. Because of difficulties in valuing all aspects of fitness and health—particularly survival after retirement—cost-effectiveness analysis is generally preferred. Allowance must be made for inflation, the discount rate (except in a “steady state” analysis), marginal costs of program expansion, opportunity costs incurred by participants, the changing fabric of society, the economic multiplication of investment in fitness, and anticipated participation rates. Benefits may be observed by the individual (improved health), the corporation (reduced turnover and absenteeism, increased productivity, fewer injuries), and the state (reduced direct and indirect costs of illness, improved lifestyle, reduced demand for geriatric services). Program costs vary widely with the activity that is undertaken, but even daily walking involves the participant in some expense. Employee programs often cost $500-$750 per participant/year, while, depending on the sport and local speculation by land “developers”, community programs may cost $175-$1,000 per participant/year. Cost/effectiveness analyses allow governments to reach informed decisions, but they cannot always answer associated ethical problems such as determining the value of human life, and the rights of the individual as opposed to those of society. PMID:21267294

Shephard, Roy J.

1986-01-01

424

Interaction and learning: An analysis of two freshman physics courses

NASA Astrophysics Data System (ADS)

The influence of digital technology has gradually increased through the years to the point where it impacts almost every part of our experience in some way. Educators are expected increasingly to supplement or even replace lecture and chalkboard practices with alternative strategies. Beyond integrating new technologies into the learning environments are the new forms of learning that some believe are implied by the nature of digitally mediated instruction itself. The use of multimedia technologies for learning in many cases is thought to facilitate a move away from teacher-centered practices of instruction toward learner-centered strategies of both delivery and assessment. This study was an investigation of effects that may be encountered when alternative forms of classroom delivery are introduced. It was a mixed-mode investigation of classroom culture and student performance in two sections of a physics course for undergraduate engineering students. The content for these two classes was identical as were the learning resources available to students. Both classes employed multiple methods of presentation combining face-to-face methods with classroom and online digital learning tools. The most distinctive differences between them were found in the classroom practice itself. One class received what may be called a traditional teacher-centered presentation focusing on solving math problems in physics. The other employed dense student to instructor and student-to-student interaction in the classroom with a learning approach characterized by inquiry methods of content delivery. The investigation asked three questions. First it sought to identify what expectations students brought to the classroom about what they would experience and how they would be taught. Second it examined how the tools and practices used to facilitate learning actually affected the classroom culture. Finally the study explored what affect if any the pedagogical practices students experienced had on their measured performance outcomes. These students were strongly influenced by their teacher-centered background and were not expecting any new learning strategies. They found significantly different classroom cultures between the two classes and achieved performance results that clearly were affected by the delivery techniques they experienced.

Clark, Dexter

2005-08-01

425

Calculation of four-particle harmonic-oscillator transformation brackets

NASA Astrophysics Data System (ADS)

A procedure for precise calculation of the three- and four-particle harmonic-oscillator (HO) transformation brackets is presented. The analytical expressions of the four-particle HO transformation brackets are given. The computer code for the calculations of HO transformation brackets proves to be quick, efficient and produces results with small numerical uncertainties. Program summaryProgram title: HOTB Catalogue identifier: AEFQ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFQ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1247 No. of bytes in distributed program, including test data, etc.: 6659 Distribution format: tar.gz Programming language: FORTRAN 90 Computer: Any computer with FORTRAN 90 compiler Operating system: Windows, Linux, FreeBSD, True64 Unix RAM: 8 MB Classification: 17.17 Nature of problem: Calculation of the three-particle and four-particle harmonic-oscillator transformation brackets. Solution method: The method is based on compact expressions of the three-particle harmonics oscillator brackets, presented in [1] and expressions of the four-particle harmonics oscillator brackets, presented in this paper. Restrictions: The three- and four-particle harmonic-oscillator transformation brackets up to the e=28. Unusual features: Possibility of calculating the four-particle harmonic-oscillator transformation brackets. Running time: Less than one second for the single harmonic-oscillator transformation bracket. References:G.P. Kamuntavi?ius, R.K. Kalinauskas, B.R. Barret, S. Mickevi?ius, D. Germanas, Nuclear Physics A 695 (2001) 191.

Germanas, D.; Kalinauskas, R. K.; Mickevi?ius, S.

2010-02-01

426

Experimental Development and Physical Analysis of Jet and Vortex Actuators

NASA Technical Reports Server (NTRS)

The Vortex generator consists of a cavity with a lightweight actuator plate. The actuator plate acts like a piston pumping air out of the cavity on the down-stroke and sucking air into the cavity on the upstroke. The actuator is placed asymmetrically over the cavity opening, forming narrow and wide slots when viewed from the top. The actuator depending on amplitude, frequency, and slot spacing produces several flow fields (free jet, wall jet, vortex flow). Computational simulation of the actuator-generated flows have been developed and applied to several actuator flow modes. The objectives of this paper are to study the physics of the actuator-induced flow and to develop computational simulations of the actuatorgenerated flows. This work should provide an impetus for designing similar active flow control systems suitable for aircraft applications. The computational simulation uses a time-accurate full Navier-Stokes (NS) solver known as FTNS3D (a full NS version of CFL3D solver). A Multi-block moving grid has been developed and used for the computational study of the flow fields produced by the vortex generator. For three-dimensional computations, ten multi-block grids are used and for two-dimensional computations, six multiblock grids are used. The grid blocks adjacent to the actuator plate move with the plate motion, and second-order interpolation is used along the block interfaces. Periodic response of the flow has been observed to develop after three cycles of the plate sinusoidal motion.

Kandil, Osama A.; Yang, Zhi; Lachowicz, Jason T.

2000-01-01

427

An analysis of the DuPage County Regional Office of Education physics exam

NASA Astrophysics Data System (ADS)

In 2009, the DuPage County Regional Office of Education (ROE) tasked volunteer physics teachers with creating a basic skills physics exam reflecting what the participants valued and shared in common across curricula. Mechanics, electricity & magnetism (E&M), and wave phenomena emerged as the primary constructs. The resulting exam was intended for first-exposure physics students. The most recently completed version was psychometrically assessed for unidimensionality within the constructs using a robust WLS structural equation model and for reliability. An item analysis using a 3-PL IRT model was performed on the mechanics items and a 2-PL IRT model was performed on the E&M and waves items; a distractor analysis was also performed on all items. Lastly, differential item functioning (DIF) and differential test functioning (DTF) analyses, using the Mantel-Haenszel procedure, were performed using gender, ethnicity, year in school, ELL, physics level, and math level as groupings.

Muehsler, Hans

428

NASA Astrophysics Data System (ADS)

ACAT2011 This volume of Journal of Physics: Conference Series is dedicated to scientific contributions presented at the 14th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT 2011) which took place on 5-7 September 2011 at Brunel University, UK. The workshop series, which began in 1990 in Lyon, France, brings together computer science researchers and practitioners, and researchers from particle physics and related fields in order to explore and confront the boundaries of computing and of automatic data analysis and theoretical calculation techniques. It is a forum for the exchange of ideas among the fields, exploring and promoting cutting-edge computing, data analysis and theoretical calculation techniques in fundamental physics research. This year's edition of the workshop brought together over 100 participants from all over the world. 14 invited speakers presented key topics on computing ecosystems, cloud computing, multivariate data analysis, symbolic and automatic theoretical calculations as well as computing and data analysis challenges in astrophysics, bioinformatics and musicology. Over 80 other talks and posters presented state-of-the art developments in the areas of the workshop's three tracks: Computing Technologies, Data Analysis Algorithms and Tools, and Computational Techniques in Theoretical Physics. Panel and round table discussions on data management and multivariate data analysis uncovered new ideas and collaboration opportunities in the respective areas. This edition of ACAT was generously sponsored by the Science and Technology Facility Council (STFC), the Institute for Particle Physics Phenomenology (IPPP) at Durham University, Brookhaven National Laboratory in the USA and Dell. We would like to thank all the participants of the workshop for the high level of their scientific contributions and for the enthusiastic participation in all its activities which were, ultimately, the key factors in the success of the workshop. Further information on ACAT 2011 can be found at http://acat2011.cern.ch Dr Liliana Teodorescu Brunel University ACATgroup The PDF also contains details of the workshop's committees and sponsors.

Teodorescu, Liliana; Britton, David; Glover, Nigel; Heinrich, Gudrun; Lauret, Jérôme; Naumann, Axel; Speer, Thomas; Teixeira-Dias, Pedro

2012-06-01

429

Temporal and spatial analysis in knowledge-based physics problem-solving

NASA Astrophysics Data System (ADS)

Physics problems as stated in textbooks are typically informal and incomplete, and not amenable to the direct application of the general laws of physics. A theory of analysis for automatically solving such problems is presented. In particular, the theory provides a detailed methodology for constructing a formal problem representation, called physical representation, upon which physics laws may be appropriately selected and instantiated. With the equations generated by these laws, the solutions to these problems are obtained through strictly mathematical manipulations. This theory provides a well-structured domain language, in which it is relatively easy to state mechanical knowledge and mechanics problems. In the language the notion of basic physical phenomenon for representing the knowledge of physical situations and events is introduced. This notion serves as both the building block for the physical representation and as a vehicle for accessing the appropriate physical laws. Both basic physical phenomena and more traditional temporal entities, instants, and intervals may be used as time references. This dual-system representation facilitates bi-level abstractions of time necessary to avoid discontinuities introduced by short impulsive phenomena, e.g., collisions, and corresponds well with human-like temporal reasoning. The language also includes an ontology of space, using multiple abstractions to account for its inherent complexity, and representation schemes for physical laws and equations. The other key ingredient of the theory is a repertoire of ordered knowledge sources, formulated to specify the derivation procedures of a physical representation. The domain language, in which these knowledge sources are written, has a structure which is useful as a theoretical basis for determining their ordering and inference step sizes. This practice has proven crucial for building knowledge-based systems that are easy to debug and modify. The theory was implemented and tested in a computer program which has successfully solved several relatively difficult problems selected from a widely used textbook. Methods implemented in the program for intelligently selecting appropriate physics laws and for solving equations are also discussed.

Lee, Xiang-Seng

430

NASA Astrophysics Data System (ADS)

This volume of Journal of Physics: Conference Series is dedicated to scientific contributions presented at the 15th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT 2013) which took place on 16-21 May 2013 at the Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China. The workshop series brings together computer science researchers and practitioners, and researchers from particle physics and related fields to explore and confront the boundaries of computing and of automatic data analysis and theoretical calculation techniques. This year's edition of the workshop brought together over 120 participants from all over the world. 18 invited speakers presented key topics on the universe in computer, Computing in Earth Sciences, multivariate data analysis, automated computation in Quantum Field Theory as well as computing and data analysis challenges in many fields. Over 70 other talks and posters presented state-of-the-art developments in the areas of the workshop's three tracks: Computing Technologies, Data Analysis Algorithms and Tools, and Computational Techniques in Theoretical Physics. The round table discussions on open-source, knowledge sharing and scientific collaboration stimulate us to think over the issue in the respective areas. ACAT 2013 was generously sponsored by the Chinese Academy of Sciences (CAS), National Natural Science Foundation of China (NFSC), Brookhaven National Laboratory in the USA (BNL), Peking University (PKU), Theoretical Physics Cernter for Science facilities of CAS (TPCSF-CAS) and Sugon. We would like to thank all the participants for their scientific contributions and for the en- thusiastic participation in all its activities of the workshop. Further information on ACAT 2013 can be found at http://acat2013.ihep.ac.cn. Professor Jianxiong Wang Institute of High Energy Physics Chinese Academy of Science Details of committees and sponsors are available in the PDF

Wang, Jianxiong

2014-06-01

431

Power quality and harmonic instrumentation selection

The proliferation of adjustable speed drive (ASD) systems in commercial and industrial settings has prompted a new awareness of the impact of harmonics and other power quality (PQ) concerns. The PQ issues have a direct bearing on the reliability of these systems and the ability to perform the desired tasks in an interruption free manner. Details presented include identifying power quality problems, selecting the proper type of monitoring instruments, and interpretation of data. Included are typical instrument specifications and cost. Additionally the advent of artificial intelligence tools for PQ analysis and the resulting impact on providing solutions is described.

Stebbins, W.L.; Golden, P.

1996-05-01

432

Investigating Student Communities with Network Analysis of Interactions in a Physics Learning Center

NASA Astrophysics Data System (ADS)

We describe our initial efforts at implementing social network analysis to visualize and quantify student interactions in Florida International University's Physics Learning Center. Developing a sense of community among students is one of the three pillars of an overall reform effort to increase participation in physics, and the sciences more broadly, at FIU. Our implementation of a research and learning community, embedded within a course reform effort, has led to increased recruitment and retention of physics majors. Finn and Rock [1997] link the academic and social integration of students to increased rates of retention. To identify these interactions, we have initiated an investigation that utilizes social network analysis to identify primary community participants. Community interactions are then characterized through the network's density and connectivity, shedding light on learning communities and participation. Preliminary results, further research questions, and future directions utilizing social network analysis are presented.

Brewe, Eric; Kramer, Laird; O'Brien, George

2009-11-01

433

Singular Harmonic Maps and Applications to General Relativity

NASA Astrophysics Data System (ADS)

The study of axially symmetric stationary multi-black-hole configurations and the force between co-axially rotating black holes involves, as a first step, an analysis on the "boundary regularity" of the so-called reduced singular harmonic maps. We carry out this analysis by considering those harmonic maps as solutions to some homogeneous divergence systems of partial differential equations with singular coefficients. Our results extend previous works by Weinstein (Comm Pure Appl Math 43:903-948, 1990; Comm Pure Appl Math 45:1183-1203, 1992) and by Li and Tian (Manu Math 73(1):83-89, 1991; Commun Math Phys 149:1-30, 1992; Differential geometry: PDE on manifolds, vol 54, pp. 317-326, 1993). This paper is based on the Ph.D. thesis of the author (Singular harmonic maps into hyperbolic spaces and applications to general relativity, PhD thesis, The State University of New Jersey, Rutgers, 2009).

Nguyen, Luc

2011-01-01

434

On the measurement of a weak classical force coupled to a harmonic oscillator: experimental progress

Several high-precision physics experiments are approaching a level of sensitivity at which the intrinsic quantum nature of the experimental apparatus is the dominant source of fluctuations limiting the sensitivity of the measurements. This quantum limit is embodied by the Heisenberg uncertainty principle, which prohibits arbitrarily precise simultaneous measurements of two conjugate observables of a system but allows one-time measurements of a single observable with any precision. The dynamical evolution of a system immediately following a measurement limits the class of observables that may be measured repeatedly with arbitrary precision, with the influence of the measurement apparatus on the system being confined strictly to the conjugate observables. Observables having this feature, and the corresponding measurements performed on them, have been named quantum nondemolition or back-action evasion observables. In a previous review (Caves {ital et} {ital al}., 1980, Rev. Mod. Phys. {bold 52}, 341) a quantum-mechanical analysis of quantum nondemolition measurements of a harmonic oscillator was presented. The present review summarizes the experimental progress on quantum nondemolition measurements and the classical models developed to describe and guide the development of practical implementations of quantum nondemolition measurements. The relationship between the classical and quantum theoretical models is also reviewed. The concept of quantum nondemolition and back-action evasion measurements originated in the context of measurements on a macroscopic mechanical harmonic oscillator, though these techniques may be useful in other experimental contexts as well, as is discussed in the last part of this review. {copyright} {ital 1996 The American Physical Society.}

Bocko, M.F. [Department of Electrical Engineering, University of Rochester, Rochester, New York 14627 (United States)] [Department of Electrical Engineering, University of Rochester, Rochester, New York 14627 (United States); Onofrio, R. [Dipartimento di Fisica `Galileo Galilei`, Universita di Padova, I-35131 Padova (Italy)] [Dipartimento di Fisica `Galileo Galilei`, Universita di Padova, I-35131 Padova (Italy)

1996-07-01

435

Physical and genetic analysis of the ColD plasmid.

The plasmid ColD-CA23, a high-copy-number plasmid of 5.12 kilobases, encodes colicin D, a protein of approximately 87,000 daltons which inhibits bacterial protein synthesis. Colicin D production is under the control of the Escherichia coli SOS regulatory system and is released to the growth medium via the action of the lysis gene product(s). A detailed map of the ColD plasmid was established for 10 restriction enzymes. Using in vitro insertional omega mutagenesis and in vivo insertional Tn5 mutagenesis, we localized the regions of the plasmid responsible for colicin D activity (cda), for mitomycin C-induced lysis (cdl), and for colicin D immunity (cdi). These genes were all located contiguously on a 2,400-base-pair fragment similar to a large number of other Col plasmids (A, E1, E2, E3, E8, N, and CloDF). The ColD plasmid was mobilizable by conjugative transfer by helper plasmids of the IncFII incompatibility group, but not by plasmids belonging to the groups IncI-alpha or IncP. The location of the mobilization functions was determined by deletion analysis. The plasmid needs a segment of 400 base pairs, which is located between the mob genes and the gene for autolysis, for its replication. Images PMID:3007432

Frey, J; Ghersa, P; Palacios, P G; Belet, M

1986-01-01

436

Investigation of the Harmonic Optimization Approaches in the New Modular Multilevel Converters

Modular multilevel converter (MMC) is a new type of multilevel converter. Similar to cascaded multilevel converters, each arm consists of several submodules and each submodule includes one separate DC source in parallel. Based on the analysis of its structure and working mechanism, this paper presents two harmonic optimization techniques, known as optimized harmonic stepped-waveform (OHSW) technique and optimal minimization of

Li Qiang; He Zhiyuan; Tang Guangfu

2010-01-01

437

Numerous obesity loci have been identified using genome-wide association studies. A UK study indicated that physical activity may attenuate the cumulative effect of 12 of these loci, but replication studies are lacking. Therefore, we tested whether the aggregate effect of these loci is diminished in adults of European ancestry reporting high levels of physical activity. Twelve obesity-susceptibility loci were genotyped or imputed in 111,421 participants. A genetic risk score (GRS) was calculated by summing the BMI-associated alleles of each genetic variant. Physical activity was assessed using self-administered questionnaires. Multiplicative interactions between the GRS and physical activity on BMI were tested in linear and logistic regression models in each cohort, with adjustment for age, age2, sex, study center (for multicenter studies), and the marginal terms for physical activity and the GRS. These results were combined using meta-analysis weighted by cohort sample size. The meta-analysis yielded a statistically significant GRS × physical activity interaction effect estimate (Pinteraction?=?0.015). However, a statistically significant interaction effect was only apparent in North American cohorts (n?=?39,810, Pinteraction?=?0.014 vs. n?=?71,611, Pinteraction?=?0.275 for Europeans). In secondary analyses, both the FTO rs1121980 (Pinteraction?=?0.003) and the SEC16B rs10913469 (Pinteraction?=?0.025) variants showed evidence of SNP × physical activity interactions. This meta-analysis of 111,421 individuals provides further support for an interaction between physical activity and a GRS in obesity disposition, although these findings hinge on the inclusion of cohorts from North America, indicating that these results are either population-specific or non-causal. PMID:23935507

Ahmad, Shafqat; Rukh, Gull; Varga, Tibor V.; Ali, Ashfaq; Kurbasic, Azra; Shungin, Dmitry; Ericson, Ulrika; Koivula, Robert W.; Chu, Audrey Y.; Rose, Lynda M.; Ganna, Andrea; Qi, Qibin; Stan?áková, Alena; Sandholt, Camilla H.; Elks, Cathy E.; Curhan, Gary; Jensen, Majken K.; Tamimi, Rulla M.; Allin, Kristine H.; Jørgensen, Torben; Brage, Soren; Langenberg, Claudia; Aadahl, Mette; Grarup, Niels; Linneberg, Allan; Paré, Guillaume; Magnusson, Patrik K. E.; Pedersen, Nancy L.; Boehnke, Michael; Hamsten, Anders; Mohlke, Karen L.; Pasquale, Louis T.; Pedersen, Oluf; Scott, Robert A.; Ridker, Paul M.; Ingelsson, Erik; Laakso, Markku; Hansen, Torben; Qi, Lu; Wareham, Nicholas J.; Chasman, Daniel I.; Hallmans, Göran; Hu, Frank B.; Renström, Frida; Orho-Melander, Marju; Franks, Paul W.

2013-01-01

438

Second Harmonic Breakdown in KSTAR

An 84-GHz electron cyclotron heating (ECH) system is being installed on the KSTAR tokamak. KSTAR adopts ECH-assisted start-up for the flexibility and reliability of the KSTAR operation with the plasma breakdown voltage reduced. The available maximum power of the 84 GHz ECH system is presently 500 kW with maximum duration of 2 s. Currently, the second harmonic ECH-assisted start-up is under consideration because a low toroidal field of B{sub T}{approx}1.5 T is desirable for safety and also for the high-beta experiments in the initial operation phase. The studies in this paper are on the effectiveness of the second harmonic breakdown using a 0-D time dependent plasma evolution code and the comparison with the recent DIII-D experimental results on the second harmonic pre-ionization.

Bae, Y. S.; England, A. C.; Kwon, M.; Lee, G. S. [National Fusion Research Center, 52 Eoeun-dong, Yuseong-gu, Daejeon (Korea, Republic of)

2007-09-28

439

Evaluation of harmonic suppression devices

An assessment has been conducted of five commercially available devices to determine their ability to provide clean sinusoidal voltage to nonlinear loads and to eliminate harmonic currents demanded by nonlinear loads. The devices tested were a passive series-shunt filter, a delta-wye isolation transformer, a ferroresonant magnetic synthesizer, an active power line conditioner, and an active injection mode filter. These devices were installed in existing Department of Energy facilities that had substantial non-linear loads which drew a significant harmonic current. These devices were then compared in the following categories: cancellation of harmonic currents, supply of nondistorted voltage, supply of regulated voltage, elimination of transients and impulses, efficiency, reliability, and cost.

Tolbert, L.M. [Oak Ridge National Lab., TN (United States); Hollis, H.D.; Hale, P.S. Jr. [Army Center for Public Works, Alexandria, VA (United States)

1996-09-01

440

Physical activity and sedentary behaviour are associated with metabolic and mental health during childhood and adolescence. Understanding the inter-relationships between these behaviours will help to inform intervention design. This systematic review and meta-analysis synthesized evidence from observational studies describing the association between sedentary behaviour and physical activity in young people (<18?years). English-language publications up to August 2013 were located through electronic and manual searches. Included studies presented statistical associations between at least one measure of sedentary behaviour and one measure of physical activity. One hundred sixty-three papers were included in the meta-analysis, from which data on 254 independent samples was extracted. In the summary meta-analytic model (k?=?230), a small, but significant, negative association between sedentary behaviour and physical activity was observed (r?=??0.108, 95% confidence interval [CI]?=??0.128, ?0.087). In moderator analyses, studies that recruited smaller samples (n?physical activity; r?=??0.233, 95% CI?=??0.330, ?0.137) or were assessed to be of higher methodological quality (r?=??0.176, 95% CI?=??0.215, ?0.138) reported stronger associations, although effect sizes remained small. The association between sedentary behaviour and physical activity in young people is negative, but small, suggesting that these behaviours do not directly displace one another. PMID:24844784

Pearson, N; Braithwaite, R E; Biddle, S J H; van Sluijs, E M F; Atkin, A J

2014-01-01

441

A meta-analysis of published studies with adult human participants was conducted to evaluate whether physical fitness attenuates cardiovascular reactivity and improves recovery from acute psychological stressors. Thirty-three studies met selection criteria; 18 were included in recovery analyses. Effect sizes and moderator influences were calculated by using meta-analysis software. A fixed effects model was fit initially; however, between-studies heterogeneity could not

Kathleen Forcier; Laura R. Stroud; George D. Papandonatos; Brian Hitsman; Meredith Reiches; Jenelle Krishnamoorthy; Raymond Niaura

2006-01-01

442

Filamentation effects and second-harmonic spectra in laser-produced plasmas

Sideway scattered second-harmonic spectra emitted from a 1064-nm-laser-produced plasma have been observed to originate from nonlinear coupling near the critical surface. The time evolution of the second-harmonic optical density confirmed the possibility that a plasmon issued from the resonant absorption of the incident beam can recombine with a photon ([omega][sub 0]) to give a transverse wave of frequency 2[omega][sub 0]. A plasmon issued from a parametric decay instability may also, by coalescence with an incident photon, give a transverse wave at a shifted second-harmonic frequency. The threshold of such a combination is determined. Moreover, irregular plasma-parameter variations and the perturbed spatial uniformity of the incident beam appear to alter the second-harmonic spectra. An oscillatory structure of the optical density of the observed second harmonic is interpreted as a result of the coupling physics involved and of laser-beam filamentation.

Khalfaoui, A.H.; Abdelli, S.; Kerdja, T.; Ghobrini, D. (MDRTE, Centre de Developpement des Technologies Avancees 2, boulevard Frantz Fanon, Alger-gare, Boite Postale 1017, Alger 16000 (Algeria))

1993-08-01

443

Time reconstruction of harmonic emission in molecules near the ionization threshold

NASA Astrophysics Data System (ADS)

Using the example of the H2+ molecular ion and its isotopes, we show how the Coulomb explosion triggered by ionization of the molecule can be used to reconstruct the emission times and identify the physical mechanism contributing to the emission of near- and below-threshold harmonics (BTH). The key idea is that recombination responsible for the harmonic emission halts Coulomb explosion at different times, depending on the final vibrational state of the molecule. As a consequence, interferences between different vibrational channels show up, enabling enhanced temporal resolution in the harmonic spectrum. The reconstruction of the emission times for BTH shows that they are associated with the so-called short trajectories and that the time–energy mapping for such harmonics is possible, similar to the well-known mapping for the plateau harmonics.

Riviére, P.; Morales, F.; Richter, M.; Medisauskas, L.; Smirnova, O.; Martín, F.

2014-12-01

444

ERIC Educational Resources Information Center

In this article we use the pendulum as the vehicle for discussing the transition from classical to quantum physics. Since student knowledge of the classical pendulum can be generalized to all harmonic oscillators, we propose that a quantum analysis of the pendulum can lead students into the unanticipated consequences of quantum phenomena at the…

Barnes, Marianne B.; Garner, James; Reid, David

2004-01-01

445

This meta-analysis investigates differences between the effect sizes of physical punishment and alternative disciplinary tactics for child outcomes in 26 qualifying studies. Analyzing differences in effect sizes reduces systematic biases and emphasizes direct comparisons between the disciplinary tactics that parents have to select among. The results indicated that effect sizes significantly favored conditional spanking over 10 of 13 alternative disciplinary tactics for reducing child noncompliance or antisocial behavior. Customary physical punishment yielded effect sizes equal to alternative tactics, except for one large study favoring physical punishment. Only overly severe or predominant use of physical punishment compared unfavorably with alternative disciplinary tactics. The discussion highlights the need for better discriminations between effective and counterproductive use of disciplinary punishment in general. PMID:15898303

Larzelere, Robert E; Kuhn, Brett R

2005-03-01

446

FE-Based Physical Model of LPMBDCM for Integrated Motor Drive System Analysis

This paper introduces an accurate phase variable model with detailed evaluation of the force ripple for the linear permanent magnet brushless DC motor (LPMBDCM) drive system analysis. The mover position dependent variables of the physical model are obtained from finite element (FE) solutions by the cubic spline interpolation. Considering the effect of the snubber circuits in the power electronic devices,

Lizhan Zeng; Xuedong Chen; Xianpeng Nong; Xiaogang San

2008-01-01

447

The purpose of the present study was to examine whether indirect aggression was distinct from physical aggression across developmental periods. Participants were 3,089 Canadian children aged 4 to 7 years (Time 1), 6 to 9 years (Time 2), and 8 to 11 years (Time 3). Confirmatory factor analysis using an accelerated longitudinal design confirmed a 2-factor model that was stable

Tracy Vaillancourt; Mara Brendgen; Michel Boivin; Richard E. Tremblay

2003-01-01

448

NASA Astrophysics Data System (ADS)

Two methods of data analysis are compared: spreadsheet software and a statistics software suite. Their use is compared analysing data collected in three selected experiments taken from an introductory physics laboratory, which include a linear dependence, a nonlinear dependence and a histogram. The merits of each method are compared.

Peterlin, Primož

2010-07-01

449

Challenges for Cyber-Physical Systems: Security, Timing Analysis and Soft Error Protection

Challenges for Cyber-Physical Systems: Security, Timing Analysis and Soft Error Protection Frank to controlling the power grid are outlined. From these economic and safety threats, we de- rive an immediate need and validate worst-case timing scenarios that have to be guaranteed in order to meet deadlines in safety

Mueller, Frank

450

ERIC Educational Resources Information Center

Two methods of data analysis are compared: spreadsheet software and a statistics software suite. Their use is compared analysing data collected in three selected experiments taken from an introductory physics laboratory, which include a linear dependence, a nonlinear dependence and a histogram. The merits of each method are compared. (Contains 7…

Peterlin, Primoz

2010-01-01

451

Observations of the gamma-ray burst (GRB) phenomenon with the Swift satellite (Gehrels et al. 2004) haveA COMPREHENSIVE ANALYSIS OF SWIFT XRT DATA. II. DIVERSE PHYSICAL ORIGINS OF THE SHALLOW DECAY ABSTRACT The origin of the shallow decay segment in Swift XRT light curves remains a puzzle. We analyze

Zhang, Bing

452

PHYSICAL REVIEW E 88, 062714 (2013) Trend and fluctuations: Analysis and design of population ecosystems sharing a common average dynamics or common trend. We explain how model parameters, including. At the same time, nontrivial trends are pervasive in those systems, be it in the laboratory, society

Cocco, Simona

453

ERIC Educational Resources Information Center

Objectives: To develop a comprehensive inventory of state physical education (PE) legislation, examine trends in bill introduction, and compare bill factors. Methods: State PE legislation from January 2001 to July 2007 was identified using a legislative database. Analysis included components of evidence-based school PE from the Community Guide and…

Eyler, Amy A.; Brownson, Ross C.; Aytur, Semra A.; Cradock, Angie L.; Doescher, Mark; Evenson, Kelly R.; Kerr, Jacqueline; Maddock, Jay; Pluto, Delores L.; Steinman, Lesley; Tompkins, Nancy O'Hara; Troped, Philip; Schmid, Thomas L.

2010-01-01

454

ERIC Educational Resources Information Center

Much of physical education curriculum in the developed world and specifically in Australia tends to be guided in principle by syllabus documents that represent, in varying degrees, some form of government education priorities. Through the use of critical discourse analysis we analyze one such syllabus example (an official syllabus document of one…

Rossi, Tony; Tinning, Richard; McCuaig, Louise; Sirna, Karen; Hunter, Lisa

2009-01-01

455

Analysis and Synthesis of Facial Image Sequences Using Physical and Anatomical Models

We present a new approach to the analysis ofdynamic facial images for the purposes of estimating and resynthesizingdynamic facial expressions. The approach exploits asophisticated generatire model of the human face originallydeveloped for realistic facial animation. The face model, whichmay be simulated and rendered at interactive rates on a graphicsworkstation, incorporates a physics-based synthetic facial tissueand a set of anatomically motivated

Demetri Terzopoulos; Keith Waters

1993-01-01

456

Climate Change Impacts and Adaptation Analysis Â How to Link Physical Climate Data and Economic There are a number of structural and conceptual differences between the information provided by climate change models of economic concepts applied to climate change impact and adaptation policy assessment, and to illustrate how

457

ERIC Educational Resources Information Center

This meta-analysis investigates differences between the effect sizes of physical punishment and alternative disciplinary tactics for child outcomes in 26 qualifying studies. Analyzing differences in effect sizes reduces systematic biases and emphasizes direct comparisons between the disciplinary tactics that parents have to select among. The…

Larzelere, Robert E.; Kuhn, Brett R.

2005-01-01

458

Destructive Physical Analysis of Flight- and Ground-Tested Sodium-Sulfur Cells

NASA Technical Reports Server (NTRS)

Destructive physical analysis (DPA) was used to study the effects of microgravity on the sulfur electrode in sodium-sulfur cells. The cells examined in this work were provided by the Air Force Research Laboratory (AFRL) from their program on sodium-sulfur technology. The Naval Research Laboratory (NRL) provided electrical characterization of the flight-tested and ground-tested cells.

Wasz, Margot L.; Carter, Boyd J.; Donet, Charles M.; Baldwin, Richard S.

1999-01-01

459

ANALYSIS OF SOME PHYSICAL PROPERTIES OF CERIUM COMPOUNDS IN THE ANDERSON MODEL

E 1105 ANALYSIS OF SOME PHYSICAL PROPERTIES OF CERIUM COMPOUNDS IN THE ANDERSON MODEL P the theory of Lacroix-Lyon-Caen et al., who have calculated the magnetic susceptibility of a cerium Kondo of the exchange parameter 0393n(EF) and the Kondo temperature TK of some cerium compounds from susceptibility

Paris-Sud XI, Université de

460

NASA Astrophysics Data System (ADS)

The majority of existing science, technology, engineering, and mathematics (STEM) research studies compare women to men, yet a paucity of research exists that examines what differentiates female career choice within the physical sciences. In light of these research trends and recommendations, this study examines the following question: On average, do females who select physics as compared to chemistry doctoral programs differ in their reported personal motivations and background factors prior to entering the field? This question is analyzed using variables from the Project Crossover Survey data set through a subset of female physical science doctoral students and scientists (n =1137). A logistic regression analysis and prototypical odds ratio uncover what differentiates women in the physical sciences based on their academic achievement and experiences ranging from high school through undergraduate education. Results indicate that females who have negative undergraduate chemistry experiences as well as higher grades and positive experiences in undergraduate physics are more likely to pursue a career in physics as opposed to chemistry. Conclusions suggest that a greater emphasis should be placed on the classroom experiences that are provided to females in gateway physics courses. Analyses show that women are not a single entity that should only be examined as a whole group or in comparison to men. Instead women can be compared to one another to see what influences their differences in educational experiences and career choice in STEM-based fields as well as other academic areas of study.

Dabney, Katherine P.; Tai, Robert H.

2014-06-01